Chemical engineering education

Material Information

Chemical engineering education
Alternate Title:
Abbreviated Title:
Chem. eng. educ.
American Society for Engineering Education -- Chemical Engineering Division
Chemical Engineering Division, American Society for Engineering Education
Publication Date:
Annual[ FORMER 1960-1961]
Physical Description:
v. : ill. ; 22-28 cm.


Subjects / Keywords:
Chemical engineering -- Study and teaching -- Periodicals ( lcsh )
serial ( sobekcm )
periodical ( marcgt )


Chemical abstracts
Additional Physical Form:
Also issued online.
Dates or Sequential Designation:
1960-June 1964 ; v. 1, no. 1 (Oct. 1965)-
Numbering Peculiarities:
Publication suspended briefly: issue designated v. 1, no. 4 (June 1966) published Nov. 1967.
General Note:
Title from cover.
General Note:
Place of publication varies: Rochester, N.Y., 1965-1967; Gainesville, Fla., 1968-

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
01151209 ( OCLC )
70013732 ( LCCN )
0009-2479 ( ISSN )
TP165 .C18 ( lcc )
660/.2/071 ( ddc )

UFDC Membership

Chemical Engineering Documents


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There are more than 100 billion
barrels of potential new oil on the
North American continent. But it
will have to be dug-not pumped-
out of the ground. It's in the form of
low-grade hydrocarbon solids. Yet,
the world needs so much more

making things happen with petroleum energy

oil in years to come that Atlantic
Richfield is already working on
ways to extract it and get it moving.
Projects like this take imagination
and fresh viewpoints. The kind that
come from young innovators like
yourself. We need you-and your

kind of ideas-to keep making
great things happen. Talk to our
interviewer when he's on your
campus. Or write to: Mr. G. O.
Wheeler, Manager Professional
Recruitment, 717 Fifth Avenue,
New York, N.Y. 10022.

t. ,U


Department of Chemical Engineering
University of Florida
Gainesville, Florida 32601

Editor: Ray Fahien

Associate Editor: Mack Tyner

Business Manager: R. B. Bennett

Publications Board and Regional
Advertising Representatives:

CENTRAL: James Weber
Chairman of Publication Board
University of Nebraska
Lincoln, Nebraska 68508
WEST: William H. Corcoran
California Institute of Technology
Pasadena, California 91109
SOUTH: Charles Littlejohn
Clemson University
Clemson, South Carolina 29631
University of Houston
Houston, Texas 77004
EAST: Robert Matteson
College Relations
Sun Oil Company
Philadelphia, Pennsylvania 19100
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Secretary's Department
E. I. du Pont de Nemours
Wilmington, Delaware 19898
NORTH: J. J. Martin
University of Michigan
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NORTHWEST: R. W. Moulton
University of Washington
Seattle, Washington 98105
J. A. Bergantz
State University of New York
Buffalo, New York 14200
D. R. Coughanowr
Drexel University
Philadelphia, Pennsylvania

Chemical Engineering Education


3 Editorial

5 Letters from Readers

10 The Educator
Professor Richard Balzhiser

32 Departments of Chemical Engineering
Hail Purdue, R. A. Greenkorn

34 Views and Opinions
On the Recruitment of Chemical
Engineers, E. J. Henley

42 The Laboratory
Taylor Axial Diffusion, R. R. Hudgins

25 Book Review

44 Problems for Teachers

25 Division Activities

47 News

Feature Articles
6 Engineering and Public Affairs: Some Di-
rections for Education and Research,
E. H. Blum

II In the Shadows of Power, R. E. Balzhiser

14 Technical Careers for the Disadvantaged,
G. Lessells, H. T. Brown, and R. C.

20 Engineering Opportunities for Negro and
Indian Youth, B. M. Avery

23 The University in International Affairs,
F. M. Tiller

26 Flow and Transfer at Fluid Interfaces,
Part II, L. E. Scriven

48 Canon and Method in the Arts and
Sciences, R. Aris

CHEMICAL ENGINEERING EDUCATION is published quarterly by the Chemical
Engineering Division, American Society for Engineering Education. The publication
is edited at the Chemical Engineering Department, University of Florida. Second-class
postage is paid at Gainesville, Florida, and at DeLand, Florida. Correspondence
regarding editorial matter, circulation and changes of address should be addressed
to the Editor at Gainesville, Florida 32601. Advertising rates and information are
available from the advertising representatives. Plates and other advertising material
may be sent directly to the printer: E. 0. Painter Printing Co., 137 E. Wisconsin
Ave., DeLand, Florida 32720. Subscription rate is $10 per year in U.S., Canada, and

WINTER, 1969


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.The BEST Opportunities

Yet, being the best makes it that much harder to
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it takes an aggressive and imaginative R & D team
to maintain Texaco's leadership role in the petro-
leum and petrochemical industry. An important part
of this team are Chemical Engineers... men like
yourself constantly searching for better ways. It
is through their efforts, as well as their professional
colleagues and an aggressive management team,
that Texaco stays out front.
You, too, can be part of this winning combination.
For Chemical Engineers with a B.S., M.S., or Ph.D.
the professional and economic rewards of a Texaco
career in process and product development have

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BEST opportunities for advancement, while enjoying
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Texaco has immediate openings at its laboratories
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coming U. S. Citizens.
Interested candidates are invited to send their
resume to: W. R. Hencke, Texaco, Research & Tech-
nical Department, P. O. Box 509, Beacon, N. Y.
12508. Texaco is an equal opportunity employer.


Recruitment and Human Values

It is well known that the percentage of college
students entering engineering has been steadily
decreasing while salaries for engineering gradu-
ates continue to rise. Why, in the face of eco-
nomic incentive and improved career guidance
materials, are students not going into engineer-
At first it was believed that potential engi-
neering students were moving to the sciences as
a result of its better association in the public
mind with space-age glamor and its lower re-
quirements for a bachelor's degree. The result
was a frenzied pressure to reduce the hours in
an engineering curriculum that is expected to
produce both a broadly educated person and a
professionally competent engineer in four packed
years. The purpose was not to improve the qual-
ity of engineering education, but merely "to com-
pete". Now however, there are indications that the
shift of students has not been into science, but
instead into the humanities and the social
An explanation for this shift can be obtained
from an observation that is made by Professor
Henley in this issue of CEE: In the previous
generation, engineering students were obtained
largely from less affluent and "blue collar" fami-
lies. These young men saw, in an engineering
career, the possibility of upward economic and
social mobility. Today however, the sons of these
same engineers are not themselves interested in
engineering. Along with many others from
higher income families, they are less concerned
about material gain and social status than they
are about the social and human problems of our
society. Professor Henley quite rightly argues
that we should improve the flexibility and versa-
tility of our undergraduate programs in order to
attract students from the upper classes. But we
believe that it is also essential that we recruit
more minority group students, who, like those
of the last generation, are seeking improved
status and living conditions.
We further believe that we need to impress
upon the idealistic young men who might be
attracted by the social sciences that they can

indeed serve their fellow man in a tangible way
through an engineering career. For too long we
have let the humanists suggest that they are the
salvation of mankind and that the "technologists"
are the destroyers, the polluters, and the dehu-
manizing materialists. Instead of using things
and loving people, they charge us with loving
things and using people.
It is likely that these negative attitudes have
developed because our professional goals have
not been understood from a sufficiently broad
perspective. While our immediate purpose may
be to produce improved goods, these are only
means to an end, not ends in themselves. Our
ultimate aim is to serve our fellow man and to
insure him his intrinsic human worth and dig-
nity. Accordingly, if our goal is to serve man-
kind, it is our responsibility to work to eliminate
starvation and to see that the benefits of tech-
nology and education diffuse to all peoples every-
where. If our goal is to insure human dignity,
we will see that the psychological and economical
barriers that inhibit full participation of minor-
ity group members in the engineering profession
are eliminated. If service is indeed our goal,
our profession must then be identified with the
prevention of war and social strife through an
attack on its causes, with the enhancement of
man's freedom (and humanization) through the
elimination of drudgery, and with the reduction
of pollution through imaginative research.
When we can convince our idealistic youth
that the goals of our profession can be thereby
implemented and expressed in terms of people
and their needs, we should not need to jeopardize
the quality of our programs in order to attract
more students.

In order to focus attention on these matters,
CEE is devoting much of this issue to the subject
of engineering and public affairs. Our spring issue
will emphasize the related theme "New Directions
for Engineering!" Through these two issues, CEE
hopes to show that the continued growth of
technology need not be feared as a negation of
human values, but can instead be construed as an
essential component to their survival. -RWF

WINTER, 1969



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from our READERS

I read your editorial in the latest issue of Chemical
Engineering Education and found it quite interesting. ...
While I fully agree with everything you said in your
editorial I think it should be broadened by leaving out
the word "chemical" throughout. Engineering has devel-
oped with one root in science, other roots in the engineer-
ing sciences, and its trunk is a multi-channel communica-
tion cable with branches in operation and equipment de-
sign, in laboratories, pilot plants, and processing plants.
Its leaves and fruits are products and goods of our con-
sumer economy. Without its roots, it will die; without
its trunk, the leaves and fruits will not develop; and
without its fruits it has no reason for existence. This is
essentially quoted, in part paraphrased, from your first
paragraph. I could go on and continue this way through-
My point is that we must now begin to recognize the
subservience of the adjective to the noun. I think it is
time perhaps past time for us to accept the fact
that we are engineers first and then, oh yes, chemical or
electrical or civil or other kinds of engineers including,
today, many many with strong interdisciplinary interests
and commitments. I think there is need for a strong na-
tional unified engineering profession, an organization
something like the American Association for the Ad-
vancement of Science, a journal structure to further
breakdown the barrier resistances to communications
among various kinds of engineering the word "kinds"
here used in its classical sense.
It seems to me that there is little today which truly
characterizes any particular stripe of engineer. I think
it is necessary for us to maintain the departments as
foci around which engineering schools function but I
think it is high time that we recognize and foster, ad-
ministratively and in the practice of our profession, the
idea that we are all members of one profession and that
the interactions of engineers of all kinds with scientists,
political scientists, economists, humanists, and those
from the health professions are NECESSARY if we as
a profession are to contribute to the important problems
of our era.
I wish we could subscript the adjective the way we
use subscripts in our journal articles. We would then
ENGINEERINGheminica or EngChem and
ENGINEERINGElectrical or EngEle, etc.
as meaningful designations for our professional identities.

H. E. Hoelscher, Dean
University of Pittsburgh

EDITOR'S NOTE: In reply to a letter from the editor,
Dean Hoelscher stated that he was not trying to limit
chemical engineering, but to express the hope that we
will soon realize that engineering must become a single
unified profession lest we "fragment ourselves out of
the business."

I would like to make some comments on Dr. Griskey's
opinion"Students, Faculty and Professionalism," par-
ticularly his derogatory implications about the University
of California at Berkeley.
Berkeley is no paradise for students, particularly for
lower division undergraduates; no large computer dom-
inated state school can be. But to imply that the "Berke-
ley syndrome" is characterized by "staff members that
do not care" is to do a great disservice to the many facul-
ty members who are always open, concerned, and inter-
ested in the students well being.
As a graduate student in the Chemical Engineering
Department, I have had the opportunity to observe the
conscientious efforts of many professors seeking student
opinions and ideas. Many of the busiest professors -
measured in terms of research publications, administra-
tive duties, etc. are among the most concerned and
most helpful.
A much more important facet of the Berkeley which
I know is that many staff members make an honest at-
tempt to understand the opinions and ideas of their stu-
dents. We have several men in our department who are
quite separated from their students in age, background,
life style, and philosophy but yet make conscientious
attempts to get an honest view of the student mind.
They are aware that their "professionalism" has not
been a final solution to their society's local or global
problems. They are also aware that the codes and paths
which they have followed with integrity and distinction
are not the only ones possible and in fact may not be
the best ones for today's young. They often disagree
strongly with the actions and ideas expressed to them.
But their disagreement is based on their view of the
merits of the ideas and actions not on the length of hair
or the style of dress associated with them. These men
do not view the students as "characters" with "all kinds
of weird customs" as does Dr. Griskey, but rather as
human beings who are reacting to their own boundary
conditions and are trying to solve the problems they see.
Not all nor even most of Berkeley's faculty meet this
description. But there are a sufficient number of these
journeyman to make life at Berkeley an exciting and
stimulating experience.
I would like to cite a recent action by individuals on
the Berkeley faculty as one example of the changing
attitudes here. This fall, during the turmoil precipitated
by the Regents' action against course in which Eldridge
Cleaver was to participate, many concerned faculty mem-
bers and administrators held open meetings in various
places all over campus to discuss the nature and the
background of the situation. The tone of these meetings
was frank and informal; Nobel Prize winners were chal-
lenged by first quarter freshmen. This aggressive at-
tempt at communication on the part of these men and
the students who helped plan the program goes well
beyond Dr. Griskey's "open door" policy.
Finally, I would like to suggest that Chemical Engin-
eering Education publish a column'giving student views
on the issues raised by Dr. Griskey's article, particularly
his view of the campus situation.
Thomas A. Massaro, Student
University of California, Berkeley
Letters (Continued on page 29)

WINTER, 1969



The RAND Corporation,
New York, New York

Sometimes by design, more often by default,
chemical engineers are becoming increasingly in-
volved in forming and executing public policy.
As such areas as public health, resource manage-
ment, environmental control and weather modifi-
cation assume still greater social importance,
chemical engineers' involvement will continue to
increase. Thus, the question about the profes-
sional melding of engineering and public policy
is no longer whether it should take place, but
Few engineers now involved in public policy
-or, more generally, "public affairs"-prepared
formally for their current jobs. Many became
active in public policy areas late in their ca-
reers, to satisfy professional demand or per-
sonal interests. Others, such as the author
became involved early in their careers, usually
after preparing informally (e.g., through extra
courses and reading) or in some cases -
after taking graduate work outside engineering
in fields such as law. Although these informal
routes have served well thus far, the feeling is
growing among those who have travelled them
that something better and more thorough is
Two main reasons underly this feeling: pro-
fessional competence and supply. In the last few
years, economics and related social sciences have
begun to emerge as semi-practical disciplines
relevant to (and used in) devising public policies.
Much of the growing managerial "revolution" in
Federal and municipal agencies has, for example,
been spearheaded by economists and guided by

Any views expressed in this paper are those of the
author. They should not be interpreted as reflecting the
views of The RAND Corporation or the official opinion
or policy of any of its governmental or private research
This paper is adapted from a talk presented to Col-
loquium on Socio-Economic Planning, New York Academy
of Sciences, March 16, 1967, when the author was a
member of the Princeton University faculty.

Ed Blum, received his BS degree in ChE from Carne-
gie Institute and the MA and PhD (64) from Princeton
University. In 1965, after a year's post-doctoral work,
he joined Princeton as an Assistant Professor of Chemi-
cal Engineering, where he also served as a member of
the graduate program faculty at the Woodrow Wilson
School of Public and International Affiairs, as coordina-
tor of the graduate program in Engineering and Public
Affairs, and as Chairman of the Ad Hoc Committee on
Systems Engineering.
In 1967, Ed joined the RAND Corporation as Assist-
ant to the Vice President for Research. Currently, he is
a group leader and member of the senior professional
staff in RAND's System Scences Department. In addi-
tion, since early 1968, Ed has been in New York as
leader of RAND's New York City Fire Project, which is
engaged in the first comprehensive, systematic study of
urban fire protection.

relatively complex economic principles. Although
many of the forms and procedures will evolve-
and perhaps disappear the economic precepts
(many unfamiliar to engineers) are likely to
survive. Similarly, although the effects are yet
even less apparent, ideas and principles from
other social sciences are being introduced into
basic levels of the policy process. Engineers pro-
fessionally involved in this milieu need to know
and understand not only the catchwords of these
"new influences", but also their bases and their
implications for technical research and design.
Professional competence now requires much
more than non-technical veneer.
Also, because the current routes are informal
and the opportunities often unclear (in most
cases, the man still shapes the job, rather than
vice versa), too few people choose to follow them.
Those who do and, like the author, have need for
others, find the supply far less than their demand.
Many engineers apparently (from conversations)
would like to pursue joint engineering-public pol-
icy careers, but either do not know how or are
discouraged by the lack of help (or by active
opposition) available in engineering schools.
This kind of career obviously is not for every-
one, nor should it be. Perhaps no more than sev-
eral percent of all engineers need be directly in-
volved in public policy, especially if those who are
involved are sufficiently sensitive and qualified.


What I propose is a concerted effort to develop a meaningful
systematic professional discipline (or compound discipline)
that will enable us at least partially to understand and control
the interaction between people and technology.

But for those several percent, something more is
needed. It is to them that the following is dedi-

Man's relation to technology reflects the root
problem of his existence: man has the ability to
give form and coherence to his world, even
though that world always limits his attempts to
do so. Man does not completely control his en-
vironment, but neither do the forces beyond his
control completely determine his life. Where he
can influence his environment, man's actions in-
evitably reshape his world, whether or not he
chooses to direct his efforts toward some con-
scious goal. When he acts, man implicitly chooses
a course and a form for his world; if, as has been
his wont, he chooses not to control the course, he
may not like the form that results.
Modern cities provide the most conspicuous
evidence that technology has too often led life
into unduly stressful modes because man has
abdicated the attempt to control his own work.
The modern city is dramatic proof that people
and technology interact whether or not we study
or attempt to control that interaction. Indeed,
unless we do study an attempt to control it, this
interaction between people and technology (which
I denote by "engineering and public affairs")
may lead to future cities far less liveable and de-
sirable than those we know today. We cannot
simply assume that everything will evolve bene-
To direct the interaction between people and
technology toward the achievement of objectives
man wants, therefore, I propose intensive re-
search and education in engineering and public
Neither research nor education in this area
is totally new, of course; fragmentary efforts
exist in many places. Research in engineering
and public affairs, often impelled more by neces-
sity than by design, has been carried out in some
university planning, economics, and engineering
departments, and in some planning and "sys-
tems" firms. Education in engineering and pub-
lic affairs, often called by other names,1 has been

started at several universities, perhaps most no-
ticeably at Stanford (where it is called "Engi-
neering-Economic Systems"), at Dartmouth, and
at Princeton. But these efforts, even where they
have continued, have frequently been ad hoc,
faltering, and difficult to evaluate. Very little
sense of unity or discipline has yet appeared.
What I propose is a concerted effort to de-
velop a meaningful, systematic professional dis-
cipline (or compound discipline) that will enable
us at least partially to understand and control
the interactions between people and technology.
Such a discipline would form an integral part of
both engineering and socio-economic planning.
Since it is now clearly impossible to point to the
best or ultimate forms for engineering and public
affairs, I would like to suggest some preliminary
directions for education and research.


Although many important problems involv-
ing interactions between people and technology
arise in the city, I would extend engineering and
public affairs' domain beyond the urban region to
include topics such as:

Individual and mass
transportation, and the
Personal and mass com-
Resource management

Waste management
Ecology (in general)
Urban problems
Large-scale civil plan-
ning and organization,
including moderiniza-
tion and development
Architecture and con-
Public Health
Weather modification
Environmental control

1A number of universities have programs (usually
outside engineering) titled something like "Science and
Human Affairs" or "Science and Politics." These vary
widely in emphasis and content. Some are devoted to
bridging the gap implied by the term "two cultures";
others deal more with substantive issues of mutual in-
terest to scientists (or engineers) and humanists (or
social scientists). Programs of the latter type that deal
with interactions, rather than just with isolated topics
from one field or the other, would for present purposes
come under the rubric of engineering and public affairs.

WINTER, 1969

Shell is a pair of sneakers-made from
our thermoplastic rubber.
Shell is a milk container-we were a
pioneer in the all-plastic ones.
Shell is a clear, clean country stream
-aided by our non-polluting detergent mate-
Shell is a space capsule control-ener-
gized by Shell's hydrazine catalyst.
Shell is food on the table-made more
plentiful by Shell's fertilizers.
Shell is mileage gasoline-developed
through Shell research.
Shell is a good place for Chemical
Engineers to build a career.

Shell is an integrated research, engineering, marketing and product application methods;
exploration and production, manufacturing, and carrying out research and development
transportation, marketing organization with to support all of these. Information about
diverse technical operations and business openings throughout Shell may be obtained
activities throughout the United States. by signing at the Placement Office for an
Chemical Engineers are vital to the Com- interview with our representative, or by
pany, applying their knowledge to recover- writing to Recruitment Manager, The Shell
ing oil from the ground; designing and Companies, Department C, Box 2099,
operating oil, chemical and natural Houston, Texas 77001. Shell is an
gas processing plants; developing new equal opportunity employer.

Shell Oil Company/Shell Chemical Company/Shell Development Company/Shell Pipe Line CorporatTon.

. technical and social considerations cannot be divorced .
it is vital to consider both engineering and public affairs
and the interactions between them in analyzing problems
and formulating plans and policies

In these areas, technical and social considera-
tions cannot properly be divorced. Conclusions
derived from considering only one or the other,
or both separately, are likely to be misleading,
if not erroneous. First, the assumptions and
values inherent in purely technical and social
analyses are quite different, indeed often conflict-
ing, and rarely explicitly stated. Thus, meshing
the results of separate technical and social con-
siderations without dealing with the interactions
is likely to lead to plans and policies beset by
internal contradictions and inconsistencies.1 Such

.diverse backgrounds and viewpoints are often
quite fruitful invention and discovery often
arise at the boundaries of special fields .

products will satisfy neither the technical nor the
social objectives, and will clearly be undesirable.
Second, and perhaps even more basic, con-
sidering engineering and public affairs separately
is likely to prevent proper definition of the prob-
lem to be solved. Social scientists and engineers
both have attitudinal and methodological bases
that cause them to frame and examine problems
in certain traditional ways. Since social scien-
tists generally have had little to do with engi-
neering (or science, with the important excep-
tion of those who have examined the politics of
"big science"), they are often inclined to accept
the statement of the technical problem, and the
"feasible" solutions, as given. Similarly, engi-
neers are inclined to regard the statement of the
non-technical part of the problem also as given,
and hence exempt from questioning and reformu-
Since neither social scientists nor engineers
1A technical package consisting of many components
may be (and often is) assembled and "optimized" accord-
ing to criteria quite incompatible with those desired so-
cially or potentially, e.g., minimum short-terms direct
cost (ignoring benefits, long-term costs, and indirect
"social" costs), technical efficiency (related usually to
one scarce input, ignoring all other scarce inputs and the
costs and benefits of outputs), maximum production, etc.
Even if the criteria are explicitly stated, which they often
are not, they are so different from the criteria used ordi-
narily in public affairs (equitability, benefits to special
groups, scope for individual initiative, etc.) and use such

are accustomed to dealing with the other's spe-
cialty, the most important parts of the problem
statement may fall between them, accepted by
both without questioning as the other's concern.
Even if the problem is sufficiently conventional
that its technical and social aspects are well un-
derstood, the social scientists and engineers, by
failing to question each other's part of the prob-
lem statement, may end up solving totally differ-
ent problems. And each may, by concentrating
on the points most interesting to him, ignore the
interactions between engineering and public af-
fairs that may be more important than either
Thus, in the areas listed above, it is vital to
consider both engineering and public affairs, and
the interactions between them, in analyzing prob-
lems and formulating plans and policies. It would
also appear valuable to consider the compound
field, including the interactions, in research.
Drawing on a compound discipline may enable
one to recognize weaknesses in current argu-
ments and current practices that professionals in
the particular fields have "learned to live with"
or disregarded. Indeed, diverse backgrounds and
viewpoints are often quite fruitful within engi-
neering and the natural or social sciences; inven-
tion and discovery often arise at the boundaries
of special fields, as the growth of astrophysics,
biochemistry, bioengineering, mathematical eco-
nomics, etc., will attest. It would not be hard to
imagine similar or perhaps even greater innova-
tion occurring at the boundaries of engineering
and public affairs.
(Dr. Blum discusses Directions for Education and
Research beginning on page 38)

different scales that reconciling discrepancies is extremely
First, it is often hard even to recognize where con-
flicts exist, because the criteria are expressed in different
terms which refer to different value systems. Second,
since the technical and social alternatives are usually of-
fered as complete packages, within which compromises
and trade-offs have been made according to the respective
(different) criteria, it is difficult to extract from the total
packages parts compatible with over-all criteria. Even
if one can dissect the different packages to obtain com-
patible parts, one has no assurance that the parts will
function well together as a system.

WINTER, 1969

11 educator


This feature article was contributed
by Professor Stuart Churchill, University
of Pennsylvania and former chairman at
the University of Michigan.

The students and faculty of the Department
of Chemical and Metallurgical Engineering of the
University of Michigan have a proud tradition
of active participation in athletics. Many stu-
dents, and usually superior ones, have won recog-
nition in formal intercollegiate competition. Bob
Bird recently stated in CEE that the faculty of
Chemical Engineering Department at the Univ-
sity of Wisconsin confines its athletic interests
to canoeing and golfing. The faculty at Michigan
choose more vigorous sports, including skiing
(one member even has a row-tow in his back-
yard), tennis (they challenge all other depart-
ments at the annual AIChE meeting), ice-hockey
(several have backyard rinks for practice), touch-
football, basketball, baseball, squash racquets,
and handball.
Dick Balzhiser fitted quite naturally into this
environment both as a student and later as a
faculty member. He completed his baccalaureate
in four years, ranking at the top of the entire
class of 800 in engineering, and still found time
to play varsity football, to take an active part in
an incredible number of other extracurricular
functions, and to support his family (which then
included two children) by working as a research
He did not secure the position of first-string
fullback until the middle of the second season
because the coaches were somewhat distracted
by the priority he gave to laboratories over foot-
ball practice. However, once given a chance to
play he demonstrated his superiority in spite of
limited practice.
As an undergraduate he did not receive fi-
nancial support related to his athletic activities.
However, when he began graduate work he se-
cretly accepted a position as Assistant Freshman
Football Coach (primarily as an excuse to be
out on the practice field every fall afternoon).
We became concerned that this responsibility
might impede his doctoral work and awarded him
a Fellowship the next year with the proviso that

he stop such "moonlighting". We presumed he
had resisted temptation until the coach credited
the upset of Iowa's championship team to the
superb job of scouting done by Dick. Dick was
embarrassed but rationalized this misdeed on the
basis that he had refused to accept any payment
and had driven his own (very old) car to Iowa
Despite such diversions Dick completed his
doctoral work in due course. He has since done
an outstanding job of teaching and research, re-
ceiving numerous awards. He has also found time
for scholarly, professional and administrative
work, and to provide leadership in an amazing
list of community, religious, business, social and
political activities, culminating in a term as
Alderman and Mayor Pro-Tem of Ann Arbor and
in a year in Washington, D.C. as a White House
It is hard to predict what Dick Balzhiser will
do next. What ever it is will be well-done.

Biographical Material
Dr. R. E. Balzhiser is professor of chemical engineer-
ing at the University of Michigan. Along with his
athletic letters he also holds BS, MS, and PhD degrees
from Michigan. His teaching career started as instructor
there in 1957 and his outstanding teaching and research
activities resulted in promotion through the ranks to
professor in 1967.
Among the honors and awards received by Dick the
following are mentioned most frequently:
Western Conference Award (Big Ten) for proficiency
in both athletics and scholarship
Outstanding Young Professor in College of Engineer-
Outstanding Young Man of Ann Arbor, Junior Cham-
ber of Commerce Award
Elected Mayor Pro-Tem by fellow councilmen
Outstanding Young Man of Michigan (one of five)
White House Fellow
Dick continued his interest in nuclear engineering
as project director for over $600,000 of research work
for the Atomic Energy Commission and the Aeronautical
System Division in liquid metal technology. He is a
consultant to a large chemical company and editor of a
"Chemical Engineering Series" of textbooks for a well
known publisher.
Some of Dick's activities and experiences as a White
House Fellow are detailed in the next article. While in
the Defense Department he assisted in organization and
incorporation of Alliance for Civic Action, a group con-
cerned with the nondestructive application of military
resources to society's problems.
The White House Fellows Program was established
by President Johnson in 1964 to give rising leaders from
all fields one year of "firsthand, high-level experience
with the workings of the Federal Government.



University of Michigan
Ann Arbor, Michigan

Historians will long reflect on the eventful
period through which this nation recently passed.
It is doubtful that any period in the nation's his-
tory has produced, with such prolfic regularity,
events with the profundity and gravity of those
occurring between August 1987 and November
1968. From the burning of Detroit to Richard
Nixon's election to the Presidency, this country
has experienced the tragedy of assassination, a
confrontation with the Poor, the frustration of a
Pueblo, brinkmanship in Cyprus and the Middle
East, the commitment of troops to streets of our
cities, the near collapse of the world's economy,
a struggle with both friend and foe in Vietnam,
the surprising exits of Lyndon Johnson and
George Romney from the Presidential race, the
hope of arms control, the.brutal display of Soviet
insecurity in their invasion of Czechoslovakia,
and an unprecedented test of our democratic
political processes.
historic period from September 1967 -
August 1968, it was my privilege along with
fifteen other young men and women to serve as
White House Fellows in our nation's capitol. We
were the third such group to spend a year in the
shadows of power that radiate from the White
House. The program was initiated by President
Johnson in 1965 with the stated purpose of ex-
posing young potential leaders to the decision-
making process at the top level of the federal
government. Each Fellow is assigned to a mem-
ber of the President's Cabinet or to key Presi-
dential advisors in the White House.
Superimposed on this assignment is an exten-
sive educational program consisting of numerous
meetings with the President and his major ad-
visors, senators, congressmen, board, bureau and
agency heads, governors, mayors, corporate, uni-
versity and union presidents and officials, ambas-
sadors, columnists, and civil rights leaders. These
meetings were supplemented in the past year
with two field trips to New York which provided
an opportunity to meet with Mayor John Lind-
say and his staff, residents of ghettos, some of the
young militants of Bedford Stuyvesant, the edi-

tors of the New York Times, David Rockefeller
and his associates in the Chase Manhattan Bank
and the Urban Coalition, McGeorge Bundy and
officials of the Ford Foundation, and Secretary
General of the United Nations, U Thant, and sev-
eral foreign UN ambassadors. Without exception,
our discussions were frank and productive and
provided each of us with an incomparable expos-
ure to the problems and personalities of our
nation and the world.
of Defense where I was fortunate to serve
under two of the nation's most capable men,
Robert McNamara and Clark Clifford. Robert
McNamara's philosophy of involvement was
quickly and clearly spelled out my first day at
the Pentagon. Observers had no place in his
office; understanding required immersion in the
affairs of the department and it was to that end
that he urged me to select specific projects and
commit myself to a year of action not merely
observation. I soon came to find that indeed the
Pentagon under Robert McNamara (particu-
larly his immediate staff offices) was a beehive of
activity from early morning to well into the eve-
ning hours, interrupted only by an occasional
half hour trip to the squash courts to maintain
the physical and mental edge required to operate
under the tremendous pressure that confronts
defense officialdom.

WINTER, 1969

Few Americans fully appreciate his (Mc-
Namara's) deep sensitivity to the social
problems of the world and his long-
standing commitment to their resolution.

The McNamara record is far too long and
the man much too complex to discuss here in
depth, but I feel compelled to share several of my
observations. Most acknowledge (including his
adversaries on Capitol Hill) his brilliant mind,
the computer-like precision with which it func-
tions, and his almost infinite capacity for work.
Few Americans fully appreciate his deep sensi-
tivity to the social problems of the world and his
long-standing personal commitment to their reso-
lution. He consumed valuable "political capital",
both with the military and the Congress, in his
efforts to correct those social injustices which he
felt were properly a concern of the Defense
His move to the presidency of the World Bank
might have been anticipated by one who studied
his Montreal speech of May 18, 1966, "Security
in the Contemporary World", in which he related
world security to the economic development of
the lesser developed countries in the world. My
personal disappointment in his departure from
Defense was tempered by the realization that his
talents would become focused on this important
Much speculation surrounded this move, but
it appeared to me one that was clearly advantage-
ous to both himself and the President. He had
served longer than any of his predecessors in
this most grueling position during a most turbu-
lent period of our history. He appeared anxious
for the shift in emphasis afforded by the bank
presidency. The President, while retaining his
highly regarded counsel on an informal basis,
was clearly in a position to begin to ease the ten-
sions that had developed between his highly
principled Secretary of Defense and the House
Armed Services Committee in recent years.
These differences had contributed to the deteri-
oration in relations between Congress and the
White House which jeopardized the needed tax
bill and other high priority legislative needs.
His appointment of Clark Clifford proved to
be another example of the political genius of Lyn-
don Johnson. The new Secretary appealed to the
hawks and doves alike, as well as the military and
the Congress. Taking full advantage of the
greater flexibility that a fresh appointee pos-

sesses, Secretary Clifford proceeded to resolve
skillfully the sharp differences in matters such as
the nuclear frigates, authorized by Mendel Riv-
ers', House Armed Services Committee, but never
built by the Defense Department. He likewise
aided substantially in achieving the spending
cuts within the Defense Department necessitated
by subsequent tax action in Congress.
Monday morning staff meetings under the
latter were a sharp contrast to those under Mc-
Namara. Briefing by junior officers were re-
placed by a frank discussion of timely issues
facing the Department. Interaction among sen-
ior civilian defense officials and the Joint Chiefs
of Staff picked up noticeably as did the enthusi-
asm of all participating. Decisions were seldom
made during these weekly sessions, but the ex-
change of ideas that took place was invaluable
to me in better understanding the attitudes of
key participants on important issues before the
Pentagon was devoted to two assignments.
The first consumed seven months and involved
participation in an all-encompassing study of our
Vietnam commitment. My observations and con-
clusions based on this experience alone could
easily comprise a volume. Without undertaking
such a task here, let me simply say that our ef-
forts in that corner of the globe were placed in
much better perspective by this assignment. I
found our motives, if not always our means, to
be completely defensible in virtually every in-
stance. Individual decisions by each of four ad-
ministrations seemed quite reasonable when eval-
uated in the context of the period in which they
were made. However, the decisions of today must
not be prejudiced by those of the past; we cannot,
regardless of the resources we commit, make the
Vietnamese government a viable political entity
by our actions alone. This is clearly their re-
sponsibility, and our commitments must be made
with regard to their ability and willingness to
carry out the reforms necessary to win the broad
based support of the people. At the same time
our pressing needs at home and elsewhere in the
world cannot be ignored in such decisions. With
these factors in mind, I welcomed the eventual
decision by the President to suspend the bombing
and hopefully move closer to a negotiated settle-
ment of the bloody conflict that has wearied sev-
eral generations of Vietnamese people and
sharply divided two generations of Americans.


For the final five months of my tenure in the
Department, I served as Executive Secretary of
the Civil Disturbance Steering Committee, an
advisory group established by Secretary Clifford
to work with the military in planning and pro-
gramming the use of military resources for civil
disorder control. It provided an excellent ex-
posure to the methodical manner in which the
military responds to the chain of command
emanating from the White House. Activities in
this assignment ranged from formulating the
agenda for Steering Committee meetings to at-
tending daily briefing sessions with officials from
the District of Columbia, the National Park Serv-
ice, the Justice Department and the White House
throughout the tense period during and following
the Poor People's Campaign in the Capitol.
Both assignments provided an excellent op-
portunity to contribute to the decision-making
process. Integration into each of these positions,
while awkward at times, proceeded with remark-
able ease considering my somewhat unique posi-
tion in the Department. I was aided consider-
ably by the involvement of my predecessors, a
respectable civil service rating in the Depart-
ment, and the recognition and respect auto-
matically shown for one housed in the Secretary's
suite of offices with a White House appointment.
In many ways the White House Fellows
served as sort of shadow cabinet. Individually,
we became well informed on many of the major
issues confronting our respective departments.
We communicated frequently with one another,
in some cases, on a more regular basis than the
senior Cabinet officials to whom we were as-
signed We were unencumbered by administra-
tive assistants and the bureaucratic channels,
and thus were freer to interact than officialdom
itself. The very nature of our role provided us
with ready access to many issues, programs, and
concerns that were percolating through the sys-
tem. We had daily contact with people at all
levels within each department so that we often
saw sides of an issue that were blurred or de-
leted by the bureaucratic massaging to which
most matters are subjected. The process fre-
quently enhanced communications within the de-
partments to which we were assigned, in that we
crossed lines of authority and areas of responsi-
bility that full-time employees were unable or
were not expected to bridge. In this way, our
contributions were frequently difficult to define,
only occasionally recognized, and generally best
left unclaimed.
WINTER, 1969

In many ways the White House Fellows
served as sort of a shadow cabinet.

To be certain, we observed the often cited
weaknesses of a gigantic bureaucracy groping to
deal effectively with mounting problems at home
and abroad. At the same time, we observed a
remarkable array of talent, laboring with dedica-
tion and conviction, to meet the constantly emerg-
ing problems of the nation and the world. With-
out exception, we developed a peculiar sense of
loyalty and respect for the man or men under
whom we worked. We came to know govern-
ment as a collection of humans and not an assem-
blage of buildings and institutions located on the
shores of the Potomac. We found it subject to
frailties and prejudices of humans just as the
corporations, institutions and firms from which
we had come. Names became people and pedes-
tals became desks, across which most of us sat
at one time or another. The decision makers
suddenly appeared as men upon whom unbeliev-
able pressures were constantly imposed and who
recognized the limitations and uncertainty which
surrounded each decision that flowed from their
office. It is indeed difficult for us to take for
granted any longer the processes by which the
government interacts with its people, with its
institutions, or with other nations.
I'm sure that my experiences were shared by
my colleagues in their respective departments.
To some we were looked upon as intruders or
opportunists, somewhat idealistic in our ap-
proach to the problems of government. To oth-
ers we represented a breath of fresh air and hope
for the future. To John Gardner we clearly were
the manifestation of an idea which he had con-
ceived before joining the President's Cabinet. To
the President, we represented a link to the gen-
eration with which he has had the most difficulty
in communicating. The program was clearly a
gamble for him, but one that he took with a great
deal of enthusiasm and hope. The 68 of us, who
have been fortunate enough to experience the
enlightenment of involvement and commitment
to the future, believe we have fulfilled his confi-
dence and expectations. As he told Mrs. Johnson,
. "when Lyn and Lucinda first vote, I hope
they will be voting for a member of this Associa-
tion." To those of us who served in the shadow of
the President of the United States, that is the
ultimate in compliments.


Mobil Chemical
Edison, N. J. 08817

Rutgers University
New Brunswick, N. J. 08903

Squibb Institute for Medical Research
New Brunswick, N. J. 08903

The need to provide career guidance of a
special kind for underprivileged and disadvan-
taged youth is heavily documented. The prob-
lems of ghetto dwellers-transmitted at an early
age to their children-is told in such reports as
the one by the President's Commission on Civil
Disorders. Unfortunately, professional career
guidance has almost always been directed to the
middle-class school, whether urban or suburban.
The rural slum and city ghetto provide very lit-
tle motivation to children and lead to an unre-
ceptive audience. Study shows, in general, that
the occasional Negro or Mexican-American
Chemical Engineer did not come from a com-
pletely deprived background. There was gen-
erally a parent or relative who got across the
value of a good education. The comparative ab-
sence of minority chemical engineers is a result
of many things: discrimination, apathy, finan-
cial deprivations and poor communication.
Recognizing the need for a special approach
and program, the National Career Guidance
Committee and AIChE appointed to Task Force
on Career Guidance for Disadvantaged and Un-
derprivileged Youth in early 1968. The initial
mission of the Task Force was to define the role
that a national professional society might play in
guidance of disadvantaged youth toward science
and engineering careers. The Task Force in-
cluded interested white chemical engineers and
several black chemical engineers possessing per-
sonal familiarity with the problems of the dis-
In May 1968, the Task Force presented its
recommendations to the National Council of
AIChE. Major emphasis was placed on a state-
ment of objectives, to be adopted as an expres-
sion of purpose and relevance by Council. This


G. A. Lessels received his BS in ChE Practice from
MIT in 1950. He is Manager of Process Development for
the Coatings Division of Mobil Chemical Company in
Edison, New Jersey. He is active in AIChE nationally
and at the local section level, currently being chairman
of the national career guidance task force for disadvan-
taged youth which developed the material in this article.
He is a licensed PE in Ohio and Illinois, and has published
papers covering technical areas and subjects relating to
professionalism and management.

recommendation was accepted and resulted in the
following commentary:
"Since AIChE already has a strong career guidance
role, the Institute fully endorses the concept of local
section programs to encourage underprivileged and dis-
advantaged youth toward professional and technical
careers in science and engineering. No longer should ex-
tensive human resources go untapped because of artificial
barriers or poor communications particularly at a time
when there is an increasing national need for scientific
'In addition, we as members of AIChE are sorely con-
scious of the deepening racial division within our coun-
try, and of the enormous effort that must be expended
to alleviate the continuing polarization of the American
community. We realize that positive steps must be taken
to solve the problems of the underprivileged, and we
would like to contribute to the long-term solution."

The Task Force recommended, in addition,
that its mission be broadened to include develop-
ment of means for practical progress toward
these objectives. As a result, the Task Force was
invited to under take the job of defining and
establishing methods and techniques that could
be implemented by Local Sections of the Insti-
tute. Further, it was asked to coordinate Local
Section activity and to function for the period
of time necessary to modify the program in re-
sponse to experience and level of acceptance.


- 'N

Henry T. Brown is senior research engineer at Squibb
Institute for Medical Research, New Brunswick, N. J.
He received the ChE from University of Cincinnati and
MS from MIT in 1956. For ten years he was associated
with Esso Research and Engineering and presently is also
an extension course lecturer in School of Pharmacy, Co-
lumbia University. His activities include research and
development of processes with special interests in fermen-
tation, solid support catalysts, and ion exchange.

By September 1968, a program had been com-
pleted and was endorsed by AIChE Council. This
program stresses a maximum of flexibility in
order to best suit the needs of the particular
community and local group. Key aspects of the
Task Force "package" are presented in the fol-
lowing discussion.

The approach that is utilized to institute a
career guidance program will largely determine
its success. To have an effective program, exist-
ing career guidance activities must be modified to
recognize the needs of underprivileged and dis-
advantaged youth. While no one plan may be
applicable for each and every area, certain ap-
proaches should ease the task of implementing
a program suited to the individual needs of the
community. It is highly recommended that local
groups direct their activities to areas with high
concentrations of the disadvantaged and under-
privileged. These are the communities where
traditionally the needs are greater and the career
guidance activities are weak, minimal, or pos-
sibly non-existent.
In most cases the best approach for the local
group is to enlist support of local industry, estab-
lish ties with community, minority and equal op-
portunity groups, and work through the ghetto
schools and school officials. Where possible, Chem-
ical Engineers will find it advantageous to work

with other professional societies who have active
programs in this same area. In all cases minority
members of the Institute and other technical
minority personnel must definitely be involved to
the fullest extent. Cooperative efforts with indus-
try, the school, and community groups should
permit maximum gain for the youth from limited
resources and manpower that are available to
most local groups. Many of these groups, in addi-
tion to offering their experience and talents to
the program will help to bridge any communica-
tion gap with underprivileged youth and guaran-
tee continuing support of the program.

Recognition of minority community organiza-
tions, their leader, and their goals must be a part
of the local group's program, if counselling is to
be successful. The approach should be the same
as used for any other community project that
requires action people must be made to feel a
part of the program if they are to act coopera-
tively to pursue the program's goals.
In most cases the internal structure of or-
ganizations that aid disadvantaged and under-
privileged groups, provide for programs of edu-
cation and counselling of youth. Many prefer
working through the communities' school. As
examples, with respect to the black community,

Robert C. Ahlert received the BSChE from the Poly-
technic Institute of Brooklyn, MS from UCLA and PhD
from Lehigh University (1964). He gained the greater
part of his industrial experience as a research engineer
and supervisor for the Rocketdyne Division of North
American Rockwell. In 1964, he joined the staff of Rut-
gers University as Executive Director of the Bureau of
Engineering Research and Associate Professor of Chemi-
cal Engineering. His interests include combustion, the
thermodynamics of condensation from gas mixtures, and
simulation of stream processes.

WINTER, 1969

Right nowWestvaco engineers
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And chemicals for coatings,
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for environmental control
Your job:
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See our campus representative. Or write to:
Roger Keehn, Westvaco Building, 299 Park Avenue, New York, N.Y. 10017

I West Virginia
Pulp and Paper
An Equal Opportunity Employer

Industry involvement is important to the program's success.
Local groups are encouraged to solicit support for both manpower and
for adoption of programs affecting employment of the underprivileged.

the Urban League has the "Tomorrow's Scien-
tists and Technicians' (TST)" program, CORE
has an education committee, the NAACP has
youth and education committees, and many anti-
poverty agencies and newly formed urban coali-
tions have educational programs for the disad-
vantaged. All committees have programs aimed
at counselling underprivileged youth. The more
militant Afro-American, Black Pride, Black Na-
tionalist and Black Power groups place a strong
emphasis on education of black youth and have
committees that function in this area. Depending
on the local situation, the latter groups may have
broad contacts with youth and must not be
omitted when trying to set up a meaningful ca-
reer guidance program that will enhance confi-
dence. The organizations cited are for illustra-
tive purposes; similar considerations apply in
dealing with any minority group organization.
It is naive to expect only one leader or only
one opinion from a minority community, just as
no one opinion or one leader can speak for all
other Americans. In most cases, the goals may
not differ between groups, and what really mat-
ters is the ego or the personalities involved.

The ghetto school should be a prime target.
To obtain the greatest exposure possible, career
guidance activities are best undertaken at the
school or at a location inside the ghetto area.
Programs that reach elementary disadvantaged
youth are definitely recommended and should be
encouraged. Such contacts would stimulate
awareness and motivate youngsters to obtain the
high school background that is required for ad-
mission to a technical school or college. One such
program is the Cincinnati Saturday Enrichment
Program which combines career guidance with
some remedial assistance. Without such pro-
grams, engineers who visit high schools in under-
privileged areas will find it difficult to communi-
cate or stimulate interest in science or engineer-
ing. The occasional high school student who is
motivated by this late contact will be poorly pre-
pared to pursue a college course. It is important
to develop good working relations with school
officials-particularly science teachers and guid-
ance counsellors. Prior contact with state and

local school officials, and professional guidance
societies may help to establish proper rapport.
The main point to emphasize is that industry and
professional societies provide equal opportunity
in science and engineering careers, to all who are
qualified, and are encouraging youth to take ad-
vantage of these opportunities.

Industry involvement is important to the pro-
gram's success. Local groups are encouraged to
solicit support for both manpower and for adop-
tion of programs affecting employment of the
underprivileged. Industry must encourage par-
ticipation of professionals in the program. Un-
fortunately, some professionals from minority
groups have disassociated themselves from such
an activity over concern for unfavorable public-
ity for their employers. Once corporate sanction
is given, the stigma is removed, and the man no
longer feels trepidation over activities that deal
with his minority group.
Plant tours for underprivileged youth is an-
other area where industry's help is needed. Dur-
ing the tours emphasis on opportunities that are
available, with examples of technical jobs held
by minority group employees, helps to convince
these youth that there is more than talk involved.
Industry can provide part-time and summer
jobs for the underprivileged to furnish funds for
students in need of assistance to complete their
education. In some instances, jobs that have in-
volvement with science can be made available as
aids to motivation. Of course, state laws on
minimum employment age must be observed in
programs like this.

When presenting materials to these youths, it
is important to recognize that there exists a wide
distribution of attitudes and talents. The two
extremes encountered may be:
Those young people who are bright and adjustable
but who are poorly motivated to seek an improved
status in life,
The frighteningly large group who can barely read
or write and whose attitudes are so atrophied by social
or economic conditions that basic communication is

WINTER, 1969

The need is so great for technical people that all groups constitute
an untapped reservoir of talent and technical ability. Industry
can ill-afford to pass over such talent in a period of technical

manpower shortage the development
resources is an appropriate reward .
While the differences are more pronounced
among high school students, the problem exists
even at the grade school level. An effective
motivation and career guidance program must
be geared to provide for both groups of students
and, hence, must be tailored for the needs of the
area served.
Minority youth may question the credibility
of programs instituted by predominately white
organizations. This attitude has been created by
the failure of some highly publicized programs
which are nothing more than "show case" ef-
forts in this area. A recent article in the Harvard
Business Review* points out some of the reasons
for skepticism, which make any white-oriented
or middle-class program, regardless of its bene-
fits, subject to failure. Hence, the inclusion of
minority group professionals and technicians in
planning and presentation should be a require-
ment that is not taken lightly. Students will be
able to relate and respond better to successful
minority workers. Local groups must also be
prepared to answer questions that may arise
from students with relatively aggressive atti-
The level of the presentation should be the
same as for any youth of similar age. The young-
sters should leave with some idea about what an
engineer or technician does, what are his qualifi-
cations, and what are his rewards. The main
point to communicate is that there are oppor-
tunities in technical fields for everyone who is
qualified. The need is so great for technical peo-
ple that all groups constitute an untapped reser-
voir of talent and technical ability. Industry can
ill-afford to pass over such talent in a period of
technical manpower shortage; there is no eco-
nomic justification to exclude anyone with these
particular skills.
Generally, the series of program steps used
to implement career guidance for the disadvan-
taged and underprivileged are not fundamentally
different from other programs in this area. They

Haynes, "Equal Job Opportunity: The Credibility
Gap", Harvard Business Review, July (1968).

of these human

Developing an awareness, an interest, and a knowl-
edge of careers available in science and engineering
through talks, posters, films, and scientific presentations.
A large number of pilot talks, panel discussion outlines,
booklets, film lists, and "A Chemical Magic Show" are
Sustaining interest this may be accomplished
by the assignment of an engineer or a scientist to a par-
ticular school to deal with specific problems or projects
in the school. School science clubs centered around young-
sters with strong interest should be organized to act as
a nucleus for expanding interests and motivation. In
addition, groups should encourage programs that allow
individual contact with high school students and tours
of industrial plants.
Supporting in-school career guidance Provision
should be made for specific assistance for guidance coun-
sellors and science and math teachers so that they can
speak authoritatively to students about technical careers.
Help for students may be required in a number
of ways. Students who are motivated may be
inadequately trained. In such cases, the local
group should work with school and college offi-
cials to set up required supplemental programs.
College scholarship funds, for most students,
must be identified. Also, summer and/or part-
time employment must be secured for students in
need of resources to complete their education.

Many Local Sections of AIChE are well along
with programs of the type proposed. However,
the results of these activities will be uncertain
for many years. In the near future, acceptance
by minority communities and improved com-
munication with the youth of urban ghettos and
rural slums will be positive evidence of progress.
The real goal of more minority group scientists
and engineers will be many years in attainment.
Sustained effort and continuing innovation will
be required for a relatively long period, but the
development of these untapped human resources
is an appropriate reward for Chemical Engineer-
ing and allied professions.
Special acknowledgment is due Messrs. H. A.
Abramson, A. F. Stancell, and T. Tomkowit of
the AIChE Task Force for their contributions
to the preparation of this article.



IVarathon Oil Company was founded in Find-
lay, Ohio in 1887; however its ultramodern
Denver Research Center is located at the foot-
hills of the Rockies. The company is a producer,
transporter, refiner and marketer of crude oil and
petroleum products on five continents throughout
the world.
The Denver Research Center was established
to make discovery of new petroleum reserves more
economical, to help recover a larger percentage
of oil in present fields, to develop more profitable
refining and chemical processes, and to develop
new products.
Marathon employs more than 8,000 persons
at its offices around the world including its head-
quarters in Findlay. There are over 300 em-
ployees at the Denver Research Center of which
more than half are scientists and engineers.
Using engineering research to determine ways
to recover more of the oil from known deposits
is an important part of the work at the Research
Center. It includes projects aimed at stimulating
wells so they will produce more oil; in situ com-
bustion; and fluid injection processes, such as
miscible displacement, which are more efficient
than conventional techniques where gas or water
are used to drive oil to a production well.
Reservoir mechanics comprise another signifi-
cant part of the engineering work at the Denver
Research Center. The transient behavior of oil

reservoirs and the flow of fluids through porous
media are important phases of this work. Mathe-
matical models, which simulate reservoir behav-
ior, provide insight into future behavior of oil
bearing reservoirs.
Chemical engineers are also engaged in the
pilot plant study of existing refinery and chemical
processes as well as in the evaluation and devel-
opment of new processes and new chemicals.
Projects are underway, for example, on petro-
chemical processes to make monomers and other
basic components for polymers.
At Marathon's Research Center, qualified en-
gineers are provided with both the challenge and
incentive in supplying answers to these problems.
Your further inquiry is invited.

Mr. L. Miles
Personnel Supervisor
Dept. CE-2, P. O. Box 269
Littleton, Colorado 80120






The University of Oklahoma
Norman, Okla. 73069

Why should we in the College of Engineering
be interested in the scientific development of Ne-
gro and Indian High School students?
The most obvious reason is that the minority
groups represent an untapped source of students
not only for engineering but for all the sciences.
Surveys conducted by the engineering societies
have indicated that the number of Negro and
Indian engineers and scientists is far less than
would be expected from either the size of the
population or the number of college graduates. In
other words, many of these students' capabilities
are not being developed properly.
Secondly, as part of an institution of higher
learning we should represent the more progres-
sive element of our society; therefore, it is our
responsibility to be at the forefront not only
academically and professionally, but also socially.
If one considers the minority groups' role in en-
gineering and science, one should come to the
conclusion that their future participation can do
nothing but expand until they have filled the
present vacuum. My question is "Why should
we eat the dust of others already moving in this
direction of progress?" "Why shouldn't we, and
why can't we, lead the way in this area of human
development?" Before I leave this stream of
thought, I should like to point out that we are
actually depriving our white engineering students
of an opportunity of learning and understanding
minority group people and their problems.
Dr. Hollomon, President of the University of
Oklahoma, has told us several times that we
should plan our programs to react to the needs
of the state; that we should use our knowledge
to help solve the human and social problems of
our time; and that we must work together and
be interested in the University as a whole. There
are few better ways for us to work together as
a college or university than to apply our knowl-

Bert M. Avery is Assistant Director of the School of
Chemical Engineering and Materials Science at the Uni-
versity of Oklahoma. He holds BS and MS degrees in
Chemical Engineering from OU. For several years he
was associated with IBM as a systems engineer on Shell
Oil Account in Houston, Texas, before assuming his
present position at OU in 1968.

edge to upgrade minority group students in sci-
ence and mathematics. In addition, no one can
deny that a definite need of our state is to de-
velop the potential of our minority groups so they
are in a position to help themselves as well as
the state in the forms of tax revenue, leadership,
and racial harmony.
Helping educationally deprived students rea-
lize their educational capabilities is one way we
can do our part to help relieve some of the racial
strife in our nation.
At this point I would like to explain how the
School of Chemical Engineering and Materials
Science got so involved in this problem. In April
of 1968 three things occurred concurrently.
An AIChE task force report on career guidance
was received that pointed out that the number of Negro
engineers and scientist was very small. Also, there are
two urgent reasons to interest Negro students in engi-
neering: The general need for engineers, and the need
to correct a social situation of national importance.
Dr. Hollomon, then president designate of OU,
talked to the entire engineering faculty and in that talk
urged us to turn out knowledge and skills to solving
social and human problems in this state and across
An article by Zelbert Moore and Paul Galloway,
"Those You Never Know", appeared in an edition of
The Sooner magazine that was dedicated to the plight of
the Negro student at the University of Oklahoma.
As a result of these three events I was
prompted to ask during a CEMS faculty discus-
sion of our high school recruiting program,
"Why don't we recruit black students?"


. We should represent the more progressive element of our society .
Dr. Hollomon, President of the University of Oklahoma, has told us that we should
use our knowledge to help solve human and social problems .

Utilizing the AIChE task force report, num-
erous discussions with NAACP, Urban League,
Oklahomans for Indian Opportunity, Negro
principals and high school teachers, faculty
members of OU and UCLA, and fellow Black
graduate students, I came up with three basic
Lack of knowledge on the part of minority group
high school teachers and students of the opportunities
available in engineering.
Even if these opportunities were understood, the
great majority of students have inadequate background
in mathematics and science to pursue engineering
Improper motivation from the home of the student.
Believing that there is a great source of
capable engineers and scientists within the Negro
and Indian communities, we in Chemical Engi-
neering and Materials Science sponsored an En-
gineering Conference "Engineering Opportunities
for Negro and Indian Youth" for Oklahoma high
school principals, superintendents, science teach-
ers, and counselors on September 27 and 28 at
the University of Oklahoma.

The program that involved 30 high school peo-
ple, Negro and Indian students, Engineering fac-
ulty members, and specialities in the field of Sci-
ence Education was designed around one central
objective. That objective was to determine as
best we could the barriers that exist for Negro
and Indian youth in terms of their progress to-
ward science oriented careers and possibly de-
termine some ways of cracking those barriers.
The first part of the session was a series of speak-
ers presenting information in a variety of areas
from Federal Education Programs to innovative
experiments being conducted at UCLA. The pur-
pose of these presentations was to provide par-
ticipants will as much current information as
possible concerning all areas that involve educa-
tionally disadvantaged.
The second part of the session was the real
heart of the program and would determine the
success or failure of the Conference. The par-
ticipants were divided into discussion groups con-
sisting of three to four high school participants,
one Negro or Indian student, one of the Confer-

ence speakers, and an OU faculty member. These
groups, under the direction of Engineering fac-
ulty members, utilized the knowledge acquired in
the first part of the session and their own experi-
ences to determine possible solutions to the fol-
lowing problems:
1. How to best communicate to students the oppor-
tunities in engineering?
2. How to determine which students are qualified
for a career in engineering?
3. How the University may help to better prepare
the student for engineering study?
4. The need for a relationship between the student
and the University community.
5. The difficulty of freshman curriculum.
These along with many other problems were
discussed and as a result we hope to obtain
enough information to allow us to implement
some constructive practical programs that will
work over a long period of time.


We are presently analyzing the various ideas
generated by the Conference and therefore are
not in a position to justify the rightness or the
wrongness of the following suggestions.

There should be high school visitations by engi-
neering faculty members and whenever possible they
should be accompanied by an engineering student who
belongs to the same ethnic group as the high school
A film should be made that would show the Negro
and Indian engineering student in various classroom,
laboratory, and social activities. The film should be one
the student could identify with and say to himself, "If
that student can do it, so can I."
A summer program designed to acquaint the high-
school science teachers with engineering. Also, introduce
introductory courses in engineering at high school level
which might be taught by engineers from industry or the
Industry and government should implement pro-
grams for high school teachers and students that would
give them a first hand look at engineering.
All of these programs should start with seventh
and eighth graders, and because of the generally low
economic status of the minority groups, the financial or
materialistic rewards should be emphasized; however,
the professional status and pride of accomplishment
should not be overlooked.

WINTER, 1969

There are few better ways for us to work together than to apply our
knowledge to upgrade minority group students in science and mathematics .

Finally, we need a method of demonstrating or
giving evidence to Negro and Indian students that jobs
and opportunities really do exist within industry.

We must curtail the "creaming" process of apply-
ing a selectivity procedure for admission to the Univer-
sity that eliminates 90% of the Negro and Indian stu-
dents. This involves tests that measure white middle
class values, inadequate counseling, and so on. The ACT
should be reexamined to determine its validity for de-
prived groups. Special counseling and guidance is

Coordinate and conduct summer sessions involving
the best mathematics and science educators throughout
the state and bring them together with the students who
have had low quality instruction in these areas. This
should occur every summer from the seventh grade
through college. Because many of these students must
work in the summer to put clothes on their backs we
must not only pay all expenses but also reimburse them
for the money they would have made had they worked
instead of attending the summer session.
Send university students into high schools as jun-
ior counselors. In many cases, the educationally dis-
advantaged student may communicate better with a
college student nearer his age and with his same cul-
tural background.
There must be a university commitment on the
part of the president, deans, and faculty members to
support specialized programs.
a) Reserve 10% of admissions for students that can-
not meet the usual requirements.
b) These students should have special counseling and
programs such as a year pre-engineering on a
pass-fail basis.
c) Tuition should be cancelled for any student from
a family that makes less than $5,000 a year.
d) Scholarships that would provide full support for
all undergraduate years. The Negro and Indian
student is often affected by problems and situa-
tions that white students take in stride. The addi-
tional burden of supporting themselves is more
than most students can handle.
e) Support of minority group instructors and gradu-
ate assistants. We can't afford to apply the usual
criteria used for hiring faculty. Instead, we must
ask the question "can they do the job that needs
to be done?"
f) Establish science centers about the state where
students and secondary school teachers could come
for help and additional training. These could be
manned by graduate assistants, part time instruc-
tors, interested faculty.


There is a genuine feeling among the non-white
students that the university system is geared to the
white-student, his background, his social elevation, his
values. The non-white are treated uniformily the same,
but not equally.
We need more representation of non-whites in
administrative and faculty positions. Faculty needs to be
more tolerant and understanding concerning cultural
differences. We need an environment that supports and
encourages students in their endeavor to establish values
that are best for them.
A "social awareness" program should be imple-
mented in Engineering colleges. This would be an ef-
fort to involve students and faculty in social programs
in the community.


An effective system of tutorial instruction would
not only aid the new student in course work, but might
create a feeling of belonging. The tutorial sessions must
be taken to the student in his dorm or places of residence.
This might be a very worth while project for the various
engineering clubs.
Specialized counseling by concerned individuals
is a must.

In general we concluded, for any program that
proposes to work and produce practical results
we must have from those involved an intense
interest and an almost zealous commitment. We
must not be overly skeptical of new and tradi-
tionally unacceptable modes of operation. We
must be willing to accept the challenge of sup-
porting broad comprehensive programs which
may involve and affect all areas of university
life. We must develop the flexibility to accept
the different cultural values possessed by the
non-white students.
Any programs that are proposed should at
least include the following:
1) Emphasis on the dignity of the individual.
2) Produce massive system changes.
3) Have built in incentives and guarantees
for the young people who would partici-
4) Must include all educationally disadvan-
taged-Red, Black, White, Brown, Yellow
and combinations thereof.
I think we in Chemical Engineering and Ma-
terials Science at the University of Oklahoma
have made the commitment. Will you not join us?


- i-F--Q -r E s





In accepting world leadership, the United
States has assumed vast and unfamiliar responsi-
bilities over a remarkably short period of time.
A mere twenty-five years separate U. S. military
involvement in Viet Nam from the Neutrality
Act which in 1939 forbade U. S. shipping from
entering dangerous waters. A truly incredible
change in attitude has emerged as traditional
isolationism has slowly faded from the contem-
porary scene.
Many people nurse a nostalgic hope that the
world will return to a simpler time, that the U. S.
can wash its hands of worrisome problems in re-
mote lands. But these problems will not disap-
pear, and the U. S. cannot cease being concerned
with them. Headlines and taxes will continue
to remind the nation's citizens that foreign af-
fairs are an integral part of their lives.
In a democratic society, foreign policy de-
pends upon decision-makers educated and trained
in the common society with their actions being
passed upon ultimately by the electorate. Thus
the effectiveness of democratic government in
foreign policy is limited by the quality of educa-
tion as well as the traditions and dedication of
both its citizens and its leaders. Without a sound
education and understanding of world affairs,
neither elected officials nor the nation's citizenry
can expect to act intelligently in the critical inter-
national arena.
While the heavy burden of policy-making con-
tinues to be the responsibility of government,
private citizens are becoming involved in inter-
national affairs on an increasing scale. In the
earlier days of technical assistance, the govern-
ment generally took direct responsibility for for-
eigh programs and frequently employed tempo-


Frank M. Tiller, M. D. Anderson professor of Chemi-
cal Engineering and Director of International Affairs
obtained his bachelor's degree from the University of
Louisville in 1937 and his PhD from the University of
Cincinnati in 1946. In 1962 he was awarded a Doutor
Honoris Causa by the University of Brazil. He has been
a staff member at Cincinnati, Vanderbilt, Lamar Tech,
and the Instituto de Oleos in Rio de Janeiro. As consult-
ant, adviser and coordinator, his services have been ren-
dered through a variety of organizations including the
Fulbright Commission, Organization of American States,
and Agency for International Development. Tiller has.
received a number of awards for articles appearing in
AIChE publications.

rary consultants for guidance. Although techni-
cal experts mobilized for short-term junkets can
provide valuable service, experience has shown
that a variety of problems of underdeveloped
countries do not yield to such efforts. Fire-fight-
ing methods do not provide the careful planning
and sustained supervision that many technical
assistance programs require. Therefore, there
has been a trend in recent years to enlist non-
governmental organizations to carry out long-
range foreign programs on a contract basis, an
arrangement which represents an attractive al-
ternative to the use of temporary consultants and
diplomatic personnel serving short terms at their
posts. Private citizens in organizations with con-
tractual obligations find themselves intimately
involved in the implementation of United States
foreign policy.

WINTER, 1969





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Brandenburg, Ky. Urea Planning, Scheduling,
Charleston, Tenn. Nitrogen ChEroduction, Sales,
Joliet, Ill. Acids ME Production, Sales,
CHEMICALS Lake Charles, La. Hydrazine IE Accounting,
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-Agricultural Niagara Falls, N.Y. Polyurethane Transportation Poject Enineering
Pasadena, Texas Carbon Dioxide Marketing (Plant Startup &
Rochester, N.Y. Animal Health Construction),
Saltville, Va. Products Research Engineering,
Automotive Chemicals Technical Service
Other derivatives

Alumina ChE
Burnside, La. Aluminum IE Manufacturing
METALS Chattanooga, Tenn. Aluminum Extrusions ME Production
-Aluminum Gulfport, Miss. Aluminum Sheet, Plate, Metallurgy Sales
-Brass Hannibal, Ohio Coils Met. Engineering Maintenance
-Ormet, Corp. East Alton, Ill. Brass Fabricated Parts Accounting Fn e
New Haven, Conn. Sheet & Strip Brass Business Adm. Finance
Sedalia, Mo. Roll Bond Ind Tech. Metals R&D
Wire & Cable Ind. Mgmt.

Carbonizing Paper Marketing
Fine Printing Papers ChE Process Engineering
FOREST PRODS, West Monroe, La. Specialty Paper Chemistry Plant Engineering
PAPER & FILM Pisgah Forest, N.C. Products Pulp & Paper Research & Dev.
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Production Control
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Financial Analysis.



In many parts of the world, a shortage of
well-trained people rather than lack of capital is
the major obstacle to progress. Educational pro-
grams are an essential factor in breaking the
manpower bottleneck which impedes self-sus-
tained economic development. Since educational
programs are necessarily long-range in nature,
continuity and experienced leadership are essen-
tial. U. S. universities like the University of
Houston are uniquely equipped to provide such
All this suggests three challenges which con-
front American universities. The first is to train
experts in international affairs. The second is to
instill in the coming generations of citizens and
community leaders a basic understanding of the
importance and complexity of world affairs so
that they not only will be able to review intelli-
gently policies of the government but also will be
better prepared to take a personal part in foreign
activity if called upon. The third is for the uni-
versity itself to take an active part in foreign
programs under both governmental and private



Members of the ChE Division are reminded
that the closing date for nominations for the
sixth annual ChE Division 1969 Lectureship
award is February 15, 1969. Nomination forms
may be obtained from Dr. George Burnet, ChE
Department, Iowa State University, Ames, Iowa,
50010. The award is sponsored by the Minnesota
Mining and Manufacturing Company.

ASEE Annual Meeting, 23-26 June 1969,
Pennsylvania State University. Chemical Engi-
neering Division Program will consider educa-
tional aspects of selected interactions between
chemical engineering and important social prob-
lems: 1. Health Problems, 2. New Energy
Sources, 3. Urban Affairs. For further details,
contact Chemical Engineering Division Program
Chairman, K. B. Bischoff, Department of Chemi-
cal Engineering, University of Maryland, College
Park, Maryland 20742.

book reviews

Unit Operations of Chemical Engineering, 2nd
Ed., W. L. McCabe and J. C. Smith.
McGraw-Hill Book Company, Inc. (1967),
pp viii + 1007, $15.50 .
The second edition of this book, like the first,
is an undergraduate treatment of unit operations.
It is divided into five sections: Introduction, Fuid
Mechanics, Heat Transfer and Its Applications,
Mass Transfer and Its Applications, and Opera-
tions Involving Particulate Solids. Section 1 (In-
troduction) contains one chapter which consists
of a brief presentation of the basic laws and
concepts needed for the understanding and mas-
tery of the material to follow. Section 2 (Fluid
Mechanics) contains eight chapters covering
fluid statics, the flow of fluids through conduits
and past immersed objects, pumping and meter-
ing of fluids, and agitation and mixing of liquids.
Both incompressible and compressible fluids are
treated and some material on non-Newtonian
fluids is included. Section 3 (Heat Transfer and
Its Applications) contains seven chapters cover-
ing conduction, convection, radiation, heat ex-
changers, and evaporation. Section 4 (Mass
Transfer and Its Applications) consists of eight
chapters covering phase equilibria, distillation,
diffusion, absorption, humidification, leaching
and extraction, and crystallization. Section 5
(Operations Involving Particulate Solids) con-
tains five chapters covering properties and han-
dling of solids, size reduction, mixing, mechanical
separations, and drying.
Throughout the book, the treatment of equip-
ment and theory is well balanced and many
example problems illustrating the principles and
theory set forth are included. In addition, most
chapters contain a number of excellent problems
for which a solution manual is available from the
Those familiar with the first edition will find'
a number of changes incorporated in this edition.
Most of the long chapters in the first edition
have been broken down into a number of shorter
chapters in the present edition and the material
considerably rearranged and updated by the in-
clusion of material from transport phenomena.
The book is well written and relatively free
from errors. It is highly recommended.
Georgia Institute of Technology

WINTER, 1969

1968 Awa-ld .fecd4te


Part II Models

University of Minnesota
Minneapolis, Minn.

In the opening part of the lecture I reviewed
the evolution of chemical engineering thought
about mechanisms of transfer between fluid
phases. I attempted to identify various stages
of the development and went so far as to try to
draw some lessons from the historical record
as I perceive it. The lessons I offered seem to me
to contradict the viewpoint from which the loud-
est attacks on fundamental chemical engineering
are launched. Now let us turn again to the goal
of understanding flow and transfer at fluid

W E SET THE STAGE by recalling the con-
trast between boundary conditions on in-
compressible flow at rigid walls and at free
surfaces. At a solid surface all relative velocity
vanishes; it follows that the normal and tangen-
tial parts of the nearby velocity field are given

X2 av!i
Vn- O. ( x

HI a6 X=0
TT -1

where X is the perpendicular distance from the
solid At a free interface it is the tangential
part of viscous traction that vanishes; conse-
quently the relative velocity nearby consists of

n Vn10 (2H vn10 VII*I O)

II IIlO X(HvIII0+ VII vn )

where H is the local mean curvature of the inter-
face The most important point to make here
is that near a free interface the rate of convec-
tion away from or toward it is directly propor-
tional to the distance from it just as in the
stagnation flow featured below and the pro-
portionality factor is the rate of interface dila-
tion by both "surface inflation" and "surface
stretch". Now it is clear from the expression

*Based on the main part of the 1968 Annual Lecture
to the Chemical Engineering Division, ASEE at the
University of California at Los Angeles June 18, 1968,
sponsored by the 3M Company.

for total convective and diffusive flux, vc-DVc,
together with the convection diffusion equation,
that flow parallel or antiparallel to the direction
of transfer has the greatest effect on transfer
rate. What implications for interphase transfer
can we draw from this fact?
There must obviously be transfer from ele-
ments of one fluid phase to elements of the second
fluid phase. So regardless of the violence of con-
vective movements executed by fluid elements,
the ultimate mechanism of interphase transfer
(at least as long as the motions remain continu-
ous) must be by molecular diffusion. However,
the molecular diffusion process can be and usu-
ally is strongly affected by convective motions.
This is especially true in the vicinity of fluid
interfaces, an important point that too often
has been overlooked in the literature. The effect
of convection on diffusion, as governed by the
convective diffusion equation, will be one of my
main themes.
That diffusion in some neighborhood of the
interface is the controlling resistance to inter-
phase transfer, is generally presumed and is
indeed so in many laboratory and practical siuta-
tions. We will not discuss exceptions here.
The effect of convection on diffusion is cer-
tainly strong around a turbulently agitated inter-
face. It is logical to ask where in the chaotic
jumble of transitory local flows the effect is
strongest (Figure 1). The question can be
answered by dissecting the jumble into recog-
nizable parts and then examining those parts in
detail. In a paper before the Annual Meeting of
the AIChE in 1964 Raymond W. C. Chan and I
proposed that chaos can be resolved, to a fair
approximation so far as convective diffusion is
concerned, into mixed populations of relatively
simple, practically laminar, small-scale flows
which we call microflow elements (Figure 2).
The lifetimes of these flows are related to time-
scales of the agitating turbulence, especially the
intermittency of larger scale incursions on them;
we will not, however, attempt here to discuss
basic aspects of turbulence and its interactions


Plug flow
(no surface dilation)
Subsurface sweep
r (no surface dilation)
Nearly parallel

Circulating bubbles
aW ond drops

T3- ----]-IT

Where does convection most influence diffusion?

(mild surface dilation) H -
Curvilinear dilation) "surface roll cells
(strong surface dilation) / \ / (Fortescue & Pearson)


Fig. 1.-Populations of Microflow Elements. Fig. 2.-Some

with fluid interfaces. For our purposes the basic
types of surface flows should be classified ac-
cording to rate of surface dilation and thus conv-
vective influence on interphase transfer (Figure
2). We note that well-ordered flows as well as
chaotic ones can be modeled by combinations of
microflow elements (examples in Figure 3).
More noteworthy, we find that we can rational-
ize existing transfer models (Figures 4 and 5
in which, for simplicity, the situation in the
second phase is disregarded) and systematically
point out alternatives to them (Figure 6).

Fictitious film Steady diffusion,
(Lewis & Whitman) finite zone

Surface renewal F 4 r Penetration,
(Higbie, Danckwerts) p infinite zone

(Dobbins, Toor &

Fig. 4.-Standard Transfer Models.

finite zone

The film model (Figure 4) corresponds in
effect to a thin layer in steady plug-like flow
along the interface and bathed beneath by fluid
that is somehow kept completely mixed. All of
the other models correspond to one or another
local flow regime that is intermittently, suddenly
and, in most cases, completely interrupted by
turbulent action and then instantaneously re-
established with the participating fluid replaced
to some extent (in Figures 4- 6 the persistent
regime is indicated on the left, the interruptive
event on the right). It becomes clear that not
one of the earlier models corresponds to a flow
regime in which convection influences diffusion
at all: this effect is represented only in the nature
of the intermittent interruptions.
Chan and I argued that in the mixed popula-
tion at a turbulent interface it is the flows dis-
playing strong surface dilation (or contraction,
of course) that most strongly influence diffusion;
we suggested that the convective effect of these
flows swamps all others; and we proposed that
it can be modeled by a single population of

Basic Flows-"Microflow Elements." Fig. 3.-Some Composite Flows.

steady, irrotational stagnation flows at least
on the liquid side of gas-liquid interfaces. These
flows are the purest embodiment of the above
formulas for relative velocity near an interface.
More about them shortly.

Subsurface renewal

- w

Penetration with
altered concen-
tration profile;
infinite zone

Subsurface mixing 'C
-zone Likewise;
(Marchello & Toor) ___ finite zone

Fig. 5.-More Transfer Models
ments one favors in trying to understand
interphase transfer, the first step is to solve the
differential equation describing transport within
the elements, and this requires that boundary
conditions and, frequently, initial conditions be
chosen. In all of the earlier models film, pene-
tration, and hybrids these choices are the sole
means of accounting for convective transport
(regarded as convective mixing in some in-
stances). As indicated in Figure 7, the differen-
tial equation has been that for pure diffusion.
The correct equation is that for convective dif-
fusion, in Figure 7 shown in somewhat simplified
form, with a class of velocity fields characterized
by a parameter a. The appropriate boundary and
initial conditions may depend upon relative mag-
nitudes of a penetration depth for convective dif-

Snbsurface sweep Diffusion with
to interface

Mild surface
(Nobody yet)
Strong surface
(Chan, Majoch)

Diffusion with
slight convection
perpendicular to

Unsteady convective

Fig. 6.-Transfer Models with Real Convection.

WINTER, 1969


l Z Z 0 1

Mathematics of Model Elements

2 c(z, o)]
Film and oc. a d c (, t) chosen to repre-
penetration: t 2 c(, t) sent flow somehow
aS c(L, t)

Convective c 2e t 2 2) representing
diffusion: St v *x t; a) flow

Solution: Lt ; c(z 0) L, a] = dc/ instantaneous
Fig. 7.-Mathematics of Model Elements.
fusion, not pure diffusion, and a hydrodynamic
depth scale, all usually related to turbulence
properties beyond our present scope. In any case,
the differential equation system is solved for the
instantaneous flux across the interface, which
remains a function of the age of the microflow
element, of the parameter (s) characterizing
flow within it, and of any parameters in the
initial and boundary conditions (for example,
the depth at which concentration is supposed to
remain constant in film-type models: L in Fig-
ure 7).
The second step, in cases of chaotically agi-
tated interfaces, is to calculate the surface-area-
average flux over the population (or populations)
of currently existing microflow elements, each of
which occupies some small patch in the surface
mosaic. As indicated in Figure 8, the procedure
Instantaneous average 3 = 1 jiLt(dA) ;... L(dA), a(dA)]dA
flux over area A

Distribution function, (t ) 6A(t) dt =
e.g. surface-element ages A6t(CA) *'

Average flux (assumed (T) = (t) (t ; 7)dt
stationary in time) 0
Fig. 8.-Mathematics of Populations of Elements
is to introduce (for each population) a distribu-
tion of fractional surface area over age of the
microflow elements and over the quantities that
characterize flow and transfer in them. Integra-
tion over age and these quantities completes the
calculation if the gross regime is stationary in
time, the result being a formula for time-and-
surface-area-average flux in terms of the para-
meters that appear in the distribution function
- for example, the mean lifetime of a microflow
element, or the rate of "renewal" of microflow
elements. Ideally the distribution function would
be chosen for its fidelity to real populations of
microflow elements. Unfortunately little is
known about the latter. On the other hand,
Hanratty (1956) and others since have noticed
that a final formula for average flux is insensi-
tive to some changes in the distribution function

on which it is based. Writers on interphase
transfer have identified distribution functions
in tables of integral transforms, papers on resi-
dence time distributions, and elsewhere and have
selected functions to work with chiefly for their
mathematical tractability. With one exception
they have been one-variable distribution func-
tions, the variable being surface lifetime, which
stands unambigously for lifetime of an element
provided there is no surface dilation. The con-
venient qI = s exp(-st) of Danckwert's pioneer-
ing 1951 paper is a familiar example (recall that
s is both the fractional rate of replacement of
elements and the reciprocal of the mean life-
The one published exception is the two-
variable distribution function in Harriott's note-
worthy 1962 paper. The two variables are dic-
tated by the microflow model and are element
lifetime and thickness of the plugflow zone (see
upper diagram in Figure 5). Harriott took the
joint function to be a product of two single-
variable functions, namely the familiar exponen-
tial distribution of lifetimes and the slightly
more general gamma distribution of thicknesses
(cf. Figure 9). Actually Harriott's microflow
element is more complicated than anything we
have discussed because it is only partially re-
placed in each interruptive event and conse-
quently remembers something of its past. This
non-Markovian feature together with the two-
variable distribution function evidently forced a
monumental Monte Carlo style calculation of
transient approach to the statistically stationary
transfer regime.
Another exception is the two-variable distri-
bution function demanded by steady, irrotational
stagnation flow elements that Chan analyzed and
my current collaborator L. V. Majoch has con-
sidered further. The variables are element age t
and stagnation flow strength a. In the absence
of contraindications the simplest hypothesis is
once again that the joint function is the product
of two independent single-variable functions (cf.
Figure 9).
Populations Distributed Over Two Parameters

J(TA) = f j(t;L)t (t)O(L)dLdt,
0 0

(Harriott, in effect)

3Cr,a) = ff j(t ;a)(t)4(a)dadt, Chan, Majoch
0 -c
Fig. 9.-Populations Distributed Over Two Parameters.


If and when a single type of microflow ele-
ment does not dominate the transfer situation -
or does not lead to a desired functional form of
average flux one can turn to mixed popula-
tions of different types of elements. Danckwerts
noted the possibility in his 1951 paper. The
example in Figure 10 corresponds to two popu-
lations of the sort made especially convenient by
tables of Laplace transforms; the two are dis-
tinguished by different mean element lifetimes
(T = 1/s1, 72 = 1/s2).

r(Ti ,p) = P1f Ji(t)ti(t;Ti)dt Zp = 1

CD -t/T
Example: j(C r 2, p) = p / jl(t)e 1 d(t/Tl)
O -t/T2
+ (l-p) j2(t)e d(t/T2)
Fig. 10.-Mixed Populations.
At this point I have sketched a crude but
serviceable conception of turbulent fluid inter-
faces, which I believe is more detailed and rea-
listic and pedagogically attractive than any
available heretofore, and I have delineated for
the first time the general strategy for modeling
turbulent action by means of populations of
microflow elements. This strategy should work
equally well, incidentally, in treating some turbu-
lent reaction systems, for instance. So far as
flow and transfer are concerned, the strategy suf-
fers from the lack of experimental data on the
population dynamics of local flows at chaotically
agitated fluid interfaces. Just as importantly, it
suffers from the lack of development of mathe-
matical models of microflow elements with "real
convection." The remainder of the lecture is
devoted to the latter, that is, to some relevant
solutions of the convective diffusion equation.
EDITOR'S NOTE: The remainder of the lecture will be
published in the Spring Issue of CEE.
Angelo, J. B., Lightfoot, E. N., and Howard, D. W.,
AIChE J. 12, 751-760 (1966).
Byers, C. H., and King, C. J., AIChE J. 13, 628-644
Chan, W. C., "Transfer across flowing interfaces: stag-
nation-flow models," Parts B, C, F of Ph.D Disserta-
tion, Univ. of Minn., 1964.
Chan, W. C., and Scriven, L. E., "Absorption into irrita-
tional stagnation flow: a case study of convective dif-
fusion theory," MS. submitted to I&EC Funda.
Danckwerts, P. V., I&EC 43, 1460-1467 (1951).
Danckwerts, P. V., Kennedy, A. M., and Roberts, D.,
Chem. Eng. Sci. 18, 63-72 (1963).

Drew, T. B., Trans. AIChE 26, 26-80 (1931).
Harriott, P., Chem. Eng. Sci. 17, 149-154 (1962).
Higbie, R. W., Trans. AIChE 31, 365-389 (1935).
King, C. J., I&EC Funda. 5, 1-8 (1966).
Kishinevskii, M. Kh., Zh. Priklad. Khim. 27, 382-390
(1954). AERE translation available from Special
Libraries Association.
Kishinevskii, M. Kh., and Pamfilov, A. V., Zh. Priklad.
Khim. 22, 1173-1182 (1949).
Koppel, L. B., Patel, R. D., and Holmes, J. T., AIChE J.
12, 941-955 (1966).
Langmuir, I., Collected Works of Irving Langmuir, Vol.
2, Part 1, Pergamon Press, London 1960.
Levich, V. G., Physicochemical Hydrodynamics, Prentice-
Hall, Inc., Englewood Cliffs 1962.
Perlmutter, D. D., Chem. Eng. Sci. 16, 287-296 (1981).
Ruckenstein, E. and Berbente, C. P., AIChE J. 13, 1205-
1207 (1967).
Scriven, L. E., and Pigford, R. L., AIChE J. 4, 382-10S
Scriven, L. E., and Pigford, R. L., AIChE J. 5, 397-402
Spriggs, T. W., Grgurich, D. A., and Scriven, L. E., "In-
teraction of circular vortices with mobile interfaces:
a physical model of surface renewal," MS. to be sub-
mitted to AIChE J.
Walker, W. H., Lewis, W. K., and McAdams, W. H.,
Principles of Chemical Engineering, McGraw-Hill,
New York (1st ed. 1923, 2nd ed. 1927, 3rd ed. 1937).


(Continued from page 5)

The Spring 1968 issue of CEE was very interesting. I
am particularly glad to see evidence of a forum for
opinions like those of Lenz (Industry Needs Scientific
Engineers Not Engineering Scientists).
During my several years as teacher and department
chairman, I felt chemical engineering educators in ASEE
were talking only to themselves in a positive feedback
situation leading to a runaway reaction on teaching en-
gineering science. Lenz's points are very valid from my
experience in industry in research and now in operations,
and from the statements of colleagues and competitors.
The quotes from Fulton and Souders present points that
all teachers should ponder.
Perhaps recitation of a coalescence of some recent
experiences in recruiting will help teachers comprehend
what a number of industrialists are trying to say. Funda-
mentals seem to be taught as an end unto themselves, not
as tools to be used in the true engineering sense, because
most of the teachers' time, research and study are focused
on fundamental phenomena. Unfortunately the student
lacks the experience to differentiate between the teacher's
environment and the things that really need to be done in
industry. Consquently, the new graduate is unprepared
to face the situation when he learns that the very import-
ant problems of industry and society are usually inter-
disciplinary. Too frequently he retreats from situations
offering real opportunity for growth and prosperity to
the security of organizations with large sections of people
working in the same discipline. It is truly a shame that
Letters (Continued on page 44)

WINTER, 1969

John O'M. Bockris, University of Pennsylvania, and S. Srinivasan,
State University of New York, Downstate Medical Center.
Available Spring
Sets forth the theoretical basis of electrochemical energy con-
version. Unlike other books, this work considers the basic
electrode kinetics of the fuel cell.

HEAT TRANSFER, Second Edition
Jack P. Holman, Southern Methodist University. 432 pages,
Revision of a standard text for undergraduate courses. Con-
tains new material on thermal contact conductance, radiation
network analysis, conduction shape factors, an analytical model
for liquid metal heat transfer, and many other topics.

Jack P. Holman, Southern Methodist University. Available Spring
Offers a brief, broad coverage of all aspects of thermodynamics
for undergraduate introductory courses. The emphasis is on
simplicity, clarity, and teachability, and the coverage includes
both macroscopic and microscopic thermodynamics with an
introduction to transport gases. Conventional power cycle ap-
plications and introductory material on direct energy conversion
schemes are also presented.

Robert D. Kersten, Florida Technological University. Available
The first book of its kind to treat both analytical methods in
engineering the classical continuous approach and the "dis-
crete" approach usually associated with numerical methods.
It proceeds from the typical cases, which can be mathematically
treated by the classical approach, to the more difficult cases,
which must be handled by some numerical technique.

Robert E. Treybal, New York University. McGraw-Hill Series in
Chemical Engineering. 688 pages, $15.75
Provides a vehicle for teaching the characteristics, principles,
and techniques of design of equipment for mass transfer op-
erations. Theoretical principles are applied to the practical
problems of equipment design.

Warren L. McCabe, North Carolina State University, and Julian
C. Smith, Cornell University. McGraw-Hill Series in Chemical
Engineering. 1,007 pages, $15.50
Presenting a unified treatment of standard unit operations at
the junior-senior level, all material in this second edition has been
updated in the light of the many significant improvements
which have occurred since the first edition was published.

Second Edition
Max S. Peters and Klaus D. Timmerhaus, both of the University
of Colorado. McGraw-Hill Series in Chemical Engineering. 805
pages, $16.50
Presents an overall analysis of the major factors involved in
process design with emphasis on economics in the process in-
dustries and in design work. Costs involved in industrial pro-
cesses, capital investments and investment returns, cost esti-
mation, cost accounting, optimum economic design methods,
and other relevant subjects are covered both quantitatively and

Hilbert Schenck, Jr., University of Rhode Island. Available Janu-
ary, 1969. Soft and Hard Cover
Provides the student involved in research or thesis activities
with sufficient information to help him find a project, and pre-
sents him with the criteria to judge the suitability of his chosen
subject. Considerable information is given on how to carry out
a library search.

Hilbert Schenck, Jr., University of Rhode Island. 304 pages,
Applicable to almost any engineering laboratory course, this
work deals with the basic principles of engineering experi-
mentation rather than its hardware.

A McGraw-Hill Book Company
330 West 42nd Street
.G. HNew York, New York 10036
WINTER, 1969


HA IL PURDCEE features a large state
university that emphasizes
HAIL* PD ^both undergraduate and
graduate education.

"All that professors worry about is research
and publication."
"Students don't even know what a reboiler
looks like!"
"Chemical engineers do not have enough
mathematics to keep up with other engineers."
"Economics is important; engineering is us-
ing money."
"Engineering is science."
"Core programs are best."
And so it goes. When one collects a week's
worth of comments from colleagues, students, in-
dustrial visitors, professors from other depart-
ments and other universities, and the man on the
street, the sum equals quandary.

What is the best way for a professional school
to educate a young man or woman to become a
chemical engineer? Obviously, there is disagree-
ment among the people involved and opinions
continually change. To use current jargon, we

must try to optimize the situation. What follows
outlines briefly our approach at Purdue and,
though we are sure it is not a stationary point,
we believe it is a sound intermediate one.
We believe the major educational problem
facing us is to prepare students not only for
immediate entry into professional activity but
for remaining effective in a rapidly advancing
technological community. We believe students
must be given an education solidly rooted in the
fundamentals of science and engineering rather
than a mere capability for manipulating current
methods. To make certain they are capable of
extending their scientific and engineering knowl-
edge throughout their careers, they must be
taught how to appy fundamentals to new prob-
Students must associate with teachers who
are themselves students, engaged in day-to-day
learning through scholarly activity. This requires
a strong commitment of the faculty to individual
and cooperative research, so the excitement of
discovery and learning can cascade from indi-
vidual professors into the graduate and under-
graduate programs. We agree with those who
believe it is not desirable, nor probably even pos-
sible, to separate research and teaching and still
maintain the scholarly atmosphere necessary to
prepare students for today's technology.


Students must associate with teachers who
are themselves students, engaged in day-
to-day learning through scholarly activity.

Our faculty's research interests cover the
areas of adaptive control, equilibrium properties
of mixtures (both gas and liquid), surface reac-
tion mechanisms of catalysis, transport in dis-
persed systems, rheologic and fluid flow studies
with special emphasis on pulsatile flow and un-
steady state systems, mathematical modeling and
experimental analysis of process kinetics, and the
physical and chemical characteristics of multi-
component systems.
Currently, for example, one of our staff mem-
bers is forming a series of algorithms for the
control of distributed systems; another is meas-
uring partial volume at infinite dilution to de-
termine the component properties of mixtures;
a group is studying the meaning of the dispersion
tensor in non-uniform, anisotropic porous media.
A special laboratory is being built by one of our
faculty for measuring the surface properties of
catalysts. A few other examples of current re-
search are: the effect of reactor surface on proc-
ess kinetics; application of hybrid computer for
chemical process simulation; the study of heat
transfer to bubbles rising in fluidized beds.
In our research efforts we are loosely organ-
ized on a group basis so that professors who have
a common interest may share projects, and, in
addition, carry out their own individual research.
For example, we have a group collectively
studying transport in dispersed systems. It hap-
pens that much of the mathematics and statisti-
cal modeling for individual studies in this area-
those for porous media, dispersion of drops, and
fluidization of solid particles-have a common
base; here we work together. We go on from
there to work individually. The result is a saving
of time, sharing of experience, more efficient use
of equipment-and, we think, a broadening of
the experience open to students. The value of the
system-for both students and faculty-is also
amplified by the ability to have group seminars
which become more workable because of the
sharing experience.
Graduate studies are not simply a continua-
tion of the scheme of undergraduate education at
a more advanced level, such as might be achieved
by a prescribed curriculum of advanced courses.

Rather, each student works out his own program
of self-education to meet his own special inter-
ests and needs. Apart from the student's efforts
to become professionally competent, he seeks to
develop and utilize his own intellectual and crea-
tive power and thus make his maximum contribu-
tion to society.
We are fortunate that the nine schools and
departments in the Schools of Engineering at
Purdue have the opportunity to engage in inter-
disciplinary research with each other and with
several special organizations such as the thermo-
physical properties research center, the labora-
tory for applied industrial control, the jet pro-
pulsion center and the bioengineering group.
Thus, our faculty and students are exposed to a
broad category of facilities and problems.

We have organized the chemical engineering
part of the undergraduate program into five se-
quences: transport; thermodynamics and kine-
tics; control; design, computer applications, and
optimization; and electives. We are fortunate
that our senior class usually numbers about 100,
enabling us to offer a series of elective courses
designed either to prepare students for graduate
school or for more intensive study of topics not
fully covered in the normal sequences.
While we have adopted the transport ap-
proach to teaching physical operations, we have
turned it around. We teach stage operations
first, the transfer operations, then the physics of
transport phenomena-the integral balances be-
fore the differential balances. We believe the stu-
dent will get a better hold on the whole subject
this way.
For our control sequence, we have a some-
what unusual laboratory which features several
micro experiments, an all-purpose experiment,
and analog computing equipment which may be
used for adaptive control of these experiments.
We have broken our senior design sequence
into two courses-the first of which emphasizes
the modern mathematical tools of economics and
optimization while the second course includes the
strategy of design and three different types of
computational sections from which the student
may choose: one emphasizing computer simula-
tion; another, the more classical approach to the
design of several small processes; the third, a
large case study brought in by an industrial

WINTER, 1969

We offer six elective courses-the students
must take two. Three are aimed at graduate
work; chemical equilibrium, applied chemical en-
gineering mathematics, computer simulation.
Three are more general; polymer science and en-
gineering, statistical design and analysis, petro-
leum refinery engineering.
Our junior and senior laboratories are parts
of definite course sequences. In this way, the
theory and techniques the student learns in class
are also studied physically in the laboratory. The
students measure transport properties in the
junior laboratory; the emphasis in the senior
laboratory is on synthesis and application of stu-
dents' knowledge to open-ended problems in
chemical engineering.
Our students are taught how to use the com-
puter as sophomores, and we are presently en-
gaged in including computer applications in every
undergraduate course. We have direct teletype
input to the CDC 6500 and IBM 7094 so students
can call programs at any time to calculate course
Approximately one-fourth of our students
participate in the Purdue Cooperative Engineer-
ing Education Program, spending alternate se-
mesters in formal class work and in one of 44
industrial companies. The association with in-
dustry and actual problems is a very valuable
addition to education. We find our co-op students
appreciate the fundamental flavor of their aca-

demic work.

Chemistry, of course, is the distinguishing
feature of a chemical engineering program, and
competence in chemistry as well as physics and
mathematics is the mark of a chemical engineer.
Although we are often in the noisy minority con-
cerning the role of chemistry in engineering, we
firmly believe the difference is a necessary one.
This tends to give us flexibility and identity as
well as a spirit of independence from the re-
mainder of engineering disciplines on campus.
This attribute is of value in the performance of
our job as liason between engineering and chem-
Looking back over these paragraphs and
comparing them to the comments we have all
heard, it is plain we are not "all things to all
people." We have problems, certainly-of time,
facilities, financing. These we live with and strive
to change, as did our predecessors and as will
those who follow us.
But we do believe scholarly activity and teach-
ing at a university must go hand-in-hand. We do
believe the best education is one based on science
and engineering fundamentals. We are convinced
we must show the student the best way to use
these fundamentals and implant in him the desire
to continue to learn throughout his professional

views and opinions I

University of Houston
Houston, Texas 77004

Professor Metcalfe in his excellent article
"Where Are The Engineers" proposes that we
reverse the trend of "declining acceptance of en-
gineering as a course of study" by "stronger re-
cruitment and greater retention of entering stu-
dents."* This is a very popular viewpoint. The
"grass roots" approach is strongly endorsed by
the AIChE, as has been pointed out by Kuebe
and Kovacs "More Chemical Engineers Neces-
sary: A Problem in Career Guidance."**
T. B. Metcalfe, CEE, 2, 142, (1968).
**W. R. Kube and W. L. Kovacs, CEP, 64, No. 68, 95


Since past recruiting efforts have met with
only very limited or, at best, local success, it
seems appropriate to question the efficacy of this
approach. (There may also be a question of
ethics, but this is admittedly a highly debatable
point.) Personally, I am unenthusiastic about re-
cruiting activities because 1) in the long run,
all competitive advertisement must be self-
cancelling and 2) it has diverted our attention
from the real problem; one does not find a cure
for a disease by looking at the symptoms.
The average American engineering students
of the forties and fifties were first-generation
college students from 'blue collar' homes. The
status of being an engineer and the attending
salary were very meaningful to this "upward



Professor Henley urges:
Full implementation of ASEE Goals report,
followed by the establishment of engineering
graduate schools on a professional basis.
More versatile undergraduate programs, de-
signed to attract the sons and daughters of col-
lege graduates and to encourage newer graduate
research areas.
Stronger chemical engineering graduate pro-
grams in environmental, microelectronic, bio-
medical, or ocean engineering.
AIChE disapproval of graduate work in de-
parftments that have less than thirty graduate
students and ten faculty members.
The requirement of one year of introductory
undergraduate work in the U. S. before admis-
sion of foreign students to graduate school.

mobile" segment of the population. It is my con-
tention that one of the primary defects of our
present engineering programs is that we are still
attracting primarily this shrinking segment of
the college population. We are failing to 'trade
up.' We are not attracting the sons and daugh-
ters of college graduates. The engineering col-
lege at too many of our 'prestige' universities has
become the campus stepchild.
As a group, we appear to be caught in a quag-
mire of reactionary thinking, and I fear that
unless we take a few risks and make fundamental
changes, our programs will not attract the type
of students we want and industry needs. Un-
fortunately, too many of the students we have
now in engineering have a clearly defined, bread-
and-butter attitude toward their studies. We
need a few hippie types !
As Professor Metcalfe clearly points out, the
growth has moved away from the traditional
engineering fields. Chemical engineering is losing
its viability, and the situation is deteriorating, not
improving. It is sad to note that the number of
chemical engineering departments that have been
able to make contributions to, or to mount sig-
nificant programs in the newer fields such as
environmental, microelectronic, biomedical, or
oceanographic engineering is close to zero. What
is even more deplorable is the large number of
departments which have started programs in
these areas and failed, or even worse, have in-
adequately staffed and funded programs. By and
large, we have not succeeded in creating an en-
vironment in which new programs can become

Having stated, in a general way, the malaise
from which we suffer, I would like to briefly pin-
point some of the more serious illnesses in our
current graduate and undergraduate programs
and some of the things we can do to correct them.
Most of these problems are cited and documented
in the ASEE Goals Study whose critics have
chosen to adopt an "I'm all right Jack" attitude
even though it is abundantly clear that we are
not attracting the type and numbers of students
the industry needs.
Graduate Programs The ma j o r i t y of
graduate programs are too small, too fragmented,
and too undernourished to offer its too-few stu-
rents an exciting educational experience, or the
opportunity to do meaningful research. Too
many of the student research projects produce
information which is new to the student, but of
questionable value to the skilled practitioner.
The student knows this, and is discouraged by it.
As a symptom of this situation, consider the
desultory chemical engineering seminar as it
exists at too many institutions; student partici-
pation is practically nil; the majority of the staff
does not attend.
The bread-and-butter aspects that character-
ize undergraduate education at many schools has
infiltrated a large number of the graduate
schools. The situation is appreciably aggravated
by the high percentage of foreign students at
many schools. It is my contention that the ma-
jority of the Asian foreign students should be
admitted to graduate school only after first com-
pleting one year of indoctrinary undergraduate
work in the United States. The very large per-
centage of foreign students (greater than 20
percent) at some schools is unhealthy; they can-
not be assimilated. A young professor from a
university in Missouri told me that when he tried
to recruit one of his own seniors for graduate
school the boy turned to him and said, "Gee,
Professor, I thought graduate school was only for
foreign students!"
Many of the difficulties stemming from the
lack of excitement and intellectual stimulation
at many engineering schools could be surmounted
by increased institutional specialization and a
more general pooling of resources. A five man
department with research specialties in fluid dy-
namics, control theory, air pollution, kinetics,
and mass transfer probably has no viable pro-
gram in any of these fields; a department with
five men working on related catalysis problems

WINTER, 1969

Our average graduate has had the
benefit of neither a sound cultural nor a
good scientific education. He is as
ignorant of lasers and holography as he
is of music and poetry.

should achieve a leading position in its field. (As
a point of fact, I do not believe that the AIChE
should permit graduate work in departments that
have less than thirty graduate students and ten
faculty members.)
We should also recognize that students who
are taking three or four stiff courses cannot si-
multaneously do good research. We are making
a rat race out of our graduate programs by over-
loading the students to the point where they have
no time for outside reading or the pursuit of
intellectual interests.
Undergraduate Programs Too often these
represent academic straight jackets and, as such,
are outmoded and rejected by the type of stu-
dents we would like to have. Our average gradu-
ate has had the benefit of neither a sound cultural
nor a good scientific education. He is as ignorant
of lasers and holography as he is of music and
poetry. His education lacks versatility.
The undergraduate students' lack of versatil-
ity is a major contributing factor to the inability
of graduate engineering departments to move
into new academic and research areas. Whether
we like it or not, we are trapped in a cycle which
has proven veritably impossible to break. It is
very difficult to convince a chemical engineer
graduate student to do research on anything
except heat, mass, and momentum transfer, con-
trol, or kinetics.
I believe that many of the major problems
discussed here can be alleviated by the full im-
plementation of the Goals Report, followed by the
establishment of engineering graduate schools on
a professional basis. Michigan State's success
in attracting an increased number of students
following a major curriculum reform holds a les-
son for all of us.* The recent liberalization of
course requirements at Michigan, Northwestern,
Minnesota, Ohio State, Pennsylvania, and Lehigh
are salutory. Failure to make major changes in
our programs and our approach to engineering
education must result in a continuing erosion in
the quality and quantity of students attracted
into engineering in general and chemical engin-
eering in particular.
*C & E News, Aug. 28, 59, (1968).


My- I M IPRSN 8SFlaws

W. Leighton Collins, Executive Secretary
The American Society for Engineering Education
2100 Pennsylvania Avenue, North West
Washington, D. C. 20037
Dear Mr. Collins,
Please send me an ASEE application blank
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-- -


The world of Union Oil

salutes the world

of chemical engineering

We at Union Oil are particularly indebted to the colleges
and universities which educate chemical engineers.
Because their graduates are the scientists who contribute
immeasurably to the position Union enjoys today:
The twenty-ninth largest manufacturing company in
the United States, with operations throughout
the world.
Union today explores for and produces oil and natural gas
in such distant places as the Persian Gulf and Alaska's
Cook Inlet. We market petroleum products and petro-
chemicals throughout the free world.
Our research scientists are constantly discovering new
ways to do things better. In fact, we have been granted
more than 2,700 U.S. patents.
We and our many subsidiaries are engaged in such
diverse projects as developing new refining processes,
developing new fertilizers to increase the food yield, and
the conservation of air and water.
Today, Union Oil's growth is dynamic.
Tomorrow will be even more stimulating.
Thanks largely to people who join us from leading
institutions of learning.
If you enjoy working in an atmosphere of imagination and
challenge, why not look into the world of Union Oil?
Growth...with innovation. Union Oil Company of California.



Directions for Education and Research

(Continued from page 9)

Even if engineers (and social scientists) were
to agree in principle that they should consider
social (and technical) objectives and conse-
quences, most would not be likely actually to do
so if they did not know how. Concomitantly,
lacking a tradition that demands the larger per-
spective, most would not feel impelled to develop
new methods and expand their field of view once
they found that their current methods were in-
adequate. One of the main reasons, or excuses,
advanced by practitioners in the separate disci-
plines for not working in the joint area of en-
gineering and public affairs is the lack of ade-
quate methodology, and one of the main reasons
advanced for not working on methodology is the,
lack of overt demand.
We can break this circular deadlock either by
developing methodology or by creating effective
demand, e.g., by requiring better research on
important questions. Because we now know lit-
tle about multi-disciplinary research, methodol-
ogy developed in a vacuum is likely to be sterile.
The best methodology, we might surmise, will
ensure from concerted, high-quality efforts to
solve important problems. Methods will arise
from such efforts because the problems will de-
mand them, much the way "systems analysis"
arose at The RAND Corporation and aerospace
companies because large-scale defense and space
problems required something new.
Virtually every topic listed in the previous
section abounds with problems that require re-
search. I would like here to call particular at-
tention to some that may not be well known.
Housing and Construction: Since the industry
is now highly fragmented and oriented toward
short-term profits, research and innovation have
had little impact. Builders thus far have made
little use of "systems analysis", new materials,
1Building codes have traditionally been singled out as
major villains. A new building code that permits the use
of new materials, a so-called performance code, has re-
cently been adopted in New York City.

or new methods of construction. Much of this
slow adaptation seems to have been due to politi-
cal and institutional obstacles, lack of venture
capital, and social inertia.1 New ideas and ap-
proaches, accounting for the strong interaction
between engineering and public affairs, could
initiate a true revolution in our ways of costs of
living. (Our current houses and communities are
surely not the penultimate). Indeed, since the
field seems ripe for substantial innovations, pri-
vate industry should find it most attractive, once
the ideas are developed. There seem to be excel-
lent chances for the ventursome to make large
(legitimate) profits, so that government need not
shoulder the entire housing load.
Clothing: Several thousand years ago, when
our current concepts of clothing were formed,
only natural materials slightly refined from
their natural state -were available to be used.
Understandably, then, clothing's functions and
forms were tailerod to accentuate these materials'
strengths and minimize their weaknesses. Today,
even though we have hundreds of radically new
materials available, we retain, without much
modification, patterns shaped to meet entirely
different needs. We still regard polymeric ma-
terials as "synthetic fibers," to be spun, cut, and
formed in traditional ways as direct substitutes
for wool, silk, flax, cotton, and leather. Perhaps
we should re-examine clothing's basic objectives
-functional (control temperature and ventila-
tion "comfortably," provide physical support,
etc.) and aesthetic-to see how we might revise
our concepts of clothing to take special advantage
of the new materials' properties. (That is, we
should overcome the "hidden persuaders" of tra-
dition and design inertia.) These new concepts
not only might free us from current technical
limitations (e.g., permanently bulky materials for
Arctic wear, or extensive wardrobes for variable
climates) but also might liberate artistic imagina-
tions to create entirely new styles. The rapid
adoption of inexpensive nonwoven fabrics (used
in so-called paper garments) would indicate that


A person educated in engineering and public affairs has the skills to understand technical and social
phenomena and their interaction to formulate and test predictive models for the phenomena and their
interaction to understand and be able to work with the environment... to apply systematic methods for
analyzing and synthesizing complex, interacting, large scale systems, in which many things may be uncertain.

popular acceptance under the right conditions
should pose few serious problems.
Institutional adaptation: Limiting rates of in-
formation flow that govern the diffusion of new
ideas, new patterns, and new technologies in or-
ganizations are dimly understood. We need re-
search to discover what would be ideal or near-
ideal conditions, and to find management princi..
ples to speed the diffusion process, to make
change simpler and more effective.
Radical Change: While we seem to under-
stand fairly well how to deal with marginal
change (i.e., with small improvements in our cur-
rent ways of doing things), we still seem quite
ill-equipped to understand and deal with radical
change, with totally new developments, such as
the automobile, the jet airplane, and the com-
puter, that permit us to do what could not be
done before. We have not done well at predicting
even their effects on technology, and we have
done far less well at anticipating their interac-
tion with public affairs (what we could term the
public adjustment and control problem). While
American society seems to have survived this
poor anticipation (although it shows a few
bruises), some less-developed societies (for whom
the changes have been even more radical) have
not proved so resilient. Research into the nature
of radical change could be most fruitful.
Medicine: In the area of engineering and
public affairs, medicine offers considerable chal-
lenge in public health, waste management, diag-
nostics, hospital and clinic location, financing, and
organization, child-care and geriatric-care sys-
tems, etc. In the area of child-care, for example,
one might examine the means, costs, benefits,
social ramifications, policy implications, etc., of
providing thorough medical-psychiatric attention
to young children, especially to those children
who now receive no attention at all, (Part of the
current difficulty stems from a "profession prob-
lem" not unlike that faced among bureaucracies
and in parts of engineering.)
Science, Technology, and National Power: It
seems ironic that, in the midst of clamor about a
"technology gap" and concern over nuclear pro-
liferation, few people are seriously examining the
relations between science, technology and na-
tional power. Indeed, economists have acknowl-
WINTER, 1969

edged only recently the major role technology has
played in American economic growth, and most
of their models to date have been correlative
rather than explanatory, so that extrapolation to
other countries or to the future will be difficult.
At the national-international level, it is hard to
imagine a much more important area for re-
search. And since it involves detailed interaction
between technology and public policy, it demands
an approach that transcends either engineering
or public affairs alone.

Although no doubt much engineering-public
affairs work will be carried out by multi-disciplin-
ary teams composed largely of specialists, we also
appear to need individuals professionally trained
in both engineering and public affairs. Within
this genre, we might aim for either of two initial
"products," depending on the student's inclina-
tions and abilities:
(1) A "sophisticated engineer" aware of the
total design context and of legal, politi-
cal, economic, and social considerations.
(2) A public affairs-oriented person well
versed in the procedures and uses of sci-
ence and technology and in scientific
methods of decision-making.
Both types of training would seem to be valu-
able for research and analysis on problems involv-
ing strong engineering-public affairs interaction.
And both might also be valuable for policy for-
mulation and administration in the area of en-
gineering and public affairs. The "sophisticated
engineer," for example, might have a particular
advantage as a project manager on technical
projects of social concern.
Worthwhile projects require the cooperation
of people with a wide variety of backgrounds-
engineers, economists, political scientists, socio-
logists, architects, lawyers, etc.-and must have
a project leader who can coordinate their efforts.
To coordinate effectively, the project leader must
be able to see the problem as a whole and be able
to place the most important specialized sub-prob-
lems in the relevant total context. He should
have professional competence (although not
necessarily expertise) in economics and politics,
and be able to organize and hold the respect of a

Limiting rates of information flow that govern
the diffusion of new ideas, new patterns, and new
technologies in organizations are dimly understood.

team of diverse specialists, to make certain that
their contributions work together as efficiently
as possible toward the overall objectives.
The scientifically versed public affairs person
might be most valuable if he worked in areas
where there are important scientific and techni-
cal problems, but where technically trained peo-
ple designated as such have not been given im-
portant policy-making responsibility (as, for ex-
ample, in foreign policy). The man's public af-
fairs training would give him proper credentials.
With these credentials he would be able to draw
on his technical background to bring scientific
and technical considerations into larger policy-
making roles. To be effective, however, and to be
able to sell his ideas in the face of opposition, he
could need more than cursory technical exposure
appended to a social science education. His tech-
nical abilities and credentials also must be of high
To deal with these problems, the students of
both types should be skilled in analysis and ex-
perienced, through research and summer work,
in using analysis to achieve realistic or "practi-
cal" goals. At the minimum, they should be profi-
cient in engineering and economic analysis. If
possible, they should be proficient in a number
of other social sciences as well. To be most effec-
tive, their analytical skills should be long-lived.
Thus, we should stress fundamental principles
and relevant mathematics, so that the students
will be prepared to cope effectively with tomor-
row's technology and the problems it will bring.
In general, we might say that engineering
and public affairs education should prepare a
student to
(a) Possess the tools needed to obtain a quan-
tative understanding of technical and so-
cial phenomena and their interaction.
(b) Be able to formulate and test predictive
"models" for the phenomena and their
(c) Understand and be able to work with the
(d) Understand and be able to apply syste-
matic methods for analyzing and synthe-
sizing complex, interacting, large-scale
systems, in which many things may be

Princeton University's program in the area
of engineering and public affairs is still under de-
velopment. At this point it consists of several
alternative routes:
* First, Princeton's Woodrow Wilson School of
Public and International Affairs gives careful
consideration to applicants who have completed
their undergraduate work in engineering, science,
or mathematics but who look forward to careers
in public affairs requiring preparation in social
* Second, the University encourages a person
who has earned his Master's degree in a technical
or scientific discipline but who does not wish to
work professionally in this discipline to develop
his skills by supplementing his technical educa-
tion with academic work in public affairs.
Third, the University encourages scientists
and engineers with some years of professional
experience to enroll in the public affairs program.
These people may then develop important careers
in public programs that require not only technical
competence but applied social science knowledge
as well.
0 Fourth, the Woodrow Wilson School encour-
ages technically educated persons with a strong
interest in systematic analysis applied to govern-
mental programs to enroll in the public affairs
graduate program, where they may, in coopera-
tion with the School of Engineering and Applied
Science, strengthen their technical and analytical
skills and learn to apply them creatively to vari-
ous governmental programs.
Fifth, a student who wants to undertake
graduate study simultaneously in engineering,
and public affairs may follow a combined pro-
gram of study approved by the School of Engi-
neering and Applied Science and the Woodrow
Wilson School. He may qualify for both a Mas-
ter's degree in Engineering and a Master's degree
in Public Affairs.
In addition, engineering graduate students
interested in public affairs are encouraged to en-
roll in those graduate courses at the Woodrow
Wilson School for which they are qualified.
Thus far, Princeton has had about a dozen
students who have completed the formal two-
degree joint program and many others who have
followed their options. Although it is too early
to tell whether their joint training has indeed
helped them, the few indications available appear


would you like to write "The

Formation of Perhydrophenalenes

and Polyalkyladamantanes

by Isomerization of

Tricyclic Perhydroaromatics?"

How's that again? Well, never mind
-Bob Warren, Ed Janoski, and Abe
Schneider already wrote it. They're
chemists in Sun Oil Company's Re-
search and Development Department.
Their paper is just one of many re-
sulting from imaginative and origi-
nal basic research conducted at Sun
Maybe basic research and technical
papers aren't your cup of tea. But
isn't the kind of company that in-
vests in and encourages such projects
the kind of company you'd like to
work for?
Especially when the company does
things like pioneer the $235 million

Athabasca oil sands project in North-
ern Alberta to multiply the world's
petroleum resources; plan a new $125
million processing facility in Puerto
Rico; expand the Toledo Refinery to
the tune of $50 million; sponsor the
"Sunoco Special" and the racing team
of Roger Penske and Mark Donohue
in big league sports car racing to
competition-prove and improve Sun-
oco products for the public; pursue a
continuing program for air and water
pollution control; beautify Sunoco
service stations everywhere.
Sunoco is geared for growth. We
need men and women to grow with
us and build a future. We have open-

ings in Exploration, Production,
Manufacturing, Research, Engineer-
ing, Sales, Accounting, Economics,
and Computer Operation. Locations
- Philadelphia, Toledo and Dallas
You may write us for an appoint-
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Career Opportunities Guide," or con-
tact your College Placement Director
to see Sun's representative when on
campus. SUN OIL COMPANY, Indus-
trial Relations Dept. CED, 1608 Wal-
nut Street, Philadelphia, Pa. 19103 or
P. O. Box 2880, Dallas, Texas 75221.
An Equal Opportunity Employer M/F .



University of Waterloo
Waterloo, Ontario, Canada
The phenomenon of axial diffusion is very
important to the understanding of chemical re-
actors and pipeline flow. Yet, the opportunities
for visualizing this phenomenon are few. All too
often the student must accept a textbook descrip-
tion of axial diffusion without ever being able to
observe it. An experiment is described which
permits such observation using inexpensive ap-
paratus to give results of reasonable accuracy.

The apparatus, shown schematically in Fig. 1,
is a modification of that used by G. I. Taylor* in
his original experiments with axial dispersion in
laminar flow. A capillary tube 200 cm in length
and about 0.05 cm inside diameter is used. Tracer
material is injected into the tube through an
axially mounted hypodermic needle of diameter
smaller than the capillary bore. The tracer ma-
terial is a solution of from 1 to 4 per cent potas-
sium permanganate. The flow may be set ap-
proximately at any desired value by trial and er-
ror. A small bubble of air is injected into the
capillary through the syringe, and its progress
is timed through a measured length. The eleva-
tion of the pressurizing bulb and the opening of
the needle valve are adjusted for the desired flow.
The average velocity Um is accurately determined,
however, from the progress downstream of the
centroid x, of the tracer patch.
At this point, the student should calculate the
Reynolds number (Re = dump/I, where d= inside
diameter of the capillary, p = density of the li-
quid, and t = viscosity of the liquid) to verify
that the flow is laminar (Re < 2300).
With water flowing at this known velocity,
the syringe is filled with KMnO solution and a
small sample injected into the moving stream.
One or two tries are generally required for the
student to learn to inject a dark slug of KMnO0
solution into the stream without causing back-
*Taylor, G. I., Proc. Roy Soc., A219, 186 (1953).

Robert R. Hudgins is assistant professor and associate
chairman of the Department of Chemical Engineering,
University of Waterloo, Waterloo, Ontario, Canada. He
received his BASc (1959) and MASc (1960) degrees
from University of Toronto, and his PhD from Princeton
University (1964). His research interests are kinetics,
catalysis, and reactor design.

3 .2

Fig. 1. APPARATUS 1, capillary tube; 2, fluorescent bulb; 3,
hypodermic syringe; 4, hypodermic needle; 5, serum cap; 6 tracer
solution; 7, rubber tube; 8, pressurizing bulb; 9, comparison tube;
10, stopcock "S"; 11, needle-valve; 12, water reservoir.
flow towards the water reservoir. In our experi-
ence, however, this method of preparing tracer
pulses is more convenient and accurate than the
original technique of Taylor. After several min-
utes, during which the axial concentration gra-
dient is established, a stopcock "S" is closed, flow
is stopped and the axial concentration profile is
measured using comparison tubes of different
strengths of KMnO4 solution. Comparison tubes
are cut from the capillary stock material in about
10 cm lengths, and filled with various strengths
of KMnO4 solution prepared by diluting the
tracer solution with water to form solutions of
the following strengths: 1, 2, 3, 4, 6, 8, 10, 15,
20, 30, 40, 50, 60, 70, 80, 90, and 100 per cent
of the tracer solution. An adequate measurement
can be made using only the solutions above the
10 per cent level; however, the tails of the Gaus-
sian distribution will be sacrificed from the ob-


servations. In making a comparison, some stu-
dents find it convenient to construct a piece of
paper with a vertical slit about 2 mm wide, and
long enough to fit across both the main capillary
and the comparison tube. The slit is moved back
and forth to where the colors in the two tubes
are identical and the x-coordinate of that com-
position is recorded. The tubes are illuminated
from behind by means of a 4-ft 40 watt fluores-
cent bulb, which provides very uniform lighting.
After the measurements have been made at
the first station, stopcock "S" is reopened and
flow is resumed until the tracer has moved sub-
stantially further downstream. The flow is again
stopped, and the axial concentration profile re-
corded. Typical results are shown in Fig. 2.
From these data, estimates are made of the axial
dispersion coefficient k, and the molecular dif-
fusivity D of KMnO4 in water.

Before a simple analytical solution may be
obtained for the axial concentration profile, the
radial concentration gradient must decay to a
fraction of their initial values. At that time the
average axial concentration gradient relative to
a coordinate xl travelling with the mean velocity
of the fluid is given by the Gaussian expression:*
M 1
C (4kt)12 exp [--(x-x) /4kt] (1)

where M = mass of solute in the tracer pulse,
A = cross sectional area of the tube (7a2), k =
the effective axial dispersion coefficient, x = axial
coordinate, x,= the x-coordinate of the centroid
of the tracer patch at time t. t is the accumulated
time of flow from the moment the tracer is in-
jected. From any concentration profile, the value
of x, is conveniently determined by averaging the
distances between points having the same con-
centration. From Equation (1),

M 1 (x x)2
In C = n A (4,kt) 1/2 4kt

Concentration profiles are recorded at two differ-
ent points in the tube, and the resulting slopes
are combined to give:

k 1 1 (t t 1 1 (3)
4 S1 S2 t 2

According to Taylor's theory,

k = a u2 (4)
192 D
where a is the radius of the capillary, u, is the
maximum velocity, which in laminar flow equals
2 Um. From Equation (4) the molecular diffusion
coefficient D for KMnO1 in water may be calcu-
This experiment is very helpful in demon-
strating the role of radial concentration gradi-
ents. It can be easily seen from its radial con-
centration profile that the tracer patch moves
down the capillary with a pointed front and a




1 t
t =









Thus, a plot may be made of In C versus (x-x) 2

as in Fig. 3 from which the slope s =

*This solution is analogous to that for molecular dif-
fusion from an instantaneous planar source of tracer
into a stationary medium, as given by J. Crank, The
Mathematics of Diffusion, Oxford University Press, 1956.
In the stationary case, the general dispersion constant k
is replaced by the molecular diffusivity D.





20 -

40 50 60 70 110 120 130 140 150
= 840 sec; x, = 53.0 cm; Curve II:
2340 sec; x, = 129.3 cm.

100 2C
(X-XI)2 cm2


WINTER, 1969


hollow rear. When flow is stopped, the radial
profile quickly disappears. Estimated from the
Einstein relation,* this time of disappearance
should be in the order of 20 sec in the present
system. After flow is restarted, the radial con-
centration profile reappears. The student can
witness the formation of the axial concentration
gradient by noting the presence of a non-uniform
laminarr) velocity profile and a small radial
variation in concentration both in front of and
behind the tracer patch. The fact that the radial
concentration gradient has decayed to a fraction
of its initial value, while remaining the cause of
the axial spreading frequently seems paradoxical
to a student who has not seen the dispersion
phenomenon. However, actual observation of the
dispersing tracer during its journey helps resolve
this paradox.
It is a straightforward matter to derive an
alternative to Equation (1) to describe a step-
input tracer rather than a puse tracer. In prac-
tice, however, our experience indicates that step
inputs of about 4% KMnO, solution do not fit
the predicted results as well as pulse inputs in a
horizontal tube. The discrepancy would appear
to result from small density differences between
water and KMnO, solution. The use of pulse
tracers obviates this difficulty to a large extent.
Finally, Taylor showed that the characteristic
Gaussian pattern did not appear until the follow-
ing inequality was satisfied:

L/uo << 3.82
An order of magnitude estimate is required for D
initially, to estimate how long flow must proceed
before the axial concentration profile will become
Gaussian. Using the calculated value of the mo-
lecular diffusivity, it must finally be verified that
the above inequality was, in fact, obeyed.
For the results shown in Fig. 1, the molecular
diffusion coefficient was calculated to be 0.7 x
10-5 cm2/sec which compares favourably with
Taylor's value of 0.80 x 10-5 cmisec.


The author wishes to acknowledge the assist-
ance of Messrs. J. Buchanan and V. Arunachalam
in setting up and developing the apparatus.

*D=x2/27, where x2 is mean square displacement and
T the time over which the displacement occurs. We may
set x2 a2 for present purposes.

problems for teachers

The following problem on transport phenomena
were contributed by Professor Ray Fahien, University
of Florida.
A nuclear engineer is interested in predicting
the temperature buildup in a nuclear reactor in
which an annular fuel element is cooled by main-
taining the inner and outer walls at a tempera-
ture To. The fuel element is initially at To also.
At time t = 0, the nuclear reaction is permitted
to take place and heat is liberated in the annulus
at a rate (assume constant) of S,(Btu/ft3-hr).
a. Show how his problem is analogous to the
momentum transport problem of unsteady state
flow in an annulus of radii R, and R2, of an in-
compressible fluid of density p and viscosity [,
with a velocity in the z direction of v. and under
a pressure drop (including gravity) of (po--PL-
b. Write expressions for the total heat trans-
port Q Btu/hr from the reactor walls and for the
analogous momentum quantity. Repeat for the
average velocity V and the analogous energy
c. Show how a knowledge of V (t) can be
used to obtain Q(t).
d. Show that this analogy can also be used
in more complicated systems such as those in
which several cooling tubes penetrate a cylin-
drical fuel element even though an analytical
solution is not possible. Derive the general re-
lation between V and Q and outline a procedure
whereby experimental data on V can be used to
obtain Q. State which dimensionless variables
should or should not be made the same in each


(Continued from page 29)

the near-endless font of tax dollars diverting engineering
teachers into science research and gradautes into massive
science-oriented programs is costing industry so much of
the basic engineering talent needed for the expansion
and profits to pay the taxes and clean up our environ-
ment. If more "scientific engineers" were trained, the
outlook for our companies, plants and cities would be
Rex T. Ellington, Mgr.
Sinclair Oil Corp.
Editor: The article by Dr. Sleicher entitled "Humanities
and Social Science In Engineering Curricula" in the
Spring, 1968 edition of Chemical Engineering Education
was read with interest. Having been exposed to some 18
years of industrial experience with two major United
States corporations, the need for development of "values"


is readily apparent to me.
How many companies will deliberately avoid develop-
ment of products primarily geared towards destruction of
fellow human beings?
How many industries will take the lead in controlling
pollution, even when the cost will reduce profits and divi-
dends, at least for several years?
How many individual engineers will consciously turn
the attention of management toward their worthy peers,
even at the risk of being passed by themselves?
How many graduate students and their advisors would
refrain from early publication of a research effort, to
avoid destroying the efforts of another group or institu-
tion working in a similar field?
In other words, how many of us at any level of our
society are more interested in others than in ourselves?
Can courses in humanities change these basic patterns of
human behavior? Or is a far more drastic, more un-
popular and more "unsettling" change needed? And
could it be that even 2000 years later, the needed change
still begins and ends with the Person who said, "So what-
ever you wish that men would do to you, do so to them,
for this is the law and the prophets."
Leigh E. Nelson
Hastings, Minn.

It is gratifying to find that there are others who
assert the validity of a macroscopic derivation of the
basic equations of irreversible thermodynamics. How-
ever, it is not immediately obvious why Professor Wallis
considers his derivation more correct conceptually and
more useful in practice than ours[CEE, 2, No. 3, 109-112
(1968)]. The question of using the idea of "lost work"
as opposed to the "rate of entropy generation per unit
volume" involves something more than a matter of taste
despite the fact that Iw-TS,. (It is not clear how Pro-
fessor Wallis distinguishes between the system property,
S, and entropy production, Sp.)
The assumptions inherent in Professor Wallis' Equa-
tions (1) and (2) are certainly not less tenable than the
assumptions of the bilinear form of the entropy produc-
tion and the restricted definitions of the fluxes and forces
in the microscopic derivation according to Onsager. How-
ever, such assumptions must be examined for generality.
Although at this point in the derivation there are no
limitations imposed on the magnitude of the fluxes or
forces, our derivation shows that lost work (or entropy
production) can be treated as an exact differential only
for the case of discontinuous or steady state systems in
which no work is transferred at any stage of the process.
Further extension to other processes can be made only
as approximations to special cases.
Aside from these details, the critical point in Profes-
sor Wallis' derivation, as well as ours, is the utilization
of the concept of an exact differential, the significance
of which has been apparently overlooked in previous
derivations based on the microscopic approach.
As a final point, Professor Wallis raises the question
"of just why 's' should be a homogeneous function of the
second degree in the fluxes or potentials." In an earlier
paper [Sliepcevich and Finn, Ind. Eng. Chem. Fund.
Quart. 2, 249 (1963)], we attempted to show that the
assumption of small fluxes or forces leads to an arbitrary

analytic function for which all terms of higher order than
two can be neglected as a first approximation. However,
such a series expansion raises some questions as to the
method of combining the terms without making some a
priori assumptions regarding symmetry. On the other
hand, to the extent that lost work can be represented as
a quadratic in either the fluxes and forces, it seems
reasonable to conclude from our Equation (3), and the
basic postulates following it, that lost work is a homo-
geneous function of the second degree in the fluxes or
In summary, the principal difference between our
derivation and the one proposed by Professor Wallis is
that we have attempted to show how, and under what
conditions, the functional form of lost work arises as a
direct consequence of the mass, energy and entropy bal-
ances and the Gibbs' equation. We prefer this approach
rather than simply asserting the form of the function.
C. M. Sliepcevich
University of Oklahoma

I have noted with some dismay the continued claims
by C. M. Sliepcevich and co-workers to having achieved
a derivation of the Onsager reciprocal relations of irre-
versible thermodynamics from macroscopic principles
alone. In-as-much as it is well known that this cannot
be done without the benefit of additional microscopic
information such as time reversibility in the dynamics of
molecular encounters, it is tempting to pass these claims
off as being preposterous were it not for their reputation
and their potential for misleading the uninitiated. As
noted by the authors of the most recent publication, a
negation of their macroscopic "derivation" was offered
previously by F. C. Andrews, but this criticism has been
inconclusive. The matter of whether lost work could be
regarded under certain prescribed conditions as being
path independent is treated correctly by Sliepcevich et. al.
The actual error in the recent publication occurs as
follows: having concluded that the lost work has the
generic form

dg = X dx + Y dy


with dg an exact differential and X. Y the affinities or
&driving forces for transfer conjugate to x and y, the
authors use the special case or "rate form" of (1.1)

dg g Xx + Yy = X dx+ dy
do do do


together with the postulate that g assumes the quadratic

g = ax + fxy + yy


with dependence of a, 8, y upon state variables per-
mitted. The argument proceeds by using Eulers theorem
to reexpress (2.1) as

g = [ax + 3y] x + [ 23 + yy] y


WINTER, 1969

dg = gd = [ax + 2 P y] xdo

+ [1 x + yy] yd (2.3)

Then by assuming that dx = xd0 and dy yd0 may be
regarded as independent differentials in (2.3), the square
bracket coefficients of (2.3) are compared with (1.1) to
conclude that

X = ax+ 2-

from which

yX 2 fY

(ay --- 2)
(y 4 p)

2 Y- x+yy

-2 PY + aX

(ay 4- 2)

obey the reciprocity relation. This procedure is, of course,
equivalent to identifying the square bracket coefficients

of x and y in (2.2) individually with X and Y in (1.2),
and is clearly invalid for one could just as well have
written (2.2) as

g = [ax py] x + [yy] y (2.4)

and concluded by the same argument

the asymmetrical

X = ax + py

Y = yy

The difficulty with the procedure is that in (2.1)
there is but one independent variation, that of the time
parameter 0. The source of the difficulty may be traced

to the fact that (2.1) with g positive definite is not a
proper statement of the postulate of irreversible thermo-
dynamics. Rather, it is necessary to proceed from (1.2)

with the postulate that the fluxes, x and y are linear in
the affinities, X and Y. to deduce (2.1). Ovbiously the
values of a, p, y are determined by the symmetrical por-
tion of the phenomenological matrix alone, and no amount

of manipulating the g forms can yield conclusions about
the remainder of the phenomenological matrix. Although

we have the restriction that g is positive definite, there

is nothing to say that g be an "even function" of x and y.
Finally, your authors seem not to have recognized that
if molecular models are even conceivable which violate
microscopic reversibility and yet are compatible with the
phenomenological approach, one need go no further to
conclude that the macroscopic theory per se has no more
inherent capability of predicting reciprocal relations than
it has of predicting numerical values of transport coeffi-
cients, short of direct measurement.
Duane W. Condiff
Carnegie-Mellon University

In lieu of advertising, the follow-
ing have donated funds for the sup-
Industrial institutions:
Mallinckrodt Chemical Works
The Procter and Gamble Company
Standard Oil (Indiana) Foundation
The Stauffer Chemical Company
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Yale University



A symposim entitled "A Critical Review of
the Foundations of Relativistic and Classical
Thermodynamics" will be held April 7-8, 1969 at
the University of Pittsburgh. Professor I. Prigo-
gine will be the keynote speaker and Professors
A. C. Eringen, E. A. Guggenheim and P. T.
Landsberg will deliver papers of paramount im-
portance. The symposium will probe the funda-
mental concepts, ideas, postulates, and laws of
thermodynamics in depth. International partici-
pation is expected. For additional information
contact: Dr. Alan J. Brainard, Dept. of Chemical
and Petroleum Engineering, 103 State Hall, Uni-
versity of Pittsburgh, Pittsburgh, Penn. 15213.

ACS Aids the Disadvantaged
The Council of the American Chemical So-
ciety at its San Francisco meeting in April 1968
recognized the needs of the disadvantaged seg-
ment of our population in relation to unemploy-
ment and lack of education. In mid-summer a
special Subcommittee on Education and Employ-
ment of Disadvantaged Persons (Project SEED)
assembled a biracial panel of ACS leaders to seek
out specific ideas, programs, and courses of action
by which colleges and universities, the chemical
industry, and the ACS could assist disadvantaged
Specific proposals for ACS action now being
considered in depth by Project SEED task force
groups are as follows:
Education in Writing Research Proposals
and Grants This task force will con-
sider ways to assist small colleges, par-
ticularly Negro colleges, in writing pro-
posals for research and teaching grants;
Industrial Summer Trainees This group
will consider ways to encourage the lower-
ing of requirements for industrial summer
trainees and suggest a mechanism to en-
courage industry to expand its summer
hiring program overall.
Education of High School Guidance Coun-
selors This task force will consider a
program to describe to guidance counse-
lors, particularly in disadvantaged areas,
the career opportunities in science.
Project Catalyst Last summer, the ACS
sponsored a pilot program in which 10

disadvantaged students were employed for
the summer at college or university labo-
ratories. This task force will evaluate last
summer's program and make plans for a
similar program for next summer to in-
volve perhaps as many as 500 underprivi-
leged students. The task force is also ex-
pected to consider the possibility of a
winter Project Catalyst program in which
jobs will be provided for high school stu-
dents in university laboratories in the
afternoons or evenings.
Technicians Employment Service-The task
force will try to determine if the ACS
could develop a technicians employment
service to provide hiring and training
assistance to disadvantaged people.
Veterans Training and Employment Pro-
grams Returning veterans from disad-
vantaged areas are constantly faced with
the problem of lack of job opportunities.
The task force will attempt to develop
plans which can be implemented in coop-
eration with the ACS local sections and
with local industries to provide meaning-
ful training and hiring programs to bene-
fit returning veterans.
Refresher Training for Graduates from
Small, Less Efficient Colleges This task
force will attempt to develop a plan or
program for providing refresher training
for graduates of these schools to enable
them to meet the requirements and stand-
ards of graduate schools.
Upgrading Small Colleges-This task force
will investigate ways in which the ACS
might act to upgrade the smaller institu-
tions and provide the necessary resources
and advice to assist these small schools.
Tutorial Assistance This task force is
endeavoring to establish a national pro-
gram to provide tutorial assistance to
disadvantaged students at all levels.
Each of the task force groups will also con-
sider the relationship of the proposal under study
to other programs which may be presently under
way in other organizations.
This information was furnished by Dr. Steph-
en T. Quigley Director of Office of Chemistry and
Public Affairs, ACS 1155 Sixteenth Street N. W.,
Washington, D. C. 20036 who may be contacted
by interested readers for details on current needs
and accomplishments of Project SEED.

WINTER, 1969



University of Minnesota
Minneapolis, Minnesota 55455

In a famous passage of his Gifford lectures,
"The Nature of the Physical World", Sir Arthur
Eddington compared the mathematician's and
the poet's view of waves generated on water by
the wind. In the first, two expressions relate the
surface forces to the constants of the waveform
leading to the conclusion that a wind of less than
half a mile per hour will leave the surface un-
ruffled, capillary waves appear at one mile per
hour and gravity waves at two. For contrast
Eddington quotes the beautiful sestet of the
fourth sonnet in Rupert Brooke's cycle '1914'.
There are waters blown by changing winds to laughter
And lit by the rich skies, all day. And after,
Frost, with a gesture, stays the waves that dance
And wandering loveliness. He leaves a white
Unbroken glory, a gathered radiance,
A width, a shining peace, under the night.
The comparison is most sensitively drawn and
its rapier ring makes some of the more recent
exchanges in the conflict of the cultures sound
like the clang of clashing cutlasses. Eddington
had previously shown how farfetched is the phy-
sicist's picture of the real world -"it is not
reality but the skeleton of reality"1-and he goes
on to contrast 'symbolic knowledge' with its ana-
lytical techniques with the 'intimate knowledge'
that defies codification. This is not the place to
pursue or defend Eddington's epistemology, but
the example provides a delicate statement of the
problem of the relation of the sciences to the
It is hard to resist the feeling that here is a
matter of deep significance to which the scientist
and engineer should be increasingly sensitive.
We are fortunate at Minnesota to have an excep-
tionally fine course in our Humanities depart-
ment that makes this issue a matter of lively
*The substance of this paper was given as one of the
Olin Lectures in the Department of Engineering and
Applied Science at Yale in February 1968.

concern. This course, initiated and taught with
more than ordinary verve and perception by my
colleague Mischa Penn, opened my eyes to the
depth and subtlety of the problem and I confess
that I find it difficult and elusive to a degree -
far more difficult to get to grips with than the
more mundane research that I pursue in the con-
text of chemical engineering science. It is not
that the latter is a banaustic enterprise, uncon-
genial to the atmosphere of a university, for in
fact at any rate in the department in which
I have the good fortune to be a member it has
much of the spirit of natural philosophy in the
sense which that term acquired in the 17th cen-
turn and in which it is understood when it is
understood today. One aspect of the difficulty
can perhaps be illustrated in one of the words
of my title.
Used in a mathematical context, the word
'canon', or more usually 'canonical form', must be
defined precisely and all deviations rigidly ex-
cluded. Thus the Jordan canonical form of a
matrix is a unique presentation of it and can be
determined by a finite sequence of operations.
But used in a literary context even in one so
humble as a title the word 'canon' immediately
recalls rich overtones. The original word in
Greek was for a reed when used as a tool and
later a tool whether made of reed or not. Most
often it is the tool of the builder or carpenter,
used to measure length or check level and direc-
tion. Besides being straight it had to be inflex-
ible and was often provided with a scale. From
this come the metaphorical meanings: (i) writ-
ten laws or standards of ethics or behaviour;
(ii) the exemplary man; (iii) the rules of phi-
losophers and grammarians; (iv) an ordinance
fixing tribute; (v) a list or index (derived from
the marks on a scale) ; (vi) the canon of the
mass (derived from the associated lists of


The motivation of the natural philosopher is surely the compelling desire to see the
structure of his subject and the longing to carve out an understanding of some
part of it that will be significant in content and beautiful in form.

saints). There are a number of quite special
meanings such as the ear of a bell, a size of type
and mode of musical composition and there is the
normal christian usage, current since the second

O K a uw u T1 S TT I T C W s,
or the regulara fidei'. Of course in the title the
word means a standard of judgment, but the
point is that the literary use immediately evokes
a whole spectrum of meaning in a way that the
scientific does not.
This difference between the arts and sciences
is however a superficial one and the bonds that
unite scholars from all disciplines are far
stronger and more significant than the divisive
influences. Moreover it seems of vital importance
that engineers should retain a lively appreciation
of this, both in industry and the university.
Without it, there will be no vision among the
captains of industry and the people will surely
perish: without it, the university will certainly
degenerate into that atrocious artifact of the
administrative mind, the multiversityy". I would
like to suggest that a sense of craftsmanship and
a feeling for form and structure are foremost
among the sympathies that will keep the sciences
and humanities together, however diverse their
expressions of these may be. The historian and
philosopher, just as often as the physicist or
mathematician, must have wished, whilst listen-
ing to a symphony of Mozart's or a quartet of
Beethoven's, that he could write just one paper
of comparable quality, that he could present the
key thesis of each section with that kind of clar-
ity, develop it with like finesse, interweave it
with the other threads of his argument as subtly
and recapitulate with such power.
The motivation of the natural philosopher (be
he mathematician, pure or applied, chemist, phy-
sicist, engineer or what have you) is surely the
compelling desire to see the structure of his
subject and the longing to carve out an under-
standing of some part of it that will be signifi-
cant in content and beautiful in form. To this
end he will use the canons of his craft rigour,
elegance, seriousness and universality as may
be illustrated by considering one of the elemen-
tary theorems of the theory of numbers.

The Greeks were well acquainted with the
integers and with rational numbers, but they also
had equations like x2 = 2 for the ratio of the
length of the diagonal to the side of a square.
What is more they had the penetration to ask
the question, "Is the square root of 2 a rational
number?" The proof that it is not is commonly
attributed to Pythagoras and, as a simple exem-
plar of the canons I have mentioned, it can
scarcely be improved upon. For suppose there
are mutually prime integers such that p/q V2,
then p2 = 2q2. But since the factors of p2 are
just those of p duplicated and 2 is a factor of p2,
it must also be a factor of p. Let p = 2r, then
p2 = 4r2 = 2q2 and q2 = 2r2. But now the argu-
ment can be repeated to show that 2 is a factor
of q and this is contrary to the hypothesis that
p and q had no common factor. It therefore
follows that there are no integers such that
p2 -- 2q2. There are pairs of integers such as
1,414,213,562 and 1,000,000,000 that will suffice
for any practical purpose, but none that will
satisfy the equation perfectly.
The canons of rigour, elegance, seriousness
and universality are fully exemplified here. Rig-
our is maintained by the precise logic of the
demonstration. There has been neither looseness
of thought nor approximation in number. Ele-
gance is seen in the spare economy of the proof
and in the classic beauty of the 'modus tollendo
tollens'. The notion of seriousness, as Hardy calls
it in his "Mathematician's Apology",2 is more
difficult to define, but it is clearly present here
in the way in which the class of object we have
called numbers is enlarged. The theorem tells
us that close packed though the rational num-
bers are, they are not the scales of leviathan and
an irrational can come between them. Finally,
its universality is seen in the fundamental im-
portance of the number system, pervading much
of mathematics and most of science.
Now the same canons surely apply in litterae
humaniores. The rigour of the mathematician
is mirrored in the formal constructions of the
arts, in the logic of a philosophical argument or
the build up of evidence in an exposition of his-
tory. Admittedly it is the fashion in some of the
arts today to break down the form. At one time
we used to be told that an artist could only

WINTER, 1969

safely take to the abstract mode after he had first
mastered the traditional disciplines of his craft.
His breaking down of the form was then held
to be an extension of it to new modality and
meaning. Nowadays we are not often encour-
aged to seek meaning in art and the cramping
effect of discipline on creativity is held to be so
serious that it can be safely dispensed with. Yet
a large body of art remains to show us that form
does not destroy creativity the peotry of the
Divine Comedy is not diminished by Dante's
acceptance of the restrictions of terza rima,
rather it is enhanced by his mastery of it.
Stephen Spender in a most interesting essay on
"The Making of a Poem"3 speaks of the terrify-
ing challenge of poetry. "Can I think out the logic
images?" he asks. "How easy it is to explain

Christ our Lord" shows, but it banishes all no-
tion of solemnity in a burst of holy hilarity.
There is plenty of verse and art that is solemn
enough, but which it is more than a little diffi-
cult to take seriously.
Finally we look for some note of universality
in humanistic work of real significance. We
value the Aeneid, pace the quondam Professor
of Poetry at Oxford, not because the adventures
of Aeneas were superior to those of other wan-
derers, but because in recounting them Virgil
has touched on so many themes of human experi-
ence with that terseness and penetration which
is one of the chief glories of the Latin tongue.
It is this quality of universality that made it
possible for Ronald Knox to use couplets from
the Aeneid to illumine an altogether different

The canon of seriousness in science has nothing to do with possible application to the useful arts
any more than seriousness in the humanities has to do with solemnity .
if the canons of their several arts should tend to bring together the humanist and scientist,
must they not be forced apart by the diversity of their methods? .

here the poem that I would have liked to write!
How difficult it would be to write it. For writing
it would imply living my way through the imaged
experience of all these ideas, which here are
mere abstractions, and such an effort of imagina-
tive experience requires a lifetime of patience
and watching."
Again, is it not the principle of economy,
which is the hall mark of scientific elegance,
also a keynote of humanistic thought? Ockham's
razor was propounded in a philosophy dominated
by metaphysics: it was adopted and adapted by
the natural philosophers "we are to admit,"
says Newton, "of no more causes of natural
things then are both true and sufficient to explain
their appearances; for nature is simple and af-
fects not the pomp and superfluous causes."4 In
letters or in verse we commonly deplore excess
verbiage and for a writer to be told some of his
words are not bearing any weight is damaging
criticism indeed.
The canon of seriousness in science has noth-
ing to do with possible application to the useful
arts any more than seriousness in the humanities
has to do with solemnity. Hopkins' sonnet5
"I caught this morning morning's minion,
kingdom of daylight's dauphin, dapple-dawn-
drawn Falcon ."
is serious enough, as its superscription "To

wandering and adventure.6
But if the canons of their several arts should
tend to bring together the humanist and scientist,
must they not be forced apart by the diversity of
their methods? Here again I would plead that
there is as much, if not more, in common than
there is to divide, and that a lively appreciation
of each others methods would promote a valuable
sympathy between scientist and humanist. The
genesis of a poem or work of art, a critical essay
or philosophical discourse, a mathematical dis-
covery or an engineering invention lies in an
idea or problem and the act of creation can only
begin with the recognition of it. The literary
critic is the engineer of the world of letters for
he is concerned to bring out into the light and
into action the work of the author just as the
engineer seeks to apply the discovery of the sci-
entist. This does not mean that there is not a
creative, or recreative, element in good engineer-
ing or in good criticism, but criticism is, in a
sense, a derivative activity. The "Diary of Anne
Franck" lies in paperback alongside a dozen
gripping and even perceptive books of the second
world war and many have been moved by the
reading of it. Yet if John Berryman is correct,
no one has really perceived the masterpiece that
it is, nor got down to the critical problems that
a worthy analysis of it would present. Here is


the recognition of a problem at the root of the
work of a humanist. It is comparable to the
recognition of an idea at the root of a work of
art. Among humanists, the poet is par excellence
the opener of eyes, showing us the significance of
some matter. In the realm of the sciences the
mathematician is par excellence the refiner of
concepts, turning and shaping them until they
are precisely true to experience. Each, in his
way, sits like a diamond cutter over a stone,
seeking the cleavage plane of truth along which
the slightest blow will open up the rough gem
and reveal the perfection of its intrinsic beauty.
Each however has the problem of recognizing
the true worth of the matter beneath its rough,
amorphous exterior. This first phase of recog-
nition may include the inspiration of the moment
in which the artist conceives the idea that he
wishes to bring to birth according to his metier,
but may be distinguished from the moment of
illumination, in which the resolution of a diffi-
culty may appear, or the moment of vision in
which the toilsome ascent of a Pisgah is suddenly
But, granted the recognition of the problem
or idea, there follows for both scientist and
humanist the gestative period of cogitation. Ideas
and images, many of them unfruitful and inap-
propriate, are mulled over and mixed together,
taken to pieces and reassembled. Stephen Spen-
der speaks of concentration as the sine qua non
of creative writing. He distinguishes it from
"the kind of concentration required for working
out a sum. It is the focusing of the attention in
a special way, so that the poet is aware of all
the implications and possible developments of
his idea, just as one might say that a plant was
not concentrating on developing mechanically in
one direction, but in many, towards the warmth
and light with its leaves, and towards the water
with its roots, all at the same time".3 Perhaps
this is different in kind from the concentration
required for "working out a sum" by a routine
method, but it is precisely the sort of concentra-
tion that is required for fruitful original work
in the sciences.
Some, it would seem, are gifted with the
ability to work out a complete structure in their
heads, as Mozart is said to have composed much
of his music. Others like Beethoven have to feel
their way through draft after draft towards a
final statement. From the mine of his memory
or the recesses of the subconscious where the

. in this craft of our common language should
lie the first and final bond between scholars
of all disciplines, for all have the same interest
in maintaining a sound currency of words.

composition had been going on, Mozart was able
to set down the overture to Don Giovanni in a
single night but the main theme of the first
movement of the Beethoven's 7th Symphony
emerged only after six pages of "changing, re-
flecting, and testing", as he himself described it.
Into the art of heuristic in a mathematical
context George Polya has given most valuable
insights by his work on mathematical discovery.7
He shows very vividly how the problem may be
tackled, how one works from both ends in search-
ing out the pattern of the solution and how in-
duction and analogy play their role in plausible
reasoning. In plausible reasoning the formal
modes of demonstrative logic become tentative.
For example, the modus tollendo tollens must be
replaced by "A implies B, but B is unlikely,
therefore A is less credible." This is the kind of
reasoning which is used, not only in feeling out
the way to the solution of a problem, but also
in understanding a demonstrative argument and
in gaining confidence in it. Indeed Polya con-
cludes the second of the Princeton volumes with
the remark that "we are led to suspect that a
good part of our reliance on demonstrative rea-
soning may come from plausible reasoning."
This emphasis on the process of creation is
not to deny the importance of inspiration and
the flash of illumination. The classic examples
the Poincar6 gives in his "Science et M6thode"
are so well known that they need not be repeated
here. They show, as he himself said, that sudden
illumination is a manifest sign of previous sub-
consicous work perhaps over a long period.8
There must surely be an analogy here with the
resolution of "Problems" as they may arise in
humanistic scholarship and creative art. At
times the several stages of the creative process
seem to have been fused into one incandescent
period of intense activity. One thinks of Handel
completing the "Messiah" in little over three
weeks between August 22 and September 12 of
1741, of Schubert writing no less than eight
songs on October 15, 1815 or of his sending his
song "The Trout" to Josef Huettenbrenner, call-
ing it "another one which I have just written
here at Anselm Huettenbrenner's at twelve
o'clock midnight". These are the exceptions that

WINTER, 1969

Among humanists, the poet is the
opener of eyes; (among scientists) the
mathematician is the refiner
of concepts .

prove the rule that the beauty of creative work
in the sciences or the arts is more the shine of
"plough down million" than "the hurl and glid-
ing" that rebuffs "the big wind".5 Often too
the moment of luminence in literature or philoso-
phy cannot come without the laboured argument
or prior discipline. "He who has been instructed
thus far in the science of Love, and has been led
to see beautiful things in their due order and
rank", says Diotima, "When he comes toward
the end of his discipline, will suddenly catch
sight of a wondrous thing, beautiful with the
absolute Beauty".9 The main body of the 15th
chapter of St. Paul's first letter to the Corin-
thians is a lengthy discussion of the reality of
the resurrection. But then comes a pause a
reticence of holy writ, as St. Peter Damian has
it, "wherein silence itself cries out that some
greatness is at hand" before the incomparable
majesty of "Behold I show you a mystery; we
shall not all sleep, but we shall all be changed;
. I am not for a moment suggesting that
this is mere rhetoric it is vastly more but,
if it has the divine qualities of revelation, it has
also the human beauties of a great work of art.
The final stage of polishing or verification is
of equal importance though perhaps calmer than
the others. The imaginative leap having been
made, logic takes over to tighten up each part
and to ensure that the connections are sound.
The kind of imagination needed here is that
which is capable of keeping the whole structure
- poem, paper or prelude in its proper por-
tion and scale. As any editor of a scientific or
technical journal will testify this is an aspect
of the presentation of research that receives all
too little attention, and perhaps scholarly jour-
nals in other fields suffer in the same way.
But surely in this craft of our common lan-
guage should lie the first and final bond between
scholars of all disciplines, for all have the same
interest in maintaining a sound currency of
words. Perhaps the breakdown of commerce be-
tween the arts and sciences, whenever it obtains,
is a reflection of the inflation of the domestic
currency within each camp. The great words of
the tradition of western civilization liberal,
intellectual, rational, humane are in danger of

becoming a paper currency with no backing,
deprived of their buying power as effectively by
academic verbicides as some of the words of our
common life trust, friends, gracious have
been abused by the writers of newspaper head-
lines and advertising copy. There was a time
when Latin was the lingua franca of the edu-
cated world but, serviceable enough though it
still would be, there is little hope of reinstating
it. We may have to learn to read two or three
other languages in order to keep up with the
literature of our professions, but we rarely at-
tempt to write in anything but our native tongue.
All the more reason therefore that we should
cultivate this to the best of our ability, perhaps
to find through this medium, not a massage, but
the common empathy that is needed if our uni-
versities are to remain centres of liberal learning.

1. A. S. Eddington. The Nature of the Physical
World. London. Dent. Everyman's Edn. p. 307.
2. G. H. Hardy. A Mathematician's Apology. Cam-
bridge University Press, Cambridge. 1940.
3. S. Spender. The Making of a Poem. Norton. New
York. 1962. p. 54.
4. I. Newton. "De Mundi Systemate". Hyp. I.
5. G. M. Hopkins. Collected Poems. "The Windhover".
6. R. Knox. Spiritual Aeneid. Longmans, Green and
Co. London. 1919.
7. G. Polya. Mathematical Discovery. Vols. I and II.
John Wiley and Sons, New York. 1962, '65. Mathematics
and Plausible Reasoning. Princeton University Press.
1954. "How to Solve It". Doubleday-Anchor, New York.
1957. I have endeavored to illustrate his ideas in a
chemical engineering context in the Teacher's Manual to
my forthcoming "Elementary Chemical Reactor Analy-
sis". Prentice-Hall, Englewood Cliffs. 1969.
8. See J. Hadamard's "Psychology of invention in
the mathematical field" for a considerable discussion of
this. Graham Wallas in "The Art of Thought" (1926)
comments on the experience of Poincare and the psysi-
cist Helmholtz.
9. Plato. Symposium 211. Translation is Bridges' in
his anthology "The Spirit of Man." (1915).

Dr. Rutherford Aris was born in England in 1929,
studied mathematics in the University of Edinburghand
taught it to engineers there. He has degrees from the
University of London (B.Sc. (Math); PhD. (Math. and
Chem. E.); D.Sc.). He worked a total of seven years in
industry, but since 1958 he has been in the Chemical
Engineering Department at the University of Minnesota
enjoying the liveliness of its interests, both technical and
cultural, and endeavouring to contribute to this vitality
and communicate it to his students.


i .

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Full Text


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"It is more important to carry on research than it is to pay dividends." The speaker was Lammot du Pont. The year was gloomy 1932, and he was president of Du Pont. A proposal had been made to pare the research budgets in order to protect the dividend. As it turned out, the company was strong enough to pay for both, and it hasn't missed paying for either in the past sixty years. But there was no doubt which way Lammot du Pont would have decided back in 1932. And today, we invest more than $100 million a year in the quest for new knowledge and better products. It is precisely this attitude towards research and development that attracts so many graduates every year. And that makes Du Pont such an exciting and rewarding place to work. There is no formal training period. Our men go into responsible jobs from the first day. They work in small groups where individual contribu tions are promptly recogn ized and rewarded. Promotions come from within the company. They do significant work of positive benefit to society. And they work with the best men in their fields in a crackling technical environment that provides every facility needed. If our attitude towards research and work agrees with yours, why not suggest that your students sign up for a talk with a Du Pont recruiter? Or that they write our College Relations Manager, Wilmington, Delaware 19898, for a dditional information on opportunities in their fields. <@!DID) IIU 11 s.,


EDITORIAL AND BUSINESS ADDRESS Department of Chem i ca l Eng in ee r ing University of Flor i da Gainesville Florida 3260 1 E ditor : Rny Fahi en A s sociate Editor : Mack Tyn er Business Manager : R. B. B ennett Pub l ications Board and Regional Advertising Represen t atives : WEST: William H Corcoran Chairman of Publication Board D e partment of Chemical Engineering California Institute of Technology P asa dena, California 91109 SOUTH: Charles Littl ejo hn Department of Chemical Engineering Clemson University Clemson, South Carolina 29631 EAST: Rob ert Mcitt e son College Relations Sun Oil Company Philadelphia, Pennsy l vania 19100 E. P Bartkus Secretary's Departm e nt E. I. du Pont de N e mours Wilmington, Delaware 19 898 NORTH: J J Martin Department of Chemical Engin ee ring University of Michigan Ann Arbor, Michigan 48104 J. A. B er gant z Department of Chemical Engineering University of Buffalo Buffalo, N. Y. 14200 C E:t-.TRAL: Jam es W e b er D ep artment of Chemical Engineering University of Nebraska Lincoln, Nebraska 68508 SUMMER, 1968 Chemical Engineer i ng Educa t ion VOLUME 2 NU M BER 3 D epa r tmen ts 99 Editorial 98 Letters from Readers SUMMER 1968 104 Departments of Chemica l Eng i neeri n g University of Washington, R. W Moulton 100 The E ducator Professor Olaf Hougen 139 Views and Opi n ions Thermodynamics : Death and Transfigura tion, Jam es L. Thron e Where are the Engineers?, T. B M e tcalfe 129 The Classroom Programmed Instruct i on in Thermody namics, Charl e s E. Wal es 126 The Labor a tory ChE Kinetics Laboratory, K enne th B Bischoff 135 Book Rev i ews 137 Problems for Teacher s Feature Article s 109 Irreversible Thermodynamics, C M. Sliepcevic h and H T Hash emi 113 Approaches to Statist i ca l Thermodynamics, M V. Sussman 120 The New Stoichiometry, E. M Ros en and E. J. H en l ey 107 DIVISION ACTIVITIES Scriven Delivers Annual Lecture CHEMICAL ENGINEERING EDUCATION is published quarterly by the Chemical Engineering Di vis io n, American Society for Engineering Education. Th e publication i s ed i te d at the Chemical Engineering D epartment, University of Florida. Application to m a il at second ~ c las s postage rate s is pe ndin g at Ga in esv ill e Florida, and at additional m a iling offices. COrrespondence regard in g ed it or i a l matter, circulation a nd changes of address s hould b e addressed to t h e Editor at Gainesville Florida 326 01 Advertising rates and informati o n a r e ava il ab l e from the advert i s in g represe ntati ves Plates and other advertis in g material m ay be se nt directly to the p r inter : E. 0. Painter Printing Co., 1 37 E. Wiscon s in Ave. D eLa nd, Florida 3 2720. Subscription rates on request. 97


----New fro,n BONALD PROCESS ENGINEERING CONTROL Mack Tyner and Frank P. May, both University of Florida An introduction to linear control theory for college students and practicing engineers Emphasis is on the universality of the control problem in process engineer ing through mathematic al equations that apply equally to components from all technologies. Linearization of non-linear forms a nd its limitations are discussed early in the book. Both the root locus method and the fre quency response method are stressed as means of control sys tem a n alysis, and Nyquist diagram s, Bode plots, and Nichols charts which serve as useful analytical tech niques. are demonstrated in many o f the illustrative examples. Attention is directed to the u se of both digital and ana lo g computers An Instructor 's Supplement is available. 1968. 472 pages. $14.00 Publishers since 1900 The Ronald Press Company 79 Madison Avenue New York N.Y 10016 from the READERS Editor: Please refer to th e article on the common th ermody namic s co ur se by Manning and Ca njar in your w int er issue, page 11. Why s hould the chemical e n g in eeri n g s taff at Car n egie have to put up with (a) a compromise, (b) co nf erences to make the comprom i se work? I advise the staff to screa m loudly and try to get out of the bed of Procrustes. Editor: Ernest W. Thi e l e University of Notre Dame The ASEE might render a rea l serv i ce to our cou ntr y if it cou ld get pages 78 and 79 Spring CEE into the hands of every se nator and congressman in the country, with a forceful l etter of transmittal ca llin g attention to the analogy of General Hershey and Adolph Hitl er .as implied in "The Rise and Fall of the Third Reich" and alluded to in the la st paragraph on page 78 98 John E. Kiker, Jr University of Florida Acknowledgments The following have donated funds for the s up port of CHEMICAL ENGINEERING EDUCA TION: Atlantic Ri c hfi e ld Company C F. Braun a nd Company Dow Chem i ca l Company Mallinckrodt C hemic a l Works Monsanto Company Olin Mathieson Chemical Corporat ion The Procter and Gamble Compa ny 3M Company Standard Oil (Indiana) Foundation The Stauffer C hemical Compa n y CHEMICAL ENGINEERING EDUCATION


from the EDITOR Since we wanted our first issues of CHEMI CAL ENGINEERING EDUCATION to have as broad an appeal as possible, we included articles in a number of areas of modern chemical engi neering. But in this issue, we are using a dif ferent approach: we are emphasizing the areas of thermodynamics, kinetics, and stoichiometry the subjects that were joined together many years ago in a three-volume work called "Chemical Pro cess Principles." As our "ChE Educator" we are featuring one of the brilliant authors of that work, Professor Hougen, and, as our "ChE De partment" his Alma Mater, the University of Washington Olaf Hougen might well be called the inspira tional and intellectual father of modern chemical engineering: he is the inspirer of many promi nent chemical engineers who were his students; he developed the areas of chemical engineering thermodynamics and kinetics ; and he played an important role in the development of transport phenomena when he brought Professor Bird back to Wisconsin and charged him with the responsi bility of placing the engineering computation of heat, mass, and momentum transfer on a sound theoretical and scientific basis.* In this day of continued debate on the merits of the so-called "chemical engineering science" approach, there are lessons to be learned from the example of this great man. The first and most important lesson is that we cannot expect to know what is at the end of the research path before we get there; i.e no one could know a priori what applications would arise from the first course in mass transport which Professor Bird began to teach back in 1954; nor could Professors Hougen and Watson initially know the extent to which the theoretical subject of chemical kinetics could be extended and applied to the flow, batch, and fluidized reactors of chemical engineering practice; nor could the profession know many de cades ago that chemical plants would be designed on the basis of the thermodynamic properties of substances that were predicted by the theoretical methods developed by these same two men Al though talk about the "practicality" of thermody, :, Professor Bird reco g nized the inspiration and incen tive placed before him by Professor Hougen in the pr e face of his t e xt on "Transport Phenomena 1 with th e coded acronym: "Thi s book is dedi c ated to Olaf Hougen S UMMER, 1968 namics persisted throughout the 1950's, today not even the Neanderthals of the profession ques tion the importance of thermodynamic informa tion on enthalpies, free energies, heats of reaction and P-V-T data to modern industry. The lesson we must again learn is that chemical engineers and particularly young teachers and graduate stu dents-must be provided an opportunity to delve into those areas of science that are unexplored even if applications are not clearly visible. (An important area of this type today is the en tire field of bioengineering and biomedical engi neering). It is certainly destructive to stifle the curiosity and dull the initiative of our young scholars by harassing them with demands that they show the immediate application of their work. These men need instead the same kind of encouragement Professor Hougen provided Pro fessor Bird and others. But another lesson that can be learned from Professor Hougen's career is one that must be learned by many of these same young scholars ; namely, that the work of the engineering scholar should ultimately be placed-by himself or by others-in a form that is usable to the practicing engineer For the real utility of the work of Hougen and Watson lies in the fact that these authors prepared numerous charts that could be easily used by the engineer in practice (e g. to find the final conditions in a Joule Thomp s on expansion or to predict enthalpy or PVT changes in a process.) Without such a step, the important work of the scholar may long go unheeded by engineers in industry who do not have the time or academic background to use it The AIChE Research Committee is currently studying the problem of the industry-academic gap. President Max Peters has often spoken of it and it was forthright l y discussed in the last issue of CEE by Bob Lenz. Perhaps one answer lies in our thinking again about the work of Olaf Hougen in not only developing the Chemical Pro cess Principles but also in further making them applicable to real engineering problems. CHEMI CAL ENGINEERING EDUCATION in this issue is proud to present articles on the "Chemical Pro cess Principles Today" and to acknowledge the debts of the profession to a pioneering educator and a very warm and sensitive human being R.W.F. 99


t!l Na educator This article was contributed by an anonymous associate of Professor Hougen. Olaf Andreas Hougen, Emeritus Professor of Chem i ca l Engineering at the University of Wis cons in has pursued a distinguished career in the field of che mical engineer in g educat ion. He has been one of the l eaders in bringi n g the profession from a state of empirica l practice to a state where it i s firmly based upon sound basic prin cip l es of chem i stry, physics, a nd mathematic s. He was born in Manitowo c, Wisconsin, on October 4, 1893, the son of a prominent pastor, who was a pioneer in the deve l opment of the Norwegian Evangelical Lutheran Ch ur ch of Americ a When Olaf was four years o ld, his fa ther was ass i gned a pastorate in Decorah, Iowa, and it was there that Olaf received hi s e lem en tary grade schoo l educat i on. While the materi a l resources of the H ougen fami l y were limited one of Olaf's daily chores was to take the family's cow to pasture and back-it was a family rich in intellectual and soc ial activities, w ith constant encouragement to the children to ach i eve high educational attainments Proximity to Luther Co ll ege and the fact that he had severa l attrac tive sisters made the Hougen home in Decorah the center of much li ve l y soc ial act i vity. The fam il y later moved to the State of Washington, where Olaf graduated from Tacoma High School. He then decided to enroll at the University of Washington in the Department of Chemical En gineering, which was headed by Dr. H.K. Ben son, one of the ear l y l eaders in the development of chemical engineering as a separate educational d i scip lin e At the Un i versity of Washington, Olaf established a distinguished career, both aca d e mically and in extracurricu l ar act i v iti es. He received his BS degree in 1915, cum laude, and was a member of Tau Beta Pi, Phi Beta Kapp a, and other honorary societies. After graduation, he spent one year with the American Smelting and Refining Company, at their Tacoma plant. Then with the encourage100 A GREAT TEACHER OLAF A. HOUGEN ment of Dr. Ben son, Olaf decided to take up graduate work in chemical engineering. He chose the University of Wisconsin because of the na tionally recognized work of C. F. Burgess (founder of the Chemica l Engineering Dep art ment and of the various Bur gess companies, in cluding the Burgess Battery Compa ny) 0. L. Kowalke (prominent in gas manufacture re search; Chairman of the Chemica l En gineering Department for 25 years), and 0 P. Watts (leader in the field of applied e l ectrochemistry). After two years at Wisconsin, first as a Graduate F e llow and then as a full time Instructor, h e served in World War I, 1918-1919, in the Chemi cal Warfare Service, assigned to chemical engi neering work at the Saltville, Virginia, plant. Following his discharge from the armed forces, he spent one year with the Carborund um Com pany, in their research l aborator ie s at Niagara Falls, New York, where his work was lar ge l y focused upon the development of refractory ma terials. The post war upsurge in student enrollment that was felt throughout the country resulted in an invitation being extended to Olaf to resume his Wisconsin connection. He accepted, and re turned to Madison in the fa ll of 1920 as an As s i stant Professor. Since that time until his re tirement in 1964, h e has been associated continu ously with the University of Wisconsin, except for severa l leave s of absence. He rose through the various academic ranks, and served three terms as Chairman, totaling to 8 years Hi s first graduate degree, Chemical En gi neer was earned in 1918; hi s PhD was received in 1925, number 4 in a list that now includes over 200 names. When Olaf Hougen started his career as a teacher, chemical engineering courses were large l y qualitative in character; the pioneering texts of Walker, Lewis and MacAdams and of B adger a nd McCabe had not yet been published. ThroughCHEMICAL ENGINEERING EDUCATION



Despite his many honors, Olaf remains a modest person, with a warm and outgoing personality; with a host of friends not only in University circles but in the Madison commun ity as well. out hi s career at Wisconsin, Olaf was a leading force in bringing abo ut a constant modernization and up grad in g of the und ergraduate c urriculum, includin g the establishment of unit operations theory a nd laborator y courses, c hemic a l engi neering thermodynamics, and kinetics and re a:ctor des i g n. It was through hi s influence that Bird, Stewart, a nd Li ghtfoot wrote their text, Transpo rt Ph enomena, which ha s had such a w id espread impact in chemica l engineering edu cation in rece nt years When Olaf star ted hi s teaching career at Wiscon s in, graduate enro llm ent in c hemical engi neering was l ow, being ge nerally limited to one or two graduate fellows and to the yo ung mem bers of the teaching staff working for their de g rees. While some growth took p l ace, it was great l y acce l erated when Olaf in recognition of hi s substantial research contributions w i th limi ted s up port, received a grant in 1941 of $100,000 from the University R esearch Committee, using funds g i ven by the Wiscon s in Alumni Research Foundation. Thi s g rant enabled him to start a program of graduate research that not on l y re s ulted in a sharp in crease in the number of gradu ate s tudents but also enab l ed him to ini tiate a program of staff additions. He was l argely re sponsible for bringing in K. M. Watson (who later resigned), C C Watson, W.R. Marshall, E. N. Lightfoot, W E. Stewart, and R. B. Bird all of whom contr i buted great l y to making Wiscon s in's Department of Chemical Engineering one of the leading ones in this country When Olaf H o u gen joined the Wisconsin staff, his unusual talent s as a classroom teacher became apparent at once. While his courses were de manding, his enthusiasm, his clarit y of expos i tion, hi s exce ll ent organization of subject matter and his fresh approach to so lving chemical eng neering problems won him immediate acceptance by the students as be in g one of the outstanding teachers in the College of Engineerin g Olaf ha s always treated his students w ith courtesy and respect, and ha s enco ur aged them to do orig i nal ana l yt i ca l thinkin g in so l ving difficult problems. Olaf Hougen early recogn i zed that the ideal teacher strikes an effective balance between class room teaching and research, and he constant l y 102 s trov e to match this id ea l with the hi g h degree of s u ccess that his assoc iat es fully appreciate. Over the years, he ha s trained 44 PhD's with so mewhat le ss than h a lf now being in educationa l work. The w idel y disseminated influ ence that O l af h as had in graduate ed u cat ion in illu strated by his aca demic "Family Tr ee," s hown in the ac companying figure, which was prepared by R. B. Bird and presented to Olaf at a recognition dinner given in hi s honor on October 8, 1966. On this c hart the white numbers on a black background indicat e those persons who have at sometime held univer sity professorships Olaf's publications cover a wide diversity of s ubjects in the field of chemical e ngineerin g, and total to over ninety. Olaf Haugen's influence in the field of chemical engineering education ha s been felt not only through hi s classroom teaching and his direction of graduate research, but also by the publication of a series of widely used text books. I ndustria l Ch emica l Calculations, published in 1931 with K. M Watson as co-author, was l ater followed by the three vo lum e ser ies, Chemical P r oc es s P r inci ples (Material and Energy Balances; Thermody namic s; Kineti cs ), again w i th K. M Watson as co author. The se texts have been highl y success ful, and have been translated into Italian, Japan ese, a nd Spanish Many honors and awards have come to Olaf Hougen because of his distinguished career in engineering education and research. He has de livered many invited lecture s at ot her universi ties, and before in dustrial gro up s. Hi s major awards are as fo ll ows. Awards Based on Contributions in Engineering Education 1. The Warren K. Lewis A ward of the American In s titut e of Chemical Engineers, 1964. Second recip i ent of the award 2. The Lamme A ward o f the American Society for Engineering Education 1961. This i s cons id ered the major award of the ASEE. 3. Appointment to the Burgess Research Professor s hip at th e University of Wi sco nsin, 1955-1961. 4. Benjamin Smith Reynold s Award for Excellence in T e aching Future Engineers, 1955. An award of $1, 000 given annually to an outstanding Wi sc onsin Faculty member. Fir st recipient of the award. C HEMICAL ENGINEERING EDUCATION


Professor R B B i rd presented the academ ic "f amily tree to Pro f e s so r Hougen at a dinner in his honor Award s From Professional Societie s 1. American Chemical Society Award in Industrial and Engineering Chemistry, spo n sored by the Esso Research and Engineering Co mpany, 1961. 2. Founders Award, American In st itute of Chemical Engineers, 1958. 3. Institute Lectur er, American Institute of Chemical Engineers, 1950 The seco nd l ect urer to receive this honor. 4. William H Walke r Award of the American In s ti tute of C h emica l Engineers, 1944. Internationa l Recogn i tion and Awa r d s 1. Scientific Atta cht'!, U. S. State Department. As s i g ned to American Embassy, Stockholm and cov er in g Denmark, Finland, Iceland, Norway, and Sweden 1961-63 2 Hono r ary Doctor of Science Degre e from the Nor wegian Institute of Technology, Trondheim, Nor way, at 50th Anniversary Celebration, 1960 3. Honorary m e mb er, Indian Institute of Chemical Engineers, 1958. 4 Fulbright Profes sorsh ip To Norwe g ian In s titute of Technology, 1951 To Kyoto Univer s ity, Japan, 1957-58. 5. Invited to give keynote address b efo r e the Deut sche Bunsen Gesellschaft, Dui sbe rg, West Ger many, 1953. Despite h i s ma n y honors, Olaf remains a modest person, with a warm and outgoing per sonality; with a host of friends not on l y in Uni versity circles, but in the Madi so n community as well Olaf Hougen was married in 1919 to Olga M Berg and one daughter, Esther, was born to them. Esther is married to F G. Taylor, and has SUMMER, 1968 3 children, in whom the Hougen grandparents take great pleasure. One of Olaf's brothers, Joel 0 Hougen, is presently the Alcoa Professor of Chemical Eng i neering at the University of Texas A nephew, Wendell T Berg, is a chemical engi neer with Union Oil Company. The nationally known CBS commentator, Eric Sevareid, is one of his nephews. Because of his Norwegian ancestry, Olaf has taken a prominent role in N orwegian Ameri can activities, as well as developing and main taining strong ties with Norway. He is a member of Sons of Norway and of Ygdrasil Literary So ciety Because of his activities in 1940 45 as Wis consin Treasurer for American R elief for Nor way, he rece i ved a citation from King H aakon of Norway As a resu l t of his father's influence, religion has been a strong and continuous force in his life He has participated extensive l y in the activities of Luther Memorial Church, a large church located in the University area Olaf is a long stand in g member of the Optimist C l ub, and has served as an officer. Golfing is h i s chief out door recreation, and keeps him in exce ll ent physi cal condition. Though Olaf retired in 1964, he is still actively interested in h i s department and in the c h emica l engineering profession. He frequently is at his office, and the members of the staff have the bene fit of his counsel and advice. He truly is one of the revered elder statesmen of the chem i cal engi neering profession. 103


[eJ ft Ii department UNIVERSITY OF WASHINGTON R. W. MOULTON, H ead History ( 1900-1968) In 1895 the University of Washington moved from downtown Seattle to its present location about 4 miles northeast of the city center. Denny Hall was the first structure built and in its base ment there were facilities for what was known then as the Chemistry Department. Chemical Engineering at the University of Washington had its roots in the Chemistry Department. In 1904 Dr. Henry K. Benson joined the fa culty of the University and while his educational background was in chemistry his intere s ts were motivated strongly toward industrial chemistry. Dr. Benson was interested in the application of chemistry to agriculture and he was a leader in the chemurgy movement in the Pacific North west. He was extremely conscious of the pulp and paper industry locally and throughout the world. He did much research during his lifetime in field s related to the production of pulp from wood and other forest products. In 1919, Dr. Benson was appointed executive officer of the Department of Chemistry and Chemical En g ineering as it was known at that time. He serve d in that capacity until 1947. In 1911, an organization called the Chemical En g ineering Club was formed at the University of Washington. At that time leaders from chemi cal industry in the Pacific Northwest together with appropriate faculty members at the Univer sity of Washington established the first chemical engineering curriculum. This curriculum was so mewhat weighted toward pulp and paper and alrn coal and gas technology. This curriculum was the precursor of the chemical engineering program as it is known today. In 1922, Professor Warren L. Beuschlein joined the faculty of the department. Professor Beuschlein had received his Bachelor of Science in Chemical Engineering degree from the Uni versity of Washington and his Master of Science degree in Chemical Engineering from the Cali fornia Institute of Technology Professor Beu104 schlein became a dominant figure in the thinking of the faculty of the department during his tenure on the campus. He died suddenly in September 1944. Profe ss or Beu sc hlein's research interests were quite broad. He made important contribu tions in the areas of the manufacture of charcoal from wood waste, the high pressure hydrogena tion of coal, the fix at ion of nitrogen from air, and in the manufacture of pulp from forest products. The first doctorate degree in Chemical Engi neering on record was that awarded to Dr Cal vert D. Wright in 1931. Dr. Wright joined the faculty a t Pennsylvania State University and was active in research dealin g with the utiliza tion of coal during his tenure there. Durin g the 20 's the department graduated a considerable number of individuals, some of whom obtained significant national prominence in their profes sional careers. Among these are Mr. Samuel G. Baker, Dr. Olaf A. Hougen, Mr. Victor Mills, and Dr. Waldo Semon. Mr. Baker had inportant re sponsibilities with the DuPont Company before his retirement. Dr. Hougen became a leading educator and spent most of his professional life at the University of Wisconsin. Mr. Mills was employed at the Procter and Gamble Company for most of his professional life and made sig nificant contributions to their new product de velopment. Dr. Waldo Semon was associated with the Goodrich Rubber Company and was their research director before retirement. Accreditation of chemical engineering de partments was initiated originally by the Ameri can Institute of Chemical Engineers in 1925. The University of Washington's department of Chemi cal Engineering became the first department ac credited in the Pacific Northwest and this action took place in 1926 In the middle 30's accredi tation was first carried out by AIChE for the new organization, the Engineer s Council for Pro fessional Development. In 1930, Dr. Kenneth A. Kobe, a new PhD in Chemical Engineering from the University of Minnesota joined the faculty. Dr. Kobe was a very energetic, enthusiastic faculty member. DuCHEMICAL ENGINEERING EDUCATION


Many prominent chemical engineers, including Olaf Hougen received their education at the University of Washington in Seattle. ring his eleven years on the faculty he published well over 100 significant papers dealing with his area of research and related works. Dr. Kobe resigned from the department in 1941 to accept a position on the faculty of the Department of Chemica l Engineering at the University of Texas. Dr. Frank B. West joined the department in 1939. He left later during the war years The author became affiliated with the department in 1941, as did Dr. Joseph L. McCarthy. Both Dr. McCarthy and the author are still active mem bers of the Chemical Engineering faculty. The post-war years have produced extensive changes in the department. There has been a dramatic increase in the number of faculty mem bers, the size of the undergraduate classes, the size of the graduate program, and the amount and kind of facilities devoted to the department. These changes have created the department as it exists today. Chemical Engineering Today The faculty of the Department of Chemical Engineering now number fourteen individuals. Four of these men have joint appointments; two with Nuclear Engineering, and two with Forest Resources. The College of Forest Resources has developed within the last few years a Bachelor of Science degree program in Pulp and Paper Technology. Because of the long and deep in terest of the Department of Chemical Engineer ing in the field of pulp and paper these two joint appointments were established and serve to main tain close and good working relationships in this area. The Department of Chemical Engineering played a significant role in the formation of a Nuclear Engineering Department at the UniSUMMER, 1968 versity of Washington. The first courses in nu clear engineering on this campus were given by the Department of Chemical Engineering. An early interest in the facilities at Richland, Wash ington dating back to about 1950 initiated some of this enthusiasm for the nuclear industry. Nu clear Engineering evolved into a group effort of five engineering departments and was eventually established as a separate department wholly at the graduate level. Dr. A. L. Babb, a member of the Chemical Engineering faculty, serves as its chairman. The joint appointments in Nuclear Engineering serve to emphasize the close tie of chemical engineering to nuclear engineering. In 1953 the Department of Chemical Engi neering was established as a separate department. Prior to 1953 there had been what was then called the Department of Chemistry and Chemical Engi neering under one chairman who reported to the Dean of Arts and Sciences for Chemistry and the Dean of Engineering for Chemical Engineering. While this was a reasonably good arrangement it was decided in 1953 to formally separate the two departments. After separation the two depart ments occupied the same facilities and for all practical purposes continued in the same manner as before. The Department of Chemical Engi neering owes much of its tradition and strength to the Department of Chemistry which has always been a strong department at the University of Washington. After literall y decades of effort in planning and study a new building for the Department of Chemical Engineering was authorized and com pleted in September 1966, in time for the 1966-67 school year. This new building increased the gross square feet allocated to the department from 30,000 square feet to 72,000 square feet. 105


The first courses in Nuclear Engineering were given by the Department of Chemical Engineering ... Dr Babb's involvement in the development of the artificial kidney has received international recognitioh Not only was there an increase in space but the space was now functionally suited for the needs of the department. Each faculty member now has his own office, and his own research areas. There are a l so many types of specialized research areas built into the building for the needs of the depart ment. The philosophy followed in the design of the building was to provide for a maximum de gree of flexibility. The building committee and the faculty as a whole felt that it was unwise to be highly precise about how space would be used five and ten years in the future. The under graduate program in the depart ment has underg one a major revision in the l ast few years The cha n ges that have been made in the curriculum provide for more options in plan ning the stud ent s' programs. There is a core of required courses for the department (which is not common to a ll engineering departments) On top of this quota of required courses both in chemical engineering and related fields the stu dents have the option of choosing technical elec tives amounting to 15 quarter credits and electives in the area of hum anistic and social sciences amount ing to 30 quarter credits. B y judicious choosing of electives the student can plan his undergraduate program to be a foundation for graduate work or alternatively he can plan for direct employment in industry following gradu ation. Following this l atter course he can spec ialize to some extent depending upon his intere sts. If h e so chooses, he can take some courses in the field of pulp and paper technology, or he can en hance his background in fluid mechanics, heat transfer, or other selected chemical engineering areas. The graduate program of the department is the one that ha s changed most significant l y in the la st twenty years. At the end of World War II there were from four to six graduate students At the present time there are of the order of sixty grad uate st udent s in attendance. Current re search activities of the faculty encompass the areas of reaction kinetics, transport phenomena fluid mechanic s, heat transfer, mass transfer, bio engineering, interfacial phenomena, polymers, 106 cellulose and lignin, thermodynamics and phase equilibria, process dynamics and control, and ap plied mathematics. None of the faculty members exact l y duplicate each other's interests, although there i s some overlapping. The fourteen faculty members received their doctorate degrees almost ent irel y from different schools. Schools repre se nted are the University of Illinois, the Univer s it y of California, Yale University, the Univer sity of Minnesota, Massachusetts Institute of Technology, Princeton Uni'versity, the U ni versity of Wisconsin, McGill University, the University of Washington, the State University College of Forestry at New York, and the University of Michigan. It i s obvious from the spectrum of research interests and the backgrounds of the faculty that there is a considerab le breadth built into the faculty of the department. Future Trends It is risky to predict the future with any degree of definiteness. Within the College of Engineering and within the Department of Chem ical Engineering there is considerable interest today in various interdisciplinary areas The most prominent of these at the present time is the cooperative programs being developed with the medical schoo l. Fortunately, the Universit y of Washington has on the same campus a very good medical school. This school has been de ve loped since World War II. Many cooperative programs are a lre ady established A prominent example of one of these is Dr. Babb's involve ment with Dr. Scribner in the development of the art ificial kidney. This work has received na tional and international recognition. Other re search areas are being jointly prosecuted at the present time and it is certain that this work will expand in the future The area of marine sciences is another inter di E: cip lin ary area that is receiving a high degree of support on the campus at this time The Uni versity has an outstanding department of ocean ography and has recently received federal fund ing through a sea-grant award. A new division of marine sc ien ce has been established with vari ous segments of engineering being a part of this program. Other areas of cooperation will certainly de velop. About the only thing that can be stated with some conviction is that chem ic a l engineering will be different in the future than it is today. CHEMICAL ENGINEERING EDUCATION


CHEMICAL ENGINEERING DIVISION ACTIVITIES Scriven Delivers Annual Lecture The 1968 ASEE C h e mical En g ineering Divi sion Lecturer is Dr. L. E. Scriven of the Univer sity of Minnesota. The purpose of this award lecture i s to recognize and encourage outstand in g achievement in an important field of fundamental chemical engineering theory or pract i ce The 3M Co mpan y provides the financial s upport for this annual lecture award Bestowed a nnually upon a d i s tingui s hed engi neering educator who delivers the Annual Lecture of the C hemical Engineerin g Division, the award consists of $1,000 and an engraved certificate. These were presented to t hi s year's Lecturer Dr. L. E. Scriven, at the Annual Chemica l En gi neerin g Divi s ion Banquet held June 19, 1968 at the University of Ca liforni a, Los Angeles, Ca li fornia Dr. Scriven spoke on "Flow a nd Trans fer at Fluid Interface s A paper based upon hi s lecture will be published in an early i ss ue of CHEMICAL ENGINEERING EDUCATION. PREVIOUS LECTURERS 1963, A. B. Metzner, Univers i ty of Delaware, "Non-Newtonian fluids." 1964, C. R. Wilke, University of Ca liforni a, "Mass transfer in turbulent flow." 1965, Leon Lapidus, Princeton University, "As pects of modern control theory and applica t i on 1966, Oct ave Levenspiel, Illinoi s Institute of Tech nolog y, "Changing Attitudes to Reactor De s ign." 1967, Andreas Acrivos, Stanford University, Matched Asympototic Expan sio n s." BIOGRAPHIC SKETCH L E. Scriv e n was born in 1931 in Battle Creek, Michigan. He graduated from the University of Ca li fornia, Berk e ley with hono rs in 1952, where he won th e University Gold Medal for academic achievement and was e lect ed to Tau Beta Pi and Phi Beta Kappa. He went on to do grad uat e work in c hemi ca l engineering at the Uni versity of Delaware and received the MChE and the PhD SUMM ER, 1968 degrees in 1954 and 1956 respective l y. While there he was e lected to Phi Eta Kappa and held NSF and Shell predoctoral fellowships. After three years a s a Research Engineer with th e Shell Deve l opment Company, Emeryville, Ca li fornia, Dr. Scriven joined the faculty of the University of Minnesota where he is now Professor of Chemica l Engineering. In 1963 h e was Guest Investigator at the Rockefe ll er In sti tute and in 1967 Visiting Professor at the University of P ennsy lvania. In 1960 he was corecip ient (with C. V. Sternling) of th e Colburn Award of the American In stitute of Chemical Engineers for the outstand in g paper pub l ished by the Institut e His teaching abilities were recognized in 1966 by the Distinguished T e aching Award of the University of Minnesota In st itute of Techno l ogy. In research and scho l ar ly act ivitie s hi s inter es ts hav e ce nt ered about fluid mechanics, some associated mathe matical methods and the application of engineering to biology He ha s published highly sig nificant papers on continuum theory of transport and transformat i on pro cesses, int erface physics, interface transfer and dynamic instability and pattern. Dr. Scriven is Advisory Editor for the Prentice-Hall Series in the Chemical and Physi ca l Engineering Sciences and is wide l y known for his editor ship of T h eory of Energy and Mass Transfer by A. V. Lykov and Y A. Mikhay l ov, tran s lated in 1961 from th e Russian by W. Begell Many indu s trial firms have ca ll e d upon him as a consultant or l ecturer. 107


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IRREVERSIBLE THERMODYNAMICS* C. M. SLIEPCEVICH and H. T. HASHEM! Univ e rsity of Oklahoma Norman, Oklahoma 73069 Th e mac r oscopi c approach to irr e ver sibl e th er modynamics originally pro pos e d by Sli e pc e vich and Finn in 1963 is amplifi e d to demonstrat e that, of th e f ou r possibl e alternatives fo r obtaining the re ciprocal relations, flu xe s and forces for syst e ms und e r the simultan e ous influence of t w o pot e ntial diff e r e nc e s, on e alterna tiv e is id e ntical to th e re sults obtained by Onsag er JN. A PREVIOUS PAPER by Sliepcevich and Fmn a macroscopic approach for deriving the linear laws, which relate the fluxes to the forces for irreversible processes under the simultaneous influence of two potential differences, was pro posed. Subsequent to this publication a number of readers raised questions regarding the validity of this derivation and whether the fluxes and forces so derived had any physical significance. More recently Andrews 1 has published a negation of the macroscopic derivation as extended by Sliepcevich and Hashemi 11 ; however his para phrasing of the macroscopic approach does not appear to be tenable. In an attempt to amplify the macroscopic derivation, a simple example of a one-dimension.: al, one-component system under the influence of two potential differences will be used. Multi component systems will not be considered since in these cases the definition of heat is at best am biguous 2 5 and therefore, it is meaningless to re late the fluxes to physically significant quantities. Furthermore, systems under the influence of viscous dissipation forces or external fields ( e.g., magnetic) pose some unresolved problems on their inclusion in the energy balance equations. An analysis of the complications introduced by the presence of electrical and magnetic fields has been presented by Martin. 0 ,:, Presented at th e Annual Meeting of ASEE, June 19-22, 1967. SUMMER, 1968 J N GENERA~, th? literature of irreversible thermodynamics raises some profound questions as to its range of practical usefulness; an excel lent review has been published by Wei. 1 2 In order to circumvent definitional dilemmas associated with more complex systems-w hich would serve no purpose other than to detract from the prin cipal focus of this paper-attention will be given on l y to a s impl e process fam ili ar to chemical en gineers. Until agreement can be reached on the validity of the derivation for the simplified sys tem treated herein, it would be folly to attempt to cover the more complex cases. The system to be analyzed in this paper is a one-dimensional, one-component system in which the properties such as temperature T, pressure P, and chemical potential are assumed to be uniform throughout. Likewise, the properties of this same component which composes the sur roundings are assumed to be uniform throughout and are denoted by the subscript i, v iz. Ti, Pi, ,i, which in general are different from the pro perties of the system. Obviously, then, disconti nuities in the properties exist at the boundaries a nd for this reason it has been called a discon~ tinuous system 4 Neglecting kinetic a nd potential energy effects (without loss in generality) the following equations apply when a quantity of mass oMi, having a specific enthalpy, h;, and a quantity of heat oQ, are transferred simu ltane ous ly and irreversibly across the boundary of the system at Ti such that no work i s done. Energy balance: -h1 0M 1 + o (uM) = oQ (a) Entropy balance: o (sM) = o ( ~ ;) + olw sjoM1 + T (b) Mass balance: oM = oM; Gibbs equation: ou = Tos Pov (c) (d) 109


Defining equation: = h Ts = u + Pv 2-Ts (e) where u, s, v are the specific internal energy, en tropy and volume, respectively, is the chemical potential, and lw is the l ost work as defined in Equation (b) so that a~w = Sv = total entropy production. Combining these equations yields 8lw = [8 ( ~i ) + si8M] (T1 T) + 8M (.i .) (f) Replacing the potential differences by ~'s, noting that ~/J.T = si~T + ~. and converting to the differential form Equation (f) becomes dlw = (~T) d ~ 1 + (~wr) dM (1) Equation 1 is valid to the extent that Equations (a) through (e) hold, and no other restrictions are required. Although Equation 1 was derived for the discontinuous system the same form of the equation holds for steady state systems. How ever, in the latter case it is customary to replace the ~'s in Equation 1 by the gradients, namely -grad T and grad .. Another aspect of Equation 1, which is com monly overlooked, is that it is perfectly valid subject to the aforementioned restrictions-ir respective of whether dlw i s path dependent or path independent. In genera l, dlw for closed systems is regarded as path dependent because heat Q and work W are path dependent. How ever, if either Q or W is zero, then the non-zero quantity becomes path independent, as required by the first l aw energy balance, and in this case dlw becomes path independent. For open systems in which a transfer of mass occurs across the boundaries as well as a transfer of heat and work, then it is conceivable that the energy term associated with mass transfer is path dependent if the properties of the mass being transferred vary with the amount of mass transported. How ever, for discontinuous or steady state systems, the properties are invariant at the boundary so 0 Since 0 ; = s, then it follows that si (T 1 T) + (.; .)= (.i) Pi>T (.i) P.,T + (.i) P 1 ,T 1 (.) P,T = (.;) P. T (.) PT = ~. r ,, 110 that the energy term associated with mass trans fer is path independent. Therefore for the case of either discontinuous or steady state, open sys tems in which no work is done, dlw is an exact differential. In reality it is not essential to the objectives of this paper to argue further regarding the ne cessity and sufficiency of the condit ion s for which dlw can be treated as path independent or an exact differential. As will be seen in the follow ing development, the subsequent restrictions to systems under the influence of very small po tential differences or gradients ( or fluxes) is equivalent to considering only those processes for which dlw is an exact differential; in other words the linear laws and the bilinear form of the en tropy production or lo st work equation are tanta mount to the assumption that dlw is an exact differential. Therefore, it is permissible to ex press Equation 1 as Q dlw (~T) d~ + (~ T) dM = ( 0 ~~ ) d ~ 1 + ( : : ) ~ dM (2) T1 M T 1 Once the conditions of exactness implied by Equa tion 2 are recognized, the remainder of the macro scopic derivation of the reciprocal relations is a lmo st trivial. FLUXES AS INDEPENDENT VARIABLES EQUATION 1 CAN BE expressed in rate form: (3) where the dot above the symbol denotes the time (0) derivative. From Equation 3 and well-established thermo dynamic concepts, four postulates can be in ferred : 0 I. lw = l~ ( $ 1 M) Since both ~i and M are continuous functions of T and ~ /1T, ''"'' It i s int er esting to note that the form of Equation 1 is similar to the decrea se in availability or maximum work which is an exact differential. 8 Likewis e dlw i s path independent for a process between two prescribed states in which no work is transferred. In other words the lost work, lw, can b e no gr e ater, nor l e ss, than th e maximum work that could have been transferred if each step of the process was carried out reversibly. CHEMICAL ENGINEERING EDUCATION


lw can be expressed as a function of two inde pendent variables, namely ( $ i M) (Ll-T, Ll.f. vl' ) ( ~ i LlJJ-T ) or (M, Ll.T). IL lw (0,0) = 0. If ___g_ a nd Mare each equal T 1 to zero, so i s lw. a lw III -. (0,0) 0 __g__ Ti = 0 and a l':" (0 0) = 0. o M Since lw is always positive and is a cont inu o u s, even function, with continuous derivatives, IV. 0 2 lw --. The equivalence a M a __g__ T1 of the cross partial s follows immediatel y from the first po s tulate. Referring to Equation 3 and recalling that ac cording to Fourier 's l aw, Q ---Ll-T, and according to Fick' s law, M '--"' Ll..'1', it i s postulated that lw is a homogeneous function of the second degree in _g_ and M (or in Ll-T and t,.. '1' ) at least to a first T 1 a pproximation for small fluxes or forces. Thu s Equation 3 can be expressed in general functional form for the case in which lw is time indepen dent, such as for discontinuous or steady state sys tem s,1 ( Q ) lw = lw M (4) It i s to be noted that Equation 4 implies that dl~ i s an exact differential in __g__ and M T 1 Appl y ing Euler's theorem for homogeneous functions of the second degree to Equation 4: SUMMER, 1968 l~ = ( a l: ) ~i + ( : : ) ( 5) 0-. Q Ti M __ Tl Recalling the definition of the time derivative d (z) / d0 = z so that dz = zd0, Equation 5 becomes, after multiplying throug h by d0 dlw = ( o lw_ ) d ~1 + ( a l~ ) dM a_SL a M T 1 M Q (6) T i Since dlw is exact the coefficients of the differentials of __g__ and M in Equations 2 and 6 T i can be equated. Thu s, ( a lw ) ( o lw ) Ll-T = o__g__ = Q T 1 o M Ti M (7) (8) The right-hand partial differentials of Equation s 7 and 8 can be expanded in a MacLaurin series neglecting terms higher than second order. Ll-T = ( o lw_ ) = ( o2l-v: 2 )~ a _g_ o _g_ T, T 1 M Ti 0, 0 ( 0 2 lw ) + Q M a M o~ o,o (9a) (9b) Ll.. '1'= ( 0 2 lw ) Q -1 L T 7 2 Q i Q o ~oM o,o Ti (10a) 111


Q t:;.,1 = L21 + L 22 M Ti (10b) where the L's are substituted for the second order, partial differential, constant coefficients. Note part i cular l y that since the second order cross par tia l s are equa l then L, 2 L 21 Equations 9b and 10b can be solved for and M without des T1 troying the symmetry ( equivalence of cross par tials) to obtain (11) (12) where the L's denote the terms containing the L's. It can be shown easily that L 2 L 2 1, since L1 2 L 21 The forces as defined by Equations 7 and 8 and the fluxes as given by Equations 11 and 12 are identical to those of Onsager. 3 7 SELECTION OF OTHER INDEPENDENT VARIABLES A S NOTE D in Postulate I above, lw could just as well have been expressed in terms of other independent variables. For example, inste ad of Equation 4, one cou l d have started w i th lw = lw(t:,.T, t:,.'l') (13) By utilizing the same procedures as above, it can be shown that Equations 11 and 12 will result In this case the fluxes and forces are defined as Flux = Q = ( ~~ ) and Force= t:,.T (14) Ti a t:,.T M Flux= M = ( a l~ ) and Force= t:,. 'l' (15) a t:,.'l' Q T l In the paper by Sliepcevich and Finn the fluxes and forces were defined in the above manner It can also be shown that these definitions are equiv a lent to those of Onsager.**':' Simi l ar l y, Equations 16 and 17 could have been used as starting points '" '"' 'In reality, the definitions of the fluxes and forces as given by Equations 14 and 15 are more consistent with the treatment of the Onsager coord in ates in the bilinear form of the e ntropy equation as intensive, rather than ex tensive, variables. 112 ( Q ) lw lw T ;, t:,., 1 (16) or lw = lw(t:,.T, M) (17) to obtain Equation s 11 and 12. Of the four possibilities, Equations 4, 13, 16 and 17, Equation 17 would represent the most logical choice since t:,. T and M are the quantities that can be measured directly. CONCLUSION J T IS SUBMITTED that the foregoing macroscopic approach constitutes a valid derivation of the Onsager reciprocal relations without re course to the theorem of microscopic reversibility. Recent experimental evidence has caused some physicists to question the validity of t;he time re versal invariance principle on wh ich the theorem of microscopic reversibility is based. N otwith sta nding, the assumptions and postu l ates for the macroscopic derivation presented herein are Dr. C. M. Sliepcevich is George Lynn Cross Research Professor at the University of Oklahoma. He was edu cated at the University of Michigan (PhD '48) and has taught at the University of Oklahoma since 1955. He has received many awards for outstanding contributions to r esearch and teaching in engineering and in 1967 won the University of Michigan Segui-centennial Award for dis tinguished alumni. Dr. Sliepcevich's interests include thermodynamics, re action kinetics and catalysis, high pressure design, energy scattering, process dynamics, cryogenics, and flame dy namics. (Photo on left). Dr. H. T. Hash emi is a consu lting engineer and vice president of University Engineers, Inc., Norman, Okla homa. He was educated at Abadan Technical Institute, Tulsa University, and University of Oklahoma (PhD '65). His interests include the fields of cryogenic processing and storage, hydrodynamics, thermodynamics, secondary recovery of petro l eum, and soil mechanic s. (Photo on right) CHEMICAL ENGINEERING EDUCATION


equally tenable to those involved in the micro scopic derivation since both are consistent with empirical observations on related physical phe nomena. The principal result of the Onsager develop ment is that the reciprocal relations, derived by application of the theorem of microscopic re versibility, permit a direct comparison of fluxes and forces with physically, identifiable quanti ties. On the other hand, the macroscopic deriva tion presented herein achieves the same result by virtue of the fact that dlw and dlw can be treated as exact differentials for the conditions under which the equations of irrever s ible thermody namics hold and to the extent that the funda mental laws of classical macroscopic thermody namics are valid. In other words, since the lost work is already known a priori to be path inde pendent (when no work is done at any stage of the process) no new information is gained by re sorting to the theorem of microscopic reversi bility. ACKNOWLEDGMENT The criticisms of F. Andrews and F. Mixon were invaluable. This work was supported in part by the Air Force Office of Scientific Re sea rch, Grant AF-AFOSR-563-65. REFERENCES 1. Andrews, F. C., Ind. and Eng. Chem. Fund 6, 48, 1967. 2. Bearman, R J. and Crawford, J. G., J. Chem Phys. 28, 136, 1958. 3. Co l ema n, B. D. and Truesdell, C ., J. Chem. Phys. 33, 28, 1960. 4. deGroot, S R. and Mazur, P., Non Equilibrium Th er modynamics, Chapter XV, Inter science Publish ers, Inc., New York, 1962. 5. Kirkwood, J. G. and Crawford, B., Jr., J. Phys. Chem. 56, 1048, 1952. 6. Martin, J. J. "The Symmetrical Fundamental Prop erty Relations of Thermodynamics," Presented at the San Francisco meeting of the American Institute of Chemica l Engineers, May 1965. 7. Onsager, L., Phys. Rev. 37, 405, 1931; 38, 2265, 1931. 8. Sliepcevich, C M. and Finn, D. in Chemical Engi n eers' Handbook, 4th ed., pp. 4-42, 4-44, and 4-69, McGraw Hill Book Co., Inc., New York, 1963. 9. Sliepcevich, C. M and Finn, D., Ind. Eng. Chem. Fund, 2, 249, 1963. 10 Sliepcevich, C. M., Finn, D., Ha shemi, H., and Heymann, M., Ind. Eng Chem. Fund. 3, 276, 1964 11. Sliepcevich, C. M. and Hashemi, H. T. "Recipro cal Relations in Irreversible Processes." Presented at the Philadelphia meeting of the American Institute of Chemi cal Engineers, December 1965. 12. Wei, James, Ind. and Eng. Chem. 58, 55, 1966. SUMMER, 1968 APPROACHES TO ST A TISTICAL THERMODYNAMICS* M. V. SUSSMAN T ufts University M e dford, Mass. Statistical thermodynamics connects classical thermodynamics which describes the energetic interactions of macro scopic systems with the properties of the micro sco pic or molecular con stituents of a system. The connection expands the application of thermodynamics to extreme temperature, solid state, thermo electric, and other phenomena. It permits derivation of equa tions of state, and calculation of thermodynamic properties from spectroscopic data. It provides insights to many thermodynamic properties, par ticularly the entropy. Like many other worth while goals, statistical thermodynamics may be approached in a number of ways. The various approaches each have their strong proponents and detractors and the selection of an approach is often a subjective decision reflecting the user's mathematical sophistication, epistemological phi lo sop hy and teacher' s prejudice. My purpose here is to outline the more com mon approaches to statistical thermodynamics, necessarily in qualitative terms and with more emphasis on the similarities than the differences. My point of view is summarized by the mountain scape sketched in Fig. 1. In the brief time avail able I will run you over the various trails, passes and pathways which have been used to connect microscopic to macro scopic thermodynamic ba havior. ''' Presented at the Annual Meeting of ASEE, June 19-22, 1967. 113


FIGURE MAXIMIZE-'"-'>'P. lnP. L._, I I LIFT ,,..._ \<:NI ':,, W=--------, lT n 1 ) ,. MATHEMATICAL EXPERT TRAIL TRUE ENSEMBLE AVERAGE MO ST LIKELY "CONDITION" TRAIL NECESSIT Y TOW MINIMIZE H=:Z:::~1n9 CONNECTING ENSEMBLE TO SYSTEM OF INTEREST QUASI ERGODIC H Y POTH EQUAL A PRIORI PROBABILITY INFORM ATION SYSTEM VISITS ALL PARTS OF SYSTEM IS JUST AS LIKELY TO BE IN ONE PHASE SPACE IN TIME NEEDED PHASE STAT E AS IN ANY OTHER OF EQUAL ENERGY FOR A MACRO MEASUREMENT ( ) ... TIME AVG = ENSEMBLE AVG p = p ETHEORY ENSEMBLE OF ALL POSSIBLE STATES CLASSICAL MECHANICS "f'n-DIMENSIONAL" PHASE SPACE CONTAINS TOTAL SPECTRUM OF THE MECHANI CA L STATES OF A SYSTEM QUANTUM MECHANICS S CHRCJDINGER EQUATION SPECIFIES ALL POSSIBLE DISCRETE QUANTUM STATES OF A SYSTEM Statement of Basic Problem All approaches to the problem start from the following common ground. 1. Recognition that every macroscopic system has a fantastically detailed microscopic structure, and that the existence of this micro structure makes possible an astronomically large number of different arrange ments of the microscopic elements (quantum state s ) which are completely consistent with the macroscopic system's properties. 2. A realization that there is no way of knowing which arrangement or state actually represents the system and therefore, all (or a most representative portion of) the possible micro-states must be con sidered in determining the system's properties The basic problem of statistica l thermody namics is therefore the assignment of a weight (a probability) to each possible micro-state which reflects its contribution to the properties of the macroscopic system. It is in the rationalization of the averaging technique, that is, in the derivation of the func114 tion (called a "distribution" function) assigning weight or probability to each micro state, that a variety of approaches are used. All approaches arrive at essentially the same result: For a dosed constant -volume system in equilibrium with a heat bath the probability of the i'th micro state is equal to (1) where E1 is the energy of state i and {3 and Z are constants of the equilibrium system. The sum of a ll the probabilities = 1, and therefore 1 z exp (3Ei Z = li exp {3Ei (2) Z is called the "partition function," or "sum over states." {3 is shown to be 1 / kT. The expected energy of the macroscopic system is equal to: CHEMICAL ENGINEERING EDUCATION


( E > = o ln Z 0 (3 and the entropy of the system i s equal to S = klP; In Pi (or S = k In W) (3) (4) (5) From here the expressions of classical thermo dynamics are obtained by straightforward, unso phisticated mathematical techniques. Ensemble of States Let us now explore the Fig. 1 mountain be ginning at its base-the concept of an ensemble of all possible microscopic states of a macroscopic system. In quantum mechanics, the Schrodinger equation specifies the possible discrete macro scopic or quantum states of a system. The totali ty of these states is the quantum mechanical representation of the ensemble. An alternate and older view of the ensemble is provided by classical mechanics where a many dimensional hyperspace is used to chart the total spectrum of mechanical states of a ll the microscopic constituents of the system that are consistent with the macroscopic knowledge about the system. This hyperspace is called the "phase space" of the system. Having set up the ensemb l e of all possible states in either quantum mechanical or classical mechanical terms, it becomes necessar y to con nect the ensemble to the macroscopic system of interest. The connection i s made in the ways indi cated in Fig. 1. Quasi-Ergodic Hypothesis The average properties of an ensemble are re l ated to the properties of a given macroscopic sys tem by making an assumption about the actual mechanical behavior of the macroscopic system, viz: A property measurement (for example pres sure) made on a macroscopic system is a time average property measurement rather than an in sta ntaneous property measurement. The measure ment time is long on a microscopic scale and with in the measurement time interval the system visits ( or comes arbitrari l y close to) all points in the phase space of the ensemble It therefore fol lows that a time average property of a macro system is the same as an ensemble average prop erty. SUMMER, 1968 I II II con dit1on A ~= I n= 3 I In.= 4 I I n. E = 3 + 2 = 5 I I 4 Wa = 311! =4 1 II If condition B n 3 = I n 2 = I n 0 =2 n. = 4 I I n 1 Ei =5 W = ....i1._=12 b 2!1! I! E E ~--=3 E=2 2 3 ..----,--E=3 E= 2 2 3 Figure 2.-Most likely "con dition ." Condition "B" is more likely than condition "A" because W b > W n The validity of the ergodic hypothesis is ques tionable particularly because systems can be imagined where the hypothesis does not hold; for example, an ideal gas in a rigid parallel wall con tainer whose particles are so arranged as to move perpendicular to the parallel faces of the con tainer, and in such a manner that no collision oc curs between the particles. This system would not visit all regions of phase space, that is go through all configurations of its particles' positions and velocities consistent with the total energy of the system. Equal A-Priori Probabilities Another method of connecting the ensemble to the macro-system of interest is to assign equal statistical weight or probability to all equal micro states of the ensemble. This is a reasonable as sumption because knowing only the energy of the system, we have no basis for chasing one micro state over any other micro-state having the same energy. The system has an equal likelihood of being in all such micro-states. Therefore, its average property is the average over all the equally likely states A corollary of this approach is that the prob ability of a micro-state is a function of the energy of that state only, that is, 115


p IP. IQ IP. = I 'b Figure 3.-Moment of a di stribution. P1 = f (Energy of state i) (7) The third way of connecting an ensemble to the system of interest indic ated in Fi g 1 i s the information theory approach which implicitly agrees with the equal probability assumption, al though it does not make the assumption exp licitl y More will be sa id about this l ater True Ensemble Average We now turn to the trails ascending from our base camp to the "distribution function" (Fig. 1). Given that ensemble average properties are the same as the macroscopic properties of a sys tem, the system property (M) is found by inte grating over phase space M = f p(p,q,t) M(p,q) dpdq (8) where p and q are the genera lized coordinates of phase space; t is time and p is a density function which gives the probability of finding a state point in any unit volume of phase space A mathematical theorem due to Liouville is then u sed to s how that the density function is inde pendent of time dp / dt = 0 if p i s a constant or a function of the energy of the entire system. (When this condition prevails the ensemble is sa id to be in statistical equi librium). A suitable function is p = exp (.\ + ,BE) which lead s to the conclusion that the probability of a state is proportional to exponen tial ( ,BE s tnt e ) 116 Thi s i s the route taken by the professional s tatistical mechanician. It requires considerable mathematic a l sophistication. It i s thorough, ele gant, rigorous, and generally unsuitable for pre senting the useful concepts of statistical thermo dynamics to undergraduates. Most likely "Condition" An alternate route to the "distribution func tion" I have called the "most likel y condition." It is supposed to be a short cut since it attempts to evaluate the average property of an esemble, not by covering all states in the ensemble, but only the most likely states, as represented by the most likely "condit ion. The "condition" of a system is the set of occupancy numbers (n1) which designate the number of microscopic particle s in each of the energy levels accessible to a system's particles. For example, Fig. 2 shows a system which has only four particles. The "a -condition" of that system is given by the set of occupancy numbers (n1) ; n 1 = 3; n 2 = 1. The sum of the n 1 is equal to the total number of particles in the system, in this case 4 ; and the energy of the system is equal to E = ln; E ; = (3 x 1) + (1 x 2) = 5 energy units Now, three 1-energy unit particles and one 2-en ergy unit particle can be permuted in 4 !/ 3 !1 = 4 ways. ( The g eneral rule for the number of per mutations of N total objects where N is equal to ln;; is W = N !/ 1rn1 !) Condition "b", given by n = 1, n 2 = 1, n 0 = 2, allows for 12 accomoda tions or permutations. Therefore, if we were betting on condition "a" or "b" we would put our money on "b" as the more likel y "condition." Quite clearly, the most likel y "co ndition" of any system is that set of n;'s ( consistent with the system's energy) which produces the maximum number of permutations. It can be shown that as the number of particles becomes very large the likelihood of any condition other than the most likely condition becomes very small. There fore, the ensemble as a whole can be described with rea so n a ble accuracy in term s of it s most likely "condition" and the set of n/s that cor respond to that most likely condition is simply found by maximizin g the number of permuta tions W or In W taking into account the fact that ln1 = N and l n1 E1 = E t This technique if fol lowed carefully, and if certain pitfalls are avoided, eventually leads to an expression for the partition function of a multiparticle system in CHEMICAL ENGINEERING EDUCATION


terms of the allowed energ y levels of its consti tuent particles. The pitfalls and somewhat odd rationalizations used to arrive at this final result offset the shortcut promised by averaging over the most likely condition rather than over the en tire ensemble. In this approach S kln W. Mathematical Necessity Using the equal a-priori probability assump tion, the probability of a state is a function only of its energy ( s ee eq. 7). If we have two systems at equilibrium with a thermostatic bath whose size is such that fluctuations of the energy of one system will have no effect on the energy of the bath or the energy of the other system, then we c a n state P i = f (E 1 ) P i = f(Ei) (7) (9) where E 1 represents an allowed energy state of the first system and E i represents an allowed energy state of the second system. Now, considering both systems together the probability of the first sys tem being at E 1 and the s econd system at E i must be P1 a uaj = f(Ei + E j ) = P 1 Pj (10) therefore f (E1 + Ei) = f (Ei) f (Ei) (11) The only function satisfyin g (11) is an expo nential Therefore P 1 = f (E;) (1) and we are again at the top of the mountain. A mathematical consequence of (1) and the classi cal definition of entropy is that S, can be shown to be equal to S = klP 1 ln P1 (13) This is the approach taken by Denbigh ,2 An drews/ and others. It is straightforward enough to be taught to undergraduates, requiring only a cceptance of the fact of the existence of a multi tude of qu a ntum states and the assumption of the equal probability of equal energy quantum states. A maximization computation i s avoided. Information Theory Approach The Information Theory approach, while us ing exactl y the same mathematical forms estab lished in the older statistical thermodynamic lierature, has a somewhat different philosophical or logical orientation. It s tates that statistical ,:, Particles a r e as s umed to be di s tinguishable. Al s o, Stirlings approximation, In n! = n In n n, is used. SUMMER, 1968 thermodynamics is not a physical theory whose validity depends either on the truth of additional basic assumptions, such as ergodic behavior or equal probability, or on experimental verification. It is instead a form of statistical inference; a technique for making the best estimates on the basis of incomplete information. If experiment al verification is not obtained this is not a short coming of the statistical thermodynamics, but of the information supplied. The relationship S = -k!.P; ln P1 (13) occupies the primal position in this approach. The equation is the basic equation of Shannon's "Mathematical Theory of Information" and is identified with thermodynamic entropy. Maxi mizing (13) subject to the constraints that IP1 = 1, (The system must be in some state) and IP 1 E 1 = E; (The system has energy ( E ) } leads immediately to 1 P 1 = z exp -,BE1 (1) It is the contention of the information theo rists that maximizing -IP ln P subject to con straints produces the least biased distribution of probabilities; a distribution which is maximally non-commital with regard to missing informa tion. An identical technique using a different ra tionale was suggested by Pauli who showed that the distribution functions are obtained by mini mizing the Boltzmann Hfunction H IP1 ln P 1 subject to constraints. The latter technique is discussed in detail by Tolman. 3 Taking !, P ln P to an extremum is not a new idea. The "informa tion theorists" however give it new importance by insisting that it is the most fundamental ap proach to statistical mechanics, because evaluat ing the Pi is a problem in guessing (i.e., statistics) and not physics, and therefore there need be no further concern with Ergodicity or Equiproba bility and their justification. From an undergraduate teaching point of view, the information theory approach is almost as simple as the previously mentioned mathemati cal necessity approach. The student is asked to accept, without proof, the axiom that maximizing S subject to the known properties of a system produces a minimally biased set of P;'s. The mathematics of maximization are reasonably straightforward. The trouble with the axiom is that it does not relate to much in the undergradu117


ate's experience whereas other thermodynamic and mathematical axioms usually have some in tuitive acceptability. Smoothing Function A way of making the axiom more acceptable is to demonstrate qualitatively that maximiz ing -! P i In Pi or minimizing +I P 1 ln P 1 is a smoothing operation which tends to minimize the "moment" (lower the center of gravity) of a plot of Pi vs. i. As qualitative example, assume that we have a system which is capable of existing in a great number of possible states, and we are asked to arbitrarily assign probabilities to each of these states. The states can be ordered in a sequence, and indexed by an integral subscript i. Assume that all we know about this system is that it must be in some state P 1 In Fig. 3, line b is an arbitrarily assigned distribution for this system which is constrained only by the fact that the s um of the ordinates equals unity, that is IP1 = 1. This is not an unbiased distribution because I have put maxima and minima in this distribution, that is, I have given some states more weight than others, without information that would jus tify so doing. The relative smoothness of the arbitrary curve in Fig. 3, can be represented by the mathematical index (14) which evaluates the "moment" of the distribution about the horizontal axis. The "moment" in creases as the magnitude of the singularities or extrema in the system increase, and conversely, decreases as the center of gravity of the distribu tion drops, that is as the curve becomes more uniformly smooth. In fact, it is a straightfor ward exercise in calculus of variation to show that the minimum "moment" corresponds to line "a," a constant value of P 1 which is certainly the smoot hest possible curve. If, in the smoothness index, (Eq. 14) we replace one P1 with a mono tonic function of P 1 that is ln P;, we should ex pect similar behavior. In other words, the effect of maximizing -IP1 In P1 is to smooth out our distribution. The advantage of the logarithmic function is that it allows expressing S as a func tion of the probabilit y of the microstates, and it prevents Pi from taking on negative values. Allow me to end with a speculative aside. Maximizing entropy smooths a distribution. Thi s 118 suggests to me that it might be possible to re state the principle in terms of geodesics. I say this because I would assume that a maximally smooth curve shou ld have a minimum arc len gth. I have tried using a criterion of "minimum arc length' to find a distribution function, har boring secret hopes that the criterion would lead to -2-Pi ln P1 and even more general expressions for new entropies. I regret that I've not been suc cessfu l. The geodesic idea (that an unbiased dis tribution has minimum arc len gth) nevertheless continues to intrigue me and I would welcome thoughts of others on how to work it into a se l ection formalism. References 1. Andrews, F C., "Equ ilibrium Statistical Mechan ics," John Wiley & Sons, Inc., 1963. 2. Denbigh, K., "The Principles of Chemical Equi librium," Cambridge University Press, 1961. 3 Tolman, R. C., "The Principles of Statistical Me chanics," Oxford University Press, 1942 Dr. M. V. Sussman is Professor of Chemical Engi neering and Department Chairman at Tufts University and is presently on l eave with NSF in New Delhi working on an Indian Engineering Education program. In August he will be an NIH Fellow at the Weizmann Institute studying biological thermodynamics and mechanochemis try. Dr. Sussman has degrees from City College of New York (BChE) and Columbia University (MS and PhD). Thermodynamics is a compulsive hobby with him and som e of the ideas expressed in this article will appear in a book to be published by Wiley. Join THE AMERICAN SOCIETY FOR ENGINEERING EDUCATION and Receive CHEMICAL ENGINEERING EDUCATION ::::::'~~.:::~;;;:; :::1~.t&ii.;.r~~It:$$}:;;~1 W. Leighton Collins, Executive Secretary The American Society for Engineering Education 2100 Pennsylvania Avenue, North West Washington, D. C 20037 Dear Mr. Collins, Please send me an ASEE application blank I would like to join the Chemical Engineering Division. Nam e -------------------------------------------------------------~'.'.'.'.'. Address -----------------------------------------------!::::::: AJGJi~,~~ CHEMICAL ENGINEERING EDUCATION


uni S UMMER 1968 The world of Union Oil salutes the world of chemical engineering We at Union Oil are particularly indebted to the colleges and universities which educate chemical engineers. Because their graduates are the scientists who contribute immeas urably to the position Union enjoys today : The twenty-sixth largest manufacturing company in the United States with operations th roughout the world Union today explores for and produces oil and natural gas in such distant places as the Persian Gulf and Alaska s Cook Inlet. We market petrol eum products and p etro chemicals throughout the free world Our research scientists are constantly discovering new ways to do things better. In fact we have been granted more tha n 2 700 U S. patents We and our many subsidiaries are engaged in such diverse projects as developing new refining processes develop1 ng new fertilizers to increase the food yield and the conservation of air and water Today Union Oil s growth is dynamic Tomorrow will be even more stimulating. Thanks larg ely to people who join us from leading institutions of learning. If you enjoy working in an atmosphere of imagination and challenge why not look into the world of Union Oil? Growth ... with innovation Un ion Oil Company of California n 119


The New Stoichiometry* EDWA R D M. ROSEN Monsanto Company St. Lo u is, Misso uri ERNEST J. HENLEY Univ er sity of Houston Ho us to n T exas In May of this year we sent a questionnaire to a ll AIChE accredited schools to determine the s ubject matter now included in sto ichiometr y or the equivalent first course in c hemic a l engineer in g. The replies to this questionnaire indicate quite clearly that 1) the overwhelming majority of the courses are st ill in the mold cast by Hou gen and Watson in the 1940 's, and 2) there i s a cer tain amount of experimentation, dealing mostly with the int roduction of computer techniques into the curricu lum. This introduction of computing techniques into material and energy balance courses must ultimatel y give rise to what we call 'the new sto ichiometry.' The new sto ichiometry, in turn, will form the foundation for the computer aided design and simulation courses which we expect will find a place in all chem i cal engineering cur riculums within a decade. It see ms appropriate to examine fir st, therefore, the elements of a computer aided design system Table I is a partial listin g of computer a ided chemical design systems. Of the industr y pro gra m s, the CHEOPS is considered by man y to be the gra ndfather because of the wide publicity it received in the early 1960's The CHEVRON pro gram, which i s oriented towards h ydrocar bons, has been made operational at the Univer sity of Ca li fornia, Berkeley The PEDLAN pro gram is one of the first to be written in a problem oriented language and requires a Fortran pre compiler The C HIPS KELLOGG, PECOS, and UOS programs are availab l e through service com panies, as i s PACE R which was originally de veloped at Purdue and D artmo uth. Th e CHESS pro gra m is in operation at the University of Presented at the Annual Meeting of ASEE, June 1720, 1968. 120 COMPUTER AIDED CHEMICAL PROCESS DESIGN SYSTEM PROCESS PHYSICAL LAN G UA G E PROPERTIES COSTING F i g. 1.-Elements in computer aided chemical process desi g n syste m s Hou ston, and its capability is now being greatly extended with help of a Themi s grant, ONR Co ntract N0014-68-A-0151. SLE D, under devel opment at Michigan, is analogous to PEDLAN in Table I. Computer Aided Chemical Process Design Systems Industry CHEOPS-Chemical Engineering Optimization Sys tem, Shell Oil C HEVRON General Heat and Material Balancing Program, CHEVRON Research Company PEDLAN-Process Engineering Design Language, Mo bil Oil Compa n y Service Companies CHIPS-Chemical En gi neering Information Proces s ing System, IBM Service Bureau KELLOGG Flexible Flowsheet-M. W. Kellogg PECOS-Be c ht e l Company UOS-Unit Operation s Simulator, Bonner and Moore (Fl uo r Compa ny ) Education Institutions CHESS-Chem i cal Engin eer ing System Simulator Univer s ity of Houston MAEBE Material and Energy Balance Execution, Univer s ity of Tennessee PACER-Process and Case Evaluator Routine, Dartmouth SLED-Simplified Language for Engineering Desi g n, Univers it y of Michigan SPEED-UP-Simulation Program for the Economic Evaluation and Design of Unsteady State Processes, Imp er i al Co ll ege that it utilize s a problem oriented lan g ua ge. MAEBE is a first generat ion material and energy balance program, and SPEED UP is not fully im plemented. If a stoc hiometr y course i s to serve as a pre c ursor to a computer aided design course, we must ana l yze the design system in terms of its com ''' A comp l ete tabulation and discussion of computer aided design systems i s given by Evans, Stewart, and Sprague, CEP, Vol. 64, No. 4, 1968. CHEMICAL ENGINEERING JOURNAL


FRAC. SYS. SUB-EXEC. PROG. EXCHANGER PROG. FRAC. PROG. BUBBLE POINT PROG. DEW POINT PROG. FLASK PROG, LEVEL 5: MASTER EXEC. CONTROL LEVEL 4: SPECIAL SUB-EXEC. PROGS. LEVEL 1: PHYSICAL PROPERTIES EQUIL. K ENTHALPY SP. GR. VISCOSITY PROG. PROG. PROG. PROG. Fig. 2.-Building blocks in a preliminary d esign and capital cost system for fractionating columns. ponent parts to see what fundamental principles are involved. Figure I shows the five component parts: 1. The process langua ge which converts the languag e of the engineer to that of the computer 2 The physical property package which generates the n ecessary information regarding transport, P-v-T, and thermodynamic properties 3 The mathematical representation of the building blocks (transfer functions, if you will) 4. The material and energy balance 'executive program' which links the building blocks 5. Costing programs, which may include some sort of optimization program. In Figure 2 we see a more detailed breakdown of the blocks in Figure 1 as they are used in the design of a fractionation column. On the lowest level we have the physical property tables or equations. These are really a part of a system which includes subroutines to produce enthalpy values, equilibrium constants, etc. Next there is a second level of thermodynamic calculations which use the lower level physical property programs. Dew point, bubble point, and flash programs are the examples cited On the third tier we have the transfer func tions for the building blocks; the mathematical SUMMER, 1968 representation of the classic unit operations. The level four function ties together the block of pro grams comprising the fractionation system, and overseeing the whole conglomeration of subpro grams which comprise the bottom four levels we have an executive control program which takes into consideration all input and output format and everything else that goes into a well formulatl:)d system. If one of the objectives of the 'new stoichio metry' is to train a student to create and use computer aided design systems, it is necessary to define the topics which must be included. In Figure 3 we define the five building blocks for the new stoichiometry. We have (1) thermodynamics and (2) classi cal stochiometry; these two blocks together form the manual method block in the 'Hougen-Watson mold.' The other three elements, (3) linear alge bra, (4) so lution of equations, and (5) algorithm development, together with (1) and (2) are the required building blocks for machine method cal culations. The remainder of this paper details the material in building blocks (3), (4), and (5). The examples used are from our forthcoming book "Material and Energy Balance Computa tion," John Wiley (June 1968). 121


THE NEW STOICHIOMETRY Fig. 3.-Elements of the new stoichiometry. Linear algebra, in the words of Rutherford Aris, "is the proper language of stoichiometry." Indeed, linear algebra is the only type of algebra digital computers can do; they cannot handle non linear problems. Consider, for example, Gibb's Rule of Stoichiometry, Figure 4. It states that the maximum number of linearly independent chemical reactions in a set of reactions is equal to the number of chemical species known (from experiment) to be present, minus the rank of the atom matrix. The atom matrix for a five com ponent mixture consisting of CO, H 2 CH a OH, CO2, andH 2 O is shown in Figure 5, where the rows are the species and the columns the atoms. The determination of the rank of this matrix is an exercise in linear algebra. A classic technique for determining the rank of a matrix is the Gram Schmidt method where .we attempt to construct a set of m orthogonal vectors, Y 1 Y 2 ... YM from X1, X 2 ... XM. If the length of a Y vector is zero, then orthogonalization is impossible, and the X vector is parallel to one of the others. The procedure is shown in Figure 6: the rank of the atom matrix in Figure 5 is three. Thus, accord ing to the Gibb's Rule of Stoichiometry, there are are two independent reactions. Taking the two reactions shown in Figure 7 as the independent reactions we construct the reaction matrix in Figure 7. The rows are the species; the columns the stoichiometric coeffi cients for reactions (1) and (2). The matrix formulations of the material balance lead logi cally and simply to the elegant statement for the ( MAX. NUMBER OF ) ( NUMBER ) LINEARLY INDEPEN= OF DENT REACTIONS SPECIES M N ( RA NK OF THE) ATOM MATRIX R Fig. 4 .Gibbs rule of stoichiometry. 122 conservation of atoms s hown in Figure 8. The product of the transpose of the reaction matrix times the atom matrix must be zero. We hope that this example is a convincing demonstration of Aris' axiom. Next we consider the nature and function of block four, the so lution of nonlinear equations. In the i sot hermal fla s h vaporization shown in Figure 9, f H (a) and fu(a) are two valid and identical so lution s of the material balances. In these equations a = L / V and Ki = Yi / xj Since Zi, the feed composition is known, and K is known, ATOMS SPECIE C 0 H co 1 1 0 H 2 0 0 2 CH 3 0H 1 1 4 CO 2 1 2 0 H 2 0 0 1 2 Fig 5.-Atom matrix for a five component system, example 1. G IVEN: Xl' X2' XM yl Xl y2 X Ci" x2) = Yl yl yl 2 YM-1 Fig 6.-The Gram-Schmidt procedure for example 1. Rank, R = 3. CHEMICAL ENGINEERING EDUCATION


REACTION SPECIE 1 2 co -1 1 H2 -2 -1 CH 3 OH 1 CO 2 -1 H 2 O 1 M = 5 3 = 2 CO+ 2H 2 = CH 3 OH (1) CO + H = H 2 O + CO (2) 2 2 Fig. 7.-Reaction matrix for two linearly independent reactions. these are simp l y non-linear equations in one un known, a. They can be solved readily by any number of one-dimensional, non-linear root find ing techniques. In Figure 10 we have a plot of both fn (a) and fn(a) vs. a. The root at fn(a) = f n (a), has been successfully found and is, as it should be, identical for both eq uati ons. There are, however, major differences in the shape of the curves, and we see that the f u (a) function gives us two roots, REACTION MATRIX ATOM MATRIX C -2 1 0 :) (f 1 ~) 0 = 0 -1 0 -1 1 2 1 Fig. 8 -The conservation of atoms. one of which is spurious. Clear l y, if we are to avoid such pitfalls we can not blindly set up and solve material and energy balances and feed the resulting equations to a computer. In this 'one-dimensional' example we had only one non-linear equation to deal with Let us now examine the multi-dimensional set of equations SUMMER, 1968 F BY N I i=l N ) t-, i=l z i .. I VAPOR LIQUID I REARRANGEME N T: N =) z K. Yi i l. ~l 1 + a (K i N N > -L X Yi = l. '-" i= l i= l 1 L x. l. 1. 1) z.(l K .) l. l. + a (K. ]. fR( a, ) 1) = Fig 9.-Isothermal flash equations, example 2. which will arise from the flowsheet for the cata l yt ing dehydrogenation of propane, Figure 11. We note immediately that there are two recycle streams, S12 and S2, which preclude a straight through solution to the material and energy bal ances. f H Or fR BUBBLE POINT 0 V a =F 1. DEW POINT Fig 10.-Plot of functions f H (a) and fn (a) for example 2. One method of handling problems of this type is by 'tearing' the flowsheet and estimating a composition. If, for instance, we tear stream S13 (between the str ipper and absorber) and guess at the composition for S7, we are able to ca l cu l ate all of the remaining process streams, S1 S13 in the sequence S8, S12, S10, S11, S2, S3, 123


S4, S5, S9, S6, S13. If we have guessed the com position S7 correctly, then S13 will equal S7. If not, we have to re-estimate S7 and try again. This physical situation is given a mathemati cal formulation in Figure 12. We estimate the stream vector X, calculate the process vector cp (X) and if cp (X) equals X we are finished. If not we pass through a convergence block which, hopefully, will give us a new X which is a better approximation to cf> (X). Since the X stands for all unknown parameters of temperature, pressure, compositions, and properties, it is apparent that the solution of problems of this type are primarily exercises in the solution of large sets of non linear equations in many unknowns. FRESH PROPANE FEED Sl S2 S4 ABSORBER SS RECYCLE The methods of the new stoichiometry provide the tools for the development of useful algorithms, which is building block five for the machine meth ods. By useful algorithms we mean a well defined set of statements that lead to the solution of a problem. In order to obtain the output of any building block as a function of the input to the block, and hence to set up our design system, we must have algorithms. Let us now see how we would use our knowledge of thermodynamics and non-linear equation solving techniques to develop S6 S 9 S 13 PRODUCT COLUMN STRIPPER \ \ S8 r------N S7 Sll SlO PRODUCT Fig. 11.-Flowsheet for catalytic dehydrogenation of propane to propylene, example 3. The next block in our 'new stochiometry' is a not-so-new subject, thermodynamics. The rigor ous formulation of material and energy balances requires a deeper background in thermodynamics than is now attempted in the majority of material and energy balance courses. For example, if a chemical reaction takes place thermodynamics tells us that at equilibrium the stoichiometric co efficient times the chemical potential equals zero ( Figure 13) In terms of the reaction extent, e the number of moles of component i present at any time is n1 = n1 0 + a1e, where n1 0 is the initial number of moles. The final equation from which we cal culate the composition of the reaction mix given free energy data and the initial number of moles is a non-linear function in one unknown, cp ( e) = 0. To obtain this equation we needed thermodynamics. 124 ESTIMATED STREAM CONVERGENCE BLOCK CALCULATED STREAM 0(X) PROCESS FRESH FEEDS PRODUCTS AND WASTE F (X) = (X) X = 0 ; X 0 Fig. 12.-The convergence block as an equation solver. an algorithm to calculate the composition of a mixture in physical and chemical equilibrium. CHEMICAL ENGINEERING EDUCATION


CONDIT I ON O F EQUILIBRIUM AT T AN D PIS N \ a Li l. 1. i=l 0 FO R ID EAL CONDITIONS 0 ln P = + RT 1. 1. 1. N RT I (X, i ln P. = 1. i.=l FOR: n. = n. + a 1. 1.0 1. SOL VE : (/J ( e) = 0 N I 0 a ii i=l e Fig. 13 -Use of thermodynamics, example 4. In Figure 14 we have a simple system in which we have a flash vaporization plus a series of M chemical reactions (j = 1 to j = M). There are N components (i = 1 to i = N). The component balances as well as the overall balance are shown in Figure 14 and our final equation is shown in Figure 15 in terms of Ki which, as before, is y J x i F z. 1. I V APO R LI Q UID I CO MP ONEN T B ALANC E M Fz = Vy. + Lx. -I 1. 1. 1. j=l OVE RALL BALAN C E N M a .. l.J F = V + L l l ai j e J i=l j = l Fig 14.-Model of process. SUMMER, 1968 V L x. 1. e. J If the temperature and pressure and the feed composition zi are fixed, f(a) is one equation in two unknowns, a and e To solve the equation we propose the algorithm shown in Figure 15 We (1) estimate the e reaction extents, (2) solve for a, ( 3) calculate the material balances, ( 4) check to see if the equilibrium constant has been satisfied. If it is not, we make a new estimate of e and start again. The new estimate is usually made using a W egstein or similar convergence forcing routine. What we have tried to demonstrate in this paper are (1) the techniques now being used by industry in the formulation of computer aided design and simulation systems and (2) how these may be incorporated into existing stochiometry courses to produce the 'new stoichiometry.' BY REARRANGEMENT M ) a .. 1-J j=l e .) + K. a J ]_ 1. ESTIMATE e 1 e 2 ... eM 2 SOLVE FOR a f( a, ) 3. CALCULATE xi AND yi FROM RESULTS OF STEP 2 4 EVALUATE \ LI G~ J = L RT -ln K. = ~( y .) J J ]_ j 1, 2 ... M Fig. 15. Suggested algorithm. Professor Henley is Associate Dean and Professor of Chemical Engin e ering at the Cullen College of Engineer ing, University of Houston. He received his BS from the University of Delaware and an MS and Dr. Eng. Sci. from Columbia University He served on the faculty at Columbia from 1953 to 1958, was associated with Stevens Institute of Technology from 1958 to 1964, and from 1964 to 1966 was Chief-of-Party of the AID mission at the University of Brazil. He is the author of over 50 re search papers, and five books, and is the editor of the Advances in Nuclear Science and E n gi n eering. He has done extensive consulting for government and industry and is a member of the Board of Directors of three pub licly-held corporations. 125


[eJ ;j tjl laboratory K~* KENNETH B. BISCHOFF Th e University of T exas t A us tin, T exas Th e backgrou n d of the current ex t ent of chemical en gi neerin g ki net ics laborato ry wor k is b rie fly discuss e d along with some obs erv ations on labo r atory operation. Th e statistical results of a survey on this topic a re presented and indicate that although many departments ha ve labo ratory work, there are a num b er that do no t. As an aid to the introduction of more experimen ts, a list of successfully used reactions is gi ven Finally, a detailed ex ampl e of an experimen t use d at th e University of T exas is discussed. It is rea lized that some type of formal chemi cal engineering kinetics course is a vital part of chemical engineering education. Utilizing the aspects of applied chemistry through reactor de sign is a unique feature which differentiates chemical engineers from other engineers. In the 1940's Hougen and Watson began to systematically treat chemical reactor de s ign which resulted in their well-known textbook. Even then, it was felt that this was essentially graduate level material. It was not until the late 1950's that many chemical eng ineerin g depart ments had undergraduate courses dealing with reactor design. During the last decade this seems to have c han ged in that now most department s have some sort of undergraduate lecture course in this area. Although the trend had started, the Dynamic Objective s Report1 of AIChE, with it s recommendation that more emphasis be placed upon the chemical content of the c urriculum un doubtedly also had an effect. In recent years with the introduction of courses on transport phenomena, proce ss d y namic s and control opt imiz ation, along with ki,:' Pr ese nted at the annual meeting of ASEE, Jun e 1922, 1967. t P rese nt addres s: D e partment of C h e mi ca l Engineer ing, University of Maryland, Co ll ege Park, Md. 126 Dr. Bischoff was ed ucat ed at the Illinoi s In s titute of T ec hnolo gy He ha s written man y art icl es in the fields of c h em i ca l r eact ion e n g in eeri n g and bioengineering and has rece ntl y written a textbook (w ith D. M. Himm elb lau ) o n "Process Analysis and Simul atio n ." netic s into the curriculum, the time available for extensive laboratories ha s been s teading decre as ing. The major aims of thi s paper will be to first discus s what i s currently done in the chemical engineering departments of the U.S. and Canada concerning chemical engineering kinetic s l a bora torie s and to li s t so me examples of chemical re actions wh i ch co uld be used by other departments to introduce kinetics experiment s into their cur riculum. The final part of the paper will describe in detail an experiment u se d with success at the University of Texas. Survey of Chemical Engineering Kinetics Laboratory Work A survey of the North American dep art ment s was conducted to obtain data on the exte nt of chemical engineerin g kinetic s laboratorie s. ReTABLE I Extent of Kinetics Laboratory Work '' Topic Separate c h em i ca l e n g in eeri n g kinetics labo ra to ry co u rse and / or taught in co junction with c hemi ca l e ngin eeri n g kinetics l ec tur e co ur se Experiments in other chemical engi n ee rin g laborator y co ur ses No c h e mical e ngin eer ing kinetics exper im e nt s. ,:, Note: 76 / 145 replies were received. Nu mb er of Departments 8 4 1 28 CH EMICAL ENGINEERING EDUCATION


TABLE II. Type of Chemical Reaction Type Homo ge neous H eteroge neou s non-catalyti c Catalytic Rea ction engineering / design study Number of Department s 38 6 20 16 plies were received from 76 of 145 surveys mailed. The results are shown in Table I from which it is seen that very few departments have either a separate kinetics laboratory course or have one taught in conjunction with the chemical engineer ing kinetics lecture coures. These two categories from the survey have been lumped together, since there is not a clear distinction between them. Most of the present work is designed as a part of other existing laboratory cources. In other words, the term "unit operations laboratory" quite often seems to be something of a misnomer since things other than this topic are studied. Thus, about half of the replies indicated that they had some work dealing with kinetics and, in fact, several departments had more than one experiment of this type. Perhaps the most interesting figure in Table I is the fact that 28 departments indicated that they had essentially no work at all. This seeming ly large lack does need some qualifications, since most students do get some exposure to kinetics in physical chemistry. However, it does seem that chemical engineering kinetics laboratory experi ence is lacking in a substantial fraction of chemi cal engineering departments. Several depart ments are presently in the process of adding ki netics experiments, but many are not. Table II indicates various types of reactions that have been used for the laboratories. It can be seen that the major emphasis has been with homogeneous reactions, probably because they are the easiest to perform and obtain consistent re sults. Heterogeneous catalytic reactions are also fairly extensively used, probably because of their great practical interest. Very few non-catalytic heterogeneous reactions were reported. The final category of reaction engineering design study seems to have a relatively small amount of work, but this may be somewhat ambiguous. Many of the homogeneous and heterogeneous reactions are run for "engineering" purposes and could posSUMMER, 1968 TABLE III. Examples of Reactions Used for Kinetics Experiments Homogen e ous 1. Ethyl acetate sap onification 2. Acetic anhydride hydrolysis 3. Methyl acetate hydrolysis 4. Ethyl acetate hydrolysis 5. Acetone bromination 6. Isopropanol oxidation to acetone 7. Acetic acid + ethanol esterification 8. Benzaldehyde oxidation to benzoic acid 9. Permanganate reduction with dissolved hydrogen 10 Crystal violet hydrolysis 11. Methyl acetate s aponification 12. Phthalic anhydride + butanol esterification (pilot plant scale) 13. Ethylene glycol + periodate 14. Hydrogen peroxide + iodide (iodine clock reaction) 15. Ethylene-propylene polymerization 16. Formaldehyde + methanol esterification 17. N.N-dimethylaniline + ethyl iodide (by DTA) Heterogeneous, non-catalytic 1. Coke oxidation on cracking catalyst 2. Corrosion kinetics 3. Cyclohexane hydrogenation 4. Cu + + -H + ion exchange 5. Cottonseed oil hydrogenation 6. Pyrolysis of plastics Catalytic 1. Ammonia decomposition, iron oxide 2. Cumene cracking, silica-alumina 3. Ammonia oxidation, platinum gauze 4. Toluene hydrogenation, Raney nickel 5. Isopropanol (liq.) dehydrogenation, nickel 6. Propylene oxidation, copper oxide 7. Acetaldehyde decomposition, copper gauze 8. Benzene alkylation, acid catalyst 9. Propylene disproportionation to ethylene + 2-butene, cobalt oxide-molybdena-alumina 10 Sulfur dioxid e oxidation 11. n-Propanol dehydrogenation 12. Cumene hydrogenation 13. Styrene hydrogenation 14. 1-Hexanol dehydration 15. Catalytic cracking 16. Permanganate reduction with dissolved hydrogen, Ag + sibly be included here also. Many of the depart ments out of the 16 indicated that an important part of this topic was the use of analog or digital computers to simulate chemical reactor operation. Also, the various reactions were run in a variety of reactors such as tubular, stirred tank, as well as batch. Table III presents a list of the actual chemi cal reactions used, which might serve as an aid to those who are trying to find proven reactions for their own laboratories. The saponification of ethyl acetate is the most popular reaction in use, 127


propably because of its good kinetic characteris tics, the ease of measuring the results, and the experiment devised by Kendall. 2 Detailed Example An example of a chemical engineering re action kinetics experiment that has worked well in our laboratorie s at the University of Texas is ethyl acetate saponification in a tubular reactor. Kendall 2 has given a very complete discussion of the system he developed to study the effects of different flow patterns in the reactor. Our system has many features in common with his but the emphasis i s somewhat different. A major aspect of our system is to measure and interpret the ef fects of non-plug flow in the liquid phase tubular reactor and to interpret these results quantita tively in terms of mathematical models. The fact that the ethyl acetate sapon ifi cation is a very "clean" second order reaction with no side reactions is given to the student as basic data. The reaction is run in a Tygon tube of 0 .6 15 cm diameter and 810 cm (35 feet) long, looped through baffles in a section of glass pipe which serves as a constant temperature water bath. Gravity feed lines from bottles of ethly acetate and sodium hydroxide are run through the con stant temperature water feed tank to attain reaction temperature and joined in a Y section at the reactor tube entrance Analysis of product samples is by a simple titration method similar to that described by Kendall. Electrical conductivity methods were tried but did not work any better and were somewhat more complicated than sim ple titration. In order to have high conversions of 50-90 % the reactor is run at a temperature of 100 F, where the rate constant is 0.22 liter / gm mole second, and with the feed concentrations of both reactants C 0 = 0.2 gm mole / liter. Since non-plug flow is most pronounced under laminar condi tions, the flow rates range between Reynolds numbers of 100 to 3000. A comparison of the experimental data with theoretical predictions from the axial dispersion model (see Levenspiel3) is required, using the established correlations of the axial dispersion coefficients. Results of some of the recent student data are shown in Figure 1. At the turbulent end of the range, the plug flow equations give good agreement with the experimental data. At the lower flow rates, although there is quite a bit of 128 1.0-----------------7 z 0 c:n es > :z 0 u 0 DISPERSION 1000 2000 REYNOLDS NUMBER Figure 1.-Student data for ethyl acetate s aponification in a tubular reactor. scatter it is seen that the plug flow predictions are not very good and the data approach the axial dispersion model line. The data actua ll y fa ll most ly between the two predictions, but this may be caused by the looped Tygon tube which would lead to less effective axial dispersion than that predicted by the correlations for straight tubes. In any event, the experiment not only gives an example of tubular plug flow reactor results but also illustrates quantitatively the effects of non plug flow. Conclusions The survey of chemical engineering kinetics experiments indicated that many departments do have some work in this area, but there are a l arge number that do not. Very few departments have separate kinetics laboratory or one taught in conjunction with a lecture course. In addition to the statistical information, the survey produced a rather lar ge se lection of chemi cal reactions that apparently have been success fully used. These have been tabulated to help in structors find experiments that might develop their own laboratories Finall y, an example of an experiment used at the University of Texa s was discussed in some detail and the types of results than can be obtained in a student labora tory were indicated REFERENCES 1. "Dynamic Objectives for Chemica l Engineering," Chem. Eng Prog. 57, (10), 69, 1961. 2. Kendall, H B., in "Small Scale Equipment for Chemical Engineering Laboratories," ed R. N. Maddox, Chem. Eng. Prog. Symp. Ser. No. 70, 63, 3-15, 1967 3. Levenspiel, 0 "Chemical Reaction Engineering," John Wil ey and Sons, Inc., New York, 1962. CHEMICAL ENGINEERING EDUCATION


ti Na classroom The Student The Teacher View Programmed Instruction* The Psychologist CHARLES E. WALES W ri ght State University Dayton, Ohio 45431 Th e potential of programmed instruc tion as an e ducational d evice is d e monstra t e d by its presen t use in th e classroom, in d us tri a l training programs, the continuing e ducation program of the me dical profession, and by the recent interest of several larg e corporations who have en t ered the educa tio n business with systems bas e d on programmed instruction. This paper de scribes a set of thermodynamics programs d eve lo ped at P ur d ue University and ex amin es th eir potential from th e viewpoint of th e student w ho use d them, th e t eac h er and th e psychologist. Various aspects of the design of these programs are examined including l inear versus branched styl e, step size, concrete illustrations of abstract concepts and perceptua l organizers Th e programs and the textbook are compared in terms of their ability to tra n smit in formation to the student. Th e program is d escribed as pschologically superior b e cause it shapes b e havior from th e simpl e to th e complex and guides the student so h e avoids misconceptions which mus t b e un l earned F ina ll y, the value of the programs in freeing class time for more va luabl e ac tivities is described If yo u as ked Harvard psychologist B. F. Skinner 1 what programmed in str uction can do for ed ucation he wo uld reply, "What i s now taught by teacher, textbook, lecture or film can be tau g ht in half the time ... by a teaching machine u s in g programmed in s truction. Before you dismiss Skinner's claim yo u s hould caref ull y consider the fact that R C A, IBM GE Westinghouse and severa l ot her l arge corporat ion s have recentl y P rese nt ed at the Annual Meeting of ASEE, Jun e 19-22, 1967. SUMM ER 196 8 sta ked a claim in th e e ducation bu s iness with sys tems that invol ve programmed instruction ma terials. In addition, many industrial firms al read y u se programmed instru c tion to teach basic s kill s to their e mplo ye e s And the medical pro fession i s using programmed in st ruction in a pro gram of continuing e duc a tion. While Skinner's claim of a 50 % ga in m ay be a little unrealistic, it s hould be clear that programmed instruction ha s definite potential as an educationa l device. In the di sc ussion that follows I will examine this po tential from three view points: that of the educa tional psycho l ogist who applies the theorie s of ps y chology to the classroom; m y own viewpoint as a teacher w ho h as written, experimented with and u s ed pro grams in m y teaching over a period of five years ; and the viewpoint of the st ud ent w h o h as st udied from m y pro gra ms WHAT IS PROGRAMMED INSTRUCTION? The co ncept of pro gra mmed instruction was introduced by Skinner in 1954. Since that time t hree method s of pre se ntation and two different s tyles h ave been developed. The three m e thod s are: 1. Co mputer ass i sted in str uction: the st udent operates a typewriter linked to the com puter which conta in s the programmed ma terial. 2. Teaching machine s any device wh i ch me chanica ll y controls the presentation of the program to the st udent. 3. Programmed t ex t s, which pl ace the mater ial in the hand s of the student Ea c h method ha s it s advantages, but the pro gram med text i s ba sic to the other two. There fore, this discussion w ill be limited to that meth od. 129


The two program styles are ca ll ed lin ear and branched Table I shows an examp l e of a simp l e linea r program, a ser ie s of quest i ons and answers. To u se th i s program the student covers the an swer w ith a s heet of paper, reads the question and thinks or writes hi s answer He then un covers the program answer and checks hi s work. T ab l e II s h ows a branched program In this case the student reads the question, selects one of the given answers, and then checks hi s choice against t h e answer g i ve n in the program. W hen he se le cts the correct answer he proceeds to the next question. Table I. Simple Linear Program Consider the open system, steady state process shown below, mixing operation with salt and water 5Q. How many flow rate unknows are there? 5A. Three flow rate unknown s: A, B, C. 6Q How many composition unknowns? 6A. Six compos ition unknown s, two in eac h stream. Th e tota l number of flow rate a nd composition unknowns is 9. 7Q. What is th e total number of material balance equa tions that can be written? 7 A. Three material balanc e eq uations can be written: sa lt balanc e water balance strea m balance 8Q How many of these material balance eq uation s are independent ? 8A. Two material balan ce equations are independent. Program Versus Text If you have had no previous personal contact with programs your first question will probably be, why a program in stead of a text? The answer to this question is provided by the psychologist Ausubel2 who identifie s the most crucial condition affecting the acq ui sition and transfer of knowl130 TABLE II. Physical Material Balance Calculations Two or more process units may be included in the system chosen for a material balance calculation. For example, Figure 8 shows two driers used in series to remove water from salt In this problem it is pos sible to write material balances not only for each unit but also for the pair of units combined Figure 8 A Section 1 Q. 1220 lbs / hr of wet salt (A) are s uppli ed to the two stage drier system shown in Figure 8 Assume steady state operation. How many unknown flow rates are there in this system: Your A. 5 unknowns 4 8 Section 2 See section 4 7 9 A. 6 equat ion s. No. You co unt ed material balances around unit 1 and unit 2 What about balances arnund both units? Go to sectio n 7. Section 3 A. 4 independent eq uation s Correct. All the other equa tions are dependent, they can be derived by adding or s ubt rac ting the four independent equ ations. Is it possible to so lv e a salt and a stream balance around unit one, a stream balance around unit two, and a s tream balance around both units? Your A. Yes No Section 4 See sectio n 6 11 A. 5 unknown s. Check the problem again, you probably co unted the flow rate of s t ream A as an unknown The flow rate of this stream is g iven and s hould be used as the "basis" for your calculatio n s Section 5 A. 9 equat ion s. Correct. You can write a stream, salt, and water balance around eac h unit and around both units combined. Now, how man y of these equations are independ e nt? Your A. 4 eq uation s 6 See section 3 8 CHEMICAL ENGINEERING EDUCATION


Table I I. (Continued ) Section 6 A. Your answer is yes. The correct answer is no. It is impossible to get an answer if you use three equations of the same kind (i.e., stream balances). Try it if you have doubts. Go to section 3. Sectio n 7 A. 4 unknowns. Correct. The unknowns are stream flow rates B, C, D, and E Streams B and D are pure water so there are no composition unknowns in this problem. Next, what is the total number of equations that re late these 4 unknown variables? Your A. 4 equations 6 9 S ection 8 See section 10 2 5 A. 6 independent equations. No. You have correctly reasoned that not all three equations in one set (i.e., unit one) may be used. But it is also impossible to use all three equations of one kind( i.e., salt balances) Go to section 5. Section 9 A. 8 unknowns. No. You have counted 4 composition unknowns for the water streams which are pure water. Go to section 1. Section 10 A. 4 equations. No. You didn't read the question care fully. What is the total number of equations you can write for this system that involve the stream flow rate unknowns? Go to section 7. edge as the internal logic and the organization of the material. The usual text is logically sound but psychologically incongruous because it segre gates material by topic, does not clarify the re lationship between topics, and presents material at a uniform level of abstraction instead of build ing from the simple to complex As a resu l t the student treats meaningful material as if it were rote in character. He memorizes formulas, learns type problems, performs mechanical manip u la tions and both l earning and retention are reduced. By contrast, Ausbel identifies the program as a psychologically correct device because it is con structed around the basic organizing concepts of SUMMER, 1968 the discipline and ideas are arranged sequentially to build the hierarchial structure that matches the way in which psychologists believe knowledge is organized and stored in the human nervous system The method used to construct a program illustrates Ausubel's point First, the basic con cepts of the course must be identified and or ganized into a logical pattern. Second, a detailed set of performance objectives such as those shown in Table III are prepared for each concept. Then the teacher begins the final step, the writing of the questions and answers that will lead the stu dent from the objectives he learned in the prev ious program to the objectives of the new pro gram. It is the combination of all these steps that gives the program its great strength. Table Ill First Law of Thermodynamics-Summary A. State Properties (Q 1-3) 1. Define a state property: a property that depends only on a point's location, not on the path used to get the1 e. 2. Name 5 state properties: P,T,V,U,H. B. Pat h Propert i es (Q 4 12) 1. Define a path property: A property that depends on the path used. Q and W are path properties 2. Use a P V diagram to prove that W depends on the path used C. First Law of T h ermodyna m ics for a Closed System (Q 13 32) 1. State the first law of thermodynamics for a closed system: Q w c = u 2 u 1 = ~u 2. Define internal energy a Q W = U for any closed system, any ma terial. b. ~U = C ,. (T 2 T 1 ) for any ideal gas process and for an isometric process for any material which has a constant C,.. c. Units, BTU / lb mole or BTU / l b d Zero point, arbitrary 3. Apply the First Law to a Closed System Ideal Gas Real Material a Closed Isothermal Process Q w c = u 2 u 1 Q w c = u 2 u 1 = C ,. (T 2 Tl) Q W C = 0 U = cf,(P,T) Q=W c b Closed Adiabatic Process Q w 0 = ~u = c ,, ~T Q w 0 = ~u W 0 = Cv~T, for Q = 0 R +w o = -(Tl T 2 ) U :;;; ,l,.(P,T) y 1 'I' PlVl P 2 V 2 +W c = ---~-y 1 ,:, Part of the Performance Objectives for the program on the first law. 131


By its Socratic form the program provides the student w ith many of the best features of fine tutorial in str u ct i on. The program shapes the stu dent's understanding by establishing s im p l e be haviors which are gradua ll y combined and modi fied until they lead to the final performance ob jectives which include both abstract concepts and concrete app li catio n s. Programs were the primary vehicle for trans mitting information in the thermodynamics course I taught at Purdue last semester The stu dents also had the regular text and they were told which sect i ons of the text they should study. At the end of the semester they were given a ques t i onna ir e which asked, "If you had to choose between good programs or a good text as the basis for st ud y in a class, which would prefer? Some of their anonymous replies were : "The program, you can understand it rather than memorize i t In a program a person can usually tell which points h e did not understand, whereas in a text he may not understand the who l e material." "The program, it forces yo u to stop and think and not just read, I tend to read over things in a text." As you can see, the st u dents identified many of the factors predicted by the psychologists. In a ll twenty-five st ud ents preferred the program wh il e three preferred the text One of those who picked the text gave t h e fo ll owing reason "I wo ul d probably choose a good text because that i s more fam ili ar, but I never read a text that l eft me w ith as clear an understanding of the s ubject as the programs did." Because the material in the programs i s not exact l y the same as that in the text I asked the st udent s t h e add i t ion al ques tion, Would yo u have preferred to have the ma terial in the programs wr itt en in text form with o ut the question s a n d answers?" Twent y -six re plied no; two were und ecided. Linear or Branched Programs As he creates t he program the teacher must make many decisions. First he must choose the s t y le of the program, eit he r linear or br a nched The line ar sty le was chosen for my thermod y n a mi cs 1Tiater i a l because it provides the most di rect control of the shaping process. In addition, the line ar program makes the student a more ac tive l ear n er To answer each question he must reformulate t h e material in terms of hi s own vo cabulary, b ackgro und and struct ur e of ideas. Ac132 Table IV. First Law of Thermodynamics-Self Quiz 7. Th e flow work term s do not appear in the equation Q W 0 = .c,.H, the first l aw of thermodynamics for an open system. Does one of the terms in this equa tion include the flow work energy? If so which one? a. Q b. W O C .c,.H d none of the above 7a. The term Q accounts for the energy transferred to or from the system as heat. Flow work is not included in this term. Return to question No. 7. 7b. Th e term W O accounts for the energy transferred to or from th e system as shaft work. Flow work occurs when a stream crosses the boundary of a system Some of the flow work energy may be converted to shaft work in a g iv en process but the two types of work e ner gy are not directly re lated. Reread the pro gram from just after A31 to Q33, then return to question No 7 7c. This answer is correct. The flow work is accounted for by the entha lp y H = U + PV. The terms U and PV are added because U represents the energy car ried by a stream that enters (or leaves) and PV represents the flow work done at the boundary when that stream enters (or l eaves) the system. 7d This answer is not correct. In an open system, flow work occurs whenever a stream e nters or leav es the system. One of the terms in the first law mu st ac count for this energy. Reread the program from just after A31 to Q33, then return to question No. 7 ,:, sampl e Self-Quiz question for the program on the first l aw. cording to the psychologists these acts are cru c i a l to the l earning process. In a sense the lin ear program i s an experience in guided discovery. The student participates in the development of the first l aw and in the application of the law to different reversib l e and irrever sib le processes. The students find this partic i pation stimulating. In response to the question, "What is the great est strength of the programs? they replied: "Hav ing the student answer the questions to work out the principles for himself." "I got in to the act of actua ll y developing equations." In a branched program the student does not construct answers to the questions. Instead, he demonstrates that he ha s learned something by choosing the correct answer from a set of given answers. Thi s behavior is most appropriate for a testing s ituation and that is exactly how the branched program has been used here. Table IV CHEMICAL ENGINEERING EDUCATION


is part of the branched program used as the Self Quiz at the end of the program on the first law A branched program requires that each question have one correct answer and two or three rea sonable alternates or distractors. Since each incorrect answer must provide s ome feedback in format i on to the student, more effort i s req ui red to construct a branched program. In some types of materia l there are no logica l a l ternates and the branched program cannot be used. However, when these a l ternates ex i st, the branched pro gram can be very effective in teaching the stu dent to discriminate between similar ideas Step Size The second decis i on the teacher must make is one of step size Skinner's original concept of a linear program invo l ved a short, one or two sen tence question properly cued or prompted to in sure the correct answer would be forthcom i ng. Recently, several, p sy chologists have questioned the wisdom of the small step. For example Resnick 3 has said "good students become bored with too many sma ll steps and come to resent the time spent on such programs." Ausubel2 a l so sup ports this conclusion with the thought that sma ll steps often artificia ll y and unnecessarily "frag ment ideas so that their interrelationships are ob scured and their logical structure destroyed By a trial and error process I came to the same con clusion, the small step does not suit the ability of the engineering student Using feedback from my students I finally evolved the program style shown in Tab l e V. These programs invo l ve rela tive l y large steps, meaningful, unprompted ques tions comb i ned with un i nterrupted sections of exp l anatory mater i a l. This style integrates the best features of a textbook, the lecture that fi ll s in the gaps l eft by the text, and the recitation or discussion that supplements both. Guiding the Student Some of you may question the idea of care fully guid i ng the student through derivations, proofs and sample problems. In fact you may pre fer the incomplete ideas presented in textbooks because you want the student to provide the neces sary clarification for himself. I agree that the student should learn to think for himself but I would argue that this struggle should not take place when the student is learning bas i c concepts. This reasoning is supported by Ausubel who says, "Excessively difficult material makes for an unSUMMER, 1968 Table V -Sample Page from the first law programs Since we can always use a path such as (1-a-2) be t ween any two p oints this equation can be used to evaluate D. H for any ideal gas process This is an im p o r tant characteristic of a state property a n y pa t h be tween two points can be used to evaluate the change in a state prope r ty 37Q. An ideal gas is compressed adiabatically in an open system process, can the work for this process be evaluated with the following equation? W O= D.H = f C"dT = C"(T .. T;) 37 A Yes, the D.H of an ideal gas always equals CP(T 0 T;). 38Q. If a real material is compressed a di a b at i ca ll y in an open system process, can the work for this process be evaluated with the equation w 0 = D.H = f c 1 ,dT 38A. No. The equation W 0 = t,.H is valid for any ma terial, but t,.H = J CPdT is valid only for an i so barbic process for all real materials. The enthalpy of an i d eal gas is a function of only the temperature. The definition D.H = CP(T 0 T;) proves that when T 0 = Ti, D.H = 0. Pressure has no effect on the enthalpy of an ideal gas We can reach the same con c lusion by noting that both U and the (PV) product (note PV = RT) are function s of only the temperature Since H = U + PV = U+RT the enthalpy of an ideal gas must al so be a function of only th e temperatur e 2. Isothermal Process 39Q. Write the first law for an open system, combine it with the definition of D.H for an ideal gas and prove that Q = W O for an isothermal process invo l ving an ideal gas. 39A Q W 0 = H 0 Hi = Cl'(T 0 T 1 ) Since T 0 = T 1 Q W 0 = 0 Q=Wo desirably large number of initial errors and mis conceptions that have to be unlearned This in terferes with further learning, it l owers the stu dent's self confidence and motivation, and pro motes task avoidance It is not that the student doesn t want to learn on his own, but rather that he lacks the necessary self-critica l abil i ty. The student usually finds it easy enough to manipu l ate words so as to create an appearance of knowledge and thereby to delude himself and others that he really understands. Does that sound like some 133


of your students? B y contrast, consider the fol lowing reactions of my students to the programs : "They don't let you get a misconception." "We could go back over a question to clarify points." "Being able to correct ideas before going on to new material." "You can't go on unle ss what came before is understood." Other Factors We have considered severa l of the factors the psychologist considers crucial to effective learn ing. They are: organization aro und the broadest principles, systematic sequential organization which s hapes the st udents behavior, and an ac tive learner who reformulates ideas in hi s own words. There are two additional factors to be considered. First the psychologists say that new, abstract subject matter should include concrete-empiri cal illustrations and analogies to clarify mean ings. For this reason, my programs include both theory and example problems. The student's re action to this combination is very positive. Their response to the question, "What i s the greatest strength of the programs?," was: "Working w ith the material as it is intro duced." "Seeing how each concept can be related to a problem right after the concept is presented." The second factor to be considered is what the psychologist would call an integrative perceptual organizer, a device which helps the student relate sim ilar concepts and discriminate between over lappin g ideas. In my thermodynamics programs this organization is accomplished by relating each concept and calculation to an appropriate phase diagram. As each subject is introduced it is re lated to a process line on a projection of the three dimensional s urface for an ideal gas. For ex ample, the concept of reversible shaft work is re lated to the area under a process curve drawn on a P-V diagram. The concept of reversible heat transfer is related to the area under a process curve drawn on a T-S diagram. When real ma terials are introduced the appropriate three-di mensional models and projections of the models are used to relate the process co ndition s to the change in a state property. The students response to the question, "Did you find the emphasis on the graphical representation of each process helpful in understanding the material?" varied from 134 "definitely"; and "very helpful"; to "yes, I can picture what is happening"; "yes, it was some thing basic to refer to" ; and 'yes, I need a physi cal feeling for something to really understand it." In a ll twenty-six students found this graphical approach helpful, two others liked the approach but were confused by the great number of graphs presented. Programs Free the Teacher Designed as carefully as they are, you would expect programs to teach a subject and teach it well The response of my students to the question "Do you think the programs helped you le arn more than you usuall y do?", bears this out The students' reply was a unanimous yes When asked if the programs helped them un derstand more than usual, twenty-seven students said yes; one was undecided. Part of the students' react i ons can probably be attributed to the Haw thorne effect, but I'm not willing to admit that this is a major factor I don't think engineering stude nts are that naive. The fact that graduate st udents ask me for copies of my programs to st udy for their qualifying exams is further sup port for the value of the programs. Hopefully, by now I have convinced you that programs can be of significant va lue in an engi neering course. If not, let me tempt you with one final attribute of programmed instruction. Dur ing the past semester I taught an entire course in thermodynamics using the set of programs I have developed. Each program and its accompanying problem set were assigned as homework. There were no le ct ure s in this course, class time was completely free for other activities. In a typical class meeting I spent from five to twenty minutes answering the students' questions about the ma terial in the program and discussing the home work problems. During the rest of the period we did a variety of things; we probed the concept to greater depth, we extended the concept to new situat ions and we applied the concept to indus trial type problems. Those of you who would like to find time to put some engineering in the engi neering curriculum should be especially eager to try programs. By increasing the efficiency of the transmission of knowledge, the programs can give you the time you need for other activities. This, I might point out, is exactly the role the psychologists predict for programmed instruc tion. Ernest Hilgard, a former chemical engi neer, head of the Department of Psychology and CHEMICAL ENGINEERING EDUCATION


dean of the Graduate Division at Stanford put it this way 4 the program does not replace the teacher but can hopefully free the teacher from routine exposition, and give time for doing the things that only the teacher can do," teaching students to think for themselves. Programmed instruction can help you give your students a better education; I hope the in formation I have presented here will encourage you to try programs in your classroom. Refer e nc es 1. Skinner, B. F., Harvard Educational Review, 31, (4), 1961. 2. Ausubel, D. P The Psychology of Meaningful Verbal L e arning, Grune & Stratton New York, 1963, (pp. 213, 208, 212). 3. Re s nick, L. B Harvard Educational Review, 33, ( 4), 1963. 4 Hilgard, E. R., Stanford Today, Serie s 1, (6), S e pt. 1963. Dr Charles E Wales i s an associate profes s or of engi neering and the Presid e nt's assistant for e ducational r e search and development at Wright State University. His '"Na book reviews E n gi neer i n g Th er mody n ami c s M. W. Zemansky and H. C Van Ness, McGraw-Hill (1966). Professors Zemansky and Van Ness have writ ten a text on thermodynamics with the "common core" course in mind As such, the text repre sents a combination of and selection from the ma terial offered in the conventional beginning cour ses in thermodynamics in the chemical and me chanical engineering curricula. In following this path the authors had to judge that certain topics included in these portions of the typical chemical engineering program would either be deleted, or discussed in other courses A similar statement, but with different topics in mind, applies equally well to the typical mechanical engineering pro gram. Viewed against the background of the typical chemical engineering program, there are certain features which make this book different. First, there are a number of applications discussed in the text which are not presently included in this part, if indeed in any part, of the chemical engi neering program. In this category are such top ics as "bars in tension and compression" (chap. 2), "work in straining a bar" (chap. 3), "work SUMMER, 1968 pr es ent a ss ignment include s organizing and presenting a se rie s o f seminar s on effective t e aching techniques for th e Wright State faculty. He wa s educated at Wayn e Stat e (BSChE), University of Michigan (MSChE), and Purdu e University (PhD). Professor Wales has written programmed instruction material in the areas of material balance calculations and basic thermodynamic s His programs have been or are being u s ed on an experimental basis at Purdue, Kansas State, West Virginia, Ohio, and Wright State univ e rsities, at th e Universities of Texas and Missouri (Columbia), and at Ohio College of Applied Science in changing the polarization of a dielectric in a parallel plate capacitor" (chap. 3) "work in changing the magnetization of a magnetic solid" ( chap. 3) and some of those discussed in "ap plications" (chap. 14). Secondly, a number of the classical experi ments are discussed. This includes the determina tion of "J" factor mechanical equivalent of heat (chap 4), determination of ( o U / o Ph of a gas (chap. 5), reversible change of volume of a gas ( chap 7), and the measurement of latent heat of vaporization (chap. 11) to cite a few. By the di s cussion of experimental methods and the in clusion of experimental data in some figures, I believe the authors are attempting to impress on the student the physical significance of the quan tities which are later used in the solution of prob lems. This is a part of education which is ap parently being phased out in the fundamental sciences and mathematics. Looking at the other side of the coin, the missing material, the chemical engineer will note that "fugacity" is not mentioned. The theorem of correspondence states is introduced and used only in one problem-11.1. Also, only mixtures of ideal gases are considered. Nothing is in cluded on heats of solution, or properties of real mixtures, and very little on thermochemistry. Also, the development and use of the humidity 135


,,,,, ~ k ~,~-~~ >>::.~: :::~( :. .. ........ ''-,~-----. ""-,.~~--: .. '-::? COLUMBUS WATERED HERE In August 1492, the crews of Columbus expeditionary ships Santa Maria, Pinta and Nifia took enough water from this well in Palos Spain to last until they reached the New World Now, 475 years later, the well is still in use, but as a tourist attraction. Several Fluor employees and their families toured this part of Spain during 1967. Why not? They were living there as part of the team building a refinery for Rio Gulf de Petroleos at La Rabida, the site from which Columbus actually sailed. The Rio Gulf project is just one of some thirty foreign jobs currently under way by Fluor. Fluor s principal engineering centers are located in the United States and Europe. Almost every plant Fluor builds is engineered in one of four support facilities ... Los Angeles, Hous ton, London or Haarlem, Holland. But an en gineer who starts at one of these offices may eventually end up at a foreign jobsite ( if he chooses to do so) Right now there are openings in Los Angeles and Houston for Chemical Engineers with a B.S. degree or higher. Areas of specialty include process design, process development computer and project engineering Why not join a company wi th an international flavor and with international opportunities? For more details write our college recruiters, Frank Leach in Los Angeles or Ed Hines in Houston. THE FLUOR CORPORATION LTD 136 ENGINEERS & CONSTRUCTORS 2 500 South Atlantic Boulevard, Los Angeles Californi a 900 22 3137 Old Spanish Trail Houston Texas 77 0 2 1 AN EQUAL OPPORTUNITY EMPLOYER CHEMICAL ENGINEERING EDUCATION


chart a nd calc ul ation of dewpoints a nd bubble points using R aou lt 's l aw-top i cs common to practically a ll initial chem i cal eng in eering cour ses are not considered. Undoubtedl y, many mechanical engineer s re viewing this book wou l d find that some of their favorite topics have been omitted or treated with brevity and, conversely, some topics h ave been covered more extensively than is usually the case. The book is we ll written a n d the level of mathematics-rnme partial d iff erent i a l equations are u sed s uch that the second year, or certain l y the first semester third year, st ud ent sho ul d h ave no trouble. If a student c a nnot l earn the the principles of thermodynamics from this book, i t should certain l y not be due to the mathematics u sed Each chapter i s conc lud ed wit h a numb er of problems which appear to offer the user a rea esonable cho i ce; i. e some difficult o n es a nd som 3 n ot so difficult. Apparently, the prob l ems were se l ected so a s li de ru l e i s the only type of com puter necessary The usage of this book by chemical eng in eers depends upon how our program s deve l op over the next few years If we move to more common core courses-and thermodynamics is one of the prime areas where such movement is possible-this book "Engi neerin g Thermodynamics," s houl d be serious l y cons i dered for use. J ames H. Weber University of Nebraska ti b a problems for teachers I Th e following solutions to th er mody namics p r obl e ms p ublish e d in GEE Spring q u art er pp 9 5 -96, 1968, we r e p re par e d by Prof ess o r s R K. Ir e y and J H. Pohl at th e Univ er sity of Flo r ida. W e contin ue to so l i c it qu e stio n s on s u bj ec ts of g ener al e n gin eer ing o r sci e ntifi c i n t ere st to b e p re s e nt e d i n this d e pa r tm en t. 1. (a) C o nsid e r u as u( s,x ; ) ctu = (au.\. cts + '(!~ ) -~xi asJx. 4-;r 's,x, B y anal ogy with II du = Tds L, F'j ,dxj ( au. j=cdu. as) = T and y) = -Fj (N + l x, "i s,xi. (b) The Maxw e lf re l at 1 oris are SUMMER, 1968 e qs ) (c ) i ) N + l fo r a to tal of 4(N + l) e qs. 3 N(N + l) ii )..:....-~ for a t ot al of 2N(N + l) e q s iii ) Tak e t h e d e rivativ e o f "\f q and s ub s titu te du in to t h e e quation 2 (a) ct 'P q = s dT t dxj 1' C o n s id er th e t o tal d e rivativ e of 'V q = "'f q(T x t.) i = l N. d ~ q = (ffi dT + t(~)-~xj X 1 j= OIC.J T,Xi, thu s {~l :c s and (~) : -F;. x, x, r,t, S in ce d:z"o/. dT.} Xj dK; IT w e have /tJFj' ~.rj i, \()xJT,X i Consid e r s = s(T it) ands = s(T,F\). Then r~ ,., d) ds = mx. dT + ,l. ~; -gx; and J=I I T,. (i) ds = ~'\ dT + t (i1) .dFi \lJTh, JI ,, r,,, (ii) c -,. = (~\ = T t_a,).. and ., c)T 'J; \"R ..-, C 1~ = (-:;.);_ = T (~>t. (iii) Us e th e Ma x w e ll relations, ~) (i!J f.) ( Js \ --(~) = n... A~D ofJ.r;.c)T F I 11.,J'j 1 J and th e re lati o ns (iii) in (i) and (ii) Th e n s e t th e r i g h t of (ii) e qual t o th e ri g ht of (i) ~.-ci: r[t(~4 1;: ~i +,&,(f,!),. i. ~'} ,, ,, 1 I f ~ i s c on s tant .i Jt-,, (dx;) c .. c .. = T Z ('f#k _. .' 1'f~"' 1'. )=I X,,JCJ F,:.,Ff I f ti i s co n st ant t h e r e sult is th e s am e (b) Fr o m (i) ab ove ds = l~)J.T + f (()F1) .. .d.x. \T ,=, clT x., x. 1 J F ro m t h e exac tn ess of thi s equation foC;, ~ T(iBJ lc3 x .. ara. .. I ,X.L 1-,,4 H o ld T co n st ant in t his e quation and in teg rat e w ith re sp ec t t o all x ;. Th e l owe r limi t i s a re f e r e nce value T h e u p p e r limit i s variabl e I ex; ci7 T t (: (~;i). d x j 1 Xj X;.,XJ 137


would you like to write ''The Formation of Perhydrophenalenes and Polyalkyladamantanes by lsomerization of Tricyclic Perhydroaromatics?'' How's that again? Well, never mind -Bob Warren, Ed Janoski, and Abe Schneider already wrote it. They're chemists in Sun Oil Company's Re search and Development Department. Their paper is just one of many re sulting from imaginative and origi nal basic research conducted at Sun Oil. Maybe basic research and technical papers aren't yo ur cup of tea. But isn't the kind of company that in vests in and encourages such projects the kind of company you'd like to work for? Especially when the company does things like pioneer the $235 million 138 Athabasca oil sands project in North ein Alberta to multiply the world's petroleum resources; plan a new $125 million processing facility in Puerto Rico; expand the Toledo Refinery to the tune of $50 million; sponsor the "Sunoco Special" and the racing team of Roger Penske and Mark Donohue in big le ague sports car racing to competition-prove and improve Sun oco products for the public; pursue a continuing program for air and water pollution control; beautify Sunoco service stations everywhere Sunoco is geared for growth. We need men and women to grow with us and build a future. We have openings in Exploration Production, Manufacturing, Research, Engineer ing, Sales, Accounting, Economics, and Computer Operation. Locations Philadelphia, Toledo and Dallas areas. You may write us for an appoint ment, write for our book "Sunoco Career Opportunities Guide," or con tact your College Placement Director to see Sun s representative when on campus. SUN OIL COMPANY, Indus trial Relations Dept. C D, 1608 Wal nut Street, Philadelphia, Pa. 19103 or P. O. Box 2880, Dallas, Texas 75221. An Equal Opportunity Employ e r M /F CHEMICAL ENGINEERING EDUCATION


[jft?l views and opinions THERMODYNAMICS: DEA TH AND TRANSFIGURATION JAMES L. THRONE Ohio University Ath ens Ohio 45 70 1 In a recent article 1 I criticized vehemently present approaches to the teaching of thermo dynamics. In particular, I argued that thermo dynamics at present is based on mysticism and magic when dealing with the fundamental con cepts such as temperature, energy, and entropy. I argued that what was needed was a rational approach to the development of concepts and their application to chemical engineering and that, for the non-thermodynamicist, in particular, thermodynamics should be viewed as a hand maiden to the major chemical engineering areas such as kinetic s, process design and control, and transport mechanics. In this paper, then, I offer a program which attempts to prepare the graduate engineer for a career in which thermodynamics plays an im portant, but not dominant, role. While this pro gram also has limitation, I should hasten to point out that it has been used successfully at Ohio University on a first-semester graduate level for some time. Statistical or Mechanical Approach? As I pointed out in the earlier paper, I con sider that the fundamental concepts of thermo dynamics are three in number : 1. The concept of temperature 2. The concept of energy 3. The concept of entropy Traditionally, there are two major ways of intro ducing these concepts: 1. Th e intuitive approach, somet im es referre d to as a phenomenological approach, in which, for exa mple the co nc ept of temperature i s regarded as a primitive con cept, lik e force and displacement, and therefore, not re quiring definition, mer e ly illustration. 2. The statistical approach, in which it is necessary to identify a constrai nt in the system of d esc ribing equations ,:, A bio grap hy of Dr. Throne is available in CEE 2 92, 1968 SUMMER, 1968 with one of the co n cepts. The describing eq uations may deal with e n ergy in kinetic form ( classical approach), or quantum form, or even level of information form (Tribus). As I stated earlier, probably the only time the statistical approach is applied in traditional grad uate level chemical engineering first courses is in shoring up otherwise weak and faltering develop ments of the concept of entropy. It is apparent that if the proper approach to the development of the concept of entropy is employed, no shoring up is needed and, hence introduction of statistical concepts into a first course is not needed Traditionally the intuitive approach to chemi cal engineering thermodynamics has been "mole culeless mechanical thermodynamics," with em phasis on steady-state operations of system con taining continua of material. To say that this ap proach represents a crazy-quilt of sterile applica tions of sound principles of mathematics and clas sical physics and empirical rules-of-thumb so typical of chemical engineering in the thirties would undoubtedly insult many so-called chemical engineering thermodynamicists. In this program, I attempt to establish a firm, rational basis for the determination of a working program (no pun intended) I emphasize establishment of rigorous axioms on which we can evaluate the empirical concepts presently in vogue in the literature. 2 Undoubtedly, I cannot hope to pre scribe a single remedy that will cure the multiple ills plaguing authors of articles and textbooks in one, introductory course. It is my primary goal to make the average graduate student aware of the maladies, so that he can intelligently evaluate work in his chosen field of endeavor. Our Program: Goals and Gaols We begin the course by reviewing the funda mental laws of thermodynamics as primitive con cepts, requiring no definition. We then construct concepts total and path differentiation from a mathematical viewpoint. Concepts such as work ,:'The texts we have been using, along with the support ing reference material, are listed in Table 1. 139


introduced in metric form as being the result of relationships between generalized forces and differential displacements.** The close relation ship between fluid mechanical systems and ther modynamic systems is then discussed, and the genera lized concepts of enthalpy and heat capa cities (in terms of generalized forces and dis placements) are developed, with speci fic examples in linear extension, surface extensio n and pres sure-volume The theorems of Caratheodory, Pfaff, inaccessible states, and mathematical de velopment of constitutive equations for entropy, reversible heat and temperature are developed. Shaw's method of Jacobian of Transformation and the development of Maxwell's equations are presented, with extension of Shaw's method to multi-component systems. The se equations are then applied to the generation of equat ion such as the Gibbs-Duhem Equation. Partial molar properties, multicomponent sys tems, and the natural appearance of the chemical potential are presented. With special emphasis on gases, rules for the development and evaluation of constituitive equations are presented, along with fugacity and perfect mixtures of perfect and nonideal gases. It is emphasized that fugacit y is the true thermodynamic pressure. The role a-nd limitation of chemical potential, the phase rule, and degrees of freedom are then developed. We then consider first and higher order phase transitions, developments of Clapeyron and Er henfe st equations from direct integration of Max well's equations and from L'Hopital's rule, and their physical implications in s ingle component and multicomponent systems We then expend considerable effort in apply ing the Gibbs-Duhem equation to the selection of constitutive relationships between partial pres s ure composition and temperature, emphasizing Raoult' s law of ideal systems, Henry's law of equations. It is important to note here that we emphasize the approximate empirical nature of these constitutive equations; we do not let these equations live by themselves, as it were. Application of constitutive equations to engi neering systems such as heat of mixing and volume change, depression of freezing point, os**It is important to not e that standard approaches to work utilize affine coordinates. While developments of concepts in affine coordinates are satisfactory for explicit problem-solving, development of general concepts, par ticularly when thermodynamics is used in transport me chanics, must be made in metric coordinates. 3 4 140 TABLE I. Books Used in First Co ur se in Graduate Thermodynamics Required Texts: 1. Denbigh, K. G. The Principles of Chemical Equi librium, 2nd Ed., Cambridge 1966. 2. Tribus, M., Thermostatics and Thermodynamics, D. Van Nostrand, Co., 1961. Recommended Reading Reference: 1. Zemansky, M .W. Heat and Thermodynamics, 4th Ed., McGraw-Hill, 1957. 2. Guggenheim, E. A., Thermodynamics, 3rd Ed., North Holland Publishing, 1957. 3. Dodge, B. F., Chemical Engineering Thermodynam ics, McGraw-Hill, 1944. 4. Smith, J. M., Introduction to Chemical Engineering Thermodynamics, McGraw-Hill, 1949. 5. Cou ll, J., and Stuart, E. B., Equilibrium Thermo dynamics, Wiley, 1964. 6. Lewis, G. N. and Randall, M., Pitzer, K. S. and Brewer, L., Thermodynamics, 2nd Ed., McGraw Hill, 1961. 7. Bosnjakovic, F., Technical Thermodynamics, Holt, Rinehart and Winston, 1965. 8. Gibbs, J. W., The Scientific Papers of., Volume 1, Thermodynamics, Dover, 1961. 9. Weber, H. C., and Meissner, H. P., Thermodynamics for Chemical Engineers, 2nd Ed., Wiley, 1957. 10. Van Wylen, G. J., Thermodynamics, Wiley, 1959. 11. Fong, P., Foundations of Thermodynamics, Oxford, 1961. 12. Bridgman, P. W. The Nature of Thermodynamics, Harper, 1961. 13. Fermi, E., Thermodynamics, Dover, 1956. motic pressure, and such, follow. Thermodynamic consistency tests and their relative reliability are stressed. Finally, we introduce concepts of thermo dynamics of the steady state, dealing with the concept of entropy production and the phenome nological coupling tensor between fluxes and forces. We discuss "Curie's theorem" and its logical basis as a fundamental theorem of tensor calculus, 6 and the faults of the present state of irreversible thermodynamics (linear "Onsager i st" approach) and it s future role in thermody namics. We conclude by examining real engi neering examples of steady-state thermodynamics in coupled systems such as heat-mass transfer, kinetics-fluid flow, and fuel cell technology. To implement the development of the course, I present, in flow diagram form, apparent inter actions in the major areas of thermodynamics. This diagram is s hown below. While I do not pretend to imply that this flow diagram is wholly correct or complete, it does serve graphically to illustrate chemical engineering thermodynamics. CHEMICAL ENGINEERING EDUCATION


T H E R M O D Y N A M I C S N o m e n c l a tur e T e mp e r a tur e C o nc e t En e r gy C o n c e p t T h e rm o d y n a mi c C o nsist e ncy T e s t s Irr ev e rsibl e Th e rm o dyn a mi c On sa g e r I Curi e Non-Ons a g e Thermodynamics: Who Cares? F i r st L a w P h ys i cal Pr o p e rti es I so S y s t e ms Cl os e d Sys t e m F low Sys t em B e rn o uilli Equ a ti o ns R e v e r sib il it H ea t E n g i nes Fr e e E n e r gy First it is important that the above program makes no mention of cycles, refrigerators, en gines, TS diagrams, Mollier Charts, compressi bility curves, etc. This is done deliberately. Em phasis is placed on understanding of underlying mathematical, mechanical, chemical, and physical principles. Interrelationships between thermo dynamics, kinetics, and mechanics are continu ally emphasized and illustrated through engineer ing examples Why? It is my belief that rational understanding of the role of thermodynamics in the overall concept of chemical engineering comes, not from the ability of the student to calculate coefficients in equation s of state-given critical properties, b u t from his ability to understand the usefulness and limitations of the present concepts of thermodynamics. It is his ability to intelli g ently and rationally question existing practice s, n o t blindly calculate and manipulate empirical equations, that will make him a valuable member of the chemical engineering community Conclusion Classical thermodynamicists with their minds intently focussed on new P-V-T correlations or n th degree refinement in the current Mollier dia gram for steam or ammonia, are being by-passed and circumvented by people who n ee d to answer thermodynamic questions dealing with biological SUMMER, 1968 C o ns t ituti ve E qu at i ons ( Eq u a ti o n s of S t a t e ) E n t r o p y C onc e p t Ph ase Rul e Thi r d L a w Cl a p ey r on Ehr e nfes t Many Ph a s e Stat i stical Th e rm o dyn a mic Entr o p y as a M e a sur e of Dis o rd e r P a rtiti o nin g o i : En e r g y M o l ec ul a r Int e racti o ns metabolism, kindey or fuel cell operation, kinetic fluid flow interaction, cyclic operation of non ideal transport systems thermomechanical foun dations of nonlinear visocelastic media, nonFick ian diffusion, sewage disposal and anti-pollution systems We cannot afford to ignore the challenge of modern chemical engineering by offering ma terial that was designed to support chemical en gineering Edisonianism of the 30's. It is my opinion, then, that Dr. Bates' ap proach ("First Aid to Ailing Thermodynamics") will eventually lead to the death of thermody namics as it is traditionally taught To this, I s ay, good riddance For, like the Phoenix of Egyptian mythology, from its ashes shall rise anew a thermodynamics founded on the rational principles of Gibbsian mechanics. REFERENCES 1. Throne, J. L., C h em. Eng. Ed 1 70-71, (1966). 2. Giles, R., "Mathematical Foundations of Thermo dynamic s ," The Macmillan Co New York, 1964. 3 Throne, J L., "Applications of Ten s or Calculus in C hemical Engineering," McGraw-Hill Book Co New York, to be published. 4. Brillouin, L "Tensors in Mechanic s and Elastic ity," Academic Press, New York, 1964. 5. Tribus, M., Thermo s tatics and Thermodynamics," D Van Nostrand Co Inc., New York. 6. Fitts, D. D "Non e quilibrium Th e rmodynamics: A Phenom e nological Theory of Irrever s ibl e Processes in Fluid Sy s tems," McGraw-Hill Book Co ., New York 1962 141


WHERE ARE THE ENGINEERS?* T. B. METCALFE University of Southwestern Lo uisiana Lafayette, La. In spite of our usual confident reliance upon the balance between supply and demand, the re lationship between the output of our engineering colleges and the need for practicing engineers does not seem to be following the rule. All of the factors which we would expect to contribute to a great demand for engineers seem to be present. Engineering employment has reached new highs and graduating students of engineering colleges are offered a half dozen or more jobs upon gradu ation. There are complaints from many potential employers that they are unable to fill their quotas. Indeed, the meteoric rise in the employment of technicians in the engineering field, while largely due to a heretofore unfilled need for this kind of service, is also greatly influenced by the unavail ability of young engineers. Incentives are certainly present in the current situation. The satisfaction to the individual of making a contribution to technical advancement has never been greater and recognition on the part of the general public of the contribution of engineers is well established. Salaries and other remuneration for engineers are at new peaks, higher than those for most other career profes sionals, at least in the years immediately follow ing graduation Engineering starting salaries are increasing and at a rate higher than the rate of increase for other professionals. Thus, the high and unsatisfied demand seems to have created the expected result of increased incentives for the study of engineering. Wh y then, should there be any shortage of engineers? Many contend that there is no shortage, or rather, they cite statistics to show that there is a consis tent increase in the number who choose to study engineering. They conclude that we should not fear a shortage as long as the trends continue A comprehensive study published in the J anu ary, 1966 Jou rna l of the Am erican Soci ety for En gineering Education, by the ECAC ( committee for analysis of engineering enrollment) presented data in total engineering enrollments between 1949 and 1962. They note the large contribution of veterans under the government educational ,:,Prese nted to th e Spring Meeting of the Gulf-South west Se c tion ASEE, Co llege Station, T exas 21 March 1968. 142 Dr. T. B. Metcalfe is Head of the Department of C hemi ca l Engineering at the University of Southwestern Louisiana. His background and exper i ence includes de grees from Georgia Institute of Technology and the University of T exas ; faculty positions at West Virginia Institute of T ec hnology a nd the University of Hou ston; and professional exper ience with Shell Oil Company, U. S. Naval Reserve (WW II) and Dow Chem ical Com pany. program s who swelled the enrollment in the years immediatel y following World War II and a lso during 1954-56 s ubsequent to the Kore a n milit ary involvement This analysis illustrated that if the enrollment of veterans was not included in the totals, the fluctuations in enrollment of engineer ing students are much reduced and a definite and consistent trend was evident. It was concluded that the apparent appreciation in engineering enrollments of about 13,500 each year ( during the entire thirteen-year period covered) mi g ht be con fidently extrapolated for another few years It becomes the responsibility of engineering educators to perceive the changes in trends, and to exert the necessary influence to reverse unde sirable ones. Two conditions which contribute markedly to the rate of output of engineers are (1) the number of entering college students choosing engineering as a career and (2) the re tention of tho se students through grad uation from engineering college. The desirability of, and the incentive to, study engineering must be com municated to the high sc hool and junior high school public (student, parent and counselor). Depending upon the success of this contact, more ( or fewer) students may choose the profession of engineering The statistics upon which Figure 1 is based illustrate that in the years 1949 to 1952 there was indeed a marked decrease in the total enrollment in universities in our country. This was undoubtedly due both to the then declining number of World War II veterans enrolling and the decrease in the enrollment of younger men CHEMICAL ENGINEERING EDUCATION


,. 2.6 i //; 4' .., / 'f_,.'f I \ / / Engtneer\ng P eroeiiugcof T otal Co ll e&e Enrollmem b y ye:ir r t ou u: TH E II D S \11 E l3U! ER II G EIIR O LUI E:rt 9 1 ,-r"' l l t 5 B 1 ,-,t-c-, r, .,, ,,.. ~ / ,, ,, ._/-,/'\ '" I -."-,, "" \,,,/ /' ; \ / I 250 : ~r\ ... I ,.' p : /0.o : \ .. 0 I j \ '-...,.,_M 67 4 5 5 }2} C ........... C I ~o \ ", --. ........_,....._c_...c:-c...._,_,_, 5 27 0 \ ./ I \i T 01a l Enrn llm cnls B y Y ea r T Toul Co ll ege En ro llment E T ot al Engi nee rin g Enrol l m e nt 200 1 0 150 \ \ '-o \ E nroll me ntTr i! nda (eee Figure I ) J 950 52 5 4 56 51 60 62 64 66 students due to the Korean involvement. Subse quent to that period, however from 1952 to the present no disregard of veterans or any other group is necessar y to allow the recognition of a consistent, rapidly upward trend in the total en rollment of college men students in our colleges and universities. Comparison of trends in the total college enrollment and in engineering enroll ments show the same fluctuations with variations in the trend for the most part occurring at the same times. However, the variations are greater in the case of the engineering enrollment and the ECAC prediction of an appreciation of 13,500 each year has been exceeded considerably each of the last 4 years, with an ever increasing rate. A significant difference in total enrollment and engi neering enrollment is the occurrence of a peak in engineering enrollment in 1957 and a subse quent four-year decline in that enrollment, during which four years, the rise in total college enroll ment s lowed only s lightly. In 1961, while total college enrollments con tinued to climb ( due, no doubt, to the coming of college age of the unusually large number of post war babies), engineering enrollments began again to rise. Each year s ince, the rise has been at a larger rate Since our analysis of incentives has been di s cussed earlier in terms of comparison to other professions and careers, it is logical to evaluate the trend s in engineering enrollments in terms of comparison to the overall enrollment The sig nificance of the 1957 reversal in the upward trend of engineering enrollment s is clarified b y the curve of Figure 2 which represents the fraction SUMMER, 1968 of total enrollment represented by engineers. The percentage of en g ineers in the total college popu lation rached a peak in 1957 after having risen consistently during the po s t-Korean period. Sub se quent to 1957 this percentage has persistently dropped, until at the present time, it is little more than half of the 1957 value of nearly 15 per cent. This is taken to be a clear indication of a ser ious and dangerous lack of rapport with the po tential college student on the part of engineering educators There is small comfort in the existence of an upward trend in engineering enrollments in view of the fact that the shortage of engineers is not being relieved and the increase in engineering enrollments falls so far short of the increase in total college enrollment. To be most meaningful the s tatistics must be expressed in terms of the various disciplines. The classical disciplines of Chemical, Civil, Electrical, and Mechanical Engineering account for about half of all engineering students Industrial and Petroleum Engineering are the only other disci plines with appreciable fractions of total engi neerin g enrollments In 1952 there were in ECPD accredited departments 3,822 entering freshmen students who wished to study Chemical Engineering, and in 1962, at the end of the re portin g b y ASEE, there were 3,862, an only s li g htl y larger number (see Figure 3). Reflecting the difference in total engineering enrollments at the sta rt and at the end of this period, the nearly equal numbers of students in Chemical Engineer ing represented 8 per cent ( of total engineering enrollment) in 1952 and hardly more than 7 per cent in 1962. Thus while maintaining the num143


ber of its students, Chemical Engineering has de clined slightly in public acceptance as an engi neering discipline. By comparison, and considering the absolute numbers for the beginning and end of the ten year span as well as the trends, it is evident from the curves (Figure 3) that enrollments in Civil Engineering have dropped slightly, while their percentage has dropped from 11 to 9 per cent. There has been a more marked drop in the number of Mechanical Engineers and their percentage is down from 17 to 12 per cent of the total. Both Industrial and Petroleum Engi neering disciplines have shown large decreases in the number of students and in their fraction of the total engineering enrollment during this per iod. Only Electrical Engineering has shown a marked increase in number of students This has resulted in an increase in its fraction of the total from 16 to 20 per cent. It becomes evident that the classical disci plines are not generally increasing in spite of the marked increase in total engineering enrollments. The increase is distributed among the newer dis ciplines, each representing smaller numbers of engineering students. These newer disciplines, while offshoots of the classical disciplines, have completely divorced themselves from the parent departments except in the case of Electrical Engi neering. The growth of the Electrical Engineer ing discipline can be attributed to their absorp tion of a number of new interests such as Elec tronics and Communications. This action on the part of Electrical Engineers to retain within a single discipline the widely varied interests which represent different appli cations of the same engineering principles is con sidered a wise one and one which should be emu lated by other disciplines. New branches of engi neering often are created because of the recog nition on the part of their practitioners that their interests stem from more than one of the classical disciplines, and therefore, they consider them selves separate from both. Preferable to this proliferation of engineering disciplines would be an interdisciplinary interest on the part of the parent disciplines. This would tend to unify and strengthen engineering instead of weakening it as does the current practice of splintering. Having determined the total enrollments as the potential with which we have to work, it is now interesting to observe the retention of this group of students. Over a ten-year period, the average retention for Chemical Engineering 144 "'"'. "\~ "" '"'"'" : 6 (Figure 4) shows that after the first year the number of students enrolled for their second year is only 90 per cent, and those persisting to the third year only 73 per cent of the entering fresh men. Sixty-seven per cent persisted to their fourth year, and finally 61 per cent were gradu ated with the B S. degree after four years. In Civil Engineering, 5 per cent were lost in the first year, with 95 per cent remaining; 90 per cent remained for their third year and a slight ap preciation then resulted in the fourth year class of 92 per cent of their entering freshmen. At the end of four years, 80 per cent of the entering Civil Engineering classes were gr.aduated. Mechanical and Electrical Engineering appreciated 6 and 7 per cent, respectively, in the second year after which their number declined so than Mechanical Engineering Departments graduated 85 per cent of their entering freshmen and Electrical Engi neering, 83 per cent. Thus, among these disci plines only Chemical Engineering shows no in crease at any level during the college career. Rather, the number dropping out of Chemical En gineering during each year is significant. We can conclude that engineering educators must face up to the fact of a declining acceptance of engineering as a course of study by college students. Instead of fatalistic acceptance, we must strive to reverse this trend and provide greater numbers of graduated professionals by stronger recruitment of high school and junior college graduates and by greater retention of entering students who choose an engineering course of study. CHEMICAL ENGINEERING EDUCATION


MARATHO N: DYNAMIC PROGRESS Marathon Oil Company was founded in Find lay, Ohio in 1887; however its ultramodern Denver Research Center is located at the foot hills of the Rockies. The company is a producer transporter, refiner and marketer of crude oil and petroleum products on five continents throughout the world. The Denver Research Center was established to make discovery of new petroleum reserves more economical, to help recover a larger percentage of oil in present fields, to develop more profitable refining and chemical processes, and to develop new products. Marathon employs more than 8,000 persons at its offices around the world including its head quarters in Findlay. There are over 300 em ployees at the Denver Research Center of which more than half are scientists and engineers. CHEMICAL ENGINEERING AT MARATHON Using engineering research to determine ways to recover more of the oil from known deposits is an important part of the work at the Research Center. It includes project s aimed at stimulating wells so they will produce more oil; in s itu com bustion; and fluid injection processe s, such as miscible displacement, which are more efficient than conventional techniques where gas or water are used to drive oil to a production well. Reservoir mechanics comprise another signifi cant part of the engineering work at the Denver Research Center. The transient behavior of oil reservoirs and the flow of fluids through porous media are important phases of this work. Mathe matical models, which simulate reservoir behav ior provide insight into future behavior of oil bearing reservoirs. Chemical engineers are also engaged in the pilot plant study of existing refinery and chemical processes as well as in the evaluation and devel opment of new processes and new chemicals. Projects are underway, for example, on petro chemical processes to make monomers and other basic components for polymers. At Marathon's Research Center, qualifid en gineers are provided with both the challenge and incentive in supplying answers to these problems. Your further inquiry is invited. Mr. L. Miles Personnel Supervisor Dept. CE-1, P. 0. Box 269 Littleton, Colorado 80120 AN EQUAL OPPORTUNITY EMPLOYER MAR A T HO N OIL COM PA N Y DENVER RESEARCH CENTER LITTLETON, COLORADO


Professor, What Do You Think? Process Design Technical Sales Refinery Engineering Research With all the opportunities available today you probably often hear this question fr o m your students. You can be a major factor in his career If you find yourself in this situation wh y not consider an industry that can offer a fu ll range of Chemical Engineering Oilfield Production Plant Design Development Technical Service assignments and advancement opportunities? Standard Oil Company of California has cha ll en g in g assignments in just about any area that would interest Chemical Engineers These initial assignments will test their ability and can lead to advancement in many areas Should you or any of your stud e nt s wish addit io nal information on our indu s try or C o mpany writ e t o: Mr. Robert E Rodman C oo r dinat o r Pr o f ess i o n a l Empl oy m e n t Stand a rd Oil C o mp a n y of Ca li fo rni a 225 Bu s h Str eet S a n Fr a n cisco C a l ifo rn ia 94 1 20 Standard Oil Company of California An Equal Opportunity Employer

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