Chemical engineering education ( Journal Site )

Material Information

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


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:
oclc - 01151209
lccn - 70013732
issn - 0009-2479
lcc - TP165 .C18
ddc - 660/.2/071
System ID:

Full Text


M. RUKW K AN 3. A A 3 AD




INDUSTRIAL SPONSORS: T4h owiow compauea donated
e, fo,4 U.e L dppo.t o, CHEMICAL ENGINEERING EDUCATION dWing 1975:



DEPARTMENTAL SPONSORS: The /loawi 113 depatmeos
cam la4ded lo tMe d appold o4 CHEMICAL ENGINEERING EDUCATION in 1975
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TO OUR READERS: If your department is not a contributor, please ask your
department chairman to write R. B. Bennett, Business Manager, CEE, Depart-
ment of Chemical Engineering, University of Florida, Gainesville, Fla. 32611.

Department of Chemical Engineering
University of Florida
Gainesville, Florida 32611

Editor: Ray Fahien
Associate Editor: Mack Tyner
Business Manager: R. B. Bennett
(904) 392-0881

Editorial and Business Assistant: Bonnie Neelands
(904) 392-0861
Publications Board and Regional
Advertising Representatives:
Homer F. Johnson
University of Tennessee
Vincent W. Uhl
University of Virginia
CENTRAL: Leslie E. Lahti
University of Toledo
Camden A. Coberly
University of Wisconsin
WEST: William H. Corcoran
California Institute of Technology
George F. Meenaghan
Texas Tech University
University of Houston
James R. Couper
University of Arkansas
EAST: G. Michael Howard
University of Connecticut
Leon Lapidus
Princeton University
Thomas W. Weber
State University of New York
NORTH: J. J. Martin
University of Michigan
Edward B. Stuart
University of Pittsburgh
NORTHWEST: R. W. Moulton
University of Washington
Charles E. Wicks
Oregon State University
D. R. Coughanowr
Drexel University
Stuart W. Churchill
University of Pennsylvania
University of California, Santa Barbara


Chemical Engineering Education

62 The Texaco-Yale Student Consulting
W. Delgass and C. Ware
88 Analog Simulation of Sampled-Data
Control Systems
M. Rutkowski and P. Deshpande

76 The Educator
Cheddy Sliepcevich of U. of Oklahoma
56 Departments of Chemical Engineering
Newark College of Engineering
52 Views and Opinions
Too Much ChE Research and Teaching
Is Dull . Dull . Dull
H. McGee
66 Classroom
Diamonds Are a Thermodynamicist's
Best Friend
R. Nelson
84 Curriculum
Identity, Breadth, Depth in a Cooperative
E. Rhodes
68 Laboratory
Prediction of Temperature and Oxygen
Distributions During Aerobic Microbial
S. Finger, T. Regan, T. Cadman and
R. Hatch
80 Tubular Flow of Pseudoplastic Fluids
C. Weinberger

51 Division Activities
79 News
50 Letters
99 Book Review

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 DeLeon Springs, Florida. Correspondence
regarding editorial matter, circulation and changes of address should be addressed
to the Editor at Gainesville, Florida 32611. 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., P. 0. Box 877,
DeLeon Springs, Florida 32028. Subscription rate U.S., Canada, and Mexico is $10 per
year, $6 per year mailed to members of AIChE and of the ChE Division of ASEE,
and $4 per year to ChE faculty in bulk mailing. Write for prices on individual
back copies. Copyright 1975. Chemical Engineering Division of American Society
for Engineering Education, Ray Fahien, Editor. The statements and opinions
expressed in this periodical are those of the writers and not necessarily those of the
ChE Division of the ASEE which body assumes no responsibility for them. Defective
copies replaced if notified within 120 days.
The International Organization for Standarization has assigned the code US ISSN
0009-2479 for the identification of this periodical.


The American Society for Engineering Education ex-
pects to begin publishing an annual Transactions in Engi-
neering Education, beginning in December, 1975. Its pur-
pose is to provide a medium for the publication of high
quality articles that are of significance and long-lasting
interest to the engineering education community. The
articles may pertain to any aspect of engineering educa-
tion: educational research, learning theory, teaching meth-
ods, review of on-going projects, administration, organiza-
tion, guidance, finance, technical research as it pertains to
education, and other areas.
The articles may be of any length appropriate to the
subject, but on the average are expected to be about 2,400
words. All articles will be carefully reviewed by referees
expert in engineering, engineering education, and ap-
propriate allied disciplines. Criteria for selection will be
based on the significance of the subject to engineering edu-
cation, quality of the treatment, and long-lasting value of
the article.
Papers to be submitted for the first annual issue should
be sent, in five copies, by May 15, 1975 to me at the follow-
ing address: Bureau of Engineering Teaching, ECJ 10.322,
University of Texas, Austin, Texas 70712
Dr. Billy V. Koen


This is an announcement of our summer program on
"New Developments in Modeling, Simulation and Optimiza-
tion of Chemical Processes" to be held at Massachusetts
Institute of Technology on July 28 through August 6, 1975.
This special summer program will present basic principles
and techniques for computer-aided design and control of
industrial-scale chemical processes. Topics to be covered
include steady-state process simulation, process optimiza-
tion, dynamic modeling and simulation of chemical process
synthesis, and comprehensive problem-oriented computing
systems for chemical process design. For further informa-
tion, please contact: Director of the Summer Session,
M.I.T., Room E19-356, Cambridge, Mass. 02139.
Lawrence B. Evans

For the third consecutive summer, a short course
entitled, "Fundamentals and Applications of Minicom-
puters" will be offered by the Center for Industrial and
Institutional Development at the University of New
Hampshire. This course is designed for the engineering/
manager who must have sufficient awareness of the ap-
plications of minicomputers to enable him to specify and
utilize them in his operation. Participants with and with-
out computer experience will benefit from this integrated

treatment of minicomputer concepts. For further infor-
mation write: CIID, Kingsbury Hall, U. of New Hamp-
shire, Durham, New Hampshire.
Audrey Savage

The University of Michigan announces an engineering
short course this summer in "Applice Numerical
Methods to the solution of practical engineering prob-
lems and their implementation on digital computers. The
course will be held June 23-27, 1975. For additional in-
formation write U. of Michigan, Ann Arbor, Michigan.
Viola E. Miller
Here is a roster of our -1975 Summer Courses in Con-
tinuing Engineering Education. June 9-13: Perturbation
Techniques and Differential Equations, W. Sirignano;
Three-dimentional Descriptive Geometry and Computer
Graphics, Y. Hazony, S. Slaby; Digital Signal Processing,
K. Steiglitz. June 16-20: The Statistical Design of Engi-
neering Experimenta, J. Hunter; The Design and Analysis
of Railroad Tracks, A. Kerr; Modern Process Control, R.
Andres, E. Johnson; Advanced Modeling of Combustion
in Internal Combustion Engines, F. Bracco; Groundwater
Hydrology and Pollution, R. Cleary. June 23-27: Water
Pollution Science and Technology, R. Cleary; Prediction
for Production and the Arts of Charts, J. Hunter. July
7-11: The Numerical Solution of Ordinary Differential
Equations of Engineering Importance, L. Lapidus. July
14-18: Mathematical Methods of Engineering Analysis I,
A. Cakmak. July 21-25: Mathematical Methods of Engi-
neering Analysis II, A. Cakmak. August 4-8: Compiler
Design, J. Ullman, T. Szymanski; The Finite Element
Method in the Simulation of Contaminant Transport
Processes in Hydrologic Systems, G. Pinder, W. Gray.
August 18-22: The Finite Element Method in Surface
and Subsurface Hydrology, G. Pinder, W. Gray.
If there are any questions write: Summer Course
1975, Princeton University 08540.
Joyce W. Dean




operation with the CACHE (Computer Aides to Chemical
Engineering Education) committee, is initiating the
publication of proven computer-based homework problems
as a regular feature of this journal. Instructions for sub-
mission of problems appears on page 38 of the Winter
1975 CEE or can be obtained by writing Dr. Gary Powers,
Carnegie-Mellon University, Pittsburgh, Penn. 15213.


views and opinions



H. A. McGEE, JR.
Virginia Polytechnic Institute
and State University
Blacksburg, Virginia 24061

W E ARE LIVING IN ONE of the most excit-
ing, challenging, and potential-laden times
in the history of the profession of chemical
engineering. In response to these crucial times,
one would imagine that the academic depart-
ments of chemical engineering at the universities
of our land would be uproarious centers of fer-
ment and activity. All too frequently they are
not such centers however, for when judged by
what could be done, much of what actually does
occur in campus laboratories and classrooms can
only be described as dull . dull . dull. As-


!ring in particular, let us look at university
professors as a class. Certainly a central element
in the behavior of professors is academic tenure
--that phenomenon so incredulous to our in-
dustrial colleagues whereby a professor of
chemical engineering, or of any other discipline,
must be, not may be, granted absolute job security
for life. The tenured professor cannot be re-
moved, and certainly a developing professional
atrophy or incompetence are not viable grounds
for even questioning his status. Or, as my col-
leagues would say, rather he then becomes a
department head.
Our universities are also very special enclaves
that are in their own way extraordinarily pro-
vincial. This apartness from the world is dra-
matically evident in the distinctly Leftist position
of most professors on political and social ques-
tions. Leftist speakers who openly advocate even
murder and the violent overthrow of the govern-
ment receive the rapt attention of university

audiences, while mildly Rightist types are hooted
off of the lecture platform. In contrast to this far
liberal perspective on other peoples' problems,
professors are typically extreme conservatives-
far to the right of Barry Goldwater-in their
views of their department, or their discipline, or
their own personal affairs. The concept of tenure
is sacrosanct and no consideration of its possible
modification can be tolerated. Meaningful curricu-
lum revision is extraordinarily difficult, and
affirmative action is the only proper moral and
social perspective, until, of course, my department
is expected to add or is prohibited from releasing
a patently unqualified woman or black.
A third deterministic element in the profes-
sion of professoring is the commitment to re-
search and creative scholarship. There are, of
course, the scholarly and pedagogical arguments
of the importance of basic research, of the
importance of basic research, of the necessity of
a current faculty, and of insuring a vigorous and
intellectually stimulating environment. But

Henry A. McGee, Jr. is a scientist/engineer by education and by
experience. He is professor and head of the ChE department at
VPI & SU. His current research interest is the application of very
unusual high energy chemistry to the development of highpowered
chemically pumped lasers. He is active in AIChE and this essay is
abstracted from a popular invited talk he has given around the
country as an AIChE Tour Lecturer. His comments on teaching and
research are as a participant rather than as an observer. The critique,
"which is as much self-directed as otherwise, is meant to be good
natured, but with a sharp significance."


academic prestige and economic factors have also
played a non-trivial role. Anyone who, like the
physicists, can make a bang as enormous as that
of a thermonuclear explosion or who can other-
wise change the character of our national life,
just must be reckoned with, and this enchantment
has continued through the development of nuclear
power, the space program, the environmental and
ecology movement, and now the energy problem.
The broad economic implications of new high
technology industry that springs from good re-
search are also very compelling, and these are
perhaps most visible around Cambridge and Palo
Alto. Thus all universities now insist upon re-
search as well as teaching. To gain professional
esteem, a professor must be an able grantsman;
and thereby the evaluation of the worth of a
professor is performed only in part by his on-
campus peers and superiors. Rather it is the
granting agencies in Washington who significant-
ly determine the fate of the aspiring professor.
Enormous expansions in enrollments have
meant similar expansions in the numbers of adults
employed to instruct these young people. Hence
there are both many more professors than ever
before, more of them spend more time on "re-
search" than ever before, and the scientific litera-
ture is, not unexpectedly, growing as never before.
Not just in chemistry at Harvard and Wisconsin,
or in theoretical physics at Caltech, or in bio-
chemistry at Berkeley, but all institutions sub-
scribe to this doctrine that is now somewhat
tritely referred to as "publish or perish."

tional liberal wisdom, professors as a class
are also very egalitarian and very intense about
things like civil liberties and democratic due pro-
cess. Therefore the wisest decision on any ques-
tion is that resulting from discussion-seemingly
interminable discussion-and voting. This equali-
ty idea also means that the most innovative and
creative people are frequently neither sought for
faculty appointments nor do such people neces-
sarily find the idea of an academic career to be
inherently attractive. Few professors of music,
for example, would be happy with the idea of a
Burt Bacharach or a Leonard Bernstein as a pro-
fessional colleague. And as in all democratic
organizations, the purposes and goals of the uni-
versity or the department must then be defined in
such a way that all can contribute. Respectable

research must be defined in a way that the average
professor of rather ordinary abilities can extend
the scholarly frontiers and fill the scientific litera-
ture. In addition, and in complete harmony with
our egalitarian commitment, we divorce excel-
lence in a skill from learning about a skill, for
otherwise the gifted individual would be at an ad-
vantage. Our universities then often employ teach-
ers of engineering without especial regard to
whether they themselves are also good engineers.
Let's look at a few of the techniques used by
professors, certainly not overtly with devious in-

Why should we worry if nobody cares about our re-
sults. Yeah-it's scholarly, it's correct, it's publishable,
and besides we're tenured!
tent, but rather naturally and involuntarily, to
form and to shape the bounds of what we at the
universities know as respectable scholarship.1
For example, please realize that a professor
can devote his entire career to teaching and
scholarship, publishing many papers in learned
journals, giving talks at meetings of his profes-
sional society, being well recognized by his peers,
without ever once running the slightest risk of
being wrong about anything that he has ever
published or said. Not infinite wisdom, but rather
this requires only that one carefully structure
the kind of knowledge that he seeks. How can
one be wrong about p-V-T measurements? Or
vapor-liquid equilibria? Or pressure drop
measurements? The worst that could happen
would be technical problems of perhaps a poorly
calibrated thermometer. Thus rather than inven-
tive thinking, most professors tend to gather data,
and usually even that is in areas where the re-
sults will be unexceptional, where broader interest


is meager, and where one cannot possibly be in
error on other than some minor technical point.
Industry contributes in its own way to this
state of affairs, for clearly a company will only
support work at a university that is non-sensitive,
or that which will in no way compromise patent
positions, or that which is tedious and uninterest-
ing to the in-house research force. In short, in-
dustry supports only that academic work that is
technically located where the real action is not.
There are good reasons for this, but they are
reasons that we must carefully reconsider, because
change toward a more mutually beneficial sym-

Once only the brightest minds delved into
mathematical abstractions . but the democratic
idealism of most professors prohibits
any thought that perhaps theories
are best left to superior minds. With patience, a Taylor
Series expansion, and the aid of the computer anyone
can and does author a theory today.

biosis of industry and academe is essential. This
necessity for change has and will continue to
promote many thoughtful discussions, but let us
here not digress from our exploration, not of the
needed changes, but rather of the effect at the
universities of the now prevailing attitudes.


of experimental procedures and equipment.
Our scholarly publications tend to be recitations
of the technical or logical consequences of the ap-
plication of this or that method. Multi-valued
problems in which decisions hinge upon creative
insight or hypotheses or perhaps on just plain
hunches are shunned. Thus all knowledge becomes
forced to be like geometry or thermodynamics
wherein the answer to the problem may be logical-
ly deducted from the problem statement. The great
complexity and variety of scientific equipment is
of particular value in this pursuit of "proper
scholarship." We have System 370's, mass spectro-
meters, nmr machines, esr machines, ESCA ma-
chines, and the like that are sufficiently large, ex-
pensive, and complex to readily convince both
one's self and one's peers of the high scientific
merit of his work, when in reality the work is
frequently more commonplace than it is imagina-

tive. The jargon and the technical complexity can
then satisfactorily mask the unexceptional and
even trivial merit of the activity.
Although it is only a part of the human per-
sonality, professors insist upon submerging all
else in a single-minded pursuit of total objectivi-
ty, passion and emotion are shunned, and it is
essential that one be diligently neutral regarding
the outcome of his scholarship. Academe has al-
most lost the contrasting attitude that although
objectivity is essential, when it is all alone, it sure-
ly represents a severe truncation of real
knowledge in the real world applied to real prob-
The egalitarian commitment of academia has
also radically altered the concept of a theory. Once
only the brightest minds delved into mathematical
abstractions of the nature of reality. Einstein,
Schroedinger, and more recently the Bardeen,
Cooper, Schrieffer theory of superconductivity
and the rules on the reactivity of organic com-
pounds first proposed by Woodward and Hoffman
are examples of these rare and grand insights.
But the democratic idealism of most professors
prohibits any thought that perhaps theories are
best left to superior minds. With patience, a
Taylor Series expansion, a sort of crude pleasure
in number crunching, and the aid of the computer
anyone can and does author a theory today. And
the scientific literature is full of wonderfully com-
plex notations, and constructions, and perhaps
sometimes even mathematically elegant descrip-
tions of the commonplace.
To interpret these observations as anti-truth
or counter to the scientific method to which we all
pledge allegiance is to miss the point entirely.
Rather we wish to show how professors can easily
and inconspicuously and unknowingly mask their
lack of real scientific and engineering creativity
by their concentration on the analytical as opposed
to the synthetic aspects of any question. Thus the
nature or the shape or the kind of knowledge that
is being produced by faculty members is a strong
function of the personality traits of the professors
themselves. This circumstance is self perpetuat-
ing, for the exceptional student, who is by defini-
tion, the student that is analytically astute though
perhaps not aggressive or innovative, receives
maximum reinforcement and naturally emulates
his mentors. Just as naturally, he gravitates into
an academic career of his own-and the situation
(Continued on page 94.)


Some of the metals we mine

are more precious than gold.

An ounce of cold steel can do
wonders for a warm smile.
But it must be a very special
steel. Strong, yet ductile. Hard,
yet smooth.
It must not rust or stain.
And it must remain unchanged
through ice-cold sodas and red-
hot pizzas.
At Union Carbide we mine or
process the alloying metals that
make possible this special steel
and hundreds of others.
We produce over 60 different
alloys and alloying metals.

Manganese, tungsten, silicon,
chromium, vanadium.
Not exactly households words.
But combined with iron, alu-
minum and other metals they
have transformed the world we
live in.
If it weren't for alloys there
would be no high-strength steels
for buildings and bridges.
No jet engines or aircraft
No sophisticated tools.
No electric motors for shavers,
typewriters or vacuum cleaners.

No computers, or lightbulbs,
or television sets.
When you think of them this
way, our alloying metals become
very precious indeed.
Whether they're as far away
as a rocket on its way to the
moon. Or as close to your heart
as a brace shaping a beautiful

Today, something we do
will touch your life.

An Equal Opportunity Employer



[M6Jti department


New Jersey Institute of Technology
Newark College of Engineering
Newark, New Jersey 07102

TRY have been major educational elements
since Newark College of Engineering initiated
degree programs in 1919.
Recent changes have brought about a new
institutional name, New Jersey Institute of Tech-
nology, (under which Newark College of Engi-
neering continues as a cohesive form for engineer-
ing education) ; a new multi-million dollar facili-
ty; and a continuity of curriculum updating. A
seasoned faculty with long experience at the Insti-
tute has had exceptionally positive relations with
NJIT undergraduate and graduate students, as

well as a record of active participation in all im-
portant aspects of the institution and of profes-
sional life.
In recent years the department graduated an
average of 100 chemical engineering students per
year-roughly 80 B.S., 18 M.S. and two D.Sc.
students per year, a far cry from its first graduat-
ing class of three, more than a half century ago.
A particularly distinctive aspect of the edu-
cational operation is the affiliation and relation-
ship of the members of the two allied divisions
of the department-chemical engineering and
chemistry. Cooperative ventures in interdisciplin-
ary research, multidisciplinary graduate and
undergraduate curricula, and collaboration on de-
partmental curricula changes are routine
practices. From a table of organization viewpoint
Chemistry has 17 faculty members and Chemical


Engineering 13; but from a viewpoint of aca-
demic realities the two divisions act as one in
considerations affecting the department.
As a stable and senior department of the Insti-
tute, Chemical Engineering/Chemistry employs
an excellent reputation on campus for its ap-
proach to teaching, research educational activi-
ties, student relations and involvement in active
faculty governance.
Within the professional societies there has
been a long record of active participation in
AIChE, ACS and ASEE, represented by many
different forms of local and national organization-
al involvement.


NOLOGY (NJIT) started as Newark
Technical School in 1881 and has operated under
a number of names in its 90-year history.
Originally funded by community leaders and later
by a joint commitment by City and State, the
Institute still enjoys an arrangement by which
the State contracts with the Board of Trustees for
the providing of education. The original purpose
of the Institute 90 years ago was to provide a
wealth of skilled talent for New Jersey industry;
in large respect this purpose still stands since
the majority of chemical engineering graduates,
as well as those of other engineering disciplines,
are absorbed into the tremendous variety of
regional industry.
When formal degree programs were organized
in the Fall of 1919 chemical engineering became
one of the first degree-granting departments,
capitalizing on the strength of existing chemistry
courses and related offerings. While titled
Chemical Engineering, instruction in chemistry
continued, establishing the rapport that continues
in certain aspects today.
Another interesting feature of NJIT's depart-
ment is the strength-in-service of the faculty and

In recent years the department graduated
an average of 100 ChE students per
year, roughly 80 B.S., 18 M.S. and
2 D.Sc. students per year-
a far cry from its first graduating
class of three, more than half a century ago.

particularly the fact that only a few men have
headed the department in more than 50 years:
the late Vernon T. Stewart served as chairman
from 1920 to 1946. An institutional reorganization
in 1946 separated chemistry and chemical
engineering administratively for 20 years. Under
this arrangement Dr. M. Lelyn Branin headed
chemistry and Dr. Charles L. Mantell was brought
in from industry to readjust chemical engineering
offerings to post-war professional needs.
Curriculum was revised, courses in plant de-
sign and chemical engineering kinetics were in-
troduced; a master's program in chemical
engineering was started in 1947 and AIChE ac-
creditation for the undergraduate curriculum was
received in 1950. Student interest in professional
societies revived and the AIChE chapter was rein-

Joe Joffe, Chairman of Chemical Engineering and Chemistry.

In 1963 Dr. Mantell retired and Dr. Joseph Joffe was
appointed chairman of chemical engineering; Professor
George C. Keeffe, who had long been associate chairman,
continued in that role. In 1966, upon the retirement of
Dr. Branin as head of chemistry, the two areas were re-
united as one department under Dr. Joffe. The continuity
of department fidelity is perhaps best noted by the fact
that Dr. Joffe will retire in 1975 with 43 years of service
and Professor Keeffe in 1976 with 40 years of service.
Among the many factors that have contributed
to the growth and productivity of Chemical
Engineering/Chemistry at NJIT was the gift of
a nearby industrial building in the 1950s which
enabled the department to provide the facilities
necessary for large undergraduate and graduate


g-s'x as- a-^^^^^^*^^^^^^^'&'y-^^^MWI^^^

While some new buildings were added in the
post-war years, NJIT's city location precluded
any extensive expansion until the 1960s when
urban renewal and several State college bond
issues encouraged wholesale growth. NJIT's
campus was able to expand from five buildings on
two acres to more than a dozen on 20 acres, the
most notable and latest of which is the new $7
million chemical engineering/chemistry complex.
The physical growth in the 1960's was the pre-
lude of discussion about broadening the education-
al offerings. Until the past decade only degree
programs in engineering had been offered. In re-
cent years a discernible interest in related pro-
fessional career paths has led to viable programs
in engineering science, computer science, and in-
dustrial management; undergraduate and gradu-
ate programs have established in these fields.
Other degree programs have been added as well
but the deciding factor in the change of name
from Newark College of Engineering to New
Jersey Institute of Technology was the creation
of New Jersey's first public school of architecture
as part of NCE in 1973. The new NJIT name be-
came effective January 1, 1975.
Throughout its history the Departmental ob-
jectives of its undergraduate curriculum has been
to provide a quality education which will enable
graduates to either enter the chemical engineer-
ing profession directly or alternately, to enter
graduate school well-rounded in theory and ap-
plication. The objectives of the graduate pro-
grams have been to broaden and deepen the
student's mastery of chemical engineering and
related subjects so that he might participate to
the fullest extent in the advancement and practice
of the chemical engineering profession.

given to the chemical engineering/chemistry
department at NJIT, the leadership and faculty
support given to its educational effort is especially
significant. As mentioned Dr. Joseph Joffe oper-
ates as overall chairman with Professor George
Keeffe as associate chairman of chemical engi-
neering and Dr. Howard Kimmel as associate
chairman of chemistry.
It has been largely under this leadership-
and during the past ten years-that the depart-
ment has been able to achieve the national
prominence it now has. This period also marked
the most dynamic growth in terms of student en-

Process Control simulation on EAI TR 20 Analog Computer.

rollment, faculty growth and physical expansion.
More than half of the present instructing staff of
chemical engineering joined the faculty in the
late 1960s as well as one-third of the chemistry
faculty. In addition, Dr. L. Bryce Andersen, dean
of academic affairs, and Dr. Wladimir Phillippoff,
internationally-known rheologist, are members of
the chemical engineering department. Most of
the teaching staff are professional engineers and
have extensive industrial experience.

L. Bryce Andersen, Vice President of Academic Affairs.
Ernest N. Bart, Fluid Mechanics, Heat Transfer, Mini
Computers and Applied Mechanics.
Hung T. Chen, Thermodynamics, Separation Theory
(Parametric Pumping), Process Dynamics and Control.
Teddy Greenstein, Low Reynolds Number Hydro-
dynamics, Biochemical Engineering, Heat Transfer.
Deran Hanesian, Chemical Reaction Engineering,
Fluidization, Process Dynamics and Control, Process Simu-
lation and Optimization.
Ching-Rong Huang, Rheology, Biorheology, Biomedical
Engineering, Polymerization Kinetics, Catalysis.
Joseph Joffe, Chairman of Department of Chemical
Engineering and Chemistry, Thermodynamics (Equations
of State, Vapor-Liquid Equilibria, Properties).
George C. Keeffe, Associate Chairman, Chemical Engi-
neering, Mass Transfer, Solid Waste Recovery Processes,
Photo-chemical Reactions.
Saul I. Kreps, Chemical Reaction Engineering, Catalysis
and Catalytic Reactor Design.
John E. McCormick, Computer Applications to Engi-
neering Problems, Applied Mathematics, Mass Transfer.
Wladimir Philippoff, Foundation Research Professor,
Angelo Perna, Mass Transfer, Solid Waste Disposal,
Air and Water Pollution.
Edward C. Roche, Jr., Process and Equipment Design,
Process Simulation and Computer Applications.
Jerome J. Salamone, Assistant Chairman, Chemical
Engineering, Non Newtonian Technology, Fluid Mechanics,


Heat Transfer.
Dimitrios Tassios, Applied Thermodynamics (Vapor-
Liquid Equilibria), Air Pollution, Technology Assessment.

As one would expect from such a large staff
the research interests encompass a broad spec-
trum. The chemistry faculty, in addition to the
standard areas of research, (physical, analytical,
inorganic and organic), are conducting research
in the areas of water and air pollution, enzymatic
removal of pollutants, polymers, biomedical and
photochemical induced reactions. Funded research
is currently being carried out in the areas of
water pollution, blood rheology, hazardous waste
disposal and process synthesis. Several NSF
undergraduate equipment grants have helped to
develop undergraduate laboratory experiments.
During the past year the members of the
department have published 37 papers and pre-
sented 23 papers at national and international
meetings. Additional activities of department
faculty include consulting for the private and
public sector as well as reviews for technical
journals, and government agencies.

N 1969 GROUND WAS BROKEN for the
Chemical Engineering/Chemistry complex,
(Tiernan Hall) which was completed in 1972 at
a cost of $7 million. The facility was designed as
an office, educational and research complex, com-
plete with the latest capabilities for audio-visual
instruction. Its four-stories and basement con-
tain a gross area of 140,500 square feet. The
basement contains complete machine shop facili-
ties, a modern rheology research lab, a sub-
critical nuclear reactor facility, equipment storage
area and a student lounge. Instructional class-
rooms are on the first floor. With the exceptions
of two large freshmen lecture halls, classrooms
are designed to hold no more than 25 students.
The second floor contains all the undergraduate
chemistry laboratories. With the exception of
department's minicomputer facilities, the third
and fourth floors consist completely of research
One of the distinctive features of the complex
is the undergraduate laboratory facility which
includes a four-story high-head area, housing the
unit operations laboratory and a separate process
dynamics control laboratory. The unit operations
facilities consist of separate areas on each floor

interconnected by a high-head area. The base-
ment laboratory area, the largest in square foot-
age, contains experiments related to heat, mass,
and momentum transfer as well as several liquid-
solid separation experiments. The first floor is
basically a solids-fluids area where the drying
and fluidized bed experiments are located. The
second floor is used for housing experimental
apparatus associated with the undergraduate re-
search program and student project studies as-
sociated with the unit operations laboratory
course. The third floor area contains a reaction
kinetics laboratory. The experiments involve a
60 foot tubular reactor, backmix reactors in series,
heterogeneous catalysis, surface properties of
catalysts, non isothermal batch reactor, and a
batch fermentation unit. The fourth floor con-
tains process dynamics experiments in liquid level
control, frequency response analysis and on-line
reactor temperature controller tuning. Both EAI
-in, rwu

George Keeffe, Associate Chairman of Chemical Engineering.
TR-20 and EAI TR-48 analog computers are
available. Additional control simulation is pro-
vided if desired by an Autodynamics Process
Control Trainer.
The laboratory experimental equipment units
are essentially of pilot plant size and were recent-
ly purchased as part of the department's educa-
tional modernization philosophy.
A computation facility includes mini-com-
puters, analog computers and teletypes for the
on-campus UNIVAC 3 computer and a State-wide
370/158 IBM System. The analog capability con-
sists of two fully equipped TR-20 machines, with
DVM, oscilloscope and x-y plotter accessories and
two TR-48 machines. Mini-computer equipment


includes a Wang console and five satellite key-
boards, and two programmable 9000 series Hew-
lett-Packard systems. The 9100A H-P is com-
plete with extended memory, printer and marked
paper reader. The newer 9820A unit has two, read
only, memory blocks one of which is a math pack-
age and the other is a user definable package.
Since the unit has a compiler anyone familiar with
modern computer programming can rapidly learn
to program the unit. In addition, the 9820A is
equipped with an alpha numeric printer allowing
for convenient formating of printed statements.
Programs for use with the H-P systems are de-
signed and used by students for data reduction
in conjunction with experiments in both the unit
operations and process dynamics and control
laboratories. This equipment is reserved for the
use of the faculty and students of the department.
The department takes great pride in the facilities
and the resulting compliments expressed by
visitors from both the industrial and academic

NJIT has as its goal, an educational balance
between technical and non-technical subjects so
that the student graduating is not only technically
competent, but reasonably sophisticated in social
matters. Presently a total of 137 semester hours
are required.
The mathematics and physics requirements
satisfy ECPD standards and chemistry require-
ments meet AIChE standards. The chemistry
contribution to the undergraduate ChE curricu-
lum is significant in that the courses are designed
specifically for the engineering student and are
given to engineers by chemists who are colleagues.
All the chemistry courses-freshman chemistry,
organic chemistry, and physical chemistry-are
oriented toward the basic educational needs of a
chemical engineer.
Recognizing the need for greater exposure to
modern analytical techniques, the chemistry facul-
ty developed a sophomore analytical chemistry
program which now will be required by all ChE
students. The purpose is to give students the ex-
perimental experience in analytical techniques
that will be needed in junior and senior laboratory
In the humanities/social and organizational
sciences, 27 credit hours are required, providing
for non-technical subjects in every semester.

There are five elective and four required courses
in this sequence. This requirement is based upon
a historic desire at the school to prepare its gradu-
ates for corporate management opportunities.
The standard chemical engineering subjects-
calculations, process industries, thermodynamics,
heat, mass, and momentum transfer, reaction
kinetics, process dynamics and control, plant de-
sign, and chemical engineering laboratory-pro-
vide an additional 39 credit hours and another 9
hours of chemical engineering and technical elec-
tives are permitted. The program is more flexible
than it seems because of a great deal of freedom
in the "technical" and "ChE" electives. A student
can use these three courses to develop a solid
footing in chemistry, biochemistry, environ-
mental sciences, nuclear chemistry/ physics,
mathematics/computers, and others as well.
Although the courses on campus reflect the
engineering aspects of the institution, a wider
variety of liberal arts and life science programs
can be considered in conjunction with a neighbor-
ing institution, Rutgers-Newark.
Internally, department programs are flexible
and can be fitted into fields which include
medicine, ecology, law, management, chemistry,
process operations, research and design.
The focal points of the undergraduate curricu-
lum are the senior Process and Plant Design
course and the senior chemical engineering labora-

The undergraduate lab facility includes a
four-story, high-headed area for unit
operations lab and a separate process
dynamics lab. The former consists of
separate areas on each floor interconnected
by a high-headed area.

stories. In the Plant Design course the process and
equipment design of process units is covered
through three basic exercises focusing on process
design, equipment design, and process-equipment
parameter studies utilizing simulation models.
The emphasis of the process design segment is
to cover the flow and equipment sequence along
with raw materials and location factors. Also the
establishment of process operating conditions,
material and energy balances, and the evaluation
of necessary physical and thermodynamic data.
The second segment concentrates on the prepara-
tion of preliminary investment and operating cost


estimates, noting the size and/or mechanical de-
signs of equipment, and the utility and instrumen-
tation requirements. The third segment is an ex-
posure to the interrelationships of process and
design variables via the utilization of process
simulation programs. The course is conducted
through a group-oriented workshop atmosphere
with written and oral summaries of accomplish-
The selection of the specific examples for
student solution requires some care in that the
process must be non-propriety, basic process data
must be readily available, and the scope such that
a solution can be obtained within the duration of
the course period. With these constraints prob-
lems have been formulated in conjunction with
various industrial firms, and then used in the
process and plant design course. The development
of these design problems requires considerable
effort, and thus NJIT has actively participated in
the case study series as organized by Dr. Buford
D. Smith at Washington University (St. Louis,
In the undergraduate chemical engineering
laboratory, the students are required to complete
one experiment in each of the areas of heat, mass
and momentum transfer and chemical reaction
engineering. The remaining experiments in the
two semester sequence are chosen by the students
working in groups of three in accordance with
their interest and desire for specialization.
The Process Dynamics and Control Laboratory
is integrated with the course. Students spend nine
weeks on theory and then seven weeks on pilot
plant scale control experiments covering liquid
level control, frequency response analysis, and
on-line, chemical reactor temperature controller
tuning for optimum control settings. Analog
computations in control are also investigated by
simulation of chemical reactions with concentra-
tion control by a proportional controller.
On the graduate level, standard master's and
doctoral programs are available in chemical
engineering. The degree of chemical engineer also
available after 24 hours of course work and a
minimum of twelve credits for a professional proj-
ect. Although most of the candidates are part-
time evening students, with the number ranging
between 80 and 100, the department is concentrat-
ing on developing a larger full-time day program.
At the present time, there are about 20 full-time
master's and doctoral candidates.
The Chemistry Division offers a program lead-

ing to the Master of Science in Engineering
Science. The requirements include a minimum of
thirty credits which include the option of a six
credit Master's Thesis or a three credit Master's
Project. Nine course credits are prescribed in the
areas of Inorganic, Physical and Organic
Chemistry. The remaining credits are electives.

Unit Operations Lab Gas Absorption Experimental Apparatus.

basically a commuting one with the prob-
lems and attitudes associated with a metropolitan
atmosphere. The majority of students hold down
part-time jobs to help subsidize their educational
and living expenses. Since NJIT is primarily
engineering-oriented, there are many demands on
a student's time. The department takes pride in
its student organizations and in the recognition
such societies have received. A close student-
faculty relationship is characteristic of the de-
partment life. This close relationship has been
nurtured primarily by the active student chapters
of AIChE (established 1950) and Omega Chi Ep-
silon (established 1957 as Eta Chapter), and a
recently formed Biochemical Club, and has been
encouraged by an open door policy on the part
of the faculty. D




Purdue University,
West Lafayette, Indiana 47907

Texaco Research Center
Beacon, New York 12508

T HE PRIMARY FUNCTION of an engineer-
ing department is to teach students the basic
scientific and engineering principles which will
become the foundation of their technical know-
ledge. Since most students will apply this

We have tried to create an industrial
experience in which students are
direct participants rather than
observers . the vehicle is a set of two or
more problems from which a graduate
consultant team selects one on which to work
full time for one week.

knowledge in industrial jobs, it is important for
them, and for the university, to maintain a strong
communication link with industry. In fact,
weakness of this communication may be the major
contributor to the complaint sometimes heard that
the attitude of engineering graduate students does
not match industrial needs. Summer jobs and co-
operative programs provide important industrial
experience from which students gain perspective
on the importance of various areas of course work
and a basis on which to make career decisions.
This experience is not available to all students,
however. In the following we describe a program
which has been designed in a cooperative effort
by Texaco and Yale to provide a taste of industrial
experience in graduate chemical engineering. De-
velopment of the program was spurred by a re-
cent article on the effectiveness of graduate
chemical engineering education.1

Increasing pressure to shorten the time spent
in education rules out extensive industrial con-
tact as a general solution to this communication
problem. While plant trips and lectures by in-
dustrial personnel provide some exposure to the
practice of engineering in industry, they are
tutorial in nature and may not be readily in-
corporated into the students "experience." In an
attempt to maximize the benefit of a short ex-
posure to industry we have tried to create an
industrial experience in which students are direct
participants rather than observers.

N ITS PRESENT FORM, the vehicle for pro-
viding this experience is a set of two or more
problems supplied by Texaco, from which a team
of graduate student consultants selects one on
which to work full time for one week. In the first
trial run during the summer of 1973, two prob-
lems were offered by the Process Analysis Group
at Texaco's Beacon Research Laboratories. One
problem on catalyst poisoning had received only
preliminary attention while the other on design
of a laboratory reactor for determination of true
reaction kinetics in two phase flow had a tentative
solution being tested in the laboratory. A six man
student team received the problems on a Friday.
The following Monday the group traveled to Bea-
con for a meeting with Dr. Ware, their Texaco
contact. The meeting was devoted to clarification
of the problem statement and definition of project
objectives. The visit also included lunch with
several members of the Texaco staff and a tour of
the Beacon Laboratory. On return to Yale, the
students chose the reactor design problem (see
inset) and over the next three days generated
three designs and a written report on their work.
The students worked completely independently al-
though both authors were available to answer
specific questions. A typed version of the report
was mailed to Dr. Ware the next week and a week
later he visited Yale to hear oral presentations of


ma viM
W. N. Delgass did his doctoral work at Stanford University
under Professor Michel Boudart. He joined the Yale Faculty as an
Assistant Professor in 1969 after a postdoctoral year at the Uni-
versity of California, Berkeley. He is currently Associate Professor
of Chemical Engineering at Purdue University. His principal re-
search interest is the study of heterogeneous catalysis by Mossbauer
and X-ray photoelectron spectroscopy. (Right)
C. H. Ware, Jr., received his undergraduate education at Prince-
ton University and a PhD at the University of Pennsylvania. He
joined Texaco Inc. in 1959, served as Adjunct Associate Professor,
Columbia University, and assisted in the development of computer-
aided education at the University of Pennsylvania. He recently be-
came an independent consultant. His major interests are new
methods for improving and accelerating research/development/de-
sign activities. (Left)

the work and discuss the suitability of the solu-
tions to industrial objectives.
While a week is a short time in which to ac-
complish the stated goals, other student work was
suspended and each student spent more than 60
hours in this total immersion effort. In addition
to acquiring new chemical engineering knowledge,
students had an opportunity to exercise creativity
in their approach to the problem and to practice
both oral and written technical communication.
In this first trial run students received a small
consulting fee from departmental gift funds.

about the program and felt it a valuable ex-
pansion of their experience. Most of them had
little previous contact with industry and felt that
the visit to the Beacon Research Laboratories and
the discussion with Texaco personnel were
particularly useful. They were surprised and
somewhat uneasy at the generality of the prob-
lem statements but particularly as a result of dis-
cussions with their Texaco contact, came away
with distinct impressions of the depth and scope

of chemical engineering research. Perhaps the
greatest new lesson they learned was the prepara-
tion of a contingency chart to guide application
of a general solution to a specific case. In the be-
ginning the students had a little trouble treating
the problem as a job to be done rather than an
exercise on which they were being examined.
This uneasiness left by the end of the project,
however, and the students gained some self-con-
fidence when they found that in a short time in a
relatively new area they could generate creative
ideas of merit. An unexpected result was the
difficulty the students had in organizing for a
team effort. The ironing out of initial disagree-
ments gave the students in this group the added
benefit of experience in team cooperation.
Both as a new dimension in graduate chemical
engineering at Yale and as a means of establish-
ing better communications with industry this
program has been a success. The benefit to the
students is obvious from their comments. Discus-
sions with Texaco personnel have already revealed
several areas in which special lectures or material
from Texaco could augment our courses. It is too
early to predict whether any joint technical efforts
will arise from this association but it seems clear
that such a possibility is unlikely without close

not a finished product, some novel ideas
were presented and merit further consideration.
The primary solution, use of a stratified packed
bed to relax nonidealities, had already been em-
ployed by Texaco in a different situation. Other
parts of the solution included reactor configura-
tions which had not been tried before. The under-
lying assumption that experimental design data
would be used to aid in formulation of a solution
to the problem was also noteworthy. Thus the
benefit to Texaco was more than just the satis-
faction of making a contribution to education.
As the program is now constructed, presenta-
tion of a good problem is crucial. There is a need
to balance several important factors:
* problems must be important from an industrial view-
the time required to prepare a problem statement must
not be excessive
the problems must be broad in scope and amenable to
solution by an (imaginative) application of chemical
engineering principles (no "trick" problems)
proprietary information must be protected.



Both as a new dimension in graduate ChE
and as a means of establishing better
communications with industry this program
has been a success . while student solutions
are not a finished product . some
novel ideas were presented.

The first factor was taken into account by choos-
ing problems from, or closely related to, current
research interests. By choosing the man most
familiar with the problem as the industrial con-
tact, the preparation of the problem statement
was made easy. Problems considered to date are
in the areas of research methodology (eliminating
non-ideal flow) or application of the open litera-
ture to research problems and decisions. This re-
sults in problems having broad scope, usually
without using or generating proprietary informa-
During the summer of 1974, students received the
problems one day before the trip to Texaco. This limits
the amount of background they can gather as a basis
for asking questions but will leave more time for working
on the chosen problem. Since choosing the right problem
to work on is such an important component of research,
we have sought ways of including experience in this
area. We considered presenting a problem, which is not
capable of solution because sufficient information cannot
be obtained. The time is so short, however, that it is un-
likely that students can accumulate sufficient background
to identify its insolubility in time to switch to a more
fruitful one. An obvious wrong answer also lends an
undesirable air of examination to the procedure. We
have decided to limit the number of problems suggested
to three and, if an insoluble problem is offered, to
identify it by the end of the visit to Texaco (second day)
to minimize wasted effort.
We look forward to continued development of this
program and hope that some of the ideas presented here
will be useful to others in strengthening ties between
industry and academia.

Development of this program has been made
possible by the support of Messrs. Peter L. Paull,
Roland A. Beck, Irving D. Pollock and Edward
R. Christensen at Texaco and Professor R. W.
Wheeler, Department of Engineering and Applied
Science, Yale University.

1. Daubert, T. E., S. E. Isakoff, R. B. Long, J. E. Vivian
and C. J. Pings, "Effectiveness of Graduate ChE Edu-
cation," Chem Eng. Ed. 7, 84 (1973).

Problem Statement
(1) make a recommendation for design
and operation of laboratory packed bed reactors
for gas-liquid flow, or,
(2) provide a detailed plan of experi-
mental research which would provide the basis
for such a recommendation, including the inter-
pretation and recommendation which would be
made for each possible outcome of the planned
Operation must provide for 40-90% con-
version of the limiting reactant in the feed.
Two reactor volumes must be covered by
the recommendation: 100 cc. maximum, and 500
cc. maximum, representing small and inter-
mediate scale experiments.
Many new petroleum and petrochemical
processes are based upon novel catalysts or novel
applications of existing catalysts. We will only
concern ourselves with catalysts used in packed
bed reactors. At the present time there is no way
to predict rates of reactions of commercial in-
terest from a knowledge of a catalyst's physical
and chemical properties, method of preparation,
etc. These rates must be established empirically.
In the normal course of development of
an idea from its inception to commercialization,
the empirical determination of catalyst perform-
ance plays an important role. Included in a typical
project is the evaluation of a small quantity of
satalyst, usually about 100 cc. and, later, the
evaluation of larger quantities, roughly 500 cc. In
many processes, reactants are present as liquids
and gases at reactor conditions. These so-called
mixed-phase operations give rise to non-idealities
in the fluid flow which affect the apparent catalyst
activity, selectivity and aging rate, the three
major performance characteristics. The objective
in the design of laboratory reactors and in choos-
ing their operating conditions is, primarily, to
eliminate the non-idealities and thus obtain re-
actor performance which is representative of the
intrinsic catalyst behavior. Failing that, the ob-
jective would be to provide a sound basis for cor-
recting experimental data to obtain results which
are representative of the true behavior. (A non-
proprietary literature survey was included). E


41 4

In fact at Sun Oil we've just adopted a new system
that promotes it. Internal Placement System.
Here's how it works. Say you're in Production
and you decide to take a crack at Marketing.
Next opening in Marketing we'll tell you. You can
apply and be considered. First. You have freedom
to experiment and move around at Sun. You
learn more and you learn faster.

* Why do we encourage job hopping? Because
,we happen to believe our most valuable corporate
assets are our people. The more our people
know, the stronger we are. Now-you want to
know more? Ask your Placement Director when
a Sun Oil recruiter will be on campus. Or write
for a copy of our Career Guide. SUN OIL
COMPANY, Human Resources Dept. CED.
1608 Walnut Street, Philadelphia, Pa. 19103.

An Equal Opportunity Employer M/F


Program at the 1975 Annual Meeting
Submitted by Prof. William D. Baasel of Ohio University

Would you like to know how your department
should be financed, how your curriculum should
be changed, how to properly train foreign stu-
dents, how to obtain research grants, or how to
act as an expert witness? Then come to the ASEE
annual meeting at Colorado State University from
June 16 to June 19, 1975. A program on each of
these topics will be presented by your division,
the Chemical Engineering Division of ASEE. Be-
sides this, there will be hundreds of other events
plus women's and children's programs. We hope
to see all of you there.
There are five sessions which the chemical en-
gineering division of ASEE will be sponsoring
and another which it will be cosponsoring. One of
these events was thought to be of such importance,
that it has been designated a miniplenary. It con-
cerns the method of financing a university and de-
partments within a university. It is entitled,
"Should a University Be Run Like a Business".
Many universities, both public and private, are
having financial problems today, and it appears
that they are likely to increase rather than dimin-
ish. In 1978 the number of people reaching the
age of 18 will peak. From then on for the next
decade, at least it is predicted the number of stu-
dents entering our American universities will de-
crease. There are some predictions that there will
be ten to fifteen percent fewer students in higher
education 10 years from now than at present.
With fewer students this will mean less tuition
money, and hence a greater financial pinch.
Whenever there is a financial crisis there are
attempts to reorganize, and currently that trend is
taking the form of running the university system
within a state as a large business. Many uni-
versities receive subsidies based on the number of
students they attract and retain. It is recognized
that engineering, medicine, dentistry, and agricul-
ture, cost more to operate, and these programs re-
ceive higher per capital support than the liberal
arts programs. However, within a given area, the
support of the program is based on the student
credit hours generated. This leads to problems. In
the early 1970's when the engineering enrollment

dropped one third, many schools had to fire fac-
ulty and curtail course offerings. Now as the en-
rollment is on the upswing, the reverse occurs and
other areas of the university are feeling a cost
Harold Enarson, the President of Ohio State
University, in an editorial in the Sept. 7, 1973
issue of Science noted,
To the new managers, the university is just another
large system. It has raw material (students), a labor
force (faculty and support personnel), instruments
of production (classrooms, laboratories, libraries), a
production schedule (academic requirements, classes
admitted, and classes graduated), management (the
trustees and central administration) and a production
index (the cost of producing a student credit-hour).
The managerial revolution creates the exact reverse of
the goals that are sought. The impact of multiple
sources of regulation on the university is to discourage
flexibility, cripple initiative, dilute responsibility and
ultimately to destroy true accountability.
Universities have always had the problem of
evaluating teaching and research. For the latter,
one could count publications. Teaching, however,
has defied any such quantitative evaluation. Now
there is another such dilemma. The quality of one
program compared to another defies qualitative
measurement, while the cost of producing a stu-
dent credit hour can easily be determined. A three
hour monolog per week by a professor may not be
as beneficial as a self-paced course or an open
laboratory, but it may cost less. Lecturing to 500
students in freshman psychology is more profit-
able than a senior elective course in modern con-
trol theory and practice. Yet the control course
may require more effort by the instructor. A
chemical engineering department may have no
course which is required by other majors with
which it can pad its student credit hours. The
equipment in some laboratories may be too ex-
pensive to duplicate, so the number of students
per laboratory is kept low and the cost high.
The very important problem of relating the
quality of education to its cost will be addressed
by five panel members at the 1975 annual meeting
(Continued on page 79.)




West Virginia University
Morgantown, WV 26506*

preciate having some guide through the
thicket of definitions and derivations that usually
accompany introductory courses. Numerous say-
ings and designs have been used over the years
(Prins, 1948; Guggenheim, 1949; Burgett, 1972;
Marino, 1973; Gangi et al., 1972). I believe that
a simple geometric construction is best and here-
with submit my candidate for "best of show."
The shape of a square within a diamond is
easily remembered, and the working relation-
ships are easily derived. The first law, dE = dq-
dwout, provides a starting point to fill in the terms.
Partial derivatives of the various energies are
shown to be equal to nonenergy variables. Partial
derivatives of the nonenergy variables are related
through crossed partial derivatives of the
energies. The diamond is useful because it pro-
vides a graphic representation of the relations
between basic thermodynamic variables.

T HE FIRST LAW OF thermodynamics states
that energy may be converted from one form
to another, so that the total energy flow into a
system is the sum of the various types of energy
involved. If the energy flow is due only to heat
absorbed, dq, and (piston or shaft) work done
by, the system, dwout, then dE = dq -dwout. A
second measure of energy is called enthalpy, H,
and is often used when we are dealing with con-
stant pressure systems. The Helmholtz free
energy, A, is a measure of maximum work at
constant temperature. And the Gibbs free energy,
G, is related to chemical reactions and equilibria

* Current address: Pigments Dept., E. I. DuPont de
Nemours Co., Inc., Newport, DE 19804.

at constant temperature and pressure.
To formalize the relations, draw a diamond
with a square inside it, and divide the square into
four smaller squares, as shown in the accompany-
ing drawing. In the top three sections, place the
definition of total energy flow in terms of heat and
work. Place dE in the pointer, TdS (the equiva-
lent of dq here) in the left corner box and -PdV
(the equivalent of -dwot) in the right corner
box. Fill in the remainder of the boxes by "re-
versing" the terms through the center, so that
TdS in the upper left becomes -Sdt in the low-
er right and -PdV in the upper right becomes
VdP in the lower left. To fill in the pointers, re-
call that dH goes next to the heat term TdS (and
at constant pressure the other term, VdP would
drop out) and that dA goes next to the work
term -PdV (and at constant temperature the
other term -SdT would drop out). This leaves
only one place for dG.
The pointer terms are defined as the sums
of the adjacent box terms. The pattern may be


- .

Ralph D. Nelson, Jr., earned a B.A. in chemistry at Colby College
in 1960 and a Ph.D. in chemistry at Princeton University in 1963.
Following research and teaching posts at the National Bureau of
Standards, Middlebury College, Brown University, and West Vir-
ginia University, he earned an M.S.E. in chemical engineering at
West Virginia University in 1974. Research into molecular motions
in the liquid state has been supplemented by development of time-
shared computer applications. He has recently joined the Pigments
Department of Du Pont.

inverted, reflected, or rotated to produce the same
relationship between the terms. I find this par-
ticular arrangement most suitable. Note that the
algebraic signs of the terms are explicit and do
not depend on the direction of operation, as is
the case with other mnemonics. The various
energies are defined as changes, so that absolute
values for energies are not implied. Burgett's
mnemonic "Good Processes Have Several Energy
Variables, All Tied," Marion's "SPorTiVe," and
Shih-Ching Su's (C.Y. Wen, private communica-
tion) "The Gibbs Potential Has Several Excep-
tionally Valuable Applications" are all present in
the diamond's derivative terms.

first partial derivatives of the various
energies to nonenergy variables. Only adjacent
pointer energies are involved in the Maxwell re-
lations. The procedure should not be memorized,
hut understood. The definition of each pointer
term involves two box terms. Adjacent pointer
terms have one box term in common, e.g. dE =
TdS -PdV dA = -SdT -PdV. The partial
derivative of E with respect to V, holding S
constant is -P, exactly the same result as taking
the partial derivative of the adjacent pointer
energy with respect to the common box term's

differential variable, holding the uncommon box
term's differential variable constant. For this
case we get
dE dA
dV dV )T
Try working the three others out yourself, com-
paring them with expressions in standard thermo-
dynamics texts. Maxwell's relations are handy for
replacing a term which is hard to evaluate, such
as (dA/dV),, with one which can be evaluated
from available data, such as -P.
The Euler relations result from the inherent
equality of the crossed partial derivatives of the
energy variables related as shown in the diagram.
The result of two successive partial differentia-
tions of energy with respect to the nonenergy
variables used in equilibrium thermodynamics is
independent of the order in which the differentia-
tions are carried out, e.g.

dS H

(dP )-

d \(dE dT
dV dS ; v S- dV )s

The pattern may be inverted, reflected,
or rotated to produce the same relation-
ship between the terms. The algebraic
signs of the terms are explicit and do not
depend on the direction of operation.

The result on one side is the partial derivative of
the nondifferential variable in a box with respect
to the differential variable in an adjacent box,
holding the original box's differential variable
constant. The other side is the same, except that
we start in the adjacent box. Derive the other
three yourself for practice. Euler relations may
be used to evaluate the changes in one nonenergy
variable as a second is held constant and a third
is changed. Thus we find that -(dS/dP)T is the
same as (dV/dT) ..


T HE SCHEME ABOVE IS useful for closed
systems, surrounded by walls impervious to
(Continued on page 99.)





University of Maryland
College Park, Maryland 20742

many processes which are of current com-
mercial or environmental interest. For example,
it is being studied commercially as a means of
energy production and has long been used for
horticultural purposes such as composting. En-
vironmental examples of aerobic decomposition
include various types of waste disposal, strip
mine reclamation, and the decomposition of oil
spills in the ocean.
Although aerobic microbial growth has been
used for centuries, e.g., in composting, it is often
practiced more as an art than a science. This is
not surprising when one considers the complexity
of the biochemical processes by which materials
are decomposed. The microorganisms which
carry out the decomposition require a suitable en-
vironment in terms of nutrients in the substrate,
temperature range, oxygen content, and moisture
content. In addition, a biochemical source of
energy is needed for the decomposition to occur.
Thus, in order to develop an accurate mathe-
matical model of the aerobic microbial process
it is necessary to consider oxygen transfer into as
well as carbon dioxide and thermal diffusion out
of the decomposing mass.

T HE THERMAL AND mass diffusion aspects
of decomposition are described by Fourier's
and Fick's Laws, respectively. When chemical re-
action source and sink terms are included, the
following equations for the temperature and
oxygen distributions result:

R k d2T
H2 dy

-R = cD2 + v(X N.)

It is more difficult to determine the mathematical
form of the reaction term, R, in Equations 1 and
2, i.e., the rate expression for the complex bio-
chemical reactions taking place during decom-
The energy for the numerous biochemical re-
actions occurring during decomposition comes
from the biological oxidation of some of the
available carbon.1 2 The biological oxidation of
organic compounds to carbon dioxide and water is
a complicated process being made up of several
successive enzyme catalyzed reactions.3 However,
the overall reaction (unbalanced) can be written

SuBstrate+O2 +NH 3 + Microbes+CO +H2 0

If one considers the substrate to decompose via
carbohydrate oxidation a balanced form of Equa-
tion 3 can be written

(C6 H12 06) n+WO +dNH3 CaO cNd+YCO2 +ZH2 0
6 12 6 n 2. 3 a b c d+YC2 2

The values of a, b, c, d, W, Y and Z can be cal-
culated from mass balances on the carbon, oxygen
and hydrogen. Assuming the composition of cell
material to be similar to yeast which is 47% C,
6.5% H, 31% 0 and 8.5% N4 and that about 0.4 g
of cell material are produced per gram of sub-
strate, the values of a, b, c and d are: a = 2.82 n;
b = 4.69 n; c = 1.40 n; d= 0.436 n. Using these


values, a mass balance for the oxygen gives
W = 3.03 n, moles CO,/mole substrate consumed
Similarly, mass balances for the carbon and hy-
drogen give
Y = 3.18 n, moles CO,/mole substrate consumed
Z = 4.31 n, moles CO2/mole substrate consumed
The respiratory quotient (RQ) of a reaction
is a measure of the amount of CO2 produced per
unit of 02 consumed, i.e.,
RQ = moles CO2 produced/moles 0, consumed = Y
The reaction shown in Equation 4 has a respira-
tory quotient of 1.05. Experimental studies5' 6
have measured the respiratory quotient of labora-
tory compost piles undergoing aerobic decomposi-
tion and found that it is approximately 0.9. From
this experimental evidence and Equation 5 it can
be deduced that the biological oxidation of the
substrate is the predominant oxidative reaction
taking place during aerobic decomposition. This
is not surprising since the other reactions taking
place during aerobic decomposition rely upon the
biological oxidation to supply the energy necessary
for these reactions to proceed. Therefore, in the
mathematical model the biological oxidation will
be the limiting reaction considered.
Using this model the rate of substrate de-
composition according to Michaelis-Mentin
kinetics (assuming oxygen limitation) is given
by the Monod equation:
V (M)X
R = max(6)
K +X
Since the reaction rate is assumed to be limited
by the rate of oxygen diffusion, K, > > X, and

R = -ax (M)X (7)

The temperature sensitivity of m-,,nx is given by

Pmax = A' e-E/RgT (8) where
Substituting this into Equation 7 one gets

R = A'e -E/RT (M)X (9)

If we further assume that the microorganisms
are in a linear growth phase, their concentration

Aerobic decomposition is being studied as
a means of energy production . examples
include various types of waste disposal,
strip mine reclamation, and the
decomposition of oil spills in the ocean.

would remain relatively constant and under these
conditions Equation 9 reduces to

R =A -E/RT X
R =Ae g X

where A = A' (M). This equation can now be
substituted into the transport Equations (1 and
2) to give

2 -E/R T
d T AH X
dy2 k

dX 1 (X d XN + A -E/R T
dy2 CdY Ni) = g X
dy cD 1 cD

According to the model the bulk diffusion term
is given by

i N~ N0 C
2 2

But Equation 4 indicates that the oxygen and
carbon dioxide are approximately in a state of
equimolar counterdiffusion and therefore XNi
, 0. This reduces Equation 12 to

dX A -E/RT
+ e X
dy cD


Converting Equations 11 and 14 to dimensionless
variables gives

d2T* -B/T X*

d2 = + C e-B/T X*
dy 2
B = E/R; C = ; D = o
cD k (Tm-o

The temperature in the exponential term is not
made dimensionless since doing so would not
simplify the solution of the equations. Equations
15 and 16 can now be solved simultaneously with
the proper boundary conditions to get the temper-
ature and oxygen distributions desired.



PUTER was chosen -T- <1
to solve this problem
since it provided the P40.5
flexibility to study the
effects of changes in the
parameters B, C and DREF PA 2 A
as well as give a rapid B/2000 REF B/20T
solution to Equations 15
and 16. The program
used to determine the
temperature and oxygen -10"(D'-Bx *
distributions is shown in
Figure 1. Table 1 sum-
marizes the potentio-
meter values and ampli-
fier outputs. + RE.

The portion of the .
program in the upper -- A
half of Figure 1 is de-
voted to calculating the
forcing function, e(D'-B/T)X, where D' in D.
The value of B, which is related to the activation
energy, is controlled by P3. The value of P3 must
actually be set at B/20,000 in order to get proper
scaling. P7 controls the value of the pre-exponen-
tial constant, D, and it accomplishes this by being
set at the value of 10 e(D'-B/T o). The output of
A6 is eD'-"/B and as can be seen in Figure 1, this
is generated by an internal integration loop. This
method for generating the exponential function
is discussed by Cadman and Smith8 and eliminates
the problems caused by the use of a non-linear
exponential circuit.
The output of A7 is the forcing function,
eD'-B/TX, which is then integrated twice to get
T* as a function of y*. Actually the output of the
second integrator is 10T* for scaling purposes.
In many systems, the temperature and oxygen
fluxes at y* = 0 are approximately zero. When
this condition is met Equations 15 and 16 indi-
cate that X* is linearly related to T*. The linear
relationship between X* and T* is derived as

dX*/dy* = (C/D) dT*/dy* (17)
X* = (C/D) ddy* + X*o (18)

1* = dy* + T*1o (19)


X* = (C/D)(T* T*Io) + X*o0

at y* = 0: dT*/dy*=0,dX*/dy*=0,T*=T*Io
at y* = 1: X* = 1

This linearity is used to simplify the program
by replacing the integrators for X* with a much
simpler circuit and indeed, this is the way in
which X*, or to be more exact, 10X*, is generated.
P12 controls the value of C/D, P13 controls X*Jo
and P10 and P11 are both set at the value of
In working with the program, the most sensi-
tive parameter has been found to be the ex-
ponential part of the forcing function, eD'-"B/. The
value of B, which is related to the activation
energy, can usually be estimated from data in
the literature. Thus in fitting experimental data
the value of P3 is known independently and the
values of P7, P10, P12 and P13 are adjusted to
get the best data fit. P11 is set to exactly equal
P10 (T*lo) and therefore is not an independent
parameter. P10 and P13 control the values of
the boundary conditions, T* 1o and X* 1o respective-
ly. Therefore, the computer predictions are es-
sentially controlled by two parameters, C and D,
which are controlled by P12 and P7 respectively.


Thomas M. Regan is Director of the Department's Laboratory for
Biochemical Engineering and Environmental Studies. His research has
been concentrated on mass transfer and some biological and medical
applications of mass transfer. Currently, he is on leave and studying
human nutrition at Columbia University as a Special Fellow of the
National Institutes of Health. Dr. Regan serves as a consultant to
industry and government organizations and is a member of AIChE.
(Below left)

Randolph T. Hatch is engaged in teaching and research in the
field of Biochemical Engineering. Hatch received his BS degree from
the University of California, Berkeley and his MS and PhD degrees
from the Massachusetts Institute of Technology. He is a member of
AIChE, ASM, ACS and serves as the advisor for the student chapter
of AIChE. (Below right)



Amplifier Outputs

Component Outuput or Value-
Amp. I -T
4 D'-/T

4 D-/'1'


Pot 1

B D'-B/T dT
T dy'
D' -B/T

_-D' -//T *

dy *

T* + T*


0. -

D '-I/T
0. 1

T* I

And Potentiometer Settings

Estimated Max. Valu,
-400 K
-0.1 I

0.01 -

e Scaled Value
-100 B/T2

1000 eD'-B/T
10000 0'

-.01 -1000 '-/T dT
-1.0T -!02 dy*

0. o00 eD-B/T

-0.1 -100 D'-B/T x*

-1.0 -10 dT

1.0 10T*
1.0 10T* I 10T*1]
1.0 10x*

on0 TO/100 Ref.
.000 B/2000 Ref.

10 D'-B/T[o

X* '

Stanley M. Finger is a Pollution Control Engineer at the Naval
Ship Research and Development Center (Annapolis, Md.) specializing
in the development of technologies and equipment to eliminate
pollution from ships. He is working toward his PhD in ChE at
the University of Maryland. He received his MS from the University
of Maryland and his BS in chemistry from Pratt Institute. Mr.
Finger is a member of AIChE, ACS, Tau Beta Pi, Pi Mu Epsilon and
Sigma Xi. (Above left)
Theodore W. Cadman is engaged in teaching and research di-
rected to process control and simulation. He serves as Director of
the Laboratory for Process and Simulation at University of Maryland.
Dr. Cadman received his BS, MS, and PhD from Carnegie Mellon
University. He is a member of the AIChE, ACS, NSPE and ISA.
(Above right)


T HE VALIDITY OF Equations 15 and 16 were
tested against available data from compost
piles. The boundary conditions used were
at y* 0 dT*/dy* 0, dX*/dy* = 0,
T* =T*, aty*= 1 X* = 1
where y* = 0 represents the center of the pile
and y* = 1 represents the outside surface. The
experimental data of temperature distributions
in actual compost heaps was supplied by the
Butler County Mushroom Farms.t The value for
the activation energy was determined from rate
versus temperature data on laboratory compost
heaps5 and was found to be 1.11 x 104 cal/mole.
The experimental compost data were then fitted
by varying the values of the other model para-
meters. The shape of the computer was very
sensitive to changes in the pre-exponential con-
stants and were affected to a much smaller degree
by the boundary conditions.
Correlations between the model and two sets
of data are shown in Figures 2 and 3. y* 0
represents the center of the compost pile with the
outside surface being at y* = 1. The temperature
range in the two graphs is from 27C (T* = 0)
to 1270C (T* = 1) and the oxygen combination
range is from 0% o0 (X* = 0 to 21% 02 (X* = 1).


The two sets of data were taken from separate
compost piles at a height of 3 feet from the bot-
tom of the pile. The piles were 7 feet wide and
approximately 61/2 feet high. The computer pre-
dictions were within 1 C of the measured temper-
atures for 9 of the 14 data points, i.e., 64% of
the points, and were within 20C for 13 of the
14 data points. The maximum deviation between
the model predictions and the measured tempera-
tures was 30C. The oxygen distributions pre-
dicted are reasonable in that they predict low
oxygen concentrations in the interior of the pile,
as have been found experimentally9, 10 The model
further predicts that the oxygen concentration
rises rapidly as the outer edge of the pile is ap-
proached until at the surface the oxygen concen-
tration is equal to atmospheric conditions (X* =
1 or 21% by volume).
The values of the model parameters used to
obtain the computer predictions in Figures 2 and
3 are given in Table 2. The dimensionless para-
meter C, which is related to the oxygen distribu-
tion varies by 7% of the average value for the
two data sets, while D, which is related to the
temperature distribution, varies by 8% of the
average. The relative constancy of the model
parameters would be expected since the data were
obtained on similar compost piles and therefore
only small variations were anticipated.


computer predictions
Experimental measurements

0. 6



0.0 0.0 0.2 0.4 0.6 0.0 1.'0

FIGURE 2. Correlations For Compost Heap 1.


computer predictions
0.8 x experimental measurements




0.0 0.2 0.4 0 6 0. 8 1.T

FIGURE 3. Correlations For Compost Heap 2.

T HE SUCCESS WITH which the model pre-
dicted temperature and oxygen distributions
gives strong support to the assumptions made in
its development. Specifically, proof of the oxygen
limitation assumption is very important in com-
mercial activities such as composting since the
rate at which the process is carried out could be
significantly increased by improved aeration.
The mathematical model presented here will be
used to study the effects of process modifications
to improve such activities. Similarly, the use of
the biological oxidation reaction as the pre-
dominant oxidative reaction is important in help-
ing to understand and control aerobic microbial
It should also be noted that the basic mathe-
matical form of the model is applicable to any
problem in which simultaneous heat transfer,
mass transfer and reaction are taking place. The
analog computer program that was developed can
be adapted to solve the resulting coupled
differential equations by simply varying the
model parameters and boundary conditions. Al-
though the equations and computer program
were developed for a cartesian coordinate system,
they could be extended to solve problems in other
coordinate systems, e.g., radial distributions in
cylindrical or spherical systems. E
(Continued on page 100.)


Today for tomorrow.

JOHN H. SEINFELD, California Institute of
Technology. 1975, 400 pages, $22.50.
Here is a quantitative and rigorous approach to
the basic science and engineering underlying the
air pollution problem. The most comprehensive
single book available on the subject, it provides
an in-depth treatment of air pollution chemistry,
atmospheric transport processes, combustion
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ROBERT V. THOMANN, Manhattan College.
1972, 286 pages, $18.50.
Using both mathematical models of environmental
responses and management and control schemes,
the text provides a series of analytical tools for
describing and forecasting the effects of the sur-
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stream or estuary, presents information on water
quality criteria and wastewater inputs, establishes
a point of departure for evaluating the worth of
water quality improvement projects and discusses
the benefits of applying cost/benefit analysis to

LINVIL G. RICH, Clemson University. McGraw-
Hill Series in Water Resources and Environ-
mental Engineering. 1973, 405 pages, $17.50.
Solutions Manual
While covering a broad spectrum of environ-
mental topics, the focus is on the system as a
whole and how its components interact rather
than the components themselves. This systems ap-
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vironmental phenomena, as well as in the selection
and design of engineered facilities needed for con-
trolling the environment. Although water environ-
ment is considered in greatest detail, also included
are air pollution and its control, solid waste man-
agement and radiological health. The mathematics
of systems analysis and computer solutions is used

H. C. PERKINS, University of Arizona. 1974,
407 pages, $16.50. Solutions Manual
To date, this is the only truly engineering-oriented
text on the subject that draws upon the student's
background in analyzing and solving problems in
air pollution. The treatment is sufficiently de-
tailed to enable chemical, mechanical, and sanitary
engineering students to solve a variety of prob-
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of air pollution is included along with numerous
applications-type problems.

HAL B. H. COOPER, JR., University of Texas at
Austin, and AUGUST T. ROSSANO, JR., Uni-
versity of Washington. 1971, 278 pages, $14.50.
A discussion of principles and methods used for
testing of gaseous and particulate materials be-
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in use for gaseous and particulate particles.

AUGUST T. ROSSANO, JR., University of Wash-
ington, and HAL B. H. COOPER, JR., University
of Texas at Austin. 1969, 214 pages, $19.50.
The book provides a comprehensive and balanced
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A clear and unified treatment of various thermo-
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wide range of applicability of the basic laws of
thermodynamics. Beginning with a comprehensive
review of the first and second laws, the text ex-
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multi-component compressible systems; stability;
phase and chemical equilibrium; thermodynamics
of elastic system, interfacial-tension system, mag-
netic system, and electric system; cryogenics; and
the third law and negative Kelvin temperatures.

Second Edition
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of the City University of New York, MICHAEL
both of Rensselaer Polytechnic Institute. 1975,
492 pages, $16.50. Solutions Manual
Important changes in this revision include a con-
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550 pages, $19.50.
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Third Edition
J. M. SMITH, University of California at Davis,
and H. C. VAN NESS, Rensselaer Polytechnic
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neering. 1975, 632 pages, $19.50.
Including a new chapter on solution thermody-
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FORD, and CHARLES R. WILKE, all of the Uni-
versity of California, Berkeley. 1975, 672 pages,
Compared to the 1952 version Absorption and Ex-
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of mass transfer. Emphasis is on the practical
aspects and real problems that demand an under-
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are minimized by explicit citation of over 1,100
contemporary references.

of the United States Naval Academy. 1973, 480
pages, $17.00.
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1970, 544 pages, $17.50.
By developing principles of kinetics and reactor
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U. of Oklahoma
Norman, Oklahoma 73069

IT WAS SHORTLY AFTER completing his
undergraduate degree (University of Michi-
gan) that Cedomir M. "Cheddy" Sliepcevich be-
gan a long list of engineering "firsts."
In 1942 he undertook the first electron micro-
scopic study of crystals of hydration from Port-
land cement, which contributed to an increased
understanding of the hardening process. Then,
during his doctoral research, he pioneered the de-
sign of equipment for carrying out chemical re-
actions at high pressures and high temperatures.
In subsequent work, both in the laboratory and in
the development of industrial processes, Sliepce-
vich made important contributions to the under-
standing of high pressure technology of reaction
kinetics, and of catalysis. The magnitude and
quality of these contributions ultimately led to
his selection as the recipient of the American
Chemical Society's International Ipatieff Prize in
Cheddy began his teaching career as a gradu-
ate assistant. Upon completion of his doctoral
work he was appointed assistant professor of
Chemical and Metallurgical Engineering at his
alma mater, the University of Michigan, 1948.
With G. G. Brown he pioneered the development
of a generalized system approach to thermo-
dynamics which is widely used today.

This "Student
Family Tree" shows
the 60 Ph.D. students
who now hold prominent
positions in govern-
ment, industry
and education.

While on the faculty at Michigan, he and his
graduate students developed the laboratory facili-
ties and programs which permitted them to con-
duct classical experiments in light and energy
scattering. These experiments led to fundamental
extensions in the theory of energy scattering and
constituted one of the first applications of high-
speed computers for non-military, scientific re-
search resulting in three widely acclaimed
volumes on the mathematics related to light and


energy scattering. This pioneering work was
particularly cited in his receiving the American
Society for Engineering Education's Curtis Mc-
Graw Research Award in 1958.
In the late 1940's Cheddy initiated one of the
first research programs in bio-engineering in this
country. The principal contributions from this
effort were the development of one of the earliest
clinical, artificial kidneys and the techniques for
using streaming potential to measure blood flow
in remote portions of the body.

N FEBRUARY, 1955, HE JOINED the Uni-
versity of Oklahoma faculty as professor and
chairman of Chemical Engineering. From 1956
through 1962, he served as associate dean of the
College of Engineering with full responsibilities
for all research activities, graduate study,
accreditation, faculty recruitment and develop-
ment. His leadership was the basis for a complete
renewal and revitalization of the College of
In July 1958, he became chairman of the
School of General Engineering in addition to his
duties as associate dean. Convinced that the tra-
ditional engineering disciplines-mechanical en-
gineering, chemical engineering and electrical en-
gineering-had much in common, he implemented
a core curriculum concept in the undergraduate
program in which approximately 70 per cent of
the course requirements for all engineering pro-
grams were effectively identical.
This concept not only gave the student better
preparation for coping with rapidly advancing
technology but it also permitted optimum use of

university resources. The initiation of the core
curriculum also led to the development of a
flexible curriculum in General Engineering which
met the full requirements for ECPD accreditation
while allowing the tailoring of individual pro-
grams to meet the background and career goals
of the students. Through his leadership, the
College of Engineering created a graduate pro-
gram that cut across disciplines both within and
outside the College of Engineering. These con-
tributions to engineering education earned him
the ASEE's George Westinghouse Award in 1964.
In January, 1963, Cheddy relinquished all ad-
ministrative responsibilities to devote full time to
teaching and research as a George Lynn Cross Re-
search Professor of Engineering-the youngest
person to receive this distinction at the University
of Oklahoma.
While at Oklahoma he has developed three
highly productive laboratories for investigating
system identification and process control, chemical
and physical phenomena at elevated pressures,

In 1963 Cheddy relinquished all administrative


He and his graduate students developed
the lab facilities and programs to conduct
classical experiments in light and energy
scattering . These experiments led
to fundamental extensions in the
theory of energy scattering.
This work was . cited in the ASEE
McGraw Research Award to him in 1958.

and the fundamental behavior of flames. The
Flame Dynamics Laboratory has become inter-
nationally recognized for its significant contribu-
tions to fire research, and recently this laboratory
played a major role in evaluating the escape
worthiness and occupant survival in automobiles
and buses.
Additionally he has directed the program of
20 master's students, 44 Ph.D. students, one Doc-
tor of Engineering student, and is currently
serving as committee chairman for five students.
In the 1960s Cheddy became involved in the
development and evaluation of a novel process
for removal of water from dilute aqueous solu-
tions. This process uses an exchange crystalliza-
tion technique to take advantage of some unique
thermodynamic properties of ice and water.
Several patents have been issued on this process
in the United States and foreign countries. Cur-
rently he is directing the operation of a 75,000
gallon per day demonstration plant which he and
his associates designed, developed, and built in
Norman for desalinating sea and brackish water.
This privately supported pilot plant appears to
provide a substantial cost advantage and energy
savings over other desalination techniques. It is



He is regarded as the key to LNG technology.

expected that the process soon will be available
In addition to his academic and public service
activities, Cheddy has maintained an active con-
sulting practice. Through his consulting work
with Continental Oil Company in Ponca City, he
became Director of Research and Engineering.
He managed and pioneered the research, de-
velopment, and implementation of the first com-
mercial process for liquefaction and ocean trans-
port of liquefied natural gas. These original efforts
became the basis for the current development of
a multibillion dollar industry for the processing,
transport, and utilization of LNG. His technical
leadership in conjunction with this major effort

Cheddy at home with his wife, Cleo.
Cheddy at home with his wife, Cleo.

has made Sliepcevich an internationally recog-
nized name. He is regarded my many as the father
of LNG technology, and in 1962 his contributions
were recognized by designation as a National
Sigma Xi Lecturer on the subject of "Liquefied
Natural Gas-A New Source of Energy."
In 1974 Cheddy Sliepcevich was named En-
gineer of the Year by the National Society of
Professional Engineers, and Oklahoma has re-
cently honored him by inducting him into the
Oklahoma Hall of Fame.
Other honors include: The University of
Michigan's Sesquicentennial Award for dis-
tinguished alumni (1967), membership in the Na-
tional Academy of Engineering (1972), and Peter
C. Reilly Lecturer at the University of Notre
Dame (1972). E


Continued from page 51.

of ASEE in a miniplenary scheduled for 10:00
a.m., Wednesday, June 18. The panel consists of
Ruth S. Stockton, a Colorado State senator, who
is on the appropriations committee which has a
very strong say over university funding; William
K. Coors, a member of the Board of Trustees of
the Colorado School of Mines and President of
Adolf Coors Company; Brage Golding, president
of San Diego State University and previous presi-
dent of Wright State University and department
head of chemical engineering at Purdue Uni-
versity; Neal Pings, vice provost at the California
Institute of Technology and chairman of the
chemical engineering division of ASEE; and
L. Bryce Andersen, Dean of Engineering at the
New Jersey Institute of Technology. This is a
topic which concerns every educator.
A session at 3:45 p.m. on Tuesday, June 17,
which should also attract many non-chemical en-
gineers is one which will consist of progress re-
ports on innovative programs in engineering.
Four schools have made extensive changes in the
traditional ways of presenting engineering and
will discuss the successes and problems they en-
countered. All of these programs are currently in
The West Virginia Program in design oriented
education will be presented by John T. Sears, pro-
fessor of Chemical Engineering. Wilmer T.
Kranich, head of Chemical Engineering at
Worchester Polytechnic Institute will discuss
their program which replaces course requirements
with competency demonstrated by projects and
examinations. Ohio University's tutorial program
will be explained by Professor Nicholas Dinos of
the chemical engineering department. This pro-
gram is based on the Oxford Cambridge Tutorial
concept, and is for exceptional students. The
final presenter will be Professor Clyde H.
Sprague, Coordinator of Engineering at the Uni-
versity of Texas of the Permian Basin. This new
university is operating all their engineering
courses on a self-paced basis.
The theme of the 1975 convention is "Engi-
neering Education for World Development." On
Wednesday at 1:45 p.m. there will be four papers
given at a session entitled, "How Should Chem-
ical Engineers Train Foreign Students from De-
veloping Countries." Speakers from the Uni-
versity of Kansas, Toledo, Pittsburgh, and Mis-

souri will discuss how they have changed tradi-
tional programs to make them more useful to
foreign students when they return to their own
countries. They will discuss how to give them
more managerial, practical knowledge, and lab-
oratory skills.
A panel of experts will convene on Monday,
June 16 at 4:00 p.m. to inform you what a de-
partment head can do to obtain research funds for
new faculty members. They should be able to tell
us how all our departments can obtain five digit
research grants for inexperienced proposal writ-
The 3M award lecture which is always a high-
light of the meeting will be given at 1:30 p.m. on
Tuesday, June 17. The speaker had not been
selected at press time.
Have you ever wondered what your legal and
moral obligations are if you are called as an ex-
pert witness in a trial? Can a lawyer twist you
around his thumb? The meeting scheduled for
Wednesday, June 18, at 3:45 p.m. and entitled,
"Law, Technology, and the Role of the Expert,"
should provide you with the answers.
If this is not enough, the division also is spon-
soring the annual banquet on Tuesday night. It
features a presentation by Robert Fergason, Dean
of Engineering at the University of Idaho. He
will talk about his experiences in Ecuador and
Peru. Bring your wives to this one.
There is also a business luncheon on Wednes-
day which all should attend so that you may shape
the future of your society.

s news

Dr. Joseph F. Gross has been appointed new Head of
the Chemical Engineering Department at The University
of Arizona. Dr. Gross succeeds Dr. Don H. White, the
founding Head of the Department, who stepped down last
year to devote more time to teaching, research and Uni-
versity/industry relations. The Department searched na-
tionwide and then elected to reach into its ranks for the
new Head.
Dr. Gross came to The University of Arizona in 1972
from the Physical Sciences Department of the Rand Cor-
poration in Santa Monica, California.
Dr. Gross was educated at Pratt Institute in Brooklyn,
New York, and at Purdue University, West LaFayette,
Indiana. In 1957, he was a Fulbright Scholar in Germany.
He has published over fifty technical papers and holds
membership in several learned and professional societies.


N laboratory


Drexel University
Philadelphia, Pennsylvania 19104

N THE FLOW OF POLYMER melts, one of
the most striking phenomena commonly ob-
served is pseudoplastic behavior or the decrease
in apparent viscosity with increasing rate of
shear. Although certainly a majority of chemical
engineers will encounter such behavior at some
point in their careers, the chemical engineering
undergraduate's exposure to such effects is usual-
ly limited to one, or perhaps two, problems in a
course in momentum transport. In the experi-
ment described below, we at Drexel University
have attempted to deepen the student's exposure
to this, and other, interesting aspects of the flow
of polymeric fluids.
The experiment consists of measuring the
rates of drainage, by gravity, of a non-Newtonian
fluid from a tank through vertical tubes of various
lengths and diameters. These measurements, plus
that of the overall head-distance between the
fluid surface and the tube exit, permit the student
to determine the material constants K and n in
the familiar power-law equation:

r = K y ,-1 7, (1)
where r and y are the shear stress and rate of
shear, respectively.
Although the experiment appears straight-
forward, the analysis of the data contains an in-
teresting twist, arising from determination of
the frictional losses in the tube. Except for a
small kinetic energy correction, the overall
frictional losses simply equal the read loss; but
the overall frictional losses consist of those in
the tube and "other" losses. For many non-New-
tonian fluids these "other" losses are of the same
order of magnitude as those in the tube and thus
cannot be neglected. Most of these "other" losses
occur in the region of converging flow upstream
of the tube entrance1 although those associated
with velocity rearrangement at the tube exit and
in the tube's entrance region also contribute.2

The origin of these converging-flow losses can be
explained qualitatively by the fact that at least
some polymeric solutions possess a much higher
extensionall viscosity" than shear viscosity, and
upstream of the tube entrance, the motion is pre-
dominantly an extensional deformation. For these
solutions, then, the converging-flow losses can be
several orders of magnitude greater than those for
a Newtonian fluid of comparable shear viscosity.
The student, therefore, is introduced to the
phenomena of pseudo-plastic behavior and high
converging-flow losses. In addition, the experi-
ment itself parallels an instrument used widely
in industry, the capillary viscometer. Finally, the
data analysis illustrates clearly the use of both
the mechanical energy balance equation and the
quasi-steady state approximation.

M OST STUDENTS SELECT as their objective
the determination of the power-law con-
stants of the particular fluid used. For this ob-
jective, they need to determine the apparent vis-
cosity, ap,,p, or the local ratio of shear stress to

Charles B. Weinberger completed his undergraduate work at
the University of California and his graduate work at the Uni-
versity of Michigan (PhD, 1970), all in Chemical Engineering. His
industrial experience ranges from studies of wheat-peeling and
mass transfer and thermodynamic characteristics of molten salts to
polymer processing-the latter with DuPont (1970-72). He joined
Drexel University in 1972. His current teaching and research interests
are in the areas of polymer processing, rheology, and fluid mechanics.



- I---





FIGURE 1. Sketch of Apparatus.

shear stress to rate of shear, 7/y. Since

Lapp = K n-1

velocity distribution in the tube introduces an
error of less than 1% in lwf. As mentioned earlier,
the total lost work, lwf, includes both frictional
losses in the tube and "other" losses, lwt l1w, re-
spectively. hwt is the tube frictional loss exclusive
of extra losses associated with velocity rearrange-
ment in the tube's entrance region, or:

w (dp L (4)
dz p

where (dz is the equivalent pressure gradient
Sdp ,.

downstream of the entrance region and L is tube
length. lwo can be estimated by forming a Bagley-
type plot3 that is, by determining the ordinate
intercept on a plot of lwf versus tube length, keep-
ing diameter and flow rate constant. For an in-
elastic non-Newtonian fluid (only approximated
by the fluids we use) lwo includes viscous losses
in the converging section and at the tube exit,
as well as the extra losses in the tube's entrance
region associated with developing the velocity
profile in the tube. For the fluids that we use, lwo
(2) consists primarily of converging-flow losses; for
the student to confirm this, however, he must go
to the literature to find means to predict the mag-
nitude of the other terms.
The friction loss in the tube is then deter-
mined by difference,
hVt = lwf lwo (5)


the dependence of apparent viscosity on shear
rate for n =/ 1 is immediately obvious.
The first step, then, is to determine the shear
stress at the walls of the tube, rw. To do this, a
mechanical energy balance is taken over surfaces
(1) and (2) of Fig. 1. The quasi-steady state ap-
proximation is applied, thereby eliminating the
unsteady-state term (the student can easily per-
form a quick numerical computation to check the
validity of this approximation). The pressure
terms cancel and the kinetic energy at surface (1)
is negligible, leaving:
2u d-- g (z, z) + lwt = 0 (3)
For the fluid we use, the first term of Eq. (3),
the kinetic energy term, is less than 10% of the
other terms; thus, an assumption of a parabolic

From a second mechanical energy balance and
a momentum balance on the fluid in the tube,
the wall shear stress is
p D lt (6)
-- 4 L (6)

The second step is then to determine the shear
rate at the wall yw, one procedure is to use the
Weissenberg-Rabinowitsch-Mooney equation:

y, = 3/4+ 1/4 -r,- (7)

32Q (8)

The derivation of Eq. (6) is described verbally
and the derivation is left to the student. (An in-
teresting pedagogical benefit of the derivation of
Eq. (6) is the necessity to use Leibnitz's formu-
la) .4 A plot of T, versus 0, along with Eq. (7),



yields T, (y,-) and thus Iap, (y), (Note that Tw
should depend only upon tube diameter, not
length.) This procedure, since it relies on locally
differentiated data, is subject to considerable data
scatter. Such scatter can be minimized by assum-
ing the existence of a power-law fluid, for which

where the relationshipK (9)
where the relationship

K = K' (


300 I I I I




can be derived from Eq. (6). By plotting log r,v
versus log 0, the constants K' and n, and thus K
and n, can be obtained.

The draining tank is cylindrical, 31 cm high
and 20 cm in diameter; copper tubes, ranging in
diameter from 0.3 to 0.8 cm and in L/D from 11
to 110, have screw fittings for easy attachment
and removal from the tank. A screen, placed two
cm above the tube entrance inhibits vortex forma-
tion. Flow rates are measured by catching and
weighing the fluid issuing from the tube in a
measured period of time.
The fluid consists of 0.5 wt% Separan AP30, a
high-molecular weight polyacrylamide obtained
from the Dow Chemical Co., dissolved in a 1:2,


d 5.5cm-+

4 -
4 -

x 2-

p2 d = 9.0 cm
/0 16.4 cm3/sec
D = 0.793cm -
\lwo T = 320C
0I I I I I
0 20 40 60
FIGURE 2. Determination of "other" Frictional Losses, Iwo,,
As the Ordinate Intercept.

80 100

200 300

400 500

FIGURE 3. Flow Curve in Terms of Consistency Variables.

by weight, glycerol-water solvent. Results with a
lower concentration of polymer, 0.25 wt%, were
unsatisfactory because effects of the solution's
elasticity precluded accurate estimation of lwo,
and thus lwt. Of course, other polymer solutions
could also be used; we note that aqueous solutions
possess the advantage of being easy to clean up.
For each diameter the overall head, ZI-Z2, re-
quired to maintain a given flow rate is measured
for various tube lengths. Recall that Q must be
kept constant as L is varied in order to determine
lwo, which depends upon Q and tube diameter.
The fluid depth in the tank should be kept
sufficiently large so that lwo does not depend on
this depth. The necessary experimental trial and
error procedure required to maintain Q constant
(quasi-steady-state) is rather simple. A plot of
lwf versus L for each tube diameter extrapolated
to zero tube length then yields lwo; an example is
shown in Fig. 2. These losses can be compared to
the entrance-region losses for Newtonian fluids
in laminar flow.5
Once the extra losses have been determined,
Tw can be calculated from Eq. 3, 4 and 5. Assum-
ing the applicability of a power-law fluid model,
log Tw is plotted versus log 4, as shown by Fig. 3;
this plot yields the values n=0.65 and K'=4.25
dyne-sec"/cm2. From Eq. 10, K=3.91, and thus
I.pp = 3.91 17y -0.35


his own experimental objective and the
flexibility of the draining-tank apparatus permits
the pursuit of several other objectives. In addi-
tion to the traditional analysis of an unsteady


0 0.317
-2 0.634
O 0.793

n = 0.65

flow situation, two such studies include:
* Dependence of converging-flow losses upon flowrate
and tube diameter,
* Using only water, comparison of entrance-region pres-
sure drop with that of fully developed flow as a func-
tion of Re and L/D for turbulent flow of water in
circular tubes.
The first study permits a prediction of the de-
pendence of the first normal stress difference on
shear rate [1].


In any laboratory experiment, the chemical
engineering educator is most interested in the
specific teaching values of the experiment. In this
particular experiment, there are several. First,
the student gains valuable practical experience
with several analytical concepts-specifically,
momentum and mechanical energy balances,
Leibnitz's formula, and the quasi-steady state
approximation. Second, the apparatus simulates
an instrument used widely industrially, the capil-
lary viscometer. Finally, the experimental appara-
tus, which is simple to operate and yields accurate
results, illustrates such complex non-Newtonian
flow behavior as shear-thinning viscosity and high

viscous losses in converging flow.

d depth of fluid in tank, cm
D tube diameter, cm
K, K' material constants in power-law model, dyne-se
L tube length, cm
1w lost work, cm2/sec2
n material constant in power-law model, dimensionless
p pressure
Q volumetric flow rate, cm3/sec
u velocity in axial direction
z distance coordinate
Greek Letters
y rate of shear, sec-1
p. viscosity, P
p density, gm/cm3
T- shear stress, dyne/cm2
4) consistency variable, sec-1

1. Oliver, D. R., MacSporran, W., and Hiorns, B. M.,
J. Appl. Poly. Sci., 14, 1277 (1970).
2. Han, C. D., Trans. Soc. Rheol., 17, 375 (1973).
3. Bagley, E. B., J. Appl. Phys., 28, 624 (1957).
4. Middleman, S., The Flow of High Polymers, Inter-
science, New York 1968.
5. Weissberg, H. L., Phys. Fluids, 5, 1033 (1962).


At Fluor Engineers and Constructors, Inc. our 4
billion dollar plus backlog offers all kinds of practical
applications opportunities for chemical engineers to
help provide solutions to the energy problem.
At Fluor Engineers and Constructors, Inc. we de-
sign and build facilities for the hydrocarbon processing
industry-oil refineries, gas processing plants, and
petrochemical installations. We are very active in
liquefied natural gas, methyl fuel, coal conversion, and
nuclear fuel processing.

If you want to find out about opportunities, loca-
tions you can work in (world wide) and why Fluor is
the best place to apply what you have learned, meet
with the Fluor recruiter when he comes to your campus
or contact the College Relations Department directly.

Fluor Engineers and Constructors, Inc.
1001 East Ball Road
Anaheim, CA 92805






University of Waterloo
Waterloo, Ontario, Canada

Engineering at Waterloo it became apparent
that the popularity of the Cooperative Programme
would cause the department to become quite large
and, in so doing, provide many good opportunities
for innovation in curriculum development.
Firstly, there was the opportunity to offer a
wide variety of specialist courses. In addition, a
concentrated technical and non-technical curricu-
lum was possible because the cooperative work
terms would provide the practical experience
needed by the chemical engineering undergradu-
ate. In developing such a curriculum in a very
short time there was the danger that it would
lack cohesion and purpose. Also the departmental
size and the inevitable on-off discontinuity of the
cooperative system could cause the students to
have a lack of identity. The Waterloo programme
was developed to exploit the advantages and to
anticipate and avoid the disadvantages.

One hundred and twenty first-year students
enroll in September of each year in Chemical
Engineering. (This is in contrast to the ap-
proximately five hundred other engineering
students who enroll in General Engineering. One
other department, Systems Design, also enrolls
into its first year programme.) One advantage of
a first year chemical group is to provide a sense
of identity for the students, who are often lost
in the vastness of a large university and need "to
belong." The effects of this identity advantage
are intangible, but there are a few indications:
for example, in the level of the ChE mathematics
marks which more often than not are higher than
the rest of engineering, which takes exactly the

same course. Certainly the ChE first year students
get to meet and know their professors early in
their first term. For example in September of
1974 the ChE class is being taught in one way
or another by at least ten ChE faculty members.
In this 1A term the students receive the same
Mathematics, Chemistry and Physics (see Table
I for curriculum content) courses as the rest of
engineering. In addition, they obtain a course in
Measurement and a course given by and for
Chemical Engineers, namely, "Introduction to
Engineering Concepts I" which is an introduction
to the basic methods and principles used by
engineers in the analysis and design of physical
processes. Topics covered by means of lectures,
case studies and problem assignments are: units,
dimensions, measurements, mass balance, be-
haviour of fluids, non-technical and social impli-
cations of the engineers work, freehand sketching
and blueprint reading. One non-technical elective
can also be selected from a choice of three
specially designed for the freshman student.
In January, the ChE class divides and one
stream goes to industry while the other (1B
class) continues for a second term of studies. This
streaming has the advantage of reducing the class
size, and ensuring the subsequent year-round use
of the university physical plant and teaching re-
sources. The courses taught during this term are
again general to all of engineering except, "In-
troductory Engineering Concepts 2" which ex-
tends the topics covered in the previous course to
include energy balances, unsteady state behaviour
of engineering systems, and laboratory experi-
ments to illustrate the physical principles dis-
In the term beginning in early May, the
students who were in industry return for their 1B
term and the group which has already taken the
1B term now moves out into industry. Thus, the
classes alternate with terms on-campus and terms


1B Winter and Summer 1975
Introductory eng. concepts
Calculus 1 cont'd.
Algebra 1 cont'd.
Digital Computation
Electricity and Magnetism

One of these courses in
each term

2A Fall and Winter 1975-76 2B Summer and Fall 1976

Calculus 2

Organic chemistry 1
Physical chemistry 1
Inorganic chemistry 1
Non-technical elective

Differential equations
Transport processes 1.
Organic chemistry 2
Physical chemistry 2
Physical chemistry lab.
Non technical elective

3A Winter and Summer 1977 3B Fall and Winter 1977-78

Applied mathematics

Transport process 2.
Heat transfer
Inorganic chemistry 2

Instrumental methods of
chemical analysis
Chemical engineering

4A Summer and Fall 1978
Process dynamics and
Engineering economics
Process design and
technical seminar
Technical elective
Technical or non-
technical elective

Chemical engineering
Transport processes 3. Mass
Chemical reaction
Technical elective

Non-technical elective

4B Winter 1979
Research-design project or

Process systems design or
Technical elective project

3 Technical electives
Technical or non-
technical elective

in industry until they combine again in the final
4B term before graduation. Table I shows the cur-
riculum facing the 1975 Freshman and the way
in which he is expected to progress through the
B.A.Sc. programme.
Some special features are contained in the
programme which reflect the earlier discussion of
our concern with the advantages and disadvant-
ages associated with the large department.

* Each student can select from six to eight technical

TABLE I Curriculum of the 1974 Freshman


M .A.Sc. THESIS STUDENTS must take at
least four graduate courses at least half of
which must be taken from the list shown in Table
III. Course work M.A.Sc. students must take
eight courses and write an Engineering Report.

Early in the history ChE at Waterloo it
became apparent the popularity of the
Co-Op program would cause the department
to become quite large, and provide
many good opportunities for
innovation in curriculum development.

Ph.D. students must take at least a further four
courses beyond the M.A.Sc. requirement and in
addition must pass the Research Proposal exam
and defend a Ph.D. thesis. The Graduate course
programme of the department fits again into the
group pattern and students in collaboration with


1A Fall 1974
Introductory eng. concepts

Calculus 1
Algebra 1
General Chemistry
Topics from scientific
Introduction to the
sciences of man
Topics from the arts and

elective courses at least three of which must be taken
from an option package (see below for details). Breadth
and depth!
* The undergraduate student has the opportunity to select
from four to six non-technical courses from offerings
across the whole university. Breadth!
* A set of seven mathematics courses culminating in a
course in "Applied Mathematics" (3A Term) are core
content of the programme. Depth!
* A set of three transport processes courses and one
chemical engineering laboratory is core content. Depth!
* Chemical engineering thermodynamics, instrumental
methods, chemical reaction engineering, process dy-
namics and control, engineering economics and technical
seminar are all core courses. Breadth!


Five to seven Technical Elective courses must
be selected by the undergraduate. To ensure each
student obtains a reasonably deep understanding
of at least one area of interest, a minimum of
three courses must be chosen from one of the
option groups listed in Table II. These course
groupings reflect the main interests of the faculty
members in the department. The other technical
electives may be chosen from other ChE offerings
or from other science, mathematics or engineer-
ing courses offered within the university provid-
ed the associate chairman of the department

their supervisors may plan a personalized curricu-
lum which will provide them with depth of
knowledge in their own special area of interest
and breadth of knowledge of some of the latest
developments in the field of ChE generally.

TABLE II Undergraduate Technical Electives

1. Transport Processes
Selected topics in process applications
Physico-chemical properties of gases & liquids
Air Pollution
Non-Newtonian flow and heat transfer
2. Mathematical Analysis and Control
Chemical engineering analysis
Process dynamics and control 2
Process control laboratory
3. Polymer Science and Engineering
Introduction to polymer science
Physical chemistry of polymers
Polymer laboratory
4. Extractive and Process Metallurgy
Introduction to extractive metallurgy
Metallurgical chemistry
Principles of high temperature extractive metallurgy
5. Biochemical and Food Engineering
Introduction to biochemical engineering
Fermentation operations
Food processing
6. Pollution Control Engineering
Selected topics in process applications
Air pollution
Introduction to biochemical engineering
Water pollution
7. Research and Design
Research-design project 1
Research-design project 2
Process systems design
Technical elective report
8. Non-Technical
The Chemical Engineer as an Entrepeneur

been assessing all the Ph.D. programmes
offered in the Provincial Universities. The Water-
loo doctoral programme and its plans for the
coming years was approved by the external con-
sultants, however, a general recommendation was
that "Ph.D. programmes in addition to the usual
scholarly goals, have as one of their aims an effort
to develop entrepeneurship in students since this
is a quality so badly needed at present in Canada."
At Waterloo we have taken this as a challenge
and we have prepared a course entitled, "The
Chemical Engineer as Entrepeneur." The course

will be available to 4B undergraduates and
graduates. "Engineering Economics" or its
equivalent will be required as a prerequisite. The
course is intended as an elementary introduction
to the mechanism by which an individual may
develop a small business for the purpose of
supplying goods or services to the chemical or
resource processing industries. The view present-
ed is that of an individual engineer who must per-
form most of the technical and management func-
tions himself, with the occasional help of profes-
sional specialists, rather than that of new enter-
prise management as practiced by large corpora-
tions. The main purpose of the course is to give
a familiarity with the problems and methods of
launching in Canada a new small enterprise in
the chemical technology field. Technical, economic,
legal and financial aspects will be outlined over a
broad spectrum of topics. The proposed course
has generated enthusiasm among many under-
graduates and graduates and expected enroll-
ments are high.
Curriculum development is a continuous pro-
cess at Waterloo. Many iterations have been
made for the curriculum to reach its present form

A general recommendation was that,
"Ph.D. programs in addition to the usual
scholarly goals, have as one of their aims
an effort to develop entrepeneurship in
students since this quality is so
badly needed in Canada" . we
have taken this as a challenge.

in just a few years. Usually new ventures are
first discussed at the Departmental Curriculum
and Graduate Review Committee levels. Each of
these committees contain active student represen-
tatives. Changes are less frequent now than they
were three or four years ago and when they are
made, questions such as whether or not they add
breadth or depth to the programme or whether
they can provide the student with a greater sense
of identity with his chosen career and department,
are of paramount importance.
The last word on the curriculum is given to
students who have been through it all!


Peter Douglas and Gordon Hayward (Class of '74)

"Like any first year students, the ones at Waterloo


TABLE III Graduate Courses

1. Transport Processes
Theory and applications of transport phenomena
Behaviour and properties of particulate material
Statistical theory of matter
Special topics in transport processes
Selected applications of the statistical theory
2. Mathematical Analysis and Control
Process optimization
Advanced mathematics in engineering research
Statistics in engineering
Chemical reactor analysis
Selected topics in analysis of chemical processes
Heat and concentration waves
3. Polymer Science and Engineering
Principles of Polymer Science
Physical properties of polymers
Polymer synthesis and characterization
Solution properties of macromolecules
Selected advanced topics in polymer science and
4. Extractive and Process Metallurgy
Applied physical inorganic chemistry
High temperature metallurgy
Special topics in hydrochemical metallurgy
Special topics in high temperature metal extraction
5. Biochemical and Food Engineering
Principles of biochemical engineering
Advances in biochemical engineering
Special topics in biochemical engineering
6. Research and Design
Oral exam for the Ph.D.
Research proposal for the Ph.D.
Graduate research seminar
Engineering report for the course work M.A.Sc.
Thesis for M.A.Sc.
Thesis for Ph.D.
7. Non-Technical
The Chemical Engineer as an Entrepeneur

initially find themselves a little lost or confused and
overburdened with work in their new environment. With
the ChE class smaller and separate from the other engi-
neering disciplines the first year students are usually a
more closely-knit group which is helpful. In addition, the
ChE faculty (28) make themselves very approachable to
the students. This is encouraged with "coffee and donuts
talk sessions," and class professors assigned to first year
classes. Class professors act as resource persons, counsel-
lors, and motivators. Sometimes they give a few lectures.
For example, ours spent time teaching us speedy slide-rule
pushing. Generally, the first two years of the programme
included many courses in the fundamentals of chemistry,
physics and mathematics. Looking back over the years,
we remember these courses to have been uninteresting
because they seemed to lack apparent ties to practical
applications. For this reason, these first two years were
probably the most difficult for us. A major improvement

now has more ChE professors teaching first and second
year courses. An introduction to ChE through a programme
provided for interested high school students in which first
and second year students participate also helps relate
pure science and math to ChE problems [1].
In the third and fourth years, heat, mass and momen-
tum transfer are taught. In addition, the student may
choose technical electives and begin to specialize in the
specific area of his choice. We choose both the transport
and control options hoping that we would be better suit-
ed to a variety of chemical industries rather than just
the polymer or food industry. In the fourth year the
student is required to work on either a research or design
project and is able to effectively apply many of the tools
which heretofore (in his academic career) have been limit-
ed to text book problems. The research projects provide
for specific interests beyond the scope of the other elec-
tives. In this way, one of us studied turbulent heat
transfer in a wind tunnel, a project which is rather un-
conventional for chemical engineers.
Aside from academics, the co-op programme plays an
important role in the development of a chemical engineer
at Waterloo. Although highly technical jobs may be diffi-
cult to come by in the first year and may employ more
body than mind there are enough jobs for everyone who
wants to work (one of us spent one work term unloading
box cars, a somewhat unusual work term). In the final
work terms most of the students are performing as
graduate engineers in their chosen field. For example one
of us spent his final work term designing heat exchangers
for the chemical industry.
Work reports are written after each work term. They
describe a project which was conducted during that term.
They seemed to be a chore at the time but looking back
they helped develop skills in writing which is often a
weak area of engineers. Work term jobs are usually lo-
cated in Ontario with a few scattered across Canada and
the odd jobs in the U.S. and Europe. Major employers
are pulp and paper, petrochemical, chemical, food and
steel processing companies. In 1974 averaged salaries
ranged from $615/month for first year students to
$670/month for fourth year students.
The social life at Waterloo depends on the individual.
Our leisure time was somewhat curtailed by a heavy work
load but a host of on-campus activities were available.
These ranged from a well developed intramural sports
programme to drama, concerts, pubs, dances, movies, etc.
Kitchener-Waterloo and the surrounding communities have
many fine pubs with the German culture very pre-
dominant (typical of this area).
In summary, our years at Waterloo were not the
easiest, but were very rewarding. We found that although
we were taught to be chemical engineers, the underlying
discipline of applying the laws of nature to design may be
applied to just about any field. In this way we think we
are well prepared for a wide variety of careers." 0


"Waterloo Program for High Schools," E. Rhodes, Chem.
Eng. Education, 44-47, Winter (1974).




Drexel University
Philadelphia, Pennsylvania 19104

Bechtel, Inc.
San Francisco, California 94119

DATA control systems in a chemical
engineering curriculum is usually accompanied
by a control laboratory in which the student
operates a process under computer control and
investigates the performance of various control
algorithms. If a process computer is not avail-
able, some insight into the design and operation
of sampled-data control systems can be obtained
through simulation on an analog computer. Simu-
lation also has the added advantage that various
control strategies, which would be impractical to
try with a physical system, can be implemented
on the analog computer. The purpose of this
article is to illustrate the techniques of simulat-
ing sampled-data control systems on a commercial
analog computer. This is followed by an example
in which these techniques are applied to a
practical problem. It is believed that the material
presented in this paper will be helpful as an exer-
cise to those who teach or are engaged in work
in the area of sampled-data control systems in
chemical engineering.

ed on the general topic of analog simulation
of sampled-data control systems. Osburn (1) has
described the application of integrators for track-
and-hold operation. He has discussed the use of
these track and hold amplifiers for stepwise cal-
culations, solution of certain partial differential
equations, and for parameter sweep studies.
Kingma (2) has described an equipment called
a D (Z) simulator which can be used to simulate

digital controllers without analog-to-digital and
digital-to-analog conversion. The simulator uses
a modified boxcar generator as the sample-and-
hold element. The control pulses for these sample-
and-hold elements are generated by one-shot multi-
vibrators. He has applied the procedure to design
of a deadbeat controller for an error-sampled
unity-feedback system.
Clemence (3) has studied the application of
track and hold amplifiers for simulation of
sampled-data control systems using digital logic.
He has utilized the two complimentary outputs of
a flip-flop to drive the track-and-hold amplifiers.
His paper includes an example of digital control
of a multirate system. In a later article Clemence
(4) has described the simulation of a three-mode
digital controller by means of track-and-hold
Corripio, et al (5) have studied the analog

Michael A. Rutkowski is a graduate student in the department
of chemical engineering at Drexel University, Philadelphia, Pennsyl-
vania. He obtained his B.S. in chemical engineering at Drexel in 1973.
Pradeep B. Deshpande completed his undergraduate degree in
chemistry from Karnatak University, Dharwar, India. He obtained
his B.S. and M.S. degrees in chemical engineering from the University
of Alabama and his Ph.D. degree in chemical engineering from the
University of Arkansas. His six years of industrial and teaching
experience includes a year at I.I.T., Kanpur and a year at Drexel
University, Philadelphia, Pa. Currently he is with the Simulation
and Advanced Control Section at Bechtel, Incorporated in San
Francisco, California.


simulation of frequency response of digital con-
trol systems. Their paper includes an excellent
description of the application of logic components
for simulation purposes.


AN EAI 580 ANALOG/HYBRID computer was
used in this study. The analog portion of this
computer contains 38 amplifiers-10 of which can
be used as integrators, 50 potentiometers, 8 multi-
pliers, 3 comparators and function relays, 4 track-
store units, 4 D/A switches, 8 log diode function
generators, and a trunk tray. The logic expansion
group on this computer contains 2 counters, 16
AND-gates, 2 general purpose registers (each
containing 4 flip-flops), 2 differentiators, and 2
switches. It is assumed that the reader is familiar
with analog computer programming so that only
the logic elements will be discussed here followed
by their application to simulation of sampled-
data control problems.
The logic components necessary for simulation
of sampled-data control systems on the analog
computer are: AND gates, flip-flops, counters,
and track/store units. The method of operation
of these components is described below.

An AND gate is a basic logic element which has two
or more logic inputs. (A logic signal can assume either
of the two values: ZERO (zero volts) and ONE (+ 5
volts). The logic ZERO and logic ONE are also referred
to as low and high, respectively). The output of an AND
gate is high (logic ONE) if, and only if, all the inputs are
high. If any of the inputs are low, the output is also low.
A simplified schematic of an AND gate is shown in Figure
l(a). The output of the gate is referred to as the true
output and the complimentary output (which is the op-
posite of the true output, e.g., if true output is logic 1,
the complimentary output is logic 0) is referred to as the
false output. The inputs of all the AND gates on this
computer are normally high so that a gate with un-
patched inputs has a logic ONE true output.

A flip-flop on this computer has three patchable in-
puts and a true and a false output. See Figure 1(b), and
enable patch terminal labeled E can remain unpatched
or can be patched to logic ONE source patch terminal to
enable the flip-flop. A logic ZERO patched to the E input
inhibits the flip-flop. A logic ONE patched to the set (S)
input causes the flip-flop to set (i.e. true output is logic
ONE) on the next clock pulse. A logic ONE patched to
the reset (R) input causes the flip-flop to reset (i.e. the
true output is logic ZERO) on the next clock pulse. A
logic ONE patched to both S and R inputs causes the


d-t I

0 rWNI

1. i, d

oI111" IN'll

(d) O~l C-Alo

iput to d, d1 ad "lid i

-"o ,lw I,, t te4 n
Intgrator watched as a T/S Ln

FIGURE 1. Logic Components.

flip-flop to trigger to the opposite logic level on each
clock pulse. There are three clock-rate pushbuttons
(106, 105, 101,) which select the clock rate for the logic
elements on this computer. If the 101 clock rate push-
button is depressed, the computer provides 10 pulses of
logic ONE per second. The clock output is logic ZERO
between pulses. Similarly, 105 and 106 pushbuttons pro-
vide one clock pulse every 10 microseconds and every
microsecond, respectively.

A counter has three patchable inputs (S, R, and Ci)
and a true and a false output. The schematic of a counter
is shown in Figure 1(c). A pair of thumbwheel switches
are used to present the counter to any number from 00
to 99. If a clock signal of 10 pulses per second (which is
obtained from a 101 patch terminal on the logic patch-
board) is applied to the Ci input of the counter patched
as shown in Figure 1(c), the counter counts down from
the number preset by the thumbwheels one count per
input pulse. Every time the count reaches 00 the false out-
put of the counter outputs a pulse (i.e. the false output
goes high). The false output of the counter is connected
back to set (S) patch terminal through a Gate so that
the preset number selected by the thumbwheels is loaded
into the counter every time the counter reaches 00. An
example of the input-output relationship of a counter is
shown in Figure 1(d).

The track-store (T/S) unit has one or more analog
inputs, a logic input, and an analog output. A schematic
of a track store unit is shown in Figure 1(e). When the



ltr G t1

(c) Patchin. of a Count

logic input (referred to as Track input and labeled "T"
on the T/S unit) is logic ONE, the analog output is minus
the analog input. If the T input switches from logic ONE
to logic ZERO the unit switches from TRACK mode to
the STORE mode. In the STORE mode the output of the
T/S unit remains constant and equals the value of the
output at the instant of switching. The input/output re-
lation of a T/S unit is illustrated by an example in
Figure 1(f). From the previous discussion it is clear that
the output of a flip-flop with both of its inputs patched
to logic ONE can be used as a logic "T" input for track
and store operation.
The computer used in this study is equipped with T/S
units. However, if T/S units are not available, an inte-
grator can be patched as shown in Figure 1(g) to per-
form the track and store operation. When the logic OP
signal is high, the integrator will store and when the
logic IC signal is high, the integrator will track. Here,
the true and false outputs of a flip-flop can be connected
to the logic OP and logic IC terminals, respectively, so
that the integrator will perform the track and store opera-

control 1er r -
1 e (S)

FIGURE 2. Sampled-data Control System.

feedback sampled-data system shown in
Figure 2. The objective of the exercise would be
to simulate this control system on the analog
computer and study the response C (t) of the
plant to changes in set point employing a well-
known expression for the control algorithm,
D (Z). This in turn means that we must repre-
sent the control algorithm and the zero-order
hold on the analog computer. The plant transfer
function is continuous and can be represented on
the analog computer by usual means.
Simulation of D(z) Controller:
The pulse transfer function of the controller

DM (z) (1)
S (z)

where M = manipulated variable
E = error

If we specify the nature of the response, it is
possible to obtain an expression for the output of
the controller. The time domain expression is
usually of the type

M* (t) = aoE* (t) + as E* (t T) ...
-[boM* (t T) + bM* (t 2T) +....]

where M* and E* represent discrete values of M
and E, respectively, a's and b's are constants and
T is the sampling period.
Thus, from equation (2) it is clear that in
order to simulate a digital controller we must be
able to perform the sampling, storing, and delay-
ing operations on the analog computer.
The sampling operation is performed by a
track-store unit. A square wave of period T is
used to drive the T/S unit. As mentioned earlier,
clock-rate selection of 10,6 105, and 10 pulses per
second is possible on this analog computer. The
high pulse rates of 105 and 106 pulses per second
are of little use for process control applications.
However, the clock-rate of 10 pulses per second
can be used for generating a square wave.
If a sampling period of T 0.2 seconds is
desired, a square wave can be generated simply
by means of a flip-flop whose set (S) and reset
(R) inputs are connected to a 101 clock-rate
patch terminal. The input/output relationships of
a flip-flop and the patching in this configuration
are shown in Figure 3(a). If a sampling period
other than T = 0.2 seconds is desired, it will be
necessary to use a counter (5). Consider the gene-
ration of a square wave with a period T seconds.
The patching for this purpose is shown in Figure
3 (b). Since we would like the output of the flip-
flop to be a square wave of period T, the counter
must output two pulses per time period T (i.e.
0.5 T seconds between output pulses). It will be
demonstrated by an example that if the counter
is to output 2 pulses per second, the value to be
set on the counter thumbwheels must equal the
period between output pulses (0.5 T seconds)
divided by the period between the input pulses
(0.1 seconds) minus one to account for the pulse
that reloads the preset value into the counter
i.e. 5 T 1. As an example, suppose we like the
output of a flip-flop to be a square wave of period
T = 1 second. Then, the counter output must be
2 pulses per second (or 0.5 seconds per pulse).
If we set the counter to 5T 1 4, the counter
will output a pulse every 0.5 seconds. The input/
output relationship of the elements of Figure 3



C ,
gate 7_ outout

0 pl


counter input 0 4 3 2 1 0 4 3 2 ] 0
-...... .p,. t l I t
,, .-f .op o-,t _.5 7
0.5 scons

FIGURE 3. Generation of Square Waves.

(b), are shown in Figure 3 (c). These square
waves are used to perform the sampling opera-
tion. To sample an input, a T/S unit is patched
as shown in Figure 4 (a). If a signal is to be
delayed by one sampling period, T, two T/S units
are used in tandem as shown in Figure 4 (b). As

L_" I

nalo input / output

Trick-And-Hold Operaior

II -
tr~ts -4
1 1

t d b,

I0 pulst1 tr
a __ OR --

R(t) = 5 (1 e-/2)

L nF to T/s-
L [ I LIJ L 7 ;mut tT T/S
TIS i otpuot

I npo T/S-2 o utpu
(cl input/output of T/S Unit,

FIGURE 4. Track-and-Hold Operation.

The digital PID controller is represented in
the time domain as

m,,= mn,-1 + k. (e,, -e,,-) + Te- + T
(e. -2e,,- +1 e,,-,) (4)
kc = gain constant


Input/Output -nd Petching of a Fllp-rlc

before the true output of the flip-flop generating
a square wave is patched to the T input of the
first T/S unit. The false output of the same flip-
flop is patched to the T input of the second T/S
unit. Thus, when the T input of T/S-1 is high the
same input of the second T/S unit is low.
Consider the combined operation of two T/S
units. When the T input of T/S -1 switches to
high, the analog output of this unit is minus
the analog input. During this period the T input
of T/S -2 is low and the output of this unit re-
mains constant. It is equal to the value of the
analog input to the T/S 1 unit at the instant
when the T input to T/S 1 switches to high.
When the T input of T/S 1 switches to low, the
output of this unit is held constant at a value it
had at the instant of switching but during this
period the T input to T/S 2 is high and the
second unit tracks its analog input. The value of
the output of T/S 2 during this period is the
value of the analog input to T/S 1 during the
preceding sampling period and a sampling delay
of one period T is thus accomplished. An example
of the combined operation of two T/S units for
a ramp input is shown in Figure 4 (c). It is
clear that this procedure can be used for obtain-
ing sampling delay of more than one sampling
period by utilizing additional T/S units.
These techniques will now be applied to analog
simulation of the digital control system of Figure


For the purpose of this illustration, the re-
sponse of the control system to a change in set
point will be obtained on the analog computer
using the digital PID algorithm. The response
will be compared with that obtained analytically
through modified z-transform analysis. The ex-
pression for the change in set point which the
control system is subjected to is

(b Gen- aIt; -n of Sample e'l r,

71 = integral time constant, sec.
TD = derivative time constant, sec.
T = sampling period, sec.
e = error
m = manipulated variable
The subscript n refers to the value of the variable
at the nt' sampling instant, (n-1) refers to its
value one sampling period before the nth and
so on. In this study, KI, = 2.61, I = 2.512, TD =
0.628, and T = 0.4. The process transfer function
involves a time lag. In this study a fourth order
Pade approximation was used for simulating the
transportation lag. The analog computer diagram
of the control system with a digital PID controller
and a zero-order hold is shown in Figure 5.

*A- -r ^ s2^5 '


I '1 7rCj j
C 150 4L

Analog Computer Diagram of the Sampled-Data Control System.

Theoretical Analysis
The response of the control system using the
PID control algorithm can be obtained analytically
through z-transform analysis. Since a delay is in-
volved, it is convenient to use the modified z-trans-
forms. The parameters of the control algorithm
are the same as those used in simulation.
Referring to Figure 2, the block diagram re-
duction yields
C (z)_ HG(z) D(z)
R (z) 1- +HG(z) D(z) (5)
To obtain D (z), the z-transform of equation (4)
is taken to get

D(z) E(z) -
E (z) -

7.1233 10.8054z-1 +- 4.0977z-
1 z-1


1 e-st e-1.468S
HG(z) = Z[H(S) G(S)] = Z 3
s 3.34s+1

z-3 (1 z-1) Z 3.34s+
Equation (7) can be simplified via the modified
z-transform. Thus,

HG(z) = z-3 (1 z-) Z e -

z-3 (1 z-1)Zm 3.34s 1

From the Tables of modified z-transforms (7),
Equation (8) can be evaluated. Thus,


HG(z) z- 0.041 + 0.719z-1
1 0.8871z-1
R(t) = 5(1- e-t/2)
R(z) (1 z-1) (1 0.8187z-)


Equation (5) can now be solved for C(z) which
after simplification gives

J (z)
C(z) -K(z)


J(z) -- 0.264z-5 + 0.0627z-6 -0.5518z-7
+ 0.2670z-8
K(z) 1.0 3.7058z-1 + 5.1379-2 3.158z-3
+ 1.0184z-4 0.4620z-5 0.4957z-"
+ 1.4587z-7 1.0343z-8 + 0.2412z-9

Equation (11) can be solved by long division to ob-
tain the values of the response at various sam-
pling instants.


THE RESULTS OF ANALOG simulation are
shown in Figure 6. Also shown on the figure
is the analytical solution.
The slight discrepancies in the two solutions
are the result of the approximate nature of the
Pade circuit and normal potentiometer round-off
errors. However, the difference is slight and can
be neglected for the purpose of this work.
It is believed that the material presented here
will serve s a useful exercise in analog simulation
of sampled-data control systems. With additional


I > J

Response of the Sample-Data Control System.

analog and logic components, the general pi
cedure described here can be used for simulati
other algorithms such as dead beat algorithm (
and Dahlin's algorithm (8).


trols for the analog and logic componen
For simulation of sampled-data control system
it is necessary that all the integrators be set
the OPERATE mode at the instant the fil
clock pulse occurs, after the logic RUN pus
button is depressed. To achieve this synchronize
tion, an AND gate and a flip-flop are utilized
shown in Figure 7. Figure 7 also shows the timi
diagram of the synchronization circuit.
Consider the operation of the circuit.
general assume that the RUN pushbutton is
pressed between two clock pulses. The true o0
put of the flip-flop is low until the first clock pu
occurs. Since the SET input of this flip-flop
patched to a logic ONE signal, its true outp
changes to high at the first clock pulse and
mains high after the first clock pulse. At the fil

FIGURE 7. Synchronization Diagram.

clock pulse both the inputs of the AND gate are
high. Therefore, the true output of the gate goes
high at the instant the first clock pulse occurs.
Since the true output of the gate is patched to OP
*- logic input of all the integrators, they are set in
the OPERATE mode at the instant the first clock
pulse occurs. Thus, all the logic and analog com-
ponents start operating at the same time once the
RUN pushbutton is depressed. E


1. Osburn, James 0., Track and Store With Your Com-
puter, Instruments & Control Systems, Vol. 37, No-
vember 1964. PP. 145-146.
2. Kingma, Y. J., Analog Simulator for Digital Con-
trollers, Simulation, February, 1968. PP. 65-68.
ro- 3. Clemence, C. R., Simulation of Digital Control Sys-
tems on an Analog Computer with Digital Logic,
ng Simulation, February, 1970. PP. 89-91.
7) 4. Clemence, C. R., Analog Simulation of a Digital
Three Mode Controller, Simulation, January, 1972.
PP. 35-36.
5. Corripio, A. B. et al, Analog Simulation of Frequency
Response of Digital Control System, Simulation,
February, 1974. PP. 49-55.
n- 6. Smith, C. L., Digital Computer Process Control, In-
ts. text Publishers, Scranton, Pennsylvania, 1972. PP.
as, 136-183.
in 7. Kuo, B. C. Analysis and Synthesis of Sampled-Data
st Control Systems, Prentice Hall, Englewood Cliffs,
N. J. 1963.
h- 8, Dahlin, E. B., Designing and Tuning Digital Con-
za- trollers, Instruments and Control Systems, Vol. 41,
as No. 6 June 1968 P. 77.



ao, al, . .
bo, bl,...


= constants of Equation (2).
= constants of Equation (2).
= response of controlled variable.
= pulse transfer function of the digital contr4

= error, R(t) C(t).
= zero order hold.
= proportional gain constant.
=- manipulated variable.
= set point
= laplace transform variable
= sampling period, seconds.
= time, seconds
=_ z-transform variable
=modified z-transform variable

= integral time constant.
= derivative time constant.

-= sampled variable


Too Much ChE Research and
Teaching Is Dull, Dull, Dull: McGEE
(Continued from page 54.)


professorial, let us now consider more care-
fully the resulting characteristics of the specific
species called chemical engineering.
As a profession we are justly proud of our
great breadth, for we are the only applied science
profession with in-depth training in chemistry as
well as in physics and mathematics. Our back-
ground and perspective as scientist-engineers
makes for flexibility and adaptability that is the
envy of our sister disciplines. A good chemical
engineer is rather fearless, ready to attack any
problem, and usually with salutary results.
Meanwhile back at the academy, chemical
engineering departments nationwide receive about
two-thirds of their support for research from one
agency-the National Science Foundation.
Omitting the recent (and fortunately rapidly
growing) RANN program office, the NSF has
supported broad basic research wherein any ap-
plication of research results to our pressing na-
tional problems has depended upon only very
slightly biased serendipity. Where are the mission
oriented agencies in the support of teaching and
research programs in chemical engineering?
Where are the many offices-ONR, AFOSR, ARO,
etc.-of the Department of Defense? Where is
NASA? The Atomic Energy Commission? The
Office of Coal Research, Health, Education and
Welfare? Can it be that the community of
chemical engineering professors and their labora-
tories have relatively little to offer to assist these
governmental program officers that are directing
huge research and development programs toward
identified national goals?
One can get a good idea of what chemical
engineering professors and their students are
doing by leafing through any issue of the AIChE
Journal or Chemical Engineering Science where
the ratio of papers from universities to those
from all other sources combined is typically 15
to 1. The following listing presents a few words
descriptive of typical papers. In reading these, it
is the inference of a tone or a perspective that
is intended; the specific subject matter is unim-
portant; and certainly there is no intent to argue
that these papers are worthless.

* An analysis of the motion of simultaneously growing
and rising bubbles in a superheated liquid agreed with
available data. An analytical solution to the equations
of motion was obtained for little bubbles, but the
authors had to settle for a numerical solution for the
big bubbles.
* A very elegant and neat eigenfunction analysis was
presented for the problem of heat transfer between
two immiscible fluids flowing down an inclined plane
with one fluid on top of the other. Water and mercury
were used as a test case.
* Thermodynamic analysis was applied to the calcula-
tion of activity coefficients at infinite dilution in tern-
ary liquid mixtures using experimental temperature-
composition data. With the assumptions of low pres-
sures and no heat of mixing, the calculational scheme
was applied to the ethanol-isopropanol-water system.
* One can measure the viscosity of an oil by noting the
time required for a metal cylinder to fall through a
vertical column of the oil. An elegant mathematical
analysis of the fluid entrance and exit effects around
such a falling cylinder has been presented.
* Joule-Thomson coefficient data have been obtained on
several ternary mixtures of simple gases and compared
with predictions using several popular equations of
state. Several earlier proposed ways of combining con-
stants in the equations of state were tested for their
relative efficacy.

All of these papers are from chemical engineering
departments and describe "research" that is no
more than a year or so old. To be sure, these
papers were selected to illustrate the thesis of
this essay, but the task of discrimination was

The "practice-oriented" curriculum ... is a
false remedy that cannot occur at a
respectable university, for teaching with-
out the accompanying scholarship toward
the continued evolution of the discipline, is sterile.

very, very easy, for the overwhelming bulk of
university papers are well illustrated in tone by
the above sampling.


F THE ABOVE IS AN indication of the nature
of our scholarship, it is also, of course, a good
indication of the nature of our teaching as well.
If the professor, for whatever reasons, is content
to do mundane scholarship, his teaching will also
lack this flair of creative vitality. Such a pro-
fessor may do a good job of presenting the text-
book, and perhaps that is adequate for teaching


freshman calculus. But it certainly is not adequate
for professional education in chemical engineer-
ing where the future of our society is going to
depend upon the innovative and inventive
character of our graduates. Not how well they
know yesterday's textbook, but how well they can
invent totally new syntheses of ideas and concepts
is the crucial question. And it is exactly here, of
course, that the student's association with a crea-
tive teacher/scholar is so terribly important. Cer-
tainly the greatest teachers of chemical engineer-
ing are also themselves the greatest researchers
and scholars in chemical engineering. But curious-
ly, the inverse is not true, for great researchers
are not necessarily great teachers.
If one may safely correlate the nature of uni-
versity scholarship as a reflection of the character
of the engineering professor's mind and pre-occu-
pations, perhaps it is this same state of mind
that primarily determines what other professions
and what the lay public thinks of us as a class.
Could this have a bearing then on the esteem of
engineering in the eyes of many, the view of
engineering as the cause of problems rather than
a means for their solution, and on the closely re-
lated circumstance of our greatly diminished en-
rollments ? Could it bear upon the fact that gradu-
ate education in chemical engineering is increas-
ingly left to foreign students as our own young
people fail to be attracted by our graduate pro-
grams? Surely there must be some relationship.

-dull work at our universities is that of a
plaintive call for a return to an earlier time,2 to
a curriculum and to attitudes that are very
reminiscent of 30 years ago. According to this
argument, we should educate young people who
are more able to step into a chemical engineering
design situation and immediately perform. We
must know more about pipes, pumps, valves, ma-
terials of construction, equipment, and economics,
with instruction provided by experienced
practitioners regarding creative scholarship and
and the necessity of publication that were noted
This "practice-oriented" curriculum and
philosophy with its highly practical and im-
mediately utilitarian sort of response is evidently
shared by many.3 It is however a false remedy that
cannot occur at a respectable university, for teach-
ing without the accompanying scholarship toward

the continued evolution of the discipline is sterile.
Even if such a "practice" orientation did develop
we would be abandoning all claim to being pro-
fessionals to adopt a self-imposed exile as tech-
nicians. We have too many examples already of
technological expertise applied in a manner ob-
livious to the social and human aspects of the
particular situation.
The world needs chemical engineers with the
contemplative character of the liberally educated
person who will thereby be better able to temper
his technological and scientific insights with wise
perspectives on the workings of society and on the
nature of man. Such attitudes are frequently
foreign to the hard-driving chemical engineer in
practice as well as to his mentors back at the
university. But they are attitudes that are none-
theless essential to the profession. The assertions
of many thoughtful and humane individuals are
correct, for science and technology are in fact
the causal agents of many of our most pressing

Why I published that
in a ChE Journal

human problems. Our responsibility to correct
these and to insure more humanely sensitive ap-
plications of science cannot be negated by claims
of the amorality of science any more than we can
expect a diminution of further abuses of science
until we as practitioners well integrate our
humanistic awareness into our technology.


dullness of research at the universities is


the claim that the meaning or value of the work
is unimportant when compared with the principle
thrust or motivation which is after all-the edu-
cation of students. Our task in academic research,
so the argument goes, is one of the teaching the
principles of basic and engineering science, of
training students, and of acquiring, cataloging,
and interpreting a generally useful long-range
pool of fundamental knowledge. Working on real
problems may even be detrimental to the principle
goal of training students, for he would then have
to be concerned with economics, societal impact,
the press of a time constraint by which deadline
his work would have to be completed, proprietary
interests, and all the rest. All of this is so con-
fusing and unnecessary when the object really is
to teach a student to analyze a technical situation
and to reach logical conclusions from his observa-
Unfortunately, in our efforts to delineate and
illustrate scientific principles, we often exorcise
those very aspects of the problem that make it
exciting and meaningful and that illustrate the
real world. The claim of such educators that they
are, after all, primarily concerned with the train-
ing of the student are frightening, for if this be
true, they are training the student for a world
that does not exist. Though one can argue that
it is now, after commencement, the task of in-
dustry to sensitize the junior engineer to all of
these creative components of engineering, there
is nonetheless a great danger, for the student has
had instilled into his attitudinal structure in his
formative years and by people that he greatly
admires, a totally unreal picture of what his pro-
fession is all about.

heart out of university research, as we shall
now see.
Consider now a tone or character of research
that is today all too uncommon in chemical engi-
neering departments around the country. And so
unnecessarily so except for the "professorial syn-
drome" that we described at the beginning of
this essay. All of the following examples are
taken, purely as a result of familiarity, from work
underway in this Department where we have been
making a conscious and prolonged effort to
brighten the dull glow. There is certainly no as-
sertion that these are the things that chemical
engineering educators should be doing, and we

will again suggest that one diminish the specific
subject matter in order to infer or sense an at-
titude or a tone-an altogether different tone
from that pictured in the earlier listing.
Renewable natural resources as feed stocks
for the production of useful chemicals is a vital
concern in these times of shortages of hydro-
carbons, concerns for environmental quality, and

Unfortunately, in our efforts to delineate
scientific principles, we often exorcise the
very aspects of a problem that make it
exciting and meaningful and that illustrate
the real world . the student has had instilled
into him a totally unreal picture of what
his profession is all about.

the need for energy efficiency. One immediately
thinks of plants as such a source, but they pro-
duce mostly carbohydrates (starches and sugars),
and, in contrast to hydrocarbons, we immediately
are concerned with basically reductive rather than
oxidative catalysis. Cellulose, the most common
organic material on earth, can be enzymatically
degraded to its monomer, glucose-a process that
is being studied at the Army Natick Labs, Berke-
ley, VPI&SU, and elsewhere. With an inexpensive
source of glucose, one now asks about the
chemistry to other products such as hydroxy-
methylfurfural and from there to amides and
other compounds. Sugar cane could be an ex-
cellent source of cellulose since it is, from a photo-
synthetic perspective, one of the most efficient
plants known. Glucose can be fermented to
ethanol--an important operation when ethylene
is scarce and its use to make other products is
more profitable. Interestingly, a Japanese firm
has recently announced a new polymer called
Pollulan which is derived from the fermentation
of starch. And certainly tough materials can be
made from such renewable resource feedstocks,
for the largely protein hide of a rhinoceros can
deflect a high-powered rifle bullet fired at close
So we have a possible carbohydrate based
chemical economy based upon renewable resources
with all of the innovative chemical engineering
expertise that is implied in such a vision. So
what's new in boiling heat transfer? You say
you've found a new way to study the effect of
liquid wetting of the heat transfer surface?
Consider another example, plants directly


produce a variety of valuable products including
foods, flavors, alkaloids and sterioids useful as
pharmaceuticals. Many of the valuable materials
from plants occur in small concentrations or in
relatively rare species. The important compounds
may also occur only in specific organs of the plant
as for example in the seed or in the bark or roots.
Conceivably many of these sorts of substances
could be produced in pure cell cultures in opera-
tions not too unlike a fermentation and at con-
siderable savings in cost. The production of
penicillin by deep tank fermentation is a familiar
example of the success of such a biological pro-
cess. The biochemists, of course, first grew the
penicillin mold on a shallow nutrient layer on
the bottom of an Erlenmeyer flask, so their idea
of large scale production was merely to use mil-
lions of Erlenmeyers. Dense cell cultures suspend-
ed in a nutrient solution and stirred in a closed
reactor with sparged in sterilized oxygen was, of
course, a chemical engineering development of
enormous significance in the modern pharma-
ceutical industry. Plant cells could be similarly
grown, and the production of useful substances of
plant origin may then be possible with simple
harvesting from the undifferentiated plant cells.
It may be possible to stimulate the production
of specific alkaloids, steroids, hormones, and
vitamins from appropriate cells. For example,
vitamin A or carotene from carrot cells is a
legitimate possibility as is morphine from the cul-
ture of opium poppy cells. Progesterone, a female
hormone and the essential ingredient of the oral
contraceptive, is made from a precursor extracted
from the Mexican yam. These sweet potato cells
then represent an excellent candidate for com-
mercially advantageous tissue culture. Finally,
there has been much discussion of possible anti-
carcinogens from plants, that is, drugs that would
attack cancer in humans. So here again we see
exciting potential for developing continuous tissue
culture and continuous harvesting as a chemical
engineering process. It may even be possible
through genetic manipulation and cell fusion to
produce interspecies crossings leading to "com-
mercially tailored" plants that could never occur
in nature.
So we have plant tissue culture for the con-
tinuous production of female hormones, vitamins,
and anti-cancer drugs. And so what's new with
thermodynamics? You say you have found the
Lennard-Jones intermolecular potential function
to be superior to the square-well function in cor-

relating Sage and Lacy's p-V-T data on n-butane ?
Consider another totally different example. In
industrial chemistry, reaction specificity is the
name of the game. With a tunable laser, one can
do bond-specific photochemistry, and in fact one
can be so selective that he can separate isotopes.
For example, in a mixture containing HR and DR,
using a laser, one can selectively excite DR where-
upon it will react with a chemical fixing reagent,
F, that is also present to yield a mixture of HR
and DF which can now be separated by some rou-
tine scheme and the deuterium regenerated. Or

Some of the most crucial problems of our time
will be solved, if at all, by the judicious application
of chemistry. Chemical engineers are the best
qualified, but we must move away from conven-
tional wisdom of total devotion to analysis
and the concomitant shunning of synthesis.

apply this same idea to the separation of fission
essential U235 and U238, or to fusion essential Li6
and Li7. The significance of innovations in this
area is evident when one recalls that the gaseous
diffusion plant at Oak Ridge initially used about
one-tenth of the entire electric power production
of the United States. The laser technique works,
for two Israeli workers have recently described
an experimental device using laser excitation,
ionization, and electrostatic separation to efficient-
ly produce enriched U235 from the natural isotopic
mixture in what appears to be a chemical engi-
neering innovation of the first order.4
discipline of applying the laws of nature to design may be
In addition to isotope separation, the laser can be
used as a pollution monitor by recording the back scatter
from a laser pulse in an arrangement that is very reminis-
cent of radar. It is not necessary to sample or probe the
air over the plant. One merely beams in a laser pulse
from outside the gate and looks at the backscatter to
determine both volatile contaminants and particulates.
So we have lasers for uranium isotope separation,
Buck Rogers ray guns, and a sort of probeless pollution
monitor. And so what's new in fluid mechanics? You
say your latest data reveal a revised exponent on the
Reynolds number in your pressure drop correlation equa-
Such a listing can go on and on. With the continuing
interest in synthetic hydrocarbons, Fischer-Tropsch
chemistry takes on a new attractiveness. Here a mixture
of CO and H2 at a few atmospheres pressure and moderate
temperatures is catalytically converted to a mixture of
olefins and paraffins in a reaction that could become of
singular significance in fuel conversion processes. But it
his not attracted much interest in academic circles.
A modicum of library research and talking to
people in the field will reveal the shockingly poor


state of our understanding and experience in the
chemistry of coal. Conceivably, the fused ring
molecules found there could be split, isomerized,
and oxidized to, say, terephthalic acid. But coal
chemistry is almost unheard of in academe.
The food processing industry involves essentially
chemical engineering unit operations, but with materials
and under constraints of temperature, sanitation, and the
like that are generally foreign to the chemical engineer
whose education has been "petrochemical centered." The
opportunities there for real impact in canning, freeze
drying, quick freezing, evaporation, and waste treatment
are enormous. But the universities are mostly silent.
Polymer chemistry is generally at or near the
bottom of a priority listing of areas of specializa-
tion judged important or most scholarly by most
chemistry departments. Excellent polymer science
programs have been only recently established at
a few universities, most notably at the University
of Massachusetts and at Case Western Reserve.
But first class programs in polymer engineering
with all of the contact with industry that is
necessarily entailed are virtually non-existent at
Enough of these examples. The list is far from
encyclopedic. It probably does not even contain
all of the areas of maximum significance and
utility, to which a chemical engineering depart-
ment might address itself, but one can sense ex-
tensive and fascinating possibilities and, more
importantly, a tone or an attitude that is very
much unlike the current situation at most uni-
versities. To interpret this discussion of plant
tissue culture, or lasers, or coal chemistry as
suggesting that these are the things that chemical
engineers should be doing is to miss the point
completely. Not the merit of these specific ideas,
but rather I seek to paint a tone of activity in
chemical engineering that is today surprisingly
Or finally and on a more homely note, my son
took a course in high school called "bachelor cook-
ing." Quite predictably, once you understand the
workings of most academic minds, most of the
class time was devoted to learning about the
various spices and flavors, their sources and how
they were produced, the construction of a stove
and the temperature distribution in the oven,
electric vs gas vs microwave fired ovens, chemical
reactions that occur in the cooking processes, and
so forth. The fact that one was a great cook and
could produce a terrific roast or a great apple pie
was quite beside the point. It seemed that one
could be a master chef and obtain only an average

or even below average grade in that course. Home-
ly though it may be, this little example is nonethe-
less a reasonable metaphor of the approach of
most academicians to teaching and learning.

S 0, WHAT CAN WE CONCLUDE from all of
this? First that chemical engineering is too
dull, that this flatness is, in significant measure,
a reflection of the dominant preoccupations of
the university professors, and, most importantly,
that the situation is both unnecessary and fear-
ful. Some of the most crucial problems of our
times will be solved, if at all, by the judicious ap-
plication of chemistry. Chemical engineers are
the people best qualified to do it, but we must
move away from the conventional wisdom of a
total devotion to analysis and the concomitant
shunning of synthesis that is now so evident.
Rather, our teaching and scholarship must present
the essential and complementary values of both.
To see only the objective and logical side of every-
thing strips the heart and the zest out of our pro-
fession-and out of life as well. Reason and logic
can only order and categorize, but we need grand
insights and leaps to totally new adaptions of
chemical engineering expertise that are charac-
terized by descriptors such as invention, creativi-
ty, and synthesis. This will mean a greater em-
phasis on "process" oriented research rather than
on just more "phenomena" research as usual. Our
students can be mathematical supermen, and
great engineering scientists, but without the abili-
ty to invent, they will be failures as engineers.
And in those still very few departments where this
devotion to the new and the provocative counters and
augments our conventional attention to thermodynamics,
kinetics, advanced mathematics, and so on, the natural
and certainly not unexpected excitement of it all attracts
new adherents like a tumbling snowball. []

1. Many of the characteristics of the professional calling
have been taken from "The End of the American
Era" by Andrew Hacker, Atheneum, New York,
N. Y., 1970.
2. W. C. Reid, Chem. Eng. 77, No. 27, 147(1970).
3. Editors, Chem. Eng. 78, No. 7, 99(1971), and in
sessions presented at national AIChE meetings, and
most recently planned for the 67th Annual Meeting
in Washington in December, 1974.
4. Science 183, 1172(1974).
5. Original cartoons furnished courtesy of the chemical
engineering department of Virginia Polytechnic
Institute and State University, Blacksburg, Va.


book reviews

Mathematical Methods of Chemical
Engineering. Vol. 3. Process Modeling
Estimation and Identification.
By J. H. Seinfeld and L. Lapidus.
Prentice-Hall, 545 pages.
Reviewed by R. Aris, University of Minnesota

Any topic in applied mathematics which has
attained reasonable maturity will have acquired
a considerable primary and secondary literature
into which the engineer must dig in his efforts to
master its methods. But, if his first steps may
seem simple, like those of the descent to Avernus,
the task of really penetrating the subject and win-
ning his way back again to the daylight is, as
Virgil says, another story-'hoc opus, hic labor
est'. Hence the peculiar value of reliable guides to
that nether world of mathematical ideas that lies
at the foundation of our profession and provides
the basis for understanding of chemical processes.
Lest it seem ambiguous to commend one's friends
as guides to the underworld, I hasten to add that
they are no flunkeys of the tourist industry but

members of that select company of erudite guides
of which Virgil himself is the best known. For
this book will not yield much to the casual reader
who thinks he can breeze through it with half his
attention, but will be found invaluable by the
serious student who wants to understand the mod-
ern theory of estimation and identification.
In stressing these, the second and third di-
visions of the book, I am not overlooking the early
discussion of modeling and Laplace transform. A
brief introductory chapter leads to a discussion of
the types of equation that are of value in modeling
chemical processes. The emphasis here is not on
illustrating the details of actual derivations, but
on the rationale of model building and the types of
system that arise and their inter-relations. This is
followed by an excellent survey of the Laplace
transform which includes both the discrete z-
transform and a treatment of the numerical in-
There are of course many books available on
the Laplace transform and several on modeling,
though the treatment here is admirably clear, but
what makes this book uniquely valuable is the sub-
sequent discussion of stochastic models, estima-
tion theory and process identification. This covers
(Continued on page 100.)

Continued from page 67.

the passage of matter. If open systems are con-
sidered, the energy flow associated with the flow
of matter must be added to each energy defini-
tion, i.e. dE = TdS PdV + IXidni, where
ti is the chemical potential of species i and dni is
the change in the number of moles of species i in
the system. Note that E is related to extensive
measures of the system. We can speak of molar
entropy, molar volume, and number of moles in
the extensive measures. The enthalpy change has
one less extensive change in its definition, re-
placing the -PdV used in dE with VdP. Similar-
ly, dA has one intensive change in its definition,
while dG has two intensive changes, VdP and
The intensive counterpart of 4itdni is
-Inid/pi, and if we draw a second diamond for
energy relations in which the intensive term
-ZnidMi is used, we replace the pointer terms,
dE, dH, dA, dG, with new energy variables
d(TS-PV), d(TS), d(-PV), and 0 (the last
not being a definition). Gangi, Lamping, and Eu-

bank elaborate on the relations involving this side
of the diamond and have a copyrighted design,
called a THERMODORM, to illustrate them. The
definition of d (TS -PV) involves one intensive
term; those of d(TS) and d(-PV) involve two.
Additional relations may be developed if heat
capacities are related to entropy, if electromotive
force is related to Gibbs free energy, or if equili-
brium constants are related to Gibbs free energy.
The reader is encouraged to elaborate these as an
exercise. The frequent use of AH TAS in place
of AG for processes occurring at constant tempera-
ture and pressure may be understood in terms of
the diamond. At constant T and P we have simply
dG = 1tidni, which is what d Hwould be at con-
stant pressure if we subtracted out the TdS term.

C. Burgett, CHEMTECH, March, 1972, p. 189.
A. F. Gangi, N. E. Lamping, and P. T. Eubank, Chem.
Eng. Educ., Winter, 1972, pp. 30-35.
E. A. Guggenheim, "Thermodynamics-an Advanced
Treatise" Interscience, New York, 1949, p. 21.
P. A. Marino, AIChE Student Members Bulletin, Spring,
1973, p. 9.
J. A. Prins, J. Chem. Phys. 16, 65 (1948).


Continued from page 72.

A = A'(M)/K,
A' = pre-exponential kinetic constant
B = E/Rg
c = oxygen concentration, moles/liter
D = AH Xo L2
k(Tm To)
D' = In D
D = diffusivity of oxygen
E = activation energy
H = heat of reaction (per unit of 02 consumed)
k = thermal diffusivity
Ks = Michaelis constant
L = thickness of decomposing mass
(M) = concentration of microorganisms
Ni = molar flux of species i
R = rate of substrate decomposition
R = universal gas constant
T = temperature, K
Tm = maximum anticipated temperature
To = minimum anticipated temperature
T/(Tm To)
T*Io = value of T* at y* = 0
= specific growth rate of microorganisms
hmax = maximum specific growth rate of
X = oxygen concentration, mole fraction
Xo = oxygen concentration in the atmosphere
X* = X/Xo,
X*]o = value of X* at y* = 0
y = distance from center of the decomposing mass
y* = y/L

1. Gray, K.R., "Accelerated Composting," Comp. Sci.,
7, 29 (1967).
2. Gotaas, H.B., "Composting," World Health Organi-
zation, Geneva, 1956.
3. Aiba, S., et al., "Biochemical Engineering," Aca-
demic Press, New York, 1965.
4. Humphrey, A.E., "Future of Large-Scale Fermen-
tation for Production of Single-Cell Protein," in
R. I. Mateles & S. R. Tannenbaum, Eds., "Single
Cell Protein," M.I.T. Press, Cambridge., 1968, p. 334.
5. Schulze, K. L., "Rate of Oxygen Consumption and
Respuratory Quotients During the Aerobic De-
composition of a Synthetic Garbage," Comp. Sci., 1,
36 (1960).
6. Wiley, J. S. and G. W. Peace, "A Preliminary Study
of High-Rate Composting," Proc. Am. Soc. Civil
Eng., 81, Paper No. 846 (1955).
7. Fuller, W. H. and S. Bosma, "The Nitrogen Require-
ments of Some Municipal Composts," Comp. Sci., 6,
26 (1965).
8. Smith, T. G. and Cadman, T. W., "Learn About Ana-
log Computer-Part 7: Function Generation," Hydro-
carbon Processing, 33 (Aug. 1968).

9. Lambert, E. B. and A. C. Davis, "Distribution of
Oxygen and Carbon Dioxide in Mushroom Compost
Heaps as Affecting Microbial Thermogenesis, Acidity,
and Moisture Therein," J. Agr. Res., 48, 587 (1934).
10. Titjen, C., "Conservation and Field Testing of Com-
post," Comp. Sci., 5, 8 (1964).

ChE Book Review
Continued from page 99.

some areas of comparatively recent development
and there is no other reference where a useful
introduction can be found in one place. This de-
mands an introduction to probability theory which
is provided in chapter 4 where the concept of the
random variable and its characterisation is care-
fully explained. Next comes a discussion of sto-
chastic processes, their description and governing
equations. Of particular value here is the ex-
planation of the differences between the calculus
of Ito and that of Stratonovich. The sixth chapter
on the theory of residence time distributions dis-
covers a habitat where the behavior of both de-
terministic and stochastic models can be observed.
The remainder of the book is devoted to par-
ameter estimation and process identification, the
former being the appropriate task when the struc-
ture of the model is fully known, the latter when
it is unknown. In both cases there is a natural dis-
tinction between linearity and nonlinearity with a
simpler set of methods for the linear. In the esti-
mation problem, algebraic, differential equation
and stochastic models are discussed, as are fre-
quency domain, moment, gradient and search
methods. There follows a valuable chapter on the
design of experiments in the light of the estima-
tion problem.
In introducing the subject of the realization of
systems for which the structure of the model is
unknown the dual concepts of controllability and
observability are first explained and some specific
algorithms are then developed. The final chapter
is on process identification of nonlinear systems,
a problem of peculiar difficulty which brings the
student near to the frontier of the subject.
For anyone giving a course in methods of proc-
ess analysis at a graduate level this book will pro-
vide a splendid text, while, for the student want-
ing to study the subject on his own, its organiza-
tion and clarity make it equally useful. Altogether
it is one of the best books in the Prentice-Hall
Series in the Physical and Chemical Engineering




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dignified, motivational environment to work and grow. If you or someone you know loves
life and wants to live it wisely, get in touch with us. Recruiting and College Relations, P.O.
Box 1713, Midland, Michigan 48640.

-Trademark of The Dow Chemical Company





In the energy field, there aren't

any easy answers

which is one very good reason for
considering Atlantic Richfield for your career.

It's energy that has created and maintains the fabric
of today's civilization. That's basic.
But providing energy in vast amounts today-and
preparing for the greater needs of tomorrow-is a
tougher and more challenging problem than ever
Now, new answers must be found to developing and
utilizing energy-and its by-products-if we are to
maintain our energy-based standards of living.
We want the best brains we can find to help us arrive
at these answers. We want people sensitive to the
human and natural environment-and realistic enough

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to know that preserving both must come from tough,
intelligent, dedicated work .. backed by outstanding
resources in capital, research and experience,
such as those of Atlantic Richfield.
If tackling such large-scale, significant problems is
one of your criteria in selecting a job, join us. We can
offer you a career rich in challenge, rich in meaningful
work, rich in personal reward.
See our representative on campus or your Placement
Director. Should that not be convenient, write
J. T. Thornton, Atlantic Richfield Company
515 South Flowers Street, Los Angeles, CA.

AtlanticRichfieldCompany 0
An equal opportunity employer, M/F.

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