The bonding force of cellulosic materials for water

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Title:
The bonding force of cellulosic materials for water
Physical Description:
Book
Creator:
Stamm, Alfred J ( Alfred Joaquim ), b. 1897
Hansen, Lawrence A
Forest Products Laboratory (U.S.)
University of Wisconsin
Publisher:
United States Dept. of Agriculture, Forest Service, Forest Products Laboratory ( Madison, Wis )
Publication Date:

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Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 29346869
oclc - 756501440
System ID:
AA00020632:00001

Full Text


'F ~ - -
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TilEt O(NDING I)I Ct Or CLLUI SIC MATERIALS
MIR WATEI (IIOM SIrClIC VOLUMt
AND Th11EPMAL DATA)
October 1937


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Of fbr^M'


VT'
ti Lii ~ I


UNIVERSITY OF FLORIDA


N


UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
FOREST PRODUCTS LABORATORY
Madison, Wisconsin
In Cooperation with the University of Wisconsin


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THE B01TIING FORCE OF CELLULSIC MATERIALS FOR TATER

(FROM SPECIFIC VOLU_-.' AD THERMAL DATA)1


By A. J. STAIZI
and L. A. HAITSJT



An attempt was made in a previously reported research (14) to
determine the volumetric contraction occurring in the water adsorbed by
cellulosic materials. Apparent density measurements of wood and cellulose
containing various amounts of adsorbed water were made in benzene. Ben-
zene causes no swelling of cellulosic materials, indicating that its
affinity for cellulosic materials is small. This, together with the
fact that the internal surface of contact is relatively small, would
make the adsorption compression of benzene negligible. It is question-
able, however, that benzene penetrates the void structure of the dry
cell walls completely. For this reason the benzene can be relied upon
as a displacing medium only when the moisture content of the cellulosic
material is sufficiently high for water to have opened up or itself
filled all of the void structure. It was shown that the volumetric con-
traction occurring in the adsorbed water could be calculated down to a
moisture content of about 6 percent from the measurements in benzene.
Below this point accurate data for the true density of the cellulosic
materials are required to make the calculations.

Howard and Hulett (6) have determined the density of carbon in
helium and have shown that at room temperatures the helium is practically
nonadsorbed. Davidson (3) similarly concluded that helium is nonadsorbed
on cellulose. Because of its low molecular weight it should further
penetrate the void structure completely. Hence,measurements of the
density of the same cellulosic materials used in the previous investiga-
tion were made in helium.

The essential features of the apparatus used for making the density
measurements are shown in figure 1. A and B are two Pyrex glass bulbs of
about 200-cc. capacity, separated by a stopcock S1. The sample bulb A
can be removed at the ground-glass joint J and fT-led with the cellulosic
material by removing the stopcock. S1, S2, and J are provided with mer-
cury seals to prevent leaks. M is a mercury manometer, which was read
with a cathetometer to 0.005 cm. L is a 200-cc. bulb used to keep the
mercury level in the right-hand arm of M at the same p-ooint for all the

1
-Presented at the 14th Colloid Symposium, Minneapolis, Minn., June 10-12,
1937. Published in the Journal of Physical Chemistry, Vol. 4l, iTo. 7,
Oct. 1937.


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micacuremnr.ts by adju.tin, the pressure over L with stopcocks S- ana. S4.
This mande urnnecessary iny volumL corrections. The whole app-ratus was
immersed in a thermostatically controlled water bath at 30 C. + 0.01'.

The volume of A was determined by calibration with w.a;ter. With
A emnnt,- the anr/iratus was completely evacuated, helium waz admitted to
3, the -irossurc determined, and then the pressure was acain dotermincd
after expansion into A. The volume of 3B plus the connection tubes coul
then be calculated from the volume of A and the two pressures, usinr' the
perfect eas law. The same procedure was followed in d.eterminin'. the voil
apace ir A when filled with a sample of !ood or cellulose. The material
was oven-dried at 105 C. nrior to filling the bulb and then v-acuum-
dried at 105 C. for about 21 hours after assembly of the apparatus
by surroundinC'the bulb with a heating coil jacket. A final vacuum of
about lG-- .m. of .ercury was attained. The system was then brought to
300 C. an' held for aCout half a driy before making; the measurements, to
insure th-ermal equilibrium. WeiLhinjs of. the sa-zile bulb were made at
atmospheric pressure just after the vacuum dryin amnd aainr after a series
of expansions.

Density measurements wore also lade in water and benzene in ,'C,-cc.
plate-top pycnometers. The air was removed from the submer-e. :.-.aterials
in the half-filled pycrnomters by carefully applying: a vacu-:-: anf releas-
inj until no sign of air bubbles was obtained up to a vacuum 'hLch causeJ.
boiling of the liquid when the pycnometers were immersed in. an ice bath.

The densities of the following materials deterzinei in -elium,
water, and benzene, are given in table 1: benzene-alco?.ol extracted ":>.ite
spruce sawdust of 40 to 60 mesh; the same in the expa-ded aer::el form
(g); standard cotton linters alpha-cellulose; a r.c'm -.-ce s-n-fite
pulp anri the sG..:e after beating for 20 hours; an. spruce a-n male
lignin prepared by the modified sulfuric acid methoC. of the F-rest
Products Laboratory (ll). The expanded aerogel was prepared. accc'rd.in.
to the method of Kistler (8), usinr methanol an-d acetone as i.itermedin."e
replacing_ agents. 'easurements on control clocks showed that a lsar:e
proportion of the normal shrinkage occurred in the finial e:-x )j.sior. step,
regardless of the technic used. Because of this shrinka-e t-he ,ensity
value for the expanded ".wool determined in cenzer.no, alt.c.,.- j:rc.ter than
the correz-,ondirn density value for the uriex-andel. wood, was not so -reat
as the density value determined in helium. In all cases the density
values determir.od in ;eliu, are intermediate between ;-..so determined
in waiter a:'.1 those determined in benzenec, as has been -re'-io':ly
reported (3, 12). The difference betweun the heli',- a .n benzene values
for te cotton is racticay the sa a tl.at found by Davidcn (s).
for tL!.e cotton, is -practically thhe sane -In ... -1


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Table l.--Densities of wood, cellulose, and lignin substance at 30 C.

:Helium displacement : Water displacement :Benzene displacement
: ------------------------- ---------------------
: Den- : Aver-: Num- : Den- : Aver-: Hum- : Den- : Aver-: '.LTm-
Substance : sity : age :ber of: sity : age :ber of: sity : ne :ber of
error:deter-: : error:deter-: : error:dceter-
mina- : mina- mina-
S:tions : : :tions : : :tions
- - ---------- -- -- -- -- t -- -- ft -- -- -- -- t --- --


Extracted white : .
spruce........... :.1.4603: 0.0005:


Expanded aerogel :
from extracted
white spruce..... :1.46o4:

Standard cotton :
llnters.......... 1.585:

Spruce sulfite
pulp:
Unbeaten ....... 1.570
Beaten ......... :1.593

Spruce lignin
(modified sulfur-:
ic acid method)..:l.377

Maple lignin
(modified sulfur-:
Ic acid method)..:1,406
ftf


.0004:


.0012:


.0024:
.0022:



.0008:



.0011:


10 :1.5332:0.0002:


4 :1.530


7 :1.6028:



6 :1.590 :
6 :1.616



10 :1.399



6 :1.4,22


.0003:



.0005:
.0008:



.0010:



.0007!


2 :1.444



1 :1.450


2 :1.571



2 :1.555
2 :1.578



2 :1.366



2 -1.388


The volume contraction occurring in the cellulosic material-
adsorbed water system was calculated from the previously determined data
in benezene (l4), using the newly found density values in helium as the
true densities-of the cellulosic materials. The external pressure P in
kilobars that would be required to cause this volume change Av per grax,
of water, on the basis of the volume change occurring entirefy-in the
water phase, was then calculated from the following compressibility
relationship for water given by Gibson (5):


Av = 0.307 log 2.923 + P
2.923


(1)


The values for white spruce, cotton, and sulfite pulp are plotted in
figure 2. The values for the beaten and the unbeaten pulp were so nearly
identical that only the average value is plotted.

R1234, -3-


:0.007



.005


.0005:




Li,




Campbell nnd Russell (2) have doubted whether helium completely
penetrates the void structure of cellulose, because they obtained density
values for swollen cellulose in benzene by replacement of water with al-
cohol and of alcohol with the benzene that were slightly greater than the
helium values. This difference, it seems, can be better explained by
assuming that a small amount of water was net replaced inr. their measure-
ments, rather than by assuming that the helium fails to penetrate the
cellulose completely. In order to meet these investigator's objections.
however, it seemed advisable to attempt determining the compression
effect by an entirely different method.

Katz (7) has shown that a qualitative proportionality exists between
the initial heat of solution or the heat of swelling of binary aqueous
systems and the accompanying volume change. He gives values for the ratio
o/o ranrgin- from 1 to 3 x o10-3 for a series of solutions and swelling
systems in which C-o is the volume change in cubic centinuters and Ho is
the heat of solution or swelling in gram-calories resulting when 1 g. of
water is added to an infinite amount of dry solute- or swelling material.
It is apparent that this relationship cannot be general, as there should
be a greater change in volume per unit thcr:.al charge forl a mcre ccmpres-
sible liquid than for a less compressible liquid. It thus seemed logical
to substitute the change in internal prEss:--e ?Pe, which causes the change
in volume,for the change in volume and thus compare values of the differen-
tial ratio Pe/H. Partial differential values are used, as ccmpre.zion
may occur in both constituents of the liquid-liquid systems considered.

Gibson (5) gives the relationship between the specific compression
of water, the internal or intrinsic pressure change, and the externally
applied pressure which can be expressed in the follcwin, partial differe1-
tial form:

= 0.507 log 2.23+ Pe+ P (2)+
xI 2.923 + Ie

where _4-Y represents the partial compression of :he water per gra= of
x1
water resulting from the partial internal pressure cane of the water
Pe in kilobars caused by the presence of the solute an4. the external
pressure change P in kilobars. The martial specific c_:rression can be
obtained by plotting the compression oer gram of soluti':. against the
weight fraction of the winter and dra'.ing tnrigents to the curve. The
intercept of the water axis gives the -artial specific cocpression for
water in a solution the comTnosition of which is represented by the point
of tangency (9).

The external -pressure P that would case the sane volume change in
the solvent as occurs in the process of solution ')-^ ae calculated from
equaation 1 exTresaed in a partial form:
2.J23+P
vi V = 0.307 1o- 2.- p+ (3)
2 o,1j


Rl234








in which vI is the specific volume of the water and 71 is the partial
specific volume of the water in the system, obtainable in a similar wa-'
to the partial specific compression.

Gibson (5) gives data for both the specific volume an- the compres-
sibility of a sulfuric acid-water system. From these data the external
pressure required to give the partial specific volume change of the
water can be calculated, using equation 3, and the change in the inter-
nal pressure that causes the change in compressibility can be calculated,
using equation 2. These values are given in table 2. The data show that
the internal pressure change of water in the solutions is equal to the
external pressure required to cause an equal change in volume in the
water alone. It is thus valid to consider the pressure changes in
figure 2 equivalent to internal p-oressure changes.

Table 2.--Change in partial internal pressure of water in aqueous
sulfuric acid solutions calculated from the specific
volumes and from the specific compressions

Weight :Specific volume: External :Partial specific:Change in
Solute:fraction: minus partial : pressure on :compression of : partial
Sof :specific volume: H20 to give : H20 per kilo- : internal
H20 : of H20 :volume change: bar : pressure
S__ :: of H20
: :-a A ) : ,1
(xl) (vI :) (P) : x e)

Kilobars Kilobars
S S ~



H 2SO 4 0:0 0.30: 26.8 0. 004g 26.C
'0723 : .293 21.3 .0055 21.o
:.1365 : .193 9.3 .0110 .-7
: .2167 : .093 3.0 .0225 2.5
:.4o4. 03 95 0312 5
.6699 .012 .28 .0367 25
.7333 .008 .17 .030 : .13
.8734 .oo4 .0 .0390 .o4



Table 3 gives the ratios of the partial internal pressure chi to
the partial heat of solution of water in aqueous solutions of organic
compounds, inorganic acids, bases, and salts, and salts of organic acids
all of which dissolve with the evolution of heat. The partial internal
pressure changes were calculated from specific volume data only (Inter-
national Critical Tables), as specific compression data wore available
only for the sulfuric acid solutions. The heat of solution data with
the exception of that for sulfuric acid (10) were also obtained from the
International Critical Tables. Because of the difficulty of obtaining
accurate graphical values for V, and for H at high concentrations of


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-5-









water, the values for the ratio Pc/H could not be determined at concentra-
tions hi,-her than those given in table 3 with any degree of accuracy. In
all oases where miscibility is complete, the r-itios of Pe/H for zero con-
centration of water are about equal, the avurae deviation from the
avurae value 12.5 being 4 percent. The sw-ei constancy exists for all
the data at high concentrations of Wateri In some cascs theo ajroeement
is good over the Whole concentration range, whereas in other cases, such
as that of sulfuric acid, the ratio decreases at inter.modiate concentra-
tions* In the case of the salts and bases the agreement is -cod ui. to
concentrations approaching saturation.

This relationship fails to hold for exothermic solutions, The ex-
pansion accompanying the absorption of heat is invariably too sruall, and
in some cases there is a .,li-ht contraction accompanying the absorption
of heat. The relationship also fails in cases where the constituent
other than water is more compressible than water. As neither of these
cases a-nlies to cellulose-water systems, it seemed justifiable to apply
the ratio Pe/-H = 12.5 kilobars per kilojoule in The calculation of Pe
from thermal data. Values of Pe for the ':-od anQ" cotton. calculated from
the heat of' swelling data (13) that were obtained from vapcr pressure
data (13, 15) and from direct heat of swelling: data (1) are plotted in
figure 2, together with the values of P obtained frc-.- adsorption compres-
sion. The agreement is good. It tends to substantiate the contention
that true density values for cellulosic materials can 'e obtained in
helium and strengthens the validity of the calculated internal pressure
values.

The values of Pe represent the increase in the internal pressure of
water, so that the normal internal pressure of water, which is about
12.5 kilobars, should be added to these values to obtz-in the total inter-
nal pressure. The data thus show that the initial bondirng force of
cellulosic materials for water is about twice that of ,,ater for itself.
This seems much more reasonable than the value of severnfoli to eightfold
greater calculated from the data of Filby .mini Ma-:ss (4), especially i,
the li-ht of the fact that the initial attractive force of sulfuric
acid for water is only three times that of water for w2ter (see table 3).
It is of interest to note that the sur-face-boun.d water r corresoondine to
the inflection point of the moisture conter.t-relative va.' or pressure
curves, 5 to 6 percentt for wood ani alout 3 percent for cott-:n, exhibits
the came internal pressure of a-out 22.5 k-ilobars for 'oth 'ood and
cotton. The average force with which all the water i- hole. belol, the
fiber-saturation pcint varies for t.,, different cellulo.ic -interials;
15.5 kilobars for the wcod, l4.7 for tIe cotton, and 1-3.7 for the pulp,
or 24, 17, anrm g percent greater than the fcrce with w.aic> waterr holds
water.


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Table 3.--Relationship between the change in the partial internal -rcs-
sure of water and the partial heat of solutionI of water in
the formation of various aqueous solutions


Weight : Specific
fraction: volume minus
of H20 : partial
specific
volume of
H20


(xl)


(v. y )


Changes in par-: Partial heat
tial internal : of solution
pressure of : of H20
H20


(T)


(i)


* : -


Glycerol









Glycol..


0.0
.1
.2
.3
.4
.5
to
.6
.7

.0
.1
.2


.5
.6
.7
.8


(:
(:
(:
HKo3z ... (
(:
(:
(:


0.040
.028
.023
.019
.012
.010
.0075
.oo4
.004-

.053
.o44
.035
.026
.019
.o14
.009
.005
.002

.198
.190
.163
.136
.086
.058
.036
.011


Kilobars

1.00
.69
.55
.45
.28
.22
.16
.09

1.4o
1.15
.88
.63
.45
-325
.20
.11
.o45

10.2
9.3
7.0
5.0
2.7
1.6
.9
.25


XiloJoules


0.0O1
.056
.o43
.037
.027
.021
. oL4
.o14
.008

.100
.0865
.065
.o49
.0375
.029
.022
.0125
.0035

.90
.80
.59
.39
.22
.13
.O0
.02


(continued on next page)


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Solute


Ratio




P


12.3
12.3
12.8
12.2
o10.4
10.5
11.4
11.2

i4.o
13.3
13.5
12.9
12.0
11.2
9.1
12. g

11.3
11.6
11.8
12.8
12.0
12.3
11.2
12.5















Digitized by the Internet Archive
in 2013









http://archive.org/details/bondin00fore








Table 3.-- Continued.

Weight : Specific :Charkgo in par-:Partial heat :
Solute : frac- :volume minus :tial internal : of solution : Ratio
tion : partial : pressure of : of E)0
of H20 : specific : H20
volume of
: : H20 :
(Xl) ( l) (P) (H) .'

7.: lobars 1 ilojoules

(: 0.0 : 0.129 4.80 0.43 : 11.2
( .1 : .093 3.00 .37 S.I
( .2 : .068g 1.95 : .25 7-.
( .3 : .038 1.00 .14 : 7.1
3P04""(: 4 :4 .028 .70 .03 .7
( .5 .021 .50 .05 1. 0
S .6 : .010 .23 .02 : 11.5
( .7 : .006 : .13 .015 : 11.5

.0 : .306 26.5 : 1.92 : 13.3
( .05 : .292 23.0 1.75 13.1
.10 .260 17.5 1.50 : .7
( .15 : .182 : .5 : 1.12 7.6
S .20 : .106 : 3.6 : .7 4.6
- S4. ( .30 .052 1.4 .43 53.3
2014-(: .40 : .0355 : .92 .26 3.5
( .50 : .0265 : .64 : .14 4.6
S .60 : .0170 : .4o .08 5.0
( .70 : .0095 .22 .o4 : 5.5
S .80 .oo45 .10 .015 6.7
S .90 : .0025 .05 .004 : 12.5
. C
( .425 : .115 : .00 .420 9.5
( .5 .083 2.57 .255 : 10.1
KOH.....(: .6 .045 1.20 .110 10.9
( .7 : .014 .33 .027 : 12.2
S .8 : .0075 -.17 .014 : 12.1
::
S .6 : .io4 : 3.50 : .295 : 11.9
TaOH.... ( .7 .068 1.95 .14o 13.9
S .8 : .023 .55 .C- : 13.7



(continued on next page)


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/j









Table 3.-- Continued.


S Specific
:volume minus
partial
S specific
Volume of
H20


:Ch"n'ges in par-:Partial heat
: tial internal : of solution
pressure of : of
EH20 H20


(


0


KC2H302


(U)


Solute


(: .7
MgCl. ..2 (

(: .4
(: .5
(: .6
ZnOl2...( .7
"(: .8

(: .9

(: .7
Li0l....(: .8
(: .9

(: .6
CuCl2...(: .7
(: ,8


xl1



.4
.5
.6
.7
.8
.9

.7
.*
.9

.7
.7
.g


Kilojoules :


Kilobars

0.97
.66
.43
.175
.032
.013

.13
.045
.013

1.15
.4:
.20

.80
.28

1.4
1.0
.58
.40
.20
.09

.33
.20
.09

M
.52
.20


(Table 3 concluded)


R1234


0.038
.027
.018
. 008
.0015
* 0005


.002
.ooi05


.004

.o44
.020
.009

.032
.012

.052
039
.024
.017
.009
.oo4

.o14
.009
.oo4

.032
.022
.009


IJeight
frac-
tion
of
H20


Ra tio


(P)
(F)


12.9
12.4
12.3
13.5
14.5
13.0

13.0
12.8
13.0

12.0
12.6
13.3
ll.k
11.2

10.8
11.5
12.1
12.1
11.1
11.2

3.6
12.0
12.

14.5
14.4
12.5:


(vI Vl) : (T) :
-------.------: __---- -- _---- --- *- .


0.075
.053
.035
.013
.0022
.001

.010
.0035
.001

.096
.038
.015

.070
.025

.130
.087
.o48
.033
.01U
.008

.095
.01(18
GOlg
.007

.055
.036
.016


(
NaC2H 3 2(:


(.
aOal2. .. (:
(.









S







PM'EREITCES


(1) Argue, G. H., and iiaajs, 0.: Can. J. Research 12, 564 (1935).
(2) Campbell, W. G., and Russell, J. K.: Quart. Rev. Forest
Products Lab. (Canada), Jan.-Mar., p. 24 (1935).
(3) Davidson, G. F.: J. Textile Inst. l1, T175 (1927).
(4) Filby, E. A., and :,aass, 0.: Can. J. Research 7, 162 (1932).
(5) Gibson, R. E.: J. Am. Chem. Soc. 56, 4 (1934); 57, ".4, 1551 (1935).
(6) Howard, H. C., and Hulett, G. A.: J. Phys. Chem. 28, 10S2 (1924).
(7) Katz, J. R.: Koninkl. Akad. Wetenscharn'-en Amsterdam, Proc. Sec.
Sci. 13, 975 (1910) (in En:-lish); Trans. Faraday Soc. 29, 279
(1933).
(S) Kistler, S. S.: J. Phys. Chem. 36, 52 (1932).
(9) Lewis, G. IT., and Randall, M.: Thcrroiyn-itmics, p. 3g. The -;:cGrai-,-
Hill Book Co., New York (1932).
(10) Marschall, A. L.: in H. S. Taylor's Treatise on Physical Chemistry,
1st edition, Vol. I, p. 217, D. Van Nostrand Co., 1f.!' York
(1924).
(11) Sherrard, E. C., and Harris, E. .: Ind. S-n-. Chem. 24, 103
(1932).
(12) Stamm, A. J.: J. Phys. Chem. 33, 398 (1929).
(13) Stamm, A. J., and Loughbornuu;h, 1. K.: J. Phys. Chem. 39, 121 (1935).
(14) Stam-i, A. J., and Seborg, R. 'M.: J. Phys. Chem. 39, 133 (1935).
(15) Urquart, A. R., and Williams, A. M.: J. Textile Inst. 15, T559
(1924).


R1234


-7-




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'I'
/ II
ii
( l i
!


I

i *

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M 3I356 r


riguarg 1.--Aparatius fo'r edater-
mir.in4 the roid Yolune of
cellule sic materiali lby gas
d.i spiarcesmnt.


' } --"-T OIL PL/ k&7


.
r---

t


I



/


/ C L EOD G US.E,






N
i
iI
! !




\


1


(- .







/




F- .. ~ -


M FTER/hqL ME
DENSI r
WHITE SPRUCE 0
SULPHITE PULP 0

COTTON LINERS (b

I

0
0


THOD


THEfMAIOL
*


(VPQUHPfA4r A0 WILL4MS)
a (ARG'UE 4AN'< A44,4SS) I

Fieare 2.--The external pressure that would
cause a cor" r"--;ion of water equal to the
volumetric contraction occurring on its
adsorption by wood, cotton, and pulp, or the
equivalent internal pressure change that
causes the contraction for different moisture
contents determined from both density and
thermal data.


0 I .I- I I I I I I I I i I I
0 Z 4 6 8 /0 IZ 1/4 / 16 8 zo ZZ 2 4 26 28
MOISTURE CONTENT (PERCENT OF DRY WEIGHT)
it 313 f


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/ UNIVERSITY OF FLORIDA
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