More remarks:

On p. 69, the quadratic fits provide good $R^2$ values, but the
overlaying the fitted graphs on top of the scatterplot you have
in Figure 5.1 might not look so good.  The quadratic functions
are the best we can do with only 16 datapoints, but they are
inadequate.  Each is a parabola that approaches infinity as
ef increases, which is clearly not right.  However, they may
serve as reasonable fits for the restricted range of ef considered
here.

On p. 74, last sentence, you mention Figures 5.6-5.9.  These
figures are called empirical distribution functions of fiber 
diameter measurements.  While it is true that the means from
these distributions appear to decrease monotonically with
ef for each concentration, the same cannot quite be said for
the right tails of the distributions for concentrations 21% 
and 25%.  Figures 5.6 and 5.8 have some crossing of the cdfs
at the 90th percentile.  I might say something like

"Empirical cumulative distribution functions for fiber diameters
at each combination of electric field and concentration are shown 
in Figures 5.6-5.9.  These augment the analysis of the means in
Figure 5.1 and provide more evidence that diameter decreases with 
electric field at each concentration."

A comment I have for you, but not for inclusion in the manuscript:
- The slight crossing of the functions in the right tails of the
distributions may be due to sampling error.  The software used to
generate these empirical CDFs does not report number of fiber 
diameters measured.  Without such a sample size, statistical 
comparisons of distribution functions is not possible.

A question: in Figure 5.10, you have the distn of fiber diameter
from each concentration at ef=1.0.  Why don't you have means
from these ef*conc combinations to use in Figure 5.1?

Figures 5.14-5.17 are fine,  and so are their descriptions on p.82.
They are called histograms, and you may want to say this in the text.  
Why did you switch gears from plotting histograms of orientation angles, 
but empirical cumulative distribution functions for diameters? Just curious.

*****
The data plotted in Figure 5.20 do not appear to agree with those
listed on p. 125.  Are they supposed to?  The F-ratio for interaction
of conc & ef on mean anisotropy should be based on 3 numerator
degrees of freedom if there are 4 concentrations, and 2 if there
are 3 concentrations (there are only three plotted in Figure 5.20).
*****

Bottom of p. 88 should read something like
"Avg. pore diameter and basis weight are both plotted together
against electric field in Figures 5.22-5.24."

There are some typos on p. 98-99.  They're my fault:

p. 98, 3rd paragraph, 1st sentence: 

"Partial correlation . . . associations between pairS of response
variables ..."

p. 98, 3rd paragraph, 2nd sentence: 

The SQUARED partial correlation . . . is r^2_{APD,AFD;model}=0.207

p. 98, 3rd paragraph, 2nd sentence: 
The SQUARED partial correlation . . . is r^2_{APD,AR;model}=0.0127.

p. 98, 3rd paragraph, last sentence: 

"Niether of these correlationS are ..."

p. 99, 1st paragraph, 1st sentence: 

"the linear association goes away AFTER dependence on electric ..."