The Equations Left Behind

The latest Rheology Bulletin (link not available yet) announced the death of Professor Dr. Joachim Meissner this year.  During graduate school, I often spoke Meissner's name, because of his work in constitutive equations.  In 1972, Arthur Lodge and Meissner used phenomenological arguments to show that the first normal stress difference and shear stress are proportional to each other when a single strain is applied at time zero [1].

This relationship is supported by many experiments and constitutive equations.  During graduate school, I used the above equation to infer the sample thickness in my optical rheometer [2].

In addition to single-step strains, I and others did work on reversing double-step strains, where a second strain is in the opposite direction to the first.  Osaki and co-workers [3] proposed a relationship similar to the equation shown above:

When Venerus and Kahvand published their study of mechanical double-step strain rheology [4], Lodge somehow heard of the work and proved and generalized the second equation for multiple reversing step strains where the absolute value of the strain is constant.  Following this chain of events, I started referring to the second equation as the Osaki-Lodge relationship.  (I always thought this chain of events showed scientific collaboration at its best.)

[1] Lodge, A.S.; Meissner, J. Rheol. Acta 1972, 11, 351-352.

[2] Brown, E.F. et al., Rheol. Acta 1995, 34, 221-234.

[3] Osaki, K. et al. J. Polym. Sci., Part B: Polym Phys. 1981, 19, 517-527.

[4] Venerus, D.C.; Kahvand, H. J. Rheol. 1994, 38, 1297-1315 (with an appendix by Lodge).

Surely You're Joking (#11): Knock Knock

Knock, knock
Who's there?
The fluid mechanics
The fluid mechanics who?
The fluid mechanics, so they're out today.



Knock, knock
Who's there?
Rheology
Rheology who?
Real?  Gee!  I thought they were fake!

I Acknowledge I Have a Problem with This

We just wrapped up our summer intern cycle at ConAgra Foods [1], and I noticed a pattern in the final presentations.  All the presentations I observed used the words "Acknowledgements."  According to the dictionary, this is the British spelling of the word.  If you're going to add that extra e, then you might as well put a discussion of the latest rumours on your "shed-yule".
I suspect that this British spelling slips by because the base word is spelled acknowlege acknowledge, and the extra e doesn't look out of place the way that extra u in rumours does to American eyes.

[1]     Information on internships at ConAgra can be found here.  The main opportunities are in food science, but other interested parties are welcome to apply.

Jobs Report (August '11)

Keyword searches (rheolog*) conducted on August 7 found 31 jobs on Monster and 20 jobs on Careerbuilder.

3 for the price of 1!

The folks who organize the triennial International Symposium on Food Rheology would like you to be careful with your travel funds in 2012.  Instead of going to the Food Colloid conference in Copenhagen AND the Food Oral Proceesing Conference in Baune (France) AND the Rheology Congress in Lisbon, you can attend their conference in Zurich.

Hello Cleveland!

This year's SOR meeting will be in Cleveland, OH.  Any current or former children of Cleveland who would like to introduce their city to the readers of the blog, send me a note at rheolworldblog -at- gmail.com.  (I did some writeups for Santa Fe last year.)

Poll of the Month (July)

From the last post comes the current poll of the month.  Which is the best basic rheology book?

Jobs Report (July '11)

Keyword searches (rheolog*) conducted on July 3 found 39 jobs on Monster and 15 jobs on Careerbuilder.

The Wisdom of Crowds

A recent discussion at LinkedIn's SOR group asked which introductory rheology book was best.  This was the most popular discussion in recent memory.  People mentioned--

• The Rheology Handbook by T. Mezger (twice)
• Handbook of Elementary Rheology by H. Barnes (twice)
• Rheology: Principles, Measurements, and Applications by C.W. Macosko
• Understanding Rheology by F.A. Morrison
• An Introduction to Rheology by H.A. Barnes, J.F. Hutton, and K. Walters (twice)
• A Practical Approach to Rheology and Rheometry by G. Schramm
  (This book is self-published by ThermoFisher)
• Rheological Methods in Food Processing Engineering by J.F. Steffe and C.R. Daubert (twice)
• Bioprocessing Pipelines: Rheology and Analysis by J.F. Steffe
  (Both the Steffe books are available online for free download.)
• There was a mention of a book by K. Walters; it's either the one co-authored with Barnes listed above or Rheology: An Historical Perspective co-authored with R.I. Tanner

Breaking Radio Silence

I'm back with a some new posts over the next few days.  I haven't posted, because, to bluntly put it, there hasn't been anything I'd like to discuss.