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[an error occurred while processing this directive] Report from The Society of Rheology 78th Annual Meeting

By Rebecca Perry, SPS Reporter, Bowdoin College

  What is Rheology?
Rheology, a branch of mechanics, is the study of those properties of materials which determine their response to mechanical force. The word rheology was coined in the 1920's to represent the science of the deformation and flow of matter, and The Society of Rheology was officially formed on December 9, 1929. Meetings of The Society have been held at least annually since that time. The Society has sponsored publication of technical and scientific papers in this field in various journals, currently in its own Journal of Rheology.

Rheology enters in some form into almost every study of material properties, and many physicists, chemists, engineers, biologists and mathematicians find a common meeting ground in The Society's meetings and publications. It is a small society compared to many others, membership currently being about 1,700. The membership represents a wide spectrum of individuals from academic, industrial, and governmental institutions whose activities include both phenomenological and molecular theories, instrumentation, the study of many types of materials such as polymers, metals, petroleum products, rubber, paint, printing ink, ceramics and glass, foods, biological materials, floor preparations and cosmetics, and a wide range of practical applications.

On Tuesday, October 10th I drove from Bowdoin College to Portland, Maine to serve as reporter for the Society of Physics Students at The Society of Rheology’s 78th Annual Meeting. I was welcomed at the reception desk with a press nametag and an abstract book with more than one hundred pages (see photograph at left). The talks and posters listed in the book all somehow related to The Society of Rheology’s stated purpose of advancing "the science of the deformation and flow of matter."

The talks and posters were classified into eleven categories of which "Microfluidics, Confined Systems and Thin Films" included the greatest number of talks. Each of the first three mornings of the meeting started with a plenary lecture. On Tuesday, I arrived just in time to hear Dr. Robert C. Armstrong present his talk entitled "Rheology and Energy."

Dr. Armstrong is the Bingham award winner for 2006 and the department head of Chemical Engineering at MIT. In his talk, he addressed the energy challenge that the world will be faced with over the next fifty years. As Armstrong spoke to an almost full conference hall, he cited impressive numbers to get our attention. The world used 14.2 terawatts of power during a recent year, he told us, and the world energy demand is expected to double by 2050. Currently, only 4 out of the 410 exajoules of energy used each year are produced using renewable resources. In order to meet the growing demand for energy without vastly increasing carbon dioxide emissions, Armstrong encouraged the rheologists present to direct their research towards drag reduction, enhanced oil recovery, and efficiency of energy production and use. The part of Armstrong’s talk which struck me the most was his analogy between energy production and food resources. He urged us as a civilization to switch from a hunter-gatherer method of obtaining energy to a farming paradigm. Rather than harvesting energy from far-away oil wells, Dr. Armstrong would like to see us "growing" energy where we need it with solar power, wind power, biofuels, and other yet-to-be-discovered energy generation methods.


After Armstrong’s address, the scientists mingled over coffee (see photo at left) before splitting up into four conference rooms for a full morning of talks. Because I studied flowing foams in an REU program at Indiana University last summer, I chose to attend the series of talks about Suspensions, Colloids & Granular Materials. Here, I heard speakers from Harvard University, the University of Delaware, Columbia University, and a lab in Champs sur Marne, France.

The small group of speakers I heard from in the morning clued me in to the diverse geographical range of the participants at the conference. Also represented were institutions in Mexico, Iran, Belgium, Canada, Spain, Germany, Finland, Japan, India, and various other countries. The variety in geographical range was matched by the diversity of fields represented at the conference. While some speakers were physicists, as I expected, the majority were chemical engineers. Other kinds of engineers, applied mathematicians, materials scientists, and researchers from national labs and industry also presented at the conference.

During the lunch break, I had the opportunity to speak with Dr. Andy Kraynik, the President of The Society of Rheology and Dr. John Brady, editor of the Journal of Rheology.

Dr. Kraynik works on simulations of foams at Sandia National Laboratories and has attended all of the annual meetings of The Society of Rheology since 1977. He is very enthusiastic about this particular society because it is "highly functional" and the members are "enthusiastic about the meetings." Reasons why he thinks the meeting attendees are so enthusiastic are the relatively small size of the conferences (300-350 people), which allows for "easy networking," the comparatively low registration fee, and the nice social events like coffee breaks built into the schedule. He himself has found the conferences to be a great place to meet and reconnect with friends.

Trevor Ng of MIT presenting his research on bread dough.  

When asked about the role played by industry in The Society of Rheology, Dr. Kraynik informed me that in the early years of the society there were many presidents from industry but that there has been less direct involvement recently. Still, he believes industry does affect what people choose to research because, beyond scientific curiosity, many people are motivated by "addressing important problems" which lends itself to collaborations with industry.

As for physics students hoping to enter the field of rheology, Dr. Kraynik recommends a strong mathematics background and courses in fluid mechanics, classical mechanics, and the physics of soft condensed matter. John Brady recommends any course offered in continuum mechanics or continuous systems such as a course covering the propagation of sound waves.

John Brady, the editor of the Journal of Rheology, is a chemical engineer at the California Institute of Technology where he models suspensions in complex fluids. One reason Dr. Brady enjoys chemical engineering is the vast range of spatial scales addressed by the field; I learned from him that chemical engineers research everything from electrons in computer chips to particulates in global air circulation patterns. As the elected editor of the society’s journal, Brady chooses referees and communicates with authors about their articles.

As editor, Dr. Brady was able to tell me about the current big topics in rheology. He said that "microrheology is a newly emerging" area that takes advantage of semiconductor processes. Microrheology allows for the characterization of expensive materials using just small samples. As in many areas of physics, "a lot of applications for biological [research has] helped reinvigorate what is going on in the field." For example, optical tweezers can be used to study particles in suspension in live cells. A third exciting area of rheology which Dr. Brady introduced me to is the study of electrorheological and megnetorheological materials whose state (liquid or solid) can be controlled with electric and magnetic fields.

Dr. Nina Shapley of Columbia University presenting on flows of suspended particles.  

For the afternoon, I attended the talks on Paper, Pulp & Industrial Processes. These talks largely focused on properties of materials at a much bigger spatial scale than the colloid talks I listened to in the morning. The scientists I heard from studied bread dough (see photograph), mozzarella cheese, microbubble suspension, and tar sands. As Mr. Muliawan mentioned in his talk on the rheological properties of Mozzarella cheese, all the topics discussed in the set of afternoon talks had implications for designing and optimizing manufacturing processes.

To wrap up the day, I stopped by The Society of Rheology coffee and cookie break and spoke with some of the industrial vendors advertising along the edges of the room. Overall, attending the meeting was very informative. As an undergraduate physics student, I found it interesting to see how a professional conference runs and to find out more about rheology. I came away from the conference surprised by the range of disciplines from which one can address questions in the field of rheology and impressed by the cross-disciplinary, cross-cultural nature of the forum that the conference provided.

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