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Winter's long-standing interest in experimental rheology began about 30 years ago when he could not find suitable rheological material data for his numerical calculations. Soon it became obvious that obtaining rheological data was not the main problem; converting these data into useful rheological material functions such as time spectra, viscosity, and modulus was the most difficult step. Little help was available here. A breakthrough came with Baumgaertel’s 1987 discovery of a robust method of converting dynamic mechanical data from the frequency to the time domain. This suddenly allowed an efficient data analysis and gave increased insight into the underlying phenomena. Since then, after much collaborative work, the data anlysis methods have become user-friendly and comprehensive while giving answers within minutes. The new methods have found widespread application. The original code was developed in collaboration with M. Baumgaertel and P. Soskey. M. Mours converted the original DOS code to visual C++ and introduced many methods from the literature. Recently, in collaboration with international experts, we extended the IRIS code and began to access molecular theory, non-linear viscoelasticity theory, and molecular simulation.
Winter has been educated mostly in Stuttgart, Germany, but he also studied in Berlin (Germany), Stanford (California), and Madison (Wisconsin). He is faculty at the University of Massachusetts Amherst since 1979. He received the Bingham Medal of the Society of Rheology, the v. Humboldt Price, and a Creativity Award of NSF. Winter is editor of Rheologica Acta since 1989. Winter and his group have been studying the rheology of polymers near transition states (phase separation, ordering transitions, connectivity transitions, crystallization, electric field induced gelation) with a wide range of experimental methods. Besides experimental rheology, Winter's group also develops novel polymeric materials through processing.
Wagner is Professor for Polymer Engineering and Polymer Physics at the Technical University (TU) of Berlin. He was born in Stuttgart, Germany in 1948. As a Physics Major, he took a PhD in Chemical Engineering at the Institute for Polymer Processing of Stuttgart University. After 2 years as a post-doc in Polymer Physics with Prof. J. Meissner at the ETH Zürich, and after 9 years of industrial experience, he returned to Stuttgart University in 1988 as Professor for Fluid Dynamics and Rheology. In 1998/99, he was Dean of the Faculty of Chemical Engineering and Engineering Cybernetics of Stuttgart University. In 1999, he moved to TU Berlin. Wagner’s scientific interests include constitutive equations for polymeric systems, the application of rheology to polymer processing, and structure-property relations for polymers. He has published to date over 100 papers on solid state physics, carbon and graphite technology, and rheology and processing of polymer melts. In 1981, he received the annual award of the British Society of Rheology (together with Meissner, Laun, and Münstedt). The Institute of Materials, London, awarded him the Swinburne Award 2002. Wagner was President of the German Society of Rheology (DRG) from 1991 to 2003, and he is Secretary of the European Society of Rheology (ESR) since 1996.
Rothstein is an Assistant Professor of Mechanical and Industrial Engineering at the University of Massachusetts. He received his Ph.D. under the supervision of Gareth McKinley at MIT. Rothstein’s background is in hydrodynamic stability, experimental non-Newtonian and Newtonian fluid dynamics, extensional and shear rheology, and novel non-invasive optical measurement techniques. He has published a number of papers in these areas including a recent article in Physics of Fluids which was awarded the prestigious Francois Frenkiel award for significant contribution to the field of fluid mechanics by a young investigator. He has designed and developed a filament stretching rheometer capable of simultaneously measuring tensile stress, strain and flow induced birefringence of complex fluids in transient homogeneous uniaxial extensional flows. His work on the behavior of polymer solutions and wormlike micelle solutions in extensional flows and mixed shear and extensional flows has led to the development of new constitutive models capable of accurately capturing the non-equilibrium dynamics and the prediction of stress-conformation hysteresis.