Research Rheological

Analyses of amylodextrins could be subdivided into two types, namely, structural analyses and rheological measurements. The former is more of interest to the basic researcher whilst both are of use to the applications researcher. Rheological measurements will not be discussed in this review and the reader is referred to works by Collyer and Clegg (4), Mitchell (5) and Robinson (6) for information on that particular subject. 

Foam rheology has been a challenging area of research of interest for the yield behavior and stick-slip flow behavior (see the review by Kraynik [229]). Recent studies by Durian and co-workers combine simulations [230] and a dynamic light scattering technique suited to turbid systems [231], diffusing wave spectroscopy (DWS), to characterize coarsening and shear-induced rearrangements in foams. The dynamics follow stick-slip behavior similar to that found in earthquake faults and friction (see Section XU-2D). 

To date, there has been relatively little work reported on the mesophase pitch rheology which takes into account its liquid crystalline nature. However, several researchers have performed classical viscometric studies on pitch samples during and after their transformation to mesophase. While these results provide no information pertaining to the development of texture in mesophase pitch-based carbon fibers, this information is of empirical value in comparing pitches and predicting their spinnability, as well as predicting the approximate temperature at which an untested pitch may be melt-spun. 

Advanced adhesives are composite liquids that can be used, for example, to join aircraft parts, thus avoiding the use of some 30,000 rivets that are heavy, are labor-intensive to install, and pose quality-control problems. Adhesives research has not involved many chemical engineers, but the generic problems include surface science, polymer rheology and thermodynamics, and molecular modeling of materials... 

Molecularly motivated empiricisms, such as the solubility parameter concept, have been valuable in dealing with mixtures of weakly interacting small molecules where surface forces are small. However, they are completely inadequate for mixtures that involve macromolecules, associating entities like surfactants, and rod-like or plate-like species that can form ordered phases. New theories and models are needed to describe and understand these systems. This is an active research area where advances could lead to better understanding of the dynamics of polymers and colloids in solution, the rheological and mechanical properties of these solutions, and, more generally, the fluid mechaiucs of non-Newtonian liquids. 

Many of the crucial problems for researchers in this area are the same as the ones encountered in other areas of surface and interfacial science. The research of chemical engineers on high-performance ceramic materials, field-induced bioseparations, and fouling also addresses phenomena such as agglomeration and clustering in dispersions and rheology of dispersions. For EPIDs,... 

The aim of this chapter is to summarize some of the research findings on xylan, a natural polymer extracted from corn cobs, which presents a promising application in the development of colon-specific drug carriers. Physicochemical characterization of the polymer regarding particle size and morphology, composition, rheology, thermal behavior, and crystallinity will be provided. Additionally, research data on its extraction and the development of microparticles based on xylan and prepared by different methods will also be presented and discussed. 

His research interests include EHL, mixed lubrication, nanotribology, thin film rheology, molecular dynamics simulations, etc., and he has more than 70 papers published in international journals. Professor Hu received the Edmond E. Bisson Award from STLE in 2003. He is now an Associate Editor of the Proceedings of IMechE, Part J, Journal of Engineering Tribology. 

The authors appreciate the support by research grants from the Korea Science and Engineering Foundation (KOSEF) through the AppUed Rheology Center (ARC) at Korea University. 

This study was supimrted by research grants flnm the Korea Science and Engineering Foundation (Project No. R11-2000-088-02009-0) through the Applied Rheology Center. 

Hill, R. G. Wilson, A. D. (1988b). A rheological study of the role of additives on the setting of glass ionomer cements. Journal of Dental Research, 68, 89-94. 

Center of Excellence in Extrusion and Pol3uner Rheology, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, W3mdmoor, Pennsylvania, USA Conesponding author Charles I. Onwulata, E-mail address Charles.Onwulata ars.usda.gov... 

Center of Excellence in Extrusion and Polymer Rheology, Eastern Regional Research Center, Agricultural Research Service, U.S. 

Rheo-NMR [86] methods have been shown to be well-suited to emulsion rheology studies [28] and could be combined with any of the topics described above. The combination of structural and rheological measurements is a promising area for further research. 

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