Rheology And Fourier Transform Rheology On Water Based Systems

The influence of shear fields on water-based systems was investigated within this thesis. The non-linear rheological behaviour of spherical and rod-like particles was examined with Fourier-Transform rheology under LAOS conditions. As a model system for spherical particles two different kinds of polystyrene disper- sions, with a solid content higher than 0.3 each, were synthesised within this work. Due to the differences in polydispersity and Debye-length, differences were also found in the rheology. In the FT-rheology both kinds of dispersions showed a similar rise in the intensities of the magnitudes of the odd higher harmonics, which were predicted by a model. The, in some cases additionally appearing second harmonics, were not predicted. A novel method to analyse the time domain signal was developed, that splits the time domain signal up in four characteristic functions. Those characteristic functions correspond to rheological phenomena. In some cases the intensities of the Fourier components can interfere negatively. FD-virus particles were used as a rod-like model system, which already shows a highly non-linear behaviour at concentrations below 1. % wt. Predictions for the dependence of the higher harmonics from the strain amplitude described the non-linear behaviour well at large, but no so good at small strain amplitudes. Ad- ditionally the trends of the rheological behaviour could be described by a theory for rod-like particles. An existing rheo-optical set-up was enhanced by reducing the background birefringence by a factor of 20 and by increasing the time resolution by a factor of 24. Additionally a combination of FT-rheology and rheo-optics was achieved. The influence of a constant shear field on the crystallisation process of zinc oxide in the presence of a polymer was examined. The crystallites showed a reduction in length by a factor of 2. The directed addition of polymers in combi- nation with a defined shear field can be an easy way for a defined change of the form of crystallites.

Dispersionen sind ein heterogenes Gemisch aus zwei Stoffen, die sich nicht miteinander mischen. In der vorliegenden Arbeit werden sowohl Suspensionen bestehend aus einer festen dispersen Phase in einem flussigen Dispersionsmedium, Emulsionen bestehen aus zwei nicht mischbaren Flussigkeiten als auch Schaume, gebildet aus einer Gasphase dispergiert in einer Flussigkeit, untersucht. Als Hauptcharakterisierungsmethode dient die Fourier Transformations-Rheologie (FT-Rheologie), welches eine mechanische Charakterisierungsmethode im nichtlinearen Bereich darstellt.

New trends in the cereal industry deal with the persistent need to develop new food goods tailored to consumer requirements and, in the near future, to the scarcity of food resources. Concepts of sustainable food production and food products as health and wellness promoters, the use of organic ingredients such as new ancient cereals to produce redesigned old staple foods, or the use of byproducts in designed food or feed formulations, in accordance with the bioeconomy and sustainability principles, are current topics that act as driving forces for innovation. The structure of cereal-based food products, especially in the case of gluten- or wheat-free foods, has proven to be a determinant for food appeal and strongly impacts consumer acceptance. It is well known that products with the same chemical composition can present very different structures, resulting in differently perceived texture and sensory properties and, therefore, rheology is an important tool for the food cereal industries. These are topics that act as driving forces for innovation and will be discussed in the present Special Issue.

Providing a comprehensive review of the state-of-the-art advanced research in the field, Polymer Physics explores the interrelationships among polymer structure, morphology, and physical and mechanical behavior. Featuring contributions from renowned experts, the book covers the basics of important areas in polymer physics while projecting into the future, making it a valuable resource for students and chemists, chemical engineers, materials scientists, and polymer scientists as well as professionals in related industries.

This volume covers the most recent progress of research work on electrorheological (ER) and magnetorheological (MR) industrial applications related to controllable damping, ER/MR fundamental mechanisms, and understanding the potential of new classes of field responsive materials. The proceedings have been selected for coverage in: • Materials Science Citation Index® • Index to Scientific & Technical Proceedings® (ISTP® / ISI Proceedings) • Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings) • CC Proceedings — Engineering & Physical Sciences Contents:Materials TechnologyPhysical MechanismStructures and PropertiesApplication of Magnetorheological FluidsApplication of Electrorheological Fluids Readership: Graduate students, academics and researchers in new materials, applied physics, condensed matter physics, and nonlinear science, chaos & dynamical systems. Keywords:Rheology;Complex Fluid;Electro-Rheology;Magneto-Rheology;Suspension;New Material;Damper;Polarization

This text provides comprehensive coverage of fibers used in food formulations, starting with the understanding of their basic chemical structure and how they are present and organized in the cell wall structure, their physicochemical and functional properties, their impact on the digestive process and their role and preventive action against various chronic diseases including colon cancer. The book focuses on traditional and new fiber rich sources, incorporating an integrated approach in terms of the technological and engineering processes used to obtain and incorporate them in traditional foods, plus their characterization, extraction and modification. The study of processing conditions including the chemical, physical and enzymatic processes of fiber extraction and modification are also covered, including traditional and emerging processing technologies, plus the application of fibers in the development of new products and processes. Science and Technology of Fibers in Food Systems integrates knowledge of fibers from their basic structural and property aspects and the applications of these ingredients to extraction process analysis, modification and feasibility for use at the industry level. The chapters incorporate the physiological aspects related to the consumption of fiber for prevention of serious diseases.

Unconventional reservoirs are usually complex and highly heterogeneous, such as shale, coal, and tight sandstone reservoirs. The strong physical and chemical interactions between fluids and pore surfaces lead to the inapplicability of conventional approaches for characterizing fluid flow in these low-porosity and ultralow-permeability reservoir systems. Therefore, new theories and techniques are urgently needed to characterize petrophysical properties, fluid transport, and their relationships at multiple scales for improving production efficiency from unconventional reservoirs. This book presents fundamental innovations gathered from 21 recent works on novel applications of new techniques and theories in unconventional reservoirs, covering the fields of petrophysical characterization, hydraulic fracturing, fluid transport physics, enhanced oil recovery, and geothermal energy. Clearly, the research covered in this book is helpful to understand and master the latest techniques and theories for unconventional reservoirs, which have important practical significance for the economic and effective development of unconventional oil and gas resources.

Advances in Food Rheology and Its Applications presents the latest advances in the measurement and application of food rheology, one of the most important tools for food companies when characterizing ingredients and final products, and a predictor of product performance and consumer acceptance. Split into two main focuses, the book gives in-depth analysis of the general advances in the field, with coverage of the relationship between food microstructure and rheology, the use of tribology in the study of oral processing, the use of large amplitude oscillatory shear (LAOS) measurement and Fourier-transform rheology in food, and the influence of fibers and particle size distribution on food rheology, as well as many other advances. Written by a leading international team of authors, the book provides an in-depth and state-of-the-art coverage of this essential topic on the consumer acceptance of food. Brings together top researchers in the field of rheology, providing in-depth and state-of-the-art coverage on an area of study essential for managing the quality of foods and gaining consumer acceptance Presents in-depth coverage of advances in rheology, many of which have never been featured before, including tribology, large amplitude oscillatory shear measurement, and the influence of fibers and particle size distribution on food rheology Contains information that is highly relevant to the industrialist who wants to improve the rheological properties of the foods with which they are working