Deformation and flow

Rheology is the science of the deformation and flow of matter. It is concerned with the response of materials to appHed stress. That response may be irreversible viscous flow, reversible elastic deformation, or a combination of the two. Control of rheology is essential for the manufacture and handling of numerous materials and products, eg, foods, cosmetics, mbber, plastics, paints, inks, and drilling muds. Before control can be achieved, there must be an understanding of rheology and an ability to measure rheological properties. 

Rheology is the science that deals with the deformation and flow of matter under various conditions. The rheology of plastics, particularly of TPs, is complex but understandable and manageable. These materials exhibit properties that combine those of an ideal viscous liquid (with pure shear deformations) with those of an ideal elastic solid (with pure elastic deformation). Thus, plastics are said to be viscoelastic. 

Rheology deals with the deformation and flow of any material under the influence of an applied stress. In practical apphcations, it is related with flow, transport, and handling any simple and complex fluids [1], It deals with a variety of materials from elastic Hookean solids to viscous Newtonian liquid. In general, rheology is concerned with the deformation of solid materials including metals, plastics, and mbbers, and hquids such as polymer melts, slurries, and polymer solutions. 

Rheology concerns the study of the deformation and flow of soft materials when they respond to external stress or strain. If the ratio of its shear stress and shear rate is a straight line, the material is termed Newtonian otherwise, it is termed non-Newtonian (Figure 4.3.2(a)). As the slope of the curve is the viscosity rj, a shear-thinning fluid exhibits a reduced viscosity as the shear stress increases, whereas a shear-... 

Rheology is the study of the deformation and flow behavior of materials, both fluids and solids. See, e.g., Barnes et al. (1989). 

The science of the deformation and flow of matter the study of a range of phenomena extending from the plastic flow of solids to the behaviour of fluids under extreme conditions. Rheometer... 

The science that deals with the deformation and flow of matter is called rheology. An important rheological concept is the shear force, sometimes called the shear stress, or the force that causes a layer of a fluid material to flow over a layer of stationary material. The rate at which a layer of a fluid material flows over a layer of stationary material is called the shear rate. A fluid flowing through a tube, for example, would be the fluid material, while the tube wall would be the stationary material. An important rheological measurement that is closely related to the resistance to flow is called viscosity. The technical definition of viscosity is the ratio of shear stress to shear rate ... 

Note 3 Deformations and flows used in conventional measurements of properties of viscoelastic liquids and solids are usually interpreted assuming incompressibility. 

The branch of science related to the study of deformation and flow of materials was given the name rheology by Bingham, whom some call the father of modern rheology. The prefix rheo is derived from the Greek rheos, meaning current of flow. The study of rheology includes two vastly different branches of mechanics—fluid and solid. The polymer scientist is usually concerned with viscoelastic materials that act as both solids and liquids. 

Rheology is the study of deformation and flow of materials. Polymers are viscoelastic materials, meaning they can act as liquids and as solids. 

RHEOLOGY. The study of the response of materials to an applied force. Rheology deals with the deformation and flow of matter. 

In contrast to the disapline of mechanics, wherein the responses of bodies to unbalanced forces are of concern, rheology concerns balanced forces which do not change the center of gravity of the body. Since rheology involves deformation and flow, it is concerned primarily with the evaluation... 

Rheology is the science of deformation and flow of matter. In food rheology, the matter of interest is food, and the importance of its deformation and flow relate to several important properties. Of these, texture is the most important. Texture is one of four quality factors of foods the others are flavor, appearance, and nutrition. In the food industry, there are other properties and processes in which rheology has an important role. They include formulation, manufacturing, transportation, and shelf stability. The measurement of the rheological properties of foods provides the food scientist and engineer with critical information necessary for the successful development and delivery of formulated foods to the consumer. 

In the definition of rheology there are two processes, deformation and flow. Deformation suggests the presence of solid-like behavior and flow suggests the presence of fluid-like behavior. Many foods have both solid and fluid properties. The objective of this section is to provide methods for the evaluation of the rheological properties of foods. In Chapter HI, flow properties of foods are the focus. In Chapter H2, deformation properties are the focus. 

The theology (deformation and flow) of coal has been studied in an effort to apply it to characteristics of coal in coal mines coal elasticity (quality of regaining original shape after deformation under strain) has also been studied. However, it may be quite difficult to obtain meaningful measurements of coal elasticity. For... 

Rheology is the study of the deformation and flow of matter under the influence of an applied stress. Commonly a sample such as a polymer or gel is placed between two flat plates or between two concentric cylinders and the stress is applied by moving one plate or cylinder relative to the other while the resulting strain is measured using a pressure transducer. We can define a number of categories of rheological behaviour as a... 

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