Rheological behavior influence

I. M. El-Gamal and E. A. M. Gad. Low temperature rheological behavior of umbarka waxy crude and influence of flow improver. Rev Inst Franc Petrol, 52(3) 369-379, May-June 1997. 

Funami, T., Hiroe, M., Noda, S., Asai, I., Ikeda, S., and Nishinari, K. (2007). Influence of molecular structure imaged with atomic force microscopy on the rheological behavior of carrageenan aqueous system in the presence or absence of cations. Food Hydrocolloids 21, 617-629. 

Oscillatory shear experiments are the preferred method to study the rheological behavior due to particle interactions because they directly probe these interactions without the influence of the external flow field as encountered in steady shear experiments. However, phenomena that arise due to the external flow, such as shear thickening, can only be investigated in steady shear experiments. Additionally, the analysis is complicated by the different response of the material to shear and extensional flow. For example, very strong deviations from Trouton s ratio (extensional viscosity is three times the shear viscosity) were found for suspensions [113]. 

Fig. 54 Influence of the pigment concentration on the rheological behavior. P.Y.73 in air drying alkyd resin paint.

In this section, the parameters influencing the mean diameter dR resulting from the Rayleigh instability are examined. Hereafter, the second fragmentation regime is not considered because a narrow size distribution is already obtained after the first one. The parameters that influence dR are the applied stress a, the viscosity ratio p, the rheological behavior, and the way the shear is applied. 

The principal cement and admixture factors that influence the rheological behavior in HPC, particularly at very low water-cement ratios, are the following (1) the quantity of tricalcium aluminate (C3A) and to a lesser degree... 

Several factors can be identified as being crucial for the foaming of immiscible polymer blends the blend morphology, the phase size of the blend constituents, the interfacial properties between the blend partners, and, last but not least, the properties of the respective blend phases such as the melt-rheological behavior, the glass transition temperature, the gas solubility, as well as the gas diffusion coefficient. Most of these factors also individually influence the melt-rheological behavior of two-phase blends. 

The surface chemistry of fumed silica is extremely important because of its influence on the rheological behavior of the formulation. Three types of chemical groups can be formed on the surface of the particle depending on the processing procedures ... 

All the above formulas are one-parameter equations, i.e. they relate the dispersion viscosity only to the volume fraction of particles contained in it. This limits the range of applicability of the equations to not very high dispersion concentrations. To take account of the influence of the structure of concentrated dispersions on their rheological behavior, Robinson [12] suggested that the viscosity of dispersions is not only propertional to the volume fraction of solid phase, but is also inversely proportional to the fraction of voids in it. (At about the same time Mooney [40], who proceeded from a hydrodynamic model, arrived, using theoretical methods, at the same conclusion). Robinson s equation contains the relative sedimentation volume value — S, which depends on the particle size distribution of the dispersion... 

Genovese, D. B., Acquarone, V. M., Youn, K.-S., and Rao, M. A. 2004. Influence of fructose and sucrose on small and large deformation rheological behavior of heated Amioca starch dispersions. Food Sci. Technol. Int. 10(1) 51-57. 

In order to understand or study heat transfer phenomenon, the rheological behavior of a fluid food must be known as a function of both temperature and shear rate. For convenience in computations, the effect of shear and temperature may be combined in to a single thermorheological (TR) model. A TR model may be defined as one that has been derived from rheological data obtained as a function of both shear rate and temperature. Such models can be used to calculate the apparent viscosity at different shear rates and temperatures in computer simulation and food engineering applications. For a simple Newtonian fluid, because the viscosity, r), is independent of shear rate, one may consider only the influence of temperature on the viscosity. For many foods, the Arrhenius equation (Equation 2.42) is suitable for describing the effect of temperature on t] ... 

However, additional factors must be considered in order to understand and fuially predict the rheological behavior of silica-resin mixtures. In particular, the type and strength of particle interactions and the influence of adsorption processes on these interactions are key factors which govern the rheology of liquid media containing pyrogenic silica for rheology control. 

Opota O, Maillols H, Acquier R, etal. Rheological behavior of aqueous solutions of hydroxypropylcellulose influence of concentration and molecular mass [in French]. Pharm Acta Helv 1988 63 26-32. 

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