Homogenization Characteristics

A homogeneity index or significance coefficienf has been proposed to describe area or spatial homogeneity characteristics of solids based on data evaluation using chemometrical tools, such as analysis of variance, regression models, statistics of stochastic processes (time series analysis) and multivariate data analysis (Singer and... 

At a first approximation, a gaseous or a liquid sample without suspended particles should have ideal homogeneity characteristics for all the constituents. As we are mainly concerned about solid samples when talking about CRMs for micro-analytical techniques, we should look for materials having expected intrinsic homogeneity for their constituents. 

As pointed out by Ortega-Borges and Lincot, the relative independence of the majority of CD processes on hydrodynamic conditions explains the excellent lateral homogeneity characteristic of this technique, since the deposition depends not so much on mass transport in the solution as on chemical reaction rates. 

Full signs downflow, hollow signs upflow. Plotted curve Homogenization characteristics of Newtonian liquids, from [41]. 

Fig. 23 Homogenization characteristic of a screw stirrer in draught tube for non-Newtonian liquids with pseudoplastic viscoelastic properties. For the sign explanation see Fig. 22, from [41],... 

Using the approach of Ford and Ulbrecht, influence of rheological properties (Newtonian, pseudoplastic, viscoelastic) on the homogenization characteristics was also satisfyingly taken into account for turbine stirrers [44] and other stirrer types [45]. 

Homogenization characteristics of a mechanically agitated polymerization reactor in terms of NO = /(Reeff = Ndfp/pe( ) have been published for various stirrer types and pseudoplastic liquids with power-law behavior (Opara, 1975, Tebel et al, 1986). The homogenization time is compared to that for Newtonian fluids (Opara, 1975), and the homogenization properties of a... 

A number of animal model systems have been developed to provide tumor microenvironments that mimic the clinical situation. However, there are no perfect animal models for drug development. The adequacy of any specific animal model depends on its validity, selectivity, predictability, and reproducibility (22). In cancer chemotherapy, animal models are selected to simultaneously demonstrate antitumor efficacy and evaluate systemic toxicities in an intact organism. Ideally, the tumor system under study in the animal model should be genetically stable over time, with homogeneous characteristics that mimic human tumor biology. In oncology, a variety of diverse animal models for human tumors have been developed. These models can be broadly categorized in to three... 

Viewed in this way, it would have been more favorable, if in the case of the homogenization characteristic the term... 

In liquids with high viscosities, on the other hand, the gas bubbles are larger and furthermore the liquid circulation is reduced with the result that the mixing time is longer. For the homogenization characteristics which apply under such conditions, see [613], Other papers over this subject are [324, 483]. 

P. Todtenhaupt [547] investigated the homogenization characteristic of a stirred column with 5 stirrers on the same shaft and flow from bottom to the top. Turbine, cross-beam, MIG and propeller stirrers were used. The stirred column was provided with round baffles, but did not possess partition trays between the individual stirred sections. Turbine stirrers performed the best and propeller stirrers conveying downwards the worst. For these two stirrer types the following process relationships apply ... 

Flow marker studies in screw extruders for rubber compounds were initiated by Menges and Lehnen [M19] to evaluate the mixing and homogenizing characteristics of various screw designs. These studies feed equal-viscosity... 

Hypothesis 3 The companies within the same industry category will have homogeneity characteristics and heterogeneity characteristics in comparison with the other industries. 

Fig. 1. Schematic representation of homogeneous and inhomogeneous broadening. Identical centers, i.e. atoms with the same velocity or ions in identical sites, have similar homogeneous characteristics. All centers contribute to make up the inhomogeneously broadened transition.

Montante, G, and Magelli, F. (2004) Liquid homogenization characteristics in vessels stirred with multiple Rushton turbines mounted at different spacings CFD study and comparison with experimental data. Chem. Eng. Res. Des., 82 (9), 1179-1187,... 

According to Alencar and Almeida (2010), segments of pipelines that have homogeneous characteristics can be divided into sections. Age of piping, soil type, pressure and pipeline diameter are some of the homogeneous characteristics that can be considered. 

Porous substrates should have a smooth surface with constant and homogeneous characteristics (wettability) and a narrow pore size distribution. Pores much larger than average and grains broken out of the surface, or irregularities in the porous substrate, may result in defects in the separation layer applied on it. Therefore, surface modification or formation of intermediate layer(s) is necessary to prepare a thin and defect-free membrane. 

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