Porosity dependent

The particle size and thus surface area of iron oxides and also the porosity depend strongly on the conditions under which crystal growth takes place. For example, high rates of growth at low temperatures may lead to poorly ordered crystals with surface areas of up to several hundred m g , whereas low surface area crystals may grow at higher temperatures and at slow rates of formation. In natural environments, such ex-... 

The dependence of diffusivity in silicate melts on composition is related to how melt structure (including degree of polymerization and ionic porosity) depends on composition. One the one hand, as Si02 concentration increases, the melt becomes more polymerized and the viscosity increases. Hence, diffusivity of most structural components, such as Si02 and AI2O3, decreases from basalt to rhyolite. On the other hand, as Si02 content increases, the ionic porosity increases. The increasing He diffusivity from basalt to rhyolite to silica, opposite to the viscosity... 

TABLE 10. Variation of silica porosity depending on the experimental parameter of the chemical treatment... 

The raw data in gel permeation chromatography consist of a trace of detector response, proportional to the amount of poly mer in solution, and the corresponding elution volumes. A typical SEC record is depicted in Fig. 3-8. It is normal practice to use a set of several columns, each packed with porous gel with a different porosity, depending on the range of molecular sizes to be analyzed. 

The membrane material varies from alumina, zirconia, glass, titania, cordierite, mulUte, carbon to such metals as stainless steel, palladium and silver. The resulting pore diameter ranges from 10pm down to4 nm and the membrane thickness varies from 3 to 10 pm. The membrane porosity depends on the pore size and is 40-55%. 

Other factors that play a key role in designing the filter are its mechanical integrity and filtration capacity. The former is defined by mechanical integrity factor MIF, which, for a given wall porosity, depends on cell geometry via... 

Figure 8 Porosity dependence of impact strength for snow and snow-silicate mixture.

Figure 11 Schematic illustration explaining porosity dependence of impact strength.

K. J. Kim, P.V. Stevens and A.G. Fane, Porosity dependence of pore entry shape in track-etched membranes by image analysis. /. Membrane Sci., 93 (1994) 79. 

Almost all solid-liquid systems change with time and treatment, and parameters in SLS design such as settling rate, permeability and porosity depend upon history of slurry. Therefore, continuous monitoring of operation and characteristics of suspension system is important. 

The capability of retaining water vapor within the layer is to a certain extent the reason why it can be used as a steering parameter for the final tungsten metal powder properties. The water vapor retention capacity of the layer depends on the layer height and its porosity. The layer height can be chosen within limits in connection with the temperature. The porosity depends on the oxide powder properties. The macroporosity is a consequence of the agglomerate size of the oxide powder (which is related to the size of the crystallized APT particles prior to decomposition) and the microporosity is due to... 

If the solution is cooled by casting on a chilled metal belt, the surface adjacent to the belt will be skinned whereas the surface adjacent to the air/solution Interface will be skinless. This is just the opposite to that which usually occurs in wet and dry processes. The skin thickness is approximately equal to the thickness of a single cell wall and can either be Integral (totally nonporous) or nonintegral (some porosity) depending on the... 

Gimenez, D., R.R. Allmaras, D.R. Huggins, and E.A. Nater. 1997. Prediction of the saturated hydraulic conductivity-porosity dependence using fractals. Soil Sci. Soc. Am. J. 61 1285-12 2. 

Packed sphere rW r, = sphere radius e = porosity (dependent on packing mode)... 

Often, sintering is used as a post-treatment process to provide strength to agglomerates (see Sections 7.3 and 8.3) or modify the porosity. Depending on how the sintering process is controlled, the agglomerate shrinks and densifies (up to almost 100 % density or 0 % porosity) or porosity is maintained and, sometimes, even increased (see Section 5.3.2). 

I. Growth or Tumble Agglomeration (see Chapter 7) The mechanism of growth (see Section 7.1) of this method, the addition of single or aggregated particles to the outside of an agglomerate that increases in size, results in a typical structure with rather constant porosity. Porosity depends mostly on the size, distribution, shape, and surface... 

When sediments are progressively buried, they are compacted, and pore fluid is expelled. We consider compaction in this program with the following assumptions (Perrier and Quiblier 1974) (1) the volume of solid matrix is preserved throughout compaction and (2) porosity depends only on burial depth and can be expressed as... 

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