Matrix porosity

The family of agarose-based gels, Sepharose, Sepharose CL, and Sepharose Fast Flow, are bead-formed gels prepared from 2, 4, or 6% agarose solutions. The matrix porosity decreases and rigidity of the bead structure increases with increasing agarose concentrations. The open pore structure and broad... 

While there is no direct data to support this statement, we have found vastly different shelf-lives for products which contain essentially similiar trace metal levels, surface oils, and absolute densities. We can find no other explanation for the differences in shelf-life other than matrix porosity. This area needs to be further studied in order to confirm this hypothesis and then take advantage of it to improve the shelf-life of spray dried flavorings. 

C. Bettini, R., Colombo, P, Massimo, G., Catellani, P. L., and Vitali,T. (1994), Swelling and drug release hydrogel matrices Polymer viscosity and matrix porosity effect, Ear. J. Pharm. Sci., 2,213-219. 

In regenerators the porosity Hg of the matrix is not constrained by pressure considerations, but the overall porosity that includes the confining tube must not exceed the value given by equation (29). However, high values of the matrix porosity may lead to insufficient matrix heat capacity. The heat capacity ratio is given by... 

Fig. 8. Matrix porosity versus permeability reduction in faults. The upper trend describes the range of permeabilities observed within actively deforming cataclastic deformation bands. Permeabilities ate enhanced at low porosities, and slightly reduced at high porosities. The lower trend describes how inactive faults after burial show highly reduced permeability relative to the matrix. This permeability reduction gets more significant with increasing matrix porosity.

Fig. 3-11. Effect of matrix porosity on solute BTCs obtained for a 120-jrm fracture at a distance of 0.76 m (Grisak Pickens, 1980).

The entity LW/q depends only on the geometry of the flow path and the flowrate whereas the second entity, called the Materials Property Group, MPG, depends on the rock matrix porosity, the pore diffusion coefficient and the retardation coefficient that is determined by the sorption coefficient. 

Water residence time X Distance along flow direction z Distance into matrix 5 Fracture aperture f Flow porosity p Matrix porosity... 

Owing to increasing effective stresses with depth. Young s moduli increase rapidly while permeabilities and porosities decrease rapidly with depth. Note that matrix porosities were not included in the table. At the 750-m depth, the properties were also calculated assuming that only 1/3 of the fractures observed in the... 

It Is a well known fact In heterogeneous catalysis, that the catalytic activity Is generally not directly proportional to the concentration of active sites but depends also on hydrodynamic conditions In the surrounding of the particles, on particle size and matrix porosity. It Is furthermore well understood, that various transport phenomena have to be taken Into account, mainly dlffuslonal transport processes which necessarily are preceding to the reaction step Itself. 

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