Permeable particle

All packing materials produced at PSS are tested for all relevant properties. This includes physical tests (e.g., pressure stability, temperature stability, permeability, particle size distribution, porosity) as well as chromatographic tests using packed columns (plate count, resolution, peak symmetry, calibration curves). PSS uses inverse SEC methodology (26,27) to determine chromatographic-active sorbent properties such as surface area, pore volume, average pore size, and pore size distribution. Table 9.10 shows details on inverse SEC tests on PSS SDV sorbent as an example. Pig. 9.10 shows the dependence... 

The Biopharmaceutics Classification System (BCS)3 defines four classes of compounds based upon solubility and permeability. Particle size and size distribution... 

Because of the similarity with the SGC model the modified Donnan model will be called the Stern-Donnan (SD) model. The SD model is newly derived and intended to be of use for a description of ion adsorption in porous or permeable particles without having to specify the permeability or porosity precisely. The SD model with small islands... 

Permeable particles containing large pores are used in separation and reaction engineering as adsorbents and catalysts. Perfusion chromatography, developed in 1990 [1] for the separation of proteins, is based on the concept of augmented dif-fusivity by convection [2], which combines the contributions of mass transport by convection and diffusion in adsorbent pores. An example of flow-through particles is given in Fig. 3.4-1 where wide pores are of the order of 7000 A and polymeric microspheres contain small diffusive pores. 

This approach, by combination of dimensional analysis and the permeability-particle size relationship may be used to yield a capillary number No useM for the correlation of Sx with drainage conditions experimental data are presented in Figure 8.39 where d is the average particle size ... 

Figure 7.3 Schematic representation of the transport mechanism through mixed matrix membranes with (a) conventional and (b) high aspect ratio permeable particles.

Figure 1. Pressure filtration data plotted as P/J (= Xp/k) so a lower slope is indicative of a more permeable particle compact. Note that the top two curves represent the same slurry filtered at constant pressure and constant rate, while the lower two curves are constant rate filtration of the higher salt samples.

Many recent studies on HSs show that humic molecules are associated and/or entangled, forming aggregates in most of the pH range (Simpson et al. 2002 Rizzi et al. 2004 Sutton and Sposito 2005 Kawahigashi, Sumida, and Yamamoto 2005 Baigorri et al. 2007a,b Kucerik et al. 2007), and behave as soft, permeable particles (Duval et al. 2005). Thus, the PSM appears to be a more realistic view of humic particles. 

G Ooms, PF Mijnlieff, HL Beckers. Frictional forces exerted by a flowing fluid on a permeable particle, with particular reference to polymer coils. J Chem Phys 53 4123-4134, 1970. 

Transient mass transfer between a fluid in motion and a permeable particle (a) internal resistance only (most common case) (b) internal and external resistance and (c) external resistance only. 

The primary purpose of matrix acidizing in sandstones is to remove formation damage caused by clay and other siliceous fine particles plugging near-wellbore permeability. Particles may be naturally occurring or may have been introduced into... 

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