Porosity 2, effective

The physical properties of the catalyst (specific surface area, porosity, effective thermal conductivity, effective diffusivity, pellet density, etc.). 

All voids in the subsurface medium are classified as porosity. When pore spaces are interconnected so that water can flow between them, the medium is said to be permeable. The actual openings that permit water flow are referred to as effective porosity. Effective porosity is calculated as the ratio of the void spaces through which water flow can occur to the bulk volume of the medium (expressed as a percentage) as follows ... 

R. Fu et al Interpretation of porosity effect on strength of highly porous ceramics. Scripta Metall. et Matl. 25, 1583-1585 (1991)... 

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. 

Another problem with pulverized samples is that their packing density varies as a function of the depth. This is known as the porosity effect, and for the Bragg-Brentano geometry, it may be expressed using two different approaches ... 

Anisotropic parameters obtained employing neutron data, where scattering occurs on nuclei, are more reliable because in the x-ray diffraction, the anisotropy reflects stronger and potentially improperly accounted absorption/porosity effects in addition to a deformation of the electron density. Overall, atomic anisotropy obtained from powder diffraction data should be carefully analyzed, especially if preferred orientation is present. 

Rietveld minimization continued by including porosity effects, which were refined with the majority of other parameters fixed and then released. The fit improves and Rwp is reduced to 15 %. To this point, the refinement of the grain size and strain broadening effects and their anisotropy, as well as the coordinates of atoms in the organic molecule could not be easily conducted due to noticeable correlations the resulting shifts of fi ee least squares parameters were forcing the solution out of a global minimum. 

Figure 7.30. The observed and calculated powder diffraction patterns of mazMoyOiz after preferred orientation, individual atomic parameters of the Mo and O atoms were refined together with some profile parameters and correction for porosity effects. The difference (fi" - is shown using the same scale as both the observed and calculated data but the plot is truncated to fit within the range [-3000,3000] for clarity. The inset clarifies the range between 73 and 86 20.

The porosity of the canopy is therefore n = 1- (n/4)ad. Using stem densities and diameters reported for the short- and tail-form of S. alterniflora [627], ad = 0(0.001)-0(0.01). In these marsh canopies the solid volume fraction ( ad) is sufficiently small to make the porosity effectively 1. However, in some freshwater marshes the solid volume fraction can be as high as 15%, corresponding to ad 0.2, and np = 0.8 (Fox et al., 2002 [196]). In mangrove swamps the solid volume fraction can be as high as 45%, np = 0.55, within the root zone [401],... 

This paper reports on the structural and porosity effects of different platinum salts included in the synthetic gel used to synthesize various types of mesoporous silica solids in the presence of a polyglycol ether (non-ionic) surfactant as template. 

Abdulhalim I, Lakhtakia A, Lahav A, Zhang F, Xu J (2008) Porosity effect on surface plasmon resonance from metallic sculptured thin films. Proc SPIE 7041 70410C... 

One approach that has been used is to compress the particles into a porous plug, measure the capillary pressure and then calculate the contact angle. This approach suffers from uncertainties due to particle packing, surface roughness, shape and porosity effects [40]. Another approach is to estimate the surface tension of the... 

Figure 11.19. Effect of filler and porosity on compressive strength of cement, (a) Filler effect, S= 120,000 (b) porosity effect, S = 120,000(1 - Pf. (Auskern and Horn, 1971.)...

Porosity effects during the charging process have long been considered in discussions of the faradaic and capacitive contributions to the current, especially in the case of electronically conducting polymers. For instance, the peaks of cyclic voltam-mograms were attributed to the faradaic process while the plateaus of the cmrent were considered to be an indication of the capacitive term [99,105,106,211-215]. However, this straightforward analogy to the metal/solution interface does not work in reality the obviously faradaic process of the redox transformation of the redox species in the surface layer does not lead to a direct current, unlike similar reactions for solute species. 

Standard nanosilicas A-300 and A-380 (Sbet=337 and 378 mVg, pore volume Vp=0.714 and 0.943 cm /g, respectively, estimated from LT [77.4 K] adsorption isotherms of nitrogen) were heated at 673 K for several hours to remove adsorbed organics and residnal HCl and rehydrated in air. Silica 200DF (Crosfield, Sbet=540 mVg, Fp=0.34 cmVg) possessing nanopores and narrow mesopores was used to compare intrapartiele (200DF) and textural (nanosilica) porosity effects on the behavior of bound water and coadsorption of water and methane. Bidistilled water and conunercial methane (99% purity) were used (Gun ko et al. 2011c). 

Itotia IK, Drayton RF (2002) Porosity effects on coplanar waveguide porous silicon interconnects. 

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