Porosity macro

The effective diffusivity and permeability of the porous alumina sample G1 were measured in the Graham diffusion cell and in the permeation cell (Salejova et al., 2004), cf. Table 1. The porosity e is separated into macro-porosity macro corresponding to large pores and nano-porosity nano corresponding to small pores, and s — smacro + 8nano- The boundary in the classification between macro-and nano-pores is somewhat arbitrary selected as the inflection point on the integral mercury porosimetry curve in Fig. 14. 

The boundary condition of zero accumulation on the interface between macropores and solid phase is imposed. The effective diffusivity of the porous sample G1 with bimodal pore size distribution is summarized in Fig. 16, where the sample macro-porosity macro is varied on the horizontal axis. This effective diffusivity is compared with a situation where the diffusion transport in nanopores is omitted. The contribution of the transport through the nano-porous solid phase to the total diffusion flux is significant. The calculated effective... 

Infiltration rate Water content Particle size distribution Frozen soil Bulk density Clay mineralogy Macro porosity... 

Mean pore size either the pore size distribution or the specific porosity divided by the specific surface area. Pores are divided into three categories macro (30-50 nm), meso (intermediate size), and micro (less than 2 nm). 

Column materials (reference) Skeleton size, (im Macro, (im Meso, nm Surface Area, m2/g HPLC CEC Feed Porosity Observed Porosity Permeabili ty (K), [m2] x 1014 Analytes... 

According to the macropore formation mechanisms, as discussed in Section 9.1, the pore wall thickness of PS films formed on p-type substrates is always less than twice the SCR width. The conductivity of such a macroporous silicon film is therefore sensitive to the width of the surface depletion layer, which itself depends on the type and density of the surface charges present. For n-type substrates the pore spacing may become much more than twice the SCR width. In the latter case and for macro PS films that have been heavily doped after electrochemical formation, the effect of the surface depletion layer becomes negligible and the conductivity is determined by the geometry of the sample only. The conductivity parallel to the pores is then the bulk conductivity of the substrate times 1 -p, where p is the porosity. 

Only limited information is available on the effect of active site structure on activity of polymer-supported quaternary ammonium ion catalysts for alkylation of phenylacetonitrile (Eq. (7)). Dou and co-workers 10l) reported approximately the same activity for six different type 1 (2) and type 2 (14) Dowex105) ion exchange resins. Conversions of 5(1-70% were obtained in 10 h at 70 °C using 0.1 mol each of phenylacetonitrile and 1-bromobutane, 40 ml of 50% NaOH and 1 4 g (3.5-18 mequiv) of resin. The triphase mixtures were vigorously stirred by a method not reported. The similar results from resins of widely different cross-linking and porosity, both macro-... 

In the Tbilisi area, the Middle Eocene sequence is a volcanic erupted structure with a very high density of interconnected micro fractures and a relatively smaller number of macro fractures with apertures in the mm range. The matrix rock is of low porosity and low permeability and is not considered to contain any significant reservoir volume. The fields have been producing since 1974 by open-hole wells of which a large number have experienced water break through. 

Physical properties Density Specific gravity Pore structure True density as measured by helium displacement Apparent density Specification of the porosity or ultrafine structure of coals and nature of pore structure between macro, micro, and transitional pores... 

Specimen BET surface area - I l .rr Micro- Meso- Macro- porosity" porosity porosity" Average pore diameter, Dave Standard Pore radius of the deviation of maximum differential PSD, a pore volume, Surface fractal dimension, tfsurf,SP Low-end thickness, High-end thickness, ad. max... 

Now, to explain the operation of the PFIEBR, it is proposed that the interdiffusion in the adhering liquid thin layer is the rate-determining step, then, it is possible to consider that n = 1 in Equation 7.33, since for this transport process the diffusion rate, k, is proportional to concentration [38], This approach is based on the assumption that states that the rate-determining process during the dynamic ionic exchange in zeolite columns determines the diffusion in the zeolite secondary porosity, that is, the transport process in the macro- and mesoporosities formed by the matrix inserted between zeolite crystals and the diffusion in the zeolite primary porosity, that is, in the cavities and channels which constitute the zeolite framework [38], This fact is experimentally justified later. With the help of Equations 7.33 through 7.35, we obtain ... 

---