Mixed permeability

The air-void content of asphalt concrete mixes affects mix permeability and is therefore very important from a pavement durability standpoint. The permeability of various sulfur-extended binder mixes, prepared at a variety of air-void contents, was measured with an air permeameter similar to that described in Ref. 16. The results, presented in Figure 7, indicate that the sulfur-extended binder mixes exhibit an air voids vs. 

Figure 39.2 Schematic representation of H2- neutral H atoms (metals) and (b) mixed permeable membranes in the separation of H2/ ionic-electronic conductivity membranes N2 mixtures for two different separation mecha- (nonstoichiometric oxides). The chemical poten-nisms (a) permeation of molecules (PIMs) and tial gradient for H2 is illustrated qualitatively.

Keywords sintering mix, permeability, on-line test, gas seepage Abstract... 

Off-line detection device of sintering mix permeability was shown in Figure 2. It was calculated by Eq. (1) as follows ... 

Voice formula should be considered as standard in the experimental process, which is used to calculate permeability index under different parameters. Then the function relation between permeability index and the parameters could be determined, which will be checked by Voice formula at last. Voice formula is used to assess sintering mix permeability in industry, which is the method and principle of off-line measuring permeability. 

The permeability index measuring device after researched and developed is equipped with full set of measuring and controlling instrument which are convenient for installation and maintenance. On-line measuring method of sintering mix permeability is possible. 

The synthetic and plasmid DNAs are mixed and join their sticky ends spontaneously. They are covalently bound together by DNA ligases, when the resulting hybrid plasmid is inserted into bacterial cells. Dilute calcium chloride solutions render the bacterial membranes permeable and allow the passage of ONA into the cells. 

Addition of Inert Filter Aids. FUtet aids ate rigid, porous, and highly permeable powders added to feed suspensions to extend the appheabUity of surface filtration. Very dilute or very fine and slimy suspensions ate too difficult to filter by cake filtration due to fast pressure build-up and medium blinding addition of filter aids can alleviate such problems. Filter aids can be used in either or both of two modes of operation, ie, to form a precoat which then acts as a filter medium on a coarse support material called a septum, or to be mixed with the feed suspension as body feed to increase the permeabihty of the resulting cake. 

Leaching is the removal of a soluble fraction, in the form of a solution, from an insoluble, permeable sohd phase with which it is associated. The separation usually involves selective dissolution, with or without diffusion, but in the extreme case of simple washing it consists merely of the displacement (with some mixing) of one interstitial liquid by another with which it is miscible. The soluble constituent may be solid or liquid and it may be incorporated within, chemically combined with, adsorbed upon, or held mechanically in the pore structure of the insoluble material. The insoluble sohd may be massive and porous more often it is particulate, and the particles may be openly porous, cellular with selectively permeable cell walls, or surface-activated. 

Applicability/Limitations. In-situ treatment can be used when it is uneconomical to haul or when infeasible or uneconomical to dig or pump the contaminated waste matrix for treatment in a reactor. This approach should be used whenever excavation or removal causes an increased threat to human health. It can reduce the cost of a remediation program. Because chemicals are applied to the contaminated waste matrix, specifically soil and groundwater, a potential exists for reaction with the soil. Permeability problems can occur as the result of precipitate formation. This can result in inadequate mixing of the contaminant with the treatment chemical. Gas generation may also occur. 

Heterogeneity, nonuniformity and anisotropy are terms which are defined in the volume-average sense. They may be defined at the level of Darcy s law in terms of permeability. Permeability, however, is more sensitive to conductance, mixing and capillary pressure than to porosity. 

Once the precoating stage is completed the process slurry is pumped into the filter, the forming cake is retained on the plates and the filtrate flows to further processing. When the solids are fine and slow to filter a body-aid is added to the feed slurry in order to enhance cake permeability. However, it should be kept in mind that the addition of body-aid increases the solids concentration in the feed so it occupies additional volume between the plates and increases the amount of cake for disposal. Likewise, for all those applications when the cake is the product, precoat and filter-aid may not be used since they mix and discharge together with the cake. 

To prevent the surrounding air from mixing with the supply air, the air shower should use air-permeable filter material with a harder, load-bearing, nonflammable outer shell and an inner layer of softer material with a high air resistance. This design requires that the supplied air be filtered. 

Semi-permeable membranes are quasi-two-dimensional barriers which, given a fluid mixture of two or more species of particles (usually two different molecular species, mixed or in solution) on one side, allow the passage either way through the membrane of one or more, but not all, of the molecular species, in either direction. This gives the possibility of separating, at... 

Siegrist RL, OR West, MI Morris, DA Pickering, DW Greene, CA Muhr, DD Davenport, JS Gierke (1995) In situ mixed region vapor stripping in low-permeability media. 2. Pull-scale field experiments. Environ Sci Technol 29 2198-2207. 

In the diaphragm-cell process, a solid cathode (iron) is used where hydrogen is evolved [reaction (15.4)]. Porous asbestos diaphragms are used to prevent mixing of the catholyte and anolyte, but owing to the finite permeability of these diaphragms, the alkaline solution that is produced near the cathode stiU contains important levels of chloride ions as an impurity. 

Cold groundwaters descend to the permeable zones. Mixing of the deep fluids with the cold waters brings about a rapid decrease in temperature and there by results in the precipitation of Fe-rich chlorite of about 0.5 of Fe/Fe - - Mg ratio. 

Aluminum trichloride, a cheap, abundant waste product of the chemical industry, forms a gel under certain conditions with carbonates and on mixing with alkalies. Laboratory and field tests showed that aluminum trichloride can be used as a gel-forming agent for reducing the permeability of waterconducting channels [673]. 

Aluminum Citrate. Aluminum citrate can be used as a crosslinker for many polymers the gels are made of low concentrations of polymer and aluminum citrate in water. This crosslinker provides a valuable tool, in particular, for in-depth blockage of high-permeability regions of rock in heterogeneous reservoirs. The formulations can be mixed as a homogeneous solution at the surface. 

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