Characteristics liquid permeability

Typically, the liquid permeabilities are obtained with water being the permeate and expressed in terms of L/h-m -bar. The gas permeabilities are often expressed in terms of air or nitrogen permeabilities. The retention characteristics can be generally and generically obtained by using some model molecules. The most commonly used model molecules are polyethylene glycol (PEG) polymers which are linear and flexible in nature, and... 

The overall performance of membranes is related to two main characteristics their permeability and their permselectivity (separation ability). For porous membranes, the selectivity and the membrane cutoff depend on the pore size and the pore size distribution of the separative layer. The membrane permeability and the membrane thickness fix the viscous flux for a given transmembrane pressure. The viscous flux of a liquid, J, across a porous medium is given by Darcy s law ... 

Individual objects possess a characteristic physical property like electronic conductivity, ion conductivity, magnetic susceptibility, gas diffusivity, or liquid permeability. Mixing of at least two distinct types of objects (of guest and host material) that... 

The characteristics of the pore system in reservoir rocks is important for the understanding of the flow of liquids through the rocks, particularly in relation to the recovery of hydrocarbons. Commonly used methods in the assesment of these characteristics of reservoir rocks are optical microscopy of thin sections and measurements of total porosity by mercury dilatometry and of air or liquid permeabilities. 

Filter aids as well as flocculants are employed to improve the filtration characteristics of hard-to-filter suspensions. A filter aid is a finely divided solid material, consisting of hard, strong particles that are, en masse, incompressible. The most common filter aids are applied as an admix to the suspension. These include diatomaceous earth, expanded perlite, Solkafloc, fly ash, or carbon. Filter aids build up a porous, permeable, and rigid lattice structure that retains solid particles and allows the liquid to pass through. These materials are applied in small quantities in clarification or in cases where compressible solids have the potential to foul the filter medium. 

Sites suitable for conventional SVE have certain typical characteristics. The contaminating chemicals are volatile or semivolatile (vapor pressure of 0.5 mm Hg or greater). Removal of metals, most pesticides, and PCBs by vacuum is not possible because their vapor pressures are too low. The chemicals must be slightly soluble in water, or the soil moisture content must be relatively low. Soluble chemicals such as acetone or alcohols are not readily strippable because their vapor pressure in moist soils is too low. Chemicals to be removed must be sorbed on the soils above the water table or floating on it (LNAPL). Volatile dense nonaqueous liquids (DNAPLs) trapped between the soil grains can also be readily removed. The soil must also have sufficiendy high effective porosity (permeability) to allow free flow of air through the impacted zone. 

To design the optimal diffusion layer for a specific fuel cell system, it is important to be able to measure and understand all the parameters and characteristics that have a direct influence on the performance of the diffusion layers. This section will discuss in detail some of the most important properties that affect the diffusion layers, such as thickness, hydrophobicity and hydrophilicity, porosity and permeability (for both gas and liquids), electrical and thermal conductivity, mechanical properties, durability, and flow... 

Productive wells in vapour-dominated systems discharge steam only. Characteristically, wells in liquid-dominated systems discharge a mixture of water and steam. The steam forms essentially by depressurization boiling of the reservoir water. It is, however, not uncommon that some wells drilled into liquid-dominated systems discharge dry steam or possess a higher steam to water ratio than can be accounted for by depressurization boiling. The reason for this is partial or complete immobilization of the water in the aquifer due to the effects of capillary pressure and relative permeability. 

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