Surface area membrane

Fig. 3. A commercial dialysis faciUty showiag the dialysis section of a German brewery where alcohol is removed from beer. Technical dialysis modules contain up to 50,000 capillaries and around 23 m (250 ft ) of membrane surface area. Typical plants might contain between 50 and 100 modules.

Figure 4 is a schematic of a typical hemodialyzer. Although other geometries are stiH employed, the preferred format is a hoUow fiber hemodialyzer about 25 cm in length and 5 cm in diameter. Devices typically contain 6,000 to 10,000 capillaries, each with an inner diameter of 200 p.m and a wall thickness of around 10 p.m. Mean total membrane surface area is 1.1 0.4. Well over 60 million hemodialyzers were produced in 1992. Because of... 

These mixing motions will tend to improve drug absorption for two reasons. Any factor that increases rate of dissolution will increase the rate (and possibly the extent) of absorption, especially for poorly water-soluble drugs (BCS Classes II and IV). Since rate of dissolution depends on agitation intensity, mixing movements will tend to increase dissolution rate and thereby influence absorption. As rate of absorption depends directly on membrane surface area, and since mixing increases the contact area between drug and... 

Fig. 5-9. Total number of stages and total membrane surface area versus membrane selectivity for the separation of 1 kg s-1 of a racemic mixture at a membrane permeability of 1.6 x 10 2 kg m 2.s, yielding both enantiomers at 95 % purity [55].

Factors that influence drug dialyzability in chronic ambulatory peritoneal dialysis include drug-specific characteristics (e.g., molecular weight, solubility, degree of ionization, protein binding, and VD) and intrinsic properties of the peritoneal membrane (e.g., blood flow, pore size, and peritoneal membrane surface area). 

Fig. 5. Methane conversion and oxygen flux during partial oxidation of methane in a ceramic membrane reactor. Reaction conditions pressure, 1 atm temperature, 1173 K, feed gas molar ratio, CH Ar = 80/20 feed flow rate, 20 mL min-1 (NTP) catalyst mass, 1.5 g membrane surface area, 8.4 cm2 (57).

The lateral compressibility, i.e. the relative area change upon an imposed membrane tension, decreases slightly more than linearly with the chain length. This means that it is more difficult to expand the membrane surface area of a long-chained lipid than a shorter one. In Figure 20 dimensionless units are used, which means that the surface tension is given in units kT/as. 

Lassgaard-Jorgensen et al. [19] calculated that the rate of reactions involved in SMR is much higher than the rate of penetration of methane through the membrane. Lin et al. [20] have observed that the methane conversion strongly depends on the space velocity and the amount of methane per membrane surface area... 

P a Membrane surface area Drug release mechanisms... 

Bundle Preparation. Packages of multifileiment yarns are backwound to prepare bundles necessary for the manufacture of a reverse osmosis module. A proprietary winder for this operation has been designed and constructed at Albany International Research Co. This device is capable of helically winding multifilament yarns into bundles around a mandrel. This is done in a manner such that the resulting bundle has uniform cylindrical dimensions and uniform fiber density. This minimizes channeling and optimizes exposure of membrane surface area. 

Table V displays data recorded at the test facility in Roswell, New Mexico, maintained by the Office of Water Research and Technology, U. S. Department of Interior. This facility delivers a feed of brackish water pretreated to control bacterial growth and to deliver a feed free of chlorine. Modules 148 and 152 were nominally identical samples. They are constructed of fiber bundles approximately 2 inches in diameter, 10 inches in length and containing approximately 25 square feet of membrane surface area. The increase in productivity over time can be explained by an increase in feed temperature over the course of the test. The decline in rejection of module 148 is not fully understood. However, it is probable that the decline is similarly the responsibility of a temperature increase. Recent data indicates a stabilization at a rejection level of 94%.

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