Penetration impedance

DCEs are not spermicidal. However, DCEs effectively impede sperm penetration (impedance). Incorporation of N9 facilitates impedance and confers cidal properties. 

The gas around the arc plasma takes away a part of its heat by radiatioii. At high temperatures, the gas loses its specific gravity, becomes light weight and diminishes in momentum (< mv ). As a result, the gas is rendered incapable of penetrating through the arc plasma to quench it. The flow of gas through the thick of the arc plasma is thus impeded. 

Figure 5 presents the capacitance-frequency dependence from impedance spectroscopy measurements for CS48 and CS15 in acidic and organic medium. In the low frequency region (from ImHz to lOOmHz) nearly a complete penetration of the ions into the pores is allowed and the quite stable values indicate the domination of the capacitive behavior at the electro 1 ytc/carbon interface. All the curves show a typical drop of... 

Figure 15.2(a). The membrane impedes further penetration of even smaller particles through the porous filter media. In many filtration applications, this filtration mechanism is valid for an axial velocity greater than about 4 to 6 m/s. 

Taken together, the data presented here show that many phenyl- and in-dolealkylamines are hallucinogenic in man and behaviorally active in animals. In both series, primary amines penetrate the blood-brain barrier with difficulty, although this seems to be more of a problem with tryptamines (and even N-monoalkyltryptamines) than with phenethylamines. This situation is somewhat alleviated in the presence of an alpha-methyl substituent. The primary amines are also prone to rapid metabolism by oxidative deamination. Metabolism, however, can be impeded by the presence of an alpha-methyl or N-alkyl function. 

In the materials processing industry, size reduction or comminution is usually carried out in order to increase the surface area because, in most reactions involving solid particles, the rate of reactions is directly proportional to the area of contact with a second phase. Thus the rate of combustion of solid particles is proportional to the area presented to the gas, though a number of secondary factors may also be involved. For example, the free flow of gas may be impeded because of the higher resistance to flow of a bed of small particles. In leaching, not only is the rate of extraction increased by virtue of the increased area of contact between the solvent and the solid, but the distance the solvent has to penetrate into the particles in order to gain access to the more remote pockets of solute is also reduced. This factor is also important in the drying of porous solids, where reduction in size causes both an increase in area and a reduction in the distance... 

Cationic/hydrophobe modified hydroxyethyl celluloses, (E) and (F), eliminate sperm penetration, even though they are not spermicidal. These DCEs physically impede sperm penetration, without affecting motility. 

The shutdown property of separators is measured by measuring the impedance of a separator while the temperature is linearly increased. Figure 7 shows the actual measurement for Celgard 2325 membrane. The heating rate was around 60 °C/min, and the impedance was measured at 1 kHz. The rise in impedance corresponds to a collapse in pore structure due to melting of the separator. A 1000-fold increase in impedance is necessary for the separator to stop thermal runaway in the battery. The drop in impedance corresponds to opening of the separator due to coalescence of the polymer and/or to penetration of the separator by the electrodes this phenomenon is... 

Dielectric spectroscopy, also known as impedance spectroscopy, has been used for process analysis for some time, as it offers the ability to measure bulk physical properties of materials. It is advantageous to other spectroscopic techniques in that it is not an optical spectroscopy and is a noncontact technique, allowing for measurement without disturbing a sample or process. The penetration depth of dielectric spectroscopy can be adjusted by changing the separation between the sensor electrodes, enabling measurement through other materials to reach the substrate of interest. Because it measures the dielectric properties of materials, it can provide information not attainable from vibrational spectroscopy. 

Specimen 19 tested for Impedance after exposure to salt spray tests shows a low charge transfer resistance of 4300 0 cm and a fairly high double layer capacitance of 316 pF cm . This shows the Increased tendency of NaCl solution to penetrate the paint film exposed to salt spray test. The capacitance Is even higher for specimen 21 prepared with no phospho-chromic rinse. 

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