Dielectric breakdown method

Sioux and Teissie [203] loaded propidium iodide in 70% leukocytes in whole blood using the dielectric breakdown method. The entrapped drug showed a half-life of longer than 4 hours at 4 and 37°C. When compared with the nonpulsed cells, leukocytes loaded with the drug showed 10 times more accumulation in the inflammation area than in control areas. 

The dielectric breakdown offers a third method for the build up of cell models. Zimmermann and coworkers could show that under appropriate conditions cells can be fused with other cells and liposomes ( 9). By means of this method lipids from artificial liposomes can be incorporated into the membrane of cells (80). 

ASTM D149, 97 (2004). Standard test method for dielectric breakdown voltage and dielectric strength of electrical insulating materials at commercial power frequencies. 

ASTM D-149. Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies. 

The second group consists of properties that are important at very high electric field strengths, such as electric discharge, dielectric breakdown and arc resistance. They may be regarded as the ultimate electrical properties. Properties of the first group are directly related to the chemical structure of the polymer those of the second are greatly complicated by additional influences in the methods of determination. 

Classic texts on dielectric breakdown phenomena are by Whitehead (1951) and O Dwyer (1973). A more recent book by Dissado and Fothergill (1992) provides a comprehensive review of advances since then. Sillars (1973) gives a good review of test methods and materials. Discharge testing techniques are described by Kxeuger (1964). 

ASTM D 149-90 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies, 11 pp (DOD Adopted) (FSC 9330) (MR) (Comm D-9)... 

The electric strength or dielectric breakdown test method (ASTM D-877) indicates the absence, or presence, of free or suspended water and other contaminant matter that will conduct electricity. A high electric strength gives no indication of the purity of an oil in the sense of degree of refinement or the absence of most types of oil-soluble contaminants. This test method is of some assistance, when applied to an otherwise satisfactory oil, to indicate that the oil is free of contaminants of the type indicated above in practice, this ensures that the oil is dry. 

Tables 3.70 through 3.72 summarize the effect of one-year South Florida outdoor exposure on the electrical and mechanical properties of FEP. Little change has occurred in the dielectric breakdown strength, dielectric constant, and dissipation factor of FEP due to exposure. Tensile strength and break elongation measurements are essentially unchanged. The only decline is in the MIT flex life (ASTM D2176) of the one-year sample, which could be due to measurement error. The reason for a decrease in flex life could be the MIT method that has a high degree of uncertainty. Certainly, the other mechanical properties do not support the measured decline in the flex life.

These five factors are difficult to measure and control routinely due to a need for special equipment and procedures. A number of indirect properties have been defined to measure the impact of the five parameters. They include specific gravity, tensile strength, break elongation, dielectric breakdown strength, and heat of fusion. These properties are measured by relatively simple and quick methods. 

Dielectric breakdown voltage and dielectric strength 4031 Method A D 149-64... 

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