Breakdown, electrical

Numerous phenomena (e.g., enormous changes in the electronic current flowing, mechanical and chemical changes of the liquid and electrodes and optical phenomenon taking place during 

There are two principal views on dielectric breakdown generation. The first favors the cavitation-bubble mechanism, and the second involves electronic phenomena occurring in the studied system. The major differences between the bubble and electronic models of electrical breakdown lie in the importance attached to the temporal development of events which precede a spark, i.e., a moment considered as the breakdown. In the former case, it is proposed that ionization and current growth begin to occur in the gaseous phase after nucleation of a bubble, whereas, in the latter case, these processes begin first in the liquid areas. Among these two schools several models based on a different approach to the source of the increased conductivity of Uquids under electrical stress have been proposed. 

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Electrica.1 Properties. The electrical properties of SF stem primarily from its effectiveness as an electron scavenger. To accomplish electrical breakdown in a dielectric gas, primary electrons must gain sufficient energy to generate appreciable numbers of secondary electrons on molecular impact. Sulfur hexafluoride interferes with this process by capturing the primary electrons, resulting in the formation of SF or SF ions and F atoms (29) ... 

Sulfur Pentafluoride. Sulfur pentafluoride [10546-01-7] is thought to be formed during the electrical breakdown of SF and also to be present in plasma reactions involving SF. A number of theoretical studies have been reported (110—113). 

J. M. Meek and J. D. Craggs, Electrical breakdown ofGases,]ohn Wiley Sons, Inc., New York, 1978. 

Test results Any disruptive discharge or electrical breakdown during the application of high voltage should be considered as a dielectric failure. 

The largest outlet for the bituminous plastics has been for automobile battery boxes. Bituminous battery boxes do, however, have a susceptibility to electrical breakdown between the cells and in Europe their use has been mainly confined to the cheaper batteries installed initially in new cars. Bituminous compositions have also been used for toilet cisterns and to some extent for cheap containers. They are no longer important. 

Back corona is caused by the electrical breakdown of gas in the dust layer. This breakdown produces positive ions, which drift toward the negative discharge electrode. The presence of ions with opposite polarity causes a reduction in the particle-charge and -collection efficiency. To avoid this problem, several methods are used. These include... 

Glasses for electrical and electronic components are represented by the lead tubing and cathode-ray-tube screen and cone glasses. These glasses do not operate under severe corrosion conditions, but surfaces must not leach excessive alkali under damp conditions or electrical breakdown can occur. The glass compositions are formulated to give the maximum electrical resistivity and moisture resistance compatible with other necessary properties. 

Albella, J. M. Electric Breakdown in Anodic Oxide Films 23... 

Electric Breakdown in Anodic Oxide Films Parkhutik, V. P. Albella, J. M. Martinez-Duart, J. M. 23... 

Electric Breakdown in Anodic Oxide Films Physics and Applications of Semiconductor Electrodes Covered with Metal Clusters Analysis of the Capacitance of the Metal-Solution Interface. Role of the Metal and the Metal-Solvent Coupling Automated Methods of Corrosion Measurement... 

Dispersed Electrocatalytic Materials Electrical Breakdown of Liquids 25... 

In recent years work was started in which this sort of phenomena are smdied at the cell level, particularly the electrical breakdown of cell membranes and the fusion of neighboring cells under the influence of electric fields. These studies are of great value, in particular, for the further development of cell engineering and gene technology. 

Lymphocytes are of two sizes smaller lymphocytes, with a diameter of 6-8 pm, and larger lymphocytes, with a diameter up to 18 pm. They are found not only in blood, but in lymph and in every tissue of the body. Larger lymphocytes are believed to be cells that differentiate into T and B lymphocytes when activated by specific antigens. The life span of lymphocytes may vary from a few days to many years. Lymphocytes have been suggested as potential carriers for transporting macromolecules, particularly DNA, to other cells. Low molecular weight exogenous substances can be introduced into lymphocytes by electrical breakdown methods. 

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