DISCRETE NONLINEAR-PROBABILISTIC MODEL OF THE EQUIVALENT ELECTRICAL RESISTANCE OF A LAYER OF METAL GRANULES

Two strategies for constructing nonlinear-probabilistic models of the equivalent electrical resistance of a layer of metal granules at their spark-erosion and plasma-erosion treatment and algorithms for their implementation are presented. A method for taking into account the parametric properties of such loads in their nonlinear and nonlinear-probabilistic models is described. Based on the data of direct experiments, the distributions of the electrical resistance of a layer of aluminum granules in tap water were obtained for eleven fixed values of the discharge current in it for both the leading and trailing edges of its pulses. The features of these distributions are described for different edges of the discharge current pulses. It has been proved that the obtained distributions can be adequately described by the normal law. The parameters of the normal law for each distribution obtained as a result of direct experiments are founded by the method of moments. A nonlinear-probabilistic model of the equivalent electrical resistance of a layer of aluminum granules in tap water is created, taking into account the main hysteresis of the dependence of resistance on current. It is shown that at large values of discharge currents, the nonlinear-probabilistic model of the equivalent electrical resistance of the layers of metal granules tends to degenerate into a nonlinear model. References 27, figures 4

Discharge Characteristics and Plasma Erosion of Various Dielectric Materials in the Dielectric Barrier Discharges

The objective of this study is the investigation of dielectric barrier discharges (DBDs) with the solid plates and the flexible polymer films. A high capacitance with a high dielectric constant and a small thickness is responsible for the discharge of a high plasma current with a low operation voltage; here, the thin flexible polyimide film ensured a high capacitance, and is comparable to the thick solid-plate alumina. In the long-duration test of the dielectric-surface plasma erosion, the solid plates show a high resistance against the plasma erosions, while the polymer films are vulnerable to the etching by the plasma-species chemical reaction. The polymer-film surface, however, was reinforced remarkably against the plasma erosion by the silicone-paste coating.