A new generator of two successive shock waves focused to a common focal point has been developed. Cylindrical pressure waves created by multichannel electrical discharges on two cylindrical composite anodes are focused by a metallic parabolic reflector - cathode, and near the focus they are transformed to strong shock waves. Schlieren photos of the focal region have demonstrated that mutual interaction of the two waves results in generation of a large number of secondary short-wavelength shocks. Interaction of the focused shockwaves with liver tissues and cancer cell suspensions was investigated. Localized injury of rabbit liver induced by the shock waves was demonstrated by magnetic resonance imaging. Histological analysis of liver samples taken from the injured region revealed that the transition between the injured and the healthy tissues is sharp. Suspension of melanoma B16 cells was exposed and the number of the surviving cells rapidly decreased with increasing number of shocks and only 8 % of cells survived 350 shocks. Photographs of cells demonstrate that even small number of shocks results in perforation of cell membranes., J. Beneš, P. Šunka, J. Králová, J. Kašpar, P. Poučková., and Obsahuje bibliografii
Significant impact on navigation operation by hydropower plant (HPP) operation is mostly in diversion channels of hydropower plants, when these channels are used for navigation as well. It is caused by sudden changes in flow rate of hydropower plants, which is connected to providing of support serveces for electric power system. The objective of the esearch is t determine limits of acceptable hydropower plant operation or propose pecautions which enable harmonizaton of opposing interests of navigation and power generation. and Obsahuje seznam literatury