Abstract: Metal and/or partial metal dentures having a surface modified by a pulsed electron beam system. The system includes an explosive emission cathode, an accelerating gap formed by the cathode and plasma anode, and an electron collector where the metal and/or partial metal dentures are fixed, and placed into a magnetic field. The surface of the modified metal and/or partial metal denture has high reflectance like a mirror polished surface and high corrosion resistance.

Abstract: A Pulsed Electron Beam System is developed and applied for the surface modification of the metal and/or partial metal dentures. The system is consisted with an explosive emission cathode, accelerating gap formed by the cathode and plasma anode, and an electron collector where the metal and/or partial metal dentures are fixed, and placed into a magnetic field. The method can provide a modified metal and/or partial metal denture surface with high reflectance as a mirror polished surface and high corrosion resistance.

Abstract: This invention provides an excavator 1 for crushing a matter to be excavated, existing in an excavating hole in which a discharge liquid is fed, by electric discharge between a plurality of electrodes generated by high-voltage pulses. The excavator comprises a high-voltage pulse generator 2; a plurality of electrodes 17, 18, at least one of which is given a high voltage from the high-voltage pulse generator 2; discharge liquid circulating system 3, 4, 5a, 5b; and optimum condition setting devices 13, 14, 15, 16. Also, this invention provides an excavation method in which at least one of the parameters for excavation efficiency of i) load voltage required for crushing the matter to be excavated; ii) single pulse energy; and iii) quantity of discharge liquid, is optimized for minimization of power consumption required for excavation by using the excavator of this invention.

Abstract: A method of crushing or smashing nonconductive materials such as natural ore materials and concretes by a discharge voltage requires a large amount of energy for crushing or smashing. Products produced by crushing or smashing have not been recycled effectively as new nonconductive raw materials. A value set by the quality and a thickness of the nonconductive materials to be crushed, an impulse voltage Uo, a time constant .tau. and a spark constant A is defined as a parameter P of an electric circuit. By setting the value of P to 0.02.ltoreq.P.ltoreq.1.0 to cause crushing, energy stored in the circuit can be utilized effectively. Accordingly, uniformcrushedor smashed matter with high quality can be manufactured effectively.

Abstract: A method of solid insulator destruction comprising the steps of placing electrodes on a surface of a solid insulator, covering an area of the surface the solid insulator proximate the electrodes with liquid having greater electrical insulative properties against pulse voltage than the solid insulator; and applying a pulse voltage across said electrodes having a rise time to breakdown of the solid insulator of about t where t=2.times.10.sup.-6 .times.S.sup.0.3 (sec) and S (cm) is the distance between the electrodes. The solid insulator material includes at least one of rock, permafrost, ice and artificial solids including concrete, ceramics, and plastics.