Abstract: Water and meat pieces (P) are pumped through a conduit (100), the walls of which are made of plastic having an acoustic impedance close to that of water. The conduit is immersed in a tank (400) full of water. A shock wave generator 200 (capacitor discharge through electrodes) creates a shock wave in the water. A preferably tubular wave guide directs the shock pulse onto the conduit. The shock wave passes through the conduit without substantial reflection because the impedance of the conduit wall matches the impedance of the water. The shock wave tenderizes and sterilizes the meat. Continual plasma discharges are repeated rapidly enough that all of the meat passing through is treated.

Abstract: A filter includes a housing having an inlet and an outlet. A filter core including a filter media is movably disposed within the housing with the inlet and the outlet in fluid communication with opposite sides of the core and a pressure responsive surface in fluid communication with said inlet. The filter also includes a valve supported on the filter core and moveable into a sealing position to prevent fluid from passing to the outlet when said core moves within said housing response to fluid pressure acting against said pressure responsive surface.

Abstract: Apparatus for generating a pulsed plasma in a liquid medium wherein a pulse forming network is provided to supply a high energy pulse to spaced electrodes for creating a spark channel and initiating the plasma. The pulse forming network is impedance matched to the average impedance of the plasma channel established between the electrodes. The network generates a 5 to 20 microsecond pulse in the gigawatt power range to effect energy transfer to the plasma before significant expansion can occur.

Abstract: Apparatus for purifying confined liquids and slurries by means of a spark discharge wherein the inner surface of the treatment vessel is designed to include a reflector section adjacent to a pair of electrodes and a concentrating section for intensifying the shock wave generated by the discharge between the electrodes. An external power source is coupled through a pulse forming network to the electrodes. The network is impedance matched to the impedance of the plasma arc generated between the electrodes to provide a high power pulse to the electrodes. The establishment of the plasma produces an extremely high pressure shock wave, u.v. radiation fringing on X-ray and electrohydraulic pressurization to alter the characteristics of the liquid therein.

Abstract: A speaker which is driven by an audio amplifier has a feedback coil wound on the coil mandrel adjacent to the speaker's drive coil. A first degenerative feedback element is provided for applying degenerative feedback to the audio amplifier in proportion to the current flowing through the speaker's drive coil. A second degenerative feedback elements is provided for applying degenerative feedback to the audio amplifier in proportion to the voltage induced in the feedback coil. The first and second degenerative feedback elements are arranged to be additive so that the total degenerative feedback applied to the audio amplifier is equal to the sum of the degenerative feedback from both degenerative feedback elements to thereby prevent acoustical peaks from being produced in the audio spectrum of the speaker.