Abstract: The present invention discloses attenuated Clostridium perfringens organisms that express a substantially nontoxic alpha-toxin. The expressed alpha-toxin is a deletion mutein that relative to the alpha-toxin of the mature alpha-toxin of Clostridium perfringens strain 13, is missing at least nine consecutive amino acid residues including His68. The present invention also discloses attenuated organisms that encode the muteins, as well as the use of such attenuated organisms as vaccines.

Abstract: The present invention discloses attenuated Clostridium perfringens organisms that express a substantially nontoxic alpha-toxin. The expressed alpha-toxin is a deletion mutein that relative to the alpha-toxin of the mature alpha-toxin of Clostridium perfringens strain 13, is missing at least nine consecutive amino acid residues including His68. The present invention also discloses attenuated organisms that encode the muteins, as well as the use of such attenuated organisms as vaccines.

Abstract: A matrix powder for formation along with an infiltrant into a matrix for use as a wear element or for use in retaining at least one discrete hard element. The matrix powder includes crushed sintered cemented tungsten carbide particles. The composition of the crushed sintered cemented tungsten carbide comprises between about 6 weight percent and about 13 weight percent binder metal and between about 87 weight percent and about 94 weight percent tungsten carbide.

Abstract: A method is provided for producing multiple polycrystalline diamond and/or CBN bodies. The method involves mixing a temporary binding agent, such as paraffin, with a quantity of the crystals and then molding or extruding that mixture to produce temporarily held bodies. The temporarily held bodies are then placed in a reaction chamber and surrounded by a pressure transmitting medium, such as powdered cemented tungsten carbide. Preferably, the paraffin is removed by heat and vacuum. The reaction chamber is then pressed and heated thereby creating discrete polycrystalline diamond and/or CBN bodies of approximately the same shape and size as the temporarily held bodies. The preferred embodiment also includes the step of placing a separating layer of cobalt and graphite powder around the temporarily held bodies before they are surrounded by the pressure transmitting medium.

Abstract: A color television camera including a selectively removable infrared (IR) rejection filter and controllable weighting luminance signal matrixing circuitry features increased low-light sensitity. During low-light conditions, the infrared rejection filter is removed from the optical path of the camera, permitting infrared light to pass to the camera's imaging means; the weighting of the controllable weighting luminance signal matrixing circuitry is altered to provide a more accurate visual representation; and the color subcarrier signal is disabled so that the camera produces only a black-and-white signal.

Abstract: A polycrystalline diamond (PCD) body with improved thermal stability is disclosed which comprises a PCD body which has had at least one of its previously empty pores infiltrated by a silicon containing alloy. According to the process of the invention, a porous PCD body is obtained, preferably by acid leaching a PCD body which was formed in the presence of a metal catalyst such as cobalt. The porous PCD body is then surrounded by either the desired silicon containing alloy, or by the constituents of that alloy, each preferably in powdered form. The PCD body with its surrounding material is then heated and pressed to temperatures sufficient to melt the surrounding material (thereby forming the silicon alloy if not already formed) and to cause it to infiltrate into the pores. After the infiltration, it is preferred to remove the excess silicon containing alloy from the external surfaces of the PCD body, such as by an acid bath. It is also preferred to include several porous PCD bodies per process cycle.

Abstract: A synchronizing apparatus for compensating for cable length changes between a remote color television camera and a local control point is described. The color camera is of the type adapted to receive a "gen-lock" type reference signal for synchronization. The apparatus is responsive to the "gen-lock" signal and the signal from the television camera for generating a "gen-lock" type signal phase advanced to compensate for cable delays.