Abstract: A communications system of an underwater defense system is decoupled from unmanned underwater vehicle (UUV) when the UUV is deployed under the surface of the water. A housing attached to the UUV has a communications wire spooled therein with a first end of the wire coupled to the UUV. Once underwater, the housing separates from the UUV causing the communications wire to be paid out from the housing. As a result, a pulling force is applied to the housing via the communications wire. Communications electronics are coupled to a second end of the communications wire. The communications electronics includes an RF antenna switchably coupled to an RF receiver operating at a first frequency and to an RF transmitter operating at a second frequency. A buoy is coupled to the communications electronics to float same to the surface of the water such that the RF antenna breaks the surface of the water.

Abstract: A device and method for communicating from an underwater vehicle by surfag an antenna in a towed buoy without surfacing the underwater vehicle. The underwater vehicle has control circuitry and sensors allowing the control circuitry to receive data from sensors measuring velocity, acceleration, distance to bottom, depth of vehicle, and ambient acoustic noise. The buoy is towed behind the vehicle on a tether having insulated wires therethrough which link the antenna to the vehicle. The buoy is positively buoyant.

Abstract: A composite yet monolithic free abrasive grinding lap includes a sintered porous matrix of ceramic or metal material and a quantity of silicon filler material, substantially completely filling the pores of the sintered porous matrix preform at least throughout an effective region of the lap that is to come in contact with a workpiece to be acted upon by the lap. The lap may further have a multitude of abrasive particles embedded in the filler material at the effective region. The lap is made by first slip-casting a preform, then freezing and freeze-drying the same, followed by lightly sintering the dry preform into a porous matrix preform, bringing the temperature of the preform to above the melting point of the silicon filling material, and filling the pores with the filling material in its molten state.

Abstract: A contamination capacitance probe system is disclosed that capacitively mtors whether or not two or more fluids or materials that have to remain separated have been mixed or mingled and that provides first and second control signals respectively representative of the unmingled and mingled conditions. The system includes a capacitance sensor constituted by spaced-apart first and second capacitor plates of preselected size and spacing. The plate size and spacing is selected to render negligible any effect that the different materials or fluids or materials might have on the capacitance of the sensor. Circuit means are disclosed that includes a capacitance to frequency convertor, a frequency to voltage convertor, and a Schmidt trigger operative to provide the first and second control signals. The contamination capacitance probe system of the present invention is operable with any two or more fluids or materials having different dielectric constants and that are either immiscible or miscible.