Abstract: The process and apparatus for extracting the products of kerogen in situ from an oil shale body by supplying energy selectively to the kerogen by high frequency electric fields in the frequency range between 100 kilohertz and 1000 megahertz at an intensity which heats the kerogen to a temperature range between 250.degree. C. and 500.degree. C. to allow pyrolysis of the kerogen prior to substantial heat transfer to the surrounding mineral portions of the oil shale.

Abstract: A compact heating and cooling system in which air ducts are connected to a host exchanger system through which a coolant fluid from a condensing unit or a heating fluid from a compact water heater is selectively directed by a control circuit so that the system may be mounted outside a building to be heated and/or cooled.

Abstract: An imaging system, particularly useful for acoustic medical diagnosis of a human subject, utilizes an array of radiating elements or sonic transducers located side-by-side and positioned along the subject. Signals received by the transducer are applied to a pair of pattern generation circuits which weight the individual signals by factors of +1, -1 or 0. Graphs of the weighting factors as a function of transducer location have the likeness of cosinusoidal and sinusoidal Fresnel patterns, these patterns being produced by the two circuits. Upon reception of signals, the weighted signals of each pattern are summed together, multiplied by cosinusoidal and sinusoidal reference signals and then summed together to provide a radiation pattern which converges from the array to a focal point in front of the array while eliminating a diverging pattern from a virtual focus behind the array.

Abstract: An electromagnetic wave ring resonator is disclosed including means to spatially rotate the electromagnetic field distribution of waves resonant therein about the direction of propagation of such waves to enable such waves to resonate with opposite senses of circular polarization, and means, including a laser amplifier medium, to provide different indices of refraction to resonant waves of the same sense of circular polarization as they pass through such laser amplifier medium in different directions. With such arrangement the two mentioned means enable the waves to resonate with four different frequencies. In a laser gyroscope using such ring resonator the electromagnetic field distribution rotating means includes a catoptric arrangement which, together with the last-mentioned means, reduces the loss, scatter and linear birefringence associated with the ring resonator included in such gyroscope.

Abstract: A microwave tube having a heated cathode with a rare earth magnet positioned inside the evacuated envelope of the tube and at least partially shielded from thermal radiation from the cathode and/or anode so that the magnet may be operated at elevated temperatures while protected from environment such as oxygen in the air to prevent degradation of the magnetic properties of the magnet at temperatures up to 500.degree. C. during processing of the tube or up to 250.degree. C. during operation of the tube with thermal shielding from the hot cathode preventing any surface of the magnet from exceeding such temperatures.

Abstract: A deflection amplifier gain correction circuit for a beam penetration color cathode ray tube having a split high voltage anode in which the deflection waveform is shaped as a non-linear function of the final anode voltage and as a function of a dynamic focus waveform used for the electrostatic focussing system in the cathode ray tube. The shape of the correcting waveform is adjusted by adjusting the amounts of the dynamic focus waveform and the anode switching voltage waveform which are multiplied to produce a resulting waveform which varies as a function of deflection position and anode voltage and is summed with a waveform which is a non-linear function of anode voltage. Such a system can be adjusted for each individual display unit to compensate for production variations in a color penetration tube using two different colored phosphors.

Abstract: A modulation system for use in generating a multiphase carrier for digital communication systems which avoids phase and amplitude errors due to temperature and voltage variations inherent in balanced mixers, when used as phase modulators. In this invention, resistive divider networks are used to generate the output vector array. Each output vector thus, has an independent resistive adjustment which has no effect on the other vectors to provide individual and separately aligned phase vectors which are selected for transmission by an addressable multiplexer to provide a phase modulated carrier representing multiplex input data.

Abstract: An amplifier having a gain control terminal amplifies an input signal to produce an output signal of a desired magnitude. A gain control circuit coupled between the input and output signals and to the control terminal includes detectors of the input and output signal amplitudes. The control circuit further includes a first impedance network connected to the control terminal and a feedback circuit connected in series therewith, the feedback circuit including a second impedance network complementary to the first impedance network. A feedback signal of the feedback circuit is multiplied by the amplitude of the input signal and combined with the amplitude of the output signal and a reference signal at a summing point of the feedback circuit to maintain a response time of the control circuit which is essentially invariant with respect to the amplitude of the input signal.

Abstract: A system for electronically producing and displaying target position history trails in a PPI radar. Digital target positions within a selected sector zone from all targets meeting predetermined amplitude and duration criteria are stored in a memory for single azimuth scans at predetermined intervals. The data from the scans are interleaved and read out of the memory for display with the real time PPI targets. When the memory is filled, the oldest plots from each target are dropped to make room for new plots.

Abstract: An underwater mapping system in which a swath of terrain, much wider than a sonar beam width, is observed by means of a sonar beam scanned in the cross track plane of a ship. Filtering and correlation techniques are employed to compensate for distortions in echoes emanating from the ocean bottom by a selection of filter coefficients in accordance with the orientation of the sonar beams and by providing a simulated echo envelope for correlation.

Abstract: A heat exchanger for efficiently transferring heat from a first fluid body to a second fluid body within a selected container, tank or reservoir, comprising an elongated tubular hoselike plastic body of deformable material wrapped around the container and filled with the first heated fluid, the plastic body being deformable under the pressure of the first fluid so as to conform to the exterior surface of the container whereby more efficient transfer of heat between the fluids is achieved.

Abstract: Apparatus for fracturing and/or heating subsurface formations wherein an alternating current electric field is produced in the frequency range between 100 kilohertz and 100 megahertz between electrodes spaced apart in the formation and a radio frequency generator supplying a voltage between said lines with suitable loading structures tuned to the frequency of the generator to resonate the electrodes as a parallel wire transmission line which is terminated in an open circuit and produces a standing wave having a voltage concentration at the end of the line.

Abstract: A method of producing fluid organic products from kerogen in situ in a body of oil shale by the application of alternating electric fields having a frequency between 100 kilohertz and 100 megahertz to heat the kerogen in the oil shale to a temperature in the range of 200.degree. C. to 360.degree. C. and to maintain the kerogen in this temperature range for a period of time sufficient to convert a substantial portion of the kerogen in oil shale to fluid organic products which may be collected through fissures produced in the oil shale formation by flowing to a well bore having a collection sump.

Abstract: A microwave cooker digitally programmed in any of a plurality of different cycles whose digital programs are selected from a front panel display. Programs include a cook cycle, a defrost cycle, and/or a defrost and cook cycle, in which a body of refrigerated food to be heated is subjected to microwave energy for a predetermined time in the oven, and then allowed to set for a predetermined time to allow heat produced in the food body by said microwave energy to at least partially disperse throughout the body thereby equalizing the temperature of different food body regions and then applying additional microwave energy for a predetermined time to cook said food body.

Abstract: A fluid valve for a beverage-making appliance such as a coffee brewer, for example, which valve comprises a housing which contains a valve actuating means and which is closed at its inlet end by a filter, the filter being dome-shaped and having a small central aperture whereby air bubbles in a fluid within the valve may escape upwardly and out so that the valve may be used in appliances subject to microwave radiation.

Abstract: A novel anode structure for electron discharge devices, for example, a crossed field oscillator of the magnetron type is fabricated by uniting nonthermally substantially similar cylindrical members each having a boundary wall member and plurality of vane members. The vane member edges are provided with alternate clearance or contacting mating notches to position an annular strap or straps in the complete anode assembly. Less expensive metal castings, such as aluminum, and other suitable vacuum materials, and such techniques as pressure welding and interference fits may be employed without expensive brazing procedures to result in a simplified less expensive anode structure. Different anode vane configurations are simply implemented, such as V-shapes, utilizing castings or similar structures which when joined together form the composite anode assembly.

Abstract: A digitally programmed microwave oven having a microwave generator energized by a high voltage power supply connected to an alternating current source through mechanically actuated oven door interlock switches, with the power supply regulating the current supplied to the microwave generator to compensate for peak voltage variations in the alternating current source by resonating the output of the power supply in the region of the frequency of the alternating current source in which the power supply is initially energized by a semiconductor switch actuated by a computer to accurately control the time of initial supply of power to said power supply at a point which minimizes the input current surge to said resonant circuit by actuating said semiconductor switch at a time substantially .pi./2 radians of said frequency after the zero voltage point of said alternating current source.

Abstract: A compact heating and cooling system in which air ducts are connected to a heat exchanger system through which a coolant fluid from a condensing unit or a heating fluid from a compact water heater is selectively directed by a control circuit so that the system may be mounted outside a building to be heated and/or cooled.

Abstract: A radar system having automatic compensation to the heater power applied to the final output tube for changes in the peak tube power output. Substantially constant peak power is attained for radar pulses of varying widths and over a plurality of range scales. A controlled voltage is derived in accordance with the peak of the anode power or current coupled to the final transmitter tube. The control voltage is amplified to operate a free-running bistable multivibrator the output of which is transformer coupled to the heater of the output tube.

Abstract: A safety interlock system is disclosed for microwave ovens or other high voltage electrical apparatus incorporating sensor means for detecting any malfunction. Means are provided for interrupting line input power or actuating a failure indicating device or a combination of both. Thermally actuated means, such as bimetallic or meltable elements, as well as circuit breakers, relays and fuses are described. The sensor means are associated with each of the interlocks and do not carry regular equipment load current until such time as a malfunction of the companion interlock occurs. Replacement of the faulty equipment by authorized personnel and manual resetting of the interrupt or indicating means before the oven is energized again reduce the risk of accidental radiation, electrical shock or damage to the apparatus. .Iadd.