Abstract: Method for destroying radioactive graphite and silicon carbide in fuel elements containing small spheres of uranium oxide coated with silicon carbide in a graphite matrix, by treating the graphite fuel elements in a molten salt bath in the presence of air, the salt bath comprising molten sodium-based salts such as sodium carbonate and a small amount of sodium sulfate as catalyst, or calcium-based salts such as calcium chloride and a small amount of calcium sulfate as catalyst, while maintaining the salt bath in a temperature range of about 950.degree. to about 1,100.degree. C. As a further feature of the invention, large radioactive graphite fuel elements, e.g. of the above composition, can be processed to oxidize the graphite and silicon carbide, by introducing the fuel element into a reaction vessel having downwardly and inwardly sloping sides, the fuel element being of a size such that it is supported in the vessel at a point above the molten salt bath therein.
Abstract: An apparatus and method for improving the performance of a satellite communications modem is disclosed. The invention is particularly applicable to mobile satellite receivers, and includes a variable-gain automatic frequency controlled (AFC) loop, the gain of which is controlled adaptively, based on the AFC lock status and the lock status of the modem's inner loop, in addition to other parameters determined by the invention.
Abstract: Apparatus and a method are disclosed for eliminating fiber distortions ("fiber swimming") and separations ("fiber fish eyes") via a premliminary step taken prior to consolidation of "green", fiber-reinforced metal matrix materials. The apparatus includes a first member for supporting the "green" metal matrix material pack, a second member to cover the "green" pack, the thermal coefficient of expansion of the first member being smaller than the thermal coefficient of expansion of the second member, the second member being secured to the first member atop the "green" pack to form a retort, and the entire retort being heated to an off-gassing temperature, where the second member bows outwardly away from the pack to relieve pressure from the pack.
Abstract: A regulated and constrained current source is used to drive the cathodes of a hot cathode gas discharge lamp to provide heating during lamp operation. In one embodiment, the regulated current source is time shared between the lamp cathodes and the lamp arc.
Abstract: The ACCELERATION DISTORTION RESISTANT RING LASER GYRO (RLG) (10) shown here includes a control mirror (12) subject to distortion beyond the path length control capabilities of the RLG (10) when subjected to intense translational acceleration in the direction (20) perpendicular to the face of the control mirror (12). An anti-parallel compensating mirror (14) is provided to offset the path length change. Additional design flexibility may be obtained by replacing the compensating mirror (14) with a compensating group of mirrors.
Abstract: A method of precision cutting fabric material while obtaining cleanly cut edges involves placing the material on a flat support surface, identifying one or more regions of material to be cut, placing adhesive tape on both sides of the material, and then using an appropriate tool to first squeeze the tape into the fabric at the cutting region, and effecting the cutting of the taped material. A reinforcing woven fabric constituent for incorporation into a metal matrix composite, produced by the method, is also disclosed.
Abstract: A design of a power plant which uses hydrocarbon fuels in conjunction with solar power to produce electricity. The power plant consists of an array of heliostats for concentrating sunlight on a central solar receiver. The heat energy thus gathered is used to create steam which runs a steam turbine. Steam to run the steam turbine can alternately or modularly be obtained from the exhaust gas of a turbo-burner and fuel added to a furnace. The solar energy gathered may be stored as hot fluid in a thermal storage tank or used immediately in the power plant. A thermal shield may be employed over the solar central receiver to insulate the solar central receiver, provide leak and fire protection and shield the solar central receiver from solar radiation.
Abstract: Equivalent circuit parameters of a piezoelectric resonator are measured in order to precisely control the amplitude and/or frequency of oscillation of an oscillator including the resonator, or to compensate for variations in the amplitude and/or frequency of oscillation. Significant variations are caused by shunt capacitance, and to a lesser degree, series resistance. The equivalent circuit parameters are measured by exciting the resonator at a plurality of frequencies, measuring responses of the resonator at the frequencies, including a complex response at one of the frequencies, and determining a value of the shunt capacitance from the responses. Preferably, the resonator is simultaneously and continuously excited at three different frequencies, one of which is approximately the resonant frequency of the resonator.
Abstract: For use with a quartz angular rate sensor, a frequency and phase-locked synthesizer recovers a reference signal virtually free of phase noise, and generates a quadrature-phase reference signal for complex demodulation of the angular rate signal. The synthesizer also ensures a precisely adjusted phase shift of approximately zero across the drive tines of the sensor. Moreover, the digital synthesizer provides a precise numerical indication of the drive frequency, which can be used for compensation and automatic tuning of filters, such as a tracking filter, a filter in an automatic gain control, and notch filters in the phase and/or frequency detectors in the digital synthesizer. The tracking filter is used as a pre-filter for the synthesizer, and is responsive to a passband-width control signal generated from the magnitude of the frequency and phase error signal controlling the frequency generated by the synthesizer.
Abstract: A method for thermomechanically processing gamma titanium aluminide alloy wrought products comprises the following steps: a) a near gamma titanium aluminide alloy ingot is cast; b) the ingot is hot isostatically pressed (HIP'ed) to seal off casting defects; c) the HIP'ed ingot is prepared into suitable forging preforms with or without intermediate homogenization heat treatment; d) the forging preforms are isothermally forged into suitable end product preforms at temperatures sufficiently close to the phase line between the alpha+gamma and alpha-two+gamma phase fields so as to break down the ingot microstructure and to yield a largely equiaxed gamma microstructure; and e) the end product preforms are processed into the desired wrought end products through a controlled rolling process or a closed-die forging operation.
Type:
Grant
Filed:
May 31, 1994
Date of Patent:
August 22, 1995
Assignee:
Rockwell International Corporation
Inventors:
Sheldon L. Semiatin, Sami M. El Soudani, Donald C. Vollmer, Clarence R. Thompson
Abstract: An analog VLSI circuit having a network of resistive elements and switches is provided for discriminating between an object and the background in a sensor image of a scene. A sensor system captures two-dimensional visual images and identifies edges of objects. The output of the imaging system is mapped onto the switched resistive grid. The presence of object edges causes switches to open at corresponding grid points in the resistive network. The periphery of the grid is connected to a first voltage, while a central point of the grid is connected to a second voltage. An edge map contour of open switches surrounding the central point causes the voltage at every point within the contour to rise to the second voltage, while every grid point outside the contour settles to the first voltage. Thus, the object enclosed by the edge map contour is labeled or tagged with the second voltage and the surrounding background is characterized by the first voltage.
Abstract: The invention uses transferable solder bump connection techniques in combination with a disposable test board to test and burn-in "as received" (i.e., untested) dies. Using transferable solder bumps, a die is first attached to the top of a disposable test board. The test board can be designed to allow 100% functional testing of the die as well as burn-in. Dies that successfully complete the test and burn-in process are considered to be "known good dies." Next, heat is applied to remove the known good die from the test board. A property of the invention is that solder bumps transfer with the die such that it can be used immediately in a flip-chip configuration and affixed to a MCM or other circuit board.
Abstract: An ESD protection circuit for the pads of an integrated circuit (IC) using silicide-clad diffusions is disclosed. The circuit uses a robust N+ diode with N-well block, an output NFET and a large transient clamp, each with a distributed, integrated N-well drain resistor to prevent the IC from avalanching and leakage during the Human Body Model and Charged Device Model tests for ESD.
Type:
Grant
Filed:
July 26, 1994
Date of Patent:
August 8, 1995
Assignee:
Rockwell International Corporation
Inventors:
Eugene R. Worley, Addison B. Jones, Rajiv Gupta
Abstract: A dissolved wafer micromachining process is modified by providing an etch control seal around the perimeter of a heavily doped micromechanical structure formed on a substrate. The micromechanical structure is fabricated on a wafer using conventional methods including the formation of a trench that surrounds and defines the shape of the micromechanical structure in the substrate. The etch control seal comprises a portion of the substrate in the form of a raised ring extending around the perimeter of the micromechanical structure and its defining trench. Selected raised areas of the heavily doped micromechanical structure and the top of the raised etch control seal are bonded to a second substrate. A selective etch is then used to dissolve the first substrate so that the heavily doped micromechanical structure remains attached to the second substrate only at the bonded areas.
Abstract: A method to fabricate a tuning fork resonator gyro which uses non-piezoelectric substrate structure is proposed. The tuning fork structure can be effectively rendered piezoelectric for activation and sensing by thin film deposition of a piezoelectric material. Electrical excitation of the piezo film excites vibrations in the structure of the drive tuning fork, and the gyro signal generated due to rotation can be picked up from the piezo film on the signal tuning fork. Most piezoelectric films have a much higher piezoelectric coupling than crystalline quartz, the material used in the prior art. The piezoelectric films on mechanically hard non-piezoelectric substrates are simpler for fabrication, electroding, and have a number of other advantages over the prior art. Fabrication of the tuning fork structures can be done more simply than the prior art, and deposition of the piezo films can be accomplished by sol-gel, or other thin film techniques.
Type:
Grant
Filed:
August 23, 1993
Date of Patent:
August 1, 1995
Assignee:
Rockwell International Corporation
Inventors:
Mohsen Khoshnevisan, Manouchehr E. Motamedi, Ratnakar R. Neurgaonkar
Abstract: Power is provided to a fluorescent lamp by connecting a source of alternating electrical current, consisting of a series of alternately positive and negative current pulses, to the lamp and shaping the current pulses such that the absolute value of the current increases as a function of time within each pulse.
Abstract: A force application system for a disc brake assembly in which twin pistons engage a configured load plate featuring stiffening ribs at specific locations to maximize the stiffness thereof seeking to provide uniformity of pressure transmitted therethrough to a friction pad. Additional uniformity of pressure is achieved by forming recesses in the backing plate of the friction pad proximate regions of pressure peaks. A singular recess at the point of pressure peak or recesses defined in a pattern identified by infinite element analysis may be utilized to optimize uniformity of pressure distribution.
Abstract: A hydrostatic bearing having two axial grooves on opposite sides of the bearing for breaking the rotational symmetry in the dynamic force coefficients thus reducing the whirl frequency ratio and increasing the damping and stiffness of the hydrostatic bearing.
Abstract: A digital signal processing system for interfacing with a central control having at least a control port. The system has a control processor having an interface port connected to the control port of the central control. The control processor also has at least first, second and third ports. At least first, second and third kernel processors for running software application tasks have first, second and third ports connected to the first, second and third ports of the control processor, respectively, each of the kernel processors having a plurality of channel ports connected to a bus for providing a plurality of channels. The control processor in response to data received from the central control establishes one of a plurality of software application tasks in each of the kernel processors.
Abstract: A ring laser gyroscope detector lens system for mounting on a ring laser gyroscope body having a resonant cavity. The ring laser gyroscope body has CW and CCW counterpropagating light beams propagating in a plane normal to the rate input axis of the ring laser gyroscope. The ring laser gyroscope detector lens system comprises a means for extracting a component of each of the CW and a CCW light beams from the cavity and for providing extracted CW and CCW beams. A means for combining the extracted CW and CCW beams to form an interference light source receives the extracted light. A planar array of detector element receives light from an objective lens means responsive to the interference light source. The objective lens means is typically a cylindrical lens that forms an interference light source pattern on the planar array of detector elements. A bias and amplification means is provided for conditioning each of the detectors in the array to be independently responsive to incident light intensity.