Abstract: A circuit board assembly (10) having a plurality of circuit board subassemblies (12) having a device (14) for releasably electrically and mechanically connecting the subassemblies (12) into a general configuration of a plane, the subassemblies (12) having a device (16) for electrically and mechanically interconnecting the subassemblies (12) into a system back plane (18). One or more brackets (20) interlock a plurality of the generally planar subassemblies (12) for stability.

Abstract: An optical O-plate compensation device, in accordance with the invention, uses an inorganic thin film which is grown by physical vapor deposition at oblique incidence. The resulting thin film exhibits a biaxial form birefringence and performs, in a liquid crystal display (LCD), in a similar manner to uniaxial films with its extraordinary axis oriented obliquely at about 45.degree. with respect to the surface of the film. The invention makes possible a significant improvement in the gray scale properties and contrast ratios of liquid crystal displays (LCDs) over a wide range of viewing angles.

Abstract: An apparatus having a distortion cancelling feedback signal that suppresses undesired signal components. One embodiment of the present invention is comprised of a balanced mixer coupled to a common-mode detector, a filter and having a resulting feedback signal that suppresses the common-mode component of the mixer output signal while allowing the differential component of the mixer output signal to pass on to additional processing.

Abstract: Newton rings on a liquid crystal display (LCD) are avoided by connecting the frame of the LCD to the chassis without deflecting the frame outward toward the chassis. A first connecting mechanism coupled to the frame and to the chassis at least partially secures the frame to the chassis by prohibiting movement of the frame relative to the chassis in a first direction, but allows at least partial movement of the frame relative to the chassis in a second direction non-parallel to the first direction. A second connecting mechanism coupled to the frame and to the chassis at least partially secures the frame to the chassis by prohibiting movement of the frame relative to the chassis in the second direction, but allows at least partial movement of the frame relative to the chassis in the first direction. In combination, the coupling mechanisms prohibit movement of the frame relative to the chassis in both the first and second directions.

Abstract: A quadrifilar antenna has first, second, third and fourth quadrature antenna elements with signals in a respective quadrature phase relationship. The antenna elements are coupled through a quadrature matching network to a transceiver circuit representing a load or a source. The matching network includes first, second and third transmission lines which are arranged in a "Z" configuration. The first transmission line matches impedances between the first and second antenna elements and communicatively couples the second antenna element with a quarter wavelength phase shift of its signals to the first antenna element. The second transmission line matches impedances between the third and fourth antenna elements and communicatively couples the fourth antenna element with a quarter wavelength phase shift of its signals to the third antenna element.

Abstract: An optical component assembly is created with reduced defects in the adhesion and alignment between the optical components. A first rigid optical component is placed into a cavity. A second rigid optical component is placed into the cavity such that it is supported by a first support device which prevents a first end of the second rigid optical component from contacting a corresponding first end of the first rigid optical component. Air is evacuated from a chamber formed between the first and second rigid optical components. The support of the first support device is removed so that the first end of the second rigid optical component comes into contact with the first end of the first rigid optical component with a layer of adhesive material sandwiched therebetween. A force is applied to urge surfaces of the first and second rigid optical components toward one another to improve adhesion between the two.

Abstract: An enhanced differential amplifier circuit includes an injected inverted signal to the differential amplifier. As the AGC amplifier attenuates, the inverted signal becomes increasingly significant in the total gain ratio, thereby extending its operating range. Both a single current source and dual source implementation are disclosed.

Abstract: An engine power enhancement/pollution control system which utilizes a vortex air separator. The invention comprises a compressor for receiving air from the environment and providing high pressure air output. The high pressure air output is cooled to partially liquefied air having a mass fraction of less than 30% liquid. A vortex air separation apparatus is provided for separating the partially liquefied air into gaseous nitrogen enriched air and liquid oxygen enriched air. The oxygen enriched air is introduced to an internal combustion engine, thereby enhancing the power of the engine and minimizing pollution thereof.

Abstract: The invention is a contaminant removal system for purifying air. Incoming air is cooled to a cryogenic temperature. A vortex tube further cools the cooled air so as to solidify contaminants therein. A filter system then filters out the solidified contaminants from the air.Use of a vortex tube minimizes the amount of moving parts. This reduces maintenance and concommitant costs involved with operation. The present system has a long life. The vortex tube is relatively inexpensive.

Abstract: This invention is an apparatus and method for determining a set of instantaneous values of optimum flight path for a gliding vehicle at any time t, by determining, at each time t, altitude and position information associated with the vehicle, and wind profile information as a function of the altitude of the vehicle; determining, at each time t, the effective glide slope ratio of the vehicle as a function of the altitude of the vehicle, and then integrating the effective glide slope ratio, at each time t, from the destination point toward the current position and altitude of the vehicle. The invention also contemplates converting such time-dependent value of optimum flight path into a set of control commands for control surface actuators on the vehicle.

Abstract: A novel method is disclosed for removing or eliminating anisotropic material properties typically found in conventionally rolled or otherwise processed aluminum-lithium alloy products obtained from conventional aluminum fabrication mills. The method comprises imparting a predetermined amount of strain to the conventionally rolled alloy sheet whereby the alloy experiences dynamic recrystallization. Through this process, the mill-imposed crystallographic texturing, which initially sets up the undesired anisotropic characteristics, is eliminated. A preferred technique for imparting strain to the sheet stock is superplastic forming.

Abstract: The present invention is a system for the comminution of passivating layers on particles to facilitate particle digestion. A vessel comprises a lower portion and an upper portion. The lower portion has an inner surface with an increasing cross sectional area in the upward direction. The upper portion is in fluid communication with the lower portion. The upper portion has an inner surface with a substantially constant cross sectional area. A focused ultrasonic source is positioned so as to sonicate material in the lower portion. At least one fluid inlet is so arranged and constructed relative to the lower portion to introduce fluid into a lower section of the lower portion in a manner so as to cause helical, upward circulation of any particles in the lower portion. A flow re-direction mechanism is positioned in the upper portion so as to stop the helical, upward circulation of the particles and to convert the circulation to an upward, substantially non-circular flow.

Abstract: A fastening system for securing modular panels to an underlying support structure. The fastening system includes a number of pad members, preferably made of foamed material, secured to the underside of each panel, and a saw-like apparatus carried by the pad members for severing the pad members from the vehicle structure. One side of each of the pad members is secured to the panel underside. The other side of each pad member is secured to an appropriate location on the vehicle structure in such a manner that the outer surface of the panel, when the panel is properly secured on the vehicle body, lies flush with the outer surface of the vehicle body.

Abstract: An apparatus for maintaining useful consciousness and reducing the risk of injury for a subject exposed to high levels of acceleration with substantial components in the +G.sub.Z or -G.sub.Z direction while in a vehicle. It comprises a buoyancy force suit for supporting the subject with a buoyancy force, the force suit including at least two layers of flexible material, each layer being relatively impermeable to a substantially incompressible fluid having a specific gravity approximating blood being locatable in a space between the layers. A pressure helmet supports the subject's head with a gas pressure force. A Pressure Transfer System (PTS) provides pressure transfer and equalization between the suit and the pressure helmet. The PTS comprises a fluid reservoir segment and a gas reservoir segment. The fluid segment is in fluid communication with the space between the layers of the buoyancy force suit for maintaining a substantially constant fluid level within the suit at all times.

Abstract: A method for forming a structurally reinforced panel member, and the panel itself, is disclosed. The method requires disposing a first set of sheets of curable composite material atop a tool forming surface, wrapping a plurality of mandrels with a second set of sheets of curable composite material, arranging the wrapped mandrels in side by side relation atop the first set of sheets, curing the structural assembly, and then removing the mandrels from the cured structural assembly. In this way, the structural assembly includes interior channels obtained when the mandrels are removed from the cured structural panel member. The material portions defining the channels provide increased strength for the structural assembly.

Abstract: A process for manufacturing stiffened composite skin panel structures possessing novel hollow crown-shaped stiffener elements, and further including any combination of forward spars, aft spars, and transversely extending shear ties. The novel process embraces fabrication and curing of these structures without the use of mandrels. In practicing the method, the crown-shaped stiffeners, spars and shear ties are integrally bonded to a planar or curved skin structure to provide axial stiffness in semimonocoque components such as aircraft wings, stabilizers, fuselages, etc. The method of fabrication yields highly producible, structurally efficient composite aircraft components.

Abstract: A magnetically variable inductor for high power, high frequency applications which includes a solenoid with a magnetic core therein, disposed coaxially around a conductor for carrying the high power, high frequency signal and a variable current source coupled with the solenoid so that a manipulation of the current through the solenoid results in a variable inductance for said conductor. Also disclosed are additional features of ferrite rings disposed around each end of the magnetic core, a shield disposed between the core and the solenoid, and a sheath disposed around the solenoid.

Abstract: A structural armor assembly including a superplastically formed sandwich member having on one side one face sheet of high toughness, high-strength titanium alloy material, and on the other side a second face sheet made of non-superplastically formable metal matrix composite abrasive material. Abrasive materials in the form of "KEVLAR".RTM. or "SPECTRA".RTM. are provided inside cells in the sandwich member to serve as a "catcher's mitt" to absorb part or all of the energy of the ballistic fragments after they have been abraded by the material of the second face sheet.

Abstract: A composite signal recognizer separator, and PSK, AM, FM demodulator apparatus for processing received communication signals. The receiver utilizes N demodulators cascadely-coupled, where N is equal to or greater than the number of co-channel signals or perceived interference. Detailed in both dual and single stages cascaded fashion, the receiver first tracks to a predominant (stronger) signal, and regeneratively improves track on other (weaker) signals by subtracting predominant noise portion from the input of further demodulation stages. A unified approach to PSK carrier phase tracking, character data tracking, and recovery clock tracking is utilized.

Abstract: In a radio transmitter, a PM input signal is provided directly to a frequency synthesizer. The synthesizer includes a PLL having a reference frequency input signal and a controlled frequency output signal. The PLL includes a frequency divider which is directly connected in a feedback circuit path between the controlled frequency output signal and the PLL's phase-detector. The frequency divider has a frequency control input signal for setting a division ratio N for the divider, and a PM circuit has as input signal the PM input signal and the frequency control input signal. The PM circuit provides an offset signal to the phase detector output, so that the PLL creates a correcting phase signal resulting from the offset signal. The magnitude of the offset signal changes as a function of the change in the value of N.