Abstract: A broadband gigahertz frequency range radio receiver useful in electronic warfare and other applications for incoming signal detection and identification purposes. The receiver is based on Fourier transform examination of incoming signal characteristics and provides real time accomplishment of these tasks by way of using a simplified one-bit digital representation of the incoming signals and a resulting reduction of the computational load associated with the Fourier transform operation. The receiver precedes the Fourier transform operation with signal processing which may include, for example, a limiting amplifier and two bandpass filters. Two incoming signal accommodation is provided, a characteristic which is particularly improved over the characteristics of popular presently used receivers in this field.

Abstract: A new apparatus and method for making a carbon or graphite reinforced composite is described. A rigid carbon foam preform is placed within a sealed flexible bag. A vacuum is created within the bag. Matrix resin is introduced into the bag, through an inlet valve, and is amply impregnated into the preform. The resulting resin-filled preform is exposed to a heat source to cure the preform. The resulting carbon or graphite reinforced composite structure is then removed from the bag.

Abstract: A two-photon absorbing chromophore of the formulaD--Ar--Awherein Ar is selected from the group consisting of ##STR1## D is selected from the group consisting of ##STR2## and A is selected from the group consisting of ##STR3## wherein R.sub.1 and R.sub.2 are alkyl groups having 8 to 12 carbon atoms, and wherein R.sub.1 and R.sub.2 are the same or different.

Abstract: A method for preparing optical quality, thin films of polymers and co-polymers, as well as blends of such polymers or co-polymers with flexible polymers and co-polymers which comprises(a) preparing a solution of the polymer or co-polymer or blend in a suitable solvent;(b) forming a film from the solution;(c) cooling the thus-formed film to a temperature below the freezing point of the solvent; and(d) dissolving the solvent out of said film at a temperature below the melting point of the solvent.This method can be employed to prepare films of high optical clarity for electro-optical device applications. Because of their thermal stability, mechanical strength and chemical resistance, films prepared according to this method can also be used as filters and separation membranes.

Abstract: A two-dimensional, electrically-multiplexed robotic tactile sensor realized by capacitively coupling a piezoelectric film such as a polyvinylidene fluoride (PVDF) polymer film to a monolithic silicon integrated circuit. The disclosed integrated circuit incorporates 64 identical sensor electrodes arranged in a symmetrical 8.times.8 matrix and physically adjacent electronic amplification for each sensor electrode signal. The response of a typical tactile sensor is linear for loads spanning the range of 0.8 to 135 grams of force and provides a response bandwidth of 20-25 Hz. Stability and response reproducibility limitations often associated with piezoelectric-based tactile sensors are resolved by a pre-charge voltage bias sequence for the PVDF film which initializes the pre-and post-load sensor responses. Recognition of sharp-edge, square, trapezoid, isosceles triangle, circle, toroid, slotted screw, and cross-slotted screw shapes using the sensor is also disclosed.

Abstract: An improved method for producing a fiber-reinforced ceramic composite having a monazite interface between the reinforcing fiber and the ceramic matrix, which comprises the steps of coating each filament in a continuous fiber tow with an aqueous sol that forms monazite after high temperature heat treatment, heat treating the thus-coated fiber tow to provide a coated tow having a layer of monazite thereon, embedding the fiber in a suitable ceramic matrix, and densifying the composite.

Abstract: An adaptor detachably mounted on an ocular of night vision goggles for quly adjusting the objective lens focus to clearly view far and near objects. The adaptor includes a positive optical power or close-up lens mounted in a holder pivotally mounted between a stowed, inoperative position and an operative position locating the close-up lens in axial alignment with the objective lens of the ocular. The close-up lens has an effective diameter substantially smaller than the diameter of the objective lens to raise the F/number of the objective lens/close-up lens combination for increasing the depth of focus for enhanced near viewing. Auxiliary illumination is provided by a battery powered infra-red Light Emitting Diode (LED) mounted in the adaptor and energized by a switch as the lens holder moves toward its operative position.

Abstract: An antenna test body for providing azimuth and elevation rotation having a rotating cylinder contained within said test body and an arc sector under the test body capable of providing elevation rotation. The test body provides a phase stationary center point under rotation of both azimuth and elevation.

Abstract: A system for the forced air de-icing of aircraft is described which includes a source of pressurized air and an axisymmetric, high momentum focused air jet nozzle having an inlet of diameter D and an outlet of diameter d with an axisymmetric contour therebetween defined by a converging portion of first radius near the inlet and a reflex portion of second radius near the outlet, the converging and reflex portions being connected by a convergent conical portion tangent to both the converging and reflex portions and having an angle of convergence equal to or less than 30.degree., wherein D is equal to or greater than 2d, the first radius is equal to or greater than D, the second radius is equal to or greater than d, and the length of the nozzle is equal to or greater than 1.5 D, and an insulated conduit for conducting pressurized air from the source to the nozzle.

Abstract: A novel rolling element bearing assembly comprises an inner race, an outer race, a plurality of rolling elements, and a carbon-carbon composite retainer. The carbon-carbon composite retainer is fabricated by providing a woven tube, cutting the woven tube into suitably sized rings, piercing the rings for rolling bearing elements, and densifying the resulting retainer. Alternatively, the tube can be densified, then cut into a plurality of retainer blanks which are then pierced. For use at operating temperatures above about 650.degree. C., ceramic coatings, such as silicon carbide (SiC), silicon nitride (Si.sub.3 N.sub.4) and boron nitride (BN) can be used to provide oxidation resistance for the carbon-carbon composite retainer at such elevated temperatures.

Abstract: An apparatus and method for providing small size, high gain corner reflection of radio frequency signals for use in military and commercial applications. Conventional corner reflector practice is combined with electronic amplifying reflection devices such as the superregenerative amplifier to provide an array of antennas and amplifiers spread over each planar surface of a corner reflector. The specific antenna used may be selected from a plurality of various antenna types depending on the application. As in a conventional corner reflector, the amplified signal is reflected at the same angle and in the opposite direction of the incident signal.

Abstract: A simplified, low-cost analog system for displacing the perceived source of a stereophonic studio signal from an inherent location within the listener's head to selected fixed alternate locations such as thirty degrees on either side of and a few feet in front of the listener. The disclosed system employs selected analog filters including ear canal resonance-simulating pinna related filters and signal delaying multiple poled Bessel filters to displace the apparent sound source to the predetermined external locations. The audio filter elements are preferably implemented with operational amplifiers with the pinna related filter enhancing frequencies around 5 KHz, and with the output of the pinna related filter being sent directly to one audio channel, and the output of the delay filter is sent to the other channel. Two signal channels can be processed simultaneously using a symmetrical circuit for the other input channel and mixing together the outputs.

Abstract: Gamma titanium aluminide alloys having the composition Ti-(45.5-47.5)Al-(0-3.0)X-(1-5)Y-(0.05-1.0)W, where X is Cr, Mn or any combination thereof, and Y is Nb, Ta or any combination thereof (at %), are treated to provide specific microstructures. To obtain duplex microstructures, the annealing temperature (T.sub.a) range is the eutectoid temperature (T.sub.e)+100.degree. C. to the alpha transus temperature (T.sub..alpha.)-30.degree. C.; to obtain nearly lamellar microstructures, the annealing temperature range is T.sub..alpha. -20.degree. C. to T.sub..alpha. -1.degree. C.; to obtain fully lamellar microstructures, the annealing temperature range is T.sub..alpha. to T.sub..alpha. +50.degree. C. The times required for producing these microstructures range from 0.25 to 15 hours, depending on the desired microstructure, alloy composition, annealing temperature selected, material section size and grain size desired.

Abstract: High temperature melting niobium-titanium-chromium-aluminum-silicon alloys having a wide range of desirable microstructures, excellent microstructural and morphological properties, superior oxidation resistance at temperatures from 1000.degree. C. to 1500.degree. C., and good low temperature toughness and good high temperature strength and creep resistance are described which comprise generally two- or three-or four-phase alloys systems having compositions (31-41)Nb-(26-34)Ti-(8-10)Cr-(6-12)Al-(9-18)Si. Two-phase beta+Nb.sub.5 Si.sub.3 -base alloys can be obtained by increasing the Nb/Ti ratio, while three-phase beta+Nb.sub.5 Si.sub.3 -base+Ti.sub.5 Si.sub.3 -base alloys or four-phase beta+Nb.sub.5 Si.sub.3 -base+Ti.sub.5 Si.sub.3 -base +Ti.sub.3 Si-base alloys can be obtained by decreasing the Nb/Ti ratio.

Abstract: A novel microfocusing laser surgical probe for use in intraocular surgery combines a high power laser with a gradient index (GRIN) lens to provide sufficient energy density at a focal point inside the eye to achieve laser induced breakdown and destroy fibrovascular membranes resulting from diabetes and other diseases. The gradient index lens steeply focuses the light close to its end so that the energy density of the light widely diverges beyond the focal point to reduce the potential for damage to the underlying retina. The gradient index lens also focuses the light far enough from the end of the lens to prevent damage to the lens itself. In a first embodiment, an open transmission line couples a YAG laser to a gradient index lens so that the light is still collimated when it strikes the lens. This first probe may be articulated by the use of mirrors or other optical devices.

Abstract: An engine casing structure for a gas turbine engine or the like is described which comprises two substantially tubular shaped axially adjacent abutting casing portions and a rotatable clamping ring on one casing portion having a plurality of lugs which engage a corresponding plurality of lugs on the axially adjacent casing portion providing a positive clamping force between the two casing portions, the clamping ring being held in place by a small plurality (eight or fewer) of bolts.

Abstract: A method for communicating graphic data such as plotted two-dimensional curves to a user such as a sight impaired person is disclosed. The disclosed arrangement uses haptic or tactile stimulation of a user's extremity such as is relied--upon in the Braille code fingertip communication already known to many sight impaired persons. Computerized control over a Braille character-like display and use of the computer mouse as a data selection input device; are included in the invention. The invention also includes provision of data enhancement and data interpretation aids including axis names, multiple curve identifications, grid line identifications and the addition of audio information such as tick sounds and spoken utterances to supplement the tactile communication. A computer-based embodiment of the invention is disclosed, this in the form of hardware block diagrams, software flow diagrams and computer code listing, the latter being primarily in microfiche appendix form.

Abstract: Structure and fabrication details are disclosed for AlGaAs/GaAs microwave HBTs having improved thermal stability during high power operation. The use of a thermal shunt joining emitter contacts of a multi-emitter HBT is shown to improve this thermal stability and eliminate "current-crush" effects. A significant reduction in thermal resistance of the disclosed devices is also achieved by spreading the generated heat over a large substrate area using thermal lens techniques in the thermal shunt. These improvements achieve thermally stable operation of AlGaAs/GaAs HBTs up to their electronic limitations. A power density of 10 mW/.mu.m2 of emitter area is achieved with 0.6 W CW output power and 60% power-added efficiency at 10 GHz. The thermal stabilization technique is applicable to other bipolar transistors including silicon, germanium, and indium phosphide devices.

Abstract: A video camera system combining a charge coupled device (CCD) with a rotating prism optical element is disclosed. The rotating prism optical element moves an optical image on the transducer surface of the CCD array in precise synchronism with a CCD array clock which is transferring charge between transducer sites of the array. Since charge transfer occurs in synchronism with image movement, the exposure of transducer sites to image blurring or smearing additional optical energy is eliminated. The disclosed apparatus is particularly useful for high-speed, high-resolution, military, possibly airborne, camera systems. The invention also contemplates resolution of color images, with the use of color selective filters over adjacent columns of the CCD imaging array. The invention additionally contemplates utilizing a rotating prism optical element with other types of detectors.

Abstract: A laser radar system in which a laser beam is used to illuminate a target region of interest. The density of the laser radiation at the target plane is low enough that the reflected energy from diffusing portions of the target is not detectable by the laser radar receiver. Target reflections from retroreflective portions of the target such as glint signal reflections are also not initially detectable by the radar however these reflections are of such greater signal strength that the radar system is arranged to respond to the glint signals after they are enhanced by optical processing which includes re-illumination of the target glint area by a phase conjugated and parametrically amplified enhancement of the original reflected glint signal. Plural uses and alternate arrangements of the invention are included.