Abstract: A non-mechanical optical switch is provided for alternately switching a monochromatic or quasi-monochromatic light beam along two optical paths. A polarizer polarizes light into a single, e.g., vertical component which is then rapidly modulated into vertical and horizontal components by a polarization modulator. A polarization beam splitter then reflects one of these components along one path and transmits the other along the second path. In the specific application of gas filter correlation radiometry, one path is directed through a vacuum cell and one path is directed through a gas correlation cell containing a desired gas. Reflecting mirrors cause these two paths to intersect at a second polarization beam splitter which reflects one component and transmits the other to recombine them into a polarization modulated beam which can be detected by an appropriate single sensor.

Abstract: Apparatus for characterizing the magnetic field of a device under test includes a device for nullifying the ambient magnetic field in a test environment area with a constant applied magnetic field, a device for rotating the device under test in the test environment area at least nearly through a complete circle, a device for sensing the magnetic field at a sensor location which is along the circumference of rotation as a function of the rotation angle for successive ones of a set of predetermined orientations of the device under test to obtain a profile of the magnetic field at the sensor location as a function of the rotation angle for each one of the predetermined orientations, a memory for storing the profiles, and a processor coupled to the memory for characterizing the magnetic field of the device from the magnetic field profiles thus obtained.

Abstract: A payload retention device (10) for grappling and retaining a payload (14) in docked position on a supporting structure (18) in the cargo bay of a space vehicle. The device comprises a two-fault tolerant electromagnetic grappling system comprising electromagnets (30A,30B) for attracting and grappling a grapple strike plate (20) affixed to the payload when in proximity thereto and an electromechanical latching assembly comprising a pair of independent latching subassemblies. Each subassembly comprises a set of latching pawls (29) which are driven into latching and unlatching positions relative to a grappled payload by a pair of gearmotors (40), each equipped with a ratchet clutch drive mechanism (75, 76) which is two-fault tolerant with respect to latching such that only one gearmotor of the four needs to be operational to effect a latch of the payload but is single fault tolerant with respect to release of a latched payload.

Abstract: A High Temperature Solder Device for Flat Cables includes a microwelder, an anvil which acts as a heat sink and supports a flexible flat ribbon cable that is to be connected to a multiple pin connector. The microwelder is made from a modified commercially available resistance welding machine such as the Split Tip Electrode microwelder which consists of two separate electrode halves with a removable dielectric spacer in between. The microwelder is not used to "weld" the items together, but to provide a controlled compressive force on, and energy pulse to, a solder pre-form placed between a pin of the connector and a conductor of the flexible flat ribbon cable. When the microwelder is operated, an electric pulse will flow down one electrode, through the solder pre-form and back up the other electrode. This pulse of electrical energy will cause the solder pre-form to heat-up and melt, joining the pin and conductor.

Abstract: A portable diagnostic image analysis instrument for retinal funduscopy in which an eye fundus image is optically processed by a lens system (24) to a CCD device (32) which produces recordable and viewable output data and is simultaneously viewable on an electronic view finder 36. The fundus image is processed to develop a representation of the vessel or vessels from the output data.

Abstract: An improved NDE method utilizes a laser source with modulator and scanning mirror, a pancake shape eddy current detecting coil, a lock-in amplifier, a system controller, and an impedance gain/phase analyzer. The laser is directed by the scanning mirror to a specimen to be analyzed. A very localized or small area of the specimen is impacted directly by the laser beam creating a thermal and stress wave in the specimen. An impedance gain/phase analyzer is connected to the eddy current detecting coil and to a lock-in amplifier through the system controller. The lock-in amplifier is also synchronized to the laser modulator. The system controller is used to control the lock-in amplifier, scanning mirror, and to process data from the analyzer. Raster scanning of the laser beam across the speciment allows the detection by the coil of the laser generated thermal and elastic strains induced in the specimen by the laser. The rastering of the laser beam is controlled by the controller by positioning the mirror.

Abstract: A remote maintenance monitoring system retrofits to a given hardware device with a sensor implant which gathers and captures failure data from the hardware device, without interfering with its operation. Failure data is continuously obtained from predetermined critical points within the hardware device, and is analyzed with a diagnostic expert system, which isolates failure origin to a particular component within the hardware device. For example, monitoring of a computer-based device may include monitoring of parity error data therefrom, as well as monitoring power supply fluctuations therein, so that parity error and power supply anomaly data may be used to trace the failure origin to a particular plane or power supply within the computer-based device. A plurality of sensor implants may be rerofit to corresponding plural devices comprising a distributed large-scale system. Transparent interface of the sensors to the devices precludes operative interference with the distributed network.

Abstract: The invention relates to a method and apparatus for frequency spectrum analysis of an unknown signal in real time based upon integration of 1-bit samples of signal voltage amplitude corresponding to sine or cosine phases of a controlled center frequency clock used to time the samples taken, but preferably corresponding to both sine and cosine phases of the center frequency clock which is changed after each integration interval to sweep the frequency range of interest in steps. Integration of samples during each interval is carried out over a number of cycles of the center frequency clock spanning a number of cycles of an input signal to be analyzed. The invention may be used to detect the frequency of at least two signals simultaneously.

Abstract: A Joule-Thomson cryogenic refrigeration system capable of achieving high temperature stabilities in the presence of varying temperature, atmospheric pressure, and heat load is provided. The Joule-Thomson cryogenic refrigeration system includes a demand-flow Joule-Thomson expansion valve disposed in a cryostat of the refrigeration system. The expansion valve has an adjustable orifice that controls the flow of compressed gas therethrough and induces cooling and partial liquefaction of the gas. A recuperative heat exchanger is disposed in the cryostat and coupled to the expansion valve. A thermostatically self-regulating mechanism is disposed in the cryostat and coupled to the J-T expansion valve. The thermostatically self-regulating mechanism automatically adjusts the cross-sectional area of the adjustable valve orifice in response to environmental temperature changes and changes in power dissipated at a cold head.

Abstract: A low friction, object guidance, and gripping finger device for a robotic end effector on a robotic arm, having a pair of robotic fingers each having a finger shaft slideably located on a gripper housing attached to the end effector, each of the robotic fingers having a roller housing attached to the finger shaft. The roller housing has a ball-bearing mounted centering roller located at the center, and a pair of ball bearing mounted clamping rollers located on either side of the centering roller. The object has a recess to engage the centering roller and a number of seating ramps for engaging the clamping rollers. The centering roller acts to position and hold the object symmetrically about the centering roller with respect to the X axis and the clamping rollers act to position and hold the object with respect to the Y and Z axis.

Abstract: A method and apparatus for testing steel components for temperature embrittlement uses magneto-acoustic emission to nondestructively evaluate the component. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an AC current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be umembrittled and a test component. Magnetic remanence is determined by applying a DC current to the electromagnets, then turning the magnets off and observing the residual magnetic induction.

Abstract: A composite nut is shown which permits a fastener to be inserted or removed from either side with an indicator of fastener engagement. The nut has a plurality of segments, preferably at least three segments, which are internally threaded, spring-loaded apart by an internal spring, and has detents on opposite sides which force the nut segments into operative engagement with a threaded member when pushed in and release the segments for quick insertion or removal of the nut when moved out. When the nut is installed, end pressure on one of the detents presses the nut segments into operative engagement with a threaded member where continued rotation locks the structure together with the detents depressed to indicate positive locking engagement of the nut. On removal, counterclockwise rotation of the nut relieves the endwise pressure on the detents permitting internal springs to force the detents outward and allowing the nut segments to move outward and separate to permit quick removal of the fastener.

Abstract: A method for determining Richardson Number, Ri, or its reciprocal, RRi, for clear air turbulence prediction using measured potential temperature profiles and determining the vertical gradient of potential temperature, d.theta./dz. Wind vector from the aircraft's instrumentation versus potential temperature dw/d.theta. is determined and multiplied by d.theta./dz to obtain dW/dz. Richardson Number or its reciprocal is then determined from the relationship ##EQU1## for use in detecting a trend toward a threshold value for the prupose of predicing clear air turbulence. Other equations for this basic relationship are disclosed together with the description of a method for combining of other atmospheric observables using multiple regression techniques to produce improved warnings of clear air turbulence.

Abstract: Poly(1,3,4-oxadiazoles) (POX) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)-1,3,4-oxadiazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The polymerizations are carried out in polar aprotic solvents such as sulfolane or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl)-1,3,4-oxadiazole monomers are synthesized by reacting 4-hydroxybenzoic hydrazide with phenyl-4-hydrobenzoate in the melt and also by reacting aromatic dihydrazides with two moles of phenyl-4-hydroxybenzoate in the melt. This synthetic route has provided high molecular weight POX of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the large variety of activated aromatic dihalides which are available.

Abstract: A whole body cleansing agent for bathing with a small quantity of water in microgravity conditions which consists essentially of a paste comprising an acyltaurate, a skin conditioner, a hair conditioner, and a preservative. Also disclosed is a method of bathing with a small quantity of water which includes the steps of wetting the skin and hair with a small quantity of water, lathering the skin with the paste, rinsing the lather from the skin and hair with a small quantity of water to produce a rinse water containing the cleansing agent, defoaming the rinse water and supplying the defoamed rinse water to a water reclamation unit for recycle thereof.

Abstract: Polyimidazoles (Pl) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethylacetamide, sulfolane, N-methylpyrrolidinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl)imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl)imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxyphenyl)imidazole monomer.

Abstract: An oxidation resistant coating for titanium alloys and titanium alloy matrix composites comprises an MCrAlX material. M is a metal selected from nickel, cobalt, and iron. X is an active element selected from Y, Yb, Zr and Hf.

Abstract: A phase shifter having a reference path and a delay path, light sources, and superconductive switches. Each of the superconductive switches is terminated in a virtual short circuit, which may be a radial stub. Switching between the reference path and delayed path is accomplished by illuminating the superconductive switches connected to the desired path, while not illuminating the superconductive switches connected to the other path.

Abstract: A superconducting bearing for a rotating member having a magnet at each extremity of the rotating member; having a bearing made of a material exhibiting Type II superconducting properties, the bearing is formed as a recess in the superconducting material in the form of a cylindrical, closed-end orifice. The bearing exerts levitation forces on the magnets at each extremity of the rotating member. Several methods for controlling the levitation forces exerted by the bearing on the magnets at each extremity of the rotating member are shown. One method is to construct the bearing from two different types of superconducting materials. Another method is to provide heating elements in the bearing. A further method is to provide an electromagnetic coil above the bearing. The bearing could also be segmented or have material removed to control the levitation forces.

Abstract: A non-destructive method for determining elastic moduli of isotropic or anisotropic or homogeneous or nonhomogeneous material. The material is subjected to x-radiation for determining the density of the material at a sufficient number of discrete measurement points over the material to create an image of local material density variation. Ultrasonic waves are propagated through the material to determine transit times for each wave at points corresponding to the measurement points. Using the determined density and transit times for each of the measurement points, the elastic moduli at each measurement point is determined. The elastic moduli provides a means for analyzing the mechanical performance of the material. In one aspect, the determined elastic moduli are inputted into a finite element method code for determining mechanical response of the material.