Abstract: A direct reading inductance meter is comprised of a crystal oscillator for generating a reference frequency f.sub.r and an LC tuned oscillator for generating an initial frequency f.sub.o which, when mixed with the reference, produces a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f.sub.x, a difference frequency (f.sub.r -f.sub.x) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

Abstract: Processing of raw analog echo data from a side-looking synthetic aperture radar receiver into images on board an airborne radar platform is made feasible by utilizing charge-coupled device (CCD) semiconductor technology. CCD circuits are utilized to perform input sampling, presumming, range correlation and azimuth correlation in the analog domain. These radar data processing functions are implemented for "single-look" or "multiple-look" imaging radar systems.

Abstract: Hydrogen is produced by the solar photolysis of water in a first photo-oxidation vessel with a transparent wall in the presence of a water soluble photo-oxidizable reagent and an insoluble hydrogen recombination catalyst. Simultaneously oxygen is produced in a second photo-reduction reactor with a transparent wall in the presence of an insoluble photo-reduction reagent catalyst. When spent, the solution from the first reactor is fed into the second reactor. A reaction occurs in the dark in which the redox reagents are regenerated, and the regenerated photo-oxidation reagent solution is recycled to the first reactor. The photo-oxidation reagent is preferably a europium salt, and the first reactor also contains a hydrogen recombination catalyst such as platinum supported on glass beads.

Abstract: The yield of photonically excited gas phase reactions is increased by extracting excess energy from unstable, excited species by contacting the species with the surface of a finely divided solid.

Abstract: A solar energy collection system including a plurality of energy receivers supported in suspension by an array of radially extending booms above a field of heliostats which serves to reflect a plurality of beams of solar energy toward said receivers. Each of said receivers is characterized by a curved target surface substantially totally illuminated by the reflected beam. A network of interconnected conduits for conducting a working fluid along a tortuous path in juxtaposition with the target surface of each receiver, whereby the working fluid is heated for converting radiant energy to heat, and a network of conduits for collecting and conducting heated working fluid away from the receivers.

Abstract: In one exemplary embodiment, a load regulating mechanical latch is provided that has a pivotally mounted latch element having a hook-shaped end with a strike roller-engaging laterally open hook for engaging a stationary strike roller. The latch element or hook is pivotally mounted in a clevis end of an elongated latch stem that is adapted for axial movement through an opening in a support plate or bracket mounted to a structural member. A coil spring is disposed over and around the extending latch stem and the lower end of the coil spring engages the support bracket. A thrust washer is removably attached to the other end of the latch stem and engages the other end of the coil spring and compresses the coil spring thereby preloading the spring and the latch element carried by the latch stem. The hook-shaped latch element has a limited degree of axial travel for loading caused by structural distortion which may change the relative positions of the latch element hook and the strike roller.

Abstract: One embodiment of a low to high temperature energy conversion system includes a decomposition chamber in which ammonia (NH.sub.3) is decomposed into hydrogen and nitrogen by absorbing heat of decomposition from a low temperature, e.g., 300.degree. C energy source. The separated hydrogen and nitrogen are then supplied to a recombination chamber wherein they recombine to produce ammonia. The recombination process is associated with a significant increase in temperature, used to increase the temperature of a fluid to temperatures on the order of 500.degree. C.

Abstract: A spatial filtered Q-switched laser system is disclosed having means to prevent ionization of air in close proximity to the aperture of the spatial filter. A compound lens system having an astigmatic focus is disposed between the laser and the spatial filter for defocusing the light beam emanating from the laser in the vicinity of the aperture of the spatial filter to an intensity below that which produces ionization of air. The preferred construction of the compound lens system as viewed from the laser comprises a cylindrical lens and a pair of positive lenses.

Abstract: A novel aldehyde-containing polymer (ACP) is prepared by reaction of a polysaccharide with periodate to introduce aldehyde groups onto the C.sub.2 - C.sub.3 carbon atoms and by introduction of ether and ester groups onto the pendant primary hydroxyl to modify solubility characteristics. The ACP is utilized to absorb nitrogen bases such as urea in vitro or in vivo.

Abstract: Zinc orthotitanate (Zn.sub.2 TiO.sub.4) suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc-deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by co-precipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400.degree. to 600.degree. C to remove volatiles and is then rapidly heated at 900.degree. to 1200.degree. C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment.

Abstract: A precision capacitive shaft encoder providing a d-c signal corresponding to the angular position of a shaft. Two variable capacitances are coupled in tandem by a rotatable shaft. Each capacitor has a capacitance that varies linearly with a change in the angular position of the shaft, and the sum of the two capacitances is always constant for any angular position of the shaft. Each capacitance is alternately coupled to a reference d-c voltage and a discharge circuit. The capacitances are electrically coupled in series and the charge periodically acquired at the junction of the capacitances is a function of the position of the shaft. An error-compensating voltage is imposed on the junction when the capacitances are coupled to the reference voltages, and the junction is coupled to sample-and-hold apparatus provided with a error-correcting circuit.

Abstract: A polymer system and resulting method useful for absorbing fats or oils which comprises forming a solid, network polymer having a minimal amount of cross-linking. The polymer that remains solid at a swelling ratio in oil or fat of at least ten and thus provides an oil absorption greater than 900 weight percent.

Abstract: An improved accumulator particularly adapted for use in controlling the pressure of a stream of fluid in its liquid phase utilizing the fluid in its gaseous phase. The accumulator is characterized by a shell defining a pressure chamber having an entry throat for a liquid and adapted to be connected in contiguous relation with a selected conduit having a stream of fluid flowing through the conduit in its liquid phase. A pressure and volume stabilization tube, including an array of pressure-relief perforations is projected into the chamber with the perforations disposed adjacent to the entry throat for accommodating a discharge of the fluid, in either gaseous or liquid phases, while a gas inlet and liquid to gas conversion system is provided for the chamber and connected with a source of the fluid for continuously pressurizing the chamber for controlling the pressure of the stream of liquid.

Abstract: Failure detection and substitution of a spare module is provided in a system having a plurality of phase staggered modules connected in parallel to deliver regulated voltage from an unregulated source. Phase control signals applied to the active converter modules are applied to the spare module through NOR gates associated with and disabled by the power output of respective active modules such that failure of any one enables its phase control signal to be applied to the spare module, thus controlling the spare module to operate in the phase position of the failed module. A NAND gate detects when any one active module fails and enables a gate in the spare module, thus activating the spare module.

Abstract: The contrast produced from a photographic transparency is controlled by placing the transparency between a pair of partially reflecting mirrors forming walls of an optical cavity. Mirrors are used to trap a collimated laser beam illuminating the transparency so that at least a portion of the beam energy is passed through the transparency plural times. The distance that the light beam travels between the mirrors is controlled as a function of the wavelength of the beam energy to control the phase of light interference in the beam passing through the transparency, thereby controlling the intensity of the beam derived from the mirror downstream of the transparency. The contrast of the transparency is increased or decreased, depending upon whether constructive or destructive interference for the beam energy is provided by the mirror spacing. For a negative input transparency a low to high contrast projected negative or positive image can be obtained.

Abstract: An inexpensive, lightweight reflective assembly member having good optical quality is provided. The reflective assembly is particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors. The reflective assembly may consist of a thin lamina reflective surface member and a lightweight substrate member of cellular structure. The respective materials may be chosen so that the coefficient of thermal expansion will be approximately the same. The substrate can comprise a cellular glass block while the reflective lamina member can be a thin sheet of glass with appropriate reflective coating. The lamina and cellular substrate member can be bonded together to form the reflective assembly. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface.

Abstract: A method for attaching a fused-quartz mirror to a conductive metal substrate which comprises the steps of tinning one surface of a fused-quartz mirror with a solder of substantially pure indium, tinning a metallic substrate with an indium eutectic alloy consisting essentially of indium, bismuth, lead and tin having a melting point substantially below that of indium, heating the eutectic alloy to a temperature substantially above its melting point, but below that of the solder, floating the mirror into place, and subsequently cooling the alloy to a temperature substantially below its melting point.

Abstract: The formation of voids through interdiffusion in bimetallic welded structures exposed to high operating temperatures is inhibited by utilizing an alloy of the parent materials in the junction of the parent materials or by preannealing the junction at an ultrahigh temperature. These methods are also used to reduce the concentration gradient of a hardening agent.

Abstract: A replaceable, prefilled electrode enclosed in a plastic seal and suitably adapted for attachment to a reusable, washable cap having snaps thereon is disclosed. The apparatus is particularly adapted for quick positioning of electrodes to obtain an EEG. The individual electrodes are formed of a sponge body which is filled with a conductive electrolyte gel during manufacture. The sponge body is adjacent to a base formed of a conductive plastic material. The base has at its center a male gripper snap. The cap locates the female snap to enable the electrode to be positioned. The electrode can be stored and used quickly by attaching to the female gripper snap. The snap is correctly positioned and located by mounting it in a stretchable cap. The cap is reusable with new electrodes for each use. The electrolyte gel serves as the contact electrode to achieve a good ohmic contact with the scalp.

Abstract: A wideband heterodyne receiver for a laser communication system is disclosed which includes a front end having a cooled photomixer contained in a hermetically sealed spaced quality housing designed for wide bandwidth transmission. The photomixer is coupled through a wideband preamplifier to the receiver back end which includes a frequency tracking network and demodulating equipment. The receiver is capable of tracking a doppler frequency shift of 750 MHz, positive or negative, and has an instantaneous intermediate frequency information bandwidth of 400 MHz. The receiver system is also capable of operating over a wide temperature range and is designed to be suitable for use in outer space communication.