Abstract: A constant magnification optical tracking system for continuously tracking a moving object. More particularly, a constant magnification optical tracking system is disclosed wherein a traveling objective lens (14) maintains a fixed relationship to an object (10) to be optically tracked. The objective lens (14) is chosen to provide a collimated light beam (32) oriented in the direction of travel of the moving object (10) A reflective surface (18) is attached to the traveling objective lens (14) for reflecting an image of the moving object (10) to the lens. The moving object (10) is maintained at the focal point of the traveling objective lens (14). In an exemplary embodiment, the object to be tracked is a free-falling object, and the traveling objective lens is mounted on a holding structure (16) slidably attached to a vertically-extending guiding member (38) so that the free-falling object (10) will be located at the focal point of the objective lens for at least a portion of its free-fall path.

Abstract: Fluorinated alkyl or alkylether 1,2,4-oxadiazole compounds are prepared by cyclizing the corresponding alkyl or alkylether imidoylamidoximes in vacuo or in an inert atmosphere at a temperature within the range of 40.degree. to 100.degree. C. for a period of 8 to 144 hours in the presence of an acid compound which can accept ammonia to form a salt. The imidoylamidoximes usable in this process may be either polymeric or nonpolymeric. The products, when polymeric, have excellent heat, chemical and solvent resistance.

Abstract: A flush mounting, cavity-backed, dual orthogonal slot antenna in which improved radiation pattern characteristics are obtained by making the spiral slot pattern elliptical in the aperture plane. A cavity (11) and a flanged aperture plate (11a) are shown in which one slot pair (12 and 13) is orthogonal with respect to another slot pair (14 and 15) within the aperture plate (11a). Coaxial split-tube baluns (12a and 14a) are used to drive the junctions between corresponding slot pairs. Optional cavity dielectric (18) is provided and a drive coupling arrangement includes a four port comparator hybrid (30) having .ltoreq. and .DELTA. ports (17 and 16) respectively, for alternate excitation to produce a single lobe or a double lobe pattern with null. Switching apparatus is provided to connect a common terminal (26) to either of the ports (17 or 16).

Abstract: The direct fluid contact heat exchange with H.sub.2 SO.sub.4 at about 330.degree. C. prior to high temperature decomposition at about 830.degree. C. in the oxygen release step of several thermochemical cycles for splitting water into hydrogen and oxygen provides higher heat transfer rates, savings in energy and permits use of cast vessels rather than expensive forged alloy indirect heat exchangers. Among several candidate perfluorocarbon liquids tested, only perfluoropropylene oxide polymers having a degree of polymerization from about 10 to 60 were chemically stable, had low miscibility and vapor pressure when tested with sulfuric acid at temperatures from 300.degree. C. to 400.degree. C.

Abstract: A low-noise electrode suited for sensing electrocardiograms when chronically and subcutaneously implanted in a free-ranging subject. The electrode comprises a pocket-shaped electrically conductive member with a single entrance adapted to receive body fluids. The exterior of the member and the entrance region is coated with electrical insulation so that the only electrolyte/electrode interface is within the member remote from artifact-generating tissue. Cloth straps are bonded to the member to permit the electrode to be sutured to tissue and to provide electrical lead flexure relief.

Abstract: This invention relates to improved lightweight, high temperature resistent, electrically conductive, palladium containing, polyimide films and methods of preparing same for use in aerodynamic and space application. A palladium (II) ion-containing polyamic acid solution is prepared by reacting an aromatic dianhydride with an equimolar quantity of a palladium II ion-containing salt or complex and the reactant product is cast as a thin film onto a surface and cured at approximately 300.degree. C. to produce a flexible electrically conductive cyclic palladium containing polyimide. The source of palladium ions is selected from the group of palladium II compounds consisting of LiPdCl.sub.4, Pd[S(CH.sub.3).sub.2 ].sub.2 Cl.sub.2,Na.sub.2 PdCl.sub.4, and PdCl.sub.2.

Abstract: An hermetic seal 10 for a linear rod 12 having a portion thereof projected axially through a port 20 defined in a wall for a pressure chamber 14 and supported thereby for omni-directional motion. The seal is characterized by a resilient, impervious, cylindrical body having a first section concentrically related to the shaft and integrally affixed thereto comprising a linear ordered array of annular flutes 22, a second section integrally affixed to the wall of the chamber and concentrically related to the port comprising a second linear ordered array of annular flutes 24, and a third section interposed between said first and second sections and integrally affixed thereto in coaxial alignment therewith comprising an annular ordered array of linear flutes 26 concentrically related to the shaft, whereby axial, angular, and pivotal motion of the rod is accommodated.

Abstract: Efficiency of silicon solar cells containing about 10.sup.15 atoms/cm.sup.3 of chromium is improved about 26% by thermal annealing of the silicon wafer at a temperature of 200.degree. C. to form chromium precipitates having a diameter of less than 1 Angstrom. Further improvement in efficiency is achieved by scribing laser lines onto the back surface of the wafer at a spacing of at least 0.5 mm and at a depth of less than 13 micrometers to preferentially precipitate chromium near the back surface and away from the junction region of the device. This provides an economical way to improve the deleterious effects of chromium, one of the impurities present in metallurgical grade silicon material.

Abstract: A fuselage structure is disclosed in which the skin is comprised of layers of a matrix fiber reinforced composite, with the stringers reinforced with the same composite material. The high strength to weight ratio of the composite, particularly at elevated temperatures, and its high modulus of elasticity, makes it desirable for use in airplane structures.

Abstract: An object is to provide for receiving a circularly polarized signal from an antenna feed (10) connected to orthogonally spaced antenna elements (11, 12, 13, 14) and for transmitting a linearly polarized signal through the same feed without switches, and without suffering a 3 dB polarization mismatch loss, using an arrangement of hybrid junctions. The arrangement is comprised of two dividing hybrid junctions (15, 16), each connected to a different pair of antenna elements and a summing hybrid junction (17). In one embodiment, a receiver (18) is connected to the summing hybrid junction directly. A diplexer (19a or 19b) is used to connect a transmitter (20a or 20b) to only one pair of antenna elements.

Abstract: A flexible, adjustable refractory filler (1) is disclosed for filling gaps between ceramic tiles (10, 11) forming the heat shield of a space shuttle vehicle, to protect its aluminum skin (20) during atmospheric re-entry. The easily installed and replaced filler (1) consists essentially of a strip of ceramic cloth (3) coated, at least along both its longitudinal edges (4, 5), with a room temperature vulcanizable silicone rubber compound with a high emittance colored pigment. The filler may have one or more layers (2, 3), as the gap width requires. Preferred materials are basket-weave aluminoborosilicate cloth, and a rubber compounded with silicon tetraboride as the emittance agent and finely divided borosilicate glass containing about 7.5% B.sub.2 O.sub.3 as high temperature binder. The filler cloth strip or tape is cut to proper width and length, inserted into the gap, and fastened with previously applied drops of silicone rubber adhesive.

Abstract: In combination with the ground vehicle A powered by a waste heat generating electric motor 16, a cooling system 10 including a generator 17 for driving off refrigerant vapor from a strong refrigerant-absorbant solution, including a solar collector 12, an air-cooled condenser 30 connected with the generator for converting the refrigerant vapor to its liquid state, an air-cooled evaporator 38 connected with the condenser for returning the liquid refrigerant to its vapor state, and an absorber 18 is connected to the generator and to the evaporator for dissolving the refrigerant vapor in the weak refrigerant-absorbant solution, for thus providing a strong refrigerant solution, a pump 22 for establishing a pressurized flow of strong refrigerant-absorbant solution from said absorber through the electric motor, and thence to the collector.

Abstract: New 1,1,1-triaryl-2,2,2-trifluoroethanes in which the aryl radicals carry one or more substitutents have been prepared by condensation of trifluoroacetophenones with substituted phenyl compounds in the presence of catalytic quantities of trifluoromethylsulfonic acid. The reaction can be carried out under reflux in toluene or, for strikingly better results in certain cases, reactants are simply stirred at room temperature for about 24 to 48 hours.

Abstract: Static charges and agglomeration of particles in a fluidized bed system are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction.

Abstract: A microwave switching power divider for selectively dividing and switching microwave energy among a plurality of outputs to other microwave devices includes a pair of parallel, spaced-apart circular ground planes defining a microwave cavity with multi-port microwave power distributing switching circuitry formed on opposite sides of a thin circular dielectric substrate disposed beween the ground planes. The power distributing circuitry includes a conductive disk located at the center of the substrate and connected to a source of microwave energy. A plurality of tapered radial power dividing transmission lines for intercepting the standing waves are symmetrically disposed about and connected to the conductive disk. Within each line, a high speed, low insertion loss switching diode and a DC blocking capacitor are connected in series between the outer end of a transmission line and an output port.

Abstract: An improved suspension system for an uncrowned wheel rolling on a flat track characterized by a wheel frame assembly including a wheel frame and at least one uncrowned wheel connected in supporting relation with the frame and adapted to be seated in rolling engagement with a flat track, a load supporting bed, and a plurality of flexural struts interconnecting the bed in supported relation with the frame, each of said struts being disposed in a plane passing through the center of the uncrowned wheel surface along a line substantially bisecting the line of contact established between the wheel surface and the flat surface of the truck and characterized by a modulus of elasticity sufficient for maintaining the axis of rotation for the wheel in substantial parallelism with the line of contact established between the surfaces of the wheel and track.

Abstract: A large volume multiple-path nuclear pumper laser which has improved characteristics over previous cylindrical nuclear pumped laser systems. Large volumes of gas are excited by using internal high reflectance mirrors that are arranged so that the optical path crosses back and forth through the excited gaseous medium. By adjusting the external dielectric mirrors of the laser, the number of paths through the laser cavity can be varied. Output powers have been obtained that are substantially higher than the output powers of previous nuclear laser systems.

Abstract: An aerial vehicle rotating in gyroscopic fashion about one of its axes having an optical system operative to scan an area below the vehicle in determined relation to vehicle rotation. A sensing device is provided to sense the physical condition of the area of scan and optical means are associated therewith to direct the physical intelligence received from the scan area to the sensing means. Means are provided to incrementally move the optical means through a series of steps to effect sequential line scan of the area being viewed keyed to the rotational rate of the vehicle.

Abstract: A method and apparatus for measuring Faraday rotation of a received rf signal. The disclosure describes a specific implementation of a simultaneous orthogonal polarization receiver which compensates for a 3 db loss due to splitting of a received signal into left circular and right circular polarization channels. The compensation is achieved by rf and modulation arraying utilizing a specific receiver array which also detects and measures Faraday rotation in the presence or absence of spin stabilization effects on a linear polarization vector. Either up-link or down-link measurement of Faraday rotation is possible utilizing the method and apparatus disclosed herein.

Abstract: Disclosed is a magnetically latching solenoid including a pull-in coil and a delatching coil. Each of the coils is constructed with a combination of wire materials, including material of low temperature coefficient of resistivity to enable the solenoid to be operated at cryogenic temperatures while maintaining sufficient coil resistance. An armature is spring-biased toward a first position, that may extend beyond the field of force of a permanent magnet. When voltage is temporarily applied across the pull-in magnet, the induced electromagnetic forces overcomes the spring force and pulls the armature to a second position within the field of the permanent magnet, which latches the armature in the pulled-in position. Application of voltage across the delatching coil induces electromagnetic force which at least partially temporarily nullifies the field of the permanent magnet at the armature, thereby delatching the armature and allowing the spring to move the armature to the first position.