Abstract: A method for monitoring a thin film of polyimide material on the surface of a liquid crystal display uses nonlinear second-order surface spectroscopy to monitor the condition of a surface. Electromagnetic radiation is directed towards the surface and the second harmonic or other second-order frequency responses are monitored to detect the state of the surface. Preferably, a laser, input optics and output optics are utilized to create the second-order frequency response that is detected.

Abstract: The invention is a process and apparatus for forming structural members from layers of uncured composite material. The apparatus comprises a first station having at least one tape dispensing module, a second station where tape layers that have been deposited on a tool are vacuum treated in order to remove air entrapped between layers of the tape, and a track system which enables movement of the tool between the first and second stations as well as a tool storage station. The process of building the structural members comprises dispensing tape from each of the modules at the first station onto a tool, then removing entrapped air from between layers of deposited tape, then dispensing further layers of tape, then removing entrapped air, etc., until the desired tape configuration has been achieved. Until such built-up structural member is cured, it is stored in racks in the tool storage station. A unique "partial ply" module is disclosed for applying tape segments to the side forming surfaces of the tool.

Abstract: A coating for sealing carbon--carbon composites against hydrogen. The coating comprises a first layer of silicon carbide and a second layer of a glass, glass-ceramic or a low-melting-point metal such as tin or an alloy thereof. Particularly when such second layer is a glass, e.g. an SiO.sub.2 -containing glass, or a glass-ceramic, preferably the silicon carbide coating is pretreated, e.g. by oxidation thereof to form a thin layer of SiO.sub.2 prior to application of the glass layer. The glass layer can be an SiO.sub.2 glass formed by sputtering or by decomposition of tetraethylorthosilicate (TEOS) applied to the oxidized silicon carbide coating. An alkali metal oxide, e.g. Na.sub.2 O, or an alkaline earth metal oxide, e.g. BaO, can be added to the SiO.sub.2 glass.

Abstract: APPARATUS AND METHOD FOR MULTIPLE PROCESSOR SOFTWARE DEVELOPMENT include a host computer 10, a control processor 12, and a bus 16 between them and one or more nodes 14. Each node 14 includes a master processor 22 and one or more slave processors 24, all of the processors 22, 24 sharing a memory 26. Multiple processor application software may be developed using the host computer 10 and control processor 12 by concurrently monitoring every processor 22, 24 of every node 14. Each master processor 22 is monitored directly through a master transmit/receive buffer 20 between it and the bus 16, and each slave processor 24 of each node 14 is monitored indirectly through a slave transmit/receive buffer 38 in the node's shared memory 26, the buffer 38 extending between that slave processor 24 and that node's master processor 22.

Abstract: The composite duct system includes a first, duct portion; a second, duct foam portion; and, a third duct portion. The first duct portion has a first surface for permitting a flowable medium to be conveyed adjacent thereto, and a second surface. The first duct portion is formed with a first fiber reinforced resin system. The second duct foam portion has a first surface bonded to the second surface of the first duct portion. The foam portion is formed of fire retarding material derived from a resin system. The third duct portion has a first surface bonded to a second surface of the foam portion. The third duct portion is formed of a second fiber reinforced resin system. Thus, a system is created having an internally sandwiched foam insulation.

Abstract: A nozzle for mixing of two reacting fluids wherein the first reactant, flowing across the nozzle, exhibits a variation in reactivity towards the second fluid, introduced through the nozzle and mixing and reacting with the first fluid within the nozzle, and wherein the nozzle is configured to permit this second fluid to be introduced in a way as to compensate for the variation in reactivity and to produce uniform reactant mixture from the two fluids.

Abstract: A housing is provided which is positionable adjacent a surface of a material to be treated. The housing and the surface of the material cooperate to form a reaction chamber. An exposure environment is provided having a plurality of components within the reaction chamber. A first component comprises charged particles. A second component comprises chemically active neutral particles. A third component comprises electromagnetic radiation. When the housing is so positioned adjacent a surface and the desired exposure environment is provided, the surface is altered as desired for cleaning, material removal or as preparation for adhesive bonding or etching.

Abstract: A fiber optical "T" coupler for sending and receiving signals on the same fiber optic element to facilitate ease of building and operating fiber optic communications networks. The fiber optical "T" coupler has three GRIN lenses, a receiving GRIN lens, a transmitting GRIN lens and a focusing GRIN lens, each having a focusing end and a collimating end. The transmitting GRIN lens' and the focusing GRIN lens' collimating ends are attached to and optically connected to the collimating end of the receiving GRIN lens. Fiber optic elements can be connected to the GRIN lenses focused ends for receiving signals to be collimated or for sending focused signals from the collimated end of the GRINs. Thus a light emitting transducer sends light to the transmitting GRIN lens and through the receiving GRIN lens to a fiber optic element. The same fiber optic element brings light to the receiving GRIN lens which is optically connected to the focusing GRIN lens which focuses the light on a light detecting transducer.

Abstract: A fiber optic coupler having a first lens element for inputting a point source of light from an optical cable and outputting a collimated light, optically coupled to one or more lens elements for receiving an input of collimated light from the first lens element and outputting a focused point of light into a fiber optic cable. The lens elements can be gradient index lens. The lens elements can be of varying sizes such that the first lens element can optically connect to one or more smaller lens elements to couple or split optical signals for two way communication on the optical cables.

Abstract: An estimate of amplitude of a sinusoidal signal is computed from a value of the signal by computing the value of a quadrature-phase signal and computing the amplitude based on the value of the signal and the value of the quadrature-phase signal. The quadrature-phase signal is computed, for example, by a Hilbert transform. The amplitude is approximated as the sum of the magnitude of one value and an even polynomial of the other value when the magnitude of the other value is relatively small. The amplitude is computed precisely by an iterative application of the approximation. In an automatic gain control, for example, the desired value is substituted for the actual amplitude in the iterative formula, to compute an error estimate that always has the same sign as the actual error. Therefore, the automatic gain control converges to set the amplitude of the sinusoidal signal to the desired value.

Abstract: A method is provided for hypersonic laminar flow control which uses the effect of boundary layer stabilization by an ultrasonically transparent coating. A hypersonic body surface is covered by the coating which absorbs the flow disturbance energy and does not trip the boundary layer flow. In one embodiment, the coating is made from a porous material of regular structure containing cylindrical blind microholes normal to the body surface. In another embodiment, the porous material has random distributions of pore shape and orientation. Extraction of the flow disturbance energy by pores causes stabilization of the boundary layer on the coated surface and leads to laminar-turbulent transition delay. The method can be used to decrease the aerodynamic drag of hypersonic vehicles and reduce heat transfer on vehicle surfaces.

Abstract: A Fourier transform interferometer for rapid scanning of scenes such as explosions wherein an incoming beam of light to be analyzed is split by a beam splitter into a first portion and a second portion. The first portion of the incoming light is sent down one arm of the interferometer where it passes through a rotating scanning cube for changing the path length in that arm of the interferometer. The light is then reflected by a retro mirror and sent back through the scanning cube to the beam splitter for sending a portion of the returning beam to a detector. The second portion of the incoming light is sent down a second arm of the interferometer where it passes through a compensator. The light is then reflected by a retro mirror and sent back through the compensator to the beam splitter for sending a portion of the returning beam to a detector. The first and second portions of the incoming light having differing path lengths interfere and the detector measures the fringes created.

Abstract: This invention relates to modulating light transmitted in an optic fiber. A passive light modulating device such as a polarizing material, a filter, or an attenuator is placed between two facing collimated ends of GRIN lenses attached to two optic fibers. The passive light modulating device modulates the light in the desired manner as it is transmitted between the two optic fibers. An active light modulating device such as a switch or an amplifier may also be used between the two GRIN lenses to actively modify the transmitted light.

Abstract: A concentrating solar array consisting of a roll of reflective film which is stretched between tension wires strung between a pair of wire stays. There is a roll of film and a take up roll such that the film can be unrolled from the storage roll and pulled toward the take-up roll to replace degraded film. A pair of extension arms holds a solar cell at a fixed position relative to the solar concentrator film surface to receive concentrated sunlight. The roll of reflective film ensures the life requirements of the solar concentrator can be met in space, by replacing exposed concentrator film as it degrades.

Abstract: A process is provided for protecting, containing, and/or completing fragile microelectronic and microelectromechanical (MEM) structures on a low conductivity substrate during anodic wafer bonding of a covering wafer. The wafer includes raised areas that contact the substrate at selected bonding regions to support the wafer as a covering structure over the substrate. The covering wafer includes additional raised areas, such as pillars or posts, that contact selected electric circuit lines on the substrate to form temporary shorts through the wafer. During anodic bonding of the wafer to the substrate, the temporary shorts maintain the connected circuit lines and microstructures at nearly the same electric potential to prevent unwanted arcing and electrostatic forces that could damage the fragile structures. The pillars or posts can be formed at the same time as the raised bonding areas, but on unwanted and otherwise unused portions of the covering wafer.

Abstract: This invention provides a molten salt, solar central smooth tube receiver that is able to effectively absorb a peak solar flux of 1.42 MW/M.sup.2 by constructing the receiver from low cycle fatigue 625 alloy. Although higher flux levels are attainable for a smooth tube receiver by reducing the tube diameter to increase the salt's heat transfer coefficient, the receiver's size is optimized at this flux level to minimize capital and performance costs. Analogously, material provides substantial performance and capital cost improvements for receivers constructed with internally enhanced film coefficient tubes. The receiver's cost is minimized by utilizing autogenously welded and drawn tubing with the weld located at the tube's neutral axis to provide minimal strain at the weld.

Abstract: Leakage of propellants such as oxygen and hydrogen in an enclosed environment in the atmosphere can lead to fires or explosions. For storage tanks on reusable launch vehicles such as the space shuttle where propellant is to be stored in the cargo bay of the vehicle, the storage tank should be filled while the vehicle is at a safe altitude to avoid the dangers associated with propellant leakage. The invention a process for filling propellant tanks at safe altitudes where if there is propellant leakage ignition will not occur. The process involves launching the vehicle with an inert gas in the storage tanks, dumping the inert gas and filling the tanks in the cargo bay from the main propellant tanks during the launch once the vehicle is at a safe altitude. The propellant can be dumped overboard and the storage tanks filled with an inert gas in case of a mission abort if the vehicle needs to make an emergency landing.

Abstract: The flight vehicle includes an elongated central body having a central axis defined therein and a circumference. A plurality of elongated portions are positioned about the central body. A plurality of airbreathing engines are axisymetrically positioned about the central axis of the central body and between the respective elongated portions. Each flowpath includes a forebody, an inlet, an isolator duct, a combustor, a nozzle, and a mechanism for injecting fuel into the combustor. The forebody externally compresses the air flow. The inlet is downstream of the forebody to capture air flow. The isolator duct is downstream of the inlet to further reduce velocity of the air flow. The combustor is downstream of the isolator duct and finally, the nozzle is downstream of the combustor. The fuel/air mixture is burned in the combustor and expanded in the nozzle for providing thrust. A control mechanism is positioned about the central body for providing control of the flight vehicle.

Abstract: This invention reduces a molten salt, solar central receiver's size, pressure loss and cost by using a loose-tight-loose twist, twisted-tape insert inside the receiver's tubes to enhance the tube's heat transfer coefficient. This twist staging is designed to provide a higher heat transfer coefficient in the receiver's central region where the solar flux is high and a reduced pressure loss at the low solar flux entrance and exit end regions. Because the twisted-tape enhances the tube's heat transfer ability it can be made larger in diameter than a smooth bore tube at an equivalent pressure loss. This reduces the number of tubes which results in a substantial reduction in receiver cost.

Abstract: The invention is a process for simultaneously improving at least two mechanical properties of mill-processed (.alpha.+.beta.) titanium alloy, which may or may not contain silicon, which includes steps of heat treating the mill-processed titanium alloy such that the (.alpha.+.beta.) microstructure of said alloy is transformed into an (.alpha.+.alpha..sub.2 +.beta.) microstructure, preferably containing no silicides. The heat treating steps involve subjecting the mill-processed titanium alloy to a sequence of thermomechanical process steps, and the mechanical properties which are simultaneously improved include (a) tensile strength at room, cryogenic, and elevated temperatures; (b) fracture toughness; (c) creep resistance; (d) elastic stiffness; (e) thermal stability; (f) hydrogen embrittlement resistance; (g) fatigue; and (h) cryogenic temperature embrittlement resistance. As a consequence of the process, the (.alpha.+.alpha..sub.2 +.beta.) microstructure contains equiaxed alpha phase strengthened with .alpha.