Abstract: A method for stabilizing shelf life conductivity of conductive coatings such as polypyrrole or nickel sulfide on a substrate such as fiberglass, by incorporating in such conductive coating a polyphenol or a polysiloxane. The polyphenol is derived from a phenolic material in the form of a phenol-formaldehyde monomer or an oligomer of phenol-formaldehyde, and the polysiloxane is derived from a siloxane. Upon heating, the phenolic material cures to a polyphenol and the siloxane is converted to a polysiloxane, forming the stabilizing material on the conductive polypyrrole or nickel sulfide coated substrate. The phenolic material is preferably incorporated directly into the solution formulation for preparing the conductive nickel sulfide or polypyrrole on the substrate, and the polyphenol stabilizer is formed together with the conductive coating on the substrate by heating.

Abstract: A chemiluminescent dye penetrant composition is provided for detecting cracks and other defects in the surface of an object, which comprises a carrier, preferably in the form of a nonionic surfactant, a small amount of a fluorescent dye soluble in the surfactant and a minor amount of hydrogen peroxide. The dye penetrant is applied to the surface of the object and excess dye penetrant is removed therefrom. An oxalate ester or oxalate amide is then applied to the treated surface and reacts with the dye penetrant in the cracks and defects to luminesce, and produces self illuminated penetrant indications at the location of the cracks and defects. Oxalate esters such as bis(2,4,6 trichlorophenyl) oxalate are preferred. The oxalate ester or oxalate amide can be mixed with inert conventional developer materials such as talc or fumed silica.

Abstract: Aerodynamic boundary layer control apparatus comprising a panel assembly having one surface for immersion in an ambient fluid flow and provided with perforations, a first array of fluid transporting channels fluidly coupled with various ones of the perforations, a second array of fluid transporting channels overlapping the first array of channels, and a suction-generating apparatus fluidly coupled with the second array of channels. An opposing surface of the panel assembly has a contour congruent with that of the aircraft wing or body structure to which it is to be removably attached. The suction-generating apparatus applies a suction force to the second array of channels to draw the ambient fluid into the first array of channels to enable conformace of the fluid with the one surface.

Abstract: An apparatus and method using a neural network processor for target detection is described. An array of injection mode infrared detectors, whose output signals convey intensity change information of detected objects in a pulse train output form is combined with a frequency division multiplexer to apply the information to a minimum number of multiplexed channels, and transmit the detector output signals to the processor in a continuous mode. A multi-layer neural network processor is used to localize global information and concentrate on areas of interest through matrix transformation applied by the various neural layers.

Abstract: An apparatus and a method for measuring the temperature of a reactive metallic workpiece sealed within a retort prior to and during diffusion bonding of the workpiece. The apparatus includes temperature measuring instruments disposed adjacent preselected portions of the workpiece within the retort, thermal conducting means connecting the instruments with display devices located outside the retort, conduits coupled with the interior of the retort and with the display devices, each of the conduits including a first end portion communicating the interior of the retort with vacuum generating means and a second end portion including at least one tubular region through which the thermal conducting means pass to connect with the display devices, and means for sealing the first and second end portions to maintain an evacuated state within the retort after a vacuum is applied thereto.

Abstract: A composite fastener, preferably in the form of a rivet, which comprises a shank having a first head integrally formed on one end thereof, the shank and head formed of a high temperature thermoplastic matrix material selected from the group consisting of a polyether ether ketone resin and a polyamide imide resin, and having continuous reinforcing fibers, such as graphite fibers, axially oriented in substantially parallel relation throughout the shank, the fibers being flared and extending continuously into the head and substantially evenly flared and swaged therein, thereby forming a fastener having high shear and high tensile characteristics.

Abstract: A method and composition facilitating the inspection of structural surfaces, such as fuel tank walls, to identify or locate cracks, flaws and other defects. The composition is a system of materials including a dye-containing penetrant material and a chemiluminescent material which reacts with the dye in the penetrant material. The method involves application of the two materials sequentially such that they react chemically to produce light which is visible to the naked, unaided eye, thereby eliminating the need for electrically-powered or "hot" light.

Abstract: A method and apparatus for traveling wave attenuation measurement in the UHF and VHF frequency bands. The test set up comprises a ramp structure located in the quiet zone of a parallel plate set up. The RAM specimen to be tested is attached to the top ramp surface starting at the highest point of the ramp. The time domain signal is gated to reject all scattering except the contribution from the ramp surface. The inverse Fourier transform of the gated time data results in the frequency response of the ramp. The RCS from ramp with RAM material attached is normalized to that of the perfectly conducting surface to provide a relative attenuation of the surface traveling wave.

Abstract: A process is disclosed for fabricating a metal aluminide composite which comprises providing a metal aluminide, such as titanium aluminide, or a titanium aluminide alloy, and a reinforcing fiber material, such as silicon carbide fiber, and placing an interlayer or diffusion barrier layer in the form of a metal selected from the group consisting of silver, copper and gold, and alloys thereof, between the metal aluminide and the reinforcing fiber material. The interlayer metal can be a foil of the metal or in the form of a coating, such as a silver coating, on the reinforcing fiber material. The metal aluminide, the reinforcing fiber material, and the metal interlayer, e.g., in the form of a packet of a plurality of alternate layers of metal aluminide alloy and reinforcing fiber material, each layer being separated by the metal interlayer, is pressed and heated at an elevated temperature, e.g., ranging from about 900.degree. to about 1200.degree. C., at which diffusion bonding occurs.

Abstract: A digital preprocessor anti-aliasing filter system for digitally processing input data from a sensor and feeding this processed input data to a primary processor. An analog-to-digital converter is provided for sampling analog input data and converting this input data to digital signals. At least one data processing filter module is provided for receiving the digital signals and processing these signals to filter out selected undesirable frequencies and odd multiples of these frequencies. The filtered output from the filter module is at a sample rate which is substantially an integer multiple of the primary processor sample rate. Therefore, extreme attenuation is provided at these selected undesirable frequencies.

Abstract: A rocket deceleration system for a spacecraft, comprises a first set of active canted rockets for attenuating a horizontal velocity of the spacecraft and a portion of the vertical velocity thereof. A second set of active canted rockets attenuate the remainder of the vertical velocity. A third set of available canted rockets attenuate a wide range of horizontal velocities, regardless of the vehicle roll position about its vertical axis. The first set, second set and third set of rockets form a ring and combine to form a total number of rockets being divisible by the numeral 6. Each rocket is 180.degree. from an opposing rocket on the other side of the ring. A programmable controller identifies rockets to be fired to attenuate horizontal and vertical spacecraft velocities.

Abstract: A method and apparatus for establishing discrete zones of pressure at the surface of a perforated panel of the type typically used for laminar fluid flow control includes a first array of channel members fluidly communicating with perforations in the panel, all of the channel members in the first array extending in a first direction and being substantially parallel to one another, and a second array of channel members fluidly communicating with the fluid in the first array of channel members, all of the channel members in the second array extending in a second direction and being substantially parallel to one another, where the first and second arrays of channel members being disposed in crossing relationship with a source of pressure being applied to the second array of channel members. By this arrangement, control of fluid flow in at least one of the first and second arrays results in discrete zones of pressure at the surface of the panel.

Abstract: A computer program is disclosed for specifying and solving a fluid transfer problem. Schematic manager means are provided for generating and modifying a pictorial representation of a fluid system schematic having a plurality of components. The schematic manager means Is fluid and process independent. Replicator means are provided for generating a set of simultaneous equations from the pictorial representation and for assuring that the schematic manager remains fluid and process independent. A generic run-time simulation module is provided for solving the set of simultaneous equations, thereby allowing the computer program to adapt to variations in component state and fluid state as a function of system parameters. A fluid and property database manager is invoked by the simulation module, for allowing simulation of fluid flow processes having fluid states which may be unknown at the time of model creation.

Abstract: Circulation of temperature controlled fluid through cavities in structure stiffening members of hypersonic aerospace vehicles precludes destructive temperature gradients in such members and preserves stress residuals for functional requirements.

Abstract: A novel method for sealing the end of tubing connected to and extending from a container housing workpieces to be thermally processed using mechanical as well as thermal means. The invention also contemplates a novel tubing member for connection to such a container, where the sealing material is disposed within the tubing member prior to insertion of the tubing into the container. After fixing the tubing in the container, a plurality of locations along the length of the tubing are identified where mechanical closure of the tubing is effected. Then, the tubing is heated to a temperature sufficiently high to melt the contained sealing material at the crushed locations, such that a metallurgical seal is formed inside the tubing at the crushed locations.

Abstract: A self-powered, mobile maintenance apparatus for continuously supplying slush hydrogen as a powering fuel to an aerospace vehicle prior to take-off including a first apparatus for obtaining liquid hydrogen from the vehicle, a second apparatus for generating slush hydrogen, a third apparatus for delivering the liquid hydrogen obtained from the vehicle to the second apparatus for generating slush hydrogen so that the liquid hydrogen can be converted to slush hydrogen, pump apparatus communicating with the second apparatus generating slush hydrogen for developing a vacuum in a region of the second apparatus for generating slush hydrogen so that a solid hydrogen fraction is produced, and apparatus for delivering the slush hydrogen mixture to the aerospace vehicle to be used as the powering fuel.

Abstract: A liner for a primary vessel comprises a plurality of attached, corrugated continuous sheets of membrane-type material. Each sheet has a herringbone pattern of repetitive parallelogram-like elements. Each parallelogram-like element is bounded at its four sides by bends to adjacent parallelogram-like elements, each sheet having minimally developed corrugations. The continuous sheets are therefore supportable by bearing walls of the primary vessel and may follow any deflections of these walls under conditions of structural stress and thermal deformation.

Abstract: A method and apparatus for irrigating perforations in the surface of a perforated material during surface treatment operations. The apparatus includes a three-layer substrate of predetermined length including a first fluid-interactive layer, a second resilient layer, and a third rigidifying layer. In the method, the substrate is placed beneath the perforated surface to be treated with the perforated material overlying the first layer. Thereafter, the surface treatment tool is used to apply and remove pressure to and from the surface during performance of the surface treatment operation. In this way, as the surface is treated, fluid applied to the surface during the operation is caused to pass back and forth to and from the first layer and through the perforations to irrigate the perforations and thereby keep them from becoming clogged.

Abstract: A test coupon for metal matrix composites is provided with means for structurally isolating the reinforcing fibers in the gage section from the reinforcing fibers in the clamped end regions of the coupon, when the latter is subjected to creep testing, so that the results of creep testing can be more accurately indicative of the creep properties associated with the fiber-reinforced metal matrix composite material in the coupon gage section. More particularly, the test coupon of the invention is provided with a plurality of slots or cut-out regions disposed in a section located between the clamped end regions and the centrally located gage section. The plurality of slots, which can be provided in longitudinally and/or laterally staggered arrays, effectively causes structural isolation of the reinforcing fibers in the gage section from the clamped reinforcing fibers located in the end regions of the coupon.

Abstract: A method and apparatus for effecting superplastic forming of metal workpieces at temperatures greater than 1000.degree. C., wherein both oxidation and creep deformation of the tooling are minimized. The process is achieved by heating forming surfaces of ceramic forming dies to temperatures in excess of 1000.degree. C., and using metal housings to impart high loading conditions to seal the workpiece within a chamber for superplastic forming. More specifically, the metal housings are used not only for load bearing purposes, but also for creating an evacuated chamber within which superplastic forming can take place. The ceramic dies, on the other hand, are positioned on opposing sides of the workpiece region to be superplastically formed, and are insulated from, while being contained within, the metallic dies.