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 phenolformaldehyde, 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 foam absorber having electromagnetic energy attenuation characteristics comprising an open cell reticulated polyurethane foam impregnated with a conductive ink applied to a surface of the foam substrate. The conductive ink is applied as by spraying to a surface of the foam, coating such surface and gradiently loading the foam with the ink by penetration of the ink in gradually decreasing amount into the foam to a final depth therein. The conductive ink is comprised of an epoxy resin carrier and a combination of carbon and a metal such as silver, copper or nickel, preferably silver. The ink is applied as a curable mixture containing a solvent, to the foam substrate, the solvent is evaporated following coating and penetration of the ink into the foam, and the epoxy carrier of the ink in the foam substrate is cured.

Abstract: An integral structure and thermal protection system, particularly designed for hypersonic aerospace vehicles, is comprised of a hard external shell or outer face sheet formed of a ceramic matrix, such as silicon carbide, and a rigid insulator core in the form of foamed ceramic, such as silicon carbide, the outer face sheet being integrally connected to the insulator core. A prime strucutral material, such as an aircraft structural member, is integrally connected as by bonding or brazing to the insulator core, the core being attached to the prime structural material or aircraft structural member by an inner face sheet forming the outer skin of such structural member.

Abstract: A foam absorber having electromagnetic energy attenuation characteristics comprising an open cell reticulated polyurethane foam impregnated with a conductive ink applied to a surface of the foam substrate. The conductive ink is applied as by spraying to a surface of the foam, coating such surface and gradiently loading the foam with the ink by penetration of the ink in gradually decreasing amount into the foam to a final depth therein. The conductive ink is comprised of an epoxy resin carrier and a combination of carbon and a metal such as silver, copper or nickel, preferably silver. The ink is applied as a curable mixture containing a solvent, to the foam substrate, the solvent is evaporated following coating and penetration of the ink into the foam, and the epoxy carrier of the ink in the foam substrate is cured.

Abstract: Process for fabricating a superplastically formed trusscore structure from a pair of core elements each formed of a pair of metal sheets of a superplastic material, e.g. titanium. The sheets of each core element are welded together along pairs of closely spaced weld lines, one core element having an even number and the other core element an odd number of such pairs of parallel weld lines. A slot is provided between the weld lines of each pair of weld lines. The two core elements are placed together, with the pairs of weld lines of one core element displaced laterally, preferably midway between the pairs of weld lines of the other core element. Face sheets are applied in contact with the outer sheet of each of the core elements, and the periphery of the assembly is sealed as by welding. The resulting forming pack asssembly is placed in the cavity of a forming die.

Abstract: A cross-flow heat exchanger comprising according to a preferred embodiment a shell formed of two concentric cylinders providing an annular space. A number of tubes and baffles are arranged in the annular space such that one fluid flows through the tubes in a helical fashion in the annular space and the second heat exchange fluid flows in a counter helical path in such annular space across the tubes, constrained by the baffles in such annular space. In another embodiment cross-flow is also achieved using spirally shaped tubes and spirally shaped baffles.

Abstract: Process for making a panel structure by superplastic forming from a pair of face sheets disposed on opposite sides of a core sheet, the core sheet being bonded as by welding to the face sheets along a plurality of spaced weld areas, the core sheet and face sheets having superplastic characteristics, which comprises placing a restraining sheet of superplastic material in contact with one of the face sheets and subjecting the forming pack of the face sheets and core sheet, together with the restraining sheet, to superplastic forming in a die while applying a back pressure against the restraining sheet. The back pressure is lower than the internal pressure and maintains the restraining sheet in contact with the adjacent face sheet while maintaining the other face sheet in contact with a surface of the die.

Abstract: A crew protection system designed to isolate an aircraft crew and provide a means for safely evacuating an aircraft, particularly hypersonic vehicles, in emergency situations. The crew compartment is designed within the forebody of the main vehicle. The forebody is designed so as to separate cleanly from the main vehicle as by generation of a circumferential structural break, in the event of a catastrophic failure or explosion of the main vehicle fuel tank. In the event of such an uncommanded failure of the main tank and propellant combustion, resulting in the above noted structural failure, the resultant pressure impulse thrusts the forebody containing the crew compartment clear from the remainder of the vehicle. The provision of a system of baffles in the forebody between the crew compartment and the fuel tank, and the shape of the forebody and the materials used in its construction mitigate the effects of the blast pressure impulse on the crew.

Abstract: Process for producing a cap flange structure, particularly a sinewave I-beam structure comprises joining together a pair of metal sheets in a predetermined area spaced from the opposite outer edge portions of the sheets, and leaving the area between the adjacent sheets along the two opposite edge portions unattached. The joined together portion of the resulting assembly is formed into a sinewave configuration which forms the web of the I-beam structure. The unattached edge portions of the assembly of adjacent sheets is introduced into a die cavity and the die cavity is heated and a gas under pressure is inserted into the area between the sheets of the unattached edge portions, and expanding the sheets of the unattached edge portions into the shape of the die cavity against the wall of the cavity by an accordion expansion without any substantial stretching or thinning of the sheets, while simultaneously moving such sheets in the die cavity.

Abstract: In a heat exchanger system wherein a primary conditioning fluid is reactive with a fluid to be conditioned, a leak safe arrangement of concentric tubes disposed across the conditioned fluid flow path having the reactive primary fluid in a central duct surrounded by inert fluid in an outer duct so that single failure leak of primary conditioning fluid or inert fluid presents no risk of harmful reaction with conditioned fluid. The heat exchanger system is used in an air collection and enrichment system in a hypersmic vehicle propulsion system.

Abstract: An electrically conductive article comprising a dielectric substrate, such as a fabric, e.g., fiberglass fabric, and an electrically conductive inorganic nickel sulfide layer which is adherent to the substrate and has good electrical conductivity and stable electrical characteristics at high temperature. Such article is produced by contacting a porous dielectric substrate, such as fiberglass fabric, with an aqueous solution containing a soluble nickel salt, such as nickel sulfate, and a sulfur donor, such as sodium thiosulfate, drying the resulting wet substrate at ambient temperature, and heating the resulting substrate at elevated temperature of about 100.degree. C. to about 400.degree. C. to form an electrically conductive layer of nickel sulfide on the substrate.

Abstract: A reciprocating rotary tool driver is driven by a motive source which provides power to its tool through a splined shaft while the rotating tool is oscillated in a vertical mode by means of spur gear, worm gear, and crank means.

Abstract: A tank arrangement particularly adapted for processing parts in chemical milling operations, especially for circulation of water-base maskant fluid. The system includes a tank containing up-flow and down-flow draft tubes, each containing a low speed, high volumetric displacement impeller which minimizes shear stresses imparted on the maskant liquid. The up-flow tube provides circulation and establishes rapid surface flow velocities to prevent congealing of maskant liquid and the down-flow tube provides localized circulation and produces a fluid elevation change. A weir is provided at the top of each of the draft tubes, the use of which combined with the low speed impellers break up and disperse entrained air. The draft tubes include baffle plates suitably located to prevent the formation of vortices above, within and below the tubes. Adjustable fluid flow deflector plates are provided adjacent to the lower ends of the draft tubes to eliminate "dead spots" in the tank work zone.

Abstract: An electrically conductive article comprising a dielectric substrate, such as a fabric, e.g., fiberglass fabric, and an electrically conductive inorganic nickel sulfide layer which is adherent to the substrate and has good electrical conductivity and stable electrical characteristics at high temperature. Such article is produced by contacting a porous dielectric substrate, such as fiberglass fiber, with an aqueous solution containing a soluble nickel salt, such as nickel sulfate, and a sulfur donor, such as sodium thiosulfate, drying the resulting wet substrate at ambient temperature, and heating the resulting substrate at elevated temperature of about 100.degree. C. to about 400.degree. C. to form an electrically conductive layer of nickel sulfide on the substrate.

Abstract: A high speed aircraft fitted with a unitary, rotatable wing coupled to the craft's fuselage at a hollow turret or solid pivot pin, enabling it to operate with the wing in either of two ninety degree opposed positions.

Abstract: Semi-interpenetrating polymer networks having improved processibility and compatibility are prepared by combining a linear polymer comprised of a thermoplastic polyisoimide and a short chain thermosetting polymer in the form of a cross-linkable oligomer comprised of a thermosetting imide or isoimide oligomer containing unsaturated terminal groups, e.g., an acetylene-, a maleimide-, a nadimide- or a benzocyclobutene-terminated imide or isoimide oligomer. In the resulting blend at least one of the diamine and dianhydride moieties of the structural backbone unit of the polyisoimide and of the cross-linkable oligomer are the same, and preferably both of the components of the blend have the same structural backbone unit.

Abstract: A process for fabricating an electronic device on a non-conductive polymer substrate, particularly from the family of polyaniline, comprises applying a covalent doping agent, such as an R.sup.+ donor compound, where R is an organic group, e.g., methyl iodide, to a preselected portion of a base-type non-conductive polymer substrate containing carbon-nitrogen linkages, and converting such preselected portion of the polymer substrate to an electrically conductive polymer portion, by covalent linkage of the R groups of such donor compound, to nitrogen atoms of the non-conductive polymer substrate. Electronic devices, such as resistors, capacitors, inductors, printed circuits and the like, can be provided by the invention process, in the form of light-weight polymers containing no metal, and which are stable and wherein the conductive portions are non-diffusing.

Abstract: A primary load bearing structure particularly adapted for hypersonic aerospace vehicles utilizing a cryogenic liquid fuel, and comprised of a plurality of rigid load bearing, fluid passageways or tubes connected together in the form of a panel structure. Such panel structure and the passageways or the tubes thereof form the outside surface of the aerospace vehicle and are also positioned adjacent to or integral with a wall of the cryogenic liquid fuel tank. During flight, cryogenic liquid fuel is passed through the tubes to provide cooling for the external surface of the vehicle. When the aerospace vehicle is on the ground, the load bearing tubes can be evacuated to provide insulation for the cryogenic liquid fuel tank to thus prevent formation of frost and liquid air on the outside surface of the tank, as well as on the external surface of the aerospace vehicle and prevent heat transfer to the tank.

Abstract: A shoe holder particularly adapted for use in dyeing, cleaning or polishing shoes without touching the shoe, comprises a generally U-shaped flexible handle having a forward arcuate portion and a rear arcuate portion. A forwardly extending toe end is connected to the lower end of the forward arcuate portion for insertion into the toe of a shoe, and has a bent and rearwardly extending portion connected thereto. A tongue is also connected to the toe end and extends forwardly, both the tongue and bent rearwardly extending portions making contact with the inside of a shoe. The rear arcuate portion of the handle has connected to its lower end a heel end for insertion into the heel of a shoe, and terminating in an angled forwardly extending portion, for greater rigidity. The holder is in the form of an essentially unitary structure.

Abstract: Solution blending of (a) a conductive polymer containing carbon-nitrogen linkages, such as polyaniline, having an organic group or an inorganic group, e.g., derived from an anhydride or an aromatic multisulfonic acid, covalently linked to nitrogen atoms of the polymer and (b) a malemide, particularly a bismalemide, e.g., the bismaleimide prepared by reacting 1,3 bis (3 aminophenoxybenzene) with 2 units of maleic anhydride, or a bismaleimide terminated oligomer, in a suitable solvent. On removal of solvent and heating to cure the bismaleimide, a continuous phase blend of the conductive polymer and the bismaleimide is formed, having good electrical conductivity and strength. The solution blend can be applied as a coating on a substrate or can be processed to a powder which can be compressed into parts. The conductive blend can be melted and cured without the evolution of volatiles.