Abstract: A filament wound fiber reinforced resin matrix composite structure. The structure is particularly adapted for use as a torque drive diaphragm in a rotary wing aircraft hub. The structure comprises a substantially flat diaphragm and a rim. The diaphragm has a central hole therethrough for receiving a shaft and the rim has an inward turning flange for attachment. The diaphragm has an attachment means surrounding the central hole. An alternative embodiment of the structure is a hollow disc having first and second substantially flat diaphragm sides with a rim. The sides have concentric central holes therethrough and attachment means surrounding the holes. The structure comprises a resin matrix, fibers wound substantially tangentially to the central hole with sufficient tension in a multiple circuit pattern to form the structure, and fibers wound with sufficient tension in an essentially circumferential manner to reinforce the rim of the structure.

Abstract: A method for fabricating ribbed electrodes that accommodates the shrinkage which occurs during thermal cycling reducing the cracks caused by the confining stresses of a mold. A composition comprising a metal selected from the group consisting of nickel, copper and mixtures thereof with chromium onto a ribbed mold. The mold and composition are prefired in a reducing atmosphere forming a ribbed electrode. The ribbed electrode is removed from the mold and sintered in a reducing atmosphere.

Abstract: Apparatus for damping blade lead/lag motion on a hingeless helicopter rotor assembly, including a hub, blades and flexbeam(s) interposed between the root end of the blades and the hub. Rigid, radial links extend the length of the flexbeams for attachment to the outboard ends thereof. Lead/lag motion at the outboard end of the flexbeam causes flexbeam bending, which is converted to radial translation of the links. This radial translation of the links and likewise the blade lead/lag motion is damped by damper means connected between the inboard ends of the links and the hub.

Abstract: An electrochemical cell separator plate formed from a mixture of carbonizable resin and coke particles, wherein the plate is molded from the resin and coke particles, carbonized, and graphitized. The particle size distribution of the coke is selected so that expansion occurring during graphitization minimizes the rupture of carbonized bonds within the separator plate. The separator plates have improved properties over separator plates formed from graphite particles including increased density, decreased porosity and increased corrosion resistance. The coke particle plates are more energy efficient to manufacture than graphite particle plates.

Abstract: An apparatus for making composite sheets that are homogeneous, dense, and have an even surface. The apparatus comprises an oscillating plate unit that vibrates in a direction transverse to a belt means. Composite pre-mix is deposited on the conveyor belt which draws it under the oscillating plate. The oscillating plate has three sections: a curved plate section; an inclined plate section and a flat plate section. The composite pre-mix is metered by the curved plate section, compacted by the inclined plate section and maintained compacted by the flat plate section. These thus formed composite sheets may be cured and are particularly adapted for use in fuel cell structures such as electrode substrates.

Abstract: An apparatus, process and use for making hydrogen from a hydrocarbon feedstock and steam using heat stored in a vessel followed by the regeneration of the vessel to restore the heat. Regeneration is done by preheating within the vessel a hydrogen purge gas and regeneration combustion products recycle and mixing the preheated gases with an oxygen containing gas so that they combust within the vessel in a fuel rich mode and heat material disposed in the vessel. This is the heat which is used in converting the hydrocarbon feedstock to hydrogen. The regeneration combustion products are recycled (and substituted for the cooling capacity of the oxygen containing gas) to recover the heat remaining in the vessel following the hydrogen make cycle simplifying reactor bed design and improving operational flexibility. The process is applied to provide hydrogen to a fuel cell.

Abstract: Gas depolarized cathodes having hydrophobic barrier layers for circulation electrolyte electrochemical cells; methods of making said cathodes; and methods of electrolyzing solutions of halide containing compounds using said electrodes. Typically, in electrochemical cells cathodes are oriented vertically resulting in significant electrolyte pressure against the cathode. The barrier layer comprising fluorocarbon polymer and carbon results in substantially no electrolyte leakage through the cathode when the electrolyte pressure is up to three pounds per square inch above ambient.

Abstract: A low temperature processable moisture resistant polyimide and fiber reinforced composite of such a polymer and methods for making the same. The polyimide resin has repeating polymer units of the formula ##STR1## wherein n is 2 to about 20 and the molecular weight of the polymer chain is such that the polymer absorbs below about 0.2% by weight moisture at room temperature. The polyimide is made by reacting 4,4'(hexafluoroisopropylidene)bis(o-phthalic anhydride) with a diamine having the formula H.sub.2 N(CH.sub.2).sub.n NH.sub.2 wherein n is 2 to about 20 to form a polyamic acid. The polyamic acid is imidized to form the polyimide prepolymer and then further polymerized by exposing the polyimide prepolymer to heat to form the polymer described above. The composite can be made using the above process by coating fibers with the polyimide prepolymer, stacking layers of the coated fibers in a mold, and hot pressing the stacked impregnated fibers.

Abstract: A filament wound fiber reinforced resin matrix composite structure. The structure is particularly adapted for use as a torque drive diaphragm in a rotary wing aircraft hub. The structure comprises a substantially flat diaphragm, a rim, rim reinforcement fibers and at least one fiber reinforcement ring. The diaphragm has a central attachment means for receiving a shaft and the rim has an attachment means. An alternative embodiment of the structure is a hollow disc having first and second substantially flat diaphragm sides with a connecting rim, rim reinforcement fibers and at least one fiber reinforcing ring for each diaphragm side. The sides have centrally located attachment means.

Abstract: A low temperature processable, thermoplastic polyimide and methods for making and using the same. The polyimide has repeating polymer units of the formula ##STR1## wherein n is 2 to about 20 and the molecular weight of the polymer chain is about 5,000 to about 50,000. The polymer is made by reacting 4,4'-(hexafluoroisopropylidene)bis(o-phthalic anhydride) with a diamine having the formula H.sub.2 N(CH.sub.2).sub.n NH.sub.2 wherein n is 2 to about 20 to form a polyamic acid. The polyamic acid is imidized to form the polyimide described above. The polyimide is particularly adapted to use as a hot melt adhesive by placing it between two articles and applying heat and pressure.

Abstract: An amorphous hydrated metal oxide primer for adhesively bonded articles results in a bond resistant to crack propagation. A plurality of articles at least one of which is metal are bonded to one another through a layer of polymeric adhesive. The metal article has a layer of amorphous hydrated metal oxide formed by applying and subsequent hydrolysis of a layer of M.sub.x OR.sub.y. In the formula M.sub.x OR.sub.y, x is 1, y is 3 or 4, M is any metal capable of forming a stable alkoxide and R is an organic radical. The bonded joint is preferably made by applying to a surface of at least one metal article a layer of M.sub.x OR.sub.y wherein x is 1, y is 3 or 4, M is any metal capable of forming a stable alkoxide and R is an organic radical. The metal article having a layer of metal alkoxide is exposed to moisture and a temperature of about 25.degree. C. to about 125.degree. C. and adhesive is placed in contact with and between the metal article and other article.

Abstract: An improved mirror substrate, that is particularly adapted for use as a laser mirror, has significantly improved transverse strength and polishability and a method of making the same. The composite comprises graphite fibers coated with an oxidized silicon carbide layer. The coated fibers alternate with layers of glass to form a composite, preferably having a central plane of symmetry across its central plane.

Abstract: An apparatus for heating air wherein the combustion is dispersed in direct proximity to a metal hydride fuel storage means in order that the combustion heat effects the release of hydrogen from the metal hydride. The combustion area contains a catalyst and a semipermeable membrane separates the hydride fuel storage means and the combustion area. The temperature of the metal hydride is raised to effect initial release of hydrogen which passes through the semipermeable membrane, mixes with air and is combusted at the catalyst. The heat of combustion, in direct proximity to the metal hydride, perpetuates the hydrogen release.

Abstract: A method for determining the temperature of a fluid particularly adapted to the determination of droplet temperatures. A fluorescent monomer and a quencher are added to a fluid and the monomer is excited by directing an energy source of a proper wavelength at the fluid. The excited monomer then combines with the quencher to produce a fluorescent exciplex in the fluid. The temperature of the fluid is determined by detecting the fluorescence from the excited monomer and exciplex in the fluid. The ratio of fluorescence of these species provides data from which the temperature can be determined.

Abstract: A high speed method of producing continuous length magnet wire coated with a high solids content polymer coating composition. Copper or copper alloy wire segments are joined by brazing utilizing a braze whose melting point is greater than 1000.degree. F. and less than 1600.degree. F. The thus formed joint has a tensile strength greater than 27,000 p.s.i., and is capable of being conformed to the circumference of the wire substrate without substantially altering the surface integrity of the wire. The continuous length magnet wire is preheated to an elevated temperature. The preheated wire is coated with a noncirculating polymer enamel composition having a high solids content and a high viscosity at high speed. The enamel coated wire is then cured.

Abstract: A method for repairing a multilayer coating on a carbon-carbon composite having a CVD silicon nitride outercoating by applying a coating of CVD silicon nitride. It has been found that if a multilayer coating containing CVD silicon nitride on a carbon-carbon composite is broken the entire composite will fail to survive at elevated temperatures due to oxidation. However, the deposition of silicon nitride on such a composite will affect repair such that the newly coated composite will substantially resist oxidation at temperatures up to 1750.degree. C. and above. Preferably the coated composite is maintained at a temperature of about 1500.degree. C. and a gaseous mixture containing silicon tetrafluoride and anhydrous ammonia is passed over the composite at a partial pressure of the reactant gases less than about 10 millimeters mercury.

Abstract: Articles and method for containing molten nickel and methods for making the former. The material used is a high density silicon nitride that is very resistant to the corrosive properties of molten nickel alloys. The composition needed to produce such a containing article comprises polycrystalline silicon nitride containing (by weight) about 0.6% to about 8% alumina, about 15% yttria and about 2% to about 5% silica or amorphous silicon nitride containing about 2% to about 6% alumina, and about 15% yttria and about 2% to about 5% silica. The articles are formed by cold pressing and sintering methods. These articles are particularly useful in processes for molding and (RSR.TM.) spinning molten nickel alloys.

Abstract: Anodes having NiCo.sub.2 O.sub.4 catalyst used in the electrohydrodimerization of acrylonitrile to adiponitrile result in anode voltage requirements of less than about 2000 millivolts at 100 milliamperes per square centimeter of anode area. Typically, oxygen evolving anodes comprised of lead or carbon steel are utilized in the hydrodimerization of acrylonitrile to adiponitrile resulting in high voltage requirements. Anodes containing NiCo.sub.2 O.sub.4 catalyst require substantially reduced voltages and perform well in the conventional electrochemical adiponitrile production environment.

Abstract: Molten carbonate fuel cells having anodes, cathodes, and matrices of specific characteristics result in improved cell performance as electrolyte is lost due to evaporation, reaction, etc. The anode has a mean pore diameter less than that of the cathode, a porosity sufficient to contain enough electrolyte to provide for the electrolyte lost, and a ratio of maximum pore diameter at 90% electrolyte fill to maximum pore diameter at 10% electrolyte fill of less than about three. The cathode has a larger mean pore size than that of the anode, a thickness greater than about 0.050 cm, a porosity greater than about 78%, and pore-size distribution such that, when the anode electrolyte content changes from 90% to 10% fill, the cathode electrolyte content changes from about 40% to about 25% fill. In addition, the cathode has about 20% of its pore volumes in pores less than about 0.5.mu. resulting in a surface area of the cathode above about 1 m.sup.2 /g.

Abstract: An electrochemical cell separator plate formed from a composition of carbonizable resin, coke, and graphite particles, and methods of making and using the same. The separator plate has an improved balance of properties such as flexural modulus. The plates are formed by molding a composition of carbonizable resin, coke, and graphite particles, surface grinding the plate and then carbonizing and graphitizing the plate. The composition comprises about 40% to about 60% of carbonizable resin and about 60% to about 40% of a coke-graphite mixture. The coke-graphite mixture comprises about 30% to about 90% of coke particles and about 70% to about 10% of graphite particles. These separator plates may be used in, for example, fuel cells.