Abstract: A process for making a cast article from an aluminum alloy includes first casting an article from an alloy having the following composition, in weight percent: 1 Silicon (Si) 14.0-25.0 Copper (Cu) 5.5-8.0 Iron (Fe)   0-0.8 Magnesium (Mg) 0.5-1.5 Nickel (Ni) 0.05-1.2  Manganese (Mn)   0-1.0 Titanium (Ti) 0.05-1.2  Zirconium (Zr) 0.12-1.2  Vanadium (V) 0.05-1.2  Zinc (Zn)   0-0.9 Phosphorus (P) 0.001-0.

Abstract: High quality films, preimpregnated tape (prepegs) and composites have been fabricated from polyimide precursor “salt-like” solutions. These “salt-like” solutions have a low viscosity (5,000 to 10,000 cp) and a high solids content (50-65% by weight) and can be coated onto reinforcing fiber to produce prepegs with excellent tack and drape at 12-15% residual solvent (˜4-6% water from thermal imidization reaction). The processing of these types of prepegs significantly overcomes solvent removal problems and allows excellent fiber wet out. In addition, the physical characteristics of the polyimide precursor “salt-like” solutions permits processing into high-performance materials through the use of standard prepregging and composite fabrication equipment. The resultant composites are of high quality.

Abstract: The present invention is directed to a method and apparatus for producing a highly-textured surface on a copper substrate with only extremely small amounts of texture-inducing seeding or masking material. The texture-inducing seeding material is delivered to the copper substrate electrically switching the seeding material in and out of a circuit loop.

Abstract: The present invention provides a turbulence model that has been developed for blade-element helicopter simulation. This model uses an innovative temporal and geometrical distribution algorithm that preserves the statistical characteristics of the turbulence spectra over the rotor disc, while providing velocity components in real time to each of five blade-element stations along each of four blades, for a total of twenty blade-element stations. The simulator system includes a software implementation of flight dynamics that adheres to the guidelines for turbulence set forth in military specifications. One of the features of the present simulator system is that it applies simulated turbulence to the rotor blades of the helicopter, rather than to its center of gravity. The simulator system accurately models the rotor penetration into a gust field. It includes time correlation between the front and rear of the main rotor, as well as between the side forces felt at the center of gravity and at the tail rotor.

Abstract: A method for producing polymeric diacetylene thin films having desirable nonlinear optical characteristics has been achieved by producing amorphous diacetylene polymeric films by simultaneous polymerization of diacetylene monomers in solution and deposition of polymerized diacetylenes on to the surface of a transparent substrate through which ultraviolet light has been transmitted. These amorphous polydiacetylene films produced by photo-deposition from solution possess very high optical quality and exhibit large third-order nonlinear optical susceptibilities, such properties being suitable for nonlinear optical devices such as waveguides and integrated optics.

Abstract: A weld joint round tool. A heavy walled central mounting ring has a mounting plate joined thereto that forms the foundational structure to which all of the moving parts are anchored. Rounding/clamping is performed by twenty-four simultaneously activated shoes that are connected by linkage arms to a central actuator ring. The shoes are expanded or retracted by rotating the actuator ring, which in turn pushes or pulls on each linkage. The ring is rotated by an AC servo motor linked to a gear reducer, the output of which drives a stationary pinion gear to move a rack mounted on the actuator ring. The weld joint round tool is mounted on the end of a cantilevered mandrel structure, which is inserted into the cylinders to be welded. Once the tool is positioned at the joint between the two cylinders, the shoes are expanded to clamp the inner diameter of the two cylinders so that welding can take place.

Abstract: A space suit sizing device using a ball nut and screw drive mechanism to shorten and lengthen components of a space suit. The device includes a rotatable member having an outer race formed on an inner surface thereof, and a translatable member having an inner race formed on an outer surface thereof. A plurality of recirculating balls are located in a space defined by the inner and outer races. As the rotatable member is rotated by hand, the translatable member is caused to move in and out of the rotatable member. Since one component of the space suit is connected to the translatable member, the length of this component varies in accordance with the position of the translatable member.

Abstract: A silicon-base ceramic substrate is provided with a mullite coating by flame-spraying heated crystalline mullite powders onto a substrate that is preheated to a temperature in excess of 800.degree. C. The mullite immediately crystallizes as it solidifies.

Abstract: A composite solid electrolyte film for a lithium battery comprising a dispersion of small reinforcing particles such as alumina in a binder rein such as polyethylene oxide. The particles are coated with a compatible lithium salt such as lithium iodide and the alumina particles preferably have a size below 0.5 microns.

Abstract: An ambient temperature, high density, rechargeable lithium battery includes a Li.sub.x Mg.sub.2 Si anode which intercalates lithium to form a single crystalline phase when x is up to 1.0 and an amorphous phase when x is from 1 to 2.0. The electrode has good reversibility and mechanical strength after cycling.

Abstract: A microporous structure with layered interstitial surface treatments, and method and apparatus for preparation thereof. The structure is prepared by sequentially subjecting a uniformly surface-treated structure (10a) to atomic oxygen treatment to remove an outer layer (16) of surface treatment to a generally uniform depth, and then surface treating the so exposed layer with another surface treating agent. The atomic oxygen/surface treatment steps may optionally be repeated, each successive time to a lesser depth, to produce a microporous structure having multilayered surface treatments. The apparatus (200) employs at least one side arm (228) from a main atomic oxygen-containing chamber (202). The side arm (228) has characteristic relaxation times such that a uniform atomic oxygen dose rate is delivered to a specimen (239) positioned transversely in the side arm (228) spaced from the main gas chamber (202).

Abstract: This invention is a process for making a semi-interpenetrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide having the following repeating unit: ##STR1## Provided is an improved high temperature matrix resin which is capable of performing at 316.degree. C. in air for several hundreds of hours. This resin has significantly improved toughness and microcracking resistance, excellent processability and mechanical performance, and cost effectiveness.

Abstract: A liquid supply control is disclosed for a heat transfer system which transports heat by liquid-vapor phase change of a working fluid. An assembly (10) of monogroove heat pipe legs (15) can be operated automatically as either heat acquisition devices or heat discharge sources. The liquid channels (27) of the heat pipe legs (15) are connected to a reservoir (35) which is filled and drained by respective filling and draining valves (30, 32). Information from liquid level sensors (50, 51) on the reservoir (35) is combined (60) with temperature information (55) from the liquid heat exchanger (12) and temperature information (56) from the assembly vapor conduit (42) to regulate filling and draining of the reservoir (35), so that the reservoir (35) in turn serves the liquid supply/drain needs of the heat pipe legs (15), on demand, by passive capillary action (20, 28).

Abstract: A reusable earth-to-orbit vehicle 28 with an orbital stage 10 sized to fit into a payload bay equipped, earth-return-capable space vehicle 26 such as the United States Space Shuttle. The orbital stage 10 is equipped with a reusable rocket engine 13 capable of operation from the earth's surface to earth orbit. The orbital state 10 propels itself into earth orbit with the help of boosters 11 that separate and return to earth before orbit is reached. After delivering its payload 12, the orbital stage 10 is placed in the earth-return-capable space vehicle's payload bay 29 and returned to earth for reuse.

Abstract: Apparatus for measuring the relative stability of two signals is disclosed comprising means for mixing the two signals down to a beat note sine wave and for producing a beat note square wave whose upcrossings are the same as the sine wave. A source of reference frequency is supplied to a clock divider and interval counter to synchronize them and to generate a picket fence for providing a time reference grid of period shorter than the beat period. An interval counter is employed to make a preliminary measurement between successive upcrossings of the beat note square wave for providing an approximate time interval therebetween as a reference. The beat note square wave and the picket fence are then provided to the interval counter to provide an output consisting of the time difference between the upcrossing of each beat note square wave cycle and the next picket fence pulse such that the counter is ready for each upcrossing the dead time is avoided.

Abstract: A technique for producing thrust by generating a hybrid plume plasma exhaust is disclosed. A plasma flow is generated and introduced into a nozzle which features one or more inlets positioned to direct a flow of neutral gas about the interior of the nozzle. When such a neutral gas flow is combined with the plasma flow within the nozzle, a hybrid plume is constructed including a flow of hot plasma along the center of the nozzle surrounded by a generally annular flow of neutral gas, with an annular transition region between the pure plasma and the neutral gas. The temperature of the outer gas layer is below that of the pure plasma and generally separates the pure plasma from the interior surfaces of the nozzle. The neutral gas flow both insulates the nozzle walls from the high temperatures of the plasma flow and adds to the mass flow rate of the hybrid exhaust. The rate of flow of neutral gas into the interior of the nozzle may be selectively adjusted to control the thrust and specific impulse of the device.

Abstract: An aromatic condensation polyimide film that is approximately 90% transparent at 500 nm, useful for thermal protective coatings and the like and the process for preparing same are disclosed. An essential feature of the invention for achieving maximum optical transparency films requires utilizing recrystallized and/or sublimated specific aromatic diamines and dianhydride monomers and introducing bulky electron-withdrawing groups and separator groups into the polymer molecular structure. The incorporation of bulky electron-withdrawing groups in the diamine portion of the polymer structure serves to reduce the formation of inter-chain and intra-chain charge transfer complexes which normally cause large absorptions in the UV-visible range. Incorporation of separator atoms into either the diamine or dianhydride monomers serves to reduce the amount of conjugation and inter-and intra-chain electronic interactions and thereby lessen charge transfer complex formation.

Abstract: Sulfone-ester polymers containing pendent ethynyl groups and a direct and multi-step process for preparing same are disclosed. The multi-step process involves the conversion of a pendent bromo group to the ethynyl group while the direct route involves reacting hydroxy-terminated sulfone oligomer or polymers with a stoichiometric amount of 5-(4-ethynylphenoxy)isophthaloyl chloride. The 5-(4-ethynylphenoxy)isophthaloyl chloride and process for preparing same are also disclosed.

Abstract: A surface of an article adapted for relative motion with a fluid environment is finished by coating the surface with a fluid adhesive, covering the adhesive with a sheet of flexible film material under tension, and setting the adhesive while maintaining tension on the film material whereby the tensioned film material is bonded to the surface by the adhesive.

Abstract: Thermocouples of the present invention provide stability and performance reliability in systems involving high temperatures and vacuums by employing a bimetallic thermocouple sensor wherein each metal of the sensor is selected from a group of metals comprising molybdenum and iridium and alloys containing only those two metals. The molybdenum, iridium thermocouple sensor alloys provide bare metal thermocouple sensors having advantageous vapor pressure compatibilities and performance characteristics. The compatibility and physical characteristics of the thermocouple sensor alloys of the present invention result in improved emf, temperature properties and thermocouple hot junction performance. The thermocouples formed of the molybdenum, iridium alloys exhibit reliability and performance stability in systems involving high temperatures and vacuums and are adaptable to space propulsion and power systems and nuclear environments.