Abstract: The use of hydrocarbon fuels for cooling hypersonic aircraft and missile structures and engines is accomplished by passing fuel through cooling channels in the vehicle. A multicomponent hydrocarbon fuel having a pyrolyzing component which cracks in a supercritical temperature range (above 900.degree. F.) and thus absorbs heat is used in combination with a diluent fuel or fuel component which reduces the rate at which cracked hydrocarbons recombine in the cooling channels, thus causing coking which can clog cooling channels and also release heat to the structure to be cooled. The cracked fuel having absorbed heat and remaining in it's cracked state is in a condition to burn more quickly and energetically in the combustion chamber along with the hot diluent fuel, thus providing an efficient use of the heat absorbed in the cooling process and increasing the performance of the vehicle.

Abstract: A high-energy laser 10 comprising a ring of lesser-powered laser modules 12,14,16 from each of which an output is taken to be projected so that they all arrive in phase on a distant target. To phase-lock the outputs of all the serial laser modules, the path lengths (l) of the laser modules are made equal, the path length around the large loop which includes all the laser modules is made an integral multiple of the laser-module path length, and at least two different feedback loops are employed.

Abstract: A thermal insulation system comprising an insulator core formed of ceramic material and, an outer layer integrally connected on an inner surface to a first side of the insulator core, the outer layer comprising a woven material impregnated with a ceramic matrix. In one embodiment, a thermal insulation blanket is formed having a flexible insulator core formed of ceramic fibrous materials, an outer layer integrally connected to one side of the insulator core, and an inner layer connected to a second side of that core. The inner layer is formed of woven material. In a second embodiment, a thermal insulation tile is formed including a rigid insulator core formed of ceramic material and an outer layer integrally connected to an inner surface to a first side of insulator core. The outer layer comprises a woven ceramic material impregnated with a ceramic matrix.

Abstract: An attenuator of electromagnetic radiation, such as radar, is described wherein a single attenuator sheet in the nature of "spacecloth" is placed in front of a plurality of reflective layers wherein each of the reflective layers is tuned to reflect a narrow band of radiation of a selected frequency and transmit other frequencies; and each of the reflective layers is spaced from the attenuation layer at a distance of one-fourth of the wavelength of electromagnetic radiation to which it is tuned. In a preferred embodiment each of the reflective layers comprises elongated narrow conductive areas arranged in spaced apart columns and rows in a generally non-conductive area.

Abstract: A method for monitoring a surface is provided. Nonlinear second order surface spectroscopy is used to monitor the condition of a surface. Conditions such as corrosion, contamination and deposition may be monitored. According to the present invention, 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 present invention relates to a method and an apparatus for enhancing the optical image of information-containing symbols captured off highly reflective surfaces using a conventional optical touch camera. The method involves positioning the imaging assembly of the touch camera atop an information-containing coded symbol located on a component surface, positioning a diffuser element between the coded symbol and the imaging assembly, and moving the diffuser element into juxtaposition with the coded symbol before imaging the coded element.

Abstract: A method for ensuring complete penetration of a friction stir weld using a rotating pin friction stir welding tool comprising chamfering the bottom of the plates to be welded along the faying edges. Placing the plates on a back up plate. Inserting the pin friction stir welding tool into the plates to the depth of the chamfer and translating it along the faying surface to plasticize the material in the plates. The plasticized material will flow into the volume defined by of the chamfer at the bottom of the plates and the back up plate. A visual inspection will show if the weld penetrated fully through the plates if the chamfered volume is filled with material which flowed in while plasticized.

Abstract: The present invention is a method for identifying a Most-Probable-Point (MPP) in original space obviating the need for a probability transformation, for use in first order/second order reliability analysis. It comprises generating the linear approximation of a limit-state-function, g(x) about the median, mean point, or mode of random variables, x of g(x). g(x) is defined so that g(x)f0 denotes a failure set. The Most-Probable-Point-Locus (MPPL) of g.sub.1, MPPL.sub.1, is constructed by the steps of: i) identifying the mode of x; ii) identifying the MPP of g.sub.1 (x)=c, where c is an arbitrary constant, and iii) constructing said MPPL.sub.1 by connecting said mode of x from step i), above, and the MPPs corresponding to different c's from step ii), above. A quadratic search algorithm is to identify point MPP.sub.1, the intersection of MPPL.sub.1 and g(x)=0, based on the following convergence criteria: ##EQU1## The process is then stopped, unless the convergence criteria are not satisfied. g.sub.

Abstract: A rotatable member is positioned coaxial with a joint between a first element and a second element. The joint defines an angle to be measured. The rotatable member has coded information thereon. First and second sensing heads are attached to respective elements. Coded information is arranged on the rotatable member so as to periodically pass in readable proximity to the sensing heads once every revolution of the rotatable member. A decoding system is provided for each sensing head. Each decoding system includes threshold circuitry, a state machine, and a pulse generator for providing a timing strobe. A first timer uses a timing strobe from the first sensing head for continuously determining the average elapsed time for one complete revolution of the rotatable member. A second timer uses timing strobes from the first and second sensing heads to continuously determine the average elapsed time for the coded information on the rotatable member to travel from the first sensing head to the second head.

Abstract: The present invention is a method for enhancing reaction rates when digesting chemical systems which form passivating layers. Particles are introduced into a digestion fluid bath. Digestion is allowed to proceed until passivating layers of digestion products have partially formed on the particles. The layers constitute a diffusion barrier to the digestion fluid and reduce the digestion rate. The particles are periodically conveyed through an ultrasonic beam to remove portions of the passivating layers. Thus, fresh surfaces of the particles are exposed to the digestion fluid bath. The periodic conveyance is such that a desired rate of digestion is obtained.

Abstract: A pyrochemical process is utilized to recover 99% of the remaining transuranium materials from plutonium-uranium extraction waste. One step of the overall pyrochemical process involves the electrochemical separation of the waste components. A solid anode and a solid cathode are used in this electrochemical separation step to electrorefine in single or multiple steps. The solid anode and solid cathode are selected from certain preferred anodic and cathodic materials. Where multiple electrorefining steps are used to obtain more complete electroseparation, this is achieved by employing in the multiple electrorefining steps both a solid anode, suitably graphite, and a molten metal anode containing a mixture of the actinide and rare earth elements. This results in greater separation than can be realized through electroseparation by use of either anode alone.

Abstract: A tube nozzle having a thermal insulative barrier in it to prevent thermal fatigue cracks due to thermal transients in tube nozzles for all kinds of pipe joints that carry fluids with temperatures that change rapidly. This is particularly useful in mixing tees, where two different temperature fluids meet. The use of this invention could increase safety and reliability of processing streams in processing plants involving fluids maintained at various constant or fluctuating temperatures.

Abstract: A method for the densification of a shaped nickel base single crystal alloy article utilizing a pre-HIP, a hot isostatic pressing (HIP) step, and post-HIP solution heat treatment to enhance removal of casting porosity in a finished article.

Abstract: A temperature-responsive actuator for a sealing assembly comprises first and second annular members each having a camming surface for engagement with one another, the first and second annular members being positioned against each other so that they are nested and together exhibit a height "h" at ambient temperatures, the first annular member having a coefficient of thermal contraction less than the coefficient of thermal contraction of the second annular member so that when the thermal actuator is subjected to temperatures less than ambient temperatures, the first and second annular members contract different amounts such that the "effective" height of the actuator becomes "h+.tangle-solidup.h".

Abstract: Copper alloy rocket engine combustion chamber linings have been found to deteriorate when exposed to cyclic reducing/oxidizing (redox) environments which are a consequence of the combustion process. This deterioration, known as blanching, can be characterized by increased roughness and bum through sites in the wall of the combustion chamber lining and can seriously reduce the operational lifetime of the combustion chamber. The blanching problem can be significantly reduced by depositing a thin layer of Cu-30.sup.v /.sub.o Cr (a copper matrix with 30.+-.10 volume percent of chromium) on the inside wall of the combustion chamber. The microstructure of the Cu-30.sup.v /.sub.o Cr coating consists of finely distributed chromium (Cr) particles in a copper (Cu) matrix. When exposed to an oxidizing environment at high temperatures, the coating forms a protective chromium scale which is stable in hydrogen atmospheres (e.g., substantially unreduced by high pressure hydrogen). The Cu-30.sup.v /.sub.

Abstract: An engine power enhancement/pollution control system which utilizes a vortex air separator. The invention comprises a compressor for receiving air from the environment and providing high pressure air output. The high pressure air output is cooled to partially liquefied air having a mass fraction of less than 30% liquid. A vortex air separation apparatus is provided for separating the partially liquefied air into gaseous nitrogen enriched air and liquid oxygen enriched air. The oxygen enriched air is introduced to an internal combustion engine, thereby enhancing the power of the engine and minimizing pollution thereof.

Abstract: A liquid hydrogen-liquid oxygen (LH.sub.2 -LOX) rocket engine system wherein a conventional oxidizer turbo pump is replaced with a jet pump--a jet oxidizer pump. Beneficial features of the jet oxidizer pump system, over a conventional oxidizer turbo pump system, include: 1) it does not require a complicated seal system, 2) it has no moving parts, and 3) it is lighter. All these features improve the operational reliability of the rocket engine while decreasing its manufacturing cost.

Abstract: An anode wick for use with electrochemical fuel cells, in accordance with the invention, establishes a physical connection between a fuel cell's anode membrane surface and a liquid water reservoir. Wicking action substantially ensures the cell's anode surface is continually bathed in water. Two mechanical check valves are incorporated to effectively prevent mixing of gaseous hydrogen and oxygen gases in the event the fuel cell system's water tanks become over pressurized. This design can effectively eliminate the need for some of a conventional fuel cell system's pumps and/or compressors. Advantageously, the invention also reduces the overall weight and mechanical complexity of the fuel cell system, thereby improving system reliability.

Abstract: Penetration Enhancing Compounds for use in welding is characterized as comprising select alkali metals and alkali earth metals and halogens.

Abstract: A photon-counting spatial light modulator that has an avalanche photodiode structure and is designed to operate in Geiger mode is sensitive to a single photon of light. An avalanche photodiode having an applied electric field is excited by an optical wave comprising one or more photons whose energies exceed the band-gap energy of the photodiode material. This localized electrical excitation alters the refractive index of the material through various effects, most notably the transient thermo-optic effect and the photorefractive effect. A second optical wave is incident during or shortly after the electrical excitation, and comprises photons whose energy is less than or nearly equal to the band-gap energy. This second optical wave is then used to read out the avalanche-induced variation in refractive index.