Abstract: An optical power source is disclosed that collects the spectra of the light emissions created in a combustion chamber to provide its optical output signals that serve the needs of optical networks. The light spectra is collected by a collection ring serving as an optical waveguide.

Abstract: A method of growing atomically-flat surfaces and high-quality low-defect crystal films of polytypic compounds heteroepitaxially on polytypic compound substrates that are different than the crystal film. The method is particularly suited for the growth of 3C-SiC, 2H-AlN, and 2H-GaN on 6H-SiC.

Abstract: A coating-substrate combination having high specular reflectivity at high temperatures reaching 800.degree. C. in a vacuum is described. The substrate comprises pure nickel metal or a nickel-containing metal alloy such as stainless steel having a highly polished reflective surface. The coating is a layer of silver deposited on the substrate to a thickness of 300 .ANG. to 3000 .ANG.. A 300 .ANG. to 5000 .ANG. protective coating of silica, alumina or magnesium fluoride is used to cover the silver and to protect it from oxidation. The combination is useful as a parabolic shaped secondary concentrator for collecting solar radiation for generating power or thermal energy for satellite uses. The reflective layer and protective coating preferably are applied to the reflective surface of the substrate by electron beam evaporation or by ion sputtering.

Abstract: A system and a method for measuring three-dimensional velocities at a plurality of points in a fluid employing at least two cameras positioned approximately perpendicular to one another. The cameras are calibrated to accurately represent image coordinates in world coordinate system. The two-dimensional views of the cameras are recorded for image processing and centroid coordinate determination. Any overlapping particle clusters are decomposed into constituent centroids. The tracer particles are tracked on a two-dimensional basis and then stereo matched to obtain three-dimensional locations of the particles as a function of time so that velocities can be measured therefrom. The stereo imaging velocimetry technique of the present invention provides a full-field, quantitative, three-dimensional map of any optically transparent fluid which is seeded with tracer particles.

Abstract: A method and apparatus for cold gas reinjection in through-flow and reverse-flow wave rotors having a plurality of channels formed around a periphery thereof. A first port injects a supply of cool air into the channels. A second port allows the supply of cool air to exit the channels and flow to a combustor. A third port injects a supply of hot gas from the combustor into the channels. A fourth port allows the supply of hot gas to exit the channels and flow to a turbine. A diverting port and a reinjection port are connected to the second and third ports, respectively. The diverting port diverts a portion of the cool air exiting through the second port as reinjection air. The diverting port is fluidly connected to the reinjection port which reinjects the reinjection air back into the channels. The reinjection air evacuates the channels of the hot gas resident therein and cools the channel walls, a pair of end walls of the rotor, ducts communicating with the rotor and subsequent downstream components.

Abstract: A process for providing elemental metals or metal oxides distributed on a carbon substrate or self-supported utilizing graphite oxide as a precursor. The graphite oxide is exposed to one or more metal chlorides to form an intermediary product comprising carbon, metal, chloride, and oxygen. This intermediary product can be further processed by direct exposure to carbonate solutions to form a second intermediary product comprising carbon, metal carbonate, and oxygen. Either intermediary product may be further processed: a) in air to produce metal oxide; b) in an inert environment to produce metal oxide on carbon substrate; c) in a reducing environment to produce elemental metal distributed on carbon substrate. The product generally takes the shape of the carbon precursor.

Abstract: A self lubricating, friction and wear reducing composite material useful over a wide temperature range of from cryogenic temperature up to about 900.degree. C. contains 60-80 wt. % of particulate Cr.sub.2 O.sub.3, dispersed in a metal binder of a metal alloy containing Cr and at least 50 wt. % of Ni, Cr or a mixture of Ni and Cr. It also contains 5-20 wt. % of a fluoride of at least one Group I, Group II, or rare earth metal and, optionally, 5-20 wt. % of a low temperature lubricant metal. Such as Ag, Au, Pt, Pd, Rh and Cu. This composite exhibits less oxidation instability and less abrasiveness than composites containing chromium carbide, is readily applied using plasma spray and can be ground and polished with a silicon carbide abrasive.

Abstract: A fiber preform is partially infiltrated with a ceramic material.A porous solid polymer is formed by reaction forming the infiltrated preform which is then pyrolized. Microporous carbon in the composite matrix is converted into silicon carbide.

Abstract: A improved thermal barrier coating and method for producing and applying such is disclosed herein. The thermal barrier coating includes a high temperature substrate, a first bond coat layer applied to the substrate of MCrAlX, and a second bond coat layer of MCrAlX with particles of a particulate dispersed throughout the MCrAlX and the preferred particulate is Al.sub.2 O.sub.3. The particles of the particulate dispersed throughout the second bond coat layer preferably have a diameter of less then the height of the peaks of the second bond coat layer, or a diameter of less than 5 .mu.m. The method of producing the second bond coat layer may either include the steps of mechanical alloying of particles throughout the second bond coat layer, attrition milling the particles of the particulate throughout the second bond coat layer, or using electrophoresis to disperse the particles throughout the second bond coat layer.

Abstract: Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2 -trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

Abstract: A test system is disclosed that enables the testing of microwave components in a controlled environment without disturbing that environment. The system includes a test fixture which holds the calibration standards and the component being tested, and environmental control chamber, and a microwave switching system. The system provides a coaxial connection to microwave testing equipment, such as an automatic network analyzer (ANA) and facilitates both calibration and testing while maintaining environmental integrity.

Abstract: The present invention teaches a method of producing a textured surface upon an arbitrarily configured titanium or titanium alloy object for the purpose of improving bonding between the object and other materials such as polymer matrix composites and/or human bone for the direct in-growth of orthopaedic implants. The titanium or titanium alloy object is placed in an electrolytic cell having an ultrasonically agitated solution of sodium chloride therein whereby a pattern of uniform "pock mark" like pores or cavities are produced upon the object's surface. The process is very cost effective compared to other methods of producing rough surfaces on titanium and titanium, alloy components. The surface textures produced by the present invention are etched directly into the parent metal at discrete sites separated by areas unaffected by the etching process. Bonding materials to such surface textures on titanium or titanium alloy can thus support a shear load even if adhesion of the bonding material is poor.

Abstract: A detection method is integrated with a filtering method and an enhancement method to create a fluorescence sensor (10) that can be miniaturized. The fluorescence sensor (10) comprises a thin film geometry including a waveguide layer (16), a metal film layer (20) and sensor layer (32). The thin film geometry of the fluorescence sensor allows the detection of fluorescent radiation over a narrow wavelength interval. This enables wavelength discrimination and eliminates the detection of unwanted light from unknown or spurious sources.

Abstract: A coating for protecting titanium aluminide alloys, including the TiAl .gamma.+Ti.sub.3 Al (.alpha..sub.2) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000.degree. C. is disclosed. This protective coating consists essentially of titanium, aluminum, and chromium in the following approximate atomic ratio:Ti(41.5-34.5)Al(49-53)Cr(9.5-12.

Abstract: A system and method for reducing skin friction of an object in relative motion to a fluid. A skin forming a boundary between the object and the fluid, the skin having holes through which micro-blowing of air is blown and a transmitting mechanism for transmitting air through the skin. The skin has an inner layer and an outer layer, the inner layer being a low permeable porous sheet, the outer layer being a plate having high aspect ratio high porosity, and small holes. The system may further include a suction apparatus for suctioning air from the outer layer. The method includes the steps of transmitting air through the inner layer and passing the air transmitted through the inner layer to the outer layer. The method may further include the step of bleeding air off the outer layer using the suction apparatus.

Abstract: A diffusion barrier to help protect titanium aluminide alloys, including the coated alloys of the TiAl.gamma.+Ti.sub.3 Al (.alpha..sub.2) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000.degree. C. is disclosed. The coating may comprise FeCrAlX alloys. The diffusion barrier comprises titanium, aluminum, and iron in the following approximate atomic percent:Ti-(50-55)Al-(9-20)Fe.This alloy is also suitable as an oxidative or structural coating for such substrates.

Abstract: The invention as disclosed herein teaches apparatus whereby the instantaneous dynamic static pressure and the steady-state static pressure may be simultaneously measured within a supersonic or subsonic gaseous fluid flow field. The dynamic static pressure is measured by an electronic transducer and the steady-state static pressure is measured by pneumatic means.

Abstract: A system for supporting and selectively positioning an ion thruster (12) relative to a surface (14) of a spacecraft includes three angularly spaced thruster support assemblies (16, 17, 18). Each thruster support assembly includes a frame (20) which has a rotary actuator (42) mounted thereon. The rotary actuator is connected to an actuator member (36) which is rotatably connected to a thruster attachment member (19) connected to a body of the thruster. A stabilizer member (30) is rotatably mounted to the frame and to the thruster attachment member. The thruster is selectively movable in the pitch and yaw directions responsive to movement of the actuator members by the actuators on the thruster support assemblies. A failure of any one actuator on a thruster support assembly will generally still enable limited thruster positioning capability in two directions.

Abstract: The present invention is directed to an apparatus for manufacturing a free standing solid metal part. In the present invention metal droplets are ejected in a nozzleless fashion from a free surface pool of molten metal by applying focused acoustic radiation pressure. The acoustic radiation pressure is produced by high intensity acoustic tone bursts emitted from an acoustic source positioned at the bottom of the pool which directs the acoustic energy at the pool surface. The metal droplets are electrostatically charged so their trajectory can be controlled by electric fields that guide the droplets to predetermined points on a target. The droplets impinge upon the target and solidify with the target material. The accretion of the electrostatically directed solidified droplets forms the free standing metal part.

Abstract: A scanning mode sensor and method is provided for detection of flow inhomogeneities such as shock. The field of use of this invention is ground test control and engine control during supersonic flight.Prior art measuring techniques include interferometry, Schlieren, and shadowgraph techniques. These techniques, however, have problems with light dissipation.The present method and sensor utilizes a pencil beam of energy which is passed through a transparent aperture in a flow inlet in a time-sequential manner so as to alter the energy beam. The altered beam or its effects are processed and can be studied to reveal information about flow through the inlet which can in turn be used for engine control.