Abstract: Disclosed is a method of fabricating a semiconductor on insulator composite substrate comprised of a semiconductor layer adjacent an insulator substrate, the defect density profile of the semiconductor layer being low and relatively uniform, a relatively thin region of the semiconductor layer at the semiconductor/insulator interface having a substantially greater defect density. The method comprises the steps of depositing the semiconductor layer adjacent the insulator substrate, amorphizing a buried portion of the semiconductor layer without damaging the insulator substrate such as to release contaminants into the semiconductor layer, recrystallizing the amorphous portion of the semiconductor or layer, removing a portion of the semiconductor layer so as to expose the recrystallized layer, and depositing an additional semiconductor layer on the recrystallized layer to provide an essentially defect free semiconductor layer of any desired thickness.

Abstract: The Array Processor of the present invention is comprised of a plurality of modular Elemental Processors, the modules being of a number of different functional types. These modules are associated so that the Elemental Processors are architecturally parallel to one another. The principal flow of data within the Array Processor, based on the simultaneous transfer of data words within the Elemental Processors, is thereby correspondingly parallel. The modules are also architecturally associated as functional planes that lie transverse to the Elemental Processors. Each functional plane is thereby comprised of an array of modules that are each otherwise associated with a separate Elemental Processor. Further, the modules of a given functional plane are of a single functional type. This allows the data of a two-dimensionally structured data set, present within the Array Processor, to be processed identically and in parallel by a common logical operation as provided and performed by a functional plane.

Abstract: Apparatus for calibrating and testing infrared detection devices is provided. The apparatus comprises a substrate which supports a target pattern of dielectric material which is at least partially absorbing to infrared radiation. A heater is used to supply heat to the substrate. Since the substrate and dielectric material have different emissivities, an apparent temperature difference is perceived by an IR detection device. As a consequence, temperature differences as low as about 0.02.degree. C. and below can be generated for calibrating and testing IR imaging devices.

Abstract: The rate of temperature change of an infrared detector produced by a cooling source in a typical Joule-Thomson cryostat (or other cooling device such as closed cycle cooler) is reduced by interposing a thermal filter between the detector and cooling source. The thermal filter comprises at least two layers of a first material having a good heat conductivity and high heat capacity, such as copper, separated by a layer of a second material having a high thermal resistance, such as an adhesive, e.g., a silicone rubber. The thermal filter of the invention is a thermal analog of an electrical filter which smooths out voltage or current oscillations.

Abstract: A semiconductive substrate, such as a silicon wafer, is mounted on a baseplate for inclusion in an optical device such as a liquid crystal light valve. An optical flat presses the top surface of silicon wafer toward the baseplate and against an O-ring seal surrounding a fluid adhesive. The fluid adhesive hydrostatically distributes the force of compression to guarantee optical flatness and self-compensation for the amount fluid adhesive surrounded by the O-ring. The optical flatness of the semiconductor substrate is limited only by the flatness of the optical flat against which it is compressed. Parallel alignment of the optical flat, the substrate and the baseplate is achieved by reflecting a laser beam through the semiconductive substrate and observing the interference fringes therein, while adjusting the relative alignment so as to maximize the distance between fringes.

Abstract: The present invention provides a circuit comprising (1) a logic element responsive to data of first and second negative voltage potentials, the logic element having a depletion mode MESFET data input gate, and (2) a depletion mode MESFET transmission gate operatively associated with the data input gate for enabling the selective serial transmission of data therethrough to the logic element in response to clock signals of third and fourth negative voltage potentials, the pinch-off threshold voltage of the data input gate being between approximately the first and second negative voltage potentials, the pinch-off threshold voltage of the transmission gate being between approximately the third and fourth negative voltage potentials, said third negative voltage potential being approximately equal to or more negative than said second negative voltage potential, said first negative voltage potential being more positive than said second negative voltage potential, and said fourth negative voltage potential being more

Abstract: A novel ethynylation process is disclosed which provides an expanded series of novel ethylnyl-terminated aromatic compounds having base sensitive substituents and which facilitates the economic preparation of prior art ethynyl-substituted aromatic compounds.

Abstract: Beam deflection apparatus 50 has first and second conductors 64 and 68 positioned transversely in the path of beam 67 and has a resistive connector 78 to be tuned to deflection amplifier 52 and transmission line 54 to provide magnetic deflection. Capacitive plates 74 and 76 are charged by the deflection current to provide substantially equal electrostatic deflection in the same direction.

Abstract: Apparatus for providing an amplified, phase-conjugated output beam. A nonlinear medium, gain medium, and output device are disposed along an optical path to form a ring resonator. An external laser source provides laser light to one end of the nonlinear medium which induces stimulated Brillouin scattering in the medium. Light provided by the gain medium at a first predetermined frequency is reflected from the acoustic waves traversing the nonlinear medium at a second predetermined frequency. The reflected light traverses the optical path through the gain medium and impinges upon the other end of the nonlinear medium, where it is further reflected from the acoustic waves. This reflected light is frequency shifted to the original predetermined frequency. A portion of the light at the predetermined frequency is coupled out of the resonator as an amplified phase-conjugated output beam by means of the output device. Alternatively, output beams at both the first and second predetermined frequencies may be provided.

Abstract: A process is provided for forming the native oxide on a semiconductor surface comprising Hg.sub.1-x Cd.sub.x Te, where x ranges from 0 to 1. The process comprises exposing the semiconductor surfce to a mixture of ozone and oxygen containing an effective amount of ozone sufficient to form a native oxide thereon. The desired amount of ozone is conveniently obtained by passing oxygen from a source through an ozone generator provided with a source of high voltage.

Abstract: A method is provided for accelerating and improving the recovery of GaAs solar cells from the damage which they experience in space under high energy particle irradiation scuh as electrons, protons and neutrons. The method comprises combining thermal annealing with injection annealing. Injection annealing is the recovery from radiation damage resulting from minority carrier injection into the damaged semiconductor, nonradiative minority carrier combination of the injected minority carriers, transfer of the recombination energy to the crystal lattice and utilization of this energy to remove the defects caused by the high energy particle irradiation. The combined annealing of this invention is implemented by heating the solar cells to a moderate temperature (on the order of about 200.degree. C. to 300.degree. C.

Abstract: An improved organic acid activated liquid solder flux is provided by combining a carboxylic acid derivative of a condensed nuclear hydrocarbon, such as 1-naphthylacetic acid, with a flux base, such as rosin, and a solvent, such as isopropyl alcohol. Application of this mixture to solder joints to be made results in faster solder reflow and easier removal of flux residue than with a flux of substantially the same composition not employing the carboxylic acid. Any residues remaining are non-corrosive.

Abstract: Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, in pH range of about 1 to 3 and temperature range of about 20.degree. to 80.degree. C., results, before any coke is burned off the catalyst, in selective abstraction of vanadium and nickel, removal of sulfur, increase in surface area, and increase in pore volume of the catalyst. Subsequent cobalt doping of demetallized catalyst followed by calcination promotes decoking, additional sulfur removal and additional increase in surface area and pore volume. The process results in substantially complete regeneration of catalytic activity.

Abstract: The removal of metals, especially vanadium, from spent hydrofining catalyst is accomplished by a two-step process. Treatment with a gaseous sulfur-containing reagent brings the metals to the surface of the catalyst and converts them to sulfides, which are then efficiently removed by contact with a heteropoly acid such as molybdophosphoric acid. Treatment of deactivated hydrodesulfurization catalysts such as Co-Mo supported on alumina by this process results in substantially complete regeneration of catalytic activity.

Abstract: Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, to which dilute hydrogen peroxide is added, results in a significant enhancement in the rate and extent of carbon and metals removal. Forms of deposited vanadium intractable by other treatments are also removed. The process results in substantially complete regeneration of catalytic activity.

Abstract: Low reflectivity surfaces are formed by particle track etching of a dielectric material such that the horizontal scale of surface texture is less than the wavelength of incident radiation and the depth of texture is equal to or greater than said wavelength. As a consequence, the reflection coefficient is thereby reduced by a factor of at least two, and light is more efficiently transmitted into the material. For solar cells encapsulated in transparent material, efficiency of absorption of solar radiation may be improved by at least about two times per etched surface, or to less than about 2% for the air/transparent material interface and to less than about 15% for the transparent material/solar cell interface.

Abstract: Increased solubility of heavy fractions of coal (e.g., coal liquefaction bottoms and coal solubilization bottoms) is obtained by oxygen-alkylation or oxygen-acylation of weakly acidic protons such as phenolic and carboxylic functionalities by means of a phase transfer reaction. Phenolic and carboxylic functional substituents, which are very polar, are converted to relatively nonpolar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic and water phases with a solid phase suspended in the medium). A quaternary ammonium or phosphonium salt is reacted with alkali or alkaline earth base to produce the corresponding quaternary ammonium or phosphonium base (an example of a phase transfer reagent). This quaternary base is non-nucleophilic and readily removes the phenolic and carboxylic protons but does little else to the coal structures.

Abstract: Solid, naturally-occurring carbonaceous materials such as coal, lignite, peat and the like are treated by oxygen-alkylation or oxygen-acylation employing a phase transfer reaction under mild conditions. The treated coal may then be liquefied, gasified, pyrolyzed, solubilized or otherwise further processed to obtain useful products therefrom. For example, liquid products derived from coal so treated are more compatible with petroleum products and evidence lower viscosity and boiling range than liquid products not so treated. The solubility of coal bottoms is increased in common organic solvents as compared with coal bottoms derived from untreated coal.The phase transfer reaction chemically alters phenolic and carboxylic functional substituents. These two very polar functional groups are converted to relatively non-polar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic and water phases with a solid phase suspended in the medium).

Abstract: Coal liquids are rendered compatible with petroleum liquids by selective oxygen alkylation or oxygen acylation of weakly acidic protons such as phenolic and carboxylic functionalities by means of a phase transfer reaction. Phenolic and carboxylic functional substituents, which are very polar, are converted to relatively non-polar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic/water). A quaternary ammonium or phosphonium salt is reacted with alkali or alkaline earth base (caustic) to produce the corresponding quaternary ammonium or phosphonium base (an example of a phase transfer reagent). This quaternary base is non-nucleophilic and readily removes the phenolic and carboxylic protons, but does little else to the coal liquid molecules. After the removal of the weakly acidic protons by the quaternary base, the phenoxides and carboxylates which are produced then undergo O-alkylation or O-acylation.

Abstract: Highly caking coals are formed by selective oxygen-alkylation or oxygen-acylation of moderately, weakly or non-caking coals, employing a phase transfer reaction which chemically alters phenolic and carboxylic functional substituents. These two very polar functional groups are converted to relatively non-polar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic and water phases with a solid phase suspended in the medium). A quaternary ammonium or phosphonium salt is reacted with alkali or alkaline earth base to produce the corresponding quaternary ammonium or phosphonium base (an example of a phase transfer reagent). This quaternary base is non-nucleophilic and readily removes the phenolic and carboxylic protons but does little else to the coal structures. After the removal of the weakly acidic protons by the quaternary base, the phenoxides and carboxylates which are produced then undergo O-alkylation or O-acylation.