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High density hexagonal boron nitride prepared by hot isostatic pressing in refractory metal containers (open access)

High density hexagonal boron nitride prepared by hot isostatic pressing in refractory metal containers

Boron nitride powder with less than or equal to the oxygen content of starting powder (down to 0.5% or less) is hot isostatically pressed in a refractory metal container to produce hexagonal boron nitride with a bulk density greater than 2.0 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a cansister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800{degrees}C and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.21 g/cc. Complex shapes can be made.
Date: December 31, 1990
Creator: Hoenig, C. L.
System: The UNT Digital Library
Improved catalysts and method (open access)

Improved catalysts and method

An improved catalyst and method for the oxyhydrochlorination of methane is disclosed. The catalyst includes a pyrogenic porous support on which is layered as active material, cobalt chloride in major proportion, and minor proportions of an alkali metal chloride and of a rare earth chloride. On contact of the catalyst with a gas flow of methane, HCl and oxygen, more than 60% of the methane is converted and of that converted more than 40% occurs as monochloromethane. Advantageously, the monochloromethane can be used to produce gasoline boiling range hydrocarbons with the recycle of HCl for further reaction. This catalyst is also of value for the production of formic acid as are analogous catalysts with lead, silver or nickel chlorides substituted for the cobalt chloride. 8 figs., 3 tabs.
Date: December 31, 1990
Creator: Taylor, C. E. & Noceti, R. P.
System: The UNT Digital Library
Improved morphology in electrochemically grown conducting polymer films (open access)

Improved morphology in electrochemically grown conducting polymer films

A conducting polymer film with an improved space filling is formed on a metal electrode surface. A self-assembling monolayer is formed directly on the metal surface where the monolayer has a first functional group that binds to the metal surface and a second chemical group that forms a chemical bonding site for molecules forming the conducting polymer. The conducting polymer is then conventionally deposited by electrochemical deposition. In one example, a conducting film of polyaniline is formed on a gold electrode surface with an intermediate monolayer of p-aminothiophenol.
Date: December 31, 1990
Creator: Rubinstein, I.; Gottesfeld, S. & Sabatani, E.
System: The UNT Digital Library
Improved thermal storage module for solar dynamic receivers (open access)

Improved thermal storage module for solar dynamic receivers

This invention relates to a thermal storage apparatus and more particularly to an apparatus for use in conjunction with solar dynamic energy storage systems. The invention is comprised of a thermal energy storage system comprising a germanium phase change material and a graphite container.
Date: December 31, 1990
Creator: Beatty, R. L. & Lauf, R. J.
System: The UNT Digital Library
A method and apparatus for continuous electrophoresis (open access)

A method and apparatus for continuous electrophoresis

A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least on of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.
Date: December 31, 1990
Creator: Watson, J. S.
System: The UNT Digital Library
Method for Improving the Growth of Cadmium Telluride on a Gallium Arsenide Substrate (open access)

Method for Improving the Growth of Cadmium Telluride on a Gallium Arsenide Substrate

A method for preparing a gallium arsenide substrate, prior to growing a layer of cadmium telluride on a support surface thereof. The preparation includes the steps of cleaning the gallium arsenide substrate and thereafter forming prepatterned shapes on the support surface of the gallium arsenide substrate. The layer of cadmium telluride then grown on the prepared substrate results in dislocation densities of approximately 1{times}10{sup 6}/cm{sup 2} or less. The prepatterned shapes on the support surface of the gallium arsenide substrate are formed by reactive ion etching an original outer surface of the gallium arsenide substrate and into the body of the gallium arsenide substrate to a depth of at least two microns. The prepatterned shapes have the appearance of cylindrical mesas each having a diameter of at lease twelve microns. After the mesas are formed on the support surface of the gallium arsenide substrate, the substrate is again cleaned.
Date: December 31, 1990
Creator: Reno, John L.
System: The UNT Digital Library
A method for joining ceramic shapes (open access)

A method for joining ceramic shapes

The invention is a method for joining shapes of ceramic materials together to form a unitary ceramic structure. In the method of the invention, a mixture of two or more chemical components which will react exothermically is placed between the surfaces to be joined, and the joined shapes heated to a temperature sufficient to initiate the exothermic reaction forming a joining material which acts to bond the shapes together. Reaction materials are chosen which will react exothermically at temperatures below the degradation temperature of the materials to be joined. The process is particularly suited for joining composite materials of the silicon carbide-silicon carbide fiber type.
Date: December 31, 1990
Creator: Rabin, B. H.
System: The UNT Digital Library
Method of recovering hazardous waste from phenolic resin filters (open access)

Method of recovering hazardous waste from phenolic resin filters

A method has been found for treating phenolic resin filter, whereby the filter is solubilized within the filter cartridge housing so the filter material can be removed from the cartridge housing in a remote manner. The invention consists of contacting the filter within the housing with an aqueous solution of about 8 to 12M nitric acid, at a temperature from about 110 to 190{degree}F, maintaining the contact for a period of time sufficient to solubilize the phenolic material within the housing, and removing the solubilized phenolic material from the housing, thereby removing the filter cartridge from the housing. Any hazardous or other waste material can then be separated from the filter material by chemical or other means.
Date: December 31, 1990
Creator: Meikrantz, David H.; Bourne, Gary L.; McFee, John N.; Burdge, Bradley G. & McConnell, John W., Jr.
System: The UNT Digital Library
Method of separating organic contaminants from fluid feedstreams with polyphosphazene membranes (open access)

Method of separating organic contaminants from fluid feedstreams with polyphosphazene membranes

A method is provided for separating polar hydrocarbons from a fluid feedstream. The fluid feedstream is flowed across a first surface of a polyphosphazene semipermeable membrane. At least one polar hydrocarbon from the fluid feedstream permeates through the polyphosphazene semipermeable membrane to a second opposed surface of the semipermeable membrane. Then the permeated polar hydrocarbon is removed from the second opposed surface of the polyphosphazene semipermeable membrane. Outstanding and unexpected separation selectivities on the order of 10,000 were obtained for methylene chloride when a methylene chloride in water feedstream was flowed across the polyphosphazene semipermeable membrane in the invented method.
Date: December 31, 1990
Creator: McCaffrey, R. R. & Cummings, D. G.
System: The UNT Digital Library
Passive decay heat removal system for water-cooled nuclear reactors (open access)

Passive decay heat removal system for water-cooled nuclear reactors

This document describes passive decay-heat removal system for a water-cooled nuclear reactor which employs a closed heat transfer loop having heat-exchanging coils inside an open-topped, insulated evaporator located inside the reactor vessel, below its normal water level, in communication with a condenser located outside of containment and exposed to the atmosphere. The heat transfer loop is located such that the evaporator is in a position where, when the water level drops in the reactor, it will become exposed to steam. Vapor produced in the evaporator passes upward to the condenser above the normal water level. In operation, condensation in the condenser removes heat from the system, and the condensed liquid is returned to the evaporator. The system is disposed such that during normal reactor operations where the water level is at its usual position, very little heat will be removed from the system, but during emergency, low water level conditions, substantial amounts of decay heat will be removed.
Date: December 31, 1990
Creator: Forseberg, C. W.
System: The UNT Digital Library
Phosphazene polymer containing composites and method for making phosphazene polymer containing composites (open access)

Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

The object of the invention is to provide a composite material comprised of phosphazene polymer. A feature of phosphazene-containing composites is their superior stiffness, thermal stability, and hardness which is lacking in more typical composite constituents. An advantage of using phosphazene composites is a wider range of applications, including uses in harsh environments. Another object of the present invention provides a method for producing phosphazene-containing composite materials through a pultrusion process. In brief, these and other objects are achieved by a composite produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite. 2 figs., 6 tabs.
Date: December 31, 1990
Creator: Allen, C. A.; Grey, A. E.; McCaffrey, R. R.; Simpson, B. M. & Stone, M. L.
System: The UNT Digital Library
Plenum type crystal growth chamber (open access)

Plenum type crystal growth chamber

Crystals are grown in a tank which is divided by a baffle into a crystal growth region above the baffle and a plenum region below the baffle. A turbine blade or stirring wheel is positioned in a turbine tube which extends through the baffle to generate a flow of solution from the crystal growing region to the plenum region. The solution is pressurized as it flows into the plenum region. The pressurized solution flows back to the crystal growing region through return flow tubes extending through the baffle. Growing crystals are positioned near the ends of the return flow tubes to receive a direct flow of solution.
Date: December 31, 1990
Creator: Montgomery, K. E.
System: The UNT Digital Library
Precision wire feeder for small diameter wire (open access)

Precision wire feeder for small diameter wire

This invention is comprised of a device for feeding small diameter wire having a diameter less than .04 mm (16 mil) to a welding station which includes a driving wheel for controllably applying a non-deforming driving force to the wire to move the free end of the wire towards the welding station; and a tension device such as a torque motor for constantly applying a reverse force to the wire in opposition to the driving force to keep the wire taut. 1 fig.
Date: December 31, 1990
Creator: Brandon, E. D.; Hooper, F. M. & Reichenbach, M. L.
System: The UNT Digital Library
Preparation of high specific activity technetium-96 (open access)

Preparation of high specific activity technetium-96

The present invention relates to a method of producing Tc-96 from the proton irradiation of a rhodium target and a technique for isolating under remote hot cell conditions the Tc-96 from the proton irradiated target.
Date: December 31, 1990
Creator: Mausner, L. F.; Srivastava, S. C. & Prach, T.
System: The UNT Digital Library
Process and apparatus for coal hydrogenation (open access)

Process and apparatus for coal hydrogenation

In a coal liquefaction process an aqueous slurry of coal is prepared containing a dissolved liquefaction catalyst. A small quantity of oil is added to the slurry and then coal-oil agglomerates are prepared by agitation of the slurry at atmospheric pressure. The resulting mixture is drained of excess water and dried at atmospheric pressure leaving catalyst deposited on the agglomerates. The agglomerates then are fed to an extrusion device where they are formed into a continuous ribbon of extrudate and fed into a hydrogenation reactor at elevated pressure and temperature. The catalytic hydrogenation converts the extrudate primarily to liquid hydrocarbons in the reactor. The liquid drained in recovering the agglomerates is recycled. 1 fig.
Date: December 31, 1990
Creator: Ruether, J. A. & Simpson, T. B.
System: The UNT Digital Library
Process for alloying uranium and niobium (open access)

Process for alloying uranium and niobium

Alloys such as U-6Nb are prepared by forming a stacked sandwich array of uranium sheets and niobium powder disposed in layers between the sheets, heating the array in a vacuum induction melting furnace to a temperature such as to melt the uranium, holding the resulting mixture at a temperature above the melting point of uranium until the niobium dissolves in the uranium, and casting the uranium-niobium solution. Compositional uniformity in the alloy product is enabled by use of the sandwich structure of uranium sheets and niobium powder.
Date: December 31, 1990
Creator: Holcombe, Cressie E.; Northcutt, Walter G.; Masters, David R. & Chapman, Lloyd R.
System: The UNT Digital Library
Process for forming one or more substantially pure layers in substrate material using ion implantation (open access)

Process for forming one or more substantially pure layers in substrate material using ion implantation

The method comprises selecting an implantable element and a substrate material to be implanted which, at the implant/anneal temperatures, have limited mutual solubility and have no intermediate phases formed. In an example, Be is implanted with 11 {times}10{sup 17} Al/cm{sup 2} at 200 keV and then annealed for 1 h at 500 C. Rutherford backscattering shows that layer formation occurred during the anneal. SEM shows rectangular Be defects in the Al layer. Other examples of implantable elements and suitable substrate materials are tabulated. 6 figs, 1 table. (DLC)
Date: December 31, 1990
Creator: Musket, R. G.; Brown, D. W. & Munir, Z. A.
System: The UNT Digital Library
Process for the recovery of strontium from acid solutions (open access)

Process for the recovery of strontium from acid solutions

The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid.
Date: December 31, 1990
Creator: Horwitz, E. P. & Dietz, M. L.
System: The UNT Digital Library
Process of converting starch to glucose and glucose to lactic acid (open access)

Process of converting starch to glucose and glucose to lactic acid

This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)
Date: December 31, 1990
Creator: Tsai, TenLin; Sanville, C. Y.; Coleman, R. D. & Schertz, W. W.
System: The UNT Digital Library
Production of aluminum-26 (open access)

Production of aluminum-26

This invention is a method of producing Al-26 from potassium chloride by exposing it to a proton beam in order to break potassium and chlorine atoms into smaller pieces, which include Al-26. The Al-26 is isolated from the potassium chloride and substances produced by the beam by means of extraction and ion exchange.
Date: December 31, 1990
Creator: Steinkruger, F. J. & Phillips, D. R.
System: The UNT Digital Library
Production of hollow aerogel microspheres (open access)

Production of hollow aerogel microspheres

A method is described for making hollow aerogel microspheres of 800--1200{mu} diameter and 100--300{mu} wall thickness by forming hollow alcogel microspheres during the sol/gel process in a catalytic atmosphere and capturing them on a foam surface containing catalyst. Supercritical drying of the formed hollow alcogel microspheres yields hollow aerogel microspheres which are suitable for ICF targets.
Date: December 31, 1990
Creator: Upadhye, Ravindra S. & Henning, Sten A.
System: The UNT Digital Library
Real time Faraday spectrometer (open access)

Real time Faraday spectrometer

This invention is comprised of a charged particle spectrometer that contains a detection system which embodies the benefits of both foil-light emissions and faraday cups, yet it does not interfere with the particle beam. 5 Figs. (GHH)
Date: December 31, 1990
Creator: Smith, T. E. Jr.; Struve, K. W. & Colella, N. J.
System: The UNT Digital Library
Robot arm apparatus (open access)

Robot arm apparatus

A robot arm apparatus is provided for inspecting and/or maintaining an interior of a steam generator which has an outside wall and a port for accessing the interior of the steam generator. The robot arm apparatus includes a flexible movable conduit for conveying inspection and/or maintenance apparatus from outside the steam generator to the interior of the steam generator. The flexible conduit has a terminal working end which is translated into and around the interior of the steam generator. Three motors located outside the steam generator are employed for moving the terminal working end inside the steam generator in ``x,`` ``y,`` and ``z`` directions, respectively. Commonly conducted inspection and maintenance operations include visual inspection for damaged areas, water jet lancing for cleaning sludge deposits, core boring for obtaining sludge deposits, and scrubbing of internal parts.
Date: December 31, 1990
Creator: Nachbar, H. D.
System: The UNT Digital Library
Selective epitaxy using the GILD process (open access)

Selective epitaxy using the GILD process

The present invention comprises a method of selective epitaxy on a semiconductor substrate. The present invention provides a method of selectively forming high quality, thin GeSi layers in a silicon circuit, and a method for fabricating smaller semiconductor chips with a greater yield (more error free chips) at a lower cost. The method comprises forming an upper layer over a substrate, and depositing a reflectivity mask which is then removed over selected sections. Using a laser to melt the unmasked sections of the upper layer, the semiconductor material in the upper layer is heated and diffused into the substrate semiconductor material. By varying the amount of laser radiation, the epitaxial layer is formed to a controlled depth which may be very thin. When cooled, a single crystal epitaxial layer is formed over the patterned substrate. The present invention provides the ability to selectively grow layers of mixed semiconductors over patterned substrates such as a layer of Ge{sub x}Si{sub 1-x} grown over silicon. Such a process may be used to manufacture small transistors that have a narrow base, heavy doping, and high gain. The narrowness allows a faster transistor, and the heavy doping reduces the resistance of the narrow layer. The …
Date: December 31, 1990
Creator: Weiner, K. H.
System: The UNT Digital Library