964 Matching Results

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Direct Graphene Growth on Metal Oxides by Molecular Epitaxy

Description: Patent relating to the controlled, layer-by-layer growth of graphene on a useful, magnetizable/and or insulating substrate using molecular beam epitaxy (MBE).
Date: June 13, 2013
Creator: Kelber, Jeffry A.
Partner: UNT College of Arts and Sciences

Graphene Magnetic Tunnel Junction Spin Filters and Methods of Making

Description: Patent relating to methods of forming a few molecule thick graphene layer on a ferromagnetic layer, at temperatures and conditions consistent with integration with silicon-based complementary metal oxide semiconductors (Si CMOS).
Date: May 25, 2012
Creator: Kelber, Jeffry A. & Zhou, Mi
Partner: UNT College of Arts and Sciences

[Letters Patent for Flutter Wheels]

Description: Letters patent granting rights to James Stewart for an improvement to flutter wheels used to drive gins, mills, and other machinery.
Date: October 24, 1828
Creator: United States. Patent Office.
Partner: UNT Libraries Special Collections

Silicon tetrafluoride generation. [Patent application; from hexafluorosilicic acid]

Description: This invention is directed to a process of generating silicon tetrafluoride (SiF/sub 4/) from aqueous solutions of hexafluorosilicic acid (H/sub 2/SiF/sub 6/), comprising reacting an aqueous solution of H/sub 2/SiF/sub 6/ with a concentrated aqueous salt solution to produce a precipitate, separating and drying the precipitate, and heating the precipitate in an inert atmosphere to decompose the precipitate producing SiF/sub 4/.
Date: January 3, 1982
Creator: Hansen, K.C. & Yaws, C.L.
Partner: UNT Libraries Government Documents Department

Transistorized power switch and base drive circuit therefore

Description: A high power switching circuit is disclosed which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn-off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.
Date: March 24, 1981
Creator: Lee, F.C. & Carter, R.A.
Partner: UNT Libraries Government Documents Department

Grate assembly for fixed-bed coal gasifier

Description: A grate assembly for a coal gasifier of a moving-bed or fixed-bed type is provided for crushing agglomerates of solid material such as clinkers, tailoring the radial distribution of reactant gases entering the gasification reaction zone, and control of the radial distribution of downwardly moving solid velocities in the gasification and combustion zone. The clinker crushing is provided by pinching clinkers between vertically oriented stationary bars and angled bars supported on the upper surface of a rotating conical grate. The distribution of the reactant gases is provided by the selective positioning of horizontally oriented passageways extending through the grate. The radial distribution of the solids is provided by mounting a vertically and generally radially extending scoop mechanism on the upper surface of the grate near the apex thereof.
Date: December 31, 1992
Creator: Notestein, J. E.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

Imaging Fourier transform spectrometer

Description: This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.
Date: September 13, 1993
Creator: Bennett, C.L.
Partner: UNT Libraries Government Documents Department

Analysis of hydrogen isotope mixtures

Description: Disclosed are an apparatus and a method for determining concentrations of hydrogen isotopes in a sample. Hydrogen in the sample is separated from other elements using a filter selectively permeable to hydrogen. Then the hydrogen is condensed onto a cold finger or cryopump. The cold finger is rotated as pulsed laser energy vaporizes a portion of the condensed hydrogen, forming a packet of molecular hydrogen. The desorbed hydrogen is ionized and admitted into a mass spectrometer for analysis.
Date: December 31, 1992
Creator: Villa-Aleman, E.
Partner: UNT Libraries Government Documents Department

Automatically processed alpha-track radon monitor

Description: An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.
Date: May 2, 1991
Creator: Langner, G. H. Jr.
Partner: UNT Libraries Government Documents Department

Cermet crucible for metallurgical processing

Description: A cermet crucible for metallurgically processing metals having high melting points comprising a body consisting essentially of a mixture of calcium oxide and erbium metal, the mixture comprising calcium oxide in a range between about 50 and 90% by weight and erbium metal in a range between about 10 and 50% by weight.
Date: December 31, 1994
Creator: Boring, C.P.
Partner: UNT Libraries Government Documents Department

Compact acoustic refrigerator

Description: This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.
Date: December 31, 1991
Creator: Bennett, G. A.
Partner: UNT Libraries Government Documents Department

A device for the determination of low concentrations of oxygen in carbonaceous materials

Description: Oxygen in carbonaceous materials is converted to carbon monoxide (CO) by pyrolyzing the material in a stream of oxygen-free helium. The CO is reacted with Ni{sup 63}, a radioactive isotope of nickel, to form nickel tetracarbanyl (Ni{sup 63}(CO){sub 4}) which is carried by the helium stream into a flow-through gas proportional counter. The quantity of Ni(CO){sub 4} is determined by the radioactivity of the gas as measured by the gas proportional counter. After exiting the flow through counter the Ni{sub 63}(CO){sub 4} is destroyed by exposing it to high temperatures. The Ni{sub 63} is retained within the apparatus while the CO is flushed from the system after being oxidized to carbon dioxide (CO{sub 2}). The detection limit is estimated to be less than 1 part per billion oxygen for a 10 mg sample.
Date: December 31, 1991
Creator: Schultz, H.
Partner: UNT Libraries Government Documents Department

Durable zinc oxide-containing sorbents for coal gas desulfurization

Description: Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel as a matrix material, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.
Date: December 31, 1994
Creator: Siriwardane, R.V.
Partner: UNT Libraries Government Documents Department

End moldings for cable dielectrics

Description: End moldings for high-voltage cables are described wherein the dielectric insulator of the cable is heated and molded to conform to a desired shape. As a consequence, high quality substantially bubble- free cable connectors suitable for mating to premanufactured fittings are made. Disclosed are a method for making the cable connectors either in the field or in a factory, molds suitable for use with the method, and the molded cable connectors, themselves.
Date: December 31, 1993
Creator: Roose, L.D.
Partner: UNT Libraries Government Documents Department

Fiber optic monitoring device

Description: This invention is comprised of a device for the purpose of monitoring light transmissions in optical fibers comprises a fiber optic tap that optically diverts a fraction of a transmitted optical signal without disrupting the integrity of the signal. The diverted signal is carried, preferably by the fiber optic tap, to a lens or lens system that disperses the light over a solid angle that facilitates viewing. The dispersed light indicates whether or not the monitored optical fiber or system of optical fibers is currently transmitting optical information.
Date: December 31, 1992
Creator: Samborsky, J. K.
Partner: UNT Libraries Government Documents Department

Generation of low-divergence laser beams

Description: This invention is comprised of an apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting, and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.
Date: December 1992
Creator: Kronberg, J. W.
Partner: UNT Libraries Government Documents Department

High adherence copper plating process

Description: A process is described for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.
Date: December 31, 1992
Creator: Mignardot, H.
Partner: UNT Libraries Government Documents Department

High speed door assembly

Description: This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.
Date: December 31, 1991
Creator: Shapiro, C.
Partner: UNT Libraries Government Documents Department

Plenum type crystal growth chamber

Description: 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.
Partner: UNT Libraries Government Documents Department