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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

Vanadium-pumped titanium x-ray laser

Description: A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions.
Date: February 13, 1991
Creator: Nilsen, J.
Partner: UNT Libraries Government Documents Department

Hydride compositions

Description: Disclosed are a composition for use in storing hydrogen and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the H equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to H, and then heating below the softening temperature of any of the constituents. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P{sub H}{sub 2} and determining H/M from the isothermic function of the composition.
Date: February 7, 1994
Creator: Lee, Myung W.
Partner: UNT Libraries Government Documents Department

Sample push out fixture

Description: This invention generally relates to the remote removal of pelletized samples from cylindrical containment capsules. V-blocks are used to receive the samples and provide guidance to push out rods. Stainless steel liners fit into the v-channels on the v-blocks which permits them to be remotely removed and replaced or cleaned to prevent cross contamination between capsules and samples. A capsule holder securely holds the capsule while allowing manual up/down and in/out movement to align each sample hole with the v-blocks. Both end sections contain identical v-blocks; one that guides the drive out screw and rods or manual push out rods and the other to receive the samples as they are driven out of the capsule.
Date: February 22, 2000
Creator: Biernat, John L.
Partner: UNT Libraries Government Documents Department

Narrow groove welding gas diffuser assembly and welding torch

Description: A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.
Date: February 4, 2000
Creator: Rooney, Stephen J.
Partner: UNT Libraries Government Documents Department

Method and Apparatus for separation of heavy and tritiated water

Description: An object of the present invention is to provide a method for separating and recovering hydrogen isotopes that avoids the disadvantages of the prior art, is more simple, and allows for continuous hydrogen isotope separation and recovery. The disclosed invention does not require the use of isotope exchange reaction catalysts and/or hydrogen sulfide gas. The present invention achieves the advantages of the thermal diffusion and the chemical exchange processes. The disclosed invention provides a method for separating and recovering hydrogen isotopes from a fluid containing the hydrogen isotopes by providing counter-current cold and hot streams of the fluid containing the hydrogen isotopes separated by a proton exchange membrane made of thermally insulating and chemically transparent material that allows exchange of heavy and light hydrogen isotopes there through. The heavier isotopes migrate to the cold stream producing a deuterium and tritium-enriched fluid, while lighter isotopes migrate to the hot stream producing a lighter isotope-enriched fluid. The heavy and light isotopes are withdrawn from the cold and hot streams respectively. According to the present invention, the fluid is water or hydrogen gas, and the desired hydrogen isotope species are deuterium and/or tritium. Further, according to the present invention, the streams of said high and low temperature fluids are interconnected at their respective top and bottom ends forming a continuous loop, and a feed stream is provided at an intermediate portion of either hot or cold stream to feed the process.
Date: February 28, 2000
Creator: Lee, Myung, W.
Partner: UNT Libraries Government Documents Department

Actinide halide complexes

Description: A compound of the formula MX{sub n}L{sub m} wherein M = Th, Pu, Np,or Am thorium, X = a halide atom, n = 3 or 4, L is a coordinating ligand selected from the group consisting of aprotic Lewis bases having an oxygen-, nitrogen-, sulfur-, or phosphorus-donor, and m is 3 or 4 for monodentate ligands or is 2 for bidentate ligands, where n + m = 7 or 8 for monodentate ligands or 5 or 6 for bidentate ligands, a compound of the formula MX{sub n} wherein M, X, and n are as previously defined, and a process of preparing such actinide metal compounds including admixing the actinide metal in an aprotic Lewis base as a coordinating solvent in the presence of a halogen-containing oxidant, are provided.
Date: February 7, 1991
Creator: Avens, Larry R.; Zwick, Bill D.; Sattelberger, Alfred P.; Clark, David L. & Watkin, J. G.
Partner: UNT Libraries Government Documents Department

Ball-mounting fixture for a roundness gage

Description: A ball mounting fixture for a roundness gage is disclosed. The fixture includes a pair of chuck assemblies oriented substantially transversely with respect to one another and mounted on a common base. Each chuck assembly preferably includes a rotary stage and a wobble plate affixed thereto. A ball chuck affixed to each wobble plate is operable to selectively support a ball to be measured for roundness, with the wobble plate permitting the ball chuck to be tilted to center the ball on the axis of rotation of the rotary stage. In a preferred embodiment, each chuck assembly includes a vacuum chuck operable to selectively support the ball to be measured for roundness. The mounting fixture enables a series of roundness measurements to be taken with a conventional rotating gagehead roundness instrument, which measurements can be utilized to determine the sphericity of the ball.
Date: February 16, 1982
Creator: Gauler, Allen L. & Pasieka, Donald F.
Partner: UNT Libraries Government Documents Department

Bag-out material handling system

Description: A bagging device for transferring material from a first chamber through an opening in a wall to a second chamber includes an outer housing communicating with the opening and having proximal and distal ends relative to the wall. An inner housing having proximal and distal ends corresponding to those of the outer housing is mounted in a concentrically spaced, sealed manner with respect to the distal end of the outer housing. The inner and outer housings and mounting means therebetween define an annular chamber, closed at its distal end and open at its proximal end, in which a pliable tube is slidably positioned in sealed engagement with the housings. The pliable tube includes a sealed end positioned adjacent the proximal end of the inner housing so as to maintain isolation between the first and second chambers. Displacement of the material to be bagged from the first chamber along the inner housing so as to contact the sealed portion of the pliable bag allows the material to be positioned within the pliable bag in the second chamber. The bag is then sealed and severed between where the material is positioned therein and the wall in providing a sealed container for handling the material. The pliable tube when substantially depleted slides onto a narrow portion of the inner housing to allow a new pliable tube to be positioned over the old pliable tube. Remnants of the old pliable tube are then discharged into the new pliable tube with the bagging and removal of additional material.
Date: February 26, 1982
Creator: Brak, S.B.
Partner: UNT Libraries Government Documents Department

Explosive double salts and preparation. [Patent application]

Description: A new composition of matter has been discovered which is an explosive addition compound of ammonium nitrate (AN) and diethylenetriamine trinitrate (DETN) in a 50:50 molar ratio. the compound is stable over extended periods of time only at temperatures higher than 46/sup 0/C, decomposing to a fine-grained eutectic mixture (which is also believed to be new) of AN and DETN at temperatures lower than 46/sup 0/C. The compound of the invention has an x-ray density of 1.61 g/cm/sup 3/, explodes to form essentially only gaseous products, has higher detonation properties (i.e., detonation velocity and pressure) than those of any mechanical mixture having the same density and composition as the compound of the invention, is a quite insensitive explosive material, can be cast at temperatures attainable by high pressure steam, and is prepared from inexpensive ingredients. Methods of preparing the compound and the fine-grained eutectic composition of the invention are given.
Date: February 3, 1982
Creator: Cady, H.H. & Lee, K.Y.
Partner: UNT Libraries Government Documents Department

Bag-out material-handling system

Description: A bagging device for transferring material from a first chamber through an opening in a wall to a second chamber includes an outer housing communicating with the opening and having proximal and distal ends relative to the wall. An inner housing having proximal and distal ends corresponding to those of the outer housing is mounted in a concentrically spaced, sealed manner with respect to the distal end of the outer housing. The inner and outer housings and mounting means therebetween define an annular chamber, closed at its distal end and open at its proximal end, in which a pliable tube is slidably positioned in sealed engagement with the housings. The pliable tube includes a sealed end positioned adjacent the proximal end of the inner housing so as to maintain isolation between the first and second chambers. Displacement of the material to be bagged from the first chamber along the inner housing so as to contact the sealed portion of the pliable bag allows the material to be positioned within the pliable bag in the second chamber. The bag is then sealed and severed between where the material is positioned therein and the wall in providing a sealed container for handling the material. The pliable tube when substantially depleted slides onto a narrow portion of the inner housing to allow a new pliable tube to be positioned over the old pliable tube. Remnants of the old pliable tube are then discharged into the new pliable tube with the bagging and removal of additional material.
Date: February 26, 1982
Creator: Brak, Stephen B. & Milek, Henry F.
Partner: UNT Libraries Government Documents Department

Method for Non-Intrusively Identifying a Contained Material Utilizing Uncollided Nuclear Transmission Measurements

Description: An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.
Date: February 26, 1999
Creator: Morrison, John L.; Stephens, Alan G. & S., Grover Blaine
Partner: UNT Libraries Government Documents Department

Improved eddy current angle probe

Description: Apparatus is described for detecting flaws in a tubular workpiece in a single scan. The coils of a dual coil bobbin eddy current inspection probe are wound at a 45/sup 0/ angle to the transverse axis of the probe, one coil having an angular position about the axis about 90/sup 0/ relative to the angular position of the other coil, and the angle of intersection of the planes containing the coils being about 60/sup 0/.
Date: February 11, 1982
Creator: Nance, R.A.; Hartley, W.H. & Caffarel, A.J.
Partner: UNT Libraries Government Documents Department

Process for recovering rhenium from an alloy thereof

Description: Rhenium is recovered from an alloy containing that metal and either one or both of the metals molybdenum and tungsten by the following steps: (1) heating the alloy in the presence of O/sub 2/ to remove the Re from the alloy as gaseous Re/sub 2/O/sub 7/; (2) condensing the gaseous Re/sub 2/O/sub 7/; (3) dissolving the obtained solid Re/sub 2/O/sub 7/ in H/sub 2/O; (4) treating the solution of Re/sub 2/O/sub 7/ and H/sub 2/O with KCl to form KReO/sub 4/; and (5) heating the KReO/sub 4/ in the presence of H/sub 2/ to form Re.
Date: February 3, 1982
Creator: Heshmatpour, Bahman & McDonald, Robert E.
Partner: UNT Libraries Government Documents Department

Thin-Film Absorber for a Solar Collector

Description: This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.
Date: February 9, 1982
Creator: Wilhelm, William G.
Partner: UNT Libraries Government Documents Department

Stabilizing windings for tilting and shifting modes

Description: This invention provides simple, inexpensive, independent and passive, conducting loops for stabilizing a plasma ring having externally produced equilibrium fields on opposite sides of the plasma ring and internal plasma currents that interact to tilt and/or shift the plasma ring relative to the externally produced equilibrium field so as to produce unstable tilting and/or shifting modes in the plasma ring. More particularly this invention provides first and second passive conducting loops for containing first and second induced currents in first and second directions corresponding to the amplitude and directions of the unstable tilting and/or shifting modes in the plasma ring. To this end, the induced currents provide additional magnetic fields for producing restoring forces and/or restoring torques for counteracting the tilting and/or shifting modes when the conducting loops are held fixed in stationary positions relative to the externally produced equilibrium fields on opposite sides of the plasma ring.
Date: February 26, 1982
Creator: Jardin, S.C. & Christensen, U.R.
Partner: UNT Libraries Government Documents Department

Method of glass melter electrode length measurement using time domain reflectometry (TDR)

Description: The present invention overcomes the drawbacks inherent in the prior art and solves the problems inherent in conventional Joule-heated vitrification melters, where the melter preferably comprises a vessel having a refractory liner and an opening for receiving material which is converted into molten vitreous material in the vessel. The vessel has an outlet port for removing molten vitreous material from the vessel. A plurality of electrodes is disposed in the vessel and electrical energy is passed between electrode pairs through feed material and molten vitreous material in the vessel. Typically, the electrodes erode and wear in time, and this invention seeks to monitor and evaluate the length and condition of the electrodes. The present invention uses time domain reflectometry (TDR) methods to accurately measure the length of an electrode that is subject to wear and electrolytic decomposition due to the extreme conditions in which the electrode is required to operate. Specifically, TDR would be used to measure the length and effects of erosion of molybdenum electrodes used in Joule-heated vitrification melter. Of course, the inventive concept should not be limited to this preferred environment.
Date: February 28, 2000
Creator: Tarpley, James M. & Zamecnik, John R.
Partner: UNT Libraries Government Documents Department

Variable-Period Undulators for Synchrotron Radiation

Description: A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.
Date: February 22, 2005
Creator: Shenoy, Gopal; Lewellen, John; Shu, Deming & Vinokurov, Nikolai
Partner: UNT Libraries Government Documents Department

Method of Dehalogenation using Diamonds

Description: A method for preparing olefins and halogenated olefins is provided comprising contacting halogenated compounds with diamonds for a sufficient time and at a sufficient temperature to convert the halogenated compounds to olefins and halogenated olefins via elimination reactions.
Date: February 26, 1999
Creator: Farcasiu, Malvina; Kaufman, Phillip B.; Ladner, Edward P. & Anderson, Richard R.
Partner: UNT Libraries Government Documents Department

New prodrugs based on phospholipid-nucleoside conjugates

Description: A method is described for the preparation of defined, isomerically pure phospholipid-nucleoside conjugates as a prodrug in which the drug (araC) is attached to the phospholipid by a monophosphate linkage. Key intermediates in the process involve selective blocking and deblocking of the nucleoside derivative. These particular monophosphate-linked derivatives represent a new class of prodrug, which are useful by themselves or in combination with diphosphate linked derivatives. Several new compositions involving diphosphate linked derivatives are described in which the products are isomerically pure and having defined fatty acid chain lengths.
Date: February 3, 1982
Creator: MacCoss, M.
Partner: UNT Libraries Government Documents Department

Phase stable rf transport system

Description: This invention is comprised of an RF transport system which delivers a phase-stable RF signal to a load, such as an RF cavity of a charged particle accelerator. A circuit generates a calibration signal at an odd multiple frequency of the RF signal where the calibration signal is superimposed with the RF signal on a common cable that connects the RF signal with the load. Signal isolating diplexers are located at both the RF signal source end and load end of the common cable to enable the calibration to be inserted and extracted from the cable signals without any affect on the RF signal. Any phase shift in the calibration signal during traverse of the common cable is then functionally related to the phase shift in the RF signal. The calibration phase shift is used to control a phase shifter for the RF signal to maintain a stable RF signal at the load.
Date: February 19, 1991
Creator: Curtin, M. T.; Natter, E. F. & Denney, P. M.
Partner: UNT Libraries Government Documents Department

Current-matched, high-efficiency, multi-junction monolithic solar cells

Description: In this invention, the efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga{sub 0.52}In{sub 0.48}P and GaAs. Additional lattice-matched systems to which the invention pertains include Al{sub x}Ga{sub l-x}/GaAs (x=0.3 {minus} 0.4), GaAs/Ge and Ga{sub y}In{sub 1-y}P/Ga{sub y+0.5}In{sub 0.5-{sub Y}} As (O<y<5).
Date: February 11, 1991
Creator: Olson, J. M. & Kurtz, S. R.
Partner: UNT Libraries Government Documents Department