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Preventive maintenance system for the photomultiplier detector blocks of pet scanners (open access)

Preventive maintenance system for the photomultiplier detector blocks of pet scanners

The present invention relates to a system for the preventive maintenance of the Photomultiplier Detector Blocks of PET Scanners. This system is used to automatically indicate the expected date of failure of a photomultiplier detector block and provide time for its replacement and maintenance in a scheduled preventive maintenance program, thus eliminating expensive unscheduled downtime of a PET Scanner due to photomultiplier failure.
Date: December 31, 1992
Creator: Levy, A. V. & Warner, D.
System: The UNT Digital Library
Propulsion and stabilization system for magnetically levitated vehicles (open access)

Propulsion and stabilization system for magnetically levitated vehicles

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.
Date: December 31, 1992
Creator: Coffey, H. T.
System: The UNT Digital Library
Radiation detector using a bulk high {Tc} superconductor (open access)

Radiation detector using a bulk high {Tc} superconductor

A radiation detector is provided, wherein a bulk high T superconducting sample is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil which is coupled by an input coil to an rf SQUID).
Date: December 31, 1992
Creator: Artusom, J. F.; Franks, L. A.; Hull, K. L. & Symko, O. G.
System: The UNT Digital Library
Reactor refueling containment system (open access)

Reactor refueling containment system

This report describes a method of refueling a nuclear reactor whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced.
Date: December 31, 1992
Creator: Gillett, J.E. & Meuschke, R.E.
System: The UNT Digital Library
Recovery of germanium-68 from irradiated targets (open access)

Recovery of germanium-68 from irradiated targets

This invention is comprised of a process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium,vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.0, adjusting the soluble metal halide concentration in the second ion-containing solution to a level adapted for subsequent separation of germanium, contacting the pH-adjusted, soluble metal halide-containing second ion-containing solution with a dextran-based material whereby germanium ions are separated by the dextran-based material, and recovering the germanium from the dextran-based material, preferably by distillation.
Date: December 31, 1992
Creator: Phillips, D. R.; Jamriska, D. J. Sr. & Hamilton, V. T.
System: The UNT Digital Library
Remote high temperature insulatorless heat-flux gauge (open access)

Remote high temperature insulatorless heat-flux gauge

A remote optical heat-flux gauge for use in high temperature environments. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet light. The luminescence emitted by the two thermographic-phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat flux measurements can be made by scanning the light across the surface of the gauge.
Date: December 31, 1992
Creator: Noel, B. W.
System: The UNT Digital Library
Selectable fragmentation warhead (open access)

Selectable fragmentation warhead

This report discusses a selectable fragmentation warhead which is capable of producing a predetermined number of fragments from a metal plate, and accelerating the fragments toward a target. A first explosive located adjacent to the plate is detonated at selected number of points by laser-driven slapper detonators. In one embodiment, a smoother-disk and a second explosive, located adjacent to the first explosive, serve to increase acceleration of the fragments toward a target. The ability to produce a selected number of fragments allows for effective destruction of a chosen target.
Date: December 31, 1992
Creator: Bryan, C. S.; Paisley, D. L.; Montoya, N. I. & Stahl, D. B.
System: The UNT Digital Library
Semiconductor diode laser having an intracavity spatial phase controller for beam control and switching (open access)

Semiconductor diode laser having an intracavity spatial phase controller for beam control and switching

A high-power broad-area semiconductor laser having a intracavity spatial phase controller is disclosed. The integrated intracavity spatial phase controller is easily formed by patterning an electrical contact metallization layer when fabricating the semiconductor laser. This spatial phase controller changes the normally broad far-field emission bean, of such a laser into a single-lobed near-diffraction-limited beam at pulsed output powers of over 400 mW. Two operating modes, a thermal and a gain operating mode, exist for the phase controller, allowing for steering and switching the beam as the modes of operation are switched, and the emission beam may be scanned, for example, over a range of 1.4 degrees or switched by 8 degrees. More than one spatial phase controller may be integrated into the laser structure.
Date: December 31, 1992
Creator: Hohimer, J. P.
System: The UNT Digital Library
Sensors for Monitoring Waste Glass Quality (open access)

Sensors for Monitoring Waste Glass Quality

None
Date: December 31, 1992
Creator: Bickford, Dennis F.
System: The UNT Digital Library
Simplified flangeless unisex waveguide coupler assembly (open access)

Simplified flangeless unisex waveguide coupler assembly

A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150{degrees}C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar …
Date: December 31, 1992
Creator: DiMartino, M. & Moeller, C. P.
System: The UNT Digital Library
Superconducting active impedance converter (open access)

Superconducting active impedance converter

This invention is comprised of a transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductor allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10--80 K temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology.
Date: December 31, 1992
Creator: Ginley, D.S.; Hietala, V.M. & Martens, J.S.
System: The UNT Digital Library
Superconducting thermoelectric generator (open access)

Superconducting thermoelectric generator

This invention is comprised of an apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a higher thermal conductivity than that of the superconducting material. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials, establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.
Date: December 31, 1992
Creator: Metzger, J.D. & El-Genk, M.
System: The UNT Digital Library
Superconductive wire (open access)

Superconductive wire

This invention is comprised of a superconductive article including a first metallic tube having an interior surface and an exterior surface, said interior surface defining an interior hollow cavity, a layer of superconductive material surrounding said exterior surface of said first metallic tube, and, a second metallic tube having an interior surface and an exterior surface, said interior surface adjacent to said layer of superconductive material is provided together with processes of making such a superconductive article including, e.g., inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing and/or ironing the composite intermediate article to …
Date: December 31, 1992
Creator: Korzekwa, D. A.; Bingert, J. F.; Peterson, D. E. & Sheinberg, H.
System: The UNT Digital Library
Synthesis of iron based hydrocracking catalysts (open access)

Synthesis of iron based hydrocracking catalysts

Disclosed are method of preparing a fine particle iron based hydrocracking catalyst and the catalyst prepared thereby. An iron (III) oxide powder and elemental sulfur are reacted with a liquid hydrogen donor having a hydroaromatic structure present in the range of from about 5 to about 50 times the weight of iron (III) oxide at 180C to 240C for 0 to 8 hours. Various specific hydrogen donors are disclosed. The catalysts are active at low temperature (<350C) and low pressure.
Date: December 31, 1992
Creator: Farcasiu, M.; Eldredge, P. A. & Ladner, E. P.
System: The UNT Digital Library
System and method to improve the power output and longetivity of a radioisotope thermoelectric generator (open access)

System and method to improve the power output and longetivity of a radioisotope thermoelectric generator

By using the helium generated by the alpha emissions of a thermoelectric generator during space travel for cooling the thermal degradation of the thermoelectric generator can be slowed. Slowing degradation allows missions to be longer with little additional expense or payload.
Date: December 31, 1992
Creator: Mowery, A. L., Jr.
System: The UNT Digital Library
Three Dimensional, Multi-Chip Module (open access)

Three Dimensional, Multi-Chip Module

The present invention relates to integrated circuit packaging technology, and particularly to three dimensional packages involving high density stacks of integrated circuits. A plurality of multi-chip modules are stacked and bonded around the perimeter by sold-bump bonds to adjacent modules on, for instance, three sides of the perimeter. The fourth side can be used for coolant distribution, for more interconnect structures, or other features, depending on particular design considerations of the chip set. The multi-chip modules comprise a circuit board, having a planarized interconnect structure formed on a first major surface, and integrated circuit chips bonded to the planarized interconnect surface. Around the periphery of each circuit board, long, narrow ``dummy chips`` are bonded to the finished circuit board to form a perimeter wall. The wall is higher than any of the chips on the circuit board, so that the flat back surface of the board above will only touch the perimeter wall. Module-to-module interconnect is laser-patterned on the sides of the boards and over the perimeter wall in the same way and at the same time that chip to board interconnect may be laser-patterned.
Date: December 31, 1992
Creator: Bernhardt, A. F. & Petersen, R. W.
System: The UNT Digital Library
Traveling-wave photodetector (open access)

Traveling-wave photodetector

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.
Date: December 31, 1992
Creator: Hietala, V. M. & Vawter, G. A.
System: The UNT Digital Library
Tritium extraction furnace (open access)

Tritium extraction furnace

This invention is comprised of apparatus for heating an object such as a nuclear target bundle to release and recover hydrogen and contain the disposable residue for disposal. The apparatus comprises an inverted furnace, a sleeve/crucible assembly for holding and enclosing the bundle, conveying equipment for placing the sleeve onto the crucible and loading the bundle into the sleeve/crucible, a lift for raising the enclosed bundle into the furnace, and hydrogen recovery equipment including a trap and strippers, all housed in a containment having, negative internal pressure. The crucible/sleeve assembly has an internal volume that is sufficient to enclose and hold the bundle before heating; the crucible`s internal volume is sufficient by itself to hold and enclose the bundle`s volume after heating. The crucible can then be covered and disposed of, the sleeve, on the other hand, can be reused.
Date: December 31, 1992
Creator: Heung, L. K.
System: The UNT Digital Library
Tritium monitor (open access)

Tritium monitor

This invention is comprised of a system for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream.
Date: December 31, 1992
Creator: Chastagner, P.
System: The UNT Digital Library
Ultrasonic fluid flow measurement method and apparatus (open access)

Ultrasonic fluid flow measurement method and apparatus

This invention is comprised of an apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.
Date: December 31, 1992
Creator: Kronberg, James W.
System: The UNT Digital Library
Underwater manipulator (open access)

Underwater manipulator

This invention is comprised of a self-contained, waterproof, water-submersible, remote-controlled apparatus provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer {plus_minus} 45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer {plus_minus} 10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.
Date: December 31, 1992
Creator: Schrum, Phillip B. & Cohen, George H.
System: The UNT Digital Library
Vacuum tool manipulator (open access)

Vacuum tool manipulator

This invention is comprised of an apparatus for manipulating a vacuum hose in a reactor vessel comprising a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.
Date: December 31, 1992
Creator: Zollinger, W.T.
System: The UNT Digital Library
Velocity damper for electromagnetically levitated materials (open access)

Velocity damper for electromagnetically levitated materials

A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.
Date: December 31, 1992
Creator: Fox, R. J.
System: The UNT Digital Library
Ventilation of porous media (open access)

Ventilation of porous media

Methods for distributing gases throughout the interstices of porous materials and removing volatile substances from the interstices of porous materials. Continuous oscillation of pressures and flows results in increased penetration of the interstices by flowing gases and increased transport of gaseous components out of the interstices. The invention is particularly useful in soil vapor extraction.
Date: December 31, 1992
Creator: Neeper, D.A.
System: The UNT Digital Library