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Lapped substrate for enhanced backsurface reflectivity in a thermophotovoltaic energy conversion system (open access)

Lapped substrate for enhanced backsurface reflectivity in a thermophotovoltaic energy conversion system

A method is described for fabricating a thermophotovoltaic energy conversion cell including a thin semiconductor wafer substrate having a thickness ({beta}) calculated to decrease the free carrier absorption on a heavily doped substrate; wherein the top surface of the semiconductor wafer substrate is provided with a thermophotovoltaic device, a metallized grid and optionally an antireflective (AR) overcoating; and, the bottom surface (10 ft) of the semiconductor wafer substrate is provided with a highly reflecting coating which may comprise a metal coating or a combined dielectric/metal coating.
Date: December 31, 1996
Creator: Baldasaro, Paul F.; Brown, Edward J.; Charache, Greg W. & DePoy, David M.
System: The UNT Digital Library
Mobile machine hazardous working zone warning system (open access)

Mobile machine hazardous working zone warning system

A warning system is provided for a mobile working machine to alert an individual of a potentially dangerous condition in the event the individual strays into a hazardous working zone of the machine. The warning system includes a transmitter mounted on the machine and operable to generate a uniform magnetic field projecting beyond an outer periphery of the machine in defining a hazardous working zone around the machine during operation thereof. A receiver, carried by the individual and activated by the magnetic field, provides an alarm signal to alert the individual when he enters the hazardous working zone of the machine.
Date: December 31, 1996
Creator: Schiffbauer, W.H. & Ganoe, C.W.
System: The UNT Digital Library
Remote repair appliance (open access)

Remote repair appliance

A remote appliance is described for supporting a tool for performing work at a worksite on a substantially circular bore of a workpiece and for providing video signals of the worksite to a remote monitor comprising: a baseplate having an inner face and an outer face; a plurality of rollers, wherein each roller is rotatably and adjustably attached to the inner face of the baseplate and positioned to roll against the bore of the workpiece when the baseplate is positioned against the mouth of the bore such that the appliance may be rotated about the bore in a plane substantially parallel to the baseplate; a tool holding means for supporting the tool, the tool holding means being adjustably attached to the outer face of the baseplate such that the working end of the tool is positioned on the inner face side of the baseplate; a camera for providing video signals of the worksite to the remote monitor; and a camera holding means for supporting the camera on the inner face side of the baseplate, the camera holding means being adjustably attached to the outer face of the baseplate. In a preferred embodiment, roller guards are provided to protect the rollers …
Date: December 31, 1996
Creator: Heumann, F.K.; Wilkinson, J.C. & Wooding, D.R.
System: The UNT Digital Library
Holding fixture for metallographic mount polishing (open access)

Holding fixture for metallographic mount polishing

A fixture for holding mounted specimens for polishing, having an arm; a body attached to one end of the arm, the body having at least one flange having an opening to accommodate a mounted specimen; and a means applying pressure against the outer surface of the mounted specimen to hold the specimen in contact with the polishing surface.
Date: December 31, 1996
Creator: Barth, C.H. & Cramer, C.E.
System: The UNT Digital Library
Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system (open access)

Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type and an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers.
Date: December 31, 1996
Creator: Charache, Greg W.; Baldasaro, Paul F. & Nichols, Greg J.
System: The UNT Digital Library
A thermophotovoltaic energy conversion device (open access)

A thermophotovoltaic energy conversion device

A thermophotovoltaic device and a method for making the thermophotovoltaic device are disclosed. The device includes an n-type semiconductor material substrate having top and bottom surfaces, a tunnel junction formed on the top surface of the substrate, a region of active layers formed on top of the tunnel junction and a back surface reflector (BSR). The tunnel junction includes a layer of heavily doped n-type semiconductor material that is formed on the top surface of the substrate and a layer of heavily doped p-type semiconductor material formed on the n-type layer. An optional pseudomorphic layer can be formed between the n-type and p-type layers. A region of active layers is formed on top of the tunnel junction. This region includes a base layer of p-type semiconductor material and an emitter layer of n-type semiconductor material. An optional front surface window layer can be formed on top of the emitter layer. An optional interference filter can be formed on top of the emitter layer or the front surface window layer when it is used.
Date: December 31, 1996
Creator: Charache, G. W.; Baldasaro, P. F. & Egley, J. L.
System: The UNT Digital Library
Method and apparatus for steady-state magnetic measurement of poloidal magnetic field near a tokamak plasma (open access)

Method and apparatus for steady-state magnetic measurement of poloidal magnetic field near a tokamak plasma

A method and apparatus for the steady-state measurement of poloidal magnetic field near a tokamak plasma, where the tokamak is configured with respect to a cylindrical coordinate system having z, phi (toroidal), and r axes. The method is based on combining the two magnetic field principles of induction and torque. The apparatus includes a rotor assembly having a pair of inductive magnetic field pickup coils which are concentrically mounted, orthogonally oriented in the r and z directions, and coupled to remotely located electronics which include electronic integrators for determining magnetic field changes. The rotor assembly includes an axle oriented in the toroidal direction, with the axle mounted on pivot support brackets which in turn are mounted on a baseplate. First and second springs are located between the baseplate and the rotor assembly restricting rotation of the rotor assembly about its axle, the second spring providing a constant tensile preload in the first spring. A strain gauge is mounted on the first spring, and electronic means to continually monitor strain gauge resistance variations is provided. Electronic means for providing a known current pulse waveform to be periodically injected into each coil to create a time-varying torque on the rotor assembly in …
Date: December 31, 1996
Creator: Woolley, R.D.
System: The UNT Digital Library
Method and apparatus for automatically detecting patterns in digital point-ordered signals (open access)

Method and apparatus for automatically detecting patterns in digital point-ordered signals

The present invention is a method and system for detecting a physical feature of a test piece by detecting a pattern in a signal representing data from inspection of the test piece. The pattern is detected by automated additive decomposition of a digital point-ordered signal which represents the data. The present invention can properly handle a non-periodic signal. A physical parameter of the test piece is measured. A digital point-ordered signal representative of the measured physical parameter is generated. The digital point-ordered signal is decomposed into a baseline signal, a background noise signal, and a peaks/troughs signal. The peaks/troughs from the peaks/troughs signal are located and peaks/troughs information indicating the physical feature of the test piece is output.
Date: December 31, 1996
Creator: Brudnoy, D. M.
System: The UNT Digital Library
Electronuclear ion fusion in an ion cyclotron resonance reactor (open access)

Electronuclear ion fusion in an ion cyclotron resonance reactor

A method and apparatus for generating nuclear fusion by ion cyclotron resonance in an ion trap reactor. The reactor includes a cylindrical housing having an axial axis, an internal surface, and first and second ends. First and second end plates that are charged are respectively located at the first and second ends of the cylindrical housing. A gas layer is adsorbed on the internal surface of the cylindrical housing. Ions are desorbed from the gas layer, forming a plasma layer adjacent to the cylindrical housing that includes first ions that have a same charge sign as the first and second end plates. A uniform magnetic field is oriented along the axial axis of the cylindrical housing. Second ions, that are unlike the first ions, but have the same charge sign, are injected into the cylindrical housing along the axial axis of the cylindrical housing. A radio frequency field resonantly accelerates the injected second ions at the cyclotron resonance frequency of the second ions. The second ions circulate in increasing helical orbits and react with the first ions, at the optimum energy for nuclear fusion. The amplitude of the radio frequency field is adjusted to accelerate the second ions at a …
Date: December 1, 1996
Creator: Cowgill, Donald F.
System: The UNT Digital Library
Superconducting thermoelectric generator (open access)

Superconducting thermoelectric generator

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 high thermal conductivity. 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: January 1, 1996
Creator: Metzger, John D. & El-Genk, Mohammed S.
System: The UNT Digital Library
Method for the photocatalytic conversion of methane (open access)

Method for the photocatalytic conversion of methane

The invention relates to a method for converting methane and water to methanol and hydrogen using visible light and a catalyst.
Date: December 1996
Creator: Noceti, R. P.; Taylor, C. E. & D'Este, J. R.
System: The UNT Digital Library
Down-flow moving-bed gasifier with catalyst recycle (open access)

Down-flow moving-bed gasifier with catalyst recycle

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.
Date: December 31, 1996
Creator: Halow, John S.
System: The UNT Digital Library
Retaining latch for a water pit gate (open access)

Retaining latch for a water pit gate

The present invention relates to retaining devices which are used to latch two elements or parts together and, more particularly, to gate latches for use in locking a gate to a wall bracket in a water pit utilized to store or handle hazardous materials. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame.
Date: December 31, 1996
Creator: Beale, A.R.
System: The UNT Digital Library
Multilayered nuclear fuel element (open access)

Multilayered nuclear fuel element

A nuclear fuel element is described which is suitable for high temperature applications comprised of a kernel of fissile material overlaid with concentric layers of impervious graphite, vitreous carbon, pyrolytic carbon and metal carbide. The kernel of fissile material is surrounded by a layer of impervious graphite. The layer of impervious graphite is then surrounded by a layer of vitreous carbon. Finally, an outer shell which includes alternating layers of pyrolytic carbon and metal carbide surrounds the layer of vitreous carbon.
Date: December 1, 1996
Creator: Schweitzer, Donald G. & Sastre, Cesar
System: The UNT Digital Library
Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system (open access)

Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength {lambda}{sub IF} approximately equal to the bandgap wavelength {lambda}{sub g} of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5{lambda}{sub IF} to {lambda}{sub IF} and reflect from {lambda}{sub IF} to about 2{lambda}{sub IF}; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5{lambda}{sub IF}.
Date: December 31, 1996
Creator: Brown, Edward J.; Baldasaro, Paul F. & Dziendziel, Randolph J.
System: The UNT Digital Library
Particle injector for fluid systems (open access)

Particle injector for fluid systems

A particle injector device provides injection of particles into a liquid stream. The device includes a funnel portion comprising a conical member having side walls tapering from a top opening (which receives the particles) down to a relatively smaller exit opening. A funnel inlet receives a portion of the liquid stream and the latter is directed onto the side walls of the conical member so as to create a cushion of liquid against which the particles impact. A main section of the device includes an inlet port in communication with the exit opening of the funnel portion. A main liquid inlet receives the main portion of the liquid stream at high pressure and low velocity and a throat region located downstream of the main liquid inlet accelerates liquid received by this inlet from the low velocity to a higher velocity so as to create a low pressure area at the exit opening of the funnel portion. An outlet opening of the main section enables the particles and liquid stream to exit from the injector device. This invention is particularly concerned with particle injection in connection with the calibration of inline optical particle counters.
Date: December 31, 1996
Creator: Ruch, J.F.
System: The UNT Digital Library
Light gas gun with reduced timing jitter (open access)

Light gas gun with reduced timing jitter

A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved by pneumatic means and free the projectile.
Date: December 1, 1996
Creator: Laabs, Gary W.; Funk, David J. & Asay, Blaine W.
System: The UNT Digital Library
A portable tester for determining gas content within a core sample (open access)

A portable tester for determining gas content within a core sample

A portable tester is provided for reading and displaying the pressure of a gas released from a rock core sample stored within a sealed container and for taking a sample of the released pressurized gas for chemical analysis thereof for subsequent use in a modified direct method test which determines the volume of gas and specific type of gas contained within the core sample. The portable tester includes a pair of low and high range electrical pressure transducers for detecting a gas pressure within a first pressure range of 0--25 psia or a second pressure range of 0--200 psig and for producing an electrical signal related to the detected pressure, a pair of low and high range display units electrically connected to the respective low and high range electrical pressure transducers for receiving the electrical signal produced therefrom and visually displaying the pressure of detected gas in a digital numeric readout, selector valve means in flow communication with the low and high range pressure transducers and having separate flow paths to each of the low and high range pressure transducers and a selector knob for selecting gas flow to one of the flow paths, and control valve means having an …
Date: December 31, 1996
Creator: Garcia, F. Jr. & Schatzel, S.J.
System: The UNT Digital Library
Hydrocracking and hydroisomerization of long-chain alkanes and polyolefins over metal-promoted anion-modified transition metal oxides (open access)

Hydrocracking and hydroisomerization of long-chain alkanes and polyolefins over metal-promoted anion-modified transition metal oxides

A method is described for cracking a feedstock by contacting the feedstock with a metal-promoted anion-modified metal oxide catalyst in the presence of hydrogen gas. The metal oxide of the catalyst is one or more of ZrO{sub 2}, HfO{sub 2}, TiO{sub 2} and SnO{sub 2}, and the feedstock is principally chains of at least 20 carbon atoms. The metal-promoted anion-modified metal oxide catalyst contains one or more of Pt, Ni, Pd, Rh, Ir, Ru, (Mn and Fe) or mixtures of them present between about 0.2% to about 15% by weight of the catalyst. The metal-promoted anion-modified metal oxide catalyst contains one or more of SO{sub 4}, WO{sub 3}, or mixtures of them present between about 0.5% to about 20% by weight of the catalyst.
Date: December 1996
Creator: Venkatesh, Koppampatti R.; Hu, Jianli; Tierney, John W. & Wender, Irving
System: The UNT Digital Library
Remote vacuum compaction of compressible hazardous waste (open access)

Remote vacuum compaction of compressible hazardous waste

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.
Date: December 31, 1996
Creator: Coyne, M. J.; Fiscus, G. M. & Sammel, A. G.
System: The UNT Digital Library
Cable load sensing device (open access)

Cable load sensing device

Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable no-load condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or …
Date: December 31, 1996
Creator: Beus, M. J. & McCoy, W. G.
System: The UNT Digital Library
Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide (open access)

Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixtures derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.
Date: December 31, 1996
Creator: Poston, J. A.
System: The UNT Digital Library
A tube-in-tube thermophotovoltaic generator (open access)

A tube-in-tube thermophotovoltaic generator

A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.
Date: December 31, 1996
Creator: Ashcroft, J.; Campbell, B. & Depoy, D.
System: The UNT Digital Library
Porous desulfurization sorbent pellets containing a reactive metal oxide and an inert zirconium compound (open access)

Porous desulfurization sorbent pellets containing a reactive metal oxide and an inert zirconium compound

Sorbent pellets for removing hydrogen sulfide from coal gas are prepared by combining a reactive oxide, in particular zinc oxide, with a zirconium compound such as an oxide, silicate, or aluminate of zirconium, and an inorganic binder and pelletizing and calcining the mixture. Alternately, the zinc oxide may be replaced by copper oxide or a combination of copper, molybdenum, and manganese oxides. The pellet components may be mixed in dry form, moistened to produce a paste, and converted to pellets by forming an aqueous slurry of the components and spray drying the slurry, or the reactive oxide may be formed on existing zirconium-containing catalyst-carrier pellets by infusing a solution of a salt of the active metal onto the existing pellets and firing at a high temperature to produce the oxide. Pellets made according to this invention show a high reactivity with hydrogen sulfide and durability such as to be useful over repeated cycles of sorption and regeneration.
Date: December 1, 1996
Creator: Gardner, Todd H. & Gasper-Galvin, Lee D.
System: The UNT Digital Library