56 Matching Results

Results open in a new window/tab.

Focused Ion beam source method and Apparatus (open access)

Focused Ion beam source method and Apparatus

A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.
Date: August 17, 1998
Creator: Pellin, Michael J.; Lykke, Keith R. & Lill, Thorsten B.
System: The UNT Digital Library
Improved Consolidation Process for Producing Ceramic Waste forms (open access)

Improved Consolidation Process for Producing Ceramic Waste forms

A process for the consolidation and containment of solid or semisolid hazardous waste, which process comprises closing an end of a circular hollow cylinder, filling the cylinder with the hazardous waste, and then cold working the cylinder to reduce its diameter while simultaneously compacting the waste. The open end of the cylinder can be sealed prior to or after the cold working process. The preferred method of cold working is to draw the sealed cylinder containing the hazardous waste through a plurality of dies to simultaneously reduce the diameter of the tube while compacting the waste. This process provides a quick continuous process for consolidating hazardous waste, including radioactive waste.
Date: July 24, 1998
Creator: Hash, Harry C. & Hash, Mark C.
System: The UNT Digital Library
Method and Apparatus to Produce and Maintain a thick, flowing, Liquid Lithium first wall for Toroidal Magnetic Confinement DT Fusion Reactors (open access)

Method and Apparatus to Produce and Maintain a thick, flowing, Liquid Lithium first wall for Toroidal Magnetic Confinement DT Fusion Reactors

A system for forming a thick flowing liquid metal, in this case lithium, layer on the inside wall of a toroid containing the plasma of a deuterium-tritium fission reactor. The presence of the liquid metal layer or first wall serves to prevent neutron damage to the walls of the toroid. A poloidal current in the liquid metal layer is oriented so that it flows in the same direction as the current in a series of external magnets used to confine the plasma. This current alignment results in the liquid metal being forced against the wall of the toroid. After the liquid metal exits the toroid it is pumped to a heat extraction and power conversion device prior to being reentering the toroid.
Date: October 21, 1998
Creator: Woolley, Robert D.
System: The UNT Digital Library
Attachment Apparatus (open access)

Attachment Apparatus

The present invention includes an attachment apparatus comprising a rotation limiting member adapted to be threaded onto a threaded member; and a preload nut adapted to be threaded onto the threaded member. The rotation limiting member comprises a plurality of pins; and the preload nut comprises plurality of slots, preferably wherein the plurality of pins and the plurality of slots are the same in number, which is preferably three. The plurality of pins of the rotation limiting member are filled into a corresponding plurality of slots of the preload nut to form a rotatable unit adapted to be threaded onto the threaded member. In use, the rotatable unit is threaded onto the threaded member. The present invention thus provides a unitized removable device for holes, including holes other than circular in shape, which have an established depth before an end of, or before an enlargement of the hole. The configuration of some exposed part of the device, or the head, is shaped and formed for its intended purpose, such as clamping, anchor points, eye bolts, stud anchor, and the like. The device allows for the installation, preloading and removal of all components of the device, as a unit, without damage …
Date: August 18, 1998
Creator: Morrison, Edward F.
System: The UNT Digital Library
Remote Adjustable focus Raman Spectroscopy Probe (open access)

Remote Adjustable focus Raman Spectroscopy Probe

A remote adjustable focus Raman spectroscopy probe allows for analyzing Raman scattered light from a point of interest external to the probe. An environmental barrier including at least one window separates the probe from the point of interest. An optical tube is disposed adjacent to the environmental barrier and includes along working length compound lens objective next to the window. A beam splitter and a mirror are at the other end. A mechanical means is used to translate the probe body in the X, Y, and Z directions resulting in a variable focus optical apparatus. Laser light is reflected by the beam splitter and directed toward the compound lens objective, then through the window and focused on the point of interest. Raman scattered light is then collected by the compound lens objective and directed through the beam splitter to a mirror. A device for analyzing the light, such as a monochrometer, is coupled to the mirror.
Date: July 28, 1998
Creator: Schmucker, John E.; Blasi, Raymond J. & Archer, William B.
System: The UNT Digital Library
Continuous air Agglomeration Method for high Carbon fly ash Beneficiation (open access)

Continuous air Agglomeration Method for high Carbon fly ash Beneficiation

The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carbon-free mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.
Date: September 29, 1998
Creator: Gray, McMahan L.; Champagne, Kenneth J. & Finseth, Dennis H.
System: The UNT Digital Library
Simplified Configuration for the Combustor of an oil Burner using a low Pressure, high flow air-atomizing Nozzle (open access)

Simplified Configuration for the Combustor of an oil Burner using a low Pressure, high flow air-atomizing Nozzle

The invention relates to clean burning of fuel oil with air. More specifically, to a fuel burning combustion head using a low-pressure, high air flow atomizing nozzle so that there will be a complete combustion oil resulting in a minimum emission of pollutants. The inventors have devised a fuel burner that uses a low pressure air atomizing nozzle. The improved fuel burner does not result in the use of additional compressors or the introduction of pressurized gases downstream, nor does it require a complex design.
Date: September 28, 1998
Creator: Butcher, Thomas; Celebi, Yusuf & Fisher, Leonard
System: The UNT Digital Library
Rippled beam free electron Laser Amplifier (open access)

Rippled beam free electron Laser Amplifier

A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a T{sub 0n} mode. A waveguide defines an axial centerline and . A solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.
Date: April 21, 1998
Creator: Carlsten, Bruce E.
System: The UNT Digital Library
Improved Spatial Filter for high power Lasers (open access)

Improved Spatial Filter for high power Lasers

A new pinhole architecture incorporates features intended to reduce the rate of plasma generation in a spatial filter for high-energy laser pulse beams. An elongated pinhole aperture is provided in an apertured body for rejecting off-axis rays of the laser pulse beam. The internal surface of the elongated aperture has a diameter which progressively tapers from a larger entrance cross-sectional area at an inlet to a smaller output cross-sectional area at an outlet. The tapered internal surface causes off-axis rays to be refracted in a low density plasma layer that forms on the internal surface or specularly reflected at grazing incidence from the internal surface. Off-axis rays of the high-energy pulse beam are rejected by this design. The external surface of the apertured body adjacent to the larger entrance cross-sectional area at the inlet to the elongated aperture is angled obliquely with respect to the to direction of the path of the high-energy laser pulse beam to backscatter off-axis rays away from the high-energy pulse beam. The aperture is formed as a truncated cone or alternatively with a tapered square cross-section. The internal surface of the aperture is coated with an ablative material, preferably high-density material which can be deposited …
Date: June 1, 1998
Creator: Estabrook, Kent G.; Celliers, Peter M.; Murray, James E.; DaSilva, Luiz; MacGowan, Brian J.; Rubenchik, Alexander M. et al.
System: The UNT Digital Library
Method for measuring Particulate and Gaseous Metals in a fluid stream, Device for measuring Particulate and Gaseous Metals in a fluid stream (open access)

Method for measuring Particulate and Gaseous Metals in a fluid stream, Device for measuring Particulate and Gaseous Metals in a fluid stream

A method for analyzing metal in a fluid is provided comprising maintaining a first portion of a continuous filter media substrate at a temperature coinciding with the phase in which the metal is to be analyzed; contacting the fluid to a first portion of said substrate to retain the metal on the first portion of said substrate; preventing further contact of the fluid to the first portion of substrate; and contacting the fluid to a second portion of said substrate to retain metal on the second portion of the said substrate while simultaneously analyzing the first portion for metal. Also provided is a device for the simultaneous monitoring and analysis of metal in a fluid comprising a continuous filter media substrate; means for maintaining a first portion of said filter media substrate at a temperature coinciding with the phase in which the metal is to be analyzed; a means for contacting the fluid to the first portion of said substrate; a means for preventing further contact of the fluid to the first portion of substrate; a means for contacting the fluid to a second portion of said substrate to retain metal on the second portion of the said substrate; and …
Date: October 21, 1998
Creator: Farber, Paul S. & Huang, Hann-Shen
System: The UNT Digital Library
Thermionic converter with differentially heated cesium-oxygen source and method of operation (open access)

Thermionic converter with differentially heated cesium-oxygen source and method of operation

A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided, wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.
Date: December 1, 1998
Creator: Rasor, N. S.; Riley, D. R.; Murray, C. S. & Geller, C. B.
System: The UNT Digital Library
A unique method of neutron flux determination from experimental data (open access)

A unique method of neutron flux determination from experimental data

A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.
Date: December 1, 1998
Creator: Paxton, Frank A.
System: The UNT Digital Library
Nanodisperse transition metal electrodes (NTME) for electrochemical cells (open access)

Nanodisperse transition metal electrodes (NTME) for electrochemical cells

Disclosed are transition metal electrodes for electrochemical cells using gel-state and solid-state polymers. The electrodes are suitable for use in primary and secondary cells. The electrodes (either negative electrode or positive electrode) are characterized by uniform dispersion of the transition metal at the nanoscale in the polymer. The transition metal moiety is structurally amorphous, so no capacity fade should occur due to lattice expansion/contraction mechanisms. The small grain size, amorphous structure and homogeneous distribution provide improved charge/discharge cycling performance, and a higher initial discharge rate capability. The cells can be cycled at high current densities, limited only by the electrolyte conductivity. A method of making the electrodes (positive and negative), and their usage in electrochemical cells are disclosed.
Date: December 1, 1998
Creator: Striebel, Kathryn A. & Wen, Shi-Jie
System: The UNT Digital Library
Process for strengthening aluminum based ceramics and material (open access)

Process for strengthening aluminum based ceramics and material

A process for strengthening aluminum based ceramics is provided. A gaseous atmosphere consisting essentially of silicon monoxide gas is formed by exposing a source of silicon to an atmosphere consisting essentially of hydrogen and a sufficient amount of water vapor. The aluminum based ceramic is exposed to the gaseous silicon monoxide atmosphere for a period of time and at a temperature sufficient to produce a continuous, stable silicon-containing film on the surface of the aluminum based ceramic that increases the strength of the ceramic.
Date: December 1, 1998
Creator: Moorhead, Arthur J. & Kim, Hyoun-Ee
System: The UNT Digital Library
Oxide strengthened molybdenum-rhenium alloy (open access)

Oxide strengthened molybdenum-rhenium alloy

Provided is a method of making an ODS molybdenum-rhenium alloy which includes the steps of: (1) forming a slurry containing molybdenum oxide and a metal salt dispersed in an aqueous medium, the metal salt being selected from nitrates or acetates of lanthanum, cerium or thorium; (2) heating the slurry in the presence of hydrogen to form a molybdenum powder comprising molybdenum and an oxide of the metal salt; (3) mixing rhenium powder with the molybdenum powder to form a molybdenum-rhenium powder; (4) pressing the molybdenum-rhenium powder to form a molybdenum-rhenium compact; (5) sintering the molybdenum-rhenium compact in hydrogen or under a vacuum to form a molybdenum-rhenium ingot; and (6) compacting the molybdenum-rhenium ingot to reduce the cross-sectional area of the molybdenum-rhenium ingot and form a molybdenum-rhenium alloy containing said metal oxide. The present invention also provides an ODS molybdenum-rhenium alloy made by the method.
Date: December 1, 1998
Creator: Bianco, Robert & Buckman, William R. Jr.
System: The UNT Digital Library
A rigid porous filter and filtration method (open access)

A rigid porous filter and filtration method

The present invention involves a porous rigid filter comprising a plurality of concentric filtration elements having internal flow passages and forming external flow passages there between. The present invention also involves a pressure vessel containing the filter for the removal of particulate from high pressure particulate containing gases, and further involves a method for using the filter to remove such particulate. The present filter has the advantage of requiring fewer filter elements due to the high surface area- to-volume ratio provided by the filter, requires a reduced pressure vessel size, and exhibits enhanced mechanical design properties, improved cleaning properties, configuration options, modularity and ease of fabrication.
Date: December 1998
Creator: Chiang, Ta-Kuan; Straub, Douglas, Straub L. & Dennis, Richard A.
System: The UNT Digital Library
Electrochemical storage cell containing a substituted anisole or di-anisole redox shuttle additive for overcharge protection and suitable for use in liquid organic and solid polymer electrolytes (open access)

Electrochemical storage cell containing a substituted anisole or di-anisole redox shuttle additive for overcharge protection and suitable for use in liquid organic and solid polymer electrolytes

A electrochemical cell is described comprising an anode, a cathode, a solid polymer electrolyte; and a redox shuttle additive to protect the cell against overcharging and a redox shuttle additive to protect the cell against overcharging selected from the group consisting of: (a) a substituted anisole having the general formula shown in a figure (in an uncharged state): where R{sub 1} is selected from the group consisting of H, 0CH{sub 3}, OCH{sub 2}CH{sub 3}, and OCH{sub 2}phenyl, and R{sub 2} is selected from the group consisting of OCH{sub 3}, OCH{sub 2}CH{sub 3}, OCH{sub 2} phenyl, and O{sup {minus}}Li{sup +}; and (b) a di-anisole compound having the general formula shown in a second figure (in an uncharged state): where R is selected from the group consisting of -OCH{sup 3} and -CH{sub 3}, m is either 1 or 0, n is either 1 or 0, and X is selected from the group consisting of -OCH{sub 3} (methoxy) or its lithium salt -O{sup {minus}}Li{sup +}. The lithium salt of the di-anisole is the preferred form of the redox shuttle additive because the shuttle anion will then initially have a single negative charge, it loses two electrons when it is oxidized at the cathode, …
Date: March 1998
Creator: Kerr, John B. & Tian, Minmin
System: The UNT Digital Library
Fatty acyl-CoA reductase (open access)

Fatty acyl-CoA reductase

The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.
Date: December 1, 1998
Creator: Reiser, Steven E. & Somerville, Chris R.
System: The UNT Digital Library
Self-seeded injection-locked FEL amplifier (open access)

Self-seeded injection-locked FEL amplifier

A self-seeded free electron laser (FEL) provides a high gain and extraction efficiency for the emitted light. An accelerator outputs a beam of electron pulses to a permanent magnet wiggler having an input end for receiving the electron pulses and an output end for outputting light and the electron pulses. An optical feedback loop collects low power light in a small signal gain regime at the output end of said wiggler and returns the low power light to the input end of the wiggler while outputting high power light in a high signal gain regime.
Date: December 1, 1998
Creator: Sheffield, Richard L.
System: The UNT Digital Library
Solar reduction of CO{sub 2} (open access)

Solar reduction of CO{sub 2}

The red shift of the absorption spectrum of CO{sub 2} with increasing temperature, along with CO stabilization are the foundation of a process for direct solar reduction of CO{sub 2} to liquid fuels. The result is a process capable of using renewable solar energy to directly reduce CO{sub 2} from the atmosphere or stationary sources for recycle as a liquid fuel resulting in a net decrease in CO{sub 2} in the atmosphere and decreased demand on fossil fuel. The process includes in sequence: preparation of adequately pure CO{sub 2} feed; preheating CO{sub 2} to near 1,800 K; breaking the CO{sub 2} bonds to produce CO, O{sub 2} and O; quenching the hot product mix by rapid admixture with room temperature CO{sub 2}; removing excess thermal energy to produce electricity, heat new CO{sub 2} and enable subsequent process steps; removing the remaining CO{sub 2} from the gas; removing oxygen from the gas; converting part of the product CO to H{sub 2} by the shift reaction; and, finally, catalytically synthesizing methanol from the synthetic gas.
Date: December 1, 1998
Creator: Jensen, Reed J.; Lyman, John L.; King, Joe D. & Guettler, Robert D.
System: The UNT Digital Library
Drum bubbler tritium processing system (open access)

Drum bubbler tritium processing system

A method is described for separating tritium oxide from a gas stream containing tritium oxide. The gas stream containing tritium oxide is fed into a container of water having a head space above the water. Bubbling the gas stream containing tritium oxide through the container of water and removing gas from the container head space above the water. Thereafter, the gas from the head space is dried to remove water vapor from the gas, and the water vapor is recycled to the container of water.
Date: December 1, 1998
Creator: Rule, Keith; Gettelfinger, Geoff & Kivler, Paul
System: The UNT Digital Library
Periodic equivalence ratio modulation method and apparatus for controlling combustion instability (open access)

Periodic equivalence ratio modulation method and apparatus for controlling combustion instability

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.
Date: December 1, 1998
Creator: Richards, George A.; Janus, Michael C. & Griffith, Richard A.
System: The UNT Digital Library
Method for direct production of carbon disulfide and hydrogen from hydrocarbons and hydrogen sulfide feedstock (open access)

Method for direct production of carbon disulfide and hydrogen from hydrocarbons and hydrogen sulfide feedstock

A method for converting hydrocarbons and hydrogen sulfide to carbon disulfide and hydrogen is provided comprising contacting the hydrocarbons and hydrogen sulfide to a bi-functional catalyst residing in a controlled atmosphere for a time and at a temperature sufficient to produce carbon disulfide and hydrogen. Also provided is a catalyst for converting carbon sulfides and hydrogen sulfides to gasoline range hydrocarbons comprising a mixture containing a zeolite catalyst and a hydrogenating catalyst.
Date: December 1998
Creator: Miao, F. Q. & Erekson, E. J.
System: The UNT Digital Library
Laser barometer (open access)

Laser barometer

This paper describes an invention of a pressure measuring instrument which uses laser radiation to sense the pressure in an enclosed environment by means of measuring the change in refractive index of a gas - which is pressure dependent.
Date: April 1, 1998
Creator: Abercrombie, K.R.; Shiels, D. & Rash, T.
System: The UNT Digital Library