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79
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57
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Lebanon: Background and U.S. Relations
This report provides an overview of Lebanese politics, recent events in Lebanon, and current issues in U.S.-Lebanon relations and will be updated to reflect major developments.
Date:
May 19, 2009
Creator:
Addis, Casey L.
Object Type:
Report
System:
The UNT Digital Library
Design Methodology and Consideratios for NOVA 53 MHZ RF Cavities
The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing Neutrino at Main Injector (NuMI) beamline. This beamline is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. The cavities will operate at 53 MHz and three of them will be installed in the Recycler beamline. Thermal stability of the cavities is crucial since this affects the tuning. Results of finite element thermal and structural analysis involving the copper RF cavity will be presented.
Date:
May 19, 2010
Creator:
Ader, C. & Wildman, D.W.
Object Type:
Article
System:
The UNT Digital Library
U.S.-French Commercial Ties
This report discusses the U.S. commercial ties with France, which are extensive, mutually profitable, and growing. With over $1.2 billion in commercial transactions taking place between the two countries every day of the year, each country has an increasingly large stake in the health and openness of the other's economy
Date:
May 19, 2008
Creator:
Ahearn, Raymond J.
Object Type:
Report
System:
The UNT Digital Library
Laser fusion implosion and target interaction physics
Laser plasma experiments at the Lawrence Livermore Laboratory have progressed very rapidly and have achieved new milestones in both the implosion and DT gain in laser fusion targets. New diagnostic methods were also developed for determining the state of the compressed fuel and the plasma processes which are occurring in the absorption and scattering of the laser light incident on the laser fusion pellets. A review of the program is given. (MOW)
Date:
May 19, 1977
Creator:
Ahlstrom, Harlow G. & Nuckolls, John H.
Object Type:
Article
System:
The UNT Digital Library
Supersymmetric and Kaluza-Klein Particles Multiple Scattering in the Earth
Neutrino telescopes with cubic kilometer volume have the potential to discover new particles. Among them are next to lightest supersymmetric (NLSPs) and next to lightest Kaluza-Klein (NLKPs) particles. Two NLSPs or NLKPs will transverse the detector simultaneously producing parallel charged tracks. The track separation inside the detector can be a few hundred meters. As these particles might propagate a few thousand kilometers before reaching the detector, multiple scattering could enhance the pair separation at the detector. We find that the multiple scattering will alter the separation distribution enough to increase the number of NLKP pairs separated by more than 100 meters (a reasonable experimental cut) by up to 46% depending on the NLKP mass. Vertical upcoming NLSPs will have their separation increased by 24% due to multiple scattering.
Date:
May 19, 2009
Creator:
Albuquerque, Ivone & Klein, Spencer
Object Type:
Article
System:
The UNT Digital Library
A Review of X-ray Diagnostic Calibrations in the 2 to 100 keV Region Using the High Energy X-ray Calibration Facility (HEX)
The precise and accurate measurement of X-rays in the 2 keV to 100 keV region is crucial to the understanding of HED plasmas and warm dense matter in general. With the emergence of inertially confined plasma facilities as the premier platforms for ICF, laboratory astrophysics, and national security related plasma experiments, the need to calibrate diagnostics in the high energy X-ray regime has grown. At National Security Technologies High Energy X-ray Calibration Facility (HEX) in Livermore, California, X-ray imagers, filter-fluorescer spectrometers, crystal spectrometers, image plates, and nuclear diagnostics are calibrated. The HEX can provide measurements of atomic line radiation, X-ray flux (accuracy within 10%), and X-ray energy (accuracy within 1%). The HEX source is comprised of a commercial 160 kV X-ray tube, a fluorescer wheel, a filter wheel, and a lead encasement. The X-ray tube produces a Tungsten bremsstrahlung spectrum which causes a foil to fluoresce line radiation. To minimize bremsstrahlung in the radiation for calibration we also provide various foils as filters. For experimental purposes, a vacuum box capable of 10{sup -7} Torr, as well as HPGe and CdTe radiation detectors, are provided on an optical table. Most geometries and arrangements can be changed to meet experimental needs.
Date:
May 19, 2010
Creator:
Ali, Zaheer; Pond, T.; Buckles, R. A.; Maddox, B. R.; Chen, C. D.; DeWald, E. L. et al.
Object Type:
Article
System:
The UNT Digital Library
Geant4 Developments And Applications
None
Date:
May 19, 2006
Creator:
Allison, J.; Amako, K.; Apostolakis, J.; Araujo, H.; Dubois, P.A.; Asai, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Nut and Bolt Lock
Patent for a new nut and bolt lock design that is reliable and can lock permanently if needed, including illustrations.
Date:
May 19, 1914
Creator:
Ames, Ernest R.
Object Type:
Patent
System:
The Portal to Texas History
Broad, intense, quiescent beam of singly charged metal ions obtained by extraction from self-sputtering plasma far above the runaway threshold
Dense metal plasmas obtained by self-sputtering far above the runway threshold are well suited to generate intense quiescent ion beams. The dilemma of high current density and charge state purity can be solved when using target materials of low surface binding energy by utilizing non-resonant exchange reactions before ion extraction. Space-charge-limited quiescent beams of Cu+, Zn+, and Bi+ with ~;;10 mA/cm2 have been obtained through multi-aperture gridded ion extraction up to 45 kV from self-sputtering plasmas.
Date:
May 19, 2009
Creator:
Anders, Andre & Oks, Efim
Object Type:
Article
System:
The UNT Digital Library
Engineering work plan and design basis for 241-SY ventilation improvements
There are three tanks in the 241-SY tank farm. Tank 241-SY101 and 241-SY-103 are flammable gas watch list tanks. Tank 241-SY-102 is included in the ventilation improvement process in an effort to further control air flow in the tank farm. This tank farm has only one outlet ventilation port for all three tanks. Flammable gas is released (may be steady and/or periodic) from the waste in the primary tank vapor space. The gas is removed from the tank by an active ventilation system. However, maintaining consistent measurable flow through the tank can be problematic due to the poor control capabilities of existing equipment. Low flow through the tank could allow flammable gas to build up in the tank and possibly exceed the lower flammability limit (LFL), prevent the most rapid removal of flammable gas from the tank after a sudden gas release, and/or cause high vacuum alarms to sound. Using the inlet and outlet down stream butterfly valves performs the current method of controlling flow in tank farm 241-SY. A filter station is installed on the inlet of each tank, but controlling air flow with its 12 inch butterfly valve is difficult. There is also in-leakage through pump and valve …
Date:
May 19, 1997
Creator:
Andersen, J. A.
Object Type:
Report
System:
The UNT Digital Library
Irreversible Sorption of Contaminants During Ferrihydrite Transformation
A better understanding of the fraction of contaminants irreversibly sorbed by minerals is necessary to effectively quantify bioavailability. Ferrihydrite, a poorly crystalline iron oxide, is a natural sink for sorbed contaminants. Contaminants may be sorbed/occluded as ferrihydrite precipitates in natural waters or as it ages and transforms to more crystalline iron oxides such as goethite or hematite. Laboratory studies indicate that Cd, Co, Cr, Cu, Ni, Np, Pb, Sr, U, and Zn are irreversibly sorbed to some extent during the aging and transformation of synthetic ferrihydrite. Barium, Ra and Sr are known to sorb on ferrihydrite in the pH range of 6 to 10 and sorb more strongly at pH values above its zero point of charge (pH> 8). We will review recent literature on metal retardation, including our laboratory and modeling investigation of Ba (as an analogue for Ra) and Sr adsorption/resorption, during ferrihydrite transformation to more crystalline iron oxides. Four ferrihydrite suspensions were aged at pH 12 and 50 °C with or without Ba in 0.01 M KN03 for 68 h or in 0.17 M KN03 for 3424 h. Two ferrihydrite suspensions were aged with and without Sr at pH 8 in 0.1 M KN03 at 70°C. Barium …
Date:
May 19, 1999
Creator:
Anderson, H. L.; Arthur, S. E.; Brady, P. V.; Cygan, R. T.; Nagy, K. L. & Westrich, H. R.
Object Type:
Article
System:
The UNT Digital Library
Vehicle-Wheel.
Patent for a vehicle wheel "which embodies a flexible tread and radially arranged springs for absorbing shocks and cushioning the yielding action of the parts of said tread" (lines 9-13).
Date:
May 19, 1914
Creator:
Anderson, Lycurgus
Object Type:
Patent
System:
The Portal to Texas History
The European Parliament
This report mainly discusses The European Parliament which is a key institution of 28 member European Union. The role of the European Parliament in the legislative has expanded steadily over time as the scope of EU policy has grown.
Date:
May 19, 2014
Creator:
Archick, Kristin
Object Type:
Report
System:
The UNT Digital Library
Northern Ireland: The Peace Process
For years, the British and Irish governments sought to facilitate a peaceful settlement to the conflict in Northern Ireland. After many ups and downs, the two governments and the eight parties participating in peace talks announced an agreement on April 10, 1998. However, the implementation of the resulting Good Friday The agreement continues to be difficult. This report will be updated as events warrant.
Date:
May 19, 2005
Creator:
Archick, Kristin
Object Type:
Report
System:
The UNT Digital Library
Wet Oxidation of High-Al-Content III-V Semiconductors: Important Materials Considerations for Device Applications
Wet oxidation of high-Al-content AIGaAs semiconductor layers in vertical cavity surface emitting lasers (VCSELS) has produced devices with record low threshold currents and voltages and with wall-plug efficiencies greater than 50%. Wet oxidation of buried AlGaAs layers has been employed to reduce the problems associated with substrate current leakage in GaAs-on- insulator (GOI) MESFETS. Wet oxidation of high-Al-content AlGaAs semiconductor layers in vertical cavity surface emitting lasers (VCSELS) has produced devices with record low threshold currents and voltages and with wall-plug efficiencies greater than 50%. Wet oxidation of buried AlGaAs layers has been employed to reduce the problems associated with substrate current leakage in GaAs-on- insulator (GOI) MESFETS. Wet oxidation has also been considered as a route to the long-sought goal of a IH-V MIS technology. To continue improving device designs for even higher performance and to establish a truly manufacturable technology based on wet oxidation, the effect of oxidation of a given layer on the properties of the entire device structure must be understood. The oxidation of a given layer can strongly affect the electrical and chemical properties of adjacent layers. Many of these effects are derived from the production of large amounts of elemental As during the oxidation …
Date:
May 19, 1999
Creator:
Ashby, Carol I.H.
Object Type:
Article
System:
The UNT Digital Library
Diagnostics for the laser fusion program: plasma physics on the scale of microns and picoseconds
Laser induced fusion is the forerunner of a class of inertial confinement schemes in which hydrogen isotopes are heated to thermonuclear conditions in a very short period. The process is characterized by such short time scales that fuel confinement is achieved through its' own finite mass and expansion velocity, approaching 1 ..mu..m/psec for ignition temperatures of order 10 keV (10/sup 8/ /sup 0/K). With current laser powers limited to several terrawatts one readily estimates, on the basis of energy conservation, target mass, and expansion velocity, that target size and laser pulse duration are on the order of 100 ..mu..m and 100 psec, respectively. Within these constraints, targets have been heated and confined to the point where thermonuclear conditions have been achieved. This paper describes a sampling of diagnostic techniques with requisite resolution (microns and picoseconds) to accurately describe the dynamics of a laser driven compression. As discussed in each case cited, these in turn provide insight to and quantitative measure of, the physical processes dominating the implosion. The success of the inertial confinement fusion program is strongly dependent on the continued development of such diagnostics and the understanding they provide.
Date:
May 19, 1978
Creator:
Attwood, D.T.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the Mass Difference m(B0) - m(B+)
Using 230 million B{bar B} events recorded with the BABAR detector at the e{sup +}e{sup -} storage rings PEP-II, they reconstruct approximately 4100 B{sup 0} {yields} J/{psi} K{sup +}{pi}{sup -} and 9930 B{sup +} {yields} J/{psi}K{sup +} decays with J/{psi} {yields} {mu}{sup +}{mu}{sup -} and e{sup +} e{sup -}. From the measured B-momentum distributions in the e{sup +}e{sup -} rest frame, they determine the mass difference m(B{sup 0}) - m(B{sup +}) = (+0.33 {+-} 0.05 {+-} 0.03) MeV/c{sup 2}.
Date:
May 19, 2008
Creator:
Aubert, B.
Object Type:
Article
System:
The UNT Digital Library
Thermal-envelop stone house, solar. Final technical report
The purpose of this project is to create a comfortable, low-cost heating system for a single-family house, without dependence on non-renewable energy sources. I have attempted to combine a simple solar air-heating collector with the thermal envelop concept (for thermal air circulation) and massive interior stone walls for heat storage. All building materials, with the exception of the solar glazing material and certain other solar components, are inexpensive and locally produced. Examples are: rough-cut hardwood lumber, sandstone (free for the gathering), galvanized roofing for absorberplate, concrete, concrete block, and cellulose insulation. The collector has operated with a relatively high degree of efficiency, though three 0.6 amp duct fans had to be installed in order to increase air circulation. The interior stonework has provided more than adequate heat storage, along with even heat radiation throughout cloudy periods. My main problem has been heat loss around the foundation.
Date:
May 19, 1982
Creator:
Avery, S. C.
Object Type:
Report
System:
The UNT Digital Library
Epitaxially-Grown GaN Junction Field Effect Transistors
Junction field effect transistors (JFET) are fabricated on a GaN epitaxial structure grown by metal organic chemical vapor deposition (MOCVD). The DC and microwave characteristics of the device are presented. A junction breakdown voltage of 56 V is obtained corresponding to the theoretical limit of the breakdown field in GaN for the doping levels used. A maximum extrinsic transconductance (g<sub>m</sub>) of 48 mS/mm and a maximum source-drain current of 270 mA/mm are achieved on a 0.8 µ m gate JFET device at V<sub>GS</sub>= 1 V and V<sub>DS</sub>=15 V. The intrinsic transconductance, calculated from the measured g<sub>m</sub> and the source series resistance, is 81 mS/mm. The f<sub>T</sub> and f<sub>max</sub> for these devices are 6 GHz and 12 GHz, respectively. These JFETs exhibit a significant current reduction after a high drain bias is applied, which is attributed to a partially depleted channel caused by trapped hot-electrons in the semi-insulating GaN buffer layer. A theoretical model describing the current collapse is described, and an estimate for the length of the trapped electron region is given.
Date:
May 19, 1999
Creator:
Baca, A. G.; Chang, P. C.; Denbaars, S. P.; Lester, L. F.; Mishra, U. K.; Shul, R. J. et al.
Object Type:
Article
System:
The UNT Digital Library
Direct flow in 10.8 GeV/nucleon Au+Au collisions measured in experiment E917 at the AGS.
Analysis of directed flow observable for protons and pions from Au+Au collisions at 10.8 GeV/nucleon from experiment E917 at the AGS is presented. Using a Fourier series expansion, the first Fourier component, {nu}{sub 1},was extracted as a function of rapidity for mid-central collisions (17-24%). Clear evidence for positive directed flow is found in the proton data, and a weak, possibly negative directed flow signal is observed for {pi}{sup +} and {pi}{sup {minus}}.
Date:
May 19, 1999
Creator:
Back, B. B.; Betts, R. R.; Britt, H. C.; Chang, J.; Chang, W. C.; Gillitzer, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Laser Heated High Density Fluids Probed by Coherent Anti-Stokes Raman Spectroscopy
We describe an integrated experimental method of Coherent Antistoke Raman Spectroscopy (CARS), laser-heating and diamond-anvil cell (DAC) technologies probing molecular vibrations of transparent molecular fluids at the pressure-temperature conditions of energetic detonation and Giant planetary interiors. In this method, we use a microfabricated metal toroid to conductively heat a surrounding transparent sample in a DAC, using a CW Nd:YLF laser. The laser is operated at a TEM{sub 01*} mode to match the shape of the toroid and thus produces a uniform heating area. The CARS probe utilizes two pulsed lasers with similar cavity lengths: a commercial narrow-band mode-locked Q-switched Nd:YAG laser and a home-built broadband dye laser. A strong CARS signal is then produced from the sample in the central region of laser-heated metal toroid where the two laser pulses spatially and temporally coincide. In this paper, we will demonstrate that this technique is capable of producing high quality vibrational spectra from nitrogen fluid above 2000 K and 13 GPa, where the application of spontaneous Raman spectroscopy is limited because of intense thermal radiation.
Date:
May 19, 2004
Creator:
Baer, B J & Yoo, C
Object Type:
Article
System:
The UNT Digital Library
Fused Lithium Salts: A Bibliography Covering 1950-57
None
Date:
May 19, 1958
Creator:
Baughman, D. & Maynard, G.R.
Object Type:
Report
System:
The UNT Digital Library
Fused Lithium Salts : A Bibliography Covering 1950-57
This is a bibliography referencing documents based on fused lithium salts within the years 1950-57.
Date:
May 19, 1958
Creator:
Baughman, Dorothy & Maynard, G. R.
Object Type:
Report
System:
The UNT Digital Library
IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems
With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system …
Date:
May 19, 2003
Creator:
Baxter, VAN
Object Type:
Report
System:
The UNT Digital Library