["Bush Admin. Broadens Gay Overtures" article, October 27, 2001] (open access)

["Bush Admin. Broadens Gay Overtures" article, October 27, 2001]

An article, written by David Crary for The Washington Post, about the Bush administration's early support for gay and lesbian individuals and the response from the socially conservative right as well as the left.
Date: October 27, 2001
Creator: Crary, David
System: The UNT Digital Library
Performance Enhancement of Negative Ion Sources for the JT-60U Tokamak (open access)

Performance Enhancement of Negative Ion Sources for the JT-60U Tokamak

None
Date: October 27, 2000
Creator: L.R. Grisham, M. Kuriyama, M. Kawai, T. Itoh, N. Umeda, and JT-60U Team
System: The UNT Digital Library
Fracture Behavior of Double-Ion-Exchanged Glass (open access)

Fracture Behavior of Double-Ion-Exchanged Glass

None
Date: October 27, 2000
Creator: BEAUCHAMP,EDWIN KNIGHT
System: The UNT Digital Library
Laser Filamentation of a Femtosecond Pulse in Air at 400nm (open access)

Laser Filamentation of a Femtosecond Pulse in Air at 400nm

None
Date: October 27, 2000
Creator: NELSON,THOMAS R.; LUK,TING S.; BERNSTEIN,AARON C. & CAMERON,STEWART M.
System: The UNT Digital Library
Putting 'international' back in IPEC. (open access)

Putting 'international' back in IPEC.

During the previous six annual sessions of the International Petroleum Environmental Conference (IPEC), little attention has been given to international issues. Although the US is clearly a leader in oil field research and regulatory development information is available on interesting projects throughout the world Many participants in IPEC have little exposure to international oil and gas environmental problems and solutions. Beginning with the 7th IPEC, a stronger effort is being made to include international issues in the confidence. This paper describes some of the author's experiences in working with international oil and gas environmental issues in North America, Latin America, Europe, and Asia. Among the topics to be discussed are the issues that developing oil and gas-producing nations face and the need for sensitivity to other nation's cultures and legal systems.
Date: October 27, 2000
Creator: Veil, J. A.
System: The UNT Digital Library
Review of Back Contact Silicon Solar Cells for Low Cost Application (open access)

Review of Back Contact Silicon Solar Cells for Low Cost Application

None
Date: October 27, 2000
Creator: SMITH,DAVID D. & GEE,JAMES M.
System: The UNT Digital Library
Future experiments with neutrino superbeams, beta-beams, and neutrino factories (open access)

Future experiments with neutrino superbeams, beta-beams, and neutrino factories

This report describes the goals of the next generations of accelerator-based neutrino experiments, and the various strategies that are being considered to achieve those goals. Because these next steps in the field are significantly different from the current or previous steps, novel techniques must be considered for both the detectors and the neutrino beams themselves. We consider not only conventional neutrino beams created by decays of pions, but also those which could be made by decays of beams of relativistic isotopes (so-called ''beta-beams'') and also by decays of beams of muons (neutrino factories).
Date: October 27, 2003
Creator: Harris, Deborah A
System: The UNT Digital Library
Results on diffraction at CDF (open access)

Results on diffraction at CDF

In run I CDF made an extensive range of measurements studying diffractive processes. In run II these measurements can be extended using improved triggering, new detectors and larger data samples. In these proceedings run II measurements of single diffractive dijet production and double pomeron exchange production of dijets are presented.
Date: October 27, 2003
Creator: Wyatt, A.
System: The UNT Digital Library
Comparing zonal and CFD models of air flows in large indoor spaces to experimental data (open access)

Comparing zonal and CFD models of air flows in large indoor spaces to experimental data

None
Date: October 27, 2000
Creator: Mora, Laurent; Gadgil, Ashok & Wurtz, Etienne
System: The UNT Digital Library
A localized basis that allows fast and accurate second order Moller-Plesset calculations (open access)

A localized basis that allows fast and accurate second order Moller-Plesset calculations

We present a method for computing a basis of localized orthonormal orbitals (both occupied and virtual), in whose representation the Fock matrix is extremely diagonal-dominant. The existence of these orbitals is shown empirically to be sufficient for achieving highly accurate MP@ energies, calculated according to Kapuy's method. This method (which we abbreviate KMP2), which involves a different partitioning of the n-electron Hamiltonian, scales at most quadratically with potential for linearity in the number of electrons. As such, we believe the KMP2 algorithm presented here could be the basis of a viable approach to local correlation calculations.
Date: October 27, 2004
Creator: Subotnik, Joseph E. & Head-Gordon, Martin
System: The UNT Digital Library
Metals Retention in Constructed Wetland Sediments (open access)

Metals Retention in Constructed Wetland Sediments

The A-01 wetland treatment system (WTS) was designed to remove metals from the effluent at the A-01 NPDES outfall at the Savannah River Site, Aiken, SC. Sequential extraction data was used to evaluate remobilization and retention of Cu, Pb, Zn, Mn, and Fe in the wetland sediment. Remobilization of metals was determined by the Potentially Mobile Fraction (PMF) and metal retention by the Recalcitrant Factor (RF). The PMF, which includes water soluble, exchangeable, and oxides fractions, is the contaminant fraction that has the potential to enter into the mobile aqueous phase under changeable environmental conditions. PMF values were low for Cu, Zn and Pb (about 20 percent) and high for Fe and Mn (about 60 to 70 percent). The RF, which includes crystalline oxides, sulfides or silicates and aluminosilicates, is the ratio of strongly bound fractions to the total concentration of elements in sediment. RF values were about 80 percent for Cu, Zn and Pb, indicating high retention in the sediment and 30 percent to above 40 percent for Fe and Mn indication low retention.
Date: October 27, 2004
Creator: KNOX, ANNA
System: The UNT Digital Library
Effects of Substrate Surface Defects and Te Dopant Concentration on Crystalline Quality and Electrical Characteristics of AlGaAsSb Epitaxial Layers (open access)

Effects of Substrate Surface Defects and Te Dopant Concentration on Crystalline Quality and Electrical Characteristics of AlGaAsSb Epitaxial Layers

Tellurium doped AlGaAsSb epitaxial layers were grown lattice-matched on GaSb substrates and lattice-mismatched on semi-insulating GaAs substrates by organometallic vapor phase epitaxy. Secondary ion mass spectroscopy and Hall data showed that the ratio of carrier concentration to Te concentration decreases from 40% to 5% when the Te concentration increases from 4.8 x 10{sup 17} cm{sup -3} to 1.3 x 10{sup 19} cm{sup -3}. Transmission electron microscopy (TEM) showed that the material with heavily doped Te generates a high density (about 10{sup 8} cm{sup 2}) of planar defects. Most of the Te-related defects originate at the GaSb buffer layer/AlGaAsSb epilayer interface. In addition, discrete precipitates were observed in the heavily doped AlGaAsSb layer. TEM imaging revealed amorphous defects (likely residual native oxides) along the GaSb substrate/GaSb buffer interface. High resolution TEM imaging revealed high quality growth beyond the GaSb-buffer/GaSb-substrate interfacial defects. The microstructural impact of GaSb-buffer/GaSb-substrate interface defects on the crystalline quality of AlGaAsSb layers is insignificant.
Date: October 27, 2004
Creator: Ehsani, H.; Lewis, N.; Nichols, G.; Danielson, L.; Dashiell, M.; Shellenbarger, Z. et al.
System: The UNT Digital Library
Resonant soft X-ray emission spectroscopy of liquids (open access)

Resonant soft X-ray emission spectroscopy of liquids

We present now a possible way to carry out soft-x-rayfluorescence spectroscopy of liquids. The liquid cell has a window toattain compatibility with UHV conditions of the spectrometer andbeamline, The synchrotron radiation enters the liquid cell through a 100nm-thick silicon nitride window and the emitted xrays exit through thesame window. This allows in particular liquid solid interfaces to bestudied. Such a liquid cell has been used to study the electronicstructure of a variety of systems ranging from water solutions ofinorganic salts and inertial drugs to nano materials and actinidecompounds in their wet conditions.
Date: October 27, 2004
Creator: Guo, J.-H.; Augustsson, A.; Englund, C.-J. & Nordgren, J.
System: The UNT Digital Library
Transport and Fluctuations in High Temperature Spheromak Plasmas (open access)

Transport and Fluctuations in High Temperature Spheromak Plasmas

Globally coherent magnetic fluctuations often observed during the driven phase after spheromak formation in the Sustained Spheromak Physics Experiment (SSPX) can be reduced to small amplitude by programming the magnetic flux = {Psi}{sub gun} and the discharge current = I{sub gun} in the formation gun. Scanning the edge normalized current = {lambda}{sub edge} = {lambda}{sub gun} = {mu}{sub 0}I{sub gun}/{Psi}{sub gun} above and below the minimum energy eigenvalue = {lambda}{sub FC} of the flux conserver provides a variation in the internal q = safety factor profile producing the expected q = m/n = poloidal/toroidal mode spectrum. By driving the edge with the proper {lambda}{sub gun}, the system can be operated with the poloidal/toroidal mode spectrum between the m/n = 1/2 and 2/3 modes producing low magnetic fluctuation amplitudes and high electron temperature = T{sub e} > 350 eV. Transport and confinement parameters calculated using Thomson scattering-measured T{sub e} and N{sub e} profiles coupled with the equilibrium code internal current profiles show a reduction in electron thermal diffusivity as T{sub e} increases. This scaling behavior is more classical-like than Bohm or open field line transport models where thermal diffusivity increases with T{sub e}. Electron diffusivity is calculated to be less than …
Date: October 27, 2005
Creator: McLean, H. S.; Woodruff, S.; Wood, R. D.; Hooper, E. B.; Hill, D. N.; Moller, J. et al.
System: The UNT Digital Library
A comparison of somatic mutational spectra in healthy study populations from Russia, Sweden and USA (open access)

A comparison of somatic mutational spectra in healthy study populations from Russia, Sweden and USA

Comparison of mutation spectra at the hypoxanthine-phosphoribosyl transferase (HPRT) gene of peripheral blood T lymphocytes may provide insight into the aetiology of somatic mutation contributing to carcinogenesis and other diseases. To increase knowledge of mutation spectra in healthy people, we have analyzed HPRT mutant T-cells of 50 healthy Russians originally recruited as controls for a study of Chernobyl clean-up workers (Jones et al. Radiation Res. 158, 2002, 424). Reverse transcriptase polymerase chain reactions and DNA sequencing identified 161 independent mutations among 176 thioguanine resistant mutants. Forty (40) mutations affected splicing mechanisms and 27 deletions or insertions of 1 to 60 nucleotides were identified. Ninety four (94) single base substitutions were identified, including 62 different mutations at 55 different nucleotide positions, of which 19 had not previously been reported in human T-cells. Comparison of this base substitution spectrum with mutation spectra in a USA (Burkhart-Schultz et al. Carcinogenesis 17, 1996, 1871) and two Swedish populations (Podlutsky et al, Carcinogenesis 19, 1998, 557, Podlutsky et al. Mutation Res. 431, 1999, 325) revealed similarity in the type, frequency and distribution of mutations in the four spectra, consistent with aetiologies inherent in human metabolism. There were 15-19 identical mutations in the three pair-wise comparisons …
Date: October 27, 2004
Creator: Noori, P; Hou, S; Jones, I M; Thomas, C B & Lambert, B
System: The UNT Digital Library
Analysis of Radiation Induced Degradation in FPC-461 Fluoropolymers by Variable Temperature Multinuclear NMR (open access)

Analysis of Radiation Induced Degradation in FPC-461 Fluoropolymers by Variable Temperature Multinuclear NMR

Solid state nuclear magnetic resonance techniques have been used to investigate aging mechanisms in a vinyl chloride:chlorotrifluoroethylene copolymer, FPC-461, due to exposure to {gamma}-radiation. Solid state {sup 1}H MAS NMR spectra revealed structural changes of the polymer upon irradiation under both air and nitrogen atmospheres. Considerable degradation is seen with {sup 1}H NMR in the vinyl chloride region of the polymer, particularly in the samples irradiated in air. {sup 19}F MAS NMR was used to investigate speciation in the chlorotrifluoroethylene blocks, though negligible changes were seen. {sup 1}H and {sup 19}F NMR at elevated temperature revealed increased segmental mobility and decreased structural heterogeneity within the polymer, yielding significant resolution enhancement over room temperature solid state detection. The effects of multi-site exchange are manifest in both the {sup 1}H and {sup 19}F NMR spectra as a line broadening and change in peak position as a function of temperature.
Date: October 27, 2004
Creator: Chinn, S C; Wilson, T S & Maxwell, R S
System: The UNT Digital Library
Modeling Nanocrystalline Grain Growth During the Pulsed Electrodeposition of Gold-Copper (open access)

Modeling Nanocrystalline Grain Growth During the Pulsed Electrodeposition of Gold-Copper

The process parameters of current density, pulse duration, and cell potential affect both the structure and composition of electrodeposits. The mechanism for nucleation and growth as determined from current transients yield relationships for nucleus density and nucleation rate. To develop an understanding of the role of the process parameters on grain size, as a design structural parameter to control strength for example, a formulation is presented to model the affects of the deposition energy on grain size and morphology. An activation energy for the deposition process is modeled that reveals different growth mechanisms, wherein nucleation and diffusion effects are each dominant as dependent upon pulse duration. A diffusion coefficient common for each of the pulsed growth modes demarcates an observed transition in growth from smooth to rough surfaces.
Date: October 27, 2005
Creator: Jankowski, Alan Frederic
System: The UNT Digital Library
Large-Stroke Self-Aligned Vertical Comb Drive Actuators for Adaptive Optics Applications (open access)

Large-Stroke Self-Aligned Vertical Comb Drive Actuators for Adaptive Optics Applications

A high-stroke micro-actuator array was designed, modeled, fabricated and tested. Each pixel in the 4x4 array consists of a self-aligned vertical comb drive actuator. This micro-actuator array was designed to become the foundation of a micro-mirror array that will be used as a deformable mirror for adaptive optics applications. Analytical models combined with CoventorWare{reg_sign} simulations were used to design actuators that would move up to 10{micro}m in piston motion with 100V applied. Devices were fabricated according to this design and testing of these devices demonstrated an actuator displacement of 1.4{micro}m with 200V applied. Further investigation revealed that fabrication process inaccuracy led to significantly stiffer mechanical springs in the fabricated devices. The increased stiffness of the springs was shown to account for the reduced displacement of the actuators relative to the design.
Date: October 27, 2005
Creator: Carr, E. J.; Olivier, S. S. & Solgaard, O.
System: The UNT Digital Library
Magnetic Properties of Radiation Damage in Pu (open access)

Magnetic Properties of Radiation Damage in Pu

First, we review earlier studies reporting possible magnetic characteristics for radiation defects in Pu. We then report, for {alpha}-Pu, two studies of the excess magnetic susceptibility (EMS) due to radiation damage, as a function of time and temperature. We have observed several annealing stages associated with the EMS of the accumulated self-damage and we report that annealing begins at {approx}31K, while below that temperature the displacement damage from self-irradiation of the Pu alpha particle emission and the U recoil are immobile. A detailed investigation was made of this EMS well below the first annealing stage as a function of temperature (2K < T < 15K) and time in a magnetic field of 2T. A linear increase in magnetic susceptibility is seen as a function of time for all isotherms. The excess susceptibility per alpha decay, determined from a linear fit of the slope of the time dependent EMS, is reasonably described with a Curie-Weiss law exhibiting a small negative Weiss temperature. We conclude by describing some future experiments in light of the present results.
Date: October 27, 2004
Creator: McCall, S.; Fluss, M. J.; Chung, B. W.; McElfresh, M.; Chapline, G. & Jackson, D.
System: The UNT Digital Library
Quantitative experiments with electrons in a positively chargedBeam (open access)

Quantitative experiments with electrons in a positively chargedBeam

None
Date: October 27, 2006
Creator: Molvik, A. W.; Vay, J. L.; Kireef Covo, M.; Cohen, R.; Baca, D.; Bieniosek, F. et al.
System: The UNT Digital Library
Stability Of Plasma Configurations During Compression (open access)

Stability Of Plasma Configurations During Compression

Magnetized Target Fusion (MTF) efforts are based on calculations showing that the addition of a closed magnetic field reduces the driver pressure and rise time requirements for inertial confinement fusion by reducing thermal conductivity. Instabilities that result in convective bulk transport at the Alphen time scale are of particular concern since they are much faster than the implosion time. Such instabilities may occur during compression due to, for example, an increase in the plasma-magnetic pressure ratio {beta} or, in the case of a rotating plasma, spin-up due to angular momentum conservation. Details depend on the magnetic field topology and compression geometry. A hard core z pinch with purely azimuthal magnetic field can theoretically be made that relaxes into a wall supported diffuse profile satisfying the Kadomtsev criterion for the stability of m = 0 modes, which is theoretically preserved during cylindrical outer wall compression. The center conductor radius and current must also be large enough to keep the {beta} below stability limits to stabilize modes with m > 0. The stability of m > 0 modes actually improves during compression. A disadvantage of this geometry, though, is plasma contact with the solid boundaries. In addition to the risk of high …
Date: October 27, 2006
Creator: Ruden, E L & Hammer, J H
System: The UNT Digital Library
Advancing the Ion Beam Thin Film Planarization Process for the Smoothing of Substrate Particles (open access)

Advancing the Ion Beam Thin Film Planarization Process for the Smoothing of Substrate Particles

This report addresses the advancement of the ion beam thin film planarization process for the smoothing of substrate particles.
Date: October 27, 2004
Creator: Mirkarimi, P.; Spiller, E.; Baker, S.; Robinson, J.; Stearns, D.; Liddle, J. A. et al.
System: The UNT Digital Library
Scrape-Off Layer Transport and Deposition Studies in DIII-D (open access)

Scrape-Off Layer Transport and Deposition Studies in DIII-D

Trace {sup 13}CH{sub 4} injection experiments into the main scrape-off layer of low density L-mode and high-density H-mode plasmas have been performed in the DIII-D tokamak [Luxon{_}NF02] to mimic the transport and deposition of carbon arising from a main chamber sputtering source. These experiments indicated entrainment of the injected carbon in plasma flow in the main SOL, and transport toward the inner divertor. Ex-situ surface analysis showed enhanced {sup 13}C surface concentration at the corner formed by the divertor floor and the angled target plate of the inner divertor in L-mode; in H-mode, both at the corner and along the surface bounding the private flux region inboard of the outer strike point. Interpretative modeling was made consistent with these experimental results by imposing a parallel carbon ion flow in the main SOL toward the inner target, and a radial pinch toward the separatrix. Predictive modeling carried out to better understand the underlying plasma transport processes suggests that the deuterium flow in the main SOL is related to the degree of detachment of the inner divertor leg. These simulations show that carbon ions are entrained with the deuteron flow in the main SOL via frictional coupling, but higher charge state carbon …
Date: October 27, 2006
Creator: Groth, M.; Allen, S.; Boedo, J.; Brooks, N.; Elder, J.; Fenstermacher, M. et al.
System: The UNT Digital Library
Quantitative Experiments With Electrons in a Positively Charged Beam (open access)

Quantitative Experiments With Electrons in a Positively Charged Beam

Intense ion beams are an extreme example of, and difficult to maintain as, a non-neutral plasma. Experiments and simulations are used to study the complex interactions between beam ions and (unwanted) electrons. Such ''electron clouds'' limit the performance of many accelerators. To characterize electron clouds, a number of parameters are measured including: total and local electron production and loss for each of three major sources, beam potential versus time, electron line-charge density, and gas pressure within the beam. Electron control methods include surface treatments to reduce electron and gas emission, and techniques to remove, or block, electrons from the beam. Detailed, self-consistent simulations include beam-transport fields, and electron and gas generation and consistent transport, to compute unexpectedly rich behavior, much of which is confirmed experimentally. For example, in a quadrupole magnetic field, ion and dense electron plasmas interact to produce multi-kV oscillations in the electron plasma and distortions of the beam velocity space distribution, without becoming homogenous or locally neutral.
Date: October 27, 2006
Creator: Molvik, A W; Vay, J; Covo, M K; Cohen, R; Baca, D; Bieniosek, F et al.
System: The UNT Digital Library