747 Matching Results

Search Results

Results: 1 - 24 next
open access

Zebrafish May Help Solve Ringing in Vets' Ears

Description: Article discussing research by Dr. Ernest J. Moore, professor of molecular pharmacology and audiology. This article discusses his research on tinnitus in zebrafish.
Date: May 6, 2008
Creator: Paul, Marla & Moore, Ernest J.
Partner: UNT College of Arts and Sciences
open access

Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure

Description: Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring). It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency genera… more
Date: March 6, 2008
Creator: Somorjai, Gabor A. & Park, Jeong Y.
Partner: UNT Libraries Government Documents Department
open access

CHANGING THE SAFETY CULTURE IN HANFORD TANK FARMS

Description: In 2000 the Hanford Tank Farms had one of the worst safety records in the Department of Energy Complex. By the end of FY08 the safety performance of the workforce had turned completely around, resulting in one of the best safety records in the DOE complex for operations of its kind. This paper describes the variety of programs and changes that were put in place to accomplish such a dramatic turn-around. The U.S. Department of Energy's 586-square-mile Hanford Site in Washington State was establi… more
Date: January 6, 2009
Creator: MV, BERRIOCHOA & LJ, ALCALA
Partner: UNT Libraries Government Documents Department
open access

Dose dependent effects of exercise training and detraining ontotal and regional adiposity in 4,663 men and 1,743

Description: Objective: To determine if exercise reduces body weight andto examine the dose-response relationships between changes in exerciseand changes in total and regional adiposity. Methods and Results:Questionnaires on weekly running distance and adiposity from a largeprospective study of 3,973 men and 1,444 women who quit running(detraining), 270 men and 146 women who started running (training) and420 men and 153 women who remained sedentary during 7.4 years offollow-up. There were significant invers… more
Date: January 6, 2006
Creator: Williams, Paul T. & Thompson, Paul D.
Partner: UNT Libraries Government Documents Department
open access

Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease

Description: Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with uni… more
Date: June 6, 2008
Creator: Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco & Wyrobek, Andrew J.
Partner: UNT Libraries Government Documents Department
open access

Genetic Diversity Among Botulinum Neurotoxin Producing Clostridial Strains

Description: Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore forming rod-shaped bacteria which have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and even death in humans and various other animal species. A collection of 174 C. botulinum strains were examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine genetic diversit… more
Date: July 6, 2006
Creator: Hill, K K; Smith, T J; Helma, C H; Ticknor, L O; Foley, B T; Svennson, R T et al.
Partner: UNT Libraries Government Documents Department
open access

Top Jets at the LHC

Description: We investigatethe reconstruction of high pT hadronically-decaying top quarksat the Large Hadron Collider. One of the main challenges in identifying energetictop quarks is that the decay products become increasingly collimated. This reducesthe efficacy of conventional reconstruction methods that exploit the topology of thetop quark decay chain. We focus on the cases where the decay products of the topquark are reconstructed as a single jet, a"top-jet." The most basic"top-tag"… more
Date: October 6, 2008
Creator: Almeida, L.G.; Lee, S.J.; Perez, G.; Sung, I. & Virzi, J.
Partner: UNT Libraries Government Documents Department
open access

An Update on the Status of the NIF Power Conditioning System

Description: The National Ignition Facility (NIF) Power Conditioning System provides the pulsed excitation required to drive flashlamps in the laser's optical amplifiers. Modular in design, each of the 192 Main Energy Storage Modules (MESMs) stores up to 2.2 MJ of electrical energy in its capacitor bank before delivering the energy to 20 pairs of flashlamps in a 400 {micro}s pulse (10% power points). The peak current of each MESM discharge is 0.5 MA. Production, installation, commissioning and operation of … more
Date: September 6, 2007
Creator: Arnold, P. A.; Hulsey, S.; Ullery, G. T.; Petersen, D. E.; Pendleton, D. L.; Ollis, C. W. et al.
Partner: UNT Libraries Government Documents Department
open access

Open Cavity Solutions to the Rf in Magnetic Field Problem.

Description: It has been observed [1] that breakdown in an 805 MHz pill-box cavity occurs at much lower gradients as an external axial magnetic field is increased. This effect was not observed with on open iris cavity. It is proposed that this effect depends on the relative angles of the magnetic and maximum electric fields: parallel in the pill-box case; at an angle in the open iris case. If so, using an open iris structure with solenoid coils in the irises should perform even better. A lattice, using this… more
Date: August 6, 2007
Creator: Palmer, R. B.; Berg, J. S.; Fernow, R. C.; Gallardo, J. C. & Kirk, H. G.
Partner: UNT Libraries Government Documents Department
open access

Preliminary Results from the UCLA/SLAC Ultra-High Gradient CerenkovWakefield Accelerator Experiment

Description: The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. This experiment takes advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam has been successfully focused down and sent through varying lengths of fused silica capillary tubing with two … more
Date: February 6, 2008
Creator: Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travish, G.; Hogan, M.; Ischebeck, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Using Ffags in the Creation of Neutrino Beams.

Description: A number of accelerator-based facilities have been proposed for the creation of neutrino beams: superbeams, neutrino factories, and beta beams. Fixed field alternating gradient accelerators (FFAGs) have potential uses in all of these facilities. Superbeams and neutrino factories require high power proton drivers for the production of pions; FFAGs can beneficial for accelerating protons for those machines. FFAGs can reduce the cost of accelerating muons in a neutrino factory because they enable … more
Date: August 6, 2007
Creator: Berg, J. S.
Partner: UNT Libraries Government Documents Department
open access

Effect of various errors on the Spin Tune and Stable Spin Axis

Description: Even though RHIC has two full Siberian snakes in each ring, there are various perturbations to the ideal case including orbit errors at the snakes, experiment solenoids, injection bumps, and interlaced horizontal-vertical bumps at the hydrogen jet polarimeter. These errors can cause depolarization by shifting the spin tune and tilting the stable spin direction away from vertical. Tilting of the stable spin axis can enhance horizontal depolarizing resonances. This paper presents preliminary resu… more
Date: October 6, 2008
Creator: MacKay, W. W.
Partner: UNT Libraries Government Documents Department
open access

Monte Carlo Methods in the Physical Sciences

Description: I will review the role that Monte Carlo methods play in the physical sciences. They are very widely used for a number of reasons: they permit the rapid and faithful transformation of a natural or model stochastic process into a computer code. They are powerful numerical methods for treating the many-dimensional problems that derive from important physical systems. Finally, many of the methods naturally permit the use of modern parallel computers in efficient ways. In the presentation, I will em… more
Date: June 6, 2007
Creator: Kalos, M. H.
Partner: UNT Libraries Government Documents Department
open access

D-dualized D-brane

Description: We further investigate the dimensional duality (D-duality) proposed in arXiv: 0705.0550 by mainly focusing on the properties of D-branes in this background. We derive the world-sheet correspondence of static D-branes, and discuss the fate of non-static D-branes from the world-sheet viewpoint. The quantum string production with or without D-branes is also studied fromthe time-like Liouville theory. We find that the closed string production from the background is much larger than that from D-bran… more
Date: June 6, 2007
Creator: Nakayama, Yu & Nakayama, Yu
Partner: UNT Libraries Government Documents Department
open access

The US Long Baseline Neutrino Experiment Study

Description: The US Long Baseline Neutrino Experiment Study was commissioned jointly by Brookhaven National Laboratory (BNL)and Fermi National Accelerator Laboratory (FNAL) to investigate the potential for future U.S. based long baseline neutrino oscillation experiments using MW class conventional neutrino beams that can be produced at FNAL. The experimental baselines are based on two possible detector locations: (1) off-axis to the existing FNAL NuMI beamline at baselines of 700 to 810 km and (2) NSF's pro… more
Date: August 6, 2007
Creator: Bishai, M.
Partner: UNT Libraries Government Documents Department
open access

Discovery of Non-random Spatial Distribution of Impacts in the Stardust Cometary Collector

Description: We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than {approx} 10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the s… more
Date: April 6, 2007
Creator: Westphal, A. J.; Bastien, R. K.; Borg, J.; Bridges, J.; Brownlee, D. E.; Burchell, M. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2 + (1 - y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4.MgSO4(aq) at 298.15 K

Description: Isopiestic vapor pressure measurements were made for {l_brace}yMgCl{sub 2} + (1-y)MgSO{sub 4}{r_brace}(aq) solutions with MgCl{sub 2} ionic strength fractions of y = 0, 0.1997, 0.3989, 0.5992, 0.8008, and (1) at the temperature 298.15 K, using KCl(aq) as the reference standard. These measurements for the mixtures cover the ionic strength range I = 0.9794 to 9.4318 mol {center_dot} kg{sup -1}. In addition, isopiestic measurements were made with NaCl(aq) as reference standard for mixtures of {l_b… more
Date: June 6, 2007
Creator: Miladinovic, J; Ninkovic, R; Todorovic, M & Rard, J A
Partner: UNT Libraries Government Documents Department
open access

Photoconductive Detectors with Fast Temporal Response for Laser Produced Plasma Experiments.

Description: Processes during laser plasma experiments typically have time scales that are less than 100 ps. The measurement of these processes requires X-ray detectors with fast temporal resolution. We have measured the temporal responses and linearity of several different X-ray sensitive Photoconductive Detectors (PCDs). The active elements of the detectors investigated include both diamond (natural and synthetic) and GaAs crystals. The typical time responses of the GaAs PCDs are approximately 60 ps, resp… more
Date: May 6, 2008
Creator: May, M; Halvorson, C; Perry, T; Weber, F; Young, P & Silbernagel, C
Partner: UNT Libraries Government Documents Department
open access

Resonance--Continuum Interference in Light Higgs Boson Production at a Photon Collider

Description: We study the effect of interference between the Standard Model Higgs boson resonance and the continuum background in the process {gamma}{gamma} {yields} H {yields} b{bar b} at a photon collider. Taking into account virtual gluon exchange between the final-state quarks, we calculate the leading corrections to the height of the resonance for the case of a light (m{sub H} < 160 GeV) Higgs boson. We find that the interference is destructive and around 0.1-0.2% of the peak height, depending on th… more
Date: January 6, 2009
Creator: Dixon, Lance J.; Sofianatos, Yorgos & /SLAC /Stanford U., Phys. Dept.
Partner: UNT Libraries Government Documents Department
open access

Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials

Description: Using a beam of tagged 14.1 MeV neutrons to probe for the presence of fissionable materials, we have measured n-γ-γ coincidences from depleted uranium (DU). The multiple coincidence rate is substantially above that measured from lead, tungsten, and iron. The presence of coincidences involving delayed gammas in the DU time spectra provides a signature for fissionable materials that is distinct from non-fissionable ones. In addition, the information from the tagged neutron involved in the coincid… more
Date: August 6, 2008
Creator: J.P. Hurley, R.P. Keegan, J.R. Tinsley, R. Trainham, and S.C. Wilde
Partner: UNT Libraries Government Documents Department
open access

Visualization of Scalar Adaptive Mesh Refinement Data

Description: Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Vis… more
Date: December 6, 2007
Creator: VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J. et al.
Partner: UNT Libraries Government Documents Department
open access

Photodeposition of Pt on Colloidal CdS and CdSe/CdS Semiconductor Nanostructures

Description: Semiconductor photocatalysis has been identified as a promising avenue for the conversion of solar energy into environmentally friendly fuels, most notably by the production of hydrogen from water.[1-5] Nanometer-scale materials in particular have attracted considerable scientific attention as the building blocks for light-harvesting applications.[6,7] Their desirable attributes include tunability of the optical properties with size, amenability to relatively inexpensive low-temperature process… more
Date: August 6, 2008
Creator: Dukovic, Gordana; Merkle, Maxwell G.; Nelson, James H.; Hughes, Steven M. & Alivisatos, A. Paul
Partner: UNT Libraries Government Documents Department
Back to Top of Screen