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Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site

Description: Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and character… more
Date: May 3, 2007
Creator: David Hudson, Charles Lohrstorfer, Bruce Hurley
Partner: UNT Libraries Government Documents Department
open access

Gaining analytic control of parton showers

Description: Parton showers are widely used to generate fully exclusive final states needed to compare theoretical models to experimental observations. While, in general, parton showers give a good description of the experimental data, the precise functional form of the probability distribution underlying the event generation is generally not known. The reason is that realistic parton showers are required to conserve four-momentum at each vertex. In this paper we investigate in detail how four-momentum cons… more
Date: May 14, 2007
Creator: Tackmann, Frank; Bauer, Christian W. & Tackmann, Frank J.
Partner: UNT Libraries Government Documents Department
open access

Mixing and CP violation in the D0 and B0(s) systems

Description: Recent developments for mixing and CP violation in the D0 and Bs systems are reviewed, including (i) the recently emerging evidence for D0-D0bar mixing and the interpretations of the measurements; (ii) the theoretical status of the calculations of Delta(Gamma_D) and Delta(m_D); (iii) some implications of the measurement of Bs mixing for new physics.
Date: May 7, 2007
Creator: Ligeti, Zoltan & Ligeti, Zoltan
Partner: UNT Libraries Government Documents Department
open access

LISSAT Analysis of a Generic Centrifuge Enrichment Plant

Description: The U.S. Department of Energy (DOE) is interested in developing tools and methods for use in designing and evaluating safeguards systems for current and future plants in the nuclear power fuel cycle. The DOE is engaging several DOE National Laboratories in efforts applied to safeguards for chemical conversion plants and gaseous centrifuge enrichment plants. As part of the development, Lawrence Livermore National Laboratory has developed an integrated safeguards system analysis tool (LISSAT). Th… more
Date: May 31, 2007
Creator: Lambert, H; Elayat, H A; O?Connell, W J; Szytel, L & Dreicer, M
Partner: UNT Libraries Government Documents Department
open access

Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure

Description: Laser ablation has proven to be an effective method for generating nanoparticles; particles are produced in the laser induced vapor plume during the cooling stage. To understand the in-situ condensation process, a series of time resolved light scattering images were recorded and analyzed. Significant changes in the condensation rate and the shape of the condensed aerosol plume were observed in two background gases, helium and argon. The primary particle shape and size distribution were measured… more
Date: May 31, 2007
Creator: Wen, Sy-Bor; Mao, Xianglei; Greif, Ralph & Russo, Richard E.
Partner: UNT Libraries Government Documents Department
open access

ITER Shape Controller and Transport Simulations

Description: We currently use the CORSICA integrated modeling code for scenario studies for both the DIII-D and ITER experiments. In these simulations, free- or fixed-boundary equilibria are simultaneously converged with thermal evolution determined from transport models providing temperature and current density profiles. Using a combination of fixed boundary evolution followed by free-boundary calculation to determine the separatrix and coil currents. In the free-boundary calculation, we use the state-spac… more
Date: May 31, 2007
Creator: Casper, T A; Meyer, W H; Pearlstein, L D & Portone, A
Partner: UNT Libraries Government Documents Department
open access

Geometry of non-supersymmetric three-charge bound states

Description: We study the smooth non-supersymmetric three-charge microstatesof Jejjala, Madden, Ross and Titchener using Kaluza-Klein reductions of the solutions to five and four dimensions. Our aim is to improve our understanding of the relation between these non-supersymmetric solutions and the well-studied supersymmetric cases. We find some surprising qualitative differences. In the five-dimensional description, the solution has orbifold fixed points which break supersymmetry locally, so the geometries c… more
Date: May 14, 2007
Creator: Gimon, Eric G.; Levi, Thomas S. & Ross, Simon F.
Partner: UNT Libraries Government Documents Department
open access

Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

Description: The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29}… more
Date: May 7, 2007
Creator: Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf et al.
Partner: UNT Libraries Government Documents Department
open access

Mapping the geometry of the F4 group

Description: In this paper, we present a construction of the compact form of the exceptional Lie group F4 by exponentiating the corresponding Lie algebra f4. We realize F4 as the automorphisms group of the exceptional Jordan algebra, whose elements are 3 x 3 Hermitian matrices with octonionic entries. We use a parametrization which generalizes the Euler angles for SU(2) and is based on the fibration of F4 via a Spin(9) subgroup as a fiber. This technique allows us to determine an explicit expression for the… more
Date: May 28, 2007
Creator: Bernardoni, Fabio; Cacciatori, Sergio L; Scotti, Antonio & Cerchiai, Bianca L.
Partner: UNT Libraries Government Documents Department
open access

The Performance Effect of Multi-core on ScientificApplications

Description: The historical trend of increasing single CPU performancehas given way to roadmap of increasing core count. The challenge ofeffectively utilizing these multi-core chips is just starting to beexplored by vendors and application developers alike. In this study, wepresent some performance measurements of several complete scientificapplications on single and dual core Cray XT3 and XT4 systems with a viewto characterizing the effects of switching to multi-core chips. Weconsider effects within a node… more
Date: May 14, 2007
Creator: Carter, Jonathan; He, Yun; Shalf, John; Shan, Hongzhang; Strohmaier, Erich & Wasserman, Harvey
Partner: UNT Libraries Government Documents Department
open access

ECLOUD in PS2, PS+, SPS+: AN UPDATE

Description: We present an update of our results for the electron-cloud build-up for several upgrades proposed for the LHC injectors. Specifically, we have re-examined our published results for the ecloud heat load [1] from the perspective of numerical convergence of the simulations vis-a-vis the integration time step {Delta}t. We repeated most of the simulations with ever smaller values of {Delta}t until we reached stable results, indicating numerical convergence; this was achieved at 200-500 slices per bu… more
Date: May 22, 2007
Creator: Furman, M. A.
Partner: UNT Libraries Government Documents Department
open access

Leakage of CO2 from geologic storage: Role of secondary accumulation at shallow depth

Description: Geologic storage of CO2 can be a viable technology forreducing atmospheric emissions of greenhouse gases only if it can bedemonstrated that leakage from proposed storage reservoirs and associatedhazards are small or can be mitigated. Risk assessment must evaluatepotential leakage scenarios and develop a rational, mechanisticunderstanding of CO2 behavior during leakage. Flow of CO2 may be subjectto positive feedbacks that could amplify leakage risks and hazards,placing a premium on identifying a… more
Date: May 31, 2007
Creator: Pruess, K.
Partner: UNT Libraries Government Documents Department
open access

Bounds on Unparticles from the Higgs Sector

Description: We study supersymmetric QCD in the conformal window as a laboratory for unparticle physics, and analyze couplings between the unparticle sector and the Higgs sector. These couplings can lead to the unparticle sector being pushed away from its scale invariant fixed point. We show that this implies that low energy experiments will not be able to see unparticle physics, and the best hope of seeing unparticles is in high energy collider experiments such as the Tevatron and the LHC. We also demonstr… more
Date: May 20, 2007
Creator: Fox, Patrick J.; Rajaraman, Arvind & Shirman, Yuri
Partner: UNT Libraries Government Documents Department
open access

Evaluation of Multiplexed Foot-and-Mouth Disease Nonstructural Protein Antibody Assay Against Standardized Bovine Serum Panel

Description: Liquid array technology has previously been used to show proof-of-principle of a multiplexed non structural protein serological assay to differentiate foot-and-mouth infected and vaccinated animals. The current multiplexed assay consists of synthetically produced peptide signatures 3A, 3B and 3D and recombinant protein signature 3ABC in combination with four controls. To determine diagnostic specificity of each signature in the multiplex, the assay was evaluated against a naive population (n = … more
Date: May 14, 2007
Creator: Perkins, J; Parida, S & Clavijo, A
Partner: UNT Libraries Government Documents Department
open access

Galvanic interpretation of self-potential signals associated withmicrobial sulfate-reduction

Description: We have evaluated the usefulness of the self-potential (SP)geophysical method to track the onset and location of microbialsulfate-reduction in saturated sediments during organic carbon amendment.Following stimulation of sulfate-reducing bacteria (SRB) by addition oflactate, anomalous voltages exceeding 600 mV correlated in space and timewith the accumulation of dissolved sulfide. Abiotic experiments in whichthe sulfide concentration at the measurement electrode was systematicallyvaried showed a… more
Date: May 2, 2007
Creator: Williams, Kenneth H.; Hubbard, Susan S. & Banfield, Jillian F.
Partner: UNT Libraries Government Documents Department
open access

Laser heating of solid matter by light pressure-driven shocks

Description: Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D parti… more
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Effect of Titanium Substitution on the Compatiblity of Electrodeswith Pyrrolidinium-Based Ionic Liquid Electrolytes

Description: The quest for the development of rechargeable lithium-metal batteries has attracted vigorous worldwide research efforts because this system offers the highest theoretical specific energy [1]. For this to be achieved, the repetitive deposition and stripping of lithium must be close to fully reversible. Thus, alternative electrolytes have been investigated, such as the room-temperature ionic liquid (RTILs). Lithium can be cycled with a high degree of reversibility with efficiencies exceeding 99% … more
Date: May 16, 2007
Creator: Saint, Juliette A.; Shin, Joon-Ho; Best, Adam; Hollenkamp,Anthony; Kerr, John & Doeff, Marca M.
Partner: UNT Libraries Government Documents Department
open access

Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

Description: We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 {le} z {le} 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are radio-loud, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emis… more
Date: May 30, 2007
Creator: Croft, S.; de Vries, W. & Becker, R.
Partner: UNT Libraries Government Documents Department
open access

Compact Analytic Expression for the Electric Field of a 2DElliptical Charge Distribution Inside a Perfectly Conducting CircularCylinder

Description: By combining the method of images with calculus of complex variables, we provide a simple expression for the electric field of a two-dimensional (2D) static elliptical charge distribution inside a perfectly conducting cylinder. The charge distribution need not be concentric with the cylinder.
Date: May 29, 2007
Creator: Furman, M. A.
Partner: UNT Libraries Government Documents Department
open access

Influence of chemical and magnetic interface properties of Co-Fe-B/ MgO / Co-Fe-B tunnel junctions on the annealing temperature dependenceof the magnetoresistance

Description: The knowledge of chemical and magnetic conditions at the Co{sub 40}Fe{sub 40}B{sub 20}/MgO interface is important to interpret the strong annealing temperature dependence of tunnel magnetoresistance of Co-Fe-B/MgO/Co-Fe-B magnetic tunnel junctions, which increases with annealing temperature from 20% after annealing at 200 C up to a maximum value of 112% after annealing at 350 C. While the well defined nearest neighbor ordering indicating crystallinity of the MgO barrier does not change by the a… more
Date: May 1, 2007
Creator: Schmalhorst, J.; Thomas, A.; Kou, X.; Reiss, G.; Kou, X. & Arenholz, E.
Partner: UNT Libraries Government Documents Department
open access

Effect of rogue particles on the sub-surface damage of fused silica during grinding/polishing

Description: The distribution and characteristics of surface cracks (i.e., sub-surface damage or scratching) on fused silica formed during grinding/polishing resulting from the addition of rogue particles in the base slurry has been investigated. Fused silica samples (10 cm diameter x 1 cm thick) were: (1) ground by loose abrasive grinding (alumina particles 9-30 {micro}m) on a glass lap with the addition of larger alumina particles at various concentrations with mean sizes ranging from 15-30 {micro}m, or (… more
Date: May 2, 2007
Creator: Suratwala, T I; Steele, R; Feit, M D; Wong, L; Miller, P E; Menapace, J A et al.
Partner: UNT Libraries Government Documents Department
open access

Molecular Line Emission from Massive Protostellar Disks: Predictions for ALMA and the EVLA

Description: We compute the molecular line emission of massive protostellar disks by solving the equation of radiative transfer through the cores and disks produced by the recent radiation-hydrodynamic simulations of Krumholz, Klein, & McKee. We find that in several representative lines the disks show brightness temperatures of hundreds of Kelvin over velocity channels {approx} 10 km s{sup -1} wide, extending over regions hundreds of AU in size. We process the computed intensities to model the performance o… more
Date: May 7, 2007
Creator: Krumholz, M R; Klein, R I & McKee, C F
Partner: UNT Libraries Government Documents Department
open access

A Generalized Eigensolver based on Smoothed Aggregation (GES-SA) for Initializing Smoothed Aggregation Multigrid (SA)

Description: Consider the linear system Ax = b, where A is a large, sparse, real, symmetric, and positive definite matrix and b is a known vector. Solving this system for unknown vector x using a smoothed aggregation multigrid (SA) algorithm requires a characterization of the algebraically smooth error, meaning error that is poorly attenuated by the algorithm's relaxation process. For relaxation processes that are typically used in practice, algebraically smooth error corresponds to the near-nullspace of A.… more
Date: May 31, 2007
Creator: Brezina, M; Manteuffel, T; McCormick, S; Ruge, J; Sanders, G & Vassilevski, P S
Partner: UNT Libraries Government Documents Department
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