Searches for standard model Higgs at the Tevatron (open access)

Searches for standard model Higgs at the Tevatron

A summary of the latest results of Standard Model Higgs boson searches from CDF and D0 presented at the DIS 2007 conference is reported in this paper. All analyses presented use 1 fb{sup -1} of Tevatron data. The strategy of the different analyses is determined by the Higgs production mechanism and decay channel.
Date: April 1, 2007
Creator: Vilar Cortabitarte, Rocio & /Cantabria U., Santander
Object Type: Article
System: The UNT Digital Library
ELECTROCHEMICAL CORROSION TEST RESULTS FOR TANK 241-SY-102 SUPERNATE GRAB SAMPLES (open access)

ELECTROCHEMICAL CORROSION TEST RESULTS FOR TANK 241-SY-102 SUPERNATE GRAB SAMPLES

This report describes the electrochemical corrosion scans and conditions for testing of SY-102 supernatant samples taken December 2004. The testing was performed because the tank was under a Justification for Continued Operation allowing the supernatant composition to be outside the chemistry limits of Administrative Control 5.16, 'Corrosion Mitigation program'. A new electrochemical working electrode of A516 Grade 60 carbon steel was used for each scan; all scans were measured against a saturated calomel electrode, with carbon counter electrodes, and all scans were carried out at 50 C. The samples were scanned twice, once as received and once sparged with argon to deoxygenate the sample. For those scans conducted after argon purging, the corrosion rates ranged from 0.012 to 0.019 mpy. A test for stress corrosion cracking was carried out on one sample (2SY-04-07) with negative results.
Date: April 9, 2007
Creator: JB, DUNCAN
Object Type: Report
System: The UNT Digital Library

Long-term Stability of Biogeochemically Reduced U and Cr in Contaminated Sediments

The general goal of this report is to diminish concentrations of metals/radionuclide in groundwaters of contaminated sites to below MCL values through reduction to lower solubility species.
Date: April 19, 2007
Creator: Tetsu Tokunaga, Jiamin Wan, Yongman Kim, Terry Hazen, Eoin Brodie, Zuoping Zheng, Jackie Pena
Object Type: Presentation
System: The UNT Digital Library
A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas (open access)

A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas

A high-order finite volume algorithm is developed for the Fokker-Planck Operator (FPO) describing Coulomb collisions in strongly magnetized plasmas. The algorithm is based on a general fourth-order reconstruction scheme for an unstructured grid in the velocity space spanned by parallel velocity and magnetic moment. The method provides density conservation and high-order-accurate evaluation of the FPO independent of the choice of the velocity coordinates. As an example, a linearized FPO in constant-of-motion coordinates, i.e. the total energy and the magnetic moment, is developed using the present algorithm combined with a cut-cell merging procedure. Numerical tests include the Spitzer thermalization problem and the return to isotropy for distributions initialized with velocity space loss cones. Utilization of the method for a nonlinear FPO is straightforward but requires evaluation of the Rosenbluth potentials.
Date: April 18, 2007
Creator: Xiong, Z; Cohen, R H; Rognlien, T D & Xu, X Q
Object Type: Article
System: The UNT Digital Library

Kinetic Controls on the Desorption/Dissolution of Sorbed U(VI) and Their Influence on Reactive Transport

None
Date: April 19, 2007
Creator: Zachara, J. M.; Liu, C.; Qafoku, N.; McKinley, J. P.; Davis, J. A.; Stoliker, D. et al.
Object Type: Poster
System: The UNT Digital Library
CAMS/LLNL Ion Source Efficiency Revisited (open access)

CAMS/LLNL Ion Source Efficiency Revisited

None
Date: April 17, 2007
Creator: Fallon, S. J.; Guilderson, T. P. & Brown, T. A.
Object Type: Article
System: The UNT Digital Library

Development of Modeling Methods and Tools for Predicting Coupled Reactive Transport Processes in Porous Media at Multiple Scales

None
Date: April 19, 2007
Creator: Kanel, S. R.; Loganathan, V. A.; Jeppu, G.; Kumar, A.; Srinivasan, V.; Radu, T. et al.
Object Type: Poster
System: The UNT Digital Library

Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in …
Date: April 19, 2007
Creator: Scheibe, Tim; Tartakovsky, Alexandre; Wood, Brian & Seymour, Joe
Object Type: Poster
System: The UNT Digital Library

Applying EMSL Capabilities to Biogeochemistry and Environmental Research

The Environmental Molecular Sciences laboratory (EMSL) is a national scientific user facility operated by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy's Office of Biological and Environmental Research. Located in Richland, Washington, EMSL offers researchers a comprehensive array of cutting-edge capabilities unmatched anywhere else in the world and access to the expertise of over 300 resident users--all at one location. EMSL's resources are available on a peer-reviewed proposal basis and are offered at no cost if research results are shared in the open literature. Researchers are encouraged to submit a proposal centered around one of EMSL's four Science Themes, which represent growing areas of research: (1) Geochemistry/Biogeochemistry and Subsurface Science; (2) Atmospheric Aerosol Chemistry; (3) Biological Interactions and Dynamics; and (4) Science of Interfacial Phenomena. To learn more about EMSL, visit www.emsl.pnl.gov.
Date: April 19, 2007
Creator: Felmy, Andy
Object Type: Poster
System: The UNT Digital Library
The Energy Diameter Effect (open access)

The Energy Diameter Effect

Various relations for the detonation energy and velocity as they relate to the inverse radius of the cylinder are explored. The detonation rate-inverse slope relation seen in reactive flow models can be used to derive the familiar Eyring equation. Generalized inverse radii can be shown to fit large quantities of cylinder and sphere results. A rough relation between detonation energy and detonation velocity is found from collected JWL values. Cylinder test data for ammonium nitrate mixes down to 6.35 mm radii are presented, and a size energy effect is shown to exist in the Cylinder test data. The relation that detonation energy is roughly proportional to the square of the detonation velocity is shown by data and calculation.
Date: April 20, 2007
Creator: Souers, P; Vitello, P; Garza, R & Hernandez, A
Object Type: Article
System: The UNT Digital Library
Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines (open access)

Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines

Spatially resolved measurements of deuterium Balmer and Paschen line emission have been performed in the divertor region of the National Spherical Torus Experiment using a commercial 0.5 m Czerny-Turner spectrometer. While the Balmer emission lines, Balmer and Paschen continua in the ultraviolet and visible regions have been extensively used for tokamak divertor plasma temperature and density measurements, the diagnostic potential of infrared Paschen lines has been largely overlooked. We analyze Stark broadening of the lines corresponding to 2-n and 3-m transitions with principle quantum numbers n = 7-12 and m = 10-12 using recent Model Microfield Method calculations (C. Stehle and R. Hutcheon, Astron. Astrophys. Supl. Ser. 140, 93 (1999)). Densities in the range (5-50) x 10{sup 19} m{sup -3} are obtained in the recombining inner divertor plasma in 2-6 MW NBI H-mode discharges. The measured Paschen line profiles show good sensitivity to Stark effects, and low sensitivity to instrumental and Doppler broadening. The lines are situated in the near-infrared wavelength domain, where optical signal extraction schemes for harsh nuclear environments are practically realizable, and where a recombining divertor plasma is optically thin. These properties make them an attractive recombining divertor density diagnostic for a burning plasma experiment.
Date: April 27, 2007
Creator: Soukhanovskii, V A; Johnson, D W; Kaita, R & Roquemore, A L
Object Type: Article
System: The UNT Digital Library
The silicon microstrip sensors of the ATLAS semiconductor tracker (open access)

The silicon microstrip sensors of the ATLAS semiconductor tracker

This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the Semiconductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd. supplied 92.2percent of the 15,392 installed sensors, with the remainder supplied by CiS.
Date: April 13, 2007
Creator: Collaboration, ATLAS SCT & Spieler, Helmuth G.
Object Type: Article
System: The UNT Digital Library

Scale Dependence of Biogeochemical Reaction Rates: Experimental and Modeling Approaches

None
Date: April 19, 2007
Creator: Steefel, Carl I.; Li, Li & Yang, Li
Object Type: Presentation
System: The UNT Digital Library

Responses of Desulfovibrio vulgaris to Physiological Constraints Relevant to Bioremediation in the Field

None
Date: April 19, 2007
Creator: Fields, Matthew W.
Object Type: Presentation
System: The UNT Digital Library
Annual Technical Progress Report of Radioisotope Power System Materials Production and Technology Program Tasks for October 1, 2005 Through September 30, 2006 (open access)

Annual Technical Progress Report of Radioisotope Power System Materials Production and Technology Program Tasks for October 1, 2005 Through September 30, 2006

The Office of Space and Defense Power Systems of the Department of Energy (DOE) provides Radioisotope Power Systems (RPS) for applications where conventional power systems are not feasible. For example, radioisotope thermoelectric generators were supplied by the DOE to the National Aeronautics and Space Administration for deep space missions including the Cassini Mission launched in October of 1997 to study the planet Saturn. For the Cassini Mission, ORNL produced carbon-bonded carbon fiber (CBCF) insulator sets, iridium alloy blanks and foil, and clad vent sets (CVS) used in the generators. The Oak Ridge National Laboratory (ORNL) has been involved in developing materials and technology and producing components for the DOE for more than three decades. This report reflects program guidance from the Office of Space and Defense Power Systems for fiscal year (FY) 2006. Production activities for prime quality (prime) CBCF insulator sets, iridium alloy blanks and foil, and CVS are summarized in this report. Technology activities are also reported that were conducted to improve the manufacturing processes, characterize materials, or to develop information for new radioisotope power systems.
Date: April 1, 2007
Creator: King, James F.
Object Type: Report
System: The UNT Digital Library
Performances of Multi-Level and Multi-Component Compressed BitmapIndices (open access)

Performances of Multi-Level and Multi-Component Compressed BitmapIndices

This paper presents a systematic study of two large subsetsof bitmap indexing methods that use multi-component and multi-levelencodings. Earlier studies on bitmap indexes are either empirical or foruncompressed versions only. Since most of bitmap indexes in use arecompressed, we set out to study the performance characteristics of thesecompressed indexes. To make the analyses manageable, we choose to use aparticularly simple, but efficient, compression method called theWord-Aligned Hybrid (WAH) code. Using this compression method, a numberof bitmap indexes are shown to be optimal because their worst-case timecomplexities for answering a query is a linear function of the number ofhits. Since compressed bitmap indexes behave drastically different fromuncompressed ones, our analyses also lead to a number of new methods thatare much more efficient than commonly used ones. As a validation for theanalyses, we implement a number of the best methods and measure theirperformance against well-known indexes. The fastest new methods arepredicted and observed to be 5 to 10 times faster than well-knownindexing methods.
Date: April 30, 2007
Creator: Wu, Kesheng; Stockinger, Kurt & Shoshani, Arie
Object Type: Report
System: The UNT Digital Library
SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER (open access)

SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER

A salt fog test of an iron-based amorphous metal, SAM2X5, coated Type 316L stainless steel (SS316L) cylinder was made. The cylinder was 30-inch diameter by 88-inch long, and 3/8-inch thick. One end was welded shut with a SS316L end cap before coating. The body of the cylinder and the end cap were both coated. The cylinder was coated with SAM2X5 by the HVOF thermal spray process. The coating thickness was 0.015-inch to 0.019-inch thick. The cylinder was tested in a horizontal position. Also included in the test for reference purposes were five coupons (2-inch x 2-inch x 1/8-inch) of uncoated Type 1018 carbon steel (1018CS). The test used an abbreviated form of GM 9540P. Each cycle was 6 hours in duration and the cylinder and reference samples were exposed to a total of eight cycles. The cylinder was in relatively good condition after the test. Along the body of the cylinder only two pinpoint spot sized signs of rust were seen. The 1018CS reference specimens were extensively rusted.
Date: April 23, 2007
Creator: Aprigliano, L F; Rebak, R B; Choi, J; Lian, T & Day, S D
Object Type: Article
System: The UNT Digital Library
Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky Survey (open access)

Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky Survey

We investigate faint radio emission from low- to high-luminosity Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their radio properties are inferred by coadding large ensembles of radio image cut-outs from the FIRST survey, as almost all of the sources are individually undetected. We correlate the median radio flux densities against a range of other sample properties, including median values for redshift, [O III] luminosity, emission line ratios, and the strength of the 4000{angstrom} break. We detect a strong trend for sources that are actively undergoing star-formation to have excess radio emission beyond the {approx} 10{sup 28} ergs s{sup -1} Hz{sup -1} level found for sources without any discernible star-formation. Furthermore, this additional radio emission correlates well with the strength of the 4000{angstrom} break in the optical spectrum, and may be used to assess the age of the star-forming component. We examine two subsamples, one containing the systems with emission line ratios most like star-forming systems, and one with the sources that have characteristic AGN ratios. This division also separates the mechanism responsible for the radio emission (star-formation vs. AGN). For both cases we find a strong, almost identical, correlation between [O III] and radio luminosity, …
Date: April 18, 2007
Creator: de Vries, W. H.; Hodge, J. A.; Becker, R. H.; White, R. L. & Helfand, D. J.
Object Type: Article
System: The UNT Digital Library
Evaluation of Polymer-Filler Interaction Characteristics by Force Microscopy (open access)

Evaluation of Polymer-Filler Interaction Characteristics by Force Microscopy

Silicone polymers are frequently used as cushions and inserts between load bearing parts. In this capacity, they must act to position their associated parts and distribute mechanical force as appropriate. One type of failure is specific to silicones that are filled with high surface area particulates for purposes of tailoring the polymer compressive properties. Additives such as fumed silicon oxide are presumed to have a high degree of surface interaction with the polymer matrix, thus causing the polymer to stiffen and to display greater dimensional stability as a function of temperature. However, it has been observed that the compressive behavior of these materials is not always invariant over long times. There is evidence that suggests changes in humidity and temperature can irreversibly alter the silicone-filler interaction, thereby changing the overall characteristics of parts made from such materials. As before, changes in compressive or shear stability can have serious effects on the ability of these materials to effectively position precision parts or distribute high mechanical loads. We approach the analysis of the filled systems by creating controlled layers of silicone polymers attached to silicon oxide substrates. Straight chain vinyl-silicone polymers identical to those used in the formulation of pads for stockpile …
Date: April 23, 2007
Creator: Ratto, T & Saab, A
Object Type: Report
System: The UNT Digital Library
Mechanism of Bacterial Uranium and Technetium Reduction (open access)

Mechanism of Bacterial Uranium and Technetium Reduction

None
Date: April 19, 2007
Creator: DiChristina, Thomas
Object Type: Article
System: The UNT Digital Library
Biosynthesis of a Fully Functional Cyclotide inside Living Bacterial Cells (open access)

Biosynthesis of a Fully Functional Cyclotide inside Living Bacterial Cells

The cyclotide MCoTI-II is a powerful trypsin inhibitor recently isolated from the seeds of Momordica cochinchinensis, a plant member of cucurbitaceae family. We report for the first time the in vivo biosynthesis of natively-folded MCoTI-II inside live E. coli cells. Our biomimetic approach involves the intracellular backbone cyclization of a linear cyclotide-intein fusion precursor mediated by a modified protein splicing domain. The cyclized peptide then spontaneously folds into its native conformation. The use of genetically engineered E. coli cells containing mutations in the glutathione and thioredoxin reductase genes considerably improves the production of folded MCoTI-II in vivo. Biochemical and structural characterization of the recombinant MCoTI-II confirmed its identity. Biosynthetic access to correctly-folded cyclotides allows the possibility of generating cell-based combinatorial libraries that can be screened inside living cells for their ability to modulate or inhibit cellular processes.
Date: April 5, 2007
Creator: Camarero, J A; Kimura, R H; Woo, Y; Cantor, J & Shekhtman, A
Object Type: Article
System: The UNT Digital Library
Geothermal Direct Use Feasibility Study on the Fort Bidwell Indian Reservation (open access)

Geothermal Direct Use Feasibility Study on the Fort Bidwell Indian Reservation

The Fort Bidwell Indian Reservation (FBIR) is rich in renewable energy resources. Development of its geothermal resources has the potential to profoundly affect the energy and economic future of the FBIC. Geothermal energy can contribute to making the reservation energy self-sufficient and, potentially, an energy exporter. The feasibility study assessed the feasibility of installing a geothermal district heating system to provide low-cost, efficient heating of existing and planned residences, community buildings and water, using an existing geothermal well, FB-3.
Date: April 20, 2007
Creator: Merrick, Dale
Object Type: Report
System: The UNT Digital Library