Diffusion Simulation and Lifetime Calculation at RHIC (open access)

Diffusion Simulation and Lifetime Calculation at RHIC

The beam lifetime is an important parameter for any storage ring. For protons in RHIC it is dominated by the non-linear nature of the head-on collisions that causes the particles to diffuse outside the stable area in phase space. In this report we show results from diffusion simulation and lifetime calculation for the 2006 and 2008 polarized proton runs in RHIC.
Date: January 2, 2009
Creator: Abreu,N.P.; Fischer, W.; Luo, Y. & Robert-Demolaize, G.
Object Type: Report
System: The UNT Digital Library
Lebanon: Background and U.S. Relations (open access)

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: November 2, 2009
Creator: Addis, Casey L.
Object Type: Report
System: The UNT Digital Library
Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis (open access)

Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis

Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster, since the age at death, birth date and year of death, as well as gender, can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization has shown reproducible and more precise results. In this paper we analyze teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that above-ground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ({sup 14}C) which have been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel and ten of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R2=0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 0.6 {+-} 04 years. Aspartic acid racemization also showed …
Date: November 2, 2009
Creator: Alkass, K.; Buchholz, B. A.; Ohtani, S.; Yamamoto, T.; Druid, H. & Spalding, S. L.
Object Type: Article
System: The UNT Digital Library

2008 B20 Survey Results

Describes results of a sample survey of the quality of B20, a biodiesel blend, collected from U.S. public pumps and fleets as part of a joint effort by NREL, the NBB, and engine manufacturers.
Date: February 2, 2009
Creator: Alleman, T. L. & McCormick, R. L.
Object Type: Presentation
System: The UNT Digital Library
MOSAIC: a new wavefront metrology (open access)

MOSAIC: a new wavefront metrology

MOSAIC is a new wavefront metrology that enables complete wavefront characterization from print or aerial image based measurements. Here we describe MOSAIC and verify its utility with a model-based proof of principle.
Date: February 2, 2009
Creator: Anderson, Christopher & Naulleau, Patrick
Object Type: Article
System: The UNT Digital Library
Measurement of the gamma gamma* -> pi0 transition form factor (open access)

Measurement of the gamma gamma* -> pi0 transition form factor

We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Date: June 2, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Search for Dimuon Decays of a Light Scalar Boson in Radiative Transitions Y -> gamma A^0 (open access)

Search for Dimuon Decays of a Light Scalar Boson in Radiative Transitions Y -> gamma A^0

We search for evidence of a light scalar boson in the radiative decays of the {Upsilon}(2S) and {Upsilon}(3S) resonances: {Upsilon}(2S, 3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such a particle appears in extensions of the Standaard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV in the samples of 99 x 10{sup 6} {Upsilon}(2S) and 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR detector at the PEP-II B-factory and set stringent upper limits on the effective coupling of the b quark to the A{sup 0}. We also limit the dimuon branching fraction of the {eta}{sub b} meson: {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.9% at 90% confidence level.
Date: June 2, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Search for Dimuon Decays of a Light Scalar in Radiative Transitions Y(3S) -> gamma A0 (open access)

Search for Dimuon Decays of a Light Scalar in Radiative Transitions Y(3S) -> gamma A0

The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow {Upsilon}(3S) resonance: {Upsilon}(3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction product {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} {mu}{sup +}{mu}{sup -}) at (0.25 - 5.2) x 10{sup -6} in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV. We also set a limit on the dimuon branching fraction of the {eta}{sub b} meson {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.8% at 90% C.L. The results are preliminary.
Date: June 2, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
FIRST STEPS INTO AN ENERGY EFFECIENT FUTURE (open access)

FIRST STEPS INTO AN ENERGY EFFECIENT FUTURE

Red Lake Band of Chippewa Indians proposes to develop a more sustainable, affordable and autonomous energy future for Tribal Members. The Band will develop the capacity to conduct energy audits, to implement energy efficiency measures in tribal homes, and to build more energy efficient housing. This will be done by providing direct classroom and on the job training for Tribal members to conduct the energy audits and the installation of insulation.
Date: April 2, 2009
Creator: BARRETT, JANE L.
Object Type: Report
System: The UNT Digital Library
Effect of Te Inclusions on Internal Electric Field of CdMnTe Gamma-Ray Detectors (open access)

Effect of Te Inclusions on Internal Electric Field of CdMnTe Gamma-Ray Detectors

We studied two separate as-grown CdMnTe crystals by Infrared (IR) microscopy and Pockels effect imaging, and then developed an algorithm to analyze and visualize the electric field within the crystals’ bulk. In one of the two crystals the size and distribution of inclusions within the bulk promised to be more favorable in terms of efficiency as a detector crystal. However, the Te inclusions were arranged in characteristic ‘planes’. Pockels imaging revealed an accumulation of charges in the region of these planes. We demonstrated that the planes induced stress within the bulk of the crystal that accumulated charges, thereby causing non-uniformity of the internal electric field and degrading the detector’s performance.
Date: August 2, 2009
Creator: Babalola, O.S.; Bolotnikov, A.; Egarievwe, S.; Hossain, A.; Burger, A. & James, R.
Object Type: Article
System: The UNT Digital Library
Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks (open access)

Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks

Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO{sub 2}B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for {approx} 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg {sup -1} and maximum values of {approx} 10 g kg{sup -1}. Corresponding values for PN emission factors were 4.7 x 10{sup 15} and 4 x 10{sup 16} kg{sup -1}. There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1{sigma}) …
Date: February 2, 2009
Creator: Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W. & Harley, Robert A.
Object Type: Article
System: The UNT Digital Library
Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009. (open access)

Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.

This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration …
Date: August 2, 2009
Creator: Baptista, António M.
Object Type: Report
System: The UNT Digital Library
Government Access to Phone Calling Activity and Related Records: Legal Authorities (open access)

Government Access to Phone Calling Activity and Related Records: Legal Authorities

This report summarizes legal authorities regarding access by the government, for either foreign intelligence or law enforcement purposes, to information related to telephone calling patterns or practices. Where pertinent, it also discusses statutory prohibitions against accessing or disclosing such information, along with relevant exceptions to those prohibitions.
Date: February 2, 2009
Creator: Bazan, Elizabeth B.; Liu, Edward C. & Stevens, Gina
Object Type: Report
System: The UNT Digital Library
U.S. Food and Agricultural Imports: Safeguards and Selected Issues (open access)

U.S. Food and Agricultural Imports: Safeguards and Selected Issues

The issue was explored at numerous congressional hearings in 2007 and 2008, and Members of Congress introduced a variety of bills to modify or overhaul the current system. Some sought broad reforms in the U.S. Food and Drug Administration's (FDA's) oversight of both food and drug safety, including of imports.
Date: February 2, 2009
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Troop Levels in the Afghan and Iraq Wars, FY2001-FY2012: Cost and Other Potential Issues (open access)

Troop Levels in the Afghan and Iraq Wars, FY2001-FY2012: Cost and Other Potential Issues

In February and March 2009, the Obama Administration announced its overall plans to increase troop levels in Afghanistan and decrease troop levels in Iraq for 2009 through 2011. Using several Department of Defense (DOD) data reports, this report describes, analyzes, and estimates deployed troop strength from the 9/11 attacks to FY2012 to provide Congress with a tool to assess current and future DOD war funding requests; implications for the U.S. military presence in the region; and deployment burdens on individual service members and each of the services.
Date: July 2, 2009
Creator: Belasco, Amy
Object Type: Report
System: The UNT Digital Library
Superconducting Storage Cavity for RHIC (open access)

Superconducting Storage Cavity for RHIC

This document provides a top-level description of a superconducting cavity designed to store hadron beams in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It refers to more detailed documents covering the various issues in designing, constructing and operating this cavity. The superconducting storage cavity is designed to operate at a harmonic of the bunch frequency of RHIC at a relatively low frequency of 56 MHz. The current storage cavities of RHIC operate at 197 MHz and are normal-conducting. The use of a superconducting cavity allows for a high gap voltage, over 2 MV. The combination of a high voltage and low frequency provides various advantages stemming from the resulting large longitudinal acceptance bucket.
Date: January 2, 2009
Creator: Ben-Zvi, Ilan
Object Type: Report
System: The UNT Digital Library
The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling (open access)

The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling

Glutamine synthetase assimilates ammonium into amino acids, thus it is a key enzyme for nitrogen metabolism. The cytosolic isoenzymes of glutamine synthetase assimilate ammonium derived from primary nitrogen uptake and from various internal nitrogen recycling pathways. In this way, cytosolic glutamine synthetase is crucial for the remobilization of protein-derived nitrogen. Cytosolic glutamine synthetase is encoded by a small family of genes that are well conserved across plant species. Members of the cytosolic glutamine synthetase gene family are regulated in response to plant nitrogen status, as well as to environmental cues, such as nitrogen availability and biotic/abiotic stresses. The complex regulation of cytosolic glutamine synthetase at the transcriptional to post-translational levels is key to the establishment of a specific physiological role for each isoenzyme. The diverse physiological roles of cytosolic glutamine synthetase isoenzymes are important in relation to current agricultural and ecological issues.
Date: July 2, 2009
Creator: Bernard, S. M. & Habash, D. Z.
Object Type: Article
System: The UNT Digital Library
The National Intelligence Council: Issues and Options for Congress (open access)

The National Intelligence Council: Issues and Options for Congress

The purpose of this report to describe the statutory provisions that authorize the National Intelligence Council (NIC), provide a brief history of its work, and review its role within the federal government. The report will focus on congressional interaction with the NIC and describe various options for modifying congressional oversight.
Date: September 2, 2009
Creator: Best, Richard A., Jr.
Object Type: Report
System: The UNT Digital Library
Phase 1 Final Technical Report - MgB2 Synthesis for High Field Performance (open access)

Phase 1 Final Technical Report - MgB2 Synthesis for High Field Performance

Accelerator Technology Corp. (ATC) has successfully completed its Phase 1 effort to devel-op rf plasma torch synthesis of MgB2 superconducting powder. The overall objective is to de-velop a way to introduce homogeneous alloying of C and SiC impurities into phase-pure MgB2. Several groups have attained remarkable benefits from such alloying in raising the upper critical field Hc2 from ~14 T to ~30 T (bulk) and ~50 T (thin films). But no one has succeeded in pro-ducing that benefit homogeneously, so that current transport in a practical powder-in-tube (PIT) conductor is largely the same as without the alloying. ATC has conceived the possibility of attaining such homogeneity by passing aerosol suspen-sions of reactant powders through an rf plasma torch, with each reactant transported on a stream-line that heats it to an optimum temperature for the synthesis reaction. This procedure would uniquely access non-equilibrium kinetics for the synthesis reaction, and would provide the possi-bility to separately control the temperature and stoichiometry of each reactant as it enters the mixing region where synthesis occurs. It also facilitates the introduction of seed particles (e.g. nanoscale SiC) to dramatically enhance the rate of the synthesis reaction compared to gas-phase synthesis in rf plasma reported by …
Date: November 2, 2009
Creator: Bhatia, Mohit & McIntyre, Peter
Object Type: Report
System: The UNT Digital Library
Basin-Scale Hydrologic Impacts of CO2 Storage: Regulatory and Capacity Implications (open access)

Basin-Scale Hydrologic Impacts of CO2 Storage: Regulatory and Capacity Implications

Industrial-scale injection of CO{sub 2} into saline sedimentary basins will cause large-scale fluid pressurization and migration of native brines, which may affect valuable groundwater resources overlying the deep sequestration reservoirs. In this paper, we discuss how such basin-scale hydrologic impacts can (1) affect regulation of CO{sub 2} storage projects and (2) may reduce current storage capacity estimates. Our assessment arises from a hypothetical future carbon sequestration scenario in the Illinois Basin, which involves twenty individual CO{sub 2} storage projects in a core injection area suitable for long-term storage. Each project is assumed to inject five million tonnes of CO{sub 2} per year for 50 years. A regional-scale three-dimensional simulation model was developed for the Illinois Basin that captures both the local-scale CO{sub 2}-brine flow processes and the large-scale groundwater flow patterns in response to CO{sub 2} storage. The far-field pressure buildup predicted for this selected sequestration scenario suggests that (1) the area that needs to be characterized in a permitting process may comprise a very large region within the basin if reservoir pressurization is considered, and (2) permits cannot be granted on a single-site basis alone because the near- and far-field hydrologic response may be affected by interference between individual …
Date: April 2, 2009
Creator: Birkholzer, J.T. & Zhou, Q.
Object Type: Report
System: The UNT Digital Library
Time-Resolved Molecular Frame Dynamics of Fixed-in-Space CS2 Molecules (open access)

Time-Resolved Molecular Frame Dynamics of Fixed-in-Space CS2 Molecules

Random orientation of molecules within a sample leads to blurred observationsof chemical reactions studied from the laboratory perspective. Methodsdeveloped for the dynamic imaging of molecular structures and processesstruggle with this, as measurements are optimally made in the molecular frame.Here we uselaser alignment to transiently fix CS2 molecules in space longenough to elucidate, in the molecular reference frame, details of ultrafast electronic vibrationaldynamics during a photochemical reaction. These three-dimensional photoelectron imaging results, combined with ongoing efforts in molecular alignment and orientation, presage a wide range of insights obtainable fromtime-resolved studies in the molecular frame.
Date: April 2, 2009
Creator: Bisgaard, Christer; Clarkin, Owen; Wu, Guorong; Lee, Anthony; Gessner, Oliver; Hayden, Carl et al.
Object Type: Article
System: The UNT Digital Library
An analytical model of nonproportional scintillator light yield in terms of recombination rates (open access)

An analytical model of nonproportional scintillator light yield in terms of recombination rates

This report talks about An analytical model of nonproportional scintillator light yield in terms of recombination rates
Date: February 2, 2009
Creator: Bizarri, Gregory; Moses, William W.; Singh, Jai; Williams, Richard T. & Vasil'ev, Andrey N.
Object Type: Article
System: The UNT Digital Library
The United Nations Convention on the Rights of the Child: Background and Policy Issues (open access)

The United Nations Convention on the Rights of the Child: Background and Policy Issues

This report provides an overview of the United Nations Convention of the Rights of the Child's (CRC) background and structure and examines evolving U.S. policy toward the Convention, including past and current Administration positions and congressional perspectives.
Date: December 2, 2009
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
Longitudinal Stability Calculations (open access)

Longitudinal Stability Calculations

Coupled bunch longitudinal stability in the presence of high frequency impedances is considered. A frequency domain technique is developed and compared with simulations. The frequency domain technique allows for absolute stability tests and is applied to the problem of longitudinal stability in RHIC with the new 56 MHz RF system.
Date: January 2, 2009
Creator: Blaskiewicz, M.
Object Type: Report
System: The UNT Digital Library