Study of Heterogeneouse Processes Related to the Chemistry of Tropospheric Oxidants and Aerosols (open access)

Study of Heterogeneouse Processes Related to the Chemistry of Tropospheric Oxidants and Aerosols

The objective of the studies was to elucidate the heterogeneous chemistry of tropospheric aerosols. Experiments were designed to measure both specifically needed parameters, and to obtain systematic data required to build a fundamental understanding of the nature of gas-surface physical and chemical interactions
Date: February 13, 2013
Creator: Davidovits, Paul; Worsnop, D R; Jayne, J T & Colb, C E
Object Type: Report
System: The UNT Digital Library
ARM Lead Mentor Selection Process (open access)

ARM Lead Mentor Selection Process

The ARM Climate Research Facility currently operates more than 300 instrument systems that provide ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, also known as Instrument Mentors. Instrument Mentors must have an excellent understanding of in situ and remote-sensing instrumentation theory and operation and have comprehensive knowledge of critical scale-dependent atmospheric processes. They also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets.
Date: March 13, 2013
Creator: Sisterson, DL
Object Type: Text
System: The UNT Digital Library
Dalitz Plot Analysis of the Charmless Three Body Decay B+- to K+- K+- K-+ Utilising Data Recorded by the BaBar Experiment (open access)

Dalitz Plot Analysis of the Charmless Three Body Decay B+- to K+- K+- K-+ Utilising Data Recorded by the BaBar Experiment

None
Date: May 13, 2013
Creator: Barrett, Matthew
Object Type: Article
System: The UNT Digital Library
Final Report for the DOE-BES Program Mechanistic Studies of Activated Hydrogen Release from Amine-Boranes (open access)

Final Report for the DOE-BES Program Mechanistic Studies of Activated Hydrogen Release from Amine-Boranes

Effective storage of hydrogen presents one of the most significant technical gaps to successful implementation of the hydrogen economy, particularly for transportation applications. Amine boranes, such as ammonia borane H3NBH3 and ammonia triborane H3NB3H7, have been identified as promising, high-capacity chemical hydrogen storage media containing potentially readily released protic (N-H) and hydridic (B-H) hydrogens. At the outset of our studies, dehydrogenation of ammonia borane had been studied primarily in the solid state, but our DOE sponsored work clearly demonstrated that ionic liquids, base-initiators and/or metal-catalysts can each significantly increase both the rate and extent of hydrogen release from amine boranes under moderate conditions. Our studies also showed that depending upon the activation method, hydrogen release from amine boranes can occur by very different mechanistic steps and yield different types of spent-fuel materials. The fundamental understanding that was developed during this grant of the pathways and controlling factors for each of these hydrogen-release mechanisms is now enabling continuing discovery and optimization of new chemical-hydride based hydrogen storage systems.
Date: January 13, 2013
Creator: Sneddon, Larry G. & Baker, R. Thomas
Object Type: Report
System: The UNT Digital Library
Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in AxFe2-ySe2 (A=K, Rb) Superconductors (open access)

Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in AxFe2-ySe2 (A=K, Rb) Superconductors

None
Date: March 13, 2013
Creator: Yi, M.; Lu, D. H.; Yu, R.; Riggs, S. C.; Chu, J. H.; Lv, B. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of an Excess in Bbar to D(*) tau- nubar Decays and Implications for Charged Higgs Bosons (open access)

Measurement of an Excess in Bbar to D(*) tau- nubar Decays and Implications for Charged Higgs Bosons

None
Date: March 13, 2013
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Grauges, E.; /Barcelona U., ECM et al.
Object Type: Article
System: The UNT Digital Library
Hexagon Functions and the Three-loop Remainder Function (open access)

Hexagon Functions and the Three-loop Remainder Function

None
Date: August 13, 2013
Creator: Dixon, Lance J.; Drummond, James M.; von Hippel, Matt & Pennington, Jeffrey
Object Type: Article
System: The UNT Digital Library
Application of the Principle of Maximum Conformality to Top-Pair Production (open access)

Application of the Principle of Maximum Conformality to Top-Pair Production

A major contribution to the uncertainty of finite-order perturbative QCD predictions is the perceived ambiguity in setting the renormalization scale {mu}{sub r}. For example, by using the conventional way of setting {mu}{sub r} {element_of} [m{sub t}/2, 2m{sub t}], one obtains the total t{bar t} production cross-section {sigma}{sub t{bar t}} with the uncertainty {Delta}{sigma}{sub t{bar t}}/{sigma}{sub t{bar t}} {approx} (+3%/-4%) at the Tevatron and LHC even for the present NNLO level. The Principle of Maximum Conformality (PMC) eliminates the renormalization scale ambiguity in precision tests of Abelian QED and non-Abelian QCD theories. By using the PMC, all nonconformal {l_brace}{beta}{sub i}{r_brace}-terms in the perturbative expansion series are summed into the running coupling constant, and the resulting scale-fixed predictions are independent of the renormalization scheme. The correct scale-displacement between the arguments of different renormalization schemes is automatically set, and the number of active flavors n{sub f} in the {l_brace}{beta}{sub i}{r_brace}-function is correctly determined. The PMC is consistent with the renormalization group property that a physical result is independent of the renormalization scheme and the choice of the initial renormalization scale {mu}{sub r}{sup init}. The PMC scale {mu}{sub r}{sup PMC} is unambiguous at finite order. Any residual dependence on {mu}{sub r}{sup init} for a …
Date: May 13, 2013
Creator: Brodsky, Stanley J.; Wu, Xing-Gang & Dept of Physics, Chongqing University, China
Object Type: Article
System: The UNT Digital Library
A Simple Radionuclide-Driven Single-Ion Source (open access)

A Simple Radionuclide-Driven Single-Ion Source

None
Date: June 13, 2013
Creator: Montero Diez, M.; Twelker, K.; Fairbank, W., Jr.; Gratta, G.; Barbeau, P. S.; Barry, K. et al.
Object Type: Article
System: The UNT Digital Library
Development of an Online Toolkit for Measuring Commercial Building Energy Efficiency Performance -- Scoping Study (open access)

Development of an Online Toolkit for Measuring Commercial Building Energy Efficiency Performance -- Scoping Study

This study analyzes the market needs for building performance evaluation tools. It identifies the existing gaps and provides a roadmap for the U.S. Department of Energy (DOE) to develop a toolkit with which to optimize energy performance of a commercial building over its life cycle.
Date: March 13, 2013
Creator: Wang, Na
Object Type: Report
System: The UNT Digital Library
RESULTS OF ANALYSIS OF NGS CONCENTRATE DRUM SAMPLES [Next Generation Solvent] (open access)

RESULTS OF ANALYSIS OF NGS CONCENTRATE DRUM SAMPLES [Next Generation Solvent]

Savannah River National Laboratory (SRNL) prepared two drums (50 gallons each in �Drum#2� and �Drum#4�) of NGS-MCU (Next Generation Solvent-Modular CSSX Unit) concentrate for future use at MCU in downblending the BOBCalixC6 based solvent to produce NGS-MCU solvent. Samples of each drum were sent for analysis. The results of all the analyses indicate that the blend concentrate is of the correct composition and should produce a blended solvent at MCU of the desired formulation.
Date: September 13, 2013
Creator: Peters, T. & Williams, M.
Object Type: Report
System: The UNT Digital Library
Gamma-Ray Emission Concurrent with the Nova in the Symbiotic Binary V407 Cygni (open access)

Gamma-Ray Emission Concurrent with the Nova in the Symbiotic Binary V407 Cygni

None
Date: June 13, 2013
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J. et al.
Object Type: Article
System: The UNT Digital Library
Solvent Hold Tank Sample Results For MCU-13-814, MCU-13-815, MCU-13-816, MCU-13,817, MCU-13-818 And MCU-13-819: Quarterly Sample From May 2013 (open access)

Solvent Hold Tank Sample Results For MCU-13-814, MCU-13-815, MCU-13-816, MCU-13,817, MCU-13-818 And MCU-13-819: Quarterly Sample From May 2013

Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-13-814, MCU-13-815, MCU-13-816, MCU-13-817, MCU-13-818 and MCU-13-819 received May 28, 2013 are reported. The results show that the solvent at MCU does not require an Isopar® L addition, but it will require addition of trioctylamine despite of the 272 g of TOA that was added to the solvent on June 5, 2013 based on the solvent containing a TOA level of 45% of nominal. A new TOA analysis method (HCl titration) has been used and its output was statistically similar to the results from the SVOA-TOA method. This method provides an independent method for measuring TOA and TiDG in MCU-NG solvent. An impurity containing a tert-butyl group was detected in the solvent and further analytical analysis is needed to identify it. SRNL recommends determining the impact of this impurity on the mass transfer ability of the solvent. SRNL also analyzed the SHT sample for {sup 137}Cs content and determined the measured value is above the …
Date: August 13, 2013
Creator: Fondeur, F. F. & Taylor-Pashow, K. M.
Object Type: Report
System: The UNT Digital Library
Search for neutral Higgs bosons in the multi-b-jet topology in 5.2fb-1 of ppbar collisions at sqrt(s)=1.96 TeV (open access)

Search for neutral Higgs bosons in the multi-b-jet topology in 5.2fb-1 of ppbar collisions at sqrt(s)=1.96 TeV

None
Date: June 13, 2013
Creator: Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D. et al.
Object Type: Article
System: The UNT Digital Library
Intense Terahertz Pulses from SLAC Electron Beams using Coherent Transition Radiation (open access)

Intense Terahertz Pulses from SLAC Electron Beams using Coherent Transition Radiation

None
Date: March 13, 2013
Creator: Wu, Ziran; Fisher, Alan S.; Goodfellow, John; Fuchs, Matthias; Daranciang, Dan; Hogan, Mark et al.
Object Type: Article
System: The UNT Digital Library
Needs Analysis for Dimethyl Mercury (open access)

Needs Analysis for Dimethyl Mercury

For this needs analysis, a total of 131 DMHg analytical results were collected and reviewed from the Hanford Tank Farms from 2004 to 2007. Sampling data from the Site Wide Industrial Hygiene Database (SWIHO), the Tank waste inventory System (TWINs), and prior sampling campaigns by CH2M Hill Hanford that were not available in the SWIHD database, were aggregated for analysis. Technical literature used by the Savannah River Site (SRS). Bechtel RPP·WTP, and CH2M Hill Hanford from 2003-2007, were also reviewed to identify potential DMHg exposure concerns applicable to the tank farms. After analyzing the adequacy of lhe data, information gaps were identified and recommendations for corrective actions items were developed.
Date: February 13, 2013
Creator: Schmoldt, Michael J.
Object Type: Report
System: The UNT Digital Library
Characterization of a high-temperature superconducting conductor on round core cables in magnetic fields up to 20 T (open access)

Characterization of a high-temperature superconducting conductor on round core cables in magnetic fields up to 20 T

The next generation of high-field magnets that will operate at magnetic fields substantially above 20 T, or at temperatures substantially above 4.2 K, requires high-temperature superconductors (HTS). Conductor on round core (CORC) cables, in which RE-Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (RE = rare earth) (REBCO) coated conductors are wound in a helical fashion on a fl‚exible core, are a practical and versatile HTS cable option for low-inductance, high-field magnets. We performed the first tests of CORC magnet cables in liquid helium in magnetic fields of up to 20 T. A record critical current I{sub c} of 5021 A was measured at 4.2 K and 19 T. In a cable with an outer diameter of 7.5 mm, this value corresponds to an engineering current density J{sub e} of 114 A mm{sup -2} , the highest J{sub e} ever reported for a superconducting cable at such high magnetic fields. Additionally, the first magnet wound from an HTS cable was constructed from a 6 m-long CORC cable. The 12-turn, double-layer magnet had an inner diameter of 9 cm and was tested in a magnetic field of 20 T, at which it had an I{sub c} of 1966 A. The cables were quenched repetitively without …
Date: February 13, 2013
Creator: van der Laan, Danko; Noyes, Patrick; Miller, George; Weijers, Hubertus & Willering, Gerard
Object Type: Article
System: The UNT Digital Library
ANALYTICAL RESULTS FOR MOX COLEMANITE CONCRETE SAMPLES RECEIVED ON JANUARY 15, 2013 (open access)

ANALYTICAL RESULTS FOR MOX COLEMANITE CONCRETE SAMPLES RECEIVED ON JANUARY 15, 2013

The Mixed Oxide Fuel Fabrication Facility (MFFF) will use colemanite bearing concrete neutron absorber panels credited with attenuating neutron flux in the criticality design analyses and shielding operators from radiation. The Savannah River National Laboratory (SRNL) is tasked with measuring the total density, partial hydrogen density, and partial boron density of the colemanite concrete. SRNL received twelve samples of colemanite concrete for analysis on January 15, 2013. The average total density of each of the samples measured by the ASTM method C 642, the average partial hydrogen density was measured using method ASTM E 1311, and the average partial boron density of each sample was measured according to ASTM C 1301. The lower limits and measured values for the total density, hydrogen partial density, and boron partial density are presented. For all the samples tested, the total density and the hydrogen partial density met or exceeded the specified limit. All of the samples met or exceeded the boron partial density lower bound with the exception of samples G3-M11-2000-H, G3-M11-3000-M, and G5-M1-3000-H which are below the limit of 1.65E-01 g/cm3.
Date: February 13, 2013
Creator: Reigel, M. & Best, D.
Object Type: Report
System: The UNT Digital Library
Hi Power S-band Window Optimized to Minimize Surface Electric and Magnetic Fields (open access)

Hi Power S-band Window Optimized to Minimize Surface Electric and Magnetic Fields

None
Date: May 13, 2013
Creator: Yeremian, A.D.; Dolgashev, V.A. & Tantawi, S.G.
Object Type: Article
System: The UNT Digital Library
EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1) (open access)

EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be …
Date: September 13, 2013
Creator: Clark, E.
Object Type: Report
System: The UNT Digital Library
Design Concepts for the Cherenkov Telescope Array (open access)

Design Concepts for the Cherenkov Telescope Array

None
Date: June 13, 2013
Creator: Actis, M.; Agnetta, G.; Aharonian, F.; Akhperjanian, A.; Aleksic, J.; Aliu, E. et al.
Object Type: Article
System: The UNT Digital Library
Large Cryogenic Germanium Detector. Final Report (open access)

Large Cryogenic Germanium Detector. Final Report

The goal of this project was to investigate possible ways of increasing the size of cryogenic Ge detectors. This project identified two possible approaches to increasing the individual cryogenic Ge detector size. The first approach relies on using the existing technology for growing detector-grade (high-purity) germanium crystals of dislocation density 100-7000 cm{sup -2}. The second approach is to consider dislocation-free Ge crystals.
Date: February 13, 2013
Creator: Mandic, Vuk
Object Type: Report
System: The UNT Digital Library
ANALYTICAL RESULTS FOR MOX COLEMANITE SAMPLES RECEIVED ON JULY 22, 2013 (open access)

ANALYTICAL RESULTS FOR MOX COLEMANITE SAMPLES RECEIVED ON JULY 22, 2013

The Mixed Oxide Fuel Fabrication Facility (MFFF) will use colemanite bearing concrete neutron absorber panels credited with attenuating neutron flux in the criticality design analyses and shielding operators from radiation. The Savannah River National Laboratory (SRNL) is tasked with measuring the boron oxide content of the colemanite raw aggregate material prior to it being mixed into the concrete. SRNL received ten samples of colemanite for analysis on July 22, 2013. The elemental boron content of each sample was measured according to ASTM C 1301. The boron oxide content was calculated using the oxide conversion factor for boron.
Date: August 13, 2013
Creator: Reigel, M. & Best, D.
Object Type: Report
System: The UNT Digital Library
Applicability of Nonproliferation Tools and Concepts to Future Arms Control (open access)

Applicability of Nonproliferation Tools and Concepts to Future Arms Control

None
Date: May 13, 2013
Creator: Dreicer, M & Stein, G
Object Type: Article
System: The UNT Digital Library