The QCD Phase Diagram: Large Nc, Quarkyonic Matter and the Triple Point (open access)

The QCD Phase Diagram: Large Nc, Quarkyonic Matter and the Triple Point

I discuss the phase diagram of QCD in the large N_c limit. Quarkyonic Matter is described. The properties of QCD matter as measured in the abundance of produced particles are shown to be consistent with this phase diagram. A possible triple point of Hadronic Mater, Deconfined Matter and Quarkyonic matter is shown to explain various behaviors of ratios of particles abundances seen in CERN fixed target experiments.
Date: January 31, 2010
Creator: McLerran, L.
System: The UNT Digital Library
Structural and Morphological Properties of Carbon Supports: Effect on Catalyst Degradation (open access)

Structural and Morphological Properties of Carbon Supports: Effect on Catalyst Degradation

The object of this work was to identify correlations between performance losses of Pt electrocatalysts on carbon support materials and the chemical and morphological parameters that describe them. Accelerated stress testing, with an upper potential of 1.2 V, was used to monitor changes to cathode properties, including kinetic performance and effective platinum surface area losses. The structure and chemical compositions were studied using X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy coupled with Digital Image Processing. As this is an ongoing study, it is difficult to draw firm conclusions, though a trend between support surface area overall performance loss was found to exist.
Date: July 1, 2010
Creator: Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Young, Alan; Dutta, Monica; Ahmad, Zaid et al.
System: The UNT Digital Library
Analysis of biostimulated microbial communities from two field experiments reveals temporal and spatial differences in proteome profiles (open access)

Analysis of biostimulated microbial communities from two field experiments reveals temporal and spatial differences in proteome profiles

Stimulated by an acetate-amendment field experiment conducted in 2007, anaerobic microbial populations in the aquifer at the Rifle Integrated Field Research Challenge site in Colorado reduced mobile U(VI) to insoluble U(IV). During this experiment, planktonic biomass was sampled at various time points to quantitatively evaluate proteomes. In 2008, an acetate-amended field experiment was again conducted in a similar manner to the 2007 experiment. As there was no comprehensive metagenome sequence available for use in proteomics analysis, we systematically evaluated 12 different organism genome sequences to generate sets of aggregate genomes, or “pseudo-metagenomes”, for supplying relative quantitative peptide and protein identifications. Proteomics results support previous observations of the dominance of Geobacteraceae during biostimulation using acetate as sole electron donor, and revealed a shift from an early stage of iron reduction to a late stage of iron reduction. Additionally, a shift from iron reduction to sulfate reduction was indicated by changes in the contribution of proteome information contributed by different organism genome sequences within the aggregate set. In addition, the comparison of proteome measurements made between the 2007 field experiment and 2008 field experiment revealed differences in proteome profiles. These differences may be the result of alterations in abundance and population structure …
Date: July 15, 2010
Creator: Callister, S. J.; Wilkins, M. J.; Nicora, C. D.; Williams, K. H.; Banfield, J. F.; VerBerkmoes, N. C. et al.
System: The UNT Digital Library
Dynamics of microbial community composition and function during in-situ bioremediation of a uranium-contaminated aquifer (open access)

Dynamics of microbial community composition and function during in-situ bioremediation of a uranium-contaminated aquifer

A pilot-scale system was established to examine the feasibility of in situ U(VI) immobilization at a highly contaminated aquifer (U.S. DOE Integrated Field Research Challenge site, Oak Ridge, TN). Ethanol was injected intermittently as an electron donor to stimulate microbial U(VI) reduction, and U(VI) concentrations fell to below the Environmental Protection Agency drinking water standard (0.03 mg liter{sup -1}). Microbial communities from three monitoring wells were examined during active U(VI) reduction and maintenance phases with GeoChip, a high-density, comprehensive functional gene array. The overall microbial community structure exhibited a considerable shift over the remediation phases examined. GeoChip-based analysis revealed that Fe(III)-reducing bacterial (FeRB), nitrate-reducing bacterial (NRB), and sulfate-reducing bacterial (SRB) functional populations reached their highest levels during the active U(VI) reduction phase (days 137 to 370), in which denitrification and Fe(III) and sulfate reduction occurred sequentially. A gradual decrease in these functional populations occurred when reduction reactions stabilized, suggesting that these functional populations could play an important role in both active U(VI) reduction and maintenance of the stability of reduced U(IV). These results suggest that addition of electron donors stimulated the microbial community to create biogeochemical conditions favorable to U(VI) reduction and prevent the reduced U(IV) from reoxidation and that …
Date: August 15, 2010
Creator: Van Nostrand, J. D.; Wu, L.; Wu, W. M.; Huang, A.; Gentry, T. J.; Deng, Y. et al.
System: The UNT Digital Library
Hydrogen Bonding Under High-Pressure (open access)

Hydrogen Bonding Under High-Pressure

None
Date: March 12, 2010
Creator: Manaa, M R & Fried, L E
System: The UNT Digital Library
Structural and electrochemical Investigation of Li(Ni0.4Co0.2-yAlyMn0.4)O2 Cathode Material (open access)

Structural and electrochemical Investigation of Li(Ni0.4Co0.2-yAlyMn0.4)O2 Cathode Material

Li(Ni{sub 0.4}Co{sub 0.15}Al{sub 0.05}Mn{sub 0.4})O{sub 2} was investigated to understand the effect of replacement of the cobalt by aluminum on the structural and electrochemical properties. In situ X-ray absorption spectroscopy (XAS) was performed, utilizing a novel in situ electrochemical cell, specifically designed for long-term X-ray experiments. The cell was cycled at a moderate rate through a typical Li-ion battery operating voltage range. (1.0-4.7 V) XAS measurements were performed at different states of charge (SOC) during cycling, at the Ni, Co, and the Mn edges, revealing details about the response of the cathode to Li insertion and extraction processes. The extended X-ray absorption fine structure (EXAFS) region of the spectra revealed the changes of bond distance and coordination number of Ni, Co, and Mn absorbers as a function of the SOC of the material. The oxidation states of the transition metals in the system are Ni{sup 2+}, Co{sup 3+}, and Mn{sup 4+} in the as-made material (fully discharged), while during charging the Ni{sup 2+} is oxidized to Ni{sup 4+} through an intermediate stage of Ni{sup 3+}, Co{sup 3+} is oxidized toward Co{sup 4+}, and Mn was found to be electrochemically inactive and remained as Mn{sup 4+}. The EXAFS results during cycling …
Date: June 14, 2010
Creator: Rumble, C.; Conry, T.E.; Doeff, Marca; Cairns, Elton J.; Penner-Hahn, James E. & Deb, Aniruddha
System: The UNT Digital Library
Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations (open access)

Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.
Date: July 1, 2010
Creator: Rees, E.V.L.; Kneafsey, T.J. & Seol, Y.
System: The UNT Digital Library
Novel Geometries for the LHC Crab Cavity (open access)

Novel Geometries for the LHC Crab Cavity

The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.
Date: May 1, 2010
Creator: B. Hall,G. Burt,C. Lingwood,Robert Rimmer,Haipeng Wang; Hall, B.; Burt, G.; Lingwood, C.; Rimmer, Robert & Wang, Haipeng
System: The UNT Digital Library
Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders (open access)

Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders

Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity of roughly 200 W/m-K and a CTE ranging from 7-12 ppm/ deg C, similar to that of silicon. An equivalent sized heat pipe embedded AlSiC plate has effective thermal conductivity ranging from 400 to 500 W/m-K and retains the CTE of AlSiC.
Date: January 7, 2010
Creator: Johnson, Matthew; Weyant, J.; Garner, S. & Occhionero, M.
System: The UNT Digital Library
Cleanroom Energy Efficiency: Metrics and Benchmarks (open access)

Cleanroom Energy Efficiency: Metrics and Benchmarks

Cleanrooms are among the most energy-intensive types of facilities. This is primarily due to the cleanliness requirements that result in high airflow rates and system static pressures, as well as process requirements that result in high cooling loads. Various studies have shown that there is a wide range of cleanroom energy efficiencies and that facility managers may not be aware of how energy efficient their cleanroom facility can be relative to other cleanroom facilities with the same cleanliness requirements. Metrics and benchmarks are an effective way to compare one facility to another and to track the performance of a given facility over time. This article presents the key metrics and benchmarks that facility managers can use to assess, track, and manage their cleanroom energy efficiency or to set energy efficiency targets for new construction. These include system-level metrics such as air change rates, air handling W/cfm, and filter pressure drops. Operational data are presented from over 20 different cleanrooms that were benchmarked with these metrics and that are part of the cleanroom benchmark dataset maintained by Lawrence Berkeley National Laboratory (LBNL). Overall production efficiency metrics for cleanrooms in 28 semiconductor manufacturing facilities in the United States and recorded in the …
Date: July 7, 2010
Creator: Initiative, International SEMATECH Manufacturing; Mathew, Paul A.; Tschudi, William; Sartor, Dale & Beasley, James
System: The UNT Digital Library
Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector (open access)

Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector

Many radioactive isotopes have low energy X-rays and high energy gamma rays of interest for detection. The goal of the work presented was to demonstrate the possibility of measuring both low-energy X-rays and relatively high-energy gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, or cerium bromide. The key accomplishments of the project was the building and acquisition of the LaF3:Ce nanocomposite detectors. Nanocomposite detectors are sensitive to {gamma}’s as well as n’s and X-rays.
Date: November 1, 2010
Creator: Guss, P., Guise, R., Reed, M., Mukhopadhyay, S., Yuan, D.
System: The UNT Digital Library
The Northwest Geysers EGS Demonstration Project Phase 1: Pre-stimulation coupled geomechanical modeling to guide stimulation and monitoring plans (open access)

The Northwest Geysers EGS Demonstration Project Phase 1: Pre-stimulation coupled geomechanical modeling to guide stimulation and monitoring plans

This paper presents activities and results associated with Phase 1 (pre-stimulation phase) of an Enhanced Geothermal System (EGS) demonstration project at the northwest part of The Geysers geothermal field, California. The paper presents development of a 3-D geological model, coupled thermal-hydraulic-mechanical (THM) modeling of proposed stimulation injection as well as current plans for stimulation and monitoring of the site. The project aims at creating an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (about 280 to 350 C) Zone (HTZ) located under the conventional (240 C) steam reservoir at depths of {approx}3 km. Accurate micro-earthquake monitoring initiated before the start of the injection will be used as a tool for tracking the development of the EGS and monitoring changes in microseismicity. We first analyzed historic injection and micro-earthquake data from an injection well (Aidlin 11) located about 3 miles to the west of the new EGS demonstration area. Thereafter, we used the same modeling approach to predict the likely extent of the zone of enhanced permeability for a proposed initial injection in two wells (Prati State 31 and Prati 32) at the new EGS demonstration area. Our modeling indicates that the …
Date: October 20, 2010
Creator: Rutqvist, J.; Dobson, P. F.; Oldenburg, C. M.; Garcia, J. & Walters, M.
System: The UNT Digital Library
Determination of Natural Beryllium (Be) in Soil and Swipe Samples Utilizing Yttrium/Beryllium Ratio (open access)

Determination of Natural Beryllium (Be) in Soil and Swipe Samples Utilizing Yttrium/Beryllium Ratio

1. Objective: A method to determine whether beryllium (Be) components in surface swipe samples are from a natural source is needed. 2. Methods: Soil samples and surface swipes from area facilities were analyzed for marker elements to identify source pathways for beryllium (Be). To be useful, the natural marker element must be present at reasonably consistent levels across the site, must correlate with the Be concentration, and not have the potential to be present from non-natural sources. 3. Results: The research on marker elements used to identify source pathways for beryllium (Be) concentrations demonstrates a clear correlation between Be and yttrium (Y) in natural soils on the Nevada National Security Site. The Y/Be ratio is proposed as a method to characterize the source of Be in soil and surface swipe samples and to aid in recommendations for follow up actions. Swipe samples are analyzed using an ICP/MS method and compared with results from soil samples. Natural soil constituent levels and the Y/Be Ratio range is determined for the occupied and historical facilities and surrounding areas. Y/Be ratios within the statistical range established indicate the Be is from a natural source. Y/Be ratios lower than this range indicate the presence of …
Date: September 30, 2010
Creator: unknown
System: The UNT Digital Library
Development of Tritium Permeation Analysis Code (TPAC) (open access)

Development of Tritium Permeation Analysis Code (TPAC)

Idaho National Laboratory developed the Tritium Permeation Analysis Code (TPAC) for tritium permeation in the Very High Temperature Gas Cooled Reactor (VHTR). All the component models in the VHTR were developed and were embedded into the MATHLAB SIMULINK package with a Graphic User Interface. The governing equations of the nuclear ternary reaction and thermal neutron capture reactions from impurities in helium and graphite core, reflector, and control rods were implemented. The TPAC code was verified using analytical solutions for the tritium birth rate from the ternary fission, the birth rate from 3He, and the birth rate from 10B. This paper also provides comparisons of the TPAC with the existing other codes. A VHTR reference design was selected for tritium permeation study from the reference design to the nuclear-assisted hydrogen production plant and some sensitivity study results are presented based on the HTGR outlet temperature of 750 degrees C.
Date: October 1, 2010
Creator: Kim, Eung S.; Oh, Chang H. & Patterson, Mike
System: The UNT Digital Library
The Status of De-Inventory of Security Category I/II Nuclear Materials at Lawrence Livermore National Laboratory (LLNL) (open access)

The Status of De-Inventory of Security Category I/II Nuclear Materials at Lawrence Livermore National Laboratory (LLNL)

None
Date: May 13, 2010
Creator: Riley, D C & Dodson, K
System: The UNT Digital Library
Role of Water States on Water Uptake and Proton Transport in Nafion using Molecular Simulations and Bimodal Network (open access)

Role of Water States on Water Uptake and Proton Transport in Nafion using Molecular Simulations and Bimodal Network

Using molecular simulations and a bimodal domain network, the role of water state on Nafion water uptake and water and proton transport is investigated. Although the smaller domains provide moderate transport pathways, their effectiveness remains low due to strong, resistive water molecules/domain surface interactions. The water occupancy of the larger domains yields bulk-like water, and causes the observed transition in the water uptake and significant increases in transport properties.
Date: November 19, 2010
Creator: Michigan, U.; Hwang, Gi Suk; Kaviany, Massoud; Gostick, Jeffrey T.; Kientiz, Brian; Weber, Adam Z. et al.
System: The UNT Digital Library
Tomographic Imaging of Water Injection and Withdrawal in PEMFC Gas Diffusion Layers (open access)

Tomographic Imaging of Water Injection and Withdrawal in PEMFC Gas Diffusion Layers

X-ray computed tomography was used to visualize the water configurations inside gas diffusion layers for various applied capillary pressures, corresponding to both water invasion and withdrawal. A specialized sample holder was developed to allow capillary pressure control on the small-scale samples required. Tests were performed on GDL specimens with and without hydrophobic treatments.
Date: June 25, 2010
Creator: McGill University
System: The UNT Digital Library
Electron Cloud at Low Emittance in CesrTA (open access)

Electron Cloud at Low Emittance in CesrTA

The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. A range of EC mitigation methods have been deployed and tested and their effectiveness is discussed. Measurements of the electron cloud's effect on the beam under a range of conditions are discussed along with the simulations being used to quantitatively understand these results.
Date: May 23, 2010
Creator: Alexander, J. P.; Billing, M. G.; Calvey, J.; Crittenden, J. A.; Dugan, G.; Eggert, N. et al.
System: The UNT Digital Library
In vitro High-Resolution Architecture and Structural Dynamics of Bacterial Systems (open access)

In vitro High-Resolution Architecture and Structural Dynamics of Bacterial Systems

None
Date: March 18, 2010
Creator: Malkin, A. J.; Plomp, M.; Leighton, T. J.; Vogelstein, B. & Holman, H.
System: The UNT Digital Library
Daemen Alternative Energy/Geothermal Technologies Demonstration Program Erie County (open access)

Daemen Alternative Energy/Geothermal Technologies Demonstration Program Erie County

The purpose of the Daemen Alternative Energy/Geothermal Technologies Demonstration Project is to demonstrate the use of geothermal technology as model for energy and environmental efficiency in heating and cooling older, highly inefficient buildings. The former Marian Library building at Daemen College is a 19,000 square foot building located in the center of campus. Through this project, the building was equipped with geothermal technology and results were disseminated. Gold LEED certification for the building was awarded. 1) How the research adds to the understanding of the area investigated. This project is primarily a demonstration project. Information about the installation is available to other companies, organizations, and higher education institutions that may be interested in using geothermal energy for heating and cooling older buildings. 2) The technical effectiveness and economic feasibility of the methods or techniques investigated or demonstrated. According to the modeling and estimates through Stantec, the energy-efficiency cost savings is estimated at 20%, or $24,000 per year. Over 20 years this represents $480,000 in unrestricted revenue available for College operations. See attached technical assistance report. 3) How the project is otherwise of benefit to the public. The Daemen College Geothermal Technologies Ground Source Heat Pumps project sets a standard for …
Date: May 20, 2010
Creator: Robert C. Beiswanger, Jr.
System: The UNT Digital Library
Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments (open access)

Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments

None
Date: December 21, 2010
Creator: Le Galloudec, N. R.; Cobble, J.; Nelson, S. L.; Merwin, A.; Paudel, Y.; Shrestha, I. et al.
System: The UNT Digital Library
Subcellular localization of proteins in the anaerobic sulfate reducer Desulfovibrio vulgaris via SNAP-tag labeling and photoconversion (open access)

Subcellular localization of proteins in the anaerobic sulfate reducer Desulfovibrio vulgaris via SNAP-tag labeling and photoconversion

Systems Biology studies the temporal and spatial 3D distribution of macromolecular complexes with the aim that such knowledge will allow more accurate modeling of biological function and will allow mathematical prediction of cellular behavior. However, in order to accomplish accurate modeling precise knowledge of spatial 3D organization and distribution inside cells is necessary. And while a number of macromolecular complexes may be identified by its 3D structure and molecular characteristics alone, the overwhelming number of proteins will need to be localized using a reporter tag. GFP and its derivatives (XFPs) have been traditionally employed for subcelllar localization using photoconversion approaches, but this approach cannot be taken for obligate anaerobic bacteria, where the intolerance towards oxygen prevents XFP approaches. As part of the GTL-funded PCAP project (now ENIGMA) genetic tools have been developed for the anaerobe sulfate reducer Desulfovibrio vulgaris that allow the high-throughput generation of tagged-protein mutant strains, with a focus on the commercially available SNAP-tag cell system (New England Biolabs, Ipswich, MA), which is based on a modified O6-alkylguanine-DNA alkyltransferase (AGT) tag, that has a dead-end reaction with a modified O6-benzylguanine (BG) derivative and has been shown to function under anaerobic conditions. After initial challenges with respect to variability, …
Date: June 1, 2010
Creator: Gorur, A.; Leung, C. M.; Jorgens, D.; Tauscher, A.; Remis, J. P.; Ball, D. A. et al.
System: The UNT Digital Library
Experimental Results in the Comparison of Search Algorithms Used with Room Temperature Detectors (open access)

Experimental Results in the Comparison of Search Algorithms Used with Room Temperature Detectors

Analysis of time sequence data was run for several higher resolution scintillation detectors using a variety of search algorithms, and results were obtained in predicting the relative performance for these detectors, which included a slightly superior performance by CeBr{sub 3}. Analysis of several search algorithms shows that inclusion of the RSPRT methodology can improve sensitivity.
Date: November 1, 2010
Creator: Guss, P., Yuan, D., Cutler, M., Beller, D.
System: The UNT Digital Library
Mechanical Performance of the LARP Nb{sub 3}Sn Quadrupole Magnet LQS01 (open access)

Mechanical Performance of the LARP Nb{sub 3}Sn Quadrupole Magnet LQS01

As part of the effort towards the development of Nb{sub 3}Sn magnets for future LHC luminosity upgrades, the LHC Accelerator Research Program (LARP) has fabricated and tested the quadrupole magnet LQS01. The magnet implements 3.4 m long Nb{sub 3}Sn coils contained in a support structure characterized by an external aluminum shell segmented in four sections. The room temperature pre-load of the structure is obtained by shimming load keys through bladders, pressurized during the loading operations and removed before cool-down. Temperature compensated strain gauges, mounted on structure components and coil poles, monitor the magnet's mechanical behavior during assembly, cool-down and excitation. During the first test, LQS01 reached the target gradient of 200 T/m; the gauge data indicated that the aluminum shell was pre-tensioned to the target value estimated by numerical models, but a lack of pre-load was measured in the coil inner layer during ramping. As a result, the test was interrupted and the magnet disassembled and inspected. A second test (LQS01b) was then carried out following a re-loading of the magnet. The paper reports on the strain gauge results of the first test and the analysis performed to identify corrective actions to improve the coil pre-stress distribution. The mechanical performance …
Date: August 1, 2010
Creator: Ferracin, P.; Ambrosio, G.; Anerella, M.; Bingham, B.; Bossert, R.; Caspi, S. et al.
System: The UNT Digital Library