DX magnet requirements for p-Au operation (open access)

DX magnet requirements for p-Au operation

This document addresses the question of moving the DX magnets for p-Au operations. First the beam geometry is addressed. Next, the beam sizes are covered. Finally, a conclusion is presented.
Date: January 19, 2012
Creator: Tepikian, S.; Trbojevic&#44 & D.
Object Type: Report
System: The UNT Digital Library
Grain-Scale Failure in Thermal Spallation Drilling (open access)

Grain-Scale Failure in Thermal Spallation Drilling

Geothermal power promises clean, renewable, reliable and potentially widely-available energy, but is limited by high initial capital costs. New drilling technologies are required to make geothermal power financially competitive with other energy sources. One potential solution is offered by Thermal Spallation Drilling (TSD) - a novel drilling technique in which small particles (spalls) are released from the rock surface by rapid heating. While TSD has the potential to improve drilling rates of brittle granitic rocks, the coupled thermomechanical processes involved in TSD are poorly described, making system control and optimization difficult for this drilling technology. In this paper, we discuss results from a new modeling effort investigating thermal spallation drilling. In particular, we describe an explicit model that simulates the grain-scale mechanics of thermal spallation and use this model to examine existing theories concerning spalling mechanisms. We will report how borehole conditions influence spall production, and discuss implications for macro-scale models of drilling systems.
Date: January 19, 2012
Creator: Walsh, Stuart C.; Lomov, Ilya & Roberts, Jeffery J.
Object Type: Article
System: The UNT Digital Library
Moisture desorption rates from TATB-formulations: experiments and kinetic models (open access)

Moisture desorption rates from TATB-formulations: experiments and kinetic models

None
Date: January 19, 2012
Creator: Glascoe, E. A.; Dinh, L. N.; Small, W. & Overturf, G. E.
Object Type: Article
System: The UNT Digital Library
Parametric Explosion Spectral Model (open access)

Parametric Explosion Spectral Model

Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.
Date: January 19, 2012
Creator: Ford, S R & Walter, W R
Object Type: Report
System: The UNT Digital Library
SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY (open access)

SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY

Fractures and fracture networks are the principal pathways for migration of water and contaminants in groundwater systems, fluids in enhanced geothermal systems (EGS), oil and gas in petroleum reservoirs, carbon dioxide leakage from geological carbon sequestration, and radioactive and toxic industrial wastes from underground storage repositories. When dealing with EGS fracture networks, there are several major issues to consider, e.g., the minimization of hydraulic short circuits and losses of injected geothermal fluid to the surrounding formation, which in turn maximize heat extraction and economic production. Gel deployments to direct and control fluid flow have been extensively and successfully used in the oil industry for enhanced oil recovery. However, to the best of our knowledge, gels have not been applied to EGS to enhance heat extraction. In-situ gelling systems can either be organic or inorganic. Organic polymer gels are generally not thermostable to the typical temperatures of EGS systems. Inorganic gels, such as colloidal silica gels, however, may be ideal blocking agents for EGS systems if suitable gelation times can be achieved. In the current study, we explore colloidal silica gelation times and rheology as a function of SiO{sub 2} concentration, pH, salt concentration, and temperature, with preliminary results in the …
Date: January 19, 2012
Creator: Hunt, J D; Ezzedine, S M; Bourcier, W & Roberts, S
Object Type: Article
System: The UNT Digital Library
Some kinetic properties of hydrogen corrosion in polycrystalline plutonium (open access)

Some kinetic properties of hydrogen corrosion in polycrystalline plutonium

None
Date: January 19, 2012
Creator: Saw, C K; Haschke, J M; Allen, P G; McLean, W & Dinh, L N
Object Type: Article
System: The UNT Digital Library
Upgrade scenario for the RHIC collimation system (open access)

Upgrade scenario for the RHIC collimation system

The RHIC collimation system is used to reduce background levels in both STAR and PHENIX detectors. With a push for higher luminosity in the near future, it becomes critical to check if and how the level of performance of the collimators can be improved. The following reviews a proposal for additional collimators placed further downstream of the current system and designed to intercept the tertiary halo coming out of the IR8 insertion before it can reach the triplet quadrupoles in either STAR or PHENIX. Simulations have been peformed to quantify the efficiency of additional collimator jaws in RHIC. Each figure presented in this article clearly shows that the additional mask collimators provide the expected reduction in losses around the machine, and especially to the incoming triplet to the STAR experiment (IP6), for the Yellow beam as much as for the Blue beam. Looking at compiled statistics for all three working point cases studied, proton losses around the machine are reduced by roughly one order of magnitude: at most a factor 30 for magnet losses, and at most a factor 40 for losses in spaces between magnets.
Date: January 19, 2012
Creator: G., Robert-Demolaize; Drees&#44 & A.
Object Type: Report
System: The UNT Digital Library
What Scientific Applications can Benefit from Hardware Transactional Memory? - Early experience from a commercially available HTM system. (open access)

What Scientific Applications can Benefit from Hardware Transactional Memory? - Early experience from a commercially available HTM system.

None
Date: January 19, 2012
Creator: Schindewolf, M; Schulz, M; Bihari, B; Gyllenhaal, J; Wang, A & Karl, W
Object Type: Article
System: The UNT Digital Library
Colloid Facilitated Transport of Plutonium at the Nevada Test Site, NV USA (open access)

Colloid Facilitated Transport of Plutonium at the Nevada Test Site, NV USA

None
Date: January 19, 2011
Creator: Kersting, A. & Zavarin, M.
Object Type: Book
System: The UNT Digital Library
Financial Innovation Among the Community Wind Sector in the United States (open access)

Financial Innovation Among the Community Wind Sector in the United States

In the relatively brief history of utility-scale wind generation, the 'community wind' sector - defined here as consisting of relatively small utility-scale wind power projects that are at least partly owned by one or more members of the local community - has played a vitally important role as a 'test bed' or 'proving ground' for wind turbine manufacturers. In the 1980s and 1990s, for example, Vestas and other now-established European wind turbine manufacturers relied heavily on community wind projects in Scandinavia and Germany to install - and essentially field-test - new turbine designs. The fact that orders from community wind projects seldom exceeded more than a few turbines at a time enabled the manufacturers to correct any design flaws or manufacturing defects fairly rapidly, and without the risk of extensive (and expensive) serial defects that can accompany larger orders. Community wind has been slower to take root in the United States - the first such projects were installed in the state of Minnesota around the year 2000. Just as in Europe, however, the community wind sector in the U.S. has similarly served as a proving ground - but in this case for up-and-coming wind turbine manufacturers that are trying to …
Date: January 19, 2011
Creator: Bolinger, Mark
Object Type: Book
System: The UNT Digital Library
Gold Cluster Diffusion Kinetics on Stoichiometric and Reduced Surfaces of Rutile TiO2 (110) (open access)

Gold Cluster Diffusion Kinetics on Stoichiometric and Reduced Surfaces of Rutile TiO2 (110)

None
Date: January 19, 2011
Creator: Goldman, N & Browning, N D
Object Type: Article
System: The UNT Digital Library
Note on numerical study of the beam energy spread in NDCX-I (open access)

Note on numerical study of the beam energy spread in NDCX-I

The kinetic energy spread (defined here as the standard deviation of the beam particle energies) sets the ultimate theoretical limit on the longitudinal compression that can be attained on NDCX-I and NDCX-II. Experimental measurements will inevitably include the real influences on the longitudinal phase space of the beam due to injector and accelerator field imperfections1. These induced energy variations may be the real limit to the longitudinal compression in an accelerator. We report on a numerical investigation of the energy spread evolution in NDCX-I; these studies do not include all the real imperfections, but rather are intended to confirm that there are no other intrinsic mechanisms (translaminar effects, transverse-longitudinal anisotropy instability, etc.) for significant broadening of the energy distribution. We have performed Warp simulations that use a realistic Marx voltage waveform which was derived from experimental measurements (averaged over several shots), a fully-featured model of the accelerating and focusing lattice, and new diagnostics for computing the local energy spread (and temperature) that properly account for linear correlations that arise from the discrete binning along each physical dimension (these capabilities reproduce and extend those of the earlier HIF code BPIC). The new diagnostics allow for the calculation of multi-dimensional maps of …
Date: January 19, 2011
Creator: Vay, J. L.; Seidl, P. A. & Friedman, A.
Object Type: Report
System: The UNT Digital Library
Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D (open access)

Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D

None
Date: January 19, 2011
Creator: Ferron, J.; Holcomb, C.; Luce, T.; Politzer, P.; Turco, F.; White, A. et al.
Object Type: Article
System: The UNT Digital Library
PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH (open access)

PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), and measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work …
Date: January 19, 2011
Creator: Hobbs, D.
Object Type: Article
System: The UNT Digital Library
Pressure Drop, Heat Transfer, Critical Heat Flux, and Flow Stability of Two-Phase Flow Boiling of Water and Ethylene Glycol/Water Mixtures - Final Report for Project "Efficent Cooling in Engines With Nucleate Boiling." (open access)

Pressure Drop, Heat Transfer, Critical Heat Flux, and Flow Stability of Two-Phase Flow Boiling of Water and Ethylene Glycol/Water Mixtures - Final Report for Project "Efficent Cooling in Engines With Nucleate Boiling."

Because of its order-of-magnitude higher heat transfer rates, there is interest in using controllable two-phase nucleate boiling instead of conventional single-phase forced convection in vehicular cooling systems to remove ever increasing heat loads and to eliminate potential hot spots in engines. However, the fundamental understanding of flow boiling mechanisms of a 50/50 ethylene glycol/water mixture under engineering application conditions is still limited. In addition, it is impractical to precisely maintain the volume concentration ratio of the ethylene glycol/water mixture coolant at 50/50. Therefore, any investigation into engine coolant characteristics should include a range of volume concentration ratios around the nominal 50/50 mark. In this study, the forced convective boiling heat transfer of distilled water and ethylene glycol/water mixtures with volume concentration ratios of 40/60, 50/50, and 60/40 in a 2.98-mm-inner-diameter circular tube has been investigated in both the horizontal flow and the vertical flow. The two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux of the test fluids were determined experimentally over a range of the mass flux, the vapor mass quality, and the inlet subcooling through a new boiling data reduction procedure that allowed the analytical calculation of the fluid boiling temperatures along …
Date: January 19, 2011
Creator: Yu, W.; France, D. M. & Routbort, J. L.
Object Type: Report
System: The UNT Digital Library
Reaction Between Thin Gold Wires and Pb-Sn-In Solder (37.5%, 37.5%, 25%), Part A: The Radial Reaction Inside The Solder Mounds, Its Linear Reaction Model, Statistical Variation of Reaction Rate, and Induced Structural Changes In The Solder Mounds. (open access)

Reaction Between Thin Gold Wires and Pb-Sn-In Solder (37.5%, 37.5%, 25%), Part A: The Radial Reaction Inside The Solder Mounds, Its Linear Reaction Model, Statistical Variation of Reaction Rate, and Induced Structural Changes In The Solder Mounds.

Thermodynamics favors the reaction between indium and gold, since the heat of formation of AuIn{sub 2} is 6 kcal/mole, substantially larger than the heat of formation of any other possible reaction product. Thermodynamic equilibrium between gold and the elements in the solder mound is reached only when ALL gold is converted to AuIn{sub 2}. There are two aspects to this conversion: (A) the reaction WITHIN the solder mound (called here 'radial reaction') and (B) the reaction OUTSIDE the solder mound (called here 'axial reaction') and the transition from (A) to (B). The reaction between thin gold detonator wires and the In/Pb/Sn solder mound in older detonators has been looked at repeatedly. There are, in addition, two studies which look at the reaction between indium and gold in planar geometry. All data are shown in tables I to V. It is the objective of this section dealing with aspect (A), to combine all of these results into a reaction model and to use this reaction model to reliably and conservatively predict the gold-solder reaction rate of soldered gold bridge-wires as a function of storage temperature and time.
Date: January 19, 2011
Creator: Siekhaus, W J
Object Type: Report
System: The UNT Digital Library
SUMMARY OF 2010 DOE EM INTERNATIONAL PROGRAM STUDIES OF WASTE GLASS MELT RATE ENHANCEMENT (open access)

SUMMARY OF 2010 DOE EM INTERNATIONAL PROGRAM STUDIES OF WASTE GLASS MELT RATE ENHANCEMENT

A collaborative study has been established under the U.S. Department of Energy (DOE) Office of Environmental Management International Program between the Savannah River National Laboratory (SRNL) and the V. G. Khlopin Radium Institute (KRI) in St. Petersburg, Russia, to investigate potential improvements in melt rate via chemical additions to the glass frit. Researchers at KRI suggested a methodology for selecting frit additives based on empirical coefficients for optimization of glass melting available in the Russian literature. Using these coefficients, KRI identified B{sub 2}O{sub 3}, CuO, and MnO as frit additives that were likely to improve melt rate without having adverse effects on crystallization of the glass or its chemical durability. The results of the melt rate testing in the SMK melter showed that the slurry feed rate (used as a gauge of melt rate) could be significantly increased when MnO or CuO were added to Frit 550 with the SMR-2 sludge. The feed rates increased by about 27% when MnO was added to the frit and by about 26% when CuO was added to the frit, as compared to earlier results for Frit 550 alone. The impact of adding additional B{sub 2}O{sub 3} to the frit was minor when added …
Date: January 19, 2011
Creator: Fox, K. & Marra, J.
Object Type: Report
System: The UNT Digital Library
Alternative Inspection Methods for Single Shell Tanks (open access)

Alternative Inspection Methods for Single Shell Tanks

This document was prepared to provide evaluations and recommendations regarding nondestructive evaluation methods that might be used to determine cracks and bowing in the ceiling of waste storage tanks on the Hanford site. The goal was to determine cracks as small as 1/16 in. wide in the ceiling, and bowing as small as 0.25 in. This report describes digital video camera methods that can be used to detect a crack in the ceiling of the dome, and methods for determining the surface topography of the ceiling in the waste storage tanks to detect localized movements in the surface. A literature search, combined with laboratory testing, comprised this study.
Date: January 19, 2010
Creator: Peters, Timothy J.; Alzheimer, James M. & Hurley, David E.
Object Type: Report
System: The UNT Digital Library
Design and Implementation of a Metadata-rich File System (open access)

Design and Implementation of a Metadata-rich File System

Despite continual improvements in the performance and reliability of large scale file systems, the management of user-defined file system metadata has changed little in the past decade. The mismatch between the size and complexity of large scale data stores and their ability to organize and query their metadata has led to a de facto standard in which raw data is stored in traditional file systems, while related, application-specific metadata is stored in relational databases. This separation of data and semantic metadata requires considerable effort to maintain consistency and can result in complex, slow, and inflexible system operation. To address these problems, we have developed the Quasar File System (QFS), a metadata-rich file system in which files, user-defined attributes, and file relationships are all first class objects. In contrast to hierarchical file systems and relational databases, QFS defines a graph data model composed of files and their relationships. QFS incorporates Quasar, an XPATH-extended query language for searching the file system. Results from our QFS prototype show the effectiveness of this approach. Compared to the de facto standard, the QFS prototype shows superior ingest performance and comparable query performance on user metadata-intensive operations and superior performance on normal file metadata operations.
Date: January 19, 2010
Creator: Ames, S; Gokhale, M B & Maltzahn, C
Object Type: Report
System: The UNT Digital Library
Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Biases Using Data Assimilation (open access)

Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Biases Using Data Assimilation

This is the final report for DOE grant DE-FG02-07ER64434 to Eric DeWeaver at the University of Wisconsin-Madison. The overall goal of work performed under this grant is to enhance understanding of simulations of present-day climate and greenhouse gas-induced climate change. Enhanced understanding is desirable 1) as a prerequisite for improving simulations; 2) for assessing the credibility of model simulations and their usefulness as tools for decision support; and 3) as a means to identify robust behaviors which commonly occur over a wide range of models, and may yield insights regarding the dominant physical mechanisms which determine mean climate and produce climate change. A furthe objective is to investigate the use of data assimilation as a means for examining and correcting model biases. Our primary focus is on the Arctic, but the scope of the work was expanded to include the global climate system to the extent that research targets of opportunity present themselves. Research performed under the grant falls into five main research areas: 1) a study of data assimilation using an ensemble filter with the atmospheric circulation model of the National Center for Atmospheric Research, in which both conventional observations and observations of the refraction of radio waves from …
Date: January 19, 2010
Creator: DeWeaver, Eric T.
Object Type: Report
System: The UNT Digital Library
EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION (open access)

EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION

Carbon supported Pt and Pt-Co electrocatalysts for the oxygen reduction reaction in low temperature fuel cells were prepared by the reduction of the metal salts with sodium borohydride and sodium formate. The effect of surface treatment with nitric acid on the carbon surface and Co on the surface of carbon prior to the deposition of Pt was studied. The catalysts where Pt was deposited on treated carbon the ORR reaction preceded more through the two electron pathway and favored peroxide production, while the fresh carbon catalysts proceeded more through the four electron pathway to complete the oxygen reduction reaction. NaCOOH reduced Pt/C catalysts showed higher activity that NaBH{sub 4} reduced Pt/C catalysts. It was determined that the Co addition has a higher impact on catalyst activity and active surface area when used with NaBH{sub 4} as reducing agent as compared to NaCOOH.
Date: January 19, 2010
Creator: Fox, E. & Colon-Mercado, H.
Object Type: Article
System: The UNT Digital Library
HCDF: A Hybrid Community Discovery Framework (open access)

HCDF: A Hybrid Community Discovery Framework

None
Date: January 19, 2010
Creator: Henderson, Keith; Eliassi-Rad, Tina; Papadimitriou, Spiros & Faloutsos, Christos
Object Type: Article
System: The UNT Digital Library
High statistics analysis using anisotropic clover lattices: (III) Baryon-baryon interactions (open access)

High statistics analysis using anisotropic clover lattices: (III) Baryon-baryon interactions

Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m{sub {pi}} {approx} 390 MeV, a spatial volume of L{sup 3} {approx} (2.5 fm){sup 3}, and a spatial lattice spacing of b {approx} 0.123 fm. Luescher's method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The isospin-3/2 N{Sigma} interactions are found to be highly spin-dependent, and the interaction in the {sup 3}S{sub 1} channel is found to be strong. In contrast, the N{Lambda} interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is {Lambda}{Lambda}, indicating that the {Lambda}{Lambda} interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio …
Date: January 19, 2010
Creator: Beane, S; Detmold, W; Lin, H; Luu, T; Orginos, K; Savage, M et al.
Object Type: Article
System: The UNT Digital Library
Innovative Coal Solids-Flow Monitoring and Measurement Using Phase-Doppler and Mie Scattering Techniques (open access)

Innovative Coal Solids-Flow Monitoring and Measurement Using Phase-Doppler and Mie Scattering Techniques

Fuel flow to individual burners is complicated and difficult to determine on coal fired boilers, since coal solids were transported in a gas suspension that is governed by the complex physics of two-phase flow. The objectives of the project were the measurements of suspended coal solids-flows in the simulated test conditions. Various extractive methods were performed manually and can give only a snapshot result of fuel distribution. In order to measure particle diameter & velocity, laser based phase-Doppler particle analyzer (PDPA) and particle image velocimetry (PIV) were carefully applied. Statistical methods were used to analyze particle characteristics to see which factors have significant effect. The transparent duct model was carefully designed and fabricated for the laser-based-instrumentation of solids-flow monitoring (LISM). The experiments were conducted with two different kinds of particles with four different particle diameters. The particle types were organic particles and saw dust particles with the diameter range of 75-150 micron, 150-250 micron, 250-355 micron and 355-425 micron. The densities of the particles were measured to see how the densities affected the test results. Also the experiment was conducted with humid particles and fog particles. To generate humid particles, the humidifier was used. A pipe was connected to the …
Date: January 19, 2010
Creator: Lee, Stephen Seong
Object Type: Report
System: The UNT Digital Library