Melting of bcc Transition Metals and Icosahedral Clustering (open access)

Melting of bcc Transition Metals and Icosahedral Clustering

In contrast to polyvalent metals, transition metals have low melting slopes(dT/dP) that are due to partially filled d-bands that allow for a lowering of liquid phase energy through s-d electron transfer and the formation of local structures. In the case of bcc transition metals we show the apparent discrepancy of DAC melting measurements with shock melting of Mo can be understood by reexamining the shock data for V and Ta and introducing the presence of an icosahedral short range order (ISRO) melt phase.
Date: May 26, 2006
Creator: Ross, M; Boehler, R & Japel, S
Object Type: Article
System: The UNT Digital Library
Towards an Accurate Performance Modeling of Parallel SparseFactorization (open access)

Towards an Accurate Performance Modeling of Parallel SparseFactorization

We present a performance model to analyze a parallel sparseLU factorization algorithm on modern cached-based, high-end parallelarchitectures. Our model characterizes the algorithmic behavior bytakingaccount the underlying processor speed, memory system performance, aswell as the interconnect speed. The model is validated using theSuperLU_DIST linear system solver, the sparse matrices from realapplications, and an IBM POWER3 parallel machine. Our modelingmethodology can be easily adapted to study performance of other types ofsparse factorizations, such as Cholesky or QR.
Date: May 26, 2006
Creator: Grigori, Laura & Li, Xiaoye S.
Object Type: Article
System: The UNT Digital Library
Proteomic Analysis of Calcium- and Phosphorylation-dependentCalmodulin Complexes in Mammalian Cells (open access)

Proteomic Analysis of Calcium- and Phosphorylation-dependentCalmodulin Complexes in Mammalian Cells

Protein conformational changes due to cofactor binding (e.g. metal ions, heme) and/or posttranslational modifications (e.g. phosphorylation) modulate dynamic protein complexes. Calmodulin (CaM) plays an essential role in regulating calcium (Ca{sup 2+}) signaling and homeostasis. No systematic approach on the identification of phosphorylation-dependent Ca{sup 2+}/CaM binding proteins has been published. Herein, we report a proteome-wide study of phosphorylation-dependent CaM binding proteins from mammalian cells. This method, termed 'Dynamic Phosphoprotein Complex Trapping', 'DPPC Trapping' for short, utilizes a combination of in vivo and in vitro assays. The basic strategy is to drastically shift the equilibrium towards endogenous phosphorylation of Ser, Thr, and Tyr at the global scale by inhibiting corresponding phosphatases in vivo. The phosphorylation-dependent calmodulin-binding proteins are then trapped in vitro in a Ca{sup 2+}-dependent manner by CaM-Sepharose chromatography. Finally, the isolated calmodulin-binding proteins are separated by SDS-PAGE and identified by LC/MS/MS. In parallel, the phosphorylation-dependent binding is visualized by silver staining and/or Western blotting. Using this method, we selectively identified over 120 CaM-associated proteins including many previously uncharacterized. We verified ubiquitin-protein ligase EDD1, inositol 1, 4, 5-triphosphate receptor type 1 (IP{sub 3}R1), and ATP-dependent RNA helicase DEAD box protein 3 (DDX3), as phosphorylation-dependent CaM binding proteins. To demonstrate the utilities …
Date: May 26, 2006
Creator: Jang, Deok-Jin & Wang, Daojing
Object Type: Article
System: The UNT Digital Library
Detection of Ultra High Energy Neutrinos via Coherent Radio Emission (open access)

Detection of Ultra High Energy Neutrinos via Coherent Radio Emission

None
Date: May 26, 2006
Creator: Varner, G.; Gorham, P. W.; Kowalski, R. J.; Learned, J. G.; Link, J. T.; Matsuno, S. et al.
Object Type: Article
System: The UNT Digital Library
Sampling and Analysis Plan - Waste Treatment Plant Seismic Boreholes Project (open access)

Sampling and Analysis Plan - Waste Treatment Plant Seismic Boreholes Project

This sampling and analysis plan (SAP) describes planned data collection activities for four entry boreholes through the sediment overlying the basalt, up to three new deep rotary boreholes through the basalt and sedimentary interbeds, and one corehole through the basalt and sedimentary interbeds at the Waste Treatment Plant (WTP) site. The SAP will be used in concert with the quality assurance plan for the project to guide the procedure development and data collection activities needed to support borehole drilling, geophysical measurements, and sampling. This SAP identifies the American Society of Testing Materials standards, Hanford Site procedures, and other guidance to be followed for data collection activities.
Date: May 26, 2006
Creator: Reidel, Steve P.
Object Type: Report
System: The UNT Digital Library
Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico (open access)

Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and …
Date: May 26, 2006
Creator: Mancini, Ernest A.; Aharon, Paul; Goddard, Donald A. & Barnaby, Roger
Object Type: Report
System: The UNT Digital Library
Synopsis of Cathode #4 Activation (open access)

Synopsis of Cathode #4 Activation

The purpose of this report is to describe the activation of the fourth cathode installed in the DARHT-II Injector. Appendices have been used so that an extensive amount of data could be included without danger of obscuring important information contained in the body of the report. The cathode was a 612 M type cathode purchased from Spectra-Mat. Section II describes the handling and installation of the cathode. Section III is a narrative of the activation based on information located in the Control Room Log Book supplemented with time plots of pertinent operating parameters. Activation of the cathode was performed in accordance with the procedure listed in Appendix A. The following sections provide more details on the total pressure and constituent partial pressures in the vacuum vessel, cathode heater power/filament current, and cathode temperature.
Date: May 26, 2006
Creator: Kwan, Joe; Ekdahl, C.; Harrison, J.; Kwan, J.; Leitner, M.; McCruistian, T. et al.
Object Type: Report
System: The UNT Digital Library
Dynamical Expansion of HII Regions From Ultracompact to Compact Sizes in Turbulent, Self-Gravitating Molecular Clouds (open access)

Dynamical Expansion of HII Regions From Ultracompact to Compact Sizes in Turbulent, Self-Gravitating Molecular Clouds

None
Date: May 26, 2006
Creator: Low, Mordecai-Mark Mac; Toraskar, Jayashree; Oishi, Jeffrey S. & Abel, Tom
Object Type: Report
System: The UNT Digital Library
Retardation of Uranium and Neptunium in Yucca Mountain Saturated Alluvium (open access)

Retardation of Uranium and Neptunium in Yucca Mountain Saturated Alluvium

None
Date: May 26, 2006
Creator: Sedlacek, C.; Schulmeister, M.; Reimus, P.; Scism, C.; Chipera, S. & Ding, M.
Object Type: Article
System: The UNT Digital Library
Secondary shock formation in xenon-nitrogen mixtures (open access)

Secondary shock formation in xenon-nitrogen mixtures

None
Date: May 26, 2006
Creator: Hansen, J. F.; Edwards, M. J.; Froula, D. H.; Edens, A. D.; Gregori, G. & Ditmire, T.
Object Type: Article
System: The UNT Digital Library
Middle to Late Holocene Fluctuations of C3 and C4 Vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine (open access)

Middle to Late Holocene Fluctuations of C3 and C4 Vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine

A 3.1 meter sediment core was analyzed for stable carbon isotope composition of organic matter and higher plant leaf wax (HPLW) lipid biomarkers to determine Holocene shifts in C{sub 3} (higher high marsh) and C{sub 4} (low and/or high marsh) plant deposition at the Sprague River Salt Marsh, Phippsburg, Maine. The carbon isotope composition of the bulk sediment and the HPLW parallel each other throughout most of the core, suggesting that terrestrial plants are an important source of organic matter to the sediments, and diagenetic alteration of the bulk sediments is minimal. The current salt marsh began to form 2500 cal yr BP. Low and/or high C{sub 4} marsh plants dominated deposition at 2000 cal yr BP, 700 cal yr BP, and for the last 200 cal yr BP. Expansion of higher high marsh C{sub 3} plants occurred at 1300 and 600 cal yr BP. These major vegetation shifts result from a combination of changes in relative sea-level rise and sediment accumulation rates. Average annual carbon sequestration rates for the last 2500 years approximate 40 g C yr{sup -1} m{sup -2}, and are in strong agreement with other values published for the Gulf of Maine. Given that Maine salt marshes …
Date: May 26, 2006
Creator: Johnson, B J; Moore, K A; Lehmann, C; Bohlen, C & Brown, T A
Object Type: Article
System: The UNT Digital Library
Electricity and Natural Gas Efficiency Improvements forResidential Gas Furnaces in the U.S. (open access)

Electricity and Natural Gas Efficiency Improvements forResidential Gas Furnaces in the U.S.

This paper presents analysis of the life-cycle costs for individual households and the aggregate energy and economic impacts from potential energy efficiency improvements in U.S. residential furnaces. Most homes in the US are heated by a central furnace attached to ducts for distributing heated air and fueled by natural gas. Electricity consumption by a furnace blower is significant, comparable to the annual electricity consumption of a major appliance. Since the same blower unit is also used during the summer to circulate cooled air in centrally air conditioned homes, electricity savings occur year round. Estimates are provided of the potential electricity savings from more efficient fans and motors. Current regulations require new residential gas-fired furnaces (not including mobile home furnaces) to meet or exceed 78 percent annual fuel utilization efficiency (AFUE), but in fact nearly all furnaces sold are at 80 percent AFUE or higher. The possibilities for higher fuel efficiency fall into two groups: more efficient non-condensing furnaces (81 percent AFUE) and condensing furnaces (90-96 percent AFUE). There are also options to increase the efficiency of the furnace blower. This paper reports the projected national energy and economic impacts of requiring higher efficiency furnaces in the future. Energy savings vary …
Date: May 26, 2006
Creator: Lekov, Alex; Franco, Victor; Meyers, Steve; McMahon, James E.; McNeil, Michael & Lutz, Jim
Object Type: Article
System: The UNT Digital Library
Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method (open access)

Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.
Date: May 26, 2006
Creator: B.Mi; Zhao, X. & Bayles, R.
Object Type: Report
System: The UNT Digital Library
Co-synthesis of LiFePO4 and Carbon Nanotubes (open access)

Co-synthesis of LiFePO4 and Carbon Nanotubes

The rate capabilities of LiFePO{sub 4} composites are dependent on the structure of the carbon that coats the powders, formed during co-calcination with carbon containing precursors. The addition of readily decomposed pyromellitic acid and graphitization catalysts such as ferrocene during synthesis results in coatings with low D/G (disordered/graphene) ratios, while maintaining the carbon content of the powders below 2 wt. %. This is important to avoid adversely affecting the tap density. The good correlation between the pressed pellet conductivities of the LiFePO{sub 4}/C composites and their rate capability in lithium cells is further confirmation of the importance of the carbon structure, because graphitic carbons generally have higher conductivities than disordered ones.
Date: May 26, 2006
Creator: Wilcox, James & Doeff, Marca M.
Object Type: Article
System: The UNT Digital Library
Equilibrium Beam Distribution in An Electron Storage Ring Near Linear Synchrobetatron Coupling Resonances (open access)

Equilibrium Beam Distribution in An Electron Storage Ring Near Linear Synchrobetatron Coupling Resonances

None
Date: May 26, 2006
Creator: Nash, B.; Wu, Ju-Hao & Chao, A.W.
Object Type: Article
System: The UNT Digital Library
Shedding New Light on the 3C 273 Jet With the Spitzer Space Telescope (open access)

Shedding New Light on the 3C 273 Jet With the Spitzer Space Telescope

None
Date: May 26, 2006
Creator: Uchiyama, Yasunobu; Urry, C. M.; Cheung, C. C.; Jester, S.; Van Duyne, J.; Coppi, P. et al.
Object Type: Report
System: The UNT Digital Library
High pressure, quasi-isentropic compression experiments on the Omega laser (open access)

High pressure, quasi-isentropic compression experiments on the Omega laser

The high energy density of pulsed lasers can be used to generate shockless loading in solids to high pressures and compressions but low temperatures. We have used the Omega laser to extend the capabilities of this technique to multi-Mbar pressures and compressions approaching a factor of 2 in aluminum foils. The energy from a 3.7 ns laser pulse is used to drive a strong shock through a 200 {micro}m polystyrene disc. The disc material unloads from a high-pressure state and expands across a 300 {micro}m vacuum gap where it stagnates against the sample to produce a smooth, monotonically increasing load with rise times from a few to {approx} 20 ns. Ramped compression reasing waves having peak pressures of 14-200 GPa (0.14-2.0 Mbar) and peak compressions {rho}/{rho}{sub 0} of 1.1-2.0 were generated in the aluminum samples using laser pulse energies of 400 J to 2 kJ. Wave profiles from a series of successively thicker targets loaded to 120 GPa show the evolution of the high-pressure compression wave within the sample. The initial loading in the sample is shockless, and develops into a shock at a depth of 20-25 {micro}m. We compare these wave profiles with hydrodynamic simulations from which we extract …
Date: May 26, 2006
Creator: Lorenz, K. T.; Edwards, M. J.; Jankowski, Alan Frederic; Pollaine, S. M.; Smith, R. F. & Remington, B. A.
Object Type: Article
System: The UNT Digital Library
The National Geothermal Collaborative, EERE-Geothermal Program, Final Report (open access)

The National Geothermal Collaborative, EERE-Geothermal Program, Final Report

Summary of the work conducted by the National Geothermal Collaborative (a consensus organization) to identify impediments to geothermal development and catalyze events and dialogues among stakeholders to over those impediments.
Date: May 26, 2006
Creator: Erikson, Jody
Object Type: Report
System: The UNT Digital Library
SUMMARY OF BEAM COOLING AND INTRABEAM SCATTERING. (open access)

SUMMARY OF BEAM COOLING AND INTRABEAM SCATTERING.

For heavy-particle beams in storage rings where there is no significant synchrotron radiation damping, beam cooling is an essential tool in obtaining high phase-space density high brightness beams. Advances in various types of cooling such as electron, stochastic, laser and muon cooling are covered in dedicated Conferences. In this series of Workshops (HB2002-06), discussions are aimed only at a few specific subjects which are crucial for future projects. The discussion topics in our session closely followed those discussed during the HB2004 workshop [1]. Specifically, we concentrated on the topics of electron cooling and intrabeam scattering, motivated by the design of the future high-energy coolers [2,3,4]. These cooling projects at high-energy require accurate numerical modeling and experimental verification. A variety of tasks were put together at HB2004 [1]. In our working group we discussed a progress in addressing these tasks. We had 10 presentations [5]-[14] (with additional presentations in the joint sessions) which followed by dedicated discussions. Our main topics of discussions: intrabeam scattering (IBS), electron cooling, and beam stability are summarized.
Date: May 26, 2006
Creator: Fedotov, A. V.; Meshkov, I. N. & Wei, J.
Object Type: Article
System: The UNT Digital Library
Three Affliated Tribes Renewable Energy Feasibility Study (open access)

Three Affliated Tribes Renewable Energy Feasibility Study

The Three Affliated Tribes on the Fort Berthold Reservation studied the feasibility of a commercial wind facility on land selected and owned by the Tribes and examined the potential for the development of renewable energy resources on Tribal Lands.
Date: May 26, 2006
Creator: Pete, Belvin; Good, Kent; Gordon, Krista & Ed McCarthy,
Object Type: Report
System: The UNT Digital Library
Physics Benchmarks for the ILC Detectors (open access)

Physics Benchmarks for the ILC Detectors

None
Date: May 26, 2006
Creator: Battaglia, M.; /UC, Berkeley /LBL, Berkeley; Barklow, T.; Peskin, M.; /SLAC; Okada, Y. et al.
Object Type: Report
System: The UNT Digital Library
Commercialization of a 2.5kW Utility Interactive Inverter for Distributed Generation (open access)

Commercialization of a 2.5kW Utility Interactive Inverter for Distributed Generation

Through this project, Advanced Energy Conversion (AEC) has developed, tested, refined and is preparing to commercialize a 2.5kW utility-interactive inverter system for distributed generation. The inverter technology embodies zero-voltage switching technology that will ultimately yield a system that is smaller, less expensive and more efficient than existing commercial technologies. This program has focused on commercial success through careful synthesis of technology, market-focus and business development. AEC was the primary participant. AEC is utilizing contract manufacturers in the early stages of production, allowing its technical staff to focus on quality control issues and product enhancements. The objective of this project was to bring the AEC inverter technology from its current pre-production state to a commercial product. Federal funds have been used to build and test production-intent inverters, support the implementation of the commercialization plan and bring the product to the point of UL certification.
Date: May 26, 2006
Creator: Torrey, David A.
Object Type: Report
System: The UNT Digital Library