TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media (open access)

TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of acid mine drainage remediation, waste disposal sites, hydrothermal convection, contaminant transport, and groundwater quality. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers non-isothermal multi-component chemical transport in both liquid and gas phases. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity.
Date: March 11, 2003
Creator: Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: High Performance Computing with QCDOC and BlueGene (open access)

Proceedings of RIKEN BNL Research Center Workshop: High Performance Computing with QCDOC and BlueGene

Staff of Brookhaven National Laboratory, Columbia University, IBM and the RIKEN BNL Research Center organized a one-day workshop held on February 28, 2003 at Brookhaven to promote the following goals: (1) To explore areas other than QCD applications where the QCDOC and BlueGene/L machines can be applied to good advantage, (2) To identify areas where collaboration among the sponsoring institutions can be fruitful, and (3) To expose scientists to the emerging software architecture. This workshop grew out of an informal visit last fall by BNL staff to the IBM Thomas J. Watson Research Center that resulted in a continuing dialog among participants on issues common to these two related supercomputers. The workshop was divided into three sessions, addressing the hardware and software status of each system, prospective applications, and future directions.
Date: March 11, 2003
Creator: Christ, N.; Davenport, J.; Deng, Y.; Gara, A.; Glimm, J.; MawHinney, R. et al.
Object Type: Report
System: The UNT Digital Library
Uniformity on the grid via a configuration framework (open access)

Uniformity on the grid via a configuration framework

As Grid permeates modern computing, Grid solutions continue to emerge and take shape. The actual Grid development projects continue to provide higher-level services that evolve in functionality and operate with application-level concepts which are often specific to the virtual organizations that use them. Physically, however, grids are comprised of sites whose resources are diverse and seldom project readily onto a grid's set of concepts. In practice, this also creates problems for site administrators who actually instantiate grid services. In this paper, we present a flexible, uniform framework to configure a grid site and its facilities, and otherwise describe the resources and services it offers. We start from a site configuration and instantiate services for resource advertisement, monitoring and data handling; we also apply our framework to hosting environment creation. We use our ideas in the Information Management part of the SAM-Grid project, a grid system which will deliver petabyte-scale data to the hundreds of users. Our users are High Energy Physics experimenters who are scattered worldwide across dozens of institutions and always use facilities that are shared with other experiments as well as other grids. Our implementation represents information in the XML format and includes tools written in XQuery and …
Date: March 11, 2003
Creator: al., Igor V Terekhov et
Object Type: Article
System: The UNT Digital Library
Application of Material Characterization Techniques to Electrical Forensic Analysis (open access)

Application of Material Characterization Techniques to Electrical Forensic Analysis

The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component failure event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion.
Date: March 11, 2003
Creator: Mills, T.D.
Object Type: Article
System: The UNT Digital Library
Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H (open access)

Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H

This study assessed chemical treatment options for decomposing the tetraphenylborate in High Level Waste (HLW) Tank 48H. Tank 48H, located at the Savannah River Site in Aiken, SC, contains approximately one million liters of HLW. The tetraphenylborate slurry represents legacy material from commissioning of an In Tank Precipitation process to separate radioactive cesium and actinides from the nonradioactive chemicals. During early operations, the process encountered an unplanned chemical reaction that catalytically decomposed the excess tetraphenylborate producing benzene. Subsequent research indicated that personnel could not control the operations within the existing equipment to both meet the desired treatment rate for the waste and maintain the benzene concentration within allowable concentrations. Since then, the Department of Energy selected an alternate treatment process for handling high-level waste at the site. However, the site must destroy the tetraphenylborate before returning the tank to HLW service. The research focuses on identifying treatments to decompose tetraphenylborate to the maximum extent feasible, with a preference for decomposition methods that produce carbon dioxide rather than benzene. A number of experiments examined whether the use of oxidants, catalysts or acids proved effective in decomposing the tetraphenylborate. Additional experiments developed an understanding of the solid, liquid and gas decomposition products.
Date: March 11, 2003
Creator: Lambert, D. P.
Object Type: Article
System: The UNT Digital Library
Addition of Tomographic Capabilities to NMIS (open access)

Addition of Tomographic Capabilities to NMIS

This paper describes tomographic capabilities for the Nuclear Materials Identification System (NMIS). The tomographic capabilities add weapons component spatial and material properties information that result in a more detailed item signature (template) and provide more information for physical attributes analyses. The Nuclear Materials Identification System (NMIS) is used routinely to confirm the identity of HEU components in sealed containers. It does this through a radiation signature acquired by shining a {sup 252}Cf source through the container and measuring the radiation at four detectors stacked vertically on the other side. This measurement gives a gamma and neutron radiation transmission profile of the weapons component, mixed with the radiation production due to the induced fissions in the fissile materials. This information is sufficient to match an "unknown" weapons component signature to a template signature from a reference item when measuring under controlled conditions. Tomography measures the interior of an item by making transmission measurements from all angles around the item, whereas NMIS makes the measurements from a single angle. Figure 1 is a standard example of tomographic reconstruction, the Shepp-Logan human brain phantom. The measured quantity is attenuation so high values (white) are highly attenuating areas.
Date: March 11, 2003
Creator: Mullens, J. A.
Object Type: Report
System: The UNT Digital Library
An analytical solution for estimating percolation rate by fitting temperature profiles in the Vadose Zone (open access)

An analytical solution for estimating percolation rate by fitting temperature profiles in the Vadose Zone

We present a simple analytical solution for one dimensional steady heat transfer with convection and conduction through a multi-layer system such as a vadose zone. We assume that each layer is homogeneous and has a constant thermal diffusivity. The mass/heat flow direction is perpendicular to the layers, and the mass flow rate is a constant. The analytical solution presented in this study also assumes constant known temperatures at the two boundaries of the system. Although the analytical solution gives the temperature as a function of a few parameters, we focus on the inverse application to estimate the percolation rate to high degree of accuracy (e.g., to mm/y). In some other cases the solution may also be helpful in characterizing potential lateral flow along layer divides.
Date: March 11, 2003
Creator: Shan, Chao & Bodvarsson, Gudmundur
Object Type: Article
System: The UNT Digital Library
Progress Report for DOE DE-FG03-98ER20317 ''Regulation of the floral homeotic gene AGAMOUS'' Current and Final Funding Period: September 1, 2002, to December 31, 2002 (open access)

Progress Report for DOE DE-FG03-98ER20317 ''Regulation of the floral homeotic gene AGAMOUS'' Current and Final Funding Period: September 1, 2002, to December 31, 2002

OAK-B135 Results obtained during this funding period: (1) Phylogenetic footprinting of AG regulatory sequences Sequences necessary and sufficient for AGAMOUS (AG) expression in the center of Arabidopsis flowers are located in the second intron, which is about 3 kb in size. This intron contains binding sites for two transcription factors, LEAFY (LFY) and WUSCHEL (WUS), which are direct activators of AG. We used the new method of phylogenetic shadowing to identify new regulatory elements. Among 29 Brassicaceae, several other motifs, but not the LFY and WUS binding sites previously identified, are largely invariant. Using reporter gene analyses, we tested six of these motifs and found that they are all functionally important for activity of AG regulatory sequences in A. thaliana. (2) Repression of AG by MADS box genes A candidate for repressing AG in the shoot apical meristem has been the MADS box gene FUL, since it is expressed in the shoot apical meristem and since an activated version (FUL:VP16) leads to ectopic AG expression in the shoot apical meristem. However, there is no ectopic AG expression in full single mutants. We therefore started to generate VP16 fusions of several other MADS box genes expressed in the shoot apical meristem, …
Date: March 11, 2003
Creator: Weigel, D.
Object Type: Report
System: The UNT Digital Library
Transition Metal Donor-Peptide-Acceptor Complexes: From Intramolecular Electron Transfer Reactions to the Study of Reactive Intermediates (open access)

Transition Metal Donor-Peptide-Acceptor Complexes: From Intramolecular Electron Transfer Reactions to the Study of Reactive Intermediates

The trans-polyproline (PII) oligomers (Figure 1) are unusually rigid peptide structures which have been extensively studied by our group for peptide mediated intramolecular electron transfer (ET) at long distances. We have previously studied ET across a series of metal ion donor (D) acceptor (A) oligoproline peptides with different distances, driving forces and reorganizational energies. The majority of these experiments involve generating the ET intermediate using pulse radiolysis methods, although more recently photochemical methods are also used. Results of these studies showed that ET across peptides can vary by more than twelve orders of magnitude. Using ruthenium bipyridine donors, ET reaction rate constants across several proline residues (n = 4 - 9) occurred in the millisecond (ms) to {micro}s timescale, thus limiting the proline peptide conformational motions to only minor changes (far smaller than the large changes that occur on the ms to sec timescale, such as trans to cis proline isomerization). The present report describes our large data base of experimental results for D-peptide-A complexes in terms of a model where the involvement of both superexchange and hopping (hole and electron) mechanisms account for the long range ET rate constants observed. Our data shows that the change from superexchange to …
Date: March 11, 2003
Creator: Isied, Stephan S.
Object Type: Report
System: The UNT Digital Library
Synthesis of GaNxAs1-x thin films by pulsed laser melting andrapid thermal annealing (PLM-RTA) of N+-implanted GaAs (open access)

Synthesis of GaNxAs1-x thin films by pulsed laser melting andrapid thermal annealing (PLM-RTA) of N+-implanted GaAs

We present a systematic investigation on the formation of the highly mismatched alloy GaN{sub x}As{sub 1-x} using N{sup +}-implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaN{sub x}As{sub 1-x} with x as high as 0.016 and an activation efficiency of the implanted N up to 50% have been synthesized with structural and optical properties comparable to films grown by epitaxial deposition techniques with similar substitutional N content. The effects of N{sup +} implantation dose, laser energy fluence and rapid thermal annealing temperature on the N incorporation as well as optical and structural properties of the GaN{sub x}As{sub 1-x} films are discussed.
Date: March 11, 2003
Creator: Yu, K. M.; Walukiewicz, W.; Scarpulla, M. A.; Dubon, O. D.; Wu, J.; Jasinski, J. et al.
Object Type: Article
System: The UNT Digital Library
Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays (open access)

Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays

With a sample of approximately 89 million B{bar B} pairs collected with the BABAR detector, they measure branching fractions, determine the degree of longitudinal polarization, and search for direct CP violation in the decays B{sup 0} {yields} {phi}K*{sup 0} and B{sup +} {yields} {phi}K*{sup +}. They perform a search for other charmless vector-vector B decays involving {rho} and K*(892) resonances and observe the decays B{sup +} {yields} {rho}{sup 0} K*{sup +} and B{sup +} {yields} {rho}{sup 0}{rho}{sup +}. The branching fractions are measured to be {Beta}({phi}K*{sup 0}) = (11.1{sub -1.2}{sup +1.3} {+-} 1.1) x 10{sup -6}, {Beta}({phi}K*{sup +}) = (12.1{sub -1.9}{sup +2.1} {+-} 1.5) x 10{sup -6}, {Beta}({rho}{sup 0} K*{sup +}) = (7.7{sub -2.0}{sup +2.1} {+-} 1.4) x 10{sup -6}, and {Beta}({rho}{sup 0}{rho}{sup +}) = (9.9{sub -2.5}{sup +2.6} {+-} 2.5) x 10{sup -6}. The longitudinal polarization fractions are measured to be {Lambda}{sub L}/{Lambda}({phi}K*{sup 0}) = 0.65 {+-} 0.07 {+-} 0.04 and {Lambda}{sub L}/{Lambda}({phi}K*{sup +}) = 0.46 {+-} 0.12 {+-} 0.05. They measure the charge asymmetries: {Alpha}{sub CP}({phi}K*{sup 0}) = +0.04 {+-} 0.12 {+-} 0.02 and {Alpha}{sub CP}({phi}K*{sup +}) = +0.16 {+-} 0.17 {+-} 0.04.
Date: March 11, 2003
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y. et al.
Object Type: Article
System: The UNT Digital Library
SCUBA Observations of High Redshift Radio Galaxies (open access)

SCUBA Observations of High Redshift Radio Galaxies

High redshift radio galaxies (HzRGs) are key targets for studies of the formation and evolution of massive galaxies.The role of dust in these processes is uncertain. We have therefore observed the dust continuum emission from a sample of z > 3 radio galaxies with the SCUBA bolometer array. We confirm and strengthen the result found by Archibald et al. (1), that HzRGs are massive starforming systems and that submillimeter detection rate appears to be primarily a strong function of redshift. We also observed HzRG-candidates that have so far eluded spectroscopic redshift determination. Four of these have been detected, and provide evidence that they may be extremely obscured radio galaxies, possibly in an early stage of their evolution.
Date: March 11, 2003
Creator: Reuland, M; Rottgering, H & van Breugel, W
Object Type: Article
System: The UNT Digital Library
Institute for Scientific Computing Research Fiscal Year 2002 Annual Report (open access)

Institute for Scientific Computing Research Fiscal Year 2002 Annual Report

The Institute for Scientific Computing Research (ISCR) at Lawrence Livermore National Laboratory is jointly administered by the Computing Applications and Research Department (CAR) and the University Relations Program (URP), and this joint relationship expresses its mission. An extensively externally networked ISCR cost-effectively expands the level and scope of national computational science expertise available to the Laboratory through CAR. The URP, with its infrastructure for managing six institutes and numerous educational programs at LLNL, assumes much of the logistical burden that is unavoidable in bridging the Laboratory's internal computational research environment with that of the academic community. As large-scale simulations on the parallel platforms of DOE's Advanced Simulation and Computing (ASCI) become increasingly important to the overall mission of LLNL, the role of the ISCR expands in importance, accordingly. Relying primarily on non-permanent staffing, the ISCR complements Laboratory research in areas of the computer and information sciences that are needed at the frontier of Laboratory missions. The ISCR strives to be the ''eyes and ears'' of the Laboratory in the computer and information sciences, in keeping the Laboratory aware of and connected to important external advances. It also attempts to be ''feet and hands, in carrying those advances into the Laboratory …
Date: March 11, 2003
Creator: Keyes, D E; McGraw, J R & Bodtker, L K
Object Type: Report
System: The UNT Digital Library