OXIDATION OF BE AT ELEVATED TEMPERATURE (open access)

OXIDATION OF BE AT ELEVATED TEMPERATURE

None
Date: September 20, 2004
Creator: Cook, R C & Gunther, J
Object Type: Report
System: The UNT Digital Library
Mesh independent convergence of the modified inexact Newton method for a second order nonlinear problem (open access)

Mesh independent convergence of the modified inexact Newton method for a second order nonlinear problem

In this paper, we consider an inexact Newton method applied to a second order nonlinear problem with higher order nonlinearities. We provide conditions under which the method has a mesh-independent rate of convergence. To do this, we are required to first, set up the problem on a scale of Hilbert spaces and second, to devise a special iterative technique which converges in a higher than first order Sobolev norm. We show that the linear (Jacobian) system solved in Newton's method can be replaced with one iterative step provided that the initial nonlinear iterate is accurate enough. The closeness criteria can be taken independent of the mesh size. Finally, the results of numerical experiments are given to support the theory.
Date: September 20, 2004
Creator: Kim, T; Pasciak, J E & Vassilevski, P S
Object Type: Article
System: The UNT Digital Library
The Mechanical and Thermal Design for the MICE Coupling SolenoidMagnet (open access)

The Mechanical and Thermal Design for the MICE Coupling SolenoidMagnet

The MICE coupling solenoids surround the RF cavities that are used to increase the longitudinal momentum of the muon beam that is being cooled within MICE. The coupling solenoids will have a warm-bore diameter of 1394 mm. This is the warm bore that is around the 200 MHz RF cavities. The coupling solenoid is a single superconducting coil fabricated from a copper matrix Nb-Ti conductor originally designed for MRI magnets. A single coupling magnet is designed so that it can be cooled with a single 1.5 W (at 4.2 K) cooler. The MICE cooling channel has two of these solenoids, which will be hooked together in series, for a magnet circuit with a total stored-energy of the order of 12.8 MJ. Quench protection for the coupling coils is discussed. This report also presents the mechanical and thermal design parameters for this magnet, including the results of finite element calculations of mechanical forces and heat flow in the magnet cold mass.
Date: September 20, 2004
Creator: Green, M.A.; Yang, S.Q.; Bravar, U.; Lau, W.; Li, D.; Strauss,B.P. et al.
Object Type: Article
System: The UNT Digital Library
Reconstruction Of Regulatory And Metabolic Pathways InMetal-Reducing delta-Proteobacteria (open access)

Reconstruction Of Regulatory And Metabolic Pathways InMetal-Reducing delta-Proteobacteria

Relatively little is known about the genetic basis for the unique physiology of metal-reducing genera in the delta subgroup of the proteobacteria. The recent availability of complete finished or draft-quality genome sequences for seven representatives allowed us to investigate the genetic and regulatory factors in a number of key pathways involved in the biosynthesis of building blocks and cofactors, metal-ion homeostasis, stress response, and energy metabolism using a combination of regulatory sequence detection and analysis of genomic context. In the genomes of delta-proteobacteria, we identified candidate binding sites for four regulators of known specificity (BirA, CooA, HrcA,sigma-32), four types of metabolite-binding riboswitches (RFN-, THI-,B12-elements and S-box), and new binding sites for the FUR, ModE, NikR,PerR, and ZUR transcription factors, as well as for the previously uncharacterized factors HcpR and LysX. After reconstruction of the corresponding metabolic pathways and regulatory interactions, we identified possible functions for a large number of previously uncharacterized genes covering a wide range of cellular functions. Phylogenetically diverse delta-proteobacteria appear to have homologous regulatory components. This study for the first time demonstrates the adaptability of the comparative genomic approach to de novo reconstruction of a regulatory network in a poorly studied taxonomic group of bacteria. Recent efforts …
Date: September 20, 2004
Creator: Rodionov, Dmitry A.; Dubchak, Inna; Arkin, Adam; Alm, Eric & Gelfand,Mikhail S.
Object Type: Article
System: The UNT Digital Library
Actinide Cross Section Evaluations (open access)

Actinide Cross Section Evaluations

The Livermore Computational Nuclear Physics group is charged with producing updated neutron incident cross section evaluations for all the actinides in the coming year, concentrating on neutron induced fission, neutron capture and (n,2n) cross sections. We attack this daunting task either by adopting other recent evaluations or by performing our own. Owing to the large number of nuclei involved, we seek to automate this process as much as possible. For this purpose, we have developed a series of computer codes: x41, an interface to the EXFOR database, fete, a code that translates ENDF/B formatted evaluations into a computationally convenient form, and da{_}fit, a fitting code that takes all relevant EXFOR data for a reaction or set of reactions and performs a generalized least square fit to them, subject to various constraints and other prior information.
Date: September 20, 2004
Creator: Brown, D. A.; Loyola, B. & McNabb, D.
Object Type: Article
System: The UNT Digital Library
A Computational and Experimental Investigation of Violence in a Thermal Explosion Test (open access)

A Computational and Experimental Investigation of Violence in a Thermal Explosion Test

None
Date: September 20, 2004
Creator: Yoh, J.; McClelland, M. & Maienschein, J.
Object Type: Article
System: The UNT Digital Library
A Survey of High-Quality Computational Libraries and their Impactin Science and Engineering Applications (open access)

A Survey of High-Quality Computational Libraries and their Impactin Science and Engineering Applications

Recently, a number of important scientific and engineering problems have been successfully studied and solved by means of computational modeling and simulation. Many of these computational models and simulations benefited from the use of available software tools and libraries to achieve high performance and portability. In this article, we present a reference matrix of the performance of robust, reliable and widely used tools mapped to scientific and engineering applications that use them. We aim at regularly maintaining and disseminating this matrix to the computational science community. This matrix will contain information on state-of-the-art computational tools, their applications and their use.
Date: September 20, 2004
Creator: Drummond, L. A.; Hernandez, V.; Marques, O.; Roman, J. E. & Vidal, V.
Object Type: Article
System: The UNT Digital Library
Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Iodine and Xenon (open access)

Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Iodine and Xenon

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron and proton induced nuclear reaction cross sections in the mass region of iodine and xenon (52 {<=} Z {<=} 54, 71 {<=} N {<=} 76).
Date: September 20, 2004
Creator: Hoffman, R. D.; Dietrich, F. S.; Bauer, R.; Kelley, K. & Mustafa, M.
Object Type: Report
System: The UNT Digital Library
The potential impact of renewable energy deployment on natural gas prices in New England (open access)

The potential impact of renewable energy deployment on natural gas prices in New England

Concerns about the price and supply of natural gas have deepened in recent years both nationally and in New England. Renewable energy (RE) technologies can directly hedge natural gas price risk by reducing the need to purchase variable-price natural gas-fired electricity generation, and replacing that generation with fixed-price renewable electricity supply. In addition to its direct contribution to price stability, an increasing number of studies show that renewable energy deployment can also put downward pressure on natural gas prices by reducing demand for gas among gas-fired generators. These gas price reductions are, in turn, expected to reduce electricity prices and--more importantly--directly reduce consumer natural gas bills. Many recent studies have found that this effect may be significant, substantially benefiting consumers. These studies are reviewed in the attached paper, published in the proceedings of a recent national energy conference. An important consideration is that--strictly speaking--this price reduction represents a consumer benefit that comes at the expense of producers; it therefore represents a wealth transfer, not a net gain in social welfare. That said, current concerns about the price and supply of natural gas suggest that policymakers may want to pursue actions that reduce the strain of high prices on consumer energy …
Date: September 20, 2004
Creator: Wiser, Ryan & Bolinger, Mark
Object Type: Report
System: The UNT Digital Library
Development of Lithium Lanthanide Borate Scintillator for Neutron Scattering Applications (open access)

Development of Lithium Lanthanide Borate Scintillator for Neutron Scattering Applications

We have completed the design and testing of neutron scattering instrument detectors for powder diffractometers and single crystal diffractometers. These detectors meet the performance requirements for these types of instruments at the Department of Energy Spallation Neutron Source facility.
Date: September 20, 2004
Creator: Czirr, J.B.; McKnight, T. & Merrill, D.
Object Type: Report
System: The UNT Digital Library
Future Steelmaking Processes: Final Report (open access)

Future Steelmaking Processes: Final Report

There is an increasing demand for an ironmaking process with lower capital cost, energy consumption and emissions than a blast furnace. It is the hypothesis of the present work that an optimized combination of two reasonable proven technologies will greatly enhance the overall process. An example is a rotary hearth furnace (RHF) linked to a smelter (e.g., AISI, HIsmelt). The objective of this research is to select promising process combinations, develop energy, materials balance and productivity models for the individual processes, conduct a limited amount of basic research on the processes and evaluate the process combinations. Three process combinations were selected with input from the industrial partners. The energy-materials and productivity models for the RHF, smelter, submerged arc furnace and CIRCOFER were developed. Since utilization of volatiles in coal is critical for energy and CO{sub 2} emission reduction, basic research on this topic was also conducted. The process models developed are a major product developed in this research. These models can be used for process evaluation by the industry. The process combinations of an RHF-Smelter and a simplified CIRCOFER-Smelter appear to be promising. Energy consumption is reduced and productivity increased. Work on this project is continuing using funds from other …
Date: September 20, 2004
Creator: Fruehan, R. J.
Object Type: Report
System: The UNT Digital Library