Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments. (open access)

Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments.

In light water reactors, components made of nickel-base alloys are susceptible to environmentally assisted cracking. This report summarizes the crack growth rate results and related metallography for field and laboratory-procured Alloy 600 and its weld alloys tested in pressurized water reactor (PWR) environments. The report also presents crack growth rate (CGR) results for a shielded-metal-arc weld of Alloy 182 in a simulated PWR environment as a function of temperature between 290 C and 350 C. These data were used to determine the activation energy for crack growth in Alloy 182 welds. The tests were performed by measuring the changes in the stress corrosion CGR as the temperatures were varied during the test. The difference in electrochemical potential between the specimen and the Ni/NiO line was maintained constant at each temperature by adjusting the hydrogen overpressure on the water supply tank. The CGR data as a function of temperature yielded activation energies of 252 kJ/mol for a double-J weld and 189 kJ/mol for a deep-groove weld. These values are in good agreement with the data reported in the literature. The data reported here and those in the literature suggest that the average activation energy for Alloy 182 welds is on the …
Date: May 5, 2008
Creator: Alexandreanu, B.; Chopra, O. K. & Shack, W. J.
Object Type: Report
System: The UNT Digital Library
Congressional Record: Its Production, Distribution, and Accessibility (open access)

Congressional Record: Its Production, Distribution, and Accessibility

This report provides information about the Production, Distribution, and Accessibility of Congressional Record. The Congressional Record is the most widely published account of the debates and activities in congress.
Date: May 5, 2008
Creator: Amer, Mildred
Object Type: Report
System: The UNT Digital Library
Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows (open access)

Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows

Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9 percent silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.
Date: May 5, 2008
Creator: Anders, Andre; Slack, Jonathan L. & Richardson, Thomas J.
Object Type: Article
System: The UNT Digital Library
A korarchaeal genome reveals insights into the evolution of the Archaea (open access)

A korarchaeal genome reveals insights into the evolution of the Archaea

The candidate division Korarchaeota comprises a group of uncultivated microorganisms that, by their small subunit rRNA phylogeny, may have diverged early from the major archaeal phyla Crenarchaeota and Euryarchaeota. Here, we report the initial characterization of a member of the Korarchaeota with the proposed name,"Candidatus Korarchaeum cryptofilum," which exhibits an ultrathin filamentous morphology. To investigate possible ancestral relationships between deep-branching Korarchaeota and other phyla, we used whole-genome shotgun sequencing to construct a complete composite korarchaeal genome from enriched cells. The genome was assembled into a single contig 1.59 Mb in length with a G + C content of 49percent. Of the 1,617 predicted protein-coding genes, 1,382 (85percent) could be assigned to a revised set of archaeal Clusters of Orthologous Groups (COGs). The predicted gene functions suggest that the organism relies on a simple mode of peptide fermentation for carbon and energy and lacks the ability to synthesize de novo purines, CoA, and several other cofactors. Phylogenetic analyses based on conserved single genes and concatenated protein sequences positioned the korarchaeote as a deep archaeal lineage with an apparent affinity to the Crenarchaeota. However, the predicted gene content revealed that several conserved cellular systems, such as cell division, DNA replication, and tRNA …
Date: June 5, 2008
Creator: Anderson, Iain J; Elkins, James G.; Podar, Mircea; Graham, David E.; Makarova, Kira S.; Wolf, Yuri et al.
Object Type: Article
System: The UNT Digital Library
The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota (open access)

The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced - Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial …
Date: September 5, 2008
Creator: Anderson, iain J.; Dharmarajan, Lakshmi; Rodriguez, Jason; Hooper, Sean; Porat, Iris; Ulrich, Luke E. et al.
Object Type: Article
System: The UNT Digital Library
A systematic study of J/psi suppression in cold nuclear matter (open access)

A systematic study of J/psi suppression in cold nuclear matter

Understanding the effects of cold nuclear matter on J/psi production is a key requirement in order to interpret the J/psi suppression reported in heavy-ion collisions. Based on a Glauber model, the J/psi-nucleon inelastic cross section is determined from a statistical analysis of J/psi world data on nuclear targets. The global fit of all data gives sigmaJ/psiN = 3.4 +/- 0.2 mb, significantly smaller than previous estimates, yet the chi2 of the fit is pretty large, chi2/ndf = 1.5. A similar value, sigmaJ/psiN = 3.5 +/- 0.2 +/- 1.7 mb, is obtained when the De Florian-Sassot modifications of the nuclear parton densities are included in the analysis, although we emphasize that the present uncertainties on gluon (anti)shadowing do not allow for a precise determination of sigmaJ/psiN. Finally, the possible energy dependence of the J/psi-nucleon inelastic cross section is investigated within this framework. No significant energy dependence of the J/psi-N interaction is observed.
Date: April 5, 2008
Creator: Arleo, Francois & Tram, Vi-Nham
Object Type: Article
System: The UNT Digital Library
Search for Invisible Decays of a Light Scalar in Radiative Transitions Y(3S)->gamma A0 (open access)

Search for Invisible Decays of a Light Scalar in Radiative Transitions Y(3S)->gamma A0

We search for a light scalar particle produced in single-photon decays of the {Upsilon}(3S) resonance through the process {Upsilon}(3S) {yields} {gamma} + A{sup 0}, A{sup 0} {yields} invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. If, in addition, there exists a light, stable neutralino, decays of A{sup 0} could be preferentially to an invisible final state. We search for events with a single high-energy photon and a large missing mass, consistent with a 2-body decay of {Upsilon}(3S). We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} invisible) at (0.7-31) x 10{sup -6} in the mass range m{sub A{sup 0}} {le} 7.8 GeV. The results are preliminary.
Date: November 5, 2008
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Evidence for B Semileptonic Decays into the Lambda_c Charm Baryon (open access)

Evidence for B Semileptonic Decays into the Lambda_c Charm Baryon

We present the first evidence for B semileptonic decays into the charmed baryon {Lambda}{sub c}{sup +} based on 420 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We measure the relative branching fraction {Beta}({bar B} {yields} {Lambda}{sub c}{sup +} X{ell}{sup -}{bar {nu}}{sub {ell}})/{Beta}({bar B} {yields} {Lambda}{sub c}{sup +}/{bar {Lambda}}{sub c}{sup -}X) = (3.2 {+-} 0.9{sub stat.} {+-} 0.9{sub syst.})%. The significance of the signal including the systematic uncertainty is 4.9 standard deviations.
Date: November 5, 2008
Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Branching Fractions of Bbar -> D** l^- nubar_l Decays in Events Tagged by a Fully Reconstructed B Meson (open access)

Measurement of the Branching Fractions of Bbar -> D** l^- nubar_l Decays in Events Tagged by a Fully Reconstructed B Meson

We report a measurement of the branching fractions of {bar B} {yields} D** {ell}{sup -}{bar {nu}}{sub {ell}} decays based on 417 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. Events are selected by fully reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D{sup (*)})-m(D{sup (*)}) is performed to extract the signal yields of the different D** states. We observe the {bar B} {yields} D**{ell}{sup -}{bar {nu}}{sub {ell}} decay modes corresponding to the four D** states predicted by Heavy Quark Symmetry with a significance greater than six standard deviations including systematic uncertainties.
Date: November 5, 2008
Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
Holographic Systematics of D-brane Inflation (open access)

Holographic Systematics of D-brane Inflation

We provide a systematic treatment of possible corrections to the inflaton potential for D-brane inflation in the warped deformed conifold. We consider the D3-brane potential in the presence of the most general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. This corresponds to the potential on the Coulomb branch of the dual gauge theory, in the presence of arbitrary perturbations of the Lagrangian. The leading contributions arise from perturbations by the most relevant operators that do not destroy the throat geometry. We find a generic contribution from a non-chiral operator of dimension {Delta} = 2 associated with a global symmetry current, resulting in a negative contribution to the inflaton mass-squared. If the Calabi-Yau preserves certain discrete symmetries, this is the dominant correction to the inflaton potential, and fine-tuning of the inflaton mass is possible. In the absence of such discrete symmetries, the dominant contribution comes from a chiral operator with {Delta} = 3/2, corresponding to a {phi}{sup 3/2} term in the inflaton potential. The resulting inflationary models are phenomenologically identical to the inflection point scenarios arising from specific D7-brane embeddings, but occur under far more general circumstances. Our strategy extends immediately …
Date: November 5, 2008
Creator: Baumann, Daniel; /Harvard U., Phys. Dept. /Princeton U.; Dymarsky, Anatoly; /Stanford U., Phys. Dept.; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC et al.
Object Type: Article
System: The UNT Digital Library
National Environmental Education Act of 1990: Overview, Implementation, and Issues for Congress (open access)

National Environmental Education Act of 1990: Overview, Implementation, and Issues for Congress

None
Date: September 5, 2008
Creator: Bearden, David M.
Object Type: Report
System: The UNT Digital Library
The Animal Welfare Act: Background and Selected Legislation (open access)

The Animal Welfare Act: Background and Selected Legislation

None
Date: December 5, 2008
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Employee Handbook (open access)

Employee Handbook

Welcome to Berkeley Lab. You are joining or are already a part of a laboratory with a sterling tradition of scientific achievement, including eleven Nobel Laureates and thirteen National Medal of Science winners. No matter what job you do, you make Berkeley Lab the outstanding organization that it is. Without your hard work and dedication, we could not achieve all that we have. We value you and thank you for choosing to be part of our community. This Employee Handbook is designed to help you navigate the Lab. With over 3,000 employees, an additional 3,000 guests visiting from countries around the world, a 200-acre campus and many policies and procedures, learning all the ins and outs may seem overwhelming, especially if you're a new employee. However, even if you have been here for a while, this Handbook should be a useful reference tool. It is meant to serve as a guide, highlighting and summarizing what you need to know and informing you where you can go for more detailed information. The general information provided in this Handbook serves only as a brief description of many of the Lab's policies. Policies, procedures and information are found in the Lab's Regulations and …
Date: September 5, 2008
Creator: Bello, Madelyn
Object Type: Report
System: The UNT Digital Library
Structures and Functions of Oligosaccharins: The Role of Endoglycanases (open access)

Structures and Functions of Oligosaccharins: The Role of Endoglycanases

The research proposed will investigate two projects that involve studies of the chemistry and biology of protein/protein and protein/carbohydrate interactions involved in host/pathogen interactions. Specifically, the projects involve (i) the interactions between fungal endopolygalacturonases and plant polygalacturonase-inhibiting proteins and (ii) the interactions between fungal endoxylanases and plant arabinoxylans. During pathogenesis fungi secrete families of endoglycanases that fragment the cell wall polysaccharides of the plant host. The result of endoglycanase action on cell wall polysaccharides can include weakening of the wall, penetration of host cells by the pathogen, solubilization of carbohydrate nutrients, and formation of oligosaccharins (oligosaccharides with regulatory function) that can stimulate plant defenses. We have made significant advances during the last funding period to support the hypothesis that the outcome of attempted pathogenesis can be influenced by protein/protein and protein/carbohydrate interactions in the extracellular matrices of the host and pathogen. We plan to expand on those successes by further exploring the mechanism of action of the endoglycanases and their plant-derived inhibitors, the expression of the various members of the endoglycanase families at various stages of infection and their role in the release of oligosaccharins and in pathogenicity, as well as the role played by the polysaccharide substrates in both …
Date: December 5, 2008
Creator: Bergmann, Carl W.
Object Type: Report
System: The UNT Digital Library
Modern Scientific Visualization is more than Just Pretty Pictures (open access)

Modern Scientific Visualization is more than Just Pretty Pictures

While the primary product of scientific visualization is images and movies, its primary objective is really scientific insight. Too often, the focus of visualization research is on the product, not the mission. This paper presents two case studies, both that appear in previous publications, that focus on using visualization technology to produce insight. The first applies"Query-Driven Visualization" concepts to laser wakefield simulation data to help identify and analyze the process of beam formation. The second uses topological analysis to provide a quantitative basis for (i) understanding the mixing process in hydrodynamic simulations, and (ii) performing comparative analysis of data from two different types of simulations that model hydrodynamic instability.
Date: December 5, 2008
Creator: Bethel, E Wes; Rubel, Oliver; Wu, Kesheng; Weber, Gunther; Pascucci, Valerio; Childs, Hank et al.
Object Type: Article
System: The UNT Digital Library
High Performance, Three-Dimensional Bilateral Filtering (open access)

High Performance, Three-Dimensional Bilateral Filtering

Image smoothing is a fundamental operation in computer vision and image processing. This work has two main thrusts: (1) implementation of a bilateral filter suitable for use in smoothing, or denoising, 3D volumetric data; (2) implementation of the 3D bilateral filter in three different parallelization models, along with parallel performance studies on two modern HPC architectures. Our bilateral filter formulation is based upon the work of Tomasi [11], but extended to 3D for use on volumetric data. Our three parallel implementations use POSIX threads, the Message Passing Interface (MPI), and Unified Parallel C (UPC), a Partitioned Global Address Space (PGAS) language. Our parallel performance studies, which were conducted on a Cray XT4 supercomputer and aquad-socket, quad-core Opteron workstation, show our algorithm to have near-perfect scalability up to 120 processors. Parallel algorithms, such as the one we present here, will have an increasingly important role for use in production visual analysis systems as the underlying computational platforms transition from single- to multi-core architectures in the future.
Date: June 5, 2008
Creator: Bethel, E. Wes
Object Type: Report
System: The UNT Digital Library
Drilling, Sampling, and Well-Installation Plan for the IFC Well Field, 300 Area (open access)

Drilling, Sampling, and Well-Installation Plan for the IFC Well Field, 300 Area

The 300 Area was selected as a location for an IFC because it offers excellent opportunities for field research on the influence of mass-transfer processes on uranium in the vadose zone and groundwater. The 300 Area was the location of nuclear fuel fabrication facilities and has more than 100 waste sites. Two of these waste sites, the North and South Process Ponds received large volumes of process waste from 1943 to 1975 and are thought to represent a significant source of the groundwater uranium plume in the 300 Area. Geophysical surveys and other characterization efforts have led to selection of the South Process Pond for the IFC.
Date: May 5, 2008
Creator: Bjornstad, Bruce N. & Horner, Jacob A.
Object Type: Report
System: The UNT Digital Library
The Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Congressional Issues (open access)

The Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Congressional Issues

This report provides an overview of the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW) and describes its background, objectives, and structure, including the role of the Convention's monitoring body, the CEDAW Committee. It examines U.S. policy and issues in the U.S. ratification debate, including the Convention's possible impact on U.S. sovereignty, its effectiveness in combating discrimination, and its role as an instrument of U.S. foreign policy.
Date: August 5, 2008
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
The United Nations Human Rights Council: Issues for Congress (open access)

The United Nations Human Rights Council: Issues for Congress

This report provides historical background of the Council, including the role of the previous Commission. It discusses the Council's current mandate and structure, as well as U.S. policy and congressional actions.
Date: June 5, 2008
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
The United Nations Human Rights Council: Issues for Congress (open access)

The United Nations Human Rights Council: Issues for Congress

This report provides historical background of the Council, including the role of the previous Commission. It discusses the Council's current mandate and structure, as well as U.S. policy and congressional actions.
Date: June 5, 2008
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
United Nations Reform: U.S. Policy and International Perspectives (open access)

United Nations Reform: U.S. Policy and International Perspectives

This report focuses on current U.N. reform efforts and priorities from the perspective of several key actors, including the U.S. government, the U.N. Secretary-General, selected groups of member states, non-governmental organizations (NGOs), and a cross-section of groups tasked with addressing U.N. reform. It also examines congressional actions related to U.N. reform, as well as future policy considerations.
Date: August 5, 2008
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
Community Development Block Grants: Legislative Proposals to Assist Communities Affected by Home Foreclosures (open access)

Community Development Block Grants: Legislative Proposals to Assist Communities Affected by Home Foreclosures

The increasing number of mortgage foreclosures poses a financial threat to local housing markets, financial institutions, homeowners, and state and local governments. This report contains information on Congressional action and analysis as relating to assisting communities affected by home foreclosures.
Date: August 5, 2008
Creator: Boyd, Eugene & Gonzales, Oscar R.
Object Type: Report
System: The UNT Digital Library
Local Two-Photon Couplings and the J=0 Fixed Pole in Real and Virtual Compton Scattering (open access)

Local Two-Photon Couplings and the J=0 Fixed Pole in Real and Virtual Compton Scattering

The local coupling of two photons to the fundamental quark currents of a hadron gives an energy-independent contribution to the Compton amplitude proportional to the charge squared of the struck quark, a contribution which has no analog in hadron scattering reactions. We show that this local contribution has a real phase and is universal, giving the same contribution for real or virtual Compton scattering for any photon virtuality and skewness at fixed momentum transfer squared t. The t-dependence of this J = 0 fixed Regge pole is parameterized by a yet unmeasured even charge-conjugation form factor of the target nucleon. The t = 0 limit gives an important constraint on the dependence of the nucleon mass on the quark mass through the Weisberger relation. We discuss how this 1=x form factor can be extracted from high energy deeply virtual Compton scattering and examine predictions given by models of the H generalized parton distribution.
Date: December 5, 2008
Creator: Brodsky, Stanley J.; Llanes-Estrada, Felipe J. & Szczepaniak, Adam P.
Object Type: Article
System: The UNT Digital Library

Educating Consumers: New Content on Diesel Vehicles, Diesel Exhaust Fluid, and Selective Catalytic Reduction Technologies on the AFDC

Presentation covers new content available on the Alternative Fuels and Advanced Vehicle Data Center regarding diesel vehicles, diesel exhaust fluid, and selective catalytic reduction technologies.
Date: August 5, 2008
Creator: Brodt-Giles, D.
Object Type: Presentation
System: The UNT Digital Library