Fuel Cell Research at the University of South Carolina (open access)

Fuel Cell Research at the University of South Carolina

Five projects are proposed, in an effort to supplement the efforts of fuel cell research at the University of South Carolina and to contribute to the Technical Plan for Fuel Cells of the Department of Energy. These efforts include significant interaction with the industrial community through DOE funded projects and through the National Science Foundation’s Industry/University Cooperative Research Center for Fuel Cells. The allocation of projects described below leverage all of these sources of funding without overlap and redundancy. The first project “Novel Non-Precious Metal Catalyst For PEMFCs,” (Dr. Branko Popov) continues DOE award DE-FC36-03GO13108 for which funding was delayed by DOE due to budget constraints. The purpose of this project is to develop an understanding of the feasibility and limitations of metal-free catalysts. The second project, “Non Carbon Supported Catalysts” (Dr. John Weidner), is focused on improved catalysts and seeks to develop novel materials, which are more corrosion resistant. This corrosion behavior is critical during transient operation and during start-up and shutdown. This second project will be leveraged with recent, peer-reviewed, supplemental funding from NSF for use in the National Science Foundation Industry/University Cooperative Research Center for Fuel Cells (CFC) at USC. The third project, “Hydrogen Quality,” (Dr. Jean …
Date: September 25, 2006
Creator: Van Zee, John W.
Object Type: Report
System: The UNT Digital Library
Fuel Cell Research at the University of South Carolina (open access)

Fuel Cell Research at the University of South Carolina

Five projects were conducted in an effort to supplement the efforts of fuel cell research at the University of South Carolina and to contribute to the Technical Plan for Fuel Cells of the Department of Energy. These efforts include significant interaction with the industrial community through DOE funded projects and through the National Science Foundation�s Industry/University Cooperative Research Center (NSF-I/UCRC) for Fuel Cells at USC. The allocation of projects described below leveraged all of these sources of funding without overlap and redundancy. 1. "Novel Non-Precious Metal Catalyst For PEMFCs" (Dr. Branko Popov) 2. "Non Carbon Supported Catalysts" (Dr. John Weidner) 3. "Hydrogen Quality" (Dr. Jean St-Pierre) 4. "Gasket Materials: Mechanical and Chemical Stability in PEMFC" (Dr. Y.J. (Bill) Chao) 5. "Mathematical Modeling of PEM Fuel Cells," (Dr. Sirivatch (Vatch) Shimpalee)
Date: September 25, 2006
Creator: Van Zee, John W.
Object Type: Report
System: The UNT Digital Library
A Search for the Decays B^+ to e^+\nu_e and B^+ to \mu^+\nu_\mu Using Hadronic-tag Reconstruction (open access)

A Search for the Decays B^+ to e^+\nu_e and B^+ to \mu^+\nu_\mu Using Hadronic-tag Reconstruction

The authors report on a search for the rare decay modes B{sup +} {yields} e{sup +}{nu}{sub e} and B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}} with data collected from the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. This search utilizes a new technique in which they fully reconstruct the accompanying B{sup -} in {Upsilon}(4S) {yields} B{sup +}B{sup -} events, and look for a mono-energetic lepton in B{sup +} rest frame. No signal candidates observed in either of the channels, consistent with the expected background, in a data sample of approximately 229 million B{bar B} pairs. The branching-fraction upper limits are set at {Beta}(B{sup +} {yields} e{sup +}{nu}{sub e}) < 7.9 x 10{sup -6} and {Beta}(B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}) < 6.2 x 10{sup -6} at the 90% confidence level.
Date: September 25, 2006
Creator: Klemetti, M
Object Type: Article
System: The UNT Digital Library
High Energy Neutrino Flash From Far-UV/X-Ray Flares of Gamma-Ray Bursts (open access)

High Energy Neutrino Flash From Far-UV/X-Ray Flares of Gamma-Ray Bursts

The recent observations of bright optical and X-ray flares by the Swift satellite suggest these are produced by the late activities of the central engine. We study the neutrino emission from far-UV/X-ray flares under the late internal shock model. Since the efficiency of pion production in the highest energy is higher than that of the prompt bursts, such neutrino flashes from flares can give comparable or larger contributions to a diffuse very high energy neutrino background if the total energy input into flares is comparable to the radiated energy of the prompt bursts. These signals are very important because they have possibility to probe the nature of flares (baryonic or magnetic, the photon field, the magnetic field, and so on).
Date: April 25, 2006
Creator: Murase, Kohta; /Kyoto U., Yukawa Inst., Kyoto; Nagataki, Shigehiro & /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park
Object Type: Report
System: The UNT Digital Library
Final Report: X-ray Studies of Materials Dynamics at MHATT-CAT Sector 7, Advanced Photon Source (open access)

Final Report: X-ray Studies of Materials Dynamics at MHATT-CAT Sector 7, Advanced Photon Source

This Final Report describes the scientific accomplishments that have been achieved with support from grant DE-FG02-03ER46023 during the period 12/01/02 ? 11/30/05. The funding supported a vigorous scientific program allowing the PI to achieve leadership in a number of important areas. In particular, research carried out during this period has opened way to ultrafast dynamics studies of materials by combining the capabilities of synchrotron radiation with those of ultrafast lasers. This enables the initiation of laser-induced excitations and studies of their subsequent dynamics using laser-pump/x-ray probe techniques. Examples of such excitations include phonons, shock waves, excitons, spin-waves, and polaritons. The breadth of phenomena that can now be studied in the time-domain is very broad, revealing new phenomena and mechanisms that are critical to many applications of materials.
Date: April 25, 2006
Creator: Clarke, Roy
Object Type: Report
System: The UNT Digital Library
Technology for Increasing Geothermal Energy Productivity. Computer Models to Characterize the Chemical Interactions of Goethermal Fluids and Injectates with Reservoir Rocks, Wells, Surface Equiptment (open access)

Technology for Increasing Geothermal Energy Productivity. Computer Models to Characterize the Chemical Interactions of Goethermal Fluids and Injectates with Reservoir Rocks, Wells, Surface Equiptment

This final report describes the results of a research program we carried out over a five-year (3/1999-9/2004) period with funding from a Department of Energy geothermal FDP grant (DE-FG07-99ID13745) and from other agencies. The goal of research projects in this program were to develop modeling technologies that can increase the understanding of geothermal reservoir chemistry and chemistry-related energy production processes. The ability of computer models to handle many chemical variables and complex interactions makes them an essential tool for building a fundamental understanding of a wide variety of complex geothermal resource and production chemistry. With careful choice of methodology and parameterization, research objectives were to show that chemical models can correctly simulate behavior for the ranges of fluid compositions, formation minerals, temperature and pressure associated with present and near future geothermal systems as well as for the very high PT chemistry of deep resources that is intractable with traditional experimental methods. Our research results successfully met these objectives. We demonstrated that advances in physical chemistry theory can be used to accurately describe the thermodynamics of solid-liquid-gas systems via their free energies for wide ranges of composition (X), temperature and pressure. Eight articles on this work were published in peer-reviewed journals …
Date: July 25, 2006
Creator: Weare, Nancy Moller
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF A CO2 SEQUESTRATION MODULE BY INTEGRATING MINERAL ACTIVATION AND AQUEOUS CARBONATION (open access)

DEVELOPMENT OF A CO2 SEQUESTRATION MODULE BY INTEGRATING MINERAL ACTIVATION AND AQUEOUS CARBONATION

Mineral carbonation provides a potential option for the long-term storage of carbon dioxide. Serpentine has been chosen as the feedstock mineral, due to its abundance and availability. However, the relatively low reactivity of serpentine has warranted research into physical and chemical treatments that have been shown to greatly increase its reactivity. The use of sulfuric acid as an accelerating medium for the removal of magnesium from serpentine has recently been investigated. In addition to the challenges presented by the dissolution of serpentine, another challenge is the subsequent carbonation of the magnesium ions. A stable hydration sphere for the magnesium ion reduces the carbonation kinetics by obstructing the formation of the carbonation products. Accordingly, this research has evaluated the solubility of carbon dioxide in aqueous solution, the interaction between the dissociation products of carbon dioxide, and the carbonation potential of the magnesium ion.
Date: March 25, 2006
Creator: Alexander, George; Maroto-Valer, M. Mercedes; Aksoy, Parvana & Schobert, Harold
Object Type: Report
System: The UNT Digital Library
Search for Physics Beyond the Standard Model Using Measurements of CP Violating Asymmetries in Rare B Decays: B0 to K0(S) Pi0 and B0 to K0(S) Pi0 Gamma (open access)

Search for Physics Beyond the Standard Model Using Measurements of CP Violating Asymmetries in Rare B Decays: B0 to K0(S) Pi0 and B0 to K0(S) Pi0 Gamma

This dissertation presents measurements of time-dependent CP violating asymmetries in the decays B{sup 0} {yields} K{sub s}{sup 0}{pi}{sup 0} and B{sup 0} {yields} K{sub s}{sup 0}{pi}{sup 0}{gamma} based on RUN 1-4 data collected with the BABAR detector at the {Upsilon}(4S) resonance operating at the PEP-II asymmetric e{sup +}e{sup -} collider at SLAC. It was found that the CP violating asymmetry parameters are S{sub K{sub s}{pi}{sup 0}} = 0.35{sub -0.33}{sup +0.30}(stat) {+-} 0.04(syst), C{sub K{sub g}{pi}{sup 0}} = 0.06 {+-} 0.18(stat) {+-} 0.03(syst), S{sub K{sub s}{pi}{sup 0}{gamma}} = 0.9 {+-} 1.0(stat) {+-} 0.2(syst) and C{sub K{sub s}{pi}{sup 0}{gamma}} = -1.0 {+-} 0.5(stat) {+-} 0.2(syst), where B{sup 0} {yields} K{sup +0}{gamma} decays correspond to the K{sub s}{pi}{sup 0} invariant mass interval of [0.8,1.0] GeV and B{sup 0} {yields} K{sub s}{sup 0}{pi}{sup 0}{gamma} of [1.1,1.8] GeV. All results are consistent with the Standard Model predictions.
Date: September 25, 2006
Creator: Kovalskyi, Dmytro
Object Type: Report
System: The UNT Digital Library
Natural and Enhanced Attenuation of Chlorinated Solvents Using RT3D (open access)

Natural and Enhanced Attenuation of Chlorinated Solvents Using RT3D

RT3D (Reactive Transport in 3-Dimensions) is a reactive transport code that can be applied to model solute fate and transport for many different purposes. This document specifically addresses application of RT3D for modeling related to evaluation and implementation of Monitored Natural Attenuation (MNA). Selection of MNA as a remedy requires an evaluation process to demonstrate that MNA will meet the remediation goals. The U.S. EPA, through the Office of Solid Waste and Emergency Response (OSWER) Directive 9200.4?17P, provides the regulatory context for the evaluation and implementation of MNA. In a complementary fashion, the context for using fate and transport modeling as part of MNA evaluation is described in the EPA?s technical protocol for chlorinated solvent MNA, the Scenarios Evaluation Tool for Chlorinated Solvent MNA, and in this document. The intent of this document is to describe (1) the context for applying RT3D for chlorinated solvent MNA and (2) the attenuation processes represented in RT3D, (3) dechlorination reactions that may occur, and (4) the general approach for using RT3D reaction modules (including a summary of the RT3D reaction modules that are available) to model fate and transport of chlorinated solvents as part of MNA or for combinations of MNA and selected …
Date: July 25, 2006
Creator: Johnson, Christian D.; Truex, Michael J. & Clement, T P.
Object Type: Report
System: The UNT Digital Library
RT3D Reaction Modules for Natural and Enhanced Attenuation of Chloroethanes, Chloroethenes, Chloromethanes, and Daughter Products (open access)

RT3D Reaction Modules for Natural and Enhanced Attenuation of Chloroethanes, Chloroethenes, Chloromethanes, and Daughter Products

This document describes a suite of MNA/EA reaction modules that were developed for addressing complex chlorinated solvent reactions using RT3D. As an introduction, an overview of these MNA/EA reaction modules is presented, including discussions of similarities between reaction modules, the purpose of key reaction parameters, and important considerations for using the reaction modules. Subsequent sections provide the details of the reaction kinetics (conceptual model and equations), data input requirements, and example (batch reactor) results for each reaction module. This document does not discuss reaction module implementation or validation; such information will accompany the software in the form of release notes or a supplement to the RT3D manual.
Date: July 25, 2006
Creator: Johnson, Christian D. & Truex, Michael J.
Object Type: Report
System: The UNT Digital Library
Reconfigurable Hybrid Interconnection for Static and DynamicScientific Applications (open access)

Reconfigurable Hybrid Interconnection for Static and DynamicScientific Applications

As we enter the era of petascale computing, system architects must plan for machines composed of tens of thousands or even hundreds of thousands of processors. Although fully connected networks such as fat-tree interconnects currently dominate HPC network designs, such approaches are inadequate for thousands of processors due to the superlinear growth of component costs. Traditional low-degree interconnect topologies, such as the 3D torus, have reemerged as a competitive solution because the number of switch components scales linearly with the node count, but such networks are poorly suited for the requirements of many scientific applications. We present our latest work on a hybrid switch architecture called HFAST that uses circuit switches to dynamically reconfigure a lower-degree interconnect to suit the topological requirements of each scientific application. This paper expands upon our prior work on the requirements of non-adaptive applications by analyzing the communication characteristics of dynamically adapting AMR code and presents a methodology that captures the evolving communication requirements. We also present a new optimization that computes the under-utilization of fat-tree interconnects for a given communication topology, showing the potential of constructing a ''fit-tree'' for the application by using the HFAST circuit switches to provision an optimal interconnect topology for …
Date: April 25, 2006
Creator: Kamil, Shoaib; Pinar, Ali; Gunter, Daniel; Lijewski, Michael; Oliker, Leonid; Shalf, John et al.
Object Type: Article
System: The UNT Digital Library
DWPF FLOWSHEET STUDIES WITH SIMULANTS TO DETERMINE MCU SOLVENT BUILD-UP IN CONTINOUS RUNS (open access)

DWPF FLOWSHEET STUDIES WITH SIMULANTS TO DETERMINE MCU SOLVENT BUILD-UP IN CONTINOUS RUNS

The Actinide Removal Process (ARP) facility and the Modular Caustic Side Solvent Extraction Unit (MCU) are scheduled to begin processing salt waste in fiscal year 2007. A portion of the streams generated in these salt processing facilities will be transferred to the Defense Waste Processing Facility (DWPF) to be incorporated in the glass matrix. Before the streams are introduced, a combination of impact analyses and research and development studies must be performed to quantify the impacts on DWPF processing. The Process Science & Engineering (PS&E) section of the Savannah River National Laboratory (SRNL) was requested via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 to evaluate the impacts on DWPF processing. Simulant Chemical Process Cell (CPC) flowsheet studies have been performed using previous composition and projected volume estimates for the ARP sludge/monosodium titanate (MST) stream. Initial MCU incorporation testing for the DWPF flowsheet indicated unacceptable levels of Isopar{reg_sign}L were collecting in the Sludge Receipt and Adjustment Tank (SRAT) condenser system and unanticipated quantities of modifier were carrying over into the SRAT condenser system. This work was performed as part of Sludge Batch 4 (SB4) flowsheet testing and was reported by Baich et al. Due to changes in the flammability control strategy for DWPF …
Date: May 25, 2006
Creator: Lambert, D; Frances Williams, F; S Crump, S; Russell Eibling, R; Thomas02 White, T & David Best, D
Object Type: Article
System: The UNT Digital Library
Killing Two Birds with One Stone: Can Real-Time Pricing SupportRetail Competition and Demand Response? (open access)

Killing Two Birds with One Stone: Can Real-Time Pricing SupportRetail Competition and Demand Response?

As retail choice states reach the end of their transitional, rate-cap periods, state regulators must decide what type of default supply service to provide to customers that have not switched to a competitive retail supplier. In a growing number of states, regulators have adopted real-time pricing (RTP) as the default service for large commercial and industrial (C&I) customers. Although this trend is driven chiefly by policy objectives related to retail competition, default service RTP may have the added benefit of stimulating demand response. To evaluate the potential role of RTP as a means to both ends--retail market development and demand response--we conducted a comprehensive review of experience with default RTP in the U.S. and examined the emergence of RTP as a product offering by competitive retail suppliers. Across the ten utilities with default RTP in place in 2005, between 5% and 35% of the applicable load remained on the rate. Based on interviews with competitive retailers, we find evidence to suggest that a comparable amount of load in these states has switched to hourly pricing arrangements with competitive retailers. Many customers on default or competitive hourly pricing are paying prices indexed to the real-time spot market, and thus have no …
Date: April 25, 2006
Creator: Barbose, Galen; Bharvirkar, Ranjit; Goldman, Charles; Hopper,Nicole & Neenan, Bernie
Object Type: Article
System: The UNT Digital Library
Updated Bounds on CP Asymmetries in B^0 to eta'K_S and B0 to pi^0K_S (open access)

Updated Bounds on CP Asymmetries in B^0 to eta'K_S and B0 to pi^0K_S

Previous analyses in which flavor SU(3) was used to constrain the coefficients of sin {Delta}mt and cos {Delta}mt in the time-dependent CP asymmetries of B{sup 0} {yields} {eta}'K{sub S} and B{sup 0} {yields} {pi}{sup 0} K{sub S} are updated using new rate measurements of B{sup 0} decays into {pi}{sup 0}{pi}{sup 0}, {pi}{sup 0},{eta}, {pi}{sup 0}{eta}', {eta}{eta}, {eta}{eta}', {eta}'{eta}' and K{sup +}K{sup -}.
Date: August 25, 2006
Creator: Gronau, Michael; Rosner, Jonathan L. & Zupan, Jure
Object Type: Article
System: The UNT Digital Library
State of the Art in EM Field Computation (open access)

State of the Art in EM Field Computation

This paper presents the advances in electromagnetic (EM) field computation that have been enabled by the US DOE SciDAC Accelerator Science and Technology project which supports the development and application of a suite of electromagnetic codes based on the higher-order finite element method. Implemented on distributed memory supercomputers, this state of the art simulation capability has produced results which are of great interest to accelerator designers and with realism previously not possible with standard codes. Examples from work on the International Linear Collider (ILC) project are described.
Date: September 25, 2006
Creator: Ng, C.; Akcelik, V.; Candel, A.; Chen, S.; Folwell, N.; Ge, L. et al.
Object Type: Article
System: The UNT Digital Library
Mapping Physical Formats to Logical Models to Extract Data and Metadata: The Defuddle Parsing Engine (open access)

Mapping Physical Formats to Logical Models to Extract Data and Metadata: The Defuddle Parsing Engine

Scientists, fueled by the desire for systems-level understanding of phenomena, increasingly need to share their results across multiple disciplines. Accomplishing this requires data to be annotated, contextualized, and readily searchable and translated into other formats. While these requirements can be addressed by custom programming or obviated by community standardization, neither approach has ‘solved’ the problem. In this paper, we describe a complementary approach – a general capability for articulating the format of arbitrary textual and binary data using a logical data model, expressed in XML-Schema, which can be used to provide annotation and context, extract metadata, and enable translation. This work is based on the draft specification for the Data Format Description Language and our open source “Defuddle” parser. We present an overview of the specification, detail the design of Defuddle, and discuss the benefits and challenges of this general approach to enabling discovery and sharing of diverse data sets.
Date: July 25, 2006
Creator: Talbott, Tara D.; Schuchardt, Karen L.; Stephan, Eric G. & Myers, James D.
Object Type: Article
System: The UNT Digital Library
FAMS DECOMMISSIONING END-STATE ALTERNATIVE EVALUATION (open access)

FAMS DECOMMISSIONING END-STATE ALTERNATIVE EVALUATION

Nuclear Material Management (NMM) completed a comprehensive study at the request of the Department of Energy Savannah River Operations Office (DOE-SR) in 2004 (Reference 11.1). The study evaluated the feasibility of removal and/or mitigation of the Pu-238 source term in the F-Area Material Storage (FAMS) facility during on-going material storage operations. The study recommended different options to remove and/or mitigate the Pu-238 source term depending on its location within the facility. During April 2005, the Department of Energy (DOE) sent a letter of direction (LOD) to Washington Savannah River Company (WSRC) directing WSRC to implement a new program direction that would enable an accelerated shutdown and decommissioning of FAMS (Reference 11.2). Further direction in the LOD stated that effective December 1, 2006 the facility will be transitioned to begin deactivation and decommissioning (D&D) activities. To implement the LOD, Site D&D (SDD) and DOE agreed the planning end-state would be demolition of the FAMS structure to the building slab. SDD developed the D&D strategy, preliminary cost and schedule, and issued the deactivation project plan in December 2005 (Reference 11.3). Due to concerns and questions regarding the FAMS planning end-state and in support of the project's Critical Decision 1, an alternative study …
Date: May 25, 2006
Creator: Grimm, B; Stephen Chostner, S & Brenda Green, B
Object Type: Report
System: The UNT Digital Library
Measurement of the Mass and Width and Study of the Spin of the Xi(1690)0 Resonance from Lambdac+ --> Lambda anti-K0 K+ Decay at BaBar (open access)

Measurement of the Mass and Width and Study of the Spin of the Xi(1690)0 Resonance from Lambdac+ --> Lambda anti-K0 K+ Decay at BaBar

The {Xi}(1690){sup 0} resonance is observed in the {Lambda}{bar K}{sup 0} channel in the decay {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +}, from a data sample corresponding to a total integrated luminosity of {approx} 200 fb{sup -1} recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- collider operating at {approx} 10.58 GeV and {approx} 10.54 GeV center-of-mass energies. A fit to the Dalitz plot intensity distribution corresponding to the coherent superposition of amplitudes describing {Lambda}a{sub 0}(980){sup +} and {Xi}(1690){sup 0} K{sup +} production yields mass and width values of 1684.7 {+-} 1.3(stat.){sub -1.6}{sup +2.2}(syst.) MeV/c{sup 2}, and 8.1{sub -3.5}{sup +3.9}(stat.){sub -0.9}{sup +1.0}(syst.) MeV, respectively, for the {Xi}(1690){sup 0}, while the spin is found to be consistent with value of 1/2 on the basis of studies of the ({Lambda}K{sub S}) angular distribution.
Date: September 25, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders (open access)

Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.
Date: September 25, 2006
Creator: Biswas, Asit & Sherman, Andrew J.
Object Type: Report
System: The UNT Digital Library
A STRUCTURAL INTEGRITY ASSESSMENT OF UNDERGROUND PIPING ASSOCIATED WITH THE TRANSFER OF RADIOACTIVE WASTE (open access)

A STRUCTURAL INTEGRITY ASSESSMENT OF UNDERGROUND PIPING ASSOCIATED WITH THE TRANSFER OF RADIOACTIVE WASTE

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The waste is transported between tanks via underground transfer piping. An assessment of the structural integrity of the transfer piping was performed to ensure that the present condition of the piping was sound and to provide life expectancy estimates for the piping based on anticipated service. The assessment reviewed the original design of the piping, the potential and observed degradation mechanisms, the results from past inspections of the piping, and a Fitness-For-Service evaluation for a section of piping that experienced pitting in a locally thinned area. The assessment concluded that the piping was structurally sound. Assuming that service conditions remain the same, the piping will remain functional for its intended service life.
Date: April 25, 2006
Creator: Wiersma, B
Object Type: Article
System: The UNT Digital Library
Semileptonic B Decays at the B Factories (open access)

Semileptonic B Decays at the B Factories

Recent results on inclusive and exclusive semileptonic B decays from B Factories are presented. The status and perspectives of the determination of the CKM matrix elements V{sub ub} and V{sub cb} with semileptonic B decays is discussed.
Date: September 25, 2006
Creator: Bozzi, Concezio & /INFN, Ferrara
Object Type: Article
System: The UNT Digital Library
Solid-Density Plasma characterization with X-ray scattering on the 200-J Janus Laser (open access)

Solid-Density Plasma characterization with X-ray scattering on the 200-J Janus Laser

We present collective x-ray scattering (CXS) measurements using a Chlorine He-{alpha} x-ray source pumped with less than 200 J of laser energy. The experimental scattering spectra show plasmon resonances from shocked samples. These experiments use only 10{sup 12} x-ray photons at the sample of which 10{sup -5} have been scattered and detected with a highly efficient curved crystal spectrometer. Our results demonstrate that x-ray scattering is a viable technique on smaller laser facilities making CXS measurements accessible to a broad scientific community.
Date: April 25, 2006
Creator: Neumayer, P B; Gregori, G; Ravasio, A; Price, D; Bastea, M; Landen, O L et al.
Object Type: Article
System: The UNT Digital Library
Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs (open access)

Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs

We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will …
Date: May 25, 2006
Creator: Green, Lora M
Object Type: Report
System: The UNT Digital Library
Status of the SPARC Project (open access)

Status of the SPARC Project

The SPARC project has entered its installation phase at the Frascati National Laboratories of INFN: its main goal, the promotion of an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments, is being vigorously pursued by a collaboration among ENEA-INFN-CNR-Universita di Roma Tor Vergata-INFM-ST. In this paper we will report on the installation and test of some major components, like Ti:Sa laser system, RF gun and RF power system. Advancements in the control and beam diagnostics systems will also be reported, in particular on the emittance-meter device for beam emittance measurements in the drift space downstream the RF gun. Recent results on laser pulse shaping show the feasibility of producing 10 ps flat-top laser pulses in the UV with rise time below 1 ps. First FEL experiments have been proposed, using SASE, seeding and non-linear resonant harmonics.
Date: January 25, 2006
Creator: Alesini, D.; Bertolucci, S.; Bellaveglia, M.; Biagini, M.E.; Boni, R.; Boscolo, M. et al.
Object Type: Article
System: The UNT Digital Library