Characterization of the Structure of Cation-DopedBacteriogenic Uranium Oxides using X-Ray Diffraction (open access)

Characterization of the Structure of Cation-DopedBacteriogenic Uranium Oxides using X-Ray Diffraction

Remediation of uranium contamination in subsurface groundwater has become imperative as previous research and manufacturing involving radionuclides has led to contamination of groundwater sources. A possible in situ solution for sequestration of uranium is a bacterial process in which Shewanella oneidensis MR-1 reduces the soluble (and thus mobile) U(VI) oxidation state into the less mobile UO{sub 2} crystalline phase. However, the long term stability of the UO2 compound must be studied as oxidative conditions could return it back into the U(VI) state. Incorporation of other cations into the structure during manufacture of the UO{sub 2} could alter the dissolution behavior. A wide angle x-ray scattering (WAXS) experiment was performed to determine whether or not calcium, manganese, and magnesium are incorporated into this structure. If so, the substituted atoms would cause a contraction or expansion in the lattice because of their differing size, causing the lattice constant to be altered. After several stages of data reduction, the WAXS diffraction peaks were fit using the Le Bail fit method in order to determine the lattice constant. Initial results suggest that there may be incorporation of manganese into the UO{sub 2} structure due to a .03 Angstrom decrease in lattice constant, but more …
Date: August 29, 2007
Creator: Stahlman, Jonathan M. & /SLAC, /Carnegie Mellon U.
Object Type: Report
System: The UNT Digital Library
Growth of laser damage in fused silica: diameter to depth ratio (open access)

Growth of laser damage in fused silica: diameter to depth ratio

Growth of laser initiated damage plays a major role in determining optics lifetime in high power laser systems. Previous measurements have established that the lateral diameter grows exponentially. Knowledge of the growth of the site in the propagation direction is also important, especially so when considering techniques designed to mitigate damage growth, where it is required to reach all the subsurface damage. In this work, we present data on both the diameter and the depth of a growing exit surface damage sites in fused silica. Measured growth rates with both 351 nm illumination and with combined 351 nm and 1054 nm illumination are discussed.
Date: October 29, 2007
Creator: Norton, M. A.; Adams, J. J.; Carr, C. W.; Donohue, E. E.; Feit, M. D.; Hackel, R. P. et al.
Object Type: Article
System: The UNT Digital Library
Dislocation-Radiation Obstacle Interactions: Developing Improved Mechanical Property Constitutive Models (open access)

Dislocation-Radiation Obstacle Interactions: Developing Improved Mechanical Property Constitutive Models

Radiation damage to structural and cladding materials, including austenitic stainless steels, ferritic steels, and zirconium alloys, in nuclear reactor environments results in significant mechanical property degradation, including yield strength increases, severe ductility losses and flow localization, which impacts reliability and performance. Generation IV and advanced fuel cycle concepts under consideration will require the development of advanced structural materials, which will operate in increasingly hostile environments. The development of predictive models is required to assess the performance and response of materials in extreme Gen IV reactor operating conditions (temperature, stress, and pressure), to decrease the time to rapidly assess the properties of new materials and insert them into technological applications (Gen IV and Advanced Fuel Cycle Operations).
Date: November 29, 2007
Creator: WIrth, B.D. & Robertson, Ian M.
Object Type: Report
System: The UNT Digital Library
Design for a High Energy Density Kelvin-Helmholtz Experiment (open access)

Design for a High Energy Density Kelvin-Helmholtz Experiment

While many high energy density physics (HEDP) Rayleigh-Taylor and Richtmyer-Meshkov instability experiments have been fielded as part of basic HEDP and astrophysics studies, not one HEDP Kelvin-Helmholtz (KH) experiment has been successfully performed. Herein, a design for a novel HEDP x-ray driven KH experiment is presented along with supporting radiation-hydrodynamic simulation and theory.
Date: October 29, 2007
Creator: Hurricane, O A
Object Type: Article
System: The UNT Digital Library
FRACTIONAL CRYSALLIZATION LABORATORY TESTS WITH SIMULATED TANK WASTE (open access)

FRACTIONAL CRYSALLIZATION LABORATORY TESTS WITH SIMULATED TANK WASTE

Results are presented for several simulated waste tests related to development of the fractional crystallization process. Product salt dissolution rates were measured to support pilot plant equipment design. Evaporation tests were performed to evaluate the effects of organics on slurry behavior and to determine optimum antifoam addition levels. A loss-of-power test was performed to support pilot plant accident scenario analysis. Envelope limit tests were done to address variations in feed composition.
Date: November 29, 2007
Creator: DL, HERTING
Object Type: Report
System: The UNT Digital Library
Wavelet Denoising of Mobile Radiation Data (open access)

Wavelet Denoising of Mobile Radiation Data

The investigation of wavelet analysis techniques as a means of filtering the gross-count signal obtained from radiation detectors has shown promise. These signals are contaminated with high frequency statistical noise and significantly varying background radiation levels. Wavelet transforms allow a signal to be split into its constituent frequency components without losing relative timing information. Initial simulations and an injection study have been performed. Additionally, acquisition and analysis software has been written which allowed the technique to be evaluated in real-time under more realistic operating conditions. The technique performed well when compared to more traditional triggering techniques with its performance primarily limited by false alarms due to prominent features in the signal. An initial investigation into the potential rejection and classification of these false alarms has also shown promise.
Date: October 29, 2007
Creator: Campbell, D & Lanier, R
Object Type: Report
System: The UNT Digital Library
The Color Glass Condensate and the Glasma: Two Lectures. (open access)

The Color Glass Condensate and the Glasma: Two Lectures.

These two lectures concern the Color Glass Condensate and the Glasma. These are forms of matter which might be studied in high energy hadronic collisions. The Color Glass Condensate is high energy density gluonic matter. It constitutes the part of a hadron wave function important for high energy processes. The Glasma is matter produced from the Color Glass Condensate in the first instants after a collision of two high energy hadrons. Both types of matter are associated with coherent fields. The Color Glass Condensate is static and related to a hadron wavefunction, where the Glasma is transient and evolves quickly after a collision. I present the properties of such matter, and some aspects of what is known of their properties.
Date: August 29, 2007
Creator: McLerran, L.
Object Type: Article
System: The UNT Digital Library
An effective longitudinal space-charge impedance model for beamswith non-uniform and non-axissymmetric transverse density (open access)

An effective longitudinal space-charge impedance model for beamswith non-uniform and non-axissymmetric transverse density

Use of a one-dimensional model of longitudinal space-charge(SC) impedance has been proposed for studying the microbunchinginstability in single-pass delivery systems relevant for the nextgeneration of FELs. For beams with uniform transverse density andcircular cross-section of radius r_b the SC impedance can be expressed ina handy analytical form, making this model particularly convenient. Inthis report we show how with an appropriate choice of r_b one can usethis as an effective-beam model to approximate beams with non-axissymmetric and non-uniform transverse densities.
Date: June 29, 2007
Creator: Venturini, Marco
Object Type: Report
System: The UNT Digital Library
Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments (open access)

Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments

The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. An extreme ultraviolet (XUV) imaging diagnostic at 256 eV and 68 eV provides information about heating and energy deposition within petawatt laser-irradiated targets. XUV images of several irradiated solid targets are presented.
Date: November 29, 2007
Creator: Ma, T.; MacPhee, A.; Key, M.; Akli, K.; Mackinnon, A.; Chen, C. et al.
Object Type: Article
System: The UNT Digital Library
CH Packaging Operations Manual (open access)

CH Packaging Operations Manual

This procedure provides instructions forassembling the following CH packaging payload: Drum payload assembly Standard Waste Box (SWB) assembly Ten-Drum Overpack (TDOP)
Date: November 29, 2007
Creator: Westinghouse TRU Solutions LLC
Object Type: Report
System: The UNT Digital Library
Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111) (open access)

Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111)

Morphology- and layer-dependent electronic structure and dynamics at the PTCDA/Ag(111) interface have been studied with angle-resolved two-photon photoemission. In Stranski-Krastanov growth modes, the exposed wetting layer inhibited the evolution of the vacuum level and valence band to bulk values. For layer-by-layer growth, we observed the transition of electron structure from monolayer to bulk values within eight monolayers. Effective masses and lifetimes of the conduction band and the n=1 image potential state were measured to be larger for disordered layers. The effective mass was interpreted in the context of charge mobility measurements.
Date: November 29, 2007
Creator: Yang, Aram; Yang, Aram; Shipman, Steven T.; Garrett-Roe, Sean; Johns, James; Strader, Matt et al.
Object Type: Article
System: The UNT Digital Library
Ground Water Level Measurements in Selected Boreholes Near the Site of the Proposed Repository (open access)

Ground Water Level Measurements in Selected Boreholes Near the Site of the Proposed Repository

The Harry Reid Center for Environmental Studies (HRC) at the University of Nevada, Las Vegas (UNLV) acquired quarterly and continuous data on water levels from approximately 26 boreholes that comprise a periodic monitoring network (Table 1) between October 2003 and September 2007. During this period we continued to observe and analyze short and long-term ground water level trends in periodically monitored boreholes. In this report we summarize and discuss four key findings derived from analysis of water level data acquired during this period: 1. Rapid ground water level rise after storm events in Forty Mile Canyon; 2. Seismically-induced ground water level fluctuations; 3. A sample of synoptic observations and barometric influences on short term fluctuations; and 4. Long term ground water level trends observed from mid-2001 through late-2005.
Date: November 29, 2007
Creator: Page, H. Scott
Object Type: Report
System: The UNT Digital Library
Characterization of Gatewell Orifice Lighting at the Bonneville Dam Second Powerhouse and Compendium of Research on Light Guidance with Juvenile Salmonids (open access)

Characterization of Gatewell Orifice Lighting at the Bonneville Dam Second Powerhouse and Compendium of Research on Light Guidance with Juvenile Salmonids

The goal of the study described in this report is to provide U.S. Army Corps of Engineers (USACE) biologists and engineers with general design guidelines for using artificial lighting to enhance the passage of juvenile salmonids into the collection channel at the Bonneville Dam second powerhouse (B2). During fall 2007, Pacific Northwest National Laboratory (PNNL) researchers measured light levels in the field at one powerhouse orifice through which fish must pass to reach the collection channel. Two light types were evaluated—light-emitting diode (LED) lights and halogen spot lights. Additional measurements with mercury lamps were made at the PNNL Aquatic Research Laboratory to determine baseline intensity of the current lighting. A separate chapter synthesizes the relevant literature related to light and fish guidance for both field and laboratory studies. PNNL will also review the Corps plans for existing lighting protocol at all of the Portland District projects and help develop a uniform lighting scheme which could be implemented. The specific objectives for this study are to 1. Create a synthesis report of existing lighting data for juvenile salmonid attraction and deterrence and how the data are used at fish bypass facilities. 2. Evaluate current B2 orifice lighting conditions with both LED …
Date: December 29, 2007
Creator: Mueller, Robert P. & Simmons, Mary Ann
Object Type: Report
System: The UNT Digital Library
SRNL PARTICIPATION IN THE MULTI-SCALE ENSEMBLE EXERCISES (open access)

SRNL PARTICIPATION IN THE MULTI-SCALE ENSEMBLE EXERCISES

Consequence assessment during emergency response often requires atmospheric transport and dispersion modeling to guide decision making. A statistical analysis of the ensemble of results from several models is a useful way of estimating the uncertainty for a given forecast. ENSEMBLE is a European Union program that utilizes an internet-based system to ingest transport results from numerous modeling agencies. A recent set of exercises required output on three distinct spatial and temporal scales. The Savannah River National Laboratory (SRNL) uses a regional prognostic model nested within a larger-scale synoptic model to generate the meteorological conditions which are in turn used in a Lagrangian particle dispersion model. A discussion of SRNL participation in these exercises is given, with particular emphasis on requirements for provision of results in a timely manner with regard to the various spatial scales.
Date: October 29, 2007
Creator: Buckley, R
Object Type: Article
System: The UNT Digital Library
Evaluation of Neutron Cross Sections for a Complete Set of Nd Isotopes. (open access)

Evaluation of Neutron Cross Sections for a Complete Set of Nd Isotopes.

Neutron cross sections for a complete set of Nd isotopes, {sup 142,143,144,145,146,147,148,150}Nd, were evaluated in the incident energy range from 10{sup -5} eV to 20 MeV. In the low energy region, including thermal and resolved resonances, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. In the unresolved resonance region we performed additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data. In the fast neutron region, we used the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. The results are compared to the existing nuclear data libraries, including ENDF/B-VI.8, JENDL-3.3 and JEFF-3.1, and to the available experimental data. The new evaluations are suitable for neutron transport calculations and they were adopted by the new evaluated nuclear data file of the United States, ENDF/B-VII.0, released in December 2006.
Date: October 29, 2007
Creator: Kim, H.; Herman, M.; Mughabghab, S. F.; Oblozinsky, P.; Rochman, D. & Lee, Y. O.
Object Type: Report
System: The UNT Digital Library
Comparison of the results of short-term static tests and single-pass flow-through tests with LRM glass. (open access)

Comparison of the results of short-term static tests and single-pass flow-through tests with LRM glass.

Static dissolution tests were conducted to measure the forward dissolution rate of LRM glass at 70 C and pH(RT) 11.7 {+-} 0.1 for comparison with the rate measured with single-pass flow-through (SPFT) tests in an interlaboratory study (ILS). The static tests were conducted with monolithic specimens having known geometric surface areas, whereas the SPFT tests were conducted with crushed glass that had an uncertain specific surface area. The error in the specific surface area of the crushed glass used in the SPFT tests, which was calculated by modeling the particles as spheres, was assessed based on the difference in the forward dissolution rates measured with the two test methods. Three series of static tests were conducted at 70 C following ASTM standard test method C1220 using specimens with surfaces polished to 600, 800, and 1200 grit and a leachant solution having the same composition as that used in the ILS. Regression of the combined results of the static tests to the affinity-based glass dissolution model gives a forward rate of 1.67 g/(m{sup 2}d). The mean value of the forward rate from the SPFT tests was 1.64 g/(m{sup 2}d) with an extended uncertainty of 1.90 g/(m{sup 2}d). This indicates that the …
Date: January 29, 2007
Creator: Ebert, W. L. & Engineering, Chemical
Object Type: Report
System: The UNT Digital Library
MCSNA: Experimental Benchmarking of Pu Electronic Structure (open access)

MCSNA: Experimental Benchmarking of Pu Electronic Structure

The objective of this work is to develop and/or apply advanced diagnostics to the understanding of aging of Pu. Advanced characterization techniques such as photoelectron and x-ray absorption spectroscopy will provide fundamental data on the electronic structure of Pu phases. These data are crucial for the validation of the electronic structure methods. The fundamental goal of this project is to narrow the parameter space for the theoretical modeling of Pu aging. The short-term goal is to perform experiments to validate electronic structure calculations of Pu. The long-term goal is to determine the effects of aging upon the electronic structure of Pu. Many of the input parameters for aging models are not directly measurable. These parameters will need to be calculated or estimated. Thus a First Principles-Approach Theory is needed, but it is unclear what terms are important in the Hamiltonian. (H{Psi} = E{Psi}) Therefore, experimental data concerning the 5f electronic structure are needed, to determine which terms in the Hamiltonian are important. The data obtained in this task are crucial for reducing the uncertainty of Task LL-01-developed models and predictions. The data impact the validation of electronic structure methods, the calculation of defect properties, the evaluation of helium diffusion, and …
Date: January 29, 2007
Creator: Tobin, J G
Object Type: Article
System: The UNT Digital Library
TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU (open access)

TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU

A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented.
Date: November 29, 2007
Creator: SW, PETERSEN; JG, MORSE; MJ, TRUEX & GV, LAST
Object Type: Article
System: The UNT Digital Library
Quantum geometry and gravitational entropy (open access)

Quantum geometry and gravitational entropy

Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S5 universes. In this sector we devise a"coarse-grained metric operator" whose eigenstates are well described by a single spacetime topology and geometry. We show that such half-BPS universes have a non-vanishing entropy if and only if the metric is singular, and that the entropy arises from coarse-graining the geometry. Finally, we use our entropy formula to find the most entropic spacetimes with fixed asymptotic moments beyond the global charges.
Date: May 29, 2007
Creator: Simon, Joan; Balasubramanian, Vijay; Czech, Bart Iomiej; Larjo, Klaus; Marolf, Donald & Simon, Joan
Object Type: Article
System: The UNT Digital Library
Recent Work in Multiphase Flow at NETL (open access)

Recent Work in Multiphase Flow at NETL

No abstract - only slideshow attached
Date: October 29, 2007
Creator: Syamlal, Madhava
Object Type: Article
System: The UNT Digital Library
LIGHT INDUCED TELLURIUM ENRICHMENT ON CDZNTE CRYSTALSURFACES DETECTED BY RAMAN SPECTROSCOPY (open access)

LIGHT INDUCED TELLURIUM ENRICHMENT ON CDZNTE CRYSTALSURFACES DETECTED BY RAMAN SPECTROSCOPY

Synthetic CdZnTe or 'CZT' crystals can be grown under controlled conditions to produce high quality crystals to be used as room temperature radiation detectors. Even the best crystal growth methods result in defects, such as tellurium secondary phases, that affect the crystal's performance. In this study, CZT crystals were analyzed by micro Raman spectroscopy. The growth of Te rich areas on the surface was induced by low powered lasers. The growth was observed versus time with low power Raman scattering and was observed immediately under higher power conditions. The detector response was also measured after induced Te enrichment.
Date: October 29, 2007
Creator: Hawkins, S; Eliel Villa-Aleman, E; Martine Duff, M & Douglas02 Hunter, D
Object Type: Article
System: The UNT Digital Library
Inertial Fusion Energy's Role in Developing the Market for High Power Laser Diodes (open access)

Inertial Fusion Energy's Role in Developing the Market for High Power Laser Diodes

Production-cost models for high-power laser-diodes indicate systems of 10GW peak power coupled with facilitization of semi-conductor manufacturing capacity could yield costs below $0.02/Watt. This is sufficient to make IFE competitive with other nuclear power technologies.
Date: November 29, 2007
Creator: Ladran, A. L.; Ault, E. R.; Beach, R. J.; Campbell, J. H.; Erlandson, A. C.; Felker, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Modelling of e-cloud build-up in grooved vacuum chambers usingPOSINST (open access)

Modelling of e-cloud build-up in grooved vacuum chambers usingPOSINST

Use of grooved vacuum chambers have been suggested as a wayto limitelectron cloud accumulation in the ILC-DR. We report onsimulations carried out using an augmented version of POSINST, accountingfor e-cloud dynamics in the presence of grooves, and make contact withprevious estimates of an effective secondary electron yield for groovedsurfaces.
Date: June 29, 2007
Creator: Venturini, Marco; Celata, C.; Furman, Miguel; Vay, Jean-Luc & Pivi, Mauro
Object Type: Article
System: The UNT Digital Library
In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell (open access)

In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.
Date: June 29, 2007
Creator: Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell & Wenk,Hans-Rudolf
Object Type: Article
System: The UNT Digital Library