The Continued Risk Of Troubled Assets (open access)

The Continued Risk Of Troubled Assets

August report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the risk of troubled assets, including sections on background information, strategies for dealing with troubled assets, and the future of troubled assets.
Date: August 11, 2009
Creator: United States. Congressional Oversight Panel.
Object Type: Report
System: The UNT Digital Library
Tunable wavelength soft photoionization of ionic liquid vapors (open access)

Tunable wavelength soft photoionization of ionic liquid vapors

Combined data of photoelectron spectra and photoionization efficiency curves in the near threshold ionization region of isolated ion-pairs from [emim][Tf2N], [emim][Pf2N]and [dmpim][Tf2N]ionic liquid vapors reveal small shifts in the ionization energies of ion-pair systems due to cation and anion substitutions. Shifts towards higher binding energy following anion substitution are attributed to increased electronegativity of the anion itself, while shifts towards lower binding energies following cation substitution are attributed to an increase in the cation-anion distance that causes a lower Coulombic binding potential. The predominant ionization mechanism in the near threshold photon energy region is identified as dissociative ionization, involving dissociation of the ion-pair and the production of intact cations as the positively charged products.
Date: November 11, 2009
Creator: Strasser, Daniel; Goulay, Fabien; Belau, Leonid; Kostko, Oleg; Koh, Christine; Chambreau, Steven D. et al.
Object Type: Article
System: The UNT Digital Library
A tandem-based compact dual-energy gamma generator (open access)

A tandem-based compact dual-energy gamma generator

A dual-energy tandem-type gamma generator has been developed at E.O. Lawrence Berkeley National Laboratory and Sandia National Laboratories. The tandem accelerator geometry allows higher energy nuclear reactions to be reached, thereby allowing more flexible generation of MeV-energy gammas for active interrogation applications.
Date: November 11, 2009
Creator: Persaud, A.; Kwan, J. W.; Leitner, M.; Leung, K. N.; Ludewigt, B.; Tanaka, N. et al.
Object Type: Article
System: The UNT Digital Library
Mercury Calibration System (open access)

Mercury Calibration System

U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The …
Date: March 11, 2009
Creator: Schabron, John; Kalberer, Eric; Rovani, Joseph; Sanderson, Mark; Boysen, Ryan & Schuster, William
Object Type: Report
System: The UNT Digital Library
Iter Central Solenoid Coil Insulation Qualification (open access)

Iter Central Solenoid Coil Insulation Qualification

An insulation system for ITER Central Solenoid must have sufficiently high electrical and structural strength. Design efforts to bring stresses in the turn and layer insulation within allowables failed. It turned out to be impossible to eliminate high local tensile stresses in the winding pack. When high local stresses can not be designed out, the qualification procedure requires verification of the acceptable structural and electrical strength by testing. We built two 4 x 4 arrays of the conductor jacket with two options of the CS insulation and subjected the arrays to 1.2 million compressive cycles at 60 MPa and at 76 K. Such conditions simulated stresses in the CS insulation. We performed voltage withstand tests and after end of cycling we measured the breakdown voltages between in the arrays. After that we dissectioned the arrays and studied micro cracks in the insulation. We report details of the specimens preparation, test procedures and test results.
Date: June 11, 2009
Creator: Martovetsky, N. N.; Mann, T. L.; Miller, J. R.; Freudenberg, K. D.; Reed, R. P.; Walsh, R. P. et al.
Object Type: Article
System: The UNT Digital Library
Mercury Calibration System (open access)

Mercury Calibration System

U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The …
Date: March 11, 2009
Creator: Schabron, John; Kalberer, Eric; Rovani, Joseph; Sanderson, Mark; Boysen, Ryan & Schuster, William
Object Type: Report
System: The UNT Digital Library
Estrogen and progesterone receptors have distinct roles in the establishment of the hyperplastic phenotype in PR-A transgenic mice (open access)

Estrogen and progesterone receptors have distinct roles in the establishment of the hyperplastic phenotype in PR-A transgenic mice

Expression of the A and B forms of progesterone receptor (PR) in an appropriate ratio is critical for mammary development. Mammary glands of PR-A transgenic mice, carrying an additional A form of PR as a transgene, exhibit morphological features associated with the development of mammary tumors. Our objective was to determine the roles of estrogen (E) and progesterone (P) in the genesis of mammary hyperplasias/preneoplasias in PR-A transgenics. We subjected PR-A mice to hormonal treatments and analyzed mammary glands for the presence of hyperplasias and used BrdU incorporation to measure proliferation. Quantitative image analysis was carried out to compare levels of latency-associated peptide and transforming growth factor beta 1 (TGF{beta}1) between PR-A and PR-B transgenics. Basement membrane disruption was examined by immunofluorescence and proteolytic activity by zymography. The hyperplastic phenotype of PR-A transgenics is inhibited by ovariectomy, and is reversed by treatment with E + P. Studies using the antiestrogen ICI 182,780 or antiprogestins RU486 or ZK 98,299 show that the increase in proliferation requires signaling through E/estrogen receptor alpha but is not sufficient to give rise to hyperplasias, whereas signaling through P/PR has little impact on proliferation but is essential for the manifestation of hyperplasias. Increased proliferation is correlated …
Date: May 11, 2009
Creator: Simian, Marina; Bissell, Mina J.; Barcellos-Hoff, Mary Helen & Shyamala, Gopalan
Object Type: Article
System: The UNT Digital Library
Molecular Studies of Surfaces under Reaction Conditions; Sum Frequency Generation Vibrational Spectroscopy, Scanning Tunneling Microscopy and Ambient Pressure X-Ray Photoelectron Spectroscopy (open access)

Molecular Studies of Surfaces under Reaction Conditions; Sum Frequency Generation Vibrational Spectroscopy, Scanning Tunneling Microscopy and Ambient Pressure X-Ray Photoelectron Spectroscopy

Instruments developed in our laboratory permit the atomic and molecular level study of NPs under reaction conditions (SFG, ambient pressure XPS and high pressure STM). These studies indicate continuous restructuring of the metal substrate and the adsorbate molecules, changes of oxidation states with NP size and surface composition variations of bimetallic NPs with changes of reactant molecules.
Date: November 11, 2009
Creator: Somorjai, G.A.
Object Type: Article
System: The UNT Digital Library
Designing the Ideal Uranyl Ligand: a Sterically-Induced Speciation Change in Complexes with Thiophene-Bridged Bis(3-hydroxy-N-methylpyridin-2-one) (open access)

Designing the Ideal Uranyl Ligand: a Sterically-Induced Speciation Change in Complexes with Thiophene-Bridged Bis(3-hydroxy-N-methylpyridin-2-one)

Structural characterization of a mononuclear uranyl complex with a tetradentate, thiophene-linked bis(3-hydroxy-N-methylpyridin-2-one) ligand reveals the most planar coordination geometry yet observed with this ligand class. The introduction of ethylsulfanyl groups onto the thiophene linker disrupts this planar, conjugated ligand arrangement, resulting in the formation of dimeric (UO{sub 2}){sub 2}L{sub 2} species in which each ligand spans two uranyl centers. Relative energy calculations reveal that this tendency toward dimer formation is the result of steric interference between ethylsulfanyl substituents and linking amides.
Date: September 11, 2009
Creator: Szigethy, Geza & Raymond, Kenneth N.
Object Type: Article
System: The UNT Digital Library
Characterization of Atomic and Electronic Structures of Electrochemically Active SOFC Cathode Surfaces (open access)

Characterization of Atomic and Electronic Structures of Electrochemically Active SOFC Cathode Surfaces

The objective of this project is to gain a fundamental understanding of the oxygen-reduction mechanism on mixed conducting cathode materials by means of quantum-chemical calculations coupled with direct experimental measurements, such as vibrational spectroscopy. We have made progress in the elucidation of the mechanisms of oxygen reduction of perovkite-type cathode materials for SOFCs using these quantum chemical calculations. We established computational framework for predicting properties such as oxygen diffusivity and reaction rate constants for adsorption, incorporation, and TPB reactions, and formulated predictions for LSM- and LSC-based cathode materials. We have also further developed Raman spectroscopy as well as SERS as a characterization tool for SOFC cathode materials. Raman spectroscopy was used to detect chemical changes in the cathode from operation conditions, and SERS was used to probe for pertinent adsorbed species in oxygen reduction. However, much work on the subject of unraveling oxygen reduction for SOFC cathodes remains to be done.
Date: August 11, 2009
Creator: Blinn, Kevin; Choi, Yongman & Liu, Meilin
Object Type: Report
System: The UNT Digital Library
Human Portable Radiation Detection System Communications Package Evaluation (open access)

Human Portable Radiation Detection System Communications Package Evaluation

Testing and valuation of the Human Portable Radiation Detection System Communications Package for the US Coast Guard.
Date: June 11, 2009
Creator: Morgen, Gerald P. & Peterson, William W.
Object Type: Report
System: The UNT Digital Library
X-ray Absorption Spectroscopy Characterization of Zn Underpotential Deposition on Au(111) from Phosphate Supporting Electrolyte (open access)

X-ray Absorption Spectroscopy Characterization of Zn Underpotential Deposition on Au(111) from Phosphate Supporting Electrolyte

Zn K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the structure of Zn monolayers prepared on Au(111) electrodes via underpotential deposition (UPD) from phosphate supporting electrolyte. Theoretical modeling of the XAS data indicates that the Zn adatoms adopt a commensurate ({radical}3x{radical}3)R30{sup o} ({mu}{sub sc} = 0.33) adlayer structure and reside within the 3-fold hollow sites of the Au(111) surface. Meanwhile, phosphate counter-ions co-adsorb on the UPD adlayer and bridge between the Zn adatoms in a ({radical}3x{radical}3)R30{sup o} ({mu}{sub sc} = 0.33) configuration, with each phosphorous atom residing above a vacant 3-fold hollow site of the Au(111). Significantly, this surface structure is invariant between the electrochemical potential for UPD adlayer formation and the onset of bulk Zn electrodeposition. Analysis of the Zn K-edge absorption onset also presents the possibility that the Zn adatoms do not fully discharge during the process of UPD, which had been proposed in prior voltammetric studies of the phosphate/Zn(UPD)/Au(111) system.
Date: December 11, 2009
Creator: Lee, J. R.; O'Malley, R. L.; O'Connell, T. J.; Vollmer, A. & Rayment, T.
Object Type: Article
System: The UNT Digital Library
Isotopic mass-dependence of metal cation diffusion coefficients in liquid water (open access)

Isotopic mass-dependence of metal cation diffusion coefficients in liquid water

Isotope distributions in natural systems can be highly sensitive to the mass (m) dependence of solute diffusion coefficients (D) in liquid water. Isotope geochemistry studies routinely have assumed that this mass dependence either is negligible (as predicted by hydrodynamic theories) or follows a kinetic-theory-like inverse square root relationship (D {proportional_to} m{sup -0.5}). However, our recent experimental results and molecular dynamics (MD) simulations showed that the mass dependence of D is intermediate between hydrodynamic and kinetic theory predictions (D {proportional_to} m{sup -{beta}} with 0 {<=} {beta} < 0.2 for Li{sup +}, Cl{sup -}, Mg{sup 2+}, and the noble gases). In this paper, we present new MD simulations and experimental results for Na{sup +}, K{sup +}, Cs{sup +}, and Ca{sup 2+} that confirm the generality of the inverse power-law relation D {proportional_to} m{sup -{beta}}. Our new findings allow us to develop a general description of the influence of solute valence and radius on the mass dependence of D for monatomic solutes in liquid water. This mass dependence decreases with solute radius and with the magnitude of solute valence. Molecular-scale analysis of our MD simulation results reveals that these trends derive from the exponent {beta} being smallest for those solutes whose motions are …
Date: January 11, 2009
Creator: Bourg, Ian C.; Richter, Frank M.; Christensen, John N. & Sposito, Garrison
Object Type: Article
System: The UNT Digital Library
FY 2010 Budget Summary (open access)

FY 2010 Budget Summary

This report summarizes NOAA's budget request for the 2010 fiscal year.
Date: May 11, 2009
Creator: United States. National Oceanic and Atmospheric Administration.
Object Type: Text
System: The UNT Digital Library
Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair (open access)

Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair

The three human LIG genes encode polypeptides that catalyze phosphodiester bond formation during DNA replication, recombination and repair. While numerous studies have identified protein partners of the human DNA ligases (hLigs), there has been little characterization of the catalytic properties of these enzymes. In this study, we developed and optimized a fluorescence-based DNA ligation assay to characterize the activities of purified hLigs. Although hLigI joins DNA nicks, it has no detectable activity on linear duplex DNA substrates with short, cohesive single-strand ends. By contrast, hLigIII{beta} and the hLigIII{alpha}/XRCC1 and hLigIV/XRCC4 complexes are active on both nicked and linear duplex DNA substrates. Surprisingly, hLigIV/XRCC4, which is a key component of the major non-homologous end joining (NHEJ) pathway, is significantly less active than hLigIII on a linear duplex DNA substrate. Notably, hLigIV/XRCC4 molecules only catalyze a single ligation event in the absence or presence of ATP. The failure to catalyze subsequent ligation events reflects a defect in the enzyme-adenylation step of the next ligation reaction and suggests that, unless there is an in vivo mechanism to reactivate DNA ligase IV/XRCC4 following phosphodiester bond formation, the cellular NHEJ capacity will be determined by the number of adenylated DNA ligaseIV/XRCC4 molecules.
Date: May 11, 2009
Creator: Chen, Xi; Ballin, Jeff D.; Della-Maria, Julie; Tsai, Miaw-Sheue; White, Elizabeth J.; Tomkinson, Alan E. et al.
Object Type: Article
System: The UNT Digital Library
A Novel Demountable TF Joint Design for Low Aspect Ratio Spherical Torus Tokamaks (open access)

A Novel Demountable TF Joint Design for Low Aspect Ratio Spherical Torus Tokamaks

A novel shaped design for the radial conductors and demountable electrical joints connecting inner and outer legs of copper TF system conductors in low aspect ratio tokamaks is described and analysis results are presented. Specially shaped designs can optimize profiles of electrical current density, magnetic force, heating, and mechanical stress.
Date: June 11, 2009
Creator: Woolley, Robert D.
Object Type: Article
System: The UNT Digital Library
Tank Space Options Report (open access)

Tank Space Options Report

Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.
Date: August 11, 2009
Creator: Willis, W. L. & Ahrendt, M. R.
Object Type: Report
System: The UNT Digital Library
Using Atom Interferometry to Search for New Forces (open access)

Using Atom Interferometry to Search for New Forces

Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10{sup 2} and near-future advances will be able to rewrite the limits for forces with ranges from 100 {micro}m to 1km.
Date: December 11, 2009
Creator: Wacker, Jay G.
Object Type: Article
System: The UNT Digital Library
On Soft Sngularities at Three Loops and Beyond (open access)

On Soft Sngularities at Three Loops and Beyond

We report on further progress in understanding soft singularities of massless gauge theory scattering amplitudes. Recently, a set of equations was derived based on Sudakov factorization, constraining the soft anomalous dimension matrix of multi-leg scattering amplitudes to any loop order, and relating it to the cusp anomalous dimension. The minimal solution to these equations was shown to be a sum over color dipoles. Here we explore potential contributions to the soft anomalous dimension that go beyond the sum-over-dipoles formula. Such contributions are constrained by factorization and invariance under rescaling of parton momenta to be functions of conformally invariant cross ratios. Therefore, they must correlate the color and kinematic degrees of freedom of at least four hard partons, corresponding to gluon webs that connect four eikonal lines, which first appear at three loops. We analyze potential contributions, combining all available constraints, including Bose symmetry, the expected degree of transcendentality, and the singularity structure in the limit where two hard partons become collinear. We find that if the kinematic dependence is solely through products of logarithms of cross ratios, then at three loops there is a unique function that is consistent with all available constraints. If polylogarithms are allowed to appear as …
Date: December 11, 2009
Creator: Dixon, Lance J.; Gardi, Einan. & Magnea, Lorenzo.
Object Type: Article
System: The UNT Digital Library
DWPF GC FILTER ASSEMBLY SAMPLING AND ANALYSIS (open access)

DWPF GC FILTER ASSEMBLY SAMPLING AND ANALYSIS

On March 18, 2009 a Defense Waste Processing Facility (DWPF) GC Line Filter Assembly was received at the Savannah River National Laboratory (SRNL). This filter assembly was removed from operation following the completion of Sludge Batch 4 processing in the DWPF. Work on this sample was requested in a Technical Assistance Request. This document reports the pictures, observations, samples collected, and analytical results for the assembly. The assembly arrived at SRNL separated into its three component filters: high efficiency particulate air (HEPA)-1, HEPA-2, and a high efficiency mist evaporator (HEME). Each stage of the assembly's media was sampled and examined visually and by scanning electron microscopy (SEM). Solids built up in the filter housing following the first stage HEME, were dissolved in dilute nitric acid and analyzed by ICP-AES and the undissolved white solids were analyzed by x-ray diffraction (XRD). The vast majority of the material in each of the three stages of the DWPF GC Line Filter Assembly appears to be contaminated with a Hg compound that is {approx}59 wt% Hg on a total solids basis. The Hg species was identified by XRD analysis to contain a mixture of Hg{sub 4}(OH)(NO{sub 3}){sub 3} and Hg{sub 10}(OH){sub 4}(NO{sub 3}){sub 6}. …
Date: November 11, 2009
Creator: Bannochie, C. & Imrich, K.
Object Type: Report
System: The UNT Digital Library
Paleontological overview of oil shale and tar sands areas in Colorado, Utah, and Wyoming. (open access)

Paleontological overview of oil shale and tar sands areas in Colorado, Utah, and Wyoming.

In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the ''Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005,'' Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. In addition, Congress declared that both research- and commercial-scale development of oil shale and tar sands should (1) be conducted in an environmentally sound manner using management practices that will minimize potential impacts, (2) occur with an emphasis on sustainability, and (3) benefit the United States while taking into account concerns of the affected states and communities. To support this declaration of policy, Congress directed the Secretary of the Interior to undertake a series of steps, several of which are directly related to the development of a commercial leasing program for oil shale and tar sands. One of these steps was the completion of a programmatic environmental impact statement (PEIS) to analyze the impacts of a commercial leasing program for oil shale and tar sands …
Date: February 11, 2009
Creator: Murphey, P. C.; Daitch, D. & Division, Environmental Science
Object Type: Report
System: The UNT Digital Library
XAL Adoption Experience at LCLS (open access)

XAL Adoption Experience at LCLS

XAL is a high level accelerator application framework originally developed by the Spallation Neutron Source (SNS), Oak Ridge National Laboratory. The XAL framework provides generic hierarchical view for an accelerator as well as many utility tools. In XAL, a built-in physics model calculates either single particle or beam envelope tracking for physics parameters. Modifications to the original XAL model are necessary for the Linac Coherent Light Source (LCLS). Work was done to manipulate MAD deck output within a database in support of the XAL configuration and model. The XAL graphical user interface has been replaced by a SLAC specific design. New applications based on the framework are also discussed in this paper.
Date: December 11, 2009
Creator: Chu, P.; Woodley, M.; Chan, A.; Chevtsov, S.; Fairley, D.; Grunhaus, E. et al.
Object Type: Article
System: The UNT Digital Library
Near Edge X-Ray Absorption Fine Structure Spectroscopy with X-Ray Free-Electron Lasers (open access)

Near Edge X-Ray Absorption Fine Structure Spectroscopy with X-Ray Free-Electron Lasers

We demonstrate the feasibility of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy on solids by means of femtosecond soft x-ray pulses from a free-electron laser (FEL). Our experiments, carried out at the Free-Electron Laser at Hamburg (FLASH), used a special sample geometry, spectrographic energy dispersion, single shot position-sensitive detection and a data normalization procedure that eliminates the severe fluctuations of the incident intensity in space and photon energy. As an example we recorded the {sup 3}D{sub 1} N{sub 4,5}-edge absorption resonance of La{sup 3+}-ions in LaMnO{sub 3}. Our study opens the door for x-ray absorption measurements on future x-ray FEL facilities.
Date: December 11, 2009
Creator: Bernstein, D.P.; Acremann, Y.; Scherz, A.; Burkhardt, M.; Stohr, J.; Beye, M. et al.
Object Type: Article
System: The UNT Digital Library
Separation of Highly Complex Mixtures by Two-Dimension Liquid Chromatography (open access)

Separation of Highly Complex Mixtures by Two-Dimension Liquid Chromatography

This report summarizes the progress made on the title project during the grant period. We developed a new classification of two-dimensional separations based on the observation that separations can be made in time or in space. Thus, two-dimensional separations can be made in time×time, space×space, space×time, or time×space. The two successive separations must use two different modes of chromatography that afford uncorrelated or weakly correlated patterns of retention factors for the components of the samples analyzed. Our attention was mainly focused on the separation of protein digests, particularly, on those of the digests of myoglobin and bovine serum albumin as model systems and extremely efficient temporal separations were developed. We also designed and constructed new instruments to carry out space×space separations (True Bidimensional Chromatography, HPLC2 or spacial separations) and time×space separations (a new hybrid combination of a temporal and a spacial separation that we designed).
Date: December 11, 2009
Creator: Guiochon, Georges
Object Type: Report
System: The UNT Digital Library