Financial Audit: Bureau of the Public Debt's Fiscal Years 2007 and 2006 Schedules of Federal Debt (open access)

Financial Audit: Bureau of the Public Debt's Fiscal Years 2007 and 2006 Schedules of Federal Debt

A letter report issued by the Government Accountability Office with an abstract that begins "GAO is required to audit the consolidated financial statements of the U.S. government. Due to the significance of the federal debt held by the public to the governmentwide financial statements, GAO has also been auditing the Bureau of the Public Debt's (BPD) Schedules of Federal Debt annually. The audit of these schedules is done to determine whether, in all material respects, (1) the schedules are reliable and (2) BPD management maintained effective internal control relevant to the Schedule of Federal Debt. Further, GAO tests compliance with a significant selected provision of law related to the Schedule of Federal Debt. Federal debt managed by BPD consists of Treasury securities held by the public and by certain federal government accounts, referred to as intragovernmental debt holdings. The level of debt held by the public reflects how much of the nation's wealth has been absorbed by the federal government to finance prior federal spending in excess of federal revenues. Intragovernmental debt holdings represent balances of Treasury securities held by federal government accounts, primarily federal trust funds such as Social Security, that typically have an obligation to invest their excess …
Date: November 7, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
International Trade: An Analysis of Free Trade Agreements and Congressional and Private Sector Consultations under Trade Promotion Authority (open access)

International Trade: An Analysis of Free Trade Agreements and Congressional and Private Sector Consultations under Trade Promotion Authority

A letter report issued by the Government Accountability Office with an abstract that begins "Congress granted the President Trade Promotion Authority (TPA) to negotiate agreements, including free trade agreements (FTA) in 2002. TPA stipulated negotiating objectives and procedural steps for the administration, including consulting with Congress and trade advisory committees. TPA lapsed in July 2007 amidst questions about its use. GAO was asked to review: (1) What FTAs have been pursued under TPA and why? (2) Overall, what is the economic significance of these agreements for the United States? (3) What is the nature of the consultation process for Congress and how well has it worked in practice? (4) What is the nature of the consultation process for trade advisory committees, and how well has it worked in practice? GAO interviewed staff of the Office of the U.S. Trade Representative (USTR), the International Trade Commission (ITC), congressional committees with jurisdiction, trade advisory committees, and others, and reviewed USTR documents."
Date: November 7, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
COMPARISONS OF CRYSTALLINE SILICOTITANATE AND RESORCINOL FORMALDEHYDE MEDIA FOR CESIUM REMOVAL BY IN-TANK COLUMN PROCESSING (open access)

COMPARISONS OF CRYSTALLINE SILICOTITANATE AND RESORCINOL FORMALDEHYDE MEDIA FOR CESIUM REMOVAL BY IN-TANK COLUMN PROCESSING

Chemical and thermal performance of crystalline silicotitanate (CST) and resorcinol-formaldehyde (RF) ion exchange media were predicted for column configurations designed for installation in high level waste tanks and intended for cesium removal from radioactive waste supernates. Modeling predictions for the processing of a known Savannah River Site tank waste composition were generated. In a two column configuration under presumed nominal operating conditions (432 gallon packed bed, 10 gpm liquid flow, 25 C, 45 nCi/g average breakthrough limit) with lead/lag column rotation between processing cycles, approximately two cycles were predicted to treat 1,000,000 gallons of radioactive waste with CST as compared to three cycles predicted for RF. However, this processing mode was shown to be highly unfavorable for RF due to the fact that the lead column is unnecessarily exposed to large radiation doses during movement of the cesium mass transfer zone into the lag column. Thermal modeling calculations indicated that maximum temperatures within stagnant, packed CST and RF columns containing the highest anticipated cesium loading and no active cooling will reach 128 and 78 C, respectively, within 6 days. Active cooling maintains the cesium-saturated CST and RF columns below 88 and 41 C, respectively, under stagnant flow conditions.
Date: November 7, 2007
Creator: King, W; Frank02 Smith, F; Si Lee, S & Daniel McCabe, D
Object Type: Article
System: The UNT Digital Library
The Extinction Toward the Galactic Bulge from RR Lyrae Stars (open access)

The Extinction Toward the Galactic Bulge from RR Lyrae Stars

The authors present mean reddenings toward 3525 RR0 Lyrae stars from the Galactic bulge fields of the MACHO Survey. These reddenings are determined using the color at minimum V-band light of the RR0 Lyrae stars themselves and are found to be in general agreement with extinction estimates at the same location obtained from other methods. Using 3256 stars located in the Galactic Bulge, they derive the selective extinction coefficient R{sub V,VR} = A{sub V}/E(V-R) = 4.2 {+-} 0.2. this value is what is expected for a standard extinction law with R{sub V,BV} = 3.1 {+-} 0.3
Date: November 7, 2007
Creator: Kunder, A.; Popowski, P.; Cook, K. & Chaboyer, B.
Object Type: Article
System: The UNT Digital Library
Passive Spectroscopy Bolometers, Grating- And X-Ray Imaging Crystal Spectrometers (open access)

Passive Spectroscopy Bolometers, Grating- And X-Ray Imaging Crystal Spectrometers

This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high-resolution grating spectrometer, and a novel X-ray imaging crystal spectrometer, which is of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.
Date: November 7, 2007
Creator: Bitter, M.; Hill, K. W.; Scott, S.; Paul, S.; Ince-Cushmann, A.; Reinke, M. et al.
Object Type: Article
System: The UNT Digital Library
HWMA/RCRA Closure Plan for the Basin Facility Basin Water Treatment System - Voluntary Consent Order NEW-CPP-016 Action Plan (open access)

HWMA/RCRA Closure Plan for the Basin Facility Basin Water Treatment System - Voluntary Consent Order NEW-CPP-016 Action Plan

This Hazardous Waste Management Act/Resource Conservation and Recovery Act closure plan for the Basin Water Treatment System located in the Basin Facility (CPP-603), Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Laboratory Site, was developed to meet future milestones established under the Voluntary Consent Order. The system to be closed includes units and associated ancillary equipment included in the Voluntary Consent Order NEW-CPP-016 Action Plan and Voluntary Consent Order SITE-TANK-005 Tank Systems INTEC-077 and INTEC-078 that were determined to have managed hazardous waste. The Basin Water Treatment System will be closed in accordance with the requirements of the Hazardous Waste Management Act/Resource Conservation and Recovery Act, as implemented by the Idaho Administrative Procedures Act 58.01.05.009 and 40 Code of Federal Regulations 265, to achieve "clean closure" of the tank system. This closure plan presents the closure performance standards and methods of achieving those standards for the Basin Water Treatment Systems.
Date: November 7, 2007
Creator: Evans, S. K.
Object Type: Report
System: The UNT Digital Library
Robustness Studies of Ignition Targets for the National Ignition Facility in Two Dimensions (open access)

Robustness Studies of Ignition Targets for the National Ignition Facility in Two Dimensions

Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300 eV indirect drive target design for the National Ignition Facility [J. D. Lindl, et al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of two thousand two-dimensional simulations, run with the radiation hydrodynamics code Lasnex, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is …
Date: November 7, 2007
Creator: Clark, D S; Haan, S W & Salmonson, J D
Object Type: Article
System: The UNT Digital Library
Predictive three dimensional modeling of Stimulated Brillouin Scattering in ignition-scale experiments (open access)

Predictive three dimensional modeling of Stimulated Brillouin Scattering in ignition-scale experiments

The first three-dimensional (3D) simulations of a high power 0.351 {micro}m laser beam propagating through a high temperature hohlraum plasma are reported. We show that 3D linear kinetic modeling of Stimulated Brillouin scattering reproduces quantitatively the experimental measurements, provided it is coupled to detailed hydrodynamics simulation and a realistic description of the laser beam from its millimeter-size envelop down to the micron scale speckles. These simulations accurately predict the strong reduction of SBS measured when polarization smoothing is used.
Date: November 7, 2007
Creator: Divol, L; Berger, R; Meezan, N; Froula, D H; Dixit, S; Suter, L et al.
Object Type: Article
System: The UNT Digital Library
Demonstrating fractal scaling of residence time distributions on the catchment scale using a fully-coupled, variably-saturated groundwater and land surface model and a Lagrangian particle tracking approach (open access)

Demonstrating fractal scaling of residence time distributions on the catchment scale using a fully-coupled, variably-saturated groundwater and land surface model and a Lagrangian particle tracking approach

The influence of the vadose zone, land surface processes, and macrodispersion on scaling behavior of residence time distributions (RTDs) is studied using a fully coupled watershed model in conjunction with a Lagrangian, particle-tracking approach. Numerical experiments are used to simulate groundwater flow paths from recharge locations along the hillslope to the streambed. These experiments are designed to isolate the influences of topography, vadose zone/land surface processes, and macrodispersion on subsurface RTDs of tagged parcels of water. The results of these simulations agree with previous observations that RTDs exhibit fractal behavior, which can be identified from the power spectra. For cases incorporating residence times that are influenced by vadose zone/land surface processes, increasing macrodispersion increases the slope of the power spectra. In general the opposite effect is demonstrated if the vadose zone/land surface processes are neglected. The concept of the spectral slope being a measure of stationarity is raised and discussed.
Date: November 7, 2007
Creator: Kollet, S J & Maxwell, R M
Object Type: Article
System: The UNT Digital Library
Simple Model Representations of Transport in a Complex Fracture and Their Effects on Long-Term Predictions (open access)

Simple Model Representations of Transport in a Complex Fracture and Their Effects on Long-Term Predictions

A complex fracture model for fluid flow and tracer transport was previously developed that incorporates many of the important physical effects of a realistic fracture, including advection through a heterogeneous fracture plane, partitioning of flow into multiple subfractures in the third dimension, and diffusion and sorption into fracture-filling gouge, small altered rock matrix blocks within the fracture zone, and the unaltered semi-infinite rock matrix on both sides of the fracture zone (Tsang and Doughty, 2003). It is common, however, to represent the complex fracture by much simpler models consisting of a single fracture, with a uniform or heterogeneous transmissivity distribution over its plane and bounded on both sides by a homogeneous semi-infinite matrix. Simple-model properties are often inferred from the analysis of short-term (one to a few days) site characterization (SC) tracer-test data. The question addressed in this paper is: How reliable is the temporal upscaling of these simplified models? Are they adequate are for long-term calculations that cover thousands of years? In this study, a particle-tracking approach is used to calculate tracer-test breakthrough curves (BTCs) in a complex fracture model, incorporating all the features described above, for both a short-term SC tracer test and a 10,000-year calculation. The results …
Date: November 7, 2007
Creator: Doughty, Christine; Tsang, Chin-Fu; Doughty, Christine & Uchida, Masahiro
Object Type: Article
System: The UNT Digital Library
Confidence Level and Sensitivity Limits in High Contrast Imaging (open access)

Confidence Level and Sensitivity Limits in High Contrast Imaging

In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground and space-based telescopes. Previous theoretical analysis have shown that the time intensity variations of a single speckle follows a modified Rician. It is first demonstrated here that for a circular pupil this temporal intensity distribution also represents the speckle spatial intensity distribution at a fix separation from the point spread function center; this fact is demonstrated using numerical simulations for coronagraphic and non-coronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level. In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding confidence level as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckles noise, a detection threshold up to three times higher is required to obtain a confidence level equivalent to that at 5{sigma} for Gaussian noise. The technique is then tested using TRIDENT CFHT and …
Date: November 7, 2007
Creator: Marois, C
Object Type: Article
System: The UNT Digital Library
DEVELOPING AND QUANTIFYING PARAMETERS FOR CLOSURE WELDING OVERPACKS CONTAINING RESEARCH REACTOR SPENT NUCLEAR FUEL AT HANFORD (open access)

DEVELOPING AND QUANTIFYING PARAMETERS FOR CLOSURE WELDING OVERPACKS CONTAINING RESEARCH REACTOR SPENT NUCLEAR FUEL AT HANFORD

Fluor engineers developed a Gas Tungsten Arc Welding (GTAW) technique and parameters, demonstrated requisite weld quality and successfully closure-welded packaged spent nuclear fuel (SNF) overpacks at the Hanford Site. This paper reviews weld development and qualification activities associated with the overpack closure-welding and provides a summary of the production campaign. The primary requirement of the closure weld is to provide leaktight confinement of the packaged material against release to the environment during interim storage (40-year design term). Required weld quality, in this case, was established through up-front development and qualification, and then verification of parameter compliance during production welding. This approach was implemented to allow for a simpler overpack design and more efficient production operations than possible with approaches using routine post-weld testing and nondestructive examination (NDE). . A series of welding trials were conducted to establish the desired welding technique and parameters. Qualification of the process included statistical evaluation and American Society of Mechanical Engineers (ASME) Section IX testing. In addition, pull testing with a weighted mockup, and thermal calculation/physical testing to identify the maximum temperature the packaged contents would be subject to during welding, was performed. Thirteen overpacks were successfully packaged and placed into interim storage. The closure-welding …
Date: November 7, 2007
Creator: GR, CANNELL
Object Type: Article
System: The UNT Digital Library
Foreign Aid Reform: Issues for Congress and Policy Options (open access)

Foreign Aid Reform: Issues for Congress and Policy Options

This report provides background information on foreign aid rationales and funding trends. It outlines issues Congress may consider in any reform effort and it lays out options for reform.
Date: November 7, 2007
Creator: Veillette, Connie
Object Type: Report
System: The UNT Digital Library
Political Status of Puerto Rico: Options for Congress (open access)

Political Status of Puerto Rico: Options for Congress

None
Date: November 7, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Accounting and Management Problems at Freddie Mac (open access)

Accounting and Management Problems at Freddie Mac

This report summarizes the extent of accounting and management problems at Freddie Mac. The report highlights the issues of selecting policies to report constant earnings, and undertaking certain transactions for the sake of creating a facade of reported earnings. Finally, the report discusses the consequences of these problems by stating that many of the Freddie Mac's executives have been replaced, fines were issued, and a lawsuit occurred.
Date: November 7, 2007
Creator: Jickling, Mark
Object Type: Report
System: The UNT Digital Library
Parallel Finite Element Particle-In-Cell Code for Simulations of Space-charge Dominated Beam-Cavity Interactions (open access)

Parallel Finite Element Particle-In-Cell Code for Simulations of Space-charge Dominated Beam-Cavity Interactions

Over the past years, SLAC's Advanced Computations Department (ACD) has developed the parallel finite element (FE) particle-in-cell code Pic3P (Pic2P) for simulations of beam-cavity interactions dominated by space-charge effects. As opposed to standard space-charge dominated beam transport codes, which are based on the electrostatic approximation, Pic3P (Pic2P) includes space-charge, retardation and boundary effects as it self-consistently solves the complete set of Maxwell-Lorentz equations using higher-order FE methods on conformal meshes. Use of efficient, large-scale parallel processing allows for the modeling of photoinjectors with unprecedented accuracy, aiding the design and operation of the next-generation of accelerator facilities. Applications to the Linac Coherent Light Source (LCLS) RF gun are presented.
Date: November 7, 2007
Creator: Candel, A. E.; Kabel, A. C.; Ko, Yong-kyu; Lee, L.; Li, Z.; Limborg-Deprey, C. et al.
Object Type: Article
System: The UNT Digital Library
Geant4 Applications in Space (open access)

Geant4 Applications in Space

Use of Geant4 is rapidly expanding in space application domain. I try to overview three major application areas of Geant4 in space, which are apparatus simulation for pre-launch design and post-launch analysis, planetary scale simulation for radiation spectra and surface and sub-surface explorations, and micro-dosimetry simulation for single event study and radiation-hardening of semiconductor devices. Recently, not only the mission dependent applications but also various multi-purpose or common tools built on top of Geant4 are also widely available. I overview some of such tools as well. The Geant4 Collaboration identifies that the space applications are now one of the major driving forces of the further developments and refinements of Geant4 toolkit. Highlights of such developments are introduced.
Date: November 7, 2007
Creator: Asai, M.
Object Type: Article
System: The UNT Digital Library
Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Stronthium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016 (open access)

Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Stronthium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers’ exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating …
Date: November 7, 2007
Creator: Smith, Robert W. & Fujita, Yoshiko
Object Type: Report
System: The UNT Digital Library
High Power Testing of A Fused Quartz-based Dielectric-Loaded Accelerating Structure (open access)

High Power Testing of A Fused Quartz-based Dielectric-Loaded Accelerating Structure

We report on the most recent results from a series of high power tests being carried out on rf-driven dielectric loaded accelerating (DLA) structures. The purpose of these tests is to determine the viability of the DLA as a traveling-wave accelerator and is a collaborative effort between Argonne National Laboratory (ANL), Naval Research Laboratory (NRL), and Stanford Linear Accelerator Center (SLAC). In this paper, we report on the recent high power tests of a fused quartz-based DLA structure that was carried out at incident powers of up to 12 MW at NRL and 37 MW at SLAC. We also report on test results of a TiN coated quartz structure, that exhibits good multipactor suppression.
Date: November 7, 2007
Creator: Jing, C.; Power, J. G.; Konecny, R.; Gai, W.; Yusof, Z.; Gold, S. H. et al.
Object Type: Article
System: The UNT Digital Library
How Very Massive Metal Free Stars Start Cosmological Reionization (open access)

How Very Massive Metal Free Stars Start Cosmological Reionization

The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include non-equilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the Case B approximation using adaptively ray traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of {approx}10{sup 6}. These first sources of reionization are highly intermittent and anisotropic and first photoionize the small scales voids surrounding the halos they form in, rather than the dense filaments they are! embedded in. As the merging objects form larger, dwarf sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front …
Date: November 7, 2007
Creator: Wise, John H. & Abel, Tom
Object Type: Article
System: The UNT Digital Library
RF Design of Normal Conducting Deflecting Structures for the Advanced Photon Source (open access)

RF Design of Normal Conducting Deflecting Structures for the Advanced Photon Source

Use of normal conducting deflecting structures for production of short x-ray pulses is now under consideration at Argonne's Advanced Photon Source (APS). The structures have to produce up to 4 MV maximum deflection per pair of structures with a 1 kHz repetition rate. At the same time, the structures should not cause deterioration of beam properties in the APS ring. Following these requirements, we proposed 2815 MHz standing wave deflecting structures with heavy wakefield damping. In this paper we discuss design considerations and present our current design.
Date: November 7, 2007
Creator: Dolgashev, V. A.; Borland, Michael & Waldschmidt, Geoff
Object Type: Article
System: The UNT Digital Library
The ILC Global Control System (open access)

The ILC Global Control System

None
Date: November 7, 2007
Creator: Carwardine, J.; Arnold, N.; Lenkszus, F.; Saunders, C.; Rehlich, K.; Simrock, S. et al.
Object Type: Article
System: The UNT Digital Library
High Power Tests of Normal Conducting Single-Cell Structures (open access)

High Power Tests of Normal Conducting Single-Cell Structures

We report the results of the first high power tests of single-cell traveling-wave and standing-wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the gradient potential of normal-conducting rf-powered particle beam accelerators. The test setup consists of reusable mode converters and short test structures and is powered by SLAC's XL-4 klystron. This setup was created for economical testing of different cell geometries, cell materials and preparation techniques with short turn-around time. The mode launchers and structures were manufactured at SLAC and KEK and tested in the SLAC Klystron Test Lab.
Date: November 7, 2007
Creator: Dolgashev, V. A.; Tantawi, S. G.; Nantista, C. D.; Higashi, Y. & Higo, T.
Object Type: Article
System: The UNT Digital Library
CMAD: A Self-consistent Parallel Code to Simulate the Electron Cloud Build-up and Instabilities (open access)

CMAD: A Self-consistent Parallel Code to Simulate the Electron Cloud Build-up and Instabilities

We present the features of CMAD, a newly developed self-consistent code which simulates both the electron cloud build-up and related beam instabilities. By means of parallel (Message Passing Interface - MPI) computation, the code tracks the beam in an existing (MAD-type) lattice and continuously resolves the interaction between the beam and the cloud at each element location, with different cloud distributions at each magnet location. The goal of CMAD is to simulate single- and coupled-bunch instability, allowing tune shift, dynamic aperture and frequency map analysis and the determination of the secondary electron yield instability threshold. The code is in its phase of development and benchmarking with existing codes. Preliminary results on benchmarking are presented in this paper.
Date: November 7, 2007
Creator: Pivi, M. T. F.
Object Type: Article
System: The UNT Digital Library