The National Institute of Standards and Technology: An Overview (open access)

The National Institute of Standards and Technology: An Overview

None
Date: July 29, 2002
Creator: Schacht, Wendy H.
Object Type: Report
System: The UNT Digital Library
Appropriations for FY2003: Treasury, Postal Service, Executive Office of the President, and General Government (open access)

Appropriations for FY2003: Treasury, Postal Service, Executive Office of the President, and General Government

Appropriations are one part of a complex federal budget process that includes budget resolutions, appropriations (regular, supplemental, and continuing) bills, rescissions, and budget reconciliation bills. This report is a guide to one of the 13 regular appropriations bills that Congress considers each year. It is designed to supplement the information provided by the House and Senate Appropriations Subcommittees on Treasury, Postal Service, and General Government.
Date: July 29, 2002
Creator: Gressle, Sharon S.
Object Type: Report
System: The UNT Digital Library
Proposed Transfer of FEMA to the Department of Homeland Security (open access)

Proposed Transfer of FEMA to the Department of Homeland Security

None
Date: July 29, 2002
Creator: Bea, Keith
Object Type: Report
System: The UNT Digital Library
Homeland Security: Data on Employees and Unions Potentially Affected (open access)

Homeland Security: Data on Employees and Unions Potentially Affected

This report provides data on federal employee unions and employees who would be potentially affected by the creation by the creation of a new Department of Homeland Security, as proposed by the President.
Date: July 29, 2002
Creator: McCallion, Gail
Object Type: Report
System: The UNT Digital Library
Major Tax Issues in the 107th Congress (open access)

Major Tax Issues in the 107th Congress

None
Date: July 29, 2002
Creator: Brumbaugh, David L.
Object Type: Report
System: The UNT Digital Library
Acquisition Workforce: Agencies Need to Better Define and Track the Training of Their Employees (open access)

Acquisition Workforce: Agencies Need to Better Define and Track the Training of Their Employees

A letter report issued by the General Accounting Office with an abstract that begins "GAO's continuing reviews of the acquisition workforce, focusing on the Department of Defense (DOD); the Departments of the Army, Navy, and Air Force; the Departments of Veterans Affairs, Energy, and Health and Human Services; the General Services Administration; and the National Aeronautics and Space Administration, indicate that some of the government's largest procurement operations are not run efficiently. GAO found that requirements are not clearly defined, prices and alternatives are not fully considered, or contracts are not adequately overseen. The ongoing technological revolution requires a workforce with new knowledge, skills, and abilities, and the nature of acquisition is changing from routine simple buys toward more complex acquisitions and new business practices. DOD has adopted multidisciplinary and multifunctional definitions of their acquisition workforce, but the civilian agencies have not. DOD and the civilian agencies reviewed have developed specific training requirements for their acquisition workforce and mechanisms to track the training of acquisition personnel. All of the agencies reviewed said they had sufficient funding to provide current required core training for their acquisition workforce, but some expressed concerns about funding training for future requirements and career development, particularly …
Date: July 29, 2002
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
High Resolution X-Ray Fluorescence Micro-Tomography on Single Sediment Particles (open access)

High Resolution X-Ray Fluorescence Micro-Tomography on Single Sediment Particles

This work focuses on the investigation of the distribution of contaminants in individual sediment particles from the New York/New Jersey Harbor. Knowledge of the spatial distribution of the contaminants within the particles is needed to enable (1) more sophisticated approaches to the understanding of the fate and transport of the contaminants in the environment and (2) more refined methods for cleaning the sediments. The size of the investigated particles ranges from 30-80 microns. Due to the low concentration of the elements of interest and the microscopic size of the environmental particles in these measurements, the small size and high intensity of the analyzing X-ray beam was critical. The high photon flux at the ESRF Microfocus beam line (ID13) was used as the basis for fluorescence tomography to investigate whether the inorganic compounds are taken upon the surface organic coating or whether they are distributed through the volume of the grains being analyzed. The experiments were done using a 13 keV monochromatic beam of approximately 2 {micro}m in size having an intensity of 10{sup 10} ph/s, allowing absolute detection limits on the 0.04-1 fg level for Ti, Cr, Mn, Fe, Ni, and Zn.
Date: July 29, 2002
Creator: Vincze, L.; Vekemans, B.; Szaloki, I.; Janssens, K.; Van Grieken, R.; Feng, H. et al.
Object Type: Article
System: The UNT Digital Library
Ferroelectric Cathodes in Transverse Magnetic Fields (open access)

Ferroelectric Cathodes in Transverse Magnetic Fields

Experimental investigations of a planar ferroelectric cathode in a transverse magnetic field up to 3 kGs are presented. It is shown that the transverse magnetic field affects differently the operation of ferroelectric plasma cathodes in ''bright'' and ''dark'' modes in vacuum. In the ''bright'' mode, when the surface plasma is formed, the application of the transverse magnetic field leads to an increase of the surface plasma density. In the ''dark'' mode, the magnetic field inhibits the development of electron avalanches along the surface, as it does similarly in other kinds of surface discharges in the pre-breakdown mode.
Date: July 29, 2002
Creator: Dunaevsky, Alexander; Raitses, Yevgeny & Fisch, Nathaniel J.
Object Type: Report
System: The UNT Digital Library
Trapped Electron Precession Shear Induced Fluctuation Decorrelation (open access)

Trapped Electron Precession Shear Induced Fluctuation Decorrelation

We consider the effects of trapped electron precession shear on the microturbulence. In a similar way the strong E x B shear reduces the radial correlation length of ambient fluctuations, the radial variation of the trapped electron precession frequency can reduce the radial correlation length of fluctuations associated with trapped electrons. In reversed shear plasmas, with the explicit dependence of the trapped electron precession shearing rate on B(subscript)theta, the sharp radial gradient of T(subscript)e due to local electron heating inside qmin can make the precession shearing mechanism more effective, and reduce the electron thermal transport constructing a positive feedback loop for the T(subscript)e barrier formation.
Date: July 29, 2002
Creator: Hahm, T.S.; Diamond, P.H. & Kim, E.-J.
Object Type: Report
System: The UNT Digital Library
Processing and Microstructure of Cr-Ta and Cr-Ta-Mo Composites Reinforced by the Cr2Ta Laves Phase (open access)

Processing and Microstructure of Cr-Ta and Cr-Ta-Mo Composites Reinforced by the Cr2Ta Laves Phase

The Cr-Ta alloy with an eutectic structure has a good combination of high strength and oxidation resistance at elevated temperatures up to 1200 C. It is an ideal candidate for ultrahigh-temperature applications. However, the material shows low ductility and fracture toughness at room temperature. A possible way to improve the ductility and fracture toughness is to obtain an aligned microstructure of eutectic Cr-based alloys, using a directional-solidification (DS) process, in which the feed materials with eutectic compositions are preferred. In the present work, a quantitative technique was developed to assist in monitoring and controlling the composition of the Cr-based alloys at each stage of the processing at elevated temperatures. The eutectic composition of the binary Cr-Ta alloy was determined to be Cr-9.7 at.% (atomic percent) Ta, and a drop-cast ternary Cr-9.7 at.% Ta-1.0 at.% Mo alloy was found to possess a fully eutectic structure.
Date: July 29, 2002
Creator: Wang, DF
Object Type: Report
System: The UNT Digital Library
The influence of pre-irradiation heat treatments on thermal non-equilibrium and radiation-induced segregation behavior in model austenitic stainless steel alloys. (open access)

The influence of pre-irradiation heat treatments on thermal non-equilibrium and radiation-induced segregation behavior in model austenitic stainless steel alloys.

The effect of pre-irradiation heat treatments on thermal non-equilibrium grain boundary segregation (TNES) and subsequent radiation-induced grain boundary segregation (RIS) is studied in a series of model austenitic stainless steels. The alloys used for this study are based on AISI 316 stainless steel and have the following nominal compositions: Fe-16Cr-13Ni-1.25Mn (base 316), Fe-16Cr-13Ni-1.25Mn-2.0Mo (316 + Mo) and Fe-16Cr-13Ni-1.25Mn-2.0Mo-0.07P (316 + Mo + P). Samples were heat treated at temperatures ranging from 1100 to 1300 C and cooled at 4 different rates (salt brine quench, water quench, air cool and furnace cool) to evaluate the effect of annealing temperature and quench rate on TNES. The alloys were than processed with the treatment (temperature and cooling rate) that resulted in the maximum Cr enrichment. Alloys with and without the heat treatment to enrich the grain boundaries with Cr were characterized following irradiation to 1 dpa at 400 C with high-energy protons in order to understand the influence of alloying additions and pre-irradiation grain boundary chemistry on irradiation-induced elemental enrichment and depletion profiles. Various mechanistic models will be examined to explain the observed behavior.
Date: July 29, 2002
Creator: Cole, J. I.; Allen, T. R.; Was, G. S.; Dropek, R. B. & Kenik, E. A.
Object Type: Article
System: The UNT Digital Library
Recent developments at the cathode processor for spent fuel treatment. (open access)

Recent developments at the cathode processor for spent fuel treatment.

As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a molten salt electrolyte, primarily consisting of a eutectic mixture of lithium and potassium chlorides with minor amounts of fission product chlorides, from uranium is achieved by a batch operation called cathode processing. Described in this paper are recent developments, both equipment and process-related, at the cathode processor during the treatment of blanket-type spent fuel. For the equipment developments, the installation of a new induction heating coil has produced significant improvements in equipment performance. The process developments include the elimination of a process step and the study of plutonium in the uranium product.
Date: July 29, 2002
Creator: Westphal, B. R.; Vaden, D.; Hua, T. Q.; Willit, J. L. & Laug, D. V.
Object Type: Article
System: The UNT Digital Library
An integral field spectrograph for SNAP supernova studies (open access)

An integral field spectrograph for SNAP supernova studies

A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Ia supernovae and to standardize the magnitude of each candidate by determining explosion parameters. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have very high efficiency and low spectral resolution (R {approx} 100), constant through the wavelength range (0.35-1.7{micro}m), adapted to the scientific goals of the mission.
Date: July 29, 2002
Creator: Ealet, Anne; Prieto, E.; Bonissent, A.; Malina, R.; Basa, S.; LeFevre, O. et al.
Object Type: Article
System: The UNT Digital Library
Regulatory Framework for the Geologic Repository at Yucca Mountain Nevada, USA (open access)

Regulatory Framework for the Geologic Repository at Yucca Mountain Nevada, USA

After years of geologic investigations, Yucca Mountain, Nevada has been recommended by the President of the United States and approved by the U.S. Congress for development as a geologic repository for disposal of high-level radioactive waste and spent nuclear fuel. This significant step forward in implementing national policy for the safe and environmentally sound isolation of radioactive waste was made possible, in part, by the finalization of the regulatory framework for the U.S. repository program. The Nuclear Waste Policy Act, passed in 1982 and amended in 1987, established the roles of three federal agencies responsible for interrelated regulatory aspects of radioactive waste disposal: (1) the U.S. Environmental Protection Agency (''EPA''; responsible for setting standards for public health and environmental protection); (2) the U.S. Nuclear Regulatory Commission (''NRC''; responsible for developing licensing criteria and regulations implementing the EPA's standard); and, (3) the U.S. Department of Energy (''DOE''; responsible for site selection, characterization, recommendation and repository development and operation). These agencies first published their regulations in the 1980's. In the 1992 Energy Policy Act, Congress directed the EPA to develop new public health and safety standards that were specific for Yucca Mountain and directed the NRC to revise its technical requirements and …
Date: July 29, 2002
Creator: Gil, A.V. & McKinnon, B.L.
Object Type: Report
System: The UNT Digital Library
A study of layered lithium manganese oxide cathode materials (open access)

A study of layered lithium manganese oxide cathode materials

None
Date: July 29, 2002
Creator: Eriksson, Tom A. & Doeff, Marca M.
Object Type: Article
System: The UNT Digital Library
Microscopic probabilistic model for the simulation of secondary electron emission (open access)

Microscopic probabilistic model for the simulation of secondary electron emission

We provide a detailed description of a model and its computational algorithm for the secondary electron emission process. The model is based on a broad phenomenological fit to data for the secondary emission yield (SEY) and the emitted-energy spectrum. We provide two sets of values for the parameters by fitting our model to two particular data sets, one for copper and the other one for stainless steel.
Date: July 29, 2002
Creator: Furman, M. A. & Pivi, M. T. F.
Object Type: Article
System: The UNT Digital Library
Overview of the nearby supernova factory (open access)

Overview of the nearby supernova factory

The Nearby Supernova Factory (SNfactory) is an international experiment designed to lay the foundation for the next generation of cosmology experiments (such as CFHTLS, wP, SNAP and LSST) which will measure the expansion history of the Universe using Type Ia supernovae. The SNfactory will discover and obtain frequent lightcurve spectrophotometry covering 3200-10000 {angstrom} for roughly 300 Type Ia supernovae at the low-redshift end of the smooth Hubble flow. The quantity, quality, breadth of galactic environments, and homogeneous nature of the SNfactory dataset will make it the premier source of calibration for the Type Ia supernova width-brightness relation and the intrinsic supernova colors used for K-correction and correction for extinction by host-galaxy dust. This dataset will also allow an extensive investigation of additional parameters which possibly influence the quality of Type Ia supernovae as cosmological probes. The SNfactory search capabilities and follow-up instrumentation include wide-field CCD imagers on two 1.2-m telescopes (via collaboration with the Near Earth Asteroid Tracking team at JPL and the QUEST team at Yale), and a two-channel integral-field-unit optical spectrograph/imager being fabricated for the University of Hawaii 2.2-m telescope. In addition to ground-based follow-up, UV spectra for a subsample of these supernovae will be obtained with HST. …
Date: July 29, 2002
Creator: Aldering, Greg; Adam, Gilles; Antilogus, Pierre; Astier, Pierre; Bacon, Roland; Bongard, S. et al.
Object Type: Article
System: The UNT Digital Library
CO{sub 2}-H{sub 2}O mixtures in the geologic sequestration of CO{sub 2}. I. Assessment and calculation of mutual solubilities from 12 to 100 degrees C and up to 600 bar (open access)

CO{sub 2}-H{sub 2}O mixtures in the geologic sequestration of CO{sub 2}. I. Assessment and calculation of mutual solubilities from 12 to 100 degrees C and up to 600 bar

None
Date: July 29, 2002
Creator: Spycher, Nicolas; Pruess, Karsten & Ennis-King, Jonathan
Object Type: Article
System: The UNT Digital Library
High resolution XPS study of oxide layers grown on Ge substrates (open access)

High resolution XPS study of oxide layers grown on Ge substrates

High resolution X-ray Photoelectron Spectroscopy (XPS) was used to analyze thin layers of germanium oxide grown on germanium substrates under various conditions. The results reveal the presence of high density of electron states located at the oxide/germanium interface that lead to the energy band bending. The surface of native oxide layers and that of thin oxide layer grown under dry oxygen correspond to GeO2 composition. Under Ar etching, lower oxidation states were revealed. Short in-situ heat treatment at T=400 degrees C under ultra high vacuum leads to the removal of the oxide layer. In addition, the analysis of the layer grown at T=380 degrees C under dry oxygen suggest that carbides form at the oxide/substrate interface.
Date: July 29, 2002
Creator: Tabet, N.; Faiz, M.; Hamdan, N.M. & Hussain, Z.
Object Type: Article
System: The UNT Digital Library
Environmental Aspects, Objectives and Targets Identification Process (open access)

Environmental Aspects, Objectives and Targets Identification Process

The purpose of this report is to document the environmental aspects and associated environmental impacts of the Bechtel SAIC Company (BSC) scope of work, evaluate the significance of those environmental aspects based on established criteria, and establish environmental objectives and targets for specific environmental aspects. This report is intended to be used by environmental staff in the evaluation of BSC work packages during the annual risk-based planning process. This report shall be fully reviewed and revised annually during the annual work planning process to reflect changes in BSC operations, facilities, and scope of work. Planned BSC work will be evaluated to determine if the work is covered by a previously defined activity, product or service (see Table 2); if work activities require redefinition or addition of a new activity; and if the significant evaluation for each environment aspect is still valid based on scope of planned work. New workscope initiated during the fiscal year through the Baseline Change Proposal process (i.e., not as part of the annual work plan) also will be reviewed for new environmental aspects and determination of whether the new workscope would change the significance rating of any environmental aspect. If a new environmental aspect is identified …
Date: July 29, 2002
Creator: Green, R.
Object Type: Report
System: The UNT Digital Library
SNAP Near Infrared Detectors (open access)

SNAP Near Infrared Detectors

The SuperNova/Acceleration Probe (SNAP) will measure precisely the cosmological expansion history over both the acceleration and deceleration epochs and thereby constrain the nature of the dark energy that dominates our universe today. The SNAP focal plane contains equal areas of optical CCDs and NIR sensors and an integral field spectrograph. Having over 150 million pixels and a field-of-view of 0.34 square degrees, the SNAP NIR system will be the largest yet constructed. With sensitivity in the range 0.9-1.7 {micro}m, it will detect Type Ia supernovae between z = 1 and 1.7 and will provide follow-up precision photometry for all supernovae. HgCdTe technology, with a cut-off tuned to 1.7 {micro}m, will permit passive cooling at 140 K while maintaining noise below zodiacal levels. By dithering to remove the effects of intrapixel variations and by careful attention to other instrumental effects, we expect to control relative photometric accuracy below a few hundredths of a magnitude. Because SNAP continuously revisits the same fields we will be able to achieve outstanding statistical precision on the photometry of reference stars in these fields, allowing precise monitoring of our detectors. The capabilities of the NIR system for broadening the science reach of SNAP are discussed.
Date: July 29, 2002
Creator: Tarle, G.; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E. et al.
Object Type: Article
System: The UNT Digital Library
The National Institute of Standards and Technology: An Overview (open access)

The National Institute of Standards and Technology: An Overview

None
Date: July 29, 2002
Creator: Schacht, Wendy H.
Object Type: Report
System: The UNT Digital Library
Overview of the SuperNova/Acceleration probe (SNAP) (open access)

Overview of the SuperNova/Acceleration probe (SNAP)

The SuperNova/Acceleration Probe (SNAP) is a space-based experiment to measure the expansion history of the Universe and study both its dark energy and the dark matter. The experiment is motivated by the startling discovery that the expansion of the Universe is accelerating. A 0.7 square-degree imager comprised of 36 large format fully-depleted n-type CCD's sharing a focal plane with 36 HgCdTe detectors forms the heart of SNAP, allowing discovery and lightcurve measurements simultaneously for many supernovae. The imager and a high-efficiency low-resolution integral field spectrograph are coupled to a 2-m three mirror anastigmat wide-field telescope, which will be placed in a high-earth orbit. The SNAP mission can obtain high-signal-to-noise calibrated light-curves and spectra for over 2000 Type Ia supernovae at redshifts between z = 0.1 and 1.7. The resulting data set can not only determine the amount of dark energy with high precision, but test the nature of the dark energy by examining its equation of state. In particular, dark energy due to a cosmological constant can be differentiated from alternatives such as ''quintessence'', by measuring the dark energy's equation of state to an accuracy of {+-} 0.05, and by studying its time dependence.
Date: July 29, 2002
Creator: galdering@lbl.gov
Object Type: Article
System: The UNT Digital Library
SNAP Telescope (open access)

SNAP Telescope

The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.
Date: July 29, 2002
Creator: Lampton, Michael L.; Akerlof, C. W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E. et al.
Object Type: Article
System: The UNT Digital Library