Homeland Security: First Phase of Visitor and Immigration Status Program Operating, but Improvements Needed (open access)

Homeland Security: First Phase of Visitor and Immigration Status Program Operating, but Improvements Needed

A letter report issued by the General Accounting Office with an abstract that begins "The Department of Homeland Security (DHS) has established a program--the United States Visitor and Immigrant Status Indicator Technology (US-VISIT)--to collect, maintain, and share information, including biometric identifiers, on selected foreign nationals who travel to the United States. By congressional mandate, DHS is to develop and submit for approval an expenditure plan for US-VISIT that satisfies certain conditions, including being reviewed by GAO. Among other things, GAO was asked to determine whether the plan satisfied these conditions, and to provide observations on the plan and DHS's program management."
Date: May 11, 2004
Creator: United States. General Accounting Office.
System: The UNT Digital Library
Geochemistry of Hydrofluoric Acid in Kaolinitic Soils (open access)

Geochemistry of Hydrofluoric Acid in Kaolinitic Soils

This document explores the geochemical reactions likely to occur when hydrofluoric acid is spilled on Savannah River Site (SRS) soil. In particular, we evaluate the potential of environmental damage from a one-time release of concentrated hydrofluoric acid into a trench. According to interviews with personnel involved, sometime between 1955 and 1960 drums of 50-60 per cent hydrofluoric acid were disposed in a trench in the Central Shops area. The method of disposal suggests that most of the acid would have been released at the time of burial. No evidence of drum disposal or acidic pH values was found. Therefore, the Soil and Groundwater Closure Projects group requested that we evaluate potential risk by examining the major geochemical interactions expected between hydrofluoric acid and soil. The geochemical calculations in this report were done with The Geochemist's Workbench (Registered). This program uses an extended Debye-Huckel method for calculating activity coefficients. The conclusions of this report are accurate, but some of the intermediate steps may have higher uncertainty. Hydrofluoric acid disposed in a trench in the area would have reacted with soil kaolinite to neutralize the pH to a value of about 4.2. Based on conservative assumptions, this would have occurred within the …
Date: May 11, 2004
Creator: DENHAM, MILES
System: The UNT Digital Library
Scientific Report (2002-2004) (open access)

Scientific Report (2002-2004)

OAK-B135 An overview of our work as well as two recent publications are contained in this scientific report. The work reported here revolves around the discovery of new coherent nonlinear kinetic waves in laser produced plasmas, we call KEEN waves (kinetic, electrostatic electron nonlinear waves), and optical mixing experiments on the Imega laser system at LLE with blue-green light for the exploration of ways to suppress parametric instabilities in long scale length, long pulsewidth laser-plasmas such as those which will be found on NIF or LMJ.
Date: May 11, 2004
Creator: Afeyan, Bedros
System: The UNT Digital Library
A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments (open access)

A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.
Date: May 11, 2004
Creator: Hua, F.; Mon, K.; Pasupathi, P. & Gordon, G.
System: The UNT Digital Library
NEW CATHODE MATERIALS FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS (open access)

NEW CATHODE MATERIALS FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS

Operation of SOFCs at intermediate temperatures (500-800 C) requires new combinations of electrolyte and electrode materials that will provide both rapid ion transport across the electrolyte and electrode-electrolyte interfaces and efficient electrocatalysis of the oxygen reduction and fuel oxidation reactions. This project concentrates on materials and issues associated with cathode performance that are known to become limiting factors as the operating temperature is reduced. The specific objectives of the proposed research are to develop cathode materials that meet the electrode performance targets of 1.0 W/cm{sup 2} at 0.7 V in combination with YSZ at 700 C and with GDC, LSGM or bismuth oxide based electrolytes at 600 C. The performance targets imply an area specific resistance of {approx}0.5 {Omega}cm{sup 2} for the total cell. The research strategy is to investigate both established classes of materials and new candidates as cathodes, to determine fundamental performance parameters such as bulk diffusion, surface reactivity and interfacial transfer, and to couple these parameters to performance in single cell tests. The initial choices for study are perovskite oxides based on Sr substituted LaFeO{sub 3}, where significant data in single cell tests exists at PNNL for cathodes on both YSZ and CSO/YSZ, and of Ln{sub 2}NiO{sub …
Date: May 11, 2004
Creator: Jacobson, Allan J.
System: The UNT Digital Library
The Magnesium Branch of the Tetrapyrrole Biosynthetic Pathway (open access)

The Magnesium Branch of the Tetrapyrrole Biosynthetic Pathway

It should be noted that the focus of the research changed somewhat during the course of the current award. The initial focus is indicated by the title of the current grant, ''The Magnesium Branch of the Chlorophyll Biosynthetic Pathway''. During the current grant period, Dr. Robert Willows, a postdoctoral associate, joined the faculty of McQuarie University in Australia. When he left my lab, we decided that he should independently pursue research on structure/function relationships in Mg chelatase and that our laboratories would collaborate on regulatory studies of this enzyme. Also, during the current award period, I began collaborating with Dr. Ariane Atteia and Mr. Robert van Lis, who were at the time located at the Autonomous University of Mexico. Dr. Atteia has since joined my laboratory and Mr. van Lis will also do so when he obtains his Ph.D. in the near future. These individuals bring to the laboratory their interests and expertise in the respiratory components of Chlamydomonas and their desire to become experts in tetrapyrrole metabolism. Recently, in a collaboration with Dr. David Bollivar, a former postdoctoral associate who is now at Illinois Wesleyan University, and Dr. Caroline Walker, who was at Clemson University but has since left …
Date: May 11, 2004
Creator: Beale, S. I.
System: The UNT Digital Library
Initial Operation of the NSTX Fast Tangential Soft X-Ray Camera (open access)

Initial Operation of the NSTX Fast Tangential Soft X-Ray Camera

Fast, two-dimensional, soft x-ray imaging is a powerful technique for the study of MHD instabilities in tokamak plasmas. We have constructed an ultra-fast frame rate soft x-ray camera for the National Spherical Torus Experiment. It is based on a recently developed 64 x 64 pixel CCD camera capable of capturing 300 frames at up to 500,000 frames per second. A pinhole aperture images the plasma soft x-ray emission (0.2-10 keV) onto a P47 scintillator deposited on a fiber-optic faceplate; the scintillator visible light output is detected and amplified by a demagnifying image intensifier and lens-coupled to the CCD chip. A selection of beryllium foils provides discrimination of low-energy emission. The system is installed on NSTX with a wide-angle tangential view of the plasma. Initial plasma data and an assessment of the system performance are presented.
Date: May 11, 2004
Creator: Stratton, B. C.; Feder, R.; Von Goeler, S.; Renda, G. F.; Lowrance, J. L. & Mastrocola, V. J.
System: The UNT Digital Library
Effects of Radiative Recombination and Photon Recycling on Minority Carrier Lifetime in Epitaxial GaINAsSb Lattice-matched to GaSb (open access)

Effects of Radiative Recombination and Photon Recycling on Minority Carrier Lifetime in Epitaxial GaINAsSb Lattice-matched to GaSb

None
Date: May 11, 2004
Creator: Anikeev, S.; Donetsky, D.; Belenky, G.; Luryl, S.; Wang, C. A.; Shiau, D. A. et al.
System: The UNT Digital Library
pH and resistivity of the BCP mix diluted in UPW (open access)

pH and resistivity of the BCP mix diluted in UPW

Etching plays an important role in the production of superconducting cavities (SRF). As other laboratories engaged in RF superconductivity R and D did, FNAL is also developing a facility for the chemical etching of niobium (Nb) cavities. Two techniques are common accepted for cavity etching: (1) chemical etching--buffered chemical polishing (BCP); and (2) Electropolishing (EP). Among them, at FNAL it was decided to pursue chemical etching, which is considered a reliable technique tested by several labs for many years. In the past, numerous mixtures of acids have been tested leading to the actual buffered chemical polishing mix (BCP) characterized by the following composition by volume: 1 of HF 49 %wt; 1 of HNO{sub 3} 69.5 %wt; 2 of H{sub 3}PO{sub 4} 85 %wt. Because of the dangerous nature of the chemicals involved, safety considerations require the development of a proper process and a reliable control algorithm. For the post-processing rinsing of the cavities, one needs to know the expected pH of the water used to rinse the cavity. On the other hand, for early detection of leaks in the hydraulic system, which is done by measuring the conductivity of the rinsing water used in the process, one needs to understand …
Date: May 11, 2004
Creator: al., Cristian Boffo et
System: The UNT Digital Library
Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices (open access)

Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices

Back surface reflectors have the potential to improve thermophotovoltaic (TPV) device performance though the recirculation of infrared photons. The ''hybrid'' back-surface reflector (BSR) TPV cell approach allows one to construct BSRs for TPV devices using conventional, high efficiency, GaInAsSb-based TPV material. The design, fabrication, and measurements of hybrid BSR-TPV cells are described. The BSR was shown to provide a 4 mV improvement in open-circuit voltage under a constant shortcircuit current, which is comparable to the 5 mV improvement theoretically predicted. Larger improvements in open-circuit voltage are expected in the future with materials improvements.
Date: May 11, 2004
Creator: Huang, R. K.; Wang, C. A.; Connors, M. K.; Turner, G. W. & Dashiell, M.
System: The UNT Digital Library
U.S.-Latin American Trade: Recent Trends (open access)

U.S.-Latin American Trade: Recent Trends

None
Date: May 11, 2004
Creator: unknown
System: The UNT Digital Library
Development of Laser-Ion Beam Photodissociation Methods (open access)

Development of Laser-Ion Beam Photodissociation Methods

OAK-B135 Our BES funded research is aimed at determining structure(s) of model gas-phase ions and understanding how structure influences unimolecular reactivity. The model gas-phase ions include positional isomers of di- and tri-amino acids synthesized in my laboratory, i.e., RGG, GRG, and GGR, to peptides derived from proteolytic digestion of biologically relevant proteins. We are especially interested in understanding the role of intramolecular interactions in the stabilizing ion structure and how changing the charge-site affects structure. The location of charge of gas-phase ions can be manipulated by changing the position of the charge carrying amino acid (basic vs. acidic side chains) and by derivatization of the N- and/or C-terminus. For example, the proton of [M + H]+ ions is mobile and migrates over the entire molecule, whereas Li+, Na+, and to some extent K+ prefers to bind to the C-terminal or side-chain carboxylic acid groups, and Cu+ binds exclusively to the N-terminus and/or basic side-chains such as H, K, and R. The studies are carried out using tandem TOF mass spectrometry, viz. 193 nm (6.43 eV) photodissociation, low (Elab = 10-100 eV) and high kinetic energy (Elab = 1-10 keV) collision-induced dissociation (CID) and surface-induced dissociation (SID)(Elab = 20-70 eV). These …
Date: May 11, 2004
Creator: Russell, David H.
System: The UNT Digital Library
Towards advanced electron beam brightness enhancement and conditioning. (open access)

Towards advanced electron beam brightness enhancement and conditioning.

The importance of developing higher-brightness electron beam sources for future accelerators was emphasized during the DOE-BESAC Subcommittee Meeting on the BES 20-Year Facility Roadmap held in Washington on February 20, 2003 [1]. The Subcommittee made a strong recommendation for an R&D program for high-brightness gun development. Spurred by this recommendation, a workshop was organized at Argonne National Laboratory on September 22-26, 2003 under the auspices of the ANL Theory Institute. About thirty experts in electron gun physics came for a week of intense discussion, reviewing the current state of the art and exploring ways to improve the performance of laser-driven rf photocathode guns, in particular whether an order of magnitude improvement of the beam brightness is feasible. Presentations given during the workshop can be found on the Internet at http://www.aps.anl.gov/asd/theory/presentations-online.html. This white paper grew out of the Argonne workshop. Its aim is to provide a summary of the ANL workshop and to propose an R&D program to develop advanced electron sources with an order of magnitude higher brightness than currently feasible. The budget for the R&D program for this purpose, discussed in Section 4, is estimated to be about $10M per year for ten years with an additional onetime start-up …
Date: May 11, 2004
Creator: Kim, K. J.; Carlsten, B.; Dowell, D.; Flottmann, K.; Jensen, K.; Petillo, J. et al.
System: The UNT Digital Library