Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey (open access)

Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey

The authors present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged {approx} 23 square degrees in BVI filters from {approx} 16-24 mag to investigate variability in faint sources at moderate to high Galactic latitudes. Point source completeness is found to be >83% for a selected representative sample (V - 17.5-22.0 mag, B-V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multi-epoch (10-30) observations in V spanning minutes to years modeled by light curve simulations reveal amplitude sensitivities to {approx} 0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to time-scales of an order 1 day or less using the most sampled fields ({approx} 30 epochs). The fraction of point sources is found to be generally variable at 5-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low amplitude (< 0.05 mag) and blue (B-V < 0.35) sources, possibly representing a population of {gamma} Doradus stars. Overall, the dominant population of variable sources are bluer than B-V …
Date: March 7, 2005
Creator: Huber, M E; Everett, M E & Howell, S B
Object Type: Article
System: The UNT Digital Library
Antimicrobial Properties of Diamondlike Carbon-Silver-Platinum Nanocomposite Thin Films (open access)

Antimicrobial Properties of Diamondlike Carbon-Silver-Platinum Nanocomposite Thin Films

Silver and platinum were incorporated within diamondlike carbon (DLC) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films reveals that the metals self-assemble into particulate nanocomposite structures. Nanoindentation testing has shown that diamondlike carbon-silver films exhibit hardness and Young's modulus values of approximately 37 GPa and 333 GPa, respectively. DLC-silver-platinum films exhibited antimicrobial properties against Staphylococcus bacteria. Diamondlike carbon-biofunctional metal nanocomposite films have a variety of potential medical and antimicrobial applications.
Date: March 7, 2005
Creator: CHRISTOPHER, BERRY
Object Type: Article
System: The UNT Digital Library
Characterization of Microbial Communities in TCE-Contaminated Seep Zone Sediments (open access)

Characterization of Microbial Communities in TCE-Contaminated Seep Zone Sediments

Hundreds of sites across the United States contain trichloroethene (TCE) contamination, including the Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. Previous studies have indicated that microorganisms are capable of efficiently degrading TCE to nonhazardous end products. In this project, molecular and growth based methods were used for microbial characterization of a TCE impacted seepzone where TCE degradation is naturally occurring. The results from this work provide clear evidence that the SRB may play a significant role in TCE degradation along the Twin Lakes seepline.
Date: March 7, 2005
Creator: ROBIN, BRIGMON
Object Type: Article
System: The UNT Digital Library
Advanced Process Heater (open access)

Advanced Process Heater

The Roadmap for Process Heating Technology (March 16, 2001), identified the following priority R&D needs: Improved performance of high temperature materials; Improved methods for stabilizing low emission flames; Heating technologies that simultaneously reduce emissions, increase efficiency, and increase heat transfer. This Category I award entitled ''Proof of Concept of an Advanced Process Heater (APH) for Steel, Aluminum, and Petroleum Industries of the Future'' met the technical feasibility goals of: (1) Doubling the heat transfer rates (2) Improving thermal efficiencies by 20%, (3) Improving temperature uniformity by 100 degrees F and (4) simultaneously reducing NOx and CO2 emissions. The APH address EERE's mission priority of increasing efficiency/reducing fuel usage in energy intensive industries. One component of the APH, the SpyroCorTM, was commercialized by STORM Development's partner, Spinworks LLC. Over 2000 SpyrCorsTM were sold in 2004 resulting in 480 million BTU's of energy savings, 20% reduction in NOx and CO2 levels, and 9 jobs in N.W. Pennsylvania. A second component, the HeatCorTM, a low-cost high-temperature heat exchanger will be demonstrated by Spinworks in 2005 in preparation for commercial sales in 2006. The project occurred in the 21st Congressional District of Pennsylvania. Once fully commercialized, the APH energy savings potential is 339 trillion …
Date: March 7, 2005
Creator: Tom Briselden, Chris Parrish
Object Type: Report
System: The UNT Digital Library
Micro and Nano-structure Development and Multiscale Physics at Sliding Metal Interfaces (open access)

Micro and Nano-structure Development and Multiscale Physics at Sliding Metal Interfaces

This report describes research on the response of ductile materials to extreme loading conditions and high strain rates during impact combined with sliding friction. The work is a collaboration among two groups at Los Alamos National Laboratory and a tribology research group at The Ohio State University. The work involves experimental work and computer simulations at both laboratories and continuum mechanics analysis at OSU. Results to date demonstrate the importance of vorticity and mechanical mixing near the sliding interface in the development of tribomaterial.
Date: March 7, 2005
Creator: Rigney, David A.
Object Type: Report
System: The UNT Digital Library
RADIATION DOSE CALCULATION FOR FUEL HANDLING FACILITY CLOSURE CELL EQUIPMENT (open access)

RADIATION DOSE CALCULATION FOR FUEL HANDLING FACILITY CLOSURE CELL EQUIPMENT

This calculation evaluates the energy deposition rates in silicon, gamma and neutron flux spectra at various locations of interest throughout FHF closure cell. The physical configuration features a complex geometry, with particle flux attenuation of many orders of magnitude that cannot be modeled by computer codes that use deterministic methods. Therefore, in this calculation the Monte Carlo method was used to solve the photon and neutron transport. In contrast with the deterministic methods, Monte Carlo does not solve an explicit transport equation, but rather obtain answers by simulating individual particles, recording the aspects of interest of their average behavior, and estimates the statistical precision of the results.
Date: March 7, 2005
Creator: Musat, D.
Object Type: Report
System: The UNT Digital Library
The Lawrence Livermore National Laboratory DOE-STD-3013 Surveillance Program for the Storage of Plutonium Packages (open access)

The Lawrence Livermore National Laboratory DOE-STD-3013 Surveillance Program for the Storage of Plutonium Packages

This document presents a site-specific DOE-STD-3013 (3013) surveillance program for 3013 material stored at Lawrence Livermore National Laboratory (LLNL) in the B332 Plutonium Facility. The 3013 standard requires the development of a surveillance program to assure the long-term safety of plutonium storage in 3013 compliant containers. A complex-wide Integrated Surveillance Program in Support of Long-Term Storage of Plutonium-Bearing Materials (ISP)(LA-UR-00-3246, Revision 1, March 2001) has been developed to give guidance on an acceptable surveillance approach and to set up a mechanism to integrate surveillance activities and facilitate the sharing of lessons learned. This LLNL 3013 surveillance program has been developed following guidelines established for Storage Sites in the ISP and is sufficient for the storage in the LLNL Plutonium Facility. The LLNL 3013 surveillance program must be coupled with the DOE complex wide Materials Identification and Surveillance (MIS) program and the ISP led by Savannah River Site (SRS). These programs support the technical basis for continuing safe storage of plutonium packages and provide the technical basis for the limited scope of the site-specific LLNL 3013 surveillance program. The LLNL 3013 surveillance program calls for surveillance of 3013 packages to begin approximately three years after packaging of the first oxide. One …
Date: March 7, 2005
Creator: Riley, D
Object Type: Report
System: The UNT Digital Library
Delta/Alpha-Prime Phase Transformations in a Pu-Ga Alloy (open access)

Delta/Alpha-Prime Phase Transformations in a Pu-Ga Alloy

In pure plutonium, the monoclinic {alpha} phase is the equilibrium phase at ambient temperature and pressure. The addition of a few percent of gallium, however, allows the fcc {delta} phase to be retained metastablely at ambient conditions. When the metastable {delta} phase is cooled to subambient temperatures, it partially transforms to the monoclinic {alpha}' phase, which has gallium supersaturated in the lattice. The {alpha}' phase reverts to the {delta} phase when the sample is heated above the ambient temperature. The martensite burst (M{sub b}) and reversion start (R{sub s}) temperatures are functions of the composition, heating rate, and prior thermal history. For a Pu-2.0 at% Ga alloy, the transformation hysteresis is approximately 150 C, which is large compared with other solid-solid phase transformations. Both the forward and reverse transformations are martensitic and proceed via a burst mode. Here, we use differential scanning calorimetry (DSC) and resistometry to perform fundamental studies of the {alpha}'/{delta} transformations with the goal of understanding how aging may affect {delta} phase stability, particularly the M{sub b} temperature. Because materials properties of the {alpha}' and {delta} phases are considerably different (including a density increase of 25% and an accompanying resistivity increase of 46% upon transformation from {delta} …
Date: March 7, 2005
Creator: Blobaum, K M; Krenn, C R; Wall, M A & Schwartz, A J
Object Type: Article
System: The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOL. 71) (open access)

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOL. 71)

The high energy limit of Quantum Chromodynamics is one of the most fascinating areas in the theory of strong interactions. Over a decade ago the HERA experiment at DESY in Hamburg provided strong evidence for the rise of the proton structure function at small values of the Bjorken variable x. This behavior can be explained as an increase of the gluon density of the proton with energy or correspondingly with smaller values of x. This increase can be attributed on the other hand to the large probability of gluon splitting in QCD. The natural framework for describing the gluon dynamics at small x is the Balitskii-Fadin-Kuraev-Lipatov formalism developed some 30 years ago. It predicts that the gluon density grows very fast with increasing energy, as a power with a large intercept. This increase has to be tamed in order to satisfy the unitarily bound. Over two decades ago, Gribov, Levin and Ryskin proposed the mechanism called the parton saturation, which slows down the fast rise of the gluon density. This formalism accounts for an additional gluon recombination apart from the pure gluon splitting. It leads to the very interesting non-linear modification of the evolution equations for the gluon distributions. Since …
Date: March 7, 2005
Creator: KHARZEEV, D.; STASTO, A.; TUCHIN, K. & VOGELSANG, W.
Object Type: Report
System: The UNT Digital Library
Sensor Acquisition for Water Utilities: A Survey and Technology List (open access)

Sensor Acquisition for Water Utilities: A Survey and Technology List

The early detection of the deliberate biological and chemical contamination of water distribution systems is a necessary capability for securing the nation's water supply. Current and emerging early-detection technology capabilities and shortcomings need to be identified and assessed to provide government agencies and water utilities with an improved methodology for assessing the value of installing these technologies. The Department of Homeland Security (DHS) has tasked a multi-laboratory team to evaluate current and future needs to protect the nation's water distribution infrastructure by supporting an objective evaluation of current and new technologies. The primary deliverables from this Operational Technology Demonstration (OTD) are the following: (1) establishment of an advisory board for review and approval of testing protocols, technology acquisition processes and recommendations for technology test and evaluation in laboratory and field settings; (2) development of a technology acquisition process; (3) creation of laboratory and field testing and evaluation capability; and (4) testing of candidate technologies for insertion into a water early warning system. The initial phase of this study involves the development of two separate but complementary strategies to be reviewed by the advisory board: (1) a technology acquisition strategy, and (2) a technology evaluation strategy. Lawrence Livermore National Laboratory and …
Date: March 7, 2005
Creator: Alai, M; Glascoe, L; Love, A; Johnson, M & Einfeld, W
Object Type: Report
System: The UNT Digital Library
Crystal stability and equation of state for americium: theory (open access)

Crystal stability and equation of state for americium: theory

None
Date: March 7, 2005
Creator: Soderlind, P & Landa, A
Object Type: Article
System: The UNT Digital Library
Characterization of a picosecond laser generated 4.5 keV Ti K-alpha source for pulsed radiography (open access)

Characterization of a picosecond laser generated 4.5 keV Ti K-alpha source for pulsed radiography

None
Date: March 7, 2005
Creator: King, J A; Key, M H; Chen, C D; Freeman, R R; Phillips, T; Akli, K U et al.
Object Type: Article
System: The UNT Digital Library
Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 2. LLNL Annual Site-specific Data, 1953 - 2003 (open access)

Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 2. LLNL Annual Site-specific Data, 1953 - 2003

It is planned to use the tritium dose model, DCART (Doses from Chronic Atmospheric Releases of Tritium), to reconstruct dose to the hypothetical maximally exposed individual from annual routine releases of tritiated water (HTO) and tritiated hydrogen gas (HT) from all Lawrence Livermore National Laboratory (LLNL) facilities and from the Sandia National (SNL) Laboratory's Tritium Research Laboratory over the last fifty years. DCART has been described in Part 1 of ''Historical Doses From Tritiated Water And Tritiated Hydrogen Gas Released To The Atmosphere from Lawrence Livermore National Laboratory (LLNL)'' (UCRL-TR-205083). This report (Part 2) summarizes information about annual routine releases of tritium from LLNL (and SNL) since 1953. Historical records were used to derive facility-specific annual data (e.g., source terms, dilution factors, ambient air concentrations, meteorological data, including absolute humidity and rainfall, etc.) and their associated uncertainty distributions. These data will be used as input to DCART to calculate annual dose for each year of LLNL operations. Sources of information are carefully referenced, and assumptions are documented. Confidence on all data post-1974 is quite high. Prior to that, further adjustment to the estimated uncertainty may have to be made if more information comes to light.
Date: March 7, 2005
Creator: Peterson, S R
Object Type: Report
System: The UNT Digital Library
Canister Handling Facility - Ventilation Confinement Zoning Analysis (open access)

Canister Handling Facility - Ventilation Confinement Zoning Analysis

None
Date: March 7, 2005
Creator: Draper, K. D.
Object Type: Report
System: The UNT Digital Library