Climate Change: Agencies Should Develop Guidance for Addressing the Effects on Federal Land and Water Resources (open access)

Climate Change: Agencies Should Develop Guidance for Addressing the Effects on Federal Land and Water Resources

A letter report issued by the Government Accountability Office with an abstract that begins "Climate change has implications for the vast land and water resources managed by the Bureau of Land Management (BLM), Forest Service (FS), U.S. Fish and Wildlife Service (FWS), National Oceanic and Atmospheric Administration (NOAA), and National Park Service (NPS). These resources generally occur within four ecosystem types: coasts and oceans, forests, fresh waters, and grasslands and shrublands. GAO obtained experts' views on (1) the effects of climate change on federal resources and (2) the challenges managers face in addressing climate change effects on these resources. GAO held a workshop with the National Academies in which 54 scientists, economists, and federal resource managers participated, and conducted 4 case studies."
Date: August 7, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
X-ray spectroscopic study of the charge state and local orderingof room-temperature ferromagnetic Mn oped ZnO (open access)

X-ray spectroscopic study of the charge state and local orderingof room-temperature ferromagnetic Mn oped ZnO

The charge state and local ordering of Mn doped into a pulsed laser deposited single-phase thin film of ZnO are investigated by using X-ray absorption spectroscopy at the O K-, Mn K- and L-edges, and X-ray emission spectroscopy at the O K- and Mn L-edge. This film is found to be ferromagnetic at room temperature. EXAFS measurement shows that Mn{sup 2+} replaces Zn site in tetrahedral symmetry, and there is no evidence for either metallic Mn or MnO in the film. Upon Mn doping, the top of O 2p valence band extends into the bandgap indicating additional charge carries being created.
Date: August 7, 2007
Creator: Guo, J.-H.; Gupta, Amita; Sharma, Parmanand; Rao, K.V.; Marcus,M.A.; Dong, C.L. et al.
Object Type: Article
System: The UNT Digital Library
SERDP ER-1376 Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes:Final Report for 2004 - 2006 (open access)

SERDP ER-1376 Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes:Final Report for 2004 - 2006

This project was initiated by SERDP to quantify processes and determine the effectiveness of abiotic/biotic mineralization of energetics (RDX, HMX, TNT) in aquifer sediments by combinations of biostimulation (carbon, trace nutrient additions) and chemical reduction of sediment to create a reducing environment. Initially it was hypothesized that a balance of chemical reduction of sediment and biostimulation would increase the RDX, HMX, and TNT mineralization rate significantly (by a combination of abiotic and biotic processes) so that this abiotic/biotic treatment may be a more efficient for remediation than biotic treatment alone in some cases. Because both abiotic and biotic processes are involved in energetic mineralization in sediments, it was further hypothesized that consideration for both abiotic reduction and microbial growth was need to optimize the sediment system for the most rapid mineralization rate. Results show that there are separate optimal abiotic/biostimulation aquifer sediment treatments for RDX/HMX and for TNT. Optimal sediment treatment for RDX and HMX (which have chemical similarities and similar degradation pathways) is mainly chemical reduction of sediment, which increased the RDX/HMX mineralization rate 100 to150 times (relative to untreated sediment), with additional carbon or trace nutrient addition, which increased the RDX/HMX mineralization rate an additional 3 to 4 …
Date: August 7, 2007
Creator: Szecsody, James E.; Comfort, Steve; Fredrickson, Herbert L.; Boparai, Hardiljeet K.; Devary, Brooks J.; Thompson, Karen T. et al.
Object Type: Report
System: The UNT Digital Library
Proton hexality from an anomalous flavor U(1) and neutrino masses--Linking to the string scale (open access)

Proton hexality from an anomalous flavor U(1) and neutrino masses--Linking to the string scale

We devise minimalistic gauged U(1)_X Froggatt-Nielsen models which at low-energy give rise to the recently suggested discrete gauge Z_6 symmetry, proton hexality, thus stabilizing the proton. Assuming three generations of right-handed neutrinos, with the proper choice of X-charges, we obtain viable neutrino masses. Furthermore, we find scenarios such that no X-charged hidden sector superfields are needed, which from a bottom-up perspective allows the calculation of g_string, g_X and G_SM's Kac-Moody levels. The only mass scale apart from M_grav is m_soft.
Date: August 7, 2007
Creator: Murayama, Hitoshi; Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi & Thormeiere, Marc
Object Type: Article
System: The UNT Digital Library
ANALYTICAL METHOD FOR MEASURING TOTAL PROTIUM AND TOTAL DEUTERIUM IN A GAS MIXTURE CONTAINING H2, D2,AND HD VIA GAS CHAROMATOGRAPHY (open access)

ANALYTICAL METHOD FOR MEASURING TOTAL PROTIUM AND TOTAL DEUTERIUM IN A GAS MIXTURE CONTAINING H2, D2,AND HD VIA GAS CHAROMATOGRAPHY

The most common analytical method of identifying and quantifying non-radioactive isotopic species of hydrogen is mass spectrometry. A low mass, high resolution mass spectrometer with adequate sensitivity and stability to identify and quantify hydrogen isotopes in the low ppm range is an expensive, complex instrument. A new analytical technique has been developed that measures both total protium (H) and total deuterium (D) in a gas mixture containing H{sub 2}, D{sub 2}, and HD using an inexpensive micro gas chromatograph (GC) with two molecular sieve columns. One column uses D{sub 2} as the carrier gas and the other uses H{sub 2} as the carrier gas. Laboratory tests have shown that when used in this configuration the GC can measure both total protium and total deuterium each with a detection and quantification limit of less than 20 ppm.
Date: August 7, 2007
Creator: Sessions, H
Object Type: Article
System: The UNT Digital Library
NMR structure of the N-terminal domain of the replication initiator protein DnaA (open access)

NMR structure of the N-terminal domain of the replication initiator protein DnaA

DnaA is an essential component in the initiation of bacterial chromosomal replication. DnaA binds to a series of 9 base pair repeats leading to oligomerization, recruitment of the DnaBC helicase, and the assembly of the replication fork machinery. The structure of the N-terminal domain (residues 1-100) of DnaA from Mycoplasma genitalium was determined by NMR spectroscopy. The backbone r.m.s.d. for the first 86 residues was 0.6 +/- 0.2 Angstrom based on 742 NOE, 50 hydrogen bond, 46 backbone angle, and 88 residual dipolar coupling restraints. Ultracentrifugation studies revealed that the domain is monomeric in solution. Features on the protein surface include a hydrophobic cleft flanked by several negative residues on one side, and positive residues on the other. A negatively charged ridge is present on the opposite face of the protein. These surfaces may be important sites of interaction with other proteins involved in the replication process. Together, the structure and NMR assignments should facilitate the design of new experiments to probe the protein-protein interactions essential for the initiation of DNA replication.
Date: August 7, 2007
Creator: Wemmer, David E.; Lowery, Thomas J.; Pelton, Jeffrey G.; Chandonia, John-Marc; Kim, Rosalind; Yokota, Hisao et al.
Object Type: Article
System: The UNT Digital Library
Impact of Carbon Structure and Morphology on the ElectrochemicalPerformance of LiFePO4/C Composites (open access)

Impact of Carbon Structure and Morphology on the ElectrochemicalPerformance of LiFePO4/C Composites

The electrochemical performance of LiFePO{sub 4}/C composites in lithium cells is closely correlated to pressed pellet conductivities measured by AC impedance methods. These composite conductivities are a strong function not only of the amount of carbon, but of its structure and distribution. Ideally, the amount of carbon in composites should be minimal (less than about 2 wt. %) so as not to decrease the energy density unduly. This is particularly important for plug-in hybrid electric vehicle applications (PHEVs) where both high power and moderate energy density are required. Optimization of the carbon structure, particularly the sp{sup 2}/sp{sup 3} and D/G (disordered/graphene) ratios, improves the electronic conductivity while minimizing the carbon amount. Manipulation of the carbon structure can be achieved via the use of synthetic additives including iron-containing graphitization catalysts. Additionally, combustion synthesis techniques allow co-synthesis of LiFePO{sub 4} and carbon fibers or nanotubes, which can act as 'nanowires' for the conduction of current during cell operation.
Date: August 7, 2007
Creator: Doeff, Marca M.; Wilcox, James D.; Yu, Rong; Aumentado, Albert; Marcinek, Marek & Kostecki, Robert
Object Type: Article
System: The UNT Digital Library
Temporal Representation in Semantic Graphs (open access)

Temporal Representation in Semantic Graphs

A wide range of knowledge discovery and analysis applications, ranging from business to biological, make use of semantic graphs when modeling relationships and concepts. Most of the semantic graphs used in these applications are assumed to be static pieces of information, meaning temporal evolution of concepts and relationships are not taken into account. Guided by the need for more advanced semantic graph queries involving temporal concepts, this paper surveys the existing work involving temporal representations in semantic graphs.
Date: August 7, 2007
Creator: Levandoski, J J & Abdulla, G M
Object Type: Report
System: The UNT Digital Library
Preliminary Report: Results of Computed Tracer Concentrations over Eastern China, South Korea, and Japan for 01 March to 30 May 2007 Daily Simulated Releases from Taiyuan, China (open access)

Preliminary Report: Results of Computed Tracer Concentrations over Eastern China, South Korea, and Japan for 01 March to 30 May 2007 Daily Simulated Releases from Taiyuan, China

In order to prepare for a proposed long range tracer experiment in China for the spring of 2008 time period, NARAC computed hypothetical PMCH concentrations over Eastern China, South Korea and Japan for simulated releases from Taiyuan, China. Normalized 1 kg of PMCH source strength releases were made twice a day, with wind input from global forecast weather model. We used 6-hour analysis fields valid at the start of each model run, resulting in four wind fields per day. The selected domain encompassed the region of interest over eastern Asia and the Western Pacific. Screening runs were made for each day at 0000 and 1200 UTC from 01 April, 2007 through 29 May, 2007 for a total of 90 days and 180 cases. 24-hour average air concentrations were evaluated at 22 sample cities in the three regions of interest for each case. 15 sample cities were selected to help quantify modeling results for experiment objectives. Any case that resulted in model predicted air concentrations exceeding 2.0E-02 fL/L at a sample city in all three regions was then selected for a detailed model run with source times six hours before and after evaluated in addition to the case time. The detailed …
Date: August 7, 2007
Creator: Vogt, P
Object Type: Report
System: The UNT Digital Library
Digital Television: An Overview (open access)

Digital Television: An Overview

This report details the information related to Digital Television service, policy issues, and activities in the 108th, activities, and issues in 109th Congress, and, issues in the 110th congress
Date: August 7, 2007
Creator: Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
Family Caregiving to the Older Population: Background, Federal Programs, and Issues for Congress (open access)

Family Caregiving to the Older Population: Background, Federal Programs, and Issues for Congress

This report provides an overview of the background, federal programs, and issues for Congress on family caregiving to the older population.
Date: August 7, 2007
Creator: Colello, Kirsten J.
Object Type: Report
System: The UNT Digital Library
Medicare: FY2008 Budget Issues (open access)

Medicare: FY2008 Budget Issues

None
Date: August 7, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS (open access)

LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS

In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}#14; in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.
Date: August 7, 2007
Creator: Goldschmidt, Yadin Y. & Liu, Jin-Tao
Object Type: Text
System: The UNT Digital Library
Ozone Air Quality Standards: EPA's 2007 Proposed Changes (open access)

Ozone Air Quality Standards: EPA's 2007 Proposed Changes

This report provides background on the National Ambient Air Quality Standard (NAAQS), the process used to establish them, the existing ozone standard, and EPA's proposal, as well as information regarding the potential effects of any revision to the standard.
Date: August 7, 2007
Creator: McCarthy, James E.
Object Type: Report
System: The UNT Digital Library
Energy Tax Policy: History and Current Issues (open access)

Energy Tax Policy: History and Current Issues

This report provides historical context regarding energy tax policy and discusses what may lie ahead.
Date: August 7, 2007
Creator: Lazzari, Salvatore
Object Type: Report
System: The UNT Digital Library
Scalability of the natural convection shutdown heat removal test facility (NSTF) data to VHTR/NGNP RCCS designs. (open access)

Scalability of the natural convection shutdown heat removal test facility (NSTF) data to VHTR/NGNP RCCS designs.

Passive safety in the Very High Temperature Reactor (VHTR) is strongly dependent on the thermal performance of the Reactor Cavity Cooling System (RCCS). Scaled experiments performed in the Natural Shutdown Test Facility (NSTF) are to provide data for assessing and/or improving computer code models for RCCS phenomena. Design studies and safety analyses that are to support licensing of the VHTR will rely on these models to achieve a high degree of certainty in predicted design heat removal rate. To guide in the selection and development of an appropriate set of experiments a scaling analysis has been performed for the air-cooled RCCS option. The goals were to (1) determine the phenomena that dominate the behavior of the RCCS, (2) determine the general conditions that must be met so that these phenomena and their relative importance are preserved in the experiments, (3) identify constraints specific to the NSTF that potentially might prevent exact similitude, and (4) then to indicate how the experiments can be scaled to prevent distortions in the phenomena of interest. The phenomena identified as important to RCCS operation were also the subject of a recent PIRT study. That work and the present work collectively indicate that the main phenomena …
Date: August 7, 2007
Creator: Vilim, R .B. & Feldman, E. E.
Object Type: Report
System: The UNT Digital Library
Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada and Inyo County, California. (open access)

Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada and Inyo County, California.

Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However, reaction models require knowledge of 87Sr/86Sr data for carbonate rock in the Nevada Test Site vicinity, which is scarce. To fill this data gap, samples of core or cuttings were selected from 22 boreholes at depth intervals from which water samples had been obtained previously around the Nevada Test Site at Yucca Flat, Frenchman Flat, Rainier Mesa, and Mercury Valley. Dilute acid leachates of these samples were analyzed for a suite of major- and trace-element concentrations (MgO, CaO, SiO2, Al2O3, MnO, Rb, Sr, Th, and U) as well as for 87Sr/86Sr. Also presented are unpublished analyses of 114 Paleozoic carbonate samples from outcrops, road cuts, or underground sites in the Funeral Mountains, Bare Mountain, Striped Hills, Specter Range, Spring Mountains, and ranges east of the Nevada Test Site measured in the early 1990's. These data originally were collected to evaluate the potential for economic mineral deposition …
Date: August 7, 2007
Creator: Paces, James B.; Peterman, Zell E.; Futa, Kiyoto; Oliver, Thomas A. & Marshall., and Brian D.
Object Type: Report
System: The UNT Digital Library
NEST-GENERATION TCAP HYDROGEN ISOTOPE SEPARATION PROCESS (open access)

NEST-GENERATION TCAP HYDROGEN ISOTOPE SEPARATION PROCESS

A thermal cycling absorption process (TCAP) for hydrogen isotope separation has been in operation at Savannah River Site since 1994. The process uses a hot/cold nitrogen system to cycle the temperature of the separation column. The hot/cold nitrogen system requires the use of large compressors, heat exchanges, valves and piping that is bulky and maintenance intensive. A new compact thermal cycling (CTC) design has recently been developed. This new design uses liquid nitrogen tubes and electric heaters to heat and cool the column directly so that the bulky hot/cold nitrogen system can be eliminated. This CTC design is simple and is easy to implement, and will be the next generation TCAP system at SRS. A twelve-meter column has been fabricated and installed in the laboratory to demonstrate its performance. The design of the system and its test results to date is discussed.
Date: August 7, 2007
Creator: Heung, L; Henry Sessions, H; Anita Poore, A; William Jacobs, W & Christopher Williams, C
Object Type: Article
System: The UNT Digital Library
REMOTE ANALYSIS OF HIGH-TRITIUM-CONTENT WATER (open access)

REMOTE ANALYSIS OF HIGH-TRITIUM-CONTENT WATER

Systems to safely analyze for tritium in moisture collected from glovebox atmospheres are being developed for use at Savannah River Site (SRS) tritium facilities. Analysis results will guide whether the material contains sufficient tritium for economical recovery, or whether it should be stabilized for disposal as waste. In order to minimize potential radiation exposures that could occur in handling and diluting high-tritium-content water, SRS sought alternatives to the process laboratory's routine analysis by liquid-scintillation counting. The newer systems determine tritium concentrations by measuring bremsstrahlung radiation induced by low-energy beta interactions. One of the systems determines tritium activity in liquid streams, the other determines tritium activity in water vapor. Topics discussed include counting results obtained by modeling and laboratory testing and corrections that are made for low-energy photon attenuation.
Date: August 7, 2007
Creator: Diprete, D; Raymond Sigg, R; Leah Arrigo, L & Donald Pak, D
Object Type: Article
System: The UNT Digital Library
Dispute Settlement in the World Trade Organization: An Overview (open access)

Dispute Settlement in the World Trade Organization: An Overview

None
Date: August 7, 2007
Creator: Grimmett, Jeanne J.
Object Type: Report
System: The UNT Digital Library
Intelligence Issues for Congress (open access)

Intelligence Issues for Congress

None
Date: August 7, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Exon-Florio Foreign Investment Provision: Comparison of H.R. 556 and S. 1610 (open access)

Exon-Florio Foreign Investment Provision: Comparison of H.R. 556 and S. 1610

None
Date: August 7, 2007
Creator: Jackson, James K.
Object Type: Report
System: The UNT Digital Library
Communications Act Revisions: Selected Issues for Consideration (open access)

Communications Act Revisions: Selected Issues for Consideration

This report provides an overview of selected topics which the 110th Congress has begun, or is likely, to address in its examination of telecommunications issues. This report addresses major issues, rather than addressing specific legislative activity.
Date: August 7, 2007
Creator: Gilroy, Angele A.
Object Type: Report
System: The UNT Digital Library
Freedom of Information Act (FOIA) Amendments: 110th Congress (open access)

Freedom of Information Act (FOIA) Amendments: 110th Congress

This report provides information about the Freedom of Information Act (FOIA) Amendments of 110th Congress where that statute specified nine categories of information that may be permissibly exempted from the rule of disclosure.
Date: August 7, 2007
Creator: Relyea, Harold C.
Object Type: Report
System: The UNT Digital Library