U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers (open access)

U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers

Both chemical weathering rates and fluid flow are difficultto measure in natural systems. However, these parameters are critical forunderstanding the hydrochemical evolution of aquifers, predicting thefate and transport of contaminants, and for water resources/water qualityconsiderations. 87Sr/86Sr and (234U/238U) activity ratios are sensitiveindicators of water-rock interaction, and thus provide a means ofquantifying both flow and reactivity. The 87Sr/86Sr values in groundwaters are controlled by the ratio of the dissolution rate to the flowrate. Similarly, the (234U/238U) ratio of natural ground waters is abalance between the flow rate and the dissolution of solids, andalpha-recoil loss of 234U from the solids. By coupling these two isotopesystems it is possible to constrain both the long-term (ca. 100's to1000's of years) flow rate and bulk dissolution rate along the flow path.Previous estimates of the ratio of the dissolution rate to theinfiltration flux from Sr isotopes (87Sr/86Sr) are combined with a modelfor (234U/238U) to constrain the infiltration flux and dissolution ratefor a 70-m deep vadose zone core from Hanford, Washington. The coupledmodel for both (234U/238U) ratios and the 87Sr/86Sr data suggests aninfiltration flux of 5+-2 mm/yr, and bulk silicate dissolution ratesbetween 10-15.7 and 10-16.5 mol/m2/s. The process of alpha-recoilenrichment, while primarily responsible for the observed variation …
Date: December 27, 2005
Creator: Maher, Kate; DePaolo, Donald J. & Christensen, John N.
Object Type: Article
System: The UNT Digital Library
Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu (open access)

Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu

A search for nuclear resonance fluorescence excitations in {sup 235}U and {sup 239}Pu within the energy range of 1.0- to 2.5-MeV was performed using a 4-MeV continuous bremsstrahlung source at the High Voltage Research Laboratory at the Massachusetts Institute of Technology. Measurements utilizing high purity Ge detectors at backward angles identified 9 photopeaks in {sup 235}U and 12 photopeaks in {sup 239}Pu in this energy range. These resonances provide unique signatures that allow the materials to be non-intrusively detected in a variety of environments including fuel cells, waste drums, vehicles and containers. The presence and properties of these states may prove useful in understanding the mechanisms for mixing low-lying collective dipole excitations with other states at low excitations in heavy nuclei.
Date: December 27, 2006
Creator: Bertozzi, W.; Caggiano, J. A.; Hensley, W. K.; Johnson, M. S.; Korbly, S. E.; Ledoux, R. J. et al.
Object Type: Article
System: The UNT Digital Library
METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE (open access)

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 7 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs. The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable …
Date: December 27, 2007
Creator: Fowler, K. D.
Object Type: Report
System: The UNT Digital Library
Annual Hanford Seismic Report for Fiscal Year 2007 (open access)

Annual Hanford Seismic Report for Fiscal Year 2007

This annual report documents the locations, magnitudes, and geologic interpretations of earthquakes recorded for the Hanford monitoring region of south-central Washington in fiscal year 2007 (October 2006 through September 2007). The report provides summaries of seismic events recorded during the first three quarters of fiscal year 2007 and contains a more comprehensive discussion of seismic events for the fourth quarter of the fiscal year.
Date: December 27, 2007
Creator: Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E. & Devary, Joseph L.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0385 (open access)

Texas Attorney General Opinion: GA-0385

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification; Whether a nonprofit organization that sponsors a "poker run" violates gambling statutes (RQ-0357-GA)
Date: December 27, 2005
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: GA-0386 (open access)

Texas Attorney General Opinion: GA-0386

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification; Whether a legislator may simultaneously serve as president of a municipal management district operating under chapter 375, Local Government Code (RQ-0385-GA)
Date: December 27, 2005
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-446 (open access)

Texas Attorney General Opinion: JC-446

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification; Whether a school district is required to expel a student who commits certail alcohol-and drug-related felonies within 300 feet of school property(RQ-0446-JC).
Date: December 27, 2001
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-447 (open access)

Texas Attorney General Opinion: JC-447

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification; Whether a hospital may contract exclusively with a single medical insurance provider(RQ-0407-JC).
Date: December 27, 2001
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-448 (open access)

Texas Attorney General Opinion: JC-448

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification; Validity of a rider to the general appropriation act requiring the Texas Department of Transportation to sign an agreement with the city of El Paso in order to expand funds to build a border inspection sation (RQ-0419-JC).
Date: December 27, 2001
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Obstruction of Justice: an Overview of Some of the Federal Statutes that Prohibit Interference with Judicial, Executive, or Legislative Activities (open access)
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

None
Date: December 27, 2005
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
The European Union in 2006 and Beyond (open access)

The European Union in 2006 and Beyond

None
Date: December 27, 2005
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
Obstruction of Congress: An Abridged Overview of Federal Criminal Laws Relating to Interference with Congressional Activities (open access)

Obstruction of Congress: An Abridged Overview of Federal Criminal Laws Relating to Interference with Congressional Activities

None
Date: December 27, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Using pseudo transient continuation and the finite element method to solve the nonlinear Poisson-Boltzmann equation (open access)

Using pseudo transient continuation and the finite element method to solve the nonlinear Poisson-Boltzmann equation

The nonlinear Poisson-Boltzmann (PB) equation is solved using Pseudo Transient Continuation. The PB solver is constructed by modifying the nonlinear diffusion module of a 3D, massively parallel, unstructured-grid, finite element, radiation-hydrodynamics code. The solver also computes the electrostatic energy and evaluates the force on a user-specified contour. Either Dirichlet or mixed boundary conditions are allowed. The latter specifies surface charges, approximates far-field conditions, or linearizes conditions ''regulating'' the surface charge. The code may be run in either Cartesian, cylindrical, or spherical coordinates. The potential and force due to a conical probe interacting with a flat plate is computed and the result compared with direct force measurements by chemical force microscopy.
Date: December 27, 2000
Creator: Shestakov, A I; Milovich, J L & Noy, A
Object Type: Article
System: The UNT Digital Library
Motor Vehicle Manufacturing Employment: National and State Trends and Issues (open access)

Motor Vehicle Manufacturing Employment: National and State Trends and Issues

The 110th Congress is addressing many issues that could have a major impact on the U.S. motor vehicle manufacturing industry. This includes adopting new fuel economy standards for automobiles and light trucks (P.L. 110-140), plus consideration of legislation that may be used to help promote the manufacturing of future generations of fuel-efficient vehicles (S. 2191). This report looks at four sets of issues that have received attention in Congress or among the public more widely, with respect to employment in the U.S. motor manufacturing industry.
Date: December 27, 2007
Creator: Cooney, Stephen
Object Type: Report
System: The UNT Digital Library
Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed) (open access)

Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed)

We have developed an Integrated Vehicle Simulation Testbed (InVeST). InVeST is based on the concept of Co-simulation, and it allows the development of virtual vehicles that can be analyzed and optimized as an overall integrated system. The virtual vehicle is defined by selecting different vehicle components from a component library. Vehicle component models can be written in multiple programming languages running on different computer platforms. At the same time, InVeST provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all vehicle components. InVeST has been recently demonstrated using a transmission model and a transmission controller model. The transmission model was written in SABER and ran on a Sun/Solaris workstation, while the transmission controller was written in MATRIXx and ran on a PC running Windows NT. The demonstration was successfully performed. Future plans include the applicability of Co-simulation and InVeST to analysis and optimization of multiple complex systems, including those of Intelligent Transportation Systems.
Date: December 27, 2001
Creator: Ng, Walter; Paddack, Erma & Aceves, Salvador
Object Type: Article
System: The UNT Digital Library
Children Exposed to Domestic Violence: Federal Assistance Programs (open access)

Children Exposed to Domestic Violence: Federal Assistance Programs

The impact on children of domestic violence was an issue of interest in the 109th Congress. The first session of the 109th Congress ended with the passage of the Violence Against Women and Department of Justice Reauthorization Act of 2005 (P.L. 109-162), which contained new initiatives to address concerns about children and youth exposed to and victimized by domestic violence. This report discusses existing federal programs and initiatives that have been established to assist such children and youth, and new provisions enacted in P.L. 109-162.
Date: December 27, 2006
Creator: Cooper, Edith Fairman
Object Type: Report
System: The UNT Digital Library
Zimbabwe Backgrounder (open access)

Zimbabwe Backgrounder

None
Date: December 27, 2001
Creator: Copson, Raymond W.
Object Type: Report
System: The UNT Digital Library
Presidential Transitions (open access)

Presidential Transitions

None
Date: December 27, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Federal Statutes: What They Are and Where to Find Them (open access)

Federal Statutes: What They Are and Where to Find Them

This report provides a brief overview of federal statutes and where to find them, both in print and on the internet. When Congress passes a law, it may amend or repeal earlier enactments or it may write on a clean slate. After providing an overview on the basics of federal statutes, this report gives guidance on where federal statutes, in their various forms, may be located on the Internet.
Date: December 27, 2007
Creator: Foley, Cassandra L.
Object Type: Report
System: The UNT Digital Library
Influenza Vaccine Shortages and Implications (open access)

Influenza Vaccine Shortages and Implications

This report concerns the shortage of flu vaccine in the fall of 2004 renewed discussion of the fragility of the nation's system for providing this potentially life-saving product. Some have expressed concern that this situation bodes ill for national preparedness for an influenza pandemic or a large-scale bioterrorism event. This report will describe the current system of flu vaccine production and delivery, the causes of supply problems, and options for improvement.
Date: December 27, 2004
Creator: Lister, Sarah A. & Williams, Erin D.
Object Type: Report
System: The UNT Digital Library
Advancing the Science of Natural and Enhanced Attenuation for Chlorinated Solvents (open access)

Advancing the Science of Natural and Enhanced Attenuation for Chlorinated Solvents

This report summarizes the results of a three-year program that addressed key scientific and technical aspects related to natural and enhanced attenuation of chlorinated organics. The results from this coordinated three-year program support a variety of technical and regulatory advancements. Scientists, regulators, engineers, end-users and stakeholders participated in the program, which was supported by the U.S. Department of Energy (DOE) and the Interstate Technology and Regulatory Council (ITRC). The overarching objective of the effort was to examine environmental remedies that are based on natural processes--remedies such as Monitored Natural Attenuation (MNA) or Enhanced Attenuation (EA). A key result of the recent effort was the general affirmation of the approaches and guidance in the original U.S. Environmental Protection Agency (EPA) chlorinated solvent MNA protocols and directives from 1998 and 1999, respectively. The research program did identify several specific opportunities for advances based on: (1) mass balance as the central framework for attenuation based remedies, (2) scientific advancements and achievements during the past ten years, (3) regulatory and policy development and real-world experience using MNA, and (4) exploration of various ideas for integrating attenuation remedies into a systematic set of ''combined remedies'' for contaminated sites. These opportunities are summarized herein and are …
Date: December 27, 2006
Creator: Looney, B.; Early, Thomas O.; Gilmore, Tyler; Chapelle, Francis H.; Cutshall, Norman H.; Ross, Jeff et al.
Object Type: Report
System: The UNT Digital Library
Transport, Targeting, and Applications of Metallic Functional Nanoparticles for Degradation of DNAPL Chlorinated Organic Solvents (open access)

Transport, Targeting, and Applications of Metallic Functional Nanoparticles for Degradation of DNAPL Chlorinated Organic Solvents

Dense Non-Aqueous Phase Liquid (DNAPL) such as trichloroethylene act as long term sources of groundwater contaminants and are difficult and expensive to remediate. DNAPL-contaminated sites are a significant financial liability for the Department of Energy and the private sector. The objective of this study was to engineer reactive Fe-based nanoparticles with specialized polymeric coatings to make them mobile in the subsurface and to provide them with an affinity for the DNAPL/water interface. The synthesis, characterization, and reactivity/mobility of the engineered particles, and a molecular dynamic model that predicts their behavior at the DNPAL/water interface are described in this report.
Date: December 27, 2006
Creator: Lowry, Gregory V.; Majetich, Sara; Matyjaszewski, Krzysztof; Sholl, David & Tilton, Robert
Object Type: Report
System: The UNT Digital Library
Simulation and Analysis of Large-Scale Compton Imaging Detectors (open access)

Simulation and Analysis of Large-Scale Compton Imaging Detectors

We perform simulations of two types of large-scale Compton imaging detectors. The first type uses silicon and germanium detector crystals, and the second type uses silicon and CdZnTe (CZT) detector crystals. The simulations use realistic detector geometry and parameters. We analyze the performance of each type of detector, and we present results using receiver operating characteristics (ROC) curves.
Date: December 27, 2006
Creator: Manini, H A; Lange, D J & Wright, D M
Object Type: Report
System: The UNT Digital Library