Coincidence Prompt Gamma-Ray Neutron Activation Analysis (open access)

Coincidence Prompt Gamma-Ray Neutron Activation Analysis

The normal prompt gamma-ray neutron activation analysis for either bulk or small beam samples inherently has a small signal-to-noise (S/N) ratio due primarily to the neutron source being present while the sample signal is being obtained. Coincidence counting offers the possibility of greatly reducing or eliminating the noise generated by the neutron source. The present report presents our results to date on implementing the coincidence counting PGNAA approach. We conclude that coincidence PGNAA yields: (1) a larger signal-to-noise (S/N) ratio, (2) more information (and therefore better accuracy) from essentially the same experiment when sophisticated coincidence electronics are used that can yield singles and coincidences simultaneously, and (3) a reduced (one or two orders of magnitude) signal from essentially the same experiment. In future work we will concentrate on: (1) modifying the existing CEARPGS Monte Carlo code to incorporate coincidence counting, (2) obtaining coincidence schemes for 18 or 20 of the common elements in coal and cement, and (3) optimizing the design of a PGNAA coincidence system for the bulk analysis of coal.
Date: November 10, 2002
Creator: Gardner, R. P.; Mayo, C. W.; Metwally, W. A.; Zhang, W.; Guo, W. & Shehata, A.
System: The UNT Digital Library
Recess Appointments Made by President George W. Bush, January 20, 2001- October 31, 2008 (open access)

Recess Appointments Made by President George W. Bush, January 20, 2001- October 31, 2008

This report identifies recess appointments made by President George W. Bush from the time he took office on January 20, 2001, through October 31, 2008. Basic descriptive statistics regarding these appointments are also provided.
Date: November 3, 2008
Creator: Hogue, Henry B. & Bearden, Maureen
System: The UNT Digital Library
Oligonucleotide and Long Polymeric DNA Encoding (open access)

Oligonucleotide and Long Polymeric DNA Encoding

This report summarizes the work done at Lawrence Livermore National Laboratory for the Oligonucleotide and Long Polymeric DNA Encoding project, part of the Microelectronic Bioprocesses Program at DARPA. The goal of the project was to develop a process by which long (circa 10,000 base-pair) synthetic DNA molecules could be synthesized in a timely and economic manner. During construction of the long molecule, errors in DNA sequence occur during hybridization and/or the subsequent enzymatic process. The work done on this project has resulted in a novel synthesis scheme that we call the parallel pyramid synthesis protocol, the development of a suit of computational tools to minimize and quantify errors in the synthesized DNA sequence, and experimental proof of this technique. The modeling consists of three interrelated modules: the bioinformatics code which determines the specifics of parallel pyramid synthesis for a given chain of long DNA, the thermodynamics code which tracks the products of DNA hybridization and polymerase extension during the later steps in the process, and the kinetics model which examines the temporal and spatial processes during one thermocycle. Most importantly, we conducted the first successful syntheses of a gene using small starting oligomers (tetramers). The synthesized sequence, 813 base pairs …
Date: November 24, 2003
Creator: Miller, E.; Mariella, R. P. Jr.; Christian, A. T.; Gardner, S. N. & Williams, J. M.
System: The UNT Digital Library
On the Development of a Java-Based Tool for Multifidelity Modeling of Coupled Systems: LDRD Final Report (open access)

On the Development of a Java-Based Tool for Multifidelity Modeling of Coupled Systems: LDRD Final Report

This report describes research and development of methods to couple vastly different subsystems and physical models and to encapsulate these methods in a Java{trademark}-based framework. The work described here focused on developing a capability to enable design engineers and safety analysts to perform multifidelity, multiphysics analyses more simply. In particular this report describes a multifidelity algorithm for thermal radiative heat transfer and illustrates its performance. Additionally, it describes a module-based computer software architecture that facilitates multifidelity, multiphysics simulations. The architecture is currently being used to develop an environment for modeling the effects of radiation on electronic circuits in support of the FY 2003 Hostile Environments Milestone for the Accelerated Strategic Computing Initiative.
Date: November 1, 2002
Creator: GARDNER,DAVID R.; CASTRO,JOSEPH P.; HENNIGAN,GARY L.; GONZALES,MARK A. & YOUNG,MICHAEL F.
System: The UNT Digital Library
Advances in Geochemical Testing of Key Contaminants in Residual Hanford Tank Waste (open access)

Advances in Geochemical Testing of Key Contaminants in Residual Hanford Tank Waste

This report describes the advances that have been made over the past two years in testing and characterizing waste material in Hanford tanks.
Date: November 4, 2005
Creator: Deutsch, William J.; Krupka, Kenneth M.; Cantrell, Kirk J.; Brown, Christopher F.; Lindberg, Michael J.; Schaef, Herbert T. et al.
System: The UNT Digital Library
Vadose Zone Transport Field Study: Status Report (open access)

Vadose Zone Transport Field Study: Status Report

Studies were initiated at the Hanford Site to evaluate the process controlling the transport of fluids in the vadose zone and to develop a reliable database upon which vadose-zone transport models can be calibrated. These models are needed to evaluate contaminant migration through the vadose zone to underlying groundwaters at Hanford. A study site that had previously been extensively characterized using geophysical monitoring techniques was selected in the 200 E Area. Techniques used previously included neutron probe for water content, spectral gamma logging for radionuclide tracers, and gamma scattering for wet bulk density. Building on the characterization efforts of the past 20 years, the site was instrumented to facilitate the comparison of nine vadose-zone characterization methods: advanced tensiometers, neutron probe, electrical resistance tomography (ERT), high-resolution resistivity (HRR), electromagnetic induction imaging (EMI), cross-borehole radar, and cross-borehole seismic.
Date: November 30, 2001
Creator: Gee, Glendon W. & Ward, Anderson L.
System: The UNT Digital Library
Atwater Valley Deep-Towed Sidescan Sonar Imagery and Bathymetric Survey (open access)

Atwater Valley Deep-Towed Sidescan Sonar Imagery and Bathymetric Survey

The purpose of this project was to conduct detailed surface mapping of one of the areas drilled by the Joint Industry Project with ChevronTexaco to understand gas hydrates in the Gulf of Mexico. The gently sloping, mostly flat floor of the Mississippi Canyon is interrupted by mounds and depressions that presumably reflect the complex geology and geohydrology related to turbidite deposition and pervasive salt tectonism. The seafloor mounds we mapped in this study occur in approximately 1300 water depth along the floor of the Mississippi Canyon in lease block areas Atwater Valley 13 and 14. High resolution sidescan sonar (100 kHz and 500 kHz) backscatter imagery, and chirp sub-bottom profiler data were collected using the DT1 deep-towed oceanographic mapping instrument, concentrating on the region directly adjacent to and surrounding two mounds identified as, mounds D and F, and in the region directly adjacent to and surrounding the mounds. The backscatter data have been mosaiced and normalized to provide information on the shape and extent of the mounds, the possible lateral extent of fauna, such as mussel and clam fields on the mounds, possible seep related flows and the occurrence of carbonate material. The extent of a mudflow can be mapped …
Date: November 22, 2005
Creator: Gardner, Joan M.; Czarnecki, Mike; Hagen, Rick; Nishimura, Clyde; Wood, Warren; Vaughn, Chad et al.
System: The UNT Digital Library
Use of Electrochemical Noise to Assess Corrosion in Kraft Continuous Digesters (open access)

Use of Electrochemical Noise to Assess Corrosion in Kraft Continuous Digesters

Electrochemical noise (EN) probes were deployed in two continuous kraft digesters at a variety of locations representative of corrosion throughout the vessels. Current and potential noise, the temperature at each probe location, and the value of up to 60 process parameters (flow rates, liquor chemistry, etc.) were monitored continuously during each experiment. The results indicate that changes in furnish composition and process upsets were invariably associated with concurrent substantial changes in EN activity throughout the vessels. Post-test evaluation of the mild steel electrode materials in both vessels confirmed general corrosion of a magnitude consistent with historical trends in the respective vessels as well as values qualitatively (and semi-quantitatively) related to EN current sums for each electrode pair. Stainless steel electrodes representing 309LSi and 312 overlay repairs exhibited zero wastage corrosion--as did the actual overlays--but the EN data indicated periodic redox activity on the stainless steel that varied with time and position within the vessel. Little or no correlation between EN probe activity and other operational variables was observed in either vessel. Additional details for each digester experiment are summarized.
Date: November 29, 2004
Creator: Pawel, S.J.
System: The UNT Digital Library
Optimized bunch patterns for d-Au in RHIC Run-8 (open access)

Optimized bunch patterns for d-Au in RHIC Run-8

N/A
Date: November 1, 2007
Creator: Fischer, W. & Ptitsyn, V.
System: The UNT Digital Library
FY2003 LDRD Final Annual Report Article: Pathogen Pathway Project (open access)

FY2003 LDRD Final Annual Report Article: Pathogen Pathway Project

Understanding virulence mechanisms of bacterial pathogens is vital to anticipating biological threats and to improving detectors, vaccines, and treatments. This project will characterize factors responsible for virulence of Yersinia pestis, the causative agent of plague and a biothreat agent, which has an inducible Type III secretion virulence mechanism also found in other animal, plant, and human pathogens. Our approach relies on genomic and proteomic characterization of Y. pestis in addition to a bioinformatic infrastructure. Scientific and technical capabilities developed in this project can be applied to other microbes of interest. This work will establish a significant new direction for biodefense at LLNL and expand our national and international scientific collaborations.
Date: November 10, 2003
Creator: Fitch, J P & McCutchen-Maloney, S L
System: The UNT Digital Library
Fiscal Year 2003 Integrated Monitoring Plan for the Hanford Groundwater Monitoring Project (open access)

Fiscal Year 2003 Integrated Monitoring Plan for the Hanford Groundwater Monitoring Project

This document is an integrated monitoring plan for the Groundwater Monitoring Project. It documents well and constituent lists for the monitoring required by the Atomic Energy Act of 1954 and its implementing orders.
Date: November 1, 2002
Creator: Hartman, Mary J.; Dresel, P. EVAN; Lindberg, Jon W.; McDonald, John P.; Newcomer, Darrell R. & Thornton, Edward C.
System: The UNT Digital Library
IN SITU FIELD TESTING OF PROCESSES (open access)

IN SITU FIELD TESTING OF PROCESSES

The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in …
Date: November 8, 2004
Creator: YANG, J.S.Y.
System: The UNT Digital Library
Seismic Determination of Reservoir Heterogeneity; Application to the Characterization of Heavy Oil Reservoirs (open access)

Seismic Determination of Reservoir Heterogeneity; Application to the Characterization of Heavy Oil Reservoirs

The objective of the project is to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study is performed at West Coalinga Field in California. We continued our investigation on the nature of seismic reactions from heterogeneous reservoirs. We began testing our algorithm to infer parameters of object-based reservoir models from seismic data. We began integration of seismic and geologic data to determine the deterministic limits of conventional seismic data interpretation. Lastly, we began integration of seismic and geologic heterogeneity using stochastic models conditioned both on wireline and seismic data.
Date: November 2003
Creator: Imhof, Matthias G. & Castle, James W.
System: The UNT Digital Library
Vadose Zone Transport Field Study: Status Report (open access)

Vadose Zone Transport Field Study: Status Report

Studies were initiated at the Hanford Site to evaluate the process controlling the transport of fluids in the vadose zone and to develop a reliable database upon which vadose-zone transport models can be calibrated. These models are needed to evaluate contaminant migration through the vadose zone to underlying groundwaters at Hanford. A study site that had previously been extensively characterized using geophysical monitoring techniques was selected in the 200 E Area. Techniques used previously included neutron probe for water content, spectral gamma logging for radionuclide tracers, and gamma scattering for wet bulk density. Building on the characterization efforts of the past 20 years, the site was instrumented to facilitate the comparison of nine vadose-zone characterization methods: advanced tensiometers, neutron probe, electrical resistance tomography (ERT), high-resolution resistivity (HRR), electromagnetic induction imaging (EMI), cross-borehole radar (XBR), and cross-borehole seismic (XBS). Soil coring was used to obtain soil samples for analyzing ionic and isotopic tracers.
Date: November 30, 2001
Creator: Gee, Glendon W. & Ward, Anderson L.
System: The UNT Digital Library
Speed of Presidential and Senate Actions on Supreme Court Nominations, 1900-2005 (open access)

Speed of Presidential and Senate Actions on Supreme Court Nominations, 1900-2005

This report provides information on the amount of time taken to act on all Supreme Court nominations occurring between 1900 and the present. It focuses on the actual amounts of time that Presidents and the Senate have taken to act (as opposed to the elapsed time between official points in the process).
Date: November 7, 2005
Creator: Garrett, R. Sam; Rutkus, Denis Steven & Copeland, Curtis W.
System: The UNT Digital Library
Generalized Fourier Analyses of Semi-Discretizations of the Advection-Diffusion Equation (open access)

Generalized Fourier Analyses of Semi-Discretizations of the Advection-Diffusion Equation

This report presents a detailed multi-methods comparison of the spatial errors associated with finite difference, finite element and finite volume semi-discretizations of the scalar advection-diffusion equation. The errors are reported in terms of non-dimensional phase and group speeds, discrete diffusivity, artificial diffusivity, and grid-induced anisotropy. It is demonstrated that Fourier analysis (aka von Neumann analysis) provides an automatic process for separating the spectral behavior of the discrete advective operator into its symmetric dissipative and skew-symmetric advective components. Further it is demonstrated that streamline upwind Petrov-Galerkin and its control-volume finite element analogue, streamline upwind control-volume, produce both an artificial diffusivity and an artificial phase speed in addition to the usual semi-discrete artifacts observed in the discrete phase speed, group speed and diffusivity. For each of the numerical methods considered, asymptotic truncation error and resolution estimates are presented for the limiting cases of pure advection and pure diffusion. The Galerkin finite element method and its streamline upwind derivatives are shown to exhibit super-convergent behavior in terms of phase and group speed when a consistent mass matrix is used in the formulation. In contrast, the CVFEM method and its streamline upwind derivatives yield strictly second-order behavior. While this work can only be considered …
Date: November 1, 2002
Creator: CHRISTON, MARK A.; VOTH, THOMAS E. & MARTINEZ, MARIO J.
System: The UNT Digital Library
Xyce Parallel Electronic Simulator - User's Guide, Version 1.0 (open access)

Xyce Parallel Electronic Simulator - User's Guide, Version 1.0

This manual describes the use of the Xyce Parallel Electronic Simulator code for simulating electrical circuits at a variety of abstraction levels. The Xyce Parallel Electronic Simulator has been written to support,in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. As such, the development has focused on improving the capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) A client-server or multi-tiered operating model wherein the numerical kernel can operate independently of the graphical user interface (GUI). (4) Object-oriented code design and implementation using modern coding-practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. The code is a parallel code in the most general sense of the phrase--a message passing parallel implementation--which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well …
Date: November 1, 2002
Creator: HUTCHINSON, SCOTT A; KEITER, ERIC R.; HOEKSTRA, ROBERT J.; WATERS, LON J.; RUSSO, THOMAS V.; RANKIN, ERIC LAMONT et al.
System: The UNT Digital Library
300 Area Uranium Leach and Adsorption Project (open access)

300 Area Uranium Leach and Adsorption Project

The objective of this study was to measure the leaching and adsorption characteristics of uranium in six near-surface sediment samples collected from the 300 Area of the Hanford Site. Scanning electron micrographs of the samples showed that the uranium contamination in the sediments is most likely present as co-precipitates and/or discrete uranium particles. Molecular probe techniques also confirm the presence of crystalline discrete uranium bearing phases. In all cases, the uranium is present as oxidized uranium (uranyl [U(VI)]). Results from the column leach tests showed that uranium leaching did not follow a constant solubility paradigm. Four of the five contaminated sediments showed a large near instantaneous release of a few percent of the total uranium followed by a slower continual release. Steady-state uranium leachate concentrations were never measured and leaching characteristics and trends were not consistent among the samples. Dissolution kinetics were slow, and the measured leach curves most likely represent a slow kinetically controlled desorption or dissolution paradigm. Batch adsorption experiments were performed to investigate the effect of pH and uranium and carbonate solution concentrations on uranium adsorption onto the uncontaminated sediment. Uranium adsorption Kd values ranged from 0 to > 100 ml/g depending on which solution parameter was …
Date: November 26, 2002
Creator: Serne, R. Jeffrey; Brown, Christopher F.; Schaef, Herbert T.; Pierce, Eric M.; Lindberg, Michael J.; Wang, Zheming et al.
System: The UNT Digital Library
Thermal properties of PZT95/5(1.8Nb) and PSZT ceramics. (open access)

Thermal properties of PZT95/5(1.8Nb) and PSZT ceramics.

Thermal properties of niobium-modified PZT95/5(1.8Nb) and PSZT ceramics used for the ferroelectric power supply have been studied from -100 C to 375 C. Within this temperature range, these materials exhibit ferroelectric-ferroelectric and ferroelectric-paraelectric phase transformations. The thermal expansion coefficient, heat capacity, and thermal diffusivity of different phases were measured. Thermal conductivity and Grueneisen constant were calculated at several selected temperatures between -60 C and 100 C. Results show that thermal properties of these two solid solutions are very similar. Phase transformations in these ceramics possess first order transformation characteristics including thermal hysteresis, transformational strain, and enthalpy change. The thermal strain in the high temperature rhombohedral phase region is extremely anisotropic. The heat capacity for both materials approaches to 3R (or 5.938 cal/(g-mole*K)) near room temperature. The thermal diffusivity and the thermal conductivity are quite low in comparison to common oxide ceramics, and are comparable to amorphous silicate glass. Furthermore, the thermal conductivity of these materials between -60 C and 100 C becomes independent of temperature and is sensitive to the structural phase transformation. These phenomena suggest that the phonon mean free path governing the thermal conductivity in this temperature range is limited by the lattice dimensions, which is in good …
Date: November 1, 2006
Creator: DiAntonio, Christopher Brian; Rae, David F.; Corelis, David J.; Yang, Pin & Burns, George Robert
System: The UNT Digital Library
On-Going Evaluation of Traffic Control Devices (open access)

On-Going Evaluation of Traffic Control Devices

"This project was established to provide a means of conducting small-scale research activities on an as needed basis so that the results could be available within months of starting the specific research. This report summarizes the small-scale research activities that were conducted between September 2008 and August 2009." (p. i).
Date: November 2009
Creator: Carlson, Paul J.; Bligh, Roger P.; Pike, Adam; Miles, Jeffrey D.; Menges, Wanda L. & Paulus, Susan
System: The Portal to Texas History
Eliminating Islands in High-pressure Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions (open access)

Eliminating Islands in High-pressure Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions

Magnetic islands in free-boundary stellarator equilibria are suppressed using a procedure that iterates the plasma equilibrium equations and, at each iteration, adjusts the coil geometry to cancel resonant fields produced by the plasma. The coils are constrained to satisfy certain measures of engineering acceptability and the plasma is constrained to ensure kink stability. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible. The method is applied with success to a candidate plasma and coil design for the National Compact Stellarator eXperiment [Physics of Plasma, 7 (2000) 1911].
Date: November 19, 2002
Creator: Hudson, S. R.; Monticello, D. A.; Reiman, A. H.; Boozer, A. H.; Strickler, D. J.; Hirshman, S. P. et al.
System: The UNT Digital Library
Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model (open access)

Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model

Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.
Date: November 9, 2001
Creator: Cole, Charles R.; Bergeron, Marcel P.; Murray, Christopher J.; Thorne, Paul D.; Wurstner, Signe K. & Rogers, Phillip M.
System: The UNT Digital Library
Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model (open access)

Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model

Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.
Date: November 9, 2001
Creator: Cole, Charles R; Bergeron, Marcel P; Murray, Christopher J; Thorne, Paul D; Wurstner, Signe K & Rogers, Phillip M
System: The UNT Digital Library
BASIN-CENTERED GAS SYSTEMS OF THE U.S. (open access)

BASIN-CENTERED GAS SYSTEMS OF THE U.S.

The USGS is re-evaluating the resource potential of basin-centered gas accumulations in the U.S. because of changing perceptions of the geology of these accumulations, and the availability of new data since the USGS 1995 National Assessment of United States oil and gas resources (Gautier et al., 1996). To attain these objectives, this project used knowledge of basin-centered gas systems and procedures such as stratigraphic analysis, organic geochemistry, modeling of basin thermal dynamics, reservoir characterization, and pressure analysis. This project proceeded in two phases which had the following objectives: Phase I (4/1998 through 5/1999): Identify and describe the geologic and geographic distribution of potential basin-centered gas systems, and Phase II (6/1999 through 11/2000): For selected systems, estimate the location of those basin-centered gas resources that are likely to be produced over the next 30 years. In Phase I, we characterize thirty-three (33) potential basin-centered gas systems (or accumulations) based on information published in the literature or acquired from internal computerized well and reservoir data files. These newly defined potential accumulations vary from low to high risk and may or may not survive the rigorous geologic scrutiny leading towards full assessment by the USGS. For logistical reasons, not all basins received the …
Date: November 1, 2000
Creator: Popov, Marin A.; Nuccio, Vito F.; Dyman, Thaddeus S.; Gognat, Timothy A.; Johnson, Ronald C.; Schmoker, James W. et al.
System: The UNT Digital Library