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
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
Generation of Ultra-high Intensity Laser Pulses (open access)

Generation of Ultra-high Intensity Laser Pulses

Mainly due to the method of chirped pulse amplification, laser intensities have grown remarkably during recent years. However, the attaining of very much higher powers is limited by the material properties of gratings. These limitations might be overcome through the use of plasma, which is an ideal medium for processing very high power and very high total energy. A plasma can be irradiated by a long pump laser pulse, carrying significant energy, which is then quickly depleted in the plasma by a short counterpropagating pulse. This counterpropagating wave effect has already been employed in Raman amplifiers using gases or plasmas at low laser power. Of particular interest here are the new effects which enter in high power regimes. These new effects can be employed so that one high-energy optical system can be used like a flashlamp in what amounts to pumping the plasma, and a second low-power optical system can be used to extract quickly the energy from the plasma and focus it precisely. The combined system can be very compact. Thus, focused intensities more than 10{sup 25} W/cm{sup 2} can be contemplated using existing optical elements. These intensities are several orders of magnitude higher than what is currently available …
Date: June 10, 2003
Creator: Fisch, N.J. & Malkin, V.M.
System: The UNT Digital Library
Fluid-Rock Characterization and Interactions in NMR Well Logging (open access)

Fluid-Rock Characterization and Interactions in NMR Well Logging

The objective of this project was to characterize the fluid properties and fluid-rock interactions which are needed for formation evaluation by NMR well logging. NMR well logging is finding wide use in formation evaluation. The formation parameters commonly estimated were porosity, permeability, and capillary bound water. Special cases include estimation of oil viscosity, residual oil saturation, location of oil/water contact, and interpretation on whether the hydrocarbon is oil or gas.
Date: February 10, 2003
Creator: Hirasaki, George J. & Mohanty, Kishore K.
System: The UNT Digital Library
Estimating Field-Scale Hydraulic Parameters of Heterogeneous Soils Using A Combination of Parameter Scaling and Inverse Methods (open access)

Estimating Field-Scale Hydraulic Parameters of Heterogeneous Soils Using A Combination of Parameter Scaling and Inverse Methods

As the Hanford Site transitions into remediation of contaminated soil waste sites and tank farm closure, more information is needed about the transport of contaminants as they move through the vadose zone to the underlying water table. The hydraulic properties must be characterized for accurate simulation of flow and transport. This characterization includes the determination of soil texture types, their three-dimensional distribution, and the parameterization of each soil texture. This document describes a method to estimate the soil hydraulic parameter using the parameter scaling concept (Zhang et al. 2002) and inverse techniques. To this end, the Groundwater Protection Program Science and Technology Project funded vadose zone transport field studies, including analysis of the results to estimate field-scale hydraulic parameters for modeling. Parameter scaling is a new method to scale hydraulic parameters. The method relates the hydraulic-parameter values measured at different spatial scales for different soil textures. Parameter scaling factors relevant to a reference texture are determined using these local-scale parameter values, e.g., those measured in the lab using small soil cores. After parameter scaling is applied, the total number of unknown variables in hydraulic parameters is reduced by a factor equal to the number of soil textures. The field-scale values …
Date: December 10, 2002
Creator: Zhang, Z. F.; Ward, Andy L. & Gee, Glendon W.
System: The UNT Digital Library
LLE Review, Quarterly Report: Volume 98, January-March 2004 (open access)

LLE Review, Quarterly Report: Volume 98, January-March 2004

This volume of the LLE Review, covering January-March 2004, features ''Performance of 1-THz-Bandwidth, 2-D Smoothing by Spectral Dispersion and Polarization Smoothing of High-Power, Solid-State Laser Beams'', by S. P. Regan, J. A. Marozas, R. S. Craxton, J. H. Kelly, W. R. Donaldson, P. A. Jaanimagi, D. Jacobs-Perkins, R. L. Keck, T. J. Kessler, D. D. Meyerhofer, T. C. Sangster, W. Seka, V.A. Smalyuk, S. Skupsky, and J. D. Zuegel (p. 49). Laser-beam smoothing achieved with 1-THz-bandwidth, two-dimensional smoothing by spectral dispersion and polarization smoothing on the 60-beam, 30-kJ, 351-nm OMEGA laser system is reported. These beam-smoothing techniques are directly applicable to direct-drive ignition target designs for the 192-beam, 1.8-MJ, 351-nm National Ignition Facility. Equivalent-target-plane images for constant-intensity laser pulses of varying duration were used to determine the smoothing. The properties of the phase plates, frequency modulators, and birefringent wedges were simulated and found to be in good agreement with the measurements.
Date: August 10, 2004
Creator: Goncharov, Valeri N.
System: The UNT Digital Library
Enabling Science and Technology Computation Directorate 2005 Annual Report (open access)

Enabling Science and Technology Computation Directorate 2005 Annual Report

None
Date: March 10, 2006
Creator: Anderson, S R; Zosel, M E & Miller, M C
System: The UNT Digital Library
Impact of Long-Range Dust Transport on Northern California in Spring 2002 (open access)

Impact of Long-Range Dust Transport on Northern California in Spring 2002

It has been well documented that spectacular dust storms in Asia (e.g. the events in 1998 and 2001) can affect the USA through long-range transport of dust across the Pacific. However, our observations and modeling show that the majority of dust at sites in Lassen National Park and Trinity Alps (Northern California) in spring 2002 (a year with no spectacular Asian dust events) is still from long-range intercontinental transport across the Pacific. We implemented the interactive dust emission algorithm of Ginoux et al. (2004) into the LLNL 3-D global atmospheric chemistry and aerosol transport model (IMPACT), then ran the model using a separate tracer for each dust emission region, using hi-resolution (1 x 1 degree) meteorological data from the NASA GMAO GEOS-3 assimilation system for 2001 and 2002. We also experimentally analyzed size- and time-resolved aerosol samples at Lassen National Park and Trinity Alps in the spring of 2002, which were taken as part of NOAA's ITCT 2k2 measurement campaign. The model-predicted time-series of soil dust over Northern California agrees remarkably well with our measurements, with a strong temporal correlation between the observations and intercontinental transport of dust across the Pacific in the model. Hence, we conclude that the majority …
Date: February 10, 2005
Creator: Cameron-Smith, P.; Bergmann, D.; Chuang, C.; Bench, G.; Cliff, S.; Kelly, P. et al.
System: The UNT Digital Library
Hanford Site Groundwater Monitoring for Fiscal Year 1999 (open access)

Hanford Site Groundwater Monitoring for Fiscal Year 1999

This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 1999 on the US. Department of Energy's Hanford Site, Washington. Water-level monitoring was performed to evaluate groundwater flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Measurements for site-wide maps were conducted in June in past years and are now measured in March to reflect conditions that are closer to average. Water levels over most of the Hanford Site continued to decline between June 1998 and March 1999. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of carbon-14, strontium-90, technetium-99, and uranium also exceeded drinking water standards in smaller plumes. Cesium-137 and plutonium exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in US Department of Energy Order 5400.5 were exceeded for plutonium, strontium-90, tritium, and uranium in small plumes or single wells. Nitrate and carbon tetrachloride are the most extensive chemical contaminants. Chloroform, chromium, cis-1,2dichloroethylene, cyanide, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels …
Date: May 10, 2000
Creator: Hartman, MJ; Morasch, LF & Webber, WD
System: The UNT Digital Library
Final Report - Ferrographic Tracking of Bacterial Transport (open access)

Final Report - Ferrographic Tracking of Bacterial Transport

The work performed during the past three years has been extremely productive. Ferrographic capture was utilized in analysis of several thousand field samples collected from arrays of multilevel samplers during three intensive field campaigns conducted at two shallow sandy aquifer sites in Oyster, VA. This work has shown resulted in three important conclusions: (1) Ferrographic capture provides unparalleled low quantitation limits for bacterial cell enumeration (Johnson et al., 2000). (2) The high-resolution analyses provided by ferrographic capture allowed observation of increased bacterial removal rates (from groundwater) that corresponded to increased populations of protozoa in the groundwater (Zhang et al., 2001). This novel data allowed determination of bacterial predation rates by protists in the field, a consideration that will be important for successful bioaugmentation strategies. (3) The high-resolution analyses provided by ferrographic capture allowed observation of detachment of indigenous cells in response to breakthrough of injected cells in groundwater (Johnson et al., 2001). The implication of this unique observation is that bacterial transport, specifically bacterial attachment and detachment, may be much more dynamic than has been indicated by short-term laboratory and field studies. Dynamic attachment and detachment of bacteria in groundwater may lead to greatly increased transport distances over long terms …
Date: October 10, 2002
Creator: Johnson, William P.
System: The UNT Digital Library
Presidential Appointments to Full-time Positions in Executive Departments During the 109th Congress, 2005-2006 (open access)

Presidential Appointments to Full-time Positions in Executive Departments During the 109th Congress, 2005-2006

This report provides an overview of the process for filling positions to which the President makes appointments with the advice and consent of the Senate (PAS positions). It also identifies, for the 109th Congress, all nominations to executive level full-time positions in the 15 departments. Profiles of the departments provide basic information regarding their full-time PAS positions and related appointment activity during the 109th Congress.
Date: June 10, 2008
Creator: Hogue, Henry B.; Bearden, Maureen & Ely, Dana
System: The UNT Digital Library
2001 Gordon Research Conference on Archaea: [Ecology], Metabolism. Final progress report [agenda and attendee list] (open access)

2001 Gordon Research Conference on Archaea: [Ecology], Metabolism. Final progress report [agenda and attendee list]

The Gordon Research Conference on Archaea: Ecology, Metabolism [and Molecular Biology] was held at Proctor Academy, Andover, New Hampshire, August 5-10, 2001. The conference was attended by 135 participants. The attendees represented the spectrum of endeavor in this field, coming from academia, industry, and government laboratories, and included US and foreign scientists, senior researchers, young investigators, and students. Emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate discussion about the key issues in the field today. Session topics included the following: Ecology and genetic elements; Genomics and evolution; Ecology, genomes and gene regulation; Replication and recombination; Chromatin and transcription; Gene regulation; Post-transcription processing; Biochemistry and metabolism; Proteomics and protein structure; Metabolism and physiology. The featured speaker addressed the topic: ''Archaeal viruses, witnesses of prebiotic evolution?''
Date: August 10, 2001
Creator: Daniels, Charles
System: The UNT Digital Library
Branching Fraction Limits for B0 Decays to eta' eta, eta' pi0 and eta pi0 (open access)

Branching Fraction Limits for B0 Decays to eta' eta, eta' pi0 and eta pi0

We describe searches for decays to two-body charmless final states {eta}'{eta}, {eta}'{pi}{sup 0} and {eta}{pi}{sup 0} of B{sup 0} mesons produced in e{sup +}e{sup -} annihilation. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 232 million produced B{bar B} pairs. The results for branching fractions are, in units of 10{sup -6} (upper limits at 90% C.L.): {Beta}(B{sup 0} {yields} {eta}'{eta}) = 0.2{sub -0.5}{sup +0.7} {+-} 0.4 (< 1.7), {Beta}(B{sup 0} {yields} {eta}{pi}{sup 0}) = 0.6{sub -0.4}{sup +0.5} {+-} 0.1 (< 1.3), and {Beta}(B{sup 0} {yields} {eta}'{pi}{sup 0}) = 0.8{sub -0.6}{sup +0.8} {+-} 0.1 (< 2.1). The first error quoted is statistical and the second systematic.
Date: March 10, 2006
Creator: Aubert, B.
System: The UNT Digital Library
AN EVALUATION OF HANFORD SITE TANK FARM SUBSURFACE CONTAMINATION FY2007 (open access)

AN EVALUATION OF HANFORD SITE TANK FARM SUBSURFACE CONTAMINATION FY2007

The Tank Farm Vadose Zone (TFVZ) Project conducts activities to characterize and analyze the long-term environmental and human health impacts from tank waste releases to the vadose zone. The project also implements interim measures to mitigate impacts, and plans the remediation of waste releases from tank farms and associated facilities. The scope of this document is to report data needs that are important to estimating long-term human health and environmental risks. The scope does not include technologies needed to remediate contaminated soils and facilities, technologies needed to close tank farms, or management and regulatory decisions that will impact remediation and closure. This document is an update of ''A Summary and Evaluation of Hanford Site Tank Farm Subsurface Contamination''. That 1998 document summarized knowledge of subsurface contamination beneath the tank farms at the time. It included a preliminary conceptual model for migration of tank wastes through the vadose zone and an assessment of data and analysis gaps needed to update the conceptual model. This document provides a status of the data and analysis gaps previously defined and discussion of the gaps and needs that currently exist to support the stated mission of the TFVZ Project. The first data-gaps document provided the …
Date: July 10, 2007
Creator: MANN, F.M.
System: The UNT Digital Library
INITIAL CHARACTERIZATIONS AND SRAT SIMULATIONS OF FOUR SLUDGE MATRIX STUDY SIMULANTS (open access)

INITIAL CHARACTERIZATIONS AND SRAT SIMULATIONS OF FOUR SLUDGE MATRIX STUDY SIMULANTS

The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in the Defense Waste Processing Facility (DWPF). Three compositional ranges were developed for three groups of elements in the waste. The first was high iron/low aluminum versus low iron/high aluminum. The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium. The third was high noble metals (Ag, Pd, Rh, Ru) versus low noble metals. These three options can be combined to form eight distinct sludge compositions. The sludge matrix study called for testing each of these eight simulants near the minimum acid required for nitrite destruction and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid. Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants can be used for both high and low noble metal concentration testing and high and low acid testing. This report summarizes preliminary testing of each of the four simulants at low noble metals and low acid stoichiometry. …
Date: December 10, 2009
Creator: Koopman,D. & Lambert, D.
System: The UNT Digital Library
Multicomponent Seismic Analysis and Calibration to Improve Recovery From Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado (open access)

Multicomponent Seismic Analysis and Calibration to Improve Recovery From Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado

This report describes the results made in fulfillment of contract DE-FG26-02NT15451, ''Multicomponent Seismic Analysis and Calibration to Improve Recovery from Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado''. Optimizing development of highly heterogeneous reservoirs where porosity and permeability vary in unpredictable ways due to facies variations can be challenging. An important example of this is in the algal mounds of the Lower and Upper Ismay reservoirs of the Paradox Basin in Utah and Colorado. It is nearly impossible to develop a forward predictive model to delineate regions of better reservoir development, and so enhanced recovery processes must be selected and designed based upon data that can quantitatively or qualitatively distinguish regions of good or bad reservoir permeability and porosity between existing well control. Recent advances in seismic acquisition and processing offer new ways to see smaller features with more confidence, and to characterize the internal structure of reservoirs such as algal mounds. However, these methods have not been tested. This project will acquire cutting edge, three-dimensional, nine-component (3D9C) seismic data and utilize recently-developed processing algorithms, including the mapping of azimuthal velocity changes in amplitude variation with offset, to extract attributes that relate …
Date: July 10, 2003
Creator: La Pointe, Paul; Rebne, Claudia & Dobbs, Steve
System: The UNT Digital Library
Environmental Assessment and Routing Study for the Little Mound to Ozarka 69kV Transmission Line (open access)

Environmental Assessment and Routing Study for the Little Mound to Ozarka 69kV Transmission Line

A report of an environmental assessment and alternative route analysis for the proposed 69kV transmission line.
Date: April 10, 2003
Creator: unknown
System: The Portal to Texas History
DWPF CATALYTIC HYDROGEN GENERATION PROGRAM - REVIEW OF CURRENT STATUS (open access)

DWPF CATALYTIC HYDROGEN GENERATION PROGRAM - REVIEW OF CURRENT STATUS

Significant progress has been made in the past two years in improving the understanding of acid consumption and catalytic hydrogen generation during the Defense Waste Processing Facility (DWPF) processing of waste sludges in the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME). This report reviews issues listed in prior internal reviews, describes progress with respect to the recommendations made by the December 2006 external review panel, and presents a summary of the current understanding of catalytic hydrogen generation in the DWPF Chemical Process Cell (CPC). Noble metals, such as Pd, Rh, and Ru, are historically known catalysts for the conversion of formic acid into hydrogen and carbon dioxide. Rh, Ru, and Pd are present in the DWPF SRAT feed as by-products of thermal neutron fission of {sup 235}U in the original waste. Rhodium appears to become most active for hydrogen as the nitrite ion concentration becomes low (within a factor of ten of the Rh concentration). Prior to hydrogen generation, Rh is definitely active for nitrite destruction to N{sub 2}O and potentially active for nitrite to NO formation. These reactions are all consistent with the presence of a nitro-Rh complex catalyst, although definite proof for the existence …
Date: July 10, 2009
Creator: Koopman, D.
System: The UNT Digital Library
Indian Ocean Earthquake and Tsunami: Humanitarian Assistance and Relief Operations (open access)

Indian Ocean Earthquake and Tsunami: Humanitarian Assistance and Relief Operations

On December 26, 2004, a magnitude 9.0 undersea earthquake off the west coast of northern Sumatra, Indonesia, unleashed a tsunami that affected more than 12 countries throughout south and southeast Asia and stretched as far as the northeastern African coast. Current official estimates indicate that more than 160,000 people are dead and millions of others are affected, including those injured, missing, or displaced, making this the deadliest tsunami on record. News reports suggest that the death toll may be well above 200,000. Sections of Indonesia, Sri Lanka, India, and Thailand have suffered the worst devastation. Eighteen Americans are confirmed dead, with another sixteen presumed dead, and 153 remain unaccounted for.
Date: February 10, 2005
Creator: Margesson, Rhoda
System: The UNT Digital Library
CHARACTERIZATION AND MONITORING OF NATURAL ATTENUATION OF CHLORINATED SOLVENTS IN GROUNDWATER: A SYSTEMS APPROACH (open access)

CHARACTERIZATION AND MONITORING OF NATURAL ATTENUATION OF CHLORINATED SOLVENTS IN GROUNDWATER: A SYSTEMS APPROACH

The objective of this document is to examine the use of a phased approach to characterizing and monitoring (C&M) natural attenuation processes and enhanced attenuation processes and to identify promising tools and techniques by which to accomplish the C&M. We will investigate developing techniques, such as molecular-based assessment tools, and existing tools that traditionally have not been used for monitoring the performance of environmental remediation technologies. Case studies will be used to provide examples of how non-traditional methods are being employed as characterization and monitoring tools to support MNA and EA. The document is not focused on a specific group of readers but rather is broadly directed with the intent that readers may gain information useful to their purposes. Thus, regulators may see some future characterization and monitoring techniques; end users may find novel ways to make MNA or EA more effective or efficient at their site; researchers may identify new areas for development or new and better combinations of existing methods. One consequence of this broad approach is that some readers may find certain sections either too rudimentary or too advanced for their needs. Hopefully, all will be able to use at least some of the document.
Date: August 10, 2006
Creator: Looney, B.; Michael Heitkamp, M.; Gary Wein (NOEMAIL), G.; Christopher Bagwell, C.; Karen Vangelas, K.; Karen-M Adams, K. et al.
System: The UNT Digital Library
Results of Detailed Hydrologic Characterization Tests - Fiscal Year 2002 (open access)

Results of Detailed Hydrologic Characterization Tests - Fiscal Year 2002

This report provides the results of detailed hydrologic characterization tests conducted within newly constructed Hanford Site wells during FY 2002. Results from the tests provide hydrologic information that supports the needs of RCRA waste management characterization and sitewide groundwater monitoring and modeling programs and reduces the uncertainty of groundwater flow conditions at selected Hanford locations.
Date: March 10, 2003
Creator: Spane, Frank A.; Newcomer, Darrell R. & Thorne, Paul D.
System: The UNT Digital Library
Uranium Pyrophoricity Phenomena and Prediction (FAI/00-39) (open access)

Uranium Pyrophoricity Phenomena and Prediction (FAI/00-39)

The purpose of this report is to provide a topical reference on the phenomena and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel (SNF) Project with specific applications to SNF Project processes and situations. Spent metallic uranium nuclear fuel is currently stored underwater at the K basins in the Hanford 100 area, and planned processing steps include: (1) At the basins, cleaning and placing fuel elements and scrap into stainless steel multi-canister overpacks (MCOs) holding about 6 MT of fuel apiece; (2) At nearby cold vacuum drying (CVD) stations, draining, vacuum drying, and mechanically sealing the MCOs; (3) Shipping the MCOs to the Canister Storage Building (CSB) on the 200 Area plateau; and (4) Welding shut and placing the MCOs for interim (40 year) dry storage in closed CSB storage tubes cooled by natural air circulation through the surrounding vault. Damaged fuel elements have exposed and corroded fuel surfaces, which can exothermically react with water vapor and oxygen during normal process steps and in off-normal situations, A key process safety concern is the rate of reaction of damaged fuel and the potential for self-sustaining or runaway reactions, also known as uranium fires or fuel ignition. Uranium metal and …
Date: October 10, 2000
Creator: PLYS, M.G.
System: The UNT Digital Library