Diet of Nesting Red-Cockaded Woodpecker at Three Locations (open access)

Diet of Nesting Red-Cockaded Woodpecker at Three Locations

The authors studied diets of nestling red-cockaded woodpeckers for two years on three sites in South Carolina and Georgia. Cameras recorded 33 different types of prey. Wood roaches were the most common, amounting to 50% of the prey. In addition, blueberries and saw fly larvae were collected by birds. Snail shells were also collected. Morista's index of diet overlap ranged from 0.94 to 0.99 for breeding males and females. We conclude that nestling diets are similar across the region.
Date: December 3, 1998
Creator: Hanula, James L.; Lipcomb, Donald; Franzreb, K.E. & Loeb, S.C.
Object Type: Article
System: The UNT Digital Library
Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System (open access)

Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System

Microbiologically influenced corrosion (MIC) may decrease the functional lifetime of nuclear waste packaging materials in the potential geologic repository at Yucca Mountain (YM), Nevada. Biochemical contributions to corrosion of package materials are being determined in reactors containing crushed repository-site rock with the endogenous microbial community, and candidate waste package materials. These systems are being continually supplied with simulated ground water. Periodically, bulk chemistries are analyzed on the system outflow, and surfacial chemistries are assessed on withdrawn material coupons. Both Fe and Mn dissolved from C1020 coupons under conditions that included the presence of YM microorganisms. Insoluble corrosion products remained in a reduced state at the coupon surface, indicating at least a localized anoxic condition; soluble reduced Mn and Fe were also detected in solution, while precipitated and spalled products were oxidized. Alloy 22 surfaces showed a layer of chrome oxide, almost certainly in the Cr(III) oxidation state, on microcosm-exposed coupons, while no soluble chrome was detected in solution. The results of these studies will be compared to identical testing on systems containing sterilized rock to generate, and ultimately predict, microbial contributions to waste package corrosion chemistries.
Date: December 3, 1998
Creator: Horn, J.; Martin, S.; Masterson, B. & Lian, T.
Object Type: Article
System: The UNT Digital Library
Macroscopic magnetic islands and plasma energy transport (open access)

Macroscopic magnetic islands and plasma energy transport

A model is presented, based on the combined effects of m=n=l magnetic island dynamics, localized heat sources, large heat diffusivity along magnetic field lines and plasma rotation, which may explain the multipeaked temperature profiles and transport barriers observed in tokamak plasmas heated by electron cyclotron resonant waves.
Date: December 3, 1998
Creator: Cima, G; Porcelli, F; Rossi, E & Wootton, A J
Object Type: Article
System: The UNT Digital Library
Synergistic effects in the extraction of metal ions by mixtures of dialkylphosphoric acids and substituted crown ethers. (open access)

Synergistic effects in the extraction of metal ions by mixtures of dialkylphosphoric acids and substituted crown ethers.

The extraction of alkaline earth cations from weakly acidic solutions by three dialkylphosphoric acids and various isomers of dicyclohexano-18-crown-6, both alone and in combination in toluene solutions, has been examined to determine the effect of both the crown ether stereochemistry and the structure of the organophilic anion on the magnitude of the synergistic effects. The synergistic effects have been found to differ considerably among the crown ether isomers and to vary with the extent of alkyl chain branching in the dialkylphosphoric acid. Attempts to correlate the synergistic effects with ligand strain energies from molecular mechanics calculations are described.
Date: December 3, 1998
Creator: Chiarizia, R.
Object Type: Article
System: The UNT Digital Library
Uranium Mobility During In Situ Redox Manipulation of the 100 Areas of the Hanford Site (open access)

Uranium Mobility During In Situ Redox Manipulation of the 100 Areas of the Hanford Site

A series of laboratory experiments and computer simulations was conducted to assess the extent of uranium remobilization that is likely to occur at the end of the life cycle of an in situ sediment reduction process. The process is being tested for subsurface remediation of chromate and chlorinated solvent-contaminated sediments at the Hanford Site in southeastern Washington. Uranium species that occur naturally in the +6 valence state [U(VI)] at 10 ppb in groundwater at Hanford will accumulate as U(IV) through the reduction and subsequent precipitation conditions of the permeable barrier created by in situ redox manipulation. The precipitated uranium will be remobilized when the reductive capacity of the barrier is exhausted and the sediment is oxidized by the groundwater containing dissolved oxygen and other oxidants such as chromate. Although U(IV) accumulates from years or decades of reduction/precipitation within the reduced zone, U(VI) concentrations in solution are only somewhat elevated during aquifer oxidation because oxidation and dissolution reactions that release U(IV) precipitate to solution are slow. The release rate of uranium into solution was found to be controlled mainly by the oxidation/dissolution rate of the U(IV) precipitate (half-life 200 hours) and partially by the fast oxidation of adsorbed Fe(II) (halflife 5 …
Date: December 3, 1998
Creator: Szecsody, James E.; Krupka, Kenneth M.; Williams, Mark D.; Cantrell, Kirk J.; Resch, Charles T. & Fruchter, Jonathan S.
Object Type: Report
System: The UNT Digital Library
Technical Status Report on the Effect of Phosphate and Aluminum on the Development of Amorphous Phase Separation in Sodium Borosilicate Glasses (open access)

Technical Status Report on the Effect of Phosphate and Aluminum on the Development of Amorphous Phase Separation in Sodium Borosilicate Glasses

The objective of the Tank Focus Area ''Optimize Waste Loading'' task is to enhance the definition of the acceptable processing window for high-level waste vitrification plants. One possible manner in which the acceptable processing window may be enhanced is by reducing the uncertainty of various compositional/property models through a specifically defined experimental plan. A reduction in model uncertainty can reduce limitations on current acceptance constraints and may allow for a larger processing or operational window. Enhanced composition/property model predictions coupled with an increased waste loading may decrease the processing time and waste glass disposal costs (i.e., overall lifecycle costs). One of the compositional/property models currently being evaluated by the Tanks Focus Area is related to the development of amorphous phase separation in multi-component borosilicate glasses.Described in this report is the current status for evaluating the effect of phosphorus and alumina on both simple sodium borosilicate and high-level waste glasses on the formation of amorphous phase separation. The goal of this subtask is to increase the understanding of the formation of phase separation by adding significant amounts (3-5 wt. percent) of phosphorus and alumina to well-characterized glasses. Additional scope includes evaluating the effects of thermal history on the formation of amorphous …
Date: December 3, 1998
Creator: Cozzi, A. D.
Object Type: Report
System: The UNT Digital Library
Combination RCRA Groundwater Monitoring Plan for the 216-A-10, 216-A-36B, and 216-A-37-1 PUREX Cribs (open access)

Combination RCRA Groundwater Monitoring Plan for the 216-A-10, 216-A-36B, and 216-A-37-1 PUREX Cribs

None
Date: December 3, 1998
Creator: Lindberg, JW
Object Type: Report
System: The UNT Digital Library
Advanced Emissions Control Development Program (open access)

Advanced Emissions Control Development Program

McDermott Technology, Inc. (MTI) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using the Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and hydrogen chloride and hydrogen fluoride.
Date: December 3, 1998
Creator: Holmes, M. J.
Object Type: Report
System: The UNT Digital Library
A Study of the Conservatism of Resonant Shock Test Fixtures (open access)

A Study of the Conservatism of Resonant Shock Test Fixtures

Portions of a series of end-of-life tests are described for a Sandia National Li~boratories- designed space-based sensor that utilizes a mercury-cadmium-telluride focal plane array. Variations in background intensity are consistent with the hypothesis that seasonal variations in solar position cause changes in the pattern of shadows falling across the compartment containing the optical elements, filter-band components, and focal plane array. When the sensor compartment is most fully illuminated by the sun, background intensities are large and their standard deviations tend to be large. During the winter season, when the compartment is most fully shadowed by surrounding structure, backgrounci intensities are small and standard deviations tend to be small. Details in the surrounding structure are speculated to produce transient shadows that complicate background intensifies as a function of time or of sensor position in orbit. KEYwoRDs Noise measurements, background intensity, focal plane array, mercury-cadmium-telluride.
Date: December 3, 1998
Creator: Cap, J.S.
Object Type: Article
System: The UNT Digital Library
Solar-Driven Background Intensity Variations in a Focal Plane Array (open access)

Solar-Driven Background Intensity Variations in a Focal Plane Array

Portions of a series of end-of-life tests are described for a Sandia National Li~boratories- designed space-based sensor that utilizes a mercury-cadmium-telluride focal plane array. Variations in background intensity are consistent with the hypothesis that seasonal variations in solar position cause changes in the pattern of shadows falling across the compartment containing the optical elements, filter-band components, and focal plane array. When the sensor compartment is most fully illuminated by the sun, background intensities are large and their standard deviations tend to be large. During the winter season, when the compartment is most fully shadowed by surrounding structure, backgrounci intensities are small and standard deviations tend to be small. Details in the surrounding structure are speculated to produce transient shadows that complicate background intensifies as a function of time or of sensor position in orbit.
Date: December 3, 1998
Creator: Eyer, H.H.; Guillen, J.L.L. & Vittitoe, C.N.
Object Type: Article
System: The UNT Digital Library
A Parallel Unstructured-Mesh Methodology for Device-Scale Combustion Calculations (open access)

A Parallel Unstructured-Mesh Methodology for Device-Scale Combustion Calculations

At Los Alamos we are developing a parallel, unstructured-mesh, finite-volume CFD methodology for the simulation of chemically reactive flows in complex geometries. The methodology is embodied in the CHAD (Computational Hydrodynamics for Advanced Design) code. In this report we give an overview of the CHAD numerical methodology and present parallel scaling results for calculations of flows in a four-valve diesel engine.
Date: December 3, 1998
Creator: O'Rourke, P.J.; Sahota, M.S. & Zhang, S.
Object Type: Article
System: The UNT Digital Library
Advanced Emissions Control Development Program (open access)

Advanced Emissions Control Development Program

Babcock & Wilcox (B&W) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using B&W�s new Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and the inorganic species hydrogen chloride and hydrogen fluoride.
Date: December 3, 1998
Creator: Evans, A. P.
Object Type: Report
System: The UNT Digital Library
Advanced Emissions Control Development Program (open access)

Advanced Emissions Control Development Program

McDermott Technology, Inc. (MTI) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using the Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and hydrogen chloride and hydrogen fluoride.
Date: December 3, 1998
Creator: Holmes, M. J.
Object Type: Report
System: The UNT Digital Library
Advanced Emissions Control Development Program (open access)

Advanced Emissions Control Development Program

McDermott Technology, Inc. (MTI) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using the Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and the inorganic species, hydrogen chloride and hydrogen fluoride.
Date: December 3, 1998
Creator: Evans, A. P.
Object Type: Report
System: The UNT Digital Library
Risk Based Requirements for Long Term Stewardship: A Proof-of-Principle Analysis of an Analytic Method Tested on Selected Hanford Locations (open access)

Risk Based Requirements for Long Term Stewardship: A Proof-of-Principle Analysis of an Analytic Method Tested on Selected Hanford Locations

Since 1989, the Department of Energy's (DOE) Environmental Management (EM) Program has managed the environmental legacy of US nuclear weapons production research and testing at 137 facilities in 31 states and one US territory. The EM program has conducted several studies on the public risks posed by contaminated sites at these facilities. In Risks and the Risk Debate DOE, 1995a, the Department analyzed the risks at sites before, during, and after remediation work by the EM program. The results indicated that aside from a few urgent risks, most hazards present little inherent risk because physical and active site management controls limit both the releases of site contaminants, and public access to these hazards. Without these controls, these sites would pose greater risks to the public. Past risk reports, however, provided little irdiormation about post- cleanup risk, primarily because of uncertainty about fiture site uses and site characteristics at the end of planned cleanup activities. This is of concern because in many cases current cleanup technologies, and remedies, will last a shorter period of time than the waste itself and the resulting contamination will remain hazardous.
Date: December 3, 1998
Creator: Gelston, GM; Buck, JW; Huesties, LR; Peffers, MS; Miley, TB; Jarvis, TT et al.
Object Type: Report
System: The UNT Digital Library
Uranium Mobility During In Situ Redox Manipulation of the 100 Areas of the Hanford Site (open access)

Uranium Mobility During In Situ Redox Manipulation of the 100 Areas of the Hanford Site

A series of laboratory experiments and computer simulations was conducted to assess the extent of uranium remobilization that is likely to occur at the end of the life cycle of an in situ sediment reduction process. The process is being tested for subsurface remediation of chromate- and chlorinated solvent-contaminated sediments at the Hanford Site in southeastern Washington. Uranium species that occur naturally in the +6 valence state {approximately}(VI) at 10 ppb in groundwater at Hanford will accumulate as U(N) through the reduction and subsequent precipitation conditions of the permeable barrier created by in situ redox manipulation. The precipitated uranium will W remobilized when the reductive capacity of the barrier is exhausted and the sediment is oxidized by the groundwater containing dissolved oxygen and other oxidants such as chromate. Although U(N) accumulates from years or decades of reduction/precipitation within the reduced zone, U(W) concentrations in solution are only somewhat elevated during aquifer oxidation because oxidation and dissolution reactions that release U(N) precipitate to solution are slow. The release rate of uranium into solution was found to be controlled mainly by the oxidation/dissolution rate of the U(IV) precipitate (half-life 200 hours) and partially by the fast oxidation of adsorbed Fe(II) (half- life …
Date: December 3, 1998
Creator: Resch, C. T.; Szecsody, J. E.; Fruchter, J. S.; Cantrell, K. J.; Krupka, K. M. & Williams, M. D.
Object Type: Report
System: The UNT Digital Library
Resonant Raman scattering in Nd{sub 2}O{sub 3} and the electronic structure of Sr{sub 2}RuO{sub 4} studied by synchrotron radiation excitation. (open access)

Resonant Raman scattering in Nd{sub 2}O{sub 3} and the electronic structure of Sr{sub 2}RuO{sub 4} studied by synchrotron radiation excitation.

This paper is intended to illustrate two points. The first being the extensive growth of resonant Raman soft x-ray scattering due to the emergence of third-generation x-ray sources. With these sources, the ubiquitous presence of Raman scattering near the 3d and 4d ionization thresholds has been used to elucidate the excitation process in a number of rare earth and transition metal compounds. Such scattering can produce dramatic changes in the emission spectrum, as we show in our example of inelastic scattering at the 3d threshold of Nd{sub 2}O{sub 3}. Photon-in photon-out soft x-ray spectroscopy is adding a new dimension to soft x-ray spectroscopy by providing many opportunities for exciting research, especially at third-generation synchrotrons light sources. Second, it is very effective to use theory and experiment to characterize the electronic properties of materials. In particular we confirmed in-plane oxygen-ruthenium bonding in Sr{sub 2}RuO{sub 4}, this first copperless perovskite superconductor, by analyses using calculations, soft x-ray emission spectroscopy (SXE) and photoelectron spectroscopy (PES). Measurements of this type illustrate the importance of combining SXE and PES measurements with theoretical calculations.
Date: December 3, 1998
Creator: Ederer, D. L.
Object Type: Article
System: The UNT Digital Library
Equation of state measurements at extreme pressures using laser-driven shocks (open access)

Equation of state measurements at extreme pressures using laser-driven shocks

The regime of high density and extreme pressure in hydrogen is very difficult to approach theoretically since it is a strongly correlated, partially degenerate composite of molecules, atoms, and electrons. For this reason, a number of theoretical models of the EOS of hydrogen have been proposed. This makes reliable experimental data essential as a guide to theory. We have accessed this regime by shocking liquid D2 to pressures at and above the metallic transition where we measured the thermodynamic properties of the shocked state.
Date: December 3, 1998
Creator: Cauble, R C; Celliers, P M; Collins, G W; DaSilva, L B & Gold, D M
Object Type: Article
System: The UNT Digital Library
Development of LNG-Powered Heavy-Duty Trucks in Commercial Hauling (open access)

Development of LNG-Powered Heavy-Duty Trucks in Commercial Hauling

In support of the U.S. Department of Energy's development, deployment, and evaluation of alternative fuels, NREL and the Trucking Research Institute contracted with Detroit Diesel Corporation (DDC) to develop and operate a liquid natural gas fueled tractor powered by a DDC Series 50 prototype natural gas engine. This is the final report on the project.
Date: December 3, 1998
Creator: Corporation, Detroit Diesel & Institute, Trucking Research
Object Type: Report
System: The UNT Digital Library