Quantitative Microanalysis with high Spatial Resolution: Application of FEG-DTEM XEDS Microanalysis to the Characterization of Complex Microstructures in Irradiated Low Alloy Steet (open access)

Quantitative Microanalysis with high Spatial Resolution: Application of FEG-DTEM XEDS Microanalysis to the Characterization of Complex Microstructures in Irradiated Low Alloy Steet

To assist in the characterization of microstructural changes associated with irradiation damage in low alloy steels, the technique of quantitative x-ray mapping using a field emission gun scanning transmission electron microscope (FEG-STEM) equipped with an x-ray energy Dispersive spectrometer (XEDS) has been employed. Quantitative XEDS microanalyses of the matrix and grain boundaries of irradiated specimens have been compared with previous quantitative analyses obtained using 3D-Atom Probe Field-Ion Microscopy (3D-APFIM). In addition, the FEG-STEM XEDS maps obtained from the irradiated steel have revealed the presence of 2 to 3 nm Ni-enriched 'precipitates' in the matrix, which had previously been detected using 3D-APFIM. These quantitative FEG-STEM XEDS results represent the first direct and independent microchemical corroboration of the 3D-APFIM results showing ultra-fine irradiation-induced hardening features in low alloy steel.
Date: November 14, 2001
Creator: Williams, D.B., Watanabe, M. and Burke, M.G.
Object Type: Report
System: The UNT Digital Library
Detection of Pathogens Using a Handheld PCR Thermocycler (open access)

Detection of Pathogens Using a Handheld PCR Thermocycler

None
Date: May 14, 2001
Creator: Emanuel, P; Hadfield, T; Koopman, R; Richards, J; Benett, W; Stratton, P et al.
Object Type: Article
System: The UNT Digital Library
Mechanical properties of D0 Run IIB silicon detector staves (open access)

Mechanical properties of D0 Run IIB silicon detector staves

A proposed stave design for the D0 Run IIb silicon tracker outer layers featuring central cooling channels and a composite shell mechanical structure is evaluated for self-deflection and deflection due to external loads. This paper contains an introduction to the stave structure, a section devoted to composite lamina and laminate properties and finally a section discussing the beam deflections expected for assembled staves using these laminates.
Date: June 14, 2001
Creator: Lanfranco, Giobatta & Fast, James
Object Type: Report
System: The UNT Digital Library
Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses (open access)

Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses

Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectroscopy of the fs-modified fused silica using a confocal microscopy setup. Using a 488 nm excitation source, a fluorescence at 630 nm is observed from the modified glass, which is attributed to the presence of non-bridging oxygen hole center (NBOHC) defects created by the fs pulses. The fluorescence decays with prolonged exposure to the 488 nm light, indicating that the defects are being photobleached by the excitation light.
Date: December 14, 2001
Creator: Chan, J W; Huser, T; Risbud, S H & Krol, D M
Object Type: Article
System: The UNT Digital Library
FY2001 Annual Report for EMSP Project #70108: Effects of Fluid Distribution on Measured Geophysical Properties for Partially Saturated, Shallow Subsurface Conditions (open access)

FY2001 Annual Report for EMSP Project #70108: Effects of Fluid Distribution on Measured Geophysical Properties for Partially Saturated, Shallow Subsurface Conditions

Our goal is to improve geophysical imaging of the vadose zone. We will achieve this goal by providing new methods to improve interpretation of field data. The purpose of this EMSP project is to develop relationships between laboratory measured geophysical properties and porosity, saturation, and fluid distribution, for partially saturated soils. Algorithms for relationships between soil composition, saturation, and geophysical measurements will provide new methods to interpret geophysical field data collected in the vadose zone at sites such as Hanford, WA.
Date: June 14, 2001
Creator: Berge, P. A.; Bonner, B. P.; Roberts, J. J.; Wildenschild, D.; Aracne-Ruddle, C. M.; Berryman, J. G. et al.
Object Type: Report
System: The UNT Digital Library
New Technology Demonstration Program - Results of an Attempted Field Test of Full-Spectrum Polarized Lighting in a Mail Processing/Office Space (open access)

New Technology Demonstration Program - Results of an Attempted Field Test of Full-Spectrum Polarized Lighting in a Mail Processing/Office Space

An assessment of the potential energy savings associated with the use of full-spectrum polarized lighting in a work space was initiated as part of the Department of Energy's (DOE) Federal Energy Management Program (FEMP) New Technology Demonstration Program (NTDP) in 1997. This project was intended to provide information on the effectiveness and application of this technology that could help federal energy managers and other interested individuals determine whether this technology had benefits for their occupied spaces. The use of an actual mail processing/office work area provided the capability of evaluating the technologies effectiveness in the real world.
Date: June 14, 2001
Creator: Richman, Eric E.
Object Type: Report
System: The UNT Digital Library
Hanford Site Annual Treatability Studies Report: Calendar Year 2000 (open access)

Hanford Site Annual Treatability Studies Report: Calendar Year 2000

This report provides information required to be reported annually by the Washington Administrative Code (WAC) 173-303-071 (3)(r)(ii)(F) and (3)(s)(ix) on the treatability studies conducted on the Hanford Site in 2000. These studies were conducted as required by WAC 173-303-071, ?Excluded Categories of Waste,? sections (3)(r) and (s). Unless otherwise noted, the waste samples were provided by and the treatability studies were performed for the U.S. Department of Energy, Richland Operations Office, P.O. Box 550, Richland, Washington 99352. The U.S. Environmental Protection Agency identification number for these studies is WA7890008967.
Date: February 14, 2001
Creator: McCoy, Michael W.
Object Type: Report
System: The UNT Digital Library
New Technology Demonstration Program - Results of an Attempted Field Test of Multi-Layer Light Polarizing Panels in an Office Space (open access)

New Technology Demonstration Program - Results of an Attempted Field Test of Multi-Layer Light Polarizing Panels in an Office Space

An assessment of the potential energy savings associated with the use of multi-layer light polarizing panels in an office space was initiated as part of the Department of Energy's (DOE) Federal Energy Management Program (FEMP) New Technology Demonstration Program (NTDP) in 1997. This project was intended to provide information on the effectiveness and application of this technology that could help federal energy managers and other interested individuals determine whether this technology had benefits for their occupied spaces. The use of an actual working office area provided the capability of evaluating the technology's effectiveness in the real world.
Date: June 14, 2001
Creator: Richman, Eric E.
Object Type: Report
System: The UNT Digital Library
The Stacktail Magic Numbers (open access)

The Stacktail Magic Numbers

This note will tabulate the desired phase and delay offsets for a Stacktail Momentum beam transfer function measurement as a function of beam energy and pickup leg. These phase and delay offsets were computed from beam transfer functions made around April 14, 2000. The StackTail system with these offsets will have a gain slope of about 10 MeV.
Date: March 14, 2001
Creator: McGinnis, Dave
Object Type: Report
System: The UNT Digital Library
Accuracy and reliability of China's energy statistics (open access)

Accuracy and reliability of China's energy statistics

Many observers have raised doubts about the accuracy and reliability of China's energy statistics, which show an unprecedented decline in recent years, while reported economic growth has remained strong. This paper explores the internal consistency of China's energy statistics from 1990 to 2000, coverage and reporting issues, and the state of the statistical reporting system. Available information suggests that, while energy statistics were probably relatively good in the early 1990s, their quality has declined since the mid-1990s. China's energy statistics should be treated as a starting point for analysis, and explicit judgments regarding ranges of uncertainty should accompany any conclusions.
Date: September 14, 2001
Creator: Sinton, Jonathan E.
Object Type: Article
System: The UNT Digital Library
Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis (open access)

Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.
Date: April 14, 2001
Creator: Cutler, A. R.
Object Type: Report
System: The UNT Digital Library
Spectroscopic and Microscopic Characterization of Contaminant Uptake and Retention by Carbonates in Soils and Vadose Zone Sediments (open access)

Spectroscopic and Microscopic Characterization of Contaminant Uptake and Retention by Carbonates in Soils and Vadose Zone Sediments

Historical releases and subsequent migration of toxic metals and radionuclides within the soil and vadose zone at various sites over the DOE Complex pose serious technological challenges, including the design and implementation of cost-effective remediation and/or monitoring strategies. This requires knowledge of the fundamental processes that govern contaminant mobility and reactivity with their host materials. The main research objective of this project is to assess the effectiveness of uptake and retention of selected contaminants (Co, Cs, Pb, Sr, U, and Cr) on calcium carbonate (primarily calcite), with a focus on conditions and sorbent materials relevant to the Hanford Site. This includes detailed microscopic and spectroscopic characterization of carbonate coatings and caliche from the Hanford Site, combined with experimental determination of the uptake behavior of selected contaminants on calcite surfaces and consideration of factors influencing uptake behavior and retention. The methodology relies on spectroscopic, microscopic, mineralogical, and geochemical characterization of natural and analog materials, including spatially resolved X-ray fluorescence (micro- XRF) and X-ray absorption fine-structure (XAFS) spectroscopy of uptake products. A primary goal is to determine the reaction mechanisms that govern contaminant uptake by carbonates. The expected results will have direct application for assessing the role that calcium carbonate phases play …
Date: June 14, 2001
Creator: Reeder, Richard J.
Object Type: Report
System: The UNT Digital Library
In Situ Field Testing of Processes (open access)

In Situ Field Testing of Processes

The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture …
Date: December 14, 2001
Creator: Wang, J.
Object Type: Report
System: The UNT Digital Library
Advanced High Resolution Seismic Imaging, Material Properties Estimation and Full Wavefield Inversion for the Shallow Subsurface (open access)

Advanced High Resolution Seismic Imaging, Material Properties Estimation and Full Wavefield Inversion for the Shallow Subsurface

Develop and test advanced near vertical to wide-angle seismic methods for structural imaging and material properties estimation of the shallow subsurface for environmental characterization efforts.
Date: June 14, 2001
Creator: Levander, A.; Zelt, C. A. & Symes, W. W.
Object Type: Report
System: The UNT Digital Library
A Cartesian grid embedded boundary method for the heat equation on irregular domains (open access)

A Cartesian grid embedded boundary method for the heat equation on irregular domains

We present an algorithm for solving the heat equation on irregular time-dependent domains. It is based on the Cartesian grid embedded boundary algorithm of Johansen and Colella (J. Comput. Phys. 147(2):60--85) for discretizing Poisson's equation, combined with a second-order accurate discretization of the time derivative. This leads to a method that is second-order accurate in space and time. For the case where the boundary is moving, we convert the moving-boundary problem to a sequence of fixed-boundary problems, combined with an extrapolation procedure to initialize values that are uncovered as the boundary moves. We find that, in the moving boundary case, the use of Crank--Nicolson time discretization is unstable, requiring us to use the L{sub 0}-stable implicit Runge--Kutta method of Twizell, Gumel, and Arigu.
Date: March 14, 2001
Creator: McCorquodale, Peter; Colella, Phillip & Johansen, Hans
Object Type: Article
System: The UNT Digital Library
Magnet R&D for future colliders (open access)

Magnet R&D for future colliders

High-energy colliders complementing and expanding the physics reach of LHC are presently under study in the United States, Europe and Japan. The magnet system is a major cost driver for hadron colliders at the energy frontier, and critical to the successful operation of muon colliders. Under most scenarios, magnet design as well as vacuum and cryogenic systems are complicated by high radiation loads. Magnet R&D programs are underway worldwide to take advantage of new developments in superconducting materials, achieve higher efficiency and simplify fabrication while preserving accelerator-class field quality. A review of recent progress in magnet technology for future colliders is presented, with emphasis on the most innovative design concepts and fabrication techniques.
Date: June 14, 2001
Creator: Sabbi, Gian Luca
Object Type: Article
System: The UNT Digital Library
Microbially Mediated Immobilization of Contaminants Through In Situ Biostimulation: Scale up of EMSP Project 55267 (open access)

Microbially Mediated Immobilization of Contaminants Through In Situ Biostimulation: Scale up of EMSP Project 55267

The overall goal of the proposed research is to provide an improved understanding and predictive capability of the mechanisms that allow metal-reducing bacteria to be effective in the bioremediation of redox sensitive toxic metals and radionuclides. The study is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of contaminants so that they are immobilized in situ for long time periods. The work described in this proposal will advance the technological and scientific needs associated with the long-term management of the enormous in-ground inventories of Cr, U, Tc, and Co present at numerous DOE installations throughout the country. The objectives of our project are to (1) develop an improved understanding and predictive capability of the rates and mechanisms controlling microbially mediated reduction of toxic metals and radionuclides in heterogeneous field settings, (2) quantify the impacts of hydrological and geochemical processes on the effectiveness of indigenous microorganisms to transform and immobilize radionuclides and metals in situ, (3) provide an improved understanding of the importance of microbial consortia interactions in the bacterial immobilization of radionuclides and toxic metals, and (4) determine intrinsic bioreduction rate parameters to improve our generic predictive capability of in situ …
Date: June 14, 2001
Creator: Jardine, Philip M. & Fendorf, Scott E.
Object Type: Report
System: The UNT Digital Library
HISTORY OF THE ENGINEERING PHYSICS AND MATHEMATICS DIVISION 1955-1993 (open access)

HISTORY OF THE ENGINEERING PHYSICS AND MATHEMATICS DIVISION 1955-1993

A review of division progress reports noting significant events and findings of the Applied Nuclear Physics, Neutron Physics, Engineering Physics, and then Engineering Physics and Mathematics divisions from 1955 to 1993 was prepared for use in developing a history of the Oak Ridge National Laboratory in celebration of its 50th year. The research resulted in an accumulation of historic material and photographs covering 38 years of effort, and the decision was made to publish a brief history of the division. The history begins with a detailed account of the founding of the Applied Nuclear Physics Division in 1955 and continues through the name change to the Neutron Physics Division in the late 1950s. The material thereafter is presented in decades--the sixties, seventies, and eighties--and ends as we enter the nineties.
Date: September 14, 2001
Creator: Maskewitz, B.F.
Object Type: Report
System: The UNT Digital Library
A study of sediment motion and bottom boundary layer dynamics over the Middle Atlantic Bight shelf and upper slope. Final report (open access)

A study of sediment motion and bottom boundary layer dynamics over the Middle Atlantic Bight shelf and upper slope. Final report

This report summarizes research on circulation and particle dynamics over the Middle Atlantic Bight shelf and upper slope. It includes an overview of the field experiments conducted in the waters off North Carolina, and gives the principal results from these experiments.
Date: February 14, 2001
Creator: Churchill, James H. & Williams, Albert J.
Object Type: Report
System: The UNT Digital Library
History of the Plutonium Production Facilities at the Hanford Site Historic District - 1943 - 1990 - June 2002 (open access)

History of the Plutonium Production Facilities at the Hanford Site Historic District - 1943 - 1990 - June 2002

None
Date: December 14, 2001
Creator: Cannan, S. D.
Object Type: Report
System: The UNT Digital Library
Mold Materials For Permanent Molding of Aluminum Alloys (open access)

Mold Materials For Permanent Molding of Aluminum Alloys

A test that involves immersion of the potential mod materials for permanent molds has been developed that provides a thermal cycle that is similar to the experienced during casting of aluminum in permanent molds. This test has been employed to determine the relative thermal fatigue resistance of several different types of mold materials. Four commercial mold coatings have been evaluated for their insulating ability, wear resistance and roughness. The results indicate that composition and structure of the mold materials have considerable effect on their thermal fatigue cracking behavior. Irons with a gray iron structure are the most prone to thermal fatigue cracking followed by compacted graphite irons with the least thermal fatigue cracking of the cast irons experienced by ductile iron. The composition of these various irons affects their behavior.
Date: September 14, 2001
Creator: Wallace, John F.; Schwam, David & Hong, Wen
Object Type: Report
System: The UNT Digital Library
Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999 (open access)

Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999

Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a doxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(CO){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(l) precatalysts. The reaction chemistry of the above and other Mn alkyl complexes with hydrosilanes was studied in order to probe catalysis mechanism(s). Thus, Mn(CO){sub 5} methyl, benzyl, acetyl, and benzoyl (4 p-substituents) complexes reacted with hydrosilines by four different mechanisms, which were established. A noteworthy development was that the methyl and benzoyl complexes gave moderate yields of a new ({eta}{sup 2}-Si-H) silane adduct (CO){sub 4}Mn(SiMe{sub 2}Ph)(H-SiMe{sub 2}Ph), which is stable in the presence of …
Date: April 14, 2001
Creator: Cutler, Alan R.
Object Type: Report
System: The UNT Digital Library
New insights in third phase formation in the U(VI)-HNO{sub 3}, TBP-alkane system. (open access)

New insights in third phase formation in the U(VI)-HNO{sub 3}, TBP-alkane system.

In this work, the system U(VI)-HNO{sub 3}-tributylphosphate (TBP)-n-dodecane has been revisited with the objective of gaining coordination chemistry and structural information on the species that are formed in the organic phase before and after third phase formation. Chemical analyses, spectroscopic and EXAFS data indicate that U(VI) is extracted as the UO{sub 2}(NO{sub 3}){sub 2} {center_dot} 2TBP adduct, while the third phase species has the composition UO{sub 2}(NO{sub 3}){sub 2} {center_dot} 2TBP {center_dot} HNO{sub 3}. Small-angle neutron scattering (SANS) data reveal the presence in the organic phase, both before and after phase splitting, of ellipsoidal aggregates whose formation seems to depend more on the extraction of HNO{sub 3} than that of U(VI).
Date: June 14, 2001
Creator: Jensen, M. P.; Chiarizia, R.; Ferraro, J. R.; Borkowski, M.; Nash, K. L.; Thiyagarajan, P. et al.
Object Type: Article
System: The UNT Digital Library
A spatial time series framework for modeling daily precipitationat regional scales (open access)

A spatial time series framework for modeling daily precipitationat regional scales

In this paper, a framework for stochastic spatiotemporal modeling of daily precipitation in a hindcast mode is presented. Observed precipitation levels in space and time are modeled as a joint realization of a collection of space-indexed time series, one for each spatial location. Time series model parameters are spatially varying, thus capturing space-time interactions. Stochastic simulation, i.e., the procedure of generating alternative precipitation realizations (synthetic fields) over the space-time domain of interest (Deutsch and Journel, 1998), is employed for ensemble prediction. The simulated daily precipitation fields reproduce a data-based histogram and spatiotemporal covariance model, and identify the measured precipitation values at the rain gauges (conditional simulation). Such synthetic precipitation fields can be used in a Monte Carlo framework for risk analysis studies in hydrologic impact assessment investigations.
Date: November 14, 2001
Creator: Kyriakidis, Phaedon C.; Miller, Norman L. & Kim, Jinwon
Object Type: Article
System: The UNT Digital Library