Alternative Gate Dielectrics on Semiconductors for MOSFET Device Applications (open access)

Alternative Gate Dielectrics on Semiconductors for MOSFET Device Applications

We have investigated the synthesis and properties of deposited oxides on Si and Ge for use as alternative gate dielectrics in MOSFET applications. The capacitance and leakage current behavior of polycrystalline Y{sub 2}O{sub 3} films synthesized by pulsed-laser deposition is reported. In addition, we also discuss the growth of epitaxial oxide structures. In particular, we have investigated the use of silicide termination for oxide growth on (001) Si using laser-molecular beam epitaxy. In addition, we discuss a novel approach involving the use of hydrogen to eliminate native oxide during initial dielectric oxide nucleation on (001) Ge.
Date: December 6, 1999
Creator: Norton, D. P.; Budai, J. D.; Chisholm, M. F.; Pennycook, S. J.; McKee, R.; Walker, F. et al.
Object Type: Article
System: The UNT Digital Library
Assessment of Structural Resistance of building 4862 to Earthquake and Tornado Forces [SEC 1 and 2] (open access)

Assessment of Structural Resistance of building 4862 to Earthquake and Tornado Forces [SEC 1 and 2]

This report presents the results of work done for Hanford Engineering Laboratory under contract Y213-544-12662. LATA performed an assessment of building 4862 resistance to earthquake and tornado forces.
Date: December 6, 1999
Creator: METCALF, I.L.
Object Type: Report
System: The UNT Digital Library
Comparison of the crevice corrosion resistance of Alloys 625 and 22 in concentrated chloride solution from 60 to 95 degrees C (open access)

Comparison of the crevice corrosion resistance of Alloys 625 and 22 in concentrated chloride solution from 60 to 95 degrees C

The effects of electrolyte composition and oxide film age on the crevice corrosion properties of alloys 625 and 22 were studied at temperatures ranging from 60 to 95 C in concentrated chloride electrolytes. Critical potentials were determined using conventional current density thresholds and comparisons were made between 625 and 22 on the basis of these critical potentials. Air aged 22 specimens exhibited the highest resistance to crevice corrosion at 95 C in terms of critical crevice potentials, while freshly polished 22 exhibited the lowest resistance. Studies over the entire, temperature range showed that air aged 22 is more resistant to crevice corrosion than air aged 625 as evidenced by higher critical crevice potentials. As the temperature was lowered from 95 to 8O C, critical crevice potentials for 22 either approached or exceeded experimentally determined Cr (Mo, Ni) transpassive potentials.
Date: December 6, 1999
Creator: Kehler, B. A.; Illevbare, G. O. & Scully, J. R.
Object Type: Article
System: The UNT Digital Library
Energy Transfer of Excitons Between Quantum Wells Separated by a Wide Barrier (open access)

Energy Transfer of Excitons Between Quantum Wells Separated by a Wide Barrier

We present a microscopic theory of the excitonic Stokes and anti-Stokes energy transfer mechanisms between two widely separated unequal quantum wells with a large energy mismatch ({Delta}) at low temperatures (T). Exciton transfer through dipolar coupling, photon-exchange coupling and over-barrier ionization of the excitons through exciton-exciton Auger processes are examined. The energy transfer rate is calculated as a function of T and the center-to-center distance d between the two wells. The rates depend sensitively on T for plane-wave excitons. For located excitons, the rates depend on T only through the T-dependence of the localization radius.
Date: December 6, 1999
Creator: LYO,SUNGKWUN K.
Object Type: Article
System: The UNT Digital Library
Engineering Task Plan for Routine Engineering Support for Core Sampler System (open access)

Engineering Task Plan for Routine Engineering Support for Core Sampler System

Routine engineering support is required during normal operation of the core sampler trucks and associated ancillary equipment. This engineering support consists of, but is not limited to, troubleshooting operation problems, correcting minor design problems, assistance with work package preparation, assistance with procurement, fabrication shop support, planning of engineering tasks and preparation of associated Engineering Task Plans (ETP) and Engineering Service Requests (ESR). This ETP is the management plan document for implementing routine engineering support. Any additional changes to the scope of this ETP shall require a Letter of Instruction from Lockheed Martin Hanford Corp (LMHC). This document will also be the Work Planning Document for Development Control (HNF 1999a). The scope of this task will be to provide routine engineering support for Characterization equipment as required to support Characterization Operations. A task by task decision will be made by management to determine which tasks will be done per this ETP and if additional ETPs and/or ESRs are required. Due to the unique nature of this task, the only identifiable deliverable is to provide support as requested. Deliverables will be recorded in a task logbook as activities are identified. ESRs will be generated for tasks that require more than 40 person …
Date: December 6, 1999
Creator: Boger, R. M.
Object Type: Report
System: The UNT Digital Library
Feasibility of High Yield / High Gain NIF Capsules (open access)

Feasibility of High Yield / High Gain NIF Capsules

Our original ignition ''point designs'' (circa 1992) for the National Ignition Facility (NIF) were made energetically conservative to provide margin for uncertainties in laser absorption, x-ray conversion efficiency and hohlraum-capsule coupling. Since that time, extensive experiments on Nova and Omega and their related analysis indicate that NIF coupling efficiency may be almost ''as good as we could hope for''. Given close agreement between experiment and theory/modeling, we can credibly explore target enhancements which couple more of NIF's energy to an ignition capsule. We find that 3-4X increases in absorbed capsule energy appear possible, providing a potentially more robust target and {approx}10X increase in capsule yield.
Date: December 6, 1999
Creator: Suter, L.; Rothenberg, J.; Munro, D.; Van Wonterghem, B.; Haan, S. & Lindl, J.
Object Type: Article
System: The UNT Digital Library
Global Warming: A Science Overview for the A/C Industry (open access)

Global Warming: A Science Overview for the A/C Industry

Fossil fuels (i.e., coal, oil, and natural gas) provide about 85% of the world's energy, sustaining our standard-of-living. They are inexpensive, transportable, safe, and relatively abundant. At the same time, their use contributes to problems such as air quality and acid rain that are being addressed through various control efforts and to the problem of global warming, which is now being considered by governments of the world. This talk will focus on six key aspects of the scientific findings that are leading to proposals for significant limitation of the emissions of fossil-fuel-derived carbon dioxide and limitations on emissions of other greenhouse gases that can influence the global climate, including substances used in the refrigeration and air-conditioning industries.
Date: December 6, 1999
Creator: MacCracken, M.C.
Object Type: Article
System: The UNT Digital Library
High-resolution spectroscopic diagnostics of very high-temperature plasmas in the hard x-ray regime (open access)

High-resolution spectroscopic diagnostics of very high-temperature plasmas in the hard x-ray regime

Motivated by the need for establishing a reliable database useful for the application of x-ray spectroscopic tools for the diagnostic of very high temperature plasmas, high-resolution crystal spectrometer measurements have been performed investigating the characteristic K-shell radiation of highly charged krypton and xenon. The measurements, which have been performed at the Electron-Beam-Ion-Trap (EBIT) facility of the Lawrence Livermore National Laboratory, include the investigation of the n = 2 {yields} 1 transitions in heliumlike krypton (Kr{sup 34+}) and innershell excited lithiumlike krypton (Kr{sup 33+}) utilizing a conventional reflection-type crystal spectrometer of von Hamos geometry. The electron-excitation-energy selective measurements map the contribution of the dielectronic recombination lines providing the means of accurate interpretation of the line profiles of the characteristic K{alpha} x-ray emission of plasmas. The high-resolution measurements of the n = 2 {yields} 1 transitions in heliumlike xenon (Xe{sup 52+}) and hydrogenlike xenon (Xe{sup 53+}) were based on a new transmission-type crystal spectrometer of DuMond geometry. The resolving power of the developed spectrometer was sufficient for charge state specific observation allowing the determination of the electron-impact excitation cross section for the hydrogen- and heliumlike K{alpha} transitions. The disagreement with theoretically predicted values is a measure of the magnitude of the Breit …
Date: December 6, 1999
Creator: Widmann, K
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Marketing and promoting solar water heaters to home builders (open access)

Marketing and promoting solar water heaters to home builders

This is the final report of a four-task project to develop a marketing plan designed for businesses interested in marketing solar water heaters in the new home industry. This report outlines suggested marketing communication materials and other promotional tools focused on selling products to the new home builder. Information relevant to promoting products to the new home buyer is also included.
Date: December 6, 1999
Creator: Keller, C. & Ghent, P.
Object Type: Report
System: The UNT Digital Library
Multi-method characterization of low-level radioactive waste at two Sandia National Laboratories environmental restoration sites (open access)

Multi-method characterization of low-level radioactive waste at two Sandia National Laboratories environmental restoration sites

This paper discusses the application of multiple characterization methods to radioactive wastes generated by the Sandia National Laboratories/New Mexico (SNL/NM) Environmental Restoration (ER) Project during the excavation of buried materials at the Classified Waste Landfill (CWLF) and the Radioactive Waste Landfill (RWL). These waste streams include nuclear weapon components and other refuse that are surface contaminated or contain sealed radioactive sources with unknown radioactivity content. Characterization of radioactive constituents in RWL and CWLF waste has been problematic, due primarily to the lack of documented characterization data prior to burial. A second difficulty derives from the limited information that ER project personnel have about weapons component design and testing that was conducted in the early days of the Cold War. To reduce the uncertainties and achieve the best possible waste characterization, the ER Project has applied both project-specific and industry-standard characterization methods that, in combination, serve to define the types and quantities of radionuclide constituents in the waste. The resulting characterization data have been used to develop waste profiles for meeting disposal site waste acceptance criteria.
Date: December 6, 1999
Creator: Johnson, C.E. Jr.; Galloway, R.B. & Dotson, P.W.
Object Type: Article
System: The UNT Digital Library
National Ignition Facility draft supplemental environmental impact statement to the SSM PEIS (open access)

National Ignition Facility draft supplemental environmental impact statement to the SSM PEIS

The US Department of Energy (DOE) is constructing the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) at Livermore, California. In 1997, the buried capacitors containing polychlorinated biphenyls (PCBs) were discovered during site excavation for the NIF. The capacitors and contaminated soil were cleaned up to levels protective of human health and the environment in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and its implementing regulations and in consultation with state and federal regulators. In october 1997, DOE entered into a Joint Stipulation and Order approved and entered as an order of the court on October 27, 1997, in partial settlement of the lawsuit Civ. No. 97-936 (SS) (D.D.C.), ''Natural Resources Defense Council et al. v Richardson et al.''. Paragraph 7 of the Joint Stipulation and Order provides that a Supplemental Environmental Impact Statement (SEIS) shall evaluate ''the reasonably foreseeable significant adverse environmental impacts of continuing to construct and of operating NIF at LLNL with respect to any potential or confirmed contamination in the area by hazardous, toxic, and/or radioactive materials''. On September 25, 1998, DOE announced in the Federal Register the agency's intent to prepare an SEIS for the NIF portion (Volume 3, …
Date: December 6, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Novel, Integrated Reactor/Power Conversion System. Quarterly Report, September 1 - November 30, 1999 (open access)

Novel, Integrated Reactor/Power Conversion System. Quarterly Report, September 1 - November 30, 1999

The desired design objectives and operation parameters were determined and system characteristics to be investigated were identified together with critical issues. Specific tasks were outlined and communicated to the performing personnel.
Date: December 6, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Physics research opportunities with XFEL's. (open access)

Physics research opportunities with XFEL's.

The advent of x-ray Free Electron Lasers will present a number of unique new scientific opportunities. These arise from their special characteristics which include intensely brilliant pulses of x-rays delivered in very short times, complete transverse coherence, and high photon quantum degeneracy, amongst other things. While clearly much thought needs to be given to a detailed quantitative assessment of the feasibility of various experiments using such sources, including methods of dealing with heat loads on beamline optics and radiation damage to samples, there are a number of areas in which one can see new opportunities, and other exciting possibilities about which one might speculate. In this talk the author briefly reviews some of these areas, such as x-ray holography, pump-probe type experiments, correlation spectroscopy and quantum optics experiments with x-rays.
Date: December 6, 1999
Creator: Sinha, S. K.
Object Type: Article
System: The UNT Digital Library
Radiation embrittlement studies using anomalous small-angle x-ray scattering (open access)

Radiation embrittlement studies using anomalous small-angle x-ray scattering

Anomalous small angle x-ray scattering (ASAXS) was performed on an Fe-O.9 wt.% Cu-1.0 wt.% Mn alloy subjected to annealing or electron irradiation. ASAXS takes advantage of natural variations in the atomic scattering factor which exist at energies very near an element's x-ray absorption edge. By performing systematic SAXS experiments at energies near these absorption edges of the constituent alloy elements it is possible to vary the contrast of scattering centers containing the elements and in doing so quantify scatterer composition. The results of such an analysis for the samples in this work indicate the presence of Cu-rich, Cu{sub 85}Mn{sub 15} precipitates in the alloy. By applying the maximum entropy technique to the scattering data, it was possible to extract size distributions of scattering centers fog the different treatments. The results demonstrate the ability to detect and characterize small (11 {angstrom} radius) scatterers at quite low irradiation damage levels (5x10{sup {minus} 4} displacements per atom).
Date: December 6, 1999
Creator: Alexander, D. E.; Kestel, B. J.; Seifert, S.; Jemian, P. R.; Odette, G. R.; Klingensmith, D. et al.
Object Type: Article
System: The UNT Digital Library
Round-robin testing of a reference glass for low-activity waste forms (open access)

Round-robin testing of a reference glass for low-activity waste forms

A round robin test program was conducted with a glass that was developed for use as a standard test material for acceptance testing of low-activity waste glasses made with Hanford tank wastes. The glass is referred to as the low-activity test reference material (LRM). The program was conducted to measure the interlaboratory reproducibility of composition analysis and durability test results. Participants were allowed to select the methods used to analyze the glass composition. The durability tests closely followed the Product Consistency Test (PCT) Method A, except that tests were conducted at both 40 and 90 C and that parallel tests with a reference glass were not required. Samples of LRM glass that had been crushed, sieved, and washed to remove fines were provided to participants for tests and analyses. The reproducibility of both the composition and PCT results compare favorably with the results of interlaboratory studies conducted with other glasses. From the perspective of reproducibility of analysis results, this glass is acceptable for use as a composition standard for nonradioactive components of low-activity waste forms present at >0.1 elemental mass % and as a test standard for PCTS at 40 and 90 C. For PCT with LRM glass, the expected …
Date: December 6, 1999
Creator: Ebert, W. L. & Wolf, S. F.
Object Type: Report
System: The UNT Digital Library
Sputtering of Au induced by single Xe ion impacts (open access)

Sputtering of Au induced by single Xe ion impacts

Sputtering of Au thin films has been determined for Xe ions with energies between 50 and 600 keV. In-situ transmission electron microscopy was used to observe sputtered Au during deposition on a carbon foil near the specimen. Total reflection and transmission sputtering yields for a 62 nm thick Au thin film were determined by ex-situ measurement of the total amount of Au on the carbon foils. In situ observations show that individual Xe ions eject Au nanoparticles as large as 7 nm in diameter with an average diameter of approximately 3 nm. Particle emission correlates with crater formation due to single ion impacts. Nanoparticle emission contributes significantly to the total sputtering yield for Xe ions in this energy range in either reflection or transmission geometry.
Date: December 6, 1999
Creator: Birtcher, R. C. & Donnelly, S. E.
Object Type: Article
System: The UNT Digital Library
Total Measurement Uncertainty (TMU) for Nondestructive Assay of Transuranic (TRU) Waste at the WRAP Facility (open access)

Total Measurement Uncertainty (TMU) for Nondestructive Assay of Transuranic (TRU) Waste at the WRAP Facility

This report examines the contributing factors to NDA measurement uncertainty at WRAP. The significance of each factor on the TMU is analyzed, and a final method is given for determining the TMU for NDA measurements at WRAP. As more data becomes available, and WRAP gains in operational experience, this report will be reviewed semi-annually and updated as necessary.
Date: December 6, 1999
Creator: WILLS, C.E.
Object Type: Report
System: The UNT Digital Library
Waste Receiving and Processing (WRAP) Facility Plant Management System Test Report (open access)

Waste Receiving and Processing (WRAP) Facility Plant Management System Test Report

This document contains the testing results for installation of a new server in the Waste Receiving and Processing (WRAP) facility.
Date: December 6, 1999
Creator: Palmer, M. E.
Object Type: Report
System: The UNT Digital Library
MGR External Events Hazards Analysis (open access)

MGR External Events Hazards Analysis

The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.
Date: November 6, 1999
Creator: Booth, L.
Object Type: Report
System: The UNT Digital Library
''After the Genome 5 Conference'' to be held October 6-10, 1999 in Jackson Hole, Wyoming (open access)

''After the Genome 5 Conference'' to be held October 6-10, 1999 in Jackson Hole, Wyoming

OAK B139 The postgenomic era is arriving faster than anyone had imagined--sometime during 2000 we'll have a large fraction of the human genome sequence. Heretofore, our understanding of function has come from non-industrial experiments whose conclusions were largely framed in human language. The advent of large amounts of sequence data, and of ''functional genomic'' data types such as mRNA expression data, have changed this picture. These data share the feature that individual observations and measurements are typically relatively low value adding. Such data is now being generated so rapidly that the amount of information contained in it will surpass the amount of biological information collected by traditional means. It is tantalizing to envision using genomic information to create a quantitative biology with a very strong data component. Unfortunately, we are very early in our understanding of how to ''compute on'' genomic information so as to extract biological knowledge from i t. In fact, some current efforts to come to grips with genomic information often resemble a computer savvy library science, where the most important issues concern categories, classification schemes, and information retrieval. When exploring new libraries, a measure of cataloging and inventory is surely inevitable. However, at some point we …
Date: October 6, 1999
Creator: Brent, Roger
Object Type: Article
System: The UNT Digital Library
"After the Genome 5, Conference to be held October 6-10, 1999, Jackson Hole, Wyoming" (open access)

"After the Genome 5, Conference to be held October 6-10, 1999, Jackson Hole, Wyoming"

The postgenomic era is arriving faster than anyone had imagined-- sometime during 2000 we'll have a large fraction of the human genome sequence. Heretofore, our understanding of function has come from non-industrial experiments whose conclusions were largely framed in human language. The advent of large amounts of sequence data, and of "functional genomic" data types such as mRNA expression data, have changed this picture. These data share the feature that individual observations and measurements are typically relatively low value adding. Such data is now being generated so rapidly that the amount of information contained in it will surpass the amount of biological information collected by traditional means. It is tantalizing to envision using genomic information to create a quantitative biology with a very strong data component. Unfortunately, we are very early in our understanding of how to "compute on" genomic information so as to extract biological knowledge from it. In fact, some current efforts to come to grips with genomic information often resemble a computer savvy library science, where the most important issues concern categories, classification schemes, and information retrieval. When exploring new libraries, a measure of cataloging and inventory is surely inevitable. However, at some point we will need …
Date: October 6, 1999
Creator: Brent, Roger
Object Type: Article
System: The UNT Digital Library
The Effect of Laser Surface Reconstruction of Disordered Carbons on Performance (open access)

The Effect of Laser Surface Reconstruction of Disordered Carbons on Performance

The reconstruction of the surface of disordered carbons was examined by heating carbons derived from polymethacrylonitrile (PMAN) and divinylbenzene (DVB) with a pulsed infrared laser in an argon or helium atmosphere, both fluidized and under static conditions. By graphitizing the outer surface of the carbons, it was hoped to reduce the high first-cycle losses associated with such disordered materials in Li-ion cells. The power to the sample was varied to observed the effects on surface morphology and electrochemical performance in 1M LiPF{sub 6} ethylene carbonate-dimethyl carbonate. The use various reactive atmosphere such as ethylene, 2-vinylpyridine, pyrrole, and furfuryl alcohol were also evaluated as an alternative means of hopefully forming a thin graphitic layer on the carbon particles to reduce first-cycle irreversibility. While some improvement was realized, these losses were still unacceptably high. The laser heating did improve the rate capabilities of the carbons, however. More work in this area is necessary to fully understand surface and bulk effects.
Date: October 6, 1999
Creator: EVEN JR., WILLIAM R. & GUIDOTTI, RONALD A.
Object Type: Article
System: The UNT Digital Library
Field Balancing in the Real World: Part 2 (open access)

Field Balancing in the Real World: Part 2

This paper is a follow-up to an earlier paper, Field Balancing in the Real World, which was presented at CSI Reliability Week 1997 in Nashville. Case studies of excessive vibrations on fans at ORNL will be discussed. Except for a few small sections from the earlier paper, this paper is entirely new. The case studies are new. As in the first paper, all fans are rigid-rotor type fans. Normal operation, therefore, is at less than the shaft's first critical speed. The presentation of case studies with root cause problems other than unbalance is a major departure from the first paper. We believe they belong here, since unbalance is suspected most of the time when a fan is vibrating excessively, even when it is not the root cause. In reality, unbalance is the underlying cause of the excess vibration on fans we have fixed at ORNL only about half the time. Furthermore, the analyst's credibility could be called into question upon an unsuccessful attempt at field balancing when underlying causes are later discovered and fixed. A demonstration will follow the case study presentation. The additional tests described in this paper to confirm centrifugal force (probable unbalance) will be performed.
Date: October 6, 1999
Creator: Bracher, R. K. & Surrett, Clark L.
Object Type: Article
System: The UNT Digital Library
GREET 1.5 - transportation fuel-cycle model - Vol. 1 : methodology, development, use, and results. (open access)

GREET 1.5 - transportation fuel-cycle model - Vol. 1 : methodology, development, use, and results.

This report documents the development and use of the most recent version (Version 1.5) of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy associated with various transportation fuels and advanced vehicle technologies for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter with diameters of 10 micrometers or less, and sulfur oxides) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates total energy consumption, fossil fuel consumption, and petroleum consumption when various transportation fuels are used. The GREET model includes the following cycles: petroleum to conventional gasoline, reformulated gasoline, conventional diesel, reformulated diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol, Fischer-Tropsch diesel, dimethyl ether, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; soybeans to biodiesel; flared gas to methanol, dimethyl ether, and Fischer-Tropsch diesel; and landfill gases to methanol. This report also presents the …
Date: October 6, 1999
Creator: Wang, M. Q.
Object Type: Report
System: The UNT Digital Library