Microwave annealing of ion implanted 6H-SiC (open access)

Microwave annealing of ion implanted 6H-SiC

Microwave rapid thermal annealing has been utilized to remove the lattice damage caused by nitrogen (N) ion-implantation as well as to activate the dopant in 6H-SiC. Samples were annealed at temperatures as high as 1,400 C, for 10 min. Van der Pauw Hall measurements indicate an implant activation of 36%, which is similar to the value obtained for the conventional furnace annealing at 1,600 C. Good lattice quality restoration was observed in the Rutherford backscattering and photoluminescence spectra.
Date: May 1996
Creator: Gardner, J. A.; Rao, M. V.; Tian, Y. L.; Holland, O. W.; Kelner, G.; Freitas, J. A., Jr. et al.
System: The UNT Digital Library
The efficiency calibration and development of environmental correction factors for an in situ high-resolution gamma spectroscopy well logging system (open access)

The efficiency calibration and development of environmental correction factors for an in situ high-resolution gamma spectroscopy well logging system

A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. Absolute efficiency calibration of the GSLS was performed using simple cylindrical borehole geometry. The calibration source incorporated naturally occurring radioactive material (NORM) that emitted photons ranging from 186-keV to 2,614-keV. More complex borehole geometries were modeled using commercially available shielding software. A linear relationship was found between increasing source thickness and relative photon fluence rates at the detector. Examination of varying porosity and moisture content showed that as porosity increases, relative photon fluence rates increase linearly for all energies. Attenuation effects due to iron, water, PVC, and concrete cylindrical shields were found to agree with previous studies. Regression analyses produced energy-dependent equations for efficiency corrections applicable to spectral gamma-ray well logs collected under non-standard borehole conditions.
Date: May 1, 1996
Creator: Giles, J.R.
System: The UNT Digital Library
Results from modeling and simulation of chemical downstream etch systems (open access)

Results from modeling and simulation of chemical downstream etch systems

This report summarizes modeling work performed at Sandia in support of Chemical Downstream Etch (CDE) benchmark and tool development programs under a Cooperative Research and Development Agreement (CRADA) with SEMATECH. The Chemical Downstream Etch (CDE) Modeling Project supports SEMATECH Joint Development Projects (JDPs) with Matrix Integrated Systems, Applied Materials, and Astex Corporation in the development of new CDE reactors for wafer cleaning and stripping processes. These dry-etch reactors replace wet-etch steps in microelectronics fabrication, enabling compatibility with other process steps and reducing the use of hazardous chemicals. Models were developed at Sandia to simulate the gas flow, chemistry and transport in CDE reactors. These models address the essential components of the CDE system: a microwave source, a transport tube, a showerhead/gas inlet, and a downstream etch chamber. The models have been used in tandem to determine the evolution of reactive species throughout the system, and to make recommendations for process and tool optimization. A significant part of this task has been in the assembly of a reasonable set of chemical rate constants and species data necessary for successful use of the models. Often the kinetic parameters were uncertain or unknown. For this reason, a significant effort was placed on model …
Date: May 1, 1996
Creator: Meeks, E.; Vosen, S. R.; Shon, J. W.; Larson, R. S.; Fox, C. A. & Buchenauer, D.
System: The UNT Digital Library
A review of porous media enhanced vapor-phase diffusion mechanisms, models, and data: Does enhanced vapor-phase diffusion exist? (open access)

A review of porous media enhanced vapor-phase diffusion mechanisms, models, and data: Does enhanced vapor-phase diffusion exist?

A review of mechanisms, models, and data relevant to the postulated phenomenon of enhanced vapor-phase diffusion in porous media is presented. Information is obtained from literature spanning two different disciplines (soil science and engineering) to gain a diverse perspective on this topic. Findings indicate that while enhanced vapor diffusion tends to correct the discrepancies observed between past theory and experiments, no direct evidence exists to support the postulated processes causing enhanced vapor diffusion. Numerical modeling analyses of experiments representative of the two disciplines are presented in this paper to assess the sensitivity of different systems to enhanced vapor diffusion. Pore-scale modeling is also performed to evaluate the relative significance of enhanced vapor diffusion mechanisms when compared to Fickian diffusion. The results demonstrate the need for additional experiments so that more discerning analyses can be performed.
Date: May 1, 1996
Creator: Ho, C.K. & Webb, S.W.
System: The UNT Digital Library
National synchrotron light source. Activity report, October 1, 1994--September 30, 1995 (open access)

National synchrotron light source. Activity report, October 1, 1994--September 30, 1995

This report discusses research conducted at the National Synchrotron Light Source in the following areas: atomic and molecular science; energy dispersive diffraction; lithography, microscopy, and tomography; nuclear physics; scattering and crystallography studies of biological materials; time resolved spectroscopy; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; the 1995 NSLS annual users` meeting; 17th international free electron laser conference; micro bunches workshop; VUV machine; VUV storage ring parameters; beamline technical improvements; x-ray beamlines; x-ray storage ring parameters; the NSLS source development laboratory; the accelerator test facility (ATF); NSLS facility improvements; NSLS advisory committees; NSLS staff; VUV beamline guide; and x-ray beamline guide.
Date: May 1, 1996
Creator: Rothman, E.Z. & Hastings, J.
System: The UNT Digital Library
The Hawaiian Monk Seal in the Northwestern Hawaiian Islands, 1994 (open access)

The Hawaiian Monk Seal in the Northwestern Hawaiian Islands, 1994

The following report is a summary of observational studies on the Hawaiian monk seal in the Northern Hawaiian Islands during 1994. The information provided is meant to evaluate the status and trends of monk seal populations, natural history traits such as survival, reproduction, growth, behavior, and feeding habits, and the success of various activities designed to facilitate population growth.
Date: May 1996
Creator: Johanos, Thea C. & Ragen, Timothy J.
System: The UNT Digital Library
MP Salsa: a finite element computer program for reacting flow problems. Part 1--theoretical development (open access)

MP Salsa: a finite element computer program for reacting flow problems. Part 1--theoretical development

The theoretical background for the finite element computer program, MPSalsa, is presented in detail. MPSalsa is designed to solve laminar, low Mach number, two- or three-dimensional incompressible and variable density reacting fluid flows on massively parallel computers, using a Petrov-Galerkin finite element formulation. The code has the capability to solve coupled fluid flow, heat transport, multicomponent species transport, and finite-rate chemical reactions, and to solver coupled multiple Poisson or advection-diffusion- reaction equations. The program employs the CHEMKIN library to provide a rigorous treatment of multicomponent ideal gas kinetics and transport. Chemical reactions occurring in the gas phase and on surfaces are treated by calls to CHEMKIN and SURFACE CHEMKIN, respectively. The code employs unstructured meshes, using the EXODUS II finite element data base suite of programs for its input and output files. MPSalsa solves both transient and steady flows by using fully implicit time integration, an inexact Newton method and iterative solvers based on preconditioned Krylov methods as implemented in the Aztec solver library.
Date: May 1, 1996
Creator: Shadid, J. N.; Moffat, H. K.; Hutchinson, S. A.; Hennigan, G. L.; Devine, K. D. & Salinger, A. G.
System: The UNT Digital Library
Basic data report for WQSP 1; WQSP 2; WQSP 3; WQSP 4; WQSP 5; WQSP6; and WQSP 6a (open access)

Basic data report for WQSP 1; WQSP 2; WQSP 3; WQSP 4; WQSP 5; WQSP6; and WQSP 6a

The Waste Isolation Pilot Plant (WIPP) is located in southeastern New Mexico about 30 miles east of Carlsbad, New Mexico. The WIPP was authorized by Congress in 1979 (Public Law 96-194) and given the mission to provide {open_quotes}{hor_ellipsis}a research and development facility to demonstrate the safe disposal of radioactive wastes resulting from the defense activities and programs of the United States exempted from regulation by the Nuclear Regulatory Commission.{close_quotes} The WIPP is intended to receive, handle, and permanently dispose of transuranic waste. To fulfill this mission, the U.S. Department of Energy is constructing a full scale facility to demonstrate both technical and operational principles of the permanent storage/disposal of transuranic waste. Technical aspects are those concerned with the design, construction, and performance of subsurface structures. Operational aspects refer to-the receiving, handling, and emplacement of transuranic waste in salt. The facility is also designed for in situ studies and experiments in salt. The Water Quality Sampling Program (WQSP) evaluates the physical and chemical properties of the groundwater above the repository horizon that are part of the technical performance aspects.
Date: May 1, 1996
Creator: unknown
System: The UNT Digital Library
Hanford Well Remediation and Decommissioning Plan (open access)

Hanford Well Remediation and Decommissioning Plan

This plan provides the requirements for conducting well remediation and decommissioning activities.
Date: May 17, 1996
Creator: Skoglie, D. E.
System: The UNT Digital Library
Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir, Annual Report: 1995 (open access)

Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir, Annual Report: 1995

The objective of the Ferron Sandstone project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir to allow realistic interwell and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Quantitative geological and petrophysical information on the Cretaceous Ferron Sandstone in east-central Utah was collected. Both new and existing data is being integrated into a three-dimensional model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. This report covers research activities for fiscal year 1994-95, the second year of the project. Most work consisted of developing field methods and collecting large quantities of existing and new data. We also continued to develop preliminary regional and case-study area interpretations. The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) reservoirs models, and (4) field-scale evaluation of exploration strategies.
Date: May 1, 1996
Creator: Chidsey, Thomas C., Jr. & Allison, M. Lee
System: The UNT Digital Library
Development of Ni{sub 3}Al alloys for use as transfer rolls in hot processing of steels. CRADA final report (open access)

Development of Ni{sub 3}Al alloys for use as transfer rolls in hot processing of steels. CRADA final report

The purpose of this cooperative effort was to evaluate the potential of Ni{sub 3}Al alloys, such as IC221M and IC396M, for use as transfer rolls in heating treating furnaces and slab reheating furnaces used during the normal hot processing of steel ingots into rolled products. Rolls consist of three parts: the center tube section which forms the roll surface in direct contact with the steel, and the sections welded at each end of the tube, called trunnions, which bear the load. The work in this CRADA focused on weldments and base materials. The transfer rolls in the furnaces used in the hot processing of steel have been made, almost exclusively, from iron-chromium-nickel heat resistant alloys for over 35 years. The iron-based heat resistant alloys experience a variety of problems when exposed to temperatures above 760 C including: cracking, dimensional instability, and excessive oxidation. Many defects in rolled steel products can be traced directly to rolls used in the processing. Also the demand for higher quality products, spurred in part by competition from foreign producers, requires that various avenues for improving overall quality of rolled steel products be pursued. Initial work done by the Contractor and Metallamics indicated that Ni{sub 3}Al …
Date: May 1, 1996
Creator: Santella, M.L. & McDonald, R.
System: The UNT Digital Library
Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters (open access)

Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters

The objectives of this research are: (1) to calculate and compare off site doses from atmospheric tritium releases at the Savannah River Site using monthly versus 5 year meteorological data and annual source terms, including additional seasonal and site specific parameters not included in present annual assessments; and (2) to calculate the range of the above dose estimates based on distributions in model parameters given by uncertainty estimates found in the literature. Consideration will be given to the sensitivity of parameters given in former studies.
Date: May 1, 1996
Creator: Kock, A.
System: The UNT Digital Library
Vapor scavenging by atmospheric aerosol particles (open access)

Vapor scavenging by atmospheric aerosol particles

Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.
Date: May 1, 1996
Creator: Andrews, E.
System: The UNT Digital Library
Applied Ecosystem Analysis - Background : EDT the Ecosystem Diagnosis and Treatment Method. (open access)

Applied Ecosystem Analysis - Background : EDT the Ecosystem Diagnosis and Treatment Method.

This volume consists of eight separate reports. We present them as background to the Ecosystem Diagnosis and Treatment (EDT) methodology. They are a selection from publications, white papers, and presentations prepared over the past two years. Some of the papers are previously published, others are currently being prepared for publication. In the early to mid 1980`s the concern for failure of both natural and hatchery production of Columbia river salmon populations was widespread. The concept of supplementation was proposed as an alternative solution that would integrate artificial propagation with natural production. In response to the growing expectations placed upon the supplementation tool, a project called Regional Assessment of Supplementation Project (RASP) was initiated in 1990. The charge of RASP was to define supplementation and to develop guidelines for when, where and how it would be the appropriate solution to salmon enhancement in the Columbia basin. The RASP developed a definition of supplementation and a set of guidelines for planning salmon enhancement efforts which required consideration of all factors affecting salmon populations, including environmental, genetic, and ecological variables. The results of RASP led to a conclusion that salmon issues needed to be addressed in a manner that was consistent with an …
Date: May 1, 1996
Creator: Mobrand, Lars E.
System: The UNT Digital Library
Building on the shoulders of giants. Annual report, July 1, 1994--June 30, 1995 (open access)

Building on the shoulders of giants. Annual report, July 1, 1994--June 30, 1995

The engineering giants of the late 19th and early 20th centuries set humanity on a journey from which there is no turning back. This year, we celebrated the 100th anniversary of the American Society of Heating, refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE`s) founding and a century of advancing heating, ventilating, air-conditioning and refrigerating (HVAC&R) technology. We stood on the shoulders of these engineering giants, and we viewed the Society`s achievements in a perfect perspective. My theme for this year - Building on the Shoulders of Giants - recognizes their work and describes our journey forward into ASHRAE`s second century. Through our Centennial Celebration, we involved members at all levels of the Society, from our oldest members to students, from the Executive Committee to the Board of Directors to the regions and to the local chapters and individual members. We also involved our associate societies and other related organizations. This publication describes the activities of ASHRAE for 1995.
Date: May 1, 1996
Creator: unknown
System: The UNT Digital Library
Materials sciences programs: Fiscal year 1995 (open access)

Materials sciences programs: Fiscal year 1995

The purpose of this report is to provide a convenient compilation and index of the DOE Materials Science Division programs. This compilation is primarily intended for use by administrators, managers, and scientists to help coordinate research. The report is divided into eight sections. Section A contains all Laboratory projects, Section B has all contract research projects, Section C has projects funded under the Small Business Innovation Research Program, Section D describes the Center of Excellence for the Synthesis and Processing of Advanced Materials and E has information on major user facilities. F describes other user facilities, G as a summary of funding levels and H has indices characterizing research projects.
Date: May 1, 1996
Creator: unknown
System: The UNT Digital Library
Sunrayce 1995. Technical report (open access)

Sunrayce 1995. Technical report

From June 20-29, 1995, more than a thousand college and university students from across North America tested their solar cars and strategies against the environment in Sunrayce 95. The 1,250-mile race, from Indiana to Colorado, is the third in a series of collegiate solar-car races across the United States. The tradition began in 1990 with the GM Sunrayce USA from Florida to Michigan. In 1993, the tradition continued as 34 solar cars raced more than 1,100 miles from Texas to Minnesota in Sunrayce 93. The U.S. Department of Energy, General Motors Corporation, and other organizations teamed together in a unique partnership between government and industry to sponsor Sunrayce 95. Their goal was to make learning exciting and relevant to today`s concerns and to demonstrate that brain power is more important than horsepower.
Date: May 1, 1996
Creator: King, R.; Stafford, B. & Tamai, G.
System: The UNT Digital Library
Zeroth-order design report for the next linear collider. Volume 2 (open access)

Zeroth-order design report for the next linear collider. Volume 2

This Zeroth-Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The ``design`` presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume II covers the following: collimation systems; IP switch and big bend; final focus; the interaction region; multiple bunch issues; control systems; instrumentation; machine protection systems; NLC reliability considerations; NLC conventional facilities. Also …
Date: May 1, 1996
Creator: Raubenheimer, T.O.
System: The UNT Digital Library
Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 2: Appendices (open access)

Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 2: Appendices

The identification of seismic sources is often based on a combination of geologic and tectonic considerations and patterns of observed seismicity; hence, a historical earthquake catalogue is important. A historical catalogue of earthquakes of approximate magnitude (M) 2.5 and greater for the time period 1850 through 1992 was compiled for the INEL region. The primary data source used was the Decade of North American Geology (DNAG) catalogue for the time period from about 1800 through 1985 (Engdahl and Rinehart, 1988). A large number of felt earthquakes, especially prior to the 1970`s, which were below the threshold of completeness established in the DNAG catalogue (Engdahl and Rinehart, 1991), were taken from the state catalogues compiled by Stover and colleagues at the National Earthquake Information Center (NEIC) and combined with the DNAG catalogue for the INEL region. The state catalogues were those of Idaho, Montana, Nevada, Utah, and Wyoming. NEIC`s Preliminary Determination of Epicenters (PDE) and the state catalogues compiled by the Oregon Department of Geology and Mineral Industries (DOGAMI), and the University of Nevada at Reno (UNR) were also used to supplement the pre-1986 time period. A few events reanalyzed by Jim Zollweg (Boise State University, written communication, 1994) were also …
Date: May 1996
Creator: unknown
System: The UNT Digital Library
Fitness for duty in the nuclear industry: Update of the technical issues 1996 (open access)

Fitness for duty in the nuclear industry: Update of the technical issues 1996

The purpose of this report is to provide an update of information on the technical issues surrounding the creation, implementation, and maintenance of fitness-for-duty (FFD) policies and programs. It has been prepared as a resource for Nuclear Regulatory Commission (NRC) and nuclear power plant personnel who deal with FFD programs. It contains a general overview and update on the technical issues that the NRC considered prior to the publication of its original FFD rule and the revisions to that rule (presented in earlier NUREG/CRs). It also includes chapters that address issues about which there is growing concern and/or about which there have been substantial changes since NUREG/CR-5784 was published. Although this report is intended to support the NRC`s rule making on fitness for duty, the conclusions of the authors of this report are their own and do not necessarily represent the opinions of the NRC.
Date: May 1, 1996
Creator: Durbin, N. & Grant, T.
System: The UNT Digital Library
Preliminary remediation goals for use at the US Department of Energy Oak Ridge Operations Office. Revision 1 (open access)

Preliminary remediation goals for use at the US Department of Energy Oak Ridge Operations Office. Revision 1

This technical memorandum presents Preliminary Remediation Goals (PRGs) for use in human health risk assessment efforts under the United States Department of Energy, Oak Ridge Operations Office Environmental Restoration (ER) Division. This document provides the ER Division with standardized PRGs which are integral to the Remedial Investigation/Feasibility Study process. They are used during project scooping (Data Quality Objectives development), in screening level risk assessments to support early action or No Further Investigation decisions, and in the baselines risk assessment where they are employed in the selection of chemicals of potential concern. The primary objective of this document is to standardize these values and eliminate any duplication of effort by providing PRGs to all contractors involved in risk activities. In addition, by managing the assumptions and systems used in PRG derivation, the ER Risk Assessment Program will be able to control the level of quality assurance associated with these risk-based guideline values.
Date: May 1, 1996
Creator: unknown
System: The UNT Digital Library