Laboratory Studies of the Fe K-shell Emission (open access)

Laboratory Studies of the Fe K-shell Emission

An overview is given of measurements of the Fe K-shell spectrum from low-density laboratory sources. The measurements include wavelengths, electron-impact collision cross sections, innershell ionization phenomena, dielectronic recombination resonance strengths, charge exchange recombination, electron beam polarization effects, resonance excitation, and radiative cascade contributions. K-shell spectra have now also been obtained with microcalorimeters, including microcalorimeter arrays that are twins of the ASTRO-E and ASTRO-E2 missions, which illustrate typical resolving powers and spectral capabilities.
Date: December 26, 2004
Creator: Beiersdorfer, P
Object Type: Article
System: The UNT Digital Library
High Power 938nm Cladding Pumped Fiber Laser (open access)

High Power 938nm Cladding Pumped Fiber Laser

We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous emission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results.
Date: December 26, 2002
Creator: Dawson, J; Beach, R; Brobshoff, A; Liao, Z; Payne, S; Pennington, D et al.
Object Type: Article
System: The UNT Digital Library
HADES User's Manual (open access)

HADES User's Manual

HADES is a computer code that simulates transmission radiography through a mesh and/or solid bodies. This code is a successor to an old code called XRAY. HADES is designed to be backward compatible with XRAY (i.e. it will accept and correctly parse XRAY input decks), but HADES has many more features that greatly enhance its versatility and its simulation of experimental effects. HADES can simulate X-Ray radiography, neutron radiography or GeV proton radiography using ray-tracing techniques. A short article has been published which discusses HADES' capabilities. HADES also has some capability for simulating pinhole imaging and backlight imaging. The best way to obtain HADES is to ask one of the authors for a copy. This manual covers all features in version 2.5.0 of HADES.
Date: December 26, 2002
Creator: Aufderheide, M B; Slone, D M & Schach Von Wittenau, A E
Object Type: Text
System: The UNT Digital Library
Optical People Counting for Demand Controlled Ventilation: A Pilot Study of Counter Performance (open access)

Optical People Counting for Demand Controlled Ventilation: A Pilot Study of Counter Performance

This pilot scale study evaluated the counting accuracy of two people counting systems that could be used in demand controlled ventilation systems to provide control signals for modulating outdoor air ventilation rates. The evaluations included controlled challenges of the people counting systems using pre-planned movements of occupants through doorways and evaluations of counting accuracies when naive occupants (i.e., occupants unaware of the counting systems) passed through the entrance doors of the building or room. The two people counting systems had high counting accuracy accuracies, with errors typically less than 10percent, for typical non-demanding counting events. However, counting errors were high in some highly challenging situations, such as multiple people passing simultaneously through a door. Counting errors, for at least one system, can be very high if people stand in the field of view of the sensor. Both counting system have limitations and would need to be used only at appropriate sites and where the demanding situations that led to counting errors were rare.
Date: December 26, 2009
Creator: Fisk, William J. & Sullivan, Douglas
Object Type: Report
System: The UNT Digital Library
Kootenai River Fisheries Investigation : Stock Status of Burbot : Project Progress Report 2008 Annual Report. (open access)

Kootenai River Fisheries Investigation : Stock Status of Burbot : Project Progress Report 2008 Annual Report.

Objectives of this investigation were to (1) monitor the population status and recruitment of burbot Lota lota in the Kootenai River, Idaho and British Columbia, Canada during the winter of 2006-2007; (2) evaluate the selective withdrawal system in place at Libby Dam to maintain the river temperature near Bonners Ferry between 1-4 C (November-December) to improve burbot migration and spawning activity; and (3) determine if a hatching success of 10% of eyed burbot embryos could be achieved through extensive rearing and produce fingerlings averaging 9.8 cm in six months. Water temperature did not fall below the upper limit (4 C) until mid-January but was usually maintained between 1-4 C January through February and was acceptable. Snowpack was characterized by a 101% of normal January runoff forecast. Adult burbot were sampled with hoop nets and slat traps. Only three burbot were captured in hoop nets, all at Ambush Rock (rkm 244.5). No burbot were caught in either slat traps or juvenile sampling gear, indicating the population is nearly extirpated. Burbot catch per unit effort in hoop nets was 0.003 fish/net d. Extensive rearing was moved to a smaller private pond and will be reported in the 2008-2009 annual report.
Date: December 26, 2008
Creator: Paragamian, Valughn L. & C., Laude Dorothy
Object Type: Report
System: The UNT Digital Library
Institute for Multiscale Modeling of Biological Interactions (open access)

Institute for Multiscale Modeling of Biological Interactions

The Institute for Multiscale Modeling of Biological Interactions (IMMBI) has two primary goals: Foster interdisciplinary collaborations among faculty and their research laboratories that will lead to novel applications of multiscale simulation and modeling methods in the biological sciences and engineering; and Building on the unique biophysical/biology-based engineering foundations of the participating faculty, train scientists and engineers to apply computational methods that collectively span multiple time and length scales of biological organization. The success of IMMBI will be defined by the following: Size and quality of the applicant pool for pre-doctoral and post-doctoral fellows; Academic performance; Quality of the pre-doctoral and post-doctoral research; Impact of the research broadly and to the DOE (ASCR program) mission; Distinction of the next career step for pre-doctoral and post-doctoral fellows; and Faculty collaborations that result from IMMBI activities. Specific details about accomplishments during the three years of DOE support for IMMBI have been documented in Annual Progress Reports (April 2005, June 2006, and March 2007) and a Report for a National Academy of Sciences Review (October 2005) that were submitted to DOE on the dates indicated. An overview of these accomplishments is provided.
Date: December 26, 2009
Creator: Paulaitis, Michael E.; Garcia-Moreno, Bertrand & Lenhoff, Abraham
Object Type: Report
System: The UNT Digital Library
Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms, and Pertinent Durability Testing (open access)

Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms, and Pertinent Durability Testing

The Savannah River National Laboratory (SRNL) was requested to generate a document for the Washington State Department of Ecology and the U.S. Environmental Protection Agency that would cover the following topics: (1) A description of the mineral structures produced by Fluidized Bed Steam Reforming (FBSR) of Hanford type Low Activity Waste (LAW including LAWR which is LAW melter recycle waste) waste, especially the cage structured minerals and how they are formed. (2) How the cage structured minerals contain some contaminants, while others become part of the mineral structure (Note that all contaminants become part of the mineral structure and this will be described in the subsequent sections of this report). (3) Possible contaminant release mechanisms from the mineral structures. (4) Appropriate analyses to evaluate these release mechanisms. (5) Why the appropriate analyses are comparable to the existing Hanford glass dataset. In order to discuss the mineral structures and how they bond contaminants a brief description of the structures of both mineral (ceramic) and vitreous waste forms will be given to show their similarities. By demonstrating the similarities of mineral and vitreous waste forms on atomic level, the contaminant release mechanisms of the crystalline (mineral) and amorphous (glass) waste forms can …
Date: December 26, 2008
Creator: Jantzen, Carol M.
Object Type: Report
System: The UNT Digital Library
Implementing Graph Pattern Queries on a Relational Database (open access)

Implementing Graph Pattern Queries on a Relational Database

When a graph database is implemented on top of a relational database, queries in the graph query language are translated into relational SQL queries. Graph pattern queries are an important feature of a graph query language. Translating graph pattern queries into single SQL statements results in very poor query performance. By taking into account the pattern query structure and generating multiple SQL statements, pattern query performance can be dramatically improved. The performance problems encountered with the single SQL statements generated for pattern queries reflects a problem in the SQL query planner and optimizer. Addressing this problem would allow relational databases to better support semantic graph databases. Relational database systems that provide good support for graph databases may also be more flexible platforms for data warehouses.
Date: December 26, 2007
Creator: Kaplan, I L; Abdulla, G M; Brugger, S T & Kohn, S R
Object Type: Report
System: The UNT Digital Library
Intelligent Monitoring System With High Temperature Distributed Fiberoptic Sensor For Power Plant Combustion Processes (open access)

Intelligent Monitoring System With High Temperature Distributed Fiberoptic Sensor For Power Plant Combustion Processes

The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and remove pollutants at the source, such as NOx. The basic approach in developing the proposed sensor system is three fold: (1) development of high temperature distributed fiber optical sensor capable of measuring temperatures greater than 2000 C degree with spatial resolution of less than 1 cm; (2) development of distributed parameter system (DPS) models to map the three-dimensional (3D) temperature distribution for the furnace; and (3) development of an intelligent monitoring system for real-time monitoring of the 3D boiler temperature distribution. Under Task 1, we set up a dedicated high power, ultrafast laser system for fabricating in-fiber gratings in harsh environment optical fibers, successfully fabricated gratings in single crystal sapphire fibers by the high power laser system, and developed highly sensitive long period gratings (lpg) by electric arc. Under Task 2, relevant mathematical modeling studies of NOx formation in practical …
Date: December 26, 2005
Creator: Lee, Kwang Y.; Yin, Stuart S. & Boheman, Andre
Object Type: Report
System: The UNT Digital Library
PROBABILISTIC ASSESSMENT OF A CRITICALITY IN A WASTE CONTAINER AT SRS (open access)

PROBABILISTIC ASSESSMENT OF A CRITICALITY IN A WASTE CONTAINER AT SRS

Transuranic solid waste that has been generated as a result of the production of nuclear material for the United States defense program at the Savannah River Site (SRS) has been stored in more than 30,000 55-gallon drums and various size carbon steel boxes since 1953. Nearly two thirds of those containers have been processed and shipped to the Waste Isolation Pilot Plant. Among the containers assayed so far, the results indicate several drums with fissile inventories significantly higher (600-1000 grams {sup 239}Pu) than their original assigned values. While part of this discrepancy can be attributed to the past limited assay capabilities, human errors are believed to be the primary contributor. This paper summarizes an assessment of the probability of occurrence of a criticality accident during handling of the remaining transuranic waste containers at SRS.
Date: December 26, 2006
Creator: Eghbali, D
Object Type: Article
System: The UNT Digital Library
INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES (open access)

INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES

The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and remove pollutants at the source, such as NOx. The basic approach in developing the proposed sensor system is three fold: (1) development of high temperature distributed fiber optical sensor capable of measuring temperatures greater than 2000 C degree with spatial resolution of less than 1 cm; (2) development of distributed parameter system (DPS) models to map the three-dimensional (3D) temperature distribution for the furnace; and (3) development of an intelligent monitoring system for real-time monitoring of the 3D boiler temperature distribution. Under Task 1, improvement was made on the performance of in-fiber grating fabricated in single crystal sapphire fibers, test was performed on the grating performance of single crystal sapphire fiber with new fabrication methods, and the fabricated grating was applied to high temperature sensor. Under Task 2, models obtained from 3-D modeling of the Demonstration Boiler were used to …
Date: December 26, 2004
Creator: Lee, Kwang Y.; Yin, Stuart S. & Boheman, Andre
Object Type: Report
System: The UNT Digital Library
Scalar Dark Matter From Theory Space (open access)

Scalar Dark Matter From Theory Space

The scalar dark matter candidate in a prototypical theory space little Higgs model is investigated. We review all details of the model pertinent to a relic density calculation. We perform a thermal relic density calculation including couplings to the gauge and Higgs sectors of the model. We find two regions of parameter space that give acceptable dark matter abundances. The first region has a dark matter candidate with a mass {Omicron}(100 GeV), the second region has a candidate with a mass greater than {Omicron}(500 GeV). The dark matter candidate in either region is an admixture of an SU(2) triplet and an SU(2) singlet, thereby constituting a possible WIMP (weakly interacting massive particle).
Date: December 26, 2003
Creator: Birkedal-Hansen, Andreas & Wacker, Jay G.
Object Type: Article
System: The UNT Digital Library
INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES (open access)

INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES

The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and remove pollutants at the source, such as NOx. The basic approach in developing the proposed sensor system is three fold: (1) development of high temperature distributed fiber optical sensor capable of measuring temperatures greater than 2000 C degree with spatial resolution of less than 1 cm; (2) development of distributed parameter system (DPS) models to map the three-dimensional (3D) temperature distribution for the furnace; and (3) development of an intelligent monitoring system for real-time monitoring of the 3D boiler temperature distribution. Under Task 1, the efforts focused on developing an innovative high temperature distributed fiber optic sensor by fabricating in-fiber gratings in single crystal sapphire fibers. So far, our major accomplishments include: Successfully grown alumina cladding layers on single crystal sapphire fibers, successfully fabricated in-fiber gratings in single crystal sapphire fibers, and successfully developed a high temperature distributed fiber optic …
Date: December 26, 2003
Creator: Lee, Kwang Y.; Yin, Stuart S. & Boheman, Andre
Object Type: Report
System: The UNT Digital Library
Impact of contributions of Glenn T. Seaborg on nuclear science (open access)

Impact of contributions of Glenn T. Seaborg on nuclear science

Glenn Theodore Seaborg (1912-199) was a world-renowned nuclear chemist, a Nobel Laureate in chemistry in 1951, co-discoverer of plutonium and nine other transuranium elements, Chairman of the U.S. Atomic Energy Commission from 1961-71, scientific advisor to ten U.S. presidents, active in national and international professional societies, an advocate for nuclear power as well as for a comprehensive nuclear test ban treaty, a prolific writer, an avid hiker, environmentalist, and sports enthusiast. He was known and esteemed not only by chemists and other scientists throughout the world, but also by lay people, politicians, statesmen, and students of all ages. This memorial includes a brief glimpse of Glenn Seaborg's early life and education, describes some of his major contributions to nuclear science over his long and fruitful career, and highlights the profound impact of his contributions on nuclear science, both in the U.S. and in the international community.
Date: December 26, 2000
Creator: Hoffman, Darleane C.
Object Type: Report
System: The UNT Digital Library
Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes--Final Report (open access)

Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes--Final Report

Aqueous mixed low level wastes (MLLW) containing radionuclides, solvents, and/or heavy metals represent a serious current and future problem for DOE environmental management and cleanup. In order to provide low-cost treatment alternatives under mild conditions for such contained wastes, we have proposed to use the radiation-resistant bacterium, Deinococcus radiodurans. This project has focused on developing D. radiodurans strains for dual purpose processes: cometabolic treatment of haloorganics and other solvents and removal of heavy metals from waste streams in an above-ground reactor system. The characteristics of effective treatment strains that must be attained are: (a) high biodegradative and metal binding activity; (b) stable treatment characteristics in the absence of selection and in the presence of physiological stress; (c) survival and activity under harsh chemical conditions, including radiation. The result of this project has been a suite of strains with high biodegradative capabilities that are candidates for pilot stage treatment systems. In addition, we have determined how to create conditions to precipitate heavy metals on the surface of the bacterium, as the first step towards creating dual-use treatment strains for contained mixed wastes of importance to the DOE. Finally, we have analyzed stress response in this bacterium, to create the foundation for …
Date: December 26, 2003
Creator: Lidstrom, Mary E.
Object Type: Report
System: The UNT Digital Library
Sequestering Carbon Dioxide in Coalbeds (open access)

Sequestering Carbon Dioxide in Coalbeds

The authors' long term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The major objectives of the project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized in three broad categories outlining experimentation, model development, and coal characterization.
Date: December 26, 2001
Creator: Gasem, K. A. M.; Robinson, R. L., Jr. & Radovic, L. R.
Object Type: Report
System: The UNT Digital Library
The distribution of an illustrated timeline wall chart and teacher's guide of 20th century physics (open access)

The distribution of an illustrated timeline wall chart and teacher's guide of 20th century physics

The American Physical Society's part of its centennial celebration in March of 1999 decided to develop a timeline wall chart on the history of 20th century physics. This resulted in eleven consecutive posters, which when mounted side by side, create a 23-foot mural. The timeline exhibits and describes the millstones of physics in images and words. The timeline functions as a chronology, a work of art, a permanent open textbook, and a gigantic photo album covering a hundred years in the life of the community of physicists and the existence of the American Physical Society. Each of the eleven posters begins with a brief essay that places a major scientific achievement of the decade in its historical context. Large portraits of the essays' subjects include youthful photographs of Marie Curie, Albert Einstein, and Richard Feynman among others, to help put a face on science. Below the essays, a total of over 130 individual discoveries and inventions, explained in dated text boxes with accompanying images, form the backbone of the timeline. For ease of comprehension, this wealth of material is organized into five color-coded story lines the stretch horizontally across the hundred years of the 20th century. The five story lines …
Date: December 26, 2000
Creator: Schwartz, Brian
Object Type: Report
System: The UNT Digital Library
NREL PV Working With Industry, Fourth Quarter 2000 (open access)

NREL PV Working With Industry, Fourth Quarter 2000

NREL PV Working With Industry is a quarterly newsletter devoted to the research, development, and deployment performed by NREL staff in concert with their industry and university partners. The fourth quarter contains an article that is a followup to the IEEE PVSC conference held in Alaska in September 2000, an article about two new R and D initiatives, and an article on cooperative research efforts between the NCPV and the Solar Buildings and Concentrating Solar Power programs. The editorialist is Jim Rannels, Director of the Office of Power Technologies.
Date: December 26, 2000
Creator: Poole, L.
Object Type: Book
System: The UNT Digital Library
STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH (open access)

STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; the effect of various low-NOx firing modes on ash properties and adsorptivity; and the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. This first project period, experiments were carried out to better understand the fundamental nature of the ozonation effect on ash. Carbon surfaces were characterized by surfactant adsorption, and by X-ray Photoelectron Spectroscopy before and after oxidation, both by air at 440 C and by ozone at room temperature. The results strongly suggest that the beneficial effect of ozonation is in large part due to chemical modification of the carbon surfaces.
Date: December 26, 2001
Creator: Hurt, Robert; Suuberg, Eric & Veranth, John
Object Type: Report
System: The UNT Digital Library