CRYSTALLIZATION IN MULTICOMPONENT GLASSES (open access)

CRYSTALLIZATION IN MULTICOMPONENT GLASSES

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.
Date: October 8, 2009
Creator: AA, KRUGER & PR, HRMA
Object Type: Article
System: The UNT Digital Library
A high-performance electron beam ion source (open access)

A high-performance electron beam ion source

At Brookhaven National Laboratory, a high current Electron Beam Ion Source (EBIS) has been developed as part of a new preinjector that is under construction to replace the Tandem Van de Graaffs as the heavy ion preinjector for the RHIC and NASA experimental programs. This preinjector will produce milliampere-level currents of essentially any ion species, with q/A {ge} 1/6, in short pulses, for injection into the Booster synchrotron. In order to produce the required intensities, this EBIS uses a 10A electron gun, and an electron collector designed to handle 300 kW of pulsed electron beam power. The EBIS trap region is 1.5 m long, inside a 5T, 2m long, 8-inch bore superconducting solenoid. The source is designed to switch ion species on a pulse-to-pulse basis, at a 5 Hz repetition rate. Singly-charged ions of the appropriate species, produced external to the EBIS, are injected into the trap and confined until the desired charge state is reached via stepwise ionization by the electron beam. Ions are then extracted and matched into an RFQ, followed by a short IH Linac, for acceleration to 2 MeV/A, prior to injection into the Booster synchrotron. An overview of the preinjector is presented, along with experimental …
Date: June 8, 2009
Creator: Alessi,J.; Beebe, E.; Bellavia, S.; Gould, O.; Kponou, A.; Lambiase, R. et al.
Object Type: Article
System: The UNT Digital Library
Corrosion Monitoring in Hanford Nuclear Waste Storage Tanks Design and Data From 241-an-102 Multi-Probe Corrosion Monitoring System (open access)

Corrosion Monitoring in Hanford Nuclear Waste Storage Tanks Design and Data From 241-an-102 Multi-Probe Corrosion Monitoring System

In 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was installed in double-shell tank 241-AN-102 on the U.S. Department of Energy's Hanford Site in Washington State. Developmental design work included laboratory testing in simulated tank 241-AN-102 waste to evaluate metal performance for installation on the MPCMS as secondary metal reference electrodes. The MPCMS design includes coupon arrays as well as a wired probe which facilitates measurement of tank potential as well as corrosion rate using electrical resistance (ER) sensors. This paper presents the MPCMS design, field data obtained following installation of the MPCMS in tank 241-AN-102, and a comparison between laboratory potential data obtained using simulated waste and tank potential data obtained following field installation.
Date: January 8, 2009
Creator: Anda, V. S.; Edgemon, G. L.; Hagensen, A. R.; Boomer, K. D. & Carothers, K. G.
Object Type: Article
System: The UNT Digital Library
Kalispel Resident Fish Project : Annual Report, 2008. (open access)

Kalispel Resident Fish Project : Annual Report, 2008.

In 2008, the Kalispel Natural Resource Department (KNRD) continued to implement its habitat enhancement projects for bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi). Baseline fish population and habitat assessments were conducted in Upper West Branch Priest River. Additional fish and habitat data were collected for the Granite Creek Watershed Assessment, a cooperative project between KNRD and the U.S. Forest Service Panhandle National Forest (FS) . The watershed assessment, funded primarily by the Salmon Recovery Funding Board of the State of Washington, will be completed in 2009.
Date: July 8, 2009
Creator: Andersen, Todd
Object Type: Report
System: The UNT Digital Library
Search for B^0 meson decays to \pi^0 K^0_S K^0_S, \eta K^0_S K^0_S, and \eta^{\prime}K^0_S K^0_S (open access)

Search for B^0 meson decays to \pi^0 K^0_S K^0_S, \eta K^0_S K^0_S, and \eta^{\prime}K^0_S K^0_S

We describe searches for B{sup 0} meson decays to the charmless final states {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}, {eta}K{sub S}{sup 0}K{sub S}{sup 0}, and {eta}{prime}K{sub S}{sup 0}K{sub S}{sup 0}. The data sample corresponds to 467 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation and collected with the BABAR detector at the SLAC National Accelerator Laboratory. We find no significant signals and determine the 90% confidence level upper limits on the branching fractions, in units of 10{sup -7}, {Beta}(B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}) < 12, {Beta}(B{sup 0} {yields} {eta}K{sub S}{sup 0}K{sub S}{sup 0}) < 10, and {Beta}(B{sup 0} {yields} {eta}{prime}K{sub S}{sup 0}K{sub S}{sup 0}) < 20.
Date: May 8, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Sheet Beam Klystron Instability Analysis (open access)

Sheet Beam Klystron Instability Analysis

Using the principle of energy balance we develop a 2D theory for calculating growth rates of instability in a two-cavity model of a sheet beam klystron. An important ingredient is a TE-like mode in the gap that also gives a longitudinal kick to the beam. When compared with a self-consistent particle-in-cell calculation, with sheet beam klystron-type parameters, agreement is quite good up to half the design current, 65 A; at full current, however, other, current-dependent effects come in and the results deviate significantly.
Date: May 8, 2009
Creator: Bane, K. L. F.; Jensen, A.; Li, Z.; Stupakov, G. & Adolphsen, C.
Object Type: Article
System: The UNT Digital Library
Development of pseudo-random binary arrays for calibration of surface profile metrology tools (open access)

Development of pseudo-random binary arrays for calibration of surface profile metrology tools

Optical Metrology tools, especially for short wavelength (EUV and X-Ray), must cover a wide range of spatial frequencies from the very low, which affects figure, to the important mid-spatial frequencies and the high spatial frequency range, which produces undesirable scattering. A major difficulty in using surface profilometers arises due to the unknown Point-Spread Function (PSF) of the instruments [1] that is responsible for distortion of the measured surface profile. Generally, the distortion due to the PSF is difficult to account because the PSF is a complex function that comes to the measurement via the convolution operation, while the measured profile is described with a real function. Accounting for instrumental PSF becomes significantly simpler if the result of measurement of a profile is presented in a spatial frequency domain as a Power Spectral Density (PSD) distribution [2]. For example, the measured PSD distributions provide a closed set of data necessary for three-dimensional calculations of scattering of light by the optical surfaces [3], [4]. The distortion of the surface PSD distribution due to the PSF can be modeled with the Modulation Transfer Function (MTF), which is defined over the spatial frequency bandwidth of the instrument [1], [2]. The measured PSD distribution can …
Date: June 8, 2009
Creator: Barber, Samuel K.; Soldate, Paul; Anderson, Erik H.; Cambie, Rossana; McKinney, Wayne R.; Takacs, Peter Z. et al.
Object Type: Article
System: The UNT Digital Library
Pacific Northwest National Laboratory Facility Radionuclide Emission Points and Sampling Systems (open access)

Pacific Northwest National Laboratory Facility Radionuclide Emission Points and Sampling Systems

Battelle—Pacific Northwest Division operates numerous research and development laboratories in Richland, Washington, including those associated with the Pacific Northwest National Laboratory (PNNL) on the Department of Energy’s Hanford Site that have the potential for radionuclide air emissions. The National Emission Standard for Hazardous Air Pollutants (NESHAP 40 CFR 61, Subparts H and I) requires an assessment of all effluent release points that have the potential for radionuclide emissions. Potential emissions are assessed annually. Sampling, monitoring, and other regulatory compliance requirements are designated based upon the potential-to-emit dose criteria found in the regulations. The purpose of this document is to describe the facility radionuclide air emission sampling program and provide current and historical facility emission point system performance, operation, and design information. A description of the buildings, exhaust points, control technologies, and sample extraction details is provided for each registered or deregistered facility emission point. Additionally, applicable stack sampler configuration drawings, figures, and photographs are provided.
Date: April 8, 2009
Creator: Barfuss, Brad C.; Barnett, J. M. & Ballinger, Marcel Y.
Object Type: Report
System: The UNT Digital Library
Proliferation Resistance and Physical Protection Evaluation Methodology Development and Applications (open access)

Proliferation Resistance and Physical Protection Evaluation Methodology Development and Applications

An overview of the technical progress and accomplishments on the evaluation methodology for proliferation resistance and physical protection of Generation IV nuclear energy Systems.
Date: July 8, 2009
Creator: Bari, Robert A.; Peterson, Per F.; Therios, Ike U. & Whitlock, Jeremy
Object Type: Report
System: The UNT Digital Library
The Animal Welfare Act: Background and Selected Legislation (open access)

The Animal Welfare Act: Background and Selected Legislation

None
Date: December 8, 2009
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
"Research to Improve the Efficacy of Captive Broodstock Programs and Advance Hatchery Reform Throughout the Columbia River Basin." [from the Abstract], 2007-2008 Annual Progress Report. (open access)

"Research to Improve the Efficacy of Captive Broodstock Programs and Advance Hatchery Reform Throughout the Columbia River Basin." [from the Abstract], 2007-2008 Annual Progress Report.

This project was developed to conduct research to improve the efficacy of captive broodstock programs and advance hatchery reform throughout the Columbia river basin. The project has three objectives: (1) maintain adaptive life history characteristics in Chinook salmon, (2) improve imprinting in juvenile sockeye salmon, and (3) match wild phenotypes in Chinook and sockeye salmon reared in hatcheries. A summary of the results are as follows: Objective 1: Adult and jack Chinook salmon males were stocked into four replicate spawning channels at a constant density (N = 16 per breeding group), but different ratios, and were left to spawn naturally with a fixed number of females (N = 6 per breeding group). Adult males obtained primary access to females and were first to enter the nest at the time of spawning. Jack male spawning occurred primarily by establishing satellite positions downstream of the courting pair, and 'sneaking' into the nest at the time of spawning. Male dominance hierarchies were fairly stable and strongly correlated with the order of nest entry at the time of spawning. Spawning participation by jack and adult males is consistent with a negative frequency dependent selection model, which means that selection during spawning favors the rarer …
Date: April 8, 2009
Creator: Berejikian, Barry A.
Object Type: Report
System: The UNT Digital Library
"The Success of Captive Broodstock Programs Depends on High In-Culture Survival, ..." [from the Abstract], 2006-2007 Progress Report. (open access)

"The Success of Captive Broodstock Programs Depends on High In-Culture Survival, ..." [from the Abstract], 2006-2007 Progress Report.

The success of captive broodstock programs depends on high in-culture survival, appropriate development of the reproductive system, and the behavior and survival of cultured salmon after release, either as adults or juveniles. Continuing captive broodstock research designed to improve technology is being conducted to cover all major life history stages of Pacific salmon. Accomplishments detailed in this report are listed below by major objective. Objective 1: This study documented that captively reared Chinook exhibited spawn timing similar to their founder anadromous population. An analysis of spawn timing data of captively reared Chinook salmon that had received different levels of antibiotic treatment did not suggest that antibiotic treatments during the freshwater or seawater phase of the life cycle affects final maturation timing. No effect of rearing density was found with respect to spawn timing or other reproductive behaviors. Objective 2: This study investigated the critical period(s) for imprinting for sockeye salmon by exposing juvenile salmon to known odorants at key developmental stages. Molecular assessments of imprinting-induced changes in odorant receptor gene expression indicated that regulation of odorant expression differs between coho and sockeye salmon. While temporal patterns differ between these species, exposure to arginine elicited increases in odorant receptor mRNA expression …
Date: April 8, 2009
Creator: Berejikian, Barry A.
Object Type: Report
System: The UNT Digital Library
The National Security Council: An Organizational Assessment (open access)

The National Security Council: An Organizational Assessment

The National Security Council (NSC) was established in 1947. This report describes the history of the NSC, how is structure and influence have varied over the years from one Administration to another, what its current structure and who its current members are, varying opinions as to what the role of the NSC should be, and future developments for the NSC.
Date: June 8, 2009
Creator: Best, Richard A., Jr.
Object Type: Report
System: The UNT Digital Library
Results from the B Factories (open access)

Results from the B Factories

These proceedings are based on lectures given at the Helmholtz International Summer School Heavy Quark Physics at the Bogoliubov Laboratory of Theoretical Physics, Dubna, Russia, during August 2008. I review the current status of CP violation in B meson decays from the B factories. These results can be used, along with measurements of the sides of the Unitarity Triangle, to test the CKM mechanism. In addition I discuss experimental studies of B decays to final states with 'spin-one' particles.
Date: January 8, 2009
Creator: Bevan, A. & /Queen Mary, U. of London
Object Type: Article
System: The UNT Digital Library
The UNESCO World Heritage Convention: Congressional Issues (open access)

The UNESCO World Heritage Convention: Congressional Issues

This report provides background information on the World Heritage Convention, outlines U.S. participation and funding, and highlights criteria for adding and removing sites from the World Heritage Lists. It also discusses possible issues for the 111th Congress.
Date: December 8, 2009
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
Analytical SuperSTEM for extraterrestrial materials research (open access)

Analytical SuperSTEM for extraterrestrial materials research

Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried out with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification …
Date: September 8, 2009
Creator: Bradley, J P & Dai, Z R
Object Type: Article
System: The UNT Digital Library
THE THICKNESS DEPENDENCE OF OXYGEN PERMEABILITY IN SOL-GEL DERIVED CGO-COFE2O4 THIN FILMS ON POROUS CERAMIC SUBSTRATES: A SPUTTERED BLOCKING LAYER FOR THICKNESS CONTROL (open access)

THE THICKNESS DEPENDENCE OF OXYGEN PERMEABILITY IN SOL-GEL DERIVED CGO-COFE2O4 THIN FILMS ON POROUS CERAMIC SUBSTRATES: A SPUTTERED BLOCKING LAYER FOR THICKNESS CONTROL

Mixed conductive oxides are a topic of interest for applications in oxygen separation membranes as well as use in producing hydrogen fuel through the partial oxidation of methane. The oxygen flux through the membrane is governed both by the oxygen ionic conductivity as well as the material's electronic conductivity; composite membranes like Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} (CGO)-CoFe{sub 2}O{sub 4} (CFO) use gadolinium doped ceria oxides as the ionic conducting material combined with cobalt iron spinel which serves as the electronic conductor. In this study we employ {approx} 50 nm sputtered CeO{sub 2} layers on the surface of porous CGO ceramic substrates which serve as solution 'blocking' layers during the thin film fabrication process facilitating the control of film thickness. Films with thickness of {approx} 2 and 4 microns were prepared by depositing 40 and 95 separate sol-gel layers respectively. Oxygen flux measurements indicated that the permeation increased with decreasing membrane thickness; thin film membrane with thickness on the micron level showed flux values an order of magnitude greater (0.03 {micro}mol/cm{sup 2} s) at 800 C as compared to 1mm thick bulk ceramic membranes (0.003 {micro}mol/cm{sup 2}).
Date: January 8, 2009
Creator: Brinkman, K
Object Type: Article
System: The UNT Digital Library
Condensates in Quantum Chromodynamics and the Cosmological Constant (open access)

Condensates in Quantum Chromodynamics and the Cosmological Constant

Casher and Susskind have noted that in the light-front description, spontaneous chiral symmetry breaking in quantum chromodynamics (QCD) is a property of hadronic wavefunctions and not of the vacuum. Here we show from several physical perspectives that, because of color confinement, quark and gluon QCD condensates are associated with the internal dynamics of hadrons. We discuss condensates using condensed matter analogues, the AdS/CFT correspondence, and the Bethe-Salpeter/Dyson-Schwinger approach for bound states. Our analysis is in agreement with the Casher and Susskind model and the explicit demonstration of 'in-hadron' condensates by Roberts et al., using the Bethe-Salpeter/Dyson-Schwinger formalism for QCD bound states. These results imply that QCD condensates give zero contribution to the cosmological constant, since all of the gravitational effects of the in-hadron condensates are already included in the normal contribution from hadron masses.
Date: May 8, 2009
Creator: Brodsky, Stanley J. & Shrock, Robert
Object Type: Article
System: The UNT Digital Library
Green Jobs, Education, and Workforce Training in S. 1733 and H.R. 2454 (open access)

Green Jobs, Education, and Workforce Training in S. 1733 and H.R. 2454

This report summarizes and compares provisions for green jobs training and worker adaptation assistance for climate change mitigation impacts in two recent bills.
Date: December 8, 2009
Creator: Campbell, Richard J.
Object Type: Report
System: The UNT Digital Library
Thermo-Mechanical Response of a TRISO Fuel Particle in a Fusion/Fission Engine for Incineration of Weapons Grade Plutonium (open access)

Thermo-Mechanical Response of a TRISO Fuel Particle in a Fusion/Fission Engine for Incineration of Weapons Grade Plutonium

The Laser Inertial Fusion-based (LIFE) engine is an advanced energy concept under development at Lawrence Livermore National Laboratory (LLNL). LIFE engine could be used to drive a subcritical fission blanket with fertile or fissile fuel. Current LIFE engine designs envisages fuel in pebble bed form with TRISO (tristructural isotropic) particles embedded in a graphite matrix, and pebbles flowing in molten salt Flibe (2LiF+BeF{sub 2}) coolant at T {approx} 700C. Weapons-grade plutonium (WGPu) fuel is an attractive option for LIFE engine involving the achievement of high fractional burnups in a short lifetime frame. However, WGPu LIFE engine operating conditions of high neutron fast fluence, high radiation damage, and high Helium and Hydrogen production pose severe challenges for typical TRISO particles. The thermo-mechanical fuel performance code HUPPCO (High burn-Up fuel Pebble Performance COde) currently under development accounts for spatial and time dependence of the material elastic properties, temperature, and irradiation swelling and creep mechanisms. In this work, some aspects of the thermo-mechanical response of TRISO particles used for incineration of weapons grade fuel in LIFE engine are analyzed. Preliminary results show the importance of developing reliable high-fidelity models of the performance of these new fuel designs and the need of new experimental …
Date: December 8, 2009
Creator: Caro, M.; DeMange, P.; Marian, J. & Caro, A.
Object Type: Article
System: The UNT Digital Library
STRUCTURAL ANNOTATION OF EM IMAGES BY GRAPH CUT (open access)

STRUCTURAL ANNOTATION OF EM IMAGES BY GRAPH CUT

Biological images have the potential to reveal complex signatures that may not be amenable to morphological modeling in terms of shape, location, texture, and color. An effective analytical method is to characterize the composition of a specimen based on user-defined patterns of texture and contrast formation. However, such a simple requirement demands an improved model for stability and robustness. Here, an interactive computational model is introduced for learning patterns of interest by example. The learned patterns bound an active contour model in which the traditional gradient descent optimization is replaced by the more efficient optimization of the graph cut methods. First, the energy function is defined according to the curve evolution. Next, a graph is constructed with weighted edges on the energy function and is optimized with the graph cut algorithm. As a result, the method combines the advantages of the level set method and graph cut algorithm, i.e.,"topological" invariance and computational efficiency. The technique is extended to the multi-phase segmentation problem; the method is validated on synthetic images and then applied to specimens imaged by transmission electron microscopy(TEM).
Date: May 8, 2009
Creator: Chang, Hang; Auer, Manfred & Parvin, Bahram
Object Type: Article
System: The UNT Digital Library
Thailand: Background and U.S. Relations (open access)

Thailand: Background and U.S. Relations

This report discusses the current political and economic state of Thailand, particularly in the wake of the September 2006 coup that displaced Prime Minister Thaksin Shinawatra and has resulted in continuing instability. This report also discusses the ongoing U.S.-Thai relationship, despite different policies in such areas as human rights.
Date: June 8, 2009
Creator: Chanlett-Avery, Emma
Object Type: Report
System: The UNT Digital Library
Laser Created Relativistic Positron Jets (open access)

Laser Created Relativistic Positron Jets

Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the …
Date: October 8, 2009
Creator: Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N et al.
Object Type: Article
System: The UNT Digital Library
Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations Using ARM Observations (open access)

Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations Using ARM Observations

The problems addressed by this work include cloud optical depth retrieval from satellite and surface data and 3D radiative transfer in dynamical models.
Date: December 8, 2009
Creator: Cober, Stewart G. & Barker, Howard
Object Type: Report
System: The UNT Digital Library