Partner
UNT Libraries Government Documents Department
241
Oklahoma Historical Society
44
UNT Libraries Special Collections
44
Sterling Municipal Library
12
FM Buck Richards Library
5
Patrick Heath Public Library
5
UNT Libraries
5
Virgil and Josephine Gordon Memorial Library
5
Alvin Community College
4
Carl Albert Congressional Research and Studies Center
4
46 More
Collection
Office of Scientific & Technical Information Technical Reports
153
Texas Digital Newspaper Program
89
Congressional Research Service Reports
67
Oklahoma Digital Newspaper Program
48
Tocker Foundation Grant
40
KXAS-NBC 5 News Collection
21
Government Accountability Office Reports
16
The Baytown Sun
12
Altus Times-Democrat
10
Chickasha Newspaper Collection
10
82 More
Degree Department
Country
States
Year
Month
Day
Language
Energetic Ion Transport and Concomitant Change of the Fusion Reactivity during Reconnection Events in Spherical Tori
Effects of MHD reconnection events on the beam-plasma fusion reactivity and transport of the beam ions are studied. Based on the analysis of fusion reactivity changes induced by MHD events, the conclusion is drawn that the strong drops of the neutron yield during sawtooth crashes observed in the National Spherical Torus experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)] are associated with both a particle redistribution inside the plasma and a loss of the beam ions. Mechanisms of the energetic ion transport during sawtooth crashes are analyzed, in particular, with the use of the resonance adiabatic invariant derived in this paper. A numerical simulation of the particle motion during a sawtooth crash in NSTX is done with the code OFSEF [Ya. I. Kolesnichenko, et al., Nucl. Fusion 40, 1325 (2000)] extended for a better description of the particle precession. It is shown that the motion of toroidally passing particles in NSTX can become stochastic under the influence of a crash. This stochasticity, as well as the motion along the resonance island, leads to the escape of some particles from the plasma.
Date:
July 6, 2004
Creator:
Kolesnichenko, Ya. I.; Lutsenko, V. V.; White, R. B. & Yakovenko, Yu. V.
Object Type:
Report
System:
The UNT Digital Library
Keeping Nuclear as a Viable Option for Electric Power Generation in the Brazilian Matrix
This paper discusses all alternatives that are part of the general solution for the electric energy problem in Brazil.
Date:
October 6, 2004
Creator:
Henning, F.
Object Type:
Article
System:
The UNT Digital Library
An Integrated Site-Wide Assessment of Nuclear Wastes to Remain at the Hanford Site, Washington
Since its creation in 1943 until 1988, the Hanford Site, a facility in the U.S. Department of Energy (DOE) nuclear weapons complex was dedicated to the production of weapons grade plutonium and other special nuclear materials. The Hanford Site is located in eastern Washington State and is bordered on the north and east by the Columbia River. Decades of creating fuel, irradiating it in reactors, and processing it to recover nuclear material left numerous waste sites that involved the discharge of contaminated liquids and the disposal of contaminated solid waste. Today, the primary mission of the Hanford Site is to safely cleanup and manage the site's legacy waste. A site-wide risk assessment methodology has been developed to assist the DOE, as well as state and federal regulatory agencies, in making decisions regarding needed remedial actions at past waste sites, and safe disposal of future wastes. The methodology, referred to as the System Assessment Capability (SAC), utilizes an integrated set of models that track potential contaminants from inventory through vadose zone, groundwater, Columbia River and air pathways to human and ecological receptors.
Date:
October 6, 2004
Creator:
Morse, J.G.; Bryce, R.W.; Hildebrand, R.D. & Kincaid, C.T.
Object Type:
Article
System:
The UNT Digital Library
Long Term Remote Monitoring of TCE Contaminated Groundwater at Savannah River Site
The purpose of this study was to develop a mobile self powered remote monitoring system enhanced for field deployment at Savannah River Site (SRS). The system used a localized power source with solar recharging and has wireless data collection, analysis, transmission, and data management capabilities. The prototype was equipped with a Hydrolab's DataSonde 4a multi-sensor array package managed by a Supervisory Control and Data Acquisition (SCADA) system, with an adequate pumping capacity of water samples for sampling and analysis of Trichloroethylene (TCE) in contaminated groundwater wells at SRS. This paper focuses on a study and technology development efforts conducted at the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU) to automate the sampling of contaminated wells with a multi-sensor array package developed using COTS (Commercial Off The shelf) parts. Bladder pumps will pump water from different wells to the sensors array, water quality TCE indicator parameters are measured (i.e. pH, redox, ORP, DO, NO3 -, Cl-). In order to increase user access and data management, the system was designed to be accessible over the Internet. Remote users can take sample readings and collect data remotely over a web. Results obtained at Florida International University in-house testing and …
Date:
October 6, 2004
Creator:
Duran, C.; Gudavalli, R.; Lagos, L.; Tansel, B.; Varona, J. & Allen, M.
Object Type:
Article
System:
The UNT Digital Library
Development of a Monolithic Research Reactor Fuel Type at Argonne National Laboratory
The Reduced Enrichment for Research and Test Reactors (RERTR) program has been tasked with the conversion of research reactors from highly enriched to low-enriched uranium (LEU). To convert several high power reactors, monolithic fuel, a new fuel type, is being developed. This fuel type replaces the standard fuel dispersion with a fuel alloy foil, which allows for fuel densities far in excess of that found in dispersion fuel. The single-piece fuel foil also contains a significantly lower interface area between the fuel and the aluminum in the plate than the standard fuel type, limiting the amount of detrimental fuel-aluminum interaction that can occur. Implementation of monolithic fuel is dependant on the development of a suitable fabrication method as traditional roll-bonding techniques are inadequate.
Date:
October 6, 2004
Creator:
Clark, C. R. & Briggs, R. J.
Object Type:
Article
System:
The UNT Digital Library
An Expert System to Analyze Homogeneity in Fuel Element Plates for Research Reactors
In the manufacturing control of Fuel Element Plates for Research Reactors, one of the problems to be addressed is how to determine the U-density homogeneity in a fuel plate and how to obtain qualitative and quantitative information in order to establish acceptance or rejection criteria for such, as well as carrying out the quality follow-up. This paper is aimed at developing computing software which implements an Unsupervised Competitive Learning Neural Network for the acknowledgment of regions belonging to a digitalized gray scale image. This program is applied to x-ray images. These images are generated when the x-ray beams go through a fuel plate of approximately 60 cm x 8 cm x 0.1 cm thick. A Nuclear Fuel Element for Research Reactors usually consists of 18 to 22 of these plates, positioned in parallel, in an arrangement of 8 x 7 cm. Carrying out the inspection of the digitalized x-ray image, the neural network detects regions with different luminous densities corresponding to U-densities in the fuel plate. This is used in quality control to detect failures and verify acceptance criteria depending on the homogeneity of the plate. This modality of inspection is important as it allows the performance of non-destructive measurements …
Date:
October 6, 2004
Creator:
Tolosa, S.C. & Marajofsky, A.
Object Type:
Article
System:
The UNT Digital Library
The Optimum Plutonium Inert Matrix Fuel Form for Reactor-Based Plutonium Disposition
The University of Florida has underway an ongoing research program to validate the economic, operational and performance benefits of developing an inert matrix fuel (IMF) for the disposition of the U.S. weapons plutonium (Pu) and for the recycle of reprocessed Pu. The current fuel form of choice for Pu disposition for the Department of Energy is as a mixed oxide (MOX) (PuO2/UO2). We will show analyses that demonstrate that a Silicon Carbide (SiC) IMF offers improved performance capabilities as a fuel form for Pu recycle and disposition. The reason that UF is reviewing various materials to serve as an inert matrix fuel is that an IMF fuel form can offer greatly reduced Pu and transuranic isotope (TRU) production and also improved thermal performance characteristics. Our studies showed that the Pu content is reduced by an order of magnitude while centerline fuel temperatures are reduced approximately 380 degrees centigrade compared to MOX. These reduced temperatures result in reduced stored heat and thermal stresses in the pellet. The reduced stored heat reduces the consequences of the loss of coolant accident, while the reduced temperatures and thermal stresses yield greatly improved fuel performance. Silicon Carbide is not new to the nuclear industry, being …
Date:
October 6, 2004
Creator:
Tulenko, J.S.; Wang, J. & Acosta, C.
Object Type:
Article
System:
The UNT Digital Library
Simulation of Ventilation Efficiency, Temperatures, and Relative Humidities in Emplacement Drifts at Yucca Mountain, Nevada, Using Monte Carlo and Composite Thermal-Pulse Methods
Predictions of waste canister and repository driftwall temperatures as a function of space and time are of fundamental importance to evaluating pre-closure and post-closure design requirements and performance assessment of the proposed repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. Variations in the lithostratigraphic features in densely welded and crystallized rocks of the 12.8-million-year-old Topopah Spring Tuff, especially the porosity resulting from lithophysal cavities, are projected 50 to 800 m from the Enhanced Characterization of the Repository Block cross drift to a simulated ''Panel 1'' emplacement drift. Lithophysal cavity porosity varies from 0.00 to 0.05 cm{sup 3}/cm{sup 3} in the middle nonlithophysal zone and from 0.03 to 0.28 cm{sup 3}/cm{sup 3} in the lower lithophysal zone. Many thermal properties are related to lithophysal cavity porosity, and computer code titled ''Monte Carlo Simulation of Ventilation'' (MCSIMVENT) has been developed for simulating statistical variability and uncertainty along the simulated emplacement drift. The MCSIMVENT code, which is based on a composite thermal-pulse calculation, is used to calculate pre-closure ventilation efficiency and peak post-closure temperatures and relative humidities along the simulated emplacement drift for as much as 1,000 years. Variations in lithophysal porosity along the drift can result in …
Date:
April 6, 2004
Creator:
Case, J. & Buesch, D.
Object Type:
Report
System:
The UNT Digital Library
New Reactor Design and Analysis of Non Linear Vibrations of Doubly Curved Shallow Shell Under a Thermal Gradient
The present study concerns with the effects of material orthotropy,curvature, shear ratio and circumferential modulus under the influence of a temperature distribution throughout the shell structure. Here analysis is restricted to the study of nonlinear vibration of a doubly curved shell structure considering the periodic response of a simple bending mode due to curtailment of pages. Solutions of the problems with suitable illustrations are also presented.
Date:
October 6, 2004
Creator:
Chanda, Subhash
Object Type:
Article
System:
The UNT Digital Library
Proteomic Dissection of the Mitochondrial DNA Metabolism Apparatus in Arabidopsis
This study involves the investigation of nuclear genetic components that regulate mitochondrial genome behavior in higher plants. The approach utilizes the advanced plant model system of Arabidopsis thaliana to identify and functionally characterize multiple components of the mitochondrial DNA replication, recombination and mismatch repair system and their interaction partners. The rationale for the research stems from the central importance of mitochondria to overall cellular metabolism and the essential nature of the mitochondrial genome to mitochondrial function. Relatively little is understood about mitochondrial DNA maintenance and transmission in higher eukaryotes, and the higher plant mitochondrial genome displays unique properties and behavior. This investigation has revealed at least three important properties of plant mitochondrial DNA metabolism components. (1) Many are dual targeted to mitochondrial and chloroplasts by novel mechanisms, suggesting that the mitochondria a nd chloroplast share their genome maintenance apparatus. (2)The MSH1 gene, originating as a component of mismatch repair, has evolved uniquely in plants to participate in differential replication of the mitochondrial genome. (3) This mitochondrial differential replication process, termed substoichiometric shifting and also involving a RecA-related gene, appears to represent an adaptive mechanism to expand plant reproductive capacity and is likely present throughout the plant kingdom.
Date:
January 6, 2004
Creator:
Mackenzie, SAlly A.
Object Type:
Report
System:
The UNT Digital Library
Recharge and Lateral Groundwater Flow Boundary Conditions for the Saturated Zone Site-Scale Flow and Transport Model
This analysis is designed to use existing modeling and analysis results as the basis for estimated groundwater flow rates into the saturated zone (SZ) site-scale model domains, both as recharge (infiltration) at the upper boundary (water table), and as underflow at the lateral boundaries. Specifically, this work compiles information on the recharge boundary conditions supplied to the base-case and alternate SZ site-scale flow models taken from (1) distributed recharge from the 1997 (D'Agnese et al. 1997 [DIRS 100131]) or 2001 (D'Agnese et al. 2002 [DIRS 158876]) SZ regional-scale (Death Valley Regional Flow System [DVRFS]) model; (2) recharge below the area of the 1997 (Wu et al. 1997 [DIRS 156453]) or 2003 (BSC 2004 [DIRS 169861]) unsaturated zone (UZ) site-scale flow model; and (3) focused recharge along Fortymile Wash. In addition, this analysis includes extraction of the groundwater flow rates simulated by the 1997 and 2001 DVRFS models coincident with the lateral boundaries of the SZ site-scale flow models. The fluxes from the 1997 DVRFS were used to calibrate the base-case SZ site-scale flow model. The 2001 DVRFS fluxes are used in the alternate SZ site-scale flow model.
Date:
October 6, 2004
Creator:
James, S.
Object Type:
Report
System:
The UNT Digital Library
Gothic Model of BWR Secondary Containment Drawdown Analyses
This article introduces a GOTHIC version 7.1 model of the Secondary Containment Reactor Building Post LOCA drawdown analysis for a BWR. GOTHIC is an EPRI sponsored thermal hydraulic code. This analysis is required by the Utility to demonstrate an ability to restore and maintain the Secondary Containment Reactor Building negative pressure condition. The technical and regulatory issues associated with this modeling are presented. The analysis includes the affect of wind, elevation and thermal impacts on pressure conditions. The model includes a multiple volume representation which includes the spent fuel pool. In addition, heat sources and sinks are modeled as one dimensional heat conductors. The leakage into the building is modeled to include both laminar as well as turbulent behavior as established by actual plant test data. The GOTHIC code provides components to model heat exchangers used to provide fuel pool cooling as well as area cooling via air coolers. The results of the evaluation are used to demonstrate the time that the Reactor Building is at a pressure that exceeds external conditions. This time period is established with the GOTHIC model based on the worst case pressure conditions on the building. For this time period the Utility must assume the …
Date:
October 6, 2004
Creator:
Hansen, Paul N.
Object Type:
Article
System:
The UNT Digital Library
Photometry of SN 2002ic and implications for the progenitor mass-loss history
We present new pre-maximum and late-time optical photometry of the Type Ia/IIn supernova 2002ic. These observations are combined with the published V-band magnitudes of Hamuy et al. (2003) and the VLT spectrophotometry of Wang et al. (2004) to construct the most extensive light curve to date of this unusual supernova. The observed flux at late time is significantly higher relative to the flux at maximum than that of any other observed Type Ia supernova and continues to fade very slowly a year after explosion. Our analysis of the light curve suggests that a non-Type Ia supernova component becomes prominent {approx}20 days after explosion. Modeling of the non-Type Ia supernova component as heating from the shock interaction of the supernova ejecta with pre-existing circumstellar material suggests the presence of a {approx}1.7 x 1015 cm gap or trough between the progenitor system and the surrounding circumstellar material. This gap could be due to significantly lower mass-loss {approx}15 (nu{sub omega}/10 km/s) -1 years prior to explosion or evacuation of the circumstellar material by a low-density fast wind. The latter is consistent with observed properties of proto-planetary nebulae and with models of white-dwarf + asymptotic giant branch star progenitor systems with the asymptotic giant …
Date:
May 6, 2004
Creator:
Wood-Vasey, W.M.; Wang, L. & Aldering, G.
Object Type:
Article
System:
The UNT Digital Library
Solutions to Obsolete Equipment in Operating Nuclear Power Plants
This presentation discusses solutions to obsolete equipment in operating nuclear power plants.
Date:
October 6, 2004
Creator:
Donovan, M.
Object Type:
Presentation
System:
The UNT Digital Library
A Small Secure Transportable Autonomous Lead-Cooled Fast Reactor for Deployment at Remote Sites
This presentation discusses a small secure transportable autonomous lead-cooled fast reactor for deployment at remote sites.
Date:
October 6, 2004
Creator:
Sienicki, J .J.; Smith, M. A.; Mosseytsev, A.V.; Yang, W. S. & Wade, D. C.
Object Type:
Presentation
System:
The UNT Digital Library
Coated Metal Articles and Method of Making
The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.
Date:
July 6, 2004
Creator:
Boller, Ernest R. & Eubank, Lowell D.
Object Type:
Text
System:
The UNT Digital Library
Static hybrid quarkonium potential with improved staggered quarks
The authors are studying the effects of light dynamical quarks on the excitation energies of a flux tube between a static quark and antiquark. They report preliminary results of an analysis of the ground state potential and the {Sigma}{prime}{sub g}{sup +} and II{sub u} potentials. They have measured these potentials on closely matched ensembles of gauge configurations, generated in the quenched approximation and with 2+1 flavors of Asqtad improved staggered quarks.
Date:
January 6, 2004
Creator:
Bernard, C.
Object Type:
Article
System:
The UNT Digital Library
FACTORS INFLUENCING THE FLOW AND FRACTURE OF SUPERPLASTIC CERAMICS: FINAL TECHNICAL REPORT
This is the Final Technical Report describing the achievements on this DOE program. This research program was initiated with the objective of obtaining a better understanding of the flow, and especially the superplastic flow, of representative ceramics. Detailed experiments were undertaken on the yttria-stabilized tetragonal zirconia (Y-TZP) and on various composite materials containing Y-TZP and Al{sub 2}O{sub 3}. In addition, a comprehensive theoretical interpretation was developed which showed, for the first time, that the superplasticity of ceramic materials has very significant differences from the conventional superplastic flow in metals.
Date:
February 6, 2004
Creator:
Langdon, Terence G.
Object Type:
Report
System:
The UNT Digital Library
A process for reducing the licensing burden for new products containing depleted uranium.
This report is intended to provide guidance on the process for petitioning the U.S. Nuclear Regulatory Commission (NRC) to initiate a rulemaking that could reduce the licensing burden for new products containing depleted uranium (DU), which are being investigated by the DU Uses Research and Development (R&D) Program at Oak Ridge National Laboratory (ORNL). The focus is on requirements of the NRC rulemaking process applicable to establishing new exemptions or general licenses for products and devices containing source material. NRC policies and guidance regarding such requirements are described, including a 1965 policy statement on approval of new exemptions for products containing radionuclides (''Federal Register'', Volume 30, page 3462 [30 FR 3462]; March 16, 1965) and Regulatory Guide 6.7, which addresses the contents of environmental reports that support rulemaking petitions seeking exemptions for radionuclide-containing products. Methodologies for calculating radiological and nonradiological impacts on human health (i.e., risks) associated with distributing, using, and disposing of DU-containing products are presented. Also, methodologies for completing assessments of the potential effects of accidents involving new DU-containing products and of product misuse are described. The report recommends that the U.S. Department of Energy formulate a regulatory plan for deployment of DU-containing products in areas that are …
Date:
January 6, 2004
Creator:
Ranek, N. L.; Kamboj, S.; Hartmann, H. M. & Avci, H.
Object Type:
Report
System:
The UNT Digital Library
Recent results using all point quark propagators
Pseudofermion methods for extracting all-point quark propagators are reviewed, with special emphasis on techniques for reducing or eliminating autocorrelations induced by low eigenmodes of the quark Dirac operator. Recent applications, including high statistics evaluations of hadronic current correlators and the pion form factor, are also described.
Date:
January 6, 2004
Creator:
Duncan, A. & Yoo, E. Eichten and J.
Object Type:
Article
System:
The UNT Digital Library
The CDF Silicon Vertex Detector for Run II
The 8 layer, 720k channel CDF Run II silicon detector is an essential part of the heavy flavor tagging and forward tracking capabilities of the CDF experiment. A summary of the experience in commissioning and operating this double-sided detector during the first 2 years of Run II is presented. The performances of the silicon in term of resolution, efficiency are also described. The results of the studies of radiation damage and the expected operational limits are discussed. A short description of the SVT, the Level 2 Silicon Vertex Trigger, one of the major upgrades related to the new silicon device is also presented. Finally, some of the many physics results achieved by means of the new Silicon+SVT machinery are also reviewed.
Date:
January 6, 2004
Creator:
Rossin, R.
Object Type:
Article
System:
The UNT Digital Library
Features, Events, and Processes in UZ and Transport
The purpose of this report is to evaluate and document the inclusion or exclusion of the unsaturated zone (UZ) features, events, and processes (FEPs) with respect to modeling that supports the total system performance assessment (TSPA) for license application (LA) for a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either ''Included'' or ''Excluded'', is given for each FEP, along with the technical basis for the screening decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs deal with UZ flow and radionuclide transport, including climate, surface water infiltration, percolation, drift seepage, and thermally coupled processes. This analysis summarizes the implementation of each FEP in TSPA-LA (that is, how the FEP is included) and also provides the technical basis for exclusion from TSPA-LA (that is, why the FEP is excluded). This report supports TSPA-LA.
Date:
November 6, 2004
Creator:
Persoff, P.
Object Type:
Report
System:
The UNT Digital Library
Current Status and the Future of the Irradiation Services in the HANARO Reactor
As a central plant of the Korea Atomic Energy Research Institute, Hi-flux Advanced Neutron Application Reactor, the HANARO, has been playing an important role in nuclear technology development and the utilization of radiation technology. HANARO's reputation such as a stable operation, build up of various research results and the support of the government picks up more research needs. Major utilizations of the HANARO reactor in Korea have focused on its irradiation service. It offers various types of irradiation tests for fuel and materials, which provides us with very useful information for designing and evaluating reactor materials. A number of irradiation capsules have been developed and installed in HANARO. Necessary technologies regarding HANARO are still being developed. The on-going and future researches, especially, about fuel and material irradiation including university programs and the current utilization statistics of the HANARO research reactor, are described in this article.
Date:
October 6, 2004
Creator:
Kang, Y. H.; Kim, B. G.; Cho, M. S.; Choo, K. N. & Kim, Y. J.
Object Type:
Article
System:
The UNT Digital Library
Electron exchange along the tercyclopentadienyltrimetallic scaffold: Kinetics, equilibria, and bond strengths
None
Date:
January 6, 2004
Creator:
Cammack, J. Kevin; Amouri, Hani; Leonard, Philip W.; Myrabo, Randy L. & Vollhardt, Peter C.
Object Type:
Article
System:
The UNT Digital Library