The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors (open access)

The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors

A major concern in the design of thick-liquid protected inertial fusion reactors of all types is the dynamic response of the shielding liquid to the pulsed explosions. Induced liquid motion can stress and damage solid chamber structures such as the firstwall. In a z-pinch based inertial fusion (Z-IFE) reactor this issue becomes particularly critical due to the relatively large proposed target yields of several GJ. In this paper we summarize an analysis of the liquid response taking into account ablation of target facing surfaces, pocket venting, and neutron isochoric heating. The impact of varying several reactor parameters is also discussed.
Date: October 5, 2005
Creator: Abbott, R P
Object Type: Article
System: The UNT Digital Library
Impact of spectral transition zone in reference ENIGMA configuration. (open access)

Impact of spectral transition zone in reference ENIGMA configuration.

The gas-cooled fast reactor (GFR) is one of six advanced nuclear energy systems being studied under the auspices of the Gen IV International Forum (GIF). In a bilateral International Nuclear Energy Research Initiative (I-NERI) project French and U.S. national laboratories, industry, and universities are collaborating on the development of the GFR. This effort is led by the ANL in the U.S. and the CEA in France. Some of the attractions of the GFR include: (1) Hard spectrum and core breeding ratio, BR {approx} 1. These features allow minimal waste production, improved transmutation capability, optimal and flexible use of natural resources, potentially better economy (because of use of higher power density relative to current thermal gas-cooled systems), and improved non-proliferation (no fertile blanket); (2) Temperature resistant fuel and structure elements that are favorable to tight fission product confinement and system operation at high temperature; (3) High temperature and transparent helium (He) gas coolant that allows a high thermodynamic conversion efficiency, other energy applications (e.g., hydrogen production), and ease of in-service inspection and repair; and (4) Possible direct energy conversion cycle leading to a simpler design, increased conversion efficiency, and lower investment costs. The French strategy for advanced systems includes the development …
Date: October 5, 2005
Creator: Aliberti, G.; Palmiotti, G.; Taiwo, T. A. & Tommasi, J.
Object Type: Report
System: The UNT Digital Library
Filtered cathodic arc deposition with ion-species-selectivebias (open access)

Filtered cathodic arc deposition with ion-species-selectivebias

A dual-cathode arc plasma source was combined with acomputer-controlled bias amplifier such as to synchronize substrate biaswith the pulsed production of plasma. In this way, bias can be applied ina material-selective way. The principle has been applied to the synthesismetal-doped diamond-like carbon films, where the bias was applied andadjusted when the carbon plasma was condensing, and the substrate was atground when the metal was incorporated. In doing so, excessive sputteringby too-energetic metal ions can be avoided while the sp3/sp2 ratio can beadjusted. It is shown that the resistivity of the film can be tuned bythis species-selective bias. The principle can be extended tomultiple-material plasma sources and complex materials
Date: October 5, 2006
Creator: Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon & Lim, SunnieH.N.
Object Type: Article
System: The UNT Digital Library
Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages (open access)

Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain repository. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022 (Alloy 22), the environment is represented by aqueous brine films present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the tensile stress is principally from weld induced residual stress. SCC has historically been separated into ''initiation'' and ''propagation'' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding); or that develop from corrosion processes such as pitting or dissolution of inclusions. To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment to determine the time to through-wall …
Date: October 5, 2004
Creator: Andresen, P.; Gordon, G. & Lu, S.
Object Type: Report
System: The UNT Digital Library

Harnessing Innovation for a Renewable Energy Future

Keynote presentation given by Dan Arvizu at the Green Engineering Summit held in Anaheim, California on October 5, 2006.
Date: October 5, 2006
Creator: Arvizu, D.
Object Type: Presentation
System: The UNT Digital Library
Tracking the Sun II: The Installed Cost of Photovoltaics in the U.S. from 1998-2008 (open access)

Tracking the Sun II: The Installed Cost of Photovoltaics in the U.S. from 1998-2008

Installations of solar photovoltaic (PV) systems have been growing at a rapid pace in recent years. In 2008, 5,948 MW of PV was installed globally, up from 2,826 MW in 2007, and was dominated by grid-connected applications. The United States was the world's third largest PV market in terms of annual capacity additions in 2008, behind Spain and Germany; 335 MW of PV was added in the U.S. in 2008, 293 MW of which came in the form of grid-connected installations. Despite the significant year-on-year growth, however, the share of global and U.S. electricity supply met with PV remains small, and annual PV additions are currently modest in the context of the overall electric system. The market for PV in the U.S. is driven by national, state, and local government incentives, including up-front cash rebates, production-based incentives, requirements that electricity suppliers purchase a certain amount of solar energy, and Federal and state tax benefits. These programs are, in part, motivated by the popular appeal of solar energy, and by the positive attributes of PV - modest environmental impacts, avoidance of fuel price risks, coincidence with peak electrical demand, and the location of PV at the point of use. Given the …
Date: October 5, 2009
Creator: Barbose, Galen L.; Wiser, Ryan; Peterman, Carla & Darghouth, Naim
Object Type: Report
System: The UNT Digital Library
Food Safety: Oversight and Current Issues (open access)

Food Safety: Oversight and Current Issues

None
Date: October 5, 2007
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Gasoline Prices: New Legislation and Proposals (open access)

Gasoline Prices: New Legislation and Proposals

This report provides background information and analysis regarding oil related issues and issues beyond the Energy Policy Act.
Date: October 5, 2005
Creator: Behrens, Carl E. & Glover, Carol
Object Type: Report
System: The UNT Digital Library
Funnel cone for focusing intense ion beams on a target (open access)

Funnel cone for focusing intense ion beams on a target

We describe a funnel cone for concentrating an ion beam on a target. The cone utilizes the reflection characteristic of ion beams on solid walls to focus the incident beam andincrease beam intensity on target. The cone has been modeled with the TRIM code. A prototype has been tested and installed for use in the 350-keV K+ NDCX target chamber.
Date: October 5, 2009
Creator: Bieniosek, F.M.; Henestroza, E. & Ni, P.
Object Type: Article
System: The UNT Digital Library
General Management Laws and the 9/11 Commissions Proposed Office of National Intelligence Director (NIC) and National Counterterrorism Center (NCTC) (open access)

General Management Laws and the 9/11 Commissions Proposed Office of National Intelligence Director (NIC) and National Counterterrorism Center (NCTC)

None
Date: October 5, 2004
Creator: Brass, Clinton T. & Copeland, Curtis W.
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act and "Sound Science" (open access)

The Endangered Species Act and "Sound Science"

This report provides a context for evaluating legislative proposals through examples of how science has been used in selected cases, a discussion of the nature and role of science in general, and its role in the Endangered Species Act (ESA) process in particular, together with general and agency information quality requirements and policies, and a review of how the courts have viewed agency use of science.
Date: October 5, 2006
Creator: Buck, Eugene H.; Corn, M. Lynne & Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act and "Sound Science" (open access)

The Endangered Species Act and "Sound Science"

This report provides a context for evaluating legislative proposals through examples of how science has been used in selected cases, a discussion of the nature and role of science in general, and its role in the Endangered Species Act (ESA) process in particular, together with general and agency information quality requirements and policies, and a review of how the courts have viewed agency use of science.
Date: October 5, 2006
Creator: Buck, Eugene H.; Corn, M. Lynne & Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
Party Leaders in the House: Election, Duties, and Responsibilities (open access)

Party Leaders in the House: Election, Duties, and Responsibilities

This report discusses the roles and duties of party leaders in the U.S. House of Representatives.
Date: October 5, 2001
Creator: Carr, Thomas P.
Object Type: Report
System: The UNT Digital Library

Overview of the U.S. Department of Energy's Isotope Programs

This presentation provides an overview of the U.S. Department of Energy's Isotopes Program. The charter of the Isotope Programs covers the production and sale of radioactive and stable isotopes, associated byproducts, surplus materials, and related isotope services.
Date: October 5, 2004
Creator: Carty, J.
Object Type: Presentation
System: The UNT Digital Library
Acceleressence: Dark energy from a phase transition at the seesawscale (open access)

Acceleressence: Dark energy from a phase transition at the seesawscale

Simple models are constructed for ''acceleressence'' dark energy: the latent heat of a phase transition occurring in a hidden sector governed by the seesaw mass scale v{sup 2}/M{sub Pl}, where v is the electroweak scale and M{sub Pl} the gravitational mass scale. In our models, the seesaw scale is stabilized by supersymmetry, implying that the LHC must discover superpartners with a spectrum that reflects a low scale of fundamental supersymmetry breaking. Newtonian gravity may be modified by effects arising from the exchange of fields in the acceleressence sector whose Compton wavelengths are typically of order the millimeter scale. There are two classes of models. In the first class the universe is presently in a metastable vacuum and will continue to inflate until tunneling processes eventually induce a first order transition. In the simplest such model, the range of the new force is bounded to be larger than 25 {micro}m in the absence of fine-tuning of parameters, and for couplings of order unity it is expected to be {approx} 100 {micro}m. In the second class of models thermal effects maintain the present vacuum energy of the universe, but on further cooling, the universe will ''soon'' smoothly relax to a matter dominated …
Date: October 5, 2004
Creator: Chacko, Z.; Hall, Lawrence J. & Nomura, Yasunori
Object Type: Article
System: The UNT Digital Library
Heterogeneous Shallow-Shelf Carbonate Buildups in the Paradox Basin, Utah and Colorado: Targets for Increased Oil Production and Reserves Using Horizontal Drilling Techniques (open access)

Heterogeneous Shallow-Shelf Carbonate Buildups in the Paradox Basin, Utah and Colorado: Targets for Increased Oil Production and Reserves Using Horizontal Drilling Techniques

The Paradox Basin of Utah, Colorado, Arizona, and New Mexico contains nearly 100 small oil fields producing from carbonate buildups within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to 10 wells with primary production ranging from 700,000 to 2,000,000 barrels (111,300-318,000 m{sup 3}) of oil per field and a 15 to 20 percent recovery rate. At least 200 million barrels (31.8 million m{sup 3}) of oil will not be recovered from these small fields because of inefficient recovery practices and undrained heterogeneous reservoirs. Several fields in southeastern Utah and southwestern Colorado are being evaluated as candidates for horizontal drilling and enhanced oil recovery from existing vertical wells based upon geological characterization and reservoir modeling case studies. Geological characterization on a local scale is focused on reservoir heterogeneity, quality, and lateral continuity, as well as possible reservoir compartmentalization, within these fields. This study utilizes representative cores, geophysical logs, and thin sections to characterize and grade each field's potential for drilling horizontal laterals from existing development wells. The results of these studies can be applied to similar fields elsewhere in the Paradox Basin and the Rocky Mountain region, the Michigan and Illinois Basins, and the Midcontinent region. This report …
Date: October 5, 2003
Creator: Chidsey, Thomas C.; McClure, Kevin & Morgan, Craig D.
Object Type: Report
System: The UNT Digital Library
Ventilation Model (open access)

Ventilation Model

The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation …
Date: October 5, 2002
Creator: Chipman, V.
Object Type: Report
System: The UNT Digital Library
Photonic Bandgap Waveguides - 2D PBG Materials Embedded in a GaAs/AlO Slab (open access)

Photonic Bandgap Waveguides - 2D PBG Materials Embedded in a GaAs/AlO Slab

None
Date: October 5, 2000
Creator: Chow, E.; Lin, S. Y.; Wendt, J. R.; Allerman, A. A.; Vawter, G. A.; Zubrzycki, W. J. et al.
Object Type: Article
System: The UNT Digital Library
Nuclear Car Wash sensitivity in varying thicknesses of wood and steel cargo (open access)

Nuclear Car Wash sensitivity in varying thicknesses of wood and steel cargo

The influence of incident neutron attenuation on signal strengths in the Nuclear Car Wash has been observed experimentally for both wood and steel-pipe mock cargos. Measured decay curves are presented for {beta}-delayed high-energy {gamma}-rays and thermalized neutrons following neutron-induced fission of HEU through varying irradiation lengths. Error rates are extracted for delayed-{gamma} and delayed-n signals integrated to 30 seconds, assuming Gaussian distributions for the active background. The extrapolation to a field system of 1 mA deuterium current and to a 5 kg sample size is discussed.
Date: October 5, 2006
Creator: Church, J; Slaughter, D; Asztalos, S; Biltoft, P; Descalle, M; Hall, J et al.
Object Type: Report
System: The UNT Digital Library
Federal Advertising Law: An Overview (open access)

Federal Advertising Law: An Overview

This report provides a brief overview of federal law with respect to six selected advertising issues: alcohol advertising, tobacco advertising, the federal trade commission act, advertising by mail, advertising by telephone, and commercial e-mail.
Date: October 5, 2005
Creator: Cohen, Henry
Object Type: Report
System: The UNT Digital Library
Clean Water Act Section 401: Background and Issues (open access)

Clean Water Act Section 401: Background and Issues

Section 401 of the Clean Water Act requires that an applicant for a federal license or permit provide a certification that any discharges from the facility will comply with the Act, including water quality standard requirements. Disputes have arisen over the states' exercise of authority under Section 401. Until recently, much of the debate over the Section 401 certification issue has been between states and hydropower interests. A 1994 Supreme Court decision which upheld the states' authority in this area dismayed development and hydroelectric power interest groups. The Court revisited these issues in a 2006 ruling that unanimously upheld the states' authority to condition hydropower licenses. The dispute between states and industry groups about Section 401 authority has been a legislative issue on several occasions, but Congress has not responded by modifying the provision's scope. In addition, there has been interest in clarifying whether Section 401 certification applies to nonpoint source discharges, such as rainfall runoff, as well as point source discharges from pipes or ditches.
Date: October 5, 2006
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
The Proposed Authorities of a National Intelligence Director: Issues for Congress and Side-by-Side Comparison of S. 2845, H.R. 10, and Current Law (open access)

The Proposed Authorities of a National Intelligence Director: Issues for Congress and Side-by-Side Comparison of S. 2845, H.R. 10, and Current Law

None
Date: October 5, 2004
Creator: Cumming, Alfred
Object Type: Report
System: The UNT Digital Library
Self-aggregation in scaled principal component space (open access)

Self-aggregation in scaled principal component space

Automatic grouping of voluminous data into meaningful structures is a challenging task frequently encountered in broad areas of science, engineering and information processing. These data clustering tasks are frequently performed in Euclidean space or a subspace chosen from principal component analysis (PCA). Here we describe a space obtained by a nonlinear scaling of PCA in which data objects self-aggregate automatically into clusters. Projection into this space gives sharp distinctions among clusters. Gene expression profiles of cancer tissue subtypes, Web hyperlink structure and Internet newsgroups are analyzed to illustrate interesting properties of the space.
Date: October 5, 2001
Creator: Ding, Chris H.Q.; He, Xiaofeng; Zha, Hongyuan & Simon, Horst D.
Object Type: Report
System: The UNT Digital Library
Method and apparatus for aligning a solar concentrator using two lasers (open access)

Method and apparatus for aligning a solar concentrator using two lasers

A method and apparatus are provided for aligning the facets of a solar concentrator. A first laser directs a first laser beam onto a selected facet of the concentrator such that a target board positioned adjacent to the first laser at approximately one focal length behind the focal point of the concentrator is illuminated by the beam after reflection thereof off of the selected facet. A second laser, located adjacent to the vertex of the optical axis of the concentrator, is used to direct a second laser beam onto the target board at a target point thereon. By adjusting the selected facet to cause the first beam to illuminate the target point on the target board produced by the second beam, the selected facet can be brought into alignment with the target point. These steps are repeated for other selected facets of the concentrator, as necessary, to provide overall alignment of the concentrator.
Date: October 5, 2000
Creator: Diver, Richard Boyer Jr.
Object Type: Patent
System: The UNT Digital Library