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465 Matching Results

Start Over Decade 2000-2009 Year 2004 Day 17th

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(open access)

Screening Analysis of Criticality Features, Events, and Processes for License Application

None

Date: February 17, 2004

Creator: Brownson, D.

Object Type: Report

System: The UNT Digital Library

(open access)

Higher Order Lagrange Finite Elements In M3D

The M3D code has been using linear finite elements to represent multilevel MHD on 2-D poloidal planes. Triangular higher order elements, up to third order, are constructed here in order to provide M3D the capability to solve highly anisotropic transport problems. It is found that higher order elements are essential to resolve the thin transition layer characteristic of the anisotropic transport equation, particularly when the strong anisotropic direction is not aligned with one of the Cartesian coordinates. The transition layer is measured by the profile width, which is zero for infinite anisotropy. It is shown that only higher order schemes have the ability to make this layer converge towards zero when the anisotropy gets stronger and stronger. Two cases are considered. One has the strong transport direction partially aligned with one of the element edges, the other doesn't have any alignment. Both cases have the strong transport direction misaligned with the grid line by some angles.

Date: December 17, 2004

Creator: Chen, J.; Strauss, H. R.; Jardin, S. C.; Park, W.; Sugiyama, L. E.; Fu, G. et al.

Object Type: Report

System: The UNT Digital Library

(open access)

Fundamental Understanding of Crack Growth in Structural Components of Generation IV Supercritical Light Water Reactors

This work contributes to the design of safe and economical Generation-IV Super-Critical Water Reactors (SCWRs) by providing a basis for selecting structural materials to ensure the functionality of in-vessel components during the entire service life. During the second year of the project, we completed electrochemical characterization of the oxide film properties and investigation of crack initiation and propagation for candidate structural materials steels under supercritical conditions. We ranked candidate alloys against their susceptibility to environmentally assisted degradation based on the in situ data measure with an SRI-designed controlled distance electrochemistry (CDE) arrangement. A correlation between measurable oxide film properties and susceptibility of austenitic steels to environmentally assisted degradation was observed experimentally. One of the major practical results of the present work is the experimentally proven ability of the economical CDE technique to supply in situ data for ranking candidate structural materials for Generation-IV SCRs. A potential use of the CDE arrangement developed ar SRI for building in situ sensors monitoring water chemistry in the heat transport circuit of Generation-IV SCWRs was evaluated and proved to be feasible.

Date: November 17, 2004

Creator: Balachov, Iouri I.; Kobayashi, Takao; Tanzella, Francis; Jayaweera, Indira; Jayaweera, Palitha; Kinnunen, Petri et al.

Object Type: Report

System: The UNT Digital Library

(open access)

Freight Wing Trailer Aerodynamics

Freight Wing Incorporated utilized the opportunity presented by this DOE category one Inventions and Innovations grant to successfully research, develop, test, patent, market, and sell innovative fuel and emissions saving aerodynamic attachments for the trucking industry. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck's fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Market research early in this project revealed the demands of truck fleet operators regarding aerodynamic attachments. Products must not only save fuel, but cannot interfere with the operation of the truck, require significant maintenance, add significant weight, and must be extremely durable. Furthermore, SAE/TMC J1321 tests performed by a respected independent laboratory are necessary for large fleets to even consider purchase. Freight Wing used this information to create a system of three practical aerodynamic attachments for the front, rear and undercarriage of standard semi trailers. SAE/TMC J1321 Type II tests preformed by the Transportation Research Center (TRC) demonstrated a 7% improvement to fuel economy with all three products. If Freight Wing is successful in its continued efforts to gain market penetration, the energy and environmental savings would be considerable. Each truck …

Date: October 17, 2004

Creator: Graham, Sean (Primary Investigator) & Bigatel, Patrick

Object Type: Report

System: The UNT Digital Library

(open access)

SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application of this new development. …

Date: February 17, 2004

Creator: Ilias, Shamsuddin

Object Type: Report

System: The UNT Digital Library

(open access)

Hybrid Monte Carlo-Deterministic Methods for Nuclear Reactor-Related Criticality Calculations

The overall goal of this project is to develop, implement, and test new Hybrid Monte Carlo-deterministic (or simply Hybrid) methods for the more efficient and more accurate calculation of nuclear engineering criticality problems. These new methods will make use of two (philosophically and practically) very different techniques - the Monte Carlo technique, and the deterministic technique - which have been developed completely independently during the past 50 years. The concept of this proposal is to merge these two approaches and develop fundamentally new computational techniques that enhance the strengths of the individual Monte Carlo and deterministic approaches, while minimizing their weaknesses.

Date: February 17, 2004

Creator: Larson, Edward W.

Object Type: Report

System: The UNT Digital Library

(open access)

Efficient binning for bitmap indices on high-cardinality attributes

Bitmap indexing is a common technique for indexing high-dimensional data in data warehouses and scientific applications. Though efficient for low-cardinality attributes, query processing can be rather costly for high-cardinality attributes due to the large storage requirements for the bitmap indices. Binning is a common technique for reducing storage costs of bitmap indices. This technique partitions the attribute values into a number of ranges, called bins, and uses bitmap vectors to represent bins (attribute ranges) rather than distinct values. Although binning may reduce storage costs, it may increase the access costs of queries that do not fall on exact bin boundaries (edge bins). For this kind of queries the original data values associated with edge bins must be accessed, in order to check them against the query constraints.In this paper we study the problem of finding optimal locations for the bin boundaries in order to minimize these access costs subject to storage constraints. We propose a dynamic programming algorithm for optimal partitioning of attribute values into bins that takes into account query access patterns as well as data distribution statistics. Mathematical analysis and experiments on real life data sets show that the optimal partitioning achieved by this algorithm can lead to …

Date: November 17, 2004

Creator: Rotem, Doron; Stockinger, Kurt & Wu, Kesheng

Object Type: Report

System: The UNT Digital Library

(open access)

Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells Quarterly Report

The Pennsylvania State University, under contract to the U.S. Department of Energy, National Energy Technology Laboratory will establish, promote, and manage a national industry-driven Stripper Well Consortium (SWC) that will be focused on improving the production performance of domestic petroleum and/or natural gas stripper wells. The consortium creates a partnership with the U.S. petroleum and natural gas industries and trade associations, state funding agencies, academia, and the National Energy Technology Laboratory. This report serves as the twelfth quarterly technical progress report for the SWC. Key activities for this reporting period focused on organizing and hosting three fall technology transfer meetings that will be held in Wyoming, Texas, and Pennsylvania. In addition, work has started on developing the 2004 SWC request-for-proposals which will be released during the next reporting period. During this reporting period, the efforts were focused primarily on the organizing the SWC fall technology transfer meetings.

Date: May 17, 2004

Creator: Morrison, Joel L.

Object Type: Report

System: The UNT Digital Library

(open access)

Sampling for Beryllium Surface Contamination using Wet, Dry and Alcohol Wipe Sampling

This research project was conducted at the National Nuclear Security Administration's Kansas City Plant, operated by Honeywell Federal Manufacturing and Technologies, in conjunction with the Safety Sciences Department of Central Missouri State University, to compare relative removal efficiencies of three wipe sampling techniques currently used at Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling with dry Whatman 42 filter paper, with water-moistened (Ghost Wipe) materials, and by methanol-moistened wipes. Test plates were prepared using 100 mm X 15 mm Pyrex Petri dishes with interior surfaces spray painted with a bond coat primer. To achieve uniform deposition over the test plate surface, 10 ml aliquots of solution containing 1 beryllium and 0.1 ml of metal working fluid were transferred to the test plates and subsequently evaporated. Metal working fluid was added to simulate the slight oiliness common on surfaces in metal working shops where fugitive oil mist accumulates over time. Sixteen test plates for each wipe method (dry, water, and methanol) were processed and sampled using a modification of wiping patterns recommended by OSHA Method 125G. Laboratory and statistical analysis showed that methanol-moistened wipe sampling removed significantly more (about twice …

Date: December 17, 2004

Creator: Kerr, Kent

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Environmental policy and regulatory constraints to natural gas production.

For the foreseeable future, most of the demand for natural gas in the United States will be met with domestic resources. Impediments, or constraints, to developing, producing, and delivering these resources can lead to price increases or supply disruptions. Previous analyses have identified lack of access to natural gas resources on federal lands as such an impediment. However, various other environmental constraints, including laws, regulations, and implementation procedures, can limit natural gas development and production on both federal and private lands. This report identifies and describes more than 30 environmental policy and regulatory impediments to domestic natural gas production. For each constraint, the source and type of impact are presented, and when the data exist, the amount of gas affected is also presented. This information can help decision makers develop and support policies that eliminate or reduce the impacts of such constraints, help set priorities for regulatory reviews, and target research and development efforts to help the nation meet its natural gas demands.

Date: December 17, 2004

Creator: Elcock, D.

Object Type: Report

System: The UNT Digital Library

(open access)

Gas Storage Technology Consortium Quarterly Report

Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry-driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide a …

Date: April 17, 2004

Creator: Watson, Robert W.

Object Type: Report

System: The UNT Digital Library

(open access)

A Numerical Instability in an ADI Algorithm for Gyrokinetics

We explore the implementation of an Alternating Direction Implicit (ADI) algorithm for a gyrokinetic plasma problem and its resulting numerical stability properties. This algorithm, which uses a standard ADI scheme to divide the field solve from the particle distribution function advance, has previously been found to work well for certain plasma kinetic problems involving one spatial and two velocity dimensions, including collisions and an electric field. However, for the gyrokinetic problem we find a severe stability restriction on the time step. Furthermore, we find that this numerical instability limitation also affects some other algorithms, such as a partially implicit Adams-Bashforth algorithm, where the parallel motion operator v{sub {parallel}} {partial_derivative}/{partial_derivative}z is treated implicitly and the field terms are treated with an Adams-Bashforth explicit scheme. Fully explicit algorithms applied to all terms can be better at long wavelengths than these ADI or partially implicit algorithms.

Date: December 17, 2004

Creator: Belli, E.A. & Hammett, G.W.

Object Type: Report

System: The UNT Digital Library

(open access)

Influence of Sediment Redox Conditions on Contaminant Stabilization by Apatite and FE(0)

Efficacy of stabilizing Ce, Co, and Pb by adding apatite and zero-valent Fe (Fe(0)) to contaminated wetland sediments was quantified under oxidizing and reducing conditions. The redox status and the general water chemistry of the oxidized and reduced treatments differed greatly, yet the influences of the amendments on contaminant stabilization were quite similar; both amendments significantly (p less than or equal to 0.05) reduced aqueous contaminant concentrations. Based on resin sorption studies and thermodynamic calculations, Ce existed primarily as cationic and to a smaller extent, anionic species, and Co existed almost as cationic, neutral, and organically complexed species. Based on a series of varying selective extractions, almost 50 wt-percentage of the Co and Pb were already strongly bound to the sediment, thereby limiting the potential (and need) of affecting additional immobilization through the use of amendments.

Date: May 17, 2004

Creator: Kaplan, D. I.

Object Type: Article

System: The UNT Digital Library

Oral History Interview with Robert Cassel, March 17, 2004

Access: Use of this item is restricted to the UNT Community

Interview with truck driver Robert Cassel. The interview includes Cassel's personal experiences about being employed by the Civilian Conservation Corps during the Great Depression.

Date: March 17, 2004

Creator: Dixon, Tricia Taylor & Cassel, Robert

Object Type: Book

System: The UNT Digital Library

(open access)

Unmanned Aerial Vehicles: Major Management Issues Facing DOD's Development and Fielding Efforts

Testimony issued by the General Accounting Office with an abstract that begins "The current generation of unmanned aerial vehicles (UAVs) has been under development since the 1980s. UAVs were used in Afghanistan and Iraq in 2002 and 2003 to observe, track, target, and strike enemy forces. These successes have heightened interest in UAVs within the Department of Defense (DOD). Congress has been particularly interested in DOD's approach to managing the growing number of UAV programs. GAO was asked to summarize (1) the results of its most current report on DOD's approach to developing and fielding UAVs1 and the extent to which the approach provides reasonable assurance that its investment will lead to effective integration of UAVs into the force structure, and (2) the major management issues GAO has identified in prior reports on UAV research and development."

Date: March 17, 2004

Creator: United States. General Accounting Office.

Object Type: Text

System: The UNT Digital Library

Doctoral Recital: 2004-01-17 - Jung-Won Kim, organ

Recital presented at the First United Methodist Church in partial fulfillment of the Doctor of Musical Arts (DMA) degree.

Date: January 17, 2004

Creator: Kim, Jung-Won

Object Type: Sound

System: The UNT Digital Library

(open access)

Scientific Challenges for Ensuring Clean and Reliable Water for the 21st Century

Many areas in the world are experiencing significant fresh water shortages due to drought, growing populations, increased agricultural and industrial demands, and extensive forms of pollution or water quality degradation. Many more are expected to face similar predicaments in the next 20 years. Water shortages will significantly limit economic growth, decrease the quality of life and human health for billions of people, degrade the ecologic health of natural environments, and could potentially lead to violence and conflict over securing scarce supplies of water. These concerns are not limited to the economically poor countries, of course, as many parts of the United States face similar dilemmas. These problems can be exacerbated by fluctuating imbalances between need and supply, poor water management or land use practices, social, economic, political, and trans-boundary disputes, as well as factors related to climate change. The future is one that will require significant technological advances to support the conservation, preservation, and movement of fresh water, as well as in the development of new or alternative supplies. It is also one that will also require concomitant improvements in the use of practical solutions and the ways in which the broader scientific and technical community interacts with policy-makers, water-related …

Date: August 17, 2004

Creator: Tompson, A. B.

Object Type: Article

System: The UNT Digital Library