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3-D Micro-Scale Machining Implementation (open access)

3-D Micro-Scale Machining Implementation

The KCP investigated milling, turning, and wire EDMing features at a micro-scale using existing equipment to find the limitations and hindrances to producing future designs.
Date: October 20, 2008
Creator: Boucher, Christopher L.
System: The UNT Digital Library
3D Adaptive Mesh Refinement Simulations of Pellet Injection in Tokamaks (open access)

3D Adaptive Mesh Refinement Simulations of Pellet Injection in Tokamaks

We present results of Adaptive Mesh Refinement (AMR) simulations of the pellet injection process, a proven method of refueling tokamaks. AMR is a computationally efficient way to provide the resolution required to simulate realistic pellet sizes relative to device dimensions. The mathematical model comprises of single-fluid MHD equations with source terms in the continuity equation along with a pellet ablation rate model. The numerical method developed is an explicit unsplit upwinding treatment of the 8-wave formulation, coupled with a MAC projection method to enforce the solenoidal property of the magnetic field. The Chombo framework is used for AMR. The role of the E x B drift in mass redistribution during inside and outside pellet injections is emphasized.
Date: October 20, 2003
Creator: Samtaney, R.; Jardin, S. C.; Colella, P. & Martin, D. F.
System: The UNT Digital Library
Air Force Next-Generation Bomber: Background and Issues for Congress (open access)

Air Force Next-Generation Bomber: Background and Issues for Congress

This report discusses key issues regarding funding for a next-generation bomber (NGB) program. Congress's decisions on these issues could affect Air Force capabilities and funding requirements, and the U.S. aircraft manufacturing industrial base.
Date: October 20, 2009
Creator: O'Rourke, Ronald
System: The UNT Digital Library
An Analysis of the Tax Treatment of Capital Losses (open access)

An Analysis of the Tax Treatment of Capital Losses

Several reasons have been advanced for increasing the net capital loss limit against ordinary income: as a part of an economic stimulus plan, as a means of restoring confidence in the stock market, and to restore the value of the loss limitations to its 1978 level. Capital loss limits are imposed because individuals from reducing their taxes by legalizing losses while holding assets with gains until death when taxes are avoided completely.
Date: October 20, 2008
Creator: Hungerford, Thomas L. & Gravelle, Jane G.
System: The UNT Digital Library
Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests (open access)

Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests

None
Date: October 20, 2006
Creator: Nichol, Jim
System: The UNT Digital Library
Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests (open access)

Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests

This report discusses the relationships between the United States and Armenia, Azerbaijan, and Georgia, as well as these three nations' political and economic conditions. The report also discusses key related issues in the second session of the 111th Congress, including the question of the United States' role in the South Caucasus, the significance of regional energy resources to U.S. interests, and other pertinent issues.
Date: October 20, 2009
Creator: Nichol, Jim
System: The UNT Digital Library
Arsenic in Drinking Water: Regulatory Develpoments and Issues (open access)

Arsenic in Drinking Water: Regulatory Develpoments and Issues

This report discusses issues regarding the arsenic’s health effects and how to reduce the uncertainty in assessing health risks associated with exposure to low levels of arsenic. Environmental Protection Agency (EPA) issued the current standard of 50 parts per billion (ppb) in 1975. . This report reviews EPA efforts to develop a new arsenic rule and summarizes key provisions and subsequent events.
Date: October 20, 2005
Creator: Tiemann, Mary
System: The UNT Digital Library
An Assessment of Energy-Related Career Paths of Senior Industrial Assessment Center Program Alumni (open access)

An Assessment of Energy-Related Career Paths of Senior Industrial Assessment Center Program Alumni

The purpose of this study was to assess the career paths of alumni from the U.S. Department of Energy's Industrial Assessment Center (IAC) program. IAC was originally named the Energy Analysis and Diagnostic Center (EADC) program when it began in association with four schools in 1976. The current IAC program provides funding to 26 engineering colleges, located in centers across the United States, to conduct energy, waste, and productivity assessments for small- to medium-sized manufacturing establishments within their respective regions. Through part-time employment with the university, students receive training and in turn conduct assessments for local manufacturers, under the direct supervision of engineering faculty. Annually, IAC participants conduct over 700 assessments, and each assessment generates recommendations for energy savings, energy cost savings, and waste and productivity cost savings customized for individual clients. An earlier study determined that energy savings could be attributed to alumni of the IAC program who take their IAC experiences with them to the professional workplace. During their careers, the alumni conduct additional energy assessments as well as influence energy efficiency through design, teaching and training, and other activities. Indeed, a significant level of program benefits can be attributed to the alumni. This project addressed such specific …
Date: October 20, 2003
Creator: Martin, M.A.
System: The UNT Digital Library
ASSESSMENT OF GENOTOXIC ACTIVITY OF PETROLEUM HYDROCARBON-BIOREMEDIATED SOIL (open access)

ASSESSMENT OF GENOTOXIC ACTIVITY OF PETROLEUM HYDROCARBON-BIOREMEDIATED SOIL

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays: SOS chromotest and umu-test with and without metabolic activation (S-9 mixture) were used to evaluate genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soil was taken from an engineered biopile at the Czor Polish oil refinery. The bioremediation process in the biopile lasted 4 years, and the toxicity measurements were done after this treatment. Carcinogens detected in the soil, polyaromatic hydrocarbons (PAHs), were reduced to low concentrations (2 mg/kg dry wt) by the bioremediation process. Genotoxicity was not observed for soils tested with and without metabolic activation by a liver homogenate (S-9 mixture). However, umu-test was more sensitive than SOS-chromotest in the analysis of petroleum hydrocarbon-bioremediated soil. Analytical results of soil used in the bioassays confirmed that the bioremediation process reduced 81 percent of the petroleum hydrocarbons including PAHs. We conclude that the combined test systems employed in this study are useful tools for the genotoxic examination of remediated petroleum hydrocarbon-contaminated soil.
Date: October 20, 2004
Creator: BRIGMON, ROBIN
System: The UNT Digital Library
Autonomous Control of Nuclear Power Plants (open access)

Autonomous Control of Nuclear Power Plants

A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in …
Date: October 20, 2003
Creator: Basher, H.
System: The UNT Digital Library
BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS (open access)

BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. …
Date: October 20, 2002
Creator: Liscinsky, David
System: The UNT Digital Library
BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS (open access)

BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), 35 MPa (5000 psi) steam. This project has established a government/industry consortium to undertake a five-year effort to evaluate and develop of advanced materials that allow the use of advanced steam cycles in coal-based power plants. These advanced cycles, with steam temperatures up to 760 C, will increase the efficiency of coal-fired boilers from an average of 35% efficiency (current domestic fleet) to 47% (HHV). This efficiency increase will enable coal-fired power plants to generate electricity at competitive rates (irrespective of fuel costs) while reducing CO{sub 2} and other fuel-related emissions by as much as 29%. Success in achieving these objectives will support a number of broader goals. First, from a national prospective, the program will identify advanced materials that will make it possible to maintain a cost-competitive, environmentally acceptable coal-based electric generation option. High sulfur coals will specifically benefit in this respect by having these advanced materials evaluated in high-sulfur coal firing conditions and from the significant reductions in waste generation inherent in the increased operational efficiency. Second, from a national prospective, the …
Date: October 20, 2003
Creator: Viswanathan, R.; Coleman, K.; Swindeman, R.W.; Sarver, J.; Blough, J.; Mohn, W. et al.
System: The UNT Digital Library
Centrales au gaz et Energies renouvelables: comparer des pommes avec des pommes (open access)

Centrales au gaz et Energies renouvelables: comparer des pommes avec des pommes

The fundamental conclusion that we draw from this analysis is that one should not to base itself blindly on forecasts prices of natural gas when one compare contracts at price fixes with producers of renewable energy with contracts at variable prices with promoters power stations with gas. Indeed, forecasts of the prices of gas do not succeed not to enter the associated costs with the covering of the risk, that they are connected to the negative pressure against the cover, with the CAPM, with costs of transaction or with unspecified combination of three. Thus, insofar as price stability to length term is developed, better way of comparing the two choices would be to have recourse to the data on the prices in the long term natural gas, and not with forecasts of the prices. During three last years at least, the use of these prices in the long term would have besides license to correct a methodological error who, obviously, seem to have supported unduly, and of relatively important way, power stations with natural gas compared to their competitors of renewable energies.
Date: October 20, 2003
Creator: Bolinger, Mark; Wiser, Ryan & Golove, William
System: The UNT Digital Library
CFTC Reauthorization in 2005 (open access)

CFTC Reauthorization in 2005

This report provides brief summaries of the issues in the 2005 reauthorization legislation, including (1) the market in security futures, or futures contracts based on single stocks, which were authorized by the CFMA, but trade in much lower volumes than their proponents had hoped, (2) regulation of energy derivatives markets, where some see excessive price volatility and a lack of effective regulation, and (3) the legality of futures-like contracts based on foreign currency prices offered to retail investors.
Date: October 20, 2005
Creator: Jickling, Mark
System: The UNT Digital Library
The Challenge of Data Sharing: Results of a GAO-Sponsored Symposium on Benefit and Loan Programs (open access)

The Challenge of Data Sharing: Results of a GAO-Sponsored Symposium on Benefit and Loan Programs

A letter report issued by the General Accounting Office with an abstract that begins "Data sharing among federal agencies that run federal benefit and loan programs is important for determining the eligibility of applicants and beneficiaries. A GAO symposium on data sharing highlighted various issues facing federal agencies in their efforts to prevent abuse of federal programs. Symposium speakers focused on the number of program dollars saved by interagency data exchanges. Agencies using computer matching have detected undisclosed income and welfare recipients who receive benefits from more than one state. Improved technologies offer agencies the opportunity to expand their data sharing efforts. Such technologies include computer systems that can communicate directly with other systems and computer networks that can obtain information directly from financial institutions. Symposium speakers agreed that applicants' privacy should be protected when personal information is shared among agencies, but they disagreed about the extent to which data sharing threatens it. Privacy laws and security-related technology provide individuals with some protection against the possible misuse of personal information, but symposium participants differed on whether these protections are adequate."
Date: October 20, 2000
Creator: United States. General Accounting Office.
System: The UNT Digital Library
Charge Carrier Density and signal induced in a CVD diamond detector from NIF DT neutrons, x-rays, and electrons (open access)

Charge Carrier Density and signal induced in a CVD diamond detector from NIF DT neutrons, x-rays, and electrons

This report investigates the use of x-rays and electrons to excite a CVD polycrystalline diamond detector during a double pulse experiment to levels corresponding to those expected during a successful (1D clean burn) and a typical failed ignition (2D fizzle) shot at the National Ignition Facility, NIF. The monitoring of a failed ignition shot is the main goal of the diagnostic, but nevertheless, the study of a successful ignition shot is also important. A first large neutron pulse is followed by a smaller pulse (a factor of 1000 smaller in intensity) after 50 to 300 ns. The charge carrier densities produced during a successful and failed ignition shot are about 10{sup 15} e-h+/cm{sup 3} and 2.6* 10{sup 12} e-h+/cm{sup 3} respectively, which is lower than the 10{sup 16} e-h+/cm{sup 3} needed to saturate the diamond wafer due to charge recombination. The charge carrier density and the signal induced in the diamond detector are calculated as a function of the incident x-ray and electron energy, flux, and detector dimensions. For available thicknesses of polycrystalline CVD diamond detectors (250 {micro}m to 1000 {micro}m), a flux of over 10{sup 11} x-rays/cm{sup 2} (with x-ray energies varying from 6 keV to about 10 keV) …
Date: October 20, 2005
Creator: Dauffy, L S & Koch, J A
System: The UNT Digital Library
CMM Technology (open access)

CMM Technology

This project addressed coordinate measuring machine (CMM) technology and model-based engineering. CMM data analysis and delivery were enhanced through the addition of several machine types to the inspection summary program. CMM hardware and software improvements were made with the purchases of calibration and setup equipment and new model-based software for the creation of inspection programs. Kansas City Plant (KCP) personnel contributed to and influenced the development of dimensional metrology standards. Model-based engineering capabilities were expanded through the development of software for the tolerance analysis of piece parts and for the creation of model-based CMM inspection programs and inspection plans and through the purchase of off-the-shelf software for the tolerance analysis of mechanical assemblies. An obsolete database application used to track jobs in Precision Measurement was replaced by a web-based application with improved query and reporting capabilities. A potential project to address the transformation of the dimensional metrology enterprise at the Kansas City Plant was identified.
Date: October 20, 2008
Creator: Ward, Robert C.
System: The UNT Digital Library
Coil Tolerance Impact on Plasma Surface Quality for NCSX (open access)

Coil Tolerance Impact on Plasma Surface Quality for NCSX

The successful operation of the National Compact Stellarator Experiment (NCSX) machine will require producing plasma configurations with good flux surfaces, with a minimum volume of the plasma lost to magnetic islands or stochastic regions. The project goal is to achieve good flux surfaces over 90% of the plasma volume. NCSX is a three period device designed to be operated with iota ranging from {approx}0.4 on axis to {approx}0.7 at the edge. The field errors of most concern are those that are resonant with 3/5 and 3/6 modes (for symmetry preserving field errors) and the 1/2 and 2/3 modes (for symmetry breaking field errors). In addition to losses inherent in the physics configuration itself, there will be losses from field errors arising from coil construction and assembly errors. Some of these losses can be recovered through the use of trim coils or correction coils. The impact of coil tolerances on plasma surface quality is evaluated herein for the NCSX design. The methods used in this evaluation are discussed. The ability of the NCSX trim coils to correct for field errors is also examined. The results are used to set coils tolerances for the various coil systems.
Date: October 20, 2003
Creator: Brooks, Art & Reiersen, Wayne
System: The UNT Digital Library
Comment on Origin of Groundwater Discharge at Fall River Springs (open access)

Comment on Origin of Groundwater Discharge at Fall River Springs

I'm writing at the request of the Pit River Tribe to offer my professional opinion as a geochemist regarding the origin of groundwater discharge at the Fall River Springs, Shasta Co., California. In 1997, I conducted a study of the large volume cold springs associated with the Cascade Volcanoes in northern California, in collaboration with one of my colleagues. This work was published as a Lawrence Livermore National Laboratory report (Davisson and Rose, 1997). The Fall River Springs emerge from the distal end of the Giant Crater Lava Field, a laterally extensive basalt flow that stretches from the southern flank of Medicine Lake Volcano southward for a distance of 40 km. Both Medicine Lake Volcano and the Giant Crater Lava Field have virtually no surface water drainages. Precipitation that falls in these areas is inferred to seep into fractures in the rock, where it is carried down gradient under the force of gravity. Mean annual precipitation rates on Medicine Lake Volcano and the Giant Crater Lava field are adequate to account for the {approx}1200 ft{sup 3}/sec discharge of the Fall River Springs. To evaluate the origin of the springs using geochemical methods, water samples were collected from the Fall River …
Date: October 20, 2006
Creator: Rose, T
System: The UNT Digital Library
Commercial Space Launches: FAA Needs Continued Planning and Monitoring to Oversee the Safety of the Emerging Space Tourism Industry (open access)

Commercial Space Launches: FAA Needs Continued Planning and Monitoring to Oversee the Safety of the Emerging Space Tourism Industry

A letter report issued by the Government Accountability Office with an abstract that begins "In 2004, the successful launches of SpaceShipOne raised the possibility of an emerging U.S. commercial space tourism industry that would make human space travel available to the public. The Federal Aviation Administration (FAA), which has responsibility for safety and industry promotion, licenses operations of commercial space launches and launch sites. To allow the industry to grow, Congress prohibited FAA from regulating crew and passenger safety before 2012, except in response to high-risk events. GAO evaluated FAA's (1) safety oversight of commercial space launches, (2) response to emerging issues, and (3) challenges in regulating and promoting space tourism and responding to competitive issues affecting the industry. GAO reviewed FAA's applicable safety oversight processes and interviewed federal and industry officials."
Date: October 20, 2006
Creator: United States. Government Accountability Office.
System: The UNT Digital Library
A Compact Quasi-axisymmetric Stellarator Reactor (open access)

A Compact Quasi-axisymmetric Stellarator Reactor

We report the progress made in assessing the potential of compact, quasi-axisymmetric stellarators as power-producing reactors. Using an aspect ratio A=4.5 configuration derived from NCSX and optimized with respect to the quasi-axisymmetry and MHD stability in the linear regime as an example, we show that a reactor of 1 GW(e) maybe realizable with a major radius *8 m. This is significantly smaller than the designs of stellarator reactors attempted before. We further show the design of modular coils and discuss the optimization of coil aspect ratios in order to accommodate the blanket for tritium breeding and radiation shielding for coil protection. In addition, we discuss the effects of coil aspect ratio on the peak magnetic field in the coils.
Date: October 20, 2003
Creator: Ku, L. P.
System: The UNT Digital Library
Conservation assessment for the Siskiyou Mountains salamander and Scott Bar salamander in northern California. (open access)

Conservation assessment for the Siskiyou Mountains salamander and Scott Bar salamander in northern California.

The purpose of this conservation assessment is to summarize existing knowledge regarding the biology and ecology of the Siskiyou Mountains salamander and Scott Bar salamander, identify threats to the two species, and identify conservation considerations to aid federal management for persistence of the species. The conservation assessment will serve as the basis for a conservation strategy for the species.
Date: October 20, 2006
Creator: Vinikour, W. S.; LaGory, K. E.; Adduci, J. J. & Division, Environmental Science
System: The UNT Digital Library
Contributions of weather and fuel mix to recent declines in U.S.energy and carbon intensity (open access)

Contributions of weather and fuel mix to recent declines in U.S.energy and carbon intensity

A recent (1996-2000) acceleration of declines in energy andcarbon intensity in the U.S. remains largely unexplained. This study usesDivisia decomposition and regression to test two candidate explanations -fuel mix and weather. The Divisia method demonstrates that fuel mix doesnot explain the declines in carbon intensity. The fuel mix, both overalland for electricity generation, became slightly more carbon intensiveover the study period (though the slight trend reversed before the end ofthe period). A regression-based correction to the Divisia indices,accounting for variation in heating- and cooling-degree-days, indicatesthat warmer weather accounts for about 30 percent ofthe total declines.This leaves declines of more than 2 percent per year (and an accelerationof more than 1 percent over previous decade) remaining to beexplained.
Date: October 20, 2002
Creator: Davis, W. Bart; Sanstad, Alan H. & Koomey, Jonathan G.
System: The UNT Digital Library
Cost Analysis of Fuel Cell Systems for Transportation Compressed Hydrogen and PEM Fuel Cell System (open access)

Cost Analysis of Fuel Cell Systems for Transportation Compressed Hydrogen and PEM Fuel Cell System

PEMFC technology for transportation must be competitive with internal combustion engine powertrains in a number of key metrics, including performance, life, reliability, and cost. Demonstration of PEMFC cost competitiveness has its own challenges because the technology has not been applied to high volume automotive markets. The key stack materials including membranes, electrodes, bipolar plates, and gas diffusion layers have not been produced in automotive volumes to the exacting quality requirements that will be needed for high stack yields and to the evolving property specifications of high performance automotive stacks. Additionally, balance-of-plant components for air, water, and thermal management are being developed to meet the unique requirements of fuel cell systems. To address the question of whether fuel cells will be cost competitive in automotive markets, the DOE has funded this project to assess the high volume production cost of PEM fuel cell systems. In this report a historical perspective of our efforts in assessment of PEMFC cost for DOE is provided along with a more in-depth assessment of the cost of compressed hydrogen storage is provided. Additionally, the hydrogen storage costs were incorporated into a system cost update for 2004. Assessment of cost involves understanding not only material and production …
Date: October 20, 2004
Creator: Carlson, Eric J.
System: The UNT Digital Library