Assessing the Performance of 5mm White LED Light Sources forDeveloping-Country Applications (open access)

Assessing the Performance of 5mm White LED Light Sources forDeveloping-Country Applications

Some white light-emitting diode (LED) light sources haverecently attained levels of efficiency and cost that allow them tocompete with fluorescent lighting for off-grid applications in thedeveloping world. Additional attributes (optics, size, ruggedness, andservice life) make them potentially superior products. Enormousreductions in energy use and greenhouse-gas emissions are thus possible,and system costs can be much lower given the ability to downsize thecharging and energy storage components compared to a fluorescentstrategy. However, there is a high risk of "market-spoiling" if inferiorproducts are introduced and result in user dissatisfaction. Completesystems involve the integration of light sources and optics, energysupply, and energy storage. A natural starting point for evaluatingproduct quality is to focus on the individual light sources. This reportdescribes testing results for batches of 10 5mm white LEDs from 26manufacturers. Efficacies and color properties are presented.
Date: May 3, 2007
Creator: Mills, Evan
Object Type: Report
System: The UNT Digital Library
CATALYSIS SCIENCE INITIATIVE: From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity (open access)

CATALYSIS SCIENCE INITIATIVE: From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity

In this project, we have integrated state-of-the-art Density Functional Theory (DFT) models of heterogeneous catalytic processes with high-throughput screening of bimetallic catalytic candidates for important industrial problems. We have studied a new class of alloys characterized by a surface composition different from the bulk composition, and investigated their stability and activity for the water-gas shift reaction and the oxygen reduction reaction. The former reaction is an essential part of hydrogen production; the latter is the rate-limiting step in low temperature H2 fuel cells. We have identified alloys that have remarkable stability and activity, while having a much lower material cost for both of these reactions. Using this knowledge of bimetallic interactions, we have also made progress in the industrially relevant areas of carbohydrate reforming and conversion of biomass to liquid alkanes. One aspect of this work is the conversion of glycerol (a byproduct of biodiesel production) to synthesis gas. We have developed a bifunctional supported Pt catalyst that can cleave the carbon-carbon bond while also performing the water-gas shift reaction, which allows us to better control the H2:CO ratio. Knowledge gained from the theoretical metal-metal interactions was used to develop bimetallic catalysts that perform this reaction at low temperature, allowing …
Date: May 3, 2007
Creator: Mavrikakis, Manos & Dumesic, James A.
Object Type: Report
System: The UNT Digital Library
China-U.S. Trade Issues (open access)

China-U.S. Trade Issues

This report is on China-U.S. Trade Issues.
Date: May 3, 2007
Creator: Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
Climate Change: Financial Risks to Federal and Private Insurers in Coming Decades are Potentially Significant (open access)

Climate Change: Financial Risks to Federal and Private Insurers in Coming Decades are Potentially Significant

Testimony issued by the Government Accountability Office with an abstract that begins "Weather-related events in the United States have caused tens of billions of dollars in damages annually over the past decade. A major portion of these losses is borne by private insurers and by two federal insurance programs-- the Federal Emergency Management Agency's National Flood Insurance Program (NFIP), which insures properties against flooding, and the Department of Agriculture's Federal Crop Insurance Corporation (FCIC), which insures crops against drought or other weather disasters. In this testimony, GAO (1) describes how climate change may affect future weather-related losses, (2) provides information on past insured weather-related losses, and (3) determines what major private insurers and federal insurers are doing to prepare for potential increases in such losses. This testimony is based on a report entitled Climate Change: Financial Risks to Federal and Private Insurers in Coming Decades are Potentially Significant (GAO-07-285) released on April 19, 2007."
Date: May 3, 2007
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Crop Insurance: Continuing Efforts Are Needed to Improve Program Integrity and Ensure Program Costs Are Reasonable (open access)

Crop Insurance: Continuing Efforts Are Needed to Improve Program Integrity and Ensure Program Costs Are Reasonable

Testimony issued by the Government Accountability Office with an abstract that begins "The U.S. Dept. of Agriculture's (USDA) Risk Management Agency (RMA) administers the federal crop insurance program in partnership with private insurers. In 2006, the program cost $3.5 billion, including millions in losses from fraud, waste, and abuse, according to USDA. The Agricultural Risk Protection Act of 2000 granted RMA authority to renegotiate the terms of RMA's standard reinsurance agreement with companies once over 5 years. This testimony is based on GAO's 2005 report, Crop Insurance: Actions Needed to Reduce Program's Vulnerability to Fraud, Waste, and Abuse, as well as new analyses this Committee requested on underwriting gains and administrative and operating expenses USDA paid companies. GAO discusses (1) USDA's processes to address fraud, waste, and abuse; (2) extent the program's design makes it vulnerable to abuse; and (3) reasonableness of underwriting gains and other expenses. USDA agreed with most of GAO's 2005 recommendations to improve program integrity. RMA agreed that GAO's new analyses were technically accurate."
Date: May 3, 2007
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Cuba: U.S. Restrictions on Travel and Remittances (open access)

Cuba: U.S. Restrictions on Travel and Remittances

This report examines restrictions on travel to Cuba, which have been a key and often contentious component in U.S. efforts to isolate the communist government of Fidel Castro for much of the past 40 years.
Date: May 3, 2007
Creator: Sullivan, Mark P.
Object Type: Report
System: The UNT Digital Library
Cylinder Test on C-4 (open access)

Cylinder Test on C-4

None
Date: May 3, 2007
Creator: Souers, P C
Object Type: Report
System: The UNT Digital Library
Data Brokers: Background and Industry Overview (open access)

Data Brokers: Background and Industry Overview

This report provides an overview of the data brokerage industry and more specific background on LexisNexis and ChoicePoint.
Date: May 3, 2007
Creator: Stevens, Gina M.
Object Type: Report
System: The UNT Digital Library
Design of Spintronic Materials with Simple Structures (open access)

Design of Spintronic Materials with Simple Structures

A brief comparison of conventional electronics and spintronics is given. The key features of half metallic binary compounds with the zincblende structure are presented, using MnAs as an example. We discuss the interactions responsible for the half metallic properties. Special properties of superlattices and a digital ferromagnetic heterostructure incorporating zincblende half metals are also discussed.
Date: May 3, 2007
Creator: Fong, C Y; Qian, M C; Liu, K; Yang, L H & Pask, J E
Object Type: Article
System: The UNT Digital Library
Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations (open access)

Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. …
Date: May 3, 2007
Creator: Martukanitz, R. P.
Object Type: Report
System: The UNT Digital Library
ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS (open access)

ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS

A recent study indicated that the behavior of single-ended dislocation sources contributes to the flow strength of micrometer-scale crystals. In this study 3D discrete dislocation dynamics simulations of micrometer-sized volumes are used to calculate the effects of anisotropy of dislocation line tension (increasing Poisson's ratio, {nu}) on the strength of single-ended dislocation sources and, to compare them with the strength of double-ended sources of equal length. This is done by directly modeling their plastic response within a 1 micron cubed FCC Ni single crystal using DDS. In general, double-ended sources are stronger than single-ended sources of an equal length and exhibit no significant effects from truncating the long-range elastic fields at this scale. The double-ended source strength increases with Poisson ratio ({nu}), exhibiting an increase of about 50% at u = 0.38 (value for Ni) as compared to the value at {nu} = 0. Independent of dislocation line direction, for {nu} greater than 0.20, the strengths of single-ended sources depend upon the sense of the stress applied. The value for {alpha}, in the expression for strength, {tau} = {alpha}(L){micro}b/L is shown to vary from 0.4 to 0.84 depending upon the character of the dislocation and the direction of operation of …
Date: May 3, 2007
Creator: Rao, S I; Dimiduk, D M; Tang, M; Parthasarathy, T A; Uchic, M D & Woodward, C
Object Type: Article
System: The UNT Digital Library
Food Stamp Program: Use of Alternative Methods to Apply for and Maintain Benefits Could Be Enhanced by Additional Evaluation and Information on Promising Practices (open access)

Food Stamp Program: Use of Alternative Methods to Apply for and Maintain Benefits Could Be Enhanced by Additional Evaluation and Information on Promising Practices

A letter report issued by the Government Accountability Office with an abstract that begins "One in 12 Americans participates in the federal Food Stamp Program, administered by the Food and Nutrition Service (FNS). States have begun offering individuals alternatives to visiting the local assistance office to apply for and maintain benefits, such as mail-in procedures, call centers, and on-line services. GAO was asked to examine: (1) what alternative methods states are using to increase program access; (2) what is known about the results of these methods, particularly on program access for target groups, decision accuracy, and administrative costs; and (3) what actions states have taken to maintain program integrity while implementing alternative methods. GAO surveyed state food stamp administrators, reviewed five states in depth, analyzed FNS data and reports, and interviewed program officials and stakeholders."
Date: May 3, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
International Crises and Disasters: U.S. Humanitarian Assistance, Budget Trends, and Issues for Congress (open access)

International Crises and Disasters: U.S. Humanitarian Assistance, Budget Trends, and Issues for Congress

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Issues in Dynamic Revenue Estimating (open access)

Issues in Dynamic Revenue Estimating

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Medical Malpractice Insurance: An Economic Introduction and Review of Historical Experience (open access)

Medical Malpractice Insurance: An Economic Introduction and Review of Historical Experience

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Model-Based Algorithms for Detecting Cable Damage from Time-Domain Reflectomertry Measurements (open access)

Model-Based Algorithms for Detecting Cable Damage from Time-Domain Reflectomertry Measurements

None
Date: May 3, 2007
Creator: Clark, G A
Object Type: Article
System: The UNT Digital Library
Organic Agriculture in the United States: Program and Policy Issues (open access)

Organic Agriculture in the United States: Program and Policy Issues

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site (open access)

Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site

Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and characterized before subsequent disposition. The configuration of most wells requires sampling stagnant well water with a wireline bailer. Although bailer sampling allows for the collection of depth-discrete samples, the collected samples may not be representative of local groundwater because no well purging is done. Low-maintenance, solar-powered jack pumps will be deployed in nine of these onsite monitoring wells to improve sample quality. These pumps provide the lift capacity to produce groundwater from the deep aquifers encountered in the arid environment of the NTS. The water depths in these wells range from 700 to 2,340 ft below ground surface. The considerable labor and electrical power requirements of electric submersible pumps are eliminated once these pumps are installed. Access tubing will be installed concurrent with the installation …
Date: May 3, 2007
Creator: David Hudson, Charles Lohrstorfer, Bruce Hurley
Object Type: Article
System: The UNT Digital Library
Radioactive Fallout from Terrorist Nuclear Detonations (open access)

Radioactive Fallout from Terrorist Nuclear Detonations

Responding correctly during the first hour after a terrorist nuclear detonation is the key to reducing casualties from a low-yield surface burst, and a correct response requires an understanding of the rapidly changing dose rate from fallout. This report provides an empirical formula for dose rate as a function of time and location that can guide the response to an unexpected nuclear detonation. At least one post-detonation radiation measurement is required if the yield and other characteristics of the detonation are unknown.
Date: May 3, 2007
Creator: Marrs, R E
Object Type: Report
System: The UNT Digital Library
Recommendations for new monitoring wells at Everest, Kansas. (open access)

Recommendations for new monitoring wells at Everest, Kansas.

On February 15, 2007, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) submitted Recommendations for Remedial Action at Everest, Kansas. Those Recommendations were accepted by the Kansas Department of Health and Environment (KDHE) in a letter to the CCC/USDA dated March 5, 2007. The approved Recommendations document outlines a plan for systematic groundwater sampling and monitoring at Everest to provide data necessary for the critical evaluation of remedial options - including a phytoremediation alternative - for restoration of the groundwater and protection of the surface waters of the intermittent creek at this site. Phase I of the KDHE-approved monitoring plan includes the following activities: (1) Groundwater sampling at existing monitoring wells, with analyses for volatile organic compounds (VOCs) and selected biodegradation parameters; (2) Sampling of surface waters along the intermittent creek for VOCs analyses; and (3) Periodic manual measurement and automated recording of groundwater and surface water levels in the vicinity of the intermittent creek. The locations selected for groundwater and surface water sampling and analyses under the approved monitoring program were determined in consultation with the KDHE. As a result of subsequent discussions among representatives of the KDHE, the CCC/USDA, and Argonne regarding the technical program …
Date: May 3, 2007
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Rising Energy Competition and Energy Security in Northeast Asia: Issues for U.S. Policy (open access)

Rising Energy Competition and Energy Security in Northeast Asia: Issues for U.S. Policy

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Subcommittees in the House of Representatives (open access)

Subcommittees in the House of Representatives

None
Date: May 3, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Subcommittees in the House of Representatives (open access)

Subcommittees in the House of Representatives

Subcommittees are entities created by full committees to assist them in managing their work. Service on subcommittees enables members to develop expertise in specialized fields. Subcommittees diffuse the legislative process. For the most part, they are independent, autonomous units with written jurisdictions, and, pursuant to longstanding practice, most bills are referred by a full committee to them. This report provides a brief history of subcommittees, as well as their modern role and function in Congress.
Date: May 3, 2007
Creator: Schneider, Judy
Object Type: Report
System: The UNT Digital Library
Tax Compliance: Challenges in Ensuring Offshore Tax Compliance (open access)

Tax Compliance: Challenges in Ensuring Offshore Tax Compliance

Testimony issued by the Government Accountability Office with an abstract that begins "Offshore tax evasion is difficult for the Internal Revenue Service (IRS) to address. IRS examines tax returns to deal with offshore evasion that has occurred. IRS's Qualified Intermediary (QI) program seeks to foster improved tax withholding and reporting. GAO was asked to testify on two topics. First, GAO was asked to provide information on (1) the length of, and assessments from, IRS's examination of tax returns with offshore activity and (2) the impact of the 3-year statute of limitations on offshore cases. Second, for the QI program, GAO was asked to address (1) program features intended to improve withholding and reporting, and (2) whether weaknesses exist in the U.S. withholding system for U.S. source income and QI external reviews and IRS's use of program data. GAO relied on prior work for the first topic. For the QI program, GAO used the latest data that were available and corroborated by IRS."
Date: May 3, 2007
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library