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Accounting Firm Consolidation: Selected Large Public Company Views on Audit Fees, Quality, Independence, and Choice

Description: A letter report issued by the General Accounting Office with an abstract that begins "The largest accounting firms, known as the "Big 4," currently audit over 78 percent of U.S. public companies and 99 percent of public company annual sales. To address concerns raised by this concentration and as mandated by the Sarbanes-Oxley Act of 2002, on July 30, 2003, GAO issued a report entitled Public Accounting Firms: Mandated Study on Consolidation and Competition, GAO-03-864. As part of that study, GAO surveyed a random sample of 250 public companies from the Fortune 1000 list; preliminary findings were included in the July report. This supplemental report details more comprehensively the 159 responses we received through August 11, 2003, focusing on (1) the relationship of their company with their auditor of record in terms of satisfaction, tenure relationship, and services provided; (2) the effects of consolidation on audit fees, quality, and independence; and (3) the potential implications of consolidation for competition and auditor choice."
Date: September 30, 2003
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
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Advanced Cuttings Transport Study Quarterly Technical Report: July-September 2003

Description: The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.
Date: September 30, 2003
Creator: Miska, Stefan; Takach, Nicholas; Ashenayi, Kaveh; Yu, Mengjiao; Ahmed, Ramadan; Pickell, Mark et al.
Partner: UNT Libraries Government Documents Department
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ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

Description: Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. Such systems would interpret sensor and instrument outputs, correlate them to the machine's condition, provide interpretative analyses, forward projections of servicing intervals, estimate remaining component life, and identify faults. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and turbine degradation.
Date: September 30, 2003
Creator: Angello, Leonard
Partner: UNT Libraries Government Documents Department
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Advanced Sorbents as a Versatile Platform for Gas Separation

Description: The program objective was to develop materials and processes for industrial gas separations to reduce energy use and enable waste reduction. The approach chosen combined novel oxygen selective adsorbents and pressure swing adsorption (PSA) processes. Preliminary materials development and process simulation results indicated that oxygen selective adsorbents could provide a versatile platform for industrial gas separations. If fully successful, this new technology offered the potential for reducing the cost of producing nitrogen/oxygen co-products, high purity nitrogen, argon, and possibly oxygen. The potential energy savings for the gas separations are appreciable, but the end users are the main beneficiaries. Lowering the cost of industrial gases expands their use in applications that can employ them for reducing energy consumption and emissions.
Date: September 30, 2003
Creator: Stephenson, Neil
Partner: UNT Libraries Government Documents Department
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Agriculture in WTO Negotiations

Description: The World Trade Organization’s (WTO) fifth ministerial conference (held September 10-14, 2003 in Cancun, Mexico) ended without an agreement on a framework for continuing multilateral negotiations on agricultural trade liberalization. The inconclusive end of the Cancun ministerial places in doubt the ability of WTO member countries to complete the current round of negotiations by the scheduled January 1, 2005 deadline. This report discusses the various agricultural negotiations currently underway in the WTO.
Date: September 30, 2003
Creator: Hanrahan, Charles E.
Partner: UNT Libraries Government Documents Department
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Analytical and Experimental Study of The Effects of Non-Condensable in a Passive Condenser System for The Advanced Boiling Water Reactor

Description: The main goal of the project is to study analytically and experimentally condensation heat transfer for the passive condenser system relevant to the safety of next generation nuclear reactor such as Simplified Boiling Water Reactor (BWR). The objectives of this three-year research project are to: (1) obtain experimental data on the phenomenon of condensation of steam in a vertical tube in the presence of non-condensable for flow conditions of PCCS, (2) develop a analytic model for the condensation phenomena in the presence of non-condensable gas for the vertical tube, and (3) assess the RELAP5 computer code against the experimental data. The project involves experiment, theoretical modeling and a thermal-hydraulic code assessment. It involves graduate and undergraduate students' participation providing them with exposure and training in advanced reactor concepts and safety systems
Date: September 30, 2003
Creator: Revankar, Shripad T. & Oh, Seungmin
Partner: UNT Libraries Government Documents Department
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ASPEN Plus Simulation of CO2 Recovery Process

Description: ASPEN Plus simulations have been created for a CO{sub 2} capture process based on adsorption by monoethanolamine (MEA). Three separate simulations were developed, one each for the flue gas scrubbing, recovery, and purification sections of the process. Although intended to work together, each simulation can be used and executed independently. The simulations were designed as template simulations to be added as a component to other more complex simulations. Applications involving simple cycle or hybrid power production processes were targeted. The default block parameters were developed based on a feed stream of raw flue gas of approximately 14 volume percent CO{sub 2} with a 90% recovery of the CO{sub 2} as liquid. This report presents detailed descriptions of the process sections as well as technical documentation for the ASPEN simulations including the design basis, models employed, key assumptions, design parameters, convergence algorithms, and calculated outputs.
Date: September 30, 2003
Creator: White, Charles W., III
Partner: UNT Libraries Government Documents Department
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Bioremediation of Metals and Radionuclides: What It Is and How It Works (2nd Edition)

Description: This primer is intended for people interested in environmental problems of the U.S. Department of Energy (DOE) and in their potential solutions. It will specifically look at some of the more hazardous metal and radionuclide contaminants found on DOE lands and at the possibilities for using bioremediation technology to clean up these contaminants. The second edition of the primer incorporates recent findings by researchers in DOE's Natural and Accelerated Bioremediation Research (NABIR) Program. Bioremediation is a technology that can be used to reduce, eliminate, or contain hazardous waste. Over the past two decades, it has become widely accepted that microorganisms, and to a lesser extent plants, can transform and degrade many types of contaminants. These transformation and degradation processes vary, depending on the physical-chemical environment, microbial communities, and nature of the contaminant. This technology includes intrinsic bioremediation, which relies on naturally occurring processes, and accelerated bioremediation, which enhances microbial degradation or transformation through the addition of nutrients (biostimulation) or inoculation with microorganisms (bioaugmentation). Over the past few years, interest in bioremediation has increased. It has become clear that many organic contaminants such as hydrocarbon fuels can be degraded to relatively harmless products such as CO{sub 2} (the end result of the degradation process). Waste water managers and scientists have also found that microorganisms can interact with metals and convert them from one chemical form to another. Laboratory tests and ex situ bioremediation applications have shown that microorganisms can change the valence, or oxidation state, of some heavy metals (e.g., chromium and mercury) and radionuclides (e.g., uranium) by using them as electron acceptors. In some cases, the solubility of the altered species decreases and the contaminant is immobilized in situ, i.e., precipitated into an insoluble salt in the sediment. In other cases, the opposite occurs--the solubility of the altered species increases, …
Date: September 30, 2003
Creator: Palmisano, Anna & Hazen, Terry
Partner: UNT Libraries Government Documents Department
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Breast Cancer Research Stamp: Effective Fund-Raiser but Better Reporting and Cost-Recovery Criteria Needed

Description: A letter report issued by the General Accounting Office with an abstract that begins "In America, breast cancer is reported as the second leading cause of cancer deaths among women. Given this statistic, the importance of finding a cure cannot be overemphasized. To supplement the billions of federal dollars being spent on breast cancer research, Congress passed legislation creating the Breast Cancer Research Semipostal (BCRS) to increase public awareness of the disease and allow the public to participate directly in raising funds for such research. Since the BCRS was the first semipostal issued by the Postal Service, Congress mandated, and GAO issued, a report in April 2000 on the BCRS' cost, effectiveness, and appropriateness as a fund-raiser. After the report, Congress extended the BCRS sales period through 2003. As mandated, this report updates GAO's prior work as Congress considers another extension to the BCRS sales period."
Date: September 30, 2003
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
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C1 CHEMISTRY FOR THE PRODUCTION OF ULTRA-CLEAN LIQUID TRANSPORTATION FUELS AND HYDROGEN

Description: The Consortium for Fossil Fuel Science (CFFS) is a research consortium with participants from the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University. The CFFS is conducting a research program to develop C1 chemistry technology for the production of clean transportation fuel from resources such as coal and natural gas, which are more plentiful domestically than petroleum. The processes under development will convert feedstocks containing one carbon atom per molecular unit into ultra clean liquid transportation fuels (gasoline, diesel, and jet fuel) and hydrogen, which many believe will be the transportation fuel of the future. These feedstocks include synthesis gas, a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. Some highlights of the results obtained during the first year of the current research contract are summarized as: (1) Terminal alkynes are an effective chain initiator for Fischer-Tropsch (FT) reactions, producing normal paraffins with C numbers {ge} to that of the added alkyne. (2) Significant improvement in the product distribution towards heavier hydrocarbons (C{sub 5} to C{sub 19}) was achieved in supercritical fluid (SCF) FT reactions compared to that of gas-phase reactions. (3) Xerogel and aerogel silica supported cobalt catalysts were successfully employed for FT synthesis. Selectivity for diesel range products increased with increasing Co content. (4) Silicoaluminophosphate (SAPO) molecular sieve catalysts have been developed for methanol to olefin conversion, producing value-added products such as ethylene and propylene. (5) Hybrid Pt-promoted tungstated and sulfated zirconia catalysts are very effective in cracking n-C{sub 36} to jet and diesel fuel; these catalysts will be tested for cracking of FT wax. (6) Methane, ethane, and propane are readily decomposed to pure hydrogen and carbon nanotubes using binary Fe-based catalysts containing Mo, Ni, or …
Date: September 30, 2003
Creator: Huffman, Gerald P.
Partner: UNT Libraries Government Documents Department
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Caribbean Basin Interim Trade Program: CBI/NAFTA Parity

Description: The entry into force, on January 1, 1994, of the North American Free Trade Agreement (NAFTA) has eliminated the advantage that the beneficiaries of the Caribbean Basin Economic Recovery Act (CBERA) and related provisions of the Caribbean Basin Initiative (CBI) had enjoyed in trade with the United States relative to Mexico, and gave Mexico an increasingly significant competitive edge over the CBERA countries. The scheduled further implementation of the NAFTA would have resulted in a substantial advantage to Mexico over the CBERA countries and vitiate in part the purpose of the CBERA.
Date: September 30, 2003
Creator: Pregelj, Vladimir N.
Partner: UNT Libraries Government Documents Department
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A CAVITY RING-DOWN SPECTROSCOPY MERCURY CONTINUOUS EMISSION MONITOR

Description: The work performed during this quarter by SRD scientists and engineers focused on a number of tasks. The initial acquisition of some hardware needed and the actual construction of the sampling system have begun. This sampling system will contain the pyrolysis oven to atomize the sample gas stream needed for total gaseous mercury measurements, the CRD cavity to acquire the ring-down signal needed to obtain the mercury concentration, various tubing, and temperature and pressure measurement equipment. The amount of tubing and valves have been cut to a minimum to try and reduce the resident time the sample flue gas stream is in the sampling system and minimize the possibility that the gases in the sample gas stream will react with the elements of the sampling system and change the component mixture contained in the flue gas. In an effort to minimize the equipment that needs to be close to the actual sampling port, SRD scientists decided to fiber optically couple the laser to the CRD cavity. However, the ultra-violet (UV) light needed for the mercury transition presents a problem as fiber optics can be solarized by the UV radiation thereby changing the transmission characteristics. SRD has obtained a solarization-resistant fiber. SRD scientists were then able to couple the UV laser light into the fiber and inject the output of the fiber into the CRD cavity and obtain a ring-down signal. Long-term effects of the UV radiation on the fiber optic are being monitored to detect any change in the transmission of the laser light to the cavity. Additional requirements of the mercury CRD monitor will be to not only monitor the mercury concentration continuously but also perform the measurements over extended periods of time. SRD has extended some previously performed shorter-term studies to longer time intervals. The results of these …
Date: September 30, 2003
Creator: Carter, Christopher C.
Partner: UNT Libraries Government Documents Department
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Charitable Choice, Faith-Based Initiatives, and TANF

Description: The 108th Congress has resumed efforts to pass tax incentives for private giving (S. 476, passed by the Senate on April 9, and H.R. 7, introduced May 7, 2003). However, these bills do not contain provisions intended to promote religious organizations as providers of federally funded social services – charitable choice provisions.. The House voted in 2001 to extend charitable choice rules, which now apply to a limited set of programs, to numerous new programs (H.R. 7 in the 107th Congress), as the President urged, but the Senate refused. However, in an Executive Order, President Bush on December 12, 2002, directed six cabinet-level departments and the Agency for International Development (AID) to bring policies concerning social service programs into line with charitable choice principles set forth in the Order.
Date: September 30, 2003
Creator: Burke, Vee
Partner: UNT Libraries Government Documents Department
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Coast Guard: New Communication System to Support Search and Rescue Faces Challenges

Description: A letter report issued by the General Accounting Office with an abstract that begins "Search and rescue--one of the Coast Guard's oldest missions--involves minimizing the loss of life, injury, and property damage by aiding people and boats in distress. The Coast Guard has previously reported that its 30-year-old search and rescue communication system, called the National Distress and Response System, has several deficiencies and is difficult to maintain. Thus, the Coast Guard contracted to replace and modernize it with a new system, called Rescue 21. GAO was asked to identify the status and plans of the Coast Guard's acquisition of Rescue 21 and the technical and program risks associated with Rescue 21."
Date: September 30, 2003
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
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Combustion Turbine (CT) Hot Section Coating Life Management

Description: The integrity of coatings used in hot section components of combustion turbines is crucial to the reliability of the buckets. This project was initiated in recognition of the need for predicting the life of coatings analytically, and non-destructively; correspondingly, three principal tasks were established. Task 1, with the objective of analytically developing stress, strain and temperature distributions in the bucket and thereby predicting thermal fatigue (TMF) damage for various operating conditions; Task 2 with the objective of developing eddy current techniques to measure both TMF damage and general degradation of coatings and, Task 3 with the objective of developing mechanism based algorithms. Task 4 would be aimed at verifying analytical predictions from Task 1 and the NDE predictions from Task 3 against field observations. Task 5 would develop a risk-based decision analysis model to make run/repair decisions. This report is a record of the progress to date on these four tasks.
Date: September 30, 2003
Creator: Viswanathan, R.; Gandy, D.; Krzywosz, K.; Cheruvu, S. & Wan, E.
Partner: UNT Libraries Government Documents Department
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Consular Identification Cards: Domestic and Foreign Policy Implications, the Mexican Case, and Related Legislation

Description: The debate about consular identification cards in the United States has centered around the matrícula consular, the consular identification card issued by Mexican consulates to Mexican citizens in the United States. In May 2003, the Treasury Department issued regulations allowing acceptance of the cards as proof of identity for the purpose of opening a bank account, and the cards are accepted for other purposes as well, including issuance of drivers’ licenses.
Date: September 30, 2003
Creator: Bruno, Andorra & Storrs, K. Larry
Partner: UNT Libraries Government Documents Department
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Contract Management: No Reliable Data to Measure Benefits of the Simplified Acquisition Test Program

Description: A letter report issued by the General Accounting Office with an abstract that begins "In recent years, the federal government has introduced new ways to streamline the acquisition process. One of those vehicles is the simplified acquisition procedures test program, which removes some of the procedural requirements for buying commercial goods and services. Using the test program, federal procurement officials can make purchases faster than they have in the past for procurements not exceeding $5 million. Congress mandated that GAO determine the extent to which federal executive agencies--at a minimum, the Department of Defense (DOD)--have taken advantage of the test program and any benefits realized. One way to measure use is to examine test program data from the Federal Procurement Data System (FPDS). It is the central repository of contracting information. In addition to examining FPDS data, GAO looked at data from DOD's data system."
Date: September 30, 2003
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
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Delaware Basin Monitoring Annual Report

Description: The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.
Date: September 30, 2003
Creator: Washington Regulatory and Environmental Services
Partner: UNT Libraries Government Documents Department
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DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

Description: The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated …
Date: September 30, 2003
Creator: Schobert, Harold H.; Maroto-Valer, M. Mercedes & Lu, Zhe
Partner: UNT Libraries Government Documents Department
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Development of Improved Burnable Poisons for Commercial Nuclear Power Reactors

Description: Burnable poisons are used in nuclear reactors to produce a more level distribution of power in the reactor core and to reduce to necessity for a large control system. An ideal burnable poison would burn at the same rate as the fuel. In this study, separation of neutron-absorbing isotopes was investigated in order to eliminate isotopes that remain as absorbers at the end of fuel life, thus reducing useful fuel life. The isotopes Gd-157, Dy-164, and Er-167 were found to have desirable properties. These isotopes were separated from naturally occurring elements by means of plasma separation to evaluate feasibility and cost. It was found that pure Gd-157 could save approximately $6 million at the end of four years. However, the cost of separation, using the existing facility, made separation cost- ineffective. Using a magnet with three times the field strength is expected to reduce the cost by a factor of ten, making isotopically separated burnable poisons a favorable method of increasing fuel life in commercial reactors, in particular Generation-IV reactors. The project also investigated various burnable poison configurations, and studied incorporation of metallic burnable poisons into fuel cladding.
Date: September 30, 2003
Creator: Bigelow, M. L. Grossbeck J-P.A. Renier Tim
Partner: UNT Libraries Government Documents Department
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DOE/Industry Matching Grant Program

Description: For the academic year 2001-2002, the Department of Nuclear Engineering and Radiological Sciences received $50,000 of industrial contributions, matched by a DOE grant of $35,000. We used the combined DOE/Industry Matching Grant of $85,000 toward (a) undergraduate merit scholarships and research support, (b) graduate student support, and (c) partial support of a research scientist.
Date: September 30, 2003
Creator: Lee, John C.
Partner: UNT Libraries Government Documents Department
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Earned Income Credit: Qualifying Child Certification Test Appears Justified, but Evaluation Plan Is Incomplete

Description: A letter report issued by the General Accounting Office with an abstract that begins "The Earned Income Credit (EIC), a tax credit available to the working poor, has experienced high rates of noncompliance. Unlike many benefit programs, EIC recipients generally receive payments without advance, formal determinations of eligibility; the Internal Revenue Service (IRS) checks some taxpayers' eligibility later. IRS estimated that tax year 1999 EIC overclaim rates, the most recent data available, to be between 27 and 32 percent of dollars claimed or between $8.5 billion and $9.9 billion. To address overclaims, IRS plans to test a new certification program. Because IRS's plans have garnered much attention, Congress asked us to (1) describe the design and basis for the EIC qualifying child certification program, (2) describe the current status of the program, including significant changes, and (3) assess whether the program is adequately developed to prevent unreasonable burden on EIC taxpayers and improve compliance so that the test should proceed."
Date: September 30, 2003
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
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Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

Description: It is well-known that the human thyroid concentrates iodine more than 100 times the concentration in plasma. Also well-known is the fact that large amounts of stable iodine in the diet can limit thyroid uptake of total iodine; this is the basis for administering potassium iodide following a release of radioiodine from a nuclear reactor accident or nuclear weapon detonation. Many researchers have shown enhanced concentrations of both organic and inorganic iodine in saliva and breast milk. Technetium-99 is a long-lived (231,000 year half-life) radionuclide of concern in the management of high-level radioactive waste. There is no doubt that 99Tc, if it is in groundwater, will be found in the chemical form of pertechnetate, 99TcO4?. Pertechnetate is a large anion, almost identical in size to iodide, I?. The nuclear medicine literature shows that pertechnetate concentrates in the thyroid, salivary glands, and lactating breast in addition to the stomach, liver, and alimentary tract as currently recognized by the International Commission on Radiological Protection (ICRP). The fact that large intakes of stable iodine (127I) in the diet limit uptake of iodine by the thyroid leads one to generalize that stable iodine in the diet may also limit thyroid uptake of pertechnetate. While there is at least one report that iodine in the diet blocks uptake of 99mTcO4? by the thyroid and salivary glands (which have the same Na/I symporter, the biochemical concentration mechanism), the level of protective effect seen for blocking radioactive iodine is not expected for 99TcO4? because pertechnetate does not become organically bound in the thyroid and thus is not retained for months the way iodide is. While it does account for Tc concentration in the thyroid, the existing ICRP biokinetic model for technetium does not take enhanced concentrations in salivary gland and breast tissue into account. From the survey …
Date: September 30, 2003
Creator: Strom, Daniel J.
Partner: UNT Libraries Government Documents Department
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