Natural and Passive Remediation of Chlorinated Solvents: Critical Evaluation of Science and Technology Targets (open access)

Natural and Passive Remediation of Chlorinated Solvents: Critical Evaluation of Science and Technology Targets

This report was written for multiple audiences. Each reader will likely approach the subject from a different perspective, seeking different information. The team that developed the document consisted of several technical experts on monitored natural attenuation (MNA) and included participants who were integral in the development of US EPA's chlorinated solvent MNA protocol and the subsequent US EPA and Office of Solid Waste and emergency Response (OSWER) policy directive. The primary assignment to the interdisciplinary team was to generate a summary of the state-of-the-art, particularly for chlorinated solvent applications and to identify high-priority opportunities for advancement. A diverse jury of peers reviewed the draft report; the report was edited in response to their comments.
Date: April 7, 2004
Creator: Looney, Brian
Object Type: Report
System: The UNT Digital Library
Authorized Limits Request: Radiological Clearance of Select Hanford Reach National Monument Lands (open access)

Authorized Limits Request: Radiological Clearance of Select Hanford Reach National Monument Lands

This document describes development of radiological release criteria (Authorized Limits) for Hanford Reach National Monument lands that DOE plans to release to the U.S. Department of the Interior.
Date: May 7, 2004
Creator: Napier, Bruce A. & Glines, Wayne M.
Object Type: Report
System: The UNT Digital Library
DRY TRANSFER FACILITY SEISMIC ANALYSIS (open access)

DRY TRANSFER FACILITY SEISMIC ANALYSIS

None
Date: April 7, 2004
Creator: N/A, EARNEST S - N /A KO H - N/A DOCKERY W - N/A PERNISI R -
Object Type: Report
System: The UNT Digital Library
Modeling of beam loss in Tevatron and backgrounds in the BTeV detector (open access)

Modeling of beam loss in Tevatron and backgrounds in the BTeV detector

Detailed STRUCT simulations are performed on beam loss rates in the vicinity of the BTeV detector in the Tevatron CO interaction region due to beam-gas nuclear elastic interactions and out-scattering from the collimation system. Corresponding showers induced in the machine components and background rates in BTeV are modeled with the MARS14 code. It is shown that the combination of a steel collimator and concrete shielding wall located in front of the detector can reduce the accelerator-related background rates in the detector by an order of magnitude.
Date: July 7, 2004
Creator: Drozhdin, Alexandr I. & Mokhov, Nikolai V.
Object Type: Article
System: The UNT Digital Library
Optical Properties of Passivated Silicon Nanoclusters: The Role of Synthesis (open access)

Optical Properties of Passivated Silicon Nanoclusters: The Role of Synthesis

The effect of preparation conditions on the structural and optical properties of silicon nanoparticles is investigated. Nanoscale reconstructions, unique to curved nanosurfaces, are presented for silicon nanocrystals and shown to have lower energy and larger optical gaps than bulk-derived structures. We find that high-temperature synthesis processes can produce metastable non-crystalline nanostructures with different core structures than bulk-derived crystalline clusters. The type of core structure that forms from a given synthesis process may depend on the passivation mechanism and time scale. The effect of oxygen on the optical of different types of silicon structures is calculated. In contrast to the behavior of bulk-like nanostructures, for non-crystalline and reconstructed crystalline structures surface oxygen atoms do not decrease the gap. In some cases, the presence of oxygen atoms at the nanocluster surface can significantly increase the optical absorption gap, due to decreased angular distortion of the silicon bonds. The relationship between strain and the optical gap in silicon nanoclusters is discussed.
Date: April 7, 2004
Creator: Draeger, E; Grossman, J; Williamson, A & Galli, G
Object Type: Article
System: The UNT Digital Library
An Experimental Study of Drag Reduction Devices for a Trailer Underbody and Base (open access)

An Experimental Study of Drag Reduction Devices for a Trailer Underbody and Base

Low speed wind tunnel measurements are made on a 1/16th scale generic tractor-trailer model at a width-based Reynolds number of 325,000. The model is fixed to a turntable, allowing the yaw angle to be varied between {+-}14 degrees in 2 degree increments. Various add-on drag reduction devices are mounted to the model underbody and base. The wind-averaged drag coefficient at 65 mph is computed for each configuration, allowing the effectiveness of the add-on devices to be assessed. The most effective add-on drag reduction device for the trailer underbody is a wedge-shaped skirt, which reduces the wind-averaged drag coefficient by 2.0%. For the trailer base, the most effective add-on drag reduction device is a set of curved base flaps having a radius of curvature of 0.91 times the trailer width. These curved base flaps reduce the wind-averaged drag coefficient by 18.8%, providing the greatest drag reduction of any of the devices tested. When the wedge-shaped skirt and curved base flaps are used in conjunction with one another, the wind-averaged drag coefficient is reduced by 20%.
Date: May 7, 2004
Creator: Ortega, J M & Salari, K
Object Type: Article
System: The UNT Digital Library
Prediction of External Corrosion for Steel Cylinders--2004 Report (open access)

Prediction of External Corrosion for Steel Cylinders--2004 Report

Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. This report documents activities that address UF{sub 6} Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to …
Date: July 7, 2004
Creator: Schmoyer, RLS
Object Type: Report
System: The UNT Digital Library
TOURGHREACT: A Simulation Program for Non-isothermal MultiphaseReactive Geochemical Transport in Variably Saturated GeologicMedia (open access)

TOURGHREACT: A Simulation Program for Non-isothermal MultiphaseReactive Geochemical Transport in Variably Saturated GeologicMedia

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between mineral assemblages and fluids can occur under local equilibrium or kinetic rates. The gas phase can be chemically active. Precipitation and dissolution reactions can change formation porosity and permeability. The program can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. Here we present two examples to illustrate applicability of the program: (1) injectivity effects of mineral scaling in a fractured geothermal reservoir and (2) CO2 disposal in a deep saline aquifer.
Date: December 7, 2004
Creator: Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Drift Scale THM Model (open access)

Drift Scale THM Model

This model report documents the drift scale coupled thermal-hydrological-mechanical (THM) processes model development and presents simulations of the THM behavior in fractured rock close to emplacement drifts. The modeling and analyses are used to evaluate the impact of THM processes on permeability and flow in the near-field of the emplacement drifts. The results from this report are used to assess the importance of THM processes on seepage and support in the model reports ''Seepage Model for PA Including Drift Collapse'' and ''Abstraction of Drift Seepage'', and to support arguments for exclusion of features, events, and processes (FEPs) in the analysis reports ''Features, Events, and Processes in Unsaturated Zone Flow and Transport and Features, Events, and Processes: Disruptive Events''. The total system performance assessment (TSPA) calculations do not use any output from this report. Specifically, the coupled THM process model is applied to simulate the impact of THM processes on hydrologic properties (permeability and capillary strength) and flow in the near-field rock around a heat-releasing emplacement drift. The heat generated by the decay of radioactive waste results in elevated rock temperatures for thousands of years after waste emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling …
Date: October 7, 2004
Creator: Rutqvist, J.
Object Type: Report
System: The UNT Digital Library
Princeton Plasma Physics Laboratory Annual Site Environmental Report for Calendar Year 2001 (open access)

Princeton Plasma Physics Laboratory Annual Site Environmental Report for Calendar Year 2001

The purpose of this report is to provide the U.S. Department of Energy (DOE) and the public with information on the level of radioactive and nonradioactive pollutants (if any) that are added to the environment as a result of the Princeton Plasma Physics Laboratory's (PPPL) operations. The results of the 2001 environmental surveillance and monitoring program for PPPL are presented and discussed. The report also summarizes environmental initiatives, assessments, and programs that were undertaken in 2001. PPPL has engaged in fusion energy research since 1951. The vision of the Laboratory is to create innovations to make fusion power a practical reality--a clean, alternative energy source. The Year 2001 marked the third year of National Spherical Torus Experiment (NSTX) operations and Tokamak Fusion Test Reactor (TFTR) dismantlement and deconstruction activities. A collaboration among fourteen national laboratories, universities, and research institutions, the NSTX is a major element in the U.S. Fusion Energy Sciences Program. It has been designed to test the physics principles of spherical torus (ST) plasmas. The ST concept could play an important role in the development of smaller, more economical fusion reactors. In 2001, PPPL's radiological environmental monitoring program measured tritium in the air at on- and off-site sampling …
Date: April 7, 2004
Creator: Finley, Virginia L.
Object Type: Report
System: The UNT Digital Library
Graphite Foam Heat Exchangers for Thermal Management (open access)

Graphite Foam Heat Exchangers for Thermal Management

Improved thermal management is needed to increase the power density of electronic and more effectively cool electronic enclosures that are envisioned in future aircraft, spacecraft and surface ships. Typically, heat exchanger cores must increase in size to more effectively dissipate increased heat loads, this would be impossible in many cases, thus improved heat exchanger cores will be required. In this Phase I investigation, MRi aimed to demonstrate improved thermal management using graphite foam (Gr-foam) core heat exchangers. The proposed design was to combine Gr-foams from POCO with MRi's innovative low temperature, active metal joining process (S-Bond{trademark}) to bond Gr-foam to aluminum, copper and aluminum/SiC composite faceplates. The results were very favorable, so a Phase II SBIR with the MDA was initiated. This had primarily 5 tasks: (1) bonding, (2) thermal modeling, (3) cooling chip scale packages, (4) evaporative cooling techniques and (5) IGBT cold plate development. The bonding tests showed that the ''reflow'' technique with S-Bond{reg_sign}-220 resulted in the best and most consistent bond. Then, thermal modeling was used to design different chip scale packages and IGBT cold plates. These designs were used to fabricate many finned graphite foam heat sinks specifically for two standard type IC packages, the 423 …
Date: June 7, 2004
Creator: Klett, J.W.
Object Type: Report
System: The UNT Digital Library
Injection of CO2 with H2S and SO2 and Subsequent Mineral Trapping in Sandstone-Shale Formation (open access)

Injection of CO2 with H2S and SO2 and Subsequent Mineral Trapping in Sandstone-Shale Formation

Carbon dioxide (CO{sub 2}) injection into deep geologic formations can potentially reduce atmospheric emissions of greenhouse gases. Sequestering less-pure CO{sub 2} waste streams (containing H{sub 2}S and/or SO{sub 2}) would be less expensive or would require less energy than separating CO{sub 2} from flue gas or a coal gasification process. The long-term interaction of these injected acid gases with shale-confining layers of a sandstone injection zone has not been well investigated. We therefore have developed a conceptual model of injection of CO{sub 2} with H{sub 2}S and/or SO{sub 2} into a sandstone-shale sequence, using hydrogeologic properties and mineral compositions commonly encountered in Gulf Coast sediments of the United States. We have performed numerical simulations of a 1-D radial well region considering sandstone alone and a 2-D model using a sandstone-shale sequence under acid-gas injection conditions. Results indicate that shale plays a limited role in mineral alteration and sequestration of gases within a sandstone horizon for short time periods (10,000 years in present simulations). The co-injection of SO{sub 2} results in different pH distribution, mineral alteration patterns, and CO{sub 2} mineral sequestration than the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Simulations generate a zonal distribution of mineral …
Date: September 7, 2004
Creator: Xu, Tianfu; Apps, John A.; Pruess, Karsten & Yamamoto, Hajime
Object Type: Report
System: The UNT Digital Library
Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation (open access)

Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation

Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub …
Date: September 7, 2004
Creator: Xu, Tianfu; Apps, John A.; Pruess, Karsten & Yamamoto, Hajime
Object Type: Article
System: The UNT Digital Library
Human Capital: Additional Collaboration Between OPM and Agencies Is Key to Improved Federal Hiring (open access)

Human Capital: Additional Collaboration Between OPM and Agencies Is Key to Improved Federal Hiring

A letter report issued by the General Accounting Office with an abstract that begins "Improving the federal hiring process is critical given the increasing number of new hires expected in the next few years. Congress asked GAO to report on the (1) status of recent efforts to help improve the federal hiring process and (2) extent to which federal agencies are using two new hiring flexibilities--category rating and direct-hire authority. Category rating permits an agency to select any job candidate placed in a best-qualified category. Direct-hire authority allows an agency to appoint individuals to positions without adherence to certain competitive examination requirements when there is a severe shortage of qualified candidates or a critical hiring need."
Date: June 7, 2004
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Medicare: Past Experience Can Guide Future Competitive Bidding for Medical Equipment and Supplies (open access)

Medicare: Past Experience Can Guide Future Competitive Bidding for Medical Equipment and Supplies

A letter report issued by the Government Accountability Office with an abstract that begins "The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA) requires the Centers for Medicare & Medicaid Services (CMS) to conduct large-scale competitive bidding for durable medical equipment, supplies, off-the-shelf orthotics, and enteral nutrients and related equipment and supplies provided to beneficiaries. The Balanced Budget Act of 1997 mandated that GAO study an earlier Medicare competitive bidding demonstration. To address this mandate, GAO assessed this past experience in relation to four issues that CMS might consider as it implements large-scale competitive bidding: (1) items for competitive bidding, (2) how to streamline implementation, (3) ways to collect information on specific items provided to beneficiaries, and (4) steps to ensure quality items and services."
Date: September 7, 2004
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Bills and Resolutions: Examples of How Each Kind Is Used (open access)

Bills and Resolutions: Examples of How Each Kind Is Used

This report briefly describes the process by which Congress seeks to pass a law. During this process Congress uses a bill or joint resolution, which must be passed by both houses in identical form, that is then presented to the President for his approval or disapproval.
Date: December 7, 2004
Creator: Beth, Richard S.
Object Type: Report
System: The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 111, No. 4, Ed. 1 Wednesday, January 7, 2004 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 111, No. 4, Ed. 1 Wednesday, January 7, 2004

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: January 7, 2004
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
Anti-Corruption Standards of the International Financial Institutions (open access)

Anti-Corruption Standards of the International Financial Institutions

This report is on the Anti-Corruption Standards of the International Financial Institutions.
Date: July 7, 2004
Creator: Langton, Danielle
Object Type: Report
System: The UNT Digital Library
District of Columbia: FY 2003 Performance Report Shows Continued Improvements (open access)

District of Columbia: FY 2003 Performance Report Shows Continued Improvements

Correspondence issued by the Government Accountability Office with an abstract that begins "This is the fifth consecutive year that we have reviewed the District of Columbia's performance accountability report as mandated by the Federal Payment Reauthorization Act of 1994. The act requires the Mayor of the District of Columbia to submit to the Congress a performance accountability plan containing a statement of measurable and objective performance goals for the coming fiscal year for all significant activities of the District government. After the end of the fiscal year, the District is to submit a performance accountability report on the extent to which the District achieved these goals. This requirement for the District government is similar to the requirements for executive branch federal agencies under the Government Performance and Results Act of 1993 (GPRA). GAO's report focuses on the continued progress the District has made in performance reporting. Specifically, the objectives of this report were to (1) examine the extent to which the performance accountability report is in compliance with statutory requirements, and (2) summarize some of the District's other significant performance management initiatives and identify additional opportunities for improvement."
Date: July 7, 2004
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Military Personnel: Active Duty Compensation and Its Tax Treatment (open access)

Military Personnel: Active Duty Compensation and Its Tax Treatment

Correspondence issued by the General Accounting Office with an abstract that begins "The Department of Defense's (DOD) total military compensation package for active duty members consists of both cash and noncash benefits. Since the late 1990s, Congress and the DOD have increased military cash compensation by increasing basic pay and allowances for housing, among other things. Military members also receive tax breaks, which are a part of their cash compensation. Moreover, active duty personnel are offered substantial noncash benefits, such as retirement, health care, commissaries, and childcare. In some cases, these noncash benefits exceed those available to private-sector personnel. DOD relies heavily on noncash benefits because it views benefits as critical to morale, retention, and the quality of life for service members and their families. To better understand the military compensation system, Congress asked us to provide the Chairman and Ranking Minority Member of the Senate Committee on Finance with information on active duty military compensation and its tax treatment. In January 2004, we briefed Congressional staff on our preliminary observations. Because our work identified that the combat zone tax exclusion could impact some service members, Congress asked us to focus our work on military cash compensation and to do …
Date: May 7, 2004
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Texas Register, Volume 29, Number 19, Pages 4333-4618, May 07, 2004 (open access)

Texas Register, Volume 29, Number 19, Pages 4333-4618, May 07, 2004

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: May 7, 2004
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Food Safety: USDA and FDA Need to Better Ensure Prompt and Complete Recalls of Potentially Unsafe Food (open access)

Food Safety: USDA and FDA Need to Better Ensure Prompt and Complete Recalls of Potentially Unsafe Food

A letter report issued by the Government Accountability Office with an abstract that begins "Two large food recalls completed in 2003 were associated with 8 deaths and nearly 100 serious illnesses in at least 16 states. Manufacturers voluntarily recall potentially unsafe food by notifying their customers to return or destroy it. The U.S. Department of Agriculture (USDA), for meat, poultry, and egg products, and the Food and Drug Administration (FDA), for other food, have programs to monitor voluntary food recalls, verify that companies contact their customers, and maintain recall data. GAO (1) examined the recall programs and procedures USDA and FDA use to protect consumers from unsafe foods and (2) compared their food recall authority with the authority of agencies to recall other consumer products."
Date: October 7, 2004
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Opportunities for Congressional Oversight and Improved Use of Taxpayer Funds: Budgetary Implications of Selected GAO Work (open access)

Opportunities for Congressional Oversight and Improved Use of Taxpayer Funds: Budgetary Implications of Selected GAO Work

A letter report issued by the General Accounting Office with an abstract that begins "This report contains in a single document the budgetary implications of selected program reforms discussed in past GAO work but not yet implemented or enacted. Since 1994, we have prepared annual reports similar to this product, in order to continue to assist congressional committees in identifying approaches to reduce federal spending or increase revenues. This year's report contains over 100 examples of budget options organized by budget function. Where possible, budgetary savings estimates provided by the Congressional Budget Office (CBO) or the Joint Committee on Taxation (JCT) are presented."
Date: May 7, 2004
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Watershed Management: Better Coordination of Data Collection Efforts Needed to Support Key Decisions (open access)

Watershed Management: Better Coordination of Data Collection Efforts Needed to Support Key Decisions

A chapter report issued by the General Accounting Office with an abstract that begins "Reliable and complete data are needed to assess watersheds--areas that drain into a common body of water--and allocate limited cleanup resources. Historically, water officials have expressed concern about a lack of water data. At the same time, numerous organizations collect a variety of water data. To address a number of issues concerning the water data that various organization collect, the Chairman of the Subcommittee on Water Resources and Environment, House Committee on Transportation and Infrastructure, asked GAO to determine (1) the key entities that collect water data, the types of data they collect, how they store the data, and how entities can access the data; and (2) the extent that water quality and water quantity data collection efforts are coordinated."
Date: June 7, 2004
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library