Longevity of duct tape in residential air distribution systems: 1-D, 2-D, and 3-D joints (open access)

Longevity of duct tape in residential air distribution systems: 1-D, 2-D, and 3-D joints

The aging tests conducted so far showed that duct tape tends to degrade in its performance as the joint it is applied to requires a geometrical description of a higher number of space dimensions (1-D, 2-D, 3-D). One-dimensional joints are the easiest to seal with duct tape, and thus the least to experience failure. Two-dimensional joints, such as the flexible duct core-to-collar joints tested in this study, are less likely to fail than three-dimensional collar-to-plenum joints, as the shrinkage could have a positive effect in tightening the joint. Three-dimensional joints are the toughest to seal and the most likely to experience failure. The 2-D flexible duct core-to-collar joints passed the six-month period of the aging test in terms of leakage, but with the exception of the foil-butyl tape, showed degradation in terms hardening, brittleness, partial peeling, shrinkage, wrinkling, delamination of the tape layers, flaking, cracking, bubbling, oozing and discoloration. The baking test results showed that the failure in the duct tape joints could be attributed to the type of combination of the duct tape and the material it is applied to, as the duct tape behaves differently with different substrates. Overall, the foil-butyl tape (Tape 4) had the best results, …
Date: May 30, 2002
Creator: Abushakra, Bass
Object Type: Report
System: The UNT Digital Library
Paleo-Climate and Glaciological Reconstruction in Central Asia through the Collection and Analysis of Ice Cores and Instrumental Data from the Tien Shan (open access)

Paleo-Climate and Glaciological Reconstruction in Central Asia through the Collection and Analysis of Ice Cores and Instrumental Data from the Tien Shan

While the majority of ice core investigations have been undertaken in the polar regions, a few ice cores recovered from carefully selected high altitude/mid-to-low latitude glaciers have also provided valuable records of climate variability in these regions. A regional array of high resolution, multi-parameter ice core records developed from temperate and tropical regions of the globe can be used to document regional climate and environmental change in the latitudes which are home to the vase majority of the Earth's human population. In addition, these records can be directly compared with ice core records available from the polar regions and can therefore expand our understanding of inter-hemispheric dynamics of past climate changes. The main objectives of our paleoclimate research in the Tien Shan mountains of middle Asia combine the development of detailed paleoenvironmental records via the physical and chemical analysis of ice cores with the analysis of modern meteorological and hydrological data. The first step in this research was the collection of ice cores from the accumulation zone of the Inylchek Glacier and the collection of meteorological data from a variety of stations throughout the Tien Shan. The research effort described in this report was part of a collaborative effort with …
Date: May 30, 2001
Creator: Aizen, Vladimir; Bren, Donald; Kreutz, Karl & Wake, Cameron
Object Type: Report
System: The UNT Digital Library
Cathodic arc plasma deposition (open access)

Cathodic arc plasma deposition

None
Date: May 30, 2002
Creator: Anders, Andre
Object Type: Article
System: The UNT Digital Library
The Budget for Fiscal Year 2009 (open access)

The Budget for Fiscal Year 2009

None
Date: May 30, 2008
Creator: Austin, D. Andrew
Object Type: Report
System: The UNT Digital Library
The Debt Limit: History and Recent Increases (open access)

The Debt Limit: History and Recent Increases

This report discusses how the total debt of the federal government can increase, a historical overview of debt limits, and how the current economic slowdown has led to higher deficits and thereby a series of debt limit increases, as well as legislation related to these increases.
Date: May 30, 2008
Creator: Austin, D. Andrew
Object Type: Report
System: The UNT Digital Library
CFD Simulation of Flow Tones from Grazing Flow past a Deep Cavity (open access)

CFD Simulation of Flow Tones from Grazing Flow past a Deep Cavity

None
Date: May 30, 2006
Creator: Bagwell, T.
Object Type: Report
System: The UNT Digital Library
Defense Outsurcing: OMB Circular A-76 Policy and Options for Congress-Proceedings of a CRS Seminar (open access)

Defense Outsurcing: OMB Circular A-76 Policy and Options for Congress-Proceedings of a CRS Seminar

None
Date: May 30, 2000
Creator: Bailey Grasso, Valerie
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act (ESA), Migratory Bird Treaty Act (MBTA), and Department of Defense (DOD) Readiness Activities: Current Law and Legislative Proposals (open access)

The Endangered Species Act (ESA), Migratory Bird Treaty Act (MBTA), and Department of Defense (DOD) Readiness Activities: Current Law and Legislative Proposals

This report provides a brief overview of how the Endangered Species Act (ESA)1 and the Migratory Bird Treaty Act (MBTA)2 and their relevant regulations may apply to military training and readiness activities of the Department of Defense (DOD). Military activities may “take” protected creatures directly (e.g,. killing with ordnance during rifle, gunnery or assault drills), or might destroy habitat (e.g., artillery or bombing practices), even if these results are not the purpose of the activities. The applicability of the MBTA and ESA to military readiness activities has been controversial recently and legislation has been enacted in both the 107th and 108th Congresses on these topics.
Date: May 30, 2003
Creator: Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
Energy Policy: The Continuing Debate (open access)

Energy Policy: The Continuing Debate

On April 10, 2003, the House passed comprehensive energy legislation, H.R. 6 (247- 175). The bill was a composite of four measures – H.R. 39, reported from the House Committee on Resources, H.R. 238, marked up by the House Science Committee, H.R. 1531, reported from Ways and Means, and an unnumbered bill reported out of the Energy and Commerce Committee. Unlike comprehensive energy legislation (H.R. 4) debated in the 107th Congress, H.R. 6 includes a section on electricity which has stirred some controversy. H.R. 6 would provide authorization for exploration and development of the Arctic National Wildlife Refuge (ANWR).
Date: May 30, 2003
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 4 MACROBATCH 5 (open access)

DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 4 MACROBATCH 5

The Waste Acceptance Product Specifications (WAPS)1 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP)2 and Waste Form Qualification Report (WQR)3. However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, …
Date: May 30, 2008
Creator: Bannochie, C; Ned Bibler, N & David Diprete, D
Object Type: Report
System: The UNT Digital Library
Course Notes: United States Particle Accelerator School Beam Physics with Intense Space-Charge (open access)

Course Notes: United States Particle Accelerator School Beam Physics with Intense Space-Charge

The purpose of this course is to provide a comprehensive introduction to the physics of beams with intense space charge. This course is suitable for graduate students and researchers interested in accelerator systems that require sufficient high intensity where mutual particle interactions in the beam can no longer be neglected. This course is intended to give the student a broad overview of the dynamics of beams with strong space charge. The emphasis is on theoretical and analytical methods of describing the acceleration and transport of beams. Some aspects of numerical and experimental methods will also be covered. Students will become familiar with standard methods employed to understand the transverse and longitudinal evolution of beams with strong space charge. The material covered will provide a foundation to design practical architectures. In this course, we will introduce you to the physics of intense charged particle beams, focusing on the role of space charge. The topics include: particle equations of motion, the paraxial ray equation, and the Vlasov equation; 4-D and 2-D equilibrium distribution functions (such as the Kapchinskij-Vladimirskij, thermal equilibrium, and Neuffer distributions), reduced moment and envelope equation formulations of beam evolution; transport limits and focusing methods; the concept of emittance and …
Date: May 30, 2008
Creator: Barnard, J.J. & Lund, S.M.
Object Type: Report
System: The UNT Digital Library
B1 magnet harmonics (open access)

B1 magnet harmonics

During the B0 Overpass construction for the CDF detector at Fermilab, 33 B1 magnets were measured using a bucked tangential coil. Measurements were made on the midplane, at the centerline and at {+-} 1 inch horizontal displacement. Since the coil was only 62 inches long, measurements were made at four longitudinal positions. Because of the design of the Main Ring, it was sufficient to combine data from all positions and report the harmonic spectrum for the magnet as a whole. For modeling the Scrounge-atron, it is more useful to treat each measurement position separately. The author reports here an analysis of the harmonic spectra at each probe position, based on the original data.
Date: May 30, 2000
Creator: Barnes, P. D.
Object Type: Report
System: The UNT Digital Library
The Plowshare Program: Peaceful Applications for Nuclear Detonations (open access)

The Plowshare Program: Peaceful Applications for Nuclear Detonations

The U.S. Atomic Energy Commission's Plowshare Program focused on developing the capability to use nuclear detonations for civil works projects and industrial applications. The participants envisioned canals and harbors constructed quickly and cheaply and the augmentation of natural gas, oil, and geothermal power production. The Plowshare Program began in the 1950s and ended in the 1970s. The archaeological effort to relocate and record places associated with this project has identified a unique and varied historical legacy on the landscape in the western United States and discovered that the range and types of projects considered and planned are more diverse than formerly recognized.
Date: May 30, 2008
Creator: Beck, C.; Edwards, S. & King, M.
Object Type: Article
System: The UNT Digital Library
The Cost of Iraq, Afghanistan, and Other Global War on Terror Operations Since 9/11 (open access)

The Cost of Iraq, Afghanistan, and Other Global War on Terror Operations Since 9/11

This report analyzes the war funding for the Defense Department and tracks funding for USAID and VA Medical funding.
Date: May 30, 2008
Creator: Belasco, Amy
Object Type: Report
System: The UNT Digital Library
Intelligence Issues for Congress (open access)

Intelligence Issues for Congress

This report explores the various issues currently facing Congress in regards to intelligence and counterterrorism activities, including the Intelligence Reform and Terrorism Prevention Act (P.L. 108-458), signed in December 2004; the position of Director of National Intelligence (DNI), which that act created; the importance of collaborative efforts between various intelligence agencies to successfully carry out counterterrorism measures; and other pieces of legislation relevant to such matters.
Date: May 30, 2008
Creator: Best, Richard A., Jr.
Object Type: Report
System: The UNT Digital Library
Seeing the Unseeable (open access)

Seeing the Unseeable

The SciDAC Visualization and Analytics Center for Enabling Technologies (VACET) isa highly productive effort combining the forces of leading visualization researchersfrom five different institutions to solve some of the most challenging dataunderstanding problems in modern science. The VACET technology portfolio isdiverse, spanning all typical visual data analysis use models and effectivelybalancing forward-looking research with focused software architecture andengineering resulting in a production-quality software infrastructure. One of the keyelements in VACET's success is a rich set of projects that are collaborations withscience stakeholders: these efforts focus on identifying and overcoming obstacles toscientific knowledge discovery in modern, large, and complex scientific datasets.
Date: May 30, 2008
Creator: Bethel, Edward W; Bethel, E. Wes; Johnson, Chris; Hansen, Charles; Silva, Claudio; Parker, Steven et al.
Object Type: Article
System: The UNT Digital Library
U.N. System Funding: Congressional Issues (open access)

U.N. System Funding: Congressional Issues

None
Date: May 30, 2002
Creator: Bite, Vita
Object Type: Report
System: The UNT Digital Library
Biochemistry of Dissimilatory Sulfur Oxidation (open access)

Biochemistry of Dissimilatory Sulfur Oxidation

The long term goals of this research were to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur practiced by various species of the thiobacilli. Specific adhesion of the thiobacilli to elemental sulfur was studied by electrical impedance, dynamic light scattering, laser Doppler velocimetry, and optical trapping methods. The conclusion is that the thiobacilli appear to express specific receptors that enable the bacteria to recognize and adhere to insoluble sulfur. The enzyme tetrathionate oxidase was purified from two species of the thiobacilli. Extensive structural and functional studies were conducted on adenosine 5'-phosphosulfate reductase purified from cell-free extracts of Thiobacillus denitrificans. The kinetic mechanism of rhodanese was studied.
Date: May 30, 2003
Creator: Blake, R., II
Object Type: Report
System: The UNT Digital Library
Digital Radiography of a Drop Tested 9975 Radioactive Materials Packaging (open access)

Digital Radiography of a Drop Tested 9975 Radioactive Materials Packaging

This paper discusses the use of radiography as a tool for evaluating damage to radioactive material packaging subjected to regulatory accident conditions. The Code of Federal Regulations, 10 CFR 71, presents the performance based requirements that must be used in the development (design, fabrication and testing) of a radioactive material packaging. The use of various non-destructive examination techniques in the fabrication of packages is common. One such technique is the use of conventional radiography in the examination of welds. Radiography is conventional in the sense that images are caught one at a time on film stock. Most recently, digital radiography has been used to characterize internal damage to a package subjected to the 30-foot hypothetical accident conditions (HAC) drop. Digital radiography allows for real time evaluation of the item being inspected. This paper presents a summary discussion of the digital radiographic technique and an example of radiographic results of a 9975 package following the HAC 30-foot drop.
Date: May 30, 2001
Creator: Blanton, P.S.
Object Type: Article
System: The UNT Digital Library
Inexpensive, High-Performance, Electron Gun. Final report (open access)

Inexpensive, High-Performance, Electron Gun. Final report

None
Date: May 30, 2000
Creator: Bluem, H.P.
Object Type: Report
System: The UNT Digital Library
FY01 Supplemental Science and Performance Analysis: Volume 1,Scientific Bases and Analyses (open access)

FY01 Supplemental Science and Performance Analysis: Volume 1,Scientific Bases and Analyses

The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for development as a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. To facilitate public review and comment, in May 2001 the DOE released the Yucca Mountain Science and Engineering Report (S&ER) (DOE 2001 [DIRS 153849]), which presents technical information supporting the consideration of the possible site recommendation. The report summarizes the results of more than 20 years of scientific and engineering studies. A decision to recommend the site has not been made: the DOE has provided the S&ER and its supporting documents as an aid to the public in formulating comments on the possible recommendation. When the S&ER (DOE 2001 [DIRS 153849]) was released, the DOE acknowledged that technical and scientific analyses of the site were ongoing. Therefore, the DOE noted in the Federal Register Notice accompanying the report (66 FR 23013 [DIRS 155009], p. 2) that additional technical information would be released before the dates, locations, and times for public hearings on the possible recommendation were announced. This information includes: (1) the results of additional technical studies of a potential repository at Yucca Mountain, contained …
Date: May 30, 2001
Creator: Bodvarsson, G. S. & Dobson, David
Object Type: Report
System: The UNT Digital Library
Bioenergy Crop Breeding and Production Research in the Southeast, Final Report for 1996 to 2001 (open access)

Bioenergy Crop Breeding and Production Research in the Southeast, Final Report for 1996 to 2001

Switchgrass (Panicum virgatum L.) is a native grass species to much of the US. It has shown great potential for use in production of fuel ethanol from cellulosic biomass (Lynd et al., 1991). Work in Alabama demonstrated very high dry matter yields can be achieved with switchgrass (Maposse et al. 1995) in the southeastern US. Therefore, this region is thought to be an excellent choice for development of a switchgrass cropping system where farmers can produce the grass for either biomass or forage. Another report has shown success with selection and breeding to develop high yielding germplasm from adapted cultivars and ecotypes of switchgrass (Moser and Vogel 1995). In the mid 1990s, however, there was little plant breeding effort for switchgrass with a potential for developing a cultivar for the southeast region. The main goal of the project was to develop adaptive, high-yielding switchgrass cultivars for use in cropping systems for bioenergy production in the southeastern US. A secondary objective was to assess the potential of alternate herbaceous species such as bermudagrass (Cynodon dactylon L.), bahiagrass (Paspalum notatum Flugge.), and napiergrass (Pennisetum purpureum Schumach.) that may compete with switchgrass for herbaceous bioenergy production in the southeast. During the conduct of …
Date: May 30, 2003
Creator: Bouton, J. H.
Object Type: Report
System: The UNT Digital Library
Cooperative Research and Development for Advanced Microturbines Program on Advanced Integrated Microturbine System (open access)

Cooperative Research and Development for Advanced Microturbines Program on Advanced Integrated Microturbine System

The Advanced Integrated Microturbine Systems (AIMS) project was kicked off in October of 2000 to develop the next generation microturbine system. The overall objective of the project was to develop a design for a 40% electrical efficiency microturbine system and demonstrate many of the enabling technologies. The project was initiated as a collaborative effort between several units of GE, Elliott Energy Systems, Turbo Genset, Oak Ridge National Lab and Kyocera. Since the inception of the project the partners have changed but the overall direction of the project has stayed consistent. The project began as a systems study to identify design options to achieve the ultimate goal of 40% electrical efficiency. Once the optimized analytical design was identified for the 40% system, it was determined that a 35% efficient machine would be capable of demonstrating many of the advanced technologies within the given budget and timeframe. The items that would not be experimentally demonstrated were fully produced ceramic parts. However, to understand the requirements of these ceramics, an effort was included in the project to experimentally evaluate candidate materials in representative conditions. The results from this effort would clearly identify the challenges and improvement required of these materials for the full …
Date: May 30, 2007
Creator: Bowman, Michael J.
Object Type: Report
System: The UNT Digital Library
Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System (open access)

Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System

The performance of a 1 cm{sup 2} thermophotovoltaic (TPV) module was recently measured in a photonic cavity test system. A conversion efficiency of 11.7% was measured at a radiator temperature of 1076 C and a module temperature of 29.9 C. This experiment achieved the highest direct measurement of efficiency for an integrated TPV system. Efficiency was calculated from the ratio of the peak (load matched) electrical power output and the heat absorption rate. Measurements of these two parameters were made simultaneously to assure the validity of the measured efficiency value. This test was conducted in a photonic cavity which mimicked a typical flat-plate TPV system. The radiator was a large, flat graphite surface. The module was affixed to the top of a copper pedestal for heat absorption measurements. The heat absorption rate was proportional to the axial temperature gradient in the pedestal under steady-state conditions. The test was run in a vacuum to eliminate conductive and convective heat transfer mechanisms. The photonic cavity provides the optimal test environment for TPV efficiency measurements because it incorporates all important physical phenomena found in an integrated TPV system: high radiator emissivity and blackbody spectral shape, photon recycling, Lambertian distribution of incident radiation and …
Date: May 30, 2000
Creator: Brown, E. J.; Ballinger, C. T.; Burger, S. R.; Charache, G. W.; Danielson, L. R.; DePoy, D. M. et al.
Object Type: Report
System: The UNT Digital Library