The Wild and Scenic Rivers Act and Federal Water Rights (open access)

The Wild and Scenic Rivers Act and Federal Water Rights

This report discusses federal authority over water, and federal "reserved" and non-reserved water rights. Based on the language of the act and its legislative history, it appears that the act creates federal water rights. The act does not specify the quantity of the right. The amount of the federal right is likely to vary from river to river depending on the river's flows, the unappropriated flows in the river at the time of designation, and the values for which the river is being protected.
Date: March 5, 2007
Creator: Alexander, Kristina
Object Type: Report
System: The UNT Digital Library
Gray Wolves Under the Endangered Species Act: Distinct Population Segments and Experimental Populations (open access)

Gray Wolves Under the Endangered Species Act: Distinct Population Segments and Experimental Populations

This report looks at the distinct population segments (DPSs) process as it is applied to the gray wolf. It also reviews experimental populations of wolves under the Endangered Species Act (ESA) and their protections.
Date: November 5, 2007
Creator: Alexander, Kristina & Corn, M. L.
Object Type: Report
System: The UNT Digital Library
Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments. (open access)

Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments.

In light water reactors, components made of nickel-base alloys are susceptible to environmentally assisted cracking. This report summarizes the crack growth rate results and related metallography for field and laboratory-procured Alloy 600 and its weld alloys tested in pressurized water reactor (PWR) environments. The report also presents crack growth rate (CGR) results for a shielded-metal-arc weld of Alloy 182 in a simulated PWR environment as a function of temperature between 290 C and 350 C. These data were used to determine the activation energy for crack growth in Alloy 182 welds. The tests were performed by measuring the changes in the stress corrosion CGR as the temperatures were varied during the test. The difference in electrochemical potential between the specimen and the Ni/NiO line was maintained constant at each temperature by adjusting the hydrogen overpressure on the water supply tank. The CGR data as a function of temperature yielded activation energies of 252 kJ/mol for a double-J weld and 189 kJ/mol for a deep-groove weld. These values are in good agreement with the data reported in the literature. The data reported here and those in the literature suggest that the average activation energy for Alloy 182 welds is on the …
Date: May 5, 2008
Creator: Alexandreanu, B.; Chopra, O. K. & Shack, W. J.
Object Type: Report
System: The UNT Digital Library
Plasma Diagnostic Calibration and Characterizations with High Energy X-rays (open access)

Plasma Diagnostic Calibration and Characterizations with High Energy X-rays

National Security Technologies’ High Energy X-ray (HEX) Facility is unique in the U.S. Department of Energy complex. The HEX provides fluorescent X-rays of 5 keV to 100 keV with fluence of 10^5–10^6 photons/cm^2/second at the desired line energy. Low energy lines can be filtered, and both filters and fluorescers can be changed rapidly. We present results of calibrating image plates (sensitivity and modulation transfer function), a Bremsstrahlung spectrometer (stacked filters and image plates), and the National Ignition Facility’s Filter- Fluorescer Experiment (FFLEX) high energy X-ray spectrometer. We also show results of a scintillator light yield and alignment study for a neutron imaging system.
Date: June 5, 2009
Creator: Ali, Zaheer
Object Type: Article
System: The UNT Digital Library
Impact of spectral transition zone in reference ENIGMA configuration. (open access)

Impact of spectral transition zone in reference ENIGMA configuration.

The gas-cooled fast reactor (GFR) is one of six advanced nuclear energy systems being studied under the auspices of the Gen IV International Forum (GIF). In a bilateral International Nuclear Energy Research Initiative (I-NERI) project French and U.S. national laboratories, industry, and universities are collaborating on the development of the GFR. This effort is led by the ANL in the U.S. and the CEA in France. Some of the attractions of the GFR include: (1) Hard spectrum and core breeding ratio, BR {approx} 1. These features allow minimal waste production, improved transmutation capability, optimal and flexible use of natural resources, potentially better economy (because of use of higher power density relative to current thermal gas-cooled systems), and improved non-proliferation (no fertile blanket); (2) Temperature resistant fuel and structure elements that are favorable to tight fission product confinement and system operation at high temperature; (3) High temperature and transparent helium (He) gas coolant that allows a high thermodynamic conversion efficiency, other energy applications (e.g., hydrogen production), and ease of in-service inspection and repair; and (4) Possible direct energy conversion cycle leading to a simpler design, increased conversion efficiency, and lower investment costs. The French strategy for advanced systems includes the development …
Date: October 5, 2005
Creator: Aliberti, G.; Palmiotti, G.; Taiwo, T. A. & Tommasi, J.
Object Type: Report
System: The UNT Digital Library
Radiation-induced segregation and the relationship to physical properties in irradiated austenitic alloys. (open access)

Radiation-induced segregation and the relationship to physical properties in irradiated austenitic alloys.

Radiation-induced changes in composition are studied because these changes can degrade failure of materials irradiated in nuclear reactors. In this work, the effect of alloy composition on radiation-induced segregation, hardening, and void swelling is presented. Five alloys, Fe-18Cr-8Ni, Fe-16Cr-13Ni, Fe-18Cr-40Ni, Fe-16Cr-13Ni+Mo, and Fe-16Cr-13Ni+Mo+P (all compositions in wt. %), were irradiated with 3.2 MeV protons at 400 C to a dose of 0.5 displacements per atom. The change in grain boundary composition was measured using field emission gun scanning transmission electron microscopy and the hardening was measured using Vickers indentation. Void swelling is calculated from the void size distribution measured using transmission electron microscopy. After irradiation, Cr depletes and Ni enriches at grain boundaries. Increasing bulk Ni concentration causes greater Cr depletion and Ni enrichment at grain boundaries. For alloys with 16 Cr, the addition of P reduces the Cr depletion and Ni enrichment. Hardening does not directly correlate with composition, but a framework for isolating the effect of hardening and segregation on cracking is suggested. The amount of void swelling in the irradiated material is shown to correspond inversely with segregation. Those alloys with greater segregation tend to swell less.
Date: June 5, 2002
Creator: Allen, T. R.; Cole, J. I.; Was, G. S. & Kenik, E. A.
Object Type: Article
System: The UNT Digital Library
Properties of 20% cold-worked 316 stainless steel irradiated at low dose rate. (open access)

Properties of 20% cold-worked 316 stainless steel irradiated at low dose rate.

To assess the effects of long-term, low-dose-rate neutron exposure, tensile, hardness, and fracture properties were measured and microstructural characterization performed on irradiated 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-390 C and dose rates from 0.8-3.3 x 10{sup -7} dpa/s. Irradiation caused hardening, with the ultimate tensile strength (UTS) reaching about 800 MPa near 20 dpa and appearing to saturate at higher doses. The yield strength (YS) follows approximately the same trend as the ultimate tensile strength. At higher dose, the difference between the UTS and YS decreases, suggesting the work-hardening capability of the material is decreasing with increasing dose. The hardness and yield strength increases occur roughly over the same range of dose. While the material retained respectable ductility at 20 dpa, the uniform and total elongation decreased to <1 and <3%, respectively, at 47 dpa. Fracture in the 30 dpa specimen is mainly ductile but with local regions of mixed-mode failure, consisting mainly of dimples and microvoids. The fracture surface of the higher-exposure 47 dpa specimen displays more brittle …
Date: June 5, 2002
Creator: Allen, T. R.; Tsai, H.; Cole, J. I.; Ohta, J.; Dohi, K. & Kusanagi, H.
Object Type: Article
System: The UNT Digital Library
Biological impacts and context of network theory (open access)

Biological impacts and context of network theory

Many complex systems can be represented and analyzed as networks, and examples that have benefited from this approach span the natural sciences. For instance, we now know that systems as disparate as the World-Wide Web, the Internet, scientific collaborations, food webs, protein interactions and metabolism all have common features in their organization, the most salient of which are their scale-free connectivity distributions and their small-world behavior. The recent availability of large scale datasets that span the proteome or metabolome of an organism have made it possible to elucidate some of the organizational principles and rules that govern their function, robustness and evolution. We expect that combining the currently separate layers of information from gene regulatory-, signal transduction-, protein interaction- and metabolic networks will dramatically enhance our understanding of cellular function and dynamics.
Date: January 5, 2007
Creator: Almaas, E
Object Type: Article
System: The UNT Digital Library
Low Mach Number Modeling of Type Ia Supernovae (open access)

Low Mach Number Modeling of Type Ia Supernovae

We introduce a low Mach number equation set for the large-scale numerical simulation of carbon-oxygen white dwarfs experiencing a thermonuclear deflagration. Since most of the interesting physics in a Type Ia supernova transpires at Mach numbers from 0.01 to 0.1, such an approach enables both a considerable increase in accuracy and savings in computer time compared with frequently used compressible codes. Our equation set is derived from the fully compressible equations using low Mach number asymptotics, but without any restriction on the size of perturbations in density or temperature. Comparisons with simulations that use the fully compressible equations validate the low Mach number model in regimes where both are applicable. Comparisons to simulations based on the more traditional an elastic approximation also demonstrate the agreement of these models in the regime for which the anelastic approximation is valid. For low Mach number flows with potentially finite amplitude variations in density and temperature, the low Mach number model overcomes the limitations of each of the more traditional models and can serve as the basis for an accurate and efficient simulation tool.
Date: August 5, 2005
Creator: Almgren, Ann S.; Bell, John B.; Rendleman, Charles A. & Zingale,Michael
Object Type: Article
System: The UNT Digital Library
Tracing the Fate of Enhanced Organic Carbon Production during a Southern Ocean Fe Fertilization Experiment using Natural Variations in Carbon and Nitrogen Isotopic Composition (open access)

Tracing the Fate of Enhanced Organic Carbon Production during a Southern Ocean Fe Fertilization Experiment using Natural Variations in Carbon and Nitrogen Isotopic Composition

This project focused on the N and C natural stable isotope response during SOFeX--a purposeful iron (Fe) addition experiment in the Fe limited Southern Ocean. One purpose of the study was to determine if relief of phytoplankton Fe stress would increase productivity sufficiently to enhance C export from surface to deep waters. We proposed that N and C stable isotopes would be useful for tracing this export. Iron was added to waters north and south of the Antarctic Polar Front in waters to the southwest of New Zealand. While both sites have high-nutrient, low chlorophyll conditions (HNLC) typical of Fe limitation, [SiO4] a required nutrient for diatoms was low at the northerly site and high at the southern location. The most extensive coverage occurred at the southern site. Here, FeSO4 was added four different times over an {approx}two week period. We found that: (1) Particulate organic nitrogen and carbon in the mixed layer increased by a factor of 2-3 in response to the Fe addition in the southern patch. (2) PN accumulation and NO3- drawdown were both 1-2 {micro}M during the occupation of the bloom, suggesting retention of particulates within the mixed layer of the southern patch. (3) {sub 15}N …
Date: February 5, 2005
Creator: Altabet, M.A.
Object Type: Report
System: The UNT Digital Library
Poland petroleum refinery sludge lagoon demonstration project (open access)

Poland petroleum refinery sludge lagoon demonstration project

The US Department of Energy and the Institute for Ecology of Industrial Area have been working together to develop mutually beneficial, cost-effective environmental remediation technologies such as the demonstration of bioremediation techniques for the clean up of acidic petroleum sludge impacted soils at an oil refinery in southern Poland. After an expedited site characterization, treatability study, and a risk assessment study, a remediation strategy was devised. The waste material was composed primarily of high molecular weight paraffinic and polynuclear aromatic hydrocarbons. A biopile design which employed a combination of passive and active aeration in conjunction with nutrient and surfactant application as used to increase the biodegradation of the contaminants of concern.
Date: May 5, 2000
Creator: Altman, D. J.
Object Type: Article
System: The UNT Digital Library
Accretion onto the first stellar mass black holes (open access)

Accretion onto the first stellar mass black holes

The first stars, forming at redshifts z > 15 in minihalos with M {approx} 10{sup 5-6} M{sub {circle_dot}} may leave behind remnant black holes, which could conceivably have been the 'seeds' for the supermassive black holes observed at z {approx}< 7. We study remnant black hole growth through accretion, including for the first time the radiation emitted due to accretion, with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photo-ionization and heating dramatically affect the large-scale inflow, resulting in negligible mass growth. We compare cases with accretion luminosity included and neglected to show that accretion radiation drastically changes the environment within 100 pc of the black hole, increasing gas temperatures by an order of magnitude. Gas densities are reduced and further star formation in the same minihalo is prevented for the two hundred million years we followed. Without radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of Pop III stars in minihalos are not likely to be miniquasars. Most importantly, however, our calculations demonstrate that if these black holes are indeed accreting close to the Bondi-Hoyle rate with ten percent radiative …
Date: August 5, 2009
Creator: Alvarez, Marcelo A.; Wise, John H. & Abel, Tom
Object Type: Article
System: The UNT Digital Library
Congressional Record: Its Production, Distribution, and Accessibility (open access)

Congressional Record: Its Production, Distribution, and Accessibility

This report provides information about the Production, Distribution, and Accessibility of Congressional Record. The Congressional Record is the most widely published account of the debates and activities in congress.
Date: May 5, 2008
Creator: Amer, Mildred
Object Type: Report
System: The UNT Digital Library
Secret Sessions of Congress: A Brief Historical Overview (open access)

Secret Sessions of Congress: A Brief Historical Overview

None
Date: August 5, 2003
Creator: Amer, Mildred L.
Object Type: Report
System: The UNT Digital Library
Women in the United States Congress: 1917-2007 (open access)

Women in the United States Congress: 1917-2007

This report identifies the names, committee assignments, dates of service, and (for Representatives) districts of the 244 women who have served in Congress.
Date: December 5, 2007
Creator: Amer, Mildred L.
Object Type: Report
System: The UNT Digital Library
Insulated Concrete Homes Increase Durability and Energy Efficiency (open access)

Insulated Concrete Homes Increase Durability and Energy Efficiency

New houses designed by Mercedes Homes in Melbourne, Florida, with technical support from the U.S. Department of Energy's Building America Program, save their homeowners money by using energy efficient features such as a high performance heat pump and solar control glazing to reduce cooling costs.
Date: June 5, 2001
Creator: America, Building; Hendron, B. & Poole, L.
Object Type: Book
System: The UNT Digital Library
Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms (open access)

Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.
Date: April 5, 2007
Creator: Amini, Jason M.; Munger Jr., Charles T. & Gould, Harvey.
Object Type: Article
System: The UNT Digital Library
Three-dimensional position sensing and field shaping in orthogonal-strip germanium gamma-ray detectors. (open access)

Three-dimensional position sensing and field shaping in orthogonal-strip germanium gamma-ray detectors.

None
Date: January 5, 2000
Creator: Amman, M. & Luke, P. N.
Object Type: Article
System: The UNT Digital Library
Filtered cathodic arc deposition with ion-species-selectivebias (open access)

Filtered cathodic arc deposition with ion-species-selectivebias

A dual-cathode arc plasma source was combined with acomputer-controlled bias amplifier such as to synchronize substrate biaswith the pulsed production of plasma. In this way, bias can be applied ina material-selective way. The principle has been applied to the synthesismetal-doped diamond-like carbon films, where the bias was applied andadjusted when the carbon plasma was condensing, and the substrate was atground when the metal was incorporated. In doing so, excessive sputteringby too-energetic metal ions can be avoided while the sp3/sp2 ratio can beadjusted. It is shown that the resistivity of the film can be tuned bythis species-selective bias. The principle can be extended tomultiple-material plasma sources and complex materials
Date: October 5, 2006
Creator: Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon & Lim, SunnieH.N.
Object Type: Article
System: The UNT Digital Library
Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows (open access)

Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows

Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9 percent silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.
Date: May 5, 2008
Creator: Anders, Andre; Slack, Jonathan L. & Richardson, Thomas J.
Object Type: Article
System: The UNT Digital Library
1996-2004 Trends in the Single-Family Housing Market: Spatial Analysis of the Residential Sector (open access)

1996-2004 Trends in the Single-Family Housing Market: Spatial Analysis of the Residential Sector

This report provides a detailed geographic analysis of two specific topics affecting the residential sector. First, we performed an analysis of new construction market trends using annual building permit data. We report summarized tables and national maps to help illustrate market conditions. Second, we performed a detailed geographic analysis of the housing finance market. We analyzed mortgage application data to provide citable statistics and detailed geographic summarization of the residential housing picture in the US for each year in the 1996-2004 period. The databases were linked to geographic information system tools to provide various map series detailing the results geographically. Looking at these results geographically may suggest potential new markets for TD programs addressing the residential sector that have not been considered previously. For example, we show which lenders affect which regions and which income or mortgage product classes. These results also highlight the issue of housing affordability. Energy efficiency R&D programs focused on developing new technology for the residential sector must be conscious of the costs of products resulting from research that will eventually impact the home owner or new home buyer. Results indicate that home values as a proportion of median family income in Building America communities are …
Date: September 5, 2006
Creator: Anderson, Dave M. & Elliott, Douglas B.
Object Type: Report
System: The UNT Digital Library
A korarchaeal genome reveals insights into the evolution of the Archaea (open access)

A korarchaeal genome reveals insights into the evolution of the Archaea

The candidate division Korarchaeota comprises a group of uncultivated microorganisms that, by their small subunit rRNA phylogeny, may have diverged early from the major archaeal phyla Crenarchaeota and Euryarchaeota. Here, we report the initial characterization of a member of the Korarchaeota with the proposed name,"Candidatus Korarchaeum cryptofilum," which exhibits an ultrathin filamentous morphology. To investigate possible ancestral relationships between deep-branching Korarchaeota and other phyla, we used whole-genome shotgun sequencing to construct a complete composite korarchaeal genome from enriched cells. The genome was assembled into a single contig 1.59 Mb in length with a G + C content of 49percent. Of the 1,617 predicted protein-coding genes, 1,382 (85percent) could be assigned to a revised set of archaeal Clusters of Orthologous Groups (COGs). The predicted gene functions suggest that the organism relies on a simple mode of peptide fermentation for carbon and energy and lacks the ability to synthesize de novo purines, CoA, and several other cofactors. Phylogenetic analyses based on conserved single genes and concatenated protein sequences positioned the korarchaeote as a deep archaeal lineage with an apparent affinity to the Crenarchaeota. However, the predicted gene content revealed that several conserved cellular systems, such as cell division, DNA replication, and tRNA …
Date: June 5, 2008
Creator: Anderson, Iain J; Elkins, James G.; Podar, Mircea; Graham, David E.; Makarova, Kira S.; Wolf, Yuri et al.
Object Type: Article
System: The UNT Digital Library
Measurement of CP Content and Time-Dependent CP Violation in B0 --> D*+D*- Decays (open access)

Measurement of CP Content and Time-Dependent CP Violation in B0 --> D*+D*- Decays

This dissertation presents the measurement of the Cp-odd fraction and time-dependent CP violation parameters for the B{sup 0} {yields} D*{sup +} D*{sup -} decay. These results are based on the full BABAR dataset of (467 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the PEP-II B Factory at the Stanford Linear Accelerator Center. An angular analysis finds that the CP-odd fraction of the B{sup 0} {yields} D*{sup +} D*{sup -} decay is R{sub {perpendicular}} = 0.158 {+-} 0.028 {+-} 0.006, where the first uncertainty is statistical, and the second is systematic. A fit to the flavor-tagged, time-dependent, angular decay rate yields C{sub +} = 0.02 {+-} 0.12 {+-} 0.02; C{sub {perpendicular}} = 0.41 {+-} 0.50 {+-} 0.08; S{sub +} = -0.76 {+-} 0.16 {+-} 0.04; S{sub {perpendicular}} = -1.81 {+-} 0.71 {+-} 0.16, for the CP-odd ({perpendicular}) and CP-even (+) contributions. Constraining these two contributions to be the same results in C = 0.047 {+-} 0.091 {+-} 0.019; S = -0.71 {+-} 0.16 {+-} 0.03. These measurements are consistent with the Standard Model and with measurements of sin2{beta} from B{sup 0} {yields} (c{bar c})K{sup 0} decays.
Date: January 5, 2009
Creator: Anderson, Jacob M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Through Weld Inspection of Wrought Stainless Steel Piping Using Phased-Array Ultrasonic Probes. (open access)

Through Weld Inspection of Wrought Stainless Steel Piping Using Phased-Array Ultrasonic Probes.

A study was conducted to assess the ability of phased-array ultrasonic techniques to detect and accurately determine the size of flaws from the far-side of wrought austenitic piping welds. Far-side inspections of these welds are currently performed on a “best effort” basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, four circumferential welds in 610mm diameter, 36mm thick ASTM A-358, Grade 304 vintage austenitic stainless steel pipe were examined. The welds were fabricated with varied welding parameters; both horizontal and vertical pipe orientations were used, with air and water backing, to simulate field welding conditions. A series of saw cuts, electro-discharge machined (EDM) notches, and implanted fatigue cracks were placed into the heat affected zones of the welds. The saw cuts and notches range in depth from 7.5% to 28.4% through-wall. The implanted cracks ranged in depth from 5% through wall to 64% through wall. The welds were examined with two phased-array probes, a 2.0 MHz transmit-receive longitudinal wave array and a 2.0 MHz transmit-receive shear wave array. These examinations showed that both phased-array transducers were able to detect and accurately length-size, but not depth size, all of the notches and …
Date: August 5, 2004
Creator: Anderson, Michael T.; Cumblidge, Stephen E. & Doctor, Steven R.
Object Type: Article
System: The UNT Digital Library