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CFD SIMULATIONS OF JOINT URBAN ATMOSPHERE DISPERSION FIELD STUDY 2003 (open access)

CFD SIMULATIONS OF JOINT URBAN ATMOSPHERE DISPERSION FIELD STUDY 2003

In the Spring of 2003, a series of dispersion field experiments (Joint Urban 2003) were conducted at Oklahoma City. These experiments were complimentary to the URBAN 2000 field studies at Salt Lake City (Allwine, et. al, 2002) in that they will provide a second set of comprehensive field data for evaluation of CFD as well as for other dispersion models. In contrast to the URBAN 2000 experiments that were conducted entirely at night, these new field studies took place during both daytime and nighttime thus including the possibility of convective as well as stable atmospheric conditions. Initially several CFD modeling studies were performed to provide guidance for the experimental team in the selection of release sites and in the deployment of wind and concentration sensors. Also, while meteorological and concentration measurements were taken over the greater Oklahoma City urban area, our CFD calculations were focused on the near field of the release point. The proximity of the source to a large commercial building and to the neighboring buildings several of which have multi-stories, present a significant challenge even for CFD calculations involving grid resolutions as fine as 1 meter. A total of 10 Intensive Observations Periods (IOP's) were conducted within …
Date: March 31, 2004
Creator: Lee, R L; Humphreys, T D & Chan, S T
System: The UNT Digital Library
Harmonic resolution as a holographic quantum number (open access)

Harmonic resolution as a holographic quantum number

The Bekenstein bound takes the holographic principle into the realm of flat space, promising new insights on the relation of non-gravitational physics to quantum gravity. This makes it important to obtain a precise formulation of the bound. Conventionally, one specifies two macroscopic quantities, mass and spatial width, which cannot be simultaneously diagonalized. Thus, the counting of compatible states is not sharply defined. The resolution of this and other formal difficulties leads naturally to a definition in terms of discretized light-cone quantization. In this form, the area difference specified in the covariant bound converts to a single quantum number, the harmonic resolution K. The Bekenstein bound then states that the Fock space sector with K units of longitudinal momentum contains no more than exp(2 pi^2 K) independent discrete states. This conjecture can be tested unambiguously for a given Lagrangian, and it appears to hold true for realistic field theories, including models arising from string compactifications. For large K, it makes contact with more conventional but less well-defined formulations.
Date: January 31, 2004
Creator: Bousso, Raphael
System: The UNT Digital Library
Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C (open access)

Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C

Ceramic materials have been considered as corrosion resistant coatings for nuclear waste containers. Their suitability can be derived from the fully oxidized state for selected metal oxides. Several types of ceramic coatings applied to plain carbon steel substrates by thermal spray techniques have been exposed to 90 C simulated ground water for nearly 6 years. In some cases no apparent macroscopic damage such as coating spallation was observed in coatings. Thermal spray processes examined in this work included plasma spray, High Velocity Oxy Fuel (HVOF), and Detonation Gun. Some thermal spray coatings have demonstrated superior corrosion protection for the plain carbon steel substrate. In particular the HVOF and Detonation Gun thermal spray processes produced coatings with low connected porosity, which limited the growth rate of corrosion products. It was also demonstrated that these coatings resisted spallation of the coating even when an intentional flaw (which allowed for corrosion of the carbon steel substrate underneath the ceramic coating) was placed in the coating. A model for prediction of the corrosion protection provided by ceramic coatings is presented. The model includes the effect of the morphology and amount of the porosity within the thermal spray coating and provides a prediction of the …
Date: March 31, 2004
Creator: Haslam, J J & Farmer, J C
System: The UNT Digital Library
A 16 Mev/Nucleon Cocktail for Heavy Ion Testing (open access)

A 16 Mev/Nucleon Cocktail for Heavy Ion Testing

This report gives the description of a new cocktail of heavy ions ranging from Z=7-36 at 16 MeV/Nucleon.
Date: July 31, 2004
Creator: McMahan, M. A.; Leitner, D.; Gimpel, T.; Morel, J.; Ninemire, B.; Siero, R. et al.
System: The UNT Digital Library
Range-wide success of red-cockaded woodpecker translocations. (open access)

Range-wide success of red-cockaded woodpecker translocations.

Edwards, John W.; Costa, Ralph. 2004. Range-wide success of red-cockaded woodpecker translocations. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 6. Translocation. Pp 307-311. Abstract: Red-cockaded woodpeckers (Picoides borealis) have declined range-wide during the past century, suffering from habitat loss and the effects of fire exclusion in older southern pine forests. Red-cockaded woodpecker translocations are a potentially important tool in conservation efforts to reestablish red-cockaded woodpeckers in areas from which they have been extirpated. Currently, translocations are critical in ongoing efforts to save and restore the many existing small populations. We examined the effects of demographic and environmental factors on the range-wide success of translocations between 1989 and 1995.
Date: December 31, 2004
Creator: Edwards, John W. & Costa, Ralph
System: The UNT Digital Library
Availability and abundance of prey for the red-cockaded woodpecker. (open access)

Availability and abundance of prey for the red-cockaded woodpecker.

Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 11. Prey, Fire, and Community Ecology. Pp 633-645. Abstract: Over a 10-year period we investigated red-cockaded woodpecker (Picoides borealis) prey use, sources of prey, prey distribution within trees and stands, and how forest management decisions affect prey abundance in South Carolina, Alabama, Georgia and Florida. Cameras were operated at 31 nest cavities to record nest visits with prey in 4 locations that ranged in foraging habitat from pine stands established in old fields to an old-growth stand in South Georgia. Examination of nearly 12,000 photographs recorded over 5 years revealed that, although red-cockaded woodpeckers used over 40 arthropods for food, the majority of the nestling diet is comprised of a relatively small number of common arthropods.
Date: December 31, 2004
Creator: Hanula, James, L. & Horn, Scott.
System: The UNT Digital Library
A NEW APPROACH TO RADIONUCLIDE ANALYSIS IN GROUNDWATERS (open access)

A NEW APPROACH TO RADIONUCLIDE ANALYSIS IN GROUNDWATERS

A method using liquid scintillation spectral analysis (LSSA) for analyzing mixtures of radionuclides in groundwater samples, which is fast, simple, and inexpensive, was developed and bench-tested. Samples can be measured in a field laboratory with a new commercial portable liquid scintillation instrument that provides advanced analysis, display, and computational features previously found only in large expensive laboratory models. Results can be available within hours from the time samples are collected. The analysis provides a good measure of total sample activity and a spectral index value that may detect changes in radionuclide distributions from previous analyses when counting statistic are adequate. If a sample shows no change, further analytical costs for it may be avoided. A method that rapidly and quantitatively concentrates very low levels of activity from liter-size samples in minutes was also tested. With some modest improvements in this step, this work offers a completely new methodology and approach to groundwater remediation, which can dramatically reduce analytical costs and speed monitored cleanup and closure in many types of radiological work programs.
Date: August 31, 2004
Creator: HOCHEL, ROBERTC.
System: The UNT Digital Library
Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels. (open access)

Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels.

Risch, Thomas S., and Susan C. Loeb. 2004. Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 8. Cavities, Cavity Trees, and Cavity Communities. Pp 504-505. Abstract: Although several studies have suggested that southern flying squirrels (Glaucomys volans) may have a significant negative impact on red-cockades woodpeckers (Picoides borealsi) (Loeb and Hooper 1997, Laves and Loeb 1999), the nature of the interactions between the species remains unclear. Particularly lacking are data that address if southern flying squirrels directly usurp red-cockaded woodpecker s from cavities, or simply occupy cavities previously abandoned by red-cockaded woodpeckers. Ridley et al. (1997) observed the displacement of a red-cockaded woodpecker by a southern flying squirrel that was released after being captured. Observations of nocturnal displacements of red-cockaded woodpeckers by flying squirrels, however, are lacking. Due to the difficulty of observing interspecific interactions, determining the mechanisims by which flying squirrels impact red-cockaded woodpeckers is problematic.
Date: December 31, 2004
Creator: Risch, Thomas S. & Loeb, Susan C.
System: The UNT Digital Library
Diagnostic Analysis of Silicon Strips Detector Readout in the ATLAS Semi-Conductor Tracker Module Production (open access)

Diagnostic Analysis of Silicon Strips Detector Readout in the ATLAS Semi-Conductor Tracker Module Production

The ATLAS Semi-Conductor Tracker (SCT) Collaboration is currently in the production phase of fabricating and testing silicon strips modules for the ATLAS detector at the Large Hadron Collider being built at the CERN laboratory in Geneva, Switzerland. A small but relevant percentage of ICs developed a new set of defects after being mounted on hybrids that were not detected in the wafer screening. To minimize IC replacement and outright module failure, analysis methods were developed to study IC problems during the production of SCT modules. These analyses included studying wafer and hybrid data correlations to finely tune the selection of ICs and tests to utilize the ability to adjust front-end parameters of the IC in order to reduce the rejection and replacement rate of fabricated components. This paper will discuss a few examples of the problems encountered during the production of SCT hybrids and modules in the area of ICs performance, and will demonstrate the value of the flexibility built into the ABCD3T chip.
Date: October 31, 2004
Creator: Ciocio, Alessandra & Collaboration, ATLAS SCT
System: The UNT Digital Library
Seasonal use of red-cockaded woodpecker cavities by southern flying squirrels. (open access)

Seasonal use of red-cockaded woodpecker cavities by southern flying squirrels.

Loeb, Susan C., and Deanna L. Ruth. 2004. Seasonal use of red-cockaded woodpecker cavities by southern flying squirrels. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 8. Cavities, Cavity Trees, and Cavity Communities. Pp 501-502. Abstract: Southern flying squirrels can significantly impact red-cockaded woodpecker reproductive success (Laves and Loeb 1999). Thus exclusion or removal of flying squirrels from red-cockaded woodpecker cavities and clusters may be warranted in small woodpecker populations (U.S. Fish and Wildlife Service 2003). However, development of effective and efficient protocols for southern flying squirrel control requires an understanding of the seasonal dynamics of southern flying squirrel cavity use. Most studies of southern flying squirrel use of red-cockaded woodpecker cavities have been conducted during spring (e.g., Harlow and Lennartz 1983, Rudolph et al. 1990a, Loeb 1993) and no studies have examined the effects of long term flying squirrel control on subsequent cavity use. The objectives of this study were to determine: (1) whether flying squirrel use of red-cockaded woodpecker cavities varies with season or cavity type, and (2) the long term effect of continuous squirrel removal.
Date: December 31, 2004
Creator: Loeb, Susan C. & Ruth, Deanna L.
System: The UNT Digital Library
Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina). (open access)

Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina).

Barton, Christopher, D., Diane DeSteven and John C. Kilgo. 2004. Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina). Ecol. Rest. 22(4):291-292. Abstract: Carolina bays and smaller depression wetlands support diverse plant communities and provide critical habitat for semi-aquatic fauna throughout the Coastal Plain region of the southeastern United States. Historically, many depression wetlands were altered or destroyed by surface ditching, drainage, and agricultural or silviculture uses. These important habitats are now at further risk of alteration and loss following a U.S. Supreme Court decision in 2001 restricting federal regulation of isolated wetlands. Thus, there is increased attention towards protecting intact sites and developing methods to restore others. The U.S. Department of Energy's (DOE) 312-mi2 (800-km2) Savannah River Site (SRS) in west-central South Carolina includes about 350 Carolina bays and bay-like wetland depressions, of which about two-thirds were degraded or destroyed prior to federal acquisition of the land. Although some of the altered wetlands have recovered naturally, others still have active active drainage ditches and contain successional forests typical of drained sites. In 1997, DOE established a wetland mitigation bank to compensate for unavoidable wetland impacts on the SRS. This effort provided an opportunity fir a systematic …
Date: December 31, 2004
Creator: Barton, Christopher D.; DeSteven, Diane & Kilgo, John C.
System: The UNT Digital Library
Mixing Effects on the Precipitation and Cross Flows Filtration of a Hanford Simulated Precipitated Radioactive Waste (open access)

Mixing Effects on the Precipitation and Cross Flows Filtration of a Hanford Simulated Precipitated Radioactive Waste

As part of the River Protection Project at Hanford, Washington, Bechtel National, Inc. has been contracted by the United States Department of Energy to design a Waste Treatment and Immobilization Plant to stabilize liquid radioactive waste. Because of its experience with radioactive waste stabilization, the Savannah River Technology Center of the Westinghouse Savannah River Company is working with Bechtel National and Washington Group International, to help design and test certain parts of the Waste Treatment Plant. One part of the process is the separation of radioactive isotopes from the liquid waste by a precipitation reaction and cross-flow ultrafiltration. To better understand those combined processes an experiment was performed using a simulated radioactive waste, made to prototypically represent the chemical and physical characteristics of a Hanford waste in tank 241-AN-102 and precipitated under prototypic conditions. The resultant slurry was then filtered using a cross-flow filter prototypic in porosity, length, and diameter to the plant design. An important aspect of filtration for waste treatment is the rate at which permeate is produced. There are many factors that affect filtration rate and one of the most difficult to obtain is the effect of particles in the waste streams. The Waste Treatment Plant will …
Date: March 31, 2004
Creator: DUIGNAN, MARK
System: The UNT Digital Library
High-Precision Floating-Point Arithmetic in ScientificComputation (open access)

High-Precision Floating-Point Arithmetic in ScientificComputation

At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required: some of these applications require roughly twice this level; others require four times; while still others require hundreds or more digits to obtain numerically meaningful results. Such calculations have been facilitated by new high-precision software packages that include high-level language translation modules to minimize the conversion effort. These activities have yielded a number of interesting new scientific results in fields as diverse as quantum theory, climate modeling and experimental mathematics, a few of which are described in this article. Such developments suggest that in the future, the numeric precision used for a scientific computation may be as important to the program design as are the algorithms and data structures.
Date: December 31, 2004
Creator: Bailey, David H.
System: The UNT Digital Library
Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis (open access)

Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis

We have determined the complete sequence of the mitochondrial genome of the scaphopod mollusk Graptacme eborea (Conrad, 1846) (14,492 nts) and completed the sequence of the mitochondrial genome of the bivalve mollusk Mytilus edulis Linnaeus, 1758 (16,740 nts). (The name Graptacme eborea is a revision of the species formerly known as Dentalium eboreum.) G. eborea mtDNA contains the 37 genes that are typically found and has the genes divided about evenly between the two strands, but M. edulis contains an extra trnM and is missing atp8, and has all genes on the same strand. Each has a highly rearranged gene order relative to each other and to all other studied mtDNAs. G. eborea mtDNA has almost no strand skew, but the coding strand of M. edulis mtDNA is very rich in G and T. This is reflected in differential codon usage patterns and even in amino acid compositions. G. eborea mtDNA has fewer non-coding nucleotides than any other mtDNA studied to date, with the largest non-coding region being only 24 nt long. Phylogenetic analysis using 2,420 aligned amino acid positions of concatenated proteins weakly supports an association of the scaphopod with gastropods to the exclusion of Bivalvia, Cephalopoda, and Polyplacophora, …
Date: January 31, 2004
Creator: Boore, Jeffrey L.; Medina, Monica & Rosenberg, Lewis A.
System: The UNT Digital Library
Architecture independent performance characterization andbenchmarking for scientific applications (open access)

Architecture independent performance characterization andbenchmarking for scientific applications

A simple, tunable, synthetic benchmark with a performance directly related to applications would be of great benefit to the scientific computing community. In this paper, we present a novel approach to develop such a benchmark. The initial focus of this project is on data access performance of scientific applications. First a hardware independent characterization of code performance in terms of address streams is developed. The parameters chosen to characterize a single address stream are related to regularity, size, spatial, and temporal locality. These parameters are then used to implement a synthetic benchmark program that mimics the performance of a corresponding code. To test the validity of our approach we performed experiments using five test kernels on six different platforms. The performance of most of our test kernels can be approximated by a single synthetic address stream. However in some cases overlapping two address streams is necessary to achieve a good approximation.
Date: August 31, 2004
Creator: Strohmaier, Erich & Shan, Hongzhang
System: The UNT Digital Library
The effect of using a "soft" release on translocation success of red-cockaded woodpeckers. (open access)

The effect of using a "soft" release on translocation success of red-cockaded woodpeckers.

Franzreb, Kathleen, E. 2004 The effect of using a "soft" release on translocation success of red-cockaded woodpeckers. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 6. Translocation. Pp 301-306. Abstract: Translocations of the endangered red-cockaded woodpecker have been conducted since 1986 to enhance critically small subpopulations, to minimize the likelihood of local extirpations, and to reduce the adverse effects of fragmentation and isolation among existing populations. Such attempts have had mixed success. This article compares "hard" releases with a "soft" release technique where the birds are temporarily interned in a large aviary at the release point for a period of 9 to 14 days.
Date: December 31, 2004
Creator: Franzreb, Kathleen, E.
System: The UNT Digital Library
Feasibility study and roadmap to improve residential hot water distribution systems (open access)

Feasibility study and roadmap to improve residential hot water distribution systems

Residential building practice currently ignores the losses of energy and water caused by the poor design of hot water systems. These losses include: the waste of water while waiting for hot water to get to the point of use; the wasted heat as water cools down in the distribution system after a draw; and the energy to reheat water that was already heated once before. A feasibility study and an action plan for a proposed research project involving residential hot water distribution systems is being developed. The feasibility study will use past work to estimate of hot water and energy loses caused by current hot water distribution systems in residences. Proposed research project, or roadmap, will develop recommendations for improvements to residential hot water distribution systems. The roadmap addresses the technical obstacles and gaps in our knowledge that prevent water and energy reductions and market adoption of water- and energy-efficient technologies. The initial results of the feasibility study are presented here along with a discussion of a roadmap to improve the efficiency of residential hot water distribution systems.
Date: March 31, 2004
Creator: Lutz, James D.
System: The UNT Digital Library
Neutron and Photon Transport in Sea-Going Cargo Containers (open access)

Neutron and Photon Transport in Sea-Going Cargo Containers

None
Date: August 31, 2004
Creator: Pruet, J.; Descalle, M. A.; Hall, J.; Pohl, B. & Prussin, S. G.
System: The UNT Digital Library
Stoichiometric changes in KH2PO4 crystals during laser-induced breakdown (open access)

Stoichiometric changes in KH2PO4 crystals during laser-induced breakdown

The structure of KH{sub 2}PO{sub 4} single crystals (so-called KDP) irradiated with {approx} 3-ns, 355-nm laser pulses with fluences above the laser-induced breakdown threshold is studied by a combination of Raman scattering, photoluminescence, and soft x-ray absorption spectroscopies. We compare spectra from the as-grown material, surface and bulk laser-induced damage sites, as well as from KPO{sub 3} references. Results show that irradiation with fluences above the laser-induced breakdown threshold leads to stoichiometric changes at surface damage sites but not at bulk damage sites. New spectroscopic features are attributed to dehydration products. For the laser irradiation conditions used in this study, the decomposed near-surface layer absorbs photons at {approx} 3.4 eV (364 nm). These results may explain the recently reported fact that surface laser damage sites in KDP crystals tend to grow with subsequent exposure to high-power laser pulses, while bulk damage sites do not.
Date: August 31, 2004
Creator: Negres, R A; Kucheyev, S O; DeMange, P; Bostedt, C; van Buuren, T; Nelson, A J et al.
System: The UNT Digital Library
Full-Aperture Backscatter Measurements on the National Ignition Facility (open access)

Full-Aperture Backscatter Measurements on the National Ignition Facility

The National Ignition Facility's Full-Aperture Backscatter Station (FABS) is described. The FABS uses five independent diagnostics on each of the four laser beams in the initial NIF quad to measure the energy, power, spectrum, and near-field amplitude modulations of the stimulated Brillouin and stimulated Raman backscattered light. In initial tests CO{sub 2} and C{sub 5}H{sub 12} gas-filled targets were used to create various backscatter conditions. Results are presented for tests in which 16 kJ on target produced between 0.3 kJ and 2.5 kJ of backscattered light.
Date: March 31, 2004
Creator: MacGowan, B; Chrisp, M; Froula, D H; Kirkwood, R K; Bower, D; Kelleher, T M et al.
System: The UNT Digital Library
Probing the Electronic Density of States of Germanium Nanoparticles: A Method for Determining Atomic Structure (open access)

Probing the Electronic Density of States of Germanium Nanoparticles: A Method for Determining Atomic Structure

We present first principles electronic structure calculations and photoemission measurements of the change in the valence band DOS of germanium as its dimensions are reduced from the bulk to the nanoscale. By comparing the calculated broadening of the s and s--p band peaks and the energy of surface dangling bonds to the measured DOS we identify the most likely structure of these nanoparticles. We propose that, in contrast to recent interpretations, small 2-3 nm germanium nanoparticles prepared by gas phase aggregation have a distorted diamond structure core and a thermally disordered surface.
Date: March 31, 2004
Creator: Williamson, A; Bostedt, C; van Buuren, T; Willey, T; Terminello, L; Galli, G et al.
System: The UNT Digital Library
Testing LaMgAl11O19 crystal for X-ray spectroscopy (open access)

Testing LaMgAl11O19 crystal for X-ray spectroscopy

We investigated the properties of the rare earth crystal LaMgAl{sub 11}O{sub 19} and its application to soft X-ray spectroscopy. Its relative reflectivity and half width rocking curve were measured to up to the reflection order of 28. In addition, a comparative measurement of the iron L-shell soft X-ray line emission was made on the EBIT-I Livermore electron beam ion trap by fielding the LaMgAl{sub 11}O{sub 19} crystal side by side with a rubidium hydrogen phthalate crystal in a flat crystal spectrometer. From these measurements, reflectivity and spectral resolving power were determined.
Date: March 31, 2004
Creator: Chen, H.; Beiersdorfer, P.; Baronova, E.; Kalashnikova, I. & Stepanenko, M.
System: The UNT Digital Library
Untangling CP violation and the mass hierarchy in long baseline experiments (open access)

Untangling CP violation and the mass hierarchy in long baseline experiments

None
Date: July 31, 2004
Creator: Mena, Olga; Parke, Stephen J. & Fermilab
System: The UNT Digital Library
Progress in the Peeling-Ballooning Model of ELMs: Toroidal Rotation and 3D Nonlinear Dynamics (open access)

Progress in the Peeling-Ballooning Model of ELMs: Toroidal Rotation and 3D Nonlinear Dynamics

None
Date: August 31, 2004
Creator: Snyder, P. B.; Wilson, H. R.; Xu, X. Q. & Webster, A. J.
System: The UNT Digital Library