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Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis (open access)

Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis

Article on air to blood distribution of volatile organic compounds and a linear free energy analysis.
Date: April 23, 2005
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
System: The UNT Digital Library
Energy Saving Potentials and Air Quality Benefits of Urban HeatIslandMitigation (open access)

Energy Saving Potentials and Air Quality Benefits of Urban HeatIslandMitigation

Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, …
Date: August 23, 2005
Creator: Akbari, Hashem
System: The UNT Digital Library
Aging and weathering of cool roofing membranes (open access)

Aging and weathering of cool roofing membranes

Aging and weathering can reduce the solar reflectance of cool roofing materials. This paper summarizes laboratory measurements of the solar spectral reflectance of unweathered, weathered, and cleaned samples collected from single-ply roofing membranes at various sites across the United States. Fifteen samples were examined in each of the following six conditions: unweathered; weathered; weathered and brushed; weathered, brushed and then rinsed with water; weathered, brushed, rinsed with water, and then washed with soap and water; and weathered, brushed, rinsed with water, washed with soap and water, and then washed with an algaecide. Another 25 samples from 25 roofs across the United States and Canada were measured in their unweathered state, weathered, and weathered and wiped. We document reduction in reflectivity resulted from various soiling mechanisms and provide data on the effectiveness of various cleaning approaches. Results indicate that although the majority of samples after being washed with detergent could be brought to within 90% of their unweathered reflectivity, in some instances an algaecide was required to restore this level of reflectivity.
Date: August 23, 2005
Creator: Akbari, Hashem; Berhe, Asmeret A.; Levinson, Ronnen; Graveline,Stanley; Foley, Kevin; Delgado, Ana H. et al.
System: The UNT Digital Library
Cool Colored Roofs to Save Energy and Improve Air Quality (open access)

Cool Colored Roofs to Save Energy and Improve Air Quality

Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, …
Date: August 23, 2005
Creator: Akbari, Hashem; Levinson, Ronnen; Miller, William & Berdahl, Paul
System: The UNT Digital Library
Measurement of the Branching Ratios Gamma(D*+s -> D+s pi0)/Gamma(D*+s ->D+s gamma) and Gamma(D*0 ->D0 pi0)/Gamma(D*0 -> D0gamma) (open access)

Measurement of the Branching Ratios Gamma(D*+s -> D+s pi0)/Gamma(D*+s ->D+s gamma) and Gamma(D*0 ->D0 pi0)/Gamma(D*0 -> D0gamma)

Data samples corresponding to the isospin-violating decay D*{sub s}{sup +} {yields} D{sub s}{sup +}{pi}{sup 0} and the decays D*{sub s}{sup +} {yields} D{sub s}{sup +}, D*{sup 0} {yields} D{sup 0}{pi}{sup 0} and D*{sup 0} {yields} D{sup 0}{gamma} are reconstructed using 90.4 fb{sup -1} of data recorded by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider. The following branching ratios are extracted: {Lambda}(D*{sub s}{sup +} {yields} D{sub s}{sup +}{pi}{sup 0})/{Lambda}(D*{sub s}{sup +} {yields} D{sub s}{sup +}{gamma}) = 0.062 {+-} 0.005(stat.) {+-} 0.006(syst.) and {Lambda}(D*{sup 0} {yields} D{sup 0}{pi}{sup 0})/{Lambda}(D*{sup 0} {yields} D{sup 0}{gamma}) = 1.74 {+-} 0.02(stat.) {+-} 0.13(syst.). Both measurements represent significant improvements over present world averages.
Date: August 23, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Measurement of Time-Dependent CP-Violating Asymmetries in B^0 Meson Decays to eta' K^0_L (open access)

Measurement of Time-Dependent CP-Violating Asymmetries in B^0 Meson Decays to eta' K^0_L

The authors present a preliminary measurement of CP-violating parameters S and C from fits of the time-dependence of B{sup 0} meson decays to {eta}'K{sub L}{sup 0}. The data were recorded with the BABAR detector at PEP-II and correspond to 232 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. By fitting the time-dependent CP asymmetry of the reconstructed B{sup 0} {yields} {eta}'K{sub L}{sup 0} events, they find S = 0.60 {+-} 0.31 {+-} 0.04 and C = 0.10 {+-} 0.21 {+-} 0.03, where the first error quoted is statistical and the second is systematic. They also perform a combined fit using both {eta}'K{sub S}{sup 0} and {eta}'K{sub L}{sup 0} data, and find S = 0.36 {+-} 0.13 {+-} 0.03 and C = -0.16 {+-} 0.09 {+-} 0.02.
Date: August 23, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Oxidation Resistance of Ru-Capped EUV Multilayers (open access)

Oxidation Resistance of Ru-Capped EUV Multilayers

Differently prepared Ru-capping layers, deposited on Mo/Si EUV multilayers, have been characterized using a suite of metrologies to establish their baseline structural, optical, and surface properties in as-deposited state. Same capping layer structures were tested for their thermal stability and oxidation resistance. Post-mortem characterization identified changes due to accelerated tests. The best performing Ru-capping layer structure was studied in detail with transmission electron microscopy to identify the grain microstructure and texture. This information is essential for modeling and performance optimization of EUVL multilayers.
Date: February 23, 2005
Creator: Bajt, S.; Dai, Z.; Nelson, E. J.; Wall, M. A.; Alameda, J.; Nguyen, N. et al.
System: The UNT Digital Library
An assumed partition algorithm for determining processor inter-communication (open access)

An assumed partition algorithm for determining processor inter-communication

The recent advent of parallel machines with tens of thousands of processors is presenting new challenges for obtaining scalability. A particular challenge for large-scale scientific software is determining the inter-processor communications required by the computation when a global description of the data is unavailable or too costly to store. We present a type of rendezvous algorithm that determines communication partners in a scalable manner by assuming the global distribution of the data. We demonstrate the scaling properties of the algorithm on up to 32,000 processors in the context of determining communication patterns for a matrix-vector multiply in the hypre software library. Our algorithm is very general and is applicable to a variety of situations in parallel computing.
Date: September 23, 2005
Creator: Baker, A H; Falgout, R D & Yang, U M
System: The UNT Digital Library
Linear Response to Perturbation of Nonexponential Renewal Processes (open access)

Linear Response to Perturbation of Nonexponential Renewal Processes

This article discusses the linear response to perturbation of nonexponential renewal processes.
Date: November 23, 2005
Creator: Barbi, Francesco; Bologna, Mauro & Grigolini, Paolo
System: The UNT Digital Library
Pore Fluid Effects on Shear Modulus in a Model of Heterogeneous Rocks, Reservoirs, and Granular Media (open access)

Pore Fluid Effects on Shear Modulus in a Model of Heterogeneous Rocks, Reservoirs, and Granular Media

To provide quantitative measures of the importance of fluid effects on shear waves in heterogeneous reservoirs, a model material called a ''random polycrystal of porous laminates'' is introduced. This model poroelastic material has constituent grains that are layered (or laminated), and each layer is an isotropic, microhomogeneous porous medium. All grains are composed of exactly the same porous constituents, and have the same relative volume fractions. The order of lamination is not important because the up-scaling method used to determine the transversely isotropic (hexagonal) properties of the grains is Backus averaging, which--for quasi-static or long-wavelength behavior--depends only on the volume fractions and layer properties. Grains are then jumbled together totally at random, filling all space, and producing an overall isotropic poroelastic medium. The poroelastic behavior of this medium is then analyzed using the Peselnick-Meister-Watt bounds (of Hashin-Shtrikman type). We study the dependence of the shear modulus on pore fluid properties and determine the range of behavior to be expected. In particular we compare and contrast these results to those anticipated from Gassmann's fluid substitution formulas, and to the predictions of Mavko and Jizba for very low porosity rocks with flat cracks. This approach also permits the study of arbitrary numbers …
Date: March 23, 2005
Creator: Berger, E. L.
System: The UNT Digital Library
NARAC: An Emergency Response Resource for Predicting the Atmospheric Dispersion and Assessing the Consequences of Airborne Radionuclides (open access)

NARAC: An Emergency Response Resource for Predicting the Atmospheric Dispersion and Assessing the Consequences of Airborne Radionuclides

Hazardous radioactive materials can be released into the atmosphere by accidents at nuclear power plants, fuel processing facilities, and other facilities, and by transportation accidents involving nuclear materials. In addition, the post-cold-war proliferation of nuclear material has increased the potential for terrorism scenarios involving radiological dispersal devices, improvised nuclear devices, and inadequately secured military nuclear weapons. To mitigate these risks, the National Atmospheric Release Advisory Center (NARAC) serves as a national resource for the United States, providing tools and services to quickly predict the environmental contamination and health effects caused by airborne radionuclides, and to provide scientifically based guidance to emergency managers for the protection of human life. NARAC's expert staff uses computer models, supporting databases, software systems, and communications systems to predict the plume paths and consequences of radiological, chemical, and biological atmospheric releases.
Date: August 23, 2005
Creator: Bradley, M M
System: The UNT Digital Library
PIMC Simulation of Ps Annihilation: From Micro to Mesopores (open access)

PIMC Simulation of Ps Annihilation: From Micro to Mesopores

Path Integral Monte Carlo (PIMC) can reproduce the results of simple analytical calculations in which a single quantum particle is used to represent positronium within an idealized, spherical pore. Our calculations improve on this approach by explicitly treating the positronium as a two-particle e{sup -}, e{sup +} system interacting via the Coulomb interaction. We study the lifetime and the internal contact density, {kappa}, which controls the self-annihilation behavior, for positronium in model spherical pores, as a function of temperature and pore size. We compare the results with both PIMC and analytical calculations for a single-particle model.
Date: August 23, 2005
Creator: Bug, A. R. & Sterne, P. A.
System: The UNT Digital Library
Effect of Shock Compression Method on the Defect Substructure in Monocrystalline Copper (open access)

Effect of Shock Compression Method on the Defect Substructure in Monocrystalline Copper

Monocrystalline copper samples with orientations of [001] and [221] were shocked at pressures ranging from 20 GPa to 60 GPa using two techniques: direct drive lasers and explosively driven flyer plates. The pulse duration for these techniques differed substantially: 40 ns for the laser experiments at 0.5 mm into the sample and 1.1 {approx} 1.4 {micro}s for the flyer-plate experiments at 5 mm into the sample. The residual microstructures were dependent on orientation, pressure, and shocking method. The much shorter pulse duration in the laser driven shock yielded microstructures closer to the ones generated at the shock front. For the flyer-plate experiments, the longer pulse duration allows shock-generated defects to reorganize into lower energy configurations. Calculations show that the post-shock cooling for the laser driven shock is 10{sup 3} {approx} 10{sup 4} faster than that for plate-impact shock, propitiating recovery and recrystallization conditions for the latter. At the higher pressure level, extensive recrystallization was observed in the plate-impact samples, while it was absent in the laser driven shock. An effect that is proposed to contribute significantly to the formation of recrystallized regions is the existence of micro-shear-bands, which increase the local temperature beyond the prediction from adiabatic compression.
Date: September 23, 2005
Creator: Cao, B. Y.; Lassila, D. H.; Schneider, M. S.; Kad, B. K.; Huang, C. X.; Xu, Y. B. et al.
System: The UNT Digital Library
Evidence for the Spectroscopic Signature of Aging in (delta)-Pu(Ga) (open access)

Evidence for the Spectroscopic Signature of Aging in (delta)-Pu(Ga)

Plutonium, because of its radioactive nature, ages from the 'inside out' by means of self-irradiation damage and thus produces nanoscale internal defects. The self-irradiation induced defects come in the form of Frenkel-type defects (vacancies and self-interstitial atoms), helium in-growth, and defect clusters. At present there are neither experimental nor theoretical models describing the changes in the electronic structure caused by the aging in Pu. This fact appears to be associated primarily with the absence of reasonably convincing spectroscopic evidence of the changes. This paper demonstrates that Resonant Photoemission, a variant of Photoelectron Spectroscopy, has strong sensitivity to aging of Pu samples. The spectroscopic results are correlated with an extra-atomic screening model [1], and are shown to be the fingerprint of mesoscopic or nanoscale internal damage in the Pu physical structure. This means that a spectroscopic signature of internal damage due to aging in Pu has been established.
Date: November 23, 2005
Creator: Chung, B. W.; Schwartz, A. J.; Ebbinghaus, B. B.; Fluss, M. J.; Haslam, J. J.; Blobaum, K. M. et al.
System: The UNT Digital Library
Surrogate Nuclear Reactions - An Indirect Method for Determining Reaction Cross Sections (open access)

Surrogate Nuclear Reactions - An Indirect Method for Determining Reaction Cross Sections

An indirect method for determining cross sections of reactions proceeding through a compound nucleus is presented. Some applications of the Surrogate nuclear reaction approach are considered and challenges that need to be addressed are outlined.
Date: March 23, 2005
Creator: Escher, J; Ahle, L; Bernstein, L; Burke, J; Church, J A; Dietrich, F et al.
System: The UNT Digital Library
3D Arcing for Offset Measurements with a Hamar Laser (Presentation material) (open access)

3D Arcing for Offset Measurements with a Hamar Laser (Presentation material)

This report is about 3D Arcing for Offset Measurements with a Hamar Laser on 7th International workshop on accelerator alignment.
Date: August 23, 2005
Creator: Fuss, B.
System: The UNT Digital Library
WinGEONET: What's New? (Presentation material) (open access)

WinGEONET: What's New? (Presentation material)

The name GEONET means data reduction software for the accelerator alignment community. It was developed in the early 1980's but the only thing left from the original version is the hierarchical directory structure to hold the observations and results. This poster presents the three components of WinGEONET: the Windows interface, the computational engine and the visualization tool. It also presents further developments towards a more versatile toolbox architecture.
Date: August 23, 2005
Creator: Gaydosh, M.; Langer, L. & LeCocq, C.
System: The UNT Digital Library
2004 Structural, Function and Evolutionary Genomics (open access)

2004 Structural, Function and Evolutionary Genomics

This Gordon conference will cover the areas of structural, functional and evolutionary genomics. It will take a systematic approach to genomics, examining the evolution of proteins, protein functional sites, protein-protein interactions, regulatory networks, and metabolic networks. Emphasis will be placed on what we can learn from comparative genomics and entire genomes and proteomes.
Date: March 23, 2005
Creator: Gray, Douglas L. Brutlag Nancy Ryan
System: The UNT Digital Library
2004 Reversible Associations in Structure & Molecular Biology (open access)

2004 Reversible Associations in Structure & Molecular Biology

The Gordon Research Conference (GRC) on 2004 Gordon Research Conference on Reversible Associations in Structure & Molecular Biology was held at Four Points Sheraton, CA, 1/25-30/2004. The Conference was well attended with 82 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students.
Date: March 23, 2005
Creator: Gray, Edward Eisenstein Nancy Ryan
System: The UNT Digital Library
The Slice Balance Approach (SBA): A Characteristic-Based, Multiple Balance Sn Approach on Unstructured Polyhedral Meshes (open access)
A High-Order Accurate Parallel Solver for Maxwell's Equations on Overlapping Grids (open access)

A High-Order Accurate Parallel Solver for Maxwell's Equations on Overlapping Grids

A scheme for the solution of the time dependent Maxwell's equations on composite overlapping grids is described. The method uses high-order accurate approximations in space and time for Maxwell's equations written as a second-order vector wave equation. High-order accurate symmetric difference approximations to the generalized Laplace operator are constructed for curvilinear component grids. The modified equation approach is used to develop high-order accurate approximations that only use three time levels and have the same time-stepping restriction as the second-order scheme. Discrete boundary conditions for perfect electrical conductors and for material interfaces are developed and analyzed. The implementation is optimized for component grids that are Cartesian, resulting in a fast and efficient method. The solver runs on parallel machines with each component grid distributed across one or more processors. Numerical results in two- and three-dimensions are presented for the fourth-order accurate version of the method. These results demonstrate the accuracy and efficiency of the approach.
Date: September 23, 2005
Creator: Henshaw, W D
System: The UNT Digital Library
An Overview of the Target Fabrication Operations at Lawrence Livermore National Laboratory (open access)

An Overview of the Target Fabrication Operations at Lawrence Livermore National Laboratory

The Target Engineering team at Lawrence Livermore National Laboratory (LLNL) builds precision laser targets for the National Ignition Facility (NIF) and the Omega Laser in Rochester, NY, and other experimental facilities. The physics requirements demand precision in these targets, which creates a constant need for innovative manufacturing processes. As experimental diagnostics improve, there is greater demand for precision in fabrication, assembly, metrology, and documentation of as-built targets. The team specializes in meso-scale fabrication with core competencies in diamond turning, assembly, and metrology. Figure 1 shows a typical diamond turning center. The team builds over 200 laser targets per year in batches of five to fifteen targets. Thus, all are small-lot custom builds, and most are novel designs requiring engineering and process development. Component materials are metals, polymers and low density aerogel foams. Custom fixturing is used to locate parts on the Diamond Turning Machines (DTM) and assembly stations. This ensures parts can be repeatably located during manufacturing operations. Most target builds involve a series of fabricating one surface with features and then relocating the components on another fixture to finish the opposite side of the component. These components are then assembled to complete multiple-component targets. These targets are typically built …
Date: March 23, 2005
Creator: Hibbard, R L & Bono, M J
System: The UNT Digital Library
Multi-Gev Energy Gain in a Plasma-Wakefield Accelerator (open access)

Multi-Gev Energy Gain in a Plasma-Wakefield Accelerator

None
Date: September 23, 2005
Creator: Hogan, M. J.; Barnes, C. D.; Clayton, C. E.; Decker, F. J.; Deng, S.; Emma, P. et al.
System: The UNT Digital Library
DIRECT OBSERVATION OF THE ALPHA-EPSILON TRANSITION IN SHOCKED SINGLE CRYSTAL IRON (open access)

DIRECT OBSERVATION OF THE ALPHA-EPSILON TRANSITION IN SHOCKED SINGLE CRYSTAL IRON

In-situ x-ray diffraction was used to study the response of single crystal iron under shock conditions. Measurements of the response of [001] iron showed a uniaxial compression of the initially bcc lattice along the shock direction by up to 6% at 13 GPa. Above this pressure, the lattice responded with a further collapse of the lattice by 15-18% and a transformation to a hcp structure. The in-situ measurements are discussed and results summarized.
Date: August 23, 2005
Creator: Kalantar, D H; Collins, G W; Colvin, J D; Davies, H M; Eggert, J H; Hawreliak, J et al.
System: The UNT Digital Library