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Some Novel Liquid Partitioning Systems: Water-Ionic Liquids and Aqueous Biphasic Systems (open access)

Some Novel Liquid Partitioning Systems: Water-Ionic Liquids and Aqueous Biphasic Systems

Article on water-ionic liquids and aqueous biphasic systems and some novel liquid partitioning systems.
Date: January 11, 2003
Creator: Abraham, M. H. (Michael H.); Zissimos, Andreas M.; Huddleston, Jonathan G.; Willauer, Heather D.; Rogers, Robin D. & Acree, William E. (William Eugene)
System: The UNT Digital Library
DP1 and Completely Continuous Operators (open access)

DP1 and Completely Continuous Operators

This article demonstrates a relationship between the Dunford-Pettis property and the DP1 property with a similar relationship for vector-valued continuous function spaces.
Date: February 11, 2003
Creator: Bator, Elizabeth M. & Slavens, Dawn R.
System: The UNT Digital Library
Effect of cooling water on stability of NLC linac components (open access)

Effect of cooling water on stability of NLC linac components

Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.
Date: February 11, 2003
Creator: al., F. Le Pimpec et
System: The UNT Digital Library
Global photon summary (open access)

Global photon summary

None
Date: February 11, 2003
Creator: Lee, S. W.
System: The UNT Digital Library
High-Redshift Clusters form NVSS: The TexOx Cluster (TOC) Survey (open access)

High-Redshift Clusters form NVSS: The TexOx Cluster (TOC) Survey

The TexOx Cluster (TOC) Survey uses overdensities of radiosources in the NVSS to trace clusters of galaxies. The links between radiosources and rich environments make this a powerful way to find clusters which may potentially be overlooked by other selection techniques. By including constraints from optical surveys, TOC is an extremely efficient way to find clusters at high redshift. One such field, TOC J0233.3+3021, contains at least one galaxy cluster (at z {approx} 1.4) and has been detected using the Sunyaev-Zel'dovich (SZ) effect. Even in targeted deep optical observations, however, distinguishing the cluster galaxies from the background is difficult, especially given the tendency of TOC to select fields containing multiple structures at different redshifts.
Date: February 11, 2003
Creator: Croft, S.; Rawlings, S. & Hill, G. J.
System: The UNT Digital Library
Loops in Reeb Graphs of 2-Manifolds (open access)

Loops in Reeb Graphs of 2-Manifolds

Given a Morse function f over a 2-manifold with or without boundary, the Reeb graph is obtained by contracting the connected components of the level sets to points. We prove tight upper and lower bounds on the number of loops in the Reeb graph that depend on the genus, the number of boundary components, and whether or not the 2-manifold is orientable. We also give an algorithm that constructs the Reeb graph in time O(n log n), where n is the number of edges in the triangulation used to represent the 2-manifold and the Morse function.
Date: February 11, 2003
Creator: Cole-McLaughlin, K; Edelsbrunner, H; Harer, J; Natarajan, V & Pascucci, V
System: The UNT Digital Library
An analytical solution for estimating percolation rate by fitting temperature profiles in the Vadose Zone (open access)

An analytical solution for estimating percolation rate by fitting temperature profiles in the Vadose Zone

We present a simple analytical solution for one dimensional steady heat transfer with convection and conduction through a multi-layer system such as a vadose zone. We assume that each layer is homogeneous and has a constant thermal diffusivity. The mass/heat flow direction is perpendicular to the layers, and the mass flow rate is a constant. The analytical solution presented in this study also assumes constant known temperatures at the two boundaries of the system. Although the analytical solution gives the temperature as a function of a few parameters, we focus on the inverse application to estimate the percolation rate to high degree of accuracy (e.g., to mm/y). In some other cases the solution may also be helpful in characterizing potential lateral flow along layer divides.
Date: March 11, 2003
Creator: Shan, Chao & Bodvarsson, Gudmundur
System: The UNT Digital Library
Application of Material Characterization Techniques to Electrical Forensic Analysis (open access)

Application of Material Characterization Techniques to Electrical Forensic Analysis

The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component failure event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion.
Date: March 11, 2003
Creator: Mills, T.D.
System: The UNT Digital Library
Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H (open access)

Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H

This study assessed chemical treatment options for decomposing the tetraphenylborate in High Level Waste (HLW) Tank 48H. Tank 48H, located at the Savannah River Site in Aiken, SC, contains approximately one million liters of HLW. The tetraphenylborate slurry represents legacy material from commissioning of an In Tank Precipitation process to separate radioactive cesium and actinides from the nonradioactive chemicals. During early operations, the process encountered an unplanned chemical reaction that catalytically decomposed the excess tetraphenylborate producing benzene. Subsequent research indicated that personnel could not control the operations within the existing equipment to both meet the desired treatment rate for the waste and maintain the benzene concentration within allowable concentrations. Since then, the Department of Energy selected an alternate treatment process for handling high-level waste at the site. However, the site must destroy the tetraphenylborate before returning the tank to HLW service. The research focuses on identifying treatments to decompose tetraphenylborate to the maximum extent feasible, with a preference for decomposition methods that produce carbon dioxide rather than benzene. A number of experiments examined whether the use of oxidants, catalysts or acids proved effective in decomposing the tetraphenylborate. Additional experiments developed an understanding of the solid, liquid and gas decomposition products.
Date: March 11, 2003
Creator: Lambert, D. P.
System: The UNT Digital Library
Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays (open access)

Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays

With a sample of approximately 89 million B{bar B} pairs collected with the BABAR detector, they measure branching fractions, determine the degree of longitudinal polarization, and search for direct CP violation in the decays B{sup 0} {yields} {phi}K*{sup 0} and B{sup +} {yields} {phi}K*{sup +}. They perform a search for other charmless vector-vector B decays involving {rho} and K*(892) resonances and observe the decays B{sup +} {yields} {rho}{sup 0} K*{sup +} and B{sup +} {yields} {rho}{sup 0}{rho}{sup +}. The branching fractions are measured to be {Beta}({phi}K*{sup 0}) = (11.1{sub -1.2}{sup +1.3} {+-} 1.1) x 10{sup -6}, {Beta}({phi}K*{sup +}) = (12.1{sub -1.9}{sup +2.1} {+-} 1.5) x 10{sup -6}, {Beta}({rho}{sup 0} K*{sup +}) = (7.7{sub -2.0}{sup +2.1} {+-} 1.4) x 10{sup -6}, and {Beta}({rho}{sup 0}{rho}{sup +}) = (9.9{sub -2.5}{sup +2.6} {+-} 2.5) x 10{sup -6}. The longitudinal polarization fractions are measured to be {Lambda}{sub L}/{Lambda}({phi}K*{sup 0}) = 0.65 {+-} 0.07 {+-} 0.04 and {Lambda}{sub L}/{Lambda}({phi}K*{sup +}) = 0.46 {+-} 0.12 {+-} 0.05. They measure the charge asymmetries: {Alpha}{sub CP}({phi}K*{sup 0}) = +0.04 {+-} 0.12 {+-} 0.02 and {Alpha}{sub CP}({phi}K*{sup +}) = +0.16 {+-} 0.17 {+-} 0.04.
Date: March 11, 2003
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y. et al.
System: The UNT Digital Library
SCUBA Observations of High Redshift Radio Galaxies (open access)

SCUBA Observations of High Redshift Radio Galaxies

High redshift radio galaxies (HzRGs) are key targets for studies of the formation and evolution of massive galaxies.The role of dust in these processes is uncertain. We have therefore observed the dust continuum emission from a sample of z > 3 radio galaxies with the SCUBA bolometer array. We confirm and strengthen the result found by Archibald et al. (1), that HzRGs are massive starforming systems and that submillimeter detection rate appears to be primarily a strong function of redshift. We also observed HzRG-candidates that have so far eluded spectroscopic redshift determination. Four of these have been detected, and provide evidence that they may be extremely obscured radio galaxies, possibly in an early stage of their evolution.
Date: March 11, 2003
Creator: Reuland, M; Rottgering, H & van Breugel, W
System: The UNT Digital Library
Synthesis of GaNxAs1-x thin films by pulsed laser melting andrapid thermal annealing (PLM-RTA) of N+-implanted GaAs (open access)

Synthesis of GaNxAs1-x thin films by pulsed laser melting andrapid thermal annealing (PLM-RTA) of N+-implanted GaAs

We present a systematic investigation on the formation of the highly mismatched alloy GaN{sub x}As{sub 1-x} using N{sup +}-implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaN{sub x}As{sub 1-x} with x as high as 0.016 and an activation efficiency of the implanted N up to 50% have been synthesized with structural and optical properties comparable to films grown by epitaxial deposition techniques with similar substitutional N content. The effects of N{sup +} implantation dose, laser energy fluence and rapid thermal annealing temperature on the N incorporation as well as optical and structural properties of the GaN{sub x}As{sub 1-x} films are discussed.
Date: March 11, 2003
Creator: Yu, K. M.; Walukiewicz, W.; Scarpulla, M. A.; Dubon, O. D.; Wu, J.; Jasinski, J. et al.
System: The UNT Digital Library
TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media (open access)

TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of acid mine drainage remediation, waste disposal sites, hydrothermal convection, contaminant transport, and groundwater quality. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers non-isothermal multi-component chemical transport in both liquid and gas phases. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity.
Date: March 11, 2003
Creator: Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas & Pruess, Karsten
System: The UNT Digital Library
Uniformity on the grid via a configuration framework (open access)

Uniformity on the grid via a configuration framework

As Grid permeates modern computing, Grid solutions continue to emerge and take shape. The actual Grid development projects continue to provide higher-level services that evolve in functionality and operate with application-level concepts which are often specific to the virtual organizations that use them. Physically, however, grids are comprised of sites whose resources are diverse and seldom project readily onto a grid's set of concepts. In practice, this also creates problems for site administrators who actually instantiate grid services. In this paper, we present a flexible, uniform framework to configure a grid site and its facilities, and otherwise describe the resources and services it offers. We start from a site configuration and instantiate services for resource advertisement, monitoring and data handling; we also apply our framework to hosting environment creation. We use our ideas in the Information Management part of the SAM-Grid project, a grid system which will deliver petabyte-scale data to the hundreds of users. Our users are High Energy Physics experimenters who are scattered worldwide across dozens of institutions and always use facilities that are shared with other experiments as well as other grids. Our implementation represents information in the XML format and includes tools written in XQuery and …
Date: March 11, 2003
Creator: al., Igor V Terekhov et
System: The UNT Digital Library
Development of High Power Lasers for Materials Interactions (open access)

Development of High Power Lasers for Materials Interactions

The Lawrence Livermore National Laboratory (LLNL) has a long history of developing high power lasers for use in basic science and applications. The Laser Science and Technology Program (LS&T) at LLNL supports advanced lasers and optics development both for the National Ignition Facility (NIF) as well as for high power lasers and optics technology for a broader range of government, military and industrial applications. The NIF laser is currently under construction with the first of the 192 beamlines being activated. When finished NIF will have an output energy of 2 MJ at 351 nm. This system will be used for studies of high energy density physics, equation of state and inertial confinement fusion. It is now generally acknowledged that the future of laser missile defense lies with solid state lasers. The leading laser technology for theater missile defense is under development within the LS&T and funded by the US Army SMDC. This high average power technology is based on a solid state laser operated in a heat capacity mode. In the concept the heat producing lasing cycle is separated in time from the cooling cycle thus reducing thermal gradients and allowing significantly greater average output power. Under the current program, …
Date: April 11, 2003
Creator: Hackel, L A
System: The UNT Digital Library
Experience with parallel optical link for the CDF silicon detector (open access)

Experience with parallel optical link for the CDF silicon detector

The Dense Optical Interface Module (DOIM) is a byte-wide optical link developed for the Run II upgrade of the CDF silicon tracking system [1]. The module consists of a transmitter with a laser-diode array for conversion of digitized detector signals to light outputs, a 22 m optical fiber ribbon cable for light transmission, and a receiver converting the light pulses back to electrical signals. We report on the design feature, characteristics, and radiation tolerance.
Date: April 11, 2003
Creator: Hou, S.
System: The UNT Digital Library
A Multi-Layered Image Cache for Scientific Visualization (open access)

A Multi-Layered Image Cache for Scientific Visualization

None
Date: April 11, 2003
Creator: LaMar, E C & Pascucci, V
System: The UNT Digital Library
Multiple Access in Ultra-Wideband Communications Using Multiple Pulses (open access)

Multiple Access in Ultra-Wideband Communications Using Multiple Pulses

Multiple access (MA) in UWB communication is an area of active research. To date several time-division or code-division pulse amplitude modulation (PAM) or pulse position modulation (PPM) schemes have been proposed to separate multiple users in UWB communications. Conventionally, all users employ the same pulse shape and modulate the transmit pulse based on changing amplitude or position. One concern with using the same pulse for all channels is that the multiple access interference (MAI) increases as the number of users increase. This is due to increased cross-correlation between similar pulses of the different channels, raising thus the noise floor in such systems. In this paper we introduce and study the performance of a new MA scheme in the context of multiple orthogonal transmitted-reference (T-R) short duration (nsec) chirp pulses in the presence of multipath and additive white Gaussian noise (AWGN).
Date: April 11, 2003
Creator: Nekoogar, F. & Dowla, F.
System: The UNT Digital Library
On Issues of Precision for Hardware-based Volume Visualization (open access)

On Issues of Precision for Hardware-based Volume Visualization

This paper discusses issues with the limited precision of hardware-based volume visualization. We will describe the compositing OVER operator and how fixed-point arithmetic affects it. We propose two techniques to improve the precision of fixed-point compositing and the accuracy of hardware-based volume visualization. The first technique is to perform dithering of color and alpha values. The second technique we call exponent-factoring, and captures significantly more numeric resolution than dithering, but can only produce monochromatic images.
Date: April 11, 2003
Creator: LaMar, E C
System: The UNT Digital Library
Prediction of Halocarbon Toxicity from Structure: A Hierarchical QSAR Approach (open access)

Prediction of Halocarbon Toxicity from Structure: A Hierarchical QSAR Approach

Mathematical structural invariants and quantum theoretical descriptors have been used extensively in quantitative structure-activity relationships (QSARs) for the estimation of pharmaceutical activities, biological properties, physicochemical properties, and the toxicities of chemicals. Recently our research team has explored the relative importance of various levels of chemodescriptors, i.e., topostructural, topochemical, geometrical, and quantum theoretical descriptors, in property estimation. This study examines the contribution of chemodescriptors ranging from topostructural to quantum theoretic calculations up to the Gaussian STO-3G level in the prediction of the toxicity of a set of twenty halocarbons. We also report the results of experimental cell-level toxicity studies on these twenty halocarbons to validate our models.
Date: April 11, 2003
Creator: Gute, B D; Balasubramanian, K; Geiss, K & Basak, S C
System: The UNT Digital Library
Effects of Spatial Variations in Packing Fraction of Reactor Physics Parameters in Pebble-Bed Reactors (open access)

Effects of Spatial Variations in Packing Fraction of Reactor Physics Parameters in Pebble-Bed Reactors

The well-known spatial variation of packing fraction near the outer boundary of a pebble-bed reactor core is cited. The ramifications of this variation are explored with the MCNP computer code. It is found that the variation has negligible effects on the global reactor physics parameters extracted from the MCNP calculations for use in analysis by diffusion-theory codes, but for local reaction rates the effects of the variation are naturally important. Included is some preliminary work in using first-order perturbation theory for estimating the effect of the spatial variation of packing fraction on the core eigenvalue and the fission density distribution.
Date: June 11, 2003
Creator: Terry, W. K.; Ougouag, A. M.; Rahnema, F. & Mckinley, M. S.
System: The UNT Digital Library
Enhancing the soil organic matter pool through biomass incorporation. (open access)

Enhancing the soil organic matter pool through biomass incorporation.

A study was installed in the Upper Coastal Plain of South Carolina, USA, that sought to examine the impact of incorporating downed slash materials into subsoil layers on soil chemical and physical properties as compared with the effect of slash materials left on the soil surface. Baseline levels of slash were estimated by establishing transects within harvested stands and estimating the quantity of down wood and stumps. An equivalent quantity of biomass and two times the baseline levels were incorporated into subsurface soil layers by a CMI RS 500B reclaimer/stabilizer. Two sites were examined which differed in soil textural composition: sandy vs. clay. Site differences had no impact on machine productivity and machine costs were estimated at $US 521 ha-1 and $US 633 ha-1 on the ''sandy'' and ''clay'' sites, respectively. The feasibility of the CM1 for biomass incorporation is low due to high unit area costs but increased machine productivity would reduce costs and improve its potential. Biomass incorporation improved carbon and nutrient content of each site, especially on the sandy site. Slash levels had an impact on nutrient content but the differences were not statistically significant. For the sandy site, improvements in soil physical properties were evident in …
Date: June 11, 2003
Creator: Sanchez, Felipe, G.; Carter, Emily, A. & Klepac, John, F.
System: The UNT Digital Library
Identification of a third protein 4.1 tumor suppressor, protein 4.1R, in meningioma pathogenesis (open access)

Identification of a third protein 4.1 tumor suppressor, protein 4.1R, in meningioma pathogenesis

Meningiomas are common tumors of the central nervous system, however, the mechanisms under lying their pathogenesis are largely undefined. Two members of the Protein 4.1 super family, the neuro fibromatosis 2 (NF2) gene product (merlin/schwannomin) and Protein 4.1B have been implicated as meningioma tumor suppressors. In this report, we demonstrate that another Protein 4.1 family member, Protein 4.1R, also functions as a meningioma tumor suppressor. Based on the assignment of the Protein 4.1R gene to chromosome 1p32-36, a common region of deletion observed in meningiomas, we analyzed Protein 4.1R expression in meningioma cell lines and surgical tumor specimens. We observed loss of Protein 4.1R protein expression in two meningioma cell lines (IOMM-Lee, CH157-MN) by Western blotting as well as in 6 of 15 sporadic meningioma as by immuno histo chemistry (IHC). Analysis of a subset of these sporadic meningiomas by fluorescent in situ hybridization (FISH) with a Protein 4.1R specific probe demonstrated 100 percent concordance with the IHC results. In support of a meningioma tumor suppressor function, over expression of Protein 4.1R resulted in suppression of IOMM-Lee and CH157MN cell proliferation. Similar to the Protein 4.1B and merlin meningioma tumor suppressors, Protein 4.1R localization in the membrane fraction increased significantly …
Date: June 11, 2003
Creator: Robb, Victoria A.; Li, Wen; Gascard, Philippe; Perry, Arie; Mohandas, Narla & Gutmann, David H.
System: The UNT Digital Library
Nuclear actin and protein 4.1: Essential interactions during nuclear assembly in vitro (open access)

Nuclear actin and protein 4.1: Essential interactions during nuclear assembly in vitro

Structural protein 4.1, which has crucial interactions within the spectin-actin lattice of the human red cell membrane skeleton, also is widely distributed at diverse intracellular sites in nucleated cells. We previously showed that 4.1 is essential for assembly of functional nuclei in vitro and that the capacity of 4.1 to bind actin is required. Here we report that 4.1 and actin colocalize in mammalian cell nuclei using fluorescence microscopy and, by higher resolution cell whole mount electron microscopy, are associated on nuclear filaments. We also devised a cell-free assay using Xenopus egg extract containing fluorescent actin to follow actin during nuclear assembly. By directly imaging actin under non-perturbing conditions, the total nuclear actin population is retained and is visualized in situ relative to intact chromatin. We detected actin initially when chromatin and nuclear pores began assembling. As the nuclear lamina assembled, but preceding DNA synthesis, a discrete actin network formed throughout the nucleus. Protein 4.1 epitopes also were detected when actin began to accumulate in nuclei, producing a diffuse coincident pattern. As nuclei matured, actin was detected both coincident with and also independent of 4.1 epitopes. To test whether acquisition of nuclear actin is required for nuclear assembly, the actin …
Date: June 11, 2003
Creator: Krauss, Sharon Wald; Chen, Cynthia; Penman, Sheldon & Heald, Rebecca
System: The UNT Digital Library