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Solubility of Acetaminophen and Ibuprofen in the Mixtures of Polyethylene Glycol 200 or 400 with Ethanol and water and the Density of Solute-Free Mixed Solvents at 298.2 K (open access)

Solubility of Acetaminophen and Ibuprofen in the Mixtures of Polyethylene Glycol 200 or 400 with Ethanol and water and the Density of Solute-Free Mixed Solvents at 298.2 K

Article on the solubility of acetaminophen and ibuprofen in the mixtures of polyethylene glycol 200 or 400 with ethanol and water and the density of solute-free mixed solvents at 298.2 K.
Date: October 26, 2010
Creator: Jouyban, Abolghasem; Soltanpour, Shahla & Acree, William E. (William Eugene)
System: The UNT Digital Library
Semi-supervised prediction of protein subcellular localization using abstraction augmented Markov models (open access)

Semi-supervised prediction of protein subcellular localization using abstraction augmented Markov models

Article discussing the semi-supervised prediction of protein subcellular localization using abstraction augmented Markov models.
Date: October 26, 2010
Creator: Caragea, Cornelia; Caragea, Doina; Silvescu, Adrian & Honavar, Vasant
System: The UNT Digital Library
Results of applying a non-evaporative mitigation technique to laser-initiated surface damage on fused-silica (open access)

Results of applying a non-evaporative mitigation technique to laser-initiated surface damage on fused-silica

We present results from a study to determine an acceptable CO{sub 2} laser-based non-evaporative mitigation protocol for use on surface damage sites in fused-silica optics. A promising protocol is identified and evaluated on a set of surface damage sites created under ICF-type laser conditions. Mitigation protocol acceptability criteria for damage re-initiation and growth, downstream intensification, and residual stress are discussed. In previous work, we found that a power ramp at the end of the protocol effectively minimizes the residual stress (<25 MPa) left in the substrate. However, the biggest difficulty in determining an acceptable protocol was balancing between low re-initiation and problematic downstream intensification. Typical growing surface damage sites mitigated with a candidate CO{sub 2} laser-based mitigation protocol all survived 351 nm, 5 ns damage testing to fluences >12.5 J/cm{sup 2}. The downstream intensification arising from the mitigated sites is evaluated, and all but one of the sites has 100% passing downstream damage expectation values. We demonstrate, for the first time, a successful non-evaporative 10.6 {micro}m CO{sub 2} laser mitigation protocol applicable to fused-silica optics used on fusion-class lasers like the National Ignition Facility (NIF).
Date: October 26, 2010
Creator: Adams, J. J.; Bolourchi, M.; Bude, J. D.; Guss, G. M.; Matthews, M. J. & Nostrand, M. C.
System: The UNT Digital Library
Integrated Nucleosynthesis in Neutrino Driven Winds (open access)

Integrated Nucleosynthesis in Neutrino Driven Winds

Although they are but a small fraction of the mass ejected in core-collapse supernovae, neutrino-driven winds (NDWs) from nascent proto-neutron stars (PNSs) have the potential to contribute significantly to supernova nucleosynthesis. In previous works, the NDW has been implicated as a possible source of r-process and light p-process isotopes. In this paper we present time-dependent hydrodynamic calculations of nucleosynthesis in the NDW which include accurate weak interaction physics coupled to a full nuclear reaction network. Using two published models of PNS neutrino luminosities, we predict the contribution of the NDW to the integrated nucleosynthetic yield of the entire supernova. For the neutrino luminosity histories considered, no true r-process occurs in the most basic scenario. The wind driven from an older 1.4M{sub {circle_dot}} model for a PNS is moderately neutron-rich at late times however, and produces {sup 87}Rb, {sup 88}Sr, {sup 89}Y, and {sup 90}Zr in near solar proportions relative to oxygen. The wind from a more recently studied 1.27M{sub {circle_dot}} PNS is proton-rich throughout its entire evolution and does not contribute significantly to the abundance of any element. It thus seems very unlikely that the simplest model of the NDW can produce the r-process. At most, it contributes to the …
Date: March 26, 2010
Creator: Roberts, L F; Woosley, S E & Hoffman, R D
System: The UNT Digital Library
RESPONSE OF ALUMINUM SPHERES IN SITU TO DETONATION (open access)

RESPONSE OF ALUMINUM SPHERES IN SITU TO DETONATION

Time sequence x-ray imaging was utilized to determine the response of aluminum spheres embedded in a detonating high-explosive cylinder. The size of these spheres ranged from 3/8-inch to 1/32-inch in diameter. These experiments directly observed the response of the spheres as a function of time after interaction with the detonation wave. As the spheres are entrained in the post-detonation flow field, they are accelerating and their velocity profile is complicated, but can be determined from the radiography. Using the aluminum spheres as tracers, radial velocities of order 1.6 mm/us and horizontal velocities of order 0.08 mm/us were measured at early times post detonation. In terms of response, these data show that the largest sphere deforms and fractures post detonation. The intermediate size spheres suffer negligible deformation, but appear to ablate post detonation. Post detonation, the smallest spheres either react, mechanically disintegrate, atomize as a liquid or some combination of these.
Date: March 26, 2010
Creator: Molitoris, J D; Garza, R G; Tringe, J W; Batteux, J D; Wong, B M; Villafana, R J et al.
System: The UNT Digital Library
A nanocrystal strain gauge for luminescence detection of mechanical forces (open access)

A nanocrystal strain gauge for luminescence detection of mechanical forces

Local microscale stresses play a crucial role in inhomogeneous mechanical processes from cell motility to material failure. However, it remains difficult to spatially resolve stress at these small length scales. While contact-probe and non-contact based techniques have been used to quantify local mechanical behavior in specific systems with high stiffness or stress and spatial resolution, these methods cannot be used to study a majority of micromechanical systems due to spectroscopic and geometrical constraints. We present here the design and implementation of a luminescent nanocrystal strain gauge, the CdSe/CdS core/shell tetrapod. The tetrapod can be incorporated into many materials, yielding a local stress measurement through optical fluorescence spectroscopy of the electronically confined CdSe core states. The stress response of the tetrapod is calibrated and utilized to study mechanical behavior in single polymer fibers. We expect that tetrapods can be used to investigate local stresses in many other mechanical systems.
Date: July 26, 2010
Creator: Choi, Charina; Koski, Kristie; Olson, Andrew & Alivisatos, Paul
System: The UNT Digital Library
Energy-Water Nexus (open access)

Energy-Water Nexus

Conclusions of this presentation are: (1) energy and water are interconnected; (2) new energy sources will place increased demands on water supplies; (3) existing energy sources will be subjected to increasing restrictions on their water use; and (4) integrated decision support tools will need to be developed to help policy makers decide which policies and advanced technologies can address these issues.
Date: July 26, 2010
Creator: Horak, W.
System: The UNT Digital Library
Bench-Top Impedance Measurements for a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade (open access)

Bench-Top Impedance Measurements for a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade

Simulations have been performed in Omega3P to study both trapped modes and impedance contributions of a rotatable collimator for the LHC phase II collimation upgrade. Bench-top stretched coil probe impedance methods are also being implemented for measurements on prototype components to directly measure the low frequency impedance contributions. The collimator design also calls for a RF contact interface at both jaw ends with contact resistance much less than a milliohm in order to limit transverse impedance. DC resistance measurements in a custom built test chamber have been performed to test the performance of this interface.
Date: August 26, 2010
Creator: Smith, Jeffrey Claiborne; Bane, Karl; Doyle, Eric; Keller, Lew; Lundgren, Steve; Markiewicz, Tom et al.
System: The UNT Digital Library
BDS Thin Film UV Antireflection Laser Damage Competition (open access)

BDS Thin Film UV Antireflection Laser Damage Competition

UV antireflection coatings are a challenging coating for high power laser applications as exemplified by the use of uncoated Brewster's windows in laser cavities. In order to understand the current laser resistance of UV AR coatings in the industrial and university sectors, a double blind laser damage competition was performed. The coatings have a maximum reflectance of 0.5% at 355 nm at normal incidence. Damage testing will be performed using the raster scan method with a 7.5 ns pulse length on a single testing facility to facilitate direct comparisons. In addition to the laser resistance results, details of deposition processes and coating materials will also be shared.
Date: October 26, 2010
Creator: Stolz, C J
System: The UNT Digital Library
Near infrared spectral imaging of explosives using a tunable laser source (open access)

Near infrared spectral imaging of explosives using a tunable laser source

Diffuse reflectance near infrared hyperspectral imaging is an important analytical tool for a wide variety of industries, including agriculture consumer products, chemical and pharmaceutical development and production. Using this technique as a method for the standoff detection of explosive particles is presented and discussed. The detection of the particles is based on the diffuse reflectance of light from the particle in the near infrared wavelength range where CH, NH, OH vibrational overtones and combination bands are prominent. The imaging system is a NIR focal plane array camera with a tunable OPO/laser system as the illumination source. The OPO is programmed to scan over a wide spectral range in the NIR and the camera is synchronized to record the light reflected from the target for each wavelength. The spectral resolution of this system is significantly higher than that of hyperspectral systems that incorporate filters or dispersive elements. The data acquisition is very fast and the entire hyperspectral cube can be collected in seconds. A comparison of data collected with the OPO system to data obtained with a broadband light source with LCTF filters is presented.
Date: March 26, 2010
Creator: Klunder, G. L.; Margalith, E. & Nguyen, L. K.
System: The UNT Digital Library
Spectromicroscopy study of interfacial Co/NiO(001) (open access)

Spectromicroscopy study of interfacial Co/NiO(001)

Photoemission electron microscopy (PEEM) with linearly polarized x-rays is used to determine the orientation of antiferromagnetic domains by monitoring the relative peak intensities at the 3d transition metal L{sub 2} absorption edge. In such an analysis the orientations of the x-ray polarization E and magnetization H with respect to the crystalline axes has to be taken into account. We address this problem by presenting a general expression of the angular dependence for both x-ray absorption spectroscopy and x-ray magnetic linear dichroism (XMLD) for arbitrary direction of E and H in the (001) cubic plane. In cubic symmetry the angular dependent XMLD is a linear combination of two spectra with different photon energy dependence, which reduces to one spectrum when E or H is along a high-symmetry axis. The angular dependent XMLD can be separated into an isotropic term, which is symmetric along H, and an anisotropic term, which depends on the orientation of the crystal axes. The anisotropic term has maximal intensity when E and H have equal but opposite angles with respect to the [100] direction. The Ni{sup 2+} L{sub 2} edge has the peculiarity that the isotropic term vanishes, which means that the maximum in the XMLD intensity …
Date: September 26, 2010
Creator: van der Laan, Gerrit; Telling, Neil; Potenza, Alberto; Dhesi, Sarnjeet & Arenholz, Elke
System: The UNT Digital Library
Determination of laser damage initiation probability and growth on fused silica scratches (open access)

Determination of laser damage initiation probability and growth on fused silica scratches

Current methods for the manufacture of optical components inevitably leaves a variety of sub-surface imperfections including scratches of varying lengths and widths on even the finest finishes. It has recently been determined that these finishing imperfections are responsible for the majority of laser-induced damage for fluences typically used in ICF class lasers. We have developed methods of engineering subscale parts with a distribution of scratches mimicking those found on full scale fused silica parts. This much higher density of scratches provides a platform to measure low damage initiation probabilities sufficient to describe damage on large scale optics. In this work, damage probability per unit scratch length was characterized as a function of initial scratch width and post fabrication processing including acid-based etch mitigation processes. The susceptibility of damage initiation density along scratches was found to be strongly affected by the post etching material removal and initial scratch width. We have developed an automated processing procedure to document the damage initiations per width and per length of theses scratches. We show here how these tools can be employed to provide predictions of the performance of full size optics in laser systems operating at 351 nm. In addition we use these tools …
Date: October 26, 2010
Creator: Norton, M. A.; Carr, C. W.; Cross, D. A.; Negres, R. A.; Bude, J. D.; Steele, W. A. et al.
System: The UNT Digital Library
Nuclear Material Attractiveness: An Assessment of Material From Phwr's in a Closed Thorium Fuel Cycle (open access)

Nuclear Material Attractiveness: An Assessment of Material From Phwr's in a Closed Thorium Fuel Cycle

This paper examines the attractiveness of material mixtures containing special nuclear materials (SNM) associated with reprocessing and the thorium-based LWR fuel cycle. This paper expands upon the results from earlier studies that examined the attractiveness of SNM associated with the reprocessing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR. This study shows that {sup 233}U that is produced in thorium-based fuel cycles is very attractive for weapons use. Consistent with other studies, these results also show that all fuel cycles examined to date need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities. The methodology and key findings will be presented.
Date: April 26, 2010
Creator: Sleaford, B. W.; Collins, B. A.; Ebbinghaus, B. B.; Bathke, C. G.; Prichard, A. W.; Wallace, R. K. et al.
System: The UNT Digital Library
Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts (open access)

Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts

Previously we have shown that the size of laser induced damage sites in both KDP and SiO{sub 2} is largely governed by the duration of the laser pulse which creates them. Here we present a model based on experiment and simulation that accounts for this behavior. Specifically, we show that solid-state laser-supported absorption fronts are generated during a damage event and that these fronts propagate at constant velocities for laser intensities up to 4 GW/cm{sup 2}. It is the constant absorption front velocity that leads to the dependence of laser damage site size on pulse duration. We show that these absorption fronts are driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport, and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. In addition to the practical application of selecting an optimal laser for pre-initiation of large aperture optics, this work serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.
Date: October 26, 2010
Creator: Carr, C W; Bude, J D; Shen, N & Demange, P
System: The UNT Digital Library
Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection (open access)

Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection

The behavior of the internal electric-field of nuclear-radiation detectors substantially affects the detector's performance. We investigated the distribution of the internal field in cadmium zinc telluride (CZT) detectors under high carrier injection. We noted the build-up of a space charge region near the cathode that produces a built-in field opposing the applied field. Its presence entails the collapse of the electric field in the rest of detector, other than the portion near the cathode. Such a space-charge region originates from serious hole-trapping in CZT. The device's operating temperature greatly affects the width of the space-charge region. With increasing temperature from 5 C to 35 C, its width expanded from about 1/6 to 1/2 of the total depth of the detector.
Date: October 26, 2010
Creator: Yang, G.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Kim, K. H. et al.
System: The UNT Digital Library
Mechanical and Thermal Prototype Testing for a Rotatable Collimator for the LHC Phase II Collimation Upgrade (open access)

Mechanical and Thermal Prototype Testing for a Rotatable Collimator for the LHC Phase II Collimation Upgrade

The Phase II upgrade to the LHC collimation system calls for complementing the robust Phase I graphite collimators with high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and testing of this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. A prototype collimator jaw has been tested for both mechanical and thermal compliance with the design goals. Thermal expansion bench-top tests are compared to ANSYS simulation results.
Date: August 26, 2010
Creator: Smith, Jeffrey Claiborne; Doyle, Eric; Keller, Lewis; Lundgren, Steven & Markiewicz, Thomas Walter
System: The UNT Digital Library
Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition (open access)

Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition

The chemistry, microstructure, and catalytic activity of thin films incorporating palladium were studied using scanning and transmission electron microscopies, X-ray diffraction, spectrophotometry, 4-point probe and catalytic tests. The films were synthesized using pulsed filtered cathodic arc and magnetron sputter deposition, i.e. techniques far from thermodynamic equilibrium. Catalytic particles were formed by thermally cycling thin films of the Pd-Pt-O system. The evolution and phase formation in such films as a function of temperature were discussed in terms of the stability of PdO and PtO2 in air. The catalytic efficiency was found to be strongly affected by the chemical composition, with oxidized palladium definitely playing a major role in the combustion of methane. Reactive sputter deposition of thin films in the Pd-Zr-Y-O system allowed us forming microstructures ranging from nanocrystalline zirconia to palladium nanoparticles embedded in a (Zr,Y)4Pd2O matrix. The sequence of phase formation is put in relation to simple thermodynamic considerations.
Date: November 26, 2010
Creator: Anders, Andre
System: The UNT Digital Library
Multiwavelength Observations of Radio-Quiet Quasars with Weak Emission Lines (open access)

Multiwavelength Observations of Radio-Quiet Quasars with Weak Emission Lines

This article presents radio and X-ray observations, as well as optical light curves, for a subset of 26 BL Lac candidates from the Sloan Digital Sky Survey lacking strong radio emission and with z < 2.2.
Date: July 26, 2010
Creator: Plotkin, Richard M.; Anderson, Scott F.; Brandt, William Nielsen; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; MacLeod, Chelsea L. et al.
System: The UNT Digital Library
"Snowflake" divertor configuration in NSTX (open access)

"Snowflake" divertor configuration in NSTX

None
Date: May 26, 2010
Creator: Soukhanovskii, V. A.; Ahn, J. W.; Bell, R. E.; Gates, D. A.; Gerhardt, S.; Kaita, R. et al.
System: The UNT Digital Library
Reaction cross-section predictions for nucleon induced reactions (open access)

Reaction cross-section predictions for nucleon induced reactions

None
Date: July 26, 2010
Creator: Nobre, G P; Thompson, I J; Escher, J E & Dietrich, F S
System: The UNT Digital Library
Surrogate Approaches for Neutron Capture (open access)

Surrogate Approaches for Neutron Capture

None
Date: May 26, 2010
Creator: Escher, J E; Dietrich, F S & Scielzo, N D
System: The UNT Digital Library
Direct characterization of phase transformations and morphologies in moving reaction zones in Al/Ni nanolaminates using dynamic transmission electron microscopy (open access)

Direct characterization of phase transformations and morphologies in moving reaction zones in Al/Ni nanolaminates using dynamic transmission electron microscopy

None
Date: August 26, 2010
Creator: Kim, J. S.; LaGrange, T.; Reed, B. W.; Knepper, R.; Weihs, T. P.; Browning, N. D. et al.
System: The UNT Digital Library
Kinetics of Ejected Particles During Laser-Induced Breakdown in Fused Silica (open access)

Kinetics of Ejected Particles During Laser-Induced Breakdown in Fused Silica

None
Date: July 26, 2010
Creator: Raman, R N; Negres, R A & Demos, S G
System: The UNT Digital Library
Mechanical Damage, Ignition, and Burn: Experiment, Model Development, and Computer Simulations to Study High-Explosive Violent Response (HEVR) (open access)