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Correlation Function and Generalized Master Equation of Arbitrary Age

Description: Article discussing research on correlation function and generalized master equation of arbitrary age.
Date: June 10, 2005
Creator: Allegrini, Paolo; Aquino, Gerardo; Grigolini, Paolo; Palatella, Luigi; Rosa, Angelo & West, Bruce J.
Partner: UNT College of Arts and Sciences
open access

BDDC for nonsymmetric positive definite and symmetric indefinite problems

Description: The balancing domain decomposition methods by constraints are extended to solving both nonsymmetric, positive definite and symmetric, indefinite linear systems. In both cases, certain nonstandard primal constraints are included in the coarse problems of BDDC algorithms to accelerate the convergence. Under the assumption that the subdomain size is small enough, a convergence rate estimate for the GMRES iteration is established that the rate is independent of the number of subdomains and depends … more
Date: December 10, 2008
Creator: Tu, Xuemin & Li, Jing
Partner: UNT Libraries Government Documents Department
open access

Transmission Electron Microscopy Study of Nonpolar a-Plane GaNGrown by Pendeo-Epitaxy on (112_0) 4H-SiC

Description: Pendeo-epitaxy has been applied to nonpolar a-plane GaN layers in order to observe if such process will lead to defect reduction in comparison with direct growth on this plane. Uncoalesced and coalesced a-plane GaN layers with thicknesses 2{micro}m and 12{micro}m, respectively have been studied by conventional and high resolution electron microscopy. The following structural defects have been observed in pendeo-epitaxial layers: (1) basal stacking faults, (2) threading dislocations and (3) pris… more
Date: March 10, 2005
Creator: Zakharov, D. N.; Liliental-Weber, Z.; Wagner, B.; Reitmeier, Z. J.; Preble, E. A. & Davis, R. F.
Partner: UNT Libraries Government Documents Department
open access

Mg-induced increase of bandgap in Zn1-xMgxO nanorods revealed by x-ray absorption and emission spectroscopy

Description: X-ray absorption near-edge structure (XANES) and x-ray emission spectroscopy (XES) measurements were used to investigate the effect of Mg doping in ZnO nanorods. The intensities of the features in the O K-edge XANES spectra of Zn{sub 1-x}Mg{sub x}O nanorods are lower than those of pure ZnO nanorods, suggesting that Mg doping increases the negative effective charge of O ions. XES and XANES spectra of O 2p states indicate that Mg doping raises (lowers) the conduction-band-minimum (valence-band-ma… more
Date: July 10, 2008
Creator: Pong, Way-Faung; Chiou, J. W.; Tsai, H. M.; Pao, C. W.; Chien, F. Z.; Pong, W. F. et al.
Partner: UNT Libraries Government Documents Department
open access

Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

Description: Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine mea… more
Date: July 10, 2006
Creator: Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P. & Shupe, M.
Partner: UNT Libraries Government Documents Department
open access

Web-Ice: Integrated Data Collection and Analysis for Macromolecular Crystallography

Description: New software tools are introduced to facilitate diffraction experiments involving largenumbers of crystals. While existing programs have long provided a framework for lattice indexing, Bragg spot integration, and symmetry determination, these initial data processing steps often require significant manual effort. This limits the timely availability of data analysis needed for high-throughput procedures, including the selection of the best crystals from a large sample pool, and the calculation of… more
Date: October 10, 2007
Creator: Gonzalez, Ana; Gonzalez, Ana; Moorhead, Penjit; McPhillips, Scott E.; Song, Jinhu; Sharp, Ken et al.
Partner: UNT Libraries Government Documents Department
open access

InN Nanorods Grown on Different Planes of Al2O3

Description: No Description Available.
Date: March 10, 2007
Creator: Liliental-Weber, Z.; Park, H.J.; Mangum, J.; Anderson, T. & Kryliouk, O.
Partner: UNT Libraries Government Documents Department
open access

Calculation Of Change-Changing Cross Sections Of IONS Or Atoms Colliding With Fast IONS Using The Classical Trajectory Method

Description: Evaluation of ion-atom charge-changing cross sections is needed for many accelerator applications. A classical trajectory Monte Carlo (CTMC) simulation has been used to calculate ionization and charge exchange cross sections. For benchmarking purposes, an extensive study has been performed for the simple case of hydrogen and helium targets in collisions with various ions. Despite the fact that the simulation only accounts for classical mechanics, the calculations are comparable to experimental … more
Date: October 10, 2008
Creator: Kaganovich, I. D., Shnidman, Ariel, Mebane, Harrison, Davidson, R.C.
Partner: UNT Libraries Government Documents Department
open access

Shape Determination for Deformed Electromagnetic Cavities

Description: The measured physical parameters of a superconducting cavity differ from those of the designed ideal cavity. This is due to shape deviations caused by both loose machine tolerances during fabrication and by the tuning process for the accelerating mode. We present a shape determination algorithm to solve for the unknown deviations from the ideal cavity using experimentally measured cavity data. The objective is to match the results of the deformed cavity model to experimental data through least-… more
Date: December 10, 2007
Creator: Akcelik, Volkan; Ko, Kwok; Lee, Lie-Quan; Li, Zhenghai; Ng, Cho-Kuen & Xiao, Liling
Partner: UNT Libraries Government Documents Department
open access

The Absence of Plasma in"Spark Plasma Sintering"

Description: Spark plasma sintering (SPS) is a remarkable method for synthesizing and consolidating a large variety of both novel and traditional materials. The process typically uses moderate uni-axial pressures (<100 MPa) in conjunction with a pulsing on-off DC current during operation. There are a number of mechanisms proposed to account for the enhanced sintering abilities of the SPS process. Of these mechanisms, the one most commonly put forth and the one that draws the most controversy involves the… more
Date: April 10, 2008
Creator: Hulbert, Dustin M.; Anders, Andre; Dudina, Dina V.; Andersson, Joakim; Jiang, Dongtao; Unuvar, Cosan et al.
Partner: UNT Libraries Government Documents Department
open access

Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels

Description: The NanoSIMS 50 combines unprecedented spatial resolution (as good as 50 nm) with ultra-high sensitivity (minimum detection limit of {approx}200 atoms). The NanoSIMS 50 incorporates an array of detectors, enabling simultaneous collection of 5 species originating from the same sputtered volume of a sample. The primary ion beam (Cs{sup +} or O{sup -}) can be scanned across the sample to produce quantitative secondary ion images. This capability for multiple isotope imaging with high spatial resol… more
Date: April 10, 2006
Creator: Weber, P K; Fallon, S J; Pett-Ridge, J; Ghosal, S & Hutcheon, I D
Partner: UNT Libraries Government Documents Department
open access

Practical error estimates for Reynolds' lubrication approximation and its higher order corrections

Description: Reynolds lubrication approximation is used extensively to study flows between moving machine parts, in narrow channels, and in thin films. The solution of Reynolds equation may be thought of as the zeroth order term in an expansion of the solution of the Stokes equations in powers of the aspect ratio {var_epsilon} of the domain. In this paper, we show how to compute the terms in this expansion to arbitrary order on a two-dimensional, x-periodic domain and derive rigorous, a-priori error bounds … more
Date: December 10, 2008
Creator: Wilkening, Jon
Partner: UNT Libraries Government Documents Department
open access

The polarized SRF gun experiment.

Description: RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is … more
Date: September 10, 2007
Creator: Kewisch, J.; Ben-Zvi, Ilan; Rao, T.; Burrill, A.; Pate, D.; Grover, R. et al.
Partner: UNT Libraries Government Documents Department
open access

The Formation of Contact and Very Close Binaries

Description: We explore the possibility that all close binaries, i.e. those with periods {approx}< 3 d, including contact (W UMa) binaries, are produced from initially wider binaries (periods of say 10's of days) by the action of a triple companion through the medium of Kozai Cycles with Tidal Friction (KCTF).
Date: August 10, 2007
Creator: Kisseleva-Eggleton, L & Eggleton, P P
Partner: UNT Libraries Government Documents Department
open access

Plasma Suppression of Large Scale Structure Formation in the Universe

Description: We point out that during the reionization epoch of the cosmic history, the plasma collective effect among the ordinary matter would suppress the large scale structure formation. The imperfect Debye shielding at finite temperature would induce a residual long-range electrostatic potential which, working together with the baryon thermal pressure, would counter the gravitational collapse. As a result the effective Jean's length, {tilde {lambda}}{sub J}, is increased by a factor, {tilde {lambda}}{s… more
Date: December 10, 2007
Creator: Chen, Pisin & Lai, Kwang-Chang
Partner: UNT Libraries Government Documents Department
open access

Lactonization and protonation of gluconic acid: a thermodynamicand kinetic study by potentiometry, nmr and esi-ms

Description: In acidic aqueous solutions, gluconate protonation is coupled with lactonization of gluconic acid. With the decrease of pC{sub H}, two lactones ({delta}/{gamma}) are sequentially formed. The {delta}-lactone forms more readily than the {gamma}-lactone. In 0.1 M gluconate solutions, if pC{sub H} is above 2.5, only the {delta}-lactone is generated. When pC{sub H} is decreased below 2.0, the formation of the {gamma}-lactone is observable although the {delta}-lactone predominates. At I = 0.1 M NaClO… more
Date: January 10, 2007
Creator: Zhang, Z.; Gibson, P.; Clark, S.B.; Tian, G.; Zanonato, P. & Rao, L.
Partner: UNT Libraries Government Documents Department
open access

Models of Longitudinal Space-Charge Impedance for the Study of theMicrobunching Instability

Description: A 1D model of space-charge impedance, assuming atransversely uniform beam with circular cross-section, has been proposedand is being extensively used in the modelling of the microbunchinginstability of relevance for the beam delivery systems of x-ray FELs. Inthis paper we investigate the limitation of the model when applied tostudying the effect of shot noise--one of the sources of themicrobunching instability. We make comparison witha fully 3D calculationand identify the upper end of the frequ… more
Date: March 10, 2008
Creator: Venturini, Marco
Partner: UNT Libraries Government Documents Department
open access

Long-term Variations of CO2 Trapped in Different Mechanisms in Deep Saline Formations: A Case Study of the Songliao Basin, China

Description: The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases to the atmosphere. There are numerous sedimentary basins in China, in which a number of suitable CO{sub 2} geologic reservoirs are potentially available. To identify the multi-phase processes, geochemical changes and mineral alteration, and CO{sub 2} trapping mechanisms after CO{sub 2} injection, reactive geochemical transport simulations using a simple… more
Date: June 10, 2008
Creator: Zhang, Wei; Li, Yilian; Xu, Tianfu; Cheng, Huilin; Zheng, Yan & Xiong, Peng
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Branching Fraction, Polarization, and CP Asymmetries in B0->rho0rho0 Decay, and Implications for the CKM Angle alpha

Description: We study B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider located at the Stanford Linear Accelerator Center (SLAC). We measure the branching fraction {Beta} = (0.92 {+-} 0.32 {+-} 0.14) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11} {+-} 0.04, where the first uncertainty is statistical and th… more
Date: September 10, 2008
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
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