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A RANS/DES Numerical Procedure for Axisymmetric Flows with and without Strong Rotation

Description: A RANS/DES numerical procedure with an extended Lax-Wendroff control-volume scheme and turbulence model is described for the accurate simulation of internal/external axisymmetric flow with and without strong rotation. This new procedure is an extension, from Cartesian to cylindrical coordinates, of (1) a second order accurate multi-grid, control-volume integration scheme, and (2) a k-{omega} turbulence model. This paper outlines both the axisymmetric corrections to the mentioned numerical schem… more
Date: October 30, 2007
Creator: Andrade, A J
Partner: UNT Libraries Government Documents Department
open access

Low Temperature Constrained Sintering of Cerium Gadolinium OxideFilms for Solid Oxide Fuel Cell Applications

Description: Cerium gadolinium oxide (CGO) has been identified as an acceptable solid oxide fuel cell (SOFC) electrolyte at temperatures (500-700 C) where cheap, rigid, stainless steel interconnect substrates can be used. Unfortunately, both the high sintering temperature of pure CGO, >1200 C, and the fact that constraint during sintering often results in cracked, low density ceramic films, have complicated development of metal supported CGO SOFCs. The aim of this work was to find new sintering aids for … more
Date: June 30, 2007
Creator: Nicholas, Jason.D.
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the Top Quark Mass in 1.96 TeV Proton-Antiproton Collisions Using a Novel Matrix Element Method

Description: A measurement of the top quark mass in t{bar t} {yields} l + jets candidate events, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncer… more
Date: September 30, 2007
Creator: CDF Collaboration
Partner: UNT Libraries Government Documents Department
open access

Interactions of Negative K Mesons in Flight in Nuclear Emulsion

Description: The following report discusses a survey of seventy-seven interactions of K- mesons in flight in nuclear emulsion with seven decays in flight, and finding four inelastic scatterings.
Date: April 30, 1957
Creator: Featherston, Frank Hunter
Partner: UNT Libraries Government Documents Department
open access

Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report

Description: Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, ind… more
Date: April 30, 1990
Creator: Chafetz, H. S.
Partner: UNT Libraries Government Documents Department
open access

NIF optics

Description: One of the major highlights of the technology development for the National Ignition Facility (NIF) is the optics. NIF will be the largest laser ever built, requiring 7500 large optics (over one foot across) and more than 30,000 small optics. The design, manufacture, and assembly of these important pieces have called for innovative ways to make optics of higher quality than ever before, and to do so at unprecedented speeds. The most obvious role of NIF optics is to steer the 192 laser beams thro… more
Date: August 30, 2000
Creator: Parham, T
Partner: UNT Libraries Government Documents Department
open access

Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials

Description: Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still… more
Date: November 30, 2011
Creator: Cai, Min
Partner: UNT Libraries Government Documents Department
open access

Search for Resonances in the Photoproduction of Proton-Antiproton Pairs

Description: Results are reported on the reaction {gamma}p {yields} p{bar p}p with beam energy in the range 4.8-5.5 GeV. The data were collected at the Thomas Jefferson National Accelerator Facility in CLAS experiment E01-017(G6C). The focus of this study is an understanding of the mechanisms of photoproduction of proton-antiproton pairs, and to search for intermediate resonances, both narrow and broad, which decay to p{bar p}. The total measured cross section in the photon energy range 4.8-5.5 GeV is {sigm… more
Date: June 30, 2006
Creator: Stokes, Burnham
Partner: UNT Libraries Government Documents Department
open access

Development of high-spatial and high-mass resolution mass spectrometric imaging (MSI) and its application to the study of small metabolites and endogenous molecules of plants

Description: High-spatial and high-mass resolution laser desorption ionization (LDI) mass spectrometric (MS) imaging technology was developed for the attainment of MS images of higher quality containing more information on the relevant cellular and molecular biology in unprecedented depth. The distribution of plant metabolites is asymmetric throughout the cells and tissues, and therefore the increase in the spatial resolution was pursued to reveal the localization of plant metabolites at the cellular level … more
Date: November 30, 2011
Creator: Jun, Ji Hyun
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Neutron electric form factor at Q2=0.8 2(GeV\\c)

Description: Nucleon form factors allow a sensitive test for models of the nucleon. Recent experiments utilising polarisation observables have resulted, for the first time, in a model-independent determination of the neutron electric form factor GnE. This method employed an 80% longitudinally polarised, high intensity (10 uA) electon beam (883 MeV) that was quasi-elastically scattered off a liquid deuterium target in the reaction D (e, en)p. A neutron polarimeter was designed and installed to measure the ra… more
Date: September 30, 2007
Creator: Glazier, Derek
Partner: UNT Libraries Government Documents Department
open access

Studies in ion source development for application in heavy ion fusion

Description: The overall purpose of these experiments is to contribute to the development of ion injector technology in order to produce a driver for use in a heavy-ion-fusion (HIF) power generating facility. The overall beam requirements for HIF are quite demanding; a short list of the constraints is the following: (1) Low cost (a large portion of overall cost will come from the beam system); (2) Bright, low emittance beam; (3) Total beam energy 5MJ; (4) Spot size 3mm (radius); (5) Pulse Duration 10ns; (6)… more
Date: May 30, 2004
Creator: Kapica, Jonathan G.
Partner: UNT Libraries Government Documents Department
open access

Effects of Various Blowout Panel Configurations on the Structural Response of LANL Building 16-340 to Internal Explosions1

Description: The risk of accidental detonation is present whenever any type of high explosives processing activity is performed. These activities are typically carried out indoors to protect processing equipment from the weather and to hide possibly secret processes from view. Often, highly strengthened reinforced concrete buildings are employed to house these activities. These buildings may incorporate several design features, including the use of lightweight frangible blowout panels, to help mitigate blas… more
Date: September 30, 2005
Creator: Wilke, Jason P.
Partner: UNT Libraries Government Documents Department
open access

Hydrogen Storage Properties of Lithium Aluminohydride modified by dopants and mechanochemistry

Description: Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al [1, 2] succeeded in the re-hydrogenation of NaAlH{sub 4} below 70 atm. They achieved 4 wt.% H{sub 2} reversible capacity by doping NaAlH{sub 4} with Ti and/or Fe organo-metalic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversib… more
Date: May 30, 2002
Creator: Hosokawa, Keita
Partner: UNT Libraries Government Documents Department
open access

Physical Properties of Intermetallic FE2VA1

Description: Fe{sub 2}VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe{sub 2}VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy me… more
Date: May 30, 2002
Creator: Feng, Ye
Partner: UNT Libraries Government Documents Department
open access

Ambient and elevated temperature fracture and cyclic-fatigue properties in a series of Al-containing silicon carbides

Description: A series of in situ toughened, Al, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with Al contents varying from 3 to 7 wt%. With increasing Al additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline. Fracture toughness and cyclic fatigue tests on these microstructures revealed that although the 7 w… more
Date: August 30, 2004
Creator: Yuan, Rong
Partner: UNT Libraries Government Documents Department
open access

Photon-counting single-molecule spectroscopy for studying conformational dynamics and macromolecular interactions

Description: Single-molecule methods have the potential to provide information about conformational dynamics and molecular interactions that cannot be obtained by other methods. Removal of ensemble averaging provides several benefits, including the ability to detect heterogeneous populations and the ability to observe asynchronous reactions. Single-molecule diffusion methodologies using fluorescence resonance energy transfer (FRET) are developed to monitor conformational dynamics while minimizing perturbati… more
Date: July 30, 2002
Creator: Laurence, Ted Alfred
Partner: UNT Libraries Government Documents Department
open access

Circular magnetic x-ray dichroism in rare earth compounds

Description: This report discusses the following topics: Circular magnetic x-ray dichroism at the ER L{sub 3} Edge; angular dependence of circular magnetic x-ray dichroism in rare earth compounds: and circular magnetic x-ray dichroism in crystalline and amorphous GDFE{sub 2}.
Date: September 30, 1993
Creator: Jonathan, L.
Partner: UNT Libraries Government Documents Department
open access

Interphase phenomena and the condensation of liquid metal vapors. The condensation mechanism of nitrogen tetroxide vapor

Description: Thesis. Submitted by J. Lorrain. Theoretical analyses of interphase processes involving vapors and liquids are presented. Monoatomic and reacting vapors were considered in situations such as condensation, evaporation and heat transfer between the vapor and its liquid. These developments are believed to be the most accurate to date in describing such processes. The implications of the presence of diatomic and heavier naolecules in liquid metal vapors in their condensation heat transfer are discu… more
Date: April 30, 1974
Creator: Larrain, J. & Bonilla, C.F.
Partner: UNT Libraries Government Documents Department
open access

Specific heat measurements at the spin-reorientation transition in YbFeO$sub 3$

Description: Thesis. The specific heat was measured from 2.55 to 15.7 deg K, first with no external magnetic field, and then with magnetic fields along the c-axis and a-axis of intensity of 1000, 3000, and 5800 Oe. Two specific heat anomalies were observed: a Schottky anomaly caused by the ground state exchange splitting of the Yb/sup 3+/, and spin reorientation of the Fe sublattice. (DLC)
Date: April 30, 1974
Creator: Sjolander, G W
Partner: UNT Libraries Government Documents Department
open access

Probability of detection models for eddy current NDE methods

Description: The development of probability of detection (POD) models for a variety of nondestructive evaluation (NDE) methods is motivated by a desire to quantify the variability introduced during the process of testing. Sources of variability involved in eddy current methods of NDE include those caused by variations in liftoff, material properties, probe canting angle, scan format, surface roughness and measurement noise. This thesis presents a comprehensive POD model for eddy current NDE. Eddy current me… more
Date: April 30, 1993
Creator: Rajesh, S. N.
Partner: UNT Libraries Government Documents Department
open access

Measurement of tau lepton branching fractions

Description: We present {tau}{sup {minus}} lepton branching fraction measurements based on data from the TPC/Two-Gamma detector at PEP. Using a sample of{tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} events, we examine the resonance structure of the K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} system and obtain the first measurements of branching fractions for {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1270) and {tau}{sup {minus}} {yields} {nu}{sub … more
Date: September 30, 1993
Creator: Nicol, N. A.
Partner: UNT Libraries Government Documents Department
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