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Diffusion of Slow Electrons in Gases

Description: The properties of electrons in a gas and an external electric field, e.g., agitation velocity, free path, energy lost per collision, and collision cross sections, were determined for electrons of energy less than 2 ev in a large number of gases. The computations were made from previously measured values for Townsend's energy factor or the ratio of electron agitation energy to molecule thermal energy. Results are presented for hydrogen, nitrogen, carbon dioxide, methane, ethylene, cyclopropane, … more
Date: October 24, 1961
Creator: Forester, D. W. & Cochran, L. W.
Partner: UNT Libraries Government Documents Department
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Low Temperature Thermoluminescence of Gamma Irradiated Potassium Dihydrogen Phosphate

Description: Thermoluminescence in potassium dihydrogen phosphate (KDP) induced by Co/ sup 60/ gamma irradiation at liquid nitrogen temperature (-198 deg C) was investigated. Glow curves in the temperature range --196 to 0 deg C were measured for a series of gamma exposure dosages ranging from 10/sup 4/ roentgen to 5 x 10/sup 6/ roentgen. The heating rate used for glow curve measurements was 12 deg C per minute. Twice recrystallized Mallinckrodt reagent grade potassium dihydrogen phosphate, with a grain siz… more
Date: October 19, 1962
Creator: Sims, T. M.
Partner: UNT Libraries Government Documents Department
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Low temperature heat capacity of lutetium and lutetium hydrogen alloys

Description: The heat capacity of high purity electrotransport refined lutetium was measured between 1 and 20/sup 0/K. Results for theta/sub D/ were in excellent agreement with theta values determined from elastic constant measurements. The heat capacity of a series of lutetium-hydrogen solid solution alloys was determined and results showed an increase in ..gamma.. from 8.2 to about 11.3 mJ/g-atom-K/sup 2/ for hydrogen content increasing from zero to about one atomic percent. Above one percent hydrogen ..g… more
Date: October 1, 1977
Creator: Thome, D. K.
Partner: UNT Libraries Government Documents Department
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Polariton effects in naphthalene crystals

Description: The experimental verification of the two-step nature of energy dissipation of photon energy by a crystal is the subject of this dissertation. The ..cap alpha..(O,O) Davydov component of the lowest energy singlet transition in pure strain-free napthalene single crystals is shown to exhibit an increase in absorption with increasing temperature, due to an increase in polariton damping via polariton-phonon scattering processes. (GHT)
Date: October 1, 1977
Creator: Robinette, S. L.
Partner: UNT Libraries Government Documents Department
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Synthesis and characterization of an N-(2-hydroxyethyl)-ethylenediaminetriacetic acid resin

Description: A chelating ion-exchange resin with N-(2-hydroxyethyl)ethylene-diaminetriacetic acid (HEDTA) used as the ligand chemically bonded to XAD-4 by an ester linkage, HEDTA-4, was synthesized. It is stable under normal experimental conditions with the liquid chromatograph. The structure of the resin was confirmed by an infrared spectrum, and by potentiometric titrations. The capacity of the resin was also obtained by potentiometric titration and by a nitrogen analysis. The resin was used to pack a col… more
Date: October 1, 1977
Creator: Lai, Y. F.
Partner: UNT Libraries Government Documents Department
open access

Stress induced reorientation of vanadium hydride

Description: The critical stress for the reorientation of vanadium hydride was determined for the temperature range 180/sup 0/ to 280/sup 0/K using flat tensile samples containing 50 to 500 ppM hydrogen by weight. The critical stress was observed to vary from a half to a third of the macroscopic yield stress of pure vanadium over the temperature range. The vanadium hydride could not be stress induced to precipitate above its stress-free precipitation temperature by uniaxial tensile stresses or triaxial tens… more
Date: October 1, 1977
Creator: Beardsley, M. B.
Partner: UNT Libraries Government Documents Department
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Electromigration of hydrogen and deuterium in vanadium, niobium, and tantalum

Description: The electric mobility and effective valence of hydrogen and deuterium in vanadium, niobium, tantalum and three niobium-tantalum alloys were measured. A resistance technique was used to directly determine the electric mobility of hydrogen and deuterium at 30/sup 0/C while a steady-state method was used to measure the effective valence. The use of mass spectrographic techniques on a single specimen which contained both hydrogen and deuterium greatly increased the precision with which the isotope … more
Date: October 1, 1977
Creator: Jensen, C. L.
Partner: UNT Libraries Government Documents Department
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Heated uranium tetrafluoride target system to release non-rare gas fission products for the TRISTAN isotope separator. [As replacement for uranyl stearate]

Description: Off-line experiments indicated that fluorides of As, Se, Br, Kr, Zr, Nb, Mo, Tc, Ru, Sb, Te, I and Xe could be volatilized, but except for Br, Kr, I and Xe, none of these elements were observed after mass separation in the on-line experiments. The results of the on-line experiments indicated a very low level of hydride contamination at ambient temperature and consequently, uranium tetrafluoride replaced uranyl stearate as the primary gaseous fission product target. Possible reasons for the fail… more
Date: October 1, 1977
Creator: Gill, R. L.
Partner: UNT Libraries Government Documents Department
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Disclosure and its Perceived Impact as Mediators of the Long-Term Consequences of Child Sexual Abuse

Description: The primary purpose of the present study was to investigate factors associated with childhood sexual abuse which mediate long-term effects. Of particular interest were the mediators of disclosure and its perceived impact, as well as variables related to the severity of the abuse. Also of interest were impact areas related to a history of molestation which have received little attention in the literature. Five hundred and seventy-five female undergraduates completed an extensive questionnaire wi… more
Date: October 1992
Creator: Phelan-McAuliffe, Debra
Partner: UNT Libraries
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Thermodynamics of solid and liquid group III-V alloys

Description: Solid-state electrochemical techniques are applied to the Ga-In-Sb-O system to measure some thermodynamic properties important for the analysis of solid-liquid phase equilibria in these important semiconductor materials. The standard Gibbs energies of formation of the most stable oxides of gallium and of indium are determined with a high-temperature solid-state electrochemical cell utilizing calcia-stabilized zirconia as the solid electrolyte and a (CO + CO/sub 2/) gaseous mixture as the refere… more
Date: October 1, 1978
Creator: Anderson, T. J.
Partner: UNT Libraries Government Documents Department
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Evaluation of self-interaction parameters from binary phase diagrams

Description: The feasibility of calculating Wagner self-interaction parameters from binary phase diagrams was examined. The self-interaction parameters of 22 non-ferrous liquid solutions were calculated utilizing an equation based on the equality of the chemical potentials of a component in two equilibrium phases. Utilization of the equation requires the evaluation of the first and second derivatives of various liquidus and solidus data at infinite dilution of the solute component. Several numerical methods… more
Date: October 1, 1977
Creator: Ellison, T. L.
Partner: UNT Libraries Government Documents Department
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Mass-spectrometric determination of trace elements in aqueous media without preconcentration

Description: Feasibility of using a low pressure glow discharge as an ion source for the mass spectrometric determination of trace elements in aqueous media was investigated. A cryogenically cooled hollow cathode ion source was developed to analyze aqueous samples without external preconcentration. Aqueous solutions containing seventy elements were analyzed and the detection limits, sensitivity factors, and linear regression correlation coefficients were determined. A standard test solution of trace element… more
Date: October 1, 1981
Creator: Foss, G. O.
Partner: UNT Libraries Government Documents Department
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Pre-Raphaelites: The First Decadents

Description: The ephemeral life of the Pre-Raphaelite Brotherhood belies the importance of an organization that grows from and transcends its originally limited aesthetic principles and circumscribed credo. The founding of the Pre-Raphaelite Brotherhood in 1848 really marks the beginning of a movement that metamorphizes into Aestheticism/Decadence. It is the purpose of this dissertation to demonstrate that, from its inception, Pre-Raphaelitism is the first English manifestation of Aestheticism/Decadence. Al… more
Date: October 1980
Creator: Benson, Paul F.
Partner: UNT Libraries
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A search for z boson pair production at the Fermilab Tevatron Collider

Description: This dissertation describes a search for Z/{gamma}* boson pair production decaying into {mu}{mu}{mu}{mu}, {mu}{mu}ee, and eeee final states with approximately 1 fb{sup -1} of data at the Fermilab Tevatron Collider at {radical}s = 1.96 TeV. The small cross section times branching ratio for each channel mandated a thorough study of the acceptance and efficiencies. After optimization, 1.7 {+-} 0.1 events are expected for Standard Model production with a background of 0.13 {+-} 0.03 events. One eve… more
Date: October 1, 2007
Creator: Jarvis, Chad Ryan
Partner: UNT Libraries Government Documents Department
open access

Search for stop pairs in the emu channel

Description: The Standard Model gives a satisfying description of subatomic processes at low energy (< 1 TeV). Beyond this energy scale, other models must be considered. Supersymmetry is one of them. It gives in an elegant way, solutions to several Standard Model short comings. This document reports the search for a supersymmetric signal characterized by the production of two stops decaying into two b-jets, one electron, one muon and missing energy. This study has been performed at the D0 experiment, loc… more
Date: October 1, 2007
Creator: Tissandier, Fabrice & U., /Clermont-Ferrand
Partner: UNT Libraries Government Documents Department
open access

Development and Integration of Hardware and Software for Active-Sensors in Structural Monitoring

Description: Structural Health Monitoring (SHM) promises to deliver great benefits to many industries. Primarily among them is a potential for large cost savings in maintenance of complex structures such as aircraft and civil infrastructure. However, several large obstacles remain before widespread use on structures can be accomplished. The development of three components would address many of these obstacles: a robust sensor validation procedure, a low-cost active-sensing hardware and an integrated softwar… more
Date: October 15, 2007
Creator: Overly, Timothy G.S.
Partner: UNT Libraries Government Documents Department
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Search for High-Mass Resonances Decaying into Leptons of Different Flavor (e mu, e tau, mu tau) in p anti-p Collisions at sqrt(s) = 1.96 TeV

Description: We present a search for high-mass resonances decaying into two leptons of different flavor: e{mu}, e{tau}, and {mu}{tau}. These resonances are predicted by several models beyond the standard model, such as the R-parity-violating MSSM. The search is based on 1 fb{sup -1} of data collected at the Collider Detector at Fermilab (CDF II) in proton anti-proton collisions. Our observations are consistent with the standard model expectations. The results are interpreted to set 95% C.L. upper limits on … more
Date: October 1, 2008
Creator: Tu, Yanjun
Partner: UNT Libraries Government Documents Department
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Measurement of the top-antitop quark pair differential cross section with respect to the invariant mass of the pair in proton-antiproton collisions at a center of mass energy of 1.96 TeV

Description: I present a measurement of the t{bar t} differential cross section, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using 2.7 fb{sup -1} of CDF II data. I find that d{sigma}/dM{sub t{bar t}} is consistent with the Standard Model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions. I set limits on the ratio {kappa}/M{sub Pl} in the Randall-Sundrum model by looking for Kaluza Klein gravitons which decay to top quarks. I find {kappa}/M{sub Pl} &gt… more
Date: October 1, 2008
Creator: Bridgeman, Alice
Partner: UNT Libraries Government Documents Department
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Galaxy Evolution Insights from Spectral Modeling of Large Data Sets from the Sloan Digital Sky Survey

Description: This thesis centers on the use of spectral modeling techniques on data from the Sloan Digital Sky Survey (SDSS) to gain new insights into current questions in galaxy evolution. The SDSS provides a large, uniform, high quality data set which can be exploited in a number of ways. One avenue pursued here is to use the large sample size to measure precisely the mean properties of galaxies of increasingly narrow parameter ranges. The other route taken is to look for rare objects which open up for ex… more
Date: October 1, 2007
Creator: Hoversten, Erik A.
Partner: UNT Libraries Government Documents Department
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Producao d Dijatos por Dupla Troca de Pomeron Exclusiva no Experimento D0

Description: The first search for exclusive diffractive dijet production with invariant mass {approx}> 100 GeV in Run II of the Fermilab Tevatron Collider is performed. The set of data used is the Run IIa, corresponding to an integrated luminosity of 30 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV taken with the D0 detector. At 95% CL, an upper limit for the ratio between the number of diffractive exclusive events and the number of non diffractive events is set to be 7.5 x 10{sup -6}, exclu… more
Date: October 1, 2008
Creator: Rangel, Murilo, Santana & /Rio de Janeiro, CBPF
Partner: UNT Libraries Government Documents Department
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