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Quaternary liquid/liquid equilibria of sodium sulfate, sodium sulfite and water with two solvents: Acetone and 2-propanol

Description: Aqueous solutions of sodium sulfate and sodium sulfite are produced from sodium carbonate in flue-gas scrubbers; recovery of these salts often requires multi-effect evaporators; however, a new energy-efficient unit operation called extractive crystallization has been shown to have reduced energy costs. In this process, an organic solvent is added to the aqueous salt solution to precipitate salt. Acetone is a suitable solvent for this process, better than 2-propanol. Liquid/liquid/solid equilibr… more
Date: March 1, 1994
Creator: Schiozer, A. L.
Partner: UNT Libraries Government Documents Department
open access

Chemisorption and catalytic reactivity of cobalt and sulfur monolayers on ordered molybdenum surfaces

Description: Complex Co/Mo sulfide catalysts are modelled by the chemisorption of layers on Mo single crystal surfaces. Growth and structure of overlayers on flat, stepped and kinked surfaces were investigated. Growth of Co overlayers on clean and S covered Mo surfaces was studied using AES and CO chemisorption; results reveal that Co grows as a flat monolayer on clean Mo surfaces. Co multilayers then form 3-D islands. When Co is deposited on S covered surfaces, the S overlayer migrates to the top; this top… more
Date: March 1, 1992
Creator: Knight, C. C.
Partner: UNT Libraries Government Documents Department
open access

Signal and noise analysis of a-Si:H radiation detector-amplifier system

Description: Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection … more
Date: March 1, 1992
Creator: Cho, Gyuseong
Partner: UNT Libraries Government Documents Department
open access

Energy development and CO{sub 2} emissions in China

Description: The objective of this research is to provide a better understanding of future Chinese energy development and CO{sub 2} emissions from burning fossil fuels. This study examines the current Chinese energy system, estimates CO{sub 2} emissions from burning fossil fuels and projects future energy use and resulting CO{sub 2} emissions up to the year of 2050. Based on the results of the study, development strategies are proposed and policy implications are explored. This study first develops a Base s… more
Date: March 1, 1993
Creator: Xiaolin Xi
Partner: UNT Libraries Government Documents Department
open access

Design and Implementation of a Text Editor Under Music Interactive Operating System

Description: An interactive text editor is a computer program that allows a user to create and revise a target document such as program statements, manuscript text, and numeric data through an online terminal and the computer. It allows text to be modified and corrected many orders of magnitude faster and more easily than would manual correction. The most important characteristic of the text editor is its convenience for the user. Such convenience requires a simple, mnemonic command language which is easy t… more
Date: March 1984
Creator: Hwa, Shu-Jen
Partner: UNT Libraries
open access

Development of a Text Formatted Under VAX/VMS Operating System

Description: No matter how extended the use of the computer is, the printed document is still the primary medium for the presentation information, and will continue to be for some time. The use of computing facilities for preparation and production of the document is becoming as prevalent as their use for numeric computation. Commercially, document preparation systems are now a standard facility at research institution, and they have become quite common on each computer program. A conventional document prep… more
Date: March 1984
Creator: Chow, Perng
Partner: UNT Libraries
open access

Design and test of a low jitter metal to metal contact solid dielectric switch

Description: A low jitter metal to metal contact solid dielectric switch was designed and tested. A metal to metal contact solid dielectric switch with a jitter of less than 25 ns is required for the 150 kJ experiment. Since this is one fourth the 100 ns jitter reported using exploding bridge foil (EBF) triggers, experiments to optimize this trigger were performed. A jitter of 25 ns was achieved using the EBF trigger and it was also achieved using a new type of trigger called the magnetic push trigger. This… more
Date: March 1, 1993
Creator: Domning, E. E.
Partner: UNT Libraries Government Documents Department
open access

Implantation of carbon in GaAs

Description: Carbon implanted into GaAs and thermally annealed typically exhibits very low (<3%) electrical activity. It has been demonstrated that the electrical activity of C can be significantly enhanced by co-implantation with Ga. Improved activation may result from either additional damage of the crystal lattice or from stoichiometric changes, forcing the C atoms onto As sites. To determine the relative importance of each of these effects, I have undertaken a systematic study of carbon activation in Ga… more
Date: March 1, 1992
Creator: Moll, A. J.
Partner: UNT Libraries Government Documents Department
open access

Search for first-generation leptoquarks in the jets and missing transverse energy topology in proton-antiproton collisions at center-of-mass energy 1.96 TeV

Description: The authors performed a search for the pair production of first-generation leptoquarks using 191 pb{sup -1} of proton-antiproton collision data recorded by the CDF experiment during Run II of the Tevatron. The leptoquarks are sought via their decay into a neutrino and quark, which yields missing transverse energy and several high-E{sub T} jets. Several control regions were studied to check the background estimation from Standard Model sources, with good agreement observed in data. In the leptoq… more
Date: March 1, 2004
Creator: Tsybychev, Dmitri
Partner: UNT Libraries Government Documents Department
open access

Mass spectrum analysis of K- pi+ from the semileptonic decay D+ --> K- pi+ mu+ nu

Description: The Higgs mechanism preserves the gauge symmetries of the Standard Model while giving masses to the W, Z bosons. Supersymmetry, which protects the Higgs boson mass scale from quantum corrections, predicts at least 5 Higgs bosons, none of which has been directly observed. This thesis presents a search for neutral Higgs bosons, produced in association with bottom quarks. The production rate is greatly enhanced at large values of the Supersymmetric parameter tan {beta}. High-energy p{bar p} collis… more
Date: March 1, 2004
Creator: Massafferri Rodrigues, Andre & /Rio de Janeiro, CBPF
Partner: UNT Libraries Government Documents Department
open access

Studies of Electron Correlation in the Photoionization Process

Description: Electron correlation is a result of the interaction of two or more electrons confined in a region of space, and may conveniently be treated under the formalism of configuration interaction (CI). Photoionization provides a rather direct experimental method for studying configuration interaction. The types of CI involved in the photoionization process can be divided into three categories: initial state configuration interaction (ISCI), final ionic state configuration interaction (FISCI), and cont… more
Date: March 1, 1979
Creator: Rosenberg, Richard Allen
Partner: UNT Libraries Government Documents Department
open access

Search for heavy metastable particles decaying to quark pairs at CDF

Description: We report on the search for heavy metastable particles that decay into quark pairs with a macroscopic lifetime (c{tau} {approx} 1 cm) using data taken with the CDF II detector at Fermilab. We use a data driven background approach, where they build probability density functions to model Standard Model secondary vertices from known processes in order to estimate the background contribution from the Standard Model. No statistically significant excess is observed above the background. Limits on the… more
Date: March 1, 2011
Creator: Kwang, Shawn Andrew
Partner: UNT Libraries Government Documents Department
open access

Search for the Standard Model Higgs Boson in Missing Transverse Energy and $b$-quark Final States Using Proton-Antiproton Collisions at 1.96 TeV

Description: A search for the standard model Higgs boson is performed in 6.4 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the D0 detector during Run II of the Fermilab Tevatron. The final state considered is a pair of jets originating from b quarks and missing transverse energy, as expected from p{bar p} {yields} ZH {yields} {nu}{bar {nu}}b{bar b} production. The search is also sensitive to the WH {yields} {ell}{nu}b{bar b} channel, where the charged lepton is not identified. B… more
Date: March 1, 2011
Creator: Dorland, Tyler M. & /Washington U., Seattle
Partner: UNT Libraries Government Documents Department
open access

Probabilistic Simulation of Subsurface Fluid Flow: A Study Using a Numerical Scheme

Description: There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeolo… more
Date: March 1, 1980
Creator: Buscheck, Timothy Eric
Partner: UNT Libraries Government Documents Department
open access

Nucleation and dynamics of vortices in type-II superconductors

Description: The one- and two-dimensional Ginzburg-Landau equations are numerically integrated in a slab geometry, which is appropriate for comparison to experimental work done on films. When two-dimensional variations become energetically favorable, a vortex is found to nucleate and move to the center of the film with the Gibbs free energy decreasing during the process. An important process by which the energy is lowered during this nucleation procedure is found to be the savings in condensation energy ari… more
Date: March 1, 1977
Creator: Balley, R. E.
Partner: UNT Libraries Government Documents Department
open access

Energy Spread Reduction of Electron Beams Produced via Laser Wake

Description: Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give &gt;1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis descri… more
Date: March 19, 2012
Creator: Pollock, B.
Partner: UNT Libraries Government Documents Department
open access

Electron Transfer at Sensitized Semiconductor Electrodes

Description: Electron transfer from the excited state of sensitizing dyes to the conduction band of semiconductors has been studied through photoelectrochemical techniques. Two systems were analyzed in detail: rhodamine B on ZnO and rose bengal on TiO/sub 2/. Prior to electrochemical experimentation, the adsorption characteristics of these dyes were investigated using ZnO, ZnS, and TiO/sub 2/ single crystals as substrates. Absorbance measurements of the adsorbed dye were taken as a function of the solution … more
Date: March 1977
Creator: Spitler, Mark Thomas
Partner: UNT Libraries Government Documents Department
open access

Investigation of high-precision {Lambda} hypernuclear spectroscopy via the (e,e&#x27;K{sup +}) reaction

Description: The study of {Lambda} hypernuclear structure is very interesting in point of the understanding of the interaction between {Lambda} and nucleon ({Lambda}-N interaction) and its ”strange” structure itself due to the containment of a {Lambda} hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e,e&#x27;K{sup +}) reaction spectroscopy is a powerful tool for the precise investigation of {Lamda} hypernuclear structure. The purpose of the… more
Date: March 31, 2012
Creator: Kawama, Daisuke
Partner: UNT Libraries Government Documents Department
open access

Perfluorodiethoxymethane on nickel and nickel oxide surfaces

Description: The interaction of perfluorodiethoxymethane with a nickel single crystal, Ni(100); a nickel crystal with chemisorbed oxygen, Ni(100)-c(2x2)O; and a nickel crystal with nickel oxide crystallites, NiO(100) is investigated in an ultra high vacuum environment using thermal desorption spectroscopy and high resolution electron energy loss spectroscopy. Nickel, a component of hard disk drives and stainless steel, is used to represent metal surfaces in these {open_quotes}real{close_quotes} systems. Per… more
Date: March 3, 1994
Creator: Jacobson, J.
Partner: UNT Libraries Government Documents Department
open access

Time reversal invariance in polarized neutron decay

Description: An experiment to measure the time reversal invariance violating (T-violating) triple correlation (D) in the decay of free polarized neutrons has been developed. The detector design incorporates a detector geometry that provides a significant improvement in the sensitivity over that used in the most sensitive of previous experiments. A prototype detector was tested in measurements with a cold neutron beam. Data resulting from the tests are presented. A detailed calculation of systematic effects … more
Date: March 1, 1994
Creator: Wasserman, E. G.
Partner: UNT Libraries Government Documents Department
open access

Application of photothermal deflection spectroscopy to electrochemical interfaces

Description: This dissertation discusses the theory and practice of Photothermal Deflection Spectroscopy (PDS, which is also known as probe beam deflection spectroscopy, PBDS, probe deflection technique, and mirage effect spectroscopy) with respect to electrochemical systems. Much of the discussion is also relevant to non-electrochemical systems. PDS can measure the optical absorption spectrum of interfaces and concentration gradients in the electrolyte adjacent to the electrode. These measurements can be m… more
Date: March 1, 1992
Creator: Rudnicki, J. D.; McLarnon, F. R. & Cairns, E. J.
Partner: UNT Libraries Government Documents Department
open access

Syntheses and Studies of Acetylenic Polymers

Description: Based on new diiodo aryl compounds a series of novel soluble polymers, poly(2,5-dialkoxy-1,4-phenyleneethynylene)s (PPE polymers) were synthesized using palladium-catalysis. The molecular weights (MW) range from 8,000 to 40,000. Properties such as absorption, fluorescence, and conductivity were studied. A PPE polymer with butoxy side chain exhibits a weak electrical conductivity ({sigma} = 10{sup {minus}3} S/cm) after doping with AsF{sub 5}. Absorption spectra in THF solution at room temperatur… more
Date: March 3, 1994
Creator: Ding, Yiwei
Partner: UNT Libraries Government Documents Department
open access

An economic analysis of recordable injuries at Martin Marietta Energy Systems, Inc.

Description: The William-Steiger Occupational Safety and Health Act (OSHA) was passed by the Congress and signed by the President of the United States in 1970. This law required all companies with more than 25 employees to maintain information about each recordable injury, which is defined as any occupational illness or any work-related injury requiring more extensive treatment than first aid. However, compliance with OSHA standards did not require employers to keep records regarding the costs of recordable… more
Date: March 1, 1992
Creator: Johnson, E. K.
Partner: UNT Libraries Government Documents Department
open access

Search for doubly Cabibbo suppressed decays of the charged D meson

Description: The doubly Cabibbo suppressed decayed D{sup +} {yields} K{sup +}{pi}{sup {minus}}{pi}{sup +}, D{sup +} {yields} K{sup +}{pi}{sup 0}and D{sup +} {yields} K*{sup +}{pi}{sup 0} are searched for in a 9.56 pb{sup {minus}1} data sample of e{sup +}e{sup {minus}} annihilation events collected near the {psi}(3770) resonance with the Mark 3 detector at the SPEAR storage ring, at the Stanford Linear Accelerator Center. These rare weak decays are naively expected at a rate of tan{sup 4}{theta}{sub c} relat… more
Date: March 1, 1992
Creator: Labs, J. F.
Partner: UNT Libraries Government Documents Department
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