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Slag recycling of irradiated vanadium

Description: An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were ca… more
Date: April 5, 1995
Creator: Gorman, P.K.
Partner: UNT Libraries Government Documents Department
open access

On the numerical treatment of problems in atmospheric chemistry

Description: Atmospheric chemical-radiative-transport (CRT) models are vital in performing research on atmospheric chemical change. Even with the enormous computing capability delivered by massively parallel systems, extended three dimensional CRT simulations are still not computationally feasible. The major obstacle in a CRT model is the nonlinear ODE system describing the chemical kinetics in the model. These ODE systems are usually very stiff and account for anywhere from 75% to 90% of the CPU time requi… more
Date: September 1, 1995
Creator: Aro, C.J.
Partner: UNT Libraries Government Documents Department
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Applications of Flavor Symmetry to the Phenomenology of Elementary Particles

Description: Some applications of flavor symmetry are examined. Approximate flavor symmetries and their consequences in the MSSM (Minimal Supersymmetric Standard Model) are considered, and found to give natural values for the possible B- and L-violating couplings that are empirically acceptable, except for the case of proton decay. The coupling constants of SU(3) are calculated and used to parameterize the decays of the D mesons in broken flavor SU(3). The resulting couplings are used to estimate the long-d… more
Date: May 1, 1995
Creator: Kaeding, T. A.
Partner: UNT Libraries Government Documents Department
open access

Organic transformations catalyzed by methylrhenium trioxide

Description: Methylrhenium trioxide (MTO), CH{sub 3}ReO{sub 3}, was first prepared in 1979. MTO forms stable or unstable adducts with electron-rich ligands, such as amines (quinuclidine, 1,4-diazabicyclo-octane, pyridine, aniline, 2,2{prime}-bipyridine), alkynes, olefins, 1,2-diols, catechols, hydrogen peroxide, water, thiophenols, 1,2-dithiols, triphenylphosphine, 2-aminophenols, 2-aminothiophenols, 8-hydroxyquinoline and halides (Cl-, Br-, I-). After coordination, different further reactions will occur fo… more
Date: November 1, 1995
Creator: Zhu, Z.
Partner: UNT Libraries Government Documents Department
open access

Matrix effects in inductively coupled plasma mass spectrometry

Description: The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the {open_quotes}Fassel{close_quotes} TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, exc… more
Date: July 7, 1995
Creator: Chen, Xiaoshan
Partner: UNT Libraries Government Documents Department
open access

Spectral analysis of the turbulent mixing of two fluids

Description: We describe a spectral approach to the investigation of fluid instability, generalized turbulence, and the interpenetration of fluids across an interface. The Technique also applies to a single fluid with large variations in density. Departures of fluctuating velocity components from the local mean are far subsonic, but the mean Mach number can be large. Validity of the description is demonstrated by comparisons with experiments on turbulent mixing due to the late stages of Rayleigh-Taylor inst… more
Date: September 1995
Creator: Steinkamp, M. J.
Partner: UNT Libraries Government Documents Department
open access

Bis(pentamethylcyclopentadienyl)ytterbium: An investigation of weak interactions in solution using multinuclear NMR spectroscopy

Description: NMR spectroscopy is ideal for studying weak interactions (formation enthalpy {le}20 kcal/mol) in solution. The metallocene bis(pentamethylcyclopentadienyl)ytterbium, Cp*{sub 2}Yb, is ideal for this purpose. cis-P{sub 2}PtH{sub 2}complexes (P = phosphine) were used to produce slow-exchange Cp*{sub 2}YbL adducts for NMR study. Reversible formation of (P{sub 2}PtH){sub 2} complexes from cis-P{sub 2}PtH{sub 2} complexes were also studied, followed by interactions of Cp*{sub 2}Yb with phosphines, R{… more
Date: July 1, 1995
Creator: Schwartz, D.J.
Partner: UNT Libraries Government Documents Department
open access

Nuclear magnetic resonance studies of macroscopic morphology and dynamics

Description: Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utili… more
Date: September 1, 1995
Creator: Barrall, G. A.
Partner: UNT Libraries Government Documents Department
open access

Nonequilibrium flows with smooth particle applied mechanics

Description: Smooth particle methods are relatively new methods for simulating solid and fluid flows through they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image… more
Date: July 1, 1995
Creator: Kum, O.
Partner: UNT Libraries Government Documents Department
open access

The multi-niche crowding genetic algorithm: Analysis and applications

Description: The ability of organisms to evolve and adapt to the environment has provided mother nature with a rich and diverse set of species. Only organisms well adapted to their environment can survive from one generation to the next, transferring on the traits, that made them successful, to their offspring. Competition for resources and the ever changing environment drives some species to extinction and at the same time others evolve to maintain the delicate balance in nature. In this disertation we pre… more
Date: September 1, 1995
Creator: Cedeno, W.
Partner: UNT Libraries Government Documents Department
open access

Study of clusters using negative ion photodetachment spectroscopy

Description: The weak van der Waals interaction between an open-shell halogen atom and a closed-shell atom or molecule has been investigated using zero electron kinetic energy (ZEKE) spectroscopy. This technique is also applied to study the low-lying electronic states in GaAs and GaAs{sup {minus}}. In addition, the spectroscopy and electron detachment dynamics of several small carbon cluster anions are studied using resonant multiphoton detachment spectroscopy.
Date: December 1, 1995
Creator: Zhao, Yuexing
Partner: UNT Libraries Government Documents Department
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Algorithms for biomagnetic source imaging with prior anatomical and physiological information

Description: This dissertation derives a new method for estimating current source amplitudes in the brain and heart from external magnetic field measurements and prior knowledge about the probable source positions and amplitudes. The minimum mean square error estimator for the linear inverse problem with statistical prior information was derived and is called the optimal constrained linear inverse method (OCLIM). OCLIM includes as special cases the Shim-Cho weighted pseudoinverse and Wiener estimators but a… more
Date: December 1995
Creator: Hughett, P. W.
Partner: UNT Libraries Government Documents Department
open access

An implementation of SISAL for distributed-memory architectures

Description: This thesis describes a new implementation of the implicitly parallel functional programming language SISAL, for massively parallel processor supercomputers. The Optimizing SISAL Compiler (OSC), developed at Lawrence Livermore National Laboratory, was originally designed for shared-memory multiprocessor machines and has been adapted to distributed-memory architectures. OSC has been relatively portable between shared-memory architectures, because they are architecturally similar, and OSC generat… more
Date: June 1, 1995
Creator: Beard, P. C.
Partner: UNT Libraries Government Documents Department
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A cross section measurement of charm hyperons {Xi}{sub c}{sup +} and {Xi}{sub c}{sup 0} in 250 GeV p/K/{pi}-nucleon interactions

Description: Fermilab Experiment 769 used a charge-selected, hadron beam of mean energy 250 GeV/c, composed of pions, kaons, and protons, impinging on beryllium, aluminum, copper and tungsten targets. Using a sample of approximately 4000 {Xi}{sub s}{sup {minus}} {yields} {Lambda}{sup 0}{pi}{sup {minus}} decays, measurements of the charm baryon forward cross sections times branching ratio {pi}{sup {+-}}N {yields} {Xi}{sub c}{sup +}X and {pi}{sup {+-}}N {yields} {Xi}{sub c}{sup 0}X are presented. Upper limits… more
Date: May 2, 1995
Creator: Francisco, J. & Vergara, A.
Partner: UNT Libraries Government Documents Department
open access

The Confident Amazon: Warrior-Women in the Collected Works of Christine de Pizan

Description: The purpose of this thesis is to analyze and discuss the relationship between the images and texts concerning Amazons and warrior-women in the collected works of Christine de Pizan. It evaluates Christine's interpretation of the ancient story in light of her career as an author and publisher, and it compares her imagery to other representations of Amazons and warrior-women. This study indicates that Christine reworked the myth in a way that reflects her positive of women and her desire to infl… more
Date: August 1995
Creator: Appel, Nona Faye
Partner: UNT Libraries
open access

The Influence of Flamenco on Selected Works of Picasso

Description: This thesis investigates, analyzes, and discusses Picasso's imagery in the cultural context of the nineteenth-century Spanish tradition of flamenco. Two published photographs featuring the elderly artist with the gypsy guitarist Manitas de Plata initiated the study, and led me to the conclusion that selected works by Picasso were influenced psychologically, thematically, and formally by his youth which was spent in the Andalusian province of Malaga and later in Barcelona. Picasso's early artist… more
Date: August 1995
Creator: Twell, Mary Tudor
Partner: UNT Libraries
open access

Exploring Suicide Through Painting

Description: A continuing goal of my work has been the desire to evoke strong emotive responses in relation to imagery. The content of this body of work deals with suicide, utilizing text with imagery. The content of this body of work deals with suicide, utilizing text with imagery. I have explored in this body of work the aspects of suicide and how it relates to the individual as well as the family.
Date: December 1995
Creator: Thompson, Larry
Partner: UNT Libraries
open access

Low frequency, electrodynamic simulation of kinetic plasmas with the DArwin Direct Implicit Particle-In-Cell (DADIPIC) method

Description: This dissertation describes a new algorithm for simulating low frequency, kinetic phenomena in plasmas. DArwin Direct Implicit Particle-in-Cell (DADIPIC), as its name implies, is a combination of the Darwin and direct implicit methods. One of the difficulties in simulating plasmas lies in the enormous disparity between the fundamental scale lengths of a plasma and the scale lengths of the phenomena of interest. The objective is to create models which can ignore the fundamental constraints witho… more
Date: June 1, 1995
Creator: Gibbons, Matthew Richard
Partner: UNT Libraries Government Documents Department
open access

The Effect of Relationship Support and Parenting Style on Externalizing and Internalizing Behaviors of Children with ADHD

Description: Influences between quality of intimate heterosexual relationships, parenting style, and externalizing and internalizing behavior problems of children with Attention-deficit Hyperactivity Disorder (ADHD) were examined in a sample of intact and single parent families. The perspective on marital quality was expanded to include an examination of intimate adult relationships within single parent households. Associations between the quality of custodial parents' serious dating and/or cohabiting relat… more
Date: August 1995
Creator: Walker, Frances (Frances Ann)
Partner: UNT Libraries
open access

U.S. Battleship Operations in World War I, 1917-1918

Description: This dissertation is an examination of the operations of U.S. battleships in World War I. The study examines tactical cooperation between units of the U.S. Atlantic Fleet and the British Grand Fleet and relations between the two navies; the efficiency of U.S. battleships in terms of both personnel and material; and the strategic ideas of U.S. naval leaders governing the use of capital ships. The manuscript is based primarily on records of the Department of the Navy in the National Archives and … more
Date: October 1995
Creator: Jones, Jerry W., 1964-
Partner: UNT Libraries
open access

Application of seismic tomographic techniques in the investigation of geothermal systems

Description: The utility of microearthquake data for characterizing the Northwest Geysers geothermal field and the Long Valley Caldera (LVC) was investigated. Three-dimensional (3-D) P- and S-wave seismic velocity models were estimated for the Coldwater Creek Steam Field (CCSF) in the Northwest Geysers region. Hypocenters relocated using these 3-D models appear to be associated with the steam producing zone, with a deeper cluster of hypocenters beneath an active injection well. Spatial and temporal patterns… more
Date: May 1, 1995
Creator: Romero, A. E., Jr.
Partner: UNT Libraries Government Documents Department
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