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The Development and exploration of an Adlerian family art therapy tool with families of adolescents

Description: This exploratory study drew from research in family art therapy assessment by Kwiatkowska (1978), Landgarten (1987), Kurinsky (1986), and Wilson (1988). The objectives of this study were to develop a theoretically consistent art therapy assessment tool for Adlerians to use in initial family therapy interviews and to evaluate its effectiveness in a field test with families of adolescents.
Date: August 1996
Creator: Clement-Millican, Vicki D. (Vicki Diane)
Partner: UNT Libraries

An analysis of the determinants of recovery of businesses after a natural disaster using a multi-paradigm approach

Description: This study examines the recovery process of businesses in Homestead, Florida after Hurricane Andrew in 1992. The goal of this study was to determine which organizational characteristics were useful in predicting the level of physical damage and the length of time to reopen for affected businesses. The organizational characteristics examined were age, size, pre-disaster gross sales, ownership of the business location, membership in the Chamber of Commerce, and property insurance. Three-hundred and fifty businesses in the area were surveyed.
Date: December 1996
Creator: Flott, Phyllis L.
Partner: UNT Libraries

Characterization of aspartate transcarbamoylase in the archaebacterium Methanococcus jannaschii

Description: The ATCase characterized in this study is from the extreme thermophilinc Archaebacterium, Methanococcus jannaschii. The enzyme was very stable at elevated temperatures and possessed activity from 20ºC to 90ºC. M. jannaschii ATCase retained 75 percent of its activity after incubation at 100ºC for a period of 90 minutes.
Date: December 1996
Creator: Stewart, John E. B. (John Edward Bakos)
Partner: UNT Libraries

Regenerative Amplification of Femtosecond Pulses: Design andConstruction of a sub-100fs, muon J Laser System

Description: Femtosecond lasers are a powerful tool for a wealth of applications in physics, chemistry and biology. In most cases, however, their use is fundamentally restricted to a rather narrow spectral range. This thesis deals with the construction and characterization of a femtosecond light source for spectroscopic applications which overcomes that restriction. It is demonstrated how the output of a continuously pumped Ti:sapphire femtosecond oscillator is amplified to the {mu}J level,while the pulse duration remains below 100 fs. A combination of continuous pumping, acousto-optic switching and Ti:Al{sub 2}O{sub 3} as a gain medium allows amplification at high repetition rates. By focusing the high energy pulses into a sapphire crystal, a broad-band continuum can be generated, extended in wavelengths over several hundred nanometers. To accomplish amplification of three orders of magnitude while maintaining the pulse length, a regenerative multipass amplifier system was built. The thesis describes theoretical design, realization and characterization of the system. Theoretical calculations and preliminary measurements were carried out and allow a critical evaluation of the final performance.
Date: October 1, 1996
Creator: Schumacher, Andreas B.
Partner: UNT Libraries Government Documents Department

Touch of the Goddess

Description: Novella written by a student in the UNT Honors College about a midwife accused of witchcraft in 13th century Ireland.
Date: Spring 1996
Creator: Dziorny, Mary A.
Partner: UNT Honors College

Reemergence

Description: Thesis written by a student in the UNT Honors College discussing the origins of Goddess worship, its traditions, and the reasons why contemporary women join.
Date: Spring 1996
Creator: Harper, Susan Blanche
Partner: UNT Honors College

The North American Indians and the Establishment of European Empires 1519-1676

Description: Thesis written by a student in the UNT Honors College discussing the rise of Spanish, English, and French colonialism in the Americas, the conflicts that arose with the native populations, and alliances between the colonists and various tribes.
Date: March 23, 1996
Creator: Lovette, John
Partner: UNT Honors College

Integration of Biosocial Theory into Criminology

Description: Thesis written by a student in the UNT Honors College discussing criminal behavior from a social and biological point of view, the evolution of criminology, and the definition of crime.
Date: Spring 1996
Creator: Roof, Jason G.
Partner: UNT Honors College

Three dimensional winds: A maximum cross-correlation application to elastic lidar data

Description: Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar (light detection and ranging) data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three-dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain-following winds in the Rio Grande valley.
Date: May 1, 1996
Creator: Buttler, W.T.
Partner: UNT Libraries Government Documents Department

Simulation of a field scale tritium tracer experiment in a fractured, weathered shale using discrete-fracture/matrix-diffusion and equivalent porous medium models

Description: Simulations of a tritium tracer experiment in fractured shale saprolite, conducted at the Oak Ridge National Laboratory, were performed using 1D and 2D equivalent porous medium (EPM) and discrete-fracture/matrix-diffusion (DFMD) models. The models successfully reproduced the general shape of the breakthrough curves in down-gradient monitoring wells which are characterized by rapid first arrival, a slow-moving center of mass, and a persistent ``tail`` of low concentration. In plan view, the plume shows a large degree of transverse spreading with the width almost as great as the length. EPM models were sensitive to dispersivity coefficient values which had to be large (relative to the 3.7m distance between the injection and monitoring wells) to fit the tail and transverse spreading. For example, to fit the tail a longitudinal dispersivity coefficient, {alpha}{sub L}, of 0.8 meters for the 2D simulations was used. To fit the transverse spreading, a transverse dispersivity coefficient, {alpha}{sub T}, of 0.8 to 0.08 meters was used indicating an {alpha}{sub L}/{alpha}{sub T} ratio between 10 and 1. Transverse spreading trends were also simulated using a 2D DFMD model using a few larger aperture fractures superimposed onto an EPM. Of the fracture networks studied, only those with truncated fractures caused transverse spreading. Simulated tritium levels in all of the cases were larger than observed values by a factor of approximately 100. Although this is partly due to input of too much tritium mass by the models it appears that dilution in the wells, which were not purged prior to sampling, is also a significant factor. The 1D and 2D EPM models were fitted to monitoring data from the first five years of the experiment and then used to predict future tritium concentrations.
Date: May 1, 1996
Creator: Stafford, P.L.
Partner: UNT Libraries Government Documents Department

New methods and materials for solid phase extraction and high performance liquid chromatography

Description: This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.
Date: April 23, 1996
Creator: Dumont, P.J.
Partner: UNT Libraries Government Documents Department

Characterization and refinement of carbide coating formation rates and dissolution kinetics in the Ta-C system

Description: The interaction between carbide coating formation rates and dissolution kinetics in the tantalum-carbon system was investigated. The research was driven by the need to characterize carbide coating formation rates. The characterization of the carbide coating formation rates was required to engineer an optimum processing scheme for the fabrication of the ultracorrosion-resistant composite, carbon-saturated tantalum. A packed-bed carburization process was successfully engineered and employed. The packed-bed carburization process produced consistent, predictable, and repeatable carbide coatings. A digital imaging analysis measurement process for accurate and consistent measurement of carbide coating thicknesses was developed. A process for removing the chemically stable and extremely hard tantalum-carbide coatings was also developed in this work.
Date: October 1, 1996
Creator: Rodriguez, P.J.
Partner: UNT Libraries Government Documents Department

NMR studies of DNA oligomers and their interactions with minor groove binding ligands

Description: The cationic peptide ligands distamycin and netropsin bind noncovalently to the minor groove of DNA. The binding site, orientation, stoichiometry, and qualitative affinity of distamycin binding to several short DNA oligomers were investigated by NMR spectroscopy. The oligomers studied contain A,T-rich or I,C-rich binding sites, where I = 2-desaminodeoxyguanosine. I{center_dot}C base pairs are functional analogs of A{center_dot}T base pairs in the minor groove. The different behaviors exhibited by distamycin and netropsin binding to various DNA sequences suggested that these ligands are sensitive probes of DNA structure. For sites of five or more base pairs, distamycin can form 1:1 or 2:1 ligand:DNA complexes. Cooperativity in distamycin binding is low in sites such as AAAAA which has narrow minor grooves, and is higher in sites with wider minor grooves such as ATATAT. The distamycin binding and base pair opening lifetimes of I,C-containing DNA oligomers suggest that the I,C minor groove is structurally different from the A,T minor groove. Molecules which direct chemistry to a specific DNA sequence could be used as antiviral compounds, diagnostic probes, or molecular biology tools. The author studied two ligands in which reactive groups were tethered to a distamycin to increase the sequence specificity of the reactive agent.
Date: May 1, 1996
Creator: Fagan, P.A.
Partner: UNT Libraries Government Documents Department

The photosynthetic acclimation of Lolium perenne in response to three years growth in a free-air CO{sub 2} enrichment (FACE) system

Description: Pure stands of Ryegrass were in their third year of growth in the field, exposed to either ambient (355 {mu}mol mol{sup -1}), or elevated (600 {mu}mol mol{sup -1}) atmospheric CO{sub 2} concentration. A Free-Air CO{sub 2} Enrichment (FACE) system was used to maintain the elevated CO{sub 2} concentration whilst limiting experimental constraints on the field conditions. The theoretically predicted increase in the net rates of CO{sub 2} uptake per unit leaf area (A {mu}mol mol{sup -1}) as a consequence, primarily, of the suppression of photorespiration by CO{sub 2} a competitive inhibitor of RubP oxygenation by Rubisco, was observed for the Lolium perenne studied. Also observed was a general decline in leaf evapotranspiration (E) consistent with observations of increased water use efficiency of crops grown in elevated CO{sub 2}. Enhancement of leaf A in the FACE grown L. perenne ranged from 26.5 1 % to 44.95% over the course of a diurnal set of measurements. Whilst reductions in leaf E reached a maximum of 16.61% over the same diurnal course of-measurements. The increase in A was reconciled with an absence of the commonly observed decline in V{sub c}{sub max} as a measure of the maximum in vivo carboxylation capacity of the primary carboxylasing enzyme Rubisco and J{sub max} a measure of the maximum rate of electron transport. The manipulation of the source sink balance of the crop, stage of canopy regrowth or height in the canopy had no effect on the observation of a lack of response. The findings of this study will be interpreted with respect to the long term implications of C{sub 3} crops being able to adapt physiologically to maximize the potential benefits conferred by growth in elevated CO{sub 2}.
Date: August 1, 1996
Creator: Hymus, G.J.
Partner: UNT Libraries Government Documents Department

Multifragmentation in intermediate energy {sup 129}Xe-induced heavy-ion reactions

Description: The {sup 129}Xe-induced reactions on {sup nat}Cu, {sup 89}Y, {sup 165}Ho, and {sup 197}Au at bombarding energies of E/A = 40 & 60 MeV have been studied theoretically and experimentally in order to establish the underlying mechanism of multifragmentation at intermediate energy heavy-Ion collisions. Nuclear disks formed in central heavy-ion collisions, as simulated by means of Boltzmann-like kinetic equations, break up into several fragments due to a new kind of Rayleigh-like surface instability. A sheet of liquid, stable in the limit of non-interacting surfaces, is shown to become unstable due to surface-surface interactions. The onset of this instability is determined analytically. A thin bubble behaves like a sheet and is susceptible to the surface instability through the crispation mode. The Coulomb effects associated with the depletion of charges in the central cavity of nuclear bubbles are investigated. The onset of Coulomb instability is demonstrated for perturbations of the radial mode. Experimental intermediate-mass-fragment multiplicity distributions for the {sup 129}Xe-induced reactions are shown to be binomial at each transverse energy. From these distributions, independent of the specific target, an elementary binary decay probability p can be extracted that has a thermal dependence. Thus it is inferred that multifragmentation is reducible to a combination of nearly independent emission processes. If sequential decay is assumed, the increase of p with transverse energy implies a contraction of the emission time scale. The sensitivity of p to the lower Z threshold in the definition of intermediate-mass-fragments points to a physical Poisson simulations of the particle multiplicities show that the weak auto-correlation between the fragment multiplicity and the transverse energy does not distort a Poisson distribution into a binomial distribution. The effect of device efficiency on the experimental results has also been studied.
Date: May 1, 1996
Creator: Tso, Kin
Partner: UNT Libraries Government Documents Department

Interactive graphical tools for three-dimensional mesh redistribution

Description: Three-dimensional meshes modeling nonlinear problems such as sheet metal forming, metal forging, heat transfer during welding, the propagation of microwaves through gases, and automobile crashes require highly refined meshes in local areas to accurately represent areas of high curvature, stress, and strain. These locally refined areas develop late in the simulation and/or move during the course of the simulation, thus making it difficult to predict their exact location. This thesis is a systematic study of new tools scientists can use with redistribution algorithms to enhance the solution results and reduce the time to build, solve, and analyze nonlinear finite element problems. Participatory design techniques including Contextual Inquiry and Design were used to study and analyze the process of solving such problems. This study and analysis led to the in-depth understanding of the types of interactions performed by FEM scientists. Based on this understanding, a prototype tool was designed to support these interactions. Scientists participated in evaluating the design as well as the implementation of the prototype tool. The study, analysis, prototype tool design, and the results of the evaluation of the prototype tool are described in this thesis.
Date: March 1, 1996
Creator: Dobbs, L.A.
Partner: UNT Libraries Government Documents Department

RHEED studies of Ag/Si(111) growth at low temperatures

Description: This thesis showed that it is possible to achieve well ordered growth at low temperatures when chaing fluxes during the course of the deposition. It was also demonstrated that nucleation theory fails to predict or explain at least part of the results, in particular when deposition takes place at an initially low rate, with presumably a relatively low nucleation density, followed by a change to a high flux rate. This points to an inherent lack of nucleation theory; alternative explanations are presented based on flux-independent growth as reported by Roos (Surf. Sci. 302 (1994) 37).
Date: January 2, 1996
Creator: Koehler, U.
Partner: UNT Libraries Government Documents Department

Development of a high-resolution soft x-ray (30--1500 eV) beamline at the Advanced Light Source and its use for the study of angle-resolved photoemission extended fine structure

Description: ALS Bending magnet beamline 9.3.2 is for high resolution spectroscopy, with circularly polarized light. Fixed included-angle SGM uses three gratings for 30--1500 eV photons; circular polarization is produced by an aperture for selecting the beam above or below the horizontal plane. Photocurrent from upper and lower jaws of entrance slit sets a piezoelectric drive feedback loop on the vertically deflecting mirror for stable beam. End station has a movable platform. With photomeission data from Stanford, structure of c(2{times}2)P/Fe(100) was determined using angle-resolved photoemission extended fine structure (ARPEFS). Multiple-scattering spherical-wave (MSSW) calculations indicate that P atoms adsorb in fourfold hollow sites 1.02A above the first Fe layer. Self-consistent-field X{alpha} scattered wave calculation confirm that the Fe{sub 1}-Fe{sub 2} space is contracted for S/Fe but not for P/Fe; comparison is made to atomic N and O on Fe(100). Final-state effects on ARPEFS curves used literature data from the S 1s and 2p core levels of c(2{times}2)S/Ni(001); a generalized Ramsauer-Townsend splitting is present in the 1s but not 2p data. An approximate method for analyzing ARPEFS data from a non-s initial state using only the higher-{ell} partial wave was tested successfully. ARPEFS data from clean surfaces were collected normal to Ni(111) (3p core levels) and 5{degree} off-normal from Cu(111)(3s, 3p). Fourier transforms (FT) resemble adsorbate systems, showing backscattering signals from atoms up to 4 layers below emitters. 3p FTs show scattering from 6 nearest neighbors in the same crystal layer as the emitters. MSSW calulation indicate that Cu 3p photoemission is mostly d-wave. FTs also indicate double-scattering and single-scattering from laterally distant atoms; calculations indicate that the signal is dominated by photoemission from the first 2 crystal layers.
Date: February 1, 1996
Creator: Huff, W. R. A.
Partner: UNT Libraries Government Documents Department

Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

Description: An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.
Date: May 1, 1996
Creator: Robinson, A.L.
Partner: UNT Libraries Government Documents Department

Polarization dependence of two-photon transition intensities in rare-earth doped crystals

Description: A polarization dependence technique has been developed as a tool to investigate phonon scattering (PS), electronic Raman scattering (ERS), and two-photon absorption (TPA) transition intensities in vanadate and phosphate crystals. A general theory for the polarization dependence (PD) of two-photon transition intensities has been given. Expressions for the polarization dependent behavior of two-photon transition intensities have been tabulated for the 32 crystallographic point groups. When the wavefunctions for the initial and final states of a rare-earth doped in crystals are known, explicit PD expressions with no unknown parameters can be obtained. A spectroscopic method for measuring and interpreting phonon and ERS intensities has been developed to study PrVO{sub 4}, NdVO{sub 4}, ErVO{sub 4}, and TmVO{sub 4} crystals. Relative phonon intensities with the polarization of the incident and scattered light arbitrarily varied were accurately predicted and subsequently used for alignment and calibration in ERS measurements in these systems for the first time. Since ERS and PS intensities generally follow different polarization curves as a function of polar angles, the two can be uniquely identified by comparing their respective polarization behavior. The most crucial application of the technique in ERS spectroscopy is the establishment of a stringent test for the Axe theory. For the first time, the F{sub 1}/F{sub 2} ratio extracted from the experimental fits of the ERS intensities were compared with those predicted by theories which include both the second- and third-order contributions. Relatively good agreement between the fitted values of F{sub 1}/F{sub 2} and the predicted values using the second-order theory has been found.
Date: May 1, 1996
Creator: Le Nguyen, An-Dien
Partner: UNT Libraries Government Documents Department