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The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer (open access)

The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

This dissertation presents the highest four-momentum transfer, Q^2,quasielastic (x_Bj = 1) results from Experiment E01-020 which systematically explored the 2He(e,e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q^2 = 0.8, 2.1, and 3.5 GeV^2 and missing momenta, P_miss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, R_LT, and extractoin of the longitudinal-transverse asymmetry, A_LT. This systematic approach will help to understand the reaction mechanism and the deuteron structure down to the short range part of the nucleon-nucleon interaction which is one of the fundamental missions of nuclear physics. By studying the very short distance structure of the deuteron, one may also determine whether or to what extent the description of nuclei in terms of nucleon/meson degrees of freedom must be supplemented by inclusion of explicit quark effects. The unique combination of energy, current, duty factor, and control of systematics for Hall A at Jefferson Lab made Jefferson Lab the only facility in the world where these systematic studies of the deuteron can be undertaken. This is especially true when we want to understand the short range structure of the deuteron where high energies and high luminosity/duty factor are …
Date: December 31, 2006
Creator: Ibrahim, Hassan
System: The UNT Digital Library
Synthesis and Manipulation of Semiconductor Nanocrystals in Microfluidic Reactors (open access)

Synthesis and Manipulation of Semiconductor Nanocrystals in Microfluidic Reactors

Microfluidic reactors are investigated as a mechanism tocontrol the growth of semiconductor nanocrystals and characterize thestructural evolution of colloidal quantum dots. Due to their shortdiffusion lengths, low thermal masses, and predictable fluid dynamics,microfluidic devices can be used to quickly and reproducibly alterreaction conditions such as concentration, temperature, and reactiontime, while allowing for rapid reagent mixing and productcharacterization. These features are particularly useful for colloidalnanocrystal reactions, which scale poorly and are difficult to controland characterize in bulk fluids. To demonstrate the capabilities ofnanoparticle microreactors, a size series of spherical CdSe nanocrystalswas synthesized at high temperature in a continuous-flow, microfabricatedglass reactor. Nanocrystal diameters are reproducibly controlled bysystematically altering reaction parameters such as the temperature,concentration, and reaction time. Microreactors with finer control overtemperature and reagent mixing were designed to synthesize nanoparticlesof different shapes, such as rods, tetrapods, and hollow shells. The twomajor challenges observed with continuous flow reactors are thedeposition of particles on channel walls and the broad distribution ofresidence times that result from laminar flow. To alleviate theseproblems, I designed and fabricated liquid-liquid segmented flowmicroreactors in which the reaction precursors are encapsulated inflowing droplets suspended in an immiscible carrier fluid. The synthesisof CdSe nanocrystals in such microreactors exhibited reduced depositionand residence time …
Date: December 19, 2006
Creator: Chan, Emory Ming-Yue
System: The UNT Digital Library
Nanocrystal Solar Cells (open access)

Nanocrystal Solar Cells

This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.
Date: December 15, 2006
Creator: Gur, Ilan
System: The UNT Digital Library
On the Mechanical Properties and Microstructure of Nitinol forBiomedical Stent Applications (open access)

On the Mechanical Properties and Microstructure of Nitinol forBiomedical Stent Applications

This dissertation was motivated by the alarming number of biomedical device failures reported in the literature, coupled with the growing trend towards the use of Nitinol for endovascular stents. The research is aimed at addressing two of the primary failure modes in Nitinol endovascular stents: fatigue-crack growth and overload fracture. The small dimensions of stents, coupled with their complex geometries and variability among manufacturers, make it virtually impossible to determine generic material constants associated with specific devices. Instead, the research utilizes a hybrid of standard test techniques (fracture mechanics and x-ray micro-diffraction) and custom-designed testing apparatus for the determination of the fracture properties of specimens that are suitable representations of self-expanding Nitinol stents. Specifically, the role of texture (crystallographic alignment of atoms) and the austenite-to-martensite phase transformation on the propagation of cracks in Nitinol was evaluated under simulated body conditions and over a multitude of stresses and strains. The results determined through this research were then used to create conservative safe operating and inspection criteria to be used by the biomedical community for the determination of specific device vulnerability to failure by fracture and/or fatigue.
Date: December 15, 2006
Creator: Robertson, Scott W.
System: The UNT Digital Library
Mechanistic Selection and Growth of Twinned Bicrystalline Primary Si in Near Eutectic Al-Si Alloys (open access)

Mechanistic Selection and Growth of Twinned Bicrystalline Primary Si in Near Eutectic Al-Si Alloys

Morphological evolution and selection of angular primary silicon is investigated in near-eutectic Al-Si alloys. Angular silicon arrays are grown directionally in a Bridgman furnace at velocities in the regime of 10{sup -3} m/sec and with a temperature gradient of 7.5 x 10{sup 3} K/m. Under these conditions, the primary Si phase grows as an array of twinned bicrystalline dendrites, where the twinning gives rise to a characteristic 8-pointed star-shaped primary morphology. While this primary Si remains largely faceted at the growth front, a complex structure of coherent symmetric twin boundaries enables various adjustment mechanisms which operate to optimize the characteristic spacings within the primary array. In the work presented here, this primary silicon growth morphology is examined in detail. In particular, this thesis describes the investigation of: (1) morphological selection of the twinned bicrystalline primary starshape morphology; (2) primary array behavior, including the lateral propagation of the starshape grains and the associated evolution of a strong <100> texture; (3) the detailed structure of the 8-pointed star-shaped primary morphology, including the twin boundary configuration within the central core; (4) the mechanisms of lateral propagation and spacing adjustment during array evolution; and (5) the thermosolutal conditions (i.e. operating state) at the primary …
Date: December 12, 2006
Creator: Jung, Choonho
System: The UNT Digital Library
New Synthetic Methods for Hypericum Natural Products (open access)

New Synthetic Methods for Hypericum Natural Products

Organic chemistry has served as a solid foundation for interdisciplinary research areas, such as molecular biology and medicinal chemistry. An understanding of the biological activities and structural elucidations of natural products can lead to the development of clinically valuable therapeutic options. The advancements of modern synthetic methodologies allow for more elaborate and concise natural product syntheses. The theme of this study centers on the synthesis of natural products with particularly challenging structures and interesting biological activities. The synthetic expertise developed here will be applicable to analog syntheses and to other research problems.
Date: December 12, 2006
Creator: Jeon, Insik
System: The UNT Digital Library
Novel Aryne Chemistry in Organic Synthesis (open access)

Novel Aryne Chemistry in Organic Synthesis

Arynes are among the most intensively studied systems in chemistry. However, many aspects of the chemistry of these reactive intermediates are not well understood yet and their use as reagents in synthetic organic chemistry has been somewhat limited, due to the harsh conditions needed to generate arynes and the often uncontrolled reactivity exhibited by these species. Recently, o-silylaryl triflates, which can generate the corresponding arynes under very mild reaction conditions, have been found very useful in organic synthesis. This thesis describes several novel and useful methodologies by employing arynes, which generate from o-silylaryl triflates, in organic synthesis. An efficient, reliable method for the N-arylation of amines, sulfonamides and carbamates, and the O-arylation of phenols and carboxylic acids is described in Chapter 1. Amines, sulfonamides, phenols, and carboxylic acids are good nucleophiles, which can react with arynes generated from a-silylaryl triflates to afford the corresponding N- and O-arylated products in very high yields. The regioselectivity of unsymmetrical arynes has also been studied. A lot of useful, functional groups can tolerate our reaction conditions. Carbazoles and dibenzofurans are important heteroaromatic compounds, which have a variety of biological activities. A variety of substituted carbazoles and dibenzofwans are readily prepared in good to excellent …
Date: December 12, 2006
Creator: Liu, Zhijian
System: The UNT Digital Library
Oxidations of Organic and Inorganic Substrates by Superoxo-, hydroperoxo-, and oxo-compounds of the transition metals. (open access)

Oxidations of Organic and Inorganic Substrates by Superoxo-, hydroperoxo-, and oxo-compounds of the transition metals.

Chapters 1 and 2 dealt with the chemistry of superoxo-, hydroperoxo-, and oxo- complexes of chromium, rhodium and cobalt. Chapter 3 dealt with the mechanism of oxygen-atom transfer catalyzed by an oxo-complex of rhenium. In Chapter 1, it was shown that hydroperoxometal complexes of cobalt and rhodium react with superoxochromium and chromyl ions, generating reduced chromium species while oxidizing the hydroperoxometal ions to their corresponding superoxometal ions. It was shown that the chromyl and superoxochromium ions are the more powerful oxidants. Evidence supports hydrogen atom transfer from the hydroperoxometal ion to the oxidizing superoxochromium or chromyl ion as the reaction mechanism. There is a significant H/D kinetic isotope effect. Comparisons to the rate constants of other known hydrogen atom transfer reactions show the expected correlation with bond dissociation energies. In Chapter 2, it was found that the superoxometal complexes Cr{sub aq}OO{sup 2+} and Rh(NH{sub 3}){sub 4}(H{sub 2}O)OO{sup 2+} oxidize stable nitroxyl radicals of the TEMPO series with rate constants that correlate with the redox potentials of both the oxidant and reductant. These reactions fit the Marcus equation for electron transfer near the theoretical value. Acid catalysis is important to the reaction, especially the thermodynamically limited cases involving Rh(NH{sub 3}){sub 4}(H{sub …
Date: December 12, 2006
Creator: Vasbinder, Michael John
System: The UNT Digital Library
Phase Transformation in Cast Superaustenitic Stainless Steels (open access)

Phase Transformation in Cast Superaustenitic Stainless Steels

Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.
Date: December 12, 2006
Creator: Phillips, Nathaniel Steven Lee
System: The UNT Digital Library
Single Molecule Screening of Disease DNA Without Amplification (open access)

Single Molecule Screening of Disease DNA Without Amplification

The potential of single molecule detection as an analysis tool in biological and medical fields is well recognized today. This fast evolving technique will provide fundamental sensitivity to pick up individual pathogen molecules, and therefore contribute to a more accurate diagnosis and a better chance for a complete cure. Many studies are being carried out to successfully apply this technique in real screening fields. In this dissertation, several attempts are shown that have been made to test and refine the application of the single molecule technique as a clinical screening method. A basic applicability was tested with a 100% target content sample, using electrophoretic mobility and multiple colors as identification tools. Both electrophoretic and spectral information of individual molecule were collected within a second, while the molecule travels along the flow in a capillary. Insertion of a transmission grating made the recording of the whole spectrum of a dye-stained molecule possible without adding complicated instrumental components. Collecting two kinds of information simultaneously and combining them allowed more thorough identification, up to 98.8% accuracy. Probing mRNA molecules with fluorescently labeled cDNA via hybridization was also carried out. The spectral differences among target, probe, and hybrid were interpreted in terms of dispersion …
Date: December 12, 2006
Creator: Lee, Ji-Young
System: The UNT Digital Library
Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses (open access)

Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses

This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M{sub 2}S + (0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2} was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M{sub 2}S + (0.1Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. …
Date: December 12, 2006
Creator: Yao, Wenlong
System: The UNT Digital Library
Exploration of deeply virtual Compton scattering on the neutron in the Hall A of Jefferson Laboratory (open access)

Exploration of deeply virtual Compton scattering on the neutron in the Hall A of Jefferson Laboratory

Generalized Parton Distributions (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. Deeply Virtual Compton Scattering (DVCS) is the simplest hard exclusive process involving GPDs. In particular, the DVCS on the neutron is mostly sensitive to E, the less constrained GPD, wich allows to access to the quark angular momentum. The first dedicated DVCS experiment on the neutron ran in the Hall A of Jefferson Lab in fall 2004. The high luminosity of the experiment and the resulting background rate recquired specific devices which are decribed in this document. The analysis methods and the experiment results, leading to preliminary constraints on the GPD E, are presented.
Date: December 8, 2006
Creator: Mazouz, Malek
System: The UNT Digital Library
Implementation of the Immersed Boundary Method in the Weather Research and Forecasting model (open access)

Implementation of the Immersed Boundary Method in the Weather Research and Forecasting model

Accurate simulations of atmospheric boundary layer flow are vital for predicting dispersion of contaminant releases, particularly in densely populated urban regions where first responders must react within minutes and the consequences of forecast errors are potentially disastrous. Current mesoscale models do not account for urban effects, and conversely urban scale models do not account for mesoscale weather features or atmospheric physics. The ultimate goal of this research is to develop and implement an immersed boundary method (IBM) along with a surface roughness parameterization into the mesoscale Weather Research and Forecasting (WRF) model. IBM will be used in WRF to represent the complex boundary conditions imposed by urban landscapes, while still including forcing from regional weather patterns and atmospheric physics. This document details preliminary results of this research, including the details of three distinct implementations of the immersed boundary method. Results for the three methods are presented for the case of a rotation influenced neutral atmospheric boundary layer over flat terrain.
Date: December 7, 2006
Creator: Lundquist, K A
System: The UNT Digital Library
Acculturation and Sociocultural Influences as Predictors of Family Relationships and Body Image Dissatisfaction in African American, Hispanic American, and European American Women (open access)

Acculturation and Sociocultural Influences as Predictors of Family Relationships and Body Image Dissatisfaction in African American, Hispanic American, and European American Women

Ethnic differences in etiological factors linked to body image dissatisfaction and eating disorders were examined. In addition, the interaction of acculturation and body image dissatisfaction in influencing minority women's relationships with their parents was investigated. Participants consisted of 302 undergraduates from three ethnic groups: Caucasian, Hispanic American, and African American women who were administered self-report measures. Differences were not found between the groups in body image dissatisfaction. Low self-esteem, internalization of the thin ideal, and family emphasis on weight and appearance were all related to more body image dissatisfaction for each of these groups; however, differences in degree of endorsement were also noted between the ethnic groups on these factors. Based on the interaction findings (body image x acculturation) separation from one's mother was found in the area of attitudes and emotions for the Hispanic sample but not for the African American sample on any of the parent scales. Areas for future research and implications for diagnosis and treatment of minority populations are also discussed.
Date: December 2006
Creator: Garcia-Rea, Elizabeth Ann
System: The UNT Digital Library

Accuracy Variations in Human Facial Identification Based on Time of Exposure.

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This study examined the relationship between time of exposure to the human face and accurate subsequent photo line-up identification. A volunteer group of 124 undergraduate students was divided into three approximately equal sized subgroups. The three groups were then exposed to a video or a portion of a video depicting a theft. Exposure times ranged from two minutes to 30 seconds. The subjects were then given a questionnaire and shown a photo line-up of the mock perpetrator and five foils. Subjects were asked to identify the perpetrator and mark that identification on the questionnaire. Results of the experiment indicated that the longer a subject was exposed the greater the possibility of an accurate identification.
Date: December 2006
Creator: Cowle, Kenneth M.
System: The UNT Digital Library

Adolescent Insomnia as a Predictor of Early Adulthood Outcomes

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Recent research found insomnia is a risk factor for psychiatric disorders in adults. To see if the same would be true in adolescents, the current study re-analyzed data from a national longitudinal study collected by ADDHealth that evaluated health behaviors in 4552 adolescents (mean age 14.9 years [SD 1.7]) at baseline and again 7-8 years later (n = 3489) during young adulthood. Insomnia was reported by 9.2% of the adolescents. Cross-sectionally, adolescent insomnia was associated with alcohol, cannabis, non-cannabis drugs, and tobacco use, and depression after controlling for gender and ethnicity. Prospectively, adolescent insomnia was a significant risk factor for depression diagnosis, suicidal ideation, and the use of depression and stress prescription medications in young adulthood after controlling for gender, ethnicity, and significant baseline variable. In addition, a trend was noted for suicidal attempts.
Date: December 2006
Creator: Roane, Brandy Michelle
System: The UNT Digital Library

The American Doctrine for the Use of Naval Gunfire in Support of Amphibious Landings: Myth vs. Reality in the Central Pacific of World War II.

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The United States Marine Corps and the United States Navy developed during the interwar period a doctrine that addressed the problems inherent in the substitution of naval gunfire for artillery support in an amphibious assault. The invasion of Betio Islet, Tarawa Atoll, in November of 1943 was the first test of this doctrine. It has been said many times since the war that the doctrine basically passed this test and that lessons learned at Tarawa increased the efficiency with which the Marine Corps and Navy applied the prewar doctrine during the rest of the war. An analysis of the planning and execution of naval bombardments in the Central Pacific Campaign, after the invasion of the Gilberts, does not support this claim. This analysis leads the researcher to three conclusions. First, the Japanese developed defenses against many of the effects of the gunfire support doctrine that blunted much of the force of American firepower. American planners were slow to recognize the implications of these changes and, consequently, were slow to react to them. Second, many naval commanders responsible for providing naval gunfire support for Central Pacific operations still equated tonnage of ordnance to effectiveness of bombardment, regardless of their frequent references …
Date: December 2006
Creator: Mitchener, Donald Keith
System: The UNT Digital Library

Animals That Die

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The thesis has two parts. Part I is a critical essay entitled "Lessons Under the Amfalula." Part II is the collection of poems entitled "Animals That Die."
Date: December 2006
Creator: Campbell, Susan Maxwell
System: The UNT Digital Library
An Approach Towards Self-Supervised Classification Using Cyc (open access)

An Approach Towards Self-Supervised Classification Using Cyc

Due to the long duration required to perform manual knowledge entry by human knowledge engineers it is desirable to find methods to automatically acquire knowledge about the world by accessing online information. In this work I examine using the Cyc ontology to guide the creation of Naïve Bayes classifiers to provide knowledge about items described in Wikipedia articles. Given an initial set of Wikipedia articles the system uses the ontology to create positive and negative training sets for the classifiers in each category. The order in which classifiers are generated and used to test articles is also guided by the ontology. The research conducted shows that a system can be created that utilizes statistical text classification methods to extract information from an ad-hoc generated information source like Wikipedia for use in a formal semantic ontology like Cyc. Benefits and limitations of the system are discussed along with future work.
Date: December 2006
Creator: Coursey, Kino High
System: The UNT Digital Library
The Athlete Leader Role: Interaction of Gender, Sport Type, and Coaching Style. (open access)

The Athlete Leader Role: Interaction of Gender, Sport Type, and Coaching Style.

Effective leadership is a concept shown to be important for successful team performance in the fields of business, education, and sport. In sport, the role of the athlete leader has been under-examined and specifically, how coaching behaviors can affect athlete leader behaviors and how various leadership models (e.g., trait, behavioral, situational) relate to the athlete leader role has never been studied. The present study examined how autocratic, democratic, and collaborative coaching styles affect the athlete leader behavior preferences of athletes of different genders and sport types. Three coach scenarios reflecting the three aforementioned coaching styles were created so that athletes could imagine that they were coached by the individual presented in the scenario and then rate what type of athlete leader behaviors that they would prefer given the style of the coach that they read about. Results showed that the coach scenarios failed to have a significant impact; however, significant differences were discovered between men and women and between individual and team sport athletes on variables measuring preferred performance/task, relationship, motivation, and representation behaviors. Data were gathered on the style of athletes' current coach and this variable also produced significant differences for such behaviors as resolving conflict, providing positive reinforcement, …
Date: December 2006
Creator: Wildman, Jonathan C. Jr.
System: The UNT Digital Library
Athletic Trainers and Psychological Disorders Among Athletes: An Examination of Their Abilities to Recognize, Diagnose and Intervene. (open access)

Athletic Trainers and Psychological Disorders Among Athletes: An Examination of Their Abilities to Recognize, Diagnose and Intervene.

Utilizing an analogue research design conducted via the Internet, this study assessed athletic trainers' abilities to recognize, diagnose, and intervene with a hypothetical athlete experiencing depression, and examined the impact of their gender, athlete gender, and athlete's presenting problem on their decisions. Athletic trainers' perceived competency in using psychosocial interventions with athletes, history of referring athletes to psychology professionals, and training backgrounds in psychology also were examined. Participants (270 male and 370 female certified athletic trainers) were randomly assigned to one of six conditions (Athlete Gender X Presenting Problem). After reading the appropriate vignette, they completed questions related to the athlete's psychological symptoms and diagnosis, referral recommendations, and use of psychosocial interventions if working with the athlete. The vignettes were identical except for the athlete's gender and problem. Overall, athletic trainers accurately identified the athlete's depressive symptoms/diagnosis and need for psychological referral. They rated the athlete significantly higher in Depressive Symptoms than in Anger/Agitation Symptoms and Compulsive Behavioral Symptoms, and as more likely to be experiencing a depressive disorder compared to an adjustment disorder, anxiety disorder, sleep disorder, or substance abuse disorder. Female athletic trainers provided significantly higher ratings of Depressive Symptoms than males and the injured athlete was rated …
Date: December 2006
Creator: Albinson, Courtney Brooks
System: The UNT Digital Library
Attachment Processes, Stress Processes, and Sociocultural Standards in the Development of Eating Disturbances in College Women (open access)

Attachment Processes, Stress Processes, and Sociocultural Standards in the Development of Eating Disturbances in College Women

Minimal empirical research using longitudinal data to explore integrative models of eating disorder development exists. The purpose of this study was to further explore multidimensional models incorporating parental attachment, history of stress, appraisal/coping processes, internalization of the thin-ideal, negative affect, body image, and eating disordered behavior using prospective, longitudinal data. The models were evaluated using 238 participants who completed an initial series of self-report questionnaires during their first semester in college and completed follow-up questionnaires 6 months and 18 months later. Structural equation modeling was used to examine the relationships among the factors. Analyses confirmed that college freshman with insecure parental attachment relationships and those with a history of previous stressful experiences appraised the adjustment to college as more stressful and reported feeling less able to cope with the transition; these conditions predicted increased negative affect and increased eating disturbances. Women who reported experiencing negative affect and those that endorsed internalization of the thin-ideal also reported higher levels of body dissatisfaction; these women engaged in more disordered eating attitudes and behaviors. A second model investigating negative affect as mediating the relationship between the appraisal/coping process and eating disturbances also revealed that experiencing difficulties with the transition to college predicted later …
Date: December 2006
Creator: Bradford, Jennifer Wolf
System: The UNT Digital Library
Attachment Styles in a Sample from a Correctional Drug Treatment Facility (open access)

Attachment Styles in a Sample from a Correctional Drug Treatment Facility

Substance abuse and dependence causes many problems in our society. Attachment style may be useful in the etiology of this problem. Using archival data, this study hypothesizes men in a court-ordered facility will be more likely to have an insecure attachment style. The participants were 73 males ages 18-49. The Adult Attachment Scale (AAS) was used to measure adult romantic attachment style. Through cluster analysis and conversion of the subscales of the AAS, four attachment styles were measured. Men were more likely to have an insecure attachment style especially a Fearful style. The study concludes with limitations of the results and a discussion about possible interventions based on attachment style.
Date: December 2006
Creator: Shivpuri, Michelle Yvonne
System: The UNT Digital Library

Bank Loans as a Financial Discipline: A Direct Agency Cost of Equity Perspective

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In a 2004 study, Harvey, Lin and Roper argue that debt makers with a commitment to monitoring can create value for outside shareholders whenever information asymmetry and agency costs are pronounced. I investigate Harvey, Lin and Roper's claim for bank loans by empirically testing the effect of information asymmetry and direct agency costs on the abnormal returns of the borrowers' stock around the announcement of bank loans. I divide my study into two main sections. The first section tests whether three proxies of the direct agency costs of equity are equally significant in measuring the direct costs associated with outside equity agency problems. I find that the asset utilization ratio proxy is the most statistically significant proxy of the direct agency costs of equity using a Chow F-test statistic. The second main section of my dissertation includes and event study and a cross-sectional analysis. The event study results document significant and positive average abnormal returns of 1.01% for the borrowers' stock on the announcement day of bank loans. In the cross sectional analysis of the borrowers' average abnormal stock returns, I find that higher quality and more reputable banks/lenders provide a reliable certification to the capital market about the low …
Date: December 2006
Creator: Hijazi, Bassem
System: The UNT Digital Library