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Determinacy-related Consequences on Limit Superiors (open access)

Determinacy-related Consequences on Limit Superiors

Laczkovich proved from ZF that, given a countable sequence of Borel sets on a perfect Polish space, if the limit superior along every subsequence was uncountable, then there was a particular subsequence whose intersection actually contained a perfect subset. Komjath later expanded the result to hold for analytic sets. In this paper, by adding AD and sometimes V=L(R) to our assumptions, we will extend the result further. This generalization will include the increasing of the length of the sequence to certain uncountable regular cardinals as well as removing any descriptive requirements on the sets.
Date: May 2013
Creator: Walker, Daniel
System: The UNT Digital Library
Determinants of the Applications to the Institutional Care in Turkey: Darulaceze Example (open access)

Determinants of the Applications to the Institutional Care in Turkey: Darulaceze Example

Although institutional care has started to be outmoded in the developed countries with development of different models of care, it still has a considerable place in the developing countries such as Turkey. This is because, changes in the demographic structure, extended family, and urban development of Turkey has brought about several aging problems leading older adults to end up in institutions. Loneliness was one of the significant reasons given in the Social Inquiry Survey of Applicants of Darulaceze Old-Age Institution and the basis for a micro level analysis in this study. Therefore, the main objective of the study was to determine the predictors of loneliness, including age, the state of living alone, functional independence, education, and gender. Analysis of the results indicated that these predictors have significant effects on the loneliness predominantly defined by social factors rather than medical factors. In addition, the meso and macro level analyses were employed to control the micro level analysis and see a general picture of institutional care. Thus, an academic example of diagnosing the main reasons behind the institutional care was presented to understand the context of aging in Turkey.
Date: May 2013
Creator: Esendemir, Serif
System: The UNT Digital Library
Determination of Molecular Descriptors for Illegal Drugs by Gc-fid Using Abraham Solvation Model (open access)

Determination of Molecular Descriptors for Illegal Drugs by Gc-fid Using Abraham Solvation Model

The Abraham solvation parameter model is a good approach for analyzing and predicting biological activities and partitioning coefficients. The general solvation equation has been used to predict the solute property (SP) behavior of drug compounds between biological barriers. Gas chromatography (GC) retention time can be used to predict molecular descriptors, such as E, S, A, B & L for existing and newly developed drug compounds. In this research, six columns of different stationary phases were used to predict the Abraham molecular descriptors more accurately. The six stationary phases used were 5% phenylmethyl polysiloxane, 6% cyanopropylphenyl 94% dimethylpolysiloxane, 5% diphenyl 95% dimethylpolysiloxane, 100% dimethylpolysiloxane, polyethylene glycol and 35% diphenyl 65% dimethylpolysiloxane. Retention times (RT) of 75 compounds have been measured and logarithm of experimental average retention time Ln(RTexp) are calculated. The Abraham solvation model is then applied to predict the process coefficients of these compounds using the literature values of the molecular descriptors (Acree Compilation descriptors). Six correlation equations are built up as a training set for each of the six columns. The six equations are then used to predict the molecular descriptors of the illegal drugs as a test set. This work shows the ability to extract molecular information from …
Date: December 2013
Creator: Akhter, Syeda Sabrina
System: The UNT Digital Library
Developing a Collection Digitization Workflow for the Elm Fork Natural Heritage Museum (open access)

Developing a Collection Digitization Workflow for the Elm Fork Natural Heritage Museum

Natural history collections house immense amounts of data, but the majority of data is only accessible by locating the collection label, which is usually attached to the physical specimen. This method of data retrieval is time consuming and can be very damaging to fragile specimens. Digitizing the collections is the one way to reduce the time and potential damage related to finding the collection objects. The Elm Fork Natural Heritage Museum is a natural history museum located at the University of North Texas and contains collections of both vertebrate and invertebrate taxa, as well as plants. This project designed a collection digitization workflow for Elm Fork by working through digitizing the Benjamin B. Harris Herbarium. The collection was cataloged in Specify 6, a database program designed for natural history collection management. By working through one of the museum’s collections, the project was able to identify and address challenges related to digitizing the museum’s holdings in order to create robust workflows. The project also produced a series of documents explaining common processes in Specify and a data management plan.
Date: August 2013
Creator: Evans, Colleen R.
System: The UNT Digital Library
Development of a Differential Neurocognitive Profile for Alzheimer’s Dementia and Vascular Dementia (open access)

Development of a Differential Neurocognitive Profile for Alzheimer’s Dementia and Vascular Dementia

Alzheimer’s Dementia (AD) is among the most common diseases in the Geriatric population, and its prevalence is expected to quadruple by 2047.Vascular Dementia (VaD) is the second most frequent cause of dementia, with studies indicating VaD accounts for 10-20% of dementia cases across the globe. A diagnostic model differentiating AD and VaD would be clinically and scientifically valuable, considering the treatment approaches for these conditions are different. Although there are differences between AD and VaD on their neuropsychological profiles, a diagnostic model that successfully differentiates AD and VaD on neuropsychological testing has not been developed, despite previous attempts. Our study addresses this gap in the literature by examining two diagnostic models used to predict the conversion of AD from mild cognitive impairment, and a third model was proposed to differentiate AD from VaD. We conducted ROC Analyses using the variables LM II Standard Score, Animals Total, and CDRS Sum based on a previous diagnostic model. The sensitivity and specificity for the diagnosis of mild VaD were calculated for all possible scores of each test measure. The Animals Total cutoff score of 7 achieved excellent sensitivity and specificity, receiving 96% and 92%, respectively. In this sample, patients who could name at …
Date: August 2013
Creator: Hill, Jonathan
System: The UNT Digital Library
Development of aerogel-lined targets for inertial confinement fusion experiments (open access)

Development of aerogel-lined targets for inertial confinement fusion experiments

None
Date: March 5, 2013
Creator: Braun, Tom
System: The UNT Digital Library
Development of Enabling Technologies to Visualize the Plant Lipidome (open access)

Development of Enabling Technologies to Visualize the Plant Lipidome

Improvements in mass spectrometry (MS)-based strategies for characterizing the plant lipidome through quantitative and qualitative approaches such as shotgun lipidomics have substantially enhanced our understanding of the structural diversity and functional complexity of plant lipids. However, most of these approaches require chemical extractions that result in the loss of the original spatial context and cellular compartmentation for these compounds. To address this current limitation, several technologies were developed to visualize lipids in situ with detailed chemical information. A subcellular visualization approach, direct organelle MS, was developed for directly sampling and analyzing the triacylglycerol contents within purified lipid droplets (LDs) at the level of a single LD. Sampling of single LDs demonstrated seed lipid droplet-to-droplet variability in triacylglycerol (TAG) composition suggesting that there may be substantial variation in the intracellular packaging process for neutral lipids in plant tissues. A cellular and tissue visualization approach, MS imaging, was implemented and enhanced for visualizing the lipid distributions in oilseeds. In mature cotton seed embryos distributions of storage lipids (TAGs) and their phosphatidylcholine (PCs) precursors were distribution heterogeneous between the cotyledons and embryonic axis raising new questions about extent and regulation of oilseed heterogeneity. Extension of this methodology provides an avenue for understanding metabolism …
Date: August 2013
Creator: Horn, Patrick J.
System: The UNT Digital Library
Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties (open access)

Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties

A novel class of semi-conducting ortho-carborane (B10C2H12) based polymer films with enhanced electronic and chemical properties has been developed. The novel films are formed from electron-beam cross-linking of condensed B10C2H12 and B10C2H12 co-condensed with aromatic linking units (Y) (Y=1,4-diaminobenzene (DAB), benzene (BNZ) and pyridine (PY)) at 110 K. The bonding and electronic properties of the novel films were investigated using X-ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS) and Mulliken charge analysis using density functional theory (DFT). These films exhibit site-specific cross-linking with bonding, in the pure B10C2HX films, occurring at B sites non-adjacent to C in the B10C2H12 icosahedra. The B10C2H12:Y films exhibit the same phenomena, with cross-linking that creates bonds primarily between B sites non-adjacent to C in the B10C2H12 icosahedra to C sites in the Y linking units. These novel B10C2HX: Y linked films exhibit significantly different electron structure when compared to pure B10C2HX films as seen in the UPS spectra. The valence band maxima (VBM) shift from - 4.3 eV below the Fermi level for pure B10C2HX to -2.6, -2.2, and -1.7 for B10C2HX:BNZ, B10C2HX:PY, and B10C2HX:DAB, respectively. The top of the valence band is composed of states derived primarily from the Y linking units, suggesting …
Date: August 2013
Creator: Pasquale, Frank L.
System: The UNT Digital Library
Development of the Knowledge and Attitudes Toward Near-death Experiences Scale (open access)

Development of the Knowledge and Attitudes Toward Near-death Experiences Scale

The purpose of this study was to develop an instrument to measure healthcare professionals’ knowledge and attitudes about near-death experiences (NDEs) that would demonstrate acceptable psychometric properties. In consultation with a focus group of six NDE experts, I developed the 50-item Knowledge and Attitudes toward Near-Death Experiences Scale (KANDES), including the 24-item KANDES–Attitude subscale (KANDES-A) and the 26-item KANDES–Knowledge subscale (KANDES-K). Including a pilot administration in which feedback indicated no need for revision, a total of 256 professional and student counselors completed the KANDES. Separate reliability and validity analyses were conducted for each subscale. For the KANDES–A, Cronbach’s alpha was .909, and Pearson’s r for test-retest was .748, both indicating acceptable reliability. An exploratory factor analysis indicated four factors to retain and yielded a factor solution that explained 54.87% of the variance, an acceptable amount of variance to substantiate construct validity. For the KANDES–K, Cronbach’s alpha was .816, indicating acceptable reliability. For each of the scale’s three domains, Cronbach’s alpha was .816 for Domain 1: NDE Content, .817 for Domain 2: NDE Aftereffects, and .631 for Domain 3: Experiencer Characteristics, indicating acceptable reliability. Pearson’s r for test-retest on the total KANDES–K was .812, further demonstrating acceptable reliability.
Date: August 2013
Creator: Pace, Laura
System: The UNT Digital Library
Dialogismo En El Cancionero De Miguel De Unamuno: Dialéctica De La Voz Poética (open access)

Dialogismo En El Cancionero De Miguel De Unamuno: Dialéctica De La Voz Poética

The present research is centered on Miguel de Unamuno's Songbook which is studied through the prism of the theory of dialogism elaborated by Mikhail Bakhtin. This study overcomes the limitation of Bakhtin's theory which extends solely to narrative genres, and argues that dialogism can also be applied to poetry. In this thesis I seek to rectify the critical oversight of this significant and original work of Unamuno and show that Songbook has panoply of innovative techniques aimed at creating the multiple poetic voices and dialogical interaction. Strong links are established between Bakhtin's theory, Unamuno's aesthetics and the postmodernist episteme of "the death of the author" which heralds the new era of fiction writing. I give a detailed analysis of Songbook's poetry based on Bakhtin's theory and incorporate the pragmalinguistic view of poetic discourse as a communicative act that involves a constant interaction between the addresser and the addressees. I find different types of dialogical expression in accordance with the number and the nature of different addressees at which the poet aims his discourse. This study shows that poetic tools forged by Unamuno are born of the need to express a conflictive inner world that is opposed to any type of …
Date: May 2013
Creator: Sheppard, Yanina O.
System: The UNT Digital Library
Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States (open access)

Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States

Diaspora philanthropy to India has grown rapidly over the past several decades. However, little is known about the motivations of Indians living in the U.S. to donate philanthropically to India. Extant studies have either focused on quantitative analysis of diaspora philanthropy or qualitative research on the receiving of diaspora philanthropy in India. The motivations and strategies of the Indian diaspora in the U.S. have not been explored, particularly, the informal mechanisms and strategies of making philanthropic donations to India and the obligations that underlie the practice of diaspora philanthropy remain neglected in the existing studies on diaspora philanthropy. My research addressed this gap in the existing literature on diaspora philanthropy by conducting qualitative face-to-face in-depth interviews with a snowball sample of 25 Indian engineers in San Diego, California. In my study, it was found that Indians preferred to channel funds for philanthropy in India through friends and family because of lack of trust in formal organizations and greater confidence in the activities of friends and family in India due to familiarity and better accountability. It was also found that Indians felt indebted to Indian society and the Indian nation-state for the free and subsidized education they had received in India, …
Date: December 2013
Creator: Batra, Shikha
System: The UNT Digital Library
Direct Strength Method for Web Crippling of Cold-formed Steel C-sections (open access)

Direct Strength Method for Web Crippling of Cold-formed Steel C-sections

Web crippling is a form of localized buckling that occurs at points of transverse concentrated loading or supports of thin-walled structural members. The theoretical computation of web crippling strength is quite complex as it involves a large number of factors such as initial imperfections, local yielding at load application and instability of web. The existing design provision in North American specification for cold-formed steel C-sections (AISI S100, 2007) to calculate the web-crippling strength is based on the experimental investigation. The objective of this research is to extend the direct strength method to the web crippling strength of cold-formed steel C-sections. ABAQUS is used as a main tool to apply finite element analysis and is used to do the elastic buckling analysis. The work was carried out on C-sections under interior two flange (ITF) loading, end two flange (ETF) loading cases. Total of 128 (58 ITF, 70 ETF) sections were analyzed. Sections with various heights (3.5 in.to 6 in.) and various lengths (21 in. to 36 in.) were considered. Data is collected from the tests conducted in laboratory and the data from the previous researches is used, to extend the direct strength method to cold formed steel sections. Proposing a new …
Date: May 2013
Creator: Seelam, Praveen Kumar Reddy
System: The UNT Digital Library
Dislocation Dynamics Simulations of Plasticity in Cu Thin Films (open access)

Dislocation Dynamics Simulations of Plasticity in Cu Thin Films

Strong size effects in plastic deformation of thin films have been experimentally observed, indicating non-traditional deformation mechanisms. These observations require improved understanding of the behavior of dislocation in small size materials, as they are the primary plastic deformation carrier. Dislocation dynamics (DD) is a computational method that is capable of directly simulating the motion and interaction of dislocations in crystalline materials. This provides a convenient approach to study micro plasticity in thin films. While two-dimensional dislocation dynamics simulation in thin film proved that the size effect fits Hall-Petch equation very well, there are issues related to three-dimensional size effects. In this work, three-dimensional dislocation dynamics simulations are used to study model cooper thin film deformation. Grain boundary is modeled as impenetrable obstacle to dislocation motion in this work. Both tension and cyclic loadings are applied and a wide range of size and geometry of thin films are studied. The results not only compare well with experimentally observed size effects on thin film strength, but also provide many details on dislocation processes in thin films, which could greatly help formulate new mechanisms of dislocation-based plasticity.
Date: August 2013
Creator: Wu, Han
System: The UNT Digital Library
The Disney Influence on Kindergarten Girls' Body Image (open access)

The Disney Influence on Kindergarten Girls' Body Image

Media is now a part of the early childhood world. In many countries, including industrialized and developing countries, children spend more time consuming various kinds of media. The impact of media on children's perception of their body images has been and continues to be a concern of parents and early childhood professionals. This research examined the influence of Disney movies on Thai kindergarten girls' body images and self-esteem. Thai kindergarten girls completed three measures of body self-image: the Body Figure Preference Scale, the Body Esteem Scale, and the Self-Esteem Scale. The girl participants were randomly assigned to two groups: focused on a female theme (FFT) and focused on a non-human theme (FNT). The experimental group viewed "female" Disney movie themes, while the control group viewed "animal" Disney movie themes. Girls in the experimental group expressed greater body image dissatisfaction scores after watching Disney movies, which was an expected finding. Results from the present study suggest that girls in both groups become concerned about their body esteem after video exposure. However, there was no significant difference in self-esteem between girls in FFT and FNT. In summary, the findings of this study support the belief that Disney movies influence young girls' perceptions …
Date: May 2013
Creator: Asawarachan, Tanawan
System: The UNT Digital Library
Doctoral Level Counseling Students’ Experiences and Perceptions of Learning in a Cohort Environment (open access)

Doctoral Level Counseling Students’ Experiences and Perceptions of Learning in a Cohort Environment

Learning community literature supports the use of student cohorts to enhance learning through increased peer interaction and common course work. Researchers employed the qualitative method of phenomenography to identify various ways doctoral counseling students conceptualize and experience learning in a cohort over the course of a single academic year. Participants were all 10 members of a single southwestern U.S. university counseling program doctoral cohort of full-time students between 20 and 59 years of age with 5 members 20-29, 4 members 30-39, 1 member 50-59; 8 female, 2 male; 9 White non-Hispanic, 1 African-American. Data were transcripts from 30 one-hour interviews, three for each participant over the course of their first year of study. The research team that analyzed the data consisted of three advanced counseling program doctoral students, each with research methods coursework. Results revealed nine dynamic structural aspects of learning: dialogue, diversity, knowledge, motivation, support, shared experience, relationship development, interpersonal awareness, and conflict. Findings support the use of learning communities in doctoral level counselor education programs. Cohort members demonstrated increasing awareness of the potential learning benefits of cohort interaction and developed more in depth strategies over time to utilize the cohort to enhance learning. Future counselor educators may now …
Date: August 2013
Creator: Huffman, David D.
System: The UNT Digital Library
Don Gillis's Symphony No 5½: Music for the People (open access)

Don Gillis's Symphony No 5½: Music for the People

Don Gillis wrote Symphony No. 5½ (1947) in order to reconcile the American public with modern art music. By synthesizing jazz (as well as other American folk idioms), singable melodies, and humor, and then couching them into symphonic language, Gillis produced a work that lay listeners could process and enjoy. The piece was an immediate success and was played by orchestras across the globe, but it did not retain this popularity and it eventually faded from relevancy. This study focuses on elements that contributed to the initial efficacy and ultimate decline of the work. Due to its pervasive popular influences, Symphony No. 5½ is a crystallized representation of time in which it was written, and it soon became dated. Don Gillis did not harbor the idea that Symphony No. 5½ would grant him great wealth or musical immortality; he had a more pragmatic goal in mind. He used every musical element at his disposal to write a symphonic work that would communicate directly with the American people via a musical language they would understand. He was successful in this regard, but the dialogue ended soon after mid-century.
Date: May 2013
Creator: Morrison, Sean
System: The UNT Digital Library
Double Beta Decay in Xenon-136: Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes (open access)

Double Beta Decay in Xenon-136: Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes

None
Date: August 23, 2013
Creator: Herrin, Steven
System: The UNT Digital Library
Down, Set, Like? A Study of Social Networking and Sports Fandom (open access)

Down, Set, Like? A Study of Social Networking and Sports Fandom

Sports in the 21st century have become popular across multiple industries, and a major boon to a television industry dealing with increasing audience fragmentation. So an understanding of fans' behavior is important to all parties. This study, an online survey consisting of 242 responses, examined fandom and its relationship with time spent using social networking sites and found no statistical correlation. Six uses and gratification factors obtained: human connection, network content, distraction/amusement, social integration, social surveillance, and active entertainment. The low comparative saliency of the social integration factor suggests that perhaps fandom is distinct from other ways of identifying with similarly-minded individuals (e.g. political and/or religious affiliation), or that perhaps fandom as a factor is less than sufficient to explain how/why sports fans use social networking sites.
Date: May 2013
Creator: Otteson, Gabe
System: The UNT Digital Library
Dramatizing Lynching and Labor Protest: Case Studies Examining How Theatre Reflected Minority Unrest in the 1920S and 30S (open access)

Dramatizing Lynching and Labor Protest: Case Studies Examining How Theatre Reflected Minority Unrest in the 1920S and 30S

Theatre is widely unrecognized for the compelling influence it has held in society throughout history. In this thesis, I specifically examine the implications surrounding the social protest theatre of black and Jewish American minority communities in the first half of the twentieth century. I discuss how their historical circumstance, culture, and idiosyncratic natures caused them to choose agitated propaganda theatre as an avenue for protest. I delve into the similarities in circumstance, but their theatre case studies separate the two communities in the end. I present case studies of each community, beginning with anti-lynching plays of the 1920s that were written by black American playwrights both in response to white supremacist propaganda theatre and to assert a dignified representation of the black community. However, their plays and protest movement never developed a larger popular following. My next minority theatre case study is an examination of 1930s Jewish labor drama created in protest of popular anti-Semitic theatre and poor labor conditions. The Jewish community differs from the black community in their case because the racist propaganda was produced by a man who was Jewish. Another difference is that their protest theatre was on the commercial stage by this point because of …
Date: December 2013
Creator: Goldmann, Kerry L.
System: The UNT Digital Library
Drawing Boundaries and Revealing Language Attitudes: Mapping Perceptions of Dialects in Korea (open access)

Drawing Boundaries and Revealing Language Attitudes: Mapping Perceptions of Dialects in Korea

Perceptual dialectology studies have shown that people have strong opinions about the number and placement of dialect regions. There has been relatively little research conducted in this area on Korean, however, with early studies using only short language attitude surveys. To address this gap in research, in the present study, I use the 'draw-­?a-­?map' task to examine perceptions of language variation in Korea. I ask respondents to draw a line around places in Korea where people speak differently and provide names, examples, and comments about the language spoken in those areas. With the resulting data, I use ArcGIS 10.0 software to quantitatively identify, aggregate, and map the most salient dialect areas and categories for subjects' perceptions. I also perform a content analysis of the qualitative data provided by respondents using 'keywords.' During this process, I categorize comments and labels given by respondents to find emerging themes. Finally, I stratify perceptions of respondents by demographic factors, e.g., age, sex, and urbanicity, that have often been found to be important in language variation and change. An analysis of these data suggests that Koreans' perceptions of dialect regions are not necessarily limited by administrative boundaries. In fact, the data reveal not only perceptions …
Date: May 2013
Creator: Jeon, Lisa
System: The UNT Digital Library
Drilling Down Natural Gas Well Permitting Policy:  Examining the Effects of Institutional Arrangements on Citizen Participation and Policy Outcomes (open access)

Drilling Down Natural Gas Well Permitting Policy: Examining the Effects of Institutional Arrangements on Citizen Participation and Policy Outcomes

Over the past decade the movement of natural gas drilling operations toward more suburban and urban communities has created unique policy challenges for municipalities. Municipal response is manifest in a variety of institutional arrangements, some more enabling than others regarding citizen access to public hearings. This observation lead to the main research question, “How are variations in citizen participation affecting policy outcomes?” The argument is made that institutions affecting citizen participation, in turn affect policy outcomes. If the general public is given access to public hearings, their preferences for longer setbacks will be taken into account and the approved gas wells will have greater distances from neighboring residences – effectively providing for greater safety. Given the paucity of research on the topic of natural gas drilling, the research first begins with the presentation of a theoretical framework to allow for analysis of the highly complex topic of gas well permitting, emphasizing the rule-ordered relationships between the various levels of decision making and provides a typology of collective action arenas currently used by Texas municipalities. The research uses paired case studies of most similar design and employs a mixed methods process for the collection, analysis and interpretation of the municipal level …
Date: August 2013
Creator: Long, Laurie C.
System: The UNT Digital Library
Dynamic Adhesion and Self-cleaning Mechanisms of Gecko Setae and Spatulae (open access)

Dynamic Adhesion and Self-cleaning Mechanisms of Gecko Setae and Spatulae

Geckos can freely climb on walls and ceilings against their body weight at speed of over 1ms-1. Switching between attachment and detachment seem simple and easy for geckos, without considering the surface to be dry or wet, smooth or rough, dirty or clean. In addition, gecko can shed dirt particles during use, keeping the adhesive pads clean. Mimicking this biological system can lead to a new class of dry adhesives for various applications. However, gecko’s unique dry self-cleaning mechanism remains unknown, which impedes the development of self-cleaning dry adhesives. In this dissertation we provide new evidence and self-cleaning mechanism to explain how gecko shed particles and keep its sticky feet clean. First we studied the dynamic enhancement observed between micro-sized particles and substrate under dry and wet conditions. The adhesion force of soft (polystyrene) and hard (SiO2 and Al2O3) micro-particles on soft (polystyrene) and hard (fused silica and sapphire) substrates was measured using an atomic force microscope (AFM) with retraction (z-piezo) speed ranging over 4 orders of magnitude. The adhesion is strongly enhanced by the dynamic effect. When the retraction speeds varies from 0.02 µm/s to 156 µm/s, the adhesion force increases by 10% ~ 50% in dry nitrogen while …
Date: December 2013
Creator: Xu, Quan
System: The UNT Digital Library
Dynamic Precipitation of Second Phase Under Deformed Condition in Mg-nd Based Alloy (open access)

Dynamic Precipitation of Second Phase Under Deformed Condition in Mg-nd Based Alloy

Magnesium alloys are the lightweight structural materials with high strength to weigh ratio that permits their application in fuel economy sensitive automobile industries. Among the several flavors of of Mg-alloys, precipitation hardenable Mg-rare earth (RE) based alloys have shown good potential due to their favorable creep resistance within a wide window of operating temperatures ranging from 150°C to 300°C. A key aspect of Mg-RE alloys is the presence of precipitate phases that leads to strengthening of such alloys. Several notable works, in literature, have been done to examine the formation of such precipitate phases. However, there are very few studies that evaluated the effect stress induced deformation on the precipitation in Mg-RE alloys. Therefore, the objective of this work is to examine influence of deformation on the precipitation of Mg-Nd based alloys. To address this problem, precipitation in two Mg-Nd based alloys, subjected to two different deformation conditions, and was examined via transmission electron microscopy (TEM) and atom probe tomography (APT). In first deformation condition, Md-2.6wt%Nd alloy was subjected to creep deformation (90MPa / 177ºC) to failure. Effect of stress-induced deformation was examined by comparing and contrasting with precipitation in non-creep tested specimens subjected to isothermal annealing (at 177ºC). In …
Date: December 2013
Creator: Dendge, Nilesh Bajirao
System: The UNT Digital Library
Early and Current Family Environment Among Inpatient Trauma Survivors: Associations with Multi-type Abuse and Sexual Orientation (open access)

Early and Current Family Environment Among Inpatient Trauma Survivors: Associations with Multi-type Abuse and Sexual Orientation

The present study is an exploratory analysis of associations among sexual orientation, childhood abuse, and characteristics of both early and current family environment in a sample of 80 inpatient trauma survivors. Participants were administered a background information questionnaire, Dissociative Disorders Interview Schedule, the Family Environment Scale and other instruments not analyzed in the current study. Multi-type abuse was significantly associated with low expressiveness and independence and high control in the early family, but no associations emerged with current family characteristics. Results suggest that the intergenerational transmission of family organization and moral-religious orientation occurred in the entire sample, and the transmission of family conflict patterns occurred only in the L/G/B group. Overall, participants perceived improvements in their current family environments compared to their early family environments. Findings yield support for the sexual minority stress model and mixed support for the intergenerational transmission of family characteristics.
Date: May 2013
Creator: Williams, Jennifer S.
System: The UNT Digital Library