UNT Theses and Dissertations - Browse

ABOUT BROWSE FEED

Family and Cultural Influences on Latino Emerging Adults' Career Development

Description: There is an extensive amount of research on career development, but most of the constructs studied have focused on content-oriented variables rather than process-oriented variables. While some of the studies have examined samples from ethnic minority populations, the majority of studies use ethnic minority populations as comparison groups, studying between-group differences as opposed to within-group differences. The literature is especially deficient in the are of Latino career development. The current study will examine how family and culture influence the career development of Latino emerging adults. This study will explore the influence of socioeconomic status and acculturation on the career salience and career maturity of Latino emerging adults. The quality of the parent-emerging adult relationship will also be explored for its influence on career development outcomes in this population. One hundred fifty Latino undergraduate students ages 18-24 will be recruited for participation in this study. The participants will complete questionnaires regarding demographic information, acculturation, the quality of the parent-emerging adult relationship, career salience, and career maturity.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2016
Creator: Rodriguez, Kristina
Partner: UNT Libraries

Giving Voice to Multiple Sclerosis: A Patient and Provider Investigation

Description: With the advent of the telephonic and technological healthcare revolution, pharmaceutical corporations seek to improve patient compliance and quality of life by contracting with services providers. As an employee of one such provider, working for more than three years on a medication for the neurologically degenerative disease, multiple sclerosis, this investigation utilizes a mixed methodological approach. In order to improve and diversify the clinical services provided to patients, I was contracted as a consultant. I interviewed phone and PRN nurses, developed and released a PRN survey, and interviewed patients living in the Dallas/Fort Worth, Texas area. The combined experiences and expertise of the three groups who participated would serve to inform and develop new programs and services for patients with differing disease states. The research resulted in a re-imagining of the social networking theory of health, as well as the works of Pierre Bourdieu and Michel Foucault, to serve the evolving tele-health and technologically based healthcare workplace.
Date: December 2016
Creator: Cutler, Alexander
Partner: UNT Libraries

High Driver Turnover among Large Long-Haul Motor Carriers: Causes and Consequences

Description: My thesis provides evidence supporting a theory asserting that the high level of competition that exists between motor carriers operating within long-haul trucking is the most significant factor contributing to the continuously high driver turnover rates affecting the entire logistics industry. I explore how long-haul truck drivers internalize the conflict between their identity and the aggressively competitive environment within which they work. Social science authors, industry reports, and truck driver feedback from my own ethnographic study are analyzed for contexts in order to explore the current operating definition of success for motor carriers in both monetary and human terms.
Date: December 2016
Creator: Ferrell, Christopher Lee
Partner: UNT Libraries

Improving the Long-term Performance of PVC Compositions

Description: PVC are extensively applied in many fields, such as cables, pipes, vehicles, shoes, toys and infusion bags. Generally, plasticizers are blended with PVC to improve the ability of process in industrial production; however, the toxic plasticizers will gradually migrate to the surface of products and such a leakage results in brittleness of plasticized PVC and environmental pollution. In other words, humans are frequently exposed to the potential risks. According to previous researches, cross-linked PVC was proved that it was able to hinder the migration of plasticizer. Thus, in this research, we selected some commercially used cross-linking agents and employed six different tests based on mechanical, tribological and microscopy analysis in order to seek the best solution against plasticizer migration. Thus, we expected to develop a cross-linked flexible PVC which performed improved long-term performance and extended lifetime.
Date: December 2016
Creator: Yang, Yu Chia
Partner: UNT Libraries

Increasing Number of Toys: A Case Study of Response Generalization across Novel Toys

Description: Children diagnosed with autism are often described as having limited or restricted activities that serve as reinforcers as compared to neurotypical peers. Many theories suggest that one of the many ways children develop is through participation in play. This results in children coming into contact with new environmental stimuli. The procedures used to enhance play skills for children diagnosed with autism typically involve training novel responses with novel stimuli (e.g., toys). This is often done using naturalistic procedures. Because multiple procedures are used, it is unclear what procedure or combination of procedures causes the increases in play repertoires. This study investigated an important component of the treatment package know as reciprocal imitation training. Specifically, the study examined whether increased opportunities, contingent imitation without the requirement to imitate, or contingent imitation with the requirement to imitate would increase the number of toys a child diagnosed with autism would play with. The results showed dramatic increases in the number of toys the child independently chose to play with and an increase in the spontaneous use of different response topographies across novel stimuli only when the student was required to imitate a model. The results are discussed in terms of mediated generalization, the use of common responses, stimulus class formation and stimulus class expansion.
Date: December 2016
Creator: Chaudhry, Mohsana
Partner: UNT Libraries

The Influence of Population on Wrongful Convictions

Description: With criminal cases continuing to be exonerated across the United States, research must be done on the subject to advance current practices to reduce its occurrence in the future. This study combines county population data with the National Registry of Exonerations to analyze the contributing factors to wrongful convictions and the possible effect of population on their frequency. The objective of this study was to identify specific policy changes based on the five contributing factors to wrongful convictions that could be applied to population specific areas. The results yielded multiple patterns that are discussed thoroughly. These findings allowed the introduction of policy changes and proposals for future research.
Date: December 2016
Creator: Whittington, Kari
Partner: UNT Libraries

Memory and Continuity Amidst Irreversible Decline in the Texas Big Empty

Description: This thesis interrogates sense of place and place attachment in the Big Empty on the north central Texas plains. The region stretches from the Red River on the north to the Colorado River basin on the south and from the Cross Timbers on the east to the Caprock escarpment on the west. Since 1930, the Big Empty has seen sustained and severe population decline such that some counties there now register less than a quarter the population they did at their peaks during the interwar years. Through in-depth field interviews, I examine sense of place and place attachment amidst apparently irreversible decline. I also describe conditions of postindustrial rurality arising from rolling reconfigurations of economic and social relations, particularly changes in scale in farming and the diminished centrality of productivist agriculture in local economies and culture, and how these conditions become legible through the study of place.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2016
Creator: Underwood, Robert Reed
Partner: UNT Libraries

Modeling of Fracture Toughness of Magnesium Alloy WE43 Before and After Friction Stir Processing

Description: Magnesium alloys are a popular research topic for structural applications because they have a lower density than conventional structural materials, including steel, titanium, and aluminum; however, the reliability and safety of their mechanical properties must be further proven. An important mechanical property for this purpose is fracture toughness, which is the measure of the material's resistance to crack propagation. In this study, a model of an experiment to investigate the fracture toughness of a magnesium alloy WE43 before and after friction stir processing (FSP) is developed, and the results are compared to those produced by a digital image correlation (DIC) system during an experiment from another paper. The model results of the material before FSP matched well with the DIC results, but the model of the material after FSP only partially matches the DIC results. In addition, a theoretical approach to calculating the standard fracture toughness value, KIc, from the modeling results is proposed, and is found to be a conservative approach.
Date: December 2016
Creator: Lipscomb, Celena Andrea
Partner: UNT Libraries

Modeling of Hexagonal Boron Nitride Filled Bismalemide Polymer Composites for Thermal and Electrical Properties for Electronic Packaging

Description: Due to the multi-tasking and miniaturization of electronic devices, faster heat transfer is required from the device to avoid the thermal failure. Die-attached polymer adhesives are used to bond the chips in electronic packaging. These adhesives have to hold strong mechanical, thermal, dielectric, and moisture resistant properties. As polymers are insulators, heat conductive particles are inserted in it to enhance the thermal flow with an attention that there would be no electrical conductivity as well as no reduction in dielectric strength. This thesis focuses on the characterization of polymer nanocomposites for thermal and electrical properties with experimental and computational tools. Platelet geometry of hexagonal boron nitride offers highly anisotropic properties. Therefore, their alignment and degree of orientation offers tunable properties in polymer nanocomposites for thermal, electrical, and mechanical properties. This thesis intends to model the anisotropic behavior of thermal and dielectric properties using finite element and molecular dynamics simulations as well as experimental validation.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2016
Creator: Uddin, Md Salah
Partner: UNT Libraries

Musical Ekphrasis in the Poetry of Nicolás Guillén, Federico García Lorca, and Langston Hughes

Description: Musical ekphrasis was occurring in the twentieth century in different centers around the world, Cuba: Andalusia, Spain; and Harlem, New York, simultaneously. The writers at the heart of this movement used poetry about music as a means to celebrate the cultures of the marginalized people in their lands, los negros, los gitanos, and African-Americans. The purpose of this study is to define musical ekphrasis and identify it in the works of Nicolás Guillén, Federico García Lorca, and Langston Hughes. Also explored are the common characteristics in ekphrastic poetry by the three poets and the common themes found in their ekphrastic poetry, as well as common influences. Each author is considered in the context of his surroundings and his respective culture, and how that influenced his musical tastes as well as his writing style.
Date: December 2016
Creator: Divett, Andrew Brennan
Partner: UNT Libraries

Negotiated Living: An Ethno-Historical Perspective of Punta Allen

Description: Situated within the jurisdiction of the Municipality of Tulum and within the Sian Ka'an Biosphere gives the village of Punta Allen a distinctive agency in determining their role in the on-going development of tourism in the region that is not given to other communities in the state. This unique circumstance facilitates a dialogue between the reserve, the municipality, and the business cooperatives of Punta Allen that produce a negotiated living. Through the negotiations with the reserve and Tulum, the lobster fishing and tourism cooperatives are given the opportunity to have a relatively significant role in determining the future of Punta Allen in regards to tourism.
Date: December 2016
Creator: McRae, David Thomas
Partner: UNT Libraries

Parcel-Based Change Detection Using Multi-Temporal LiDAR Data in the City of Surrey, British Columbia, Canada

Description: Change detection is amongst the most effective critical examination methods used in remote sensing technology. In this research, new methods are proposed for building and vegetation change detection using only LiDAR data without using any other remotely sensed data. Two LiDAR datasets from 2009 and 2013 will be used in this research. These datasets are provided by the City of Surrey. A Parcel map which shows parcels in the study area will be also used in this research because the objective of this research is detecting changes based on parcels. Different methods are applied to detect changes in buildings and vegetation respectively. Three attributes of object –slope, building volume, and building height are derived and used in this study. Changes in buildings are not only detected but also categorized based on their attributes. In addition, vegetation change detection is performed based on parcels. The output shows parcels with a change of vegetation. Accuracy assessment is done by using measures of completeness, correctness, and quality of extracted regions. Accuracy assessments suggest that building change detection is performed with better results.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2016
Creator: Yigit, Aykut
Partner: UNT Libraries

Particle Image Velocimetry Sensitivity Analysis Using Automatic Differentiation

Description: A particle image velocimetry (PIV) computer software is analyzed in this work by applying automatic differentiation on it. We create two artificial images that contained particles that where moved with a known velocity field over time. These artificial images were created with parameters that we would have on real PIV experiments. Then we applied a PIV software to find the velocity output vectors. As we mentioned before, we applied automatic differentiation through all the algorithm to track the derivatives of the output vectors regarding interesting parameters declared as inputs. By analyzing these derivatives we analyze the sensitivity of the output vectors to changes on each one of the parameters analyzed. One of the most important derivatives calculated in this project was the derivative of the output regarding the image intensity. In future work we plan to use this derivative combined with the intensity probability distribution of each image pixel, to find PIV uncertainties. If we achieve this goal we will find an uncertainty method that will save computational power and will give uncertainty values with computer accuracy.
Date: December 2016
Creator: Grullon Varela, Rodolfo Antonio
Partner: UNT Libraries

Privacy Preserving EEG-based Authentication Using Perceptual Hashing

Description: The use of electroencephalogram (EEG), an electrophysiological monitoring method for recording the brain activity, for authentication has attracted the interest of researchers for over a decade. In addition to exhibiting qualities of biometric-based authentication, they are revocable, impossible to mimic, and resistant to coercion attacks. However, EEG signals carry a wealth of information about an individual and can reveal private information about the user. This brings significant privacy issues to EEG-based authentication systems as they have access to raw EEG signals. This thesis proposes a privacy-preserving EEG-based authentication system that preserves the privacy of the user by not revealing the raw EEG signals while allowing the system to authenticate the user accurately. In that, perceptual hashing is utilized and instead of raw EEG signals, their perceptually hashed values are used in the authentication process. In addition to describing the authentication process, algorithms to compute the perceptual hash are developed based on two feature extraction techniques. Experimental results show that an authentication system using perceptual hashing can achieve performance comparable to a system that has access to raw EEG signals if enough EEG channels are used in the process. This thesis also presents a security analysis to show that perceptual hashing can prevent information leakage.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2016
Creator: Koppikar, Samir Dilip
Partner: UNT Libraries

"Refugees" and Others

Description: Refugees, a novel in progress, begins in the collective first-person with a group of people who live on the same residential street of middle-class homes in an east coast American city and are experiencing the most exquisitely vivid aurora borealis to appear in recorded history. But they quickly learn that this gorgeous wonder is a harbinger of civilization's demise and possibly the end of all life on the planet, because the solar storms causing the sky's fantastic nightly coloring is also slowly stripping away the atmosphere and leeching oxygen into space. This "we" narrative switches to third person, moving between two characters—Julie and Amira—as the narrative moves forward. The first chapter covers the first few months of this apocalyptic crisis, and Julie and Amira are central as they are forced decide if they still have the strength and the will to even attempt survival in these new and brutal circumstances. The second chapter, also told in third person, picks up seventeen years in the future with Aya, Amira's daughter who was six during the initial atmospheric disaster. A small group survived in an underwater refuge, recently discovered the atmosphere above had healed over time, and sent an excursion group, including Aya, to evaluate the changing environment. This chapter reveals the history and particular struggles of these characters living in this complex society, both residual and nascent. The third chapter returns to the group of neighbors—including Julie and Amira—seventeen years prior, immediately following the catastrophic event as their story continues to unfold. This chapter opens, like the first chapter, in the "we" voice, tracing the movement of the group south in a search for help and a desperate, though orderly, effort toward survival. This next phase of their journey introduces fresh conflicts and new characters and points to approaching challenges and ...
Date: December 2016
Creator: Campbell, Erin
Partner: UNT Libraries

The Relation of Perceived Motivational Climate, Mindset, and Achievement Goal Orientation to Grit in Male High School Soccer Players

Description: Grit is defined as "perseverance and passion for long-term goals." Although studied in relation to various outcomes, such as retention and academic performance, few studies have examined variables that may contribute to grit's development. Further, few studies have examined this construct in relation to sport performance or within athletic environments, despite its clear connection to sport-related constructs like mental toughness and resilience. Thus, based in achievement motivation theory, this study examined the relations of the perceived motivational climate as defined by athletes' perceptions of the coaches' behaviors (task vs. ego), athletes' perceptions of their achievement goal orientation (task vs. ego), athletes' perceptions of their implicit theory (i.e., fundamental beliefs regarding whether or not ability can change; growth vs. fixed), and athletes' perception of their level of grit. Male varsity soccer players (N = 81; Mage = 15.80 ± .81) from a large metropolitan area in the south central U.S. completed questionnaires measuring these achievement motivation constructs. The full regression model was significant, accounting for 18% of the grit variance, F(6, 74) = 2.77, p = .017. Within the full model, having a growth mindset (β = .25, p = .035) and endorsing a task goal orientation (β = .36, p = .004) predicted higher levels of grit for the athletes. Neither the coach-created motivational climate, nor the athletes' ego orientation or fixed mindset, were significantly predicted their grit scores. Consistent with Dweck and Duckworth, components of achievement motivation theory, particularly related to a task or growth perspective, may play an important role in athletes' developing a perspective that allows them to work effectively and diligently toward long-term goals.
Date: December 2016
Creator: Albert, Erin
Partner: UNT Libraries

Simulink Based Modeling of a Multi Global Navigation Satellite System

Description: The objective of this thesis is to design a model for a multi global navigation satellite system using Simulink. It explains a design procedure which includes the models for transmitter and receiver for two different navigation systems. To overcome the problem, where less number of satellites are visible to determine location degrades the performance of any positioning system significantly, this research has done to make use of multi GNSS satellite signals in one navigation receiver.
Date: December 2016
Creator: Mukka, Nagaraju
Partner: UNT Libraries

Sliding Friction and Wear Behavior of High Entropy Alloys at Room and Elevated Temperatures

Description: Structure-tribological property relations have been studied for five high entropy alloys (HEAs). Microhardness, room and elevated (100°C and 300°C) temperature sliding friction coefficients and wear rates were determined for five HEAs: Co0.5 Cr Cu0.5 Fe Ni1.5 Al Ti0.4; Co Cr Fe Ni Al0.25 Ti0.75; Ti V Nb Cr Al; Al0.3CoCrFeNi; and Al0.3CuCrFeNi2. Wear surfaces were characterized with scanning electron microscopy and micro-Raman spectroscopy to determine the wear mechanisms and tribochemical phases, respectively. It was determined that the two HEAs Co0.5 Cr Cu0.5 Fe Ni1.5 Al Ti0.4 and Ti V Nb Cr Al exhibit an excellent balance of high hardness, low friction coefficients and wear rates compared to 440C stainless steel, a currently used bearing steel. This was attributed to their more ductile body centered cubic (BCC) solid solution phase along with the formation of tribochemical Cr oxide and Nb oxide phases, respectively, in the wear surfaces. This study provides guidelines for fabricating novel, low-friction, and wear-resistant HEAs for potential use at room and elevated temperatures, which will help reduce energy and material losses in friction and wear applications.
Date: December 2016
Creator: Kadhim, Dheyaa
Partner: UNT Libraries

The Social Psychology of Social Media Reactions to Terrorism

Description: Columnists and social media users commonly stated that terrorist attacks resonate differently in the world and they speculated on some potential reasons such as familiarity, number of victims, and the difference in expectations of a country to be a stage for a terrorist attack to explain this difference. An academic perspective, more specifically a sociological one, is needed to bring light to this debate. In this study, I aimed to understand the discourse after terrorist attacks and to find out if there is a difference between reactions to terrorist attack based on where they happened. This paper embraces a text mining approach to uncover what topics are discussed after four cases of terrorist attacks and to reveal if there is a discrepancy in reactions towards terrorist attacks based on the country they happened. The study consists of two parts. In the first part, the determinants of the public interest and support and how public interest differentiates between different cases of terror attacks is explored. In the second part, topic sentiment analysis is conducted to reveal the nature of the discourse on terrorism. Using the insights from social identity theory, realistic conflict theory and integrated threat theory, I argued that social group categorization in the context of terrorism takes place in a dichotomous manner as Western and Non-Western. This argument, social self-identities being based on ‘West vs. the Rest' mentality in the context of terrorism, is supported by the statistical evidence and the topic model. Theoretical and practical implications are discussed.
Date: December 2016
Creator: Demirhan, Emirhan
Partner: UNT Libraries

The Story of Pathfinders [Family Pathfinders]: Investigating the Impact, Experiences, and Context of Re-Entry Mentoring

Description: The United States has the largest population of imprisoned persons in the world. The vast majority of these individuals eventually leave prison and re-enter society, facing a number of challenges in the process. Those who are unable to successfully re-enter society run the risk of recidivating back into the prison system. Mentoring has the potential to promote successful re-entry and help offenders to get their lives back on track. Pathfinders of Tarrant County is a unique organization. Its historical position as one of the foremost "welfare to work" programs gives it unique insight into the economic struggles of at-risk individuals and families, and its existing relationships with mentors and other community organizations gives it a rich pool of resources to draw from. By helping to connect participants with community resources, Pathfinders removes quite a bit of the complexity from seeking help at a time when vulnerable people need it most. This thesis presents an overview of how Pathfinders conducts mentoring and its unique brand of social service advocacy, including the unique and not-so unique challenges that a re-entry population may have to offer.
Date: December 2016
Creator: Hanich, Kristen Marie
Partner: UNT Libraries

The Strength of a Witness: Empowerment and Resiliency in the Aftermath of Atrocity

Description: Victims and witnesses that testify before an international criminal tribunal such as the International Criminal Tribunal for the Former Yugoslavia (ICTY) willingly subject themselves to scrutiny and bare their wounds before the world. Does this experience cause these vulnerable individuals undue psychological harm, re-traumatization, or worse? Existing literature indicates this may be the case, however using a new dataset I find the opposite to be true. Witnesses at the ICTY report feeling more positive than negative after their experiences on the stand. As the first systematic study on witness mental wellbeing, these findings contradict expectations found in previous research.
Date: December 2016
Creator: McKay, Melissa
Partner: UNT Libraries

Teaching Water Safety Skills to Children with Autism Using Behavioral Skills Training

Description: Behavioral skills training (BST) and in situ training (IST) have been evaluated as methods to teach different safety skills to individuals with developmental disabilities. Research on BST has examined topics such as gun safety, abduction prevention, poison avoidance, and sexual abuse prevention. A large safety issue that is missing from the literature is drowning prevention and water safety skills. Drowning is one of the most prevalent issues facing facing children with Autism Spectrum Disorder (ASD), particularly those who elope from their homes or caregivers. The current study aimed the effectiveness of using BST+IST to teach three water safety skills to three children with ASD. The intial form of intervention was BST with total task presentation of the skill, using verbal instruction, modeling, rehearsal, and feedback. If this intervention did not result in an increase in performance, the skill was broken down into individual component presentation, in which each component of the skill was taught using the same procedures. Results from the current study showed that BST+IST was effective in teaching all skills to all participants.
Date: December 2016
Creator: Tucker, Marilyse
Partner: UNT Libraries

Two-Phase Spray Cooling with Water/2-Propanol Binary Mixtures for High Heat Flux Focal Source

Description: Two-phase spray cooling has been an emerging thermal management technique offering high heat transfer coefficients and critical heat flux levels, near-uniform surface temperatures, and efficient coolant usage that enables to design of compact and lightweight systems. Due to these capabilities, spray cooling is a promising approach for high heat flux applications in computing, power electronics, and optics. Two-phase spray cooling inherently depends on saturation temperature-pressure relationships of the working fluid to take advantage of high heat transfer rates associated with liquid-vapor phase change. When a certain application requires strict temperature and/or pressure conditions, thermo-physical properties of the working fluid play a critical role in attaining proper efficiency, reliability, or packaging structure. However, some of the commonly used single-component working fluids have relatively poor properties and heat transfer performance. For example, water is the best coolant in terms of properties, yet in certain applications where the system operates at low temperature ambient, it cannot be implemented due to freezing risk. The common solution for this problem is to use the antifreeze mixtures (binary mixtures of water and alcohol) to reduce the freezing point. In such cases, utilizing binary mixtures to tune working fluid properties becomes an alternative approach. This study has two main objectives; (1) to experimentally investigate the two-phase spray cooling performance of water/2-propanol binary mixture, and (2) to numerically investigate the performance of an advanced heat spreader featuring high and directional thermal conductivity materials for high heat flux focal sources. The first part of the study involves experimental characterization of heat transfer performance. Tests are conducted on a small-scale, closed loop spray cooling system featuring a pressure atomized spray nozzle. The test section, made of copper, measures 10 mm x 10 mm x 2 mm with a plain, smooth surface. A cylindrical copper block, with a matching size square ...
Date: December 2016
Creator: Obuladinne, Sai Sujith
Partner: UNT Libraries

Unclean Slates: Stories

Description: Unclean Slates: Stories is a collection of seven short stories that comments on the nature of family ties, and how such ties help form a sense of identity. Each story focuses on a separate protagonist, all of whom strive for a new beginning or an escape from some aspect of their current lives. The short story cycle of this collection is held together not by place or characters, but ultimately by the theme of wishing for a new beginning: they share a desire to fix some dissatisfying element of their lives. Mostly from the point of view of blue-collar characters leading mundane middle-class lives, these stories provide commentary on what it means to run from the conditions that make up one's sense of identity. Most of the revelations formed throughout these stories lead to a sense of acceptance of these conditions, and an understanding that family and history make up part of human consciousness. While the specific locations presented in these stories are not necessarily the same, each story seeks to focus on a location that proves to be fundamental to the makeup of the protagonist. The cities and geographic locations themselves are not as important as the specifics: the schools, diners, lakes, and so forth where these characters find themselves contemplating their disillusionment about where their lives have brought them. Facing everything from postpartum depression to simply missing out on a career opportunity, these characters all experience a sense of loss that brings them together in a way that is recognizable to the reader as the collection progresses.
Date: December 2016
Creator: Gollahon, Catherine
Partner: UNT Libraries