Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Master of Music (MM) degree.

Recital presented at the UNT College of Music Voertman Hall in partial fulfillment of the Master of Music (MM) degree.

Recital presented at the UNT College of Music Voertman Hall in partial fulfillment of the Master of Music (MM) degree.

Electrical energy is used at approximately the rate of 15 Terawatts world-wide. Generating this much energy has become a primary concern for all nations. There are many ways of generating energy among which the most commonly used are non-renewable and will extinct much sooner than expected. Very active research is going on both to increase the use of renewable energy sources and to use the available energy with more efficiency. Among these sources, solar energy is being considered as the most abundant and has received high attention. The mobile phone has become one of the basic needs of modern life, with almost every human being having one.Individually a mobile phone consumes little power but collectively this becomes very large. This consideration motivated the research undertaken in this masters thesis. The objective of this thesis is to design a model for solar power based charging circuits for mobile phone using Simulink(R). This thesis explains a design procedure of solar power based mobile charger circuit using Simulink(R) which includes the models for the photo-voltaic array, maximum power point tracker, pulse width modulator, DC-DC converter and a battery. The first part of the thesis concentrates on electron level behavior of a solar cell, …

This thesis presents two major sections with the objective of introducing a new cold-formed steel (CFS) shear wall system with corrugated steel sheathings. The work shown herein includes the development of an optimal shear wall system as well as an optimal slit configuration for the CFS corrugated sheathings which result in a CFS shear wall with high ductility, high strength, high stiffness and overall high performance. The conclusion is based on the results of 36 full-scale shear wall tests performed in the structural laboratory of the University of North Texas. A variety of shear walls were the subject of this research to make further discussions and conclusions based on different sheathing materials, slit configurations, wall configurations, sheathing connection methods, wall dimensions, shear wall member thicknesses, and etc. The walls were subject to cyclic (CUREE protocol) lateral loading to study their deformations and structural performances. The optimal sit configuration for CFS shear walls with corrugated steel sheathings was found to be 12×2 in. vertical slits in 6 rows. The failure mode observed in this shear wall system was the connection failure between the sheathing and the framing members. Also, most of the shear walls tested displayed local buckling of the chord …

Grit and achievement motivation have been predictors of behavior in academia and military settings (Duckworth, Matthews, Peterson, & Kelly, 2007), but to date, research on their effects on sport performance has been limited. Given grit's predictive role in other performance domains, grit may be influential in athletes' long-term goal attainment, interacting with their achievement motives and leading to better performances. Athletes' trait levels of grit may influence how they understand and respond to messages received within motivational climates from key personnel such as from coaches and teammates. We examined potential moderating effects of grit on the relationship between motivational feedback and high school soccer players (N = 71, Mage = 15.81) performance on a soccer task, their desire to persist in the task, and their choices of task difficulty. We used hierarchical multiple regression to test the main effects of feedback and grit and to determine if grit moderated the effects of feedback on performance. Grit was a significant moderator of the feedback-shooting performance relationship, accounting for 3.9% of variance. Simple slopes analysis revealed a significant effect for low (B = 13.32, SEb = 4.44, p = .004, t = 2.99), but not high, (B = 2.11, SEb = 4.31, …

Cette analyse littéraire examine les parallèles entre les deux romans Lettres persanes de Montesquieu (1721) et Lettres d'une Péruvienne de Françoise de Graffigny (1747) en se concentrant sur le sort des femmes et leur rébellion contre la claustration. Leurs révoltes transformatrices révèlent une volonté qui refuse et puis transcende les barreaux de leur captivité pour vivre librement. La philosophie de Simone de Beauvoir (1908-1986) personnifie leurs luttes pour devenir et exister, ce qui se traduit par leur capacité de dévoiler leur vraie nature. Elles se battent contre le néant de leurs existences où elles ne peuvent que succomber aux contraintes imposées. Elles se battent pour se définir et pour devenir. Cependant, c'est Graffigny qui nous offre une réponse plus proto-féministe dépassant les paramètres masculins de la société. Son livre répond directement aux Lettres persanes pour créer une nouvelle femme iconoclaste qui transcende les barrières de la société pour se réinventer.

Foreign-born providers make up over a quarter of the physician workforce nationally. Patients in south central Pennsylvania are primarily white with limited interaction with foreigners which can produce barriers to communication and trust. This study proposes practical steps for building positive relationships between patients and their foreign-born providers. Ethnographic methods were used to interview and survey patients and providers about the relationships between foreign-born providers and patients, primarily in the Summit Health system. The results of the study provide a framework of how trust is built between patients and providers in general, suggest additional actions for foreign-born providers, and propose ways patients can do their part to achieve a positive relationship with their provider. While much of the literature on cultural competence is in the context of patients who are from minority ethnicities, this study adds to the body of research by also considering the providers as part of minority groups.

Current evidence suggests that non-medical prescription stimulant (NMPS) use is on the rise, particularly among college students. Identifying individuals at risk for regular and problematic use is a critical step towards the development of effective intervention efforts. A growing body of work has noted that individuals with elevated levels of social anxiety (SA) or social anxiety disorder are at an enhanced risk for developing substance use problems, including NMPS use disorder. Despite the relevance of SA and NMPS use among college students, no studies have attempted to examine subclinical SA or the relation between SA and NMPS use among college students specifically. Thus, the present study sought to extend this area by testing the relation of SA symptoms and NMPS use frequency among college students. A large online study of college students was conducted (N=1604) to identify 252 NMPS users (18-25 years; 68.3% female). A hierarchical linear regression was used to test the moderation of positive prescription stimulant expectancies on SA symptoms in predicting past year NMPS use frequency. A subsample of 15 participants was also brought into the lab to assess subjective (State Anxiety) and physiological (salivary cortisol) responding to a social stressor task. Overall, the current study did …

This thesis aims to develop a new type of highly stretchable strain sensor to measure large deformation of a specimen subjected to dynamic loading. The sensor was based on the piezo-resistive response of carbon nanotube(CNT)/polydimethysiloxane (PDMS) composites thin films, some nickel particles were added into the sensor composite to improve the sensor performance. The piezo-resistive response of CNT composite gives high frequency response in strain measurement, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measuring large strain (up to 26%) with an excellent linearity and a fast frequency response under quasi-static test, the delay time for high strain rate test is just 30 μs. This stretchable strain sensor is also able to exhibit much higher sensitivities, with a gauge factor of as high as 80, than conventional foil strain gauges.

Today over 1.1 million people are living with HIV/AIDS in the United States; over the last 4 decades mortality rates have decreased largely made in part because of advancement in awareness and treatment options. Treatment adherence has long been considered a vital component in decreasing HIV/AIDS related mortality and has proven to reduce the risk of transmission. However not all patients take their medicine as prescribed. This research study, sponsored by The North Central Texas HIV Planning Council explored how Patient and Provider communication impacted treatment adherence. By utilizing a mixed-methods approach survey data and semi-structured interviews were used to collect insights from both Patients and Providers. Data gleaned through the interview process provided a perspective that could not be captured by using quantitative methods alone. The results from this research yielded multiple themes related to patient and provider communication with recommendations as to how The North Central Texas HIV Planning Council could address treatment adherence, such as Providers focus on Patients perceived severity based on their understanding of disease and illness; that side-effects remain a concern for patients and should not be dismissed; and finally that the word AIDS is perceived to be more stigmatized and as such organizations …

Environmental factors can have a significant impact on an individual's health and well-being, and a primary characteristic of environments is air quality. Air sensing equipment is available to the public, but it is often expensive,stationary, or unusable for persons without technical expertise. The goal of this project is to develop an inexpensive and portable sensor module for public use. The system is capable of measuring temperature in Celsius and Fahrenheit, heat index, relative humidity, and carbon dioxide concentration. The sensor module, referred to as the "sniffer," consists of a printed circuit board that interconnects a carbon dioxide sensor, a temperature/humidity sensor, an Arduino microcontroller, and a Bluetooth module. The sniffer is small enough to be worn as a pendant or a belt attachment, and it is rugged enough to consistently collect and transmit data to a user's smartphone throughout their workday. The accompanying smartphone app uses Bluetooth and GPS hardware to collect data and affix samples with a time stamp and GPS coordinates. The accumulated sensor data is saved to a file on the user's phone, which is then examined on a standard computer.

Lisa Markley, a.k.a. "Miz Markley", is a genuinely happy person even if she is not particularly financially successful as a musician. In an effort to validate my own choices as an artist, I chose to follow her. What was intended to be a portrait of a working musician, becomes instead a feminist musical essay film about the transformative power of art making.

The primary goal of this study was to investigate the habits of college students who use pornography. The study was designed to collect data on the use of online pornography by college students. Through the use of an online survey, the study collected general demographic data and data on the frequency with which students used online pornography. The study also collected data on the general attitudes of college students towards online pornography. Participants consisted of students enrolled at the University of North Texas during the Spring 2016 semester. The participants of the study were contacted by an email requesting the student to respond to an online anonymous survey regarding their use of online pornography. The survey consisted of thirty questions and statements, primarily utilizing a five point Likert scale. Analysis of the data collected as well as a discussion of the findings are included.

A compositionally graded Ti-xCr (10≤x≤30 wt%) alloy has been fabricated using Laser Engineered Net Shaping (LENSTM) to study the microstructural phase evolution along a compositional gradient in both as-deposited and heat treated conditions (1000°C followed by furnace cooling or air cooling). The alloys were characterized by SEM BSE imaging, XRD, EBSD, TEM and micro-hardness measurements to determine processing-structure-property relations. For the as-deposited alloy, α-Ti, β-Ti, and TiCr2 (C15 Laves) phases exist in varying phase fractions, which were influential in determining hardness values. With the furnace cooled alloy, there was more homogeneous nucleation of α phase throughout the sample with a larger phase fraction of TiCr2 resulting in increased hardness values. When compared to the air cooled alloy, there was absence of wide scale nucleation of α phase and formation of ω phase within the β phase due to the quicker cooling from elevated temperature. At lower concentrations of Cr, the kinetics resulted in a diffusionless phase transformation of ω phase with increased hardness and a lower phase fraction of TiCr2. In contrast at higher Cr concentrations, α phase separation reaction occurs where the β phase is spinodally decomposed to Cr solute-lean β1 and solute-rich β2 resulting in reduced hardness.

In North Texas, the Barnett Shale underlies large areas of the Dallas-Fort Worth Metroplex (DFW), which magnifies debates about the externalities of shale gas development (SGD). Continued demand for natural gas and expansive urbanization in DFW will cause more people to come in contact with drilling rigs, gas transport, and other urban shale gas landscapes. Thousands of gas wells within the DFW region occupy a large, yet scattered land surface area. DFW city planners, elected officials, and other stakeholders must deal with current and future urban growth and the surface impacts that are associated with gas development. This research examines how shale gas landscapes affect urban land uses, landscapes, and patterns of development in DFW. The study focuses on multiple fast growing DFW municipalities that also have high numbers of gas well pad sites. This study asks what are the spatial characteristics of gas well production sites in DFW and how do these sites vary across the region; how do gas well production sites affect urban growth and development; and how are city governments and surface developers responding to gas well production sites, and what are the dominant themes of contestation arising around gas well production sites and suburban growth?

In the current study, we aimed to explore the relationship between perceived stress, spirituality and self-esteem and how they are related to psychological QOL. We found that our overall model accounted for 58% of the total variance in psychological QOL (adj. R2 = .58, F(10, 136) = 21.79, p < .001) with stress (β = -.37, p < .01) and self-esteem (β = .45, p < .01) as the significant predictors. Additionally we found that spiritual beliefs and practices moderate the relationship between stress and QOL (adj. R2= .49, F(11, 135) = 13.88, p < .001). Lastly, we conducted a principle component analysis (PCA) on our three variables of interest and outcome variable to determine whether the proposed structure of our measures holds true for our sample (i.e., LGB populations).

Students often use the web as a source of help for problems that they encounter on programming assignments.In this work, we seek to understand how students use the web to search for help on their assignments.We used a mixed methods approach with 344 students who complete a survey and 41 students who participate in a focus group meetings and helped in recording data about their search habits.The survey reveals data about student reported search habits while the focus group uses a web browser plug-in to record actual search patterns.We examine the results collectively and as broken down by class year.Survey results show that at least 2/3 of the students from each class year rely on search engines to locate resources for help with their programming bugs in at least half of their assignments;search habits vary by class year;and the value of different types of resources such as tutorials and forums varies by class year.Focus group results exposes the high frequency web sites used by the students in solving their programming assignments.

Snowmelt is one of the major sources of surface water supply and ground-water recharge in high elevation areas and can also cause flooding in snow dominated watersheds. Direct estimation of daily snowmelt requires daily snow water equivalent (SWE) measurements that are not always available, especially in places without monitoring stations. There are two alternative approaches to modeling snowmelt without using direct measurements of SWE, temperature-based and energy-based models. Due to its simplicity, computational efficiency, and less input data requirement, the temperature-based method is commonly used than the energy-based method. In the temperature-index approach snowmelt is estimated as a linear function of average air temperature, and the slope of the linear function is called the degree-day factor (DDF). Hence, the DDF is an essential parameter for utilizing the temperature-based method to estimate snowmelt. Thereby, to analyze the spatial properties of DDF, 10 years DDF from the entire state of Colorado was calculated for this research. Likewise, to study the temporal properties, DDFs for 27 years from the White Yampa water basin and the Colorado Headwaters water basin were calculated. As a part of the spatial analysis, the calculated DDFs were correlated with spatial variables (slope, aspect, latitude and elevation) and a …

Altitudinal gradients in Sub-Antarctic freshwater systems present unique opportunities to study the effect of distinct environmental gradients on benthic macroinvertebrate community composition and dispersal. This study investigates patterns in biodiversity, dispersal and population genetic structure of benthic macroinvertebrate fauna across an altitudinal gradient between two watersheds on Navarino Island in southern Chile. Patterns in diversity, density, evenness and functional feeding groups were not significantly different across the altitudinal gradient in both the Windhond and Róbalo Rivers. Taxa richness in both rivers generally increased from the headwaters of the river to the mouth, and functional feeding group patterns were consistent with the predictions of the River Continuum Concept. Population genetic structure and gene flow was investigated by sampling the mitochondrial cytochrome oxidase I gene in two invertebrate species with different dispersal strategies. Hyalella simplex (Amphipoda) is an obligate aquatic species, and Meridialaris chiloeense (Ephemeroptera) is an aquatic larvae and a terrestrial winged adult. Contrasting patterns of population genetic structure were observed. Results for Hyalella simplex indicate significant differentiation in genetic structure in the Amphipod populations between watersheds and lower genetic diversity in the Róbalo River samples, which may be a result of instream dispersal barriers. Meridialaris chiloeense exhibited weak population structure …

The prevalence of Alcohol Use Disorders is rapidly increasing among college students. The use of real time monitoring in conjunction with contingency management procedures to reduce alcohol consumption has only recently been developed. Therefore, the purpose of this study was to learn more about natural patterns of alcohol consumption in college-aged adults. A second goal was to evaluate a novel, handheld technology for obtaining reliable samples over extended time periods. College students were given a SoberLinkTM SL2 breathalyzer for eight weeks to monitor their drinking behaviors and asked to self-report the number of drinks consumed each day. Participants received one to three text messages per day to provide breath samples and earned monetary rewards for submitting samples within the allotted time. The results of this study showed that college students tend to consume alcohol during the evening hours and mostly on the weekends. There was a weak to medium correlation between average breath alcohol concentration and conditional average drinks. Compliance with prompts ranged between 77 and 84 percent and monetary earnings ranged between $152 and $160. Naturalistic observations of college drinking may aid in the development of interventions to prevent excessive drinking and the SL2 breathalyzer may have great potential …

When asked to identify what characteristics are needed to fulfill an entry level management position in their companies, recruiters replied they were looking for someone “good”. When asked why they are enrolled in a 4 year hospitality program, a student may say to acquire a “good” job. The purpose of this study was to investigate the word “good” as it relates to hospitality industry recruiters in fulfilling an entry-level management position, as well as the hospitality management students perspective of “good” related to acquiring an entry level management position upon graduation from a four year hospitality degree program. This study investigated characteristics, skills, experience, and education of an entry-level manager, as defined by hospitality industry recruiters and hospitality students as “good.” There are opportunities to ensure that development is relevant and valued by both organization and students, through greater understanding of which competencies the industry recruiter is looking for in a “good” entry-level manager. Examples of good practice that enable development of existing talent should be published, in order that industry, academia and college graduates can learn from each other. Industry will ultimately determine the strengths and weaknesses of each four year hospitality degree program, based on whether or not …

Conventional sources of emissions have been a prime target for policymakers in designing pollution control strategies. However, the evolution of shale gas activities is a growing concern over the impact of unconventional sources on urban and regional air quality. Owing to the development of Barnett Shale production, the fast-growing Dallas-Fort Worth (DFW) metroplex has encountered both types of these emissions. Oil and gas activities result in emissions of ozone precursors, notably volatile organic compounds (VOC). The major objective of this study was to evaluate the spatio-temporal distribution of VOC in order to highlight the influence of unconventional emissions. The study utilized measurements from automated gas chromatography (AutoGC) monitors to analyze the patterns of the total non-methane organic compounds (TNMOC) and relative contributions from marker species of traffic versus oil and gas activities. In this study, data from 2001-2014 was obtained from the Texas Commission on Environmental Quality (TCEQ) for fifteen monitoring sites within the North Texas region. With over a thousand wells in a 10 mile radius, two of the rural sites measured twice as much TNMOC as compared to the urban site in Dallas. Source apportionment analysis was conducted using Positive Matrix Factorization (PMF) technique. The target site located …

Today breastfeeding is a common conversation with the ever-growing holistic movement and the effort to 'go green' as demonstrated by the proliferation of the organic food industry in recent years within the United States. Breastfeeding may reduce poor health outcomes including infant morbidity and mortality. Infant mortality is a priority in Tarrant County within southeast Fort Worth as defined by this project’s client Healthy Moms – Healthy Babies – Healthy Community. The purpose of this research was to identify the contextual factors that influence breastfeeding decisions among the zip codes in southeast Fort Worth in which infant mortality is greatest. In analysis of the data among breastfeeding mothers and stakeholders, support was the greatest contribution to successful breastfeeding.