You limited your search to:

  Partner: UNT Libraries
From Development of Semi-empirical Atomistic Potentials to Applications of Correlation Consistent Basis Sets
The development of the semi-empirical atomistic potential called the embedded atom method (EAM) has allowed for the efficient modeling of solid-state environments, at a lower computational cost than afforded by density functional theory (DFT). This offers the capability of EAM to model the energetics of solid-state phases of varying coordination, including defects, such as vacancies and self-interstitials. This dissertation highlights the development and application of two EAMs: a Ti potential constructed with the multi-state modified embedded atom method (MS-MEAM), and a Ni potential constructed with the fragment Hamiltonian (FH) method. Both potentials exhibit flexibility in the description of different solid-states phases and applications. This dissertation also outlines two applications of DFT. First, a study of structure and stability for solid-state forms of NixCy (in which x and y are integers) is investigated using plane-wave DFT. A ground state phase for Ni2C is elucidated and compared to known and hypothesized forms of NixCy. Also, a set of correlation consistent basis sets, previously constructed using the B3LYP and BLYP density functionals, are studied. They are compared to the well-known to the correlation consistent basis sets that were constructed with higher-level ab initio methodologies through computations of enthalpies of formation and combustion enthalpies. The computational accuracy with regard to experiment is reported. digital.library.unt.edu/ark:/67531/metadc500219/
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 in cellular (perhaps even subcellular) context with substantial metabolic engineering implications. To visualize metabolite distributions, a free and customizable application, Metabolite Imager, was developed providing several tools for spatially-based chemical data analysis. These tools collectively enable new forms of visualizing the plant lipidome and should prove valuable toward addressing additional unanswered biological questions. digital.library.unt.edu/ark:/67531/metadc499986/
Leadership Styles and Cultural Sensitivity of Department Chairs at Texas Public Universities
As the U.S. population diversifies, so do its higher education institutions. Leadership at these institutions should be prepared for this diversification of students, faculty, and staff. The purpose of this study was to gain greater knowledge about the leadership styles and cultural sensitivity of department chairs. Survey research was used to determine if department chairs’ leadership styles correlated with their cultural sensitivity. The target population was department chairs from public universities in the state of Texas. The survey was distributed to 406 randomly selected department chairs. The participants completed three measures: Leadership Behavior Description Questionnaire (LDBQ) for leadership style, the Intercultural Sensitivity Scale (ISS) for cultural sensitivity, and a demographic questionnaire (gender, age range, race/ethnicity, and years of service as department chair). The sample included 165 usable surveys (40% return rate). The department chairs were primarily male (72%), White (78%), and over 50 (71%) years of age. First, a statistically significant negative correlation (r = -.431, p < .0001) occurred between LBDQ overall scores and overall ISS scores: As chairs scored higher on leadership ability, they scored lower on intercultural sensitivity. Second, leadership style by demographic variable displayed mixed results. No significant difference was found for leadership style by age, gender, years of service, or region of service. For ethnicity, White participants scored significantly lower than Minority participants on the LBDQ scales of consideration (t [162] = -2.021, p = .045), structure (t [162] = -2.705, p = .008), and overall (t [162] = -2.864, p = .005). Minority participants might work more diligently to increase their leadership abilities based on their higher LDBQ scores. Third, findings on intercultural sensitivity by demographic variable were mixed. No statistical significance was observed between any of the ISS scales and age, gender, years of service, and region. For ethnicity, Minority participants’ scores showed significantly lower intercultural sensitivity than White participants scores on two of six ISS subscales: interaction enjoyment (t = -2.46, p = .015) and respect (t = 2.107, p = .037). It was concluded that the Minority and White department chairs’ leadership style and intercultural sensitivity differences could be due in part to differences in the chairs’ ethnic affiliations, associated cultural backgrounds, and views of dominant versus non-dominant cultures. Recommendations for study are included. digital.library.unt.edu/ark:/67531/metadc499977/
Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications
Poor air quality can greatly affect the public health. Research studies indicate that indoor air can be more polluted than the outdoor air. An indoor air quality monitoring system will help to create an awareness of the quality of air inside which will eventually help in improving it. The objective of this research is to develop a low cost wireless sensor system for indoor air quality monitoring. The major cost reduction of the system is achieved by using low priced sensors. Interface circuits had to be designed to make these sensors more accurate. The system is capable of measuring carbon dioxide, carbon monoxide, ozone, temperature, humidity and volatile organic compounds. The prototype sensor node modules were developed. The sensor nodes were the connected together by Zigbee network. The nodes were developed in such a way that it is compact in size and wireless connection of sensor nodes enable to collect air quality data from multiple locations simultaneously. The collected data was stored in a computer. We employed linear least-square approach for the calibration of each sensor to derive a conversion formula for converting the sensor readings to engineering units. The system was tested with different pollutants and data collected was compared with a professional grade monitoring system for analyzing its performance. The results indicated that the data from our system matched quite well with the professional grade monitoring system. digital.library.unt.edu/ark:/67531/metadc499988/
Synthesis Strategies and a Study of Properties of Narrow and Wide Band Gap Nanowires
Various techniques to synthesize nanowires and nanotubes as a function of growth temperature and time were investigated. These include growth of nanowires by a chemical vapor deposition (CVD) system using vapor-liquid-solid (VLS) growth mechanism and electro-chemical synthesis of nanowires and nanotubes. Narrow band gap InSb Eg = 0.17 eV at room temp) nanowires were successively synthesized. Using a phase diagram, the transition of the nanowire from metallic- semiconducting- semi-metallic phase was investigated. A thermodynamic model is developed to show that the occurrence of native defects in InSb nanowires influenced by the nanowire growth kinetics and thermodynamics of defect formation. Wide band gap ZnO (Eg = 3.34 eV) and In2O3 (3.7 eV) were also synthesized. ZnO nanowires and nanotubes were successfully doped with a transition metal Fe, making it a Dilute Magnetic Semiconductor of great technological relevance. Structural and electronic characterizations of nanowires were studied for different semiconducting, metallic and semi-metallic nanowires. Electron transport measurements were used to estimate intrinsic material parameters like carrier concentration and mobility. An efficient gas sensing device using a single In2O3 nanowire was studied and which showed sensitivity to reducing gas like NH3 and oxidizing gas like O2 gas at room temperature. The efficiency of the gas sensing device was found to be sensitive to the nature of contacts as well as the presence of surface states on the nanowire. digital.library.unt.edu/ark:/67531/metadc499984/
A Quantitative Assessment of Site Formation at the Dmanisi Archaeological Site, Republic of Georgia
The focus of this thesis was to gather and analyze micromorphological and petrographic data on soils at the archaeological site of Dmanisi in order to better understand the extent to which the deposition and alteration of the sediments has affected the preservation of artifacts and faunal remains. A major goal of this research was to test hypothesis related to why bone material is discovered in some strata and not in others. This research focuses on the application of micromorphology (supplemented with other methods) to the soils through the use of petrographic analysis of thin sections and scanning electron microscopy. These techniques complement previous field analyses by providing a quantitative assessment of individual strata through point counting and chemical mapping. The results of this research support the hypothesis that the sediments are predominantly mafic ashes, while showing that there is very little soil development in the strata. This suggests quick episodic burial in a relatively dry climate, confirming the hypothesis for a short time sequence in the strata. Additionally, differential weathering probably did not play a significant role in the differential abundance of bone remains among the strata at Dmanisi. digital.library.unt.edu/ark:/67531/metadc499979/
Autonomic Failure Identification and Diagnosis for Building Dependable Cloud Computing Systems
The increasingly popular cloud-computing paradigm provides on-demand access to computing and storage with the appearance of unlimited resources. Users are given access to a variety of data and software utilities to manage their work. Users rent virtual resources and pay for only what they use. In spite of the many benefits that cloud computing promises, the lack of dependability in shared virtualized infrastructures is a major obstacle for its wider adoption, especially for mission-critical applications. Virtualization and multi-tenancy increase system complexity and dynamicity. They introduce new sources of failure degrading the dependability of cloud computing systems. To assure cloud dependability, in my dissertation research, I develop autonomic failure identification and diagnosis techniques that are crucial for understanding emergent, cloud-wide phenomena and self-managing resource burdens for cloud availability and productivity enhancement. We study the runtime cloud performance data collected from a cloud test-bed and by using traces from production cloud systems. We define cloud signatures including those metrics that are most relevant to failure instances. We exploit profiled cloud performance data in both time and frequency domain to identify anomalous cloud behaviors and leverage cloud metric subspace analysis to automate the diagnosis of observed failures. We implement a prototype of the anomaly identification system and conduct the experiments in an on-campus cloud computing test-bed and by using the Google datacenter traces. Our experimental results show that our proposed anomaly detection mechanism can achieve 93% detection sensitivity while keeping the false positive rate as low as 6.1% and outperform other tested anomaly detection schemes. In addition, the anomaly detector adapts itself by recursively learning from these newly verified detection results to refine future detection. digital.library.unt.edu/ark:/67531/metadc499993/
Fundamental Studies of Copper Bimetallic Corrosion in Ultra Large Scale Interconnect Fabrication Process
In this work, copper bimetallic corrosion and inhibition in ultra large scale interconnect fabrication process is explored. Corrosion behavior of physical vapor deposited (PVD) copper on ruthenium on acidic and alkaline solutions was investigated with and without organic inhibitors. Bimetallic corrosion screening experiments were carried out to determine the corrosion rate. Potentiodynamic polarization experiments yielded information on the galvanic couples and also corrosion rates. XPS and FTIR surface analysis gave important information pertaining inhibition mechanism of organic inhibitors. Interestingly copper in contact with ruthenium in cleaning solution led to increased corrosion rate compared to copper in contact with tantalum. On the other hand when cobalt was in contact with copper, cobalt corroded and copper did not. We ascribe this phenomenon to the difference in the standard reduction potentials of the two metals in contact and in such a case a less noble metal will be corroded. The effects of plasma etch gases such as CF4, CF4+O2, C4F8, CH2F2 and SF6 on copper bimetallic corrosion was investigated too in alkaline solution. It was revealed that the type of etching gas plasma chemistry used in Cu interconnect manufacturing process creates copper surface modification which affects corrosion behavior in alkaline solution. The learning from copper bimetallic corrosion studies will be useful in the development of etch and clean formulations that will results in minimum defects and therefore increase the yield and reliability of copper interconnects. digital.library.unt.edu/ark:/67531/metadc499992/
Sensitivity and Uncertainty Analysis of Occupancy-related Parameters in Energy Modeling of Unt Zero Energy Lab
The study focuses on the sensitivity and uncertainty analysis of occupancy-related parameters using Energyplus modeling method. The model is based on a real building Zero Energy Lab in Discovery Park, at University of North Texas. Four categories of parameters are analyzed: heating/cooling setpoint, lighting, equipment and occupancy. Influence coefficient (IC) is applied in the sensitivity study, in order to compare the impact of individual parameter on the overall building energy consumption. The study is conducted under Texas weather file as well as North Dakota weather file in order to find weather’s influence of sensitivity. Probabilistic collocation method (PCM) is utilized for uncertainty analysis, with an aim of predicting future energy consumption based on history or reference data set. From the study, it is found that cooling setpoint has the largest influence on overall energy consumption in both Texas and North Dakota, and occupancy number has the least influence. The analysis also indicates schedule’s influence on energy consumption. PCM is able to accurately predict future energy consumption with limited calculation, and has great advantage over Monte Carlo Method. The polynomial equations are generated in both 3-order and 6-order, and the 6-order equation is proved to have a better result, which is around 0.1% compared with real value. digital.library.unt.edu/ark:/67531/metadc499991/
The Effect of Natural Gas Well Setback Distance on Drillable Land in the City of Denton, Texas
Access: Use of this item is restricted to the UNT Community.
Municipalities protect human health and environmental resources from impacts of urban natural gas drilling through setback distances; the regulation of distances between well sites and residences, freshwater wells, and other protected uses. Setback distances have increased over time, having the potential to alter the amount and geographical distribution of drillable land within a municipality, thereby having implications for future land use planning and increasing the potential for future incompatible land uses. This study geographically applies a range of setback distances to protected uses and freshwater wells in the city limits of Denton, Texas to investigate the effect on the amount of land remaining for future gas well development and production. Denton lies on the edge of a productive region of the Barnett Shale geological formation, coinciding with a large concentration of drillable land in the southwestern region of the study area. This region will have the greatest potential for impacts to future municipal development and land use planning as a result of future gas well development and higher setback standards. Given the relatively high acreage of drillable land in industrially zoned subcategory IC-G and the concern regarding gas well drilling in more populated areas, future drilling in IC-G, specifically in IC-G land cover classes mowed/grazed/agriculture and herbaceous, would have the least impact on residential uses and tree cover, as well as decreasing the potential for future incompatible land uses. digital.library.unt.edu/ark:/67531/metadc499998/
Reading Beyond the Words: How Implementing Esl Strategies During Modified Guided Reading Affects a Deaf Student’s Language Acquisition Process
While Deaf students are not typically classified as English as a second language (ESL) students, the majority of deaf students first become fluent in a signed language, making them ideal candidates for ESL research. This case study has been designed to explore the ways in which one method of ESL reading instruction, known as modified guided reading (MGR), affects the language acquisition process, and resulting reading comprehension level, of a deaf student over eleven weeks. The study documented the student’s language acquisition development both in American Sign Language (ASL) and in English, as well as tracked the student’s growth in reading comprehension, metalinguistic awareness, and visual attention skills. The Accelerated Reader (AR) program, benchmark testing, and daily observations were used to measure growth. Findings of the study suggest that the ESL methods implemented through MGR positively impacted the student’s language acquisition process, reading comprehension level, metalinguistic awareness, and visual attention skills. Results showed an increase in all three of the student’s AR scores as follows: 31% in reading level, 13.1% in number of words read, and 13.2 % in comprehension test scores. Observations and benchmark testing revealed increased metalinguistic knowledge in word, syntactic, and pragmatic awareness. Visual attention skills were found to be the key element in allowing reading comprehension to take place and strategies for improving these skills were found to be a necessary part of the MGR process. digital.library.unt.edu/ark:/67531/metadc499994/
Études: Five Compositional and Technical Studies for Solo Organ
Études was composed as a set of five interrelated movements in the followingorder: Prelude, Introduction and Fugue, Triptych, Chorale, and Response. The pieces are compositional as well as technical studies. The movements specifically explore certain styles and forms unique to organ music, and reintroduce these elements in creative ways. As in the traditional étude, each movement contains virtuosic technical studies, which are designed to enhance manual and pedal facility and prepare the performer for advanced repertoire. digital.library.unt.edu/ark:/67531/metadc499990/
Spatial Ability in Registered Nurses
Spatial ability is the skill associated with mental relations among objects, the process of maintaining the physical aspects of an object after mentally rotating it in space. Many studies report a strong association of spatial ability with success in various areas of health care, especially surgery, radiology and dentistry. To date, similar investigations in professional nursing could not be located. Registered nurses, employed in an acute care multi-hospital setting, were surveyed using the Shipley-2Block Pattern Test, the Group Embedded Figures Test, and a newly created test of general nursing knowledge. The sample size of 123 nurses was composed of 31 male nurses and 92 female nurses. Data was collected between May and August of 2013 and analyzed using R, version 2.15.2. The present study did not demonstrate a statistically significant effect for gender differences on two measures of spatial ability. However, Cohen’s d effect sizes for mean gender differences in the present study are consistent with prior studies. This may suggest the nursing profession is comparable with other professions where males perform higher than females on spatial ability. The present study should be considered an initial step toward evaluating the relevance of spatial ability in the performance of nursing care. digital.library.unt.edu/ark:/67531/metadc499989/
A Performance Analysis of Solar Chimney Passive Ventilation System in the Unt Zero Energy Lab
The purpose of this investigation is to find out suitability of the solar chimney natural ventilation system in a Zero Energy Lab located at the University of North Texas campus, to figure out performance of the solar chimney. Reduction in the heating and ventilation and air conditioning energy consumption of the house has been also analyzed. The parameters which are considered for investigation are volumetric flow rate of outlet of chimney, the absorber wall temperature and glass wall temperatures. ANSYS FLUENT 14.0 has been employed for the 3-D modeling of the solar chimney. The dimensions of the solar chimney are 14’2” X 7’4” X 6’11”. The flow inside solar chimney is found to be laminar and the simulation results show that maximum outlet volumetric flow rate of about 0.12m3/s or 432 cfm is possible from chimney. The experimental velocity of chimney was found to be 0.21 m/s. Density Boussinesq approximation is considered for the modeling. Velocity and temperature sensors have been installed at inlet and outlet of the chimney in order to validate the modeling results. It is found that based on simulated volumetric flow rate that cooling load of 9.29 kwh can be saved and fan power of 7.85 Watts can be saved. digital.library.unt.edu/ark:/67531/metadc499996/
A Pedagogical and Methodical Approach to Unaccompanied Euphonium Literature Through Performance and Analyses of Original Works by Torstein Aagaard-nilsen
Original unaccompanied literature currently stands as one of the most understudied bodies of music in the euphonium repertory. This is largely due to a lack of access to reference recordings, live performances, and study/performance guides. Many of the commissioning projects for new euphonium music in the late 20th and early 21st centuries have promoted the composition of large scale works for euphonium and large ensembles, but very few have generated new unaccompanied pieces for euphonium. Many of the most recent commissions for unaccompanied euphonium music have been for competitions such as the Lieksa Brass Festival (Finland) and Leonard Falcone International Festival (USA). These competitions are also where many students get their only exposure to the unaccompanied repertoire. Unfortunately, there is a small number of standard unaccompanied works that are continuously recycled for these competitions and the exposure to new pieces in the repertoire is further diminished for many developing euphoniumists. This study will examine the three works for unaccompanied euphonium by Torstein Aagaard-Nilsen and provide solutions for many common technical challenges and pose suggestions for approaching and preparing this genre of music. Connections are made throughout the study to specific etudes and other unaccompanied solos that can be used as complementary and precursory studies to aid in the mastery of this literature. digital.library.unt.edu/ark:/67531/metadc499997/
A Study of Silver: an Alternative Maldi Matrix for Low Weight Compounds and Mass Spectrometry Imaging
Soft-landing ion mobility has applicability in a variety of areas. The ability to produce material and collect a sufficient amount for further analysis and applications is the key goal of this technique. Soft-landing ion mobility has provided a way to deposit material in a controllable fashion, and can be tailored to specific applications. Changing the conditions at which soft-landing ion mobility occurs effects the characteristics of the resulting particles (size, distribution/coverage on the surface). Longer deposition times generated more material on the surface; however, higher pressures increased material loss due to diffusion. Larger particles were landed when using higher pressures, and increased laser energy at ablation. The utilization of this technique for the deposition of silver clusters has provided a solvent free matrix application technique for MALDI-MS. The low kinetic energy of incident ions along with the solvent free nature of soft-landing ion mobility lead to a technique capable of imaging sensitive samples and low mass analysis. The lack of significant interference as seen by traditional organic matrices is avoided with the use of metallic particles, providing a major enhancement in the ability to analyze low mass compounds by MALDI. digital.library.unt.edu/ark:/67531/metadc499981/
Remembering the Forgotten D-day: the Amphibious Landing at Collado Beach During the Mexican War
The current historiography of the Mexican War does not give due credit to the significance of the landing at Collado Beach. No one source addresses all aspects of the landing, nor have any included an analysis of the logistical side of the operation. This thesis presents a comprehensive analysis of the operation from conception to execution in an attempt to fill the gap in the historiography. Additionally, the lessons learned and lessons forgotten from this landing are addressed as to how this landing shaped American military doctrine regarding joint operations and amphibious operations. The conclusion drawn from the historical sources supports the argument that this operation had a significant impact on the American military. The influence of this operation shows itself throughout American military history, including the establishment of amphibious doctrine by the Unites States Marine Corps and during World War II. digital.library.unt.edu/ark:/67531/metadc499987/
Does Underwriter Size Matter? Only Within the Right Context
The initial matching relationships between underwriters and bonds/issuing firms and the certification quality of underwriters, as determined by changes in the issuing firm’s financial strength post issue, are the two primary research topics in this dissertation. Based on total underwriter syndicate market share, two distinct categories, low market power (LMP) syndicates and high market power (HMP) syndicates were defined. Firm financial strength is examined based on a new factor developed in this research. A comparison of the two underwriting categories, or pools, indicates that the HMP underwriters take on firms of lower initial financial strength and additionally, the issuing firms decline more in financial strength two years following bond issuance than do firms using LMP underwriters. Notwithstanding these results, the more interesting findings are the relationships within each of these pools. In the LMP pool of underwriters, financially stronger firms used the larger LMPs to underwrite their bonds, while the weaker firms used smaller LMPs. In contrast, among HMP underwriters, the largest HMPs aligned with the firms of relatively lower financial strength. The relationships in both pools reverse when changes in financial strength are examined. Larger LMPs are associated with greater issuing firm financial decline while larger HMPs correlate with lower levels of decline in firm financial strength. Divergent patterns in initial underwriter-issuer matching and underwriter certification found in this research indicate that there are true differences in the “small” underwriting syndicates as compared to the larger syndicates. These patterns should be considered by both issuing firms and investors as both constituencies contemplate the corporate bond market. digital.library.unt.edu/ark:/67531/metadc500223/
“Werewolves and Time Machines”
This collection consists of a critical preface and five short stories. The preface considers the use of the fantastical in fiction and how it works as a tool to reach readers in comparison with realistic fiction. The stories investigate this in by following several strange characters put in everyday human situations. digital.library.unt.edu/ark:/67531/metadc500203/
Harold Shapero’s Sonata for C Trumpet and Piano: the Influence of Idiomatic Jazz Elements on a Prominent Mid-20th Century Neo-classical Composer
Harold Shapero’s Sonata for Trumpet in C and Piano is a significant work that it is rarely performed and studied. Shapero’s composition contains musical attributes that demand artistically accurate choices if the style of this jazz-influenced sonata is to be achieved. Written in 1940 in dedication to Aaron Copland, the Sonata for C Trumpet and Piano makes use of a variety of stylistic influences, blending those of early 20th century jazz with Stravinsky-influenced neo-classicism. The intent of this study is to examine the unique performance practice implications and musical considerations of Harold Shapero’s Sonata for C Trumpet and Piano in correlation to the composer’s implementation of jazz idiomatic elements within the constructs of neo-classicism. The first section of this study examines the historical context necessary for understanding the social and musical conditions of the early to mid 1940s. The second section addresses the musical elements that characterize this work; the primary focus of this section is an exploration of Harold Shapero’s implementation of jazz idioms into his first composition for trumpet. The final section of the study interprets the utilization of idiomatic jazz elements within the work so as to allow the trumpet player with little jazz experience to accurately perform the piece. digital.library.unt.edu/ark:/67531/metadc500207/
Utilizing North American Art Song Settings of Psalm Texts in Worship Services: an Annotated Guide for Singers, Voice Instructors, and Music Ministers
This dissertation provides a guide for appropriate use of North American art song settings of biblical psalms for solo voice written after 1950 in the worship services of Christian faiths. The songs analyzed are for all voice parts and a variety of accompanying ensembles. The placement of each song on a specific calendar day is guided by the individual church calendars and lectionaries, on the prevalent themes of the text, and the characteristics of the musical setting. Performance of these songs only in a concert setting limits their usefulness for singers, voice teachers, and music directors alike. A new and worthy performing context can be established by analyzing the text and musical settings. digital.library.unt.edu/ark:/67531/metadc500200/
The Ultimate Ethos: Challenges, Cooptation and Survival During Ultimate’s Adolescence
Ultimate is the fastest growing field sport in America. Created in 1968, forty-five years later the sport was still on the periphery of the mainstream but reached new heights in 2013 – two professional leagues, over 800 college teams and a broadcasting deal with ESPN – and the discussions throughout the sports’ history have never been as relevant. Self-officiation and the Spirit of the Game are the main tenets that make up the ethos of the sport and its community. These unique aspects differentiate Ultimate’s predominate culture from that of mainstream sports culture. This study shows the countercultural ties and survival of the ethos during the adolescent period of Ultimate’s evolution (1987-2010). It examines the progression of the community’s established grassroots culture and the governing body of the sport alongside the influx of young players with mainstream sports attitudes who bolstered certain organizers’ attempts to alter Ultimate in the hopes of gaining “legitimacy” through adding third-party officials, commercialization and corporate sponsorship. digital.library.unt.edu/ark:/67531/metadc500209/
Using Complexity Thinking to Build Adaptive Capacity in Schools: an Analysis of Organizational Change in California
In response to reductionist neoliberal approaches to organizational change that have been prevalent in American education since the 1980s, some educators have begun to employ a whole-systems approach to improving student learning. These approaches, based in complexity sciences, recognize the nonlinear, unpredictable nature of learning and the interconnected relationships among myriad factors that influence the teaching/learning that occurs in schools. In the summer preceding the 2011-2012 school year, a cohort of educators from California Unified School District participated in a 10-day training regarding human systems dynamics (HSD) and complexity thinking. Their goal was to build adaptive capacity throughout the district in the pursuit of improving student learning. Through analysis of the interviews from seven target participants from this training, this study investigates what target participants report regarding their use of HSD methods and models in their work in schools across the 2011-2012 school year. Findings indicate that target participants displayed distinct arcs of use of HSD methods/models. In addition, findings suggest that target participants’ need for support in learning and implementing HSD methods/models, the influence of systemic and individual history, and the role of agency affected their “arcs of use.” This study illuminates the ways in which HSD methods/models support both organizational change efforts and the ways in which teaching/learning occur in the classroom, including the applicability of HSD methods/models in building collaborative cultures and in helping students develop the kinds of thinking required in the use of 21st-century literacies. digital.library.unt.edu/ark:/67531/metadc500210/
Internet Health Information and Patient-health Professional Relationship
The purpose of this study was to investigate patient use and presentation of Internet health information and its effect on patient-health professional relationship from a sample of residents at active adult communities in Texas. Five sites were used to recruit the 260 participants between November 2012 and January 2013. The data were received using a self-administered survey. Using Cronbach’s alpha, logistic regression and regression analysis through SAS, the data revealed that older respondents are less likely to discuss web-based information with health professionals. In addition, logistic regression analysis indicated that four of the variables, IHI Sharing, educational status (bachelor degree), marital status (married), and perceived health status (excellent and very good health) predicted varied of the 20 indicators making up the patient-health professional relationship scale. Further studies are needed to enhance this research. digital.library.unt.edu/ark:/67531/metadc500212/
Implications of Punctuation Mark Normalization on Text Retrieval
This research investigated issues related to normalizing punctuation marks from a text retrieval perspective. A punctuated-centric approach was undertaken by exploring changes in meanings, whitespaces, words retrievability, and other issues related to normalizing punctuation marks. To investigate punctuation normalization issues, various frequency counts of punctuation marks and punctuation patterns were conducted using the text drawn from the Gutenberg Project archive and the Usenet Newsgroup archive. A number of useful punctuation mark types that could aid in analyzing punctuation marks were discovered. This study identified two types of punctuation normalization procedures: (1) lexical independent (LI) punctuation normalization and (2) lexical oriented (LO) punctuation normalization. Using these two types of punctuation normalization procedures, this study discovered various effects of punctuation normalization in terms of different search query types. By analyzing the punctuation normalization problem in this manner, a wide range of issues were discovered such as: the need to define different types of searching, to disambiguate the role of punctuation marks, to normalize whitespaces, and indexing of punctuated terms. This study concluded that to achieve the most positive effect in a text retrieval environment, normalizing punctuation marks should be based on an extensive systematic analysis of punctuation marks and punctuation patterns and their related factors. The results of this study indicate that there were many challenges due to complexity of language. Further, this study recommends avoiding a simplistic approach to punctuation normalization. digital.library.unt.edu/ark:/67531/metadc500160/
Educational Experiences of Youth with And/or At-risk for Emotional and Behavioral Disorders Residing in Foster Care Settings
Research examining the academic experiences of youth with emotional and behavioral disorders (EBD) residing in foster care (FC) is scarce. Research is warranted to understand the academic strengths, weaknesses, and school disciplinary experiences of youth with EBD residing in FC. Data from the National Survey of Child and Adolescent Well-being II (NSCAW II) included data on eight participants classified as EBD. Having a limited number of participants classified as EBD in the data set, I used participants’ scores on the Child Behavior Checklist (CBCL) to classify participants who may be at-risk for EBD. Analyses were conducted to determine if significant relationships existed between participants’ internalizing and externalizing scores on the CBCL and their (a) scores on assessments of academic achievement and (b) behavior problems leading to suspension or expulsion. Results indicated that participants’ scores on the CBCL were not predictive of their academic achievement or of their numbers of behavior problems leading to suspension or expulsion. digital.library.unt.edu/ark:/67531/metadc500118/
Racial/ethnic Differences in Hospital Utilization for Cardiovascular-related Events: Evidence of a Survival and Recovery Advantage for Latinos?
Evidence continues to demonstrate that racial/ethnic minority groups experience a disproportionate burden of disease and mortality in cardiovascular-related diseases (CVDs). However, emerging evidence suggests a health advantage for Latinos despite a high risk profile. The current study explored the hospital utilization trends of Latino and non-Latino patients and examined the possibility of an advantage for Latinos within the context of CVD-related events with retrospective data collected over a 12-month period from a local safety-net hospital. Contrary to my hypotheses, there was no advantage for in-hospital mortality, length of stay or re-admission in Latinos compared to non-Latinos; rather, Latinos hospitalized for a CVD-related event had a significantly longer length of stay and had greater odds for re-admission when compared to non-Latinos. Despite data suggesting a general health advantage, Latinos may experience a relative disparity within the context of hospital utilization for CVD-related events. Findings have implications for understanding the hospital utilization trends of Latinos following a CVD-related event and suggest a call for action to advance understanding of Latino cardiovascular health. digital.library.unt.edu/ark:/67531/metadc500102/
A Study of Power Generation From a Low-cost Hydrokinetic Energy System
The kinetic energy in river streams, tidal currents, or other artificial water channels has been used as a feasible source of renewable power through different conversion systems. Thus, hydrokinetic energy conversion systems are attracting worldwide interest as another form of distributed alternative energy. Because these systems are still in early stages of development, the basic approaches need significant research. The main challenges are not only to have efficient systems, but also to convert energy more economically so that the cost-benefit analysis drives the growth of this alternative energy form. One way to view this analysis is in terms of the energy conversion efficiency per unit cost. This study presents a detailed assessment of a prototype hydrokinetic energy system along with power output costs. This experimental study was performed using commercial low-cost blades of 20 in diameter inside a tank with water flow speed up to 1.3 m/s. The work was divided into two stages: (a) a fixed-pitch blade configuration, using a radial permanent magnet generator (PMG), and (b) the same hydrokinetic turbine, with a variable-pitch blade and an axial-flux PMG. The results indicate that even though the efficiency of a simple blade configuration is not high, the power coefficient is in the range of other, more complicated designs/prototypes. Additionally, the low manufacturing and operation costs of this system offer an option for low-cost distributed power applications. digital.library.unt.edu/ark:/67531/metadc500174/
The Mechanisms of Methane C–h Activation and Oxy-insertion Via Small Transition Metal Complexes: a Dft Computational Investigation
Our country continues to demand clean renewable energy to meet the growing energy needs of our time. Thus, natural gas, which is 87% by volume of methane, has become a hot topic of discussion because it is a clean burning fuel. However, the transportation of methane is not easy because it is a gas at standard temperature and pressure. The usage of transition metals for the conversion of small organic species like methane into a liquid has been a longstanding practice in stoichiometric chemistry. Nonetheless, the current two-step process takes place at a high temperature and pressure for the conversion of methane and steam to methanol via CO + H2 (syngas). The direct oxidation of methane (CH4) into methanol (CH3OH) via homogeneous catalysis is of interest if the system can operate at standard pressure and a temperature less than 250 C. Methane is an inert gas due to the high C-H bond dissociation energy (BDE) of 105 kcal/mol. This dissertation discusses a series of computational investigations of oxy-insertion pathways to understand the essential chemistry behind the functionalization of methane via the use of homogeneous transition metal catalysis. The methane to methanol (MTM) catalytic cycle is made up of two key steps: (1) C-H activation by a metal-methoxy complex, (2) the insertion of oxygen into the metal−methyl bond (oxy-insertion). While, the first step (C-H activation) has been well studied, the second step has been less studied. Thus, this dissertation focuses on oxy-insertion via a two-step mechanism, oxygen-atom transfer (OAT) and methyl migration, utilizing transition metal complexes known to activate small organic species (e.g., PtII and PdII complexes). This research seeks to guide experimental investigations, and probe the role that metal charge and coordination number play. digital.library.unt.edu/ark:/67531/metadc500116/
Britten’s Op 47, Five Flower Songs: Breaking Trends in Analysis
Benjamin Britten’s life and music have been the subject of study from early in his musical career. Current trends in psychological analysis of Britten’s music tend to focus on common themes, such as homosexuality, pacifism, the sense of the outsider, and the loss of innocence. Similarly, theoretical analyses tend either to provide general categorizations of the technical elements in Britten’s music or to apply a singular preconceived concept as a tool for understanding his compositions. These approaches have yielded significant information but leave aspects of Britten’s personality and music unilluminated. Britten’s Op. 47, Five Flower Songs, are a collection of five part songs for a cappella chorus that are often included within the canon of 20th century choral literature. This paper examines a new perspective on Britten’s music by examining the relationship between Britten’s friendships and their influence on his compositions. Through the examination of these relationships information is revealed that allows for a new method of analysis that is particularly relevant to the Five Flower Songs. The opus was dedicated to two botanists for the occasion of their 25th wedding anniversary. Contained within specific movements are extra-musical references to scientific characteristics of the flowers that are the subjects of the texts. By examining this work and important connections between other friendships and his compositional output this paper demonstrates the validity of this perspective in analyzing Britten’s life and music. digital.library.unt.edu/ark:/67531/metadc500181/
Experiences and Perceptions of Students in Music and Mathematics
Since the time of Pythagoras, philosophers, educators, and researchers have theorized that connections exist between music and mathematics. While there is little doubt that engaging in musical or mathematical activities stimulates brain activity at high levels and that increased student involvement fosters a greater learning environment, several questions remain to determine if musical stimulation actually improves mathematic performance. This study took a qualitative approach that allowed 24 high school students to express their direct experiences with music and mathematics, as well as their perceptions of how the two fields are related. Participants were divided into four equal groups based on school music participation and level of mathematic achievement, as determined by their performance on the Texas Assessment of Knowledge and Skills (TAKS). Students participated in a series of three interviews addressing their experiences in both music and mathematics, and took the Multiple Intelligences Developmental Assessment Scales (MIDAS). TAKS data and MIDAS information were triangulated with interview findings. Using a multiple intelligence lens, this study addressed the following questions: (a) How do students perceive themselves as musicians and mathematicians? (b) What experiences do students have in the fields of music and mathematics? (c) Where do students perceive themselves continuing in the fields of music and mathematics? and (d) How do students perceive the fields of music and mathematics relating to each other? Contrary to most existing literature, the students who perceived a connection between the two fields saw mathematics driving a deeper understanding of the musical element of rhythm. Not surprisingly, students with rich backgrounds in music and mathematics had a higher perception of the importance of those fields. Further, it became readily apparent that test data often played a minimal role in shaping student perceptions of themselves in the field of mathematics. Finally, it became apparent from listening to the experiences of high school students, there are many growth areas for schools in order to meet the needs of their students. digital.library.unt.edu/ark:/67531/metadc500113/
Physiological and Psychological Effects of an Acute Stressor: Comparing Coping Strategies Among Very Physically Active and Less Active Adults
The purpose of this study was to examine whether physical activity status of healthy adult males (N = 59) while in a coping strategy condition (association, disassociation, or control) influences psychophysiological responses to an acute painful stimulus. Measures of pain tolerance, state anxiety, body awareness, and salivary cortisol were investigated. Results indicated no significant differences between physical activity groups for pain tolerance, stress responses (i.e., self-reported state anxiety and cortisol levels), or body awareness. Though, those who indicated using a disassociation coping technique during the exit interview tolerated the acute, surface pain longer. More research is required to further understand the effects of physical activity and coping strategies on pain perception and psychophysiological responses. digital.library.unt.edu/ark:/67531/metadc500119/
Declining Participation in Fraternity and Sorority Life: a Comparison of Perceptions of Greek-lettered Organizations Between Affiliated and Non-affiliated Students
This quantitative study was used to determine the perceptions that may have caused a decline in membership in fraternities and sororities and to examine active organization involvement between affiliated and unaffiliated students at a single higher education institution in northeast Texas. Eight perceptions were given regarding fraternity and sorority life and why students chose to remain unaffiliated with fraternities or sororities. The instrument used was a modified version of the Extracurricular Involvement Inventory, created by Winston and Massaro (1987) and was administered to participants online via Survey Monkey. There were 206 participants total: 55.3% were female, and 44.7% were male. Regarding ethnicities, 47.0% were African American, 37.5% were Caucasian, and 15.5% were Hispanic/Latino. Out of the participants, 20.9% were in their freshman or sophomore year, 23.8% were juniors, 33.5% were seniors, and 21.8% were graduate students. Participants’ ages ranged from 18 to 32, with a mean of 22.89 (SD = 2.81). The research questions were analyzed using two techniques: logistic regression for the first question and multiple regression for the second question. Findings for the first research question indicated that lack of values, lack of diversity, poor academic attitudes, and a requirement of too much time were primary reasons unaffiliated students chose not to join a fraternity or sorority. Findings for the second question indicated that Greek-affiliated students averaged higher involvement intensity scores when compared to unaffiliated students. Practical implications and future research are discussed. digital.library.unt.edu/ark:/67531/metadc500187/
The Effect of Head Flexion/extension on Acoustic Measures of Singing Voice Quality
A study was undertaken to identify the effect of head flexion/extension on singing voice quality. The amplitude of the fundamental frequency (F0), and the singing power ratio (SPR), an indirect measure of singer’s formant activity, were measured. F0 and SPR scores at four experimental head positions were compared with the subjects’ scores at their habitual positions. Three vowels and three pitch levels were tested. F0 amplitudes and low frequency partials in general were greater with more extended head positions, while SPR increased with neck flexion. No effect of pitch or vowel was found. Gains in SPR appear to be the result of damping low frequency partials rather than amplifying those in the singer’s formant region. Raising the amplitude of F0 is an important resonance tool for female voices in the high range, and may be of benefit to other voice types in resonance, loudness, and laryngeal function. digital.library.unt.edu/ark:/67531/metadc500127/
Shall We Dance? Teaching Parents the Communication Dance to Enhance Generalized Communication in Their Children
Children diagnosed with autism exhibit deficits in communication that impact their ability to control their immediate environment. Recent research on mand training has been criticized for producing a limited number of mand topographies over a long span of time with limited generalization to novel environments. There is a body of research, however, that successfully establishes larger repertoires. Training parents as change agents may mediate generalization by teaching under naturally maintaining contingencies. Additional effects of parent training may reduce parent reports of stress, increase favorable quality of parent-child interactions, and increase reports of parental self-efficacy. The current study evaluated the effects of a generalized training framework to teach parents how to target generalized mands and expand their child’s communicative topographies. The effects of the training were evaluated using a non-concurrent multiple baseline across participants and skills. Results indicated that parents were able to effectively teach their child to mand for a variety of items and events and to substantially increase the number of different mand topographies and expand the topographies the child emitted. Parents were observed to have higher overall confidence and lower overall stress following intervention. The current study builds on previous research on generalized teaching strategies for parents that are effective in teaching a variety of responses to the child. digital.library.unt.edu/ark:/67531/metadc500157/
Hip-hop’s Tanning of a Postmodern America: a Longitudinal Content Analysis of Paradoxical Juxtapositions of Oppositional Identities Within Us Rap Song Lyrics, 1980-2013
A longitudinal content analysis of top-chart hip-hop songs’ lyrics produced between 1980 and 2013 was conducted to investigate the degree and progression of the paradoxical juxtaposition, or postmodern hybridity, of oppositional modernist identities in terms of race/ethnicity, gender, sexual orientation, sexuality, and economic lifestyle, in addition to the longitudinal diversification of artist’s race and gender demographics. Demographically, the percentage of non-African-American artists increased as the percentage of African-American artists decreased. Additionally, the percentage of songs featuring either all male or all female artists decreased, while the percentage of collaboration between male and female artists increased over time. Although hybrid oppositional identities related to race/ethnicity and gender did not increase over time, those of sexual orientation, sexuality, and economic lifestyle increased over time. In addition, materialist identities were related to the hybridity of sexual orientation and sexuality, but not to that of gender and race/ethnicity. Overall, the research found increasing postmodern hybridity within the sexualization of hip-hop songs along with intensified materialism. digital.library.unt.edu/ark:/67531/metadc500206/
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. digital.library.unt.edu/ark:/67531/metadc500204/
Synthesis, Characterization, Structural, and Optical Properties of Zinc Oxide Nanostructures Embedded in Silicon Based Substrates
Structural and optical properties of ZnO nanostructures synthesized by low energy ion implantation technique were examined. ZnO molecular ions were implanted into Si/SiO2 substrates at room temperature and then furnace annealed under different temperatures and environments. In all as-implanted samples only Zn nanostructures with varying diameters distributed into the Si/SiO2 matrices were observed. No trace of ZnO was found. The distributions of Zn nanostructures in Si/SiO2 closely matched results from Stopping and Range of Ions in Matter (SRIM) simulations. During annealing at 750 oC, Zn diffused both toward and away from the surface of the substrate and combine with oxygen to form ZnO nanostructures. At higher annealing temperatures ZnO bonding started to break down and transfer to zinc silicate (Zn2SiO4), and at 900 oC the ZnO was completely converted into Zn2SiO4. The average sizes of Zn/ZnO nanostructures depended on the ion fluence. If the fluence increased the average sizes of nanostructures also increased and vice versa. For room temperature photoluminescence (RT-PL), band-edge emission in the ultraviolet (UV) region was observed from all samples annealed at 700 oC/750 oC and were slightly blue shifted as compare to bulk ZnO. Donor-bound exciton (D,X) and acceptor-bound exciton (A,X) transitions were observed in low temperature photoluminescence (PL). The lifetime of both donor-bound excitonic emission (D, X) and acceptor-bound excitonic emission (A, X) were found to be in the picosecond (ps) range. digital.library.unt.edu/ark:/67531/metadc500222/
The Effects of Sucrose on Ethanol Consumption in Ethanol Naïve and Non-naïve Rats
Sucrose fading and intermittent access are two common procedures that induce alcohol consumption in rodents. Sucrose fading procedures involve exposing ethanol naïve rats to a mixture of ethanol and sucrose and gradually reducing the concentration of sugar. Intermittent access procedures involve providing rats with access to ethanol on alternating days. Given that rats will consume ethanol without sucrose, the role of sugar in the sucrose fading procedure is unclear. Rats must be ethanol naïve when they are exposed to treatment with sucrose fading, so there is no point of comparison to show that exposure to sugar in sucrose fading produces higher levels of drinking. There has yet to be any work that isolates the effects of sugar on the consumption of alcohol. The purpose of the present experiment was to examine the effects of sucrose on ethanol consumption in rats with different alcohol histories. Two groups of six rats were exposed to two successive sucrose fading procedures, 30 days apart and their drinking was measured 30 days after each one. One group was exposed to an intermittent access procedure to establish drinking prior to treatment with sucrose fading, the other was ethanol naïve. Following sucrose fading, all rats drank pharmacologically active doses of ethanol. For both groups consumption correlated with the concentration of sucrose and decreased in a step-wise manner as it was faded. For the ethanol experienced rats, consumption dropped below baseline levels as sucrose was faded and decreased further with the second exposure. In contrast, the ethanol-naïve rats did not decrease consumption from the first sucrose fading procedure to the second. Slight differences in peak force of responses were also observed. digital.library.unt.edu/ark:/67531/metadc500220/
Dance: a Training Package Utilizing Videotaped Self-observation to Teach Parents to Enhance Social Interactions with Children At-risk for a Developmental Delay
Previous research has demonstrated the effectiveness of programs that include a videotaped self-observation component. The self-observation protocols, however, have not been clearly specified within programs that teach and report parents’ use of general teaching strategies. The current study investigates the effects of a training package with a self-observation component to teach parents to improve teaching interactions with their children at-risk for a developmental delay using an AB design replicated across participants. Data were collected across play interactions to assess the number of parent teaching episodes, child target responses, and various parent and child relationship qualities. Relationship quality measures included parent and child affect and engagement, parent directives, parent confidence and stress, and parent and child interest. The results of this study suggest that the training package was effective in that parents engaged in higher rates of teaching, their children engaged in more desired responding, and certain aspects of the parent-child interaction were enhanced. These results are discussed in terms of the effects on the parent-child teaching interaction and implications for future use of parent self-observation techniques. digital.library.unt.edu/ark:/67531/metadc500215/
Denial of Risk: the Effects of Intentional Minimization on Risk Assessments for Psychopathic and Nonpsychopathic Offenders
Risk assessments for offenders often combine past records with current clinical findings from observations, interviews, and test data. Conclusions based on these risk assessments are highly consequential, sometimes resulting in increased criminal sentences or prolonged hospitalization. Offenders are therefore motivated to intentionally minimize their risk scores. Intentional minimization is especially likely to occur in offenders with high psychopathic traits because goal-directed deception is reflected in many of the core traits of the disorder, such as manipulativeness, glibness, and superficial charm. However, this connection appears to be based on the conceptual understanding of psychopathy, and it has rarely been examined empirically for either frequency or success. The current study examined the connection between psychopathic traits and the intentional minimization of risk factors using a sentenced jail sample. In general, offenders were able to effectively minimize risk on the HCR-20 and SAQ, while the PICTS, as a measure of cognitive styles, was more resistant to such minimization. Psychopathic traits, especially high interpersonal facet scores, led to greater minimization using a repeated measure, simulation design. Important differences in the willingness and ability to use deception were found based on (a) the content of subscales, and (b) the mode of administration (i.e., interview vs. self-report). The important implications of this research are discussed for risk assessment procedures regarding likely areas of deception and its detection. It also informs the growing literature on the connection between psychopathic traits and deception. digital.library.unt.edu/ark:/67531/metadc500221/
Examining the Relationship Between Persistence in Attendance in an Afterschool Program and an Early Warning Index for Dropout
School districts constantly struggle to find solutions to address the high school dropout problem. Literature supports the need to identify and intervene with these students earlier and in more systemic ways. The purpose of this study was to conduct a longitudinal examination of the relationship between sustained afterschool participation and the host district’s early warning index (EWI) associated with school dropout. Data included 65,341 students participating in an urban school district’s after school program from school years 2000-2001 through 2011-2012. The district serves more than 80,000 students annually. Data represented students in Pre-Kindergarten through Grade 12, and length of participation ranged from 1 through 12 years. Results indicated that student risk increased over time and that persistent participation in afterschool programming had a significant relationship with student individual growth trajectories. Slower growth rates, as evidenced through successive models, supported students being positively impacted by program participation. Additionally, participation was more meaningful if students persisted, as noted in the lower EWI rates, as compared to students who attended less consistently. digital.library.unt.edu/ark:/67531/metadc500218/
The Effects of Residual Gases on the Field Emission Properties of Zno, Gan, Zns Nanostructures, and the Effects of Light on the Resistivity of Graphene
In this dissertation, I present that at a vacuum of 3×10-7 Torr, residual O2, CO2, H2 and Ar exposure do not significantly degrade the field emission (FE) properties of ZnO nanorods, but N2 exposure significantly does. I propose that this could be due to the dissociation of N2 into atomic nitrogen species and the reaction of such species with ZnO. I also present the effects of O2, CO2, H2O, N2, H2, and Ar residual gas exposure on the FE properties of GaN and ZnS nanostructure. A brief review of growth of ZnO, GaN and ZnS is provided. In addition, Cs deposition on GaN nanostructures at ultra-high vacuum results in 30% decrease in turn-on voltage and 60% in work function. The improvement in FE properties could be due to a Cs-induced space-charge layer at the surface that reduces the barrier for FE and lowers the work function. I describe a new phenomenon, in which the resistivity of CVD-grown graphene increases to a higher saturated value under light exposure, and depends on the wavelength of the light—the shorter the wavelength, the higher the resistivity. First-principle calculations and theoretical analysis based on density functional theory show that (1) a water molecule close to a graphene defect is easier to be split than that of the case of no defect existing and (2) there are a series of meta-stable partially disassociated states for an interfacial water molecule. Calculated disassociation energies are from 2.5 eV to 4.6 eV, that match the experimental observation range of light wavelength from visible to 254 nm UV light under which the resistivity of CVD-grown graphene is increased. digital.library.unt.edu/ark:/67531/metadc500202/
A Study of Learning Outcomes of a Mobile Travel Application in Tourism Geographic Course
Mobile technologies have been adopted into education more and more. New hardware, such as smart phones and tablets, has increased the popularity of mobile technology. There are also many applications created for the fields of education and tourism. This research chose a travel application from Taiwan to apply into a tourism geographic course at the Taiwan Hospitality and Tourism College (THTC). A quasi-experiment design was applied to this study. Two classes/groups participated in the study. One class was the treatment group which used the travel app through teaching scenarios. The other group was the contrast group which used a lecture format with handouts. Both groups were given a pre-test to determine knowledge of Danongdafu Forest Park (DFP), and Taiwan tourism geography. A post-test was administered after eight weeks of teaching activities. Post intervention scores were compared to pre-intervention scores between the two groups. The results of ANOVA showed that there was no statistically significant learning difference between the treatment group and the contrast group. A paired-sample t-test analysis revealed that after eight weeks of teaching DFP content, both groups gained significantly in knowledge. Furthermore, the learning attitudes and interviews of the treatment group students indicated positive responses utilizing m-learning in teaching scenarios. Students indicated a desire to receive m-learning opportunities for future courses. digital.library.unt.edu/ark:/67531/metadc500216/
Attention and Metacognition in the Elaborated Intrusion Theory of Desire
The elaborated intrusion (EI) theory of desire is a cognitive model that describes the processes involved in craving as intrusive thoughts that are elaborated upon leading to dissonance when desires are not met. While the theory is based on a wide body of research, certain theoretical predictions have not been fully examined. Specifically, EI theory argues that mental imagery has a central role in craving, and predicts that attempts to suppress substance-related intrusive thoughts and mental imagery is related to increased craving. Further, EI theory suggests that elaboration of craving imagery is related to attention and working memory processes, however, there are questions about whether differential performance in these domains is related to craving. The current study examined the relationship between attention/working memory performance and alcohol craving in a sample of 119 young adult males. Additionally, metacognition was examined to clarify the phenomenological aspects of craving within EI theory. Attention and working memory performance did not significantly predict intrusive thought and mental imagery elaboration. Individuals with high craving reported significantly higher levels of anxiety, thought suppression, and greater strength and frequency of craving-related mental imagery. They were also more likely to try to control their own thoughts and make negative judgments on their ability to do so. The strength of craving-related intrusive thoughts, not mental imagery, was the most significant predictor of craving. Implications for the understanding of craving and treatment recommendations based on the findings are discussed. digital.library.unt.edu/ark:/67531/metadc500213/
Performance Analysis of Two Alternative Hvac Systems for the Unt Zero Energy Lab
This paper covers the simulation and comparison among three different HVAC (heating, ventilation & air conditioning)systems to achieve the goal of finding the most effective HVAC among these three in terms of human comfort, efficiency and cost considering North Texas climate. In the Zero Energy Lab at the University of North Texas, Denton, TX, the HVAC system of the building assembles with geothermal heat source. Here, water to water heat pump with radiant floor and water to air heat pump with air ducts provide heating & cooling of the building. In this paper electricity consumption, comfort, cost & efficiency analysis is done for the existing system using Energy Plus simulation software. Calibration of the simulated data of the existing system is done comparing with the actual data. Actual data is measured using 150 sensors that installed in Zero Energy Lab. After the baseline model calibration, simulation for ground source water to water heat pump, evaporative cooler with baseboard electric heater and water cooled electric chiller with baseboard electric heater (as a conventional system) is shown. Simulation results evaluate the life cycle cost (LCC) for these HVAC systems. The results of the comparison analysis among all the three HVAC systems show the most effective HVAC system among these three systems in North Texas weather. The results will make UNT Zero Energy lab a standard model towards a sustainable green future. digital.library.unt.edu/ark:/67531/metadc500201/
From Germany to Palestine: a Comparison of Two Choral Works by Paul Ben-haim – “Joram” and “Kabbalat Shabbat”
The choral music of Israeli composer Paul Ben-Haim (1897-1984) falls clearly into two distinct compositional periods. Born in Munich, Germany as Paul Frankenburger, the composer received formal, classical training at the Munich Academy of Music. His compositions from this period are an amalgamation of many styles, and they include influences of Bach, Handel, Mahler, Debussy, and Strauss. In 1933, Ben-Haim, along with other trained artists and composers, immigrated to Palestine as part of the Fifth Aliyah. Prior to this wave of immigration, Palestine had not yet received any serious composers, and musically, was still in its infancy. Eager to divorce themselves from the West and identify with their new home in the East, Ben-Haim and his fellow transplant composers sought a new musical language and a unique voice for Israel. Enamored with the exotic sounds of his new environment, Ben-Haim began to absorb elements of Eastern Mediterranean music into his compositions. As a Westerner, he was not familiar with these Eastern traditional folk song melodies, modes, and scales, and he required outside source materials from which to draw. This document examines two choral works, one from each of Paul Ben-Haim’s style periods, Joram (1933) and Kabbalat Shabbat (1968), and identifies the compositional source materials that yielded a significant change in the character and style of his work. digital.library.unt.edu/ark:/67531/metadc500208/
An Action Research Study of Community Building with Elementary Students in a Title I School
“In what ways does teaching with folk arts inspired visual arts-based instruction enhance community building among elementary students in a Title I school?” was the primary research question in this study. Agreeing with past and present day research that the construct of community is vital to social and cultural capital, this research attempts to determine how the notion of community benefits both students and teachers in the elementary art classroom. Folk art was utilized because this genre was accessible in terms of locality and familiarity among students and teachers. The purpose of this investigation was to produce teaching strategies and methods that show how community can be formed in the art classroom. The participants were elementary students, Grades 2 and 3, in a Title I school located in Denton, Texas. This investigation was conducted under an action research methodology. This approach to research is intended to be transformational, emergent, and accommodating. I recorded observations, field notes, and conversations from the participants. Emergent themes were discovered through content analysis and conceptual maps. Results from this investigation concluded transformation is only possible if the person wants change to happen. Data also showed that community and art education are symbiotic. Transformation, growth, and cultivation are demands that must be met in order for this relationship to flourish. In addition, data suggested that the role of folk arts-based lessons played a significant role in building community among second and third graders. digital.library.unt.edu/ark:/67531/metadc500214/
Social Media in Policing: a Study of Dallas-fort Worth Area City Police Departments
Social media offers numerous opportunities to companies, organizations and government agencies to communicate with people outside their organization, to promote their interests and to better serve their customers, or as in the case with government agencies, to better serve their citizens. However, little is known about how police departments in particular use social media. This research study explores why police departments use social media, how they manage their social media tools, and the problems and challenges experienced as they use social media. This qualitative study is largely guided by grounded theory. The data were collected from a study population using local police departments in the Dallas-Fort worth (DFW) area principal cities using both individual interviews with police departments’ social media officers and observations of these departments’ online social media tools (in particular, Facebook and Twitter). This study has shown that the DFW area city police departments are using social media quite extensively to keep the public informed and often for investigative purposes. There are some success factors to adopting and using these tools, such as the motivation of department staff and their benefits, successful implementation of the tools, the simplicity of using tools and that it is absolutely free. digital.library.unt.edu/ark:/67531/metadc500211/
Neural Tube Defect, Heart Defect, Oral Cleft and Their Geospatial Associations with Supermarket and Convenience Stores in the City of Dallas, Texas
Birth defects are the leading cause of infant death in the United States. Research has linked poor maternal micronutrient intake to birth defects including neural tube defects, heart defects, and oral clefts. After investigating spatial patterns of these birth defects in the City of Dallas and the neighborhood characteristics within clusters, geospatial access to supermarkets and convenience stores measured by proximity and concentrations are examined as environmental risk factors for nutrition-related birth defects. Spatial clusters of all three nutrition-related birth defects exist in the City of Dallas. Cluster for NTD occurs in vulnerable places with lower income and high minority population specifically Hispanics with no supermarkets. Cluster for heart defects mostly occurs in high income and predominantly white neighborhoods with many supermarkets. Clusters of oral clefts mostly occurs in middle-class income with relatively high minority populations with many convenience stores. For the entire study area, geographical access to supermarkets that include healthy foods are shown to be spatially reachable from most of mothers of infants with nutrition-related birth defects as well as convenience stores that typically include the majority of unhealthy processed foods with very few nutrients. Thus, not only easy geographical access to healthy food vendors but to convenience stores with low quality produces is observed at the same time. digital.library.unt.edu/ark:/67531/metadc500205/