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Multi-year Operation Effect of Geothermal Heat Exchanger on Soil Temperature for Unt Zero Energy Lab
Ground source heat pump (GSHP) uses earth’s heat to heat or cool space. Absorbing heat from earth or rejecting heat to the earth, changes soil’s constant temperature over the multiple years. In this report we have studied about Soil temperature change over multiple years due to Ground loop heat exchanger (GLHE) for Zero Energy Research Laboratory (ZØE) which is located in Discovery Park, University of North Texas, Denton, TX. We did 2D thermal analysis GLHP at particular Depth. For simulation we have used ANSYS workbench for pre-processing and FLUENT ANYS as solver. TAC Vista is software that monitors and controls various systems in ZØE. It also monitors temperature of water inlet/outlet of GLHE. For Monitoring Ground temperatures at various depths we have thermocouples installed till 8ft from earth surface, these temperatures are measured using LabVIEW. From TAC Vista and LabVIEW Reading’s we have studied five parameters in this report using FLUENT ANSYS, they are; (1) Effect of Time on soil Temperature change over Multi-years, (2) Effect of Load on soil temperature change over Multi-years, (3) Effect of Depth on soil temperature change over Multi-years, (4) Effect of Doubling ΔT of inlet and outlet of GLHE on soil temperature change over multi-years and (5) Effect on soil temperature change for same ZØE Laboratory, if it’s in Miami, Florida. For studying effect of time on soil temperature change for multi-years, we have varied heating and cooling seasons. We have four cases they are Case A: GSHP always “ON” (1) 7 months cooling and 5 month cooling and (2) 257 days are cooling and 108 days heating. Case B: GSHP “OFF” for 2 months (1) 7 months cooling and 3 months heating and (2) 6 months cooling and 4 month heating. For Studying Effect of Load on soil temperature change over multi-years, we have considered maximum temperature difference between inlet and outlet for heating and cooling season for simulation. For studying effect of doubling ΔT of inlet and outlet of GLHE, we have doubled the temperature difference between inlet and outlet of GLHP. There will be soil temperature change over year at various depths. For studying Effect of Depth on soil temperature change for multi-years, we have consider 5 depths, they are 4ft, 6ft, 8ft, 110ft and 220ft. The Densities of soil are known from site survey report of ZØE GSHP manufacturers till depth of 13ft. For studying effect of soil temperature over multi-years for same ZØE in Miami, Florida, we have considered equivalent cooling and heating season from weather data for past one year and assuming same number of days of cooling and heating for next 20 years we have simulated for soil temperature change. digital.library.unt.edu/ark:/67531/metadc407847/
Characterization of Viscoelastic Properties of a Material Used for an Additive Manufacturing Method
Recent development of additive manufacturing technologies has led to lack of information on the base materials being used. A need arises to know the mechanical behaviors of these base materials so that it can be linked with macroscopic mechanical behaviors of 3D network structures manufactured from the 3D printer. The main objectives of my research are to characterize properties of a material for an additive manufacturing method (commonly referred to as 3D printing). Also, to model viscoelastic properties of Procast material that is obtained from 3D printer. For this purpose, a 3D CAD model is made using ProE and 3D printed using Projet HD3500. Series of uniaxial tensile tests, creep tests, and dynamic mechanical analysis are carried out to obtained viscoelastic behavior of Procast. Test data is fitted using various linear and nonlinear viscoelastic models. Validation of model is also carried out using tensile test data and frequency sweep data. Various other mechanical characterization have also been carried out in order to find density, melting temperature, glass transition temperature, and strain rate dependent elastic modulus of Procast material. It can be concluded that melting temperature of Procast material is around 337°C, the elastic modulus is around 0.7-0.8 GPa, and yield stress is around 16-19 MPa. digital.library.unt.edu/ark:/67531/metadc407787/
Immunohistochemistry of the Gills of the Channel Catfish Ictalurus Punctatus: Cells and Neurochemicals That May Be Involved in the Control of Cardioventilatory Reflexes
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In teleost fishes the neurochemicals involved in sensing and responding to hypoxia are unresolved. Serotonergic branchial neuroepithelial cells (NECs) are putative O2 chemoreceptors believed to be homologous to the neural crest (NC) derived APUD (amine-precursor uptake and decarboxylation) pulmonary NECs and carotid body type-1 glomus cells. Branchial NECs contain serotonin (5-HT), thought to be central to the induction of the hypoxic cardioventilatory reflexes. However, application of 5-HT in vivo does not elicit cardioventilatory reflexes similar to those elicited by hypoxia. But previous in vitro neural recordings from glossopharyngeal (IX) afferents innervating O2 chemoreceptors in the trout gill show the same discharge response to hypoxic conditions as does that of acetylcholine (ACh) application. This evidence strongly supports the cholinergic hypothesis of chemoreceptor impulse origin rather than a serotonergic-induced impulse origin model. We therefore hypothesized that NECs contain ACh among other neurochemicals in cells belonging to the APUD series. Although serotonergic branchial NECs did not colocalize with ACh using immunohistochemical methods, several populations of ACh and/or tyrosine hydroxylase (TH) (catecholaminergic) positive, dopamine (DA) negative, cells were found throughout the second gill arch of the channel catfish Ictalurus punctatus. In addition, the NC derivation marker zn-12 labelled the HNK-1-like epitope (Human natural killer) expressed by lamellar pillar cells’ collagen column-associated pillar cell adhesion molecules (CC-PCAMs), evidence confirming their hypothesized NC origin. digital.library.unt.edu/ark:/67531/metadc407757/
The Measurement of the Third-order Elastic Constants for La3ga5sio14 (Lgs) and La3ga55ta05o14 (Lgt) Single Crystal
Recently, the development of electronic technology towards higher frequencies and larger band widths has led to interest in finding new piezoelectric materials, which could be used to make filters with larger pass band widths and oscillators with better frequency stability. Langasite (La3Ga5SiO14, LGS) and its isomorphs have enticed considerable attention of researchers as a potential substrate material for piezoelectric device applications because of its high frequency stability and fairly good electromechanical coupling factors for acoustic wave devices. Nonlinear effect including drive level dependence, mode coupling, force-frequency effect and electroelasic effect are critical for the design of these devices. Third-order elastic constants (TOEC) play an important role in a quantitative analysis of these nonlinear effects. In particular these elastic constants are of great importance when the BAW (Bulk Acoustic Wave) and SAW (Surface Acoustic Wave) sensors of force, acceleration and so on are designed. Until now Langasite (LGS) and Langatate (LGT) crystal resonators have been qualified in terms of quality factor, temperature effect, isochronism defect and material quality. One of the most important advantages of those crystals is that they will not undergo phase transitions up to its melting temperature of 1450°. Presently there is no data on TOEC of LGT crystals. Our objective is to create an experimental procedure to measure and collect the complete set of third-order elastic constants of Langasite (La3Ga5SiO14) and Langatate (La3Ga5.5Ta0.5O14) crystals and compare the new values for langasite with values previously reported. digital.library.unt.edu/ark:/67531/metadc407770/
Tribological Behavior of Spark Plasma Sintered Tic/graphite/nickel Composites and Cobalt Alloys
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Monolithic composites are needed that combine low friction and wear, high mechanical hardness, and high fracture toughness. Thin films and coatings are often unable to meet this engineering challenge as they can delaminate and fracture during operation ceasing to provide beneficial properties during service life. Two material systems were synthesized by spark plasma sintering (SPS) and were studied for their ability to meet these criteria. A dual hybrid composite was fabricated and consisted of a nickel matrix for fracture toughness, TiC for hardness and graphite for solid/self‐lubrication. An in‐situ reaction during processing resulted in the formation of TiC from elemental Ti and C powders. The composition was varied to determine its effects on tribological behavior. Stellite 21, a cobalt‐chrome‐molybdenum alloy, was also produced by SPS. Stellite 21 has low stacking fault energy and a hexagonal phase which forms during sliding that both contribute to low interfacial shear and friction. Samples were investigated by x‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x‐ray spectroscopy (EDS), and electron back‐scattered diffraction (EBSD). Tribological properties were characterized by pin on disc tribometry and wear rates were determined by profilometry and abrasion testing. Solid/self‐lubrication in the TiC/C/Ni system was investigated by Raman and Auger mapping. A tribofilm, which undergoes a stress‐induced phase transformation from polycrystalline graphite to amorphous carbon, was formed during sliding in the TiC/C/Ni system that is responsible for low friction and wear. TiC additions help to further decrease wear. Stellite 21 was also found to exhibit acceptably low friction and wear properties arising from the presence of Cr23C6 in the matrix and work hardening of the cobalt and chromium during sliding. digital.library.unt.edu/ark:/67531/metadc407776/
A Comprehensive Modeling Framework for Airborne Mobility
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Mobility models serve as the foundation for evaluating and designing airborne networks. Due to the significant impact of mobility models on the network performance, mobility models for airborne networks (ANs) must realistically capture the attributes of ANs. In this paper, I develop a comprehensive modeling framework for ANs. The work I have done is concluded as the following three parts. First, I perform a comprehensive and comparative analysis of AN mobility models and evaluate the models based on several metrics: 1) networking performance, 2) ability to capture the mobility attributes of ANs, 3) randomness levels and 4) associated applications. Second, I develop two 3D mobility models and realistic boundary models. The mobility models follow physical laws behind aircraft maneuvering and therefore capture the characteristics of aircraft trajectories. Third, I suggest an estimation procedure to extract parameters in one of the models that I developed from real flight test data. The good match between the estimated trajectories and real flight trajectories also validate the suitability of the model. The mobility models and the estimation procedure lead to the creation of “realistic” simulation and evaluation environment for airborne networks. digital.library.unt.edu/ark:/67531/metadc407760/
A Textual Analysis of the Closer and Saving Grace: Feminist and Genre Theory in 21St Century Television
Television is a universally popular medium that offers a myriad of choices to viewers around the world. American programs both reflect and influence the culture of the times. Two dramatic series, The Closer and Saving Grace, were presented on the same cable network and shared genre and design. Both featured female police detectives and demonstrated an acute awareness of postmodern feminism. The Closer was very successful, yet Saving Grace, was cancelled midway through the third season. A close study of plot lines and character development in the shows will elucidate their fundamental differences that serve to explain their widely disparate reception by the viewing public. digital.library.unt.edu/ark:/67531/metadc407774/
Shortened in Vivo Bioconcentration Factor Testing in Cyprinus Carpio
Bioconcentration factor testing serves as the most valuable surrogate for the assessment of bioaccumulation. The assessment of potentially harmful chemicals is crucial to not only the health of aquatic environments, but to humans as well. Chemicals that possess the ability to persist in the environment or that have the potential to bioaccumulate, pose a greater risk to organisms that are exposed to these chemicals. The Organization for Economic Cooperation and Development Guideline 305 outlines specific protocols to run an accurate and reliable aquatic flow-through test. However, since its adoption in 1996, very few changes have been made to accommodate the endeavor to lowering the amount of test species to run one of these said tests. Running an aquatic flow-through test, according to 305, takes much time and money as well as numerous amounts of fish. Such burdens can be eliminated through simple modifications to the standard protocols. In this study, we propose an abbreviated study design for aquatic bioconcentration testing which effectively alleviates the burdens of running a flow-through test. Four chemicals were used individually to evaluate the usefulness of the proposed shortened design; 4-Nonyphenol, Chlorpyrifos, Musk Xylene, and DDT. The study consisted of exposing Cyprinus carpio for 7 days followed by 7 days of depuration, for a total of a 14-day study. Our results for each of the four compounds are consistent with literature values, thus, demonstrating that BCFk can be accurately predicted in an abbreviated in vivo test. digital.library.unt.edu/ark:/67531/metadc407781/
The Acute Hormonal Response to the Kettlebell Swing Exercise
The purpose of this investigation was to examine the acute hormonal response to a bout of kettlebell swing exercise. Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6 ± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice per week but were inexperienced with kettlebell swings participated in this study. Participants were familiarized with the kettlebell swing exercise during an initial visit. During the subsequent experimental protocol visit, participants performed 12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the end of every round of swings. Fasted blood samples were collected pre-exercise (PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise (P30) and analyzed for total testosterone (T), growth hormone (GH), cortisol, and lactate concentrations. Participants completed a total of 227 ± 23 swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P < 0.05) throughout the exercise protocol. Lactate concentrations were significantly increased at all post exercise time points compared to PRE. T was significantly increased at IP compared to PRE. GH was significantly increased at IP, P15, and P30 compared to PRE. Cortisol was significantly increased at IP and P15 compared to PRE. 12 rounds of 30 seconds of kettlebell swing exercise induced an acute increase in T, GH, and cortisol concentrations in resistance trained men. Additionally, this exercise protocol induced a large increase in HR and lactate concentration. Thus, the kettlebell swing exercise might provide an effective method for simultaneous endurance and resistance training. digital.library.unt.edu/ark:/67531/metadc407736/
Ten Years After 9/11: the Structure and Use of Intelligence Units in Local Policing
The events of September 11, 2001 marked a paradigm shift in the strategy within all levels of law enforcement in the United States. Intelligence became the watchword of the day and with it, the movement to incorporate strategic and tactical information in daily policing. Yet while the philosophy was clear, the method and manner to which agencies were left to achieve these goals was much less designed. The federal government allocated funds to assist help agencies incorporate an intelligence function in their daily operations but which agencies and to what degree remains unclear even today. This study seeks to determine the current state of use of intelligence in municipal law enforcement agencies in the State of Texas ten years after 9/11. Through use of a survey, it assesses the frequency of use of intelligence units in local police departments in the State of Texas, identifies commonalities in their structure, and determines the state of their effectiveness. digital.library.unt.edu/ark:/67531/metadc407786/
The Effect of It Process Support, Process Visualization and Process Characteristics on Process Outcomes
Business process re-engineering (part of the Business Process Management domain) is among the top three concerns of Information Technology (IT) leaders and is deemed to be one of many important IT leveraging opportunities. Two major challenges have been identified in relation to BPM and the use of IT. The first challenge is related to involving business process participants in process improvement initiatives using BPM systems. BPM technologies are considered to be primarily targeted for developers and not BPM users, and the need to engage process participants into process improvement initiatives is not addressed, contributing to the business-IT gap. The second challenge is related to potential de-skilling of knowledge workers when knowledge-intensive processes are automated and process knowledge resides in IT, rather than human process participants. The two identified challenges are not separate issues. Process participants need to be knowledgeable about the process in order to actively contribute to BPM initiatives, and the loss of process knowledge as a result of passive use of automated systems may further threaten their participation in process improvement. In response to the call for more research on the individual impacts of business process initiatives, the purpose of this dissertation study is to understand the relationship between IT configurations (particularly process support and process visualization), process characteristics and individual level process outcomes, such as task performance and process knowledge. In the development of the research model we rely on organizational knowledge creation literature and scaffolding in Vygotsky’s Zone of Proximal Development, business process modeling and workflow automation research, as well as research on the influence of IT on individual performance. The theoretical model is tested empirically in experimental settings using a series of two studies. In both studies participants were asked to complete tasks as part of a business process using different versions of a mock-up information system. Together, the studies evaluate the effect of IT process support, process visualization and process complexity on process participant performance and process knowledge. The results of the studies show the significant influence of IT process support on individual process outcomes. The studies indicate that task performance does increase but at the cost of users’ process knowledge. Process visualization however is shown to enhance user’s process knowledge in the event of no formal process training while having no negative impact on task performance. The key contribution of this research is that it suggests a practical way to counteract potential negative effects of IT process automation by converting the use of the information system into a learning experience, where the IT itself acts as a scaffold for the acquisition of process knowledge. The results have practical implications for the design of workflow automation systems, as well as for process training. digital.library.unt.edu/ark:/67531/metadc407777/
Evaluating the Cultural Plan of Austin, Texas
This is a concurrent, mixed methods study of the impacts of Austin, Texas’s cultural plan, CreateAustin. In the study, trend analysis and a t-test were used to examine variables before and after the cultural plan was in place. At the same time, interviews with cultural planners were used to uncover other effects. My research addresses a gap in the literature between understanding the desired and actual outcomes of a cultural plan. Cultural plans are being developed by many communities in an effort to attract creative workers but they are rarely evaluated. Evaluation using a mixed methods approach is necessary to capture all the outcomes of a cultural plan, rather than the limited scope of impacts that are captured by qualitative or quantitative analyses alone. My analysis of the quantitative variables showed some significant differences between when the plan was in place and the years prior to its creation. Interviews with key stakeholders revealed the formation of new networks as a powerful outcome of the planning process. The results allowed me to gauge the overall impact of CreateAustin and make some observations about the cultural planning process in general, as well as uncover new directions for future research. digital.library.unt.edu/ark:/67531/metadc407737/
Web Information Behaviors of Users Interacting with a Metadata Navigator
The web information behaviors of users as they interacted with a metadata navigator, the Personal Information (PI) Agent, and reflected upon their interaction experiences were studied. The process included studying the complete iterative (repeated) cycle of information needs, information seeking, and information use of users interacting with an internet-based prototype metadata PI Agent tool. Detlor’s theory of web information behaviors of organizational users was utilized as a theoretical foundation for studying human-information interactions via the PI Agent tool. The qualitative research design allowed for the use of triangulation within the context of a one-group pretest-posttest design. Triangulation occurred in three phases: (a) observe, (b) collect, and (c) reflect. Observations were made as participants solved three problem situations. Participants’ computer log and print screen data were collected, and follow-up interviews were conducted once all posttest sessions ended to enable users to reflect on their experiences. The three triangulation phases ensured saturation of data and greater depth regarding the participants’ information behaviors. Content analysis occurred via exploratory pattern analysis using the posttest Problem Steps Recorder (PSR) log data and on the six interviewees’ follow-up interview data. Users engaged in iterative cycles of information needs, information seeking, and information use to resolve the presented problem situations. The participants utilized the PI Agent tool iteratively to eliminate their knowledge gaps regarding the presented problem situations. This study was the first to use PSR log data for capturing evidence of the iterative search process as defined by Detlor. The implications for best practices were inspired by participant feedback, and recommendations for further study are made. digital.library.unt.edu/ark:/67531/metadc407784/
Facebook Brand Page: an Exploratory Study of Facebook Brand Page Attributes and Their Influence on Purchase Intentions
This study explored attributes of a Facebook brand page (FBP). Seven variables were derived from the framework and applied to FBPs. The goals of this research were to discover which attributes contribute to a successful FBP, determine which attributes increase purchase intentions, and help marketers determine where to focus their efforts. A total of 421 surveys were gathered from men and women ages 18 and older. The methods of this research included factor analysis and multiple regression analysis. Results yielded two loading factors for the trustworthiness variable and supported hypotheses of trustworthiness increasing purchase intentions. It was also discovered that participation positively influences purchase intentions. It is advised that information content be monitored to avoid information overload. digital.library.unt.edu/ark:/67531/metadc407753/
Rickshaw Man
This documentary film tells the story of Mohammad in India, and Mike in the United States, who are separated by social, economic, cultural, linguistic and religious differences, and yet there is an inanimate object that connects them-the rickshaw. The film examines how rickshaw men are viewed and treated by the society they live in and also illuminates the threads of commonality between these two men to show that they are not so different from each other after all. digital.library.unt.edu/ark:/67531/metadc407779/
Social Innovation in Venture Capital Firms: Strategy, Structure, and Performance
Social innovations are solutions related to humanistic needs and the betterment of mankind with the intent of creating social value and eventual societal level changes. Social innovation therefore broadens traditional views of innovation to include processes of societal transformations and human behaviors. These social innovations are becoming more commonplace across all sectors, including capital markets. Private equity and venture capital firms in the capital markets sector engage in social innovation by investing capital with the goal of delivering both economic and social value. Despite the critical importance of venture capital (VC) in the success of social innovations through socially responsible investing, there is a paucity of research in understanding the factors that affect the performance of these social VC firms. This research gap is addressed by asking the following primary research question: What is the role of strategic and structural factors in the performance of socially innovative venture capital firms? The firm level research is theoretically based on the well-established design school. This framework highlights the overarching importance of strategy and structure in the accomplishment of firm goals. In the context of the venture capital industry, it was hypothesized that certain unique strategic and structural factors (i.e., stage of investment, age, size, and network relationships) would influence the performance of socially innovative VC firms. A moderated mediation model was proposed to examine these factors and their influence on performance variation. The sample of socially innovative VC firms was generated from the ThomsonOne Private Equity Database. The research design and methodology followed a systematic and objective process. This included identification of the sample of 381 VC firms, collection of mission statements for each VC firm, development of key word list pertaining to social innovation for content analysis and the collection of archival data on each VC firm. Content analysis was then used to identify the degree to which the firm’s strategic orientation (mission statement) was related to social innovation. Finally, both traditional and more cutting edge statistical analyses (Preacher & Hayes, 2008) were used to evaluate the moderated mediation model. The results of this study provide several key take-a-ways for both researchers and practitioners focusing on social venture capital. Firstly, results indicated that firms adopt distinct foci of social investing that directs their strategic orientation. These various foci have vastly differing effects on the firm’s overall performance, the strategic decisions they make, and the architecture of their structural design. It is therefore necessary to treat each focus area separately given differences in strategies, industry and investment focus, and market orientations. Secondly, including socially related language in the firm’s mission statement does not guarantee that a VC firm will actually implement a social orientation or seek to create the social value inherent in social innovation. Thirdly, certain investment strategies appear to be more advantageous depending of the size of the firm and the socialness of the firm’s orientation. Lastly, results supported that the adoption of a social orientation did not negatively influence firm performance. Overall, results suggest that pursuing a social orientation is viable and effective in delivering blended value strategies for VC firms engaging in social innovation. These findings offers socially oriented venture capital firms insights into strategic and structural aspects that are important to their success in achieving positive exists of their portfolio companies, thus increasing both financial and social value. digital.library.unt.edu/ark:/67531/metadc407767/
Assessing Local Governments’ Debt Financing Strategies
This dissertation assesses the importance of a specific debt instrument, the Certifi- cate of Obligation in the state of Texas. It conceptualizes the Certificate of Obligation as a type of contractual debt that enables local governments to finance their capital projects. This dissertation is guided by three research questions: (1) What are the various types of debt instruments employed by local governments and what are their relative advantages? (2) How prevalent is the use of a specific debt instrument such as Certificates of Obligation? And why would some local governments prefer to issue them while others do not? (3) To what extent does the local institutional environment, e.g., the executive authority of city managers in the council-manager form of government, affect debt financing behaviors of local governments? To examine the first research question, we created a typology to represent four ideal types of borrowing methods: (1) Contractual Debt, (2) Voter Approval/Special Tax Debt, (3) Guaranteed, and (4) Non-Guaranteed Debts. The typology examines whether or not the state mandates the referendum requirement for the use of each of these debt instruments, and at the same time determines whether each debt instrument is secured by multiple or single revenue sources. Using data we collected among municipal governments in Texas, we conducted two empirical analyses. The first analysis tests the hypothesis that Certificates of Obligation have higher borrowing costs compared to GO bonds, since a GO bond is often issued under the pledge of the bond issuers’ full-faith credit and taxing authority. We employed a two-stage least square analysis to test the general proposition in the state of Texas. Based on 741 Certificates of Obligation and GO bonds issued between 2008 and 2011, our analyses show that Certificates of Obligation are likely to incur True Interest Costs (TIC) similar to those of GO bonds. The second analysis explores factors explaining the use of Certificates of Obligation in 225 Texas charter cities. Based on Heckman’s two-stage, we found that a local government’s decision to issue Certificates of Obligation to be partly explained by the characteristics of local population, i.e., median household income, population growth, and the percentage of senior citizens living in the jurisdiction. In the case of GO bonds, we found that population size, property tax rate, debt burden, and the percentage of population with at least a college education, to be an important determinant of GO bonds. The volume of GO issuance by local governments was also related to the level of regional competition, i.e., government density. Additionally, we found that local political institutions matter and that they affect debt financing behaviors of local governments. digital.library.unt.edu/ark:/67531/metadc407780/
Churches, Social Service Access and Korean-american Elders: an Exploratory Study
This study examined how Korean co-ethnic churches serve as connections between Korean seniors and the agencies that offer social and health care services. The study developed from a pilot outreach program funded by the North Central Texas Council of Governments’ Area Agency on Aging (NCTAAA) to inform Korean seniors about Medicare-related programs between February and May of 2011. The results of the pilot program suggested that the Korean-American church can be an effective place for program outreach. The dissertation project, working in partnership with the NCTAAA and 2-1-1 services, further explored the use of Korean churches as a vehicle to connect Korean seniors to Extra Help (EH) and Medicare Saving Programs (MSP) and 2-1-1 services, a toll-free number for information about non-emergency health and social services. Fifty-three pastors were contacted to participate in a telephone survey and a face-to-face, in-depth semi-structured interview. Thirty telephone surveys and 11 face-to-face interviews were conducted. Five of the 30 pastors agreed to host program outreach presentations for the EH, MSP, and 2-1-1 services in their churches. Host churches tended to be more likely highly structured, regularly scheduled programs (e.g., Senior College) for seniors already in place. A total of 405 Korean seniors participated in the program outreach sessions. Five seniors received the EH application information, and 17 MSP application forms were distributed. Additionally, 28 seniors were assisted by phone, not only with the targeted programs, but also with other benefits information. Together, these outcomes indicate that the co-ethnic church can be a vehicle to connect Korean seniors to services offered by outside agencies. digital.library.unt.edu/ark:/67531/metadc407746/
Integrated Computational and Experimental Approach to Control Physical Texture During Laser Machining of Structural Ceramics
The high energy lasers are emerging as an innovative material processing tool to effectively fabricate complex shapes on the hard and brittle structural ceramics, which previously had been near impossible to be machined effectively using various conventional machining techniques. In addition, the in-situ measurement of the thermo-physical properties in the severe laser machining conditions (high temperature, short time duration, and small interaction volume) is an extremely difficult task. As a consequence, it is extremely challenging to investigate the evolution of surface topography through experimental analyses. To address this issue, an integrated experimental and computational (multistep and multiphysics based finite-element modeling) approach was employed to understand the influence of laser processing parameters to effectively control the various thermo-physical effects (recoil pressure, Marangoni convection, and surface tension) during transient physical processes (melting, vaporization) for controlled surface topography (surface finish). The results indicated that the material lost due to evaporation causes an increase in crater depth of machined cavity, whereas liquid expulsion created by the recoil pressure increases the material pileup height around the lip of machined cavity, the major attributes of surface topography (roughness). Also, it was found that the surface roughness increased with increase in laser energy density and pulse rate (from 10 to 50Hz), and with the decrease in distance between two pulses (from 0.6 to 0.1mm) or the increase in lateral and transverse overlap (0, 17, 33, 50, 67, and 83%). The results of the computational model are also validated by experimental observations with reasonably close agreement. digital.library.unt.edu/ark:/67531/metadc407758/
Social Support As a Moderating Factor Between Mental Health Disruption and College Adjustment in Student Veterans
Research has indicated that OEF/OIF veterans are experiencing mental health concerns following deployment. While there are increasing numbers of veterans returning to higher education institutions after discharging from the military, there is a scarcity of empirical research investigating student veterans’ experiences as they transition into college. The purpose of the current study was to examine whether social support moderates the effects of psychological distress on college adjustment among a sample of student veterans. Participants were administered a Background Information Questionnaire, measures of psychological distress (i.e., GAD-7, PHQ-9, IES-R), Multidimensional Scales of Perceived Social Support, and the Student Adjustment to College Questionnaire. Multiple regressions revealed significant main effects for the variables of interest, but analyses failed to support the hypothesis that perceived social support would moderate the effects of psychological distress on college adjustment. digital.library.unt.edu/ark:/67531/metadc407769/
An Examination of Mathematics Teachers’ Use of Student Data in Relationship to Student Academic Performance
Among educational researchers, important questions are being asked about how to improve mathematics instruction for elementary students. This study, conducted in a north Texas public school with 294 third- through fifth-grade students, ten teachers and three coaches, examined the relationship between students’ achievement in mathematics and the mathematics teaching and coaching instruction they received. Student achievement was measured by the Computer Adaptive Instrument (CAT), which is administered three times a year in the district and is the main criterion for students’ performance/movement in the district’s response to intervention program for mathematics. The response to intervention model employs student data to guide instruction and learning in the classroom and in supplemental sessions. The theoretical framework of the concerns based adoption model (CBAM) was the basis to investigate the concerns that mathematics teachers and coaches had in using the CAT student data to inform their instruction. The CAT data, based on item response theory, was the innovation. Unique in this study was the paralleling of teachers’ and coaches’ concerns and profiles for their use of the data with student scores using an empirical approach. Data were collected at three intervals through the Stages of Concerns Questionnaire, the Levels of Use interviews, and the Innovation Configuration Components Matrix from teachers and at three intervals student CAT-scaled scores. Multiple regression analyses with the concerns and CAT scores and levels of use and CAT scores were conducted to determine if relationships existed between the variables. The findings indicated that, overall, the teachers and coaches who scored high in personal concerns at the three data points remained at low levels of use or non-use of CAT data in their instruction. Only two teachers indicated movement from high intense personal concerns to high concerns regarding the impact on students. This correlated with their increased use of CAT at the three-collection points. The regression analyses indicated no correlations between the teachers’ and coaches’ concerns and the CAT and no correlations between their levels of data use and the CAT. At the exit interviews, patterns suggested that the presence of a change facilitator might have made a difference in their understanding and use of the CAT data ultimately impacting student achievement. This study sets a new precedent in the use of CBAM data and offers insights into the necessity of providing support and training in a change process. digital.library.unt.edu/ark:/67531/metadc407744/
The Effect of Menthol on Nicotine Metabolism: a Cross Species Evaluation
The effect of menthol on nicotine metabolism was examined in liver S9 fractions of four different species and in the in vivo mouse model. The purpose of this study was to investigate three parameters: (1) biotransformation of nicotine to cotinine in various species (human, mouse, rat and trout) using in vitro methods; (2) to determine if the addition of menthol with nicotine altered biotransformation of nicotine to cotinine; (3) and to assess similar parameters in an in vivo mouse model. The major findings of this study include: (1) mice appear to metabolize nicotine, over time, in a manner similar to humans; (2) menthol decreased cotinine production, over time, after a single dose in mice; and (3) menthol increased cotinine production, over time, after repeated doses, in mice. digital.library.unt.edu/ark:/67531/metadc407773/
Laser Surface Modification on Az31b Mg Alloy for Bio-wettability
Laser surface modification of AZ31B Magnesium alloy changes surface composition and roughness to provide improved surface bio-wettability. Laser processing resulted in phase transformation and grain refinement due to rapid quenching effect. Furthermore, instantaneous heating and vaporization resulted in removal of material, leading the textured surface generation. A study was conducted on a continuum-wave diode-pumped ytterbium laser to create multiple tracks for determining the resulting bio-wettability. Five different laser input powers were processed on Mg alloy, and then examined by XRD, SEM, optical profilometer, and contact angle measurement. A finite element based heat transfer model was developed using COMSOL multi-physics package to predict the temperature evolution during laser processing. The thermal histories predicted by the model are used to evaluate the cooling rates and solidification rate and the associated changes in the microstructure. The surface energy of laser surface modification samples can be calculated by measuring the contact angle with 3 different standard liquid (D.I water, Formamide, and 1-Bromonaphthalen). The bio-wettability of the laser surface modification samples can be conducted by simulated body fluid contact angle measurement. The results of SEM, 3D morphology, XRD, and contact angle measurement show that the grain size and roughness play role for wetting behavior of laser processing Mg samples. Surface with low roughness and large grain size performs as hydrophilicity. On the contrast, surface with high roughness and small grain size performs as hydrophobicity. digital.library.unt.edu/ark:/67531/metadc407788/
Boosting for Learning From Imbalanced, Multiclass Data Sets
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In many real-world applications, it is common to have uneven number of examples among multiple classes. The data imbalance, however, usually complicates the learning process, especially for the minority classes, and results in deteriorated performance. Boosting methods were proposed to handle the imbalance problem. These methods need elongated training time and require diversity among the classifiers of the ensemble to achieve improved performance. Additionally, extending the boosting method to handle multi-class data sets is not straightforward. Examples of applications that suffer from imbalanced multi-class data can be found in face recognition, where tens of classes exist, and in capsule endoscopy, which suffers massive imbalance between the classes. This dissertation introduces RegBoost, a new boosting framework to address the imbalanced, multi-class problems. This method applies a weighted stratified sampling technique and incorporates a regularization term that accommodates multi-class data sets and automatically determines the error bound of each base classifier. The regularization parameter penalizes the classifier when it misclassifies instances that were correctly classified in the previous iteration. The parameter additionally reduces the bias towards majority classes. Experiments are conducted using 12 diverse data sets with moderate to high imbalance ratios. The results demonstrate superior performance of the proposed method compared to several state-of-the-art algorithms for imbalanced, multi-class classification problems. More importantly, the sensitivity improvement of the minority classes using RegBoost is accompanied with the improvement of the overall accuracy for all classes. With unpredictability regularization, a diverse group of classifiers are created and the maximum accuracy improvement reaches above 24%. Using stratified undersampling, RegBoost exhibits the best efficiency. The reduction in computational cost is significant reaching above 50%. As the volume of training data increase, the gain of efficiency with the proposed method becomes more significant. digital.library.unt.edu/ark:/67531/metadc407775/
Relationships of Benthic Macroinvertebrate Community Structure with Land-use, Habitat, In-stream Water Chemistry, Depositional Sediment Biofilm Fatty Acids, and Surfactants in the Effluent Dominated Texas Trinity River
The Trinity River is an urbanized, effluent-dominated river, and is heavily relied upon for drinking water. The benthic macroinvertebrate community has been monitored for over 20 years, with the focus of this dissertation on three studies (1987-88, 2005, and 2011). Water quality improvement following dechlorination resulted in increased benthic metrics. Overall habitat quality, in-stream cover, surface water total organic carbon, sediment total organic carbon, near-field urban land-use, near-field forested land-use, surface water surfactant toxic units, and depositional sediment biofilm fatty acids all have statistically significant relationships with benthic macroinvertebrate metrics. These relationships are better defined with increased taxonomic resolution at the genus/species level for all benthic taxa, including Chironomidae and Oligochaeta. It is recommend that benthic identifications for state and city water quality assessments be done at the genus/species level. A novel method for quantifying depositional sediment biofilm fatty acids has been produced and tested in this dissertation. Benthic metrics are directly related to fatty acid profiles, with several essential fatty acids found only at upstream sites. digital.library.unt.edu/ark:/67531/metadc407738/
Using a Multimodal Sensing Approach to Characterize Human Thermal Comfort Level
A method to distinguish human level of comfort has been developed by using a thermal camera, physiological sensors, and a surroundings sensor. The method has successfully collected data from hominal facial features, breathing rate, skin temperature, room temperature, blood volume pressure, relative humidity, and air velocity. Participants from all genders and races were involved in two sessions of a human comfort experiment including a psychology survey session. The variables, such as room temperature and clothing are controlled to maintain steady test conditions. The region of interest was determined by body temperature and facial temperature as registered by the thermal imaging camera. To experience different levels of discomfort, participants were required to perform two different activities. The first session included an activity on the air resistance elliptical and the second session required the subjects to remain steady in front of a fan. The data was subsequently compared on all subjects to determine whether human discomfort and comfort can be predicted by using various approaches. The parameters of discomfort and comfort were simulated to characterize human levels of comfort. According to arrangement of correlation among thermal comfort responses, blood volume pressure, skin temperature, respiration, and skin conduction, we are be able to predict discomfort and comfort affective states. digital.library.unt.edu/ark:/67531/metadc407778/
Adolescent Behavior Problems and Interparental Conflict: the Moderating Role of Parent-child Attachment
The current study examined the role that parent-child attachment plays in the relationship between marital conflict and the development of behavior problems in adolescents. To evaluate the hypothesis that attachment moderates this relationship, 57 families were recruited via e-mail invitation sent to families that participated in local church youth groups, school organizations, and a treatment program designed for adolescents with behavior problems. One custodial parent and his/her adolescent child completed an online or paper version of a survey consisting of the Achenbach’s Behavior Checklists, the Inventory of Parent and Peer Attachment, and the Children’s Perception of Interparental Conflict Scale. Hypotheses were evaluated using Baron and Kenny’s (1986) procedures to test moderating effects with multiple regression analyses. Mother attachment demonstrated a significant moderation effect between the intensity of interparental conflict and the parent’s report of externalizing behavior problems. Specifically, at low conflict intensity levels, relative to low attachment security, high attachment security was associated with fewer externalizing behavior problems, whereas at high intensities of interparental conflict high attachment security was associated with more externalizing behavior problems. digital.library.unt.edu/ark:/67531/metadc407793/
Examining High School Coaches’ Likelihood to Refer To, Interest in Working With, and Plans to Hire a Sport Psychologist
The primary goal of the current study was to extend previous research suggesting that coaches are the primary gatekeepers who may be a barrier to working with athletes by examining high school coaches likelihood to refer to, interest in, and intention to hire a sport psychologist. Specifically, the current study examined relationships between high school coaches’ sex, age, and type of sport coached (i.e., contact vs. non-contact) and their likelihood to refer athletes to a sport psychologist for a variety of presenting issues (i.e., poor attentional focus, poor leadership, family issues, etc.). It also examined relationships between coaches’ sex, age, and type of sport coached (i.e., contact vs. non-contact) and their interest in working with a sport psychologist. Finally, the study examined reasons why coaches did not plan to hire a sport psychologist. An examination of the possible reasons that high school coaches do not plan to hire a sport psychologist served an exploratory purpose. Participants included 450 coaches who coached high school sports in the United States. Results indicated that female coaches and non-contact sport coaches were more likely to refer athletes to a sport psychologist for a variety of referral issues than male coaches and coaches of contact sports. Similarly, significantly more female coaches and non-contact sport coaches showed interest in working with a sport psychologist than male coaches and coaches of contact sports. Coaches who did not plan to hire a sport psychologist reported that cost, lack authority to hire, and lack of availability as primary reasons. Implications of the findings, limitations, and future directions are discussed. digital.library.unt.edu/ark:/67531/metadc407762/
Josephus’ Jewish War and the Causes of the Jewish Revolt: Re-examining Inevitability
The Jewish revolt against the Romans in 66 CE can be seen as the culmination of years of oppression at the hands of their Roman overlords. The first-century historian Josephus narrates the developments of the war and the events prior. A member of the priestly class and a general in the war, Josephus provides us a detailed account that has long troubled historians. This book was an attempt by Josephus to explain the nature of the war to his primary audience of predominantly angry and grieving Jews. The causes of the war are explained in different terms, ranging from Roman provincial administration, Jewish apocalypticism, and Jewish internal struggles. The Jews eventually reached a tipping point and engaged the Romans in open revolt. Josephus was adamant that the origin of the revolt remained with a few, youthful individuals who were able to persuade the country to rebel. This thesis emphasizes the causes of the war as Josephus saw them and how they are reflected both within The Jewish War and the later work Jewish Antiquities. By observing the Roman provincial administration spanning 6-66 CE, I argue that Judaea had low moments sprinkled throughout the time but in 66 there was something particularly different, according to Josephus. Josephus presents the governors and other important characters in the war in a very distinct way through rhetoric, narrative, and other methodology. The idea of a beginning to this revolt, no matter how obscure or hidden by Josephus, is the reason I want to examine the works of Josephus the historian. digital.library.unt.edu/ark:/67531/metadc407792/
Funds of Knowledge in a Hispanic Household: a Case Study of Family Experiences, Values, and Connections to Education
Traditionally, the field of education has often adopted a negative perspective in their views of minority families’ contributions to the educational progress of their children. However, research embodying the theoretical framework of ‘funds of knowledge’ attempts to counter that model through its assertion that all families possess extensive bodies of knowledge that have developed through social, historical, and cultural contexts. Teachers carry out studies of familial funds of knowledge in order to understand how family experiences shape the knowledge that a child brings to the classroom. There is then, the potential to use that body of knowledge to create meaningful learning experiences that connect prior understanding and experiences to classroom practice. This research served as a case study of the funds of knowledge existing in the home of a Hispanic family and the connections that existed between that knowledge and literacy. The results indicated that the family possessed extensive funds of knowledge that developed through their historical, cultural, and social experiences. They often used family networks, as well as formal and informal literacy experiences to share this knowledge with their children. A key component of the literacy value system that they communicated resulted from a desire to maintain aspects of their culture and heritage through maintaining and improving their children’s reading and linguistic abilities in Spanish. Furthermore, along with their emphasis on Spanish literacy, they held aspirations for their children related to familial and educational values that often stemmed from their expressed desire for their children to lead lives with greater opportunities and positive examples than they had experienced. digital.library.unt.edu/ark:/67531/metadc407772/
Effects of Airway Pressure, Hypercapnia, and Hypoxia on Pulmonary Vagal Afferents in the Alligator (Alligator Misssissippiensis)
The American alligator (Alligator mississippiensis) is an aquatic diving reptile with a periodic breathing pattern. Previous work has identified pulmonary stretch receptors (PSR), both rapidly- and slowly-adapting, and intrapulmonary chemoreceptors (IPCs) that modulate breathing patterns in alligators. The purpose of the present study was to identify the effects of prolonged lung inflation and deflation (simulated dives) on PSR and/or IPC firing characteristics in the alligator. The effects of airway pressure, hypercapnia, and hypoxia on dynamic and static responses of pulmonary stretch receptors (PSR) were studied in juvenile alligators (mean mass = 246 g) at 24°C. Receptor activity appeared to be a mixture of slowly-adapting PSRs (SARs) and rapidly-adapting PSRs (RARs) with varying thresholds and degrees of adaptation, but no CO2 sensitivity. Dives were simulated in order to character receptor activity before, during, and after prolonged periods of lung inflation and deflation. Some stretch receptors showed a change in dynamic response, exhibiting inhibition for several breaths after 1 min of lung inflation, but were unaffected by prolonged deflation. For SAR, the post-dive inhibition was inhibited by CO2 and hypoxia alone. These airway stretch receptors may be involved in recovery of breathing patterns and lung volume during pre- and post-diving behavior and apneic periods in diving reptiles. These results suggest that inhibition of PSR firing following prolonged inflation may promote post-dive ventilation in alligators. digital.library.unt.edu/ark:/67531/metadc407750/
Population Dynamics of Zebra Mussels (Dreissena Polymorpha) in a North Texas Reservoir: Implications for Invasions in the Southern United States
This dissertation has two main objectives: first, quantify the effects of environmental conditions on spatio-temporal spawning and larval dynamics of zebra mussels (Dreissena polymorpha [Pallas 1771]) in Lake Texoma, and second, quantify the effects of environmental conditions on survival, growth, and reproduction of young of the year (YOY) juvenile zebra mussels. These biological responses directly influence population establishment success and invasive spread dynamics. Reproductive output of the zebra mussel population in Lake Texoma was significantly related to water temperature and lake elevation. Annual maximum larval (veliger) density decreased significantly indicating a population crash, which was likely caused by thermal stress and variability of lake elevation. In 2011, temperatures peaked at 34.3°C and lake elevation decreased to the lowest level recorded during the previous 18 years, which desiccated a substantial number of settled mussels in littoral zones. Estimated mean date of first spawn in Lake Texoma was observed approximately 1.5 months earlier than in Lake Erie, and peak veliger densities were observed two months earlier. Veligers were observed in the deepest oxygenated water after lake stratification. During a 69-day in situ experiment during summer in Lake Texoma, age-specific mortality of zebra mussels was generally high until temperatures decreased to approximately 28°C, which was observed after lake turnover in late summer. No study organism died after temperatures decreased to less than 26°C, which indicates individuals that survive high summer temperatures are likely to persist into autumn/winter. Shell length growth and soft tissue growth rates were related to temperature and chlorophyll-a concentration, respectively. Growth rates of study organisms were among the highest ever reported for D. polymorpha. Water temperature and body size influenced reproduction of YOY zebra mussels in Lake Texoma. Fecundity of females were positively related to temperature; however, sperm production was negatively related to temperature, which indicates males could be more sensitive to physiologically-stressful conditions than females and could perform better in cooler waters. YOY mussels spawned up to approximately 40,000 eggs and 3.47E+08 sperm after a single-summer growing season. Reproductive effort and reproductive mass were independent of sex. YOY individuals from each study site (n = 5) were able to spawn viable gametes capable of sperm binding and egg cleavage, which provides the first evidence that YOY zebra mussels can successfully reproduce. Individual mortality of zebra mussels will likely be high in warm waters and intermittent, extreme droughts, which are observed more frequently at lower latitudes, can significantly reduce population sizes. However, rapid growth and single-season maturation can decrease generation times and could facilitate establishment and spread of zebra mussels in warm-water environments in the southern United States. digital.library.unt.edu/ark:/67531/metadc407755/
Pocky Wenches Versus La Pauvre Femme: Medical Perceptions of Venereal Disease in Seventeenth-century England and France
In early modern Europe, syphilis tormented individuals regardless of social standing. The various stages of infection rendered individuals with visible chancres or “pocky” marks throughout their body. The tertiary stage signaled the spreading of the disease from the infected parts into the brain and cardiovascular system, eventually leading to dementia and a painful death. Beginning with the initial medical responses to venereal disease in the sixteenth century and throughout the early modern period, medical practitioners attempted to identify the cause of syphilis. During the seventeenth century, English practitioners maintained that women were primarily responsible for both the creation and transmission of syphilis. In England, venereal disease became the physical manifestation of illicit sexual behavior and therefore women with syphilis demonstrated their sexual immorality. Contrastingly, French medical practitioners refrained from placing blame on women for venereal infection. The historiography of early modern discourse on venereal disease fails to account for this discrepancy between English and French perceptions of syphilis in the seventeenth century. This thesis seeks to fill the gap in this historiography and suggest why French practitioners abstained from singling out women as the primary source of venereal infection by suggesting the importance that cultural influences and religious practices had toward shaping medical perceptions. The cultural impact of the querelle des femmes and Catholic practices in France plausibly influenced the better portrayal of women within the medical treatises of seventeenth-century France when compared to Protestant England. digital.library.unt.edu/ark:/67531/metadc407748/
American Indian Worldviews, Risk Perceptions and Disaster Planning: an Exploratory Study
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It is commonly assumed that when confronted with an imminent hazard that people will react rationally, and prepare for, or at least attempt to avoid, danger from pending disasters. However, this conventional wisdom is not as evident as it appears. People prepare for, react to, or take social action to avoid hazards when they perceive the risk of danger to be threatening enough to warrant action, providing one has the will, insight and resources to do so. However, not all people perceive risks similarly. Risk is perceived differently by different people which affects risk perception and responses to hazards. This dissertation explores the relationships between American Indian worldviews, risk perceptions and disaster planning. To carry out this research 28 American Indians were interviewed. The sample consists of 14 American Indians residing in a rural are on the northern plains and 14 urban American Indians. The results only partially support that worldview is linked to risk perception and subsequent disaster planning. Other factors found to relate to risk perception and disaster planning for this non-representative sample of American Indians include various forms of social vulnerability. digital.library.unt.edu/ark:/67531/metadc407742/
Overcapacity
Overcapacity is a self-reflexive, personal journey film that explores the filmmaker's exploration of his lifelong problem with obesity and health. The film follows his progress as he discusses his weight problem with his partner and parents as well as works with a personal trainer and doctor in an effort to affect a lifestyle change while also confronting issues that have led to and perpetuate his current health situation. digital.library.unt.edu/ark:/67531/metadc407783/
Analyzing Delinquency Among Kurdish Adolescents: a Test of Hirschi’s Social Bonding Theory
This study examines the mediating effect of social bonding on delinquent behavior among Kurdish teens. Major influences to the study of self concept and delinquency based on Hirschi’s social bonding theory are reviewed. The data was collected from a sample of 100 Kurdish teens attending a Gülen affiliated school (Private Çaglayan Murat Anatolian Science High School in Şanlıurfa, Turkey) and 100 Kurdish teens attending a public (non- Gülen) school (The Public High School in Diyarbakır, Turkey). There are two dependent variables for this research project: Involvement in major delinquency and involvement in minor delinquency. The components of social bonding attachment, involvement, commitment, and belief were used as independent variables. Participants’ age ranged between 16 to 18 years. I hypothesize that the relation between the social bonding elements and delinquency should be stronger in the case of Kurdish adolescents who are more attached to conventional Turkish society. Results from binary logistic regression analyses indicate that in the absence of bonding, Kurdish teenagers tend to engage in major and minor delinquent activities. For further exploration and results, the Gülen Movement was examined as an independent variable. Findings suggest a strong relationship between the Gülen Movement and Kurdish adolescents’ probability of involvement in either major or minor delinquent activities. Finally, several directions for future research on Hirschi’s social bonding theory are recommended and some implications are drawn for deterring Kurdish adolescents from becoming involved in delinquent actions. digital.library.unt.edu/ark:/67531/metadc407795/
From Aspiration to Attainment: African American Community College Transfer Student Experiences Through Baccalaureate Degree Attainment
The purpose of this dissertation was to explore African American community college transfer student experiences through baccalaureate degree completion. The current study used qualitative methods to examine the experiences and perceptions of eighteen African American community college transfer students who recently graduated or were within 30 credit hours of graduating from a four-year university in Texas. Ten female and eight male students, ranging in age from 21 to 56 years old, with an average age of 28, composed the sample. Data were collected through semi-structured interviews which were transcribed and analyzed based on an integrated conceptual model of Padilla’s (1999) Model of Minority Student Success and Yosso’s (2005) Community Cultural Wealth Model. Findings suggest that African American community college transfer student experiences are very similar to transfer student experiences revealed in current literature. However, findings indicate students perceive their experiences differ from student of other races/ethnicities when dealing with negative stereotypes, lack of role models, and racial bias. Findings also suggest African American community college transfer student persist by employing transfer student capital, familial, aspirational, and resistant capital to learn how the traverse transfer, transition, and persistence through baccalaureate degree attainment. digital.library.unt.edu/ark:/67531/metadc407745/
Molecular and Functional Characterization of Medicago Truncatula Npf17 Gene
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Legumes are unique among plants for their ability to fix atmospheric nitrogen with the help of soil bacteria rhizobia. Medicago truncatula is used as a model legume to study different aspects of symbiotic nitrogen fixation. M. truncatula, in association with its symbiotic partner Sinorhizobium meliloti, fix atmospheric nitrogen into ammonia, which the plant uses for amino acid biosynthesis and the bacteria get reduced photosynthate in return. M. truncatula NPF1.7 previously called MtNIP/LATD is required for symbiotic nitrogen fixing root nodule development and for normal root architecture. Mutations in MtNPF1.7 have defects in these processes. MtNPF1.7 encodes a member of the NPF family of transporters. Experimental results showing that MtNPF1.7 functioning as a high-affinity nitrate transporter are its expression restoring chlorate susceptibility to the Arabidopsis chl1-5 mutant and high nitrate transport in Xenopus laevis oocyte system. However, the weakest Mtnip-3 mutant allele also displays high-affinity nitrate transport in X. laevis oocytes and chlorate susceptibility to the Atchl1-5 mutant, suggesting that MtNPF1.7 might have another biochemical function. Experimental evidence shows that MtNPF1.7 also functions in hormone signaling. Constitutive expression of MtNPF1.7 in several species including M. truncatula results in plants with a robust growth phenotype. Using a synthetic auxin reporter, the presence of higher auxin in both the Mtnip-1 mutant and in M. truncatula plants constitutively expressing MtNPF1.7 was observed. Previous experiments showed MtNPF1.7 expression is hormone regulated and the MtNPF1.7 promoter is active in root and nodule meristems and in the vasculature. Two potential binding sites for an auxin response factors (ARFs) were found in the MtNPF1.7 promoter. Chromatin immunoprecipitation-qRT-PCR confirmed MtARF1 binding these sites. Mutating the MtARF1 binding sites increases MtNPF1.7 expression, suggesting a mechanism for auxin repression of MtNPF1.7. Consistent with these results, constitutive expression of an ARF in wild-type plants partially phenocopies Mtnip-1 mutants’ phenotypes. digital.library.unt.edu/ark:/67531/metadc407747/
The Use of a Stimulus Control Transfer Procedure to Teach Spontaneous Manding to Children with Autism
Current research indicates that the inability to spontaneously communicate needs or wants may result in the acquisition of unconventional forms of requesting such as aggression and tantrums. This in turn limits the amount of access that students with autism have to neurotypical peers and social environments. The purpose of this study was to investigate the effect of using a stimulus control transfer procedure on the acquisition of spontaneous mands. Four school-aged children with autism, two boys and two girls, participated in the study. A multiple baseline design across participants was utilized to demonstrate a functional relation between the stimulus control transfer procedures and the rate of spontaneous mands. Measurement variables included the frequency of spontaneous versus multiply-controlled mands during discrete trial training on a variety of verbal operants. Effectiveness of the intervention was analyzed through visual analysis and the magnitude of effect was assessed through effect size. Visual analysis indicated that three of the four participants learned to spontaneously mand for items out of view and demonstrated generalization across targets, staff and environments. The effect size for three participants were large (d = 1.94; d = 2.2; and d = 1.4), whereas the outcome of intervention for one participant (d = 0.98) indicated moderate effect. The overall (d = 1.15) outcome demonstrated a large effect of the intervention on the rate of mands. Based on the results of this study, it is recommended that early and intensive behavior intervention programs for children with autism incorporate this type of procedure for socially significant outcomes. digital.library.unt.edu/ark:/67531/metadc407751/
The Effect of Stock Splits on Small, Medium, and Large-sized Firms Before and After Decimalization
This study examines the impact of reducing tick size and, in particular decimalization on stock splits. Based on previous studies, this study examines hypotheses in the following three areas: first, market reaction around stock split announcement and ex-dates, second, the effect of tick size on liquidity after stock split ex-dates, and third, the effect of tick size on return volatility after stock split ex-dates. The impact of tick size on market reaction around split announcement and ex-dates is measured by abnormal returns and buy and hold abnormal returns (BHARs). Also, this study investigates the long term impact of decimalization on market reaction for small, medium, and large firms for the three different tick size periods. The effect of tick size on liquidity after stock split ex-dates is measured by turnover, relative bid ask spread, and market maker count. The effect of tick size on return volatility around stock split announcement and ex-dates is measured by return standard deviation. Also, this study investigates the long term impact of decimalization on volatility after split ex-dates for small, medium, and large firms for three different tick size periods. digital.library.unt.edu/ark:/67531/metadc407794/
The Extent of Autism Knowledge of Novice Alternatively Certified Special Education Teachers in Texas
An increase in the prevalence rate of autism is not necessarily matched by a concurrent increase in the rate of highly qualified special education teachers. The low ratio of highly qualified teachers to the number of students with autism has resulted in chronic teacher shortages in this area. Alternative certification is used as a mechanism to alleviate the demand for highly qualified teachers in special education. However, alternative certification routes have often left novice teachers underprepared for teaching students with autism, more specifically in the implementation of evidence-based practices necessary for instructional effectiveness. The purposes of the study were: a) to assess the knowledge of novice alternatively certified (AC) teachers in the area of autism education; and b) to determine the extent to which age, credit hours of instruction, formal hours of instruction, amount of professional development, and number of students with autism predict the variance in knowledge scores. Participants included all novice (i.e., first-and second-year) alternatively certified special education teachers in the state of Texas. Data were collected through an electronic survey instrument disseminated state-wide to approximately 33 individuals. Multiple regression was conducted in order to determine the strongest predictors of autism knowledge scores. In addition, a multi-way ANOVA was performed to identify differences between groups. The largest predictor of knowledge of autism was hours engaged in self-directed learning. Overall, AC programs in Texas need to provide basic and core content in the area of autism to increase the knowledge of novice teachers. digital.library.unt.edu/ark:/67531/metadc407790/
Bridging the Theory-to-practice Gap: a Multivariate Correlational Study Exploring the Effects of a Graduate Online Learning Environment As a Community of Practice Framework
In this multivariate correlational study, the researcher examined the course culture of an online graduate course whose environment exhibited characteristics of a Community of practice (CoP). An online survey captured data used to explore the relationships among variables shown to describe a CoP in field environments and among student perceptions of their experience in the course culture. A canonical correlation analysis (CCA) and commonality analysis (CA) were conducted using five predictor variables and three criterion variables to evaluate the degree and direction of the relationships. The CCA revealed that the full model was significant, explaining approximately 74% of the variance among the two synthetic variates. Impact, faculty leadership, and connection were the largest contributors to the predictor variate. The criterion variate was primarily explained by value and perceived CoP, with exposure to the profession providing a smaller contribution. The CA confirmed these findings. Results from this study indicate that a CoP could be fostered in an online graduate course. The overall significance of the model indicates teachers can nurture an environment wherein graduate students will take the initiative to work with others to create and acquire knowledge that creates a sense of professional connection with each other and with the profession overall. The results of this study suggest further empirical research in implementing and assessing CoPs in online graduate courses is warranted. digital.library.unt.edu/ark:/67531/metadc407763/
Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States
Diaspora philanthropy to India has grown rapidly over the past several decades. However, little is known about the motivations of Indians living in the U.S. to donate philanthropically to India. Extant studies have either focused on quantitative analysis of diaspora philanthropy or qualitative research on the receiving of diaspora philanthropy in India. The motivations and strategies of the Indian diaspora in the U.S. have not been explored, particularly, the informal mechanisms and strategies of making philanthropic donations to India and the obligations that underlie the practice of diaspora philanthropy remain neglected in the existing studies on diaspora philanthropy. My research addressed this gap in the existing literature on diaspora philanthropy by conducting qualitative face-to-face in-depth interviews with a snowball sample of 25 Indian engineers in San Diego, California. In my study, it was found that Indians preferred to channel funds for philanthropy in India through friends and family because of lack of trust in formal organizations and greater confidence in the activities of friends and family in India due to familiarity and better accountability. It was also found that Indians felt indebted to Indian society and the Indian nation-state for the free and subsidized education they had received in India, and therefore felt obligated to make philanthropic contributions to India in order to redeem the debt that they owe to India. digital.library.unt.edu/ark:/67531/metadc407766/
An Instructional Approach to Introducing Twentieth-century Piano Music to Piano Students From Beginning to Advanced Levels: a Graded Repertoire for Mastering the Challenges Posed by Logan Skelton’s Civil War Variations
Beginning and intermediate piano students typically study the repertoire of the eighteenth and nineteenth centuries. This pedagogical approach leaves them underprepared to approach compositions written since the latter part of the twentieth-century which are significantly different in terms of harmony, rhythm, meter, and compositional procedure. Therefore, a step-by-step method is necessary to prepare a student for the challenges of learning twentieth and twenty-first century piano music. Civil War Variations (1988), by Logan Skelton, is an excellent example of a piece that presents a number of challenges characteristically found in late twentieth-century piano music. The twenty-five variations that comprise the work incorporate a series of twentieth-century musical techniques, namely complex rhythms, extreme dissonance, frequent metric changes, dissonant counterpoint, the inclusion of blues scales and rhythms, and new notations. The purpose of this study is to identify the technical, musical, structural and notational challenges posed by a work such as Logan Skelton’s Civil War Variations; examination of this piece will lead to suggestions regarding repertoire that a teacher may assign to beginning, intermediate, and advanced students in order to prepare them logically and in a step-by-step fashion to cope with and meet the challenges posed by this and other compositions having similar characteristics. digital.library.unt.edu/ark:/67531/metadc407754/
Perceived Parent-child Relationship Quality’s Moderation Effect on the Acculturation-wellbeing Relationship Among Young Adults From Immigrant Families
The current study examined relationships among acculturation, parent-child relationship quality, and selected wellbeing indicators (health-related quality of life, life satisfaction, anxiety, depression, and stress) among a group of young adults from immigrant families of Asian and Hispanic descent. The first goal of the current study was to replicate previous research demonstrating a mixed relationship between acculturation and the wellbeing indicators. The second was to explain this relationship by testing for a moderation effect of parental care on the acculturation-wellbeing relationship. An examination of differences between members of the two ethnic groups on all measured variables served an exploratory purpose. Participants included 204 participants of Asian (N =80) and Hispanic (N = 124) descent who came from an immigrant family, or a family in which at least one parent was born outside of the U.S. Eligible respondents were also current students at the University of the North Texas who fell within the age range of 18-24, and the data for the current study was selected from a larger dataset (N = 1064). Results indicated that higher acculturation levels had a positive effect on each wellbeing indicator. Father Care and Mother Care were found to be significantly positively correlated with most outcome variables but neither parental care variable moderated the acculturation-wellbeing relationship. Asian and Hispanic participants differed on a number of predicting and outcome variables. Implications of the findings, limitations, and future directions are discussed. digital.library.unt.edu/ark:/67531/metadc407791/
The Political, Economic, and Military Decline of Venice Leading Up to 1797
This thesis discusses the decline of the Venetian nobility, the collapse of the Venetian economy, and the political results of the surrender of the Venetian Republic to Napoleon Bonaparte in 1797. Topics include the formation of Venice, Venetian domination of trade, the class system in Venice prior to 1797, the collapse of the aristocracy, feudalism in Venice, Venice’s presence in the Adriatic and Aegean seas, and the rise of the middle class within the provisional democratic government. Very few historians have attempted to research the provisional democracy of Venice and how the political and class structure of Venice changed as a result of the collapse of the Republic in 1797. Using primary sources, including government documents and contemporary histories, one can see how the once dominant noble class slowly fell victim to economic ruin and finally lost their role in the political leadership of Venice all together. During this same period, the middle class went from only holding secretarial jobs within the government, to leaders of a modern democratic movement. On top of primary research, several secondary sources helped in explaining the exclusivity of the noble class and their journey from economic dominance to economic ruin and the administrative consequences of this decline for the people of the Republic. This thesis aims to fill gaps in recent research concerning Venetian political history and specifically the period between the surrender of Venice on 12 May 1797, and the signing of the Treaty of Campo Formio, in which France awarded Venice to Austria, on 18 October 1797. digital.library.unt.edu/ark:/67531/metadc407798/
Witchcraft: a Targeted Societal Discrimination Against Women in Northern Ghana
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A combination of aging and poverty is becoming dominant in African society today, at a time when African countries are expected to be recovering from poverty, and are projected to house the economic growth of the next century. The emergence of aging in African context and the aging of the world population will expose the weakness of the current mechanisms used for older people around the world. As economies grow around the world, the distribution gap between the affluent and the poor widens, and the constant struggles for wealth, power, and social status, amidst scarce resources, continue to be sustained. To remain in charge of economic resources, the powerful few devise means to disenfranchise the weak, and witchcraft accusation is one of such tools used in Northern Ghana today. A new wave of witchcraft accusation has caught the attention of many in Northern Ghana. These victims with certain socioeconomic characteristics appear helpless and without defense against such accusations. As a result, they suffer untold hardships and are often compelled to leave their homes and to reside in camps reserved for witches. This study was undertaken to identify those sociodemographic characteristics, which are commonly shared by witchcraft accusation victims. These sociodemographic characteristics can be used to predict those who are most likely to be discriminated against using accusations of witchcraft in Northern Ghana. As age places more strain on existing systems and as more people survive into old age with inadequate healthcare, more accusations may be predicted to occur against the elderly, unless enough government intervention is used to address the present redistribution of income in third world countries. digital.library.unt.edu/ark:/67531/metadc407752/
Nano-crystallization Inhibition in 5 Nm Ru Film Diffusion Barriers for Advanced Cu-interconnect
As the semiconductor industries are moving beyond 22 nm node technology, the currently used stacked Ta/TaN diffusion barrier including a copper seed will be unable to fulfill the requirements for the future technologies. Due to its low resistivity and ability to perform galvanic copper fill without a seed layer, ruthenium (Ru) has emerged as a potential copper diffusion barrier. However, its crystallization and columnar nanostructure have been the main cause of barrier failures even at low processing temperatures (300 oC -350 oC). In this study, we have proposed and evaluated three different strategies to improve the performance of the ultrathin Ru film as a diffusion barrier for copper. The first study focused on shallow surface plasma irradiation/amorphization and nitridation of 5 nm Ru films. Systematic studies of amorphization and nitrogen incorporation versus sample bias were performed. XPS, XRD and RBS were used to determine the physico-chemical, crystallization and barrier efficiency of the plasma modified Ru barrier. The nitrogen plasma surface irradiation of Ru films at substrate bias voltage of -350 V showed an improved barrier performance up to 400 oC annealing temperatures. The barrier barely started failing at 450 oC due mainly to nitrogen instability. The second study involved only amorphization of the Ru thin film without any nitrogen incorporation. A low energy ion beam irradiation/amorphization on Ru thin film was carried out by using 60 KeV carbon ions with different irradiation doses. The irradiation energy was chosen high enough so that the irradiation ions pass through the whole Ru thin film and stop in the SiO2/Si support substrate. The C-ion fluence of 5×1016 atoms/cm2 at 60 KeV made the Ru film near amorphous without changing its composition. XRD and RBS were used to determine the relationship between crystallization and barrier efficiency of the carbon irradiated Ru barrier. The amorphized Ru film showed an improved barrier performance up to 400 oC annealing temperatures similar to the plasma nitrided Ru films. The barrier barely began to fail at 450 oC due mainly to crystallization. The third study focused on a study of Al doping of nitrided Ru thin films and their crystallinity with the aim of obtaining a completely amorphous Ru based barrier and stable nitridation. The addition of 4% Al and 14% of nitrogen in Ru produced a near amorphous film. Nitrogen in the film remained stable until the annealing temperature of 450 oC for 10 min in N2 atmosphere. Crystallization growth of the film was inhibited until 450 oC. At 500 oC, the crystallization of the Ru films barely started, but the degree of its crystallization is minimal. The Ru-Al-N film was demonstrated to be an effective diffusion barrier for copper until the annealing temperature of 450 oC and began to fail at 500 oC. The Al doping was shown to stabilize the nitrogen in the Ru thin film barrier inhibiting its crystallization and leading to improved diffusion barrier performance and a gain in processing temperatures of 150 oC -200 oC over the as prepared pure Ru thin film barriers. digital.library.unt.edu/ark:/67531/metadc407743/
Examining E-loyalty Model in Social Shopping Websites: the Impact of Social Shopping Website Quality on E-loyalty Formation
The purpose of this study is to examine the formation of customer e-loyalty to a social shopping website. The formation of customer e-loyalty to a social shopping website is examined based on cognitive-affective-conative-action loyalty framework. This study proposes that customer e-loyalty is strongly associated with website quality, e-satisfaction and participation. Seven website attributes (i.e., visual aesthetics, navigation, efficiency, user friendliness, security/privacy, entertainment and community driveness) identified in previous research are employed to measure website quality that affects e-loyalty formation. There are 449 data collected from a southwestern university in the U.S., but only the responses from 333 Pinterest users are used to test the hypotheses. Exploratory factor analysis is used to identify dimensionality of social shopping website attributes, and multiple regression and linear regression analysis are conducted to test hypotheses in this study. Results of the study indicate that five significant factors including efficiency, user friendliness, security/privacy, entertainment and community driveness are directly associated with customer e-loyalty. Indeed, such website quality factors as the determinant of cognitive e-loyalty directly affect overall customer satisfaction (affective e-loyalty), customer purchase/return intention to the website (conative e-loyalty), and customer participation, positive eWOM and co-shopping (action e-loyalty). The findings of this study have provided evidence that social shopping website quality dimensions are directly associated with customer e-loyalty to the website. Also, the findings have shown important implications to ensure quality website attributes to increase customer loyalty to a social shopping website. digital.library.unt.edu/ark:/67531/metadc407782/
Photochemical and Photophysical Properties of Mononuclear and Multinuclear Closed Shell D10 Coinage Metal Complexes and Their Metallo-organometallic Adducts
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This dissertation covers the studies of two major topics: the photochemistry of mononuclear and multinuclear gold(I) complexes and synthetic approaches to tailor photophysical properties of cyclic trinuclear d10 complexes. First a detailed photochemical examination into the photoreactivity of neutral mononuclear and multinuclear gold(I) complexes is discussed, with the aim of gold nanoparticle size and shape control for biomedical and catalysis applications. Next is a comprehensive systematic synthetic approach to tailor the photophysical properties of cyclic trinuclear d10 complexes. This synthetic approach includes an investigation of structure-luminescence relationships between cyclic trinuclear complexes, an examination into their π-acid/π-base reactivity with heavy metal cations and an exploration into the photophysical properties of new heterobimetallic cyclic trinuclear complexes. These photophysical properties inspections are used to screen materials for their employment in molecular electronic devices such as organic light-emitting diodes (OLEDs) and thin film transistors (OTFTs). digital.library.unt.edu/ark:/67531/metadc407759/