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An Investigation of Preservice Teachers' Understanding of Buoyancy

The purpose of this study was to examine the conceptual understandings of 55 elementary preservice teachers for the concept of buoyancy. This study used Ausubel’s Assimilation Theory (Ausubel, 1963) as a framework for a 15-week intervention that used pre/post concept maps (Cmaps), pre/post face-to-face semi-structured interviews, and drawings as evidences for change of formation of cognitive structures. Using a convergent parallel design and mixed methods approach, preservice teachers’ conceptions were analyzed using these evidences. Results of the study show that preservice teachers held both scientific conceptions and misconceptions about buoyancy as a force before and after an instructional intervention. Of importance were the existence of robust misconceptions about buoyancy that included inaccurate scientific knowledge about the foundational concepts of gravity, weight, mass, and density. The largest gains in scientific knowledge included the concepts of gravity, surface area, opposing forces, and the buoyant force. These concepts were consistently supported with evidence from post-concept maps, post, semi-structured interviews, and drawings. However, high frequencies of misconceptions were associated with these same aforementioned concepts as well as additional misconceptions about buoyancy-related concepts (i.e., weight, density, displacement, and sinking/floating). A paired t test showed a statistically significant difference (t = -3.504, p = .001) in the total number of scientifically correct concepts for the pre-concept maps (M = 0.51, SD = .879) and post-concept maps (M = 1.25, SD = 1.542). The Cohen’s d effect size was small, .47. Even through gains for the pre/post concept maps were noted, a qualitative analysis of the results indicated that not only were there serious gaps in the participant’s scientific understanding of buoyancy, after the instructional intervention an increased number of misconceptions were presented alongside the newly learned concepts. A paired t test examining misconceptions showed that there was a statistically significant difference (t = -3.160, p = ...

Date: May 2016

Creator: Kirby, Benjamin

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Parents’ Reported Utilization, Accessibility, and Effectiveness of Academic Support Resources for Military Adolescents at Fort Hood Military Base

Academic support resources are increasingly available to military-connected youth; however, the military community, in general, tends to under-utilize available resources. The research literature has not clearly identified accessibility to military academic support resources or perceived effectiveness of resources as explanations for under-utilization of adolescent support services. The current research study examines military parents' perceptions of academic resource programs looking at how parents' perception of resource accessibility and resource effectiveness were related to program utilization. Based on qualitative analysis of military parent interviews, utilization was related to both accessibility and effectiveness. This research adds to the literature by identifying the relationship to between accessibility and utilization and reported effectiveness and utilization of academic support resources.

Date: May 2016

Creator: Booker, Dana Dean

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Paul Robert Fauchet's Symphony in B-flat: A Performance Edition for Modern Wind Band Instrumentation

Paul Robert Fauchet's Symphonie pour Musique d'Harmonie, known in the United States as Symphony in B-flat, is a four-movement composition spanning nearly thirty minutes in length and written in the style of the late romantic composers. Despite its place as one of the first symphonies for wind band, a performance of the piece that represents the composer's 1926 orchestration is difficult due to the inclusion of instruments that are no longer in common practice, including bugles, alto horns, and saxhorns. Later American editions of the work by James Robert Gillette (1933) and Frank Campbell-Watson (1948/1949) replaced these instruments, but also took several other liberties with orchestration and voicing. The primary purpose of this study was the creation of a performance edition of the Symphony for modern wind band that is accessible to a larger audience of performers and listeners. The method involved in creating the modern edition eliminates errors of extant editions and clarifies a number of the discrepancies surrounding the symphony's multiple publications. This edition attempts to retain the composer's voicing and orchestration choices. To accomplish this, the present project considered where modern instrumentation differed from the original sources and attempted to balance timbral similarities between those instruments, while also considering ease of comprehension for a modern ensemble to perform the work. Sources used to create this edition included all published editions of scores and parts, as well as a newly created full score of the 1926 printed parts. The study concludes with the inclusion of the full score of the new performance edition.

Date: May 2016

Creator: Kitelinger, Shannon Monroe

Item Type: Thesis or Dissertation

Partner: UNT Libraries

A Search for Periodic and Quasi-Periodic Patterns in Select Proxy Data with a Goal to Understanding Temperature Variation

In this work over 200 temperature proxy data sets have been analyzed to determine if periodic and or quasi-periodic patterns exist in the data sets. References to the journal articles where data are recorded are provided. Chapter 1 serves an introduction to the problem of temperature determination in providing information on how various proxy data sources are derived. Examples are given of the techniques followed in producing proxy data that predict temperature for each method used. In chapter 2 temperature proxy data spanning the last 4000 years, from 2,000 BCE to 2,000 CE, are analyzed to determine if overarching patterns exist in proxy data sets. An average of over 100 proxy data sets was used to produce Figure 4. An overview of the data shows that several “peaks” can be identified. The data were then subjected to analysis using a series of frequency modulated cosine waves. This analysis led to a function that can be expressed by equation 3. The literature was examined to determine what mathematical models had been published to fit the experimental proxy data for temperature. A number of attempts have been made to fit data from limited data sets with some degree of success. Some other papers have used a sinusoidal function to best fit the changes in the temperature. After consideration of many published papers and reviewing long time streams of proxy data that appeared to have sine wave patterns, a new model was proposed for trial. As the patterns observed showed “almost” repeating sine cycles, a frequency modulated sine wave was chosen to obtain a best fit function. Although other papers have used a sinusoidal function to best fit the changes in the temperature, the “best fit” was limited. Thus, it was decided that a frequency modulated sine wave may be a better model ...

Date: May 2016

Creator: Otto, James

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Strategic Design: An Action Research Study on Community Relations in a Texas School District

School leaders often contemplate implementing measures that will increase community and parent involvement in schools. There is a shortage of research that concisely takes school leadership through a process that details how to integrate parent and community input in a school transformation initiative and careful analysis of student outcomes. Within this study, I provide an in-depth look at one school district’s efforts to engage its community through strategic planning and mission and vision redesign. This process includes community involvement at every phase. For the purpose of this study, community refers to both community members who do not have children in the school system and parents of current students. In this study, I outline the inception of the transformation effort, the ongoing efforts to include community input in decision-making and campus implementation, and finally a review of the overarching impact on leadership, staff, students and community. Data collection analyzed in this study include assessment data, survey data, discipline data and walk through data collected by the school district.

Date: May 2016

Creator: Jund, Nicole Cathryn

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Biomass-Derived Activated Carbon through Self-Activation Process

Self-activation is a process that takes advantage of the gases emitted from the pyrolysis process of biomass to activate the converted carbon. The pyrolytic gases from the biomass contain CO2 and H2O, which can be used as activating agents. As two common methods, both of physical activation using CO2 and chemical activation using ZnCl2 introduce additional gas (CO2) or chemical (ZnCl2), in which the CO2 emission from the activation process or the zinc compound removal by acid from the follow-up process will cause environmental concerns. In comparison with these conventional activation processes, the self-activation process could avoid the cost of activating agents and is more environmentally friendly, since the exhaust gases (CO and H2) can be used as fuel or feedstock for the further synthesis in methanol production. In this research, many types of biomass were successfully converted into activated carbon through the self-activation process. An activation model was developed to describe the changes of specific surface area and pore volume during the activation. The relationships between the activating temperature, dwelling time, yield, specific surface area, and specific pore volume were detailed investigated. The highest specific surface area and pore volume of the biomass-derived activated carbon through the self-activation process were up to 2738 m2 g-1 and 2.209 cm3 g-1, respectively. Moreover, the applications of the activated carbons from the self-activation process have been studied, including lithium-ion battery (LIB) manufacturing, water cleaning, oil absorption, and electromagnetic interference (EMI) shielding.

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Date: May 2016

Creator: Xia, Changlei

Item Type: Thesis or Dissertation

Partner: UNT Libraries

The Perceptions of Policymakers on the Transfer Pathway in Texas Public Higher Education

Community college students transfer to public universities experiencing a pathway filled with complexity and inequity. Transfer students are not able to graduate at the same pace as native students at the university and complete their baccalaureate degrees 18% below the rate of native students. Policymakers have attempted to address the baccalaureate gap. This qualitative study explored the perspectives of Texas policymakers and policy influencers on the efficacy of policies intended to improve transfer outcomes. This study investigated what experience participants have with transfer policy, what their perceptions of the transfer pathway are, and how their voices can refine an understanding of policy development and ways to improve student persistence. Purposeful sampling was used to explore the perspectives of 14 Texas policymakers and those that influence policy. Findings revealed that significant gaps exist between expectations and student realities and that the completion agenda is driving policy decisions. Participants perceived that transfer students have been ignored in the completion metrics, which influence institutional priorities. Moreover, the decentralized system of independent, autonomous institutions is a major contributor to inefficiencies such as excessive student credit hours. Improving the transferability of courses was a priority recommendation of all participants both because it benefits the State’s economy and, more importantly, because it is in the best interest of students.

Date: May 2016

Creator: Faris, Kimberly A

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Design of New Monodentate Ligands for Regioselectivity and Enantioselectivity Tuning in Late Transition Metal Catalysis

The ability of gold(I) to activate many types of unsaturated bonds toward nucleophilic attack was not widely recognized until the early 2000s. One major challenge in gold catalysis is the control over regioselectivity when there are two or more possible products as a result of complicated mechanistic pathways. It is well know that the choice of ligand can have dramatic effects on which pathway is being followed but very rarely are the reasons for this selectivity understood. The synthesis of new acyclic diaminocarbenes was developed and a study of the ligand effects on the regioselectivity of a gold-catalyzed domino enyne cyclization hydroarylation reaction and a Nazarov cyclization was undertaken. New chiral acyclic diaminocarbenes were also developed and tested along side new C3-symmetric phosphite ligands in an asymmetric intramolecular hydroamination of allenes. Structure activity correlations were developed for the potential use in further rational ligand design. The synthesis of 6a,7-dihydro-5-amino-dibenzo[c,g]chromene derivatives via a gold-catalyzed domino reaction of alkynylbenzaldehydes in the presence of secondary amines was developed. These were sent to be screened for biological activity.

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Date: May 2016

Creator: Ruch, Aaron Anthony

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Influence of High Strain Rate Compression on Microstructure and Phase Transformation of NiTi Shape Memory Alloys

Since NiTi shape memory alloy (SMA) was discovered in the early 1960s, great progress has been made in understanding the properties and mechanisms of NiTi SMA and in developing associated products. For several decades, most of the scientific research and industrial interests on NiTi SMA has focused on its superelastic applications in the biomedical field and shape memory based “smart” devices, which involves the low strain rate (around 0.001 s^-1) response of NiTi SMA. Due to either stress-induced martensite phase transformation or stress induced martensite variant reorientation under the applied load, NiTi SMA has exhibited a high damping capacity in both austenitic and martensitic phase. Recently, there has been an increasing interest in exploitation of the high damping capacity of NiTi SMA to develop high strain rate related applications such as seismic damping elements and energy absorbing devices. However, a systematic study on the influence of strain, strain rate and temperature on the mechanical properties, phase transformation, microstructure and crystal structure is still limited, which leads to the difficulties in the design of products being subjected to high strain rate loading conditions. The four main objectives of the current research are: (1) achieve the single loading and the control of strain, constant strain rate and temperature in high strain rate compression tests of NiTi SMA specimens using Kolsky (split Hopkinson) compression bar; (2) explore the high strain rate compressive responses of NiTi SMA specimens as a function of strain (1.4%, 1.8%, 3.0%, 4.8%, and 9.6%), strain rate (400, 800 and 1200 s^-1), and temperature (room temperature (294 K) and 373 K); (3) characterize and compare the microstructure, phase transformation and crystal structure of NiTi SMAs before and after high strain rate compression; and (4) correlate high strain rate deformation with the changes of microstructure, phase transformation characteristics and crystal structure. ...

Date: May 2016

Creator: Qiu, Ying

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Information Structures in Notated Music: Statistical Explorations of Composers' Performance Marks in Solo Piano Scores

Written notation has a long history in many musical traditions and has been particularly important in the composition and performance of Western art music. This study adopted the conceptual view that a musical score consists of two coordinated but separate communication channels: the musical text and a collection of composer-selected performance marks that serve as an interpretive gloss on that text. Structurally, these channels are defined by largely disjoint vocabularies of symbols and words. While the sound structures represented by musical texts are well studied in music theory and analysis, the stylistic patterns of performance marks and how they acquire contextual meaning in performance is an area with fewer theoretical foundations. This quantitative research explored the possibility that composers exhibit recurring patterns in their use of performance marks. Seventeen solo piano sonatas written between 1798 and 1913 by five major composers were analyzed from modern editions by tokenizing and tabulating the types and usage frequencies of their individual performance marks without regard to the associated musical texts. Using analytic methods common in information science, the results demonstrated persistent statistical similarities among the works of each composer and differences among the work groups of different composers. Although based on a small sample, the results still offered statistical support for the existence of recurring stylistic patterns in composers' use of performance marks across their works.

Date: May 2016

Creator: Buchanan, J. Paul

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Musical and Dramatic Functions of Loops and Loop Breakers in Philip Glass's Opera "The Voyage"

Philip Glass's minimalist opera The Voyage commemorates the 500th Anniversary of Christopher Columbus's discovery of America. In the opera, Philip Glass, like other composers, expresses singers' and non-singers' words and activities by means of melodies, rhythms, chords, textures, timbres, and dynamics. In addition to these traditional musical expressions, successions of reiterating materials (RMs, two or more iterations of materials) and non reiterating materials (NRMs) become new musical expressions. However, dividing materials into theses two categories only distinguishes NRMs from RMs without exploring relations among them in successions. For instance, a listener cannot perceive the functional relations between a partial iteration of the RM and the NRM following the partial RM because both the partial RM and the NRM are NRMs. As a result, a listener hears a succession of NRM followed by another NRM. When an analyst relabels the partial RM as partial loop, and the NRM following the partial RM as loop breaker, a listener hears the NRM as a loop breaker causing a partial loop. The musical functions of loops and loop breakers concern a listener's expectations of the creation, sustaining, departure, and return to the norm in successions of loops and loop breakers. When a listener associates the satisfaction and dissatisfaction of these expectations with dramatic devices such as incidents, words in dialogues and soliloquies, and activities by singers and non-singers, loops and loop breakers in successions become dramatically functional. This dissertation explores the relations among musical and dramatic functions of loops and loop breakers in Glass's musical commemoration of Columbus.

Date: May 2016

Creator: Wu, Chia-Ying

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Electrodeposited Metal Matrix Composites for Enhanced Corrosion Protection and Mechanical Properties

In the oil and gas industry, high corrosion resistance and hardness are needed to extend the lifetime of the coatings due to exposure to high stress and salt environments. Electrodeposition has become a favorable technique in synthesizing coatings because of low cost, convenience, and the ability to work at low temperatures. Electrodeposition of metal matrix composites has become popular for enhanced corrosion resistance and hardness in the oil and gas industry because of the major problems that persist with corrosion. Two major alloys of copper-nickel, 90-10 and 70-30, were evaluated for microbial corrosion protection in marine environments on a stainless steel substrate. Copper and copper alloys are commonly used in marine environments to resist biofouling of materials by inhibiting microbial growth. Literature surveying the electrodeposition of Cu-Ni incorporated with nano- to micro- particles to produce metal matrix composites has been reviewed. Also, a novel flow cell design for the enhanced deposition of metal matrix composites was examined to obtain the optimal oriented structure of the layered silicates in the metal matrix. With the addition of montmorillonite into the Ni and Cu-Ni matrix, an increase in strength, adhesion, wear and fracture toughness of the coating occurs, which leads to an increase corrosion resistance and longevity of the coating. These coatings were evaluated for composition and corrosion using many different types of instrumental and electrochemical techniques. The overall corrosion resistance and mechanical properties were improved with the composite films in comparison to the pure metals, which proves to be advantageous for many economic sectors including the oil and gas industry.

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Date: May 2016

Creator: Thurber, Casey Ray

Item Type: Thesis or Dissertation

Partner: UNT Libraries

An Analysis of the Leadership Competency Frameworks of Nontraditional Principal Preparation Programs

This study explored the competency frameworks of nontraditional principal preparation programs to determine how they aligned to research-based best practices for school leaders. The research questions that guided this work were: To what degree are the McREL 21 Leadership Responsibilities addressed in the competency frameworks of nontraditional principal preparation programs? How do the leaders of the nontraditional principal preparation programs view the degree to which their competencies include the McREL 21 Leadership Responsibilities? A multi-case study analysis was conducted that compared the competency frameworks of four nontraditional principal preparation programs. The Knowledge is Power Program (KIPP), New Leaders, New York City Leadership Academy (NYCLA), and Teaching Trust were the nontraditional programs selected for this study. Leaders from the four organizations were interviewed. The findings from the research illustrated that a majority of the McREL 21 Leadership Responsibilities were included in the competency frameworks of nontraditional principal preparation programs. The study revealed that four of the McREL 21 were not included in any of the competency frameworks. Another finding was the lack of focus on talent management and personal dispositions in the McREL 21 Leadership Responsibilities. Nontraditional principal preparation programs are a growing avenue for principal preparation, as such their use of research on principal success was promising

Date: May 2016

Creator: Horton, Tonya Marie

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Fatigue Behavior of A356 Aluminum Alloy

Metal fatigue is a recurring problem for metallurgists and materials engineers, especially in structural applications. It has been responsible for many disastrous accidents and tragedies in history. Understanding the micro-mechanisms during cyclic deformation and combating fatigue failure has remained a grand challenge. Environmental effects, like temperature or a corrosive medium, further worsen and complicate the problem. Ultimate design against fatigue must come from a materials perspective with a fundamental understanding of the interaction of microstructural features with dislocations, under the influence of stress, temperature, and other factors. This research endeavors to contribute to the current understanding of the fatigue failure mechanisms. Cast aluminum alloys are susceptible to fatigue failure due to the presence of defects in the microstructure like casting porosities, non-metallic inclusions, non-uniform distribution of secondary phases, etc. Friction stir processing (FSP), an emerging solid state processing technique, is an effective tool to refine and homogenize the cast microstructure of an alloy. In this work, the effect of FSP on the microstructure of an A356 cast aluminum alloy, and the resulting effect on its tensile and fatigue behavior have been studied. The main focus is on crack initiation and propagation mechanisms, and how stage I and stage II cracks interact with the different microstructural features. Three unique microstructural conditions have been tested for fatigue performance at room temperature, 150 °C and 200 °C. Detailed fractography has been performed using optical microscopy, scanning electron microscopy (SEM) and electron back scattered diffraction (EBSD). These tools have also been utilized to characterize microstructural aspects like grain size, eutectic silicon particle size and distribution. Cyclic deformation at low temperatures is very sensitive to the microstructural distribution in this alloy. The findings from the room temperature fatigue tests highlight the important role played by persistent slip bands (PSBs) in fatigue crack initiation. At room ...

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Date: May 2016

Creator: Nelaturu, Phalgun

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Continuous Combinatorics of a Lattice Graph in the Cantor Space

We present a novel theorem of Borel Combinatorics that sheds light on the types of continuous functions that can be defined on the Cantor space. We specifically consider the part X=F(2ᴳ) from the Cantor space, where the group G is the additive group of integer pairs ℤ². That is, X is the set of aperiodic {0,1} labelings of the two-dimensional infinite lattice graph. We give X the Bernoulli shift action, and this action induces a graph on X in which each connected component is again a two-dimensional lattice graph. It is folklore that no continuous (indeed, Borel) function provides a two-coloring of the graph on X, despite the fact that any finite subgraph of X is bipartite. Our main result offers a much more complete analysis of continuous functions on this space. We construct a countable collection of finite graphs, each consisting of twelve "tiles", such that for any property P (such as "two-coloring") that is locally recognizable in the proper sense, a continuous function with property P exists on X if and only if a function with a corresponding property P' exists on one of the graphs in the collection. We present the theorem, and give several applications.

Date: May 2016

Creator: Krohne, Edward William

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Do Re Mi? Yes! Using Music and Visual Arts to Promote Thai Children's English Vocabulary Development

This research examines the efficacy, if any, of the Music and Visual Arts (MVA) program in improving the English vocabulary development of first grade Thai students. The researcher developed the Vocabulary Recognition Assessment (VRA) as a measure of English vocabulary development. It employs the accuracy and rapidity method of word recognition as a measurement of English language development in Thai children. Forty first grade Thai students in a Bangkok elementary school participated in the study. Participants were divided equally between an experimental group and a control group. During a nine-week period, students in the experimental group were instructed with the MVA strategy, while students in the control group were taught with the Visual Arts (VA) strategy. Paired sample t-test, ANOVA, and ANCOVA were used to analyze data from the VRA, to compare the pre-test and the post-test in terms of accuracy scores and rapidity scores of the control group and the experimental group. Data revealed that students instructed with the MVA strategy improved their English vocabulary development in terms of accuracy of word recognition significantly more than students taught English using the VA strategy. No significant difference was found between the MVA strategy and the VA strategy in terms of rapidity of word recognition. The MVA strategy could be a useful strategy for Thai early childhood teachers to use in helping Thai children learn English vocabulary.

Date: May 2016

Creator: Mathayomchan, Somsuda

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Intraoral Pressure and Sound Pressure During Woodwind Performance

For woodwind and brass performers, intraoral pressure is the measure of force exerted on the surface area of the oral cavity by the air transmitted from the lungs. This pressure is the combined effect of the volume of air forced into the oral cavity by the breathing apparatus and the resistance of the embouchure, reed opening, and instrument’s back pressure. Recent research by Michael Adduci shows that intraoral pressures during oboe performance can exceed capabilities for corresponding increases in sound output, suggesting a potentially hazardous situation for the development of soft tissue disorders in the throat and velopharyngeal insufficiencies. However, considering that oboe back pressure is perhaps the highest among the woodwind instruments, this problem may or may not occur in other woodwinds. There has been no research of this type for the other woodwind instruments. My study was completed to expand the current research by comparing intraoral pressure (IOP) and sound pressure when performing with a characteristic tone on oboe, clarinet, flute, bassoon, and saxophone. The expected results should show that, as sound pressure levels increase, intraoral pressure will also increase. The subjects, undergraduate and graduate music majors at the University of North Texas, performed a series of musical tasks on bassoon, clarinet, flute, oboe, and alto saxophone. The musical tasks cover the standard ranges of each instrument, differences between vibrato and straight-tone, and a variety of musical dynamics. The data was collected and examined for trends. The specific aims of this study are to (1) determine whether there is a correlation between IOP and sound pressure, (2) shed light on how well each instrument responds to rapid fluctuation, and (3) determine which instruments are most efficient when converting air pressure into sound output. Results of this study raised concerns shared by previous studies – that woodwind players are ...

Date: May 2016

Creator: Bowling, Micah

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Preferred Qualifications of Collegiate Athletic Directors: Opinions of Presidents and Athletic Directors

This study explored the preparation methods, qualifications and criteria that both university and athletic directors deemed necessary when searching for athletic directors. Participants completed a survey via Qualtrics online software. Two different populations were sampled for this study: 651 university presidents and 651 athletic directors whose schools compete in either Division I or II in the NCAA, resulting in 96 abd 150 usable responses respectively. Participants in both groups were primarily white males with mean ages of 62 for presidents and 52 for the athletic directors. The study provided demographic information, educational history, professional experience, and prior careers of athletic directors. The rankings of the athletic were compared to the rankings of the presidents and identified consistenncies of opinions. The respondent groups were in agreement on the qualities and ranking of many dimensions of leadershihp in this role. The top seven, for both groups, in order, were ethics, budgeting and finances skills, fundraising, communications, sport leadership, strategic management and policy, and athletic administration. This information could be used as a guide for people who want to strategically maneuver up the ranks in athletics administration. Presidents might use the information as they prepare to hire candidates for the athletic director position.

Date: May 2016

Creator: Sheffield, Cinnamon

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Decision Makers’ Cognitive Biases in Operations Management: An Experimental Study

Behavioral operations management (BOM) has gained popularity in the last two decades. The main theme in this new stream of research is to include the human behavior in Operations Management (OM) models to increase the effectiveness of such models. BOM is classified into 4 areas: cognitive psychology, social psychology, group dynamics and system dynamics (Bendoly et al. 2010). This dissertation will focus on the first class, namely cognitive psychology. Cognitive psychology is further classified into heuristics and biases. Tversky and Kahneman (1974) discussed 3 heuristics and 13 cognitive biases that usually face decision makers. This dissertation is going to study 6 cognitive biases under the representativeness heuristic. The model in this dissertation states that cognitive reflection of the individual (Frederick 2005) and training about cognitive biases in the form of warning (Kaufmann and Michel 2009) will help decisions’ makers make less biased decisions. The 6 cognitive biases investigated in this dissertation are insensitivity to prior probability, insensitivity to sample size, misconception of chance, insensitivity to predictability, the illusion of validity and misconception of regression. 6 scenarios in OM contexts have been used in this study. Each scenario corresponds to one cognitive bias. Experimental design has been used as the research tool. To see the impact of training, one group of the participants received the scenarios without training and the other group received them with training. The training consists of a brief description of the cognitive bias as well as an example of the cognitive bias. Cognitive reflection is operationalized using cognitive reflection test (CRT). The survey was distributed to students at University of North Texas (UNT). Logistic regression has been employed to analyze data. The research shows that participants show the cognitive biases proposed by Tversky and Kahneman. Moreover, CRT is significant factor to predict the cognitive bias in two ...

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Date: May 2016

Creator: Alkhars, Mohammed

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Community-based Logistics and Supply Chain Management: Developing, Testing and Validating Conceptual Models

The field of Logistics and Supply Chain Management (LSCM) suggests that transactions, collaboration, and value are important in the supply and delivery of products and services to meet the need of impoverished end-consumers. In many cases, the application of LSCM is paramount in most strategic decision-making efforts. Therefore, this research explores the applications of LSCM processes and activities within the community-based context. The methodology used to address the research questions consisted of a hybrid of mixed methods. This mixed methodology provides three essays that investigate the application and development of LSCM in the community-based context. The essays address the flow of charitable products and services through supply chains. The dissertation does not pay close attention to the first-tier suppliers’ suppliers, which is looking at the originating flow of goods and services (raw materials, manufacturing, etc.). However, the dissertation puts a focus on products and services supplied to focal organizations and how these products are then passed on to end-consumers. Essay I looks at the transaction (costs) that ensue from the supply of charitable products. Essay II analyzes a social service ecosystem and investigates how the network of organizations enable the distribution of charitable products and services. Lastly, Essay III examines the delivery of valuable services to the end-consumers, and what tools Community-Based Enterprises (CBEs) should focus on to develop and retain end-consumers in impoverished communities. The research provides conceptual models that review some fundamental LSCM achievement gaps in supplying, delivering and providing social services to end users within impoverished communities. The dissertation draws upon literature from the fields of economics, marketing, social science, and logistics and supply chain management. The dissertation uses the primary research method of unstructured and semi-structured interviews, case studies, written survey instruments and system dynamics within three studies. The studies resolve to look into the term ...

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Date: May 2016

Creator: Obaze, Yolanda

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Ours is the Kingdom of Heaven: Racial Construction of Early American Christian Identities

This project interrogates how religious performance, either authentic or contrived, aids in the quest for freedom for oppressed peoples; how the rhetoric of the Enlightenment era pervades literatures delivered or written by Native Americans and African Americans; and how religious modes, such as evoking scripture, performing sacrifices, or relying upon providence, assist oppressed populations in their roles as early American authors and speakers. Even though the African American and Native American populations of early America before the eighteenth century were denied access to rights and freedom, they learned to manipulate these imposed constraints--renouncing the expectation that they should be subordinate and silent--to assert their independent bodies, voices, and spiritual identities through the use of literary expression. These performative strategies, such as self-fashioning, commanding language, destabilizing republican rhetoric, or revising narrative forms, become the tools used to present three significant strands of identity: the individual person, the racialized person, and the spiritual person. As each author resists the imposed restrictions of early American ideology and the resulting expectation of inferior behavior, he/she displays abilities within literature (oral and written forms) denied him/her by the political systems of the early republican and early national eras. Specifically, they each represent themselves in three ways: first, as a unique individual with differentiated abilities, exceptionalities, and personality; second, as a person with distinct value, regardless of skin color, cultural difference, or gender; and third, as a sanctified and redeemed Christian, guaranteed agency and inheritance through the family of God. Furthermore, the use of religion and spirituality allows these authors the opportunity to function as active agents who were adapting specific verbal and physical methods of self-fashioning through particular literary strategies. Doing so demonstrates that they were not the unrefined and unfeeling individuals that early American political and social restrictions had made them--that instead they were ...

Date: May 2016

Creator: Robinson, Heather L

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Stable Nanocrystalline Au Film Structures for Sliding Electrical Contacts

Hard gold thin films and coatings are widely used in electronics as an effective material to reduce the friction and wear of relatively less expensive electrically conductive materials while simultaneously seeking to provide oxidation resistance and stable sliding electrical contact resistance (ECR). The main focus of this dissertation was to synthesize nanocrystalline Au films with grain structures capable of remaining stable during thermal exposure and under sliding electrical contact stress and the passing of electrical current. Here we have utilized a physical vapor deposition (PVD) technique, electron beam evaporation, to synthesize Au films modified by ion implantation and codeposited ZnO hardened Au nanocomposites. Simultaneous friction and ECR experiments of low fluence (< 1x10^17 cm^-2) He and Ar ion implanted Au films showed reduction in friction coefficients from ~1.5 to ~0.5 and specific wear rates from ~4x10^-3 to ~6x10^-5 mm^3/N·m versus as-deposited Au films without significant change in sliding ECR (~16 mΩ). Subsurface microstructural changes of He implanted films due to tribological stress were analyzed via site-specific cross-sectional transmission electron microscopy (TEM) and revealed the formation of nanocrystalline grains for low energy (22.5 keV) implantation conditions as well as the growth and redistribution of cavities. Nanoindentation hardness results revealed an increase from 0.84 GPa for as-deposited Au to ~1.77 GPa for Au uniformly implanted with 1 at% He. These strength increases are correlated with an Orowan hardening mechanism that increases proportionally to (He concentration)1/3. Au-ZnO nanocomposite films in the oxide dilute regime (< 5 vol% ZnO) were investigated for low temperature aging stability in friction and ECR. Annealing at 250 °C for 24 hours Au-(2 vol%)ZnO retained a friction coefficient comparable to commercial Ni hardened Au of ~ 0.3 and sliding ECR values of ~35 mΩ. Nanoindentation hardness increases of these films (~2.6 GPa for 5 vol% ZnO) are correlated to ...

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Date: May 2016

Creator: Mogonye, Jon-Erik

Item Type: Thesis or Dissertation

Partner: UNT Libraries

The Mystery of the Chalumeau and Its Historical Significance as Revealed Through Selected Works for Chalumeau or Early Clarinet by Antonio Vivaldi

Factual evidence concerning the ancestry of the clarinet has been a perpetual topic of debate among musicologists and organologists. Scholars have widely agreed that the clarinet, first documented in 1710, emerged from the baroque invention of the chalumeau (invented circa 1690), which in itself was an improvement upon the recorder. Considering the chalumeau’s short lifespan as the predominant single reed instrument in the early eighteenth century, the chalumeau inspired a monumental amount of literature that includes vocal and instrumental genres written by distinguished composers. Vivaldi is considered to be the most significant composer that wrote for both clarinet and chalumeau; he wrote for both instruments simultaneously throughout his life whereas his contemporaries seemingly replaced the chalumeau with the clarinet. This project will discuss Vivaldi’s proximity to the chalumeau and the clarinet and will provide an in-depth analysis of relevant works by the composer to determine how he, unlike his contemporaries, treated the chalumeau and the clarinet as separate and equally viable instruments. Following a brief history of the chalumeau and clarinet in Italy and a relevant biography of Vivaldi (Ch. 2), this document will discuss the integral Vivaldi compositions that include clarinet and chalumeau and the role of the clarinet or chalumeau in each work (Ch. 3). Chapter 4 solves the mystery of why Vivaldi continued to compose for the chalumeau while his contemporaries replaced the chalumeau with the clarinet.

Date: May 2016

Creator: Braun, Lindsay T.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Transmedia STEM Intervention Book in Middle School for Educational Change

The world is becoming a global place in which science, technology, engineering and mathematics hold a key to a successful future. To help secure this future it is important to engage students early with relevant curriculum that sparks interest and success in STEM fields. However, education reform occurs slowly, so this paper looked at a potential paradigm that can help to bring about change in a middle school environment that harnesses the long standing strengths of learning and education with the integration of technology to create changes in the pedagogy of learners and teachers. The study implemented a transmedia STEM book and evaluated the impact it had on student perceptions of STEM, school attitude, academic achievement, and preferred activity types, providing an example vehicle for change that can be adopted over time. The main findings showed that students who used a 3-Dimensional printer had higher math achievement and a more positive perception of math.

Date: May 2016

Creator: Stansell, Alicia Renee

Item Type: Thesis or Dissertation

Partner: UNT Libraries

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