You limited your search to:

 Decade: 2010-2019
 Degree Level: Doctoral
 Collection: UNT Theses and Dissertations
9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress

9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress

Access: Use of this item is restricted to the UNT Community.
Date: May 2012
Creator: Nalam, Vamsi J.
Description: The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect spent less time feeding from sieve elements and xylem, thus resulting in reduced water content and fecundity of GPA. LOX5 expression is induced rapidly in roots of GPA-infested plants. This increase in LOX5 expression is paralleled by an increase in LOX5-synthesized oxylipins in the root and petiole exudates of GPA-infested plants. Micrografting experiments demonstrated that GPA population size was smaller on plants in which the roots were of the lox5 mutant genotype. Exogenous treatment of lox5 mutant roots with 9-hydroxyoctadecanoic acid restored water content and population size of GPA on lox5 mutants. Together, these results suggest that LOX5 genotype in roots is critical for facilitating insect infestation of Arabidopsis. in Arabidopsis, 9-LOX function is also required for facilitating infection by F. graminearum, which is a leading cause of Fusarium head ...
Contributing Partner: UNT Libraries
The 1896 Vienna Tonkünstler-verein Competition: the Three Award-winning Works and Seven Anonymous Submissions with Clarinet

The 1896 Vienna Tonkünstler-verein Competition: the Three Award-winning Works and Seven Anonymous Submissions with Clarinet

Date: August 2014
Creator: Harrell, Andrea
Description: The Vienna Tonkünstler-Verein (1885-1929) was established for the sole purpose of providing extensive support to the music and musicians of Vienna. The society became renowned in Vienna for its outstanding performances of chamber music and counted among its members many of the city’s foremost musicians and composers. Johannes Brahms had a significant influence on the society as its honorary president and assisted in establishing its composition competitions, aimed at promoting and reviving under-developed chamber genres. Of particular interest to clarinetists is the Verein’s competition of 1896, which aspired to promote chamber music literature for wind instruments. Brahms’s recently completed chamber works for clarinet were clearly influential in fin-de-siècle Vienna; for of the twelve works chosen as finalists in the competition, ten included the clarinet in the chamber combination.The purpose of this document is to provide an English-language history of the Vienna Tonkünstler-Verein and a thorough account of its1896 competition based on my study of the society’s annual reports. In addition, this document will provide the first published account of the anonymous submissions for the 1896 competition. It is my hope that this paper will serve as a springboard for future endeavors aimed at uncovering the identities of the anonymous finalists ...
Contributing Partner: UNT Libraries
2D and 3D Fabrication Devices: Can They Improve Spatial Reasoning Skills in Children?

2D and 3D Fabrication Devices: Can They Improve Spatial Reasoning Skills in Children?

Date: August 2016
Creator: Zimmerman, Ellen L
Description: The purpose of this study is to evaluate the potential benefit of two hours of activities involving 2D and 3D fabricators on the spatial reasoning skills of children in Grades 4 and 5, ages 9 to 10, from a private school in Southeast Texas. Can the introduction to hands-on activities with products created with these devices and learning about how these devices operate improve spatial reasoning skills? The research also evaluates the use of the Shapes Test as a valid measure of the spatial reasoning skills of children. The Cube Design and Spatial Memory subtests of the UNIT (Universal Nonverbal Intelligence Tests) were used for evaluating the spatial reasoning skills of the participants, based on their respected validity, along with a Shapes Test that is in development. Discussion regarding gender, language, and experiential theories of spatial reasoning skill development are included in the literature review.
Contributing Partner: UNT Libraries
3D Reconstruction Using Lidar and Visual Images

3D Reconstruction Using Lidar and Visual Images

Date: December 2012
Creator: Duraisamy, Prakash
Description: In this research, multi-perspective image registration using LiDAR and visual images was considered. 2D-3D image registration is a difficult task because it requires the extraction of different semantic features from each modality. This problem is solved in three parts. The first step involves detection and extraction of common features from each of the data sets. The second step consists of associating the common features between two different modalities. Traditional methods use lines or orthogonal corners as common features. The third step consists of building the projection matrix. Many existing methods use global positing system (GPS) or inertial navigation system (INS) for an initial estimate of the camera pose. However, the approach discussed herein does not use GPS, INS, or any such devices for initial estimate; hence the model can be used in places like the lunar surface or Mars where GPS or INS are not available. A variation of the method is also described, which does not require strong features from both images but rather uses intensity gradients in the image. This can be useful when one image does not have strong features (such as lines) or there are too many extraneous features.
Contributing Partner: UNT Libraries
Absorptive Capacity:  An Empirical Examination of the Phenomenon and Relationships with Firm Capabilities

Absorptive Capacity: An Empirical Examination of the Phenomenon and Relationships with Firm Capabilities

Date: May 2012
Creator: Daspit, Josh
Description: The field of strategic management addresses challenges that firms encounter in an attempt to remain competitive. The ability to explain variation in firm success through examination of knowledge flows has become a prominent focus of research in the strategic management literature. Specifically, researchers have sought to further examine how firms convert knowledge, a phenomenon conceptualized as absorptive capacity. Absorptive capacity is the firm’s ability to acquire, assimilate, transform, and exploit knowledge. Few studies have captured the richness and multi-dimensionality of absorptive capacity, and it remains to be understood how the dimensions of the phenomenon convert knowledge. Furthermore, how absorptive capacity influences the firm remains to be understood. To address these research gaps, this dissertation seeks to (1) determine how absorptive capacity converts knowledge, and (2) determine how absorptive capacity influences firm capabilities. The research questions are investigated using structural modeling techniques to analyze data collected from software-industry firms. The findings offer contributions to the absorptive capacity and capability literatures. For example, absorptive capacity is hypothesized to consist of complex relationships among its internal dimensions. However, findings of this study suggest the relationships among the dimensions are linear in nature. This finding is in line with the theoretical foundations of and ...
Contributing Partner: UNT Libraries
Academic Advising Professional Characteristics and Standards: Do Academic Advisors Follow Recognized Professional Standards in Their Work?

Academic Advising Professional Characteristics and Standards: Do Academic Advisors Follow Recognized Professional Standards in Their Work?

Date: May 2014
Creator: Shelton, Kiesha R.
Description: There were two main purposes of this quantitative study. The first purpose was to identify characteristics associated with the selected sample of academic advisors that comprise study. Secondly, the study sought to determine how well work related activities of a selected population of academic advisors correlate with professional characteristics constructs and professional standards constructs of academic advising as a profession. The study used Habley’s (1986) characteristics of a profession to derive the studies professional characteristic construct, education activities, research activities, and professional development activities as it relates to a selected group of academic advisors work related activities. The studies professional standards construct was derived from five Council for the Advancement of Standards (CAS) professional standards for academic as it relates to a selected group of academic advisors work related activities. The study of 78 out of 210 identified full-time academic advisors at two-and four-year public colleges and universities in the North Texas Region utilized a multidimensional researcher-developed Web survey instrument designed to measure professional standards and characteristic within the field of academic advising. Study results reinforced current criticism of research and education activities within the field of academic advising showing that the lack of scholarly research and education activities among ...
Contributing Partner: UNT Libraries
The Academic and Athletic Experiences of African-american Males in a Division I (Fbs) Football Program

The Academic and Athletic Experiences of African-american Males in a Division I (Fbs) Football Program

Date: December 2013
Creator: Salinas, Silvia M.
Description: This study investigated the academic and athletic experiences of African-American males in a Division I football bowl subdivision football program. Critical race theory, identity development model, and social learning model were the theoretical frameworks used as the critical lenses in a qualitative design to examine the participants. The participants’ responses were analyzed and interpreted using thematic analysis. A qualitative research design, which included individual interviews with 10 second year African-American male football players, was used to address this research problem. The goal was to bring together both the psychological and sociological perspectives and to challenge participants to candidly describe their academic and athletic experiences and attitudes toward obtaining an undergraduate degree. Four themes were determined in the data analysis: differential treatment and determining oneself, time management, relationships, and career aspirations. In relation to the theoretical frameworks, the development of self-confidence and knowledge of balancing their academic and athletic schedules was critical for all participants. The sense of feeling different and challenged because of the differences in culture and experience was evident. From this study, university and collegiate athletics administrators may better understand the backgrounds, challenges, and learning needs of this population. As a result, higher education personnel may improve the ...
Contributing Partner: UNT Libraries
Academic Reading Online: Digital Reading Strategies of Graduate-level English Language Learners

Academic Reading Online: Digital Reading Strategies of Graduate-level English Language Learners

Date: May 2015
Creator: Knezek, Lois Ann
Description: English language learners (ELLs) face many linguistic and cultural challenges in their attempts to succeed academically. They encounter complex academic text, which is increasingly presented online. Although some research has addressed the challenges that university-level ELLs face when reading online texts, almost all of this prior work has focused on undergraduates. The purpose of the current study was to investigate the reading strategies employed by graduate-level ELLs when reading an academic English text online. Participating in the study were four foreign-born doctoral students from different first-language backgrounds—Arabic, Korean, Urdu, and Vietnamese—and the focus was on commonalities as well as differences among them. All four were enrolled in the same doctoral-level course, which included the reading of a specific online academic article as a course requirement. When reading this text individually, each student participated in a think-aloud procedure, followed by post-reading and discourse-based interviews. Analyses included unitizing data from the think-aloud protocols, coding units for strategies employed, and considering related interview commentary and classroom contributions. In their reading, these students made major use of problem-solving strategies, especially reading segments aloud and questioning. They also employed evaluative strategies as well as metacognitive strategies, which included affirming their understanding or indicating lack of ...
Contributing Partner: UNT Libraries
Academic Self-efficacy of Adult First-generation Students Enrolled in Online Undergraduate Courses

Academic Self-efficacy of Adult First-generation Students Enrolled in Online Undergraduate Courses

Date: August 2014
Creator: Jackson, Delores
Description: This study examined differences between adult first-generation (AFG) and adult-continuing generation (ACG) students’ academic self-efficacy with regard to the online courses in which they were currently enrolled. The study used an online survey methodology to collect self-reported quantitative data from 1,768 undergraduate students enrolled in an online course at a mid-sized, four-year public university in the southwestern United States; 325 cases were usable for the study. The t-tests revealed no statistically significant differences between the academic self-efficacy of the AFG and ACG students. Parents’ level of educational attainment was unrelated to adult students’ academic self-efficacy with online courses. Ordinary least-squares analysis was used to evaluate student characteristics that might be associated with academic self-efficacy in the online environment. A combination of gender, GPA, age, race/ethnicity (White, Black, Hispanic, and other), and number of previous online courses predicted a statistically significant 12% of the variance in academic self-efficacy in an online environment (p < .001). Age (p < .001) and self-efficacy were positively correlated, meaning that adult students reported greater academic self-efficacy than did younger students; and number of previous online courses (p < .001) was also positively correlated to academic self-efficacy, indicating that students with greater experience with online courses ...
Contributing Partner: UNT Libraries
Academic, Social and Emotional Functioning of College Students with Attention Deficit/hyperactivity Disorder (Adhd)

Academic, Social and Emotional Functioning of College Students with Attention Deficit/hyperactivity Disorder (Adhd)

Date: August 2015
Creator: McKelvy, Tara N.
Description: Attention deficit/hyperactivity disorder (ADHD) is frequently associated with negative occupational, social and psychological outcomes among community samples of adults; as such, it is expected that college students with ADHD face similar struggles. The research targeting this group of individuals, however, is sparse and tempered by significant limitations. The current study aimed to address methodological limitations in the current literature by including instruments to formally diagnosis ADHD and comorbid disorders, utilizing psychometrically sound instruments and comparing functioning of college students with ADHD across gender and subtype. It was hypothesized that participants with ADHD would report lower GPAs, higher levels of emotional distress and negative relationship characteristics than participants without ADHD. It was also hypothesized that participants with ADHD-combined type (ADHD-C) would report higher levels of substance and alcohol use than participants with ADHD-predominately inattentive type (ADHD-I), and that participants with ADHD-I would report higher levels of anxiety and depression than participants with ADHD-C. Women diagnosed with ADHD were expected to report higher levels of anxiety and depression than men diagnosed with ADHD; whereas, men diagnosed with ADHD were expected to report higher levels of substance and alcohol use than women. MANOVA, ANOVA and Mann-Whitney U tests were conducted to test hypotheses. ...
Contributing Partner: UNT Libraries
Accelerated Degree Program Faculty: Motivation to Teach

Accelerated Degree Program Faculty: Motivation to Teach

Date: May 2016
Creator: Grishkevich, Hanna Hults
Description: Adult educators are a growing part of American higher education. Because of their increasing prominence in adult education, it is essential to understand what roles these educators play and what motivates them to remain in the profession despite poor work prospects and conditions. Research to date, however, focuses primarily on the adult learner and not the adult educator. The purpose of this qualitative, multiple-case study was to explore the role and motivation for teaching of adult educators employed as adjunct faculty in an accelerated degree program at a small, liberal arts college in the northwest United States. Purposeful sampling was used to select the five participants for the study. All participants taught in the program for more than five years and were considered to be successful in their positions by peers, students, and administrators. The study employed a preliminary demographic survey to solicit initial background data on the instructors. Other data collection included in-depth, open-ended, face-to-face interviews, document analysis, and classroom observation. The results showed that all five participants identified the following roles and assumed them in the classroom: (a) facilitator, (b) listener, (c) specialist, (d) guide, (e) adviser, and (f) co-learner or colleague. Further results showed that all five ...
Contributing Partner: UNT Libraries
Acceptance Theories for Behavior in Conducting Research: Instructors in the Rajabhat University System, Thailand

Acceptance Theories for Behavior in Conducting Research: Instructors in the Rajabhat University System, Thailand

Date: December 2015
Creator: Laksaniyanon, Benchamat
Description: Responding to globalization and its effects on education and research development, the Thai government decided to push all public universities to become autonomous and establish a system of quality assurances. The establishment of quality assurances has had a large impact on many Thai instructors, especially in new public universities. Thai instructors are now forced to more focus on conducting research because the number of research publications is regarded as one of the main criteria for quality universities. The purpose of this study is to investigate the key factors, at the individual and university levels, which impact on the instructors' behavior in conducting research of the full-time instructors in the faculty of Management Science from the Rajabhat Universities in Thailand. The current study will help explain how and why the instructors accept or refuse to conduct research and provide insight into the salient factors motivating the instructors to produce more research by conducting HLM. Data were collected from 694 participants at 37 institutions via a questionnaire survey. The findings revealed that there was no difference among these 37 universities on behavior in conducting research. The key factors statistically influencing behavior in conducting research of the instructors were facilitating conditions, academic degree, ...
Contributing Partner: UNT Libraries
Acceptor-sensitizers for Nanostructured Oxide Semiconductor in Excitonic Solar Cells

Acceptor-sensitizers for Nanostructured Oxide Semiconductor in Excitonic Solar Cells

Date: August 2014
Creator: Berhe, Seare Ahferom
Description: Organic dyes are examined in photoelectrochemical systems wherein they engage in thermal (rather than photoexcited) electron donation into metal oxide semiconductors. These studies are intended to elucidate fundamental parameters of electron transfer in photoelectrochemical cells. Development of novel methods for the structure/property tuning of electroactive dyes and the preparation of nanostructured semiconductors have also been discovered in the course of the presented work. Acceptor sensitized polymer oxide solar cell devices were assembled and the impact of the acceptor dyes were studied. The optoelectronic tuning of boron-chelated azadipyrromethene dyes has been explored by the substitution of carbon substituents in place of fluoride atoms at boron. Stability of singlet exited state and level of reduction potential of these series of aza-BODIPY coumpounds were studied in order to employ them as electron-accepting sensitizers in solid state dye sensitized solar cells.
Contributing Partner: UNT Libraries
Accessing the Power of Aesthetics in Human-computer Interaction

Accessing the Power of Aesthetics in Human-computer Interaction

Date: August 2013
Creator: Chenyan, Xu
Description: In information systems design there are two schools of thought about what factors are necessary to create a successful information system. The first, conventional view holds that system performance is a key, so that efficiency characteristics such as system usability and task completion time are primary concerns of system designers. The second, emerging view holds that the visual design is also the key, so that visual interface characteristics such as visual appeal, in addition to efficiency characteristics, are critical concerns of designers. This view contends that visual design enhances system use. Thus, this work examines the effects of visual design on computer systems. Visual design exerts its influence on systems through two mechanisms: it evokes affective responses from IT users, such as arousal and pleasure and it influences individuals’ cognitive assessments of systems. Given that both affective and cognitive reactions are significant antecedents of user behaviors in the IT realm, it is no surprise that visual design plays a critical role in information system success. Human-computer-interaction literature indicates that visual aesthetics positively influences such information success factors as usability, online trust, user satisfaction, flow experience, and so on. Although academic research has introduced visual design into the Information Systems (IS) ...
Contributing Partner: UNT Libraries
Accomplished Teachers' Instructional Decisions About Shakespeare

Accomplished Teachers' Instructional Decisions About Shakespeare

Date: May 2013
Creator: Parris, Sheri Rene’
Description: Teachers' decisions are a powerful influence on student learning and it is important to fully document accomplished teachers' instructional decisions, as well as to investigate possible influences on those decisions. Shakespearean dramas are central to high school curricula across the U.S. and pose particular instructional challenges, therefore teachers' decisions about teaching these texts are of particular interest. There is limited empirical research, however, about these instructional decisions. Thus, the purpose of this study was to describe how four accomplished high school English teachers working on a single campus make instructional decisions about teaching a Shakespearean play. Specifically, research questions addressed teachers' decisions regarding the teaching of a Shakespearean play and various influences on those decisions (self-reports and inferences from the data). Case study methodology was used, including an inductive analysis of individual teacher interviews, classroom observations, focus group, instructional artifacts, and researcher's journal. The findings revealed that instructional activities described by these teachers addressed support for meaning-making during four stages of reading instruction: (a) before, during, and after; (b) before; (c) during; and (d) after. Comparison of these cases suggests that, although each teacher brings personal preferences and unique background knowledge to her instructional decisions, all make decisions to promote ...
Contributing Partner: UNT Libraries
Accountability in Schools:  a Study of High School Accountability Ratings and College Success

Accountability in Schools: a Study of High School Accountability Ratings and College Success

Date: August 2013
Creator: Orsborn, Shannon
Description: The purpose of this study was to determine the relationship between high school campus accountability ratings, college readiness indicators, and the percent of students who achieved first year college success. Correlation and multiple regression analyses were used to analyze the relationship between the variables. Data was analyzed for two-year and four-year postsecondary educational institutions which were divided by eight school district types. Regression analysis of the relationship between high school campus accountability ratings and the percent of students who achieved first year college success for four- year post secondary educational institutions revealed statistically significant results ranging from R2 =.179 to R2 = .220. Similar results were found for two-year post secondary educational institutions with statistically significant results ranging from R2 = .049 to R2 = .218. The results indicated negligible to small relationships between the variables. Regression results of the analysis for the relationship between college readiness indicators and the percent of students who achieved first year college success revealed statistically significant results for 2 - year post secondary educational institutions ranging from R2 = .077 to R2 = .596 and for 4 -year post secondary educational institutions ranging from R2 = .048 to R2 = .304. These results indicated ...
Contributing Partner: UNT Libraries
Accreditation Facilitation Projects:  Supporting High Quality Early Childhood Education and Care

Accreditation Facilitation Projects: Supporting High Quality Early Childhood Education and Care

Date: May 2013
Creator: Reinke, Stephanie L.
Description: High-quality early childhood education and care (ECEC) are linked to positive developmental outcomes for children. Systems have been created to define, measure and promote high-quality ECEC. National accreditation status is deemed the gold standard of a high-quality program, yet many centers are unable to achieve this without assistance. With the help of Accreditation Facilitation Projects (AFPs), many low-income centers are able to achieve accreditation. Centers collaborating with an AFP reap many benefits including financial support, ongoing training and mentoring, and guidance through the accreditation process. AFPs invest greatly in the centers they collaborate with and the longer the center takes to achieve accreditation, the more resources an AFP must expend. The purposes of this study were to understand if the educational level of center director, the total enrollment of a center, or the percentage of children receiving government subsidies could predict the time it takes for a center to complete the accreditation process while receiving assistance from an AFP, and to determine if there are differences in attitudes about program accreditation between center directors and early learning specialists who serve as accreditation mentors to the directors. Findings revealed that a) the higher educational level of program directors is associated with ...
Contributing Partner: UNT Libraries
Accuracy and Efficiency in Computational Chemistry: The Correlation Consistent Composite Approach

Accuracy and Efficiency in Computational Chemistry: The Correlation Consistent Composite Approach

Date: August 2011
Creator: Wilson, Brent R.
Description: One of the central concerns of computational chemistry is that of efficiency (i.e. the development of methodologies which will yield increased accuracy of prediction without requiring additional computational resources – RAM, disk space, computing time). Though the equations of quantum mechanics are known, the solutions to these equations often require a great deal of computing power. This dissertation primarily concerns the theme of improved computational efficiency (i.e. the achievement of greater accuracy with reduced computational cost). Improvements in the efficiency of computational chemistry are explored first in terms of the correlation consistent composite approach (ccCA). The ccCA methodology was modified and this enhanced ccCA methodology was tested against the diverse G3/05 set of 454 energetic properties. As computational efficiency improves, molecules of increasing size may be studied and this dissertation explored the issues (differential correlation and size extensivity effects) associated with obtaining chemically accurate (within 1 kcal mol-1) enthalpies of formation for hydrocarbon molecules of escalating size. Two applied projects are also described; these projects concerned the theoretical prediction of a novel rare gas compound, FKrOH, and the mechanism of human glutathione synthetase’s (hGS) negative cooperativity. The final work examined the prospect for the parameterization of the modified embedded atom ...
Contributing Partner: UNT Libraries
Accuracy and Interpretability Testing of Text Mining Methods

Accuracy and Interpretability Testing of Text Mining Methods

Date: August 2013
Creator: Ashton, Triss A.
Description: Extracting meaningful information from large collections of text data is problematic because of the sheer size of the database. However, automated analytic methods capable of processing such data have emerged. These methods, collectively called text mining first began to appear in 1988. A number of additional text mining methods quickly developed in independent research silos with each based on unique mathematical algorithms. How good each of these methods are at analyzing text is unclear. Method development typically evolves from some research silo centric requirement with the success of the method measured by a custom requirement-based metric. Results of the new method are then compared to another method that was similarly developed. The proposed research introduces an experimentally designed testing method to text mining that eliminates research silo bias and simultaneously evaluates methods from all of the major context-region text mining method families. The proposed research method follows a random block factorial design with two treatments consisting of three and five levels (RBF-35) with repeated measures. Contribution of the research is threefold. First, the users perceived a difference in the effectiveness of the various methods. Second, while still not clear, there are characteristics with in the text collection that affect the ...
Contributing Partner: UNT Libraries
Accuracy of Partner Perception and Relationship Satisfaction: Investigating Masturbatory Habits

Accuracy of Partner Perception and Relationship Satisfaction: Investigating Masturbatory Habits

Date: August 2016
Creator: Ramos, Marciana Julia
Description: An individual's perceptions of various aspects of one's romantic relationship (irrespective of whether or not the perceptions align with reality) often play a critical role in romantic relationship satisfaction. Research has demonstrated that the accuracy of an individual's perception of his or her partner is generally positively related to the individual's romantic relationship satisfaction. However, when perceiving negative or conflictual messages from a partner, an individual's accuracy of perception is negatively associated with his or her romantic relationship satisfaction. Researchers have suggested that poor accuracy in perceiving negative messages might diffuse the negative intention in a way that is less impactful to the relationship. The present study was designed to investigate accuracy in the perception of sexual topics, specifically masturbatory habits. A sample of 93 married couples (186 individuals) responded to questions about (a) their own masturbatory behaviors and (b) their perception of their partners' masturbatory behaviors to determine the accuracy of each partner's perception of his or her partner. The association between accuracy and romantic and sexual relationship satisfaction was explored, along with one potential moderating variable: attitudes toward masturbation. Perceived reason for masturbating, perceived target of arousal during masturbation, and partner's actual reason for masturbating all positively predicted ...
Contributing Partner: UNT Libraries
Accurate and Reliable Prediction of Energetic and Spectroscopic Properties Via Electronic Structure Methods

Accurate and Reliable Prediction of Energetic and Spectroscopic Properties Via Electronic Structure Methods

Date: August 2013
Creator: Laury, Marie L.
Description: Computational chemistry has led to the greater understanding of the molecular world, from the interaction of molecules, to the composition of molecular species and materials. Of the families of computational chemistry approaches available, the main families of electronic structure methods that are capable of accurate and/or reliable predictions of energetic, structural, and spectroscopic properties are ab initio methods and density functional theory (DFT). The focus of this dissertation is to improve the accuracy of predictions and computational efficiency (with respect to memory, disk space, and computer processing time) of some computational chemistry methods, which, in turn, can extend the size of molecule that can be addressed, and, for other methods, DFT, in particular, gain greater insight into which DFT methods are more reliable than others. Much, though not all, of the focus of this dissertation is upon transition metal species – species for which much less method development has been targeted or insight about method performance has been well established. The ab initio approach that has been targeted in this work is the correlation consistent composite approach (ccCA), which has proven to be a robust, ab initio computational method for main group and first row transition metal-containing molecules yielding, on ...
Contributing Partner: UNT Libraries
Accurate Energetics Across the Periodic Table Via Quantum Chemistry

Accurate Energetics Across the Periodic Table Via Quantum Chemistry

Date: December 2015
Creator: Peterson, Charles Campbell
Description: Greater understanding and accurate predictions of structural, thermochemical, and spectroscopic properties of chemical compounds is critical for the advancements of not only basic science, but also in applications needed for the growth and health of the U.S. economy. This dissertation includes new ab initio composite approaches to predict accurate energetics of lanthanide-containing compounds including relativistic effects, and optimization of parameters for semi-empirical methods for transition metals. Studies of properties and energetics of chemical compounds through various computational methods are also the focus of this research, including the C-O bond cleavage of dimethyl ether by transition metal ions, the study of thermochemical and structural properties of small silicon containing compounds with the Multi-Reference correlation consistent Composite Approach, the development of a composite method for heavy element systems, spectroscopic of compounds containing noble gases and metals (ArxZn and ArxAg+ where x = 1, 2), and the effects due to Basis Set Superposition Error (BSSE) on these van der Waals complexes.
Contributing Partner: UNT Libraries
An Action Research Study of Community Building with Elementary Students in a Title I School

An Action Research Study of Community Building with Elementary Students in a Title I School

Date: May 2014
Creator: Dew, SaraBeth
Description: “In what ways does teaching with folk arts inspired visual arts-based instruction enhance community building among elementary students in a Title I school?” was the primary research question in this study. Agreeing with past and present day research that the construct of community is vital to social and cultural capital, this research attempts to determine how the notion of community benefits both students and teachers in the elementary art classroom. Folk art was utilized because this genre was accessible in terms of locality and familiarity among students and teachers. The purpose of this investigation was to produce teaching strategies and methods that show how community can be formed in the art classroom. The participants were elementary students, Grades 2 and 3, in a Title I school located in Denton, Texas. This investigation was conducted under an action research methodology. This approach to research is intended to be transformational, emergent, and accommodating. I recorded observations, field notes, and conversations from the participants. Emergent themes were discovered through content analysis and conceptual maps. Results from this investigation concluded transformation is only possible if the person wants change to happen. Data also showed that community and art education are symbiotic. Transformation, growth, and ...
Contributing Partner: UNT Libraries
Actions Taken by Texas School Districts to Prevent Fraud

Actions Taken by Texas School Districts to Prevent Fraud

Date: May 2011
Creator: Taylor, Gordon Douglas
Description: This research is a descriptive analysis answering the question, what measures are currently taken by the leadership&#8213;boards of trustees and superintendents of schools&#8213;of Texas school districts to prevent embezzlement? The research perspective utilized was quantitative with a descriptive, cross-sectional design. Data collection was accomplished through a survey with questions constructed from the most commonly recommended strategies discovered through the review of literature. The survey was distributed to the 1031 superintendents of school districts in Texas via email. The response rate was 33% or 339 returned surveys. The data set created concentrates on the four most common preventive measures: policy and procedure, management, auditing, and ethics. These measures are considered as they function to interrupt the principles of the fraud triangle. Comparisons were completed regarding region, district size, superintendent tenure and superintendent experience. Policy adoption was found to be extremely widespread. Procedures written to fully implement policy were less prevalent. Review of management practices found problems concerning credit cards, personnel evaluations, and password access to multiple computer finance recordkeeping systems concentrated in one employee. External auditing programs were universal due to statutory mandate but internal auditors and internal audit committees were few. Ethics training for business office personnel existed but with ...
Contributing Partner: UNT Libraries
FIRST PREV 1 2 3 4 5 NEXT LAST