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A Study of Power Generation From a Low-cost Hydrokinetic Energy System

A Study of Power Generation From a Low-cost Hydrokinetic Energy System

Date: August 2013
Creator: Davila Vilchis, Juana Mariel
Description: The kinetic energy in river streams, tidal currents, or other artificial water channels has been used as a feasible source of renewable power through different conversion systems. Thus, hydrokinetic energy conversion systems are attracting worldwide interest as another form of distributed alternative energy. Because these systems are still in early stages of development, the basic approaches need significant research. The main challenges are not only to have efficient systems, but also to convert energy more economically so that the cost-benefit analysis drives the growth of this alternative energy form. One way to view this analysis is in terms of the energy conversion efficiency per unit cost. This study presents a detailed assessment of a prototype hydrokinetic energy system along with power output costs. This experimental study was performed using commercial low-cost blades of 20 in diameter inside a tank with water flow speed up to 1.3 m/s. The work was divided into two stages: (a) a fixed-pitch blade configuration, using a radial permanent magnet generator (PMG), and (b) the same hydrokinetic turbine, with a variable-pitch blade and an axial-flux PMG. The results indicate that even though the efficiency of a simple blade configuration is not high, the power coefficient is ...
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The Mechanisms of Methane C–h Activation and Oxy-insertion Via Small Transition Metal Complexes: a Dft Computational Investigation

The Mechanisms of Methane C–h Activation and Oxy-insertion Via Small Transition Metal Complexes: a Dft Computational Investigation

Date: May 2014
Creator: Prince, Bruce M.
Description: Our country continues to demand clean renewable energy to meet the growing energy needs of our time. Thus, natural gas, which is 87% by volume of methane, has become a hot topic of discussion because it is a clean burning fuel. However, the transportation of methane is not easy because it is a gas at standard temperature and pressure. The usage of transition metals for the conversion of small organic species like methane into a liquid has been a longstanding practice in stoichiometric chemistry. Nonetheless, the current two-step process takes place at a high temperature and pressure for the conversion of methane and steam to methanol via CO + H2 (syngas). The direct oxidation of methane (CH4) into methanol (CH3OH) via homogeneous catalysis is of interest if the system can operate at standard pressure and a temperature less than 250 C. Methane is an inert gas due to the high C-H bond dissociation energy (BDE) of 105 kcal/mol. This dissertation discusses a series of computational investigations of oxy-insertion pathways to understand the essential chemistry behind the functionalization of methane via the use of homogeneous transition metal catalysis. The methane to methanol (MTM) catalytic cycle is made up of two key ...
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Britten’s Op 47, Five Flower Songs: Breaking Trends in Analysis

Britten’s Op 47, Five Flower Songs: Breaking Trends in Analysis

Date: August 2013
Creator: Jackson, Christopher Michael
Description: Benjamin Britten’s life and music have been the subject of study from early in his musical career. Current trends in psychological analysis of Britten’s music tend to focus on common themes, such as homosexuality, pacifism, the sense of the outsider, and the loss of innocence. Similarly, theoretical analyses tend either to provide general categorizations of the technical elements in Britten’s music or to apply a singular preconceived concept as a tool for understanding his compositions. These approaches have yielded significant information but leave aspects of Britten’s personality and music unilluminated. Britten’s Op. 47, Five Flower Songs, are a collection of five part songs for a cappella chorus that are often included within the canon of 20th century choral literature. This paper examines a new perspective on Britten’s music by examining the relationship between Britten’s friendships and their influence on his compositions. Through the examination of these relationships information is revealed that allows for a new method of analysis that is particularly relevant to the Five Flower Songs. The opus was dedicated to two botanists for the occasion of their 25th wedding anniversary. Contained within specific movements are extra-musical references to scientific characteristics of the flowers that are the subjects of ...
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Experiences and Perceptions of Students in Music and Mathematics

Experiences and Perceptions of Students in Music and Mathematics

Date: May 2014
Creator: Cranmore, Jeff L.
Description: Since the time of Pythagoras, philosophers, educators, and researchers have theorized that connections exist between music and mathematics. While there is little doubt that engaging in musical or mathematical activities stimulates brain activity at high levels and that increased student involvement fosters a greater learning environment, several questions remain to determine if musical stimulation actually improves mathematic performance. This study took a qualitative approach that allowed 24 high school students to express their direct experiences with music and mathematics, as well as their perceptions of how the two fields are related. Participants were divided into four equal groups based on school music participation and level of mathematic achievement, as determined by their performance on the Texas Assessment of Knowledge and Skills (TAKS). Students participated in a series of three interviews addressing their experiences in both music and mathematics, and took the Multiple Intelligences Developmental Assessment Scales (MIDAS). TAKS data and MIDAS information were triangulated with interview findings. Using a multiple intelligence lens, this study addressed the following questions: (a) How do students perceive themselves as musicians and mathematicians? (b) What experiences do students have in the fields of music and mathematics? (c) Where do students perceive themselves continuing in the ...
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Physiological and Psychological Effects of an Acute Stressor: Comparing Coping Strategies Among Very Physically Active and Less Active Adults

Physiological and Psychological Effects of an Acute Stressor: Comparing Coping Strategies Among Very Physically Active and Less Active Adults

Date: May 2014
Creator: Brandt, Grace A.
Description: The purpose of this study was to examine whether physical activity status of healthy adult males (N = 59) while in a coping strategy condition (association, disassociation, or control) influences psychophysiological responses to an acute painful stimulus. Measures of pain tolerance, state anxiety, body awareness, and salivary cortisol were investigated. Results indicated no significant differences between physical activity groups for pain tolerance, stress responses (i.e., self-reported state anxiety and cortisol levels), or body awareness. Though, those who indicated using a disassociation coping technique during the exit interview tolerated the acute, surface pain longer. More research is required to further understand the effects of physical activity and coping strategies on pain perception and psychophysiological responses.
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Declining Participation in Fraternity and Sorority Life: a Comparison of Perceptions of Greek-lettered Organizations Between Affiliated and Non-affiliated Students

Declining Participation in Fraternity and Sorority Life: a Comparison of Perceptions of Greek-lettered Organizations Between Affiliated and Non-affiliated Students

Date: May 2014
Creator: Shirley, Zachary E.
Description: This quantitative study was used to determine the perceptions that may have caused a decline in membership in fraternities and sororities and to examine active organization involvement between affiliated and unaffiliated students at a single higher education institution in northeast Texas. Eight perceptions were given regarding fraternity and sorority life and why students chose to remain unaffiliated with fraternities or sororities. The instrument used was a modified version of the Extracurricular Involvement Inventory, created by Winston and Massaro (1987) and was administered to participants online via Survey Monkey. There were 206 participants total: 55.3% were female, and 44.7% were male. Regarding ethnicities, 47.0% were African American, 37.5% were Caucasian, and 15.5% were Hispanic/Latino. Out of the participants, 20.9% were in their freshman or sophomore year, 23.8% were juniors, 33.5% were seniors, and 21.8% were graduate students. Participants’ ages ranged from 18 to 32, with a mean of 22.89 (SD = 2.81). The research questions were analyzed using two techniques: logistic regression for the first question and multiple regression for the second question. Findings for the first research question indicated that lack of values, lack of diversity, poor academic attitudes, and a requirement of too much time were primary reasons unaffiliated ...
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The Effect of Head Flexion/extension on Acoustic Measures of Singing Voice Quality

The Effect of Head Flexion/extension on Acoustic Measures of Singing Voice Quality

Date: August 2013
Creator: Knight, Elizabeth Johnson
Description: A study was undertaken to identify the effect of head flexion/extension on singing voice quality. The amplitude of the fundamental frequency (F0), and the singing power ratio (SPR), an indirect measure of singer’s formant activity, were measured. F0 and SPR scores at four experimental head positions were compared with the subjects’ scores at their habitual positions. Three vowels and three pitch levels were tested. F0 amplitudes and low frequency partials in general were greater with more extended head positions, while SPR increased with neck flexion. No effect of pitch or vowel was found. Gains in SPR appear to be the result of damping low frequency partials rather than amplifying those in the singer’s formant region. Raising the amplitude of F0 is an important resonance tool for female voices in the high range, and may be of benefit to other voice types in resonance, loudness, and laryngeal function.
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Shall We Dance? Teaching Parents the Communication Dance to Enhance Generalized Communication in Their Children

Shall We Dance? Teaching Parents the Communication Dance to Enhance Generalized Communication in Their Children

Date: May 2014
Creator: Baker, Jacqueline R.
Description: Children diagnosed with autism exhibit deficits in communication that impact their ability to control their immediate environment. Recent research on mand training has been criticized for producing a limited number of mand topographies over a long span of time with limited generalization to novel environments. There is a body of research, however, that successfully establishes larger repertoires. Training parents as change agents may mediate generalization by teaching under naturally maintaining contingencies. Additional effects of parent training may reduce parent reports of stress, increase favorable quality of parent-child interactions, and increase reports of parental self-efficacy. The current study evaluated the effects of a generalized training framework to teach parents how to target generalized mands and expand their child’s communicative topographies. The effects of the training were evaluated using a non-concurrent multiple baseline across participants and skills. Results indicated that parents were able to effectively teach their child to mand for a variety of items and events and to substantially increase the number of different mand topographies and expand the topographies the child emitted. Parents were observed to have higher overall confidence and lower overall stress following intervention. The current study builds on previous research on generalized teaching strategies for parents that ...
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Hip-hop’s Tanning of a Postmodern America: a Longitudinal Content Analysis of Paradoxical Juxtapositions of Oppositional Identities Within Us Rap Song Lyrics, 1980-2013

Hip-hop’s Tanning of a Postmodern America: a Longitudinal Content Analysis of Paradoxical Juxtapositions of Oppositional Identities Within Us Rap Song Lyrics, 1980-2013

Date: May 2014
Creator: Gadley, Shawn A.
Description: A longitudinal content analysis of top-chart hip-hop songs’ lyrics produced between 1980 and 2013 was conducted to investigate the degree and progression of the paradoxical juxtaposition, or postmodern hybridity, of oppositional modernist identities in terms of race/ethnicity, gender, sexual orientation, sexuality, and economic lifestyle, in addition to the longitudinal diversification of artist’s race and gender demographics. Demographically, the percentage of non-African-American artists increased as the percentage of African-American artists decreased. Additionally, the percentage of songs featuring either all male or all female artists decreased, while the percentage of collaboration between male and female artists increased over time. Although hybrid oppositional identities related to race/ethnicity and gender did not increase over time, those of sexual orientation, sexuality, and economic lifestyle increased over time. In addition, materialist identities were related to the hybridity of sexual orientation and sexuality, but not to that of gender and race/ethnicity. Overall, the research found increasing postmodern hybridity within the sexualization of hip-hop songs along with intensified materialism.
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Development of the Knowledge and Attitudes Toward Near-death Experiences Scale

Development of the Knowledge and Attitudes Toward Near-death Experiences Scale

Date: August 2013
Creator: Pace, Laura
Description: The purpose of this study was to develop an instrument to measure healthcare professionals’ knowledge and attitudes about near-death experiences (NDEs) that would demonstrate acceptable psychometric properties. In consultation with a focus group of six NDE experts, I developed the 50-item Knowledge and Attitudes toward Near-Death Experiences Scale (KANDES), including the 24-item KANDES–Attitude subscale (KANDES-A) and the 26-item KANDES–Knowledge subscale (KANDES-K). Including a pilot administration in which feedback indicated no need for revision, a total of 256 professional and student counselors completed the KANDES. Separate reliability and validity analyses were conducted for each subscale. For the KANDES–A, Cronbach’s alpha was .909, and Pearson’s r for test-retest was .748, both indicating acceptable reliability. An exploratory factor analysis indicated four factors to retain and yielded a factor solution that explained 54.87% of the variance, an acceptable amount of variance to substantiate construct validity. For the KANDES–K, Cronbach’s alpha was .816, indicating acceptable reliability. For each of the scale’s three domains, Cronbach’s alpha was .816 for Domain 1: NDE Content, .817 for Domain 2: NDE Aftereffects, and .631 for Domain 3: Experiencer Characteristics, indicating acceptable reliability. Pearson’s r for test-retest on the total KANDES–K was .812, further demonstrating acceptable reliability.
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