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Closed-Loop Control Of Vortex Shedding By Means Of Lorentz Force, Xiaoyun Sun

Dissertations

When an incompressible fluid flows past a circular cylinder, vortex shedding occurs as soon as the Reynolds number exceeds about 40. Vortex shedding is usually undesirable, as it generates a significant increase in drag, as well an oscillating lift force on the cylinder leading to cross-stream structural vibrations. Flow control to either delay the appearance of vortex shedding or fully suppress it has attracted much attention during the last decade. The focus of this dissertation is to control vortex shedding from a circular cylinder by applying an external electromagnetic field. As in previous works, the latter is generated by electrodes …

Numerical And Experimental Investigation Of Dry Particle Coating, Ajit Mujumdar

Dissertations

Dry particle coating is an emerging field in the industries that deal with particulate products and powder processing. Compared to the widely reported experimental studies of the dry particle coating, the theoretical modeling of such processes is found to be less comprehensive. The work presented in this thesis is an attempt to fill this gap.

The first part of the dissertation aims at the numerical investigation of the hybridization system (Nara Machinery, Tokyo, Japan). The flow behavior of different materials processed in this device is analyzed using three-dimensional Discrete Element Method (DEM) as well as the computational fluid dynamics (CFD) …

Packet Data Communications Over Coded Cdma With Hybrid Type-Ii Arq, Seokhyun Yoon

Dissertations

This dissertation presents in-depth investigation of turbo-coded CDNIA systems in packet data communication terminology. It is divided into three parts; (1) CDMA with hybrid FEC/ARQ in deterministic environment, (2) CDMA with hybrid FEC/ARQ in random access environment and (3) an implementation issue on turbo decoding.

As a preliminary, the performance of CDMA with hybrid FEC/ARQ is investigated in deterministic environment. It highlights the practically achievable spectral efficiency of CDMA system with turbo codes and the effect of code rates on the performance of systems with MF and LMMSE receivers, respectively. For given ensemble distance spectra of punctured turbo codes, an …

Evaporating Crossflow Sprays In Gas-Solid Flows, Guangliang Liu

Dissertations

Injection of evaporating sprays into gas-solid flows is encountered in many engineering processes such as energy production industry and chemical industry. The phenomenon involves phase change, three-phase interactions, heat and mass transfer. All of these characteristics control the process efficiency, pollutant production and product quality. However, very limited studies are available on the evaporating spray jets in gas-solid flows, especially on the spray evaporation rate within a gas-solid medium. A combined study of experiments and theoretical analysis has been carried out here to investigate the fundamental mechanism of evaporating Crossflow spray jets in gas-solid flows.

In this study, in addition …

Study Of Vapor/Gas Permeation Using Thin Immobilized Liquid Membrane, Gordana Obuskovic

Dissertations

To improve liquid membrane selectivity and stability for removal of vapor and gases from a gas stream, a thin immobilized liquid membrane (ILM) has been studied. Low vapor pressure liquid solvent/solutions were immobilized in part of the micropores of a hydrophilic, hydrophobic or ceramic hollow fiber substrate. To prepare such thin ILMs, three approaches were used: evaporation of the a volatile solvent; acrylic acid-grafted hollow fibers providing a thin hydrophilic layer; pressurization technique.

For removal of volatile organic compound (VOC), a thin ILM of silicone oil incorporated in the micropores of a hydrophobic hollow fiber with a silicone rubber coating …

Thermochemistry And Kinetics In Pyrolysis And Oxidation Of Oxygenated Chlorocarbons And Chlorinated Aromatics, Li Zhu

Dissertations

Thermochemical. properties, Δf_H°₂₉₈, S°₂₉₈, and Cp°(T) (5<=T/K<=6000), are determined using different ab inifio and density functional theory methods for three chloromethyl radicals, CH₂Cl, CHCl₂, CCl₃, all chlorobenzenes from monochlorobenzene to hexachlorobenzene, and all chlorophenols from ortho-, meta-, para-chlorophenol to pentachlorophenol. The B3LYP/6-31G(d,p) method is used in the structure optimization. The B3LYP/6-31G(3df,2p), QCISD(T)/6-3 I G(d,p), and CB S-Q methods are used in single point calculations of total electronic energies. Harmonic vibration frequencies are scaled for zero point energies and thermal corrections. Isodesmic reaction(s) are utilized at each calculation level to determine Δf_H°₂₉₈ of each species. Contributions to S°₂₉₈ and Cp°(T) from …

Shear Strengthening Of Rc Beams Using Carbon Fiber Reinforced Polymer Laminates, Zhichao Zhang

Dissertations

Shear failure is catastrophic and occurs usually without advanced warning, thus it is desirable that the beam fails in flexure rather than in shear. Many existing reinforced concrete (RC) members are found to be deficient in shear strength and need to be repaired. Deficiencies occur due to several reasons such as insufficient shear reinforcement or reduction in steel area due to corrosion, increased service load, and construction defects. Externally bonded reinforcement such as Carbon Fiber Reinforced Polymer (CFRP) provides an excellent solution in these situations.

In order to investigate the shear behavior of RC beams with externally bonded CFRP shear …

Robust And Efficient Video/Image Transmission, Xi Min Zhang

Dissertations

The Internet has become a primary medium for information transmission. The unreliability of channel conditions, limited channel bandwidth and explosive growth of information transmission requests, however, hinder its further development. Hence, research on robust and efficient delivery of video/image content is demanding nowadays.

Three aspects of this task, error burst correction, efficient rate allocation and random error protection are investigated in this dissertation. A novel technique, called successive packing, is proposed for combating multi-dimensional (M-D) bursts of errors. A new concept of basis interleaving array is introduced. By combining different basis arrays, effective M-D interleaving can be realized. It has …

Deposition And Characterization Of Magnetron Sputtered Bcc Tantalum, Anamika Patel

Dissertations

The goal of this thesis was to provide scientific and technical research results for developing and characterizing tantalum (Ta) coatings on steel substrates deposited by DC magnetron sputtering. Deposition of tantalum on steel is of special interest for the protection it offers to surfaces, e.g. the surfaces of gun barrels against the erosive wear of hot propellant gases and the mechanical damage caused by the motion of launching projectiles. Electro-plated chromium is presently most commonly used for this purpose; however, it is considered to be carcinogenic in its hexavalent form. Tantalum is being investigated as non-toxic alternative to chromium and …

Looking Forward, Looking Back, Looking Inward: Lessons From Vital Women Leaders In Old Age, Shelly Marks Valdez Edd

Dissertations

Current social paradigms, based on established theory about the aged, consider old age as a time of drastic decline and deterioration and view the aged as nonproductive takers of society's resources. Far from using the wisdom and resources of the aged population, our society marginalizes old adults and treats them as obsolete. This study looks into the lives of nine women over the age of 65 who have found within themselves the strength, courage and determination to overcome the stereotypes of aging in order to become leaders in their old age. Life stories were obtained through personal interviews. Data from …

Unity Through Duality: An Exploration Of Paradox In Olivier Messiaen's Vingt Regards Sur L'Enfant-Jesus Vol Ii, Deirdre Hatch

Dissertations

Contemplation de l'Ellfant-Dieu de la creche et ReBards qui se posent sur lui : depuis le Regard indicible de Dieu le Pere jusqu'au Regard multiple de l'Kglise d'amour, en passant par le Regard inoui tie l'Esprit de joie, par le Regard si tendre de la Vierge, p'uis des Anges, des Mages et des creatures im'.naterieUes ou symboliques (le Temps, les Hauteurs, re Stlence, l'Etoile, la Croix). L'Etoile et la Croi:c ontle m!me theme parce que l'une ouvre etl'autre ferme la periode terre!\lre de Jesus. Le theme de Dieu se retrouve evidemment dans les "Regards du Pere", "du FiIs" et "de …

Unity Through Duality: An Exploration Of Paradox In Olivier Messiaen's Vingt Regards Sur L'Enfant-Jesus Vol. I, Deirdre Hatch

Dissertations

Olivier Messiaen is one of the major musical figures of the twentieth century. His music draws on a diverse set of influences, yet always remains unique and entirely his own. His unwavering religious beliefs constitute the source of inspiration behind most of his music. Vingt Regards sur ['Enfant-Jesus for solo piano was composed in 1944. It forms a powerful and personal musical statement concerning one of the central mysteries of the Catholic faith, the Incarnation. As such, it is an important work within Messiaen's output. Its musical language and spiritual message are typical ofMessiaen's style.

A Comprehensive Guidance Counseling Program For Jamaican Schools: A Needs Assessment, Grace Altia Kelly

Dissertations

Purpose of the Study. This study sought: (a) to identify stakeholders' perceptions of the existing guidance program in Jamaican schools and (b) to identify aspects of the Comprehensive Guidance Counseling Program (CGCP) that are desired by stakeholders in order to observe if there were any significant gaps between the perceived current and desired status of guidance in Jamaican schools.

Method. This was a self-report, descriptive survey study that involved 420 subjects (151 students, 130 teachers, 44 counselors, 37 principals, and 58 parents) from 54 schools (18 primary, 18 All-Age/Junior High, and 18 Secondary) across the three counties of …

An Examination Of Perceived Stress And Coping Patterns Of Pastoral Wives In The Nigerian Union Mission Of The Seventh-Day Adventist Church, Olufunmilayo Janet Ola

Dissertations

Purpose of Study. Most studies examining stress and coping patterns of pastoral wives have been conducted from an advanced country background. Even though all the researchers agreed that these pastoral wives do experience a certain amount of stress, very little is known about pastoral wives in third-world countries who are faced with poverty, illiteracy, diseases and cultural restraints. Therefore, the purpose of this study was to examine perceived stress and coping patterns of pastoral wives of the Nigerian Union Mission of the Seventh-day Adventist church.

Methodology. A quantitative method of collecting data was used in this study. The two psychological …

Teachers' And Students' Perceptions Of Seventh- And Eighth-Grade Science Education In A Selected Seventh-Day Adventist Union Conference, Marcel Andre Sargeant

Dissertations

Problem. Science education has long been a great concern in the United States, where less than one-third of the students perform at or above the proficient level. The purpose of this study was to investigate the status of the science program in a selected Union Conference of the Seventh-day Adventist school system. Specifically, this study investigated the perceptions of teachers and students regarding the extent to which the science program meets the criteria of the National Commission on Mathematics and Science Teaching for the 21st century and to what extent these criteria are related to academic performance as indicated by …

A Study On Various Factors And Their Relationship To Burnout Among Seventh-Day Adventist Clergy, W. Don Edwards

Dissertations

Problem. Few studies have addressed burnout among Seventh-day Adventist (SDA) clergy. Many SDA ministers report experiencing high stress in their ministries and they find it difficult to function optimally under these circumstances. Others experience serious complications that lead them to terminate their work as ministers.

Method. A quantitative research design was used for an ex post facto study of 130 pastors from the Pacific Union Conference. They completed two questionnaires: the Pastoral Services Demographic Data Sheet (PSDDS) and the Maslach Burnout Inventory (MBI).

Results. This study examined 12 variables and found that 10 variables had a significant …

Leadership Development: Continuous Improvement Through Character Assessment, Robert Scott Clark Edd

Dissertations

One of the keys to personal development is self-awareness as assessed by instruments such as the Myers-Briggs Type Indicator (MBTI) and the NEO PI-R, both of which are widely accepted reliable and valid indicators and measures of personality type. However, assessing the part of personality known as character presents challenges that are not adequately addressed by today's popular instruments leaving information needed for development incomplete or unavailable. An instrument that provides a reliable and valid assessment of character for leadership and personal development purposes could be very valuable. Qualitative methods were used for this study to investigate leaders' perceptions of …

Enabling Performance Skills: Assessment In Engineering Education, Jenny K. Ferrone Edd

Dissertations

Current reform in engineering education is part of a national trend emphasizing student learning as well as accountability in instruction. Assessing student performance to demonstrate accountability has become a necessity in academia. In newly adopted criterion proposed by the Accreditation Board for Engineering and Technology (ABET), undergraduates are expected to demonstrate proficiency in outcomes considered essential for graduating engineers. The case study was designed as a formative evaluation of freshman engineering students to assess the perceived effectiveness of performance skills in a design laboratory environment. The mixed methodology used both quantitative and qualitative approaches to assess students' performance skills and …

A Study Of Technology Implementation In Two School Districts: The Dynamics Of Leadership And Change, Rebecca D. Gillespie Edd, Ma, Ba

Dissertations

This qualitative case study investigated the role administrative leadership plays in organizational change related to the infusion of technology into district programs and pedagogical practices. School districts have been engaged in a struggle to incorporate new generations of technological advancements in meaningful ways for their students. Instructional reform and measurable performance-based outcomes are frequently conflated with the pressure to implement effective technology programs that ensure the No Child Left Behind federal mandates are met while ensuring judicious use of district funds. While technology has the potential to transform the educational process, it must align with the cultural uniqueness of the …

Making The Transition From The Field To The Classroom: The Experiences Of Novice Health Care Instructors At Private Career Colleges, Lezlee Haroun Edd

Dissertations

Health care instructors at private career colleges are responsible for training thousands of health services workers who enter the American work force annually. The number of students seeking health care occupational training at career colleges is expected to increase significantly during the next decade because the health service industry is the fastest growing section of the United States economy. At the same time, the public education system does not have the capacity to fully accommodate the future population of students seeking the postsecondary education required for these jobs. Instructors at private career colleges are typically hired directly from professional positions …

Perceptions Of Principal Effectiveness And Teacher Morale: A Study Of Public Secondary School Teachers On Guam, Michelle M.S. Santos Edd

Dissertations

For more than a decade, the public schools on Guam have suffered from low student test scores, high turnover rates and low levels of teacher morale. Although there may be many explanations for this persistent problem, an important part of any solution is improving the overall level of teacher morale, which of course, can be influenced in many ways by the actions of the principal. In an effort to determine both the level of teacher morale among secondary school teachers on Guam as well as the factors that may help explain it, including the perceived level of principal effectiveness, this …

“You Are With Someone Who Is A Fighter”: Constructing A Model Of Transformation Which Can Occur In Surviving Breast Cancer, Helen Hays Eckmann Edd

Dissertations

The American Cancer Society estimated a quarter of a million women would be diagnosed with breast cancer in 2002. For each of those, another ten women are living with or have survived this disease. At diagnosis, most women view their futures with dread. As with other extreme traumas, the diagnosis of breast cancer can bring profound transformation (Jackson, 1983; LeShan, 1994; O'Brien, 1995). In this study, seven survivors of breast cancer articulate their journeys through this disease and detail how they were able construct transformed lives. The women described how they turned tragedy into triumph. Individual interviews were conducted and …

Higher Education Administrators And Students With Disabilities: A Survey Of Administrator Knowledge And Training Needs, Maribel S. Guillermo Edd

Dissertations

Students with disabilities enroll in two-year institutions at a higher rate than in four-year institutions. The California community college system, which is the largest system of higher education in the world, enrolled 2,609,365 students with disabilities during the 2000–2001 academic year. The purpose of this study was to focus on California college administrators and their role in: (a) setting a climate that supports students with disabilities and (b) serving as a resource to faculty and staff. Administrators were surveyed regarding their (a) current knowledge and training needs; (b) personal and professional experience with individuals with disabilities; and (c) utilization of …

Career Paths To Navy Admiral, Lilly "Ericka" A. Jordan Edd

Dissertations

A significant disparity exists between the numbers of male and female personnel among high-ranking officers serving in the U.S. Navy. The general perception is that women have not been part of the Navy long enough to be in the flag officer's ranks. However, it has been over 30 years since the Navy first placed women in the ranks of flag officers. The purpose of the study is to trace the most common professional career paths followed by male and female flag officers in the U.S. Navy and to examine how certain aspects of a military career might have influenced selection …

Examining An Observation-Based Model Of Professional Development For Teachers, Donna M. Marriott Edd

Dissertations

Public education is undergoing a process of reculturation prompted by standards-based reform initiatives. Student content standards suggest fundamental changes in the way teachers, schools, and districts think about and do their work. These substantive reform efforts require a parallel reorganization in professional development processes. Traditional models that rely on episodic, large-scale workshops are insufficient to support teachers to meet the demands of a standards-driven system. San Diego City Schools has developed an innovative approach to teacher training that is context and situation specific. The observation-based model of professional development utilizes a unique training environment and process. A fully functioning classroom …

An Analysis Of The Benefits Of An Mba Degree As Reported By A Diverse Graduate Population Of A Southwestern University, Stephani Richards-Wilson Edd

Dissertations

Although numerous studies have attempted to measure the value of a Master of Business Administration (MBA) degree, most of these studies have concentrated on the extrinsic benefits of the degree, such as compensation and career progression. Furthermore, the majority of these studies have focused on students at elite MBA programs, which have traditionally served a different class of individuals than most MBA programs throughout the country. In an effort to broaden the literature in this area, this study examined both the extrinsic and intrinsic benefits of an MBA degree as self-reported by 638 MBA graduates from the University of San …

W. E. B. Du Bois's “Talented Tenth”: A Pioneering Conception Of Transformational Leadership, Ella F. Sloan Edd

Dissertations

In 1903, W. E. B. Du Bois presented a radical leadership proposal for the transformation of African American life in the United States. His theoretical concept of the “Talented Tenth” emphasized the education and training in leadership of ten percent of the African-American population. This selective group would transform the larger, uneducated segment of the population and lead them to higher levels of social acceptance and independence. This study is a historical investigation into the educational ideas of W. E. B. Du Bois's “Talented Tenth.” It describes the historical factors that led to and influenced Du Bois's development of the …

Leadership Behaviors And Communication Satisfaction: Community Colleges In Micronesia, Julie M. Ulloa-Heath Edd

Dissertations

The major purpose of this study was to examine the satisfaction of Micronesian community college faculty with communication and their perception of their department chair's leadership style. Specifically, this study examined (a) the relationship of communication satisfaction with leadership and demographic data; (b) the relationship between the Multifactor Leadership Questionnaire (MLQ) subset and the scales of the Communication Satisfaction Questionnaire (CSQ); (c) the difference between institutions in terms of satisfaction with communication or perception of leadership style; and (d) suggestions for improving communication. Significant relationship was found between the overall communication satisfaction with leadership quality and ethnicity. The data revealed …

Exploring Teachers' Experiences With The Colonial Williamsburg Teacher Institute, Emily M. Schell Edd

Dissertations

This qualitative study explored the experiences of ten teachers who participated in the Colonial Williamsburg Teacher Institute (CWTI) during an 11-year period. The researcher used in-depth interviewing to identify why these teachers participated in this institute, what they experienced and learned during the institute, and how the institute influenced their teaching as well as student learning of early American history. The participants in this study identified similar reasons for applying to the institute, which included a desire to gain more knowledge and skills to improve their teaching of early American history. Seven themes emerged as participants described their experiences during …

The Contribution Of Education, Experience, And Personal Characteristics On The Reflective Judgment Of Students Preparing For School Administration, Margaret Rae Macdonald

Dissertations

Problem. School administrators must use high levels of reasoning to deal with the complexities of today's educational system. Reflective thinking has proven to be an effective administrative tool in problem solving, staff supervision, and school improvement, yet preparation programs for school administrators have limited knowledge about what contributes to reflective judgment in their students, thus making it difficult to develop curriculum and pedagogy to enhance reflection.

Method. The Reflective Judgment Model provides the theoretical framework for this mixed methods research design that explores contributory variables that contribute to the reflective judgment of educational leadership students. The Reasoning about Current …