Digital Commons Network^™

Mixing Enhancement By Dual Speed Rotating Stirrer, Arnaud Goullet

Dissertations

Stirring is a well-known means of fluid mixing due to the emergence of complex patterns in the flow, even at low Reynolds numbers. In this work, we consider a stirrer rotating along a circular trajectory at constant speed. The fluid flow, considered incompressible, inviscid and two dimensional (in a circular container), is modeled by a point vortex model consisting of a vortex rotating in a circular container at constant angular speed. The mixing problem is addressed by considering the Hamiltonian form of the advection equations formulated in a frame of reference moving with the vortex. The dynamics of passive fluid …

Novel Internally-Staged Ultrafiltration For Protein Purification, Meredith Ann Feins

Dissertations

A new ultrafiltration technique based on a multimembrane stack has been developed to fractionate proteins closer in molecular weight than conventionally possible. The technique is illustrated here by obtaining a pure protein product from a binary protein mixture. By employing membranes in series using the same membrane without any gaskets or spacers in-between, ultrafiltration is carried out to separate two proteins relatively close in molecular weight. Flat membranes, of the same molecular weight cutoff (MWCO) 30,000 or 100,000, are stacked together in the desired number, and ultrafiltration takes place. The membrane rejection of a protein is amplified with each additional …

Nonlinear Long-Wave Interfacial Stability Of Two-Layer Gas-Liquid Flow, Tetyana Segin

Dissertations

The flow of two immiscible viscous fluids in a thin inclined channel is considered, in either a cocurrent or countercurrent regime. Following the air-water case, which is found in a variety of engineering systems, we allow the upper fluid to be either compressible or incompressible. The disparity of the length scales and the density and viscosity ratios of the two fluids is exploited through a lubrication approximation of the conservation of mass and the Navier-Stokes equations. As a result of this long-wave theory, a coupled nonlinear system of partial differential equations is obtained that describes the evolution of the interfacial …

Nobody's Ever Asked Me That Before: Middle School Students Talk About Motivation To Achieve In School Contexts, Erika Daniels Edd

Dissertations

The purpose of this study was to explore whether or not a connection exists between students' school contexts and their academic and social choices by listening to the voices of first year middle school students. The intent of this study was to provide teachers with a way to reconceptualize adolescents as learners. Research suggests that there are two distinct approaches to the study of motivation. Some researchers believe that motivation can be externally enacted through exams, assessments, and other accountability measures. Other researchers believe that motivation is internally generated through the relationships students build, through their beliefs about learning, and …

Cleaner Technologies As An Aspect Of Sustainable Tourism: Carribbean Case Studies, Fitzgerald J. Yaw Jr.

Dissertations

Tourists are becoming increasingly sophisticated in their selection of tourism destination. A major factor that has been gaining importance in their choice set is the environmental quality of their preferred destination. Tourism planners need to recognize that the sustainability of their destination and its various offerings necessitates the consideration of environmental protection and conservation-related issues. This dissertation undertakes the case study methodology to explore the link between implementing cleaner technologies, a major environmental issue, and sustainable tourism.

The Caribbean is a region in the world that is strongly dependent on tourism for its economic development. Thus the analysis of how …

Health Impacts Of Polychlorinated Biphenyls (Pcbs) In Aquatic Organisms, Marla Ann Fisher

Dissertations

Polychlorinated biphenyls (PCBs) are a major contaminant of global extent in water resources and aquatic biota. Due to its high lipid solubility, PCBs fail to be degraded and, therefore, continue to bioaccumulate throughout the environment and food chain. To determine the impact of PCBs on the immune system ofaged and juvenile Japanese medaka (Oryzias latipes), fish were injected with the coplanar PCB congener 126 and examined after 3 and 14 days. PCB 126 produced oxidative stress in both age groups of fish 14 days post-injection; however, juvenile medaka appeared more susceptible than aged fish. Humoral immunity, as determined by antibody …

Using The History Of Research On Sickle-Cell Anemia To Affect Preservice Teachers’ Conceptions Of The Nature Of Science, Eric M. Howe

Dissertations

Preservice elementary teachers enrolled in an elective biology course participated in an eight-class unit of instruction based on the history of research in understanding the disease sickle-cell anemia. Students were introduced to the disease as a “mystery” for them to solve, and subsequently developed an understanding of the disease from several disciplines in biology (e.g., genetics, ecology, evolution, molecular biology). The unit involved open-ended problems in which students examined evidence and developed explanations in a manner analogous to the reasoning used by Anthony C. Allison and his colleagues during the early to middle part of the twentieth century.

Throughout the …

The Theory Of Transpersonal Leadership: A Grounded Theory Study, Christine M. Wallace

Dissertations

This research suggests a new approach to leadership. Using a Glaserian grounded theory methodology, a new process theory of leadership was developed based on the data. These data included 26 interviews and numerous observations of individuals and situations. The result is described as the Theory of Transpersonal Leadership. This theory delves into the internal process that takes place within individuals as they make decisions regarding leadership within their own lives. The theory also includes the explanation of discovered concepts from this research. These concepts include: the Catalytic Confluence, Demand Morphism, and Symbolic Mutualism, which explain the major points within the …

The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu

Dissertations

CSO discharges have long been recognized as a significant source of water pollution. While many sources of water pollution have been controlled over the past 20 years, CSOs continue to be a main environmental concern in several areas, especially in old cities. In the past, most CSO research focused on the CSO control processes, including floatables and suspended solids removal. Few studies have been conducted in the area of the impacts of CSO discharge on the receiving water quality. To achieve this purpose, a powerful water-modeling tool, WASP 6.1, is utilized in this study. The Lower Hudson River is selected …

Multi-Spectral Light Interaction Modeling And Imaging Of Skin Lesions, Sachin Vidyanand Patwardhan

Dissertations

Nevoscope as a diagnostic tool for melanoma was evaluated using a white light source with promising results. Information about the lesion depth and its structure will further improve the sensitivity and specificity of melanoma diagnosis. Wavelength-dependent variable penetration power of monochromatic light in the trans-illumination imaging using the Nevoscope can be used to obtain this information. Optimal selection of wavelengths for multi-spectral imaging requires light-tissue interaction modeling. For this, three-dimensional wavelength dependent voxel-based models of skin lesions with different depths are proposed. A Monte Carlo simulation algorithm (MCSVL) is developed in MATLAB and the tissue models are simulated using the …

Dielectrophoretic Manipulation Of Biological And Non-Biological Analytes In A Microfluidic Channel, Dawn J. Bennett

Dissertations

Micro-total-analytical systems (μTASs) for analyzing chemical/biological substances are now used across a wide variety of applications ranging from biological warfare agent detection to the healthcare industry. The first step in the operation of a μTAS consists of concentrating and separating the analytes of interest from the background matrix and positioning them into selected locations for subsequent analysis. The use of ac electric fields was demonstrated to have promising potential for a μTAS because the application of an ac field suppresses undesirable electrolytic effects in the liquid. The main purpose of this work is to study micro-scale phenomena in a flowing …

Self-Reported Personal Problems Of Adventist Academy Students, Ellen Marsh Crosby

Dissertations

Problem. Adolescence is a time fraught with many challenges. There are no current studies prior to this one for Adventist academy students concerning the whole range of their personal problems.

Method. A survey of students in 14 Adventist academies was conducted in the regular classroom setting using the Personal Problems Checklist for Adolescents (PPC-A). The data were analyzed using descriptive and inferential statistics. Data were tested with one-way, two-way, and, three-way ANOVA and correlation coefficients to determine differences between males and females, age groups 13/14 to 18/19, and in three different settings of day, boarding, and self-supporting Adventist …

The Creation And Development Of An Afrocentric Christian College: Imani Kuumba College And Graduate School, Juanita M. Browne Edd

Dissertations

The study examines Imani Kuumba College, (IKC), an Afrocentric Christian College. Since previous research does not examine any higher institution that provides a type of learning that focuses totally on the study of the Afrocentric world, this historical case study describes a unique educational institution that proposes to teach from a focus designed to raise self-esteem for African-Americans and racial understanding for other groups by studying the African-American experience, historically, spiritually and culturally. The study begins with an introduction that outlines the environmental and societal issues that motivated the creation of this innovative institution and its unique program. After discussion …

Administrator Perceptions Of Internet-Based Distance Education In Adventist Colleges And Universities : A Mixed-Method Study, Pamela K. Cress

Dissertations

Problem . The quality of Internet-based distance education (IBDE) will increasingly become the standard by which students choose a program as higher educational options multiply due to the dramatic growth in distance education. A system-wide examination of perceptions of IBDE in Adventist highereducation is important to administrators for future institutional strategic planning purposes, systemic adoption of policies and practices that promote excellence, and identifying collaborative efforts.

Method . This was a sequential exploratory mixed-method study of the perceptions of administrators on IBDE. It was conducted collaboratively with Susan Smith who examined teacher perceptions. Data were collected for both studies from …

A Comparison Of Kinetic Family Drawings Of Firstborn And Second-Born Siblings, Lynn Anderson

Dissertations

Problem. While the Kinetic Family Drawing (KFD) is a popular assessment tool for clinicians, research on developmental issues and how siblings draw their families is lacking. The purpose of this study was to (a) describe the way siblings perceive themselves and their family interpersonal relationships as expressed in the KFD; and (b) to describe possible developmental age differences in the KFD.

Method. The KFD and a Family Dynamics Interview Schedule were administered to 50 pairs of first- and second-born children from Southwestern Michigan, ages 5-14. The data were analyzed quantitatively by the Wilcoxon Sign Test and Chi-Square, using …

K+- Induced Dilation Of Cremasteric Arterioles Involves Na+/K+Atpase And Inward Rectifier K+ Channels, Wendy Burns

Dissertations

The purpose of this study was to evaluate the possible mechanisms involved in cremasteric arteriolar dilation as a result of increased concentrations of ([K⁺]_o) extracellular potassium. Many other studies suggested that Na⁺/K⁺ ATPase or K_IR channels are responsible for potassium-induced vasodilation in other systems (2, 12, 22, 40, 46, 52, 16, 17, 25, 33, 34, 85, 99, 151). However, these studies show only partial inhibition of dilation as a result of independent blockageof each mechanism. The hypothesis of this study was that both mechanisms contribute to potassium-induced dilation seen in cremasteric arterioles. …

Optimal And Intelligent Decision Making In Sustainable Development Of Electronic Products, Meimei Gao

Dissertations

Increasing global population and consumption are causing declining natural and social systems. Multi-lifecycle engineering and sustainable development address these issues by integrating strategies for economic successes, environmental quality, and social equity. Based on multi-lifecycle engineering and sustainable development concepts, this doctoral dissertation aims to provide decision making approaches to growing a strong industrial economy while maintaining a clean, healthy environment. The research develops a methodology to complete both the disassembly leveling and bin assignment decisions in demanufacturing through balancing the disassembly efforts, value returns, and environmental impacts. The proposed method is successfully implemented into a demanufacturing module of a Multi-LifeCycle …

Selective Removal Of Nox From Catalytic Cracking Regenerator Effluent Using Wet Scrubbing With Aqueous Sodium Chlorite Solutions, Pin Gu

Dissertations

In most refineries, the flue gas from the regenerator in the fluid catalytic cracking (FCC) unit represents a key source of NOx, SOx, particulate, and CO emissions. Wet scrubbing systems have been used with great success to control particulate and SOx emissions from typical FCC regenerator flue gas. Development of relatively inexpensive and safe additives that can be used in existing scrubbing systems to oxidize and absorb NOx is important in order to increase the industrial options to meet the provisions of the Clean Air Act and recently proposed EPA rules. This paper explores the feasibility of removing NOx from …

Inroads Toward Contemporary Latina Literature: Poetry And Criticism, Adela Josefina Najarro

Dissertations

No abstract provided.

Organizational Power And Politics: More Than Meets The Eye In Program Planning, Susan Shaver

Dissertations

Organizational power and politics influence corporate training in ways not often discussed. This study explores the effects of organizational power and politics on program planning and how planning, with its inherent power and politics (see Cervero & Wilson, 1994a), influences the daily practices of corporate trainers.

This study was informed by the literature of systems theory and constructivism. Von Bertalanffy’s (1968) general systems theory, in which the whole of a system is considered to be greater than the sum of its parts, Senge’s (1990) systems view that interrelationships within organizational structures, (not events), underlie complex situations, and Lincoln & Guba’s …

Experiences And Meanings Of Maternal Ambivalence With First-Born, Early Adolescents, Teresa M. Distefano

Dissertations

A phenomenological method of qualitative inquiry is used to capture the experiences of maternal ambivalence while mothering first-born, early adolescents. From the nave descriptions of seven participants a description of and response to maternal ambivalence are examined. Major findings include three overarching domains: (1) maternal context, (2) shared essence of maternal ambivalence, and (3) participants' responses to maternal ambivalence. Findings relevant to contextual variables identified as influencing mothers' daily lives with their adolescents include: (a) perceptions of their adolescent, (b) perceptions of their adolescents changing context, and (c) participants' marital status. Data comprising the shared essence of maternal ambivalence include: …

Effects Of Writing Therapy Across Ptsd And Chronic Stress, Jennifer E. Lewis

Dissertations

Research supports the effectiveness of writing therapy in reducing physical health problems and increasing positive feelings (Pennebaker & Beall, 1986). More recently, research indicates that writing about traumatic experiences is as effective as EMDR in reducing symptoms of Post Traumatic Stress Disorder (Largo-Marsh & Spates, 1997). The current study assessed the treatment efficacy of writing therapy for individuals with varying degrees of stress related symptoms. Specifically, this study examined writing treatment for Post-Traumatic Stress Disorder and work-related chronic stress or "burnout."

The study utilized a pretest-posttest comparison group design. Repeated measurements !)n primary dependent variables were collected at pretest through …

Cellular Proliferation, Death And Histology In Gambusia Affinis Livers After Exposure To 2-Aminofluorene And Benzidine, Susan J. Lentz

Dissertations

A fundamental need exists for aquatic animals in the biomonitoring of aquatic ecosystems for environmental carcinogens. G. affinis, a small fish species, is selected for this study due to its hardiness, non-migratory nature, geographic diversity and ability to develop tumors. Molecular tools for cellular proliferation and death are examined for use with G. affinis. Additionally, these tools are used to investigate the early carcinogenic effects of 2-aminofluorene and benzidine, both individually and combined, on G. affinis livers.

Antibodies to proliferating cell nuclear antigen (PCNA), p53, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) were examined for use in G. …

Affective Expression And Behavior In Sex Offenders, Peter F. Rausch

Dissertations

This analytic variable study examined potential differences that exist among juvenile and adult sex offenders on the emotional expressiveness variables of alexithymia and affective orientation, and three behavior variables including self-defeating behavior, risk taking, and reckless behavior. In addition, the adult sex offenders' attachment style in current relationships was examined.

Research questions were tested by t -tests. The significance level for all analyses was set at the .05 level. An analysis of variance (ANOVA) was conducted to determine the primary attachment style of the adult sex offenders in current relationships.

Participants in this study were 47 juvenile sex offenders from …

Interspecies Encounters: An Ethnography Of A Veterinary Hospital, Dana Atwood-Harvey

Dissertations

There were three broad reasons for this research. The larger goal was to continue to advance the incorporation of 'other' animals and the rest of nature in general in sociological theory and research. The second was to suggest to those who have incorporated 'other' animals into their research, to include them as participants. The third was to redirect the focus of those who have incorporated 'other' animals as participants, to the impact that ideological structures and other social factors have on human-'other' animal encounters. Toward this end, I directed the focus of my study to examine human-'other' animal encounters ina …

Parallel Simulation Of Microflows By Dsmc And Burnett Equations, Yichuan Fang

Dissertations

The primary objective of this dissertation is to numerically simulate and study the heat transfer and flow characteristics in fluidic microelectromechanical system (MEMS). In typical microfluidic MEMS applications, the ratio of the gas mean-free-path to the characteristic length scale, or the Knudsen number, can be large. The traditional mathematical models of continuum fluid based on the Navier-Stokes equations may become invalid because of their constitutive relations of viscous stress and heat flux.

In this study, the direct simulation Monte Carlo (DSMC) method and the conventional Burnett equations are applied to model the microflows in microchannels from molecular and continuum point …

Pharmacophore Derivation Using Discotech And Comparison Of Semi-Emperical, Ab Initio And Density Functional Comfa Studies For Sigma 1 And Sigma 2 Receptor-Ligands, Dawoon Jung

Dissertations

This study describes the development of pharmacophore and CoMFA models for sigma receptor ligands. CoMFA studies were performed for 48 bioactive sigma 1 receptorligands using [H³ ](+) pentazocine as the radioligand, for 30 PCP derivatives for sigma 1 receptor-ligands using [³H](+)SK-F 10047 as the radioligand and for 24 bioactive sigma 2 receptor-ligands using the radioligand [H³](+)DTG in the presence of pentazocine. Distance Comparisons (DISCOtech) was used as the starting point for CoMFA studies. The conformers, derived by DISCOtech were optimized using AMi, or HF/3-21G* in Gaussian 98. The optimized geometries were aligned with the pharmacophore, …

Nonlinear Optical Properties Of Novel Nanostructured Ion Implanted Laser Ablated Silicon Using Femtosecond Pulse Excitation, Elaine Nicole Lalanne

Dissertations

The study of the nonlinear optical properties of novel nanostructured ion implanted and laser ablation of Silicon is motivated by the need for materials that exhibit large values of the real part of the third order nonlinear susceptibility (χ⁽³⁾_Re). This property is essential for light controlled phase or refractive index modulation at low power, where the optical properties are used for optical switching devices. Previous nanosecond (ns) measurements indicated values of-2.8 x 10 ^-5; esu ( γ = 532 nm) for χ⁽³⁾_Re.

The characterization of nonlinear optical properties of the samples was studied …

Effects Of Implementation Of Decaborane Ions In Silicon, Cheng Li

Dissertations

The next generations of Si microelectronic devices will require ultra shallow p-type junctions formed by implantation of B ions with energies below 1 keV, at which available beam currents are severely limited by space charge effects. To solve this problem, decaborane (B₁₀H₁₄) cluster ion implantation has been suggested as an attractive alternative to conventional B implants, because one decaborane ion implants ten B atoms simultaneously and each of the B atoms only carries approximately 1/11 of the total ion energy. Thus the same implantation depth and dose as with monomer B ions can be obtained using …

Theoretical And Experimental Studies Of The Field-Induced Phenomena In Flowing Suspensions, Nikolai Markarian

Dissertations

The present work describes results of experimental and theoretical studies of the behavior of dilute suspensions subject to high gradient AC electric fields. When a spatially non-uniform electric field is applied to a suspension, in which the particles and the suspending fluid have different dielectric permittivities andlor conductivities, the particles migrate towards the regions of high or low electric field strengths depending on the sign of their polarization. This phenomenon, referred to as dielectrophoresis, has found numerous applications for the control and manipulation of the particle motions.

Presented in Chapter 3 are the results of studying the field -induced motion …