Digital Commons Network^™

Synthesis And Characterization Of Kesterite Cu2znsns4 (Czts) Thin Films For Solar Cell Application, Mohamed M.A. Abusnina

Electronic Theses and Dissertations

The quaternary compound Cu₂ZnSnS₄ (CZTS) gained considerable attention in the last decade due to its potential as an active-layer semiconductor for low-cost thin-film solar cells. The material is composed of nontoxic and Earth-abundant constituents, has optical properties suitable for photovoltaic application, and can be synthesized using a wide variety of methods.

Polycrystalline CZTS was grown in this work using vacuum-based deposition to first deposit metal films (precursors) of Cu, Zn, and Sn. In a subsequent step, the precursors underwent an annealing treatment in sulfur vapor environment (sulfurization) to form CZTS. Using sputtering, a physical vapor deposition (PVD) …

C-Reactive Protein Interactions With Cellular Membranes And Supported Lipid Bilayers, Aml Abd Alhamed Alnaas

Electronic Theses and Dissertations

C-reactive protein (CRP) is a serum protein that binds to damaged membranes and initiates the complement immune response. Different forms of CRP are thought to alter how the body responds to inflammation and the degradation of foreign material. Despite knowing that a modified form of CRP(mCRP) binds to downstream protein binding partners better than the native pentameric form, the role of CRP conformation on lipid binding is yet unknown. In this work, three main assays were performed to characterize how conformation affects CRP-membrane interactions. The first assay utilized supported lipid bilayers that mimic the plasma membrane of apoptotic cells. The …

Middle School Noncognitive Development In A Sample Of Hispanic/Latino Youth, Jill E. Mcvey

Electronic Theses and Dissertations

This study examined the development of noncognitive skills in a sample of 4,769 Hispanic/Latino students as they went through middle school and the first year of high school using ACT Engage 6-9, an assessment designed to predict student outcomes by measuring students' behaviors and psychosocial attributes. The scales of Academic Discipline, Relationships with School Personnel, and Thinking before Acting were examined longitudinally through HLM analysis. The factors of gender and several indices of academic achievement were used to predict differences in students' starting scores and growth over time.

All factors related to academic achievement were significantly related to differences in …

A Descriptive Study Of The Effect Of Payer Source On Multiple Longitudinal Outcome Measures Within The Tbi Model Systems National Database Using Longitudinal Hlm Analyses, Melissa Carole Hofmann

Electronic Theses and Dissertations

Using longitudinal data from the TBIMS ND, this study utilized a longitudinal hierarchical linear modeling approach to describe the effect of primary payer source on individual level change in outcomes including the FIM and DRS. To facilitate the use of parametric statistics, Rasch-transformed FIM and DRS scores were utilized; thus approaching an interval level of measurement. The FIM was separated into 3 separate cognitive, mobility, and self-care subscales. In this way, rehabilitation professionals including speech, physical, and occupational therapists for this TBI sample could reference results to inform current clinical practice.

Results indicated that FIM and DRS trajectories were best …

Akratic Homo Economicus: Does The Neoclassical Economic Theory "Rational Agent" Assumption Accurately Depict Human Nature?, Marina Logachev

Electronic Theses and Dissertations

Neoclassical economic theory has long been scrutinized for its failure to be congruent with reality, often lacking generality and tractability due to, what many critics argue to be, unrealistic assumptions. One of the theory's core suppositions is a representative "rational agent" or homo economicus, whose self-interest and optimal choices, which are in state of equilibrium and efficiency are rooted in utility maximization of his well-being. Even though neoclassical economics claims to accurately depict human nature, from its very inception it has failed to incorporate human psychology and sociology into its foundations. As the behavioral and biological research became more …

Impact Of Light Pollution On Species Interactions, Kylee Grenis

Electronic Theses and Dissertations

Over half of the world's population lives in urban areas leading to night skies that are substantially degraded by artificial lights. Yet, we know little about how light pollution affects the surrounding natural communities. What we do know focuses on the impact of light pollution on individual species. Therefore, I investigated the impact of light pollution on species interactions. I determined whether light pollution is a mechanism of community change, evaluated whether there were changes in species interactions between predators and prey, and indirect and direct interactions between insect herbivores and their host plants by examining the entire life cycle …

Same Same But Different: The Self-Portraiture Of A Vietnam War Adoptee And The Poststructural Language Of Alterity, Joie Norby Lê

Electronic Theses and Dissertations

This study examines the journey of a Vietnam War adoptee and the multitude of experiences that influenced her alterity. Through the development of a poststructuralist conceptual framework, the author reveals a philosophy of difference realized by philosophers such as Michel Foucault, Gilles Deleuze, Jean-François Lyotard, and Jacques Derrida. Using the method of self-portraiture, the author illustrates how this philosophy of difference was shaped as a result of her experiences and how those experiences have informed her engagement or disengagement throughout her K-12 and post-secondary education, her work as a student, and her beliefs as an educator. The study focuses upon …

Source Apportionment Of Atmospheric Particulate Matter In Developing Countries Using Trace Elements And Stable Metal Isotope Ratios, Nitika Dewan

Electronic Theses and Dissertations

The work presented herein details the source apportionment of atmospheric particulate matter in developing countries (Kyrgyzstan in Central Asia, metropolitan cities in Northern India, and Shenzhen in China) using trace elements and stable metal isotope ratios. The first study focused on the development of a novel method for the concomitant separation of rare-earth elements in environmental samples of any geological origin. The separation procedure is based on three extraction chromatographic materials, referred to as Sr.Spec, TRU.Spec, and Ln.Spec. This triple column arrangement enables the simultaneous isolation of pure Sr and Nd fractions in less than one day and with great …

Thermal Effects On Spin Currents In Non-Local Metallic Spin Valves, Alex Hojem

Electronic Theses and Dissertations

The study of non-local spin valves (NLSVs) has recently proven to be a fertile area for both applied and fundamental research in nanomagnetism due to the unique ability to separate charge currents and spin currents. NLSVs may also prove essential for a new class of high-density hard disk read heads due to their favorable scalability. Recent studies have shown thermal effects created by high current densities play a significant role in the response of NLSVs. These thermal effects also provide the opportunity to create a pure spin current from thermal gradients via a mechanism call the spin dependent Seebeck effect …

The Association Of Preschool Enrollment And The Predictive Traits Of Special Education Identification, Sarie Elizabeth Ates-Patterson

Electronic Theses and Dissertations

Early childhood education (ECE) consists of educational programs that serve children in the preschool years and are designed to improve elementary school performance. Colorado early childhood education programming has two preschool classifications that include Colorado Preschool Program (CPP) which is determined by a student's risk factors, and the State Preschool Special Education (Preschool SPED) program which is determined by the student's identified disability prior to attending elementary school. For the two cohorts who participated in Colorado preschool programming during 2009-2010 school year, special education and demographic extant data are compared in order to study the subsequent identification for special education …

Implementing Agile Development At Scale: An Industry Case Study, Nikita Kataria

Electronic Theses and Dissertations

Agile software development methodologies are extremely popular. Their dynamic restructuring of the development process has been seen as the silver bullet for increasing the productivity of software development. A significant number of studies have analyzed the impact of implementing agile techniques. However these are mostly evaluated only in smaller team settings. There is very little reporting done on how agile development methods can be implemented at the team level and scaled up at the program/portfolio level in large software organizations.

We present the results of an empirical study conducted at Pearson Education. The study focuses on the penetration of agile …

Optimizing Vehicle Usage Using Csp, Sat And Max-Sat, Raheem T. Al Rammahi

Electronic Theses and Dissertations

Most of the companies in Iraq spend significant amounts of time and money when transferring employees between home and work. In this thesis, we model the problem of the Dhi Qar Oil company (DQOC) transportations using three modeling languages from AI: Constraint Programing (CP), Boolean Satisfiability (SAT), and Maximum Satisfiability (MAX-SAT). We then use solvers to find optimal solutions to this problem.

We show which of these solvers is more efficient when finding optimal solutions. For this purpose, we create a test suite of 360 problems to test these solvers. All solvers are applied to these problems and the final …

Relaxation Of Metals And Their Impact On Nitroxides, Priyanka Aggarwal

Electronic Theses and Dissertations

Pulsed and continuous wave electron spin resonance were used to characterize the relaxation rates of selected paramagnetic metals at 5 to 15 K or 80 K, measure the impact of these rapidly relaxing metals on the relaxation rates of nitroxide radicals in glassy mixtures and in discrete complexes, and characterize novel iron-sulfur proteins.

Spin echoes were observed at 5 to 7 K in 1:1 water:glycerol for Er(diethylenetriamine pentaacetic acid)^2- (Er(DTPA)^2-), Co(DTPA)^3- and aquo Co²⁺ with relaxation times that are strongly temperature dependent. Deep proton modulation was present on spin echo decays (Ch. 3). For Gd …

The Effect Of Morphology On Carrier Dynamics In Solution Processed Solar Cells, Alexander G. Dixon

Electronic Theses and Dissertations

This dissertation looks at the charge transport properties of solution processed solar cells and how these properties are effected by the microstructure and morphology of the material. It begins with an introduction and history of the field of solution processed solar cells, focusing on organic photovoltaics and perovskites. The physics and issues of charge transport in these materials are reviewed, and the transport probing techniques of photo-Charge Extraction via Linearly Increasing Voltage (photo-CELIV), Metal Insulator Semiconductor-CELIV (MIS-CELIV), and Resistance Photovoltage (RPV) are detailed.

The photo-CEILV technique is used to probe P3HT devices of varying molecular weights. This material is known …

Molecular Mechanisms Of Protein Thermal Stability, Lucas Sawle

Electronic Theses and Dissertations

Organisms that thrive under extreme conditions, such as high salt concentration, low pH, or high temperature, provide an opportunity to investigate the molecular and cellular strategies these organisms have adapted to survive in their harsh environments. Thermophilic proteins, those extracted from organisms that live at high temperature, maintain their structure and function at much higher temperatures compared to their mesophilic counterparts, found in organisms that live near room temperature. Thermophilic and mesophilic homolog protein pairs have identical functionality, and show a high degree of structural and sequential similarity, but differ significantly in their response to high temperature. Addressing the principles …

Leveraging Client Processing For Location Privacy In Mobile Local Search, Wisam Mohamed Eltarjaman

Electronic Theses and Dissertations

Usage of mobile services is growing rapidly. Most Internet-based services targeted for PC based browsers now have mobile counterparts. These mobile counterparts often are enhanced when they use user's location as one of the inputs. Even some PC-based services such as point of interest Search, Mapping, Airline tickets, and software download mirrors now use user's location in order to enhance their services. Location-based services are exactly these, that take the user's location as an input and enhance the experience based on that. With increased use of these services comes the increased risk to location privacy. The location is considered an …

Follower And Extender Sets In Symbolic Dynamics, Thomas Kelly French

Electronic Theses and Dissertations

Given a word w in the language of a one-dimensional shift space X, the follower set of w, denoted F_X(w), is the set of all right-infinite sequences which follow w in some point of X. Extender sets are a generalization of follower sets and are defined similarly. To a given shift space X, then, we may associate a follower set sequence {|F_X(n)|} which records the number of distinct follower sets in X corresponding to words of length n. Similarly, we may define an extender set sequence {|E …

A Near-To-Far Learning Framework For Terrain Characterization Using An Aerial/Ground-Vehicle Team, Ashkan Hajjam

Electronic Theses and Dissertations

In this thesis, a novel framework for adaptive terrain characterization of untraversed far terrain in a natural outdoor setting is presented. The system learns the association between visual appearance of different terrain and the proprioceptive characteristics of that terrain in a self-supervised framework. The proprioceptive characteristics of the terrain are acquired by inertial sensors recording measurements of one second traversals that are mapped into the frequency domain and later through a clustering technique classified into discrete proprioceptive classes. Later, these labels are used as training inputs to the adaptive visual classifier. The visual classifier uses images captured by an aerial …

Panmixia Across The Range Of The Assortatively Mating Lesser Snow Goose, Brent B. Horowitz

Electronic Theses and Dissertations

The Lesser Snow Goose has been shown to exhibit imprinted positive assortative mating on the basis of its color phases, blue and white, and it has been proposed that the geographic cline of the color phases reflects a historic allopatry of the phases. Using ddRAD-seq, thousands of SNPs were analyzed in both phases and in colonies across the range of the species to examine genetic evidence for separation of the color phases or along the two migratory pathways, which have also been hypothesized to be separate. These analyses did not reveal any genetic differentiation between the color phases nor by …

Topological Speedups, Drew Daehnhardt Ash

Electronic Theses and Dissertations

Given a dynamical system T:X rightarrow X one can define a speedup of (X,T) as another dynamical system conjugate to S:X rightarrow X where S(x)=T^{p(x)}(x) for some function p:X rightarrowZ^{+}. In 1985 Arnoux, Ornstein, and Weiss showed that any aperiodic measure preserving system is isomorphic to a speedup of any ergodic measure preserving system. In this thesis we study speedups in the topological category. Specifically, we consider minimal homeomorphisms on Cantor spaces. Our main theorem gives conditions on when one such system is a speedup of another. Moreover, the main theorem serves as a topological analogue of the Arnoux, Ornstein, …

Quinolines: Novel Synthesis And Derivatives Of Heterocyclic Bioactive Agents, Ginelle A. Ramann

Electronic Theses and Dissertations

Tuberculosis is a pulmonary disease that has ravaged the world throughout history. Even today, many developed and developing countries are experiencing this plight, made worse by the scourge of antibiotic-resistant bacteria.

Mycobacterium tuberculosis's class II fructose-1,6-bisphosphate aldolase presents an interesting target in the design of new therapies against this disease. Previous attempts to construct an inhibitor to this enzyme fell short due to poor selectivity or poor cellular uptake. However a new class of noncompetitive inhibitor based on 8-hydoxyquinoline-2-carboxylic acid presents a fresh approach. Preliminary studies indicate various modifications to this scaffold could be beneficial to its inhibitory efficacy.

Modifications …

Autonomous Collision Avoidance For A Teleoperated Uav Based On A Super-Ellipsoidal Potential Function, Mohammed Salim Qasim

Electronic Theses and Dissertations

This thesis presents the design of a super-ellipsoidal potential function (SEPF) that can be used, in a static and dynamic environment, for autonomous collision avoidance of an unmanned aerial vehicle (UAV) in a 3-dimensional space. In the design of the SEPF, we have the full control over the shape and size of the potential function. In our proposed approach, a teleoperated UAV can not only autonomously avoid collision with surrounding objects but also track the operator' control input as closely as possible. As a result, an operator can always be in control of the UAV for his/her high-level guidance and …

Crafted Places: The Use Of Place In Wisconsin Craft Beer Marketing, Joseph A. Quintana

Electronic Theses and Dissertations

This research examines place-related themes used in craft beer marketing initiatives in Wisconsin. "Place" describes the emotions and perceptions individuals hold in certain locations. Place theory, despite being universally experienced, is relatively understudied. Furthermore, this project is grounded in the recent neolocal movement - a movement towards local culture, and away from national homogenous culture. Broadly, this paper aims to understand the perceptual linkages between people and "their" place. In order to understand place and neolocal themes within these linkages, this project analyzes how individual beer names, beer-label imagery, and beer-related advertisements use familiar places to link products with a …

Rethinking The "Marginal Revolution" In The History Of Economic Thought: A Brief Examination Of The Marginal Utility Theory Before And In The 1870s, Ding Ning

Electronic Theses and Dissertations

The "Marginal Revolution," a well-known event in the history of economic thought, challenged the mainstream classical political economy and introduced new methods to economic study. The "Marginal Revolution" marked the rise of the Marginal Utility School and pushed the formulation of neoclassical economics. Because marginal utility is the core concept of the "Marginal Revolution," this thesis studies the origin of marginal utility theory by examining figures such as Bernoulli, Bentham, Dupuit, and Goseen, and the utility theory with its related topics of Jevons, Menger and Walras in the 1870s. This thesis considers the significance of the "Marginal Revolution," with particular …

When "I Do" Becomes "I Don't": Exploring Communication Behaviors And Dialectical Tensions In Broken Engagements, Chelsea Annette Hand Stow

Electronic Theses and Dissertations

Communication behaviors and precipitating events were studied in accounts provided by 109 heterosexual individuals living in the United States who had experienced at least one broken premarital engagement. Participants' responses to an exploratory survey designed by the researcher were thematically analyzed in order to determine the causes of broken engagements, communication strategies used in sharing the disengagement narrative, advice given and received, and the presence of relational dialectics (both tensions and coping strategies). Data revealed that broken engagements more closely mirror divorce than dating breakups, engagements are more likely to be broken by women than men, and disengagement more often …

A Comparison Between Propensity Score Matching, Weighting, And Stratification In Multiple Treatment Groups: A Simulation Study, Priyalatha Govindasamy

Electronic Theses and Dissertations

The application of propensity score techniques (matching, stratification, and weighting) with multiple treatment levels are similar to those used in binary groups. However, given that the application of propensity scores in multiple treatment groups is new, factors affecting the performance of matching, stratification, and weighting in multiple treatment groups are less explored. Therefore, this study was conducted to determine the performance of different propensity score techniques with multiple treatment groups under various circumstances. Specifically, the study focused on examining how the three propensity score corrective techniques perform in estimating treatment effects under (1) overt and (2) hidden types of selection …

The Role Of P38 Mapk In Protein Homeostasis And Aging, Sarah Mae Ryan

Electronic Theses and Dissertations

Aging is characterized by a failure to maintain proper protein homeostasis, potentially leading to tissue dysfunction. Though a variety of genes have been found to regulate lifespan and age-related behaviors how these genetic factors contribute to protein homeostasis has not been fully explored. Here, we report that the evolutionarily conserved aging gene p38 MAPK (p38Kb) regulates age-dependent protein homeostasis. Over-expression of p38Kb results in reduced protein aggregation, while knockout of p38Kb leads to increased protein aggregation. Furthermore, we find that p38Kb regulates protein homeostasis, lifespan, and age-dependent locomotor functions through an interaction with the Chaperone Assisted Selective Autophagy complex; a …

The Neuroprotective And Therapeutic Effects Of Anthocyanins And Their Metabolites In Vitro And In A Mouse Model Of Amyotrophic Lateral Sclerosis, Aimee Nicole Winter

Electronic Theses and Dissertations

Anthocyanins, a unique class of flavonoid compounds, have recently come to the forefront of investigative research aimed at evaluating the potential applications of natural products to human health. Evidence demonstrating the beneficial effects of anthocyanin consumption has been reported for a myriad of conditions including cancer, cardiovascular disease, and lately, neurodegenerative disease. Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) are characterized by the death of specific neuronal populations within the brain and spinal cord, leading to cognitive and/or motor impairment. While the etiology of many of these diseases is largely unknown, several factors have …

Professional Development And The Impact On Teacher Growth And Development, Sherry Kathleen Segura

Electronic Theses and Dissertations

This study involved examining the beliefs of teachers at one urban elementary school regarding how professional development has helped them meet the needs of culturally and linguistically diverse students. This study included a series of in-depth interviews with three teacher leaders. The goal was to obtain consent from them to participate in this study at their school. With a qualitative approach, this study included a narrative inquiry method to illuminate teachers' perceptions of whether professional development had a positive impact on their instruction. A series of in-depth one-on-one interviews further shed insight on which types of professional development teachers felt …

Revolutionary Technologies: Praxical Time As A Way Of Overcoming Reification, RóIsíN Lally

Leadership Studies Faculty Scholarship

This article argues that by recognizing the fundamental relationship between praxical time and dwelling as a matrix of interweaving modes of being, society can subvert the potential reification of humanity by technology. This can only be achieved through a democratic process that involves participatory agents not only at the design level but also in the event of naming future innovations. By looking at the work of Alain Badiou, it is shown how a fusion of Heideggerian-inspired phenomenology and speculative ontology is critical for the advancement of social theory, as revolutionary technologies become increasingly immersive.