VictorJuiz/thesis huggingface dataset:
Quantum-tuned Multijunction Solar Cells
Keywords: Colloidal Quantum Dots
Graded Recombination Layer

Multijunction solar cells made from a combination of CQDs of differing sizes and thus bandgaps are a promising means by which to increase the energy harvested from the Sun’s broad spectrum. In this dissertation, we first report the systematic engineering of 1.6 eV PbS CQD solar cells, optimal as the front cell responsible for visible wavelength harvesting in tandem photovoltaics. We rationally optimize each of the device’s collecting electrodes—the heterointerface with electron accepting TiO2 and the deep-work-function hole-collecting MoO3 for ohmic contact—for maximum efficiency. Room-temperature processing enables flexible substrates, and permits tandem solar cells that integrate a small-bandgap back cell atop a low thermal-budget larger-bandgap front cell. We report an electrode strategy that enables a depleted heterojunction CQD PV device to be fabricated entirely at room temperature. We develop a two-layer donor-supply electrode (DSE) in which a highly doped, shallow work function layer supplies a high density of free electrons to an ultrathin TiO2 layer via charge-transfer doping. Using the DSE we build all-room-temperature-processed small-bandgap (1 eV) colloidal quantum dot solar cells suitable for use as the back junction in tandem solar cells. We further report in this work the first efficient CQD tandem solar cells. We use a graded recombination layer (GRL) to provide a progression of work functions from the hole-accepting electrode in the bottom cell to the electron-accepting electrode in the top cell. The recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We conclude our dissertation by presenting the generalized conditions for design of efficient graded recombination layer solar devices. We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the interlayers.
Networking on the Margins:The Regulation of Payday Lending in Canada
Keywords: Payday Lending
Regulation

The contemporary emergence of payday lending as a major source of high-cost short-term credit for credit-constrained populations has prompted debates among government officials, business representatives, advocacy groups and academics over how best to regulate the industry. Such debates typically focus on the prevailing lending practices and interest charges in the industry. While critics associate these with usury, supporters of payday lenders defend them as appropriately priced responses to market demand. This dissertation seeks to contextualize, and contribute to a deeper understanding of, the terms of these debates through an exploration of the recently concluded political exercise in Canada where responsibility for the governance of payday lending has been shifted from the federal government, with its criminal law power over usury, to provincial governments with their various regulatory powers over licensing and consumer protection. The dissertation begins with the observation that there are competing moral discourses about money and interest simultaneously embedded in the financial policy-making process in Canada, a fact that has complicated regulatory efforts aimed at payday lending. While these efforts have largely been informed by varying assessments of the transparency and competiveness of the payday lending market, this dissertation contends that a conceptually more useful way of understanding this market is to study the organizational and marketing strategies employed by payday lenders to indentify and retain a stable customer base, and the reciprocal moves on the part of customers to improve upon their terms of trade. In detailing the political process which culminated in a new regulatory regime for payday lending, this dissertation draws on the “regulation through networks” literature to help explain its progress. A major contribution this dissertation makes to this explanatory approach is in its emphasis on the dual legitimation imperatives with which the network actors had to contend as they negotiated their way to a consensus on a politically acceptable regulatory structure for payday lending. This consensus has proved to be politically vulnerable because of the continuing normative conflicts embedded in official financial policy discourse, and inter alia, in the legitimation imperatives which have permeated the policy-making process.
Modulation and Control of Matrix Converter for Aerospace Application
Keywords: Power Converter
Matrix Converter
Power Supply
Aerospace

In the context of modern aircraft systems, a major challenge is power conversion to supply the aircraft's electrical nstruments. These instruments are energized through a fixed-frequency internal power grid. In an aircraft, the available sources of energy are a set of variable-speed generators which provide variable-frequency ac voltages. Therefore, to energize the internal power grid of an aircraft, the variable-frequency ac voltages should be converted to a fixed-frequency ac voltage. As a result, an ac to ac power conversion is required within an aircraft's power system. This thesis develops a Matrix Converter to energize the aircraft's internal power grid. The Matrix Converter provides a direct ac to ac power conversion. A major challenge of designing Matrix Converters for aerospace applications is to minimize the volume and weight of the converter. These parameters are minimized by increasing the switching frequency of the converter. To design a Matrix Converter operating at a high switching frequency, this thesis (i) develops a scheme to integrate fast semiconductor switches within the current available Matrix Converter topologies, i.e., MOSFET-based Matrix Converter, and (ii) develops a new modulation strategy for the Matrix Converter. This Matrix Converter and the new modulation strategy enables the operation of the converter at a switching-frequency of 40kHz. To provide a reliable source of energy, this thesis also develops a new methodology for robust control of Matrix Converter. To verify the performance of the proposed MOSFET-based Matrix Converter, modulation strategy, and control design methodology, various simulation and experimental results are presented. The experimental results are obtained under operating condition present in an aircraft. The experimental results verify the proposed Matrix Converter provides a reliable power conversion in an aircraft under extreme operating conditions. The results prove the superiority of the proposed Matrix Converter technology for ac to ac power conversion regarding the existing technologies of Matrix Converters.
The New Heretics: Popular Theology, Progressive Christianity and Protestant Language Ideologies
Keywords: Christianity
anthropology of Christianity
language ideologies
church history
progressive Christianity
liberal Protestantism
religion in Canada
reception of biblical studies
deconversion
temporality

This dissertation investigates the development of progressive Christianity. It explores the ways in which progressive Christian churches in Canada adopt biblical criticism and popular theology. Contributing to the anthropology of Christianity, this study is primarily an ethnographic and linguistic analysis that juxtaposes contemporary conflicts over notions of the Christian self into the intersecting contexts of public discourse, contending notions of the secular and congregational dynamics. Methodologically, it is based upon two-and-a-half years of in-depth participant observation research at five churches and distinguishes itself as the first scholarly study of progressive Christianity in North America. I begin this study by outlining the historical context of skepticism in Canadian Protestantism and arguing that skepticism and doubt serve as profoundly religious experiences, which provide a fuller framework than secularization in understanding the experiences of Canadian Protestants in the nineteenth and twentieth centuries. In doing so, I draw parallels between the ways that historical and contemporary North American Christians negotiate the tensions between their faith and biblical criticism, scientific empiricism and liberal morality. Chapter Two seeks to describe the religious, cultural and socio-economic worlds inhabited by the progressive Christians featured in this study. It focuses on the worldviews that emerge out of participation in what are primarily white, middle-class, liberal communities and considers how these identity-markers affect the development and lived experiences of progressive Christians. My next three chapters explore the ways that certain engagements with text and the performance or ritualization of language enable the development of a distinctly progressive Christian modality. Chapter Three investigates progressive Christian textual ideologies and argues that the form of biblical criticism that they employ, along with entrenched concerns about the origins of the Christian faith ultimately, leads to a rejection of the biblical narrative. Chapter Four examines the ways in which progressive Christians understand individual 'deconversion' narratives as contributing to a shared experience or way of being Christian that purposefully departs from evangelical Christianity. The final chapter analyses rhetoric of the future and argues that progressive Christians employ eschatological language that directs progressive Christians towards an ultimate dissolution.
Ethical Challenges and Dilemmas in Teaching Students with Special Needs in Inclusive Classrooms: Exploring the Perspectives of Ontario Teachers
Keywords: education
inclusion
special education
ethics

This study examines the ethical challenges and dilemmas that teachers experience in their work with students who have special needs in inclusive classrooms. Moreover, it investigates the ways in which teachers cope with or resolve such difficulties, the supports currently available to assist them in managing ethical issues, and their recommendations for potential supports. Accounts of ethical challenges reported by 12 teacher participants working at the elementary and secondary level were interpreted from two stages of interviews. Data were analyzed qualitatively using a constant comparison method, with data analysis occurring during and after each stage. Emergent themes were coded and categorized to elicit major and sub-themes. The ethical challenges reported by the participants primarily dealt with issues of care, equity, and fairness, where participants felt that the best interests of students were not being met. Difficulties occurred in the context of accommodations and modifications, assessment and evaluation, discipline, distribution of time and resources, and the rights of the individual student versus the group. In the accounts provided, participants consistently raised concerns about ethical dilemmas they experienced as a result of colleagues. In all of the situations that dealt with colleagues, teachers were unwilling to confront the unethical behaviors of co-workers despite their potential to harm the student. All of the teachers faced ethical challenges in the context of inclusion. While most support the practice of inclusion, concerns were raised about existing inequities, specifically in regard to the degree of inclusivity and access to learning opportunities. Shortages in supports, resources, and training were the primary reasons attributed to the teachers’ struggles. The participants’ recommendations for supports consisted of collaborative professional development opportunities, specifically in special and inclusive education. This study contributes to the growing body of literature in the ethics of inclusive and special education. It has significant implications for policy makers, certifying bodies, teacher education programs, and teachers’ professional lives as it provides insights into the ethical challenges faced by teachers in inclusive classrooms. The results of the study have the potential to influence the development of policies and practices to support both teachers and students.
An Investigation of CYP2B in Rat Brain: Regulation and Role in Drug and Toxin Response
Keywords: Brain
Cytochrome P50
Propofol
Chlorpyrifos
Nicotine
Drug Metabolism

INTRODUCTION: Cytochrome P450 2B (CYP2B) is a drug-metabolizing enzyme subfamily found in both the brain and liver, which metabolizes clinical drugs, drugs of abuse (e.g. nicotine), toxicants and endogenous neurochemicals. Brain CYP2B’s role in the local metabolism of centrally acting substrates is important to investigate because of its ability to metabolize a variety of centrally active substrates. Additionally, CYP2B regulation by genetics, and exposure to xenobiotics, results in great inter-individual differences in the brain expression of this enzyme. METHODS: We investigated the time-course of rat brain CYP2B induction after chronic nicotine treatment. Using the rat model of brain CYP2B induction, combined with intracerebroventricular (ICV) inhibition of CYP2B, we assessed the effects of brain CYP2B in the response to the anaesthetic substrate, propofol. We also investigated the role of brain CYP2B-mediated activation of the pesticide chlorpyrifos on its neurotoxicity. RESULTS: Nicotine’s induction of rat brain CYP2B was long lasting, returning to basal levels by day 7, and was unaffected by nicotinic receptor blockade. Induction of CYP2B in rat brain, by chronic nicotine treatment, reduced the anaesthetic efficacy of propofol, through increased brain CYP2B-mediated metabolic inactivation. Inhibition of brain CYP2B, using mechanism based inhibitors of the enzyme, inhibited both basal and induced brain CYP2B activity, and prolonged propofol sleep time by reducing the local brain inactivation of the anaesthetic. Inhibition of rat brain, and not hepatic, CYP2B was able to effectively block local brain production of the toxic chlorpyrifos oxon, significantly attenuating the reductions in brain acetylcholinesterase activity and body temperature. Additionally, inhibition of brain CYP2B also significantly reduced the behavioural toxicity after chlorpyrifos exposure in a chlorpyrifos (CP) dose- and time-dependent manner. CONCLUSION: These studies indicate that rat brain CYP2B enzymes are active in vivo and play a meaningful role in the local metabolism of, and the response to, centrally acting substrates (i.e. propofol, chlorpyrifos). These data provide a first demonstration of the important role that brain CYP-mediated metabolism plays in the response to centrally acting substrates (i.e. clinical drugs, toxicants, endogenous neurochemicals), potentially contributing to the inter-individual variability seen in human responses to centrally active drugs and toxicants.
The Process of Crafting an Authentic Identity in the Context of Immigration to Canada: The Muslim Experience
Keywords: Identity
Immigrants

This study looked at the experience of religion and the formation of a contemporary ethnoreligious identity in the lives of first generation Pakistani Muslim immigrant men and women who have been residents of Canada for five to ten years. The present research explored the life experiences of Muslim immigrants from Pakistan who immigrated to Canada with their immediate families and resolved the ensuing cultural dislocation. In order to understand the subjective meanings of immigrants’ lived experiences in Canada, the present study used a Grounded Theory framework. The analysis of data revealed a four stage theory of Muslim identity formation. Those stages describe the step-by-step process that highlights immigrants’ experience of culture shock, resolution of culture shock through immigrants’ reaffirmation of their religion that lays the groundwork for an authentic identity through differentiation of self from their country of origin, and formation of an authentic Muslim identity in the host society. It is proposed that the resolution of culture shock and the creation of a post-immigration identity mirrors the developmental process of Differentiation of Self and Other as outlined by Watson (2011) in her process model of becoming a self-governing person. Using their faith as a key resource to cope, these immigrants achieve a renewed sense of self and a revitalized faith. Immigrants come to an enhanced appreciation of Islam as the best system of life for themselves. An improved relationship with faith enhances immigrants’ awareness about the actual philosophy of its system and helps immigrants internalize the desirable Muslim character traits which focus on altruism, modesty, tolerance, fairness, forgiveness, and inclusion. Internalizing the pro social values of Islam brings about a fundamental shift in these immigrants’ perspectives about self and the host society. They successfully differentiate themselves from their country of origin to thrive in their adopted country. Canada provides them a conducive context which helps them access their positive potential in becoming their ideal self, the true Muslims. They come to an increased appreciation of the new society and accept it as their new home, thus form a new identity that speaks for the authentic version of Islam.
Aerostructural Analysis and Design Optimization of Composite Aircraft
Keywords: Aerostructural
Optimization

High-performance composite materials exhibit both anisotropic strength and stiffness properties. These anisotropic properties can be used to produce highly-tailored aircraft structures that meet stringent performance requirements, but these properties also present unique challenges for analysis and design. New tools and techniques are developed to address some of these important challenges. A homogenization-based theory for beams is developed to accurately predict the through-thickness stress and strain distribution in thick composite beams. Numerical comparisons demonstrate that the proposed beam theory can be used to obtain highly accurate results in up to three orders of magnitude less computational time than three-dimensional calculations. Due to the large finite-element model requirements for thin composite structures used in aerospace applications, parallel solution methods are explored. A parallel direct Schur factorization method is developed. The parallel scalability of the direct Schur approach is demonstrated for a large finite-element problem with over 5 million unknowns. In order to address manufacturing design requirements, a novel laminate parametrization technique is presented that takes into account the discrete nature of the ply-angle variables, and ply-contiguity constraints. This parametrization technique is demonstrated on a series of structural optimization problems including compliance minimization of a plate, buckling design of a stiffened panel and layup design of a full aircraft wing. The design and analysis of composite structures for aircraft is not a stand-alone problem and cannot be performed without multidisciplinary considerations. A gradient-based aerostructural design optimization framework is presented that partitions the disciplines into distinct process groups. An approximate Newton--Krylov method is shown to be an efficient aerostructural solution algorithm and excellent parallel scalability of the algorithm is demonstrated. An induced drag optimization study is performed to compare the trade-off between wing weight and induced drag for wing tip extensions, raked wing tips and winglets. The results demonstrate that it is possible to achieve a 43% induced drag reduction with no weight penalty, a 28% induced drag reduction with a 10% wing weight reduction, or a 20% wing weight reduction with a 5% induced drag penalty from a baseline wing obtained from a structural mass-minimization problem with fixed aerodynamic loads.
Inferring the Binding Preferences of RNA-binding Proteins
Keywords: Computer Science
Machine Learning
Computational Biology

Post-transcriptional regulation is carried out by RNA-binding proteins (RBPs) that bind to specific RNA molecules and control their processing, localization, stability and degradation. Experimental studies have successfully identified RNA targets associated with specific RBPs. However, because the locations of the binding sites within the targets are unknown and because RBPs recognize both sequence and structure elements in their binding sites, identification of RBP binding preferences from these data remains challenging. The unifying theme of this thesis is to identify RBP binding preferences from experimental data. First, we propose a protocol to design a complex RNA pool that represents diverse sets of sequence and structure elements to be used in an in vitro assay to efficiently measure RBP binding preferences. This design has been implemented in the RNAcompete method, and applied genome-wide to human and Drosophila RBPs. We show that RNAcompete-derived motifs are consistent with established binding preferences. We developed two computational models to learn binding preferences of RBPs from large-scale data. Our first model, RNAcontext uses a novel representation of secondary structure to infer both sequence and structure preferences of RBPs, and is optimized for use with in vitro binding data on short RNA sequences. We show that including structure information improves the prediction accuracy significantly. Our second model, MaLaRKey, extends RNAcontext to fit motif models to sequences of arbitrary length, and to incorporate a richer set of structure features to better model in vivo RNA secondary structure. We demonstrate that MaLaRKey infers detailed binding models that accurately predict binding of full-length transcripts.