VictorJuiz/thesis huggingface dataset:
Design and Development of Broadband Piezoelectric Vibration Energy Harvester Based on Compliant Orthoplanar Spring

With advancement in technology, power requirements are reduced drastically for sensor nodes. The piezoelectric vibration energy harvesters generate sufficient power to low-powered sensor nodes. The main requirement of energy harvester is to provide a broad bandwidth. A conventional linear harvester does not satisfy this requirement. Therefore, the research focus is shifted to exploiting nonlinearity to widen the bandwidth of the harvester. Although nonlinear techniques are promising for broadening a bandwidth, reverse sweep shows reduced response as compared to the forward sweep. To overcome this issue, this thesis presents the design and development of a broadband piezoelectric vibration energy harvester based on a nonlinear multi-frequency compliant orthoplanar spring. This thesis is divided into three parts. The first part presents the design and experimental study of a tri-leg compliant orthoplanar spring for a broadband energy harvesting. The harvester performance is enhanced through the use of lightweight masses, which bring nonlinear vibration modes closer. The performance of the harvester is analyzed through development of a mathematical model based on the Duffing oscillator. The experimental and numerical results are in good agreement. The parametric study shows that an optimum performance is achieved by further reducing a gap in between the vibration modes using different weight masses. In the second part of the research, multiple (bi, quad and pent) leg compliant orthoplanar springs are designed to understand their role in expanding the bandwidth and reducing gap between vibration modes. The designed harvesters are compared by calculating the figure of merits. The quad-leg design provides a better performance in terms of power density and bandwidth among all the designs. The reverse sweep response is comparable to the forward sweep in terms of bandwidth. In the final part, a magnetic force is applied to the tri-leg harvester, which enhanced the voltage output and bandwidth. In addition, vibration modes have been brought even closer by reducing the gap between the modes. Overall, the proposed harvester performance is significantly improved using multiple legs attached with piezoelectric plates and masses, bringing the modes closer in the forward and reverse sweeps, making it advantageous to harvest energy from wideband environmental vibrations.

Keywords: Compliant orthoplanar spring
Multi-mode
Multiple piezoelectric
Nonlinear vibration
Piezoelectric vibration energy harvesting
Advisor: Zu, Jean
Homophobic Bullying: Understanding Teacher, LGBTQ Youth, and Advocate Perspectives

Recent research shows that the use of derogatory terms, threats, and violence against lesbian, gay, bisexual, transgender, and questioning (LGBTQ) youth in schools continues to occur (Collier, Bos, Sandfort, 2013; Taylor Peter, 2011). Moreover, the frequency of LGBTQ youth suicides (McFarland, 1998) and the extent of short- and long-term psychosocial issues experienced by LGBTQ youth are concerning (Deisher, 1989; Mufioz-Plaza, Quinn, Rounds, 2002). Research involving teachers has found that teachers were frequently aware that homophobic bullying was occurring, but they didn’t know how, or were unwilling, to address it (Warwick, Aggleton, Douglas, 2001). The current study was a qualitative investigation of teacher, LGBTQ youth, and bullying expert and advocate perspectives on homophobic bullying. Grounded theory methods were utilized to analyze the 18 semi-structured interviews. Four themes were identified around the participants’ understanding of what homophobic bullying is: Words as Weapons, Understanding “That’s so Gay”: Harmful Discrimination or Innocuous Slang, Exclusion as a Weapon, and It’s not Getting Better. Four additional themes emerged around how to facilitate positive change in the school system: Understanding Action: Explicit and Implicit Messaging, Understanding School Culture, Suggestions for Change: Stopping the Silence, and Creating Change: Top Down or Bottom Up? More specifically, the qualitative findings illustrated that verbal homophobic bullying is rampant and perceived as challenging for school staff to address and lessen, and the climate for LGBTQ students continues to be viewed as negative and hostile. Teachers reported acting on homophobic bullying regularly, whereas LGBTQ youth participants felt teacher action was minimal. Homophobic bullying was considered by participants to be a broad issue that required attention from various micro- to macro-systems. From these findings, a model for conceptualizing the influences of change around homophobic bullying was developed and is presented here. This model utilized Bronfenbrenner’s Bioecological Systems Theory (1977; 1989; 1999) as a guide to capture the key players that participants felt were most influential on homophobic bullying, from the individual level to the larger socio-political influences.

Keywords: bullying
heterosexist
homophobic
LGBTQ
teachers
youth
Advisor: Gillis, Joseph R
Making Space for Social Innovation: What We Can Learn from the Midwifery Movement.

I contend that the emerging field of social innovation is at risk of â social innovation washingâ â organizations capitalizing on the trend of social innovation, rather than actually innovating. The current discourse is loaded with language and approaches that suggest market-force solutions to social change and largely ignore that notion that each time we attempt social innovation, we evoke a site of struggle. I draw on literature that is grounded in understanding society from a lens of domination of others to propose a strategic approach to social innovation as an alternative to current conceptualization of the term. The thesis explores the question, how can social innovation be understood or used as a strategic or intentional approach to social change? I use a reflective and iterative approach to conceptualize social innovation. I argue that for an activity or process to be considered a social innovation, it needs to accomplish three things: to have changed social practices, relations, or interactions; deeply challenged or changed our existing paradigms (or stances); and significantly changed resource flows within an existing social system. After considering several potential case studies (for example, credit unions, insurance, or the internal combustion engine), I selected midwifery. Midwifery was the only example I could find that had experienced social innovation multiple times. Prior to the invention of hospitals, all births happened in homes and within communities. Later, and in many parts of the world, birth moved into hospitals and many communities were excluded from the birthing process. Today, we are witnessing a trend toward births occurring in homes, birthing centres or hospitals, with varying degrees of community inclusion. The thesis argues that for agents to achieve social innovation they need free spaces where they can co-develop their collective identity. Next, agents need to transform current spatial and social practices, existing stances, and finally, the extent to which they can be autonomous or dependent on the existing system. The thesis explored, midwifery communities in Trinidad and Ontario and proposed a model that forefronts the production and reproduction of space as being integral to creating the conditions for generating social innovation.

Keywords: Complexity
Organizational Change
Practice
social entrepreneurship
soical innovation
Space
Advisor: Quarter, Jack
Change of International Orders: Empire, Balance of Power, and Liberal Governance

There is a persistent gap between the abstract concepts elites use to understand the elements of international orders and the actual material foundations that underpin those orders. In medieval times European societies conceived of international order in the form of Universal Monarchy, although material power was not sufficiently concentrated to permanently reach further than to the next town. In the early eighteenth century, rulers practised international order as a territorial balance of power, while territorial states were fully formed only in the early nineteenth century. This begs the question of how the abstract concepts that IR practitioners work with to order international interactions actually emerge on the ground. I propose that they result from concrete forms of representation, like warfare practices, diplomatic practices, or representative buildings, which create IRâ s macro-phenomena in the daily interactions between people. Forms of representation characterize the units of the international system and position them towards each other in relations of subordination, superiority, or equality. These spatial configurations constitute the deep generative grammar of an international order. When the forms of representation change the international order changes. I develop two mechanisms of change based on struggles over forms of representation and on contingent changes in representative forms. To trace the effects of representative forms as material signs I propose a new methodological apparatus based on Peircean semeiotics. I empirically study the transition from a medieval ordering mechanism of empire to the ordering mechanism of a territorial balance of power, and use the findings to illustrate how we might understand the potential emergence of a postmodern order in Europe.

Keywords: Europe
European integration
forms of representation
international history
international order
practices
Advisor: Adler, Emanuel
Accessing Synthetically-Challenging Isoindole-Based Materials for Assessment in Organic Photovoltaics via Chemical and Engineering Methodologies

Isoindoles are a broad class of compounds that comprise a very small space within the domain of established photoactive materials for organic photovoltaics (OPVs). Given this scarcity, combined with the performance appeal of presently and well known isoindole-based compounds such as the phthalocyanines, it is a worthy undertaking to develop new materials in this domain. This thesis aims to bring to light the suitability of five novel, or underexplored, classes of isoindole-based materials for OPVs. These classes are the boron subphthalocyanine (BsubPc) polymers, oxygen-bridged dimers of BsubPcs (Îź-oxo-(BsubPc)2), boron subnaphthalocyanines (BsubNcs), group XIII metal complexes of 1,3-bis(2-pyridylimino)isodinoline (BPI), and the boron tribenzosubporphyrins (BsubPys). The synthesis of these materials was proven to be challenging as evident in their low isolated yields, lengthy synthetic and purification processes, and/or batch-to-batch variations. This outcome was not surprising given their undeveloped chemical nature. The photo- and electro-physical properties were characterized and shown to be desirable for all classes other than the group XIII metal complexes of BPI for OPVs. Îź-Oxo-(BsubPc)2 and BsubNcs show promise in this application while BsubPc polymers and BsubPys will be subjects of future exploration. The results from the work herein aid to develop and strengthen the fundamental understanding of the structure-property relationships of isoindole derivatives. On a broader scale, the work demonstrates their versatility as functional materials for OPVs and their possible expansion to other organic electronic technologies like organic light emitting diodes and organic field effect transistors.

Keywords: isoindoles
organic electronics
organic photovoltaics
subnaphthalocyanines
subphthalocyanines
subporphyrins
Advisor: Bender, Timothy P.
Conserving Connectivity: Ecological Determinants of Gene Flow in Plants at the Landscape Scale

With intensifying global pressures of habitat loss and fragmentation, there is an increasing need to manage landscapes in a way that maintains gene flow among previously continuous populations. This requires a detailed understanding of the scale of gene flow in nature and of how aspects of the landscape support or inhibit movement. In plants, gene flow occurs through both pollen and seed, each of which may be carried by multiple vectors. This makes it challenging to characterize, and as a consequence, our understanding of the local and landscape drivers of gene flow are limited in plants compared to animals. My thesis addresses this deficiency by quantifying the contributions of landscape structure, individual plant characteristics, and directed seed dispersal to gene flow of plants in fragmented landscapes. First, I used simulations to test if models of pollen flow could be improved by incorporating individual plant characteristics that affect attractiveness to pollinators. The results showed that inter-individual variation in attractiveness explained significantly more variation than inter-mate distance. Second, I took advantage of a network of calcareous grasslands in Germany to quantify the determinants of pollen and seed-mediated gene flow in a specialist herb, Pulsatilla vulgaris. Using 1,449 individuals from 57 populations, genotyped at seven newly developed markers, I tested the efficacy of an ecological shepherding network to maintain seed-mediated gene flow among P. vulgaris populations. I found that (i) shepherding distance explained genetic differentiation better than geographic distance among populations, (ii) populations that were well connected within the network had significantly higher genetic diversity, and (iii) genetic diversity was significantly positively correlated with fitness-related traits. Paternity analysis on a subset of seven populations revealed high rates of self-pollination. Within-population patterns of pollen flow correlated with floral resources measured at the scale of individuals and patches, whereas among-population pollen flow correlated with floral resources measured at the patch scale and landscape context measured at intermediate and large spatial scales. Together my results highlight the importance of using multi-scale and multi-vector approaches when modeling gene flow in plants, and suggests that typical models based on distance alone may be insufficient to capture the complexity of pollination and seed dispersal.

Keywords: connectivity
conservation genetics
gene flow
landscape genetics
plant
Advisor: Wagner, Helene H
Feminist Practice in an International Bureaucracy: Contestation Over the Field of Peace and Security at the United Nations

This dissertation looks at the community of feminists who seek to advance women’s rights from within the UN system. It broadly asks: how does this community that is invested in a set of ideals go on to develop practices that promote organizational change within a constrained bureaucratic setting? At its heart, this dissertation seeks to understand the role of these individuals in creating change within the UN system, both at the level of normative advancement, through the adoption of new institutional rules, and also at the level of practice, in terms of making these norms meaningful in the everyday functioning of the organization as a whole. It adopts a theoretical approach that brings Bourdieu’s field theory into the IR literature on communities of practice, drawing to the foreground the dynamics of power and contestation in the field as actors struggle to drive change. In accounting for change, it analyzes how these feminists navigate emerging and persistent challenges and opportunities in and through their everyday practices, capturing their successes, failures, and compromises. It looks in particular at the practice of writing documents as key to strategic efforts to advance women’s rights. Through this approach, this dissertation makes visible the interactions between institutional constraints and strategic agency within the UN. It analyzes the case of the evolution of the ‘Women, Peace, and Security’ normative agenda, as well as the creation of UN Women, to understand the complexity of feminist engagement in these bureaucratic spaces.

Keywords: Femocrats
Practices
Security
United Nations
UN Women
Women's Rights
Advisor: Levi, Ron
Development of Quantitative Optical Coherence Tomography Methods for Cell Death Detection

Current clinical cancer treatment monitoring methods rely largely on measurements of tumour volume to assess treatment efficacy several weeks to months after the start of therapy. The development of early monitoring methods to determine a patientâ s response within the first days of a new treatment could significantly impact the overall outcome. Treatment induced cancer cell death occurs before changes in tumour volume. Cell death is characterized by a series of predictable and organized subcellular morphological changes. Light scattering theory predicts that changes in the size, shape, number density and spatial organization of subcellular structures will affect light backscattered from tissues. The objective of this thesis was to develop quantitative methods using optical coherence tomography (OCT) to non-invasively detect cell death in tissues undergoing cancer therapy. Data acquisition and analysis methods were designed to measure variations in the OCT signal resulting from morphological changes in dying cells. Specifically, parameters were developed to measure changes in the speckle intensity statistics, spectral characteristics and the temporal intensity fluctuations of the OCT signal. In a series of in vitro experiments it was demonstrated that the quantitative OCT parameters are sensitive to morphological changes related to cell death. Measured changes in the quantitative parameters 24 to 48 hours after the induction of cell death were linked to structural changes observed in the cell nucleus using light microscopy. Based on the known kinetics of cell death, early variations in the spectral parameters of the OCT signal and decorrelation rate of the speckle intensities were linked to mitochondrial morphology. Finally, preliminary studies using mouse tumour models demonstrated the feasibility of using these parameters to detect cell death in vivo.

Keywords: Apoptosis
Cell Death
Dynamic Light Scattering
Optical Coherence Tomography
Spectroscopic
Treatment Monitoring
Advisor: Czarnota, Gregory J
Kolios, Michael C
A Violent Spectacle: Terrorism in Contemporary Peninsular Drama

Terrorism and violence have long been a part of Spanish history and culture, although the twentieth and early twenty-first centuries brought a notable increase of these phenomena with the Spanish Civil War, Franco dictatorship, the Basque conflict, and the Madrid train bombings in 2004. Prior to the early 1990s – 2010s, however, there was not much evidence of this in the cultural sphere---especially on the stage, which has always served an important role in Spain. This dissertation examines the reasons behind the amplified experience of violence and terrorism in Spain in the late twentieth and early twenty-first centuries through a look at significant historical events leading up to and during these periods and notes the quotidian nature of violence in Spain at this time due to its repeated nature. This is amplified by a parallel examination of the history of theatre in Spain during the same time in order to demonstrate the effects of political upheaval on both the production (censorship placed on texts, etc.) and performance (availability of funds, actors, and spaces) of dramas. After establishing this historical connection between theatre and violence in Spain, I address the intersection of the two institutions as observed in the works of contemporary Spanish playwrights. I divide my analysis of these dramas into three thematic sections, all of which pertain to terrorism: the representations of control, ideology, and alterity. Through my treatment of these plays, I argue that frequent interaction with violence and terrorism affects the individual and the cultural identity of those forced to experience it. Additionally, I propose that the playwrights in my study employ the theatrical genre as a form of violence itself in which to combat current societal norms and responses to violence, urging the public to “think outside the box” and find a new way to deal with the issues at hand. In other words, I suggest that terrorism, like other phenomena present in society, is a social construct; it is relative, and most importantly, it is not a fixed entity. Spanish identity does not have to “go hand in hand” with violence. It can change.

Keywords: Spain
terrorism
theatre
twentieth century
twenty-first century
violence
Advisor: Davidson, Robert
Examining Novel Factors that Influence Contact-dependent Osteoblast and Osteoclast Differentiation

A dynamic equilibrium between bone destruction by osteoclasts and bone formation by osteoblasts is responsible for the maintenance of bone integrity, mineral homeostasis and protection from bone-related disease. As such, the focus of this work was to examine novel factors contributing to the contact-dependent differentiation of osteoblasts and osteoclasts. Osteoblast differentiation and maturation is stimulated by multiple external factors, two of which are ascorbic acid (AA) and bone morphogenetic protein-2 (BMP-2). Utilizing MC3T3-E1 cells and primary murine osteoblasts, we identified a novel role for EB1, a microtubule plus-end binding protein, during osteoblast differentiation. AA-stimulation strongly induced EB1 expression and EB1 knockdown significantly impaired the osteoblast differentiation program in both AA- and BMP-2-induced osteoblasts. Furthermore, we identified that EB1 function was important for the global stability of -catenin, a major signaling molecule in osteoblasts. Lastly, the influence of E-cadherin, a cell-cell adhesion and recognition molecule, was investigated in AA-stimulated osteoblasts. Up-regulation of Cdh1 (E-cadherin) paralleled that of Catnb (beta-catenin), and E-cadherin blocking antibody treatment dampened osteoblast-specific gene expression. E-cadherin is also expressed in monocyte/macrophage cells, which are precursors to osteoclasts. Receptor activator of nuclear factor-ÎşB ligand (RANKL)-stimulated osteoclast differentiation involves a period of precursor expansion followed by multiple fusion events to generate a multinucleated osteoclast. Interestingly, our results indicated that E-cadherin participated in early precursor interaction/recognition rather than during periods of osteoclast fusion. In both RAW 264.7 cells and primary murine macrophages, E-cadherin expression and surface localization was highest during early osteoclast differentiation. Utilizing E-cadherin blocking antibodies prior to the onset of fusion delayed osteoclast-specific gene expression and significantly impaired multinucleated osteoclast formation. Long-term imaging revealed that blocking E-cadherin function prolonged the proliferative phase of the precursor population while concomitantly decreasing the proportion of migrating precursors; the lamellipodium and polarized membrane extensions were identified as principal sites of fusion, establishing migration as a requirement for osteoclast differentiation. This work characterizes EB1 and E-cadherin function during osteoblast differentiation and the E-cadherin-mediated transition from proliferative to migratory activities during osteoclast differentiation. Taken together, both studies highlight the value of exploring the early intra- and intercellular events that direct osteoblast and osteoclast differentiation.

Keywords: differentiation
EB1
E-cadherin
osteoblast
osteoclast
Advisor: Harrison, Rene E.