VictorJuiz/thesis huggingface dataset:
MODELING AND DESIGN OF A SMART DOUBLE-PANEL SYSTEM FOR THE CONTROL OF SOUND TRANSMISSION INTO AIRCRAFT CABIN

Nowadays, the level of interior cabin noise in modern aircraft has been reduced significantly compared with noise levels in the past because the double-panel design of aircraft sidewall systems has been much optimized. Furthermore, new composite materials are now used in the design of trim panels and additional sound absorption materials are also used in fuselage structures. However, this improvement in interior noise reductions is limited to mid-range and high-range frequencies (above about 1000 Hz). In fact, double-panel sidewall systems currently used in aircraft designs are ineffective at reducing low-frequency sound transmission (below about 1000 Hz). Furthermore, this problem is more likely to become much worse in the future because of the rapid progress in the manufacturing of aircraft with powerful jet engines and high speeds, which lead to increases in the exterior sound level and turbulent boundary layer vibrations. During flight, the exterior fuselage skin panel of an aircraft is subjected to incident acoustic waves with a broad range of frequencies. When the incident acoustic waves transmit through the airborne and structure-borne sound paths of the aircraft double-panel structure, sound energies with mid-range and high-range frequencies are largely absorbed by the passive noise control components, while low frequency sound waves transmit into the cabin trim panel without any attenuation. These acoustic waves vibrate the trim panel, causing sound power radiation from the panel into the aircraft cabin. The control of low frequency sound radiated power can be achieved by actively attenuating the structural vibrations of the trim panel using an effective active structural acoustic control (ASAC) method. This research presents the development and application of an effective methodology of an active structural acoustic control system for the reduction of low frequency sound transmission through an aircraft double-panel sidewall structure. The implementation of multi-input-multi-output (MIMO) controllers is used for the active control system, which electrically activates a set of novel high-performance piezoelectric actuator elements and velocity error sensors. The actuator elements are installed in the cavity between the fuselage skin panel and cabin trim panel, and arranged so as to generate out-of-plane control point forces acting on the trim panel. A set of velocity sensors is bonded on the inner surface of the trim panel to measure its structural velocities and predict its sound power radiation.

Keywords: active structural acoustic methods
control system
piezoelectric actuator
Smart Structures and Materials
Advisor: Behdinan, Kamran
AFGANTSY: THE SOCIAL, POLITICAL, AND CULTURAL LEGACY OF A FORGOTTEN GENERATION

Characterized by General Secretary Mikhail Gorbachev as a “bleeding wound,” the Soviet-Afghan War left a broad imprint on the domestic front during the Soviet Union’s transition from stagnation to dissolution. From the onset of war on 25 December 1979 to the 40th Army’s withdrawal on 15 February 1989, most Soviet officials spoke only of a Limited Contingent of Soviet Troops in Afghanistan that served its “international duty.” As a result, private narratives and popular myths about those at war – known as the afgantsy – circulated for years before the Politburo chose to assemble heroic icons from the fallen. By focusing on the afgantsy, this dissertation offers a case study in the mobilization of civil protest, popular interpretation of military conflict in times of war, and its translation into postwar culture. The Soviet-Afghan war filtered through a range of domestic avenues, from emerging grassroots organizations, to conferences aimed at reinforcing the state narrative, to popular cinema. When in the years of glasnost public debate on the war was authorized, the only uniform perception of the afgantsy that emerged was that they were wrongfully deployed by the Politburo. After the Soviet Union dissolved on 26 December 1991 this verdict became redundant for many, and the historicization of the Soviet-Afghan War became a challenge for 15 independent countries. This study explores the myriad ways in which the Afghan war made an imprint on everyday life in the Soviet Union through the incorporation of a broad range of sources. These include but are not limited to recently declassified archival materials, oral history interviews, memoirs, films, and a vast range of publications that have been made accessible in the online world. More than 20 interviews were conducted, the majority of which were with afgantsy, but included soldiers’ mothers, widows, and veterans of other armed conflicts. Archival research took place at a variety of locales, among them the State Archive of the Russian Federation and the International Archive of Memorial in Moscow; the Central State Archive of Political Documentation of the Kyrgyz Republic in Bishkek; and the State Archive of the Security Service of Ukraine in Kiev.

Keywords: Afghanistan
Cold War
Post-Soviet studies
Soviet-Afghan War
Soviet Union
Veterans
Advisor: Viola, Lynne
Spacecraft Formation Approach to Asteroid Redirection for Resource Utilization

In this thesis, an overall framework is established for the redirection of near-Earth asteroids using spacecraft formation strategies in order to access and utilize asteroid resources. The framework is parsed into three critical areas of research, namely, redirection methods, trajectory transfer, and formation design and control. Additionally, research into the application of asteroid redirection methods to the related area of space debris removal is discussed. In the area of redirection methods, in-depth analyses and systematic comparisons are conducted. The performance of each method is evaluated through several multicriteria assessment techniques and Monte Carlo analysis is used to quantify the uncertainty intrinsic to the asteroid population. The redirection methods are evaluated with respect to their suitability for spacecraft formation. The trajectory transfer research focuses on the study of Arjuna-type asteroids, which are considered excellent targets for redirection missions. The research can be divided into two main studies using low-thrust methods: i) an assessment of the Arjuna domain, and ii) an approach to optimal three-dimensional transfer trajectory design. The first study investigates the feasibility of transferring an Arjuna-type asteroid using a minimized form of Gauss’s variational equations, spacecraft sizing metrics, and mission cost analysis formulae. The second study outlines the design of a stochastic optimization approach to three-dimensional asteroid transfer from its initial orbit to an orbit in the Earth-Moon system. The research employs pseudo-equinoctial exponential shaping to design the transfer trajectory and quantifies the uncertainty in asteroid parameters through Monte Carlo analysis. In the area of formation design and control, the thesis develops an optimal approach to asteroid redirection using landed thruster formations. First, the mission design for a landed formation of spacecraft is analysed and optimized from the perspective of resource utilization. Secondly, a method for determining the landing locations and thruster orientations for time-optimal detumbling of an asteroid using a landed formation of spacecraft is formulated. The method models the asteroid as a high resolution convex polyhedra, determines feasible landing locations and thrust directions, and optimizes a spacecraft formation to minimize detumbling time while ensuring full control. Through systematically presenting work in these three areas, this research helps set the groundwork for future researchers, corporations, and government agencies to seize the opportunities provided by asteroid resources.

Keywords: Asteroid Redirection
Formation Control
Orbital Dynamics
Spacecraft Formation
Space Debris
Transfer Trajectory Design
Advisor: Emami, M. Reza
Navigating Equity Through Governance: A Case Study of Micropolitical Equity Work Among School Board Trustees

ABSTRACT This study explores how trustees utilize their positions to create equitable conditions within a school district. Using a critical conceptual framework informed by policy analysis, I draw conclusions regarding the relationship between trustees’ understanding of equity and how they use power and influence at micro, meso and macro levels to affect policy. First, interviews were conducted with five retired trustees within a school district and with follow-up interviews with personnel identified by the trustees as knowing their work. Second, an analysis of policy statements and school board minutes was undertaken to examine the extent to which trustees’ understanding of equity influenced school board direction and impacted equity outcomes. Third, after all the data were collected, themes were identified for analysis and coding. The resulting thesis examines the way school district leadership functions in regards to equity. Findings indicate that with the reduction of positional power within their role, trustees are utilizing personal influence in order to affect change. This study examines the impact of this power shift in relation to the following areas: trustee and equitable hiring practices; the role of trustees in policy development; and the ability of trustees to act as a representative for their constituents in a racially and culturally diverse school board. As a result of this shift to using influence rather than the authority of their position, equitable outcomes were related to individual trustee longevity in the role, their personal preconceptions and the amount of cultural diversity within the board of trustees. This study also identifies ways in which those who seek organizational change encounter resistance.

Keywords: equity
governance
micropolitics
Ontario
strategies
trustees
Advisor: Bascia, Nina
The regulation of tissue n-acylethanolamine and arachidonoylglycerol concentrations by diet, ischemia, n-acyl phosphatidylethanolamine-specific phospholipase D and fatty acid amide hydrolase

Dietary fatty acids (DFAs) can modulate levels of n-acylethanolamines (NAEs) and arachidonoylglycerols (AGs) via the synthetic enzyme, n-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) and degradation enzyme, fatty acid amide hydrolase (FAAH). However, other parallel pathways maybe also involved. This research hypothesizes that the absence of NAPE-PLD will lower tissue NAEs; while the absence of FAAH will increase NAEs. Also, basal NAE and AG levels are lower than ischemia-induced levels, while DFA can modulate basal NAE levels. In study 1, wild-type (C57BL/6), NAPE-PLD (-/+) and NAPE-PLD (-/-) mice were fed AIN-93G diets enriched with beef tallow, canola oil, corn oil or fish oil for nine weeks then killed by microwave fixation. Results showed that NAPE-PLD (-/-) had lower levels of plasma and jejunum oleoylethanolamide (OEA), lower food intake, body weight, and body fat composition than wild-type. Also, corn oil diet elevated arachidonoylethanolamide (AEA) and AGs; while fish oil elevated docosahexaenoylethanolamide (DHEA) in all genotypes. Therefore, NAPE-PLD is specific to OEA, but not other NAE, which may play a role in regulating body composition and weight management. Also, DFA can still elevate NAE levels without NAPE-PLD suggesting it is not necessary for dietary increased NAEs. In study 2, wild-type and FAAH-KO mice were fed a standard chow diet for 9 weeks; then killed by control (microwave fixation) or partial CO2-induced ischemia or CO2-induced ischemia. Brain NAE levels were higher in the FAAH-KO than the wild-type. Interestingly, CO2-induced ischemia increased all NAEs and AGs in the wild-type mice, but only DHEA was increased in the FAAH-KO mice. Thus, FAAH may play an essential role in regulating lipid metabolism in response to ischemia. In conclusion, this work provides evidence that diet, NAPE-PLD, FAAH and ischemia are independently involved in maintaining tissue NAE levels.

Keywords: diets
endocannabinoids
fatty acids
metabolism
mice
Advisor: Bazinet, Richard P
Lateral Diffusion of Phospholipids Measured Using 31P Solid State CODEX NMR

Lateral diffusion of phospholipids is a process essential to membrane function, and its accurate determination can provide insights into the kinetics of many membrane-associated biochemical reactions. This thesis focuses on using 31P CODEX NMR to measure phospholipid lateral diffusion. A powder-average model was developed to extract phospholipid lateral diffusion coefficients from 31P CODEX NMR data, starting with theory, numerical simulations, and finally experimental data fitting. The synthesis of large, unilamellar vesicles and the CODEX experiment were both optimized for this type of measurement. This method was demonstrated to provide lateral diffusion coefficients for phospholipids in both liquid-crystalline and gel phases consistent with established literature values. This model was then used to probe electrostatic interactions between the cationic polyelectrolyte poly-lysine and various anionic phospholipids. Each species of phospholipid will have a different phosphate head group, which will appear as separate narrow resonances in a 31P CODEX spectrum. This property allows for simultaneous monitoring of each diffusing species and a simple measurement of any selectivity in the electrostatic interactions. The addition of poly-lysine to anionic liposomes proved to have a minimal effect in liposomes composed of POPG, DOPS, and TOCL, but created electrostatically-induced domains in liposomes containing DOPA. This method could prove useful in studying other electrostatic interactions between the membrane bilayer and surface-binding proteins or drugs. Lastly, the membrane-disrupting mechanism of an antimicrobial peptide KL-14 was examined. Permeability assays were conducted to probe KL-14's efficacy in various membrane compositions. Phospholipid selectivity was also investigated using 31P static and 31P CODEX NMR under MAS. In conjunction, these studies can create a more complete mechanism for this class of peptide. Three of the main types of membrane-disrupting mechanisms for this type of peptide in literature were eliminated based on experimental data, namely the barrel-stave, toroidal pore, and aggregate models. The carpet model is the remaining prevalent proposed model and could not be completely ruled out based on the data obtained in these studies, and thus remains a possibility. A better understanding of how antimicrobial peptides cause membrane disruption will aid in better rational design of therapeutics in combating the rise of antibiotic resistance.

Keywords: antimicrobial peptide
CODEX NMR
lateral diffusion
liposome
membrane
poly lysine
Advisor: Macdonald, Peter M
Multiliteracies in the Context of a Sister Class Project: Pursuing New Possibilities in Second Language Education

Despite the persistence of traditional print-based curriculum in many contexts, the growing influence of information and communication technologies (ICTs) is gradually reshaping literacy practices and literacy education in the direction of a multiliteracies approach. The research study explored the impact of a Sister Class Project that connected two classes of Grade 7 students from Canada and Hong Kong with respect to the extent to which this Internet-mediated intercultural exchange facilitated multiliteracies pedagogy. The project investigated how English language learners (ELL) in two different cities might benefit from an online learning network that enabled them to collaborate with distant partners in carrying out academic projects, learning through multiple literacy practices, and generating knowledge together. It also explored the potentials of ICTs to support ELL students in creating identity texts, which are described as innovative works produced by students who draw on their prior experiences, cultural knowledge and linguistic resources to invest their identities in and take full control of their own learning. Consequently, the project hoped to find the extent to which a new literacy approach could create contexts of empowerment to enable these students to succeed academically. The study demonstrated that the creation of identity texts could effectively promote ELL students’ learning motivation, collaborative learning, critical thinking, literacy and academic development, and identity formation. It opened up new opportunities for pedagogical changes and knowledge generation by students. The following pedagogical conclusions are proposed based on the findings: 1) Literacy instruction should scaffold learners’ previous knowledge to support academic learning; 2) Literacy instruction should provide learners with meaningful comprehensible input to support academic production; 3) Literacy instruction should affirm learners’ intellectual, cultural and personal identities in academic and social settings; 4) Literacy instruction should enable learners to deepen and extend their understanding of academic content and the target language across the curriculum; 5) Literacy instruction should engage learners in active, multiple literacy practices, in both L1 and L2, to ensure optimal academic progress.

Keywords: Culture and Identity
Literacy teaching and learning
Multiliteracies
Second language education
Sister Class Project
Advisor: Cummins, Jim
Inverse treatment planning for radiofrequency ablation

Radiofrequency ablation (RFA) offers localized and minimally invasive thermal ablation of small-to-medium sized inoperable superficial tumors. In RFA, needles are inserted into the target with image guidance and current is passed through the needles, resulting in high temperatures and consequently target ablation. However, RFA has a high local recurrence rate caused by incomplete ablation. We therefore develop a novel two-stage mathematical framework for pre-operative inverse treatment planning where first, we identify needle positions and orientations using convex and integer programming techniques, referred to as needle orientation optimization (NOO), and then we determine the optimal thermal dose delivery for full target coverage by computing simultaneous thermal and electrostatic partial differential equations, referred to as thermal dose optimization (TDO). In NOO, different methodologies using geometric approximations for needle placement with and without trajectory considerations for single, multiple, and clustered RFA applicators are presented. Using outputs from NOO, in TDO, we perform thermal dose analysis, using several thermal damage models, for targets and organs-at-risk (OARs). Finally, we present scenario-based thermal damage analysis to understand the effect of translational and rotational needle deflection on target and OAR coverage. We test our framework on three clinical cases with four different margins, for a total of 12 targets. Our methodologies provide fast treatment plans that meet clinical guidelines, and our deflection analysis indicates that, depending on thermal damage model used, uncertain needle placement may significantly impede target coverage, and therefore, clinical study into causes of deflection are recommended.

Keywords: bioheat transfer equation
cancer therapy
convex programing
integer programing
inverse planning
radiofrequency ablation
Advisor: Aleman, Dionne M
A Conductor’s Guide to Lyric Diction in Standard Chinese

Chinese choral music is a relatively recent phenomenon. Within the last century, Chinese conductors and choral ensembles have actively fostered a vibrant choral community. Furthermore, Chinese composers have taken increasing interest in the choral art, resulting in a growing body of new choral repertoire. Contemporary Chinese choral music adopts western choral approaches such as voice parts (SATB), style (bel canto), harmony and structure, but retains Chinese texts. In order to introduce Chinese choral art music to English-speaking choirs, conductors must be equipped with good resources to deepen their understanding of the choral culture in China. More importantly, they need supportive materials to help them tackle the challenges of the language. Currently there are few guides to lyric diction in Standard Chinese for singers and choral conductors. The primary goal of this study is to break down the complexity of the pronunciation of this language, using the International Phonetic Alphabet (IPA) and Pinyin systems, to provide a helpful guide to conductors in teaching Chinese choral music. A secondary goal is to introduce choral musicians to contemporary Chinese choral music. In addition to outlining the history of choral music in China, this study also includes analyses of five original compositions written within the last decade, in order to provide examples of original choral works in Standard Chinese written by Chinese composers from different geographical backgrounds: Hong Kong, China, the United States, and Canada. These analyses are supplemented with the composers’ biographies, program notes, and analytical information that may be helpful for pedagogical purposes. Through my research, I seek to champion interest in this sub-genre of music that is otherwise not well known currently in North America, both by providing a guide to teaching lyric diction in Chinese and by promoting original compositions written by modern Chinese composers.

Keywords: Choir
Choral
Conductor's Guide
Lyric Diction
Mandarin
Standard Chinese
Advisor: Apfelstadt, Hilary J
Yeast Two-Hybrid is an Effective Platform for the Discovery of Novel Inhibitors of Human Deubiquitinases

Deubiquitinating enzymes represent attractive therapeutic targets that can be leveraged towards the treatment of a variety of devastating human health disorders. This doctoral thesis recounts the establishment of the well-studied yeast two-hybrid assay as a novel platform for the discovery of ubiquitin variant inhibitors of human Deubiquitinases. Furthermore, I show that ubiquitin variants isolated against the deubiquitinase USP2 in yeast are capable of binding and inhibiting USP2 function in human cells. Taken together, the work described in this thesis highlights the potential of the two-hybrid system to serve as a method to alleviate a formidable bottle-neck that currently obstructs the development of ubiquitin variants and, in conjunction with currently available in vitro screening methods, offers a platform for the discovery of novel inhibitors against human deubiquitinases.

Keywords: Biologics
DUBs
Ubiquitin
Yeast
Advisor: Boone, Charles
Sidhu, Sachdev