VictorJuiz/thesis huggingface dataset:
Liquid Jet in Crossflow at Elevated Temperatures and Pressures

An experimental study on the characterization of liquid jets injected into subsonic air crossflows is conducted. The aim of the study is to relate the droplet size and other attributes of the spray, such as breakup length, position, plume width, and time to flow parameters, including jet and air velocities, pressure and temperature as well as non-dimensional variables. Furthermore, multiple expressions are defined that would summarize the general behavior of the spray. For this purpose, an experimental setup is developed, which could withstand high temperatures and pressures to simulate conditions close to those experienced inside gas turbine engines. Images are captured using a laser based shadowgraphy system similar to a 2D PIV system. Image processing is extensively used to measure droplet size and boundaries of the spray. In total 209 different conditions are tested and over 72,000 images are captured and processed. The crossflow air temperatures are 25°C, 200°C, and 300°C; absolute crossflow air pressures are 2.1, 3.8, and 5.2 bars. Various liquid and gas velocities are tested for each given temperature and pressure in order to study the breakup mechanisms and regimes. Effects of dimensional and non-dimensional variables on droplet size are presented in detail. Several correlations for the mean droplet size, which are generated in this process, are presented. In addition, the influence of non-dimensional variables on the breakup length, time, plume area, angle, width and mean jet surface thickness are discussed and individual correlations are provided for each parameter. The influence of each individual parameter on the droplet sizes is discussed for a better understanding of the fragmentation process. Finally, new correlations for the centerline, windward and leeward trajectories are presented and compared to the previously reported correlations.

Keywords: Air
Crossflow
Droplet size
Jet
Liquid
Trajectory
Advisor: Ashgriz, Nasser
How Age, Linguistic Status, and the Nature of the Auditory Scene Alter the Manner in which Listening Comprehension is Achieved in Multi-talker Listening Situations

Conversations in noise challenge the perceptual and cognitive capabilities of older adults and those listening in their second language (L2), and might force them to alter the balance between the contributions of bottom-up versus top-down processes involved in spoken language comprehension. We investigated the extent to which individual differences in vocabulary and reading comprehension skills are related to individual differences in spoken language comprehension. In Experiments 1 and 2 younger and older L1s as well as young L2s listened to conversations in English played against a babble background and answered questions regarding their content. Individual hearing differences were compensated for by creating the same degree of difficulty in recognizing spoken words in babble. In Experiment, 1 two-talker conversations were played with or without either real or virtual spatial separation between the talkers and masker. The results showed that all listeners performed better when there appeared to be spatial separation. The contribution of vocabulary to dialogue comprehension was larger when spatial location was virtual rather than real, whereas the contribution of reading comprehension differed as a function of age and language proficiency. In Experiment 2, three-talker conversations, with or without spatial separation, were played in either quiet or against moderate or high babble. The contribution of individual differences in vocabulary and reading comprehension skills differed among the groups, and the babble level. In both experiments compensating for differences in spoken word recognition, minimized the differences in conversation comprehension among the groups. In addition, the manner in which spoken language comprehension is achieved is modulated by the auditory scene, and the listeners' age and linguistic status.Experiment 3 investigated how the perceived compactness of sound sources affects spoken language recognition. Younger L1s, older L1s and young L2s were asked to repeat meaningless sentences played in noise, babble or speech, either with or without contrast of diffuseness between target and masker. Results showed a release of masking due to contrast, which was greater when the masker was speech compared with noise. Individual differences in speech recognition were related to individual differences in vocabulary and reading comprehension in young L2s and older L1s only.

Keywords: aging
nonnative
second language
Speech comprehension
Speech recognition
Advisor: Schneider, Bruce A
The Organizational Context of Care Transition Interventions: Case Studies from Ontario

Patient safety and quality are compromised during transitions of care across settings. Interventions targeted at improving transitions have been developed and implemented widely. However these interventions have failed to consistently demonstrate measurable improvements. The literature suggests that context plays a role in mitigating the effectiveness of the interventions, however there are few studies that examine this in depth and disagreement around the best methods to do so.The promise - and disappointment - of care transition interventions has been seen in Ontario with the limited success of the interventions implemented. This thesis explores interaction of context and the intervention through three Ontario case studies.This thesis was informed by realist evaluation, which is concerned with understanding what contextual attributes inhibit or foster the success of interventions across settings. Case studies were developed using data gathered from 40 semi-structured key informant interviews, as well as observation and document review. Realist evaluation informed the research approach, and a framework was developed to guide data interpretation and analysis. The framework addresses a gap in the literature around which attributes of context are most important. The framework divides context into external factors (policy), organizational structural characteristics, teamwork and culture, and management tools. Analysis within, and across cases was conducted to discern similarities around the interaction of context and care transition interventions. Key findings are:Pilot project funding was a lever for introducing the interventions. However, pilot interventions did not address policy barriers, and developed parallel processes for transitions, with sustainability implications.Physician leadership was important, and facilitated by remuneration incentives. A significant physician role, however, crowded out other professionals traditionally involved in transitions of care. Interventions were facilitated by prior interorganizational relationships, either formal or informal. Boundary spanners, or previous collaborations facilitated relationships in an environment where policy barriers (e.g. privacy) inhibited collaboration around transitions.Interventions are change processes that require change management efforts and support for staff buy-in. The results of this study contribute to a better understanding of how context can facilitate or obstruct change processes, and desired outcomes associated with care transition interventions.

Keywords: care transitions
case studies
patient safety
realist evaluation
Advisor: Baker, G. Ross
Analyzing the Effects of Changing Global Trade Patterns on Domestic Freight Systems

Global trade patterns are continuously changing as economies and trade policies develop and interact. Recent developments and forecasts suggest changes in such patterns are likely to continue. Global trade patterns ultimately manifest themselves in freight flows on global and domestic transportation systems, but the translation of economic flows into transportation patterns is not straightforward. Moreover, while countries may benefit from global trade, the transportation impacts are felt locally, as passenger and freight movements compete for domestic infrastructure capacity.This thesis introduces a joint transportation and trade modelling framework to analyze the effects of changing global trade patterns on domestic freight operations. A unique multi-scale modelling framework confronts the notion that it is convenient but unrealistic to draw a geographic boundary around the economy and freight transportation system. Innovative harmonization, transformation, estimation, and optimization-based methods are developed to jointly model trade at the global, national, and regional levels. Multinomial logit (MNL) models are used to include the influence of transportation disutility in global trade choice behaviours, extending the multi-scale model into the domain of random-utility-based multi-regional input-output (RUBMRIO) models, which are first comprehensively introduced and reviewed.To demonstrate the feasibility of the proposed approach, a Canada-centric model was developed that includes forty-eight countries, Canada's ten provinces and three territories, and Ontario's eleven economic regions. Validation results show that it is possible to link spatial scales with a reasonable degree of accuracy. And while Canada's industrial outputs are the sum of its provincial and regional outputs, individual provinces and regions are not just microcosms of the larger country's behaviour. Example applications of food and paper product demand shocks from the United States, as well as doubling and halving of global transportation costs, demonstrate that the economic impacts from scenarios related to global trade and their implications for freight demand and traffic patterns differ for each province of Canada and region of Ontario.

Keywords: Freight
Global Trade
Infrastructure
Input-Output
Multi-Region
Transportation
Advisor: Roorda, Matthew J
Kennedy, Chris
In Vitro and In Vivo Regulation of Pro-inflammatory Cytokines and Drug Efflux Transporters by Signal Transduction Pathways in Glial Cells: Implications in HIV-1 Neuropathogenesis and its Treatment

Cognitive impairment remains highly prevalent in human immunodeficiency virus-1 (HIV-1) infected patients due to viral replication and associated brain inflammation. One obstacle to effective treatment is poor penetration of antiretroviral drugs across blood-brain barrier (BBB) and into HIV-1 brain cellular targets (microglia, astrocytes) due to functional expression of efflux transporters [P-glycoprotein (P-gp), Multidrug resistance-associated proteins (MRPs), breast cancer resistance protein (BCRP)]. Identifying therapeutic compounds that are not substrates of these transporters but target signaling pathways involved in inflammation may benefit treatment of HIV-associated neurological complications. The aim of this PhD project was: i) to investigate signaling pathways involved in the regulation of Mrp1 and P-gp in cultured rat/human astrocytes triggered with HIV-1 glycoprotein 120 (gp120) or cytokines, ii) to implement and characterize an in vivo model of gp120-associated brain inflammation, iii) to assess the efficacy of chloroquine, minocycline and simvastatin in reversing brain inflammation in vivo and iv) to elucidate key signaling pathways involved in gp120-associated brain inflammation in vivo. We demonstrated that gp120-associated TNF-α release resulted in increased Mrp1 functional expression in primary cultures of rat astrocytes and both c-jun N-terminal kinase (JNK) and nuclear factor-кB (NF-κB) pathways were involved. In human astrocytes, we demonstrated decreased P-gp expression following exposure to HIV-1/gp120/interleukin-6 (IL-6) and involvement of NF-kB signaling in P-gp downregulation. In our in vivo model, gp120 administration resulted in a significant increase in inflammatory markers in different brain regions and in cerebrospinal fluid (CSF). Administration of anti-inflammatory compounds partially or completely reduced upregulation of these markers. Activation of mitogen-activated protein kinases (MAPKs) was also observed both in vitro and in vivo which was attenuated by the anti-inflammatory compounds. Our data demonstrate that: i) gp120 generates an inflammatory response and alters expression of efflux transporters both in vitro and in vivo, in part, through an interaction with MAPK pathway and ii) anti-inflammatory agents could partially/completely reverse this response suggesting that they could serve as a promising novel therapeutic approach for HIV-1- associated brain inflammation.

Keywords: ABC transporters
Astrocytes
Brain barriers
HIV-1 gp120
Inflammation
Signaling pathways
Advisor: Bendayan, Reina
Restorative Peacemaking Circles and other Conflict Management Efforts in Three Ontario High Schools

Violence is pervasive in many schools, and current punitive conflict management approaches in schools tend to be ineffective and disproportionately harmful to marginalized students. Restorative peacemaking circles, also known as conferences, are an alternative for managing conflict designed to improve communication, help people resolve conflicts, and help repair and build relationships among individuals in schools (Morrison, 2007; Pranis, 2005). This thesis is based on theory that such relationship-building and dialogic conflict resolution practices will contribute to reductions in school violence. This qualitative, multiple-case study of the implementation and interpretation of restorative practices at three Ontario high schools analyzed student, teacher, and administrator interviews, school documents, and participant observations. Results indicate that interview participants perceived restorative peacemaking circles (and related peacemaking practices) to be inclusive and fair processes that helped to strengthen participating students' relationships with peers and adults, contributing to reducing violence. Key factors facilitating implementation of restorative peacemaking circles and peacebuilding approaches included leadership and committed staff, quality training, and implementing responsive and proactive practices. In two schools, external facilitation resulted in limited implementation of restorative practices. This reliance on external facilitators constitutes one way schools can implement restorative practices. However, external facilitation of restorative practices by only non-school staff depended on outside funding and expertise that could become unavailable at any time, without leaving behind in-school capacity. Conflict management policies in the three schools were largely constrained by a punitive regulatory framework (e.g., suspensions and expulsions), which limited these schools' adoption of restorative initiatives. Although theorists and researchers advocate whole-school proactive initiatives and conflict-learning opportunities for diverse students, sparse evidence indicated that only one (and, even less so, one other) of the three schools had implemented any proactive peacebuilding approaches. These school-based findings will help administrators, policymakers, and scholars understand how certain restorative practices can be feasibly implemented, and used to strengthen relationships (developing social capital) and reduce school violence.

Keywords: anti-violence
conflict resolution
peacemaking
restorative justice
restorative practices
social capital
Advisor: Bickmore, Kathy
The Impact of Dual Credit Programs on College Students: A Comparative Study of Dual Credit Participants and Non-dual Credit Participants in One Ontario College

Dual Credit Programs were introduced to the province of Ontario in 2005 as part of an educational reform initiative designed to help more students graduate high school and transition to college. The number of Ontario Dual Credit Programs has grown tremendously over the years but research has not kept pace with program expansion. This study was conducted to help fill that research gap. This study investigated the impact of Dual Credit Programs on college students by focusing on a group of students who participated in dual credit courses and activities and subsequent postsecondary programs at Humber Institute of Technology and Advanced Learning (Humber College) in Toronto, Ontario. The study also included a comparison group of non-dual credit participants who attended postsecondary education at the same institution and at the same time as the dual credit participants. Best described as a retrospective longitudinal study, this mixed methods research involved three data sources: college student records, college students, and college faculty. The data used in this study was derived from the student records, an online student survey, student interviews, and faculty interviews. College students who were previously enrolled in dual credit courses and comparators with no dual credit experience were found to differ in college preparation, college engagement, and college success but not college persistence. However, independent analyses of the college records of dual credit participants showed them to differ on college persistence depending on the number of dual credit courses they completed. The findings of this study have implications for policy and practice, theory development, and future research in the dual credit area.

Keywords: at-risk students
Credit-based Transition Program
Dual Credit
Dual Enrolment
high school to college transition
Ontario Dual Credit Program
Advisor: Dietsche, Peter
Assessment of Commercial Vehicle Emissions and Vehicle Routing of Fleets using Simulated Driving Cycles

Growing concern over greenhouse gas emissions has prompted research on identifying means to control and reduce these emissions. In transportation, vehicle emissions are strongly correlated with driver behaviour. Research relating driving behaviour with emissions uses driving cycles that are assumed to be constant regardless of vehicle type for a specific area. Using a single driving cycle, however, is simplistic for emission estimation purposes as there is significant variance in the driving behaviour of different vehicle types on various road types. In this research, microsimulation models are used to generate road and vehicle specific driving cycles to improve emission estimation. Typically, the calibration of microsimulation models are carried out using vehicle counts and average speed of vehicles. A genetic algorithm is used to show that calibrating these models against acceleration data in addition to average speed and vehicle count would provide a more accurate representation of driver behaviour. This claim is validated by comparing simulation results with observed values of different parameters related to driving behaviour. The model is then used to create improved driving cycles for various types of vehicles on different types of roads. Use of simulation allows data to be collected under consistent traffic conditions for all vehicle and road types. It is also shown that using simulated driving cycles produces emission factors that are closer to the observed compared to the average speed model. Finally, as a demonstration of the application of these driving cycles, a green routing problem has been used as a test case. The test case uses the developed driving cycles to optimize the routes of a hypothetical delivery company to minimize their emissions and costs under various circumstances incorporating the effect of vehicle load in estimating emissions. Results show statistically significant differences in total distance travelled, driving time, and CO2-eq emitted as the result of different minimization criteria of distance-, time-, and emissions optimal. It is also shown that by using the proposed approach, insightful analysis of emissions under various policies of cap-and-trade vs. carbon taxing can be conducted with good accuracy without requiring technology changes or other investments, which may be expensive.

Keywords: Cap and Trade
Driving cycle
Emission modelling
Microsimulation calibration
Vehicle routing problem
Advisor: Roorda, Matthew J.
French Harpsichord Music of the Enlightenment: A Study of Jacques Duphly and the Aesthetic Context of his Life and Work.

The middle part of the eighteenth century saw seismic shifts in philosophical and political thought. Closely related to these are a range of new aesthetic ideas and the musical styles associated with them. Instrumental music, and more specifically harpsichord music of mid-eighteenth-century France, has been surprisingly sparsely studied by musicologists and performers alike. While seventeenth- and early-eighteenth-century harpsichord composers and their works have been treated extensively, there is a definite lack of understanding and knowledge of the harpsichord music of the period following the death of François Couperin in 1733 and the publication around 1728 of Jean-Philippe Rameau's last book written for solo harpsichord, Nouvelles Suites de Pièces de Clavecin. The succeeding decades were marked by a significant aesthetic shift, induced and observed by both French and foreign musicians, composers, and philosophers. I argue that these aesthetic changes are also evident in harpsichord music and can be observed in Jacques Duphly's (1715-1789) four books of harpsichord music (1744, 1748, 1756, 1768), the focus of my research.Little information has been readily available regarding Duphly's life, and up until now, no serious contemporary study has focused on this subject. As part of this dissertation, I am providing a biographical account of Duphly, from his birth in Rouen to his life in Paris, and a chronological presentation of the contents of his books. Included in this presentation is a stylistic analysis of his works, a corpus that features the traditional French harpsichord style as well as elements that were both modern and foreign. Particular attention is given to explaining the aesthetic context of mid-eighteenth-century Paris and its relation to expression in instrumental music, including the concepts of mesure and mouvement. A comprehensive review of French temperaments completes this presentation of the instrumental context of the period. Examples drawn from Duphly's four books help illustrate how these temperaments as well as aesthetic and stylistic concepts can be understood and therefore used by musicians as part of a historically informed performance practice.

Keywords: Enlightenment
France
Harpsichord
Jacques Duphly
Performance practice
Temperaments
Advisor: Parker, Mary Ann