VictorJuiz/thesis huggingface dataset:
Enhancing Anaerobic Digestion of Pulp and Paper Mill Biosludge using Thermal Treatment in a Bench-scale System

Enhancing Anaerobic Digestion of Pulp and Paper Mill Biosludge Using Thermal Treatment in a Bench-Scale System Masters of Applied Science 2015 Xian Meng Huang Department of Chemical Engineering and Applied Chemistry, University of Toronto This study examines the feasibility of using a bench-scale anaerobic digestion (AD) system to treat pulp and paper mill biosludge. Three thermal treatment methods were studied: pre-treatment, intermediate treatment and post treatment. Thermal pre-treatment of biosludge resulted in overloading of the bench-scale reactor, causing the pH to drop significantly; this in turn caused reactor acidification. Intermediate thermal treatment of digestate had a positive impact on the digestibility of the biosludge; the specific methane yield increased by 76% and 29% in two separate bench-scale experiments. Post-treatment of digestate followed by further digestion was studied in BMP tests, and it was determined that the final specific methane yield increased by 43%. Overall, anaerobic digestion of pulp and paper mill biosludge has been proven to be successful at the bench-scale level, and thermal post-treatment methods have been shown to be effective at enhancing the digestibility of the biosludge.

Keywords: Anaerobic Digestion
Biogas
Biosludge
Pulp and paper
Waste activated sludge
Advisor: Allen, D. Grant
Edwards, Elizabeth A
Pore Network Modeling of Multiphase Transport in Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers

In this thesis, pore network modeling was used to study how the microstructure of the polymer electrolyte membrane (PEM) fuel cell gas diffusion layer (GDL) influences multiphase transport within the composite layer. An equivalent pore network of a GDL was used to study the effects of GDL/catalyst layer condensation points and contact quality on the spatial distribution of liquid water in the GDL. Next, pore networks extracted from synchrotron-based micro-computed tomography images of compressed GDLs were employed to simulate liquid water transport in GDL materials over a range of compression pressures, and favorable GDL compression values for preferred liquid water distributions were found for two commercially available GDL materials. Finally, a technique was developed for calculating the oxygen diffusivity in carbon paper substrates with a microporous layer (MPL) coating through pore network modeling. A hybrid network was incorporated into the pore network model, and effective diffusivity predictions of MPL coated GDL materials were obtained.

Keywords: Gas diffusion layer
Invasion percolation
Micro-computed tomography
Microporous layer
PEM fuel cell
Pore network modeling
Advisor: Bazylak, Aimy
Supporting Student Grief: The Attitudes and Beliefs of Residence Life Professionals when Responding to Student Bereavement

Roughly one quarter of university students in North America experienced the death of a friend or family member within the last year. However, many universities do not have systems to support bereaved students. This study examines Residence Life professionals’ (RLPs’) attitudes and beliefs when responding to student grief. Twelve experienced RLPs representing 11 university campuses in Ontario were interviewed. The participants were given a hypothetical scenario in which a student who was living in residence had died. The participants answered questions about how they would respond to the physical, emotional, behavioural, interpersonal, cognitive, and spiritual impacts of grief. Ten of the 12 RLPs interviewed had been directly involved in supporting grieving students after a student’s death on their campus. The participants described how they would support students, however, most indicated that they have not received training on student bereavement, nor was training offered at their institution.

Keywords: Canada
grief
higher education
residence
student death
student services
Advisor: Childs, Ruth
Sexual Rejection in Romantic Relationships: Development, Validation, and Application of the Sexual Rejection Scale

The current research investigated, for the first time, the different ways people reject their partner for sex through the development and validation of the Sexual Rejection Scale (Studies 1 and 2). A four-factor model of sexual rejection emerged consisting of four primary sexual rejection behaviors, labelled hostile, reassuring, deflecting, and assertive. In line with past work on relationship conflict behaviors, these four behaviors differed in terms of valence and directness. Studies 3 and 4 investigated how different sexual rejection behaviors are linked with relationship and sexual satisfaction. Reassuring rejection behaviors were associated with greater satisfaction, whereas hostile behaviors predicted lower satisfaction. Results for assertive and deflecting behaviors were mixed, and interaction analyses further suggested that the consequences of direct and indirect behaviors are qualified by positive and negative valence. Implications are discussed for the use of distinct sexual rejection behaviors in navigating situations of desire discrepancy in romantic relationships.

Advisor: Impett, Emily A
Modelling of Transit Reliability and Speed using AVL Data in the City of Toronto

The objective of this study is developing mathematical models to explain the relationships between transit reliability and speed and a variety of factors, including but not limited to service characteristics of bus lines, physical infrastructures, signal timings, traffic conditions and ridership, by using AVL data of bus lines that are representative of the entire bus network in the City of Toronto with special focus on examining the effect of transit signal priority (TSP). The coefficient of variation of run time is used as the indicator of transit reliability. The modelling results of linear regression at route and segment level suggest that the increase of service distance, signalized intersection density, stop density, volume of boarding and alighting passengers and vehicle volume significantly reduces both transit reliability and speed. TSP, involved as an independent variable in the segment level analysis, demonstrates beneficial influence on improving transit reliability and speed.

Keywords: AVL data
regression analysis
transit reliability
transit speed
Advisor: Shalaby, Amer
High Performance MoxN Electrode Fabricated by Solution Precursor Plasma Spraying

Changing climate and decreasing availability of fossil fuels stimulate the use of alternative energy sources and energy storage devices such as electrochemical capacitors The current study investigates the implementation of SPPS (Solution Precursor Plasma Spraying) for the deposition of high surface area electrochemical capacitor electrodes. A high performance MoxN electrochemical capacitor electrode was produced by solution precursor plasma spraying for the first time. The best electrode exhibited an initial capacitance of 62.4 mF cm-2 at a scan rate of 100 mV sec-1. The capacitance decreased by 22% after the first 1000 cycles, but the performance then stabilized, decreasing by only 0.15% over cycles 4000 to 5000 and exhibiting a capacitance of 30mF cm-2 after 5000 cycles. SPPS is a novel deposition method, thus further understanding and optimization of the process is required to improve the performance and manufacturability, but a clear potential was proven.

Advisor: Coyle, Thomas W
Inositol Polyphosphate 4-Phosphatase Type II Contributes to Chemotherapy Resistance in Acute Myeloid Leukemia

Inositol polyphosphate 4-phosphatase type II (INPP4B) is a lipid phosphatase with diverse roles in select human cancers. It has yet to be comprehensively studied in the context of acute myeloid leukemia (AML). This investigation reports an association between overexpression of INPP4B in myeloid cell lines and resistance to DNA damaging agents. Clinical observations showed that high INPP4B expression in peripheral blood was associated with poor response to induction chemotherapy in AML patients (n=279). In vitro, AML cell lines overexpressing INPP4B exhibited reduced sensitivity and decreased apoptosis after exposure to daunorubicin chemotherapy and ionizing radiation. Preliminary evidence suggests INPP4B overexpression may confer increased redox metabolism in AML cells in vitro. Immunoblotting of a newly generated daunorubicin-resistant OCI/AML-3 cell line identified a distinct change in INPP4B-specific antibody binding compared to its parent line. In summary, INPP4B overexpression may serve as a putative clinical biomarker for intrinsic resistance to induction therapy in AML.

Keywords: AML
Chemotherapy
Daunorubicin
INPP4B
Leukemia
Resistance
Advisor: Minden, Mark D
The Effect of Omega-3 Polyunsaturated Fatty Acids on Growth and microRNA-21 Expression in Estrogen Receptor-positive Breast Cancer Cells (MCF-7)

Targeted, effective and safe therapies for breast cancer are lacking and many are turning towards complementary therapies, such as FS oil (FSO) and fish oil (FO). Interest surrounding the role of microRNA (miR) in breast cancer has piqued over the last decade, and the interaction between miR and dietary factors is emerging. This thesis examined the role of α-linolenic acid (ALA) alone or combined with eicosapentaenoic acid (EPA) and docoashexaenoic acid (DHA) at ratios seen in the serum post-FSO consumption on cell growth, miR-21 expression and molecular targets of miR-21 in estrogen receptor-positive breast cancer (MCF-7) cells. A reduction in cell growth and miR-21 expression was observed following fatty acid treatment of varying incubation times. Bcl-2 gene is one molecular target of miR-21 that was reduced by the fatty acid treatment. In conclusion, ALA alone or combined with EPA and DHA can reduce cell growth and miR-21 expression.

Keywords: Breast cancer
Cell growth
Gene expression
microRNA
Omega 3 fatty acids
Protein biomarker
Advisor: Thompson, Lilian U
Comelli, Elena M
Separate and Combined Representations of Positivity and Negativity in the Nucleus Accumbens

Reward and punishment signals in the brain are represented in many brain areas, such as the nucleus accumbens (NAcc), which has been found to encode aspects of positivity and negativity using functional magnetic resonance imaging (fMRI). Animal neuron-recording studies also suggest that the ventral striatum has multiple representations of rewards and punishments, however fMRI studies do not have the adequate resolution to provide convincing evidence of this differentiation. Using representational similarity analysis (RSA), we aimed to find separate representations of positives and negatives in the NAcc. We found valence-general voxels that did not have distinct patterns for gains and losses, as well as voxels that represented positive outcomes separate from negative outcomes. Future directions include whole brain analysis to examine areas such as the orbitofrontal cortex and amygdala, which have been suggested in both animal and human literature to have multiple representations for reward and punishment.

Keywords: Functional Magnetic Resonance Imaging
Nucleus Accumbens
Reinforcement Learning
Representational Similarity Analysis
Reward
Advisor: Cunningham, William A
Mechanical Aspects of Design, Analysis, and Testing for the NORSAT-1 Microsatellite

NORSAT-1 is a multi-payload microsatellite mission funded by the Norwegian Space Center, with three overall objectives: investigating solar radiation, space plasma research, and developing improved methods for detection and management of ship traffic. The successful development of the NORSAT-1 platform aims to lay the groundwork for additional low-cost microsatellites in the NORSAT series, and expand the Norwegian presence in space and space-based ship tracking technologies. This thesis provides some insight into the NORSAT-1 satellite platform design, and focuses heavily on the mechanical aspects of design, analysis, and testing. The structural design is detailed from the early conceptual design phases, and follows the development to the manufacturing, integration, and testing of the flight spacecraft. Validation of the design through finite element modeling is presented, along with the development and design of two honeycomb composite solar panels, and two deployable whip antennas.

Keywords: Aerospace
Design
Microsatellite
NORSAT
Satellite
Structural
Advisor: Zee, Robert E
Pharmacist Immunizers: An Analysis of their Experiences and Perceptions of Pain

OBJECTIVES: In 2012, Ontario pharmacists were granted immunization privileges for administering influenza vaccines to the public. This study explored the experiences and practices of pharmacist immunizers and the impact of immunization pain on their practice. METHOD:Semi-structured interviews were conducted with 12 pharmacists in the Greater Toronto Area. Transcribed interview data were coded and analyzed via thematic analysis. RESULTS: Pharmacists felt satisfied in their new role, despite the associated increased workload. Pharmacists felt that immunization pain was not akey consideration when administering vaccines and that pain management was not necessary. Fear was identified as more important than pain and vaccinating children was challenging and time intensive. Pharmacists’ main focus was on injection techniques when asked how they minimize pain. CONCLUSION:These findings suggest that pharmacists are accepting of their role as immunizers. More research is needed to examine impact on workload and patient satisfaction.

Keywords: Experiences
Immunizations
Interviews
Pain Management
Qualitative
Advisor: Taddio, Anna
Separating Patterns of Space and Time: Differences in Memory for Event Duration and Sequential Order

Our memories are temporally organized. However, little is known about how the duration of individual events is encoded in episodic memory. We used a virtual reality navigation paradigm where periods of navigation were interspersed with pauses of different durations. In Experiment 1, we show that the active experience of the passage of time selectively enhanced memory for duration, with no effect on memory for the temporal sequence of events. In Experiment 2, we show that active navigation interspersed with passive waiting did not result in a similar enhancement of temporal memory. Crucially, in both studies participants were able to reliably distinguish the durations of subjectively re-experienced events, but not familiar ones. This effect was unique to duration. We posit that time is represented in episodic memory in a manner akin to space, and that the hippocampally-supported ability to recollect an event enables the reinstantiation of its temporal and spatial context.

Keywords: Episodic memory
Hippocampus
Spatial navigation
Temporal order
Temporal perception
Advisor: Moscovitch, Morris
Barense, Morgan D
Illustration-inspired Visualization of Blood Flow Dynamics

Image-based computational fluid dynamics is an invaluable tool in the study and evaluation of hemodynamic factors involved in cardiovascular disease. Simulating blood flow inside a patient-specific model provides an understanding of the blood's complex behaviour without resorting to risky invasive procedures. However, detailed hemodynamic data can be difficult to present clearly using conventional flow visualization techniques. Many approaches use single snapshots in time which fail to capture the time-varying qualities of the flow dynamics; and animations retain temporal information but are constrained to a single point of view. To address these concerns, we took cues from illustration and comics to explore data-driven paradigms for visualizing blood flow. We programmatically reproduced illustrative techniques using modern computer graphics capabilities and computer vision-inspired feature-tracking algorithms. The culmination of this work produced an interactive web-based tool that allows users to explore the hemodynamics of cerebral aneurysms in a unique, immediate, and novel way.

Keywords: computational fluid dynamics
feature-tracking
hemodynamics
illustration-inspired
visualization
Advisor: Steinman, David A
Coppin, Peter
User-centred Perspectives in the Design of Innovative Technologies to Promote Physical Activity in Young People with Physical Disabilities

Background: Social support networks facilitated by technologies may be one way of addressing young people with physical disabilities' low physical activity levels. Objective: To explore the perceived benefits and impact of social networks on physical activity in young people with physical disabilities, and to identify design considerations when creating social technologies to support physical activity. Method: A 2-stage, iterative design included individual interviews and group design workshops with eleven young people aged 12 to 18 with physical disabilities. Results: Supportive environments for physical activity included those that promote fair and equitable participation, belonging through teamwork, and opportunities for interdependence. Participants perceived some benefits to using social technology for physical activity, provided it is tailored to suit their needs and abilities. Conclusions: This study contributes user-generated design recommendations for social technologies to promote physical activity in young people with physical disabilities that align with principles of inclusive design and self-determination theory.

Keywords: Health promotion
Physical activity
Rehabilitation
Social support
Social technology
Young people
Advisor: Biddiss, Elaine
McPherson, Amy
Enabling Interposer-based Disintegration of Multi-Core Processors

Silicon interposers enable high-performance processors to integrate a significant amount of in-package memory, thereby providing huge bandwidth gains while reducing the costs of accessing memory. Once the price has been paid for the interposer, there are new opportunities to exploit it and provide other system benefits. We consider how the routing resources afforded by the interposer can be used to improve the network-on-chip’s (NoC) capabilities and use the interposer to “disintegrate” a multi-core chip into smaller chips that individually and collectively cost less to manufacture than a large monolithic chip. However, distributing a system across many pieces of silicon causes the overall NoC to become fragmented, thereby decreasing performance as core-to-core communications between different chips must now be routed through the interposer. We study the performance-cost trade-offs of implementing an interposer-based, multi-chip, multi-core system and propose new interposer NoC organizations to mitigate the performance challenges while preserving the cost benefits.

Keywords: Computer Architecture
Network on Chip
Advisor: Enright Jerger, Natalie
MRI Based Quantification Of Cerebrovascular Health In Pediatric Subjects With Sickle Cell Disease

Sickle cell disease is a lifelong genetic disorder of the erythrocytes characterized by the sickling of deoxygenated hemoglobin. As a result of the sickling, children with SCD suffer from many different complications such as poor cerebrovascular health, vasculopathies and stroke. Using MR, we can quantify the degree of cerebrovascular health impairment with cerebrovascular reactivity. It was seen that children with SCD had significantly reduced CVR both regionally and globally which was then seen to be correlated with regional measures of cortical thickness. From this study, it was observed that regional deficits in cerebrovascular health are related to regional cortical thinning. Furthermore, previous studies have demonstrated impaired vasculature in patients with obstructive sleep apnea (OSA) which occurs at a high rate in SCD. Therefore, CVR was measured in SCD patients with OSA and compared against SCD patients with no-OSA to determine the effect of OSA in children with SCD.

Keywords: cerebrovascular reactivity
cortical thickness
magnetic resonance imaging
sickle cell disease
Advisor: Kassner, Andrea
“We Exist. We’re Not Just Some Fairytale in a Book”: Migration Narratives of LGBTQ2S Aboriginal People in Toronto

Over the past 60 years, the urban Aboriginal population in Canada has increased by almost 700 percent. Toronto’s population is no different; from 2001 to 2011, the Aboriginal population in Toronto grew by 87 percent. While it has been suggested that there is a high rate of Aboriginal mobility between reserves and cities, there are few qualitative studies that examine experiences of migration. Within that, little attention has been paid to narratives of Aboriginal people who are marginalized within this already marginalized community, such as the LGBTQ and two-spirited (LGBTQ2S) population. Utilizing Indigenous methodologies and a critical population health theoretical framework, semi-structured interviews were conducted with twenty-two LGBTQ2S migrants to understand urban transition narratives. The findings suggest that LGBTQ2S migrants have unique migration narratives based on their intersectional identities, which contribute to new challenges accessing housing, employment, culture, and services for this particular population.

Keywords: Aboriginal people
Canada
LGBTQ2S
migration
Toronto
Advisor: Wilson, Kathi
Modelling of Alkali-aggregate Reaction Effects in Reinforced Concrete Structures

Significant research has been performed worldwide on alkali-aggregate reaction (AAR) since its first deleterious effects on concrete structures were identified 75 years ago. According to the CSA A864-00, conventional methods become invalid for the structural assessment of AAR-affected members due to the induced anisotropy with regards to the mechanical properties of concrete. As such, there is a need for proper analysis tools to investigate the behaviour of an AAR-affected structure, and assist in identifying possible rehabilitation actions. The VecTor suite of nonlinear finite element programs, developed at the University of Toronto for the analysis of reinforced concrete structures, can be developed into such a tool. The work performed in this thesis is directed towards modifying the algorithms of VecTor2 and VecTor3 for the analysis of AAR-affected structures, as part of a comprehensive study initiated and funded by the Canadian Nuclear Safety Commission.

Keywords: alkali-aggregate reaction
finite element analysis
modelling
simulation
Advisor: Vecchio, Frank J
Measuring the Magnitude of Oral Health Inequalities within and between Canada and the United States from 1970 to 2009

Objectives: To compare the magnitude of, and contributors to, income-related inequalities in oral health outcomes within and between Canada and the United States over time. Methods: The Concentration Index (CI) was used to estimate income-related oral health inequalities from two Canadian and two American cross-sectional surveys, and decomposed to determine the potential contributors to inequalities. Results: Pro-poor inequalities were observed in oral disease outcomes and pro-rich inequalities in oral health outcomes, with greater magnitude in the United States. Decreases in inequalities for edentulism and increases in decayed teeth were observed in both countries over time. Inequalities in filled teeth decreased in the United States and increased in Canada. Socioeconomic characteristics contributed greater to inequalities than demographic characteristics, with greater contributions of income over time. Conclusions: Oral health inequalities have persisted over time in Canada and the United States and are associated with age, sex, education, and have varied over time.

Keywords: concentration index
inequalities
oral health
Advisor: Quiñonez, Carlos R