VictorJuiz/thesis huggingface dataset:
Modeling the Dynamics of Evaporator Wash Cycles
Keywords: Black liquor
Dynamic simulation
Evaporator
Scaling
Soluble scale
Wash cycle

In the pulp and paper industry, black liquor evaporation is an essential step that leads to energy and chemical recovery. Fluctuations in liquor chemistry can result in evaporator scaling events, which negatively impacts thermal efficiency and mill production. Efficient evaporator washes result in scale dissolution and recovery of the heat transfer rate. Tool development is needed to improve the current evaporator washing strategies, which are primarily based on trial and error. The focus of this work was on the modeling approach and the evaluation of the impact of evaporator wash cycles on the fluctuations in sodium and oxalate in the feed liquor. The simulation was based on the evaporation plant of a South American pulp mill, and the dynamic model was developed in Matlab Simulink. The developed model demonstrated the potential to estimate the concentration of key ions that cause scaling, and to lead to improvements in evaporator washing strategies.
Characterizing Unstable Operation in Flow Cells for CO2 Electroreduction
Keywords: CO2 electrolysis
flow cell
gas evolution
neutron radiography
synchrotron X-ray radiography
unstable performance

Carbon dioxide (CO2) reduction flow cells are a promising means of curtailing anthropogenic CO2 emissions by reducing CO2 to generate useful carbon fuels when coupled with renewable energy sources. However, operating these devices at commercially relevant conditions is typically accompanied by mass transport issues related to unstable performance that is often overlooked. This thesis contains two studies focused on identifying and characterizing the source of unstable performance in these devices. In the first study, the effect of gaseous accumulation at the cathode gas diffusion electrode interface on the performance of an alkaline flow cell was investigated. In the second study, the relationship between unstable operation and the electrolyte layer gas saturation in a flow cell was characterized. These two studies aim to provide the necessary first steps in addressing unstable operation in CO2 reduction flow cells towards achieving stable, commercially relevant operation.
Efficient Subobject-granularity Spatial Memory Safety Enforcement with In-fat Pointer
Keywords: C/C++
Computer Security
Hardware
Spatial Memory Safety
Tagged-pointer

Lack of memory safety in programming languages like C and C++ can leave programs written in these languages with exploitable memory corruption vulnerabilities. Spatial memory safety defense can catch memory corruptions from out-of-bounds pointer arithmetic. However, none of the existing works can achieve low overhead, high compatibility, and fine-grained protection at the same time. This thesis presents In-Fat Pointer, a hardware-assisted spatial memory safety defense that improves the protection granularity of existing tagged-pointer schemes using object metadata to subobject-bound granularity while maintaining their high compatibility and low overhead. In-Fat Pointer introduces multiple object metadata schemes to spare pointer tag bits from object metadata lookup, and use the spared bits with in-memory type metadata for subobject bound computation. The hardware prototype is implemented on an FGPA board, and In-Fat Pointer is evaluated in functionality, runtime and memory performance, and estimated hardware cost.
The Function of the FERM Protein Okapi in Regulating the Number of Follicle Stem Cells and Interfollicular Stalk Cells in Drosophila Ovaries
Keywords: Cell competition
Drosophila
FERM domain protein
Hippo pathway
Oogenesis
Stem cells

The FERM domain protein Okapi (Oka) is important for normal Drosophila oogenesis. I found that Oka is required in the follicle stem cell (FSC) lineage to prevent an overgrowth of FSCs. To determine how Oka regulates FSCs, I analyzed interactions between oka and Hippo pathway genes, as they have similar mutant phenotypes. Hippo is known to limit nuclear translocation and activity of Yorkie, thereby suppressing cell proliferation. I found a higher proportion of FSCs with nuclear Yorkie in oka mutants than in wild-type. Reduction of Yorkie or Hippo overexpression partially rescued the FSC overgrowth in oka mutant ovaries. Interestingly, I found that oka mutant FSCs were lost when forced to compete with wild-type FSCs, whereas hippo mutant FSCs are known to be hyper-competitive. My findings indicate that Oka regulates the number of FSCs through the Hippo pathway and is required to make FSCs competitive through an unknown mechanism.
Emergency Use Ventilator Evaluation and Assessment: Open-Source Hardware, Performance, Regulatory Requirements and Technology Readiness
Keywords: Cardinal TRL
Emergency Ventilator
System Design
Technology Readiness Level

Emergency ventilators have attracted a lot of attention and resources during the COVID-19 pandemic due to which many groups have adopted open-source hardware development models. This study reviews enforceable guidelines as presented by various public health agencies and regulators and creates an assessment framework to determine the said system’s open-source information, performance, and its compliance towards regulatory benchmarks. The study also proposes a modified Technology Readiness Level (TRL) framework accommodating the relevant changes in the development pathways due to emergency circumstances. Furthermore, it investigates the efficacy of cardinal maturity assessment systems over preceding ordinal models. A novel method of Weighted Technology Readiness Level (WTRL) is proposed to quantify the degree of technology maturity of a system. The proposed model is then applied towards the maturity assessment of emergency ventilation systems while highlighting its importance. The model is also applied to ascertain the maturity of 7 NASA technologies and is compared against pre-existing cardinal frameworks.
Driving with Distraction: Brain Activity and Oculomotor Behaviour using fMRI and Eye-tracking
Keywords: distracted driving
driving
driving complexity
eye-movements
fMRI
neural correlates of driving

Due to the importance of visual attention to safe driving, this thesis examines the effects of distraction on the neural correlates of driving behaviour and the associated eye movements. Functional magnetic resonance imaging and simultaneous eye-tracking measurements are performed during simulated driving tasks with and without auditory distraction. Results showed no significant differences in the brain activation maps between right turns, left turns with and without oncoming traffic. The introduction of distraction produced significantly increased activations in the frontal and temporal lobes, and decreased activation in the posterior brain, suggesting a decrease in resources for visual attention. Distraction also caused a decrease in gaze variability, significantly greater saccadic eye movements and a significant increase in blink rate. These results suggest that the increase in cognitive load causes decreased visual attention for the primary driving task, reflecting how the brain and eyes deal with cognitive challenges during realistic driving scenarios.
Identification and Characterization of Proteolytic Activities from S. mutans that Hydrolyzes Dentinal Collagen Matrix
Keywords: Caries
Collagenolytic/gelatinolytic enzymes
Degradation
Dentinal Collagen
Proteolytic Activities
S. mutans

Objective: To measure the proteolytic activity of S. mutans, its discrete fractions, and proteases towards demineralized human dentin. Methods: Demineralized human dentin slabs were incubated with either medium, cultures (overnight or newly inoculated) of S. mutans UA159, or different bacterial fractions (intracellular, supernatant or bacterial membrane). Media from each condition was analyzed for a collagen degradation marker, hydroxyproline. Three potential proteolytic enzymes (SMU_759, SMU_761 and SMU_1438c) from S. mutans UA159 were expressed and their activity toward dentinal collagen was measured based on hydroxyproline analysis. Results: Media only and bacterial membrane had no activity towards dentinal collagen. Overnight culture of S. mutans had the highest degradative activity (p
Residential Segregation and Inequality: Considering Barriers to Choice in Toronto
Keywords: Neighbourhood Inequality
Residential Segregation
Toronto

Segregation of visible minorities has persisted throughout time in Toronto. In examining these concentrations, the literature has been heavily focused on the notion that visible minorities are choosing to live in proximity of their respective ethno-racial groups and that these are spaces of aspiration rather than marginalization in Canada. This thesis raises questions about the assertion of ‘self-segregation’ by emphasizing affordability constraints on residential choices that are often rooted in discrimination and inequality in the housing and labor markets. Census data from 2016, the dissimilarity index and an adopted neighborhood classification scheme was used to understand the spatial patterning of visible minorities in the Toronto CMA and highlight differences in the socio-economic characteristics of visible minority dominant and white dominant census tracts. The findings invite the inference that economic opportunities play a critical role in the residential choices of visible minorities and raise concerns about the quality of life in visible minority neighborhoods.
Balancing Graph Processing Workloads Using Work Stealing on Heterogeneous CPU-FPGA Systems
Keywords: fpga
graph processing
heterogenous
load balancing
work stealing

We propose, implement, and evaluate a work stealing based scheduler, called HWS, for graph processing on heterogeneous CPU-FPGA systems that tightly couple the CPU and the FPGA to share system memory. HWS addresses unique concerns that arise with work stealing in the context of our target systems. Our evaluation is conducted on the Intel Heterogeneous Architecture Research Platform (HARPv2), using three key graph processing kernels. Weshow that HWS effectively balances workloads, and results in better graph processing performance compared to static scheduling, and a representative of existing adaptive scheduling techniques, called HAP. Improvements vary, but can be up to 100% over static scheduling, and up to 12% over HAP. We also compare to an oracle chunk self-scheduler. HWS achieves the same performance as the oracle at the maximum number of threads. These results collectively demonstrate the effectiveness of work stealing for scheduling graph processing workloads on our target platform.
An Autoethnographic Perspective on Restorative English Education in Marginalized Communities
Keywords: Adolescents
Indigenous
Literacy
Marginalized
Pedagogy
Restorative

In this autoethnographic study, the author explores how restorative English education can meet the needs of minoritized English learners with a particular focus on Indigenous learners of English. After reviewing the literature on several interrelated pedagogies, she braids together 1) stories from her childhood and adolescence in Toronto where she faced numerous types of discrimination as a Patois speaker and the child of Caribbean parents new to Canada, with 2) stories from her 10 years as a teacher in Attawapiskat as well as her time as a teacher in the ‘South”, and 3) stories shared by elders and other members of the Attawapiskat community. This autoethnography shines light on why it is problematic to impose a ‘one size fits all’ curriculum on minoritized English learners and provides concrete suggestions on how to implement restorative English education to help English learners develop a sense of self-worth while addressing social justice issues.
Development of an Expeller Extraction for Beta-carotene from Carrot Pomace via Lecithin-Linkers Microemulsions
Keywords: beta-carotene extraction
expeller extraction
food-grade microemulsions
HLD-NAC
Microencapsulation
Spray drying

This work introduces a new green extraction solvent, based on fully dilutable lecithin-linkers microemulsions (LLMs), that is used in a continuous expeller to recover -carotene from carrot pomace obtained after carrot juice production. The optimal LLMs for the extraction was identified via the HLD-NAC framework, and the predicted formulations confirmed via phase behavior studies. An expeller extraction method was developed and optimized for -carotene yield, with respect to LLMs. The results suggest that the combination of expeller and LLMs extraction have 3-6 fold increase in -carotene extraction as compared to other extraction methods. The optimal extraction is obtained with highly diluted LLMs, that lead to the lowest extraction costs. The LLMs containing extracted -carotene were microencapsulated via spray-drying to extend shelf life and prevent the release of -carotene at the stomach’s pH. The encapsulated product is a free-flowing powder that can be incorporated into a variety of products.
Development of a Novel Method for the Diagnosis of Sarcopenia Using Thigh DXA Imaging
Keywords: DXA
Sarcopenia
Strength
Thigh

Background: Sarcopenia, defined as the loss of muscle mass and function, increases the risk of falls and thus fractures and has unclear/ indistinct thresholds. Historically, sarcopenia is characterized in terms of lean mass index (LMI, lean mass/ ht2) or appendicular lean mass index (ALMI, appendicular lean mass/ ht2). However, recent studies have shown that function declines more rapidly than lean mass with age, leading to a transition in the defining criteria for sarcopenia from mass towards function. Purpose: This research investigates the thigh region of interest within a whole-body DXA scan to calculate muscle volume, area, and density, and evaluates whether these metrics perform better than ALMI and LMI in relation to function. Method: DXA scans were acquired during implementation of the Sarcopenia in Women Across the Lifespan (SarWol) study, a cross-sectional study of 30 healthy premenopausal (age 35.82 ± 7.67), 30 healthy postmenopausal (age 67.04 ± 7.47), and 26 postmenopausal women with recurrent falls (age 71.26 ± 8.82). A Hologic Discovery system was used by ISCD-trained technologists to acquire the scans. Two subregions, a mid-thigh region and a half-thigh region, normalized to the participant’s femur length were placed precisely on each whole body scan. As opposed to the commonly used cylindrical model, two truncated cone models were applied to each region, namely, a cone model and an elliptical model. Sets of parameters were extracted to distinguish the subcutaneous fat from the standard outputs of the DXA software. Then, equations were developed to obtain muscle area, density, and volume in each subregion based on each geometrical model and tissue properties. Knee-extension torque using a Biodex dynamometer was obtained for each participant in a standardized fashion. Correlation coefficients and multivariate linear regression models were used to evaluate DXA-derived parameters (ALMI, LMI and our new thigh muscle parameters) in relation to knee-extension torque and grip strength. Results: The DXA-derived muscle volume was moderately correlated to knee-extension torque while ALMI (r = 0.16, p = .130) and LMI (r = -0.01, p = 0.961) were not significantly correlated. r Mid-thigh Half-thigh Knee-Extension Torque Elliptical model 0.42 0.42 Cone Model 0.37 0.40 p
Engineering a Core-shell Electrospun Fibrous Nerve Wrap for the Local Release of FK506 (Tacrolimus)
Keywords: Coaxial electrospinning
FK506
Local drug delivery
Nerve wrap
Peripheral nerve regeneration
Tacrolimus

Local FK506 delivery enhances peripheral nerve regeneration whilst mitigating negative side-effects. We aimed to 1) develop a FK506 delivery nerve wrap with properties for clinical application, 2) sustain bioactive FK506 release, and 3) ensure the wrap is biocompatible and biodegradable. The wrap was fabricated using coaxial electrospinning with polycarbonate urethane (PCNU) and FK506. PCNU/FK506 nerve wraps were found to have a strong elastic modulus (2.38 ± 1.05 MPa) to withstand surgical manipulation and are thermally stable. The nerve wraps encapsulated and released bioactive FK506 almost completely but, burst release occurred within 12 days. Nerve wraps degraded over 60 days, did not cause major acute or chronic inflammation, and the FK506 present in nerve wraps suppressed T lymphocytes, with the result that the wraps did not cause chronic nerve compression. The PCNU/FK506 nerve wraps are a clinically-feasible adjunct device to microsurgical repair of injured nerves and can potentially enhance regeneration outcomes.
Lab-on-a-Rod: Size-based Particle Separation using Inertial Microfluidics
Keywords: Abrasive jet
Computational fluid dynamics
Microfluidics
Micromachining
Particle separation

Size-based particle separation using inertial microfluidics in spiral channels has been well studied over the past decade. Though these devices can effectively separate particles, they require a relatively large device footprint with typical outer diameters in the range of 30 mm. In this thesis, a microfluidic device with an overall diameter of 5.5 mm containing a helical channel capable of inertial particle separation fabricated using abrasive jet micromachining is described. Particle positions for several channel geometries were studied using wide-field fluorescence microscopy. A maximum separation efficiency of approximately 90% was achieved at a flow rate of 1.5 mL/min with a purity of approximately 95% at the large particle outlet. An accompanying computational fluid dynamics model was developed to allow researchers to quickly assess the separation capability of their helical or spiral devices.
First-principles Investigation of 2D Phosphorus for Energy Storage Applications
Keywords: batteries
density functional theory
energy storage
phosphorus
two-dimensional materials

Allotropes of 2D phosphorus have presented themselves as appealing candidate materials for improved energy storage systems to meet current demands. In this thesis, first-principles simulations were conducted to predict the performances of these materials. Blue phosphorene was studied as an anode material for Na-ion and K-ion batteries, and predictions of key performance indicators showed its potential. Additionally, phosphorene’s catalytic properties towards discharge and charge at the cathode for Li-air batteries were estimated. Using overpotentials as a measure of efficiency, phosphorene was able to contribute towards reasonable values showing its promise for future implementation. As phosphorene’s ambient degradation limits its more widespread implementation, strain engineering was explored as a method towards increased stability. It was found that compressive strain can induce an activation barrier towards singlet oxidation splitting, thereby inhibiting the first step of the degradation process.
Towards Effective Safety Benchmarking: Scope and Factor Selection
Keywords: Benchmarking
Boruta feature selection
Construction safety
Construction sector
Safety culture
Safety indicator

The construction industry is known for its high safety risk compared with other industries and effective safety benchmarking is essential to continuously monitor and improve safety performance. In this research, the safety culture and three categories of safety performance, namely physical injuries, psychological stresses, and unsafe events, were investigated with a self-administered survey and the data were analyzed using statistical and machine learning approaches. Two foundational elements to achieve effective safety benchmarking were examined: benchmarking scope and benchmarking factors. It was found that safety culture and performance can differ between construction sectors and geographic regions. Thus, they should be considered during the benchmarking scope determination. Factors influencing safety performance were ranked according to their importance and the top-ranked factors are recommended priority when limited resources for safety management occur.
Supporting Urban Stormwater Management Programs with a User-fee: The Evaluation of Experiences from New South Wales/Blacktown City Council, Philadelphia and Mississauga
Keywords: Municipal Works Infrastructure
Policy Tools
Stormwater Financing and Funding
Stormwater Management
Sustainablity
User-Fee

In the absence of adequate and consistent funding from traditional revenue sources, cities consider or implement a user-fee to sustainably support stormwater management initiatives. User-fees are policy tools charging customers for their consumption and utilization of a service the government delivers. Cities report favourable results as user-fees provide dedicated funding due to purposeful collection. However, it is challenging to design and administer a stormwater user-fee as staff must balance various considerations while responding to those in opposition. In fact, opposition has halted implementation in multiple cities. For instance, officials and the City of Toronto’s electorate viewed the 2017 Stormwater Charge as regressive, resulting in the initiative's abandonment. By assessing user-fee programs in three broadly comparable cities to Toronto – New South Wales/Blacktown City Council (Australia), Philadelphia (USA), and Mississauga (Canada) – this research determines if key recommendations from broadly comparable cities can inform the design and administration of a user-fee for Toronto.
The Development of English and Arabic Language and Literacy Skills of Syrian Refugee Children and Youth in Canada
Keywords: Children and Youth
Language and Literacy
Refugees

Language and literacy skills are crucial for the integration and academic achievement of refugee students. In particular, heritage language (L1) maintenance and majority language (L2) acquisition are key to achieving optimal acculturation outcomes. This study examined the performance of Syrian refugee children and youth in word reading, vocabulary and reading comprehension in Arabic and English over a one-year time period. In addition, the extent to which proximal and distal factors pertaining to the child/youth predict performance on the three measures was investigated. Findings suggest that one school year of English instruction enhanced students’ English performance and reduced the gap between them and their monolingual peers. Evidence of Arabic language progress was also demonstrated. Moreover, age and parental education were among the factors predicting English and Arabic language proficiency. Implications are discussed as well as recommendations to promote Arabic and English language and literacy skills in school-aged Syrian refugees.
Localized Globality in Colonial Korean Literature: Ch’angjo as part of the ‘Little Magazine’ Movement
Keywords: Ch'angjo
Colonial Literature
Korean Language
Korean literature
Little Magazines
Vernacularization

This thesis analyzes the Korean literary coterie magazine Ch’angjo (1919-1921) as part of the global little magazine movement of the late 19th and early 20th centuries. The analysis is conducted on three different levels of increasing depth: the material, the linguistic, and the literary semantic. Through these levels of analysis, it becomes clear that while the writers of the Ch’angjo coterie were aware of and utilizing many Western literary forms and ideologies in their writing, it was with the overarching aim of elevating their own national literature to be on par with the global literature they encountered while studying in Japan. These forms and ideas were translated into the Korean literary context, not with an aim to make Korean literature emulate the Western, but rather to indigenize these forms within a wholly Korean context. The results of these experimentations helped form the foundations of modern Korean literature.