VictorJuiz/thesis huggingface dataset:
Improving the Durability of Thermally Insulated Historic Solid Masonry Walls

Providing means of drying from the inboard face of the masonry when walls are insulated on the interior assists the overall drying potential of the faรงade. Laboratory tests simulating inward vapour pressure drives induced by solar heating were carried out on Multiple samples of RSI3.9 (R22) and RSI4.2 (R24) mineral fibre. The testing revealed that the drying potential of mineral fibre insulation was roughly equivalent to a 3 mm (1/8 in.) vented clear airspace. Combining mineral fibre insulation with a 3 mm (1/8 in.) airspace was shown to be a very effective means of providing the ventilation necessary for drying solar heated walls. The laboratory test results were incorporated into a hygrothermal computer model to simulate the potential for drying walls exposed to moisture. The laboratory tests and computer modeling have revealed that using air permeable insulation can be an effective means of assisting the drying of internally insulated walls.

Advisor: Pressnail, Kim D
A Red Light at the End of the Tunnel: Towards Optimal Red-Shifted Azobenzenes

Azobenzenes have been used for almost half a century to impart spatiotemporal control on biological systems by way of an external stimulus - light. A limitation of previously reported azobenzenes is the requirement for ultraviolet to blue light to promote trans-to-cis isomerization. Light in this range of the spectrum poorly penetrates tissue and is cytotoxic, limiting in vivo applications. Through design and synthesis of an azobenzene derivative with a fused dioxane ring and a methoxy substituent on each phenyl ring, we obtained a core structure with a bathochromically-shifted absorption spectrum. Further substitution with para pyrollidine moieties raised the pKa of this azobenzene such that a portion is protonated at physiological pH allowing it to absorb at wavelengths in the near-infrared region. The compound undergoes trans- to-cis isomerization with 720 nm light and relaxes back to the trans isomer with a half-life on the order of 1 s.

Keywords: azobenzene
optochemical genetics
photopharmacology
photoswitch
Advisor: Woolley, G. A.
Fate of Sulfur During Production of Oil Sands Petroleum Coke Derived-Activated Carbon

Oil sands petroleum coke (OSPC) is a stockpiled carbonaceous waste with increasing inventory and environmental impacts; coke utilization is the upcoming focus. The goal of this work is to promote a novel production process that converts OSPC into activated carbon, a value-added product, using sodium hydroxide (NaOH) and sequential washing. However, the fate of sulfur, a major component of OSPC and a regulated substance, during the production process is largely unknown. Sulfur was determined through simulation of sulfur chemistry and experimental quantification and speciation in the process streams. Activation with NaOH-to-coke ratio of 1.5 and water washing for 10 min completely removed sulfur from OSPC as predominantly sulfide. The product is sulfur-free, low-ash porous carbon. The proposed production process also extracts vanadium, a valuable metal, from OSPC. By washing, sulfur is separated from vanadium and unreacted NaOH which can be recycled to further enhance the feasibility of the production process.

Keywords: Activated carbon
Chemical activation
Coke utilization
Fate of sulfur
Oil sands petroleum coke
Advisor: Jia, Charles Q.
The Study of Pore Resistance in Nanoporous Gold Electrodes Using Electrochemical Impedance Spectroscopy

Electrochemical impedance spectroscopy (EIS) was conducted on nanoporous gold electrodes prepared from electrochemical dealloying of Ag-Au and Ag-Au-Pt alloys, to investigate the ion transport inside the nanopores. The impedance data was analyzed based on a transmission line model (TLM) to evaluate pore resistance, a sign of effectiveness of mass transport, in various conditions. The pore resistance was inversely proportional to the concentration of electrolyte for HClO4, Na2SO4, and NaClO4 solutions, but showed slightly enhanced conductivity at very dilute condition for HClO4. This is attributed to the much smaller size of a proton compared to Na+ leading to less ion sieving and hindrance effects. Comparing the impedance of nanoporous electrode with varying pore sizes and depths, it was concluded that shallower porous layer with smaller uniform pores and better connectivity resulted in the lowest pore resistance, and therefore, the most effective ion transport.

Keywords: Dealloying
Electrochemical Impedance Spectroscopy
Mass Transport
Nanoporous Gold
Pore Resistance
Advisor: Newman, Roger C.
Technospheric Mining of Rare Earth Elements from Bauxite Residue (Red Mud)

Due to their inherent physicochemical properties, rare earth elements (REEs) are used in many critical and emerging technologies. The demand for some REEs is increasing sharply in line with increasing demand for these technologies. Such elements are classified as critical â i.e., those that are essential in use and subject to supply risk. To satisfy the increasing demand for REEs, initiatives have been started to recover them from secondary sources, also known as technospheric mining. This study puts the emphasis on technospheric mining of REEs from bauxite residue produced by the aluminum industry. The thesis is divided into five segments: 1) thorough characterization of the bauxite residue obtained from Rio Tinto; 2) development of the leaching process to extract REEs from the bauxite residue; 3) kinetic investigation of the leaching process; 4) development of microwave pretreatment process; and 5) development of the purification process to separate REEs from the leach solution.

Advisor: Azimi, Gisele
Synthesis and Glycosylation of Various Ceramide Derivatives via Borinic Acid Catalysis

Glycosphingolipids (GSLs) have become of increased interest due to recent realization that they may place a role in neurological diseases and cancer. Chemical synthesis of GSLs from simple building blocks requires efficient, yet selective methods to develop the major two components: ceramide and the carbohydrate. Much effort has been done to develop synthesis of the individual components; however the construction of the O-glycosidic bond that connects them has been plagued with regio- and stereoselectivity issues. In the past, both the ceramide and carbohydrate had to be chemically modified for the glycosylation step to occur with good selectivity and yields, but recently unprotected ceramides have been used with protected donors. Borinic acid catalysis has been an important advance in this field, allowing for higher yields and excellent Î˛-selectivity to develop GSLs. This thesis describes the synthesis of various ceramide derivatives and their corresponding glycosylation by borinic acid catalysis.

Advisor: Taylor, Mark S
Mixed Alloy Compositions, Cascade Device Structures, and Lifetime Studies, of Boron Subphthalocyanine and its Derivatives in Organic Photovoltaic Devices

This thesis encompasses my work to advance the field of organic photovoltaics, as well as my efforts to enable others to make further steps. It first details my investigation of the novel Îź-oxo-(BsubPc)2 compound, including usage of codeposition to achieve a mixed alloy composition, and several device engineering strategies employed to increase performance. Secondly, it describes my work to establish structure-property relationships with regard to molecular degradation in boron subphthalocyanine-containing organic photovoltaic devices. Next, it presents my analysis of the effects of various mixed alloy compositions of the chloro-(chloro)n-boron subnaphthalocyanine molecule on device performance. Finally, it illustrates my work in designing and building automated data collection and artificial solar aging systems to facilitate further exploration of degradation properties. These efforts serve to identify useful molecular and device design strategies to optimize both the performance and lifetime of organic photovoltaic devices containing derivatives of the boron subphthalocyanine molecule.

Keywords: device
lifetime
organic
photovoltaic
solar
subphthalocyanine
Advisor: Bender, Timothy P
Green Processing and Waste Valorization: Sulfur Removal and Hematite Recovery from High Pressure Acid Leach Residue for Steelmaking

The current study investigates a novel and environmentally friendly waste valorization process to refine hematite from the residue of the high-pressure acid leaching (HPAL) of nickel laterite ore. The process consists of an alkaline leaching step utilizing sodium hydroxide to reduce the sulfur impurity content in the HPAL residue. This novel process is very efficient because it runs at room temperature with a significantly short residence time (10 min). The refined HPAL residue has a sulfur content below the threshold accepted by the steelmaking industry; hence, it can potentially be used as a raw material. The proposed waste valorization process has the double advantage of generating a commercially valuable product from a waste stream and simultaneously providing environmental benefits by reducing the amount of scrapped leach residue and costs associated with constructing and maintaining storage facilities.

Keywords: Alkaline leaching
Hematite recovery
High pressure acid leaching
HPAL residue
Sulfur removal
Waste valorization
Advisor: Azimi, Gisele
An Optimization Approach to Heterogeneous Coded Caching

This thesis aims to develop an optimization framework for the development of coded caching schemes that can account for various heterogeneous aspects of practical communication systems. This framework is first used to develop an optimization-based perspective on the seminal work on the fundamental limits of caching by Maddah-Ali and Niesen, and is then extended to the case where files have non-uniform popularity and length, while users have non-uniform cache sizes. The resulting optimization problem scales exponentially in the system parameters, and so simplifications of the original problem that both perform well and scale as a polynomial function of the systems parameters are developed. By considering the aforementioned heterogeneities both individually and in conjunction with one another, insights into the influence of their interactions on optimal cache content are obtained.

Keywords: Caching
Coding
Heterogeneous
Information
Optimization
Advisor: Yu, Wei
Point-of-Care Detection System for Multiplexed Bead-Based Assays

We demonstrate an optical detection system which can be used to measure multiplexed bead based immunoassays. The assays can detect the presence of multiple analytes in a small sample using a microfluidic cartridge. The system is characterized in terms of linearity and sensitivity and compared to flow cytometers – the traditional detection method. The system is validated by measuring C-reactive protein, serum amyloid A and αKlotho to demonstrate its ability to perform bead immunoassays. Serum amyloid A and αKlotho are measured simultaneously to prove multiplexing ability. The system is designed to be compact and inexpensive to allow easy conversion of the prototype detection system to one suitable for point-of-care.

Keywords: Bead Immunoassay
Point-of-care
Advisor: Aitchison, Stewart
International Students' Perceptions of Factors Affecting Academic Success in Post-Secondary Studies

This multiple case study examines international students’ perceptions of factors affecting academic success in post-secondary institutions in southern Ontario. The study used snowball sampling and a semi-structured interview format. Various factors in the literature, which are used as a framework for this thesis, demonstrate an influence on international students’ academic preparedness and success. They include: proficiency tests, length of time in host country, prior learning experience, acculturation, tolerance of ambiguity, and motivation. Other factors influencing students’ academic success are EAP programs, faculty and students’ own perceptions of academic preparedness and needs, international student centres, communication with domestic students, and immigration plans. The study revealed that, in addition to the listed factors, participants also identified mental health and identity as influencing factors. The study addresses the gap in existing research by providing a college setting for international students from various nationalities, in a Canadian context, studying in a range of post-secondary programs.

Keywords: academic
EAP
ESL
internationalization
perceptions
post-secondary
Advisor: GagnĂŠ, Antoinette
Borinic Acid-Catalyzed Sulfation and Boronic Acid-Promoted Esterification of Carbohydrates

Carbohydrates and their O-sulfates play important roles in biological functions, including cellular recognition and adhesion, neural processes, fibrosis, growth factor regulation, cancer metastasis, and cellular entry of viruses. However, preparation of sulfated carbohydrates remains a synthetic challenge with conventional methods requiring lengthy protection and deprotection steps. Described herein is our work toward the development of a method for the regioselective sulfation of fully unprotected carbohydrates using a borinic acid catalyst. Via an activated 1,2-cis-borinate intermediate, our method was shown to be robust in the sulfation of a range of substrates, including the synthesis of a sulfated galactosylceramide found in mammalian nervous systems. In addition, work on utilizing boronic acids as protective groups for the preparation of sugar fatty acid ester surfactants is also discussed.

Keywords: borinic acid
boronic acid
carbohydrate
sulfate
Advisor: Taylor, Mark S
Towards the Design of Gravity-Based Wind Turbine Foundations

Shear fatigue failure of reinforced concrete gravity-based wind turbine foundations is a major concern amongst designers, one that can potentially cause complete collapse of the whole turbine structure. In standard practice, such a failure is guarded against by using more concrete and steel, resulting in additional material and labour costs. Six SFRC and RC large-scale deep concrete beams were constructed and tested monotonically and cyclically in order to compare the contributions of conventional stirrups to the fatigue life of the beam with those of the steel fibres and verify the strain-based fatigue damage models developed at the University of Toronto. Results show that the contribution of the stirrups to the fatigue life of RC deep beams is marginal. The steel fibres, on the other hand, are a superior alternative both in terms of performance (fatigue life) and cost. Analytical results, using finite element analysis, show that the proposed fatigue models are reliable and superior to overly conservative code equations.

Advisor: Vecchio, Frank J.
Nonlinear Pattern Formation in a Multilayer Photonic Platform

An optical resonator containing a Kerr nonlinearity and supporting two coupled modes with the same polarization is investigated to reveal stable localized solutions beyond the usual formation mechanism involving a single mode. Paired breather dissipative Kerr solitons, in addition to temporally stable patterns, are demonstrated via numerical simulations that accounts for differential group delay and unequal second-order dispersions (in both magnitudes and signs). The soliton dynamics are explored from the viewpoint of modulational instability and the spatial dynamics. These results are put within the broader context of multilayer photonic platforms and address considerations relating to dispersion engineering, external coupling, and avoided crossing phenomena. Preliminary waveguide measurements show the feasibility of implementing such a structure for the stable generation of coherent optical frequency combs.

Advisor: Poon, Joyce KS
Written Narratives by Adult Chinese Plurilingual Students: Participants' Perceptions of Code-Switching and the (Re)Shaping of Identity

This study explores the experiences and intentions for code-switching with Chinese adult students in Ontario who attended an ESL or English course in a continuing education program. Three participants were given the task of writing a short story with the option to incorporate an experimental pedagogical strategy of code-switching. Using a qualitative method, data was collected from their written narratives, followed by semi-structured interviews to discuss their experiences with code-switching. The data provides a deeper understanding of code-switchingâ s role in language learning and identity (re)shaping of adults during the process of acquiring English skills. The findings suggest that the participantsâ rationalizations for code-switching in the development of writing are influenced by the teacher as an authority figure, an active engagement in learning, and the desire for conciseness and efficiency. Furthermore, code-switching in written narratives supports identity (re)shaping through the ownership of words, reflexivity in memories, and accommodation for the reader.

Keywords: code-switching
ESL
identity
plurilingualism
writing
written narratives
Advisor: Labrie, Normand
Myosin Phosphatase Rho-interacting Protein Regulates DDR1-mediated Collagen Tractional Remodeling

Collagen remodeling is essential for preserving the structure and function of highly ordered collagen arrays, which are important for the normal function of many tissues and organs. Remodeling of fibrillar collagen is mediated in part by α2β1 and α11β1 integrins, and by the discoidin domain receptors (DDR) 1 and 2, which are receptor tyrosine kinases activated by binding to fibrillar collagen. The mechanisms by which contractile forces generated by non-muscle myosin IIA (NMIIA) are regulated to mediate DDR1-dependent collagen remodeling are not defined. We considered that cell-induced tractional remodeling of type I fibrillar collagen is strongly dependent on DDR1 activity and its interaction with NMIIA. By mass spectrometry and immunoprecipitation we found a time and collagen-dependent association between DDR1 and Myosin Phosphatase Rho-interacting Protein (MRIP). This association was strongly reduced by inhibiting DDR1 tyrosine autophosphorylation. MRIP exhibited strong, time and collagen-dependent co-localization with actin stress fibers, DDR1 and NMIIA. Deletion of MRIP by CRISPR-Cas9 enhanced co-localization of DDR1 with NMIIA and increased myosin light chain and DDR1 phosphorylation in a collagen-dependent manner. Increased expression of DDR1, deletion of MRIP, reducing DDR1 activation, or inhibition of Rho-associated coiled coil kinase, all strongly affected cell adhesion to collagen and the contraction, alignment and compaction of collagen fibrils. Collectively, these data indicate that DDR1, NMIIA and MRIP comprise a critical, interacting molecular complex that mediates collagen remodeling by DDR1 adhesions.

Keywords: discoidin domain receptor 1
fibrillar collagen
myosin phosphatase rho-interacting protein
non-muscle myosin IIA
remodeling
Advisor: McCulloch, Christopher A
Local targeting of anabolic drug conjugates for treatment of bone loss after tooth extraction

Background: Prostaglandin E2 has bone-anabolic effects in vivo but its clinical utility has been hindered by side effects upon systemic administration. A conjugate of an EP4a receptor agonist and a bisphosphonate can circumvent these. Objectives: The aim of the research was to demonstrate the impact of a bone-targeting conjugate on the wound healing and bone formation process. Methods: Molars 1, 2 and 3 of rats were extracted. Treatment groups included bone substitute (BSM) alone, BSM and low dose of conjugate (LD), Bone substitute and high dose of conjugate (HD). Animals were sacrificed after 7, 14 and 28 days. Samples were analyzed via MicroCT, TRAP staining, BSE and Trichrome Goldner staining. Results: All groups showed increase in defect fill. Osteoclast count (OC) and surface area (OCS) were reduced in the HD group after 14 and 28 days. Osteoid formation was elevated in the LD group after 2 and 4 weeks.

Keywords: bone
extraction
grafting
healing
Advisor: Glogauer, Michael
Grynpas, Marc
Electrochemical Study of the Effects of Sulfur and Lead Relevant to Nuclear Steam Generators

Steam Generators contain crevices at tube surfaces where they contact tubesheets, in which solids accumulate. Within this matrix there are elusive effects of impurities including sulfate and lead ions. Exposure to environments containing reduced sulfur species can result in rapid corrosion or cracking of Ni-Fe-Cr alloys, mediated by adsorption of sulfur mainly on the nickel component. The important aspect of the lead effect is the adsorption of zero-valent species on the metal. This disrupts the surface oxide network and facilitates its undercutting. The viability of sulfate reduction at elevated temperature and the effects of sulfur and lead on nickel dissolution and undercutting of the protective oxide layer has been examined via electrochemical measurements. Experiments done at different pH suggested that sulfate reduction is more likely to occur in acidic environment. Studies on joint lead-sulfur effects on nickel at ambient temperature revealed that sulfur can replace lead and dominate the surface.

Keywords: Adsorption
Corrosion
Lead
Magnetite
Nickel
Sulfur
Advisor: Newman, Roger C.
Characterization of the inflammatory infiltrates associated with oral epithelial dysplasia and oral squamous cell carcinoma

Oral cancer is a devastating disease which represents a serious public health challenge. In this study, we evaluated a total of 49 patientsâ samples diagnosed with hyperkeratosis without dysplasia, benign polyps, epithelial dysplasia and oral squamous cell carcinoma (OSCC). Fluorescent Immunohistochemistry (FIHC), confocal microscope and multichannel colocalization (multichannel fluorescent confocal analysis or MFCA) were used to characterize the inflammatory infiltrate in OSCC and epithelial dysplasia and compare it to other conditions. Our results show a distinct profile of inflammatory cells in OSCC when compared to other lesions. Also, gradual increases in the CD4/CD8 and NLR ratios were identified when moving from hyperkeratosis to more severe pre-malignant conditions and SCC. This is an important line of research that describes a novel method to identify the population of different inflammatory cells in oral biopsies and our result supports the implementation of MFCA as a potential diagnostic marker and predictor of malignant transformation.

Keywords: Characterization of the inflammatory infiltrates
Confocal microscope
Epithelial dysplasia
FIHC
Inflammatory cells
Squamous cell carcinoma
Advisor: Magalhaes, Marco A.O.
Nash Equilibrium Seeking Over Undirected Graphs Via Multi-Agent Agreement

We consider the problem of distributed Nash equilibrium seeking over networks. In this setting, agents have limited information about the other players' actions and are forced to communicate with neighbouring agents. We start with a continuous-time gradient-play dynamics, with perfect information, under a strictly monotone pseudo-gradient assumption. In the partial information case we modify the gradient-play dynamics between players by expanding the action space. We propose an augmented gradient-play dynamics in which players can only communicate locally with their neighbours to compute an estimate of the other players' actions. We derive new dynamics based on the reformulation of the problem as a multi-agent coordination problem, over an undirected graph. We exploit the incremental passivity properties in the dynamics and show that a Laplacian feedback can be designed using relative estimates of their neighbours. We highlight that there is a trade-off between properties of the game and the communication graph.

Keywords: Consensus
Game theory
Monotone
Multi-agent
Network
Passivity
Advisor: Pavel, Lacra