VictorJuiz/thesis huggingface dataset:
Fate of Sulfur During Production of Oil Sands Petroleum Coke Derived-Activated Carbon
Keywords: Activated carbon
Chemical activation
Coke utilization
Fate of sulfur
Oil sands petroleum coke

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.
The Study of Pore Resistance in Nanoporous Gold Electrodes Using Electrochemical Impedance Spectroscopy
Keywords: Dealloying
Electrochemical Impedance Spectroscopy
Mass Transport
Nanoporous Gold
Pore Resistance

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.
Mixed Alloy Compositions, Cascade Device Structures, and Lifetime Studies, of Boron Subphthalocyanine and its Derivatives in Organic Photovoltaic Devices
Keywords: device
lifetime
organic
photovoltaic
solar
subphthalocyanine

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.
Green Processing and Waste Valorization: Sulfur Removal and Hematite Recovery from High Pressure Acid Leach Residue for Steelmaking
Keywords: Alkaline leaching
Hematite recovery
High pressure acid leaching
HPAL residue
Sulfur removal
Waste valorization

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.
An Optimization Approach to Heterogeneous Coded Caching
Keywords: Caching
Coding
Heterogeneous
Information
Optimization

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.
Point-of-Care Detection System for Multiplexed Bead-Based Assays
Keywords: Bead Immunoassay
Point-of-care

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.
International Students' Perceptions of Factors Affecting Academic Success in Post-Secondary Studies
Keywords: academic
EAP
ESL
internationalization
perceptions
post-secondary

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.
Borinic Acid-Catalyzed Sulfation and Boronic Acid-Promoted Esterification of Carbohydrates
Keywords: borinic acid
boronic acid
carbohydrate
sulfate

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.
Written Narratives by Adult Chinese Plurilingual Students: Participants' Perceptions of Code-Switching and the (Re)Shaping of Identity
Keywords: code-switching
ESL
identity
plurilingualism
writing
written narratives

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.
Myosin Phosphatase Rho-interacting Protein Regulates DDR1-mediated Collagen Tractional Remodeling
Keywords: discoidin domain receptor 1
fibrillar collagen
myosin phosphatase rho-interacting protein
non-muscle myosin IIA
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.
Local targeting of anabolic drug conjugates for treatment of bone loss after tooth extraction
Keywords: bone
extraction
grafting
healing

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.
Electrochemical Study of the Effects of Sulfur and Lead Relevant to Nuclear Steam Generators
Keywords: Adsorption
Corrosion
Lead
Magnetite
Nickel
Sulfur

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.
Characterization of the inflammatory infiltrates associated with oral epithelial dysplasia and oral squamous cell carcinoma
Keywords: Characterization of the inflammatory infiltrates
Confocal microscope
Epithelial dysplasia
FIHC
Inflammatory cells
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.
Nash Equilibrium Seeking Over Undirected Graphs Via Multi-Agent Agreement
Keywords: Consensus
Game theory
Monotone
Multi-agent
Network
Passivity

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.
Longitudinal Craniofacial Growth in Pierre Robin Sequence in Comparison with Isolated Cleft Palate and Unaffected children
Keywords: craniofacial growth
Isolated cleft palate
mandibular growth
occlusion
Pierre Robin

Background: Pierre Robin Sequence (PRS) is defined at birth by the presence of mandibular micrognathia, glossoptosis and airway insufficiency with or without cleft palate. Objectives/hypothesis: Analyze craniofacial morphology and facial growth patterns in non-syndromic PRS and compare them to isolated cleft palate (ICP) and unaffected children. Materials Methods: Craniofacial characteristics were examined at three time points by comparing digitized tracings of subjects with PRS and ICP and unaffected class I subjects. Between-group and longitudinal differences across the time points were analyzed. Results: PRS and ICP groups had significantly small maxillas compared to the unaffected group and displayed a vertical pattern of growth. PRS group had the smallest mandibles (by 8%; 9.7mm) followed by the ICP group (by 4%; 4.2mm) when compared to the unaffected group. Conclusions: Craniofacial morphology and longitudinal facial growth in subjects with PRS and ICP are similar in many areas but differ significantly from comparable unaffected children.
The Hybrid Panel-Truss Element: Developing a Novel Finite Element for the Nonlinear Analysis of Reinforced Concrete Beams and Shells
Keywords: Finite Element
Reinforced Concrete
Shear
Shell
Structural Analysis
Torsion

This research thesis presents a finite element for the nonlinear analysis of reinforced concrete beams and shells. The Hybrid Panel-Truss (HyPT) element overcomes the computational limitations that exist when working with current analysis paradigms implemented in commercial software. Instead of explicit shape functions, the element utilizes the combined actions of simpler subcomponents to capture the coupled axial, flexural and shear deformations associated with reinforced concrete structures. The finite element formulation itself is robust as only one element is required through the depth of a member, and efficient since the global degrees of freedom necessary in a structural analysis model are reduced. The predictive accuracy of the HyPT element was verified using the American Concrete Institute database of shear critical reinforced concrete beam tests. In addition, the element was used to successfully model the experimental component of this research - the first documented pure torsion tests on reinforced concrete shells.
"Something to Just Hold On To": Occasional Teaching and Collaborative Inquiry in Precarious Times
Keywords: collaborative inquiry
community
occasional teaching
precarity
teacher employment
teacher research

This thesis is the product of a collaborative inquiry involving six occasional teachers, myself included, who came together over five months to share our experiences of navigating a teacher labour market ruled by teacher surplus, job shortages, and increasing employment precarity. Together we took an inquiry stance on occasional teaching (Cochran-Smith Lytle, 2009) and explored the consequences of precarious teacher employment for teaching, learning, working, and living. Here I document the myriad ways precariousness shapes not only our career trajectories but also our everyday experiences of practice, our professional identities as educators, and our engagement in political action and institutional change efforts. I also offer specific processes and interventions that mitigate the risks of long-term employment precarity for teaching and learning. Throughout, I rely on my participantsâ words as well as my own to tell a story about our work, what it means to us, and why it matters.
The Involvement of Rhopr-CRF/DH in Feeding and Reproduction in the Blood-gorging Insect Rhodnius prolixus
Keywords: diuresis
reproduction
satiety
stress
triatomine

Rhodnius prolixus is a blood-gorging insect and vector of human Chagas disease, which is transmitted following feeding, when the insect excretes urine contaminated with the Trypanosoma cruzi parasite. Diuretic corticotropin-releasing factor-like peptide (Rhopr-CRF/DH) plays a major role in this post-prandial diuresis; however, its localization in the insectâ s central nervous system and expression of its receptor in feeding-related tissues as well as the female reproductive system suggests a multifaceted role for the hormone, beyond diuresis. Here, the involvement of Rhopr-CRF/DH in feeding and reproduction was investigated. Rhopr-CRF/DH-like staining decreased in neurosecretory cells of the CNS after feeding, and injection of the hormone resulted in intake of a significantly smaller blood meal. Adult females injected with Rhopr-CRF/DH produced and laid significantly fewer eggs, and application of Rhopr-CRF/DH to the lateral oviducts inhibited contractions. These findings have implications for vector control by highlighting targets to alter feeding, diuresis, and reproduction of this disease vector.
Development of a Weakly-Coupled Hybrid Simulation Method for Seismic Assessment and its Application to Reinforced Concrete Building Structure
Keywords: hybrid simulation
reinforced concrete structure
seismic performance assessment
structural testing

Hybrid simulation methods have attracted significant interest from researchers in structural engineering to accurately assess the seismic performance of structures. To implement hybrid simulations in a testing facility, it is necessary to properly control the boundary conditions of physically tested specimens. The objective of this study is to propose and implement a methodology for performing hybrid simulations when a limited number of actuators are available and the full control of the boundary conditions is not possible. The developed methodology is employed to evaluate the seismic performance of a RC structure where one of the first storey columns is experimentally tested with testing equipment which can control only two DOF instead of the three required for columns subjected to planar motions. The seismic assessment is performed for the cases of an intact, repaired and retrofitted structure, where externally applied Carbon Fiber Reinforced Polymer (CFRP) fabric is used for repairing and retrofitting.