VictorJuiz/thesis huggingface dataset:
A Current Re-distribution Scheme for Improved Energy Harvesting in Concentrating Photovoltaic Systems Using Fine-grained dc-dc Conversion

This thesis presents a distributed power-management architecture for concentrating photovoltaic (CPV) systems. Specifically, the Δ-conversion scheme with voltage equalization is analyzed and verified for the CPV system from Morgan Solar, Inc. This architecture uses inverting buck-boost converters, denoted Δ-converters, which equalize the voltages of neighbouring CPV cells in a series-connected string of cells and improve the systems tolerance to parameter variations. The power benefits of Δ-conversion and the Δ-converter current distributions are investigated using statistical simulations. The effectiveness of Δ-conversion in the presence of randomly distributed mismatches is demonstrated, and current cascading is identified as the main design challenge. The Δ-converter is modelled and compensated using Middlebrook's Extra Element Theorem. Analysis of measured data from a six-cell CPV system demonstrate the benefits of Δ-conversion under realistic scenarios. Experimental results from prototype systems show up to 31% power benefits in the presence of mismatches.

Keywords: power electronics
renewable energy
photovoltaic
dc-dc converter
concentrating pv
distributed power management
delta converter
mppt
digital control
extra element theorem
simulink
lso
Advisor: Trescases, Olivier
Source Analysis of Cortical Responses at Initial Cochlear Implant Use in Children who are Deaf

Deafness in early development can alter how the brain responds to sound, compromising the restoration of hearing with cochlear implants. We asked how the naïve brain responds to initial cochlear implant stimulation in children who are deaf. Results indicated large variability in initial responses. Deafness associated with GJB-2 mutations led to more uniformity in cortical responses than other etiologies. Responses associated with GJB-2 mutations were characterized by a response peak with large contributions from temporal and frontal regions of the brain. This response may reflect an early stage of auditory development. By contrast, another response type, typical of normal hearing children, received less contribution from frontal regions. Through consistent cochlear implant use, frontal regions of the brain may not be as strongly recruited. Effects of deafness in early development are heterogeneous, which may reflect differences in etiology of deafness and different stages of auditory development.

Keywords: Cochlear implants
Children
Cortical responses
Neural generators
Advisor: Gordon, Karen A.
Rational Modeling of Arching Action in Laterally Restrained Beams

It is well known that arching action in reinforced concrete slabs resulting from surrounding restraining elements is responsible for much greater collapse loads than those estimated considering flexural effects only. However, the subject needs to be better understood and simplified if it is to be reliably applied in broader practice. This thesis presents a rational treatment of the problem. By limiting the scope of investigation to one-way slab systems, for the first time an explicit method of calculating the load-carrying capacity of elastic- plastic slab strips with a laterally rigidly restrained boundary condition is derived. Application of the proposed model to specimens selected from four experiment programs proves its reliability in ultimate strength calculations. The proposed model is then employed in a parametric study of structural responses of deck slab strips. The parametric study shows that a longer span, lightly reinforced deck slab system is still adequate in strength if it is cast in higher strength concrete and sufficient lateral restraint is available.

Keywords: Arching Action
Reinforced Concrete
Advisor: Gauvreau, Douglas Paul
Molecular Weight Limit Identified for the Synthesis of Externally Initiated Poly(3-hexylthiophenes) and Further Macrocyclic Constructions

Externally initiated o-tolyl initiated poly(3-hexylthiophene) (P3HT) was synthesized according to Grignard metathesis polymerization at varying chain length to compare number average molecular weights (Mn) obtained by gel permeation chromatography (GPC) and 1H NMR end group analysis. The extent of overestimation by GPC (1.3) was determined to be lower than previously reported for low Mn polymers. However, an apparent GPC quantification limit was observed as NMR Mn correlated well to predicted results. Static light scattering studies on high Mn polymers provided evidence that the true molecular weight was more similar to GPC-derived Mn. Despite nearly 100% external initiation efficiency, at a certain Mn limit new uninitiated chains may be synthesized. It is suggested that the synthesis of externally initiated P3HT should be limited to Mn below 40 kDa to ensure fully externally initiated chains. A proposal for the synthesis of externally initiated macrocyclic P3HT will also be discussed.

Keywords: poly(3-hexylthiophene)
external initiation
gel permeation chromatography
end group analysis
size exclusion chromatography
conjugated polymers
molecular weight limit
Grignard metathesis polymerization
Advisor: Seferos, Dwight
The Mechanism of Discoidin Domain Receptor 1 Mediated Vascular Calcification

Introduction: Activation of Runt Related Transcription Factor 2 (RUNX2) is required for transdifferentiation of Vascular Smooth Muscle Cells (VSMCs) into a calcifying osteoblast-like phenotype. Our lab showed that deletion of Discoidin Domain Receptor 1 (Ddr1), decreased atherosclerotic vascular calcification in the Ldlr-/- mouse. Hypothesis: DDR1 regulates RUNX2 activity by affecting microtubule organization during VSMC mediated calcification. Results: Ddr1-/- VSMCs show reduced RUNX2 activity when compared to Ddr1+/+ VSMCs. Addition of the microtubule-destabilizing agent nocodazole inhibited both RUNX2 activity and nuclear localization in Ddr1+/+ VSMCs. Addition of the microtubule-stabilizing agent taxol rescued RUNX2 nuclear localization in Ddr1-/- VSMCs. Despite this, Taxol was unable to rescue RUNX2 activity as it eliminated activity in both genotypes. Conclusion: These findings indicate that under osteogenic conditions, Ddr1 deletion impedes the dynamic instability required for the maintenance of microtubule architecture. This prevents RUNX2 nuclear localization and transcriptional activation in VSMCs.

Keywords: Pathology
Molecular
Advisor: Bendeck, Michelle
The Effect of Bonded Reinforcing Steel on Increase in Stress in Unbonded Prestressing Steel at Ultimate State

To investigate the benefit induced by adding a small amount of bonded reinforcing steel into a fully unbonded prestressed concrete beam, two well-founded and straightforward approaches for predicting tendon stress are proposed. The primary approach utilizes a flexural analysis to calculate member deformation. The supplementary approach employs a truss model to consider the additional member deformation due to shear force. Both approaches use a simplified iterative method. With these two approaches, a systematic parametric study is conducted to investigate the effects of various factors. The results indicate that adding little bonded reinforcement does significantly increase the stress increment in unbonded tendons at ultimate state for one-point loading as expected. Moreover, a lower span-to-depth ratio, the use of high-strength concrete, and a smaller mechanical reinforcement ratio also raise the stress increment.

Keywords: Unbonded Prestressing
Partial Prestressing
Simplified Method
Advisor: Gauvreau, Douglas Paul
Design of a Power Scalable Capacitive MEMS Accelerometer Front End

This thesis presents the design, implementation and fabrication for a 0.13μm interface to a capacitive MEMS accelerometer. By varying the number of amplifier slices used in concurrence based on different full scale input ranges, the analog circuitry power scales as the input range scales. Due to the oversampling nature of typical accelerometer front ends, for a full-scale input increase of N times, the analog circuitry power reduces by N2 times. The front end has two signal amplification stages, with the first stage power scaled. The chip is 1.15mmx1.15mm and implemented in a 0.13μm CMOS process. The design was packaged with the MEMS accelerometer chip inside a 44 pin CQFP. Measured results show an output rms noise of 63μVrms in a 100Hz bandwidth. The total analog circuitry power scales very linearly with different full scale ranges. A novel simple offset removal network is also shown and confirmed via measurement results.

Keywords: Accelerometer
Interface
Power
Front End
Front-End
Power Scalable
Power-Scalable
MEMS
Advisor: Johns, David A.
Management Patterns and Outcomes of Differentiated Thyroid Cancer in Ontario: A Population-based Study

The incidence of differentiated thyroid cancer (DTC) is rising, but controversy exists in many aspects of its treatment. This study described the change in incidence of DTC in Ontario, variations in management including extent of thyroidectomy and the influence of provider volume, and the impact of these parameters on recurrence and thyroid cancer-specific death (TCSD). A population-based study identified all new cases of DTC between 1992-2007. The incidence of DTC increased dramatically (annual percentage change 7.6%). Linkage to administrative databases revealed that extent of thyroidectomy is influenced by various factors including patient gender, age, year of diagnosis, surgeon specialty, and hospital setting, but not provider volume. Total thyroidectomy is associated with a lower recurrence rate. There is a significant association between provider volume and recurrence, with lower volume surgeons having a higher recurrence risk. Extent of thyroidectomy and provider volume did not influence TCSD. Such variations in management may lead to disparities in health outcomes.

Keywords: differentiated thyroid cancer
extent of thyroidectomy
volume-outcome
incidence
Advisor: Urbach, David Robert
Shattering Kraft Recovery Boiler Smelt by a Steam Jet

Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases the likelihood of dissolving tank explosions. While industry has not dedicated much effort to smelt shattering, the safety implications require smelt shattering to be studied in detail. An experimental set-up was constructed to simulate the shattering operation using a water-glycerine solution and air instead of smelt and steam respectively. The objective was to examine how physical properties and flow characteristics affect shattering. It was found that increasing shatter jet velocity greatly reduced droplet mean diameter. Increasing the liquid flow rate greatly increased droplet size, as expected. Shattering was not significantly affected by viscosity, unless a weak shatter jet was used on a highly viscous fluid. Increasing the proximity of the shatter jet nozzle decreased droplet size.

Keywords: pulp and paper
kraft recovery cycle
recovery boiler
smelt shattering
steam jet
atomization
droplet size
smelt-water explosion
dissolving tank explosions
water-glycerine solution
air jet
shatter jet velocity effect
liquid flow rate effect
viscosity effect
shatter jet nozzle proximity effect
Advisor: Tran, Honghi
Bussmann, Markus
The Utility of Contrast-enhanced Ultrasound in the Assessment of Solid Small Renal Masses

Purpose: To compare hemodynamic of malignant and benign SRMs on CT and CEUS. Method: Seventy biopsy proven SRM underwent CEUS. Sixty-three had CT. After injection of 0.2 ml of Definity, 3min and after 0.9 ml infusion, 30 sec of data were acquires. Lesion hemodynamics relative to the cortex was evaluated both qualitatively and quantitatively. Results: Considering 15 and 20 HU as enhancement threshold, 10% to 13% of patients did not enhance on CT, while all lesions enhanced on CEUS. Papillary RCCs showed hypovascularity with 100% specificity. In other RCCs, PI, WI slope 5 to45%, 50 to100%, 10 to 90%, WO slope 100 to 50%, 100 to 10%, WO intensity at peak+30 seconds were statistically higher than benign SRMs. Conclusion: All solid SRMs enhance on CEUS, while CT does not show vascularity in 10-13% of solid SRMs. CEUS can differentiate malignant from benign SRMs by evaluating their hemodynamics.

Keywords: Contrast-enhanced ultrasound, microbubble contrast agent, solid small renal mass, kidney, cancer, Definity
Advisor: Atri, Mostafa
Exogenous Glucagon-like Peptide-2 in Neonatal Piglet Models of Short Bowel Syndrome: Does the Intestinal Adaptive Response Vary with Remnant Intestinal Anatomy?

Glucagon-like peptide-2 (GLP-2) augments intestinal adaptation in animal models of short bowel syndrome (SBS) and in adult patients with SBS. However, GLP-2 has not been used as a therapy for pediatric SBS. In this thesis, it is hypothesized that exogenous GLP-2 therapy will improve outcomes of intestinal adaptation in proximal intestinal resection (JI) and distal intestinal resection (JC) neonatal piglet models of SBS. Improvements in morphological parameters (increased small intestinal length) and histological parameters (increased jejunal villus length or jejunal crypt depth) of intestinal adaptation in JI and JC neonatal piglets treated with GLP-2 were observed. However, improved clinical outcomes (fewer days of diarrhea, fewer days on parenteral nutrition, more days on enteral nutrition alone) were only observed in GLP-2 treated JC animals. Since the JC anatomical subtype (no remnant ileum) represents the majority of clinical cases of neonatal SBS, these results support a potential role for GLP-2 therapy in pediatric SBS.

Keywords: short bowel syndrome
intestinal adaptation
glucagon-like peptide-2
Advisor: Wales, Paul W.
Robust Consistency Checking for Modern Filesystems

A runtime file system checker protects file-system metadata integrity. It checks the consistency of file system update operations before they are committed to disk, thus preventing corrupted updates from reaching the disk. In this thesis, we describe our experiences with building Brunch, a runtime checker for an emerging Linux file system called Btrfs. Btrfs supports many modern file-system features that pose challenges in designing a robust checker. We find that the runtime consistency checks need to be expressed clearly so that they can be reasoned about and implemented reliably, and thus we propose writing the checks declaratively. This approach reduces the complexity of the checks, ensures their independence, and helps identify the correct abstractions in the checker. It also shows how the checker can be designed to handle arbitrary file system corruption. Our results show that runtime consistency checking is still viable for complex, modern file systems.

Keywords: Filesystems
Consistency checking
Reliability
Runtime verification
Declarative
Datalog
Btrfs
Advisor: Goel, Ashvin
Brown, Angela Demke
Functional Interactions between the Discoidin Domain Receptor 1 and Beta 1 Integrins

The rate limiting step of phagocytosis is the binding of collagen to specific receptors, which include β1 integrins and the discoidin domain receptor 1 (DDR1). While these two receptors may interact, the functional nature of these interactions is not defined. We examined the effects of DDR1 over-expression on β1 integrin function and determined that DDR1 over-expression enhanced cell attachment through β1 integrins. These data are consistent with data showing that DDR1 over-expression enhanced cell-surface, but not total, β1 integrin expression and activation. As shown by experiments with endoglycosidase H, DDR1 over-expression increased glycosylation of the β1 integrin subunit. Collectively these data indicate that DDR1 enhances β1 integrin interactions with fibrillar collagen, possibly by affecting the processing and trafficking of β1 integrins to the cell surface. Our data provide insight into the mechanisms by which fibrotic conditions such as cyclosporine A-induced gingival overgrowth are regulated.

Keywords: Collagen
Discoidin Domain Receptor 1
Beta 1 Integrins
Remodeling
Glycosylation
Phagocytosis
Advisor: McCulloch, Christopher
Vision-based Augmented Reality for Formal and Informal Science Learning

This thesis explores the application of vision-based augmented reality in formal and informal educational environments. It focuses on the common practices, concerns, and priorities that developers and content creators in each environment frequently encounter, offering insights into how these experiences are changing with the incorporation of new digital media technologies and the hardware platforms that support them. The research outlined in this thesis uses qualitative methods, assembled around a series of twelve hour-long interviews with highly-experienced educators, developers, researchers, and designers, and analyzed using a grounded theory approach. This thesis introduces original research about the role of computer vision-based augmented reality as an educational medium, a topical discussion in information studies, museum studies, learning sciences, and a number of other fields, and makes a theoretical commitment to addressing the ways that material and virtual objects come to interact meaningfully in a variety of learning environments.

Keywords: Digital Media
Learning Sciences
Augmented Reality
Museology
Education
Informal Learning
Information Science
Qualitative Methodology
Advisor: Krmpotich, Cara
The LNX Family of Multi-PDZ E3 Ligases: Using a Mutagenesis-based Approach to Establish the Role of PDZ Domains in LNX1 Function

LNX1 belongs to a family of multi-PDZ domain containing RING-type E3 ligases. Several interactions have been mapped to its PDZ domains, but the role of each domain in LNX function has not yet been determined. To study individual PDZ domain function in the context of full length protein I generated point mutations in peptide binding sites of each of PDZ domain, and in a putative phosphoinositide binding site of LNX1 PDZ4. Peptide binding was successfully disrupted by an arginine or lysine to alanine mutation in the peptide binding cleft. A LNX1 PDZ4 mutant with lysine residues in a putative phosphoinositide binding site mutated to glutamate displayed decreased membrane localization. The impact of each PDZ mutation on cell morphology and substrate ubiquitination was also investigated. I identified a potential role for PDZ binding in auto-inhibition of RING function. Additionally, novel interactions between LNX1 and Frizzled family members were identified and characterized.

Keywords: Ubiquitin
E3 Ligase
Protein Interactions
Mutagenesis
PDZ Domain
Cell Biology
Biochemistry
Advisor: McGlade, Jane
Using Phosphine Aldehydes to Generate New Metal Complexes and the Synthesis of Chiral NHC-amino Ligands

Several new late transition metal complexes containing P-O and P-N ligands derived from 2-dicyclohexylphosphinoacetaldehyde were synthesized. A facile one-pot template method is used for the synthesis of P-N complexes, where the phosphine aldehyde and amine can undergo a condensation reaction to form a phosphine-imine metal complex in the presence of a metal precursor. Metal complexes with phosphino-enolate, imine, and oxime ligands are synthesized. Ni(II), Pt(II), Rh(I) and Ir(I) metal centres were investigated. The Rh(I) and Ir(I) complexes contain a 1,5-cyclooctadiene ligand, thus resembling Crabtree’s hydrogenation catalyst [Ir(COD)(py)(PCy3)][PF6]. These complexes are also active catalysts for olefin hydrogenation. Furthermore, the synthesis of a new chiral amine functionalized NHC ligand is explored, which has potential applications as a ligand in the metal-catalyzed enantioselective hydrogenation of polar bonds. This ligand is inspired by previous achiral hydrogenation catalysts reported by Morris et al. that displayed high activity for a variety of unsaturated substrates.

Keywords: inorganic
organometallic
catalysis
ligand
phosphine
NHC
carbene
imidazolium
hydrogenation
Advisor: Morris, Robert H.
The Role of Moral Emotions in Children's Sharing

This study examined the development of sharing and its associations with moral emotions in an ethnically diverse sample of 244 4-, 8-, and 12-year-old children. Sharing was measured through participants’ allocation of resources in the dictator game. Participants completed self-report measures of sympathy and anticipated their negatively and positively valenced moral emotions (i.e., guilt and pride) following actions that either violated or upheld moral norms. Results demonstrated an age-related increase in sharing between ages 4 and 8. For children with low levels of sympathy, sharing was predicted by negatively valenced moral emotions following the failure to perform prosocial duties. Sympathy also emerged as a significant predictor of sharing behaviour in early childhood. The implications of these results are discussed in relation to children’s developing norms of fairness and the emergence of two compensatory emotional pathways to altruistic sharing, one via sympathy and one via negatively valenced moral emotions.

Keywords: development
sharing
moral emotions
sympathy
Advisor: Malti, Tina
Grusec, Joan
Predictors of 25-hydroxyvitamin D Serum Concentrations among Non-western Immigrant Preschool Children

We determined whether children older than 1 year from non-western immigrant families had lower serum 25-hydroxyvitamin D levels than children from western born families. Children ages 1-6 years were recruited through the TARGet Kids! practice based research network. Univariable analysis revealed that non-western immigrant children had 4 nmol/L lower 25-hydroxyvitamin D (p=0.006; 95% CI:1.4-8.0) and increased odds of 25-hydroxyvitamin D <50 nmol/L (OR 1.9, 95% CI:1.3–2.9). After adjustment for known vitamin D determinants, cow’s milk intake, vitamin D supplements, season and age were significant covariates and current vitamin D supplementation had the strongest confounding effect. In order to use the ethnicity variable, we developed a new standardized geographically based closed-ended ethnicity question, which was a practical alternative to the widely used open-ended ethnicity questions. There was an association between non-western immigration and lower 25-hydroxyvitamin D in early childhood and this appears primarily related to known vitamin D determinants.

Keywords: Nutrition
Vitamin D
Early childhood
TARGet Kids!
Advisor: Maguire, Jonathon
Darling, Pauline
Mobilities of Aboriginal Youth: Exploring the Impact on Health and Social Support through Photovoice

Dramatic growth in Canada’s urban Aboriginal population has led to high rates of Aboriginal mobility. Despite much quantitative data, very little is known about the mobility experiences of Aboriginal peoples or its impacts. Furthermore, while mobility may present barriers for shaping social connections important to individual health, research in this area is minimal, especially among Aboriginal youth. Using community-­‐based participatory research (CBPR) the purpose of this thesis is to examine how mobility shapes the social networks and health of Aboriginal youth in the city of Winnipeg, Manitoba. While highlighting the use and valuableness of CBPR methods, the research demonstrates that mobility impacts both the development and maintenance of social relationships among Aboriginal youth as well as influences the types and qualities of these relationships. Additionally, mobility indirectly shapes health through its effect on social support, which was shown to impact health positively and negatively through direct and indirect pathways.

Keywords: Aboriginal health
Advisor: Wilson, Kathi