VictorJuiz/thesis huggingface dataset:
The Roles of Mineral Dusts and Coastal Aerosol in Cold and Warm Cloud Formation
Keywords: Aerosol
Atmosphere
Chemistry
Clouds
Environment

The indirect effect of atmospheric aerosol is one of the largest uncertainties in determining the Earth's radiative budget. This uncertainty has been attributed to our lack of understanding of processes leading to cloud formation. Consequently, this thesis investigates the abilities of two main types of aerosol to form warm and mixed-phase clouds.To study the mixed-phase cloud formation properties of 24 atmospherically-relevant minerals, their deposition ice nucleation properties were studied using a single experimental method. From a set of minerals present in mineral dusts it was found that feldspars were the most efficient ice nuclei. In addition, the warm cloud formation properties, or hygroscopicity (ê), of coastal ambient aerosol and its organic components were investigated in Ucluelet, BC. While the ê of 50 nm and 100 nm particles exhibited a wide size-independent variation (0.14 - 1.08), the ê of its organic fraction was estimated to be between 0.3 and 0.5.
Sharing Illness Experiences on Twitter: Conversations of Parents with Children Diagnosed with Cancer
Keywords: Childhood cancer
Health communication
Information sharing
Patient generated content
Social media
Twitter

The purpose of this research study is to identify the key themes of tweets posted by parents of children diagnosed with cancer, as well as to identify the reported motivations and benefits for using Twitter as a means to share information related to a child's cancer experience. Tweets were collected from 17 twitter accounts that belong to parents of children diagnosed with cancer, and e-mail interviews were conducted with 5 of the parents. Savolainen's framework of everyday information practice was applied in understanding the key themes of tweets posted by the parents recruited for this study. The themes include - social support and coping, casual conversations, sharing childhood cancer related facts, promoting campaigns and fundraising, raising awareness, and providing updates. The findings of this study added new information to existing research that could potentially lead to the development of a theory of online health communication during illness.
Human Trunk Multi-segment Kinematics: Sensitivity to Experimental Errors
Keywords: Kinematic Assessment
Marker Misplacement
Sensitivity Analysis
Skin Artifact
Stereophotogrammetry

Human trunk motion analysis, using optoelectronic stereophotogrammetry with skin-mounted markers, has been used as a standard practice to evaluate trunk motion. The challenge with this method is the inherent measurement errors: instrumentation error, marker misplacement error and skin movement artifact. These errors propagate into kinematic and, further, to kinetic analysis. This thesis provides the first comprehensive assessment of the impact of these errors on the accuracy of 3D kinematic analysis of the seven-segmental trunk model in able-bodied individuals during seated bending. The findings suggest that for certain movements the marker misplacement and skin movement artifact can have a profound impact on the estimation of the trunk's 3D inter-segmental joint angles, to the extent that some measurements cannot be used to derive reliable assessments. A guideline is provided that determines which kinematic data across the trunk can be used to derive meaningful judgment and which data should be used with caution.
Assessment of Upper Limb Spasticity after Stroke: Characterizing Resistance to Passive Stretch and the Impact on Active Control
Keywords: Kinematics
Robotics
Spasticity
Stroke
Upper Limb

Spasticity is a common phenomenon following stroke, characterized by involuntary resistance to passive stretch. Clinical assessments of spasticity are challenged as having poor sensitivity and do not describe the impact of spasticity on function. The purpose of this thesis was to objectively measure spasticity and establish the impact of spasticity on active, functional movement. Two studies were undertaken to A) assess kinematic variables that characterize spasticity during passive stretch and B) identify components of active, functional movement impacted by spasticity. Findings for Study 1 revealed that individuals with spasticity exhibit a measurable catch and release at fast velocities of stretch and increased resistance to passive movement at slow velocities. Findings for Study 2 revealed that stability during reaching and use of the more affected side were impacted by spasticity. This work provides a foundation for the development of a clinical assessment of spasticity that includes both passive and active components.
A Segmented Output Stage H-Bridge IC with Tunable Gate Driver
Keywords: Power Electronics
VLSI

In this thesis, an integrated H-bridge is presented for continuously optimizing the power conversion efficiency over a wide range of output current. The proposed IC incorporates both segmented output transistors and segmented gate drivers. This fully segmentation approach allows to flexibly change the on-resistance of the output stage power transistors and the output resistance of the gate drivers. Dynamic adjustment of these parameters allows to investigate the best combination of output power transistor size and gate driver size for any given load current. The IC chip is fabricated using TSMC's 0.18 um BCD Gen-2 process technology. The presented design when operating as a buck converter with a load current between 0.02 A and 4 A achieves efficiency improvements of 32% and 8% at light and heavy load current, respectively. Furthermore, the dynamically adjustable gate driver output resistance allows for suppression of the peak CEMI by 5.5 dBm.
Lanthanide-encoded Polystyrene Microparticles: Formation Kinetics and New Syntheses
Keywords: bead-based bioassays
dispersion polymerization
lanthanide-encoded
mass cytometry
microparticles
monodisperse

To obtain a better understanding of how lanthanide-encoded polystyrene microparticles are formed during their synthesis, I carried out kinetic studies of two-stage dispersion copolymerization (2-DisP) of styrene and acrylic acid, with or without added TmCl3, in ethanol in the presence of poly(N-vinyl- 2-pyrrolidone) (PVP) as a polymeric stabilizer. Particles of narrow size distribution and micrometer diameters were obtained, allowing us to compare rates of monomer conversion, Tm ion incorporation, and growth in particle size. The most striking result was that at the higher levels of TmCl3 most of the metal ion incorporation occurred late in the reaction. I examined the syntheses of polystyrene microparticles using end-functionalized macromonomers as stabilizer via dispersion polymerization (DisP). Although the synthesis in 95 % ethanol was successful, the particles were not colloidally stable in water. I also investigated the role of the co-stabilizer TX305 on the passive adsorption of proteins onto PS particles synthesized via DisP and 2-DisP.
Experimental Aeroacoustic Study of a Landing Gear in the Unsteady Flow Induced by a Propeller
Keywords: Aeroacoustics
Airframe Noise
Landing Gear Noise

An aeroacoustic study of a two-strut, two-wheel, nacelle-mounted landing gear was conducted to investigate the effects of an upstream propeller on the radiated noise. The development of a 1:10.8 scale model based on a Bombardier Q400 aircraft, consisting of a propeller, motor, nacelle, and landing gear assembly is discussed. Comparisons are made between cases with and without an actuated upstream propeller. Far-ﬁeld microphone measurements out of the airstream are presented to characterize the acoustic effects of each model component. The main strut and wheels of the model were equipped with surface-mounted microphones to measure unsteady pressures. It is shown that the noise signature of the landing gear cannot be observed over the tunnel background noise in the far-ﬁeld. Unsteady surface pressures on the main strut show dominant peaks related to vortex shedding from the drag strut for both steady and unsteady upstream conditions.
Understanding the Progression of Skeletal Muscle Dysfunction in Lung Transplant Candidates
Keywords: Exercise capacity
Lung Transplant
Muscle atrophy
Skeletal muscle

Understanding the Progression of Skeletal Muscle Dysfunction in Lung Transplant Candidates Skeletal muscle dysfunction has been linked to physical function limitations in lung transplant (LTx) recipients1. The purpose of this thesis research was to characterize muscle size, muscle strength, and functional outcomes in LTx candidates.Thirty-four LTx candidates (60 ± 8 years; 59% males) and 12 healthy controls (56 ± 9.5 years; 50% males) were included. All subjects underwent measures of muscle cross sectional area (CSA) and layer thickness (LT) of quadriceps, calf and biceps using B-mode ultrasound (US). Muscle strength of the corresponding muscles and functional tests were also assessed.LTx candidates had muscle weakness of lower limbs. Distal leg and upper limb strength and size were not impaired but exercise capacity of upper and lower limbs was significantly impaired when compared with controls. Thus, specific exercise training strategies such as resistance training are required pre- and post-transplant to target improvements in lower limb muscle function.
Associations between White Matter Microstructural Integrity and Cognition in Older Adults with Coronary Artery Disease: A Diffusion Tensor Imaging Study
Keywords: cognition
coronary artery disease
diffusion tensor imaging
executive function
memory
white matter microstructural integrity

Coronary artery disease (CAD) is associated with an increased risk of cognitive decline. Conventional neuroimaging does not fully capture the effect of CAD on cognition. This study uses diffusion tensor imaging to determine whether subtle changes in white matter (WM) microstructural integrity can further predict CAD-associated cognitive impairment. Participants (n=49) were recruited at entry into cardiac rehabilitation. Composite Z-scores were computed for executive function and memory. Diffusion weighted magnetic resonance images were acquired. WM integrity as quantified by fractional anisotropy (FA) in the left parahippocampal cingulum was significantly associated with executive function (F(1,44)=11.43, p=.002). FA in 10 other WM tracts examined was also associated with executive function but did not survive statistical correction for multiple comparisons. No associations were observed between FA in WM tracts and memory. Subtle WM microstructural changes may contribute to pathophysiological mechanisms of cognitive decline in a population prone to early neural risk for dementia.
Critical Conceptions of Graffiti in Schools
Keywords: Critical Pedagogy
Curriculum of Life
Democracy
Graffiti
Symbolic Violence

The purpose of this thesis is to examine teacher and student perceptions of graffiti found in schools. This is a qualitative study based on data collected from the interviews of ten participants (students and teachers from elementary schools). The participants were asked to comment on why they believe graffiti are produced in schools, what, if anything, should be done with graffiti in schools, and if they see any educational value in graffiti. This thesis also includes a review of literature on graffiti in schools, particularly in relation to student engagement. This thesis asserts that schools can be symbolically violent places that silence the voices of students and that it is sometimes a reaction to this violence that students write graffiti. The recommendations of this thesis include infusing critical pedagogy into learning in order to democratize schools and to enact genuine and meaningful student engagement.
Energy Harvesting using PVDF Piezoelectric Nanofabric
Keywords: Energy Harvesting
Nanofiber
Nanotechnology
Piezoelectric
PVDF

Energy harvesting using piezoelectric nanomaterial provides an opportunity for advancement towards self-powered electronics. The fabrication complexities and limited power output of these nano/micro generators have hindered these advancements thus far. This thesis presents a fabrication technique with electrospinning using a grounded cylinder as the collector. This method addresses the difficulties with the production and scalability of the nanogenerators. The non-aligned nanofibers are woven into a textile form onto the cylindrical drum that can be easily removed. The electrical poling and mechanical stretching induced by the electric field and the drum rotation increase the concentration of the piezoelectric β phase in the PVDF nanofabric. The nanofabric is placed between two layers of polyethylene terephthalate (PET) that have interdigitated electrodes painted on them with silver paint. Applying continuous load onto the flexible PVDF nanofabric at 35Hz produces a peak voltage of 320 mV and maximum power of 2200 pW/(cm^2) .
Analysis of Ultra-high Performance Fibre Reinforced Concrete Structures using Truss Models
Keywords: Beam Database
Fibre-Reinforced Concrete
Shear Beam
Strut and Tie
Truss Model
UHPFRC

Ultra-high performance fibre reinforced concrete is a novel type of cementitious material with a typical compressive strength and tensile strength of approximately 150 MPa and 7 MPa, respectively. The material has been demonstrated to carry shear in girders without the need for the addition of steel bar reinforcement. However, there is currently no method for analyzing this behaviour accurately using simple hand calculations and basic material properties. This thesis proposes a simplified method that uses truss models and stress fields to make quick and accurate ultimate load predictions. A database of shear tests conducted on UHPFRC girders was collected. It was found that the proposed truss model method for analyzing shear is more accurate than simplified methodologies that currently exist in the literature. Further work on the proposed method will consist of improved material models for tension and shear and the analysis of additional UHPFRC shear beam tests.
China's Embattled "Rule of Law": Paradoxes and the Breakthrough under Single Party Dominance
Keywords: China
Constitutionalism
Rule of Law

China's thirty years of economic development has brought on a number of crippling problems: high inequality, unbalanced development, environmental degradation and so forth. Arguably all of them coincide with China's long-enduring absence of a full-fledged legal system that could balance state power and human rights, in another word, the "rule of law". Looking into reform advancement and regression of China's legal development, this thesis argues that a "rule of law" regime as proposed by Pan Wei would either fail to come into being, or will not do the job, without constitutional and legislative reform. This thesis argues that China's centuries-old civic project is one focusing on building constitutionalism, and a Chinese Socialist Constitutional State conducive to Socialist democracy as proposed in the thesis would better reconcile the needs of the Party and society at this critical juncture, as well as in the long run.
Development Interventions and Agricultural Adaptation in a Changing Environment: A Social Network Analysis of Farmer Knowledge Transfer in Ghana
Keywords: Agriculture
Development intervention
Gender
Ghana
Knowledge transfer
Social network analysis

Formal social ties play an important role in agricultural knowledge exchange, particularly in developing-country agriculture with high exposure to development interventions. However, little is known about informal agrarian knowledge transfer in such an institutional agricultural information landscape and the consequences in terms of smallholder farm management in regions undergoing environmental change. Using a social network approach, I chart the structure of agrarian knowledge networks in six communities which have been differentially exposed to agriculture development intervention in the Brong Ahafo and Ashanti regions of Ghana. Farmer network size, density and composition were distinctly variable, with development project affiliated and male farmers tending toward larger networks and engaging in more diverse agricultural production. Furthermore, agriculture-related knowledge sources were dependent on the type of crop species produced. As promotion of diverse agriculture systems continues as a response to environmental change, understanding such social and agroecological complexities will be important for effective agriculture interventions.
Characterization of Natural Organic Matter in Bentonite Clays and Clay-rich Sediments
Keywords: Arctic
Biomarker
Clay
Natural organic matter
Nuclear magnetic resonance spectroscopy
Nuclear waste

Natural organic matter (NOM) was characterized in clays that are being considered for a used nuclear fuel sequestration concept and in clay-rich subsurface Arctic sediments. Molecular-level techniques including biomarker analysis and nuclear magnetic resonance spectroscopy were employed to gain insight into NOM chemistry. Plant waxes were identified as the main input to NOM in these samples. NOM in all samples was in an advanced state of digenesis based on several calculated degradation ratios. The compounds detected in bentonite clays are hypothesized to be mainly recalcitrant and unlikely to act as a microbial substrate. One of the Arctic sediments contained more labile material and evidence of active microbes while NOM detected in the other two Arctic sediments is hypothesized to be mainly recalcitrant. These results suggest that NOM in these samples is primarily refractory and unlikely to undergo further diagenesis. The biogeochemical stability of refractory NOM requires further study.
An Integrated Approach to Estimate Pedestrian Exposure to Roadside Vehicle Pollutants
Keywords: Dispersion
Emission
Exposure
Pedestrian
Simulation
Transportation

At many urban intersections, pedestrians and vehicles share the same space, where interactions between pedestrians and vehicles may hinder vehicle turning movements. This changes the amount of emissions generated by the vehicles, to which the pedestrians are exposed. This research investigates the pedestrian-vehicle interaction at the intersection of St. George Street and College Street in downtown Toronto. A microscopic vehicle simulation is integrated with a microscopic pedestrian simulation. Emission generation and dispersion are modelled to obtain concentration maps for emitted pollutants. The spatial-temporal data of the pedestrians are then integrated into these concentration maps to calculate pedestrian exposure to vehicle pollutants. Lastly, this framework is applied to test the effects of implementing a scramble signalling system at the intersection of St. George Street and College Street. It is found that the implementation of a scramble phase would increase exposure to Nitrogen Oxides and decrease exposure to Carbon Monoxide.
Validation of the Evidence-based Practice Confidence (EPIC) Scale among Occupational Therapists
Keywords: evaluation studies
evidence-based practice
occupational therapy
reliability
self-efficacy
validity

The objective of this study was to examine the reliability, floor and ceiling effects and construct validity of the evidence-based practice confidence (EPIC) scale among occupational therapists (OTs). A repeated measures study involving a baseline and a follow-up mail survey was conducted. One hundred and twenty-six OTs completed the baseline EPIC scale and construct validity questionnaire and 79 completed the scale at retest. Test-retest reliability, estimated using the intraclass correlation coefficient (ICC), was 0.92 (95% confidence interval (CI), 0.88-0.95). The minimal detectible change at the 95% confidence level (MDC
Efficient Fourier Transformation of Unstructured Meshes and Application to MRI Simulation
Keywords: Finite element analysis
Gaussian quadrature
MRI
Oscillatory integrals
Unstructured meshes

This thesis demonstrates different ways to compute the MRI signal in finite element magnetic resonance imaging or FE-MRI. For linear elements the MRI signal can be found analytically. The error metric for linear elements to calculate the signal with a fixed error in k-space using an adaptive Gaussian quadrature is derived using finite element function derivatives and is then extended for use in quadratic elements. The feasibility of using the numerical steepest descent (NSD) method, which is designed to compute oscillatory integrals like the MRI signal equation, was also studied. The method was found to compute the MRI signal faster than adaptive Gauss quadrature for quadratic surface elements using typical MRI imaging parameters. The feasibility of NSD is discussed for volumetric quadratic elements and for different mesh geometries.
Kriged Kalman Filtering for Predicting the Wildfire Temperature Evolution
Keywords: Kalman filtering
Kriging
mapping of spatio temporal processes
wildfire temperature modelling

Existing wildfire evolution models have been mostly developed in a deterministic modelling framework. As a complementary alternative, this thesis presents a stochastic framework based on the Kriged Kalman filter to obtain global temperature predictions given local temperature measurements. By solving the heat transfer partial differential equation driving the wildfire evolution, it is shown that the spatio-temporal mean temperature process associated with a wildfire evolving in a finite spatial domain under certain prescribed conditions can be approximated by a Fourier series. The potential of the proposed Kriged Kalman filtering framework in predicting the wildfire temperature evolution is demonstrated in simulations on temperature data generated by a simplified physical wildfire propagation model. The performance of the Kriged Kalman filter in predicting the wildfire temperature evolution is compared to that of standard Gaussian process regression.
Beyond the Pain: An Occupational Perspective on Knee Osteoarthritis
Keywords: Knee replacement
Occupational perspective
Occupations
Osteoarthritis
Secondary analysis
Thematic analysis

Total knee replacement (TKR) is an increasingly common surgery among individuals with osteoarthritis (OA). The outcomes of this surgery are positive; yet, many individuals do not fully resume their pre-TKR occupations. Literature is limited to describing the activity changes that occur but does not investigate the significance of those changes. A secondary analysis of eight purposively extracted transcripts from a primary study examining engagement in instrumental activities of daily living and personal and social roles among people with OA scheduled for surgery was conducted. A thematic analysis approach was used to examine the pre-TKR experiences of these individuals from an occupational perspective. Three themes were identified: (1) living with OA: it is more than just the knee, (2) gradually losing my occupational identity, and (3) losing too much--a "tipping point." The findings suggest that the significance of occupational changes are unique across individuals and affect their decision for surgery.