title: Turbulent Forced Convection Heat Transfer in Annular Passages

contributor:
Wade, J. H. T.
Mechanical Engineering

subject:
forced convection
heat transfer
annular passage

abstract: An experimental study of turbulent forced convection heat transfer to water flowing in a vertical annular passage is reported in this paper. The study investigates the influence of eccentricity (ranging from 0% to 80%) and diameter ratio (ranging from 1.5 to 4.0) upon the heat transfer phenomena occurring at the inner boundary of the annular passage. Dimensionless heat transfer parameters calculated from measurements made at the two locations corresponding to the maximum and minimum separation of the inner and outer boundaries of the annular passage are correlated in terms of the Reynolds number, the eccentricity and the diameter ratio. Analysis of the correlations indicates that eccentricity affects the heat transfer phenomena occurring at the two locations on the inner boundary of the annular passage in different fashions; increasing eccentricity causes the heat transfer to increase at the location corresponding to the maximum separation of the boundaries and causes the heat transfer to decrease at the location corresponding to the minimum separation of the boundaries. The magnitude of the increase or decrease in heat transfer is dependent upon the diameter ratio; at a particular level of eccentricity, the greater variations in heat transfer occur at the smaller diameter ratios. Ranges in which eccentricity does not influence heat transfer are found in connection with the larger diameter ratios. Moody friction factors calculated from measurements made with concentric annular passages are correlated as a function of Reynolds number.

abstract: Thesis

abstract: Master of Engineering (ME)


title: A Method for the Analysis of Economic Polarization: Two Case Studies; Halifax-Dartmouth, Nova Scotia and Quebec City, Quebec

contributor:
Hall, Fred
Geography

subject:
economic polaritzation
case study
nova scotia
quebec

abstract: A methodology is developed that describes the spatial-temporal trends of economic welfare levels in a region. The focus of the region is assumed to be a key city; that is, a growth pole. The methodology depicts the degree of economic polarization on the pole as time and distance change. Two case studies, Halifax-Dartmouth and its hinterland the Province of Nova Scotia and Quebec City with a hinterland 160 miles in diameter were used to test the methodology. For the 30 year period 1941-1971, the nature of economic growth in the pole cities and their hinterlands and the pole-hinterland growth relationship were determined. Some conclusions regarding the requirements for improved regional welfare levels are offered. The methodology proves itself to be sufficient for the description of spatial-temporal trends in regional welfare levels. These descriptions are suitable for use in preliminary policy formulations and subsequent preliminary plan evaluation.

abstract: Thesis

abstract: Master of Arts (MA)


title: Image, Symbol and Theme in Melville's Mardi, Moby Dick and Pierre

subject:
image
symbol
Melville
theme
Mardi
Moby Dick
Pierre

abstract:
Thesis
Master of Arts (MA)


title: Paramagnetic Cooling

contributor:
Campbell, C. K.
Physics

subject: paramagnetic cooling

abstract: A metal adiabatic demagnetization cryostat was designed and constructed. The final-temperature dependence of a single-crystal synthetic ruby was investigated as a function of applied magnetic field. The ruby was used both as a thermometer and coolant in superconducting thin-film experiments at temperatures below 1°K. Difficulties encountered in these experiments have been discussed in detail. Further improvements on the system have been suggested in the application of thin-film superconductor studies.

abstract: Thesis

abstract: Master of Science (MS)


title: Nuclear Magnetic Resonance Study of Colemanite

contributor:
Petch, H. E.
Physics

subject:
nuclear magnetic resosnance
magnetic resonance
colemanite

abstract: A single crystal of colemanite, which is ferroelectric at temperatures below about -2.0° C., has been investigated by means of nuclear magnetic resonance (n.m.r.) techniques, over a temperature range 52° C. to -136° C. The splitting b^11 the n.m.r. signal in colemanite, caused by the perturbation of the nuclear Zeeman levels by the interactions between the nuclear electric quadrupole moment and the electric field gradients existing at the boron sites at room temperature and at -40°C., has been fully analysed, using the procedure developed by lookoff and coworkers. The quadrupole coupling constants, the asymmetry parameters and the orientations of the principal axes of the electric field gradient tensors at room temperature and -40° C. are given in Tables XXV - XXII. A selected set of B^11 n.m.r. lines has been examined over the temperature range 52°C. to -136°C. This investigation suggests that the ferroelectric transition is second-order and not the order-disorder or martensitic type. The transition temperature itself has been found to depend upon the history of the crystal, but is apparently about 2°C. higher than previously reported temperatures of about -2.0° C. In addition, a previously unknown phase in colemanite is reported. A large temperature hysteresis loop is associated with the transition to the new phase; on cooling, the transition takes place at about -80°C, whereas on heating, the transition takes place at about -35° C. The point groups for the three phases have been determined as 2/m., 2 and 1 going from room temperature to -80° C., respectively. The resets of the n.m.r. investigation have been interpreted, as far as possible at present, in terms of the crystal. structure.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Baudelaire and Gautier: Some Aspects of a Literary Relationship

contributor:
Patrick, Dean
French

subject:
Baudelaire
Gautier
literary relationship

abstract: An examination of the affinities between Baudelaire and Gautier in matters of aesthetic principle, as seen in the light of their personal relations, the social climate of their times, and their works.

abstract: Thesis

abstract: Master of Arts (MA)


title: A Study of the Flow Patterns in the Gas Phase of a Bubbling Column

contributor:
Crowe, C. M.
Chemical Engineering

subject:
flow pattern
gas phase
bubbling column

abstract: The gas phase flow patterns in a bubbling column were investigated, using tracer methods to establish the residence time distributive An analogue computer obtained the moments if this distribution directly. The air flow rate and column height were varied. The results showed that as the air flow rate increased, although the voidage increased, the mean residence tine decreased. Thus an increasing proportion if the gas phase behaved as a stagnant volume. The results are correlated in terms of a mixed region model. Other work showed that an increase of liquid viscosity, or the inhibition of coalescence, affected only the stagnant volume. The rate of coalescence was investigated and an estimate of its magnitude was obtained.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Grafted Pulp

contributor:
Pelton, Robert
Chemical Engineering

subject: Pulp cellulose modification

abstract: The thesis proposed technology to graft polymers to wood pulps.

abstract:
The value and performance of Canadian premium NBSK pulps can be enhanced by attaching copolymers of maleic anhydride (MA) to the fiber surfaces, thus leading them to new applications. Kraft pulps can be treated with MA copolymers as it enters the pulp drying machine, where drying and heating results in polymer fixation. However, polymers capable of forming covalent linkages with cellulose tend to be good adhesives, dried market pulps usually cannot be redispersed (repulped).
By carefully controlling the curing conditions (i.e., the time, temperature, and pH of the polymer solution) it is possible to fix MA copolymers to pulp fibers, while also maintaining repulpability. The impact of curing on repulpability can be probed by measuring the wet tensile indices of impregnated, cured pulp sheets. We have shown that the curing conditions can be condensed into a single parameter, the product  , where  is the estimated conversion of succinic acid moieties to the corresponding anhydrides during curing, and  is the amount of added MA copolymers.
A survey of the common commercial MA copolymers identified high molecular weight (Mw) PEMA (100-500 kDa) as the most promising option, as it is possible to graft 1 and 29 kg of PEMA to each tonne of dried untreated pulp in high yield while still maintaining repulpability. PEMA grafting enhances the properties of pulp and paper in many ways, including increasing fiber swelling, increasing adsorption capacity of cationic additives, and increasing wet and dry paper strength.

abstract: Thesis

abstract: Candidate in Philosophy

abstract:
Canada is home to 9% of the world’s forests, and a forestry industry that accounts for approximately $23.7 billion of its gross domestic product (GDP) in 2019. Pulp and paper manufacturing is an important subsector in the forestry industry, contributing roughly $7 billion to Canada’s real GDP each year. In 2019, 15.4 million tonnes of wood pulp were produced, with pulp and paper exports totalling $17.7 billion. Clearly, the pulp and papermaking industry is an integral part of the Canadian economy.
Canada is a leading global supplier of wood pulp, and the largest producer of northern bleached softwood kraft (NBSK) market pulp. NBSK pulp has become the industry’s benchmark grade pulp due to its long fibers, which makes them ideal for reinforcing paper. The core objective of this research is to expand the properties of NBSK pulp by attaching polymers to the fiber surfaces, thus making them suitable for completely new high-value-added applications.
This thesis describes a completely new technology that I have developed for grafting functional polymers onto market pulps. The resulting novel market pulps are characterized by high carboxyl group content that can give stronger products and a “clickable” surface suitable for biomedical and other novel applications.


title: A Force Sensing Resistor for Monitoring Plantar Force under Foot

contributor:
de Bruin, H.
Electrical Engineering

subject:
force
resistor
plantar force

abstract: The needs for obtaining quantitative plantar force information range from basic research into foot function to assisting patients in the use of prosthetic devices. This project reviews present force monitoring techniques, describes the evaluation of a Force Sensing Resistor for monitoring plantar force and proposes a low power portable plantar force monitoring system utilizing an array of force sensing resistors.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Nitrogen-15 Isotope Effects in Bond Formation Reactions

contributor:
Bourns, A. N.
Chemistry

subject: Nitrogen-15

subject: bond-formation

abstract: Nltrogen-15 isotope effects have been measured In the simple bond formation reactions of triethylamine with methyl iodide, triethylamine with ethyl iodide and triethylamine with ethyl bromide. Tests have been performed, to establish that the reactions were unidirectional under the experimental conditions and that the chemical procedures used to convert the quaternary ammonium salts to molecular nitrogen proceeded quantitatively. The mass spectrometer data were examined by rigorous statistical tests. At 6°C. the values of the ratio of rate constants, k14/k15, were: triethylamine-methyl iodide, 1.0009 +/- 0.0005; triethylamine-ethyl iodide, 1.0007 ±0.0006; trimethylamine-ethyl bromide, 0.9994 ±0.0006. For the reaction of triethylamine with ethyl iodide the value of k14/k15 increased slightly with increasing temperature. The results have been discussed in terms of the Bigeleisen theory of isotope effects with particular reference to the correct form for the effective mass term.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Problem of Evil

subject: problem evil

abstract:
Thesis
Master of Arts (MA)


title: Isotope Effects in the Chemical and Bacterial Reduction of Sulphur Compounds

contributor:
Thode, H. G.
Chemistry

subject:
isotope effect
chemical reduction
bacterial reduction
sulphur compounds

abstract: Equilibrium exchange constants were calculated for exchange of sulphite with other sulphur compounds. The equilibrium constant for sulphur Isotope exchange between sulphate in solution and solid calcium sulphate was calculated and measured experimentally. In the chemical reduction of sulphate to sulphide S^32O-4 reacted 2.5% faster than S340-4 , in agreement with the calculated kinetic isotope effect for the step sulphate to sulphite. The isotope effect in the reduction of sulphate by Desulphovibrio desulphuricans was found to vary from 0.0 to 2.5% The results were interpreted on the basis of a mechanism involving two consecutive steps, pick-up of sulphate and reduction of sulphate to sul-phite, competing for control of the rate. The isotope effect in bacterial reduction of sulphite was studied briefly.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Baudelaire and Huysmans: A Parallel Development

subject:
baudelaire
huysmans
parallel development

abstract: An examination of the lives of Baudelaire and Huysmam, showing how they both passed through the three stages of Dandy, Decadent and Satanist on the way to a final Spirituality.

abstract: Thesis

abstract: Master of Arts (MA)


title: Dynamic Response of Inelastic Multi-Storey Building Frames

contributor:
Heidebrecht, A. C.
Engineering

subject:
dynamic response
inelastic building frames
multi-storey building

abstract:
This thesis presents an analytical method based on classical matrix methods for computing the dynamic response of elastic-plastic multi-storey building frames.
The method developed is comparatively simple and is of much use for building frames having large number of storeys. By this method, response of multi-storey buildings could be calculated on high-speed digital computers of high storage capacity. The computer program developed saves huge storage locations and thus makes it possible to analyze multi-storey frames which till now were considered as very difficult. Dynamic response of a two-storey and six-storey frame are shown to demonstrate the
utility of the method.

abstract: Thesis

abstract: Master of Engineering (ME)


title: The relationship between aerobic fitness and natural killer cell cytotoxicity in healthy children and adolescents

subject:
Exercise
Natural killer cells
Pediatrics
Aerobic fitness
Cytotoxicity

abstract: Natural killer (NK) cells are lymphocytes that can identify and destroy infected or cancerous cells without prior sensitization. Acute exercise increases total NK cytotoxic activity (NKCA) in peripheral blood. However, this may be due to the increase in NK cells in circulation post-exercise, not an improvement in the function of each cell. Interestingly, adults with higher aerobic fitness demonstrate higher NKCA/cell. The only available study in children reported lower total NKCA at baseline, but a greater increase in total NKCA with exercise in swimmers vs. non-swimmers. This study examined (1) the change in NKCA/cell following exercise in children, and (2) the relationship between aerobic fitness, pubertal status, and NKCA/cell at rest and post-exercise. Seven healthy pre- and post-pubertal children completed an aerobic fitness test on a cycle ergometer. At a second visit, participants completed a high-intensity interval cycling protocol. Blood samples were collected at rest, immediately after exercise, and after 30- and 60-minutes recovery. NKCA against a cancer cell line (K562) was quantified using flow cytometry. There was a main effect of time for NKCA/cell with a significant increase occurring between post-exercise (0.07±0.05 lysed K562 per NK) and 30-minutes recovery (0.16±0.08, p=0.014). Neither fitness nor pubertal status predicted NKCA/cell at baseline or post-exercise. The trends observed were expected, but limitations including small sample size and exclusion of elite athletes may have impacted results. This study provides a basis for future research and suggests exercise can alter NKCA/cell in children; however, the importance of aerobic fitness for NK function remains unclear.


title: Some Studies in Organo-Transition Metal Chemistry

contributor:
Maitlis, P. M.
Chemistry

subject:
organo-transition metal
metal chemistry

abstract: The work described is an extension of the ligand-transfer reactions of substituted cyclobutadienes and cyclopentadienyls previously carried out by Maitlis et al. Efforts were directed particularly to ligand-transfer reactions of n-allyl-transition metal complexes. The reactions of organic halides with metal carbonyls were also studied in attempts to isolate new organometallic derivatives.

abstract: Thesis

abstract: Master of Science (MS)


title: A Study of Ralph Cudworth Cambridge Platonist

subject:
cambridge
plato
ralph cudworth

abstract:
Thesis
Master of Arts (MA)


title: Golding and Camus: A Critical Comparison

subject:
golding
camus
critical comparison

abstract:
Thesis
Master of Arts (MA)


title: Geochemistry and Classification of Amphibolites and Related Rocks

contributor:
Shaw, D. H.
Geology

subject: geochemistry classification amphibolites rock

abstract: Amphibolites from several localities have been studied chemically. The rocks were spectrographically analyzed for Cr, V, Ni, Co, Sc, Zr, Sr, and Ba and major element analyses were done on 20 amphibolites, sediments, and igneous rocks. The chemistry of sediments and igneous rocks which right isochemically metamorphose to amphibolite has been studied. Discriminant function analyses were performed on major and minor elements, to classify rocks of known and unknown origins.

abstract: Thesis

abstract: Master of Science (MS)


title: From the Sahara's Edge: The Influence of the Desert on Gide, Saint-Exupery, and Camus

contributor:
Patrick, A. W.
Romance Languages

subject:
sahara
desert
gide
saint exupery
camus

abstract: A comparison of the experiences of Side, Saint-Exupery, and Camus in North Africa and the Sahara Desert, and an assessment of the affect of these experiences on their lives and work.

abstract: Thesis

abstract: Master of Arts (MA)


title: Cooperative Shape from Shading and Stereo for 3D Reconstruction

contributor:
Capson, David
Electrical and Computer Engineering

subject:
cooperative shape
shading
stereo
3D reconstruction

abstract: This thesis presents a survey of techniques to obtain the depth component from two-dimensional (2D) images. Two common techniques - stereo and shape from shading are examined here. Their performance is compared with an emphasis on noting the fundamental limitations of each technique. An argument is presented which suggests an adjustment of the paradigm with which stereo and shape from shading have been treated in three-dimensional vision. The theoretical development of the stereo and lighting models is followed by experiments illustrating use of these models for a variety of objects in a scene. A comparison of the results provides a motivation for combining them in a particular way. This combination is developed, and its application is examined. Using the model that is consistent for both shape and lighting, significant improvement over either stereo or lighting models alone is shown.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Philosophic Irony in the Works of Thomas Hardy

subject:
philosophic irony
Thomas Hardy

abstract:
Thesis
Master of Arts (MA)


title: An Introduction to the (Meta-) Theory of Structures

contributor:
Bruns, G.
Mathematics

subject:
metatheory
theory of structures

abstract: This thesis is intended as a self-contained, expository introduction to material found in Chapter IV of Bourbaki’s Theorie des Ensembles. With a minimum of external reference, it presents all relevant logical and set-theoretic background material and then develops and extends the notions of "species of structure", "intrinsic terms", "canonical mappings", "processes of deduction", "morphism", etc. found in this work.

abstract: Thesis

abstract: Master of Science (MS)


title: Inorganic Micro Analysis

subject:
inorganic
micro analysis

abstract:
Thesis
Master of Arts (MA)


title: Boolean Lattices, Rings and the Equivalence of Categories

contributor:
Banaschewski, B.
Mathematics

subject:
boolean lattices
rings
categories

abstract: This thesis is concerned With showing the relations among Boolean lattices, Boolean rings and Boolean spaces, It establishes that the categories of Boolean lattices and proper Boolean lattice homomorphisms, Boolean spaces and proper continuous maps, Boolean rings and proper ring homomorphisms are equivalent to each other, In the final chapter the notion of a Boolean semi-group is used to obtain an alternate characterization of a Boolean lattice.

abstract: Thesis

abstract: Master of Science (MS)


title: An Investigation of Banding in Steel by Simulation

contributor:
Kirkaldy, J. S.
Metallurgy

subject:
banding in steel
steel
investigation
banding
simulation

abstract: This thesis describes a study of the fundamental aspects of banding in steel. The banded structure is simulated by means of layer diffusion couples. Consideration is given to the amount of carbon pre-segregation that occurs in the austenitic state due to activity differences arising from a non-uniform distribution of alloying elements as well as to the segregation which occurs during subsequent transformation. A new method for the experimental determination of the off-diagonal diffusion coefficients which control the pre-segregation in ternary systems is described. Different cooling rates are used to investigate the contribution of transformation segregation toward the final structure. The effect of cooling rates on the final structure is investigated metallographically.

abstract: Thesis

abstract: Master of Science (MS)


title: Large Strain Deformation of Aluminum Alloys by Channel-Die Compression

contributor:
Embury, J. D.
Materials Science and Engineering

subject:
large strain deformation
aluminum alloy
channel-die
compression

abstract:
The mechanical properties of pure Aluminium, Al-0.2%Cu and Al-0.4%Cu at large strains were studied by channel-die compression at three different temperatures: 77K, 200K and 300K. The results were interpreted in terms of work hardening rate versus stress (0/r) diagrams. The evolution of the structure was studied on a range of scales from macroscopic to microscopic, by optical study of slip lines, X-ray diffraction for texture measurements, Electron Back-Scattering Kikuchi Patterns for local texture measurements, and by Transmission Electron Microscopy for microstructural
information. Intense shear banding was observed at large strains in all alloys at all temperatures. The texture evolution was shown to be consistent with this change in deformation mode. At low temperatures, stage HI of deformation was shown to be represented by a straight line in the 6lr diagram. Increasing the temperature lead to a dramatic decrease in work hardening rate and to an increasing concavity of the 0lr plots. The addition of solutes to pure Aluminium was shown to result in an increase of the work hardening rate, which could be represented by a simple translation of the 0/r plots on the stress axis. At large strains, all three materials experienced a stage (stage IV) of constant work hardening at low rate. The stage IV work hardening rate decreased with increasing temperature, and was not influenced by solute content. The stage Ill-Stage IV transition was very sharp at 77K and smoother at higher testing temperatures. Phenomenological models were developed for the prediction of the influence of temperature and solute content on work hardening. Moderate strains were modelled taking into account the evolution of the dislocation density into two different populations during the deformation. The influence of solutes on work hardening was modelled by considering how segregation of solute atoms at the dislocation cores influences dynamic recovery. Stage IV work hardening was considered to arise from the accumulation of dislocation debris resulting from the dynamic recovery events.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Cultural Sensitivity in Nursing: Making a World Out of Difference

contributor:
Paluch, D.
Sociology

subject:
cultural sensitivity
nursing
difference

abstract: This thesis examines the meanings that nurses attach to the concept of “cultural sensitivity”. The findings are drawn from an extensive review of nursing's formal discourse (the nursing literature) and nurses' informal discourse (indepth interviews with 31 nurses practising in Southern Ontario). An analysis of this discourse shows that there are different emphases in the formal and informal discourse, and considerable variability between nurses in how cultural sensitivity is understood. The two general orientations identified are control and humanism. A control orientation regards cultural sensitivity as a tool for increasing the efficiency of nursing care. A humanist orientation involves viewing cultural sensitivity as a process of personal growth that occurs between the nurse and client. The formal discourse in nursing tends to emphasize the control orientation while the informal discourse tends to give the humanist perspective more prominence. The thesis concludes by suggesting that efforts to promote cultural sensitivity will continue to be problematic so long as these differences in how the concept is understood are overlooked.

abstract: Thesis

abstract: Master of Arts (MA)


title: REAL-TIME UPDATING AND NEAR-OPTIMAL ENERGY MANAGEMENT SYSTEM FOR MULTI-MODE ELECTRIFIED POWERTRAIN WITH REINFORCEMENT LEARNING CONTROL

contributor:
Emadi, Ali
Mechanical Engineering

subject:
Energy management system
Reinforcement learning
Real-time
Hybrid electric vehicle
Deep reinforcement learning
Actor-Critic
Asynchronous training
High-fidelity transmission
Multi-mode electrified powertrain
Charge sustainability
Unfamiliar driving scenario
Markov decision process

abstract:
Energy management systems (EMSs), implemented in the electronic control unit (ECU) of an actual vehicle with electri ed powertrain, is a much simpler version of the theoretically developed EMS. Such simpli cation is done to accommodate the EMS within the given memory constraint and computational capacity of the ECU. The simpli cation should ensure reasonable performance compared to theoretical EMS under real-life driving scenarios. The process of simpli cation must be effective to create a versatile and utilitarian EMS. The reinforcement learning-based controllers feature pro table characteristics in optimizing the performance of controllable physical systems as they do not mandatorily require a mathematical model of system dynamics (i.e. they are model-free). Quite naturally, it can aspired to testify such prowess of reinforcement learning-based controllers in achieving near-global optimal performance for energy management system (supervisory) of electri ed powertrains. Before deployment of any supervisory controller as a mainstream controller, they should be essentially scrutinized through various levels of virtual simulation platforms with an ascending order of physical system emulating-capability. The controller evolves from a mathematical concept to an utilitarian embedded system through a series of these levels where it undergoes gradual transformation to finally become apposite for a real physical system. Implementation of the control strategy in a Simulink-based forward simulation model could be the first stage of the aforementioned evolution process. This brief will delineate all the steps required for implementing an reinforcement learning-based supervisory controller in a forward simulation model of a hybrid electric vehicle. A novel framework of loss-minimization based instantaneous optimal strategy is introduced for the energy management system of a multi-mode hybrid electric powertrain in this brief. The loss-minimization strategy is flexible enough to be implemented in any architecture of electrified powertrains. It is mathematically proven that the overall system loss minimization is equivalent to the minimization of fuel consumption. An online simulation framework is developed in this article to evaluate the performance of a multi-mode electrified powertrain equipped with more than one power source.  An electrically variable transmission with two planetary gear-set has been chosen as the centerpiece of the powertrain considering the versatility and future prospects of such transmissions.  It is noteworthy to mention that a novel architecture topology selected for this dissertation is engendered through a series of rigorous screening process whose workflow is presented here with brevity.
One of the legitimate concern of multi-mode transmission is it's proclivity to contribute discontinuity of power-flow in the downstream of the powertrain. Mode-shift events can be predominantly held responsible for engendering such discontinuity. Advent of dynamic coordinated control as a technique for ameliorating such discontinuity has been substantiated by many scholars in literature. Hence, a system-level coordinated control is employed within the energy management system which governs the mode schedule of the multi-mode powertrain in real-time simulation.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Diffusion Interactions in Copper - Rich Copper - Zinc - Tin Alloys

subject:
copper rich alloy
copper
zinc alloy
tin alloy

abstract: In this thesis, in investigation of various diffusion couple designs is discussed with the aim of enhancing the interaction between the three diffusive flow. Experimental investigation of the theoretical predictions his been carried out for infinite and finite couple boundary conditions. The four independent diffusion coefficients in the copper-rich copper-zinc-tin system have been measured it two temperatures for the dilute composition range.

abstract: Thesis

abstract: Master of Science (MS)


title: A Model for the Flow of Blood in Capillaries

contributor:
Vlachopoulos, J.
Chemical Engineering

subject:
model
blood flow
capillaries

abstract: A new constitutive equation has been developed for the flow of blood through capillaries. Pressure drop and volume flow data of Haynes and Burton and Merrill et al. have beer utilized in this development for a range of radii from 57.04 micra to 747.4 micra and a hematocrit range of 8.8% to 82.5%. A comparison has been made with the Casson equation used by Merrill and Pelletier and the advantage of this new equation over the Casson equation has been verified. The usual assumption of no-slip-at-the-wall has been verified to be valid, up to a hematocrit level of 39.3%.

abstract: Thesis

abstract: Master of Engineering (ME)


title: "La Princesse de Babylone": The Work of a Philosophe

contributor:
Conlon, P. M.
French

subject:
Bablyon
Princess of Babylon
La Princesse de Babylone
critical analysis
Philosophes
Voltaire

abstract: A critical analysis of La Princesse de Babylone, linking the thought and style with the ideas and literature of the Philosophes and of Voltaire in particular.

abstract: Thesis

abstract: Master of Arts (MA)


title: Temporal Aggregation Approaches for Few-shot Human Action Recognition in Videos

contributor:
He, Wenbo
Computing and Software

abstract: Over the past decade, the research of deep learning has dramatically progressed and achieved overwhelming performance for various tasks. This success is highly dependent on a large number of manually labeled data. However, it is not always possible to collect enough training data, meanwhile manually labelling a large amount of data is labour-intensive. To learn from a limited number of examples with supervised information, a new machine learning paradigm called Few-Shot Learning (FSL) is introduced. For the few-shot human action recognition task, the core challenge is preserving both spatial and temporal information of the video with few labeled videos. Many approaches based on Convolutional Neural Networks (CNNs) or Recurrent Neural Networks (RNNs) have been proposed to address the human action recognition task. However, these works fail to preserve the temporal information of the entire video and require a large number of training videos, hence directly applying them to solve the few-shot human action recognition would severely overfit. Currently, there are only a few approaches to address the few-shot human action recognition problem. They either focus on learning how to compare the similarity between video descriptors with few training samples or solving the training samples deficiency by data augmentation. In this thesis, we propose three approaches that preserve the temporal information of the entire video given the frame/segment features: the Discriminative Video Descriptor (DVD), Temporal Attention Vector (TAV) and Contents and Length based Temporal Attention (CLTA). These methods preserve the temporal information of the entire video by convolving frame features with the basis for small dimensional space recursively, aggregating the frame/segment features with temporal weights which are manually defined, aggregating the frame features with temporal weights which is provided by learned Gaussian distribution functions based on both length and content of the video, respectively. We evaluated our approaches on different datasets in various scenarios (regular or few-shot), our approaches achieve comparable or better results compared to the state-of-the-art approaches on different datasets.

abstract: Thesis

abstract: Doctor of Science  (PhD)

abstract: The core challenge of human action recognition in video is generating the descriptor which preserves the spatial (the content in a single frame) and temporal (the correlation between the frames) information of the video. Various actions need a different number of frames to represent. For example, it is hard to distinguish action walking and running given a single frame. Current approaches adopt Deep Neural Networks (DNNs) to study the video descriptor. However, they fail to preserve the temporal information of the entire video and require a large number of training videos, hence cannot be directly used in the few-shot scenario. In this thesis, we propose three video descriptor generation approaches that preserve the temporal information of the entire video and only introduce a few training parameters. We show that our approaches achieve comparable or better performance compared to the state-of-the-art approaches for both regular and few-shot human action recognition tasks.


title: Experimental Investigation on Inclusions in Medium Manganese Steels and High Manganese Steels

contributor:
Dogan, Neslihan
Materials Engineering

subject:
high manganese steel
steel
ASPEX
AHSS
Inclusion
Inclusion Analysis
Light-weight steels
Scanning electron microscope
Medium manganese steel
Co-precipitation

abstract:
Advanced High Strength Steel (AHSS) has become a popular steel grade among automakers to produce vehicle bodies. With improvements in strength and elongation, AHSS has evolved to its 2nd generation, including high manganese steel. Even though it has outstanding strength, the 2nd generation of AHSS faces some production problems due to its high alloying elements. With continual improvement, the 3rd generation of AHSS is currently in production. In this generation, the steel types still have a competitive strength and elongation like the 2nd generation of AHSS while having lower alloying element contents and production costs. One of the types of 3rd generation AHSS is medium manganese steel. Research related to the 2nd and 3rd generation of AHSS mainly focuses on their mechanical properties and microstructures. As there is a strong correlation between mechanical properties and inclusion characteristics, further investigation of the evolution of inclusions is still required.
In this study, high-temperature experiments were conducted to investigate the effects of metal chemistry on the inclusion evolution in liquid steel. The concentrations of manganese, aluminum, and nitrogen were varied systematically. Two and three-dimensional analysis techniques were applied to study the number, composition, and size distribution of inclusions. Electrolysis extraction was used to identify the oxide, sulfide, and nitride inclusions, whereas an automated SEM with an ASPEX feature was used to detect a larger number of inclusions for better representation of the steel matrix.
This work has established inclusion classification rules to distinguish nitride inclusions from oxide inclusions. To the best of the authors’ knowledge, this is the first discussion of this type of inclusion classification in the open literature. Based on the automated SEM (ASPEX Feature) analysis, the type of detected inclusions in medium and high manganese steels were Al2O3(pure), Al2O3-MnS, AlN(pure), AlN-MnS, AlON, AlON-MnS, and MnS inclusions. As the manganese content in the steel increased from 2% to 20%, the total amount of inclusions, especially AlN-contained inclusions, was raised. This phenomenon occurred due to the increase in nitrogen solubility with increased manganese content in the steel. The thermodynamic calculation also predicted that AlN inclusions would form when the steel was cooled or during the solidification. Moreover, AlN and MnS inclusions were observed to co-precipitate together.
Similar to manganese, the increase in the aluminum content (Al = 0.5-6%) increased the total amount of inclusions in the steel, and the dominant inclusion type is AlN. AlN and Al2O3 inclusions can be heterogenous nucleation sites for MnS inclusions. Furthermore, Al2O3 inclusions also became heterogeneous nucleation sites for AlN inclusions.
The experimental set-up was further modified to investigate the effect of nitrogen on the formation of inclusions in the medium manganese steels. The nitrogen was introduced by purging or injecting N2 gas into the steel system. Similar to the effect of manganese and aluminum, the increase in the nitrogen content also increased the total amount of inclusions. Once the nitrogen content in the steel exceeded the critical limit for the formation of AlN inclusions, AlN inclusions can be stable in the liquid steel. Moreover, regardless of the nitrogen content in the steel, AlN-MnS inclusions were formed in the slow-cooled steels. In terms of morphology, AlN inclusions can be formed of plate-like, needle, angular, agglomerate, or irregular shapes.
Furthermore, a brief investigation on the addition of calcium and nitrogen to the medium manganese steels found that calcium led to the formation of other complex inclusions, such as CAx and CAS-Other inclusions. In the medium manganese steel composition in the present study, the number of CAS-Other inclusions was dominated by (Ca,Mn)S-Oxide inclusions after the addition of Ca. However, with time and after introducing N2 gas into the steel, the number of (Ca,Mn)S-Nitride inclusions also increased. The formation of (Ca,Mn)S-Nitride inclusions resulted from the co-precipitation of CaS, MnS, and AlN.
The current work provides a better understanding of the formation mechanism of inclusions in medium manganese steels and high manganese steels. It presents complete information on the characteristics of inclusions, such as the number density, type, and morphology of inclusions. This knowledge can help steelmakers improve the steelmaking process to control the formation of inclusions, which can be problematic for the manufacture and performance of medium manganese steels and high manganese steels.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Incarnational Fruit: Authorization and Women's Anonymous Seventeenth-Century Devotional Writing

contributor:
Silcox, Mary
English and Cultural Studies

subject:
early modern
seventeenth century
gender
embodiment
devotion
relationality
interpersonal
selfhood
subjectivity
women
authorship
anonymity
readership
Eliza's Babes
An Collins
Susanna Hopton

abstract: This dissertation asserts that women’s anonymity in seventeenth-century devotional texts functions as a performance to be understood rather than a mystery to be solved. Anonymity has long been framed as merely a protean form of authorship or a barrier to the recovery of a lost literary history. The archive frequently renders anonymity invisible or reveals anonymity at the moment of its undoing; however, this study of women’s anonymity contends that, although women applied anonymity to avoid the stigma of print, their anonymity functions less as a blind than as a frame to emphasize those traits they wished most to expose. In my first and second chapters, I demonstrate how the anonymous Eliza’s Babes (1652) and the nearly anonymous An Collins’s Divine Songs and Meditacion (1653) use the anonymous text to replace the signification of sick, infertile, and therefore volatile female bodies with an imitative production of devotion that constitutes the text as a divinely-restored, alternatively-productive body through which they relate to God and reader. Readers’ positive reception of this devotional re-signification of the body’s productivity countermands stereotypes readers hold against women writing, affirms the woman writer as faithful, and reincorporates both reader and writer in a corporate body of believers through their mutual participation in devotional practices. My third chapter affirms the perceived authority of anonymity’s corporate voice through the exploration of George Hickes’s retroactive attribution of several late seventeenth-century anonymous devotional texts to Susanna Hopton. I argue that the derivative nature of the anonymous devotional collections invests them with a corporate voice Hickes finds to be a valuable asset in his defense of Hopton’s devotional acumen. Drawing together scholarship on seventeenth-century relationality and intersubjectivity, readership, devotion, and women’s health, this study reconsiders the signification of women’s anonymity and their unoriginality as a tool that facilitates agentive reading and rehabilitates women’s claim to corporate belonging.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A comparison of the physical radiation-induced bystander effect and peroxide-mediated oxidative stress in human and murine epithelial cells

contributor:
Mothersill, Carmel
Biology

subject: Radiation-induced bystander effect; ultraviolet radiation; non-targetted effects of ionizing radiation; melanin

abstract:
The effects of low doses of ionizing radiation on living things is a continually evolving area of
research. Importantly, low dose effects were historically overlooked and not properly accounted
for the assessment of risk to human health, as is the case with the contentious linear no-threshold
model. These low dose effects are now known to be relevant to human health in both accidental
and intentional exposures, including doses relevant to medical diagnostics and therapeutics.
Furthermore, there is a relative dearth of information on low dose effects in non-human species,
which necessitates further investigation and evaluation of radiosensitivity. Radiation-induced
bystander effects occur in organisms due to the receipt of signals from directly irradiated cells,
which act to communicate radiation damage to surrounding cells. Recent research has identified
one type of bystander signal which is carried by photons of biological origin, however the effects
produced in bystander cells receiving these photons has not been extensively investigated. It was suspected, based on previous research, that reactive oxygen species participate in the manifestation of this bystander effect. Three mammalian cell lines were assessed for their ability to produce bystander photons upon direct irradiation; subsequently, radiologically unexposed cells were exposed to the resulting photons and assayed for biological effects. The human cell lines used exhibited significant photon emissions and oxidative stress, clonogenic cell death,
reduced cellular metabolism, and compromised mitochondrial oxidative phosphorylation
following exposure to these photons. The use of a melanocyte cell line indicated that these
effects are attenuated by melanin, and this is suspected to occur through photoabsorption or
antioxidant mechanisms. Additionally, the same assays were conducted following cell exposure
to hydrogen peroxide at low concentrations to assess responses to oxidative stress relevant to bystander responses, indicating less overall sensitivity in the examined melanocytes. These findings are significant because they contribute to our understanding of the mechanisms behind low dose biological effects, because they further challenge the linear no-threshold model and other models based on target theory, because they provide evidence for differential responses to the physical bystander signal in non-human species, and because secondary photon emissions are likely relevant to the medical radiation sciences.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Low doses of ionizing radiation interact with living things differently than high doses. Low dose effects are now known to be relevant to human health and protection of the environment. Radiation-induced bystander effects occur in cells due to the receipt of signals from irradiated cells which act to communicate radiation damage to surrounding cells. One type of bystander signal is carried by photons emitted from directly irradiated cells, however the effects produced in bystander cells receiving these photons has not been extensively investigated. This thesis investigates the cellular effects of these “biophotons”, including cell survival, oxidative stress, and metabolism.


title: Detection of Trichomonas vaginalis, Giardia and Cryptosporidium spp. in Remote Indigenous Communities in Canada using a Point-of-Care Device

subject:
Trichomonas Vaginallis
Giardia and Cryptosporidium spp.
point-of-care
remote Indigenous communities

abstract: The Indigenous population in Canada disproportionately faces a large number of infectious diseases, such as Trichomonas vaginalis (Trich), Giardia and Cryptosporidium spp. For example, in Alberta, the highest prevalence of Trich in Indigenous women was found at 10.1%, which is concerning, considering that Indigenous people constitute 3.8% of Canada’s population. Patient samples from remote Indigenous communities are currently sent to a central processing facility, which results in wait times of up to a month. This is worsened by a lack of access to full-time healthcare staff and clinics, along with the stigma of getting tested. The aim was to explore the current diagnosis and management strategies for Trich, Giardia and Cryptosporidium spp., along with issues faced in accessing primary healthcare in remote Indigenous communities. This was done to establish parameters for the development of a diagnostic device suitable for remote areas with resource constraints and cultural considerations. This investigation was done through a literature search and three structured interviews to obtain the perspectives of a healthcare worker, a researcher, and a member from Indigenous communities in Ontario. To meet the identified needs for a locally accessible, financially affordable, user-friendly, and rapid diagnostic device, a point-of-care device should be designed. This can ensure the diagnosis of various infectious diseases based on pathogen motility for patients of any sex, with or without symptoms. Understanding the current technologies available and gaps in access to healthcare can lead to the development of a suitable diagnostic device for a variety of resource-constrained communities.


title: The Synthesis and Characterization of Dendronized Biomacromolecules

contributor:
Adronov, Alex
Chemistry and Chemical Biology

abstract:
Dendrimers are a unique class of polymer characterized by their structural perfection, monodisperse nature, and well defined, multi-valent periphery. These reasons, among others, make dendrimers an attractive polymer for use in biological systems, particularly in the field of polymer- protein therapeutics. While many therapeutics make use of a native enzyme, tethering a polymer to the therapeutic has many advantages such as increasing the lifetime of the therapeutic, and its overall efficacy. Polymer-protein therapeutics however must be selective to which biomolecules they interact with. While small molecule interactions are important to the regulation of the therapeutic, larger macromolecular interactions can often have a negative impact. It therefore becomes a challenge to construct polymer protein therapeutics that can selectively control these substrate interactions. The molecular sieving effect investigates this idea through the preparation of polymer-protein conjugates that can selectively interact with biomolecules of certain sizes.
While it has recently been shown that the molecular sieving effect can be achieved using high generation dendrimers that are quite large in size, these dendrimers are time consuming, and laborious to construct. In this work we sought out to further explore the molecular sieving effect using a series of novel linear-dendritic hybrid polymers. We hypothesized that appending a linear polymer to a lower generation dendrimer would help to prepare the larger polymeric constructs necessary for molecular sieving, in a more time- and labour-efficient manner. Furthermore, the addition of a linear polymer onto a dendrimer can have a beneficial effect the overall behaviour of the eventual conjugate.
Herein, we describe the synthesis of a library of linear-dendritic hybrid polymers and their conjugations to a model enzyme. This library consists of 9 novel linear-dendritic hybrid polymers, each varying in the generation of dendrimer used, and the size of linear polymer, PEG, appended to the dendrimer’s periphery. We first prepared these dendrimers using divergent synthesis approach, however, dendrimer core modifications post-PEGylation were unable to be performed due to complete core isolation within our dendrimers. We then developed a convergent synthesis approach to prepare these dendrimers which proved to be a better alternative as core modifications before PEGylation circumvented the issues we faced with the divergent approach. Each PEGylated dendrimer was functionalized to obtain a reactive DBCO moiety that would allow for simple conjugation to our model enzyme using click chemistry. Upon full characterization of each linear- dendritic hybrid polymer, select analogs were then conjugated to our model protein, a- chymotrypsin, which was functionalized with azide residues. SPAAC chemistry allowed for full conjugation to proceed quickly, and with minimal purification. After a full characterization of each conjugate, it was concluded that each conjugate was fully dendronized as intended.

abstract: Thesis

abstract: Master of Science (MSc)


title: Preactivated Thiomer Mucoadhesive Micelles for Anterior Ophthalmic Drug Delivery

contributor:
Sheardown, Heather
Chemical Engineering

subject: Polymers, Biomaterials, Ocular, Drug Delivery, Mucoadhesion, Dry Eye Disease

abstract:
Effective delivery of drugs to the anterior segment of the eye is notoriously inefficient due to the anatomical barriers in place. Topical administration is the most common method of drug delivery to the anterior segment. When applied to the ocular surface, topical solutions encounter barriers such as lacrimal drainage, rapid tear turnover, and reflex blinking which result in < 5% of instilled therapeutic reaching the intended tissue. One potential method to evade some of these anatomical barriers and improve the delivery of therapeutics is the use of mucoadhesive nanoparticles. These materials are designed to encapsulate a relevant ocular therapeutic and provide a means of maintaining the vehicle on the ocular surface by adhering to the mucin layer of the tear film.
To this end, the work presented herein describes the design, characterization, and testing of a novel mucoadhesive polymeric nano-micelle ocular drug delivery system. The base polymer used was selected from a system that has been previously used in the Sheardown Lab. It was composed of poly(D,L-lactide)-block-poly(methacrylic acid-co-3-(acrylamido)phenylboronic acid) (PLA-b-P(MAA-co-3-AAPBA); LMP-20). The formulation was modified to replace the 3-AAPBA monomer, which contains phenyl boronic acid as the mucoadhesive component, with a preactivated thiol monomer (pyridyl disulfide ethyl methacrylate; PDSMA) to generate a novel polymer (LMS-20) to investigate the potential for drug incorporation and mucoadhesion. Modifications of the polymer were made with small thiol molecules cysteamine (Cys; LMC-20), glutathione (GSH; LMG-20), and N-acetyl cysteine (NAC; LMA-20) with a goal of reducing cytotoxicity associated with the 2-pyridinethione leaving group.
Synthesis of the PDSMA monomer, LMS-20 and LMP-20 polymers, and modified polymers LMC-20, LMG-20, and LMA-20 were confirmed by 1H NMR. LMA-20 was chosen for further examination as it contained the most relevant thiol modification for ocular applications and was capable of nanoprecipitation to form aqueous micelles with previously developed methods. Micelles were formed from LMA-20 and LMP-20, with spherical morphology as confirmed by TEM. Effective diameters of 64 ± 5 nm and 72 ± 3 nm are reported for LMA-20 and LMP-20, respectively, as confirmed by DLS. Critical micelle concentration for LMA-20 of 217 mg/L was found via a pyrene fluorescence study, significantly lower than the concentration of intended application. LMA-20 and LMP-20 are predicted to be mucoadhesive based on results of zeta-potential studies. However, oscillatory rheology studies were inconclusive based on a negative rheological synergism. LMA-20 micelles loaded with 0.16% (w/w) Cyclosporine-A were able to provide sustained release of drug up to 3 days in vitro. These results suggest the possible future use of these preactivated thiomer-based materials for the delivery of therapeutics to the anterior segment.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: INVESTIGATING THE FUNCTIONAL RELEVANCE OF AFFERENT INHIBITION

contributor:
Nelson, Aimee
Kinesiology

abstract: Afferent inhibition is a phenomenon observed when an afferent volley evoked by peripheral nerve stimulation inhibits descending corticospinal output. Notably, this phenomenon is not observed in special populations exhibiting impairments in cognitive and/or sensorimotor function, suggesting that it plays an important role in normal human function. The overall goal of this thesis was to contribute new knowledge to the understanding of afferent inhibition. This was achieved by investigating the functional relevance of afferent inhibition and exploring methods for improving data acquisition. In study 1, I examined the relationship between long-latency afferent inhibition (LAI) and sensory afference, and determined the optimal stimulation parameters that would evoke maximal LAI. In study 2, I sought to determine the underlying neurotransmitter basis of afferent inhibition. The results showed that both LAI and short-latency afferent inhibition (SAI) are modulated by GABAA receptor activity but not GABAB receptor activity. Study 3 showed that these measures of afferent inhibition have poor-to-moderate reliability with moderately high levels of within-subject variability. In study 4, I investigated the relationship between afferent inhibition and glucose function. I found that ingestion of a glucose bolus does not modulate the magnitude or variability of afferent inhibition. In study 5, I explored the role of afferent inhibition in motor cortex organization. The results suggest that afferent inhibition may not be a mediator of motor cortex reorganization that occurs following sensory enrichment. Finally, I proposed a model of the neural pathways underlying SAI and LAI that would lead to inhibition of corticospinal output. The findings from this thesis contribute new knowledge to the afferent inhibition literature that will be useful for improving future study methodologies and understanding the linkage to human function.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: The brain plays an important role in collecting sensory information from the environment and using that information to guide the movement of our limbs in space. The key structures within the brain that are important for this process to occur correctly include the primary motor cortex and primary somatosensory cortex. The primary motor cortex is responsible for executing movements, while the primary somatosensory cortex is responsible for processing tactile information. The connectivity between these two areas is thought to be important for integrating incoming sensory information with plans for movement execution. This thesis explores how we can accurately assess the activity of these sensorimotor connections and why these connections are important for normal human function. Therefore, the findings of this dissertation will contribute to our understanding of motor control.


title: Relationship between hand anthropometry and hand strength and hand function in people with hand osteoarthritis

contributor:
MacDermid, Joy
Rehabilitation Science

subject: Hand Osteoarthritis, Hand Anthropometry, Hand strength, Hand function

abstract:
Hand Osteoarthritis (HOA) is the most common joint disease that affects the finger joints of older adults. Individuals with HOA have decreased handgrip strength and hand function. People with this condition have difficulties in grasping, gripping, twisting, and turning objects in daily living. As the disease advances structural changes such as loss of normal joint space, osteophyte formation, and bony nodules in people with HOA are common. Several investigators have examined the relationship between hand or body anthropometrics and handgrip strength and hand function in healthy diverse populations; however, no previous studies have investigated this association in people with HOA.
The purpose of this thesis was to investigate the relationship between body and hand anthropometrics with hand strength and function in people with HOA, encompassing 2 papers. The first manuscript in this thesis was to describe the relationship between body and hand anthropometric variables with hand strength in people with HOA. In addition, it sought to establish the relative contribution among those variables for hand grip and pinch strengths in people with HOA. The second manuscript in this thesis was to describe the relationship between body and hand anthropometric variables with hand function in people with HOA. Further, it examines how anthropometric and demographic factors in combination explain hand function and health status in people with HOA. Finally, the thesis addresses the implications for the studies, limitations, and conclusions.

abstract: Thesis

abstract: Master of Science (MSc)


title: Synthesis and Development of Precursor Molecules and Reactions for Atomic Layer Deposition (ALD) of Elemental Zn and Ge

contributor:
Emslie, David J. H.
Chemistry

subject: ALD, Atomic Layer Deposition, Zinc, Germanium, Solution reactivity

abstract:
Ultra-thin films of pure elements are important in microelectronics due to their wide range of applications. Atomic Layer Deposition (ALD) has drawn increasing attention as the thin films deposition technique for applications in microelectronics, due to its ability to deposit thin films with high conformality with atomic level control of the thickness of the film. However, due to the limited number of suitable precursor/co-reactant pairs available, only a few pure elements have been deposited successfully by ALD to date.
The current study involves the synthesis and identification of potentially suitable precursor and co-reactant molecules for ALD of elemental Zn and Ge, neither of which have previously been achieved. MeZnOiPr, Zn(OiPr)2, and ZnEt2 were investigated as Zn precursors while GeCl2(Dioxane), Ge{N(SiMe3)2}2, and Ge(OCH2CH2NMe2)2 were investigated as Ge precursors. Co-reactants of interest were, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin), PhSiH3, [H2Al(tBuNCH2CH2NMe2)] (LAlH2), BH3(NMe3), and AlH3(Quinuclidine). Ligand-exchange reactions between precursors and co-reactants were expected to produce unstable zinc or germanium hydride species, which would then reductively eliminate to produce the pure element. Solution reactivity studies were employed to identify potential precursor/co-reactant pairs.
Solution reactions of Zn precursors with the selected co-reactants indicated that unstable ZnH2 is produced during the reactions, and will dissociate into its elements (Zn and H2) at room temperature. These solution reactivity studies revealed that, HBpin and LAlH2 were more reactive as co-reactants than BH3(NMe3), AlH3(Quinuclidine), and PhSiH3. Additionally, MeZnOiPr and ZnEt2 exhibited the highest reactivity as precursors, although the lower reactivity of Zn(OiPr)2 may simply be due to low solubility.
Solution reactions of Ge precursors produced a polymeric mono-germanium hydride species (GeH)x, which will only dissociate into its elements upon heating at elevated temperatures. While LAlH2 indicated high reactivity with all Ge precursors, it was difficult to arrange co-reactants in order of reactivity as most reactions immediately produced insoluble (GeH)x upon mixing reagents at room temperature. Ge(OCH2CH2NMe2)2 found to be the most reactive precursor out of all Ge precursors investigated.

abstract: Thesis

abstract: Master of Science (MSc)


title: Powerless Patient: Reclaiming Agency through Patient Narratives

title: Powerless Patient: Reclaiming Agency

contributor:
Savage, Anne
English and Cultural Studies

subject:
Autopathography
Illness narrative
Patient narrative
Patient experience
Rare medical events
Healthcare professionals
Patient
Caregiver
Postoperative Cognitive Dysfunction
Postoperative Cognitive Changes
Communication
Cognitive impairment

abstract: This thesis aims to highlight the relevance of patients engaging with their patient narratives as a tool in recovery from illness and in regaining their sense of agency.

abstract:
This thesis aims to rename the term ‘illness narrative’ to a more disclosive writing called the ‘patient narrative’ as a means to focus on the patient as a person who experiences illness, instead of the illness label. Exploring patient narratives, such as Susannah Cahalan’s Brain on Fire: My Month of Madness, as a form of disclosive writing will highlight the need for this tool to act as a more personal and effective communication between patients, healthcare professionals, and caregivers. The thesis is presented in two parts: a critical essay and my patient narrative.
Part One is a critical essay that explores how engaging with patient narratives contributes to the patient reclaiming their agency and sense of identity. In three subsections, the essay highlights the difficulties patients go through with illnesses or rare medical events, as well as the emotional and physical impacts that they experience, going beyond medical symptoms. The essay focuses on three points separated into three sections. The sections are: Recognizing Pathologies and Injuries, Communication and Language in the Patient Experience, and Reclaiming Agency. Part Two is my autopathography centring on the complications encountered while seeking a common surgery. After general anaesthesia, I develop Postoperative Cognitive Changes of unknown aetiology. This greatly complicates the situation when surgery is needed, and the ensuing cognitive impairments have lasting impacts on me academically, personally, emotionally, and socially.
While both parts are distinct, together they mirror how patient narratives have the iv
potential to bridge the communication gap between medicine and humanities. As such, patient narratives can communicate connections between patients, medical communities, and a broader audience which acts to underscore the need of a deeper awareness for the importance of compassion and empathy for those experiencing any form of health challenge.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: Patient narratives are a form of expressive writing that enables the patient to regain their sense of identity and agency following a health illness. When a person first becomes a patient, they leave their known world of familiarity and comfort and enter into a new one on their health journey. Their language and ways of communicating are required to adapt to the world of medicine. The patient loses their sense of identity and agency as a result of their illness. This thesis is presented in two parts, a critical essay and my brief patient memoir, and will explore how the patient, when engaging with patient narratives such as Susannah Cahalan’s Brain on Fire: My Month of Madness, can reclaim their agency and sense of identity. The first part is an essay exploring the contributions of patient narratives. The second part is my memoir, exemplifying a patient narrative.


title: Rehabilitation in the Cardiac Surgery Intensive Care Unit

contributor:
Solomon, Patricia
Rehabilitation Science

subject:
Cardiac Surgery
Physiotherapy
Intensive Care Unit
Critical Care

abstract:
Critical illness can be iatrogenic, arising from the lifesaving measures undertaken during admission to critical care. Early mobilization (EM) of patients receiving intensive care unit (ICU)-level care may reduce the possible iatrogenic effects of critical care following cardiac surgery. While evidence supports the safety and efficacy of physiotherapy in the medical-surgical ICU, few studies have included critically ill patients with complicated, prolonged post-operative recoveries despite the worldwide frequency of cardiac surgery. This has resulted in a lack of clinical practice guidelines or systematic reviews to help guide critical care physiotherapy practice in post-operative cardiac surgery. In-bed cycling is a modality to initiate EM. However, its safety and feasibility have yet to be established in the critically ill cardiac surgery population. There is also a paucity of qualitative research investigating clinicians’ attitudes and beliefs about in-bed cycling as an acceptable rehabilitation modality.
Purposes:
(1)	To describe current physiotherapy practice for critically ill adult patients requiring prolonged admissions to ICU post cardiac surgery in Ontario via an electronic, self-administered survey;
(2)	To investigate the feasibility of in-bed cycling in a pilot study in a sample of critically ill cardiac surgery patients in Hamilton, Ontario;
(3)	To explore primary frontline clinicians’ experiences and impressions of their involvement with in-bed cycling in the cardiac surgical ICU via an interpretive description qualitative interview study.

With adequate physiotherapy staffing, in-bed cycling was found to be safe and feasible with few adverse events occurring during cycling. With an 80% response rate, our survey results suggest that Ontario critical care physiotherapists provide a variety of interventions ranging from chest physiotherapy to functional mobility. Clinicians supported the use of in-bed cycling. Concerns included how to identify appropriate patients and timing of the intervention. This thesis built upon the current critical care research by increasing the presence of the cardiac surgery population in the rehabilitation literature.

abstract: Thesis

abstract: Doctor of Rehabilitation (RhD)

abstract: Early exercise can help patients rehabilitate after a critical illness. No current research exists examining the role of in-bed cycling with patients who become critically ill after heart surgery (so called “off-track”). The thesis goals were: (1) to conduct a survey of Ontario ICU physiotherapists to understand their role treating off-track patients with a complicated post-operative recovery; (2) to determine if cycling is safe and feasible with sick patients after heart surgery in the intensive care unit (ICU); and (3) to interview staff in the Hamilton heart surgery ICU to understand their experiences with in-bed cycling. Ontario physiotherapists provide a multitude of interventions in the heart surgery ICU. Cycling was found to be safe and feasible with adequate physiotherapy staffing. Intensive care unit staff supported in-bed cycling but were concerned about choosing the right patients and how best to time its introduction. With limited evidence around physiotherapy in the heart surgery ICU, larger studies are needed.


title: Efficient Mobile Computation Offloading with Hard Task Deadlines and Concurrent Local Execution

contributor:
Todd, Terence D.
George, Karakostas
Dongmei, Zhao
Electrical and Computer Engineering

subject:
Mobile Cloud Computing
Mobile Computation Offloading

abstract:
Mobile computation offloading (MCO) can alleviate the hardware limitations of mobile devices by migrating heavy computational tasks from mobile devices to more powerful cloud servers. This can lead to better performance and energy savings for the mobile devices. This thesis considers MCO over stochastic wireless channels when task completion times are subject to hard deadline constraints. Hard deadlines, however, are difficult to meet in conventional computation offloading due to the randomness caused by the wireless channels. In the proposed offloading policies, concurrent local execution (CLE) is used to guarantee task execution time constraints. By sometimes allowing simultaneous local and remote execution, CLE ensures that job deadlines are always satisfied in the face of any unexpected wireless channel conditions. The thesis introduces online optimal algorithms that reduce the remote and local execution overlap so that energy wastage is minimized. Markov processes are used to model the communication channels.
MCO is addressed for three different job offloading schemes: continuous, multi-part, and preemptive. In the case of continuous offloading, referred to as 1-Part offloading, the mobile device will upload the entire job in one piece without interruption, when the scheduler decides to do so. In multi-part computation offloading, the job is partitioned into a known number (K) of parts, and each part is uploaded separately. In this offloading mechanism, which is referred to as K-Part Offloading, the upload initiation times of each part must be determined dynamically during runtime, and there may be waiting time periods between consecutive upload parts. Preemptive offloading is a generalization of K-Part Offloading where the number of task upload parts is unknown. In this scheme, a decision to either continue offloading or to temporarily interrupt the offload is made at the start of each time slot. Compared to the conventional contiguous computation offloading, interrupted offloading mechanisms (i.e., K-Part and preemptive offloading) allow the system to adapt when channel conditions change and therefore may result in lower mobile device energy consumption. This energy reduction will be obtained at the expense of having higher computational complexity. In this thesis, for each offloading scheme, an online computation offloading algorithm is introduced by constructing a time-dilated absorbing Markov chain (TDAMC) and applying dynamic programming (DP). These algorithms are shown to be energy-optimal while ensuring that the hard task deadline constraints are always satisfied. The optimality of these algorithms is proved using Markovian decision process stopping theory. Since the computational complexity of the proposed online algorithms, especially in the case of preemptive offloading, can be significant, three simpler and computationally efficient approximation methods are introduced: Markovian Compression (MC), Time Compression (TC), and Preemption Using Continuous Offloading (Preemption-CO). MC and TC reduce the state space of the offloading Markovian process by using a novel notion of geometric similarity or by running an optimal online offloading algorithm in periodic time steps. In Preemption-CO, while a task is offloaded preemptively, the offloading decision at every time-slot is based on non-preemptive calculations. These methods are used alone or in combination to construct practical offloading algorithms. A variety of results are presented that show the tradeoffs between complexity and mobile energy-saving performance for the different algorithms.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: STRATEGIES FOR THE INCORPORATION OF PORPHYRINS IN POLYSILOXANES AND THEIR APPLICATIONS

contributor:
Brook, Michael
Chemistry and Chemical Biology

subject: porphyrins, polysiloxanes

abstract:
Porphyrins are a class of natural and synthetic aromatic macrocycles that have received extensive investigation because of their unique chemical and optoelectronic properties. They are excellent ligands, photosensitizers and catalysts and serve critical roles in numerous biochemical reactions. Their properties and diverse applications have fascinated chemists from multiple fields, and porphyrins have been investigated in applications such as dye-sensitized solar cells, cancer treatments, and conjugated polymers among others. While porphyrins have made in-roads in multiple fields they have received at best minimal attention in the field of polysiloxane chemistry.
Polysiloxanes are a class of inorganic polymers widely used in industrial applications that possess properties including low glass transition temperatures, high thermal and oxidative stabilities, high optical transparency, and low refractive indices that are largely unmatched by organic polymers. These properties, if properly utilized, could compliment those possessed by porphyrins and lead to the development of new applications in the fields of porphyrin and polysiloxane chemistry. Unfortunately, porphyrins and polysiloxanes are not readily compatible with one another and synthetic techniques must be developed to allow for the reliable incorporation of porphyrins into polysiloxane matrices.
The objectives of this thesis are to develop strategies that allow for the ready incorporation of porphyrins into polysiloxane materials to improve existing and develop new applications for porphyrin-polysiloxane materials. These investigations led to the development of two techniques for the incorporation of porphyrins into polysiloxanes, the Piers-Rubinsztajn reaction, and ionic crosslinking. Several siloxane and polysiloxane porphyrins were prepared utilizing the Piers-Rubinsztajn reaction. These porphyrins were easily incorporated into silicone elastomers that could be utilized as dielectric, or reactive oxygen species-generating elastomers. Alternatively, ionic crosslinks could be utilized to incorporate the natural porphyrin hemin into silicone elastomers. Elastomers manufactured via this method retained the catalytic capabilities of hemin, opening the door to a new class of synthetic peroxidases. Regardless of the method of application controlling the natural tendency of porphyrins to aggregate was essential to achieving the desired properties.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Porphyrins have attracted the attention of scientists for generations who have sought to exploit their unique chemical, physical, optical, and electronic properties. Their unique properties have led to them being utilized in a multitude of applications. Despite the wide array of applications investigated, the utilization of porphyrins in polysiloxane (silicone) chemistry has received comparatively little attention. Polysiloxanes and porphyrins possess potentially mutually beneficial properties that could lead to the development of interesting materials. Unfortunately, their development is not straightforward, as porphyrins and polysiloxanes are not naturally compatible with one another. Therefore, to realize the potential benefit of porphyrin-polysiloxane materials synthetic techniques must be first developed that allow for the reliable incorporation of porphyrins into polysiloxane matrices
Two techniques were investigated for the incorporation of porphyrins into polysiloxanes. The Piers-Rubinsztajn reaction and ionic crosslinking. These methods allowed for the development of materials that had interesting applications including dielectric elastomers, reactive oxygen species generating materials and catalytic elastomers.


title: Computational and Geometric Aspects of Linear Optimization

contributor:
Deza, Antoine
Franek, Frantisek
Computing and Software

subject:
Linear Optimization
Lattice Polytopes
Diameter of Polytopes
Primitive Zonotopes

abstract:
Linear optimization is concerned with maximizing, or minimizing, a linear objective
function over a feasible region defined as the intersection of a finite number
of hyperplanes. Pivot-based simplex methods and central-path following interior
point methods are the computationally most efficient algorithms to solve linear
optimization instances. Discrete optimization further assumes that some of the
variables are integer-valued. This dissertation focuses on the geometric properties
of the feasible region under some structural assumptions. In the first part, we consider
lattice (d,k)-polytopes; that is, the convex hull of a set of points drawn from
{0,1,...,k}^d, and study the largest possible diameter, delta(d,k), that a lattice (d,k)-
polytope can achieve. We present novel properties and an enumeration algorithm
to determine previously unknown values of delta(d,k). In particular, we determine
the values for delta(3,6) and delta(5,3), and enumerate all the lattice (3,3)-polytopes
achieving delta(3,3). In the second part, we consider the convex hull of all the 2^(2^d - 1)
subsums of the 2^d - 1 nonzero {0,1}-valued vectors of length d, and denote by
a(d) the number of its vertices. The value of a(d) has been determined until d =8
as well as asymptotically tight lower and upper bounds for loga(d). This convex
hull forms a so-called primitive zonotope that is dual to the resonance hyperplane
arrangement and belongs to a family that is conjectured to include lattice polytopes
achieving the largest possible diameter over all lattice (d,k)-polytopes. We
propose an algorithm exploiting the combinatorial and geometric properties of the
input and present preliminary computational results.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: ANALYSIS OF DIFFERENT TI5553 ALLOY CUTTING STRATEGIES FOR THE IMPROVEMENT OF TOOL LIFE

contributor:
Veldhuis, Steven
Mechanical Engineering

subject:
Ti5553
Machining
Tool wear
Tool life

abstract: Titanium alloys support a wide range of practical applications due to their excellent mechanical properties. These include high strength-to-weight ratio, high mechanical strength at elevated temperatures and remarkable oxidation resistance. Machinability investigations so far have been intentionally focused on Ti-6Al-4V, which is commonly used in the aerospace research and development. However, a new classes of titanium alloys are also being developed for these applications. Ti-5Al-5Mo-5V-3C, also known as Ti5553, is included in this new category of titanium grade alloys. It corresponds to a near beta titanium alloy and generally it is employed on the production of high strength parts. Its high tensile strength combined with low weight (compared to Ti64) makes Ti5553 a suitable choice for landing gear parts and advanced structural components. However, due to the previously mentioned mechanical properties of Ti5553, machining processes can be difficult. During the cutting tests, the cutting zone experiences high cutting temperatures, and combined with a low rate of heat transfer, it generates stress and premature tool failure. By using several distinct experimental approaches, this work presents a comparison between different machining conditions (combinations of tools and coolants) to diagnose wear processes and identify better cutting parameters. The main objective of this research is to establish an understanding of how these parameters affect tribological aspects when machining Ti5553. The results of machining studies demonstrate different wear behaviour for CBN and PCD tools under various cutting environments (different coolant modes). These operating conditions can considerably affect the cutting forces leading to an increased tool life and improved surface integrity by decreasing, the residual stress and roughness, as well as work of hardening the workpiece during machining operations.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: An Analysis of On-Axis Rotation Pin-on-Disc Tribometry and its Correlation to Friction in Metal Cutting

contributor:
Veldhuis, Stephen
Mechanical Engineering

subject:
Tribology
Tribometer
Metal Cutting
PVD Coating
Microstructure
Numerical Modeling

abstract:
In metal cutting applications, development of coatings to reduce friction between tool and chip and also enhance wear resistance of the tool is an important objective.  The effectiveness of such coatings is ultimately evaluated through metal cutting trials; however, bench-scale tests can play a role in predicting some aspects of a candidate coating’s performance.  This dissertation further develops the concept of an on-axis rotation pin-on-disc tribometer for the evaluation of friction coefficient between tool and work material pairs under temperature and stress conditions similar to those experienced between tool and chip in metal cutting.
Firstly, the characteristics of the imprint formed by the spherical-tipped pin in the disc during tribometer tests are studied.  Specific focus is given to the growth of the imprint during the rotating stage of the test; the severity of pile-up of work material around the periphery of the imprint; different zones of contact at the imprint surface; and evidence of (or lack thereof) of bulk shear in the surrounding work material below the surface of the disc.
The importance of estimating the actual temperature at the pin-disc interface (inaccessible for direct measurement) is also raised.  Evidence is presented that suggests the pin-disc interface is higher for tests involving coatings with higher electrical resistivity, despite exhibiting similar temperatures 2 mm above the interface (accessible for direct measurement).  A numerical model is developed in an effort to estimate the pin-disc interface during stationary specimen tests for specific pin and disc materials under controlled conditions.  An empirical relationship is also established to express the variation of electrical resistivity with temperature for cemented tungsten carbide (6% cobalt content).
Finally, coefficient of friction results for coated and uncoated cemented carbide pins in contact with AISI 1045 steel discs are related to short duration turning trials involving the same material pairs.  Coatings exhibiting low friction coefficient result in appreciably lower cutting forces, reduced built-up edge intensity and more tightly curled chips.  The possibility that the low thermal conductivity of such coatings could be producing similar effects by forcing more heat into the chips is also explored.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract:
This dissertation further develops the concept of a pin-on-disc apparatus for evaluating the friction coefficient between materials under temperature and stress conditions similar to those experienced in metal cutting.
Firstly, characteristics of the imprint formed by the pin in the disc during tests with the apparatus are studied.  Specific focus is given to the growth of the imprint during the rotating stage of the test and different zones of contact at the imprint surface.
Secondly, the importance of estimating the actual temperature at the pin-disc interface, inaccessible for direct measurement, is raised and a numerical model developed to aid in its estimation.
Finally, coefficient of friction results generated on the apparatus are correlated to the magnitude of forces measured and other observations made during metal cutting trials involving the same material pairs.


title: Considerations for Identifying and Conducting Cluster Randomized Trials

title: Considerations For Identifying and Conducting Cluster Trials

contributor:
Garg, Amit
Health Research Methodology

subject:
Cluster randomized trial
Hemodialysis
Machine learning
Systematic review
Bibliographic Databases
Prediction
Sensitivity and Specificity
Ethics
Informed Consent
Covariate-constrained
Restricted randomization
Randomization
Balanced allocation

abstract:
Background: The cluster randomized trial design randomly assigns groups of people to different treatment arms. This dissertation aimed to (1) develop machine learning algorithms to identify cluster trials in bibliographic databases, (2) assess reporting of methodological and ethical elements in hemodialysis-related cluster trials, and (3) assess how well two covariate-constrained randomization methods balanced baseline characteristics compared with simple randomization.
Methods: In study 1, we developed three machine learning algorithms that classify whether a bibliographic citation is a CRT report or not. We only used the information available in an article citation, including the title, abstract, keywords, and subject headings. In study 2, we conducted a systematic review of CRTs in the hemodialysis setting to review the reporting of key methodological and ethical issues. We reviewed CRTs published in English between 2000 and 2019 and indexed in MEDLINE or EMBASE. In study 3, we assessed how well two covariate-constrained randomization methods balanced baseline characteristics compared with simple randomization.
Results: In study 1, we successfully developed high-performance algorithms that identified whether a citation was a CRT. Our algorithms had greater than 97% sensitivity and 77% specificity in identifying CRTs. For study 2, we found suboptimal conduct and reporting of methodological issues of CRTs in the hemodialysis setting and incomplete reporting of key ethical issues. For study 3, where we randomized 72 clusters, constraining the randomization using historical information achieved a better balance on baseline characteristics than simple randomization; however, the magnitude of benefit was modest.
Conclusions: This dissertation's results will help researchers quickly identify cluster trials in bibliographic databases (study 1) and inform the design and analyses of future Canadian trials conducted within the hemodialysis setting (study 2 & 3).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: The cluster trial design randomly assigns groups of people to different treatment arms rather than individuals. Cluster trials are commonly used in research areas such as education, public health, and health service research. Examples of clusters can include villages/communities, worksites, schools, hospitals, hospital wards, and physicians. This dissertation aimed to (1) develop machine learning algorithms to identify cluster trials in bibliographic databases, (2) assess reporting of methodological and ethical elements in hemodialysis-related cluster trials, and (3) identified best practices for randomly assigning hemodialysis centers in cluster trials. We conducted three studies to address these aims. The results of this dissertation will help researchers quickly identify cluster trials in bibliographic databases (study 1) and inform the design and analyses of future Canadian trials conducted within the hemodialysis setting (study 2 & 3).


title: s-Block Complexes of iso-Tellurazole N-Oxides

contributor:
Vargas-Baca, Ignacio
Chemistry and Chemical Biology

abstract:
The study of the macrocyclic aggregates of iso-tellurazole N-oxide has previously unveiled a wide variety of complexes with transition metal ions. The compound 3-methyl-5-phenyl-1,2-tellurazole-2-oxide and its derivatives bind soft d6, d8 and d10 metal ions exclusively by tellurium. The electron withdrawing ability of the cations strengthen the Te…O chalcogen bonding (ChB) interactions.
	In this thesis, we investigated the coordination chemistry of iso-tellurazole N-oxide with hard metal ions from elements of groups 1 and 2, as salts with weakly-coordinating anions. X-ray crystallography of the isolated products showed that the oxophilic nature of these cations results in coordination to the oxygen atom. However, formation of Te…O ChBs is not inhibited, in contrast to the cases in which oxygen binds protons or boranes.
Novel dodecameric macrocycles were obtained from experiments with Na+ cations. The large supramolecular ring folds onto itself forming a cage-like structure capable of hosting molecules such as dioxane, THF and pyrazine. Their encapsulation is facilitated by the coordination to the metal ion. In the absence of such molecular guests, a tris-tetramer structure was assembled with four sodium ions. Although full refinement of its crystal structure is yet to be completed, the tris-tetramer suggests a mechanism that leads to the formation of the dodecamers. In contrast to Na+, K+ yielded a 1-D coordination polymer of the tetramers. The more oxophilic Mg2+ yielded complexes of macrocyclic hexamers of iso-tellurazole oxides linked by C-Te…O ChBs.

abstract: Thesis

abstract: Master of Science (MSc)


title: Considerations for Optimization of the Pharmacokinetic Analysis of Blood-Brain Barrier Permeability

contributor:
Noseworthy, Michael
Biomedical Engineering

subject:
Blood-brain barrier
DCE-MRI
Pharmacokinetic Modelling

abstract: Dynamic contrast enhanced MR imaging (DCE-MRI) has commonly been used to investigate disruptions in microvascular capillary permeability in pathologies such as tumours, and in brain diseases such as multiple sclerosis. This imaging technique involves intravenous injection of a contrast agent, which can modulate MR signal contrast, while frequently acquiring images (i.e. every few seconds) as the agent perfuses through the tissue of interest. Microvascular permeability, and other parameters such as blood volume and flow (perfusion) can be quantified through application of a pharmacokinetic model on the data acquired from the MRI scan. The model requires input from both the biological (e.g. pharmacokinetic rate constants) as well as physical (i.e. scanner settings) parameters.  As there are a great many variables and different biophysical models (e.g. high blood flow, high permeability tissues, etc.) there needs to be considerations made for situations where the permeability may be only slightly different from normal.  In the brain the blood-brain barrier (BBB) is a highly selective barrier that restricts most bulk diffusion/permeability of solutes.  Changes in BBB permeability is likely only subtle in diseases such as depression or bipolar disorder, especially when compared against hypervascular-hypermemeable cancers that are void of a BBB altogether.  The problem is however, to decide which model of BBB permeability is best suited for differentiating subtle changes.  Thus the intention of this project was to investigate multiple pharmacokinetic models for the tracking of MRI contrast agent in regions of the brain with an intact BBB. In the brain, where there is strict regulation of molecules passing through the microvasculature into the extracellular space, and where more subtle disruptions might be of interest, different assumptions may be necessary. Four models were investigated: the Tofts model, the modified Tofts model, the two-compartment exchange model, and the uptake model. Scans of eight healthy subjects were analyzed, and permeability was quantified using each model. The accuracy of each model, quantified by the R\textsuperscript{2} value, were compared. Analysis found that the Tofts model performed significantly worse than the modified Tofts and Uptake models when fitting regions of the brain with a blood-brain barrier, with a p-value of 0.006. The analysis did not reveal any significant difference between the modified Tofts, Uptake or 2CX models, although perhaps it was obscured due to the limited number of data points. Further investigation is needed to determine any differences between the three top-performing models.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Axiom of choice and the partition principle

contributor:
Speissegger, Patrick
Mathematics and Statistics

subject:
set theory
zf
independence results
axiom of choice (ac)
partition principle (pp)

abstract: We introduce the Partition Principle PP, an axiom introduced by Russell in the context of its similarities and differences with the Axiom of Choice AC. We start by proving some properties of PP, and AC, and show that AC, entails PP. To address the problem of whether the converse holds, we develop the Zermelo-Fraenkel ZF set theory and examine its consistency and build a model in which AC, fails. We follow this with a discussion of forcing, a technique introduced by Paul Cohen to build new models of set theory from existing ones, which have differing properties from the starting model. We conclude by examining candidate models called permutation models where AC, fails, which may be useful as candidate models for forcing a model in which PP, holds but AC, does not. We conjecture that such a model exists, and that PP, does not entail AC.

abstract: Thesis

abstract: Master of Science (MSc)


title: Ontologies of Violence

contributor:
Kroeker, Peter Travis
Religious Studies

subject:
Violence
Ontology
Grace M. Jantzen
Jacques Derrida
Mennonites
Philosophical Theology
Deconstruction
Pacifism

abstract: This dissertation critically examines the ontological and epistemological significance of the concept of violence in French philosopher Jacques Derrida’s essay “Violence and Metaphysics” (Chapter 1), dialogues between Mennonite philosophical theologians who represent the Radical Reformation and John Milbank’s Radical Orthodoxy (Chapter 2), and the Death and the Displacement of Beauty trilogy by feminist philosopher of religion Grace Jantzen (Chapter 3). Although Derrida, Jantzen, and certain Mennonite philosophical theologians approach the problem of violence with very different concerns and frames of reference, each understand violence to have a distinctly ontological and epistemological character, while also suggesting that ontology and epistemology themselves are profoundly vulnerable to charges of violence. In Derrida’s essay “Violence and Metaphysics” language itself is imbricated in violence, and in their responses to John Milbank, Mennonite philosophical theologians Peter C. Blum and Chris K. Huebner situate their work both with and against Derrida’s supposed “ontology of violence” as they apply Christian pacifism to epistemology and seek to articulate an “ontology of peace.” In her late work in the Death and the Displacement of Beauty project, Grace Jantzen develops an epistemology that is similar to that of Blum and Huebner, while critiquing what she understands to be Derrida’s equivocation of linguistic with physical violence, all as part of her argument that the cultural habitus of the west is founded on an obsession with death that violently displaces natality with mortality. In bringing together these three sources, this dissertation uses “violence” as a diagnostic concept to assess the priorities and values of its users. Considering violence to be defined by the violation of value-laden boundaries, this study of three ontologies of violence interprets and critiques the values that Derrida’s deconstruction, philosophical Mennonite pacifism, and Jantzen’s critique of displacement seek to further and protect against violation.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation examines the early work of French philosopher Jacques Derrida (Chapter 1), debates between Mennonite philosophical theologians and John Milbank’s Radical Orthodoxy (Chapter 2), and the Death and the Displacement of Beauty trilogy by feminist philosopher of religion Grace M. Jantzen (Chapter 3). For Derrida, Jantzen, and certain Mennonite philosophical theologians the term “violence” is used to name ways of thinking, knowing, and speaking, rather than being restricted to the sphere of physical violations. This dissertation shows how these three sources each consider violence to be something that can inhere in ways of thinking about the world and our relation to it.


title: MACHINE LEARNING AND DEEP LEARNING ALGORITHMS IN THERMAL IMAGING VEHICLE PERCEPTION SYSTEMS

contributor:
Von. Mohrenschildt, Martin
Habibi, Saeid
Computing and Software

subject:
Artificial Intelligence
Computer Vision
Deep Learning
Machine Learning
Thermal Imaging
Autonomous Vehicles
Vehicle Perception

abstract: Modern Advanced Driver Assistant Systems (ADAS) focus more on daytime driving and primarily use daylight cameras as the main vision sources to detect, classify, and track objects. However, evidence has proved that autonomous driving using such a setup is compromised in the dark, and consequently, resulting in accidents. The hypothesis is that adding an infrared camera to the existing ADAS will boost the detection rate and accuracy, and further enhance the overall safety. This thesis investigates how well a standalone infrared camera performs onboard vehicle perception tasks such as object detection and classification using both machine learning and deep learning algorithms. Given a custom labeled infrared driving dataset that contains 4 classes of objects, “People”, “Vehicle”, “Bicycle”, and “Animal”, multiple attempts and improvements of training a supervised learning model, namely the linear multi-class Support Vector Machine (SVM) has been made by using various image preprocessing and feature extraction methods to detect the objects. During training, hard example mining is used to reduce the number of false classifications. This SVM employs a One-Against-All (OAA) styled approach and uses the image pyramid technique to enable multi-scale detection. On the deep learning side, a Convolutional Neural Network (CNN) based state-of-the-art detector, the YOLOv4 family including the full-sized and tiny YOLOv4 has been selected, trained, and tested at different input sizes using the same dataset. Labeling format conversion is performed to make this work. The results show that using bilateral filtering with the Histogram of Oriented Gradients (HOG) feature to train an SVM is preferable and is more accurate than the YOLOv4 family. However, the YOLOv4 networks are significantly faster. Overall, a standalone infrared camera cannot provide dominant detection results, but it can definitely supply useful information to the ADAS and complement other sensory devices for improved safety.

abstract: Thesis

abstract: Master of Applied Science (MASc)