title: Regional Growth and Northeastern Ontario Development: An Analysis of Factor Costs in Manufacturing Activity

subject:
factor costs
manufacturing activity
regional growth
northeastern ontario

abstract:
Regional growth literature indicates that the relations between the core and the peripheral regions, and the process by which growth is transmitted between regions are of prime importance in discussing growth disparities. Northeastern Ontario is a peripheral region, economically subordinate to the Ontario core region, and exhibits adverse growth conditions. Diversification of the region's resource dependent economy has been called for by many groups but has been hindered by the perception of higher manufacturing production costs, However, these costs have not been investigated. In this thesis, Northeastern Ontario centers' factor costs in manufacturing are compared with core centers' costs by utilizing a cost accounting method. The results indicate that some Northeastern locations may be cost attractive locations.
However, low costs derived for Toronto would indicate continued manufacturing concentration in the principle centers of the core region. When costs are calculated for hypothetical firms, the importance of the factor requirement structure is indicated in determining location. Northeastern locations would be attractive to firms with large land, and low labour requirements. If future analyses verify these results, alternative explanations of the development problem of the Northeast should be explored.

abstract: Thesis

abstract: Master of Arts (MA)


title: The Effects of Cohesiveness on the Persuasiveness and Persuasibility of Individuals in Two Person Groups

contributor:
Carcent, D. W.
Psychology

subject: persuasion individual group persuasive

abstract: The present study is concerned with the effects of different levels of "cohesiveness" on the persuasiveness and persuasibility of individuals in a two person verbal interaction situation. In particular, changes is verbal behavior over time are obtained. Now the sex of the participants affects the discussion and outcome is also investigated. The results indicated that favorably predisposed subjects are more persuasible than unfavorably predisposed subjects. Further, male subjects speak more than female subjects and this is reflected in the member of positive, negative and neutral statements they emit. Over-all decreases in the emission of positive statements and over-all increases in the emission of negative statements were found to accompany opinion change.

abstract: Thesis

abstract: Master of Arts (MA)


title: Role of Betaine in Transmethylation Reactions in the Barley Plant Origin of the Methylenedioxy Groups of the Alkaloid Protopine

contributor:
Kirkwood, S.
Chemistry

subject:
betaine
transmethylation reactions
barley plant
alkaloid protopine

abstract: The role of the labile methyl groups of betaine in the transmethylation reactions in the barley plants was investigated using carbon-14 methyl labelled betaine. The N-methyl groups of N-methyl tyramine, hordenine and choline were found to arise from betaine. Betaine was also administered to castor bean seedlings and the alkaloid ricinine isolated. It was found that its N- and 0-mthyl groups did not arise from betaine methyl. The origin of the methylenedioxy and N-methyl groups of the alkaloid protopine was also investigated by the tracer technique. Carbon-14 methyl labelled L-methionine, carbon-14 labelled choline and carbon-14 labelled sodium formate were fed to Dicentra species and the extent and position of labelling of the protopine molecule determined by degradation

abstract: Thesis

abstract: Master of Science (MS)


title: Reactions of L-Cyanobromolycopodine

contributor:
MacLean, D. B.
Chemistry

subject: reactions cyanobromolycopodine

abstract: The reaction of L-cyanobromolycopodine with alkali proceeds with elimination of hydrogen bromide and a new ring is formed in the process, The properties of the compound, L-cyclocyanolycopodine, resulting from this cyclization reaction have been studied and a mechanism for its formation has been postulated. The olefin corresponding to that expected from the elimination of hydrogen bromide from L-cyanobromolycepodine has been prepared indirectly and the oxidative degradation of the olefin has boon investigated.

abstract: Thesis

abstract: Master of Science (MS)


title: Electron Microscopic Study of Dissolution Morphology of Lithium Fluoride Surfaces

contributor:
Ives, M. B.
Metallurgy

subject:
lithium fluoride
study of dissolution morphology
electron microscopic study

abstract: The dislocation etch pits formed on the cleavage surfaces of lithium fluoride in an aqueous solution containing varying concentrations of ferric ions are investigated by electron microscopy. The results obtained reveal the powerful influence of the inhibitor in the stabilisation of kinks and macroledges. There is some evidence for the nucleation of dissolution at imperfections other than the dislocations. Dissolution spirals are observed in some cases suggesting the presence of helical dislocations in lithium fluoride.

abstract: Thesis

abstract: Master of Science (MS)


title: Field and Laboratory Studies on the Eastern Canada Procupine - Erethizon Dorsatum Dorsatum L.

contributor:
Delzell, D. E.
Biology

subject:
behaviour patterns
eastern canada porcupine
Erethizon d. dorsatum

abstract: The study, extending over two summers a and one university year, was an endeavour 1) to determine the existence and nature of an innate activity pattern in porcupines under laboratory conditions, 2) to determine the behaviour of porcupines in their natural habitat, 3) to compare field and laboratory data on the behaviour of the porcupine and 4) to determine the home range of the porcupine.

abstract: Thesis

abstract: Master of Science (MS)


title: Power and Uncertainty: An Analysis of the Structure of an Emergency Ward in a General Hospital

contributor:
Blumstock, R.
Sociology

subject:
power and uncertainity
emergency ward
general hospital

abstract:
This study is concerned with analyzing the ways in which the members of an organization faced with problems of unpredictability and uncertainty, adapt to the situation and achieve some degree of control over it. Chapter 1 describes the organization within which the study was conducted, and also discusses the methodology employed. Chapter 2 reviews the literature pertinent to the problem, both on the spheres of organization theory and medical sociology. Chapter 3 describes the role and mode of adaptation of the physician to the situation. Chapter 4 examines the role of the head nurse and her relations with other ward members. Chapter 4 examines the role of the head nurse and her relations with other ward members. Chapter 5 provides an analysis of the sources of tension and conflict in the ward and the final chapter contains a summery of the previous arguments and a discussion of their pertinence
to sociological theory.

abstract: Thesis

abstract: Master of Arts (MA)


title: A Study of Fission Yields with Isotope Dilution and the Mass Spectrometer

contributor:
Tomlinson, Richard
Chemistry

subject:
fission
isotope dilution
mass spectrometer

abstract:
The relative abundances of the stable and long-lived Isotopes of rubidium, cesium, strontium,
cerium, neodymium, and samarium resulting from the thermal neutron fission of U^235 and Pu^239 were determined mass spectrometrically. Special precautions were taken to eliminate or at least minimize contamination of the sub-microgram quantities of fission products with the naturally occurring elements. By using isotope dilution the yields of isotopes of different elements were related with very good precision. Sufficient information was available to evaluate from such results the absolute cumulative yields of twenty-seven mass chains for U^235 fission. It was possible from the results of the present study of make a quantitative comparison between the yields of the heavy fragments for U^235 and Pu^239 fission, with special attention being given to the fine structure supposedly resulting from the influence of nuclear shells involving 50 and 82 neutrons.

abstract: Thesis

abstract: Master of Science (MS)


title: Participation and Movement Orientation: Foundations of a Theory of Change in Voluntary Associations

contributor:
Silvers, Ronald
Sociology

subject:
movement orientation
theory of change
voluntary associations

abstract: This thesis investigates the relationship between the orientation of participants to voluntary associations and the orientation of associations to the wider society. By combining theoretical work from the field of voluntary associations with a theory of collective behaviour, a set of hypotheses is generated to analyze changes that have occurred it the Imperial Order Daughters of the Empire, a Canadian patriotic organization for women. A typology of voluntary associations is constructed, and a brief review of secondary sources shows the applicability of our theory to a wide range of voluntary social movements. The data used for this study includes association files, minutes, magazines and newspaper reports.

abstract: Thesis

abstract: Master of Arts (MA)


title: Parody in Juvenal and its Relation to the Roman Satirical Tradition

contributor:
Shepherd, D. M.
Classics

subject:
parody
juvenal
roman satire
roman satirical tradition

abstract: Present concepts of parody and ancient concepts of are discussed and defined (Chapters 1-2). The use of parody by Lucilius, Horace and Persius is discussed in Chapters 3, 4, and 5 respectively, and trends in parody, as well as the possible influence of the earlier satirists on the later satirists, are outlined. In Chapters 6-3 Juvenal’s use of parody is scrutinised at length, and possible influences upon his treatment of parody are enumerated. In the concluding chapter (9) Juvenal’s debt to and areas of superiority over his predecessors are summed up.

abstract: Thesis

abstract: Master of Arts (MA)


title: An Introduction to the Study of the Artistry of Aeneid XI

subject: artistry Aeneid

abstract:
Thesis
Master of Arts (MA)


title: Educating the Educators: Socialization into the Teaching Profession

contributor:
Silvers, R. J.
Sociology

subject:
educating
socialization
teaching profession

abstract: The study attempts to examine some of the "professional” attitudes and values of elementary school teaching as an occupation, by means of a study of the socialization process in a Teachers’ College, It is contended that sociological study of the professions would benefit by utilisation of a '’conspiracy theory” and the study attempts partly to estimate the usefulness of this theory with respect to teaching, Sociologically interesting aspects of the methods of socializing teachers are also discussed,

abstract: Thesis

abstract: Master of Arts (MA)


title: GSMBE Growthy and Characterization of InGaAs-InP Structures on SiO2 Patterned Substrates

contributor:
Simmons, J. G.
Thompson, D. A.
Engineering Physics

subject:
GSMBE Growth
InGaAs-InP
SiO2 patterned substrates

abstract: Gas source molecular beam epitaxy (GSMBE) has been used to grow InGaAs/lnP epitaxial layers in selected areas defined by SiO2-masked InP substrates, with the goal of obtaining controlled in-plane variations in the bandgap of the InGaAs wells. The ability to alter the bandgap of the semiconductor spatially over the surface in one growth procedure is desirable for integrating laser, waveguide and detector devices. To form the masked substrates, stripes (ranging in width from 2 pm to 50 pm) were opened up in SiO2 by standard photolithography. The crystal growths were carried out at various substrate temperatures (ranging from 460 °C to 510 °C) and arsenic fluxes (V/lll ratios ranging from 1.2 to 3.4). The properties of the epitaxial layers were investigated by using such analytical techniques as photoluminescence, electroluminescence and transmission electron microscopy (TEM). Photoluminescence measurements performed on waveguide stripes of decreasing width reveal an increasing red-shift of the e1-hh1 transition in InGaAs wells. The maximum red-shift occurred when growing at a high substrate temperature and a low arsenic flux. For example, a decrease in slit width from 50 pm to 10 pm resulted in a 25 meV shift of the photoluminescence peak. From cross-sectional TEM measurements, the wavelength shift observed can be attributed primarily to an increase in thickness of the InGaAs well, due to incorporation of additional indium and gallium migrating from the material on the masked regions. The interfaces in the centre of the stripe region are defect free; however, stacking faults and thickness variations are evident 1-2 pm from the edges. These results are confirmed by scanning photoluminescence, in which the maximum intensity occurs at the centre of the stripe and decreases to zero at the edges. Mapping of the peak wavelength across the stripe reveals a diffusion profile, with the edges being additionally red shifted by 10 nm. Reactive ion etching of the edge and the polycrystalline material results in a much improved spectral photoluminescence scan, in both increased intensity of the bandgap peak and elimination of lower energy peaks assumed to be correlated with edge effects. Finally, a stripe contact light emitting device, with a single 50 A quantum well InGaAs/lnP structure, was fabricated and electrically pumped. The device exhibited spectral peak wavelength shifts between narrow stripes (10 pm) and wide stripes (50 pm) of 22 nm, similar to the value observed by photoluminescence studies.

abstract: Thesis

abstract: Master of Engineering (ME)


title: GSMBE Growth and Characterization of InGaAs-InP Structures on SiO2 Patterned Substrates

subject:
GSMBE Growth
InGaAs-InP structures
SiO2 patterned substrates

abstract:
Gas source molecular beam epitaxy (GSMBE) has been used to grow InGaAs/lnP epitaxial layers in selected areas defined by SiO2-masked InP substrates, with the goal of obtaining controlled in-plane variations in the bandgap of the InGaAs wells. The ability to alter the bandgap of the semiconductor spatially over the surface in one growth procedure is desirable for integrating laser, waveguide and detector devices. To form the masked substrates, stripes (ranging in width from 2 pm to 50 pm) were opened up in SiO2 by standard photolithography. The crystal growths were carried out at various substrate temperatures (ranging from 460 °C to 510 °C) and arsenic fluxes (V/lll ratios ranging from 1.2 to 3.4). The properties of the epitaxial layers were investigated by using such analytical techniques as photoluminescence, electroluminescence and transmission electron microscopy (TEM). Photoluminescence measurements performed on waveguide stripes of decreasing width reveal an increasing red-shift of the e1-hh1 transition in InGaAs wells. The maximum red-shift occurred when growing at a high substrate temperature and a low arsenic flux. For example, a decrease in slit width from 50 pm to 10 pm resulted in a 25 meV shift of the photoluminescence peak. From cross-sectional TEM measurements, the wavelength shift observed can be attributed primarily to an increase in thickness of the InGaAs well, due to incorporation of additional indium and gallium migrating from the material on the masked regions. The interfaces in the centre of the stripe region are defect free; however, stacking faults and thickness variations are evident 1-2 pm from the edges. These results are confirmed by scanning photoluminescence, in which the maximum intensity occurs at the centre of the stripe and decreases to zero at the edges. Mapping of the peak wavelength across the stripe reveals a diffusion profile, with the edges being additionally red shifted by 10 nm. Reactive ion etching of the edge and the polycrystalline material results in a much improved spectral photoluminescence scan, in both increased intensity of the bandgap peak and elimination of lower energy peaks assumed to be correlated with edge effects.
Finally, a stripe contact light emitting device, with a single 50 A quantum well InGaAs/lnP structure, was fabricated and electrically pumped. The device exhibited spectral peak wavelength shifts between narrow stripes (10 pm) and wide stripes (50 pm) of 22 nm, similar to the value observed by photoluminescence studies.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Myth and Language

contributor:
Aldinckle, R. F.
Lang, H. W.
Divinity College

subject: myth language

abstract:
Thesis
Bachelor of Divinity (BD)


title: The Sacred Flesh: On Camus's Philosophy of the Body

contributor:
Planinc, Z.
Religious Studies

subject:
sacred flesh
Camus's philosophy
philosophy of the body

abstract: The focus of my thesis concerns what I refer to as Camus’s ‘philosophy of the body.' This study in part addresses the scholarly debate about how his texts are related. Camus himself says of certain writers that their “books form a whole, ‘in which each is to be understood in relation to the others, and in which they are all interdependent.’” ' If this understanding of authorship equally applies to Camus’s works, the question concerns linkage. What underlies this wholeness? Broadly speaking, there are three approaches to understanding the relation between his texts: thematic, philosophic, and existential. None of these ways is truly independent of the other. Each emphasizes a different aspect of Camus’s project. He is an artist, thinker and man. Once again we are returned to the question of linkage. The thematic approach tends to absolutize one mood or insight, though Camus cautions against this. The philosophical approach generally reads the texts dialectically. But Camus’s interest is in our living experience, not in a flight of the intellect. An existential approach, understood correctly, concerns not a theory of but a meditation on our concrete existence. If Camus’s works are read together as a sustained meditation on existence, the integrity of the artist, thinker and man is preserved. Each facet - beauty, truth and life - is held in a working tension as opposed to absolutizing or subsuming any one aspect. Still the question remains. What underlies this integrity? Quite literally, the body. I argue that Camus’s life work evokes a new way of seeing, thinking and speaking about the body. In this dissertation, then, I look at various ways in which the body is manifested across a selection of his essays and novels. I also consider what might be some of the implications of such manifestations.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Moby Dick as a Reaction Against Emersonian Transcendentalism

subject:
Moby Dick
Emerson
emersonian transcendentalism
transcendent

abstract:
Thesis
Master of Arts (MA)


title: Producing Fluorine-Free Polysiloxane Hierarchical Structures as Highly Biorepellent Surfaces

contributor:
Didar, Tohid
Biomedical Engineering

subject:
Hierarchical Surfaces
Polysiloxane nanostructures
Pathogen repellent surfaces

abstract: Though the past two decades have seen a dramatic increase in research toward self-cleaning repellent surfaces, multiple challenges exist in the creation of biorepellent surfaces for everyday use. Environmental concerns persist with many of the chemicals utilized in this field and the need for scalable, low-cost alternatives remains. Spread of pathogens including bacteria and viruses in healthcare and public settings also presents a need for stable surfaces. In the work presented here, we report on the current status of antimicrobial nanomaterials and coatings toward virus repellency, followed by an investigation into the application of polysiloxane nanostructures in creation of flexible hierarchical surfaces. Using n-propyltrichlorosilane (n-PTCS) coated on activated polyolefin (PO) we were able to demonstrate superhydrophobicity, reporting water contact angles above 153° paired with <1° sliding angles on hierarchical surfaces. A transfer assay, that closely mimics contact with high-touch surfaces, using Escherichia coli K-12 transfected with green fluorescent protein (GFP) reported a 1.6-log (97.5%) reduction in fluorescence on surfaces compared to planar PO controls, paired with a 1.2-log (93%) reduction in CFU/mL in comparison to control groups. Additionally, surfaces demonstrated a contact angle of 140.8° with citrated whole blood. Droplets of blood incubated on our surfaces for 15 min showed a 93% reduction in visible staining, while submersion in citrated whole blood for 20 minutes revealed an 87% reduction in blood adhered to the surfaces. The applications for these biorepellent surfaces have widespread potential, including the demonstrated need for prevention of surface contamination to minimize spread of hospital acquired infections (HAIs) within the healthcare system.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The goal of creating a surface capable of repelling biological samples continues to present challenges due to surface stability, scalability, and cost of manufacturing techniques. Beyond this, many of the existing solutions use fluorine-based chemicals that present a risk to the environment due to the difficulty in breaking down these molecules. This thesis aims to understand the current state of repellent surfaces used for biological applications, including prevention of surface contamination by bacteria and viruses, then investigates the use of more environmentally friendly methods to produce repellent surfaces. Using a silicone-based coating combined with heat induced shrinking of shape memory polymers (SMPs), we have created a flexible surface with multiscale roughness that demonstrates repellency to bacteria and whole blood.


title: SPATIAL OPTICAL ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXING FOR INDOOR VISIBLE-LIGHT COMMUNICATION SYSTEMS

contributor:
Hranilovic, Steve
Electrical and Computer Engineering

subject: Visible-Light Communication

subject: Optical OFDM

subject: Signaling Design

subject: PAPR Reduction

subject: Integration of power-line communication (PLC) and visible-light communication (VLC)

abstract:
Radio frequency (RF) spectrum congestion motivates the search for alternative communication techniques to complement radio systems. Visible light communications (VLC) is an emerging technology that exploits the recent and ever-growing increase in the usage of energy-efficient light emitting diodes (LEDs) to imperceptibly modulate the optical power output of LEDs to enable communication and augment RF networks.
Orthogonal frequency-divison multiplexing (OFDM) has been proposed as a modulation scheme for VLC due to its high spectral efficiency, ease of channel estimation and equalization, resistance to inter-symbol interference (ISI) and frequency-selective fading, efficient implementation using the Fast Fourier Transform (FFT), and compatibility with RF and power-line communication (PLC) standards that use OFDM.
One of the major drawbacks of conventional OFDM techniques is the high peak-to-average power ratio (PAPR) of OFDM signals. The peaks of the OFDM signals are clipped due to the limited dynamic range of the LED, which translates the high PAPR of the OFDM signal into non-linear distortion (NLD). This signal distortion causes bit-error rate (BER) performance degradation, especially at high optical signal-to-noise ratios (SNRs) typical of indoor VLC scenarios.
In this thesis, a new family of modulation techniques, termed spatial optical OFDM (SO-OFDM), is proposed with the aim of reducing the PAPR of conventional DC-biased optical OFDM (DCO-OFDM) by making use of the large number of LEDs typically available in indoor lighting settings. Each LED group signal is a narrowband signal consisting of a small number of subcarriers, and thus has a smaller PAPR than the original OFDM signal.
Firstly, SO-OFDM is introduced and its two key concepts of frequency-to-space mapping and spatial summing are explained. Frequency-to-space mapping is achieved by allocating a subset of OFDM subcarriers to each LED. Each LED group signal is a narrowband signal consisting of a small number of subcarriers, and thus has a smaller PAPR than the original OFDM signal. Several design variations of the subcarrier assignment to LEDs are introduced and are shown through simulations, to reduce PAPR, and NLD noise due to clipping, and improve the BER performance at high SNRs as compared to DCO-OFDM. In addition, luminous efficacy is identified as an important lighting design parameter that is impacted by modulation. Relative luminous efficacy is defined as the ratio of the luminous efficacy of a modulated LED to that of an LED driven by a DC signal, and is introduced as a metric to assess the impact of modulation on LED lighting. Relative luminous efficacy links communication parameters such as signal variance to lighting design requirements.
Secondly, a low-complexity amplify-and-forward (AF) scheme is proposed for an integrated power-line communication/visible-light communication (PLC/VLC) where SO-OFDM is used for the VLC link. Frequency translation of the incoming PLC signal is used to increase the usable bandwidth of the LED. The use of both frequency translation and SO-OFDM leads to capacity gains over DCO-OFDM in the high SNR regime.
Finally, a low-complexity variant of SO-OFDM, termed square-wave SO-OFDM (SW-SO-OFDM), is proposed. Square-wave SO-OFDM uses square-wave carriers instead of sinusoidal waves to modulate a single OFDM subcarrier signal per LED. By using square-wave carriers, SW-SO-OFDM eliminates the need for digital-to-analog converters (DACs), digital predistortion (DPD), and the FFT operation. Squarewave SO-OFDM is also shown, through simulations, to achieve BER performance gains over SO-OFDM and DCO-OFDM. In addition, an experimental demonstration of SW-SO-OFDM with 64 QAM modulation on subcarriers is described.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Visible-light communications (VLC) is an emerging technology that exploits the increasingly widespread use of light-emitting diodes (LEDs) for indoor lighting, and modulates the optical power output of the LED for data transmission.
Among the various modulation techniques that have been proposed for VLC, orthogonal frequency-division multiplexing (OFDM) offers high data rates, resistance to channel impairments, and simple channel estimation and equalization. However, OFDM signals suffer from a high peak-to-average power ratio (PAPR) which degrades the efficiency of the power amplifier in the transmitter and hinders the communication performance.
In this thesis, a new multiple-LED modulation technique, termed spatial optical OFDM (SO-OFDM), is proposed to reduce the PAPR. Using a frequency-to-space mapping, SO-OFDM divides the wideband high-PAPR OFDM signal into multiple narrowband low-PAPR signals and assigns each signal to a group of LEDs. Spatial summing of the transmitted signals occurs at the receiver allowing for the use of a conventional OFDM receiver. Several variations of SO-OFDM are introduced and are shown, using simulations, to reduce the PAPR, combat non-linear distortion (NLD), and improve the bit-error rate (BER) performance at high signal-to-noise ratios (SNRs), typical of VLC systems.
Spatial optical OFDM is also applied to a practical scenario where its PAPR reduction capability is used to improve the overall capacity of a proposed system that integrates power-line communication (PLC) and VLC.
A low-complexity variant of SO-OFDM, that uses square-wave carriers and simplifies the transmitter design by eliminating the need for digital predistortion (DPD) and digital-to-analog converters (DACs) is also proposed, and tested experimentally.


title: Role of Macrophage Scavenger Receptor 1 and Extracellular Double-Stranded RNA in Antiviral Cell Signaling

title: Antiviral Signaling Mechanisms of Extracellular dsRNA

contributor:
Mossman, Karen L.
Biochemistry and Biomedical Sciences

subject:
antiviral signaling
scavenger receptor
double-stranded RNA
type i IFN

abstract: Recognition of non-self, pathogen-associated molecular patterns is a central component of host immune response to pathogens like viruses. Intracellular detection of viral nucleic acids leads to the production of type I interferons (IFN-I) and subsequent establishment of an antiviral state in infected and neighboring cells. Viruses have evolved multiple mechanisms to counteract IFN-I responses in infected cells, however, viral nucleic acids released from dying cells can stimulate IFN-I production in surrounding or distal uninfected cells. This thesis examines the mechanisms by which cells recognize extracellular viral nucleic acids and the subsequent downstream antiviral signaling. Class A scavenger receptors (SR-As) internalize extracellular viral double-stranded RNA (dsRNA) to mediate IFN-I responses, but little is known about extracellular viral DNA. We observed that extracellular DNA is recognized and internalized by SR-As in a manner like extracellular dsRNA. Furthermore, we established that SR-A1 is sufficient in mediating extracellular dsRNA-induced cellular responses and other nucleic acid receptors like SR-J1 and DEC-205 are dispensable. Finally, a direct interaction of RNA and DNA species was demonstrated with the coiled-coil collagenous domain of SR-A1, but not the scavenger receptor cysteine rich domain of SR-A6.We elaborated the role of SR-A1 by identifying the cellular processes activated through SR-A1 following uptake of extracellular dsRNA. Cytosolic sensors are essential in mediating an antiviral response to the endocytosed dsRNA, but the mechanism of endoplasmic release and cytoplasmic entry of dsRNA remains an enigma. We demonstrated that the lack of a dsRNA-channel, SIDT2, impaired the ability of the cells to mediate an antiviral response to extracellular dsRNA. Understanding host responses to extracellular viral nucleic acids will enable the development of novel vaccines and antiviral therapeutics against RNA and DNA viruses that efficiently counteract these responses in infected cells.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Viral infections remain a threat to global health as new diseases continue to emerge. To develop effective vaccines and antivirals to combat viruses and alleviate human disease require a deeper understanding of virus-host interactions. Host cells identify virus-associated molecules to detect viruses and eliminate them whereas, viruses employ tactics to prevent the activation of the immune system. However, virus-induced cell lysis releases viral molecules that can stimulate immune responses in neighbouring uninfected cells. This thesis examines the mechanism by which cells respond to extracellular viral nucleic acids.

We showed that a protein present at the cell surface called ‘class A scavenger receptor 1’ is sufficient to internalize extracellular viral nucleic acids, leading to immune responses. The response is impaired when a channel protein, SIDT2, is absent in the cells. Further work is necessary to understand how this knowledge can be harnessed to develop vaccines and antiviral therapeutics.


title: Production routes to tune cellulose nanocrystal properties and their performance at high temperatures

contributor:
Cranston, Emily
Chemical Engineering

subject:
Cellulose
Cellulose nanocrystal
Thermal stability
Acid hydrolysis
Colloidal stability
Thermal degradation

abstract:
This thesis explores new and existing cellulose nanocrystal (CNC) production methods and evaluates their effects on CNC properties, with emphasis on their thermal performance. CNCs produced from industrial and lab-scale processes possess a wide range of surface chemistries, surface charge contents, as well as structural and morphological properties which affect their performance in CNC-based applications. Despite the broad range of available CNC properties, some challenges persist, particularly in the incorporation of CNCs into hydrophobic matrices, high brine liquid formulations, and high temperature applications. Herein, sulfated and carboxylated CNCs produced from large-scale processes were thoroughly characterized and key differences in their thermal performance and self-assembly and rheological behaviors were identified. Furthermore, an optimization study on phosphoric acid hydrolysis parameters and a novel surface modification method which deposits cellulose phosphate oligosaccharides onto CNC surfaces were proposed. The optimization study revealed that CNCs with high colloidal stability could not be produced with phosphoric acid alone; however, the weak acid hydrolysis allowed for precise control over CNC length. The deposition of oligosaccharides onto CNCs, however, resulted in highly colloidally stable CNCs possessing both phosphate and sulfate functional groups. Furthermore, this surface modification method altered CNC surface charge content, water interactions, and the viscosity of their aqueous suspensions. In these studies, however, changes in CNC thermal performance were difficult to elucidate.
As such, to further understand the effects of CNC properties on both their dried and aqueous form thermal performance, a systematic comparison of sulfated, phosphated, and carboxylated CNCs was performed. CNCs were produced with new acid blend hydrolyses (i.e., combining sulfuric and phosphoric acid) as well as existing organic acid hydrolyses and oxidation routes. The combined effects of surface chemistry and counterion profoundly affected the thermal performance of dried CNCs, whereby sulfated and carboxylated CNCs were less thermally stable with proton and sodium counterions, respectively. Additionally, dried CNCs with more surface charge groups, shorter cellulose chains, and higher specific surface areas were found to be less resistant to high temperatures. As such, the new CNCs produced with acid blends exhibited superior thermal performance in their dried form due to their lower charge contents and longer cellulose chains. In their aqueous suspension form, carboxylated CNCs far outperformed both sulfated and phosphated CNCs at high temperatures; their suspensions remained colloidally stable at temperatures up to 150°C for extended time periods. Overall, this thesis equips CNC users and researchers with knowledge and tools to expand the usage of CNCs in commercial applications, particularly those which require high temperatures such as melt-processed polymer composites and oil and gas extraction fluids.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis contributes to a broader effort in replacing non-renewable and emissions intensive materials with sustainable alternatives such as nanocellulose. Nanocelluloses are nanometer-sized (where one nanometer is one billionth of a meter) cellulose particles manufactured from wood, cotton, or other natural resources. Nanocelluloses are made within Canada on a tonne-per-day scale; this value-added wood product presents an opportunity to refresh the Canadian forest industry. While nanocelluloses have many potential applications, their usage is somewhat limited by their inability to resist heat. This thesis examines changes in nanocellulose properties at high temperatures and evaluates how nanocellulose production methods affect their particle properties and thermal performance. New production methods are explored that increase nanocellulose resistance to heat, alter their dimensions, and change their interactions with water. Overall, this work aims to expand the usage of nanocellulose in commercial products such as coatings, plastics, industrial fluids, food products, and cosmetics (to name a few) by helping researchers select the right kind of nanocellulose for their intended applications.


title: Determination of Effective Lifetime and Light Trapping Enhancement in Silicon using Free Carrier Absorption

contributor:
Kleiman, Rafael
Engineering Physics

subject:
Lifetime spectroscopy
Light trapping enhancement
Silicon
Free carrier absorption

abstract: A novel experimental technique has been developed for measuring the light trapping enhancement and the carrier recombination lifetime in silicon wafers. The technique is based on the pump/probe modulated free carrier absorption (MFCA) method, where the probe beam, attenuated by generated free carriers, carries information about the effective lifetime and the average light path enhancement in a textured silicon wafer. For the first time, a reflection mode MFCA technique is presented where the reflected part of the probe beam is used to perform measurements, while the conventional technique is based on measurements of the transmitted part of the probe beam. A theoretical model is presented to explain the behavior of the light beam in double-side polished and double-side textured silicon wafers. The model yields good agreement with the experimental results and explains the difference in the amplitudes of the reflected and transmitted signals. The results of the experimental measurements of the light path enhancement in a double-side textured sample are analyzed and the reasons for their deviation from the Lambertian limit are discussed. This work presents new applications of the MFCA technique and shows how it can be used for the simultaneous determination of more than one crucial characteristic of silicon solar cells.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Measurement and Evaluation of In-Core Gamma Heating in the McMaster Nuclear Reactor

contributor:
Buijs, Adriaan
Engineering Physics

abstract:
The emission of gamma radiation in nuclear reactors manifests itself as heat which may substantially impact irradiation applications and reactor safety. Evaluating this phenomenon can increase the efficiency and safety of the reactor and its irradiation materials. Calculating or predicting the gamma heating (GH) in a nuclear reactor is not a simple task, especially when not all parameters of the reactor are known. This dissertation incorporates various methods for verifying results, including operational data, calculations and measurements. The thesis is divided into five research chapters to illuminate uncharted areas for simulation codes and to better understand factors influencing the GH. Study 1 applies the overall system
for calculation of reactors (OSCAR-4) code system to the McMaster Nuclear Reactor (MNR) for understanding and verifying core-follow calculations against the MNR operational data. Based on this understanding, the calculational scheme presented advances to the operational fuel management data by (i) embodying an axial U-235 distribution profile and (ii) including all fissile materials present in the core. Study 2 gives insight into the impact of control rods (CR) movement on axial fuel inventory using the OSCAR-4 and Serpent-2 simulation codes. This was done to study whether OSCAR-4 performs as well as the time-consuming Serpent-2 for core-follow calculations. It was found that averaging the CRs movement can precisely predict fuel inventory without requiring detailed CRs tracking. Study 3 focused on improving MNR fuel operational data which were subsequently used in both the OSCAR-4 and Serpent-2 simulation codes. This research emphasizes the importance of applying the fuel inventory correction factor to any MNR cycle to accurately predict the fuel inventory at any given stage of a cycle. Study 4 involved the experimental measurement of GH using the SCK-CEN gamma thermometer (GT) in three irradiation sites at 27 GH values. In addition, a Serpent-2 simulation was conducted to calculate the GH at the same 27 points with an understanding
of uncertainties accompanied by the measurement. Similarly, MCNP-6 code was implemented with the same methodology used for both OSCAR-4 and Serpent-2 and showed a very good agreement with the reactor operation data and GH measurement. The computational tools program provided a good prediction and evaluation of the GH. Finally, study 5 expanded the evaluation and uncertainty quantification of the GH under several reactor core conditions and time-dependent sets. The measurements presented in this work indicate that, even over four years, the combined effects of fuel burnup and fuel management operations do not significantly change the GH level inside the beryllium site. This is likely due to the overall distribution of the MNR core configuration and fuel burnup.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: Guideline Development and Evidence Synthesis in Gastrointestinal Bleeding Prophylaxis and Coronavirus Disease 2019

contributor: Clinical Health Sciences (Health Research Methodology)

subject:
Guideline development
Gastrointestinal bleeding prophylaxis
Coronavirus Disease 2019

abstract:
The field of guideline development has made considerable progress in the past twenty
years, particularly after the introduction of GRADE in 2004. However, there are many
shortcomings in current guideline development including failure to use GRADE, low
quality systematic reviews, and excessive delays from the publication of practice
changing evidence to new recommendations. The objective of this thesis is to describe
the development of evidence-based recommendations, to document methodological
issues that arose and describe how the research team addressed the questions, and to
document how the ultimate guidelines contributed to optimization of treatment in
clinical practice. The relevant guidelines address the issues of gastrointestinal bleeding
prophylaxis and coronavirus disease 2019 (COVID-19).
The thesis begins by presenting three methodological issues that arose during the
planning and implementation of the guideline process and the initial process of how the
research team addressed the challenges. The thesis subsequently presents a published
paper that documents recommendations regarding gastrointestinal bleeding prophylaxis
in critically ill patients. Then, this thesis presents a published systematic review and
meta-analysis addressing efficacy and safety of corticosteroids in COVID-19 based on
direct evidence from patients with COVID-19, and indirect evidence from acute
respiratory distress syndrome, community-acquired pneumonia, severe acute
respiratory syndrome, middle east respiratory syndrome and influenza. Further, the
thesis includes a published paper describing recommendations regarding corticosteroids, convalescent plasma and antiviral drugs in COVID-19 on the basis of evidence
available very early during the pandemic. This thesis ends by presenting how the
methodological issues were ultimately addressed in the relevant guidelines, the
importance of the guidelines themselves, and presents perspectives on future research
and opportunities in guideline development.

abstract: Thesis

abstract: Candidate in Philosophy


title: Experimental and numerical modelling of the spray drying process for the production of thermally stable vaccine powders

contributor:
Thompson, Michael R.
Cranston, Emily D.
Chemical Engineering

subject:
Spray drying
Vaccines

abstract:
A major challenge facing the global health community is the production of thermally stable
vaccines that eliminate the need for unfavorable cold-chain storage protocols, which often require temperatures as low as -80°C. Spray drying is a promising technique to produce thermally stable vaccine powders that retain their efficacy when stored at ambient conditions. Spray drying is gaining popularity in the pharmaceutical community due to its scalability, low cost and high throughput. Processing by spray drying can rapidly immobilize the active vaccine ingredient, such as a viral vector, in an amorphous glassy matrix of a stabilizing excipient tailored to the biologic being stabilized. This encapsulation and reduction in mobility keeps the biologic isolated from mechanical, thermal or chemical stresses that cause damage and inactivation. However, choosing the best excipient, or excipient blend, and optimizing the formulation are costly and time-consuming processes and furthermore, the effects of spray drying on viral vector activity are not fully understood.
This thesis focuses on modelling the processing environment for preparing such vaccine
powders, by both experimental and numerical means, to understand the relevance of mechanical, thermal and chemical stresses on viral vector activity. Specifically, the viral vector studied here was human type 5 adenovirus (AdHu5), with intended use in tuberculosis vaccines. Mechanical stresses associated with the shear inside the nozzle of a spray dryer were experimentally studied. Viral activity losses associated with shear stresses in an atomizing nozzle were attributed to aggregation; aggregation was created by damaging the virus at very high mechanical stresses but most aggregation was attributed to dispersing the virus in the excipient solution. It was concluded that overall, mechanical stresses in the nozzle caused a minimal amount of viral activity loss compared to other processing factors during spray drying, and in fact, could have a positive influence at moderate shear rates since it actually caused the break-up of AdHu5 aggregates.
To investigate thermo-chemical stresses, it was necessary to demonstrate that acoustic
levitation of a single drying droplet was an effective screening method to select promising
excipients for spray dried vaccines, and could be used to experimentally validate a numerical
model of droplet drying. For several different sets of binary carbohydrate blends, levitated particles were found to match property and activity trends seen in spray dried powders when the surrounding temperature of the levitator matched the outlet temperature of the spray dryer. The numerical droplet drying model could predict drying time, particle size, and component distribution within a final dried particle; the component distribution was used to aid in spatially locating the viral vector which was shown to be related to vaccine thermal stability. The model predictions associated with virus location in a dried particle were confirmed experimentally using coated silica nanoparticles as virus analogues, and several different molecular weight dextrans in the mannitol/dextran blend in order to change the location of the virus.
Overall, this work provides a deeper understanding of how spray drying can be used to
produce thermally stable vaccine powders, and the arising guidance can be applied to improve
formulation development based on the end targets and applications. Shear stress was found to be a negligible source of viral vector activity loss, and the application of heat to the acoustic levitator was found to create drying conditions that allowed the levitator to create materials that mimicked the properties of spray dried powders. Finally, a numerical model was validated experimentally, with both modelled predictions and confocal laser scanning microscopy confirming that an increase in dextran molecular weight in formulations caused a decrease in viral vector and silica nanoparticles at the air-solid interface. The knowledge gained by using screening methods and mathematical models of the spray drying process can reduce the time and cost inputs of vaccine development by identifying promising excipients with minimal experimentation.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
To retain their effectiveness, most mass-market vaccines must be stored in refrigerated or
frozen conditions but the specialized equipment associated with such storage limits the success of administration programs. Creating dry powder vaccines that can be stored at room temperature is an efficient method to limit liquid vaccine wastage caused by exposure to warmer temperatures. This is achieved by combining the active ingredient with protective stabilizing materials and drying the solution into a powder using spray drying. However, identifying and developing effective dry powder products is costly and time-consuming. This research aims to reduce the costs associated with vaccine development by using other drying methods to identify potential protective sugars without the need for large-scale experiments, as well as by using mathematical models to predict the outcomes of the drying process. The effect of various stresses during the drying process on the active vaccine ingredient are evaluated to improve the effectiveness of the final dry product. Overall, the ability to produce stable dry powder vaccines will allow for more wide-spread vaccination programs and stockpiling of vaccines to better prepare for global pandemics.


title: The Role of Hydrosilanes in the Preparation of Silicones

contributor:
Brook, Michael
Chemistry

abstract:
Abstract
Silicone polymers (PDMS) are widely used for a large range of applications from automotive to cosmetic industries owing to their unique properties, such as electrical resistance, biocompatibility, and gas permeability. Conventionally, linear silicone polymers are produced by acid or base-catalyzed equilibration, leading to broad molecular weight dispersities, and high concentrations of a controversial monomer that requires removal. Therefore, in the first part of the research, we developed a new hydrolytic route to linear silicone polymers that is both simple and inexpensive. The small hydrosilane tetramethyldisiloxane (HSi(CH3)2OSi(CH3)2H) was polymerized to hydride-terminated PDMS (HSi-PDMS-SiH) using only water as a reagent, a process that has industrial potential. The product can further be converted into silicone block copolymers, elastomers, foams and resins.
We broadened the studies to consider the incorporation of different functional groups (vinyl and alkoxy groups) into silicones, including developing methods to control their precise locations in polymers and to synthesize dendritic hyperbranched silicone polymers in a controllable manner.
The ability of silanes to behave as functional reducing agents was examined. A series of model compound studies, including reduction with benzyl disulfide and tetrasulfide, were conducted to illustrate the mechanism of S-S bond cleavage using a catalytic amount of B(C6F5)3. The effect of sterics on the rates of hydrolysis of the product S-Si compounds allowed consideration of the use of this strategy to protect for thiol groups. In addition, the relative reactivities of hydrosilane with different functional groups including mercaptan (SH), disulfide (SS) and ethoxy (SiOEt) were also mapped out as follows: S-H>S-S>SiOEt. These investigations allowed us to exploit hydrosiloxanes for the reduction of the sulfur crosslinks in used rubber tires; current reuse methodologies either utilize harsh conditions or occur in low yields.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: Electric Vehicle (EV) Wireless Chargers: Design And Optimization

contributor:
Narimani, Mehdi
Electrical Engineering

subject:
Wireless power transfer
EV wireless battery charger
Inductive charging
Optimization

abstract:
Wireless charging of the EVs offers a convenient, reliable, and automatic charging of the autonomous vehicles without user interference. The focus of this thesis is the design and optimization of new structures for stationary EV wireless charging applications.
The fundamentals of the Wireless Power Transfer (WPT) system and its main components including the magnetic couplers, transmitter and receiver power converters, and control methods are studied in depth. The requirements of the EV wireless charging application and design criteria are discussed in detail. The advantages and disadvantages of each topology are highlighted, and possible candidates for EV wireless charging applications are selected.
Optimization of the resonant networks in terms of maximum efficiency and misalignment tolerance is studied. Different resonant topologies are studied in detail and their sensitivity functions are extracted. For each topology, an efficiency model is presented that includes the inverter, resonant capacitors, resonant inductor, diode-bridge, and core and conduction losses. Each topology is optimized with two different objective functions and the results are compared through the simulation and experiments. According to the optimization results, suitable topologies for the EV wireless charging application are selected.
In order to increase the power density of the wireless charging system, and save ferrite material, integrated inductors into the magnetic couplers are proposed. In this structure, the DC-DC inductor is integrated into the receiver main coil and the resonant inductor is integrated into the transmitter coil. This integration introduces new challenges to the design of the resonant network and magnetic coupler due to the unwanted cross-coupling effect. To address this issue, the fully integrated magnetic structure is optimally designed to have minimum cross-coupling. Moreover, the resonant network is designed based on an optimization problem that includes the cross-coupling into the system equations to ensure maximum efficiency. The proposed fully-integrated magnetic structure is built and experimental tests are presented to validate the performance of the proposed magnetic structure and its optimization method.
To reduce the implementation cost, size and weight a PCB-based magnetic coupler is proposed to replace the Litz wire in the magnetic coupler of the WPT system. Moreover, the proposed PCB-magnetic coupler increases the repeatability of the design and reduces manufacturing errors. The PCB-based magnetic coupler is studied through Finite Element Analysis (FEA) to minimize the AC resistance of the coil. Different parameters such including the number of the PCB layers, copper cross-section, and layer thickness are studied in detail to evaluate their effect on the coil resistance. Thermal analysis is performed to ensure the feasibility of the design under different loading conditions. A 3.3 kW/85 kHz wireless charging system is built and experimental tests are presented.
A novel modular resonant topology for fast wireless charging is proposed. A modular structure offers reliability, scalability, and better thermal management. The proposed topology is made by multi-parallel inverter legs connected to an LCC resonant network. The outputs of the resonant networks are connected in parallel to feed the transmitter coil with a high excitation current. The proposed modular system is compared with a conventional system and it showed superior performance in different aspects.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Surrogate In Vitro System to Define Initiating Events of MDS and Transition to AML Disease

contributor:
Bhatia, Mick
Biochemistry and Biomedical Sciences

abstract: Acute myeloid leukemia (AML) is an aggressive cancer that begins in the rare blood-forming stem cell subpopulation of the bone marrow, in which the ability to produce functionally specialized, mature blood cells becomes impaired. The prognosis for patients with AML is vastly grim due to a low survival rate, rapid onset, and limited, non-curative treatment options. The understanding of how healthy blood cells progress to lethal leukemic cells is lacking, making it difficult to identify biological predictors and develop novel therapeutics. However, an intermediate state termed myelodysplastic syndrome (MDS) from healthy hematopoiesis provides an opportunity to unravel the mechanisms involved in the initiation and progression of this disease to AML. Much like other cancers, the accumulation of gene mutations in blood-forming stem cells is the driving force behind initial malignancy of this tissue. Recent studies have shown that many of those recurrent mutations are directly related to abnormal DNA methylation, a type of epigenetic modification, that alters gene expression resulting in aberrant cell development. To investigate this, we have taken advantage of our previously described in vivo mouse model of MDS-to-AML transition, governed by induced genetic mutation of GSK3, and have developed an in vitro system that uniquely allows for the selection, growth, and expansion of the rare blood cells responsible for initiating disease. Here, our in vitro system has brought to light specific phenotypes that could be the culprits of early transformation and a platform to explore causal genetic and epigenetic factors that govern disease progression. I propose that the system presented in this thesis serves as a surrogate that mimics MDS-to-AML transition and can be used to perform causal experimental studies.  The overarching goal is to move the field forward by identifying tangible targets that have therapeutic intervention or predictive biomarker potential.

abstract: Thesis

abstract: Master of Science (MSc)


title: Synthesizing the Experiences of Children and Youth With Disabilities and Special Needs in Inclusive Education Using Meta-Aggregation

type: Article Dataset Thesis

contributor:
Campbell, Wenonah
Rehabilitation Science

subject: inclusion student qualitative school synthesis meta-aggregative children adolescent disability accommodation review

abstract:
It has been well established that inclusive education is important in order to achieve high-quality education for all. Recent literature reviews examining the experiences of educators, parents, and students without disabilities in inclusive educations show that most have a positive attitude towards inclusive education. However, there is an important gap in the literature surrounding inclusive education, namely the perspectives of children and youth with disabilities and special needs.
The first manuscript is a qualitative evidence synthesis on the perspectives of children and youth with disabilities and special needs regarding their experiences in inclusive education. I utilised the meta-aggregative approach developed by Joanna Briggs Institute to select, critically appraise, and synthesise qualitative studies to generate an understanding of the children’s experiences in different areas pertaining to their schooling. I suggest recommendations to be considered by policy makers and professionals working in the education system to better support students with disabilities, educators, and families.
The second manuscript presents a reflection on the experience of conducting a meta- aggregative review from my point of view as a novice researcher. I highlight the specific challenges encountered, decision-making process, and the specific lessons learned at each stage of the review process with aims to help guide reviewers taking on a meta-aggregation or other similar tasks. I used my meta-aggregative review presented in my first manuscript as an example, where applicable, to elucidate the processes and lessons learned.
Specific strategies and recommendation are outlined in this thesis that can serve to better support the implementation of inclusive education. Additionally, I present recommendations for reviewers and organizations developing literature review methods to improve the field and quality of qualitative evidence synthesis.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Inclusive education refers to the concept that all students, including students with disabilities, attend their neighbourhood schools and have the chance to participate in programs and activities with their peers. Although inclusive education is believed to be beneficial for everyone, we do not know much about the students’ experiences in these schools. In this thesis, I studied the school experiences of elementary, middle, and high school students with disabilities and special needs. While completing this study, I faced several challenges and difficult decisions. So, I described some likely challenges to doing this type of study, my decision-making process, and the specific lessons I learned while completing my first study; we hope to help guide researchers taking on similar tasks. Findings from my thesis contributes to a better understanding of students’ experiences in school. They also highlight how teachers, families, and others can help and be better supported to improve the students’ school experience.


title: Do-it-Yourself Module Systems

title: Extending Dependently-Typed Languages to Implement Module System Features In The Core Language

contributor:
Kahl, Wolfram
Carette, Jacques
Computing and Software

subject: agda, dependent types, programming, type theory, unbundling, packages, modules, records, contexts, telescopes, editor extension, emacs, org-mode, lisp

abstract:
In programming languages, record types give a universe of discourse (via so-called Σ-types);
parameterised record types fix parts of that universe ahead of time (via Π-types), and algebraic
datatypes give us first-class syntax (via W-types), which can then be used to program, e.g.,
evaluators and optimisers. A frequently-encountered issue in library design for statically-typed
languages is that, for example, the algebraic datatype implementing the first-class view of the
language induced by a record declaration cannot be defined by simple reference to the record
type declaration, nor to any common “source”. This leads to unwelcome repetition, and to
maintenance burdens. Similarly, the “unbundling problem” concerns similar repetition that
arises for variants of record types where some fields are turned into parameters.
The goal of this thesis is to show how, in dependently-typed languages (DTLs), algebraic
datatypes and parameterised record types can be obtained from a single pragmatic declaration
within the dependently-typed language itself, without using a separate “module language”. Besides this practical shared declaration interface, which is extensible in the language, we also find
that common data structures correspond to simple theories.
Put simply, the thesis is about making tedious and inexpressible patterns of programming
in DTLs (dependently typed languages) become mechanical and expressible. The situations
described above occur frequently when working in a dependently-typed language, and it is
reasonable enough to have the computer handle them.
We develop a notion of contexts that serve as common source for definitions of algebraic
datatype and of parameterised record types, and demonstrate a “language” of “package operations” that enables us to avoid the above-mentioned replication that pervades current library
developments.
On the one hand, we demonstrate an implementation of that language as integrated editor functionality — this makes it possible to directly emulate the different solutions that are
employed in current library developments, and refactor these into a shape that uses single declaration of contexts, thus avoiding the usual repetition that is otherwise required for provision
of record types at different levels of parameterisation and of algebraic datatypes.
On the other hand, we will demonstrate that the power of dependently-typed languages
is sufficient to implement such package operations in a statically-typed manner within the
language; using this approach will require adapting to the accordingly-changed library interfaces.
Although our development uses the dependently-typed programming language Agda throughout, we emphasise that the idea is sufficiently generic to be implemented in other DTLs.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: There are things we want to use from various perspectives, our tools show that this is possible without any duplication and in a practical and efficient fashion.


title: Assessing Physical Function in Low Back Pain

subject:
Low Back Pain
Physical Function
performance based measures
psychometric properties

abstract:
Physical function has been identified as a core outcome to be assessed in low back pain (LBP). However, all recommended physical function measures are Patient-Reported Outcome Measures (PROMs). Performance-Based Measures (PBMs) are important measures that are practical and are prone to fewer biases. Two systematic reviews provided evidence on the psychometric properties of PBMs but were not comprehensive. Therefore, the purpose of this study was to identify PBMs developed for or used to assess physical function in LBP and to review studies evaluating the psychometric properties of these PBMs systematically.
	The first manuscript of the thesis was the systematic review protocol developed using the COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments) manual 2018. The protocol was also registered on PROSPERO (CRD42020147968). The protocol also outlined the use of the COMINS Risk of Bias (COSMIN-ROB) checklist 2018; standard priory hypotheses and criterions developed to evaluate the results of each psychometric property; as well as a GRADE criterion (Grading of Recommendations, Assessment, Development and Evaluations) to assess the level of evidence. Two reviewers independently screened, evaluated, and extracted data.
	The second manuscript was the systematic review written in the format of a journal for future submission. Our database search identified  47 studies assessing 115 PBMs. In general, findings included five different LBP diagnoses (e.g., non-specific LBP) and different LBP durations (e.g., acute, chronic). The level of evidence of each PBM or psychometric property mainly were generated from single studies. A high risk of bias assessed by the COSMIN-ROB checklist was found for most of the included studies. Overall, the included studies' results often did not meet our priory hypotheses for good psychometric properties. Hence, most PBMs' psychometric properties were found to have a low level of evidence. There was not a single PBM that demonstrated a good level of evidence for all properties. In conclusion, significant heterogeneity was found between studies leading to a limited level of evidence. PBMs need to be used with great caution. High-quality studies that investigate PBMs' psychometric properties are needed.

abstract: Thesis

abstract: Master of Science Rehabilitation Science (MSc)

abstract:
Low Back Pain (LBP) care costs the Canadian health care system millions of dollars every year. Most clinicians and researchers use self-report questionnaires filled out by their patients to assess physical function. However, performance measures where patients perform tasks while being observed are also recommended to assess physical function. Performance-based measures can be used alone or in combination with self-report measures. To select the most appropriate performance measures, we need to know how good and trustworthy these measures are. Therefore, the purpose of this study was to collect all possible performance measures that were developed or used to assess physical function in LBP patients; then summarized the available evidence on their psychometric properties (reliability, validity and responsiveness).
 	We searched five scientific databases and found 47 studies that evaluated 115 performance measures. Most included studies were of low quality and evaluated different tests or test properties. We found that most measures were not reliable, accurate or were sensitive to change. Therefore, clinicians and researchers need caution when selecting and interpreting results of these performance measures when evaluating physical function in LBP.


title: Biolayer interferometry as a novel method for detecting autoantibodies in patients with immune thrombocytopenia

title: Autoantibodies in immune thrombocytopenia

contributor:
Nazy, Ishac
Biochemistry and Biomedical Sciences

subject:
autoantibodies
biolayer interferometry
immune thrombocytopenia
sensitivity
glycoprotein
platelet

abstract: Immune thrombocytopenia (ITP) is an autoimmune hematologic disorder characterized by a low platelet count due to increased platelet destruction or decreased production. In primary ITP, the patient can have a low platelet count (<100 billion cells/L) for clinically unknown reasons. ITP is a rare disease that affects approximately 3/100 000 adults each year and some patients may experience bleeding symptoms. Autoantibody-mediated autoimmunity plays a role in the destruction of platelets by targeting platelet glycoproteins (GPs). Autoantibodies against platelet membrane GPIIbIIIa and GPIbIX are observed in about 50% of patients through direct antigen-capture assays, and 18% in patients through indirect antigen-capture assays. It is possible that some antibodies may not be detectable due to affinity or titre, or there may be other factors involved in platelet destruction. Currently, there is no definitive diagnostic test available for ITP, as a result of low assay sensitivity and different mechanisms involved in disease pathogenesis. The objective of this study was to use a novel approach to increase autoantibody detection unique to ITP patients. Total IgG was purified from patient and control plasma samples. A streptavidin-based antigen-capture assay was optimized to test the effect of biotinylation on the detection of anti-GPIIbIIIa and anti-GPIbIX autoantibodies in primary ITP patients (n=14), secondary ITP patients (n=3), non-immune thrombocytopenic controls (n=2) and healthy controls (n=16). Streptavidin-coated biosensors were used in an optimized biolayer interferometry (BLI) assay to study autoantibodies binding to biotinylated GPIIbIIIa and GPIbIX. Detection of anti-GPIIbIIIa autoantibodies in the streptavidin antigen-capture assay had a sensitivity of 24% and anti-GPIbIX autoantibodies had a sensitivity of 25%. BLI showed binding of autoantibodies in approximately 5% of ITP samples for both GPIIbIIIa and GPIbIX. The samples that had detectable autoantibodies in the antigen-capture assay did not have detectable antibodies in the BLI assay. BLI was not able to confirm antibody detection found in enzyme immunoassays.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Platelets are blood cells involved in clotting at sites of injury. Immune thrombocytopenia (ITP) is a disease defined by a low platelet count that can lead to bleeding. ITP is a rare disease that affects 3 in 100 000 adults every year. ITP is thought to be caused by proteins known as antibodies that bind self-platelets and lead to their destruction. These antibodies are directly found on approximately 50% of patients’ platelets, and only 18% of patients have antibodies in circulation. It is possible in many patients, antibodies are present at a low concentration, or are too weak to be detected in antibody tests. In this study, a new technology known as biolayer interferometry was employed to find antibodies in a higher percentage of patients. Results showed only 6% of ITP patients had detectable antibodies in their circulation. This research will improve our understanding of antibodies in ITP.


title: Coastal Palaeoenvironmental Change and Ancient Harbour Development at Liman Tepe-clazomenae (Urla, Turkey) and Lechaion (Corinth, Greece): A Multi-Proxy Geoarchaeological and Geophysical Study

contributor:
Boyce, J
School of Geography and Geology

subject:
Liman Tepe
Clazomenae
Lechaion
ancient harbours
sediment archives
ITRAX
micro-XRF
coastal palaeoenvironmental change
multi-proxy studies
lithochemofacies
proto-harbour basins

abstract:
Ancient harbour sediment archives can provide long-term records of changes in coastal palaeoenvironments, settlement history, and anthropogenic impacts on coastal systems. In this study, multi-proxy geoarchaeological investigations were conducted at two long-occupied coastal archaeological sites (Liman Tepe-Clazomenae, western Anatolia, Turkey; Lechaion, northeast Peloponnese, Greece) to document coastal palaeoenvironmental change and harbour basin evolution. Multi-proxy core analyses (micropalaeontology, sedimentary facies) were integrated with geophysical mapping and micro-XRF core scanning (chemofacies) to investigate harbour sediment archives and to reconstruct coastal palaeoenvironments.
    At Liman Tepe-Clazomenae, the Neolithic to Early Bronze Age (ca. 6700-3000 BCE) coastal palaeogeography was reconstructed using a large subsurface database (>20 cores, ~600-line km geophysical surveys) to determine palaeoshoreline positions and potential locations of prehistoric proto-harbour basins. Geophysical mapping revealed a submerged palaeolandscape with relict river channels and shorelines recording inundation of a middle Neolithic coastal plain. A transgressive systems tract was identified by marine foreshore and shoreface deposits overlying paleosol and lagoonal sediments. Shoreline positions were estimated by back-strip analysis of the de-compacted sediment thickness from the marine transgressive surface. During the middle Neolithic (ca. 6700 BCE) the shoreline was >500 m seaward of the modern shore and transgressed to its maximum extent (~1 km inland) during the Chalcolithic (ca. 4000 BCE). After 4000 BCE, sea level decelerated and the coastline prograded under a high-stand systems tract by barrier accretion. The transition from a Late Bronze Age (LBA) proto-harbour to Iron Age semi-enclosed harbour basin was recorded by shifts in geochemical proxies (Ti/Ca, Si, Br), foraminifera, and sedimentary facies. Shifts in Ti/Ca record potential signals of land clearance and evidence for a 300-year LBA drought period (“Greek Dark Age”). Geophysical mapping of Clazomenae’s Archaic (ca. 7th-6th c. BCE) harbour basin revealed two rubble-constructed breakwater structures and a submerged headland separating east and west basins. Linear magnetic anomalies within the eastern mole indicate a buried (LBA?) pier or breakwater within the rubble mass.
    At Lechaion, a multi-proxy analysis was conducted on seven cores to determine the timing and causes of the Roman harbour decline and abandonment. Coring identified a basin-wide paraconformity surface separating harbour sediments and overlying marl deposits, which records a rapid transition from a marine-estuarine to restricted evaporitic lake environment. Rapid basin restriction was indicated by a decrease in terrigenous elements (Si, Ti, K, Fe), increased Sr and δ18O, and a shift from marine-estuarine to marsh-freshwater taxa. The event records the 6th c. CE tectonic uplift and destruction of the harbour basin, linked with uplift on the nearby Perachora Peninsula (~1.1 m) during destructive earthquakes in 524 and 551/552 CE.  No evidence was found for tsunami events proposed in previous work.
    This study has documented the development, evolution, and abandonment of harbour basins on two tectonically active coastlines with complex relative sea level histories. Palaeogeographic mapping at Liman Tepe has identified a drowned palaeolandscape with areas of high archaeological potential for submerged prehistoric sites and proto-harbour anchorage areas. At Lechaion, multi-proxy analysis has resolved a long-standing debate, demonstrating that the harbour basin decline in the 6th c. CE was caused by coastal tectonic uplift and rapid basin restriction.

abstract: Dissertation

abstract: Doctor of Science  (PhD)


title: A Microflow Cytometry-based Agglutination Immunoassay for On-site Antigen or Antibody-based Medical Diagnosis

contributor:
Xu, Chang-qing
Biomedical Engineering

abstract:
On-site medical diagnosis is of great importance as it can provide cost-effective, user-friendly, and time-saving diagnosis, especially for individuals who live in resource-limited environments. The microflow cytometry-based agglutination immunoassay (MCAIA) for on-site antigen or antibody-based medical diagnosis was proposed. A method that is based on the average transit time of assay mixtures for quantitative detection of antigens of antibodies was proposed and verified by experimental results.
C-reactive protein (CRP) detection was used to illustrate the principle of antigen detection by the MCAIA. A linear relationship between the proportion of monomers and the concentration of CRP was established when data was analyzed using amplitude. A linear relationship between the average transit time and the concentration of CRP was established. A limit of detection (LOD) of 0.09 mg/L and an assay range up to 1 mg/L were achieved when data was analyzed using transit time. The total assay time was approximately 10 min and only a 10 µL sample was needed for each detection.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody detection was chosen as a model to demonstrate the principle of antibody detection by the MCAIA. A relationship between the average transit time and the concentration of SARS-CoV-2 immunoglobulin M (IgM) was established. A LOD of 0.06 mg/L and an assay range up to 1 mg/L were achieved. A relationship between the average transit time and the concentration of SARS-CoV-2 immunoglobulin G (IgG) was established. A LOD of 0.1 mg/L and an assay range up to 1 mg/L was achieved. The assay time of the SARS-CoV-2 antibody detection was approximately 30 min and only a 10 µL sample was needed for each test.
The proposed MCAIA can be broadly applied to other kinds of antigens or antibodies for on-site detection by replacing the corresponding antibodies or secondary antibodies specific to the targeted analyte. The compacted setup is competitive with other technologies for the medical diagnosis of antigens and antibodies.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Using Parental Experiences with Sickle Cell Disease Screening and Diagnosis to Guide Health Science Education: A systematic review and integrative qualitative meta-synthesis

contributor:
Vanstone, Meredith
Health Science Education

subject:
Sickle cell disease
Screening
Diagnosis
Sickle cell

abstract: Sickle cell disease (SCD) is a chronic, lifelong, often debilitating, inherited disorder that can affect every organ system.  Affected individuals often experience repetitive pain crises, multiple hospitalizations and a diminished quality of life.  Many people at risk for SCD are unaware of their sickle cell carrier status and surprisingly health care providers’ knowledge of SCD is limited. Research literature focuses mainly on management of clinical manifestations of the disease.  This systematic review and integrative qualitative meta-synthesis aims to capture parents’ perspectives on the screening process and diagnosis of SCD or sickle cell trait (SCT). Information generated by this review will be helpful in contributing to the development or enhancement of guidelines and protocols in SCD and SCT management for health care providers and health care educators.

abstract: Thesis

abstract: Master of Science (MSc)


title: Evaluating and Improving Stakeholder Accessibility of the World Health Organization's Tuberculosis Guidelines

contributor:
Schunemann, Holger
Health Research Methodology

subject:
Guideline
Recommendation
Tuberculosis
GRADE
Evidence-Based Practice
Evidence to Decision Table

abstract:
Background: Tuberculosis (TB) is the leading cause of death from a single infectious agent worldwide. The World Health Organization’s (WHO) Global Tuberculosis (GTB) Programme issues evidence-informed guidelines with recommendations on TB. In an effort to improve the accessibility and use of these guidelines, we developed a new digitized WHO eTB catalogue of recommendations.
Objective: The objective of this thesis was to explore stakeholder engagement with WHO TB recommendations. We sought to compare the accessibility of the WHO eTB catalogue to the conventional method of accessing WHO TB recommendations, and to explore the ways in which stakeholder feedback could be incorporated into quality improvement frameworks.
Methods: We conducted a two-arm superiority randomized controlled trial through a survey among stakeholders who were past or planned future users of TB guidelines, recommendations, or policy advice. Using a 1:1 ratio, we randomly assigned participants to complete an activity using WHO eTB or the conventional website. We compared outcomes of accessibility, understanding, satisfaction and preference between groups. We incorporated qualitative feedback from free-text boxes into a quality improvement framework.
Results: From February 26 to March 24 , 2021, we received 188 survey responses, 110 participants were randomized, and 102 were included in the interim analysis. On average, participants rated the WHO eTB catalogue as more accessible across four domains when compared to the WHO TB website. There was no difference in participant understanding of recommendation strength and certainty, but the ability to locate evidence to decision tables favored WHO eTB. We also received 75 qualitative responses, 47 of which yielded five themes: purpose, navigation, presentation, organization, and outreach.
Conclusions: The WHO eTB catalogue of recommendations improved the accessibility of WHO TB recommendations and supporting evidence for stakeholders of interest. Our findings support the continued use, promotion, and quality improvement of the WHO eTB catalogue in the future.

abstract: Thesis

abstract: Master of Public Health (MPH)

abstract: Tuberculosis (TB) is a leading cause of death worldwide. The World Health Organization’s (WHO) Global TB (GTB) Programme offers guidelines with recommendations to help decision-makers use evidence on TB prevention, diagnosis, treatment, and care. With the goals of improving the accessibility and use of these recommendations, the WHO and McMaster University have worked together to develop the WHO eTB catalogue of recommendations. This catalogue allows decision-makers to search, filter, and view WHO TB recommendations. This thesis contributed to this work by exploring feedback from decision-makers to identify whether the goals of the WHO eTB catalogue were achieved. The work included creating and leading a randomized controlled trial that compared the WHO eTB catalogue to the earlier way of accessing these recommendations using the WHO publications website. This thesis also explored ways that this feedback could be used to improve the WHO eTB catalogue in the future.


title: THREE ESSAYS ON PRODUCTIVITY AND CROSS-SECTIONAL ASSET PRICING

contributor:
Balvers, Ronald
Business Administration

subject:
Production-Based Asset Pricing
Productivity Gap
Total Factor Productivity
OECD Countries
Technology Shocks
Technology Gap
R&D Stocks
R&D Intensity
Global Differences in Equity Returns
Technology Diffusion
Political Risk

abstract: It is a sandwich Thesis. The first and the second essay are joint works with my Supervisor, Dr. Ronald Balvers. The third essay is joint work with Fangxing Liu, a Ph.D. candidate (Finance) at DeGroote School of Business, where we have equally shared the work responsibility.

abstract:
First essay deals with Productivity shocks. Productivity shocks transmitted from productivity leaders to trailing sectors are systematic sources of risk. Global technology and knowledge diffusion leads to predictable patterns in productivity dynamics across countries and industries. Productivity gaps determine the level of exposure to the systematic leader productivity shocks. Firms in a country-industry with larger productivity gaps relative to the world leader are more dependent on the leader's innovations compared to their own productivity improvements. They thus have higher loadings on the leader productivity shocks and higher average stock returns. For OECD panel data, a country-industry's productivity gap significantly predicts the stock returns of the country-industry: holding the quintile of country- industry portfolios with the largest gaps and shorting the quintile with the smallest gaps generates annual returns of 9.8% (6.7% after risk adjustment with standard factors). A factor associated with the productivity gap explains country-industry portfolio returns substantially better than standard factor models. Loadings on leader-country-productivity shocks are found to have substantial correlation with productivity gaps, and leader productivity shocks are more important for stock returns than idiosyncratic productivity shocks. These findings suggest that the productivity gaps and associated higher average returns are indeed tied to systematic risk.

The second essay deals with Technology shocks. Technology shocks from technological frontier economies are a critical determinant of productivity shocks. These shocks spill over, pervading all lagging economies and are true systematic shocks. A country's aggregate technology gap with the frontier determines the potential for the systematic innovation shocks to affect it, but the country's absorption capacity determines its effective sensitivity to these shocks. We find conforming evidence that the technology gap, R&D intensity, and absorption capacity can explain stock returns. For OECD panel data, a one standard deviation increase in the technology gap increases excess stock returns by 0.578 percent per month. A one standard deviation increase in R&D intensity increases the excess return by 0.637 percent per month. An increase in absorption capacity of one standard deviation increases the excess return by 0.275 percent per month. When global FF factors are included, the results are diluted, which suggests that the FF factors may alias for the three variables associated with the systematic risk arising from frontier technology shocks.

The third essay deals with Political risk. We find that the differences in Hassan et al. (2019) political Risk proxy derived from text processing of analyst transcripts can price cross-sectional returns after controlling for standard factor risks. A mimicking factor for the political risk measure, when added to the standard Fama French 5 factor model or the Q5 model, explains the test asset returns better than these models. In our limited sample, the changes in PRisk measure captures more information about political risk than the traditional measures from Baker et al. (2016), which suggests that one can start using changes in PRisk characteristic as a political risk proxy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Controllable Delivery of Hydrophilic and Hydrophobic Drugs Using Starch Nanoparticle-based Clusters

subject:
Starch nanoparticle clusters
Cancer therapy
Tumour penetration
Multi-drug therapy

abstract:
Despite the number of treatment methods currently available, cancer remains one of the leading
causes of death in Canada and worldwide. It is therefore critical that new and more effective
means of combating this disease be developed. Nanoparticles have been extensively investigated
for their use in cancer diagnostics, imaging, and most critically in chemotherapeutic drug
delivery. One such example is starch nanoparticles (SNPs), which can penetrate dense tumour
cores based on their small size and have the capacity to be functionalized and loaded with
different types of chemotherapeutic drugs. The size of SNPs, however, limits their potential to
reach tumours due to their rapid clearance from the body. To address this challenge, we have
fabricated electrostatic complexes – or nanoclusters – composed of cationic SNPs and anionic
charge-switchable polymers that remain stable at physiological pH (7.4) and disassemble to
release the highly penetrable SNPs when exposed to the acidic (6.5) microenvironment
associated with tumours. Furthermore, recent research has indicated that the administration of
certain combinations of chemotherapeutic agents can increase the efficacy of targeted cancer
therapy while reducing the necessary dose to achieve remission. One example of this is the
administration of the relatively hydrophobic EGFR inhibitor erlotinib (Erl), which can synergize
cancer cell apoptosis with the more hydrophilic DNA damaging agent doxorubicin (Dox). Here,
we reveal the ability to engineer two functionalized SNP variants capable of loading either Dox
or Erl that can subsequently be used in nanocluster formation to deliver synergistic antitumour
therapy in vitro and in vivo. Though drug loading and dual SNP carrying nanocluster formation
remain to be assessed, SNP variant synthesis is an important step towards generating multi-drug
delivering nanoclusters.


title: A Light-Scattering and Viscosity Study of Some Branches Polymers Prepared by Graft Polymerization

contributor:
Cragg, L. H.
Chemistry

subject:
graft polymerization
light-scattering
viscosity study
high polymers

abstract: This study deals with the effects of branching in some high polymers on viscosity behaviour and on the relationship between intrinsic viscosity and molecular weight. First, the preparation of branched polymers by means of graft polymerization is described. Evidence for the occurrence of grafting, which would result in the growth of polystyrene branches on a min, or backbone, chain composed of polystyrene or a copolymer of styrene and li-vinyl-cyclohexene-1, is reviewed, Next, the design, construction, and calibration of a flexible light scattering photometer is described. The performance of this instrument is shown to bs adequate for the determination of the molecular weight and size, as well as the second virial coefficient, of a high polymer in solution. Finally, properties of the graft polymers in solution are compared, with the corresponding properties of linear polystyrene. The relationships found between intrinsic viscosity and molecular weight, as well as the values obtained for the second virial coefficient, confirm the existence of branching in the graft polymers. On the other hand, it is shown that the viscosity slope constant, Huggins' k', the of which, is often used as an indication of branching, is not affected significantly by the branching present in the graft polymers.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Modified Tuned Vibration Absorber for Light Secondary Structures

contributor:
Semercigil, S. E.
Mechanical Engineering

subject:
vibration absorber
light secondary structures

abstract: Secondary structures may have to endure severe vibration amplitudes under the influence of the primary structures on which they are mounted. A series of numerical case studies are presented in this thesis to investigate the effectiveness of a passive vibration controller which combines a conventional tuned absorber with an impact damper, to attenuate the excessive vibration amplitudes of light secondary structures. In addition, experimental measurements are reported for some selective cases and comparisons are made with numerical predictions. This suggested configuration seems to suit ideally as an add-on enhancer for existing conventional absorbers. Most of the Results are presented for random white noise excitation, and a few representative transient vibration cases are also studied.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Aesthetic Intentions

subject: aesthetics

abstract:
Thesis
Master of Arts (MA)


title: Femtosecond Laser Ablation of Selected Dielectrics and Metals

contributor:
Haugen, H.
Engineering Physics

subject:
femtosecond laser
laser ablation
dielectrics
metals

abstract: Ti: sapphire femtosecond laser ablation of dielectrics (fused silica and BK7 glass) and metals (Cu, Fe, Al) is presented. Results of laser -induced breakdown experiments in fused silica and BK7 glass employing 130 fs -1.7 ps, 790 nm laser pulses are reported. The fluence ablation threshold does not follow the scaling of ~ when pulses are shorter than 1 ps. Single-shot and multi-shot (130 fs pulse) ablation of selected materials are investigated with laser wavelengths of 395 nm, 790 nm, and 1300 nm. The ablation threshold is almost independent of the laser wavelength. The surface morphologies in metals after ultrashort pulse ablation are very different from dielectrics and semiconductors. The roughness of the ablated surface depends on the thermal properties of the metal target. The preliminary TEM result from Cu single crystal that was irradiated by single laser pulses shows few defects in the center region of the ablated crater. Single-shot ablation of single-crystal Fe induces much different surface features than on selected samples of poly-crystal Fe metal.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Liquid-Phase Oxidation of Para-Cymene: Nature of Intermediate Hydroperoxides and Relative Activity of the Alkyl Groups

contributor:
Bourns, A. N.
Chemistry

subject:
liquid-phase oxidation
para-cymene
intermediate hydroperoxides
alkyl group

abstract: Using photochemical and emulsion procedures, a study has been made of the liquid-phase oxidation of p-cymene with respect to the nature of the resulting hydroperoxides and their decomposition products, and the relative extent of oxidative attack at the methyl and isopropyl groups. Hydroperoxide decomposition was negligible in the photochemical oxidations at 60C, and the product was shown to consist of 20% primary and 80% tertiary hydroperoxide by reduction of the total product and fractionation of the resulting alcohols. The following compounds were shown to be present in the emulsion oxidation product in addition to the above mentioned hydroperoxides: dimethyl-p-tolylcarbinol, p-methylacetophenone, p-isopropylphenylcarbinol, cumic acid, p-acetobenzoic acid, p-A-hydroperoxyisopropyl, benzoic acid, and p-(I-hydroxyisopropyl) benzoic acid. By chromatographic separation of the acids and reduction of the other products, the relative extent of attack at the two positions was shown to be 1:4, identical with that of the photochemical oxidation. Pure tertiary hydroperoxide has been obtained for the first time.

abstract: Thesis

abstract: Master of Science (MS)


title: Brecciation and Associated Mobile Submagmatic Emplacement of Alkali Feldspar Rich Rocks at Lake La Cloche, Harrow Twp, Ontario

subject:
brecciation
submagmatic emplacement
alkali felsdpar
lake la cloche

abstract:
Thesis
Bachelor of Science (BSc)


title: Le Jansenisme Dans Les Romans de Mauriac

subject: Jansenism mauriac

abstract: The analysis of the novels of Francois Mauriac reveal the author's Jansenist conception of religion. In this thesis of a brief study of seventeenth century jansenism is made in order to show the background of religious convictions with which Mauriac worked and the reason why his outlook is so pessimistic. He sees man as deprived of free will, predestined either to good or to evil, as well as determined by his environment. His rigoristic theological and psychological doctrines have led him to fatalism.

abstract: Thesis

abstract: Master of Arts (MA)


title: The Pyrolytic Decomposition of 6,6-Dimethyl-2-Cyclohexen-OL Acetate: A Study of the Thermal Elimination of Allylic Esters

contributor:
Warkentin, J
Chemistry

subject:
pyrolytic decomposition
6,6-Dimethyl-2-cyclohexen-l-ol
thermal elimination
allylic esters

abstract: The acetate of 6,6-dimethyl-2-cyclohexen-l-ol was thermally decomposed and the pyrolysis products were characterized. This allylic ester decomposed with difficulty. Under conditions which led to complete decomposition of 3-acetoxcyclo-hexene, 6,6-dimethy-2-cyclohexene-l-ol acetate was virtually unreacted. Complete decomposition of the allylic acetate was achieved at about 600°C. The pyrolysis products consisted mainly of o-xylene, toluene, 5,5-dimethyl-l,3-cyclohexadiene and acetic acid. The aromatic compounds are thought to be formed from the less stable diene. Partial decomposition of ester enriched with deuterium in the 4-position, permitted estimation of the isotope effect, Ku/kD, for the pyrolytic elimination. The value obtained was about 2. Together with other experimental evidence, it indicates that the main mode of decomposition is 1,4-conjugate elimination and that allylic rearrangement, if it occurs at all, is unimportant.

abstract: Thesis

abstract: Master of Science (MS)


title: A Study of Fission Yields Using a High Sensitivity Mass Spectrometer

contributor:
Thode, H. G.
Physics

subject:
fission
high sensitivity mass spectrometer

abstract:
An electron multiplier has been developed which has increased the sensitivity of an existing mass spectrometer toy a factor of 10^5. This increased sensitivity has permitted determination of fission yields of substances that have undergone little fission. Two such samples, for which the rare gas isotopes have been analysed, are Bohemian pitchblende and the products resulting from the neutron fission of Th232,
The Bohemian ore exhibited more neutron fission than any uranium deposit previously analysed. An explanation of this effect may be obtained by consideration of the geological and chemical nature of the deposit. The neutron fission of thorium, which shows fine structure in both the xenon and krypton regions, is similar to the patterns of u235 U235 and pu239,

abstract: Thesis

abstract: Master of Science (MS)


title: Bargmann transform and its applications to partial differential equations

contributor:
Pelinovsky, Dmitry Jr
Mathematics and Statistics

subject: Bargmann, Fock, partial differential equations

abstract:
This thesis is devoted to the fundamental properties and applications of the Bargmann
transform and the Fock-Segal-Bargmann space. The fundamental properties include unitarity
and invertibility of the transformation in L2 spaces and embeddings of the Fock-Segal-Bargmann spaces in Lp for any p>0. Applications include the linear partial differential
equations such as the time-dependent Schrödinger equation in harmonic potential,
the diffusion equation in self-similar variables, and the linearized Korteweg-de Vries equation, and one nonlinear partial differential equation given by the Gross-Pitaevskii model
for the rotating Bose-Einstein condensate. The main question considered in this work in
the context of linear partial differential equation is whether the envelope of the Gaussian
function remains bounded in the time evolution. We show that the answer to this question
is positive for the diffusion equation, negative for the Schrödinger equation, and unknown
for the Korteweg-de Vries equation. We also address the local and global well-posedness
of the nonlocal evolution equation derived for the Bose-Einstein condensates at the lowest
Landau level.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Oxidation Kinetics of Zirconium at 800°C and 850°C

subject: oxidation kinetics zirconium temperature

abstract:
Thesis
Master of Engineering (ME)