title: FROM WELFARE TO WORK FOR PEOPLE WITH DISABILITIES  IN RECEIPT OF PUBLIC INCOME BENEFITS: A WICKED PROBLEM FOR POLICY MAKERS

contributor:
Gewurtz, Rebecca
Rehabilitation Science

subject: welfare, work exit, employment, people with disabilities, ODSP, mental illness

abstract: This sandwich thesis contains 3 studies using three distinct methodologies: scoping review, quantitative study, and qualitative study. This program of research explores employment for people with disabilities who are in receipt of publicly funded disability income benefits.

abstract:
Employment is a key determinant of socioeconomic inclusion and health. Yet, people with disabilities (PWD) have one of the lowest employment rates in advanced welfare states. This thesis consists of three manuscripts using three distinct methodologies to examine this phenomenon. This thesis advances knowledge in the field by examining the employment outcomes of PWD who are in receipt of public income benefits, often referred to as programs of last resort. This thesis is framed by the theory of wicked problems which serves to emphasis the stubborn problem of low employment participation rates. Despite the numerous enhancements made to social assistance programming over the last two decades to facilitate positive employment outcomes, people with mental illness remain one of the most marginalized worker populations.
Manuscript one is a scoping review identifying what is known about active labour market policies within welfare to work programs for PWD. This research acts as the foundational piece upon which the other two papers build. The purpose of the review is to present the existing body of literature on this issue across all advanced welfare states and identify the gaps in the evidence base, summarize these findings and disseminate them to policy makers and other key stakeholders.
Manuscript two is a quantitative study. It takes a narrower focus and examines a subpopulation of PWD. This study uses administrative data from Ontario’s Ministry of Community and Social Services to examine the system level factors associated with earnings-related exits from the Ontario Disability Support Program, Ontario’s public income system for PWD. The study draws on descriptive and inferential statistical procedures to provide an overview of income support recipients with mental illness who gain enough earnings to transition off social assistance. This study contributes data on the numbers behind system exits to inform program development within ODSP.
While manuscript two answers who exits ODSP for employment, manuscript three provides insight into why and how individuals succeed in exiting the system. Through a series of semi-structured interviews with three participant groups, this study explores the process of transitioning off disability income support benefits among people with mental illness. This study adds to a small but emerging literature on the economic fate of former ODSP recipients, which will help inform policy development.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Employment is a key determinant of socioeconomic inclusion and health. Employment paid at a competitive wage equips a person with the social and economic resources they need to enjoy a decent quality of life. Yet, people with disabilities (PWD) are often underemployed or excluded from the mainstream labour market. This thesis sets out to explore the barriers and facilitators to meaningful employment for PWD, with a focus on people living with serious mental illness who are in receipt of income benefits from the Ontario Disability Support Program. This body of work begins with a global exploration of active labour market policies that are used to assist PWD enter or remain in employment. It then narrows its focus to explore the system level factors that prevent or facilitate people living with serious mental illness to transition from income benefits to mainstream employment. The study findings have implications for policy development in all advanced welfare states that could enhance successful transitions from welfare to work.


title: Linearization-Based Strategies for Optimal Scheduling of a Hydroelectric Power Plant Under Uncertainty

title: Linearization-Based Scheduling of Hydropower Systems

contributor:
Swartz, Christopher L. E.
Chemical Engineering

subject: Hydropower/Hydroelectric

subject: Uncertainty

subject: Linearization

subject: Scheduling

subject: Optimization

subject: Mixed-Integer Nonlinear Programming Problem (MINLP)

subject: Mixed-Integer Linear Programming Problem (MILP)

subject: Successive Linear Programming (SLP)

subject: Piecewise Linear Approximations (PLA)

subject: Stochastic

subject: Nervousness

subject: Rolling Horizon

subject: Cascaded Reservoirs

subject: Hybrid

subject: nonconvex

subject: Start-up costs

subject: Generators

abstract: This thesis examines the optimal scheduling of a hydroelectric power plant with cascaded reservoirs each with multiple generating units under uncertainty after testing three linearization methods. These linearization methods are Successive Linear Programming, Piecewise Linear Approximations, and a Hybrid of the two together. There are two goals of this work. The first goal of this work aims to replace the nonconvex mixed-integer nonlinear program (MINLP) with a computationally efficient linearized mixed-integer linear program (MILP) that will be capable of finding a high quality solution, preferably the global optimum. The second goal is to implement a stochastic approach on the linearized method in a pseudo-rolling horizon method which keeps the ending time step fixed. Overall, the Hybrid method proved to be a viable replacement and performs well in the pseudo-rolling horizon tests.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Natural Killer Cell as Effectors in Chimeric Antigen Receptor Based Immunotherapies for Cancer

contributor:
Ashkar, Ali
Medical Sciences

subject: Cancer Immunotherapy, Natural Killer Cells, Immunology, Oncology

abstract:
Recent developments in the expansion and manipulation of primary NK cells has allowed this source of effective anti-tumour cells to be exploited for cell-based cancer immunotherapies. While ex vivo expanded primary NK cells are highly effective in the treatment of haematological malignancies, their efficacy against the solid tumour has been limited due to the presence of immune-regulatory factors in the tumour microenvironment. These factors can abrogate NK cell function by down regulating the expression of NK activating receptors, thus preventing these highly cytotoxic effector cells from activating in response to tumour challenge. Our work explores whether the expression of a tumour specific chimeric antigen receptor (CAR) on ex vivo expanded primary NK cells would allow the lost activatory signalling to be recouped, and regain their efficacy against the solid tumour.
Unfortunately, the use of primary NK cells as effectors in CAR based cell immunotherapies has been hampered by the technical limitations of producing large numbers of CAR positive primary NK cells. This has led many researchers to utilise the NK-92 cell line instead of primary cells. We demonstrate that ex vivo expanded primary CAR NK cells can be produced efficiently and demonstrate higher anti-tumour functionality than CAR NK-92.
Finally, due to the intricacies of NK cell biology, they are able to effectively discriminate between healthy and malignant targets thus preventing their cytotoxic function from being directed towards the incorrect target. This could be a key advantage in the use of primary NK cells over T cells as effectors of CAR as the off-tumour/on-target adverse effects seen with CAR T cells has severely hampered this clinical strategy. We have shown that CAR T cells but not CAR NK cells are reactive towards phenotypically non-malignant, clinically relevant, healthy cells expressing the CAR target.

abstract: Thesis

abstract: Master of Science (MSc)


title: Building A Turbidostat To Analyze Gut Microbiota Succession In Infants

contributor:
Stearns, Jennifer
Computational Engineering and Science

subject: Turbidostat, microbiome

abstract:
By continually supplying nutrients, a turbidostat presents a steady environment to analyze bacterial growth dynamics. This makes it possible to model microbial community succession in a simple and more realistic way than is possible with batch culture. The problem with current commercial turbidostats are their industrial size and price.
With the use of 3D printed parts, printed circuit boards and laser cut pieces, all readily obtained online and in collaboration with laboratories here at McMaster University, I've created a relatively cheap custom turbidostat, ideally suited for longitudinal studies of microbial consortia that can accommodate eight separate experiments simultaneously. I have modified the design to enable microbial growth at 37°C under anoxic conditions, by changing how the growth media and gas is handled. I have also improved sample collection to make it more convenient and flexible. Cell growth dynamics were interrogated separately with one strain of a facultative anaerobe (E. coli) and one strain of an obligate anaerobe (Bacteroides thetaiotaomicron) bacteria.
For the individual strains, real-time optical density and dilution rate vs time graphs were created showing that these microbes can be reproducibly cultured, holding steady optical density rates for extended periods of time. Future directions include culturing a complex community without contamination by inoculating the system with microorganisms from an infant stool sample. Community composition and metabolite dynamics could then be analyzed by sampling over time.

abstract: Thesis

abstract: Master of Science (MSc)


title: FABRICATION OF CORK-SHELL MICROCAPSULES FOR BIOMEDICAL APPLICATIONS WITH FOCUS ON ULTRASOUND TRIGGERED RELEASE

title: Externally Activated Cork-Shell Microcapsules

contributor:
Hoare, Todd
Biomedical Engineering

subject:
Drug Delivery
Ultrasound
Microcapsule
Stimuli-responsive
Smart
Delivery Vehicle

abstract:
Developing a drug delivery vehicle that can control the release kinetics of a therapeutic drug on demand has great potential to improve health by allowing health care professionals to maintain the drug concentration in its therapeutic window and increase the efficiency at which treatment is administered.
On-demand release can be triggered by a range of stimuli including magnetic, radiation, and ultrasound activation. Of the three, ultrasound is the only one indiscriminate of the chemical properties of the material and is the most widely available clinically, which makes it versatile and applicable for many systems. However, existing strategies that use ultrasound as a release stimulus either pop the microcapsules altogether (enabling no subsequent effective control over the kinetics of drug release) or require continuous ultrasonic administration (typically impractical in a clinical setting), both of which are suboptimal.  Overcoming at least of these shortcomings would vastly improve on the technology.
In this thesis, microcapsules with a complex shell were fabricated using a modified electrohydrodynamic approach named immersion coaxial electrospraying, which allowed for an increased polymer loading in the shell and improved manipulation of microcapsule size. The complex shell structure of the microcapsules incorporated silica microparticles that acted as corks plugging pores between the inside and outside of the microcapsule. The modified microcapsules were shown to release their payload in the presence of a focused ultrasound signal, while uncorked microcapsules do not release. Release kinetics were shown to be adjustable based on the number of corks initially present in the shell of the microcapsule material.
Altogether, the cork-shell microcapsules fabricated in this thesis show promise as a tunable on-demand drug delivery vehicle that is able to better control release compared to conventional ultrasound triggered microcapsules.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: This thesis focuses on the fabrication of complex microcapsules that can be deliver therapeutic drugs on-demand using ultrasound waves. These microcapsules are composed of a water-based core and a biologically inert shell into which particles are embedded.  Upon the application of ultrasound, these embedded particles (like corks on a bottle) are popped out to release the “corks” from the shell, creating pores from which the drug in the microcapsule core can be released. In the absence of ultrasound signals, the microcapsules do not release any of their contents, making these effective for “on-demand” release. These microcapsules are made using a modified process based on electrospraying which allows very precise control over the microcapsules’ physical properties, incorporating a key modification that overcomes an inherent issue with the general technique. These microcapsules also improve on currently used ultrasound triggered drug delivery systems by requiring shorter periods of ultrasound and/or enabling better control over the dynamics of drug release following the ultrasound pulse.


title: Design and Development of a Novel Photoacoustic Imaging System for Detection of Intracranial Hemorrhages

contributor:
Farncombe, Troy
Biomedical Engineering

subject: photoacoustic

abstract: Photoacoustic (PA) imaging has the potential to overcome disadvantages of optical and ultrasonic imaging techniques by combining the two imaging modalities. This allows for exploitation of endogenous contrasts (variants of hemoglobin) to generate energy with light, and provides enhanced resolution by probing for resulting acoustic signals. The resulting platform has widespread applications ranging from structural (vasculature-based) to functional (oxygenation-based) point-of-care clinical imaging. This thesis has been aimed towards the development of a PA system for detection of intracranial hemorrhages. Simulations have been performed using a photon tracking Monte Carlo program and ultrasound wave propagation modeling software, k-wave to simulate light absorption and resultant acoustic signals in tissue. Furthermore, development of a PA imaging setup utilizes a 6-ns pulsed laser operating at 532-nm with a pulse repetition frequency of 28-Hz as the light source. Ultrasonic transducers with centre frequencies ranging from 1- to 5-MHz are used to receive acoustic signals produced from the object illuminated. The system is designed in a handheld, probe-like configuration to enable point-of-care detection and/or imaging. Acoustic signals are amplified and collected through a data acquisition system and processed through software to form an image. Simulations have shown sufficient penetration through superficial tissue, and absorption of light by blood at relevant wavelengths (near-infrared range). Black plastic resin phantoms have been used to characterize point-source PA signals, and complex geometries of phantoms have successfully been imaged and reconstructed with the PA system. Phantom geometries have also been imaged through gelatin and bone. The PA system has been successfully shown to image PA absorbers in different surrounding media, providing a promising first-step towards further development of the PA system for the detection of intracranial hemorrhages. This research has shown that photoacoustic detection of intracranial hemorrhages may be possible for adult human patients with brain injuries, and that the PA system design presented should be further developed to meet this goal.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: THE DEVELOPMENT OF A LOW DENSITY RADIOCHROMIC GEL DOSIMETER

contributor: Radiation Sciences (Medical Physics/Radiation Biology)

subject: Gel Dosimetry, Radiation Dosimetry, Radiochromic Dosimeter, Radiotherapy, Quality Assurance (QA), Gelatin, Two dimensional, Three dimensional

abstract:
This research aims to develop a tissue-mimicking material and produce a 3D gelatin that has density of approximately a human lung, which is in the ranges of (0.25 – 0.35) g/cm3. Tissue equivalent models are important in order to study the radiation dose planned for patients. To achieve the desired density of a human tissue, different types of gelatin were whisked for 300 seconds using a typical hand mixer. The mechanical properties of the gelatin mixtures, standard and foamed, were evaluated by applying different forces.
The mechanical properties for the gels were measured using an indentation technique, which showed that the gels act as elastic materials. The mechanical properties of the foams were also evaluated. Mixtures that contained 300 bloom gelatin, glycerol, and sorbitol, were whisked for 60, 180, 300 seconds to achieve different densities evaluated by CT imaging. The density of the180 - and 300 - seconds gelatin foams were found to be 0.33 ± 0.16 and 0.33  0.052 g/cm3, respectively, which is similar to the human lung density. Finally, FXO gel sheets and the FXO foam sheets were irradiated and the radiosensitivity quantified by measuring transmission using a spectrometer. The change in the attenuation coefficient was linear with dose.

abstract: Thesis

abstract: Master of Science (MSc)


title: INVESTIGATING COMMON PERCEPTIONS OF SOFTWARE ENGINEERING METHODS APPLIED TO SCIENTIFIC COMPUTING SOFTWARE

contributor:
Smith, Spencer
Shankar, Sumanth
Computing and Software

subject:
Software Quality
Scientific Computing
Software Engineering
SRS
Document Driven Design
Faked Rational Process Design
Design for Change

abstract:
Scientific Computing (SC) software has significant societal impact due to its application
in safety related domains, such as nuclear, aerospace, military, and medicine.
Unfortunately, recent research has shown that SC software does not always achieve
the desired software qualities, like maintainability, reusability, and reproducibility.
Software Engineering (SE) practices have been shown to improve software qualities,
but SC developers, who are often the scientists themselves, often fail to adopt SE
practices because of the time commitment.
To promote the application of SE in SC, we conducted a case study in which we
developed new SC software. The software, we developed will be used in predicting
the nature of solidification in a casting process to facilitate the reduction of expensive
defects in parts. During the development process, we adopted SE practices and
involved the scientists from the beginning. We interviewed the scientists before and
after software development, to assess their attitude towards SE for SC.
The interviews revealed a positive response towards SE for SC. In the post development
interview, scientists had a change in their attitudes towards SE for SC
and were willing to adopt all the SE approaches that we followed. However, when it
comes to producing software artifacts, they felt overburdened and wanted more tools
to reduce the time commitment and to reduce complexity.
While contrasting our experience with the currently held perceptions of scientific
software development, we had the following observations: a) Observations that
agree with the existing literature: i) working on something that the scientists
are interested in is not enough to promote SE practices, ii) maintainability is a secondary
consideration for scientific partners, iii) scientists are hesitant to learn SE
practices, iv) verification and validation are challenging in SC, v) scientists naturally
follow agile methodologies, vi) common ground for communication has always been
a problem, vii) an interdisciplinary team is essential, viii) scientists tend to choose
programming language based on their familiarity, ix) scientists prefer to use plots to
visualize, verify and understand their science, x) early identification of test cases is
advantageous, xi) scientists have a positive attitude toward issue trackers, xii) SC
software should be designed for change, xiii) faking a rational design process for documentation
is advisable for SC, xiv) Scientists prefer informal, collegial knowledge
transfer, to reading documentation, b) Observations that disagree with the existing
literature: i) When unexpected results were obtained, our scientists chose
to change the numerical algorithms, rather than question their scientific theories,
ii) Documentation of up-front requirements is feasible for SC
We present the requirement specification and design documentation for our software
as an evidence that with proper abstraction and application of “faked rational
design process”, it is possible to document up-front requirements and improve quality.

abstract: Thesis

abstract: Master of Science (MSc)


title: Genetic causes and consequences of ancient plague pandemics: pathogen evolution and human demographic reverberations

contributor:
Poinar, Hendrik
Biology

abstract:
The plague has caused some of the most noted catastrophes in recorded history. The
Plague of Justinian (6th-8th century CE), the Black Death (14th-18th century CE) and
the current third pandemic (mid-19th-mid-20th century CE), are responsible for the
mortality of hundreds of millions of people. In this thesis, I begin to explore these
ancient pandemics from a syndemic angle. This framework considers disease events
to be caused by more than just a single pathogen, but through the complex interplay
of factors, including the pathogen(s), host resistance/susceptibility, environment and
socio-cultural dynamics. Presented in sandwich-thesis format, I use the tools offered
by ancient DNA research, upon which I have built, to observe the genetic causes and
consequences of ancient plague pandemics from three different angles. I recover and
sequence the first draft genome sequence from a strain of the plague bacterium, Yersinia
pestis, associated with the Plague of Justinian and place it within the context of modern
strains to better understand the pattern(s) behind the dissemination of the three historic
pandemics. Next, I study the demographic effects of the Black Death by sequencing the
mitochondrial genome, a maternally inherited marker useful for studying migration,
from 264 individuals dating to late-medieval England and Denmark to look for signals
of large-scale population turnover and migration. I then compare changes in frequencies
of hundreds of immune-related loci from individuals who died before, during, and after
the Black Death to better understand how human immune genes were shaped by and
helped to shape the mass mortality of Black Death. Finally, I outline the methodological
challenges faced and improvements made during the course of these projects through
the examples of a variety of diverse projects. By examining the relationships of ancient
strains of Y.pestis, the changes in host immune genetics, and the demographic effects of
plague, and integrating these results with those from other disciplines, we can begin to
understand why and how ancient pandemics of plague were so devastating to humans in
the past and how we may respond to them in the future.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Products of Turbulent Times: Continuities and Change of 17th Century Neutral Iroquoian Ceramic Technology

contributor:
Roddick, Andrew
Anthropology

abstract:
Archaeologists today increasingly consider the relationship between historical processes and the production practices of past potters. In this thesis, I utilize extant Neutral Iroquoian assemblages from Southern Ontario to explore continuities and discontinuities in ceramic production practices during a time of profound socio-demographic turbulence in the early 17th century A.D. The Neutrals contributed and responded to an increase in regional violence, migration, and cultural interaction that involved taking in refugees, escalating captive-taking raids against enemy nations, and intensifying regional trade-networks along European and indigenous routes, while also experiencing and responding to traumatic demographic losses produced by European-disease epidemics. I employ the relational and historical communities of practice approach to orient my perspectives on technical styles to the lived experiences of learning and production among Iroquoian potting communities. The distinct emergence of shell-tempered ceramics in the Spencer-Bronte Creek site cluster served as an anchor for my investigation on how Neutral potters renegotiated and articulated potting practices during times of turbulence.
    I examined pottery production practices at the chronologically sequential Christianson and Hamilton sites through a multi-attribute analysis, ceramic petrography, and oxidation analysis. In this comparative approach, I found the likely presence of more than one community of practice at each site, speaking to the possibility of migration events. I found that a significant degree of continuities in technical style and a slight decrease in skill can speak to an adaptability of ‘open learning’ production communities, where broader numbers of persons held technical knowledge as peripheral non-specialists and they could have taken up the craft during times of community member reconstitutions after epidemics. Through time, conditions of turbulence brought about a greater diversity of practices and styles among communities of production as indicated through an increased blending of alternative practices in local operational chains and a decrease in their regimentation. These alterations are likely produced through ‘micro-histories’ at play within the household production scales constituting each village.

abstract: Thesis

abstract: Master of Arts (MA)


title: High-resolution Sequence Stratigraphy, Facies Analysis, and Sediment Quantification of the Cretaceous Gallup System, New Mexico, U.S.A.

contributor:
Bhattacharya, Janok
Earth Sciences

subject:
Sequence Stratigraphy
Facies Analysis
High-Resolution
Sediment Quantification
Gallup

abstract:
The quantification of sediment budget in a well-defined ancient source-to-sink (S2S) system is vital to understand Earth history and basin evolution. Fulcrum analysis is an effective approach to estimate sediment volumes of depositional systems, given total mass balance throughout source areas to basins. The key to this approach is to quantify sediment in a closed S2S system with time controls. We analyzed Allomember E of the Cretaceous Dunvegan Alloformation in the Western Canadian Sedimentary Basin to test this sediment estimation approach. The results indicate that the sediment transported by the trunk-river generically matches the sediment estimated to be deposited in the basin. The upper-range estimate may suggest mud dispersal southward by geostrophic currents.
Deciphering the relationships between traditional lithostratigraphy and sequence stratigraphy is the key to correctly understanding time-stratigraphic relationships. High-resolution sequence stratigraphic analysis of the Cretaceous Gallup system documents the high-frequency depositional cyclicity using detailed facies analysis in extensively exposed outcrops in northwestern New Mexico, US. We identified thirteen stratigraphic sequences, consisting of twenty-six parasequence and sixty-one parasequences. Shoreline trajectories are evaluated based on the geometry of the parasequences. The results show the previously identified sandstone tongues are equivalent to high-frequency sequence sets. The depositional duration estimates of respective sequence stratigraphic units, associated with the estimated changes in relative sea level, imply that Milankovitch-cycle-dominated glacio-eustasy may be the predominant control on the high-frequency sequence stratigraphy.
Shoreline processes are more dynamic and complicated with mixed-energy dominance. The re-evaluation of the depositional environments of the Gallup system and the reconstructions of the paleogeography with temporal controls help to examine the depositional evolution in space and time. Paleogeographic reconstructions at parasequence scales allow for the documentation of the process-based lateral facies variations and the depositional evolution. The distinction between different wave-dominated facies associations is proposed based on this process-based facies analysis.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Exploring the South Asian Punjabi community's experience of having accessed mental health services for depression in Canada

contributor:
Landeen, Janet
Nursing

subject: South Asian Punjabi, depression, mental illness, mental health services, access

abstract: An interpretive description qualitative approach was utilized in this study. The main aim to was to understand the South Asian (SA) Punjabi community’s experience of having accessed mental health services for depression within Ontario, Canada. A sub-aim was to capture the participants’ conceptualizations and experiences of having depression, which provided context about this ethnic community and deepened insights into their accessibility experience. Six Punjabi persons living with depression (PLDs) and six family members were interviewed in Punjabi and/or English. Data analysis was guided by Thorne’s strategy for interpretive description. Twelve major themes detailed the challenges of PLDs and their family members regarding i) identification and understanding of depression and ii) accessing mental health support. Major themes revealing the community’s conceptualizations of depression are: i) most of us didn’t know what depression is, ii) we realized it was depression after getting help, iii) we keep depression a secret, iv) my family didn’t understand my depression, v) my family helped, vi) my family didn’t help- some made me sick, and vii) my family also became “sick”. These themes supported a better understanding of the major themes discussing the community’s access to mental health service for depression, which are: viii) we didn’t know where to get help, ix) my health providers’ lack of familiarity with my culture caused stress, x) I waited to get help, xi) treating my depression cost me, and xii) knowing my culture will help you treat me better. Findings of this qualitative study provide details of how these participants had their own unique cultural conceptualizations of depression and continue to experience difficulty with accessibility of mental health services while receiving care. Results suggest culturally tailored improvements of mental health service accessibility are required to support this population as they navigate the mental health system for their depression.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Interplay of Physical and Biogeochemical Processes in Determining Water Cap Oxygen Concentrations within Base Mine Lake, the First Oil Sands Pit Lake

contributor:
Warren, Lesley
Geography and Earth Sciences

subject: Oil sands oxygen geochemistry

abstract: Syncrude Canada’s Base Mine Lake (BML), is the first oil sands pit lake and is being used to evaluate water-capped tailings technology for fluid fine tailings (FFT) management. To be successful, pit lakes must achieve the ecological role of a natural lake, requiring the development of oxygenated water cap capable of supporting macrofauna. Due to the reductive nature of the FFT stored at the bottom, oxygen-consuming constituents (OCC) such as methane, sulfide and ammonium can be mobilized into the water cap of oil sands pit lakes, posing a threat to the success of the reclamation. Results from BML are vital to inform successful pit lake design with a further 10+ pit lakes projected for collective waste reclamation required in the region, currently awaiting permitting. This field study established BML water cap depth dependent oxygen consumption rates (OCR), identified the key OCC driving those rates and modeled the roles of biogeochemical oxygen consumption and physical mixing in establishing water cap oxygen profiles during early stage development (< 5 years post commissioning). The balance between these two discrete processes underpins the likely viability of this management strategy for oil sands FFT. Results identify high OCR, in the range of highly productive eutrophic to hyper eutrophic lakes, in the vicinity of the FFT water interface, i.e. where concentrations of OCC are highest. Observed OCR rates decreased away from the FFT water interface, as concentrations of OCC decreased. The important OCC associated with high OCR were methane and ammonium. While the OCR values in the hypolimnion were extremely high, a minimally oxic FFT water interface persisted (<10 μM O2) contrasting the anoxic hypolimnetic waters typically observed in highly productive systems. Water cap oxygen mass balance modeling revealed physical mixing of oxygen into the hypolimnion from the metalimnetic region of the BML water cap currently slightly exceeds the oxygen being consumed through biogeochemical redox cycling, explaining the persistence of low levels of oxygen to the FFT water interface in the BML water cap (~ 10 m in depth). However, higher mobilization of OCC from the FFT as FFT consolidates, and/or higher rates of microbial biogeochemical cycling as microbial communities continue to establish and grow within BML, and/or decreased physical vertical transport of O2 into the hypolimnion, would all shift the oxygen balance towards greater consumption and thus would result in the migration of the oxic-anoxic boundary and OCC higher up into the water cap where they would directly impact the surface zone oxygen concentrations. Modeling results here identify that without the physical injection of oxygen into the hypolimnion, currently observed, OCR rates would generate anoxic conditions that would reach the middle of the metalimnion within this system within 24 hours. The development of an anoxic zone would facilitate greater generation of OCC directly within the water cap through anaerobic microbial biogeochemical cycling, the high levels of sulfate (~ 2 mM) observed within the BML water cap, which exceeds water cap oxygen concentrations by 3 orders of magnitude, indicate that generation of ΣH2S within this pit lake water cap would be a substantive risk to the development of a stable surface oxic zone that can support macro fauna. In addition, the emergence of nitrification, as one of the main oxygen-consuming reactions, was assessed experimentally to determine the potential effects on the oxygen depletion in BML water. Experimental results identified active nitrification with rates in the comparative range of marine to eutrophic estuary environments, with BML water collected from the metalimnion-hypolimnion interface, i.e. where the highest conversion of ammonia to nitrate was observed in field results. However, a comparison of oxygen consumption due to nitrification based on experimental, nitrification only results versus results from the field where nitrification as well as methanotrophy and other oxygen consuming processes are possible indicate oxygen consumption due to nitrification alone in the field is six times lower than the experimental oxygen consumption observed. These results highlight the competition for oxygen by multiple processes within BML, which suppress nitrification below levels observed under ideal experimental conditions. Characterization and modelling results of BML water cap oxygen concentrations carried out in this doctoral research reveal a new understanding of the important processes driving observed oxygen concentrations. These new insights delineate the potential effects of mobilized reduced constituents in the water cap from FFT and processes that may mitigate or exacerbate these impacts. Thus these results are of significant relevance to both the oil sands industry as well as other natural or anthropogenically impacted environments with high oxygen demand.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Numerical Modelling of Turbulent Mixing in Connected Nuclear Fuel Subchannels

contributor:
Lightstone, Marilyn
Tullis, Stephen
Mechanical Engineering

subject:
nuclear
turbulence
computational fluid dynamics
CFD
subchannel
turbulent flow
heat transfer
thermal hydraulics

abstract:
The effects of appendages on flow characteristics and scalar mixing in gap-connected twin-subchannel geometries has been assessed. The assessment considers a symmetric, rectangular compound channel geometry connected by a single rectangular gap using computational fluid dynamics (CFD). Detailed numerical models (geometry and turbulence), characterizing the full test section from a reference experimental study, are generated and validated against measurements. Time varying details of the gap induced periodic structures and appendage induced vortices are captured through calculations in an unsteady Reynolds averaged Navier-Stokes (RANS) framework coupled with the Spalart-Allmaras (SA) turbulence model closing the RANS equations. Companion simulations are performed at each of two Reynolds numbers (2690 and 7500), one with and one without a gap-centered appendage. The appendage size modelled is representative of CANDU endplates. The appendage effects on flow characteristics and mixing are isolated through comparison of the associated simulations.

In the absence of appendages, fluid exchange between subchannels is dominated by quasi-periodic flow pulsations through the gap formed due to flow instability in the near gap region. Without a gap-centered appendage, the magnitude, frequency, and structure length of the gap flow pulsations are well predicted by the model at both Reynolds numbers. The total tracer transfer between subchannels is reasonably well predicted for Re = 2690 (within approximately 17% of the experimental value). The model fails to capture the measured increase in scalar transfer through the gap with increased Reynolds number, underpredicting scalar mixing by 55% at Re = 7500. An argument is presented that the use of an isotropic turbulence model in the channel (SA), which precludes the development of channel secondary flows, is the source of the discrepancy between modelled and measured mixing at Re = 7500.

Appendages, such as those introduced by end plates or bearing pads in CANDU fuel bundles, augment the exchange process between subchannels. With an appendage representative of a CANDU fuel bundle endplate introduced into the gap region, crossflow velocity and frequency are predicted to increase immediately downstream of the appendage due to flow diversion and vortex shedding. The higher local frequency is shown to be consistent with the vortex shedding frequency calculated for a stationary rectangular cylinder at the gap conditions. Further downstream, gap induced instabilities begin to re-establish as the dominant contributor to crossflow pulsations although they are not fully recovered by the test section exit. Mixing is augmented more by the appendage with increasing Reynolds number for the range examined.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
The fuel bundle and pressure tube assembly in the core of a CANDU reactor forms an intricate web of subchannels of varying geometries with interconnecting gaps. Heat generated within the fuel bundles is removed by coolant flowing through the pressure tube and within the bundle subchannels. Although flow is nominally axial along the length of the rod bundles, coolant is free to move between subchannels through the gaps by a variety of mechanisms. Detailed fluid flow in these rod bundle geometries is a complex 3D phenomenon, strongly affected by fluid turbulence and flow instabilities associated with the subchannel geometry. This flow is investigated in the current study and extended to include the effect of appendages, which hold the fuel rods in place, to determine their impact on mixing along the length of the bundle.

Particular applications of the results of this study are in the areas of nuclear reactor performance and safety. The extent of coolant exchange between subchannels affects the local subchannel flow and temperature and, as a result, local cooling at the fuel element surfaces. Fuel element cooling is a principal component of reactor analysis under both normal operating conditions and postulated accident scenarios.


title: TECHNICAL CONSIDERATIONS FOR 1H - MAGNETIC RESONANCE SPECTROSCOPY (1H-MRS) MEASUREMENT OF SPINAL CORD GAMMA-AMINOBUTYRIC ACID (GABA)

contributor:
Noseworthy, Dr. Michael D.
Nelson, Dr. Aimee J.
Biomedical Engineering

abstract: Neurometabolites in the spinal cord play a significant role in biomechanics and neural plasticity. However, due to low concentrations and the limited geometry of the spinal cord, neurometabolites are not investigated with imaging modalities or in vivo. There- fore, the goal of this 1H-Magnetic Resonance Spectroscopy (1H-MRS) research was to assess a variety of techniques that aim to improve collection and quantification of in-vivo neurometabolite data in the cervical spinal cord using a Magnetic Resonance Imaging (MRI) scanner. This is important as the cervical spine can reveal information on the upper limb and its neuronal innervation nature. In this research, a phantom study was introduced as a proof of concept to ensure data acquisition based on spinal geometry can be repeatable and accurate. T-tests were performed to identify if 1H-MRS analysis was accurate and significant (P<0.05). MR spectral fit quality was assessed using two MRS fitting software packages (LCmodel and Tarquin) to see which more appropriately fit the data, based on standard and known concentrations in phantoms. T-test results found that both software packages can significantly (P<0.05) provide useful information on the spinal cord content concentrations, although software packages use di erent estimation methods. Furthermore, physiological motion such as breathing and pulsatile flow in the vessels that surround and flow through the spinal cord (i.e. CSF, blood) contribute to the highest levels of noise in the MRS signal. Therefore, a study that included the inves- tigation of main magnetic field (B0) and RF transmit field (B1+) inhomogeneities was conducted to evaluate how physiological noise (Pulsatile flow (PPG) and Respiratory flow (RESP) data) a ects data quality. Research found that there exists a relationship between PPG data and the B0 field (Correlation of 0.71) whereas RESP data and the B1+ field also yielded a relationship (Correlation of 0.62). Additional noise reduction techniques were also investigated to determine further improvement in spinal cord MRS data acquisition to best understand neurometabolite behaviour in this challenging tissue.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The spinal cord is an area often overlooked in science and in medicine. A new investiga- tive tool is required to understand how contents of the in-vivo spinal cord interact in certain pathological settings. Using an MRI should therefore be investigated, specifically a technique termed MRS, to collect data on the contents of an area of interest within the spinal cord. After acquiring repeatedly poor data, new techniques were examined to help improve data quality. First, to ensure the MRS technique is working, data from a control phantom was analyzed. This phantom allows for calibration of the MRS technique and ensures that data is being collected properly. However, when MRS is attempted in the human spinal cord, poor data is continually collected. Therefore, noise reduction and signal boosting techniques were implemented to a certain degree of success for future MRS spinal cord applications. The results suggest that a lot of work needs to be done to improve the MRS technique for spinal cord applications, however, one day this method can be clinically relevant and help us understand the secrets that lie within the spinal cord.


title: A Study of Canadian Old Age Pension Planning

subject:
economy
pension
pension planning
old age pension planning

abstract:
Thesis
Bachelor of Arts (BA)


title: Comprehensive Characterization of Nanotransfer Printing System for Organic Electronic Devices

contributor:
Turak, Ayse
Engineering Physics

subject:
Raman
Graphene
Nanotransfer Printing
Nanoparticles
Organic Photovoltaics
Perovskites

abstract:
This thesis presents a universal transfer printing method to introduce a thin layer of interlayer nanoparticle material in the cathode-organic layer interface in organic device. The use of reverse micelles for making nanoparticles restricts the nanoparticles to be directly synthesized on the organic active layer , therefore a transfer printing method using graphene was derived and a characterization method was needed to detect the transfer of nanoparticles in the whole device system.

Raman spectroscopy was found to be the best candidate in studying these organic systems. The oxidation behavior and interaction of CVD graphene on Cu with oxygen plasma and mild annealing was monitored closely by a detailed Raman trilogy studies.  Raman results also show evidence of graphene oxide successfully transferred to the target organic layer.

Raman spectroscopy was further explored to understand all material in the transferred system including the micelles, type of nanoparticles and the organic layer, which then provides valuable insights to the evolution of the different phases of nanoparticle material formed by the reverse micelles technique. Raman was also used to confirm the first-reported formation of the hot-topic perovskites materials in reverse micelles. An extended Raman technique, the unconventional inverted-TERS, was used to detect a monolayer of micelles which was otherwise impossible for a normal Raman setting. The underlying mechanisms of this technique with high-resolution were also proposed.

In order to understand and explore the tunability of reverse micelles on nanoparticle synthesis, a study with the pervovskite material was performed. There were evidence of precursors interacting with the pyridine group in the micelles core, which affects nanoparticle formation. The size of nanoparticles is also found to be tunable by using micelles of different block lengths and different solvents.

All these findings contribute to future optimization on the nanoparticles to be transfer printed into devices interlayer and ultimately to benefit on the improvement on organic photovoltaics.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Historical Development of Canadian Public Finance and Fiscal Policy

subject:
history
development
canada
public finance
fiscal policy
finance

abstract:
Thesis
Bachelor of Arts (BA)


title: Selective laser melting and post-processing for lightweight metallic optical components

contributor:
Elbestawi, Mohamed
Veldhuis, Stephen
Mechanical Engineering

subject: Additive Manufacturing; selective laser melting; metallic optical components; Aluminum alloys; post-processing treatment

abstract:
Industry 4.0 will pave the way to a new age of advanced manufacturing. Additive manufacturing (AM) is one of the leading sectors of the upcoming industrial revolution. The key advantage of AM is its ability to generate lightweight, robust, and complex shapes. AM can also customize the microstructure and mechanical properties of the components according to the selected technique and process parameters. AM of metals using selective laser melting (SLM) could significantly impact a variety of critical applications. SLM is the most common technique of processing high strength Aluminum alloys. SLM of these alloys promises to enhance the performance of lightweight critical components used in various aerospace and automotive applications such as metallic optics and optomechanical components. However, the surface and inside defects of the as-built parts present an obstacle to product quality requirements. Consequently, the post-processing of SLM produced Al alloy parts is an essential step for homogenizing their microstructure and reducing as-built defects.
In the current research, various studies assess the optimal process mapping for high-quality SLM parts and the post-processing treatment of Al alloy parts. Ultra-precision machining with single point diamond turning or diamond micro fly-milling is also investigated for the as-built and post-processed Al parts to satisfy the optical mirror’s surface finish requirements.
The influence of the SLM process parameters on the quality of the AlSi10Mg and Al6061 alloy parts is investigated. A design of experiment (DOE) is used to analyze relative density, porosity, surface roughness, dimensional accuracy, and mechanical properties according to the interaction effect between SLM process parameters. The microstructure of both materials was also characterized. A developed process map shows the range of energy densities and SLM process parameters for each material needed to achieve optimum quality of the as-built parts. This comprehensive study also strives to reduce the amount of post-processing needed.
Thermal post-processing of AlSi10Mg parts is evaluated, using recycled powder, with the aim of improving the microstructure homogeneity of the as-built parts. This work is essential for the cost-effective additive manufacturing (AM) of metal optics and optomechanical systems. To achieve this goal, a full characterization of fresh and recycled powder was performed, in addition to a microstructure assessment of the as-built fabricated samples. Annealing, solution heat treatment (SHT) and T6 heat treatment (T6 HT) were applied under different processing conditions. The results demonstrated an improvement in microstructure homogeneity after thermal post-processing under specific conditions of SHT and T6 HT. A micro-hardness map was developed to help in the selection of optimal post-processing parameters for the part’s design requirements.
A study is also presented, which aims to improve the surface characteristics of the as-built AlSi10Mg parts using shot peening (SP). Different SP intensities were applied to various surface textures of the as-built samples. The SP results showed a significant improvement in the as-built surface topography and a higher value of effective depth using 22.9A intensity and Gp165 glass beads. The area near the shot-peened surface showed a significant microstructure refinement up to a specific depth, due to the dynamic precipitation of nanoscale Si particles. Surface hardening and high compressive residual stresses were generated due to severe plastic deformation.
Friction stir processing (FSP) was studied as a localized treatment on a large surface area of the as-built and hot isostatic pressed (HIPed) AlSi10Mg parts using multiple FSP tool passes. The influence of FSP on the microstructure, hardness, and residual stresses of parts was investigated. FSP transforms the microstructure of parts into an equiaxed grain structure.  A consistent microstructure homogenization was achieved over the processed surface after applying a high ratio of tool pass overlap of ≥60%. A map of microstructure and hardness was prepared to assist in the selection of the optimal FSP parameters for attaining the required quality of the final processed parts.
Micromachining to the mirror surface was performed using diamond micro fly-milling and single point diamond turning techniques, and the effect of the material properties on surface roughness after machining was investigated. The machining parameters were also tuned to meet IR mirror optical requirements. A novel mirror structure is developed using the design for additive manufacturing concept additive (DFAM). This design achieved weight reduction of 50% as compared to the typical mirror structure. Moreover, the developed design offers an improvement of the mirror cooling performance due to the embedded cooling channels directed to the mirror surface.
A novel mirror structure is developed using the design for additive manufacturing concept additive (DFAM). This design achieved weight reduction of 50% as compared to the typical mirror structure. Moreover, the developed design offers an improvement of the mirror cooling performance due to the embedded cooling channels directed to the mirror surface.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Vibrating Reed Type Electrometer-Amplifier for the Measurement of Direct Currents

contributor:
Thode, H.G.
Lossing, F.P.
Shields, R.B.
Physics

subject: reed, vibrating reed, electrometer, electrometer-amplifier, direct currents

abstract:
Thesis
Master of Arts (MA)


title: Does Social Networking Site Usage by Older Adults Reduce Loneliness?

title: Does SNS Usage by Older Adults Reduce Loneliness?

contributor:
Yuan, Yufei
Business

subject:
Social Capital
Loneliness
Older Adults
Social Networking Sites
SNS

abstract: As the use of social networking sites (SNSs) has become more wide-spread, some age groups have taken to the media much more readily than other groups. Older adults are lagging behind in their adoption of SNSs, while this group of the population tends to be more socially isolated and lonely. In this thesis, the uses of SNSs have been broken down into different components such as the intimacy level of the message content, types of contacts, etc. A framework for social capital is utilized, in order to bridge the knowledge gap between how older adults use social networking sites to gauge its impact on loneliness. The findings suggest that the use of SNSs increases social capital but does not directly reduce loneliness. The impact of the increase of social capital by using SNSs on loneliness is negligible.  However, increased social capital due to SNSs use tends to moderate the effects that health status, financial wellbeing and satisfaction with offline relationships have on loneliness.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The British Balance of Payments

subject:
Britain
balance of payments
payment

abstract:
Thesis
Bachelor of Arts (BA)


title: Exploring the Role of Biomarker Genetics in Cardiovascular Disease

contributor:
Pare, Guillaume
Medical Sciences

abstract:
Biomarkers provide the opportunity to identify subclinical disease states before development of the disease and apply preventative measures, facilitate research and understanding of disease mechanisms, and allow for the assessment of therapeutic measures. However, a major challenge in the field of biomarker research is to discern cause and effect, and as a result, association has often been mistaken for causation. Additionally, the pathogenesis behind chronic diseases is extremely complex, resulting from several modifiable and unmodifiable risk factors and often caused by an interaction of many biomarkers simultaneously. Furthermore, biomarker levels show marked differences across ethnicities and it is difficult to distinguish whether this is a result of environmental or genetic factors. Through longitudinal, genetic, multi-biomarker studies, these barriers can be partially overcome. This thesis addresses how advancements in genetic and biomarker research may help to gain novel insights into both known and novel biomarkers of cardiovascular disease, inform and guide clinical decision-making and validate potential disease target pathways.
Using a variety of statistical approaches, we analyzed 4,147 participants of the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial measured for 237 biomarkers and followed for an average of 6.2 years, to investigate the genetic effects on biomarkers and their relation to cardiovascular diseases. Specifically, we applied Mendelian randomization (MR) analyses to identify novel, causal mediators of coronary artery disease (CAD) and chronic kidney disease (CKD). Additionally, we used admixture mapping to explore the impact of ancestry on serum biomarker levels in the Native Latin ORIGIN population and identified genes conferring differential risk across ancestries. We identified macrophage colony-stimulating factor 1 (CSF1) and stromal cell-derived factor (CXCL12) as novel, causal mediators of CAD using MR. Similarly, MR analysis also revealed uromodulin (UMOD) and human EGF receptor 2 (HER2) as new mediators of CKD. Through admixture mapping, we have demonstrated the importance of ethnicity across a comprehensive panel of biomarkers and shown a novel method for inferring the contribution of ethnicity to phenotypic traits in admixed individuals.
By applying two major statistical methods employed in genetic epidemiology we have revealed important insights into the role of biomarkers in health and disease. Taken together, this thesis implicates new biomarkers for CAD and CKD which are potential therapeutic interventions for prevention and treatment. Furthermore, this work indicates the importance of ancestry in disease, and paves the way for clinical treatment which is tailored to ethnicity. Future studies may adopt the novel approaches presented here to identify additional causal markers of disease and biological pathways and processes which are influenced by ancestry.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Crash Landing: Citizens, The State and Protest Against Federal Airport Development, 1968-1976

contributor:
Cruikshank, Ken
History

subject: Airports; Consultation; Prime Minister Trudeau; Mirabel; Pickering; Sea Island; Liberal Party

subject: Regional Development, Expropriation

abstract:
Abstract

     	During the 1960s both the federal and provincial governments continued to take on new and larger responsibilities. During this same time period citizens began to mobilize and challenge the state on a number of social issues including race, gender, labour, urban sprawl and the environment. Citizens believed that not only did they have the right to challenge the authority of government in planning public policy, but they also had a right to participate in the decision-making process as much as any bureaucrat, expert, or elected official. In planning airports in Pickering, Ste. Scholastique and Sea Island, the federal government was opposed by citizen groups in each of these three cases. Citizens believed their voices were not being heard and that government officials did not respect them. As a result, they disrupted the meticulously laid out plans of elected officials and policy planners by drawing on evidence and expert advice. The conflict over federal airport development is an example of the evolution of the consultation process with citizens, as citizens challenged the way public policy was planned. Governments now had to justify policies like expropriation for the public good since citizen groups would form over any intrusion into their private lives. The debates over airport planning highlights the role of citizens, bureaucrats, provincial and federal politicians as they all tried to navigate the complex shifting landscape of the Canadian state.
     	By 1976 the Pickering Airport had been canceled, Mirabel was opened, and the Sea Island runway expansion would be delayed for 15 years. Although the citizen groups never had complete victories, citizen participation became more paramount to state planning after these events. Public policy planning in Canada had become far more inclusive than ever before. Whether the politicians, bureaucrats or citizens were aware of the consequences remain to be seen.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Study of the Effect of Gamma Radiation on Sporulation and Growth of Yeast

contributor:
Miller, Dr. J. J.
Biology

subject:
gamma radiation
sporulation
yeast growth

abstract: The present study was initiated with the purpose of determining and comparing the effect of gamma radiation on the capacity of yeast cells to grow and sporulate. Using a new technique by which irradiated and non-irradiated yeast cells could be scored directly, it was found that sporulating yeast cells were more sensitive to radiation than growing cells, and that the inactivation of the capacity of an irradiated yeast cell to sporulate did not affect its ability to grow. Observations on irradiated sporulating cells indicated that spore-formation and reduction division of the nucleus, are closely allied phenomena. A short discussion of a probable mechanism of action of gamma radiation on sporulating yeast is included, together with suggestions for future research.

abstract: Thesis

abstract: Master of Science (MS)


title: On the Margins of Care: Women and HIV in Atlantic Canada

title: Women and HIV Care in New Brunswick and Nova Scotia, Canada

contributor:
Herring, Ann
Warry, Wayne
Anthropology

subject:
Women
HIV
Atlantic Provinces

abstract:
This study explores the barriers to care women face living with HIV in New Brunswick and Nova Scotia, and also the health and support systems they navigate to improve their wellbeing. Women living with HIV are invisible within the epidemic and often to community sector employees, especially in the Maritime Provinces where men account for the largest number of diagnoses in Canada; this is a central theme in the data.
	The thesis is rooted in applied medical anthropology and uses qualitative and quantitative methods to capture the changing health priorities of women living with HIV as they navigate the health care systems after diagnosis. This information was used to create maps that show the availability of services in relation to women’s needs, including affordable housing, food security, accessible transportation, and reducing HIV stigma. I examine the efficiency of HIV women’s referral network in both provinces, and the way forward for organizations to meet their long-term health needs, such as widening of outreach activities and improving gendered care.
	The main findings of this study reveal that the barriers to care women face are not easily overcome by AIDS service organizations. Current support initiatives are no longer relevant to their lives because they are tailored mainly to men, but women increasingly value the referral activities of organizations. Among the most important contributions of this thesis is the envisioning of a women-centered care model that meets their health needs and acknowledges their diverse reality of their experiences.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Measurement of Natural Variations in the Isotopic Content of Boron

title: Isotopic Content of Boron

contributor:
Thode, H. G.
Chemistry

subject:
boron
isotopic content
natural variations

abstract: An investigation was undertaken to check the difference in isotopic content between two boron samples measured earlier in this laboratory by using different methods of sample preparation from those used in the previous investigation. Yields of preparation were measured throughout. Measurements using methyl borate and boron trifluoride indicated a difference of slightly over 2% in the isotopic content of the samples, whereas the difference found in the previous investigation was 3.5%.

abstract: Thesis

abstract: Master of Science (MS)


title: Isotope Effects and the Question of Reaction Mechanisms: A study of the Tschugaeff Reaction

contributor:
Bourns, A.N.
Science

subject: isotope, isotope effects, reaction mechanism, reaction mechanisms, tschugaeff reaction

abstract: Three simultaneous isotope effects have been determined for the Tschugaeff reaction, i.e., the thermal decomposition of an xanthate ester. The ratio of the rate constants, k32/k34, was found to be 1.009 for the thion sulphur atom and 1.002 for the thio-ether sulphur atom. The rate ratio k12/k13, for the xanthate carbon atom was found to have a value of 1.000. The findings of previous investigators of the Tschugaeff reaction had been consistent with either of two mechanisms. However, with the determination of the isotope effects referred to above, it has been possible to distinguish between the two possible mechanisms and to gain considerable information about the transition state of the Tschugaeff reaction. The measured isotope effects have been discussed in terms of Bigeleisen's isotopic rate equation. In addition, it has been possible to carry out theoretical calculations for each reaction mechanism by assuming an appropriate potential function and in this manner make the interpretation of the measured isotope effects more quantitative.

abstract: Thesis

abstract: Master of Science (MS)


title: Computational Actinide Chemistry: Structure, Bonding and Thermodynamics

contributor:
Vallet, Valerie
Ayers, Paul
Real, Florent
Gomes, Andre Severo Pereira
Chemistry and Chemical Biology

subject:
computational chemistry
actinides
thermodynamics
plutonium
catalysis

abstract: Universite de Lille, McMaster University

abstract:
The main question of this thesis is: do we have today the tools to efficiently
describe the structure, the bonding and the thermodynamics of actinide systems?
This broad question is answered thanks to three studies. The first
two are directly applied to the plastic industry and the nuclear plant safety.
The last one, more fundamental, concerns the benchmarking of newly developed
theoretical approach on f-element systems. First, actinides and transition
metal arene-coordinated alkyl cations have been recently proven to
be efficient catalysts for ethylene polymerizations. Interestingly, thorium,
uranium and zirconium alkyl cations? catalytic activity depends on the solvent.
To understand these behaviors and to confirm the tendency of these
complexes to engage in unusual-arene coordination, relativistic DFT calculations
combined with a characterization of the interaction thanks to the ETSNOCV
method are used. Second, in accident scenario along the reprocessing
of spent nuclear fuel, plutonium can be released in various volatile forms
(PuO2, PuO3 or PuO2(OH)2, ...). The exploration of these scenarios by the
use of simulations requires, among the various parameters, the knowledge
of the thermodynamic properties of the possibly formed elements. Our insilico
study focusses on the determination of the enthalpies of formation of
the former two species for which experimental uncertainties remain, using
multi-configurational relativistic wavefunction method. The last part of the
thesis focusses on the benchmark of the B2-PLYP functional for f-element systems,
which turns out quite accurate with respect to the experimental data
and the gold-standard CCSD(T) method.                                                                                La question générale traitée dans cette thèse est de déterminer si, aujourd’hui,
nous disposons d óutils théoriques efficaces pour d’ écrire la structure, la liaison
et les propriétés thermodynamiques de système comprenant un actinide.
Cette large question va être abordée à láide de trois études différentes. Les
deux premières sont directement liées à l?industrie plastique et à la sureté
nucléaire. La dernière, plus fondamentale concerne une analyse comparative
d?une approche théorique nouvellement développée sur des systèmes comprenant
des éléments f. Tout dábord, les cations alkyles contenant un actinide
(Th, U) ou un métal de transition (Zr) coordonné à un arène se sont révélés efficaces
pour la catalyse de la synthèse du polyéthylène. étonnamment, les activités
catalytiques des cations alkyles dépendent du solvant. Pour comprendre
cela et confirmer la tendance quónt ces complexes à se lier à l?arène, une
étude en DFT dans un contexte relativiste combinée à une caractérisation de
liaison avec la méthode ETS-NOCV fut faite. La deuxième étude vise à étoffer
les bases de données thermodynamiques qui servent à explorer numériquement
les scénarios d?accidents. Notre étude in silico porte sur la détermination
des enthalpies de formation des deux espèces pour lesquelles des incertitudes
expérimentales subsistent (PuO3 ou PuO2(OH)2, ...), en utilisant une
méthode quantique multiconfigurationnelle et relativiste. La dernière partie
de la théorie se concentre sur l?estimation de la précision de la fonctionnelle
B2-PLYP pour les éléments f, qui sávère assez précise en comparaison aux
données expérimentales et à la méthode de référence CCSD(T).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Calculations of Reduced Probability For E2 Transitions in Deformed Even-Even Nuclei

contributor:
Preston, M.A.
Physics

subject: E2, E2 transitions, deformed even-even nuclei, even-even nuclei, nuclei, reduced probability of deformed even-even nuclei

abstract: The reduced probability of E2 transitions between rotational levels built upon γ-vibrational states was calculated for even-even nuclei. General expressions were derived as functions of the spin of the initial state and a parameter γ10. Branching ratios for special cases were obtained, which compare quite favourably with experiment.

abstract: Thesis

abstract: Master of Science (MS)


title: Diffusion resistance of claddings for corrosion protection of structural alloys in molten salt reactors

contributor:
Luxat, John
Kish, Joey
Engineering Physics

subject:
claddings
coatings
diffusion resistance
materials durability
corrosion
molten salt reactor (MSR)
nuclear reactor

abstract:
Corrosion is a major challenge in the use of molten ﬂuoride salt as a coolant in molten salt reactors (MSRs). A promising way of satisfying the two requirements of high strength and corrosion resistance is to clad structural alloys with a corrosion resistant material.

Four candidate cladding and structural alloy combinations—stainless steel 316L and Incoloy 800H structural alloys either diffusion bonded to Hastelloy N or electroplated with nickel—were thermally aged at 700 °C for two to eight months. Based on measured concentration profles, the diffusion resistance of the four material combinations was compared and diffusion results were extrapolated to an end of reactor lifetime. The most important conclusion from this work is that Hastelloy N is highly likely to be signifcantly more diffusion resistant than nickel. The difference in diffusion resistance between Incoloy 800H and stainless steel 316L is relatively small.

Two methods were used for extrapolating experimental diffusion results: (1) a diffusion model and calculated diffusion coeffcients and (2) simulations with Thermo-Calc DICTRA. Some simulations were carried out with a corrosion boundary condition of near-zero chromium concentration, demonstrating the potential of simulations for predicting diffusionlimited corrosion in molten ﬂuoride salts. A surprising result of these simulations is that decreasing the thickness of Ni plating did not increase the thickness of diffusion zones in underlying structural alloys.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Three Essays on the Dynamics of Benefit Receipt in the Ontario Disability Support Program

contributor:
Spencer, Byron
Economics

subject: ODSP, Disability Benefits, Claimant Inflows and Outflows, Duration Dependence

subject: Immigration, Disability Benefit Receipt, Duration, Aging, Ontario

abstract:
This thesis focuses on the dynamics of benefit receipt in the Ontario Disability Support Program (ODSP) using individual-level administrative data from 2003 to 2013. This thesis is comprised of three self-contained essays.
The first essay examines the dynamics of disability benefit receipt in Ontario. A five-year cohort analysis is carried out for those who first received disability benefits in any year between 2004 and 2009 to estimate the proportion exiting from such benefits within five years of first benefit receipt. This analysis is extended to type of exit (e.g., died, moved, or disqualified) and nature of exit (e.g., sustained or temporary). We find that only about 18 percent of benefit recipients exit, most within one and a half years of initial benefit receipt, and that more than one-third of those who exit return within five years. Recipients are both less likely to exit and more likely to return if single, divorced, or widowed rather than married or living common law, if they have children, or if they have mental rather than physical disabilities.
The second essay identifies factors that influence ODSP benefits duration. We employ a flexible parametric technique to investigate the duration of disability benefit receipt. We also employ cure models to account for the proportion of recipients that never exit ODSP over the ten-year sample period. Of the whole sample, 20 percent of recipients completed a first spell and the remaining 80 percent were right censored. We find that time spent receiving ODSP benefits is negatively associated with education and positively associated with both age and severity of disability. Individuals who are single, divorced, separated, widowed, or immigrants have longer benefit spells as compared to those who are married, common law, and Canadian born. Individuals with children also spend longer time on ODSP than those relative without children. We provide evidence that recipient characteristics are associated with different probabilities of exiting or re-entering ODSP; that suggests that differentiated, and not ‘one size fit all’, policies are required to facilitate transitions from program dependence to economic independence.
The third essay analyzes differences in the benefit receipt rates by immigration status and age. A flexible parametric duration analysis is employed to investigate how age at entry into benefits interacted with immigration status and, for immigrants, how age at arrival in Canada affects the exit rate from disability support. We find strong evidence of differences in age-dependence of benefit receipt and exit rates across immigration status categories. At younger (18-34) and middle (35-54) ages the Canadian-born have much higher benefit receipt rates than immigrants but lower rates at older (55 and over) ages. We speculate that the difference at younger and middle ages can be explained largely by the “healthy immigrant effect” (i.e., a selection effect of relatively healthier immigrants) and at older ages by differential eligibility for, and expected income from, alternative benefit programs such as the Canada Pension Plan, Old Age Security, and the Guaranteed Income Supplement.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Alkylation of 3,4-Dihydro-B-Carbolines

contributor:
Spenser, I.D.
Chemistry

subject: alkylation carbolines

abstract: The structure of anhydro- and pseudobases obtained from N-alkyl-3,4-dihydro-B-carbolinium salts is discussed in the light of chemical and spectroscopic evidence. The behaviour of these compounds on further alkylation and the structure of the alkylation products so obtained has been investigated.

abstract: Thesis

abstract: Master of Science (MS)


title: Labour Market Policy and the Cognitive Face of Political Economy

contributor:
McBride, Stephen
Frost, Catherine
Graefe, Peter
Political Science

subject:
Labour Market
Public Policy
Labour Market Policy
Active Labour Market Policy
Canada
Political Economy
Cognition
Psychology

abstract:
A frequent question in academic and non-academic research is how particular systems are formed, maintained, and potentially, changed. This dissertation explores the question above through the intersection between political economy and public policy, specifically on accumulation: how economic and social relations come to be, endure, adapt, or fail. This is reflected in a slew of theories, paradigms, and research programmes, yet most utilize a macro or meso lens and rarely look at ‘micro’ level phenomena and processes – those involving everyday interactions and people. At this level, a significant, yet absent, component is the way individuals may come to automatically think and act through receiving information conveyed in ways that promote internalization or automaticity. The ongoing question, then, is what regimes communicate and how they do so.
	I will examine the role of active labour market policy (ALMP) in sustaining contemporary accumulation trajectories in Canada by analyzing what it communicates to policy recipients in terms of how they should conceive of themselves as workers, their expectations of the market, and of the state. However, what public policy communicates does not, in and of itself, explain how people come to internalize particular ways of thinking and acting. As such, I combine policy analysis with cognitive psychology to examine what ‘everyday’ public policy components – such as websites, forms, and job search systems - communicate, and crucially, whether they do so in a way which is conducive to ‘automatic thought’ (e.g. ‘common sense’).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation explores how public policy can shape how individuals automatically think and act, thereby informing their ‘common sense’ and rational thoughts. I will examines what Canadian active labour market policy (ALMP) communicates to policy recipients in terms of how they should conceive of themselves as workers, their expectations of the market, and of the state. I combine policy analysis with mechanisms derived from cognitive psychology to examine what ‘everyday’ public policy components – such as websites, forms, and job search systems - communicate, and crucially, whether they do so in a way which is conducive to ‘automatic thought’ (e.g. ‘common sense’). This approach fills in gaps political psychology, public policy, and the political economy of regimes.


title: The Cyclic Straining of Aluminum - 4% Copper

contributor:
Ham, R.K.
Metallurgy

subject: aluminum, cyclic straining, 4% copper, cyclic strain, cyclic straining of aluminum

abstract: In this thesis the nature and strengthening effect of the various precipitates in Al-4% Cu are reviewed, followed by a literature survey on the response of this alloy to fatigue. The first experiments described were carried out to measure the Bauschinger effect and the results of these are presented. The experimental study was further extended by cyclic straining corresponding to fatigue conditions and the results obtained are presented graphically and through electron micrographs. The fatigue behaviour was further investigated at liquid air temperature. Also, the effect of heat treatments carried out during the interruption of fatigue on a specimen containing metastable θ" precipitates is reported. All the experiments were carried out on single crystals and most of them with 112 orientation as indicated later.

abstract: Thesis

abstract: Master of Science (MS)


title: Selective Oxidation and Reactive Wetting of 2Mn-Si Steels During Continuous Hot-Dip Galvanizing

contributor:
McDermid, Joseph.R
Materials Science and Engineering

abstract:
The influence of annealing process parameters i.e. oxygen partial pressure and annealing time, on the selective oxidation and reactive wetting of Fe-0.1C-2Mn-1.3Si (wt.%) and Fe-0.1C-2Mn-1.7Si (wt.%) advanced high strength steels during continuous galvanizing was investigated. The effect of the addition of 0.05 wt.% Sn on the selective oxidation and reactive wetting of the Fe-0.1C-2Mn-1.7Si (wt.%) steel was also determined. The experimental steels were annealed at intercritical annealing temperatures at which an intercritical microstructure of 50 ferrite -50 austenite (vol.%) was obtained, calculated for each grade of steel using THERMO-CALC software considering the local equilibrium-non partitioning (LE-NP) formalism, for annealing times of 60 to 600 s in a N2-5 vol.% H2 gas atmosphere, where the oxygen potential was controlled by varying the dew point (dp) at 223 K (–50 °C), 243 K (–30 °C) and 278 K (+5 °C). For reactive wetting studies, samples were immersed in a 0.2 wt.% dissolved Al continuous galvanizing bath. The oxide chemistry, spatial distribution and morphology were found to be affected by the annealing process parameters. As a consequence, the reactive wetting of the steels by the continuous galvanizing bath could be controlled via controlling these parameters
For the Fe-0.1C-2Mn-1.3Si (wt.%) alloy, annealing under the lowest pO2 223 K (–50 °C) dp process atmosphere led to the formation of a thick, compact, multi-layer oxide comprised of film-like SiO2 and MnSiO3 with granular MnO on top. Insignificant internal oxidation was observed in this case. Increasing the process atmosphere pO2 using the 243 K (–30 °C) dew point resulted in a considerable increase in the depth of internal oxidation and decrease in the thickness of external oxides, which is indicative of the occurrence of the transition from external to internal oxidation. Under this annealing condition, surface oxides were composed of thinner film-like MnSiO3, Mn2SiO4 and SiO2 oxides, compared to the 243 K (–50 °C) dp process atmosphere, as well as MnO oxides. Further increasing the process atmosphere pO2 via raising the dew point to 278 K (+5 °C) dp resulted in modification of the surface oxides from film-like to nodule-like MnO, MnSiO3 and Mn2SiO4 particles. Prolonged annealing times were also found to increase either the thickness of external oxides or depth of internal oxidation.
For the Fe-0.1C-2Mn-1.7Si (wt.%) alloy, similar modifications in the morphology of the external oxides were observed after increasing the process atmosphere dew point from 223 K (–50 °C) to 278 K (+5 °C) dp, due to the transition from external to internal oxidation. Although steel surface was covered with thick, compact film-like SiO2, MnSiO3 and MnO under the 223 K (–50 °C) dp process atmosphere, thinner and less compact film-like and plate-like SiO2, MnSiO3 oxides and MnSiO3 nodule-like particles were identified on the surface under the 243 K (–30 °C) and 278 K (+5 °C) dp process atmospheres, respectively. MnSiO3 and Mn2SiO4 oxide particles as well as network of MnSiO3 embracing SiO2 core were found, respectively, in the bulk microstructure and along the grain boundaries in the steel subsurface. Detailed investigations into the growth kinetics of the external and internal oxides revealed that both thickness of the external oxides and depth to which internal oxides formed increased parabollically with increasing annealing time.
Poor reactive wetting was obtained for both alloys when using the lowest pO2 273 K (–50 °C) dp process atmosphere due to the formation of thick, compact oxide layer on the steel surface, which formed a barrier between the substrate and Zn bath, preventing the required Fe dissolution from the substrate surface for the formation of the desired  Fe2Al5ZnX interfacial phase. This is while a well-developed interfacial Fe-Al intermetallic layer, indicative of a good reactive wetting, was observed for both alloys when using the two higher pO2 process atmospheres (i.e. 243 K (–30 °C) dp and 278 K (+5 °C dp)), due to the presence of either thinner film-like or plate/nodule-like oxides on the steel surface after annealing. This external oxide morphology facilitated contact between the Zn-alloy bath and the substrate via a variety of mechanisms, including interfacial infiltration through cracks due to thermal coefficient of expansion mismatch between the external oxide and substrate as well as aluminothermic reduction, which resulted in Fe dissolution from the substrate and consequent formation of the Fe-Al intermetallics.
Moreover, the addition of 0.05 wt.% Sn to the Fe-0.1C-2Mn-1.7Si (wt.%) steel significantly improved the reactive wetting by the continuous galvanizing bath, which was found to be due to its beneficial effect on reducing the oxidation growth rate by segregating to the steel surface to about 150 times greater than its bulk concentration, occupying the potential sites for oxide nucleation, therefore altering the morphology of surface oxides. Under the lowest pO2 273 K (–50 °C) dp process atmosphere, the addition of Sn reduced the compactness of the external granular MnO oxides and increased their size. Under the intermediate pO2 243 K (–30 °C) dp process atmosphere, the addition of Sn altered the morphology of the surface oxides from large, thick and compact MnSiO3 and SiO2 particles to small, thin and less compact ones. Sn had its most significant effect on external oxide alteration under the highest pO2 278 K (+5 °C) dp process atmosphere, which was exemplified by changing their morphology from film-like and fine, closely spaced nodule-like MnSiO3 particles to big, widely spaced ones. The modified oxide morphology obtained due to the addition of Sn to the steel chemistry facilitated contact between the Zn-alloy bath and the substrate, thus resulted in the formation of smaller and more compact interfacial Fe-Al crystals and lower bare areas compared to the reference steel, therefore improved the reactive wetting during continuous galvanizing.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CHARACTERIZATION OF THE PREOPERATIVE IMMUNE PROFILE IN A COHORT OF PATIENTS UNDERGOING CARDIOPULMONARY BYPASS SURGERY TO PREDICT POSTOPERATIVE ANTIBODY PRODUCTION AGAINST PF4/H COMPLEXES

contributor:
Nazy, Ishac
Arnold, Donald
Biochemistry and Biomedical Sciences

subject:
PF4
Platelet
Blood
Thrombosis
Heparin
HIT
Cardiac Surgery
CABG
CPB
B cell

abstract:
Background: Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction characterized by a lowered platelet count (50% from baseline) 4-10 days after heparin exposure. Autoantibodies specific for platelet factor 4 (PF4) bind PF4 and heparin complexes (PF4/H) and activate platelets through the FcgammaRIIA receptor. Severe cases of HIT can result in thrombotic complications including deep vein thrombosis, pulmonary embolism, and death.
Pathogenic class-switched antibodies against PF4/H (IgG) are detectable in circulation as early as five days post-heparin exposure and peak at 14 days. The timeline and class of antibody found in HIT patients suggest that there must be pre-existing immunity against PF4/H. Thus, B cells producing anti-PF4/H antibodies must exist prior to heparin exposure. Cardiac surgery patients are disproportionately prone to anti-PF4/H seroconversion (up to 70%) and thus are utilized in this study as a model patient group.
Research objective: The objective of this study is to determine whether the preoperative immune profile is associated with postoperative anti-PF4/H antibody production in a cohort of patients undergoing cardiac pulmonary bypass (CPB) surgery.
Materials and methods: To characterize the preoperative immune profile, we used 1) a peripheral blood mononuclear cell (PBMC) enzyme linked immunospot (ELISPOT) assay to measure the prevalence of preoperative anti-PF4/H specific antibody secreting cells (ASC) and 2) a PF4/H-dependant enzyme immunoassay (EIA) to measure the anti-PF4/H antibodies produced by PBMCs in vitro. To characterize postoperative anti-PF4/H seroconversion in CPB patients, we used a PF4/H dependent EIA to measure in vivo levels of anti-PF4/H antibodies produced postoperatively. We also utilize a functional assay, 14C-serotonin release assay (SRA) to determine if seroconverting patients produced platelet activating antibody.
Results: All patients were able to produce anti-PF4/H spots in the ELISPOT; however, this did not correlate with the titer of antibody production in vitro nor did it correlate with antibody production in the postoperative period. Instead, we found that pre-operative in vitro anti-PF4/H IgM production was associated with post-operative IgG anti-PF4/H seroconversion (Spearman’s r=0.39, P=0.018).  We observed that 92.1% of CPB patients produced PF4/H antibody at postoperative week 3 with some combination of IgA, IgG, and IgM. Of the anti-PF4/H seropositive patients, 26% developed platelet activating antibody and were found seropositive when the SRA was supplemented with PF4 instead of heparin, while 15.7% were seropositive in the original SRA. It was noted that 4 of 10 patients that caused the most robust platelet activation were also seropositive for anti-PF4/H IgA antibody. Lastly, throughout this serosurveillance study, several patients that demonstrated unique immunological features are presented in this study as case studies. Specifically, we report the preoperative, surgical, clinical and postoperative characteristics for 3 patients of interest: 1) in a preoperative setting, a CPB patient’s PBMC were able to be activated and produce anti-PF4/H IgG antibody in vitro, 2) the second patient had platelet-activating antibodies in circulation prior to intraoperative heparin challenge and early post-surgery 3) the third patient who developed probable HIT.
Conclusions: Based on our findings, we conclude that preoperative PF4/H ELISPOTs were unable to predict post-operative production of anti PF4/H antibodies. However, preoperative in vitro production of anti-PF4/H IgM may be associated with postoperative production of anti-PF4/IgG antibody and should be investigated further as this may help to elucidate the mechanisms for anti-PF4/H production related to HIT.

abstract: Thesis

abstract: Master of Science (MSc)


title: Methods of growing crystals from aqueous solution and nuclear magnetic resonance

contributor:
Petch, H.E.
Physics

subject:
crystallization
nuclear magnetic resonance

abstract:
Large single crystals, as nearly perfect as possible, are required for magnetic resonance studies of the solid state. A limited number of substances occur naturally in crystals of sufficient size or purity for this type of experiment. Most of the nuclear magnetic resonance work done to date on single crystals has been performed using naturally occurring crystals. Section I of this thesis describes methods used to grow suitable crystals artificially, thus extending the scope of the magnetic resonance experiments.
The orthorhombic sodium dihydrogen orthophosphate dehydrate has been produced in large single crystals which were used subsequently in the study of the nuclear magnetic resonance absorption spectrum of Na-23 in this crystal. The spectrum was observed as the crystal was rotated about the three crystallographic axes which are mutually perpendicular for the orthorhombic case. A maximum of twelve lines were observed when neither of the crystallographic axes were perpendicular to the external magnetic field. The number of lines was reduced to six when one of the axes was made perpendicular to the field, while only three lines were observed when two crystallographic axes were made perpendicular to the external magnetic field.
These observed numbers of lines were interpreted by assuming four Na-23 sites, possessing identical eigenvalues and differing only in their orientation. These four sites are related by three mutually perpendicular two-fold rotation axes, each of which must be parallel to one of the three crystallographic axes. This interpretation is in complete accord with the space group P222 assigned to NaH2PO42H2O from morphological data. The complete set of properties of the quadruple coupling tensor was determined at each of the Na-23 sites. The value of the quadruple coupling constant (eQ Φzz)/h where Q is the nuclear quadruple moment and Φzz is the largest principle value of the electric field gradient tensor is: 1179.0 ± 0.5 kc/sec. The value of the asymmetry parameter η defined as (Φxx – Φyy)/Φzz is: 0.466 ± 0.005. The table of the direction cosines of the principle axes of the electric field gradient tensor with respect to the crystallographic axes appear in Table VII.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Infrared and Ultraviolet Spectra of Propynal

contributor:
King, G. W.
Chemistry

subject:
infrared
ultraviolet
ultraviolet spectra of propynal
propynal
infrared spectra of propynal

abstract: The infrar-red spectra of gaseous HC=CCHO, DC=CCHO, HC=CCDO and the Raman spectrum of liquid HC=CCHO has been measured and analysed to give the normal vibrational frequencies of the molecule in the electronic ground state. The electronic band spectrum of propynal with origin at 4144 A has been photographed under low resolution in both emission and absorption and analysed in terms of the vibrational frequencies associated with the combining electronic states. The origin band for both HC=CCHO and DC=CCHO has been photographed under high resolution and a partial rotational analysis is presented for this band. The transition responsible for the electronic spectrum has been identified as being of n ->3pi*, 3A"<- 1A' type, and the observed spectrum confirms the theoretical predictions as to the structure that results from a transition of this type.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Refraction, total reflection, and diffraction of 3.2 cm. electromagnetic waves by a dielectric prism

title: Refraction and total reflection of microwaves by a prism

contributor:
McLay, A.B.
Physics

subject:
refraction
reflection
diffraction
electromagnetic waves
prism

abstract:
A description of several experiments carried out to investigate the behaviour of 3.2 cm. microwaves on passing through a dielectric prism is given in this thesis. Chapter I contains a description of the experimental apparatus used to generate electromagnetic radiation and to measure the field intensity in a plane perpendicular to the refracting edge of the prism. Particular emphasis is placed on a description of the receiver amplifier, and on the construction of the wax prism.
In Chapter II are given the results of several preliminary investigations of the field close to, and polarized parallel to the retracting edge of the prism. Fresnel interference fringes were observed with the prism oriented as a biprism. Diffraction fringes of a 45˚ wedge, both dielectric and metallic, were observed incidentally. Evidence of the evanescent wave predicted for total internal reflection was obtained directly in this experiment where earlier evidence of such waves in the optical and microwave regions has been indirect.

abstract: Thesis

abstract: Master of Science (MSc)


title: Reducing substances in the blood of normal and alloxan treated fish

title: Fish blood reducing substances

contributor:
Nace, Paul F.
Biology

subject:
blood sugar
toadfish
catfish
blood glucose
rest reduction
alloxan
paper chromatography

abstract:
Blood sugar levels were determined in toadfish and catfish by the Folin reducing procedure and a specific enzymatic glucose procedure. The difference between the two values was considered to be the rest reduction (RR). After alloxan injection, the RR level increased greatly reaching a peak at one hour and then decreasing. The glucose level rose more slowly.
An attempt was made to study these changes in blood by paper chromatography using silver nitrate to detect reducing compounds. In normal blood, glucose, an unidentified compound, and several other reducing compounds present in small amounts were separated. The large amount or RR present after alloxan could not be detected by silver nitrate.
The significance of the results was discussed and future investigations were suggested.

abstract: Thesis

abstract: Master of Science (MSc)


title: A study of isotope abundances in chlorine

title: Isotope abundances in chlorine

contributor:
Graham, R. P.
Chemistry

subject:
isotope
chlorine
mass spectroscopy
fractionation

abstract: A study of methods for determining the relative abundances of the chlorine isotopes, and the results of mass spectrometric analyses of several chlorine-containing substances. Small variations are shown to exist in nature between the relative abundances of the chlorine isotopes in halite samples from at least two different localities. Other studies involving chlorine isotopes and their possible fractionation are included.

abstract: Thesis

abstract: Master of Science (MSc)


title: Dimensional Grain Orientation of Ordovician Turbidite Greywackes

contributor:
Middleton, G. V.
Geology

subject:
Ordovician Period
quartz
turbidite greywackes
Normanskill Formation
grain orientation

abstract:
This study describes the analysis of orientation of elongate quartz grains in turbidite greywackes of the Normanskill Formation, (Ord.) New York.
No relationship is found between grain orientation and sole features of the beds. No relationship exists between grain orientations taken at different levels above the base of the beds.
Maximum grain size and maximum elongation decrease upwards in the beds. The most elongate grains are those which most clearly show preferred orientation.

abstract: Thesis

abstract: Master of Science (MSc)


title: Range and Straggling Measurements of U-235 Fission Fragments

contributor:
Kennett, T. J.
Physics

subject:
fission fragments
thermal neutron fission
uranium

abstract: The ranges and stragglings of fission fragments from the thermal neutron fission of U-235 have been measured. Particular attention was given to the preparation of very thin uranium sources, the design of a well collimated recoil system and the preparation of the fragment catcher. The ranges and range distributions in aluminum of fission products of mass numbers 95, 140, 141 and 147 have been obtained. The range values obtained agree with previous determinations within the experimental error. The refined techniques developed in this work have enabled differential range distributions to be obtained which are more precise than any previous determinations.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Qualitative Investigation of the Health-Related Behaviours of Women at Midlife: Perceptions of Power and Control

title: The Health-Related Behaviours of Women at Midlife

contributor:
Walters, V.
Sociology

subject: women at midlife, midlife, perceptions of power and control, power and control, qualitative investigation, health-related behaviours of women at midlife

abstract:
This research examines women's ways of understanding health and illness as well as their
means of maintaining wellness. It attempts a women-centred approach to explaining health
behaviours. The research consisted of in-depth interviews with seven women from
Southern Ontario between the ages of 50 and 70. A grounded theory approach guided the
analysis. The study shows that perceptions of power and control may be at the root of
many attitudes toward health care and various health behaviours. By researching health
issues from women's perspectives, this research provides a glimpse of the way these seven
women experience midlife, and suggests the existance of perspectives that differ from
mainstream views on health and illness. It further demonstrates how theories of agency
can be used to shift the focus of sociological research from over-socialized accounts of
health-related behaviours to more empowering, woman-centred explanations. It shows that
women strive to maintain control of their health and that they pursue wellness in a manner
that enables them to keep that control.

abstract: Thesis

abstract: Master of Arts (MA)