title: Great Lakes Fish Eaters Project: Analysis of Data on Individuals Eating at Least Twenty-six Great Lakes Fish Meals per Year

contributor:
Macdonald, P.D.M.
Statistics

subject: great lakes, great lakes fish eaters, fish eaters, twenty-six great lakes fish meals, 26 great lakes fish meals, great lake fish meals,

abstract:
The Great Lakes Fish Eaters Project (Eaters Project) was funded by Health Canada to identify
individuals consuming large amounts of Great Lakes fish (≥ 26 meals over the past 1 year
period) and to document relevant contaminant information to describe the potential health risks and benefits associated with the consumption of fish from the Great Lakes. Data were analyzed on 91 participants in the Eaters Project.
The Great Lakes are home to a wide variety of fish. In this study alone, the participants have
collectively eaten over 35 different species of Great Lakes fish.
The participants of this study were asked for their opinions on the environment and their health. In addition, blood work was completed on 89 participants. The laboratory results were collected on different contaminants. Seven contaminants were considered for modeling purposes since the laboratory value was above a pre-defined detection limit in greater than 75% of the participants in this study.
These seven contaminants included six Organochlorine Pesticides: p,p'-DDE (100% of the
participants above the detection limit), hexachlorobenzene (HCB) (100%), β-
hexachlorocyclohexane (β-HCH) (92.1%), mirex (78.7%), oxychlordane (92.1%),
transnonachlor (98.9%) and one Polychlorinated Biphenyl Congener, Aroclor 1260 (100%).
Organic mercury was also modeled since it contributed on average 77.2% to a maximum of
97.5% of the total mercury value.
A 2-stage modeling approach on linear and categorical variables was done as a hypothesis
building exercise. Each contaminant was age-adjusted at the start of this modeling exercise. The age-adjusted contaminant was then used as the response variable in the second stage of the modeling of each specific contaminant.
The gender (male and female) and country of birth (Canada/Europe/US and Asian) variables
were confounded with each other. The model was be stratified on country of birth or on gender if one of the variables were found to be the only significant variable left in the full model.
Not all the contaminants that were modeled had significant results. That is, there were levels of certain contaminants that the modeling approach could not explain.
The country of birth (Canada/Europe/US and Asian) variable was important in the modeling of
some of the contaminants. This suggested stratifying by the two country-of-birth groups.

abstract: Thesis

abstract: Master of Science (MSc)


title: Local Participation, and the Structures of Political and Bureaucratic Water Management in Tijuana, Mexico

contributor:
Eyles, John
Geography

subject: local participation, bureaucratic water management, tijuana, tijuana mexico, structures of political and bureaucratic water management

abstract:
Clean water and adequate sanitation are crucial for community development and a
reduction of waterborne diseases. Despite this certainty, a viable process for achieving
this goal has yet to be formulated. This public health and development problem is not
from a lack of hydraulic or biomedical knowledge. Rather, the failure to provide
community services and infrastructure is rooted in the dynamic interplay between a hyper
formalized public sector bureaucracy and the informal practices of political parties and
patron-client relationships.
Using qualitative, semi-structured interviews and participant observation, this
study undertakes a narrative analysis of three communities and their interactions with
political parties and the public sector in Tijuana, Mexico. Bureaucratic incapacity
prevents the effective management of water and sanitation planning, programs, and
infrastructure development. A sociological analysis of organizations is applied to the
policy subsystem involving the persistent prevalence of waterborne diseases. Faced with
an unresponsive and inefficient public sector, community groups direct their local
development efforts towards political parties and the strategic use of clientelist
relationships in order to procure health care services and community infrastructure. The
role of community participation, as a means toward local empowerment and political co-option
is examined. This study also highlights the need for further research in the areas
of public accountability, public vs. private water management, and the role of
participation in community development.

abstract: Thesis

abstract: Master of Arts (MA)


title: "It's Not Probabilities, It's Possibilities": Lay Views of Disclosure Regarding Emerging Health Issues

contributor:
Elliot, Susan
Geography

subject: probability, probabilities, emerging health issues, lay views of disclosure, disclosure regarding emerging health issues

abstract:
Products and technologies provide us with significant lifestyle benefits but they can
also evolve into hazards and bring about concern for human health. A history of poor
regulatory performances has resulted in a public displeased with and skeptical of the
actors responsible for protecting the public against the unintended effects of progress.
It is within this historical and social context that the study explores the following
objectives: to understand people's responses to emerging health issues, of which there
is considerable knowledge uncertainty and little public awareness; to identify the
information needs regarding these issues, and to explore the role of government
disclosure for personal decision-making around these issues. Seven focus groups
were conducted in Hamilton, Ontario with community members from a range of
backgrounds: youth, faith, allophone immigrants, environmental, health, recreational,
and mixed. Two scenarios about potential hazards, i.e. a persistent pollutant and
extreme heatwaves from climate change, were used to generate discussion about
people's experiences with risk and knowledge. Results indicate that emerging health
issues are framed by lay individuals as a chronic societal phenomenon. Their
concerns about health and well-being, resiliency, and issue comprehension point to an
overarching preoccupation about social vulnerability, irrespective of the presence of
confirmed hazards. The analysis further revealed several roles for disclosure which
would allow for more capacity in personal decision-making; more transparent and
accountable regulatory processes, and which could lead to more trustworthy relations
between citizens and government.

abstract: Thesis

abstract: Master of Arts (MA)


title: Uncertainties in Lifetime Risk Projections for Radiation-Induced Cancer and an Assessment of the Applicability of the ICRP-60 Cancer Risk Estimates to the Canadian Population

title: Uncertainties in Radiation Cancer Risk Estimates

contributor:
Pomroy, C
Webber, C.E.
Health and Radiation Physics

subject: uncertainties in lifetime risk projections, radiation, radiation-induced cancer, lifetime risk projections for radiation-induced cancer, ICRP-60, cancer risk estimates, cancer risk estimates to the Canadian population

abstract:
The BEIR V preferred relative risk models and standard life-table techniques are used to project lifetime fatal cancer risk factors for average members of the Canadian
population. Uncertainties associated with projections are evaluated for: (1) sampling variation (statistical error), (2) extrapolation of risks to low doses and low dose rates, (3)
projection of excess lifetime cancer risks beyond the current periods of human observation in epidemiological studies, (4) the transfer of site-specific excess risk coefficients between
populations with differing baseline cancer rates, and (5) the effect of differences in the age and sex distributions among occupations in the Canadian "radiation" workforce. Results are
used to assess the applicability of the fatal cancer risk estimates recommended in ICRP publication 60 to the Canadian population.
It was found that sampling variation, extrapolating to low doses and dose rates, projecting excess risks beyond current periods of observation, and the uncertainty in how to
transfer site-specific excess risks between populations all cause substantial variations in lifetime cancer risk projections. Site-specific cancer risk projections may be
expected to vary by factors of 2 to 5, depending on the source of uncertainty.
Site-specific differences were found in the fatal cancer risk factors projected for "average" male and female workers among different occupations in the Canadian workforce.
Site-specific worker averages differed by as much as a factor 3. Female average risk factors for digestive cancers were substantially higher than male workers, while male average
risk factors tended to be higher for leukemia and respiratory cancer. Overall however, the majority of worker risk factors were within 2.5% of the site-specific projections for the
workforce as a whole.
The ICRP-60 nominal fatal cancer risk estimates, tissue weighting factors, and lifetime risk projections for prolonged radiation exposure were all in good agreement with
equivalent values derived in this report for the Canadian population. In view of the uncertainties, the results suggest the ICRP estimated cancer risks are as good as any presently available and supports the use of the ICRP recommended values for the planning and regulation of radiation protection in Canada.

abstract: Thesis

abstract: Master of Science (MS)


title: Many Voices in Dialogue: Translating Research Evidence Into Community-Based HIV Interventions

title: Many Voices In Dialogue

contributor:
Willms, Dennis G.
Anthropology

subject: dialogue, voices in dialogue, translating research evidence, community based HIV interventions, HIV interventions, HIV

abstract:
This applied research project responds to a critical problem in health and
development: how to effectively translate our research evidence to the communities
with and for whom we work in order to stimulate successful, sustainable health
promotion activities and social change. The tangible product of this research is a
handbook for health and outreach workers from immigrant communities from the Horn
of Africa living in Toronto. The handbook is a resource which will be used as a starting
point for the generation of community-based health initiatives, in this case, HIV/AIDS
prevention programs.
The research applies a conceptual approach which emphasizes participatory
action research theory and methodology, and equitable, transcontextual research
partnerships. It uses a model which merges both scientific evidence and experiential
(ethnographic) evidence of risk and vulnerability to create new understandings on
which to base the development of health programs.
Stories, grounded in ethnographic evidence, are at the heart of the research
strategy. The handbook is an example of experimental ethnographic writing: dialogue is
used to communicate research evidence, health, and skills information; and a number
of personal narrative:s have been constructed as resources to help health workers
generate dialogue on issues of risk and vulnerability, and begin a process of reflection
and action.
In a larger context, the lessons learned as this work is implemented and
evaluated in the community will contribute to the knowledge of intervention science.
The research also serves as an example of ethical anthropology and raises for
discussion ethnography's future project at the tum of the century. With attention to
how anthropologists represent their work, 'moral ethnography' can serve a larger
human project, helping us better understand what it is to be human and stimulating
moral conversations about how we want to live.

abstract: Thesis

abstract: Master of Arts (MA)


title: Relative efficiencies of alternative designs for randomized trials

contributor:
Walter, Stephen
Mathematics and Statistics

abstract: In conventional randomized controlled trials (RCT), one cannot estimate the influences of patient preferences on the treatment outcomes since all patients are randomized to a treatment without identifying their preferences. The two-stage design allows patients in the “choice group” to choose their desired treatment while those in the “random group” are randomized in the same way as in a RCT. The partially randomized design allows all patients to receive their preferred treatment. In the fully randomized design, although the patient preferences are identified at the first stage, all the patients are then randomized to each treatment. In this thesis, we discuss these four designs in detail with respect to their estimable effects, variances of the estimable effects, and the relative efficiency of each effect in different designs. Participants who are indifferent to the treatments (undecided participants) are included in the designs when evaluating the various effects. This thesis also shows the relationships of relative efficiency to other factors, such as the proportion of undecided participants, the relative preference rate between the two treatments, and with unequal numbers of participants being randomized to each treatment. We discuss the advantages and disadvantages of the designs under different scenarios and whether unequal randomization could improve efficiency.

abstract: Thesis

abstract: Master of Science (MSc)


title: DESIGN, FABRICATION, AND CHARACTERIZATION OF MICRO-ELECTROMAGNETIC DEVICES FOR MANIPULATION OF MAGNETIC PARTICLES

contributor:
Soleymani, Leyla
Engineering

abstract:
Molecular analysis for disease management is performed in equipped laboratories by specialists. This process can be slow, costly, and inaccessible in remote rural areas. This inspires the need for developing highly specific, and robust lab-on-a-chip (LOC) devices. Analyte separation is an essential step for molecular diagnosis. Among micro-scale separation techniques, magnetophoresis benefits from its high throughput, relatively non-invasive nature, integrability, and availability of magnetic particles in variety of sizes and coatings. Magnetic forces are applied on magnetically tagged objects using permanent magnets, ferromagnetic micro/nano-structures (passive), or electromagnets (active). In this thesis, we integrate active and passive elements, by coupling micro/nano-structured electromagnets with ferromagnetic materials, to capture MPs at low currents (< 50 mA). These active-passive devices are fabricated using benchtop techniques such as xurography, polymer induced thin film wrinkling, spin coating, and electrodeposition.
An efficient transport of analytes inside LOC platforms is essential for reducing the sample-to-response time and improving the limit-of-detection. Micro-electromagnetic devices are suited for this task due to their high level of controllability over the generated magnetic force. However, the magnetic force attenuates rapidly as we move away from the surface of the device. Elevating the current improves the magnetic strength in expense of destructive Joule heating and high-power consumption. In this work, we investigate the combined role of temperature and magnetic field gradients on the motion of MPs to extent the capture zone of the device beyond its surface. We show that the measured terminal velocities of particles located near the magnetic traps (∼5.5 μm) replicate the values provided by the simualtions. Remarkably, we demonstrate two orders of magnitude deviation between the experimental and simulation results for the terminal velocities of far particles (∼55.5 μm). By modelling the heat transfer of the system, we demonstrate that this inconsistency is due to the fluid movement caused by convection.
Magnetophoretic cell manipulation in a free-flow condition is beneficial in terms of high throughput and integrability. Here, after integrating the active-passive device with microfluidic channels, we successfully capture and release magnetically tagged-yeasts in a continuous flow with an applied current of 30 mA.
Micro/nanotextured lubricant-infused surfaces can be applied to LOC devices, due to their self-cleaning, frictionless, and high surface area properties. In this thesis, we integrate the wrinkling process and fluorosilanization to develop conductive lubricant-infused surfaces that are electrochemically active, slippery, and anti-biofouling. Self-assembled monolayers of fluorosilane are deposited on gold-coated shrinkable substrates. After creating the micro-wrinkled structures by heating the substrate (160°C), a lubricant is applied to the surfaces. High water contact (~150°) and low sliding angles (<5°), along with manipulation of magnetic droplets in a friction-less fashion, confirm the hydrophobicity and slipperiness of these surfaces. We demonstrate that these surfaces can prevent non-specific adhesion of proteins, which is crucial for surface-based biosensors.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: Testing for Seropositivity of the Human Immunodeficiency Virus

title: Mathematical modelling of the AIDS pandemic

contributor:
Wolkowicz, G. S. K.
Mathematics

subject:
mathematical model
disease dynamics
HIV
AIDS

abstract: This paper considers a series of models and the effect of HIV antibody testing on the dynamics of the disease. We examine HIV antibody testing in conjunction with persuasive techniques designed to encourage tested infected to behave in a sexually responsible manner. The population under consideration is a homosexual population. Analytical methods are used to obtain information about the qualitative behaviour of the models. Areas requiring further study are discussed.

abstract: Thesis

abstract: Master of Science (MSc)


title: Perceiving health and the environment: Connections, conceptions, and cognition

title: Perceiving health and the environment

subject:
qualitative analysis
health
environment
Greater Hamilton
perception
cognition

abstract:
The present study is an exploratory qualitative analysis of public perceptions of health and the environment. In-depth interviews were employed to examine perceptions of the connection between health and the environment amongst a sample of men and women of both higher and lower socio-economic status in Greater Hamilton, Ontario. The study attempts to highlight the nature of health and environment perceptions in lay publics, the variations in perceptions of health and environment within and across social groups, as well as plausible reasons for these variations in perceptions according to cognitive information processing, value orientations, and cultural models.
Variations in perceptions of the connection between health and the environment were seen to exist across social groups, namely by gender and socio-economic status. Differences in perceptions amongst those in the sample result from a myriad of possible factors ranging from social characteristics to personality traits to information processing networks. While health was largely perceived to be concrete and personalized, the environment was largely abstract and nebulous. Health was clearly articulated by those in the sample, while environment was less well-understood.
Perceptions of the connection between health and environment were articulated usually with reference to the self, seemingly significant through possible threats to health. Health was viewed as under personal control through lifestyle choices, however, the environment was perceived to be external and not within the control or responsibility of individuals. A dichotomy in the form of “health is me” and “environment is external”, representing power, control, and responsibility and nested in social values and normative frameworks, became implicit in the findings. Social cognition research was employed to account for variations in interpretation of information related to health and the environment in order to account for differences in perceptions. Cognitive structures were then employed in an attempt to locate perceptions of health and the environment with value orientations from within a cultural or mental model of these connections.

abstract: Thesis

abstract: Master of Arts (MA)


title: Ecological Illness: The Experience of Controversial Health Problems

title: The Experience of Ecological Illness

contributor:
Matthews, Ralph
Sociology

subject:
ecological illness
environmental hypersensitivity
semi-structured interviews
medical legitimation
social legitimation
sociology
psychology

abstract:
This research is based on semi-structured interviews with thirty-two people who understand themselves to be suffering from health problems called ecological illness, or environmental hypersensitivity. The research examines the experience of ecological illness.
Given that the medical status of ecological illness is controversial, and that troubles considered to be ecological illness are typically vague and non-specific, the study focuses on meanings and interpretive frameworks that are applied in the definition of such troubles; by those affected, by significant others, and by physicians. The analysis examines the nature and course over time of definitions of trouble-related identity and the social psychological and practical consequences of such definitions for respondents' illness experience. Because respondents largely define their troubles as physical health problems, a central issue in the analysis is the medical and social legitimation of illness claims.
The research found that, in the course of seeking medical treatment and legitimation for their problems, people's experiences of trouble were typically discredited. They were long unable to resolve conflicts between a self-identity as sick and others' assessments of them as "not sick" or psychologically troubled. While the eventual diagnosis of hypersensitivity was a profound relief to people in many respects, it was often not recognized and accepted by others as a basis for informal or "official'' sick role considerations. Because of scepticism toward the concept of multiple sensitivities, many people continued to feel stigmatized by their problems. The study illustrates the impact and significance of controversies within medicine for the experience of certain kinds of health problems.

abstract: Thesis

abstract: Master of Arts (MA)


title: Thyroid Function in the Salamander Amphiuma means

contributor:
Nace, Paul Foley
Biology

subject:
thyroid
salamander
amphium means

abstract: The metabolism of iodide was investigated in the adult amphibian, Amphiuma means using an adaptation of a standard clinical radio-iodine technique. The thyroid uptake of I131 after intraperitoneal injection of a tracer does was linear on arithmetic plotting for seven days. The uptake then increased to a pronounced peak at seven days.

abstract: Thesis

abstract: Master of Science (MS)


title: ON SEEING MOUSE AND THINKING HUMAN: EXPERIMENTAL SCIENCE, CORPOREAL EQUIVALENCE, AND THE LITERARY MODEL ORGANISM

contributor:
O'Brien, Susie
English and Cultural Studies

subject: Animal Studies, Science and Technology Studies, Literary Theory, Narratology, Poetics, Model Organism, Biopolitics, Genomics, Postgenomics, Post Humanism, Mice, Laboratory Animal, Embodiment

abstract: This thesis examines literary texts that represent encounters with model organisms in ways that enact an interspecies ethics that turns the narrative of bodily relationality embedded within the model organism into a source of care, friendship, respect, and mourning. My project understands model organisms as material beings as well as semiotic and narrative entities; I suggest that the very ‘materiality’ of the model organism’s body is symbolic precisely because it is designed to refer to bodies other than its own. The model organism involves a double relationality between the categories of ‘animal’ and ‘human’ because it serves as a mediator between human nature and nature at large. This is not to say that that human biology is not part of ‘nature’ but rather that anthropocentric and human exceptionalist ideologies pervade discourses of human biology and thus the model organism provides a link to our biological and corporeal ‘selves’ in a way that maintains species divisions. The texts I analyze throughout this dissertation offer alternative ways of thinking about the model organism by exposing the multiple meanings and narratives that coexist within them both as representations and as living sentient beings. This project centers around two questions: How do cultural texts represent and negotiate disconnects between how model organisms signify within scientific discourses and their broader cultural identities? How does literature specifically engage with scientific knowledge in ways that both disrupt and affirm the status of the model organism as a scientific object?

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The art of improvisation for social work relating: a new appreciation of  interdependence and control

contributor:
Sinding, Christina
Social Work

subject: theatrical improvisation, arts-informed practice, social work relating, social work education, interdependence, relating, social constructionism, mutual constitution, pedagogy, teaching, learning, practice, arts-informed education

abstract:
There is very little theoretical literature about theatrical improvisation as it connects to ideas and practices of relating and specifically to ideas and practices of social work relating. This thesis involves efforts to theorize moments of relating – of being with others – in improvisation.
A group of hospital social workers and a group of PhD social work research students participated in the study. The participants took part in improvisational workshops designed specifically for the study, as well as one-on-one and group interviews.
This thesis explores what was created between research participants in improvisational workshops: the response-ability to and for others; an experience of grappling with the desire for control; and an embodied apprehension of interdependence. The study demonstrates an embodied and uncomfortable experience of the dominance of individualism in our relating.
The study also demonstrates ways in which the art of theatrical improvisation can allow us to take up the transformative promises of social constructionism in social work relating. The thesis aims to make living space for central social constructionist concepts such as mutual constitution and interdependence – to explore and consider what happens when we fully recognize and carry these out in our practices of relating. Providing a different way into these central social constructionist concepts, this study contributes to arts-informed research, teaching and practice. More specifically, the research shows how the art of improvisation can provide transformative possibilities for social work pedagogy and the social work classroom.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
This thesis involves efforts to theorize moments of relating – of being with others – in improvisation.
A group of hospital social workers and a group of PhD social work research students participated in the study. The participants took part in improvisational workshops designed specifically for the study, as well as one-on-one and group interviews.
This thesis explores what was created between research participants in improvisational workshops: the response-ability to and for others; an experience of grappling with the desire for control; and an embodied apprehension of interdependence.
The study demonstrates an embodied and uncomfortable experience of the dominance of individualism in our relating and provides an analysis of engagement in improvisation as an alternative to a framework of independence in social work. The study contributes potential for arts-informed research, teaching, and practice, as well as social work pedagogy as it demonstrates ways in which the art of improvisation can allow us to take up the transformative promises of social constructionism in social work relating.


title: Airway Remodeling in Mouse Models of Exposure to Allergen

contributor:
Inman, Mark
Physiology and Pharmacology

subject: airway remodel mouse allergen

abstract: Asthma is .a respiratory.,disease.that affects over 300 million people world-wide and is involved in over 250000 deaths annually. Asthma is classically thought of as an allergic disease with variable airflow obstruction and airway hyperresponsiveness (AHR) associated with airway remodeling, although phenotype variations are observed in the population. Due to multiple factors including genes, gender, exposure to pathogens, environmental pollutants, diets, and obesity, a clear picture of the complex interactions between an individual's genes, the environment which they live in, and the development of an asthmatic phenotype remains elusive. Despite the availability of treatment strategies for asthma, varying degrees of airway inflammation, remodeling, and AHR remain present in an asthmatic patient. Our general hypothesis that was the basis for all studies was the following: "Airway remodeling in response to allergen exposure is a major contributing factor to AHR observed in asthmatics. Understanding the mechanisms behind the different components of airway remodeling will provide new avenues for therapeutic development aimed at improving lung function above and beyond current treatment strategies." The currently available therapeutics and management strategies for asthma are unable to prevent or reverse components of airway remodeling. It is possible that with greater understanding of the processes involved in the various indices of airway remodeling new classes of therapeutics could be developed to selectively target this broad, ill-managed aspect of asthma. Collectively the studies contained in this thesis have been linked by the general themes of greater characterization of in vivo mouse models of allergen exposure, the application of these models to mechanistically explore the biological pathways involved in the different components of airway remodeling, and the testing of novel therapeutic strategies targeting these pathways of interest.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Advances Towards Practical Implementations of Isogeny Based Signatures

contributor:
Stebila, Douglas
Computing and Software

subject:
isogeny
cryptography
elliptic curve
SIDH
signature
optimization
efficient
post-quantum
quantum-safe

abstract:
Progress in the field of quantum computing has shown that, should construction of a sufficiently powerful quantum computer become feasible, much of the cryptography used on the Internet today will be rendered insecure. In lieu of this, several approaches to “quantum-safe” cryptography have been proposed, each one becoming a serious field of study. The youngest of these approaches, isogeny based cryptography, is oriented around problems in algebraic geometry involving a particular variety of elliptic curves. Supersingular isogeny Diffie-Hellman (SIDH) is this subfields main contender for quantum-safe key-exchange. Yoo et al. have provided an isogeny-based signature scheme built on top of SIDH. Currently, cryptographic algorithms in this class are hindered by poor performance metrics and, in the case of the Yoo et al. signature scheme, large communication overhead.
In this dissertation we explore two different modifications to the implementation of this signature scheme; one with the intent of improving temporal performance, and another with the intent of reducing signature sizes. We show that our first modification, a mechanism for batching together expensive operations, can offer roughly 8% faster signature signing and verification. Our second modification, an adaptation of the SIDH public key compression technique outlined in [CJL + 17], can reduce Yoo et al. signature sizes from roughly 688λ bytes to 544λ bytes at the 128-bit security level on a 64-bit operating system. We also explore the combination of these techniques, and the potential of employing these techniques in different application settings. Our experiments reveal that isogeny based cryptosystems still have much potential for improved performance metrics. While some practitioners may believe isogeny-based cryptosystems impractical, we show that these systems still have room for improvement, and with continued research can be made more efficient - and eventually practical. Achieving more efficient implementations for quantum-safe algorithms will allow us to make them more accessible. With faster and lower-overhead implementations these primitives can be run on low bandwidth, low spec devices; ensuring that more and more machines can be made resistant to quantum cryptanalysis.

abstract: Thesis

abstract: Master of Science (MSc)


title: Micro-XRF geochemical and micropaleontological evidence for prehistoric land disturbance, Serpent Mounds complex, Rice Lake (Ontario, Canada)

contributor:
Boyce, Joseph
Earth Sciences

subject:
XRF
Archaeology
Itrax
Thecamoebians
PCA
Woodland Period
Bathymetry
Limnology
Serpent Mounds
Burial Mound
Point Peninsula
Land Disturbance

abstract: This thesis represents the first example of a pre-agricultural, pre-colonial land disturbance event in the archaeological record of North America. It demonstrates the critical importance of multivariate analysis and µ-XRF core scanning in determining precise chronologies for episodes of heightened clastic input from soil erosion, enhanced by human occupation, shellfish harvesting, and burial mound construction.

abstract:
Serpent Mounds is a prehistoric (Middle Woodland Period, ca. 2000--1000 BP) burial mound complex located on the north shore of Rice Lake, in southern Ontario, Canada.
The complex includes a 60m long and 10m wide sinuous earthwork ridge interpreted as a serpent effigy and eight smaller oval mound structures.
Archaeological excavations determined seasonal site occupation for harvesting wild rice and shellfish and conducting mortuary rites.
The timing of mound construction and site occupation is poorly constrained by limited radiocarbon dates, restricted to burials.
The site is of high cultural importance as the only known effigy mound structure in Canada and is a sacred First Nations burial ground; thus all investigation must employ non-invasive techniques.

High-resolution XRF Core Scanning and micropaleontologic analysis (testate amoebae) of 12 lake sediment cores was employed to investigate the timing of mound construction, and assess geochemical records of prehistoric land disturbance.
Land disturbance is indicated by increased sediment flux, by rising abundance of minerogenic elements (K, Ti, Zr, Si, Fe) within a distinctive silt-rich gyttja unit.
The event is also recorded in the thecamoebian assemblage, which is dominated by indicators of a eutrophic, turbid lake environment.
Principal Component Analysis and Cluster Analysis of µ-XRF data identify distinctive chemofacies across several cores.
AMS 14C dates for the prehistoric land disturbance episode correspond with the Point Peninsula occupation, indicating a protracted occupation period of \textasciitilde 750 years (2050 - 1300 cal BP) with two major peaks in soil erosion at 1900 and 1450 cal BP.
The sedimentation rate (>1.5mm/yr) during the Middle Woodland phase of enhanced erosion was comparable to that during the 1838 CE dam construction at Hastings.
The reconstructed Middle Woodland paleoshoreline and water levels indicate a shallow lake and wetland environment, with viable habitats for wild rice stands and shellfish resources.
The results demonstrate that XRF Core Scanning and micropaleontological methods are important for the investigation of culturally-sensitive archaeological sites, including sacred burial grounds where conventional archaeological excavation cannot be undertaken.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Serpent Mounds is a prehistoric (Middle Woodland Period, ca.  2000 - 1000 BP) burial mound complex located in Rice Lake, Ontario.
Archaeological excavation (1897 - 1970) determined the site was occupied by people of the Point Peninsula culture (ca.  2200 - 1350 BP) on a seasonal basis, for burial rites and shellfish gathering.
Many questions remain with regard to the date of mounds construction, how long the site was occupied, and how occupation and construction activities impacted the local environment.
The site has been designated as a National Historical Site and excavation is no longer permitted in the interest of site preservation and cultural value to First Nations.

This study investigated the history of environmental changes associated with prehistoric indigenous  and European land use changes using  minimally-invasive methods, including sonar bathymetric mapping, XRF Core Scanning and microfossil analysis of lake sediment cores.
Sonar data were employed to map the lake bottom relief (bathymetry) and to reconstruct  past changes in lake levels and shoreline positions.
µ-XRF methods measures changes in  elemental abundance in lake core samples to identify human occupation phases and land disturbance.
Microfossils (testate amoebae) track the ecosystem response to environmental changes associated with human occupation.
The geochemical and microfossil data identified an interval of increased sediment delivery to Rice Lake, coinciding with the arrival of Point Peninsula peoples.
The land disturbance is recognized in cores by an increase in zirconium (Zr), titanium (Ti) and other soil-derived elements.
During this phase, lake levels rose gradually, wetlands expanded and wild rice was abundant resource available to indigenous peoples.
Following European colonization in the 1820’s, and the construction of the Hastings Dam (1838 CE), lake levels increased rapidly by over \SI{2}{\metre}, causing a shift to a more nutrient-rich (eutrophic) lake environment and a decline in wild rice stands.
Soil erosion associated with European land clearance is recorded by in a dramatic increase in the abundance of soil-derived elements.


title: BIO-ELECTROCHEMICAL REMOVAL OF LEAD BY EXOELECTROGENS AND PHOSPHATE REMOVAL USING ZEOLITE FOR POTENTIAL INDUSTRIAL WASTEWATER TREATMENT

contributor:
Kim, Younggy
Civil Engineering

abstract:
Industrial wastewaters contain various contaminants depending on their sources, including phosphate, ammonium and heavy metals. To remove different contaminants, several physical, chemical or biological methods are applied in wastewater treatment plants. In this study, two contaminants of ionic lead and phosphate from two different wastewaters were considered separately with two different removal methods. Exoelectrogenic bacteria were studied for lead removal and application of zeolite for phosphate removal was also investigated. The examined methods were proposed for a relatively small-scale (maximum 5000 liters per day) and non-continuous treatment plant for achieving more than 90% removal of both contaminants.
The first part of this project was investigating Pb(II) removal using a bio-electrochemical method. Lead, as a toxic and non-biodegradable heavy metal, has been a major concern in the wastewater treatment area. Microbial electrolysis cells (MECs) are known to remove heavy metals effectively while the exoelectrogenic bacteria oxidize organics at the anode electrode and cations (like heavy metals) get reduced at the cathode electrode. A study has shown that Pb(II) can be reduced both at the cathode and the bioanode. In this lab-scale study, exoelectrogenic bacteria have been prepared on the anode fibers of an MEC and then the enriched bioanode was used individually in the system without applying any voltages. The effectiveness of the proposed system on Pb(II) removal in different initial pH condition and the consistency of this system were studied. Pb(II) removal mechanisms were also investigated. Results showed more than 90% Pb(II) removal in 24 hours for a wide range of pH conditions (pH 5 to 9). Moreover, adding lead after each 24 hours for four times showed the high capacity of bioanode. Two mechanisms of direct reduction and biosorption were identified as the removal mechanisms of lead. Biosorption mechanism with the contribution of 82% to lead removal had a more significant role than the reduction mechanism. It was also indicated that the exoelectrogenic bacteria played the main role in both of the removal mechanisms by providing oxidation-reduction condition and biosorption capacity.
The second aspect of this project was focused on phosphate removal using zeolite. Phosphate in wastewater and the resulting eutrophication have always been a crucial concern and have resulted in developing of different technologies for its removal. Natural zeolites with the capability of cation exchanging have been extensively studied for cation removal like ammonium. However, by pretreating zeolite and making changes on its physico-chemical properties, zeolite can also be used for removing anions like phosphate. In this aspect of the thesis, a clinoptilolite zeolite was pretreated by NaCl, Mg(OH)2 and Ca(OH)2 and the effect of pretreated zeolites on phosphate removal efficiency was investigated. Results showed no improvement with magnesium pretreatment although zeolite pretreated by sodium and calcium improved the removal efficiency. 18% phosphate removal by natural zeolite increased to 37% and 60% for zeolites pretreated by Ca(OH)2 and NaCl respectively. The existence of ammonium in the solution also increased the removal efficiency from 18% to 44% for natural zeolite and ammonium was removed itself by around 34%. Sodium and ammonium in the solution improved the removal efficiency due to being exchanged with calcium and increasing the calcium phosphate precipitation.
Regarding that, the type of zeolite and its amount of calcium were shown to be effective on phosphate removal efficiency. In all conditions, phosphate was removed by calcium phosphate precipitants using either the calcium hydroxide added or the calcium in zeolite structure. Calcium-pretreated zeolite despite its high capacity for phosphate removal had a low efficiency which was explained by the mass transfer mechanism and shaking results showed that better shaking condition could improve mass transferring here and get to 100% phosphate removal by calcium-pretreated zeolite. However, using only calcium hydroxide without any zeolite could also remove 100% of phosphate. Using calcium hydroxide provided a high removal efficiency but increased the final pH as well. Pretreated zeolite had lower efficiency than calcium hydroxide but did not change the pH significantly and had the ability to remove ammonium as well. Using a type of zeolite with a high amount of calcium in its structure and existence of ammonium and sodium in solution along with an appropriate shaking condition can reach high removal efficiency as well.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: The "Cooperative Wage Study" And Industrial Relations: A Canadian Analysis in the Steel Industry

contributor:
Graham, J.E.L.
Political Economy

subject: steel industry, steelm wage study, cooperative, industrial relations, canadian analysis

abstract: This thesis describes the introduction into Canada, from the United States, of the Cooperative Wage Study (CWS) - a scheme of joint union-management job evaluation for the removal of wage rate inequities in the steel industry. it is especially concerned with the impact of the CWS programme upon the structure of industrial relations in this industry, and with the aims and objectives of both the union and management regarding it. A comparison of the origins of the plan in both the U.S.A. and Canada is made and a survey of the development of the programme carried out in two basic steel plants in Ontario. An evaluation of the results is attempted in the light of the original objectives, together with an assessment of the importance of CWS as an industrial relations technique.

abstract: Thesis

abstract: Master of Arts (MA)


title: Characterization of Hyperbrain Networks During Joint Piano Playing Using a Complex Dynamics Framework

title: NEURAL NETWORKS DURING JOINT PIANO PLAYING

contributor:
Trainor, Laurel J.
Psychology

abstract: Social interaction is essential for human life, but we have little understanding of the neural mechanisms supporting it. Recent research has shown correlated activity between the brains of individuals (Goldstein et al. 2018; Müller et al. 2018; Dikker et al. 2017; Toppi et al. 2016) using the novel technique of Electroencephalography Hyperscanning, which allows us to record multiple persons’ electrical brain activity at the same time. Interpretation of this data, however, is still unclear: does common activity reflect social interaction or is it just a by-product of shared perception? Furthermore, there is no unifying framework on how to analyze these novel data. Although we did not find evidence for synchronous brain activity between pianists playing duets using a complex dynamics framework, we were able to differentiate music pieces with ambiguous leadership roles from those with clear leadership roles using multivariate statistical approaches (graph theory). Furthermore, ambiguous leadership network characteristics correlated with participants’ perceptions of the quality of their performances. This thesis also contributes to this field by expanding previously proposed frameworks (Duan et al. 2015) to include a complex dynamics approach and thoroughly discussing issues in hyperbrain analysis. By standardizing the protocols, interpretations, and data analysis approaches of data from EEG hyperscanning, we can better elucidate what this synchrony means, effectively helping us move the field of single-person social neuroscience towards a two person neuroscience (Dumas 2011; Schilbach et al. 2013). This has profound implications at several levels, including the quantification of high level social constructs, such as empathy or joint attention, to clinical research, where these statistics can be used as diagnosis tools for the socially impaired brain.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Study of the Reactions of Transient Silylenes with Carbonyl Compounds in Solution

contributor:
Leigh, William
Chemistry

subject: Silylene

abstract:
The reactions of the transient silylenes SiMe2, SiPh2, and SiMes2 with enolizable and non-enolizable carbonyl compounds have been studied in solution by steady state and laser flash photolysis methods.
 	These reactions have been shown to involve the initial formation of a silacarbonyl ylide intermediate, which has been detected directly in several cases and found to exhibit a broad absorption band in the λmax ≈ 500 – 650 nm range in solution. The ensuing chemistry of these intermediates depends on the nature of the carbonyl compound.
	The reactions of silylenes with enolizable carbonyl compounds generate ene-adducts formed via H-migration in the silacarbonyl ylide. Kinetic isotope effects were investigated in the reactions of the three silylenes with acetone(-d6) and camphor(-d2). The results show an isotope effect for camphor, which indicates the H-migration step is the rate-determining step in the reaction. The effects of ring strain in the carbonyl compound were investigated with dicyclopropyl ketone, relative to diisopropyl ketone. The introduction of ring strain causes a systematic decrease in the rate constants.
	On the other hand, the reactions of silylenes with non-enolizable carbonyl compounds proceed via cycloaddition. The reactions of SiMes2 with 2,2,5,5-tetramethylcyclopentanone and SiPh2 with 2-adamantanone afford [1+2] and [1+2+2]-cycloadducts, respectively. The kinetic behavior of the silylene and silacarbonyl ylide of these systems are reflective of their corresponding reaction mechanism. However, the kinetic behavior of the silacarbonyl ylides in the reactions of SiMe2 with SiPh2 with 2,2,5,5-tetramethylcyclopentanone and di-tert-butyl ketone are more complex to interpret because a stable cycloadduct is not observed.
	The trends in the reactivity of the three silylenes, and in some cases the silacarbonyl ylides, with the series of enolizable and non-enolizable carbonyl compounds studied in our group are discussed in this thesis.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Association of Genetic and Dietary Exposures with Gestational Diabetes Mellitus Risk

contributor:
de Souza, Russell
Anand, Sonia
Health Research Methodology

subject:
Gestational Diabetes Mellitus
Diet
Genetics
Diet x Gene Interaction
Pregnancy
South Asian
Pregnancy Complications
Hypertensive Disorder of Pregnancy
Gestational Weight Gain
Prospective Cohort
Systematic Review
Meta-Analysis
Maternal Health

abstract:
Background: Although lifestyle modification is the cornerstone of GDM management, the evidence base on which dietary recommendations to prevent GDM is diverse and has not been synthesized in a consistent fashion.
Objectives: The overall objective of this thesis is to assess the relationship of diet patterns, foods, and nutrients with GDM risk. Specifically, we seek to:
1)	Quantify the relationship between dietary factors and GDM and metabolic disorders of pregnancy;
2)	Compare the effects of dietary factors on markers of glycemic control, such as fasting glucose, fasting insulin, HbA1c, and the homeostatic model assessment for insulin resistance (HOMA-IR);
3)	Assess the association and interaction between carbohydrate quality, and genetic load on the risk of developing GDM using data from 2 prospective birth cohort studies.
Methods: We follow the approach set by the Cochrane Group’s Handbook for Systematic Review of Interventions to conduct meta-analyses and assess the quality of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. We analyze prospective cohort data of 2,504 women from the CHILD and START studies, which enrolled women of White-Caucasian and South Asian ethnicity. We quantify carbohydrate quality by deriving the glycemic index and load (GL), and total and added sugar intake. We construct a gene score using 102 loci that were previously associated with type 2 diabetes in genome-wide association studies.
Results: 1) The meta-analysis identified high-quality evidence that red meat increases GDM risk; however, most associations of foods and nutrients with GDM and other metabolic disorders of pregnancy are of low-quality; 2) The network meta-analysis identified that most dietary interventions given with gestational weight gain advice will lower fasting glucose; 3) In South Asians, a high GL coupled with a high genetic load increased GDM risk six fold, but a high total sugar intake in the presence of a high genetic load reduced GDM risk. This paradoxical finding may be explained by a high correlation between total sugars and other healthy foods.
Conclusions: Few valid associations between dietary factors and GDM risk exist. GL and total sugars may modify the genetic risk of GDM in South Asians but not in White-Caucasians. Further research is needed to determine effective interventions that can assist women in adopting healthier eating habits during pregnancy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Gestational diabetes mellitus (GDM) is glucose intolerance that first appears during pregnancy. Although lifestyle modification is the cornerstone of GDM management, dietary recommendations for GDM prevention are sparse. The overarching objective of this thesis is to describe the relationships between diets, foods, and nutrients and GDM and metabolic disorders of pregnancy and to understand whether carbohydrate quality can modify a genetic predisposition to diabetes.
 In the systematic literature reviews, high-quality evidence showed that red meat increases GDM risk. Moderate-quality evidence showed that several dietary factors also influence the risk of GDM and metabolic disorders of pregnancy, but most of the existing evidence is of low-quality. More high-quality studies are needed before dietary interventions can be implemented
 	In our genetic study, we observed that carbohydrate quality may modify the genetic risk of diabetes in South Asians but not in White-Caucasians and conclude that carbohydrate quality may provide only a limited assessment of overall diet quality.


title: Computer Simulation of Raw Material Receiving Facility - Queueing Study

title: Computer Simulation - Queueing Study

contributor:
Smith, A. A.
Civil Engineering

subject:
computer
computer simulation
raw material
queueing study

abstract: All physical copies are missing page 3 in this thesis. - McMaster Digitization Center

abstract: A computer simulation model was developed to simulate the receiving of raw materials at a dock for an integrated steel plant on the North shore of Lake Erie. The model was formulated to study queue build-up, berth waiting time and the effect of various unloading conditions on dock efficiency. A financial analysis, using present value techniques, was then applied to the model results in order to recommend an optimum berth staging plan under various economic conditions. Historical data on raw material receiving at Hilton Works, Hamilton, were collected and used to develop mathematical functions to describe the random nature of vessel arrivals and berth times. It was determined from this data that vessel arrivals are described by a Poisson distribution and berth times are described by an Erlang distribution. The computer model simulates the dock operation by generating random numbers according to these distributions (Monte Carlo Simulation.) Coal and ore vessel arrivals are merged and respective service times generated. Interferences occur and queues grow and diminish as the facility is simulated through the shipping seasons throughout its expected life. Various unloading rates and vessel tonnages are simulated for a single and double berth operation and the associated waiting times and queue lengths are recorded for each alternative. An economic analysis is performed on the alternatives using present value techniques. The economic analysis indicated that the optimum time to expand the dock to a double berth occurs at a tonnage level of 15 million (coal + ore). To reach this level unloading rates of 10,000 TPH for ore and 8,000 TPH for coal would have to be achieved with an average vessel tonnage of 39,000 metric tonnes. Reducing the unloading rates or average vessel tonnage would move forward the required construction of a double berth and would increase the present value for that alternative. This expansion date will also depend on future economic factors such as cost of capital and escalation rate. The other important conclusion drawn from the economic analysis was that the receiving facility should be expanded in minimum feasible increments because of uncertain economic conditions. This concept dictates that conveyors be installed at minimum capacity, i.e. -belt width and drive size, to handle the first stage tonnage only with provision in the equipment to increase capacity by replacing narrow belts with wider ones and adding additional drive units. The timing for the stages is predicted on several factors, such as: life of the initial belt, tonnage forecast, ship delay costs, and most importantly future economic conditions. For example, it would be advantageous to increase the unloading capacity with a wider belt at the time the initial belt is worn out. Belt and drive staging will take place before the expansion to a second berth in order to defer the capital investment as long as possible. The conveyor system for the second berth can be similarily staged. The study indicated that a good planning strategy would be to initially install a 1.8 m wide belt on 2.0 m wide machinery with 3-1,000 H.P. drives. This system would unload ore at approximately 7,000 t/hr. and coal at approximately 5,000 t/hr. This capability could be increased to 10,000 t/hr. for ore and approximately 8,000 t/hr: for coal by adding a 2.0 m wide belt and 1 -1,000 H.P. drive unit. These rates would be compatible with the expected unloading rates of the future fleet. The decision to increase capacity should be considered when the initial belt is worn out or when delay costs and future economics dictate expansion before that time. The study also indicated that it is poor strategy to design the second berth/conveyor system to be restricted to coal receiving only. The Computer simulation indicated ship delay time for the restricted berth to be approximately three times that for a system with capability to receive ore and coal equally at both berths on either conveyor and either stacker. It indicates that ore receiving is the most important capability and should not be restricted. Even though ore pellets unload more quickly the ore tonnage required is twice that for coal. Therefore, it is recommended to design a completely flexible system . with full provision for expansion to higher unloading rates and larger vessels (850 ft.) and with provision to unload equally from either berth to either conveyor and to have the ability to transfer material between converyors at the head end of the stacker conveyor.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: A WATER-STABLE HYBRID ORGANIC-INORGANIC PEROVSKITE FOR SOLAR CELLS BY INORGANIC PASSIVATION

contributor:
Xu, Gu
Materials Science and Engineering

abstract: This is a modified version for my previous uploaded thesis.

abstract: Organic-inorganic hybrid halide perovskite solar cells (PSCs) have been a trending topic in recent years. Significant progress has been made to increase their power conversion efficiency (PCE) to more than 20%. However, the poor stability of PSCs in both working and non-working conditions results in rapid degradation through multiple environmental erosions such as water, heat, and UV light. Attempts have been made to resolve the rapid-degradation problems, including formula changes, transport layer improvements, and encapsulations, but none of these have effectively resolved the dilemma. This thesis reports our findings on adding inorganic films as surface-passivation layers on top of the hybrid perovskite materials, which not only enhance stability by eliminating weak sites but also prevent water penetration by using a water-stable layer. The surface-passivated hybrid perovskite layer indicates a slight increase of bandgap energy (Eg=1.76 eV), compared to the original methylammonium lead iodide (MAPbI3, Eg=1.61 eV) layer, allowing for more stable perovskite layer with a small sacrifice in the photoluminescence property, which represents a lower charge diffusion rate and higher bandgap energy. Our finding offers an alternative approach to resolving the low stability issue for PSC fabrication.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Perovskite solar cells involving organic-inorganic materials present a great efficiency of converting solar energy to electricity, while the cost of raw materials and fabrication is much lower than traditional silicon solar cells. It has the potential to replace the conventional silicon solar cell panels to harvest the energy from the Sun with an easier manufacturing process. The problem before the commercialization step of perovskite solar cells is the short lifetime. In our report, we added an extra inorganic material on the surface of the perovskite layer for solar cell application, which reduces the water-induced degradation speed by establishing protective layer.


title: A Study of the Thermal-Hydraulic Behaviour of the Bruce A CANDU Moderator Using a Small-Scale Model

contributor:
Novog, David
Engineering Physics

subject: CANDU moderator

abstract:
The prediction of the moderator temperature distribution in a CANDU reactor is important in establishing its ability to act as an emergency heat sink for certain beyond design basis accidents. This analysis typically relies on computational models which are benchmarked against experimental data from small-scale test facilities. These small-scale models prioritize the matching of the Archimedes number (Ar) of the full-scale reactor, which represents the ratio of buoyancy forces to inertial forces. Concerns regarding similarity between the reactor and small-scale facilities may exist due to a large difference in scale, as well as geometric simplifications made due to practical limitations.
This study examined the behaviour within an approximately 1/16 scale facility representative of the Bruce A calandria vessel, which features a unique inlet and outlet configuration. Experimental measurements were obtained for a range of power and flow conditions. Unsteady RANS simulations of the small-scale facility were also performed using the realizable k-epsilon model.  Goals of the study included the assessment of the unique moderator inlet on the flow patterns inside the calandria vessel and how well existing CFD modelling approaches replicated these features.
The observed flow and temperature distributions in the scale facility did not appear highly sensitive to changes in Ar. For all tested conditions, a large front-to-back recirculation pattern resulted from the asymmetric inlet arrangement. Peak temperatures consistently occurred toward the front of the vessel where inertial flows were assisted by buoyancy induced flows.
Under steady-state conditions, unsteady and three-dimensional behaviour was observed within the vessel. Temperature fluctuations near the upper rear end of the vessel arose from the unstable interaction between cool downward flow from the inlets and upward buoyant flow from the tube bank. In the peak temperature regions, flow direction was relatively consistent in the upward direction.
The simulations tended to overpredict the peak temperatures within the vessel by approximately 0.5 – 3.8 ºC. This behaviour was attributed to the model tending to underpredict the upward velocities entering the base of the tube bank in the peak temperature regions. As Ar increased and buoyancy effects became more significant in determining the local velocities, agreement between the predicted and measured velocities was improved.
The similarity between the small-scale model and the full-size reactor was also assessed through comparisons to existing simulations of the full-size calandria. There was qualitative similarity between the two geometries, albeit at lower Ar for the small-scale facility. This suggested that buoyancy effects were more significant in the small-scale facility compared to the full-size calandria. This was attributed to the use of surface heating (as opposed to volumetric heating in the reactor), and relatively high surface heat fluxes caused by a reduced number of tube bank elements.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers

contributor:
Fang, Qiyin
Haugen, Harold
Wohl, Greg
Biomedical Engineering

subject: Ultrafast pulsed laser ablation

abstract:
The mechanical tools currently used in orthopedic and dental surgery are imprecise and may cause heat damage. Ultrashort pulse lasers are a promising replacement, but their ablation efficiency must be improved. The goal of this thesis was to achieve high ablation efficiency, precision, and minimal collateral damage using an ultrafast laser on bovine hard tissue. This work used two types of lasers: a Ti:Sapphire laser (210 fs, 800 nm, 1 kHz) and a fiber laser (1 ps, 1035 nm, 100 kHz - 1 MHz).
	This thesis begins with a review of the literature on laser-tissue interactions and the effect of certain laser parameters on the ablation process. The next section uses a Ti:Sapphire laser and bovine bone to explore the properties of laser-tissue interactions, including ablation threshold and incubation coefficient. Results showed that as the number of incident pulses goes up, ablation threshold goes down. The threshold range went from 1.08 ± 0.15 J/cm2 at 25 incident pulses to 0.73 ± 0.12 J/cm2 at 1000 pulses. The incubation coefficient, S, was calculated to be 0.90 ± 0.02.
	The relationship between ablation depth and fluence, scanning speed, and number of successive passes was characterized as a first step towards preparing large-cavity with high removal efficiency using a Ti:Sapphire and fiber lasers. Depth increased with fluence and number of passes, but it decreased with scanning speed.
	The influence of environmental conditions including air, compressed air flow, still water and flowing water on cavity ablation depth, and rate was investigated using a Ti:Sapphire laser with aim to enhance ablation efficiency. Findings showed that the deepest cavities and fastest ablation rates were achieved with compressed air flow. Air flow also resulted in the most precise cuts, the smoothest surfaces, and the absence of microcracks. This thesis also used a fiber laser to explore the effect of fluence and repetition rate on removal rate and ablation quality. Results indicated that ablation rate increases with fluence and pulse rate. When the repetition rate exceeded 600 kHz, the laser caused thermal and mechanical damage, indicated by the presence of amorphous carbon. The effect of environmental conditions and laser parameters such as repetition rate provide valuable insights into the ultrafast laser ablation mechanisms for medicine and biology field.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Health Technology Reassessment Frameworks

contributor:
Schwartz, Lisa
Health Research Methodology

subject:
Technology Assessment
Health Technology Reassessment
Disinvestment
Budgets
Qualitative Benefit Risk Frameworks

abstract:
BACKGROUND & OBJECTIVES
Overarching and decision-making frameworks may be used to facilitate the evaluation of prescription drug technologies to enable Health Technology Assessment (HTA) agency’s reassessment recommendations.  The objectives of this thesis were to; 1) identify overarching and qualitative decision-making reassessment framework challenges and methodological gaps and; 2) develop and/or modify a framework to address challenges/gaps.  The focus was on Canadian public prescription drug reimbursement with the hope that the findings may inform other jurisdictions.
METHODS
The first paper systematically identified drug disinvestment frameworks to describe framework components, challenges and solutions.  A qualitative descriptive study was conducted in the second paper to explore whether a qualitative benefit-risk framework (Universal Methodology for Benefit-Risk Assessment (UMBRA)) could be used or modified to further enable Health Technology Reassessment (HTR) recommendations.  The last research paper assessed the Canadian Agency for Drugs and Technologies in Health’s (CADTH’s) Therapeutic Review Process.  Enhancements to this process were developed based on previous research and published frameworks.
RESULTS
Qualitative framework components were identified, disinvestment terms captured and challenges and solutions to drug disinvestment were compiled in Chapter 2.  The participants interviewed in chapter 3 recognized that the Therapeutic Review assessment process did not include a qualitative deliberative framework.  However, participants did not consider that all steps of the UMBRA framework were transferable to the assessment phase of HTR.  Assessment of CADTH’s Therapeutic Review process, conducted in Chapter 4, found three areas for process enhancement: Therapeutic Review topic prioritization criteria; a qualitative assessment framework, and; publically accessible mechanisms for decision monitoring and performance measurement.
CONCLUSION
This thesis has identified reassessment framework enhancements that are hypothesized to address HTR challenges and specific solutions to enhance CADTH’s Therapeutic Review Framework.  Next steps include further evaluation and pilot testing of these proposed enhancements to enable additional Canadian stakeholder feedback.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis focuses on overarching and decision-making assessment frameworks whose purpose is to aid policy-makers in recommending which prescription drugs should continue to be government-funded and/or if modifications to funding should occur.  The goal of this work is to; 1) identify challenges and gaps in these frameworks and 2) develop or modify a framework to address findings.  This thesis focuses on the Canadian public prescription drug reimbursement environment.  Results identified Canadian reassessment framework enhancements which could address challenges to ultimately aid in maintaining financial and institutional stability of public health care systems.


title: Targeting Lipopolysaccharides for the Development of LPS-Binding Potentiators

contributor:
Brown, Eric
Biochemistry and Biomedical Sciences

abstract: The rise of Gram-negative pathogens that are resistant to all currently known antibiotics threatens to create a public health crisis. Gram-negative bacteria, by possessing an outer membrane, are resistant to many classes of antibiotics. Compounds that bind lipopolysaccharides (LPS) at the outer membrane, and permeabilize the cell to those otherwise impermeable antibiotics are termed ‘potentiators’. Those LPS-binding potentiators could be used in the clinic as antibiotic adjuvants to help combat Gram-negative resistance. In this project, the LPS-binding characteristics of potentiators are studied. Pentamidine, is a recently discovered LPS-binding potentiator. This work quantifies pentamidine’s affinity to LPS and suggests approaches to achieve higher affinity. This knowledge could lead to the development of safer, more effective potentiators. Additionally, this project uncovers currently commercially available drugs for their LPS-binding ability. We discovered that LPS-binding is not a sole predictor of potentiation ability. However, those compounds could be a starting point for the development of novel potentiators. Moreover, in this work, we study the interaction of polymyxins with lipopolysaccharides under mobile colistin resistance (mcr-1) conditions. We highlight that, while the mcr-1 mechanism of resistance is complex, the ability of polymyxins to interact with lipopolysaccharides and permeabilize the cell persists. This makes the development and exploitation of potentiators as tools for treating highly drug-resistant Gram-negative infections of great importance.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Evolution of "Monsters" in North American Exploration and Travel Literature 1607-1930

contributor:
Cruikshank, Ken
History

subject:
Monsters
Sasquatch
Windigo
Grizzly Bear
Explorers
Exploration Literature

abstract: In the first two centuries of European exploration of North America, accounts of monsters, including ones given by Indigenous guides, were largely accepted by Europeans as reflecting actual creatures. Gradually, under the influence of a range of factors, this dynamic shifted over time. Continued exploration, the spread of Enlightenment ideas, and changing material circumstances led to a decline in the belief in monsters—or at least put the belief in them beyond respectability, thereby enlarging the cultural gulf between various Indigenous cultures and European explorers and settlers, or at least the social elite of that latter group. In Canada, as argued here, the “sasquatch” was a hybrid creation combining Indigenous and European traditions; the windigo was an Indigenous monster tradition; the “grisly bear” was predominately a monster of the European imagination. Perceptions of each in European exploration literature followed a similar trajectory of increasing skepticism. Each evolved from creatures that were depicted as innately hostile or dangerous into somewhat more benign pop culture images as they lost their potency once the frontier receded and North America urbanized. As the gap in perspectives on monsters widened in exploration and frontier literature over the course of the nineteenth century, new narratives emerged that were much more negative in their depictions of Indigenous peoples. Frequently, this negativity, when connected with monster legends, depicted Indigenous peoples as cowardly or superstitious. With the sasquatch, European stereotypes about Indigenous people had by the 1870s partially supplanted what had once been a sense of genuine mystery regarding this frontier legend. The exploitation of windigo stories to portray Indigenous peoples as cowardly and superstitious also arose mainly after the 1870s, as earlier generations of explorers and fur traders had exhibited more receptive attitudes. Meanwhile many voyageurs and lower status trappers retained beliefs on monsters closer to their Indigenous counterparts, and as a result were often lumped into the same category as sharing premodern, superstitious beliefs by their social elites. Finally, in the third example, the “grisly bear” became a bloodthirsty monster in the European settler imagination. It was the last mainstream European monster myth, before it too largely faded away in the face of skeptical inquiry. However, such skepticism, voiced normally from afar, frequently misunderstood and misconstrued the nature of these legends, and the truths they had contained.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Identity, Employment, and Inequality: An Examination of Immigrants with Disabilities

contributor:
Zeytinoglu, Isik Urla
Business Administration

subject: inequality; multiple identities; immigrants; people with disabilities; intersectionality; employment; employment income; labour force participation; workforce diversity

abstract: Most extant studies on the relationship between workforce diversity and employment inequalities focus on the impact of a single disadvantaged identity on a single employment outcome such as pay or promotion at the organizational level. Thus, the relation between workers’ multiple identities and different dimensions of employment inequalities within the broader social context remains unclear. The goal of this thesis is to start filling this gap. I start with developing a multilevel model of employment inequalities for workers with multiple identities by integrating the social identity theory, double jeopardy hypothesis, intergroup contact theory, and theory of minority group threat. I test this model with two empirical studies using Statistics Canada’s nationally representative Canadian Survey on Disability (2012) linked with the National Household Survey (2011). Labour force participation, employment, and employment income are the dependent variables of this thesis. I examine the intersection of immigrant and disability identity dimensions by focusing on immigrants with disabilities (IwD) as compared to immigrants with no disabilities, Canadian-born with disabilities, and Canadian-born with no disabilities. Study 1 demonstrates that while immigrant and disability identities are independently negatively associated with employment and employment income, having both identities simultaneously has a positive effect on employment and employment income. Furthermore, with the increase of the residential area diversity (RAD), which is determined by the number of immigrants and people with disabilities in a community, IwD’s likelihood of employment increases but employment income decreases. Study 2 shows that the proportion of immigrants in a residential area (RA) is negatively associated with the likelihood of being in the labour force for IwD. Furthermore, perceived work discrimination is negatively associated with labour force participation for IwD. Moreover, perceived work discrimination mediates the relationship between the proportion of immigrants in an RA and labour force participation for IwD. This thesis contributes to theory by (i) developing a multi-level theoretical framework that demonstrate the complex relationship between individuals with multiple identities, organizations, and society, (ii) extending the intergroup contact theory and the theory of minority threat using empirical evidence from individuals with multiple identities rather than focusing on a single identity, (iii) examining multiple employment outcomes at once and demonstrating how employment outcomes might differ based on intersecting identities, and (iv) demonstrating the impact of societal context by incorporating RAD into analysis and showing how the employment outcomes of individuals with multiple identities differ by where they reside. I discuss practical implications of the findings for workers, employers, policymakers, and society.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis examines employment inequalities for workers with multiple identities, focusing on immigrants with disabilities. This thesis has three major findings. First, compared to those who were born in Canada and do not have disabilities, immigrants and people with disabilities are less likely to be on the job market and find a job. They receive lower employment income as well. However, immigrants who have disabilities are more likely to find a job than immigrants with no disabilities and those with disabilities who were born in Canada. Second, as the percentage of immigrants in a community increases, employment income for immigrants with disabilities decreases. Third, as the percentage of immigrants in a community increases, immigrants with disabilities’ chance of being on the job market decreases. Perceived work discrimination plays a role in being on the job market as well. Based on these findings, I provide suggestions for employers, workers, policy makers, and society.


title: Companions in this Age: A Study of Pain in Canadian Literature

contributor:
York, Lorraine
English and Cultural Studies

subject:
chronic pain
disability studies
Canadian literature
biomedicine
metaphor
Indigenous knowledges
poetics
intersubjectivity

abstract: This dissertation is informed by lived experience of disability, artistic practice, and medical practice. My dissertation is also intended to be a model of how to bring to bear professional expertise, personal history, and personal obligations on scholarship. An inter-field survey of critical lenses within the humanities is developed, making for a heterogeneous model of engagement for scholars interested in studying medicine and medical representations in literature and other artistic genres and forms. A fusion of fields is created, demonstrating that many different approaches can be brought to bear – a deliberate choice because medicine is in need of critique from the humanities. Settler/bioscientific epistemologies are unpacked alongside Indigenous epistemologies. Metaphor, intersubjectivity, Indigenous place-thought, and disability studies are also deployed. I develop a way to link all of these pieces when they use the representation of pain as a common cause. I respectfully consider Indigenous knowledge without defining same or clinicalizing their knowledges. Ultimately, I develop a pain poetics.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: AUTOANTIBODIES AND AUTOREACTIVE B CELLS IN THE BONE MARROW AND THE PERIPHERAL BLOOD OF PATIENTS WITH IMMUNE THROMBOCYTOPENIA

title: AUTOREACTIVE B CELLS IN IMMUNE THROMBOCYTOPENIA

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
Immune thrombocytopenia
Autoantibodies
Bone Marrow
B Cells
Platelets
Translational
Hematology
ELISPOT assay

abstract:
Introduction: Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by a platelet count less than 100 x 109/L. Platelet-bound autoantibodies are detected in the peripheral blood of only 40-50% of ITP patients. The subset of ITP patients who do not have detectable autoantibodies may truly be seropositive, but autoantibodies may not be detected due to limitations of the assays. Studies have also suggested that autoantibodies might be sequestered in the bone marrow where autoantibodies may impair platelet production. In addition, detecting autoreactive antibody-secreting B cells using the Enzyme-linked Immunospot (ELISPOT) assay was shown to be highly sensitive. In this study, the bone marrow and the peripheral blood compartments of ITP patients were tested for the presence of anti-GPIIbIIIa and anti-GPIbIX IgG autoantibodies and autoreactive B cells.
Methods: Bone marrow aspirate and peripheral blood samples were collected from ITP patients (n=12), non-immune thrombocytopenic patient controls (n=3), and healthy controls (n=5). Mononuclear cells were isolated and tested for the presence of anti-GPIIbIIIa and anti-GPIbIX IgG autoreactive B cells before stimulation and after stimulation with R848 and IL-2 using the ELISPOT assay. Anti-GPIIbIIIa and anti-GPIbIX IgG autoantibodies were detected in the bone marrow and the peripheral blood using the direct antigen capture assay.
Results: In our study, we detected autoantibodies and autoreactive B cells of known specificity in the bone marrow of a subset of ITP patients. Detecting anti-GPIIbIIIa and anti-GPIbIX autoantibodies in the bone marrow or the peripheral blood had a sensitivity of 42% and testing both compartments increased the sensitivity to 58%, while maintaining 100% specificity. Autoreactive B cells were detected at low frequencies with low specificity in the bone marrow and the peripheral blood of a subset of ITP patients. The majority of the ITP patients without detectable autoantibodies in the peripheral blood did not have autoantibodies in the bone marrow, and autoreactive B cells were not detected in either compartment.
Conclusion: Examining both the bone marrow and the peripheral blood compartments for autoantibodies or autoreactive B cells increased the sensitivity. Furthermore, detecting autoantibodies using the antigen capture assay is more sensitive and specific than detecting autoreactive B cells using the ELISPOT assay.

abstract: Thesis

abstract: Master of Science (MSc)


title: Electron Energy Loss Spectroscopy of Sn-Doped Indium Oxide Nanostructures

contributor:
Botton, Gianluigi
Materials Science and Engineering

subject: Plasmonics EELS ITO Spectroscopy Nanostructures TEM

abstract: This thesis presents the fabrication of Sn-doped In2O3 nanostructures on a 50 nm thick SiN membrane and their characterization using monochromated electron energy loss spectroscopy (EELS). Rapidly annealed triangular structures of varying thicknesses (71 nm and 32 nm) and lengths (between 400 nm and 1200 nm) unveil a structural crystallization, as well as a blue-shift and narrowing of surface (first and second order modes) and bulk plasmon peaks as the free carrier concentration increases. Bulk peak positions shift from 515+/-39 meV to 628+/-36 meV for 71 nm thick triangles. The second order surface plasmon modes exhibit a greater blue-shift after annealing (93 meV) than the first order modes (36 meV), consistent with the trend found in boundary element method (BEM) simulations using ellipsometry data. The Richardson-Lucy (RL) deconvolution algorithm is employed to improve the effective energy resolution and reveal these surface plasmons as well as a substrate phonon at 100+/-19 meV. Low-loss EELS spectra for 32 nm thick triangles potentially show a blue-shifting bulk plasmon from 751+/-42 meV to 912+/-42 meV with decreasing triangle size. STEM imaging of the triangle structure cross-sections may show a clustering of oxygen vacancies and indium atoms that could be responsible for this blue-shift. Core-loss EELS spectra between 380-550 eV using the oxygen K-edge signal provide evidence of a change in the bonding across the ITO/SiN interface, although its effect on the electrical properties requires further investigation.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The push towards smaller, faster electronic devices and sensing equipment has accelerated research into manipulating oscillating groups of electrons, or plasmons. So far, the building blocks of these next-generation systems use metals such as gold and silver; however, new materials must be explored for them to be commercially viable. Thin continuous films of transparent conductive oxides (TCOs) such as Sn-doped Indium Oxide (ITO) are already widely used in conventional silicon-based technologies, and in this work ITO nanostructures are fabricated to visualize their plasmonic response, in the hopes that they could be tailored towards plasmonic devices. The relationships between how these plasmons evolve with varying dimensions and the application of heat are explored using electron microscopy.


title: Expressive timing in non-expert musical production

contributor:
Trainor, Laurel
Psychology

subject: music timing expression emotion grouping development

abstract:
It is well established that musicians deviate substantially from regular timing in music performance, and numerous studies have sought to characterize the origin of different expressive deviations. However, this work has thus far been limited by the necessity of analyzing renditions produced by highly-trained adult musicians, which precludes the opportunity to ask questions about how development and formal experience might affect expressive timing.
In the present dissertation, I introduce a new paradigm for examining musical production in non-expert participants, the musical dwell time paradigm. In Chapters 2 and 3, I show that musically untrained adults and children as young as three years pause on phrase-final chords when self-pacing through chord sequences, mirroring the phenomenon of phrase-final lengthening that has been reported in expert music performance. I additionally demonstrate that by four years of age, this lengthening can be elicited by harmonic cues when other cues to phrase boundaries (metrical regularity and melodic contour) are controlled for. In Chapter 4, I show that when communicating different emotions through music, nonmusicians use expressive cues in a way that is highly consistent with expert musicians, and that there is striking similarity across participants despite a wide range of musical training. Finally, in Chapter 5, I demonstrate that children as young as 5 years olds’ performances mirror adults’ in their use of timing and loudness cues, and that their renditions become more adult-like by 7 years. Altogether, these findings corroborate previous claims that musically untrained adults are “listening experts” with substantial musical knowledge, extend these results to show that in performance musically untrained adults use timing and loudness similarly as expert musicians to delineate phrases and express emotions, and show that some elements are in place by early childhood. Overall, the musical dwell time paradigm offers a new, highly flexible method for examining musical production in participants with a wide variety of musical training.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Musicians often deviate from the durations notated in their musical score, slowing and speeding over the course of a performance. In the absence of deviations, music sounds mechanical or computerized rather than expressive. Studies of performances by highly-trained musicians have identified patterns in the way these duration changes are implemented, but no previous research has investigated whether formal musical experiences and development contribute to these patterns. I developed a simple music production apparatus that enables musically untrained adults and children to perform music. I asked participants to “perform” chord sequences under different conditions and measured the amount of time they spent on each chord. I uncovered how young children and untrained adults use timing deviations to delineate musical phrase groups and to communicate musical emotions. Overall, my work offers a new way to examine expressive timing patterns and suggest that formal training alone does not fully account for these patterns.


title: HOW URBAN-DWELLING INDIGENOUS MOTHERS EXPERIENCE SELECTING AND USING HEALTH CARE TO MEET THE HEALTH NEEDS OF THEIR INFANTS

contributor:
Wahoush, Olive
Ballantyne, Marilyn
Gabel, Chelsea
Jack, Susan M.
Nursing

subject:
Indigenous health
Maternal/Child health
Access to health care
Culturally safe care
Trauma and violence-informed care
Family centred care
Infant

abstract: Mothers typically act as gatekeepers to health care for their children, yet many Indigenous mothers report poor access to health services. Inadequate access to health services may contribute to the poor health outcomes experienced by Indigenous infants. Understanding how urban-dwelling Indigenous mothers experience selecting and using health services to meet the health needs of their infants is important to informing how health services can best support the needs of these families. This study employs qualitative interpretive description methodology guided by the Two-Eyed Seeing framework and Andersen’s Behavioural Model of Health Services Use. Interviews facilitated by ecomaps and a discussion group were conducted with 19 Indigenous mothers living in Hamilton with infants under the age of 2 years. Additional interviews with 12 health providers added further context to the mothers’ experiences. Results relate to three domains of health service use: primary care, acute care and early childhood health promotion services. Findings suggest that health providers can improve the access and use of health services by Indigenous mothers and infants through integrating three approaches to care: culturally safe care, trauma and violence-informed care and family centred care. While Indigenous-led supports may be better suited to meet the needs of Indigenous families, mainstream services can improve access and promote health service use through integrating these approaches to care. The findings have numerous implications for nursing education, practice and research as well as for health policy. Application of this evidence may result in equitable access to care, improved use of health services and better health outcomes for Indigenous infants and their families.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Access and use of health care are important to health and wellness. Indigenous infants are known to have poorer health outcomes than non-Indigenous infants in Canada, yet little is understood of how their parents access health care to meet their health needs. This thesis uses qualitative methods, including interviews and a discussion group, to ask Indigenous mothers living in a city about their experiences selecting and using health services to meet their infant’s health needs. Interviews with health providers assist with understanding how health care is delivered to these families. The results provide important strategies for nurses and other health providers to improve how they provide care. This may then improve access to health services for Indigenous parents and ultimately lead to improved health outcomes for Indigenous infants and their families.


title: Polarographic Methods for Thorium and Their Application to Magnesium-Base Alloys

contributor:
Graham, R.P.
Chemistry

subject: magnesium magnesium-base alloys, polarographic, polarographic methods, thorium

abstract:
The precipitation of thorium with certain organic reagents has been shown to afford a basis for polarographic methods for the determination of thorium. Appropriate conditions for the precipitation of thorium by certain reagents have been determined, and the advantages of a homogeneous precipitation of thorium 8-quitnolinate have been demonstrated. The precipitate
that thorium forms with m-nitrobenzoic acid has been found to be the tetra-m-nitrobenzoate.
The new polarographic methods tor thorium have been proven to be directly applicable to zirconium-free magnesium-base alloys . When zirconium is present, a simple anion exchange procedure will eliminate the interference of zirconium, and allow it's subsequent determination.The satisfactory nature of the precision and accuracy of the proposed methods, and their applicability to substances other than magnesium-base alloys, have been demonstrated.

abstract: Thesis

abstract: Master of Science (MS)


title: NON-INVASIVE BLOOD GLUCOSE MONITORING OF 95% CERTAINTY BY PRESSURE REGULATED MID-IR

abstract: To fight against diabetes mellitus, a chronicle metabolic disease, from which more than 400 million people suffer in the world, the patients have to puncture their fingers 4-5 times a day when using a glucometer for the blood glucose level checks, causing invasive pain and the risk of infection. Therefore, the non-invasive method has been urged for blood glucose monitoring, among which the mid-infrared spectroscopy (Mid-IR) response of interstitial fluid was found to be promising. However, despite the prolonged effort, the accuracy still falls well below the FDA’s requirement. To break this barrier which lasted for almost three decades, we discovered the finger contact pressure playing a critical role during the measurement, where the Mid-IR reading could be affected significantly by a small change of the finger posture. In addition, the Mid-IR absorption level was also found to be highly associated with individuals, revealing the necessity of adjusting the calibration correlation for each patient. By imposing a certain contact pressure monitored by a pressure transducer, we were able to achieve over 95% certainty from the Mid-IR measurement of glucose concentration and 100% comparability to the “true” glucose concentration for the first time. This significant enhancement of the accuracy was found to be mainly attributed to the fact that, the finger tissue undergoes certain morphological change because of the pressure, where much more interstitial fluid becomes accessible by the Mid-IR detector.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Microcell fabrication and resolution enhancement for in situ liquid cell electron microscopy

contributor:
Botton, Gianluigi
Soleymani, Leyla
Materials Engineering

subject:
in situ
electron microscopy

abstract: Liquid cell electron microscopy has been proven to provide high spatial and temporal resolution for studying liquid layers and the solid-liquid interface at the micro and nano scale. The in situ environment allows for spatial and spectral characterization and quantification of the dynamics and kinetics involved with structural and chemical changes of nanostructures, which has seen application is fields of materials science, electrochemistry, corrosion, biomaterials, and nanophysics. The rapid growth of in situ liquid cell electron microscopy has motivated the fabrication of a custom liquid cell for improved control over the experimental conditions, including cell dimensions and materials. In this work, the process flow and micro-fabrication of a custom liquid cell system are proposed and executed, with proof of operation through the in situ imaging of suspended gold nanoparticles and electrochemical characterization. The in situ TEM system is improved upon by forming 1μm diameter holes through the viewing membranes, removing the background noise contribution from imaging electrons through the windows. This allows for high resolution liquid cell imaging. This improved system is used to study the oxidative etching conditions for palladium nanocrystals, which are commonly used as catalysis for hydrogen fuel cells. The dendritic etching is studied through native etching under exposure to hydrochloric acid without the presence of oxidizing species, followed by the radiolytic generation of oxidizing radicals via the microscope electron beam, and finally by the application of electrical biasing.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
Characterization of nanomaterials has been available for several decades and has aided in the improvement of material design, such as steel strength and corrosion resistance, electrical systems such as those involved in computers and smartphones, and biological sensing and detection. Observation of dynamic process which occur at the interface between solid and liquid phases, or purely within liquid layers, has always been a challenging topic due to the difficulty of finding a stable environment for both solids and liquids to exist at the nano scale within a measurement device. In situ liquid cell electron microscopy offers the ability to image this interface with real-time data acquisition for recording of dynamics and kinetics at the nano scale. Previous work has shown the liquid cell to provide high spatial and temporal resolution of systems in an environment which mimics their native operating conditions.
This thesis addresses current developments for in situ systems and works to develop a custom liquid cell to further the applications of the liquid cell and provide improved control over experimental conditions. The work then aims to improve on current technology by increasing the spatial resolution obtainable. Finally, the technique is applied to study the structural changes of nanocrystals under various etching conditions as a demonstration of its’ capabilities.


contributor:
Robinson, H.
Civil Engineering

abstract: Title: Composite Action in the Reinforced Concrete Beam, Author: A. Shakoor Uppal, Location: Thode

abstract: This thesis involves the treatment of the reinforced concrete beam as a composite beam with incomplete interaction. Influence of the loss of interaction and other parameters on the flexural cracking, and the moment capacity of the remaining uncracked portion of the reinforced concrete beam is studied analytically.

abstract: Thesis

abstract: Master of Engineering (ME)