title: Regeneration of Lanthanum Following Precipitation of Phosphates from Waste-Waters

contributor:
Norman, J. D.
Chemical Engineering

subject: regeneration, Lanthanum, precipitation, phosphates, waste-waters, sewage treatment plants, iron, reactants

abstract:
 Government programs now underway in Ontario aim at removing phosphates from waste-waters at sewage treatment plants. At present, removal of phosphates is commonly accomplished by chemical precipitation with lime, alum, or iron. Lanthanum, a rare earth element, has been found to be an effective precipitant of phosphates. If lanthanum precipitate can be collected, and the lanthanum then regenerated so that it could be recycled for further phosphate precipitation, a very advantageous alternative to the above schemes would result.

 In this study, phosphates were precipitated from both distilled water and secondary effluent using lanthanum. For the two cases, a regeneration scheme for lanthanum was examined. The basic regeneration reactions were carried out to evaluate the kinetics and equilibria for different ratios of reactants and different reaction temperatures. Techniques for phase separation of reacted reagents were studied. Process design calculations were carried out to obtain order of magnitude figures for amounts and costs of chemicals required, amounts of sludge produced, and reactor sizes.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: A Study of Methods of Identification and Communication of User Needs to the Designer

contributor:
Siddall, J. N.
Mechanical Engineering

subject: identification, communication, user needs, designer, technology, specification

abstract:
 With the growth of technology there is recognition of the fact that communication requires improving between decision-makers and the people who will eventually use or be affected by the system under consideration. The main thrust of this work is to explore means of facilitating clear unambiguous communication of relevant needs to all parties involved in the design process.

 A number of approaches to this problem from different disciplines are reviewed. Some of these approaches are already in existence while others require adapting to the particular problems encountered in the design process.

 Suggestions are put foreward as to how these techniques can be integrated to produce a unified approach to the problem of producing a Total Specification embodying all information necessary to the designer in his capacity as decision-maker.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Modulation Division for Multiuser Wireless Communication Networks

contributor:
Zhang, Jian-Kang
Electrical and Computer Engineering

subject: Modulation Division

subject: Uniquely Factorable Constellation Pair (UFCP)

subject: Uniquely Decomposable Constellation Group (UDCG)

subject: Relay Networks

subject: MIMO

subject: Broadcast Channels

subject: Massive MIMO

abstract:
This thesis considers the modulation division based on the concept of uniquely factorable constellation pair (UFCP) and uniquely decodable constellation group (UDCG) in multiuser wireless communication networks.

We first consider a two-hop relay network consisting of two single-antenna users and a two-antenna relay node, for which a novel distributed concatenated Alamouti code is devised. This new design allows the source and relay nodes to transmit their own information to the destination node concurrently at the symbol level with the aid of the UFCP generated from both PSK and square QAM constellations as well as by jointly processing the noisy signals received at the relay node. Moreover, an asymptotic symbol error probability (SEP) formula is derived for the ML receiver, showing that the maximum diversity gain function is achieved, which is proportional to $\ln \mathtt{SNR}/\mathtt{SNR}^2$.

Then, we concentrate on the point-to-point correlated multiple-input and multiple-output (MIMO)  communication systems where  full knowledge of channel state information (CSI) is available at the receiver and only the first- and second-order statistics of the channels are available at the transmitter.  When the number of antenna elements of both ends goes to infinity while keeping their ratio constant, the asymptotic SEP analysis is carried out for either optimally precoded or uniformly precoded  correlated large MIMO fading channels using the zero-forcing (ZF) detector with equally likely PAM, PSK or square QAM constellations. For such systems, we reveal some very nice structures which inspire us to explore two very useful mathematical tools (i.e., the Szego's theorem on large Hermitian Toeplitz matrices and the well-known limit: $\lim_{x\to\infty}(1+1/x)^x=e$), for the systematic study of asymptotic behaviors on their error performance.   This new approach enables us to  attain a very simple expression for the SEP limit as the number of the available antenna elements goes to infinity.  In what follows, the problem of precoder design using a zero-forcing decision-feedback (ZF-DF) detector is also addressed.
For such a MIMO system, our principal goal is to efficiently design an optimal precoder that minimizes the asymptotic SEP of the ZF-DF detector under a perfect decision feedback.
By fully taking advantage of the product majorization relationship among eigenvalues, singular-values and Cholesky values of the precoded channel matrix parameters, a necessary condition for the optimal solution to satisfy is first developed and then the structure of the optimal solution is characterized. With these results, the original non-convex problem is reformulated into a convex one that can be efficiently solved by using an interior-point method.  In addition, by scaling up the antenna array size of both terminals without bound for such a network, we propose a novel method as we did for the ZF receiver scenario to analyze the asymptotic SEP performance of an equal-diagonal QRS precoded large MIMO system when employing an abstract Toeplitz correlation model for the transmitter antenna array.  This new approach has a simple expression with a fast convergence rate and thus, is efficient and effective for error performance evaluation.

For multiuser communication networks, we first consider a discrete-time multiple-input single-output (MISO) Gaussian broadcast channel (BC) where perfect CSI is available at both the transmitter and all the receivers. We propose a flexible and explicit design of a uniquely decomposable constellation group (UDCG)  based on PAM and rectangular QAM constellations. With this new concept, a modulation division (MD) transmission scheme is developed for the considered MISO BC.  The proposed MD scheme enables each receiver to uniquely and efficiently recover their desired signals from the superposition of mutually interfering cochannel signals in the absence of noise.  Using max-min fairness as a design criterion, the optimal transmitter beamforming problem is solved in a closed-form for two-user MISO BC. Then, for a general case with more than two receivers, a user-grouping based beamforming scheme is developed, where the grouping method, beamforming vector design and power allocation problems are addressed by employing weighted max-min fairness.

Then, we consider an uplink massive single-input and multiple-output (SIMO) network consisting of a base station (BS) and several single-antenna users. To recover the transmitted signal matrix of all the users when the antenna array size is large, a novel multi-user space-time modulation (MUSTM) scheme is proposed for the considered network based on the explicit construction of QAM uniquely-decomposable constellation groups (QAM-UDCGs).  In addition, we also develop a sub-constellation allocation method at the transmitter side to ensure the signal matrix is always invertible. In the meanwhile, an efficient training correlation receiver (TCR) is proposed which calculates the correlation between the received sum training signal vector and the sum information carrying vector. Moreover, the optimal power allocation problems are addressed by maximizing the coding gain or minimizing the average SEP of the received sum signal under both average and peak power constraints on each user. The proposed transmission scheme not only allows the transmitted signals with strong mutual interference to be decoded by a simple TCR but it also enables the CSI of all the users to be estimated within a minimum number of time slots equal to that of the users.

Comprehensive computer simulations are carried out to verify the effectiveness of the proposed uniquely decomposable space-time modulation method in various network topologies and configurations. Our modulation division method will be one of the promising technologies for the fifth generation (5G) communication systems.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: A Germanium Bolometer for the Far Infrared

contributor:
Timusk, T.
Physics

subject: Germanium, bolometer, Far Infrared, temperature, resolution

abstract: A technique has been developed for constructing low temperature germanium bolometers for use as detectors in the far infrared. Their performance has been evaluated both by measuring their responsivity and noise and comparing these with the theoretical values and also by using the bolometer in conjunction with a far infrared spectrophotometer to obtain spectra showing the theoretical resolution of 0.11 cm^-1 at 55 cm^-1 expected for this instrument.

abstract: Thesis

abstract: Master of Science (MSc)


title: N.M.R. Investigation of Nuclear Spin Isomerism in the Ammonium Ions

contributor:
Petch, H. E.
Physics

subject: N.M.R., nuclear spin, isomerism, Ammonium ions, low temperatures, absorption signals, protons

abstract:
 The possibility of isomeric nuclear spin states existing among the ammonium ions at low temperatures has been investigated for some twenty ammonium salts. Measurements have been made of the proton absorption signals at 4.2°K, and the temperature dependences, where previously unavailable, of the spin-lattice relaxation time.

 Some of the salts exhibit the normal rigid lattice spectra and second moments characteristic of distinguishable protons, but most exhibit some degree of line narrowing at 4.2°K. The data shows that thermally activated reorientations are effectively frozen out at this temperature and cannot be responsible for such narrowing.

 It is concluded that the narrow spectra, although indicative of indistinguishability among the protons, are not attributable solely to spin isomerism, but are being modified by a further mechanism, probably tunneling of the ammonium ion through the crystal field barrier.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Missirlis, Y.F.
Physics

abstract: Title: Effect of ATP and Alkaline Phosphate on Erythrocyte Deformability, Author: Marianne Vanderwel, Location: Thode

abstract:
The effect of altered spectrin phosphorylation on the
deformability properties of human erythrocyte membranes was studied
using the nucleopore filter method. The shear modulus of elasticity
was found to decrease and increase as a result of the incorporation
of ATP or alkaline phosphatase, respectively. Purified spectrin was
used to immunize rabbits, in order to obtain anti-spectrin antibodies
for future experiments.

abstract: Thesis

abstract: Master of Engineering (ME)


title: STUDIES OF MAGNETOTACTIC BACTERIA BY SOFT X-RAY MICROSCOPY

contributor:
Hitchcock, Adam
Chemistry

abstract:
Magnetotactic bacteria (MTB) are ubiquitous in aquatic environments. They biomineralize membrane-bound magnetic nanoparticles (magnetosomes), which are magnetically single-domain, single crystals of either magnetite, Fe3O4, or greigite, Fe3S4. The chain is a strong magnetic dipole, which aligns the cell with the earth’s magnetic field (magnetotaxis) and, together with chemical signatures (aerotaxis), is believed to increase the efficiency of the organism in finding an optical oxygen concentration in the sediments. As the simplest organisms, in which biomineralization occurs, magnetotactic bacteria serve as an ideal model to study biomineralization mechanism.
	In this research, soft X-ray STXM (scanning transmission X-ray microscopy) was used to characterize the chemistry and magnetism of magnetotactic bacteria (MTB) on an individual cell and an individual magnetosome basis. Two types of MTB, Candidatus Magnetovibrio blakemorei strain MV-1 and multicellular magnetotoactic prokaryotes (MMPs) were studied in this project. In addition, ptychography technique, which does not rely on X-ray optics and holds promise for imaging with wavelength-limited resolution, is used to study biomineralization and magnetism of MTB cells. A spatial resolution of 7 nm below 1000 eV is achieved with ptychography, which is the highest in the soft X-ray region so far. Precursor-like and immature magnetosomes in intact MV-1 cells with ptychography are observed and a model for the pathway of magnetosome biomineralization for MV-1 is proposed. Our results demonstrate ptychography offers a superior means to characterize the chemical and magnetic properties of magnetotactic bacteria at the individual magnetosome level.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: The Self in Crisis: Using Self-Trust to Enhance Therapeutic Practices for Patients with Chronic Suicidal Ideation

contributor:
Gedge, Elisabeth
Philosophy

subject:
suicide
mental health
depression
mental illness
bipolar disorder
chronic illness
psychology
bioethics
psychiatry
healthcare

abstract: In this thesis I set out to show that the bioethical literature concerning the treatment of chronic suicidal ideation occupies a serious omission: it does not discuss the critical function that self-trust serves in the recovery process. Self-trust is a core component of autonomy, and therefore plays a pivotal role in the shaping of one’s sense of self and his or her capacity to effectively engage in therapeutic interventions. I begin by discussing the relationship between agency and self-trust, and how this influences one’s ability to make decisions and self-advocate. Secondly, I evaluate how self-trust relates to aspects of the suicidal mind, including existential distress and negative urgency. Finally, I will offer recommendations as to how the explicit (re-) development of self-trust skills can significantly enhance the effectiveness and timeliness of contemporary dialectical treatment practices.

abstract: Thesis

abstract: Master of Arts (MA)


title: Discovering Ontology Functional Dependencies

contributor:
Chiang, Fei
Computing and Software

subject: Ontology

abstract:
Functional Dependencies (FDs) are commonly used in data cleaning to identify dirty
and inconsistent data values. However, many errors require user input for specific do-
main knowledge. For example, let us consider the drugs, Advil and Crocin. FDs will
consider these two drugs different because they are not syntactically equal. However,
Advil and Crocin are synonyms as they are two different drugs with similar chemical
compounds but marketed under distinct names in different countries. While FDs
have traditionally been used in existing data cleaning solutions to model syntactic
equivalence, they are not able to model broader relationships (e.g., synonym, Is-A
(Inheritance)) defined by ontologies.
In this thesis, we take a first step to discover a new dependency called Ontology
Functional Dependencies (OFDs). OFDs model attribute relationships based on re-
lationships in a given ontology. We present two effective algorithms to discover OFDs
using synonyms and inheritance relationships. Our discovery algorithms search for
minimal OFDs and prune the redundant ones. Both algorithms traverse the search
lattice in a level-wise Breadth First Search (BFS) manner. In addition, we have devel-
oped a set of pruning rules so that we can avoid considering unnecessary candidates
in the search lattice. We present an experimental study describing the performance
ivand scalability of our techniques. Experimental results show that both algorithms
are effective in practice and discover OFDs efficiently for large datasets with millions
of tuples. We also present a qualitative study showing that the discovered OFDs are
meaningful with high precision and recall.

abstract: Thesis

abstract: Master of Science (MSc)


title: The application of acculturation theory and the ICF framework to study the transition process from pediatric to adult healthcare guided by a knowledge translation approach

title: Applying conceptual frameworks to study healthcare transition

contributor:
Gorter, Jan Willem
Rehabilitation Science

subject:
Transition
youth with chronic health conditions
knowledge translation
ICF
acculturation theory

abstract: Background: Although research in healthcare transition is not novel, youth with chronic health conditions (YCHC) and parents still struggle with this complex process. Currently, there is limited theoretically-driven studies to inform transition research. The key foundation of this thesis is on the integration and application of theories and conceptual frameworks to studying the complexities of the transition process to inform research on a conceptual level. Purpose: Three study objectives were: 1) to gain a better understanding of the experiences of YCHC, parents, and healthcare providers with self-management during the transition process; 2) explore theoretical frameworks to guide research in transition and inform the planning and delivery of holistic transition services that is developmentally appropriate and culturally sensitive; and 3) to identify strategies to facilitate knowledge mobilization in transition. Methods: This “sandwich thesis” includes four individual scholarly works (Chapters 2-5) positioned between the introduction (Chapter 1) and the conclusions (Chapter 6). The Knowledge to Action (KTA) framework was used to framed all of my four scholarly works together. Chapter 2 was a qualitative study to examine the collective experiences YCHC, parents, and healthcare providers with self-management during transition. Chapter 3 was a critical appraisal of the literature to explored the potential application of acculturation theory in transition through the use of a clinical vignette. Chapter 4 was a scoping review about the current use of the ICF and transition research and practice. Chapter 5 was a demonstration project with the primary aim of working with youth (i.e. university students with and without a disability) and researchers to identify engagement strategies in research to develop partnerships to facilitate knowledge mobilization. Results: Key findings of Chapter 2: i) the process of self-management is interconnected and interdependent between YCHC, parents, and healthcare providers, and ii) results began to uncover cultural nuances between pediatric and adult healthcare. Key findings of Chapter 3: i) acculturation theory provides a concrete conceptual framework to guide thinking about the process of change within an individual with a change in culture to another; and ii) acculturation can become a natural framework for health systems practitioners when integrated into clinical practice frameworks.  Key findings of Chapter 4: i) the ICF broadens our view on health to include personal and environment factors, and ii) the ICF enhances multidisciplinary communication and collaboration. However, the ICF is not without limitation. Specifically, there are limited descriptions around personal and environmental factors and the underlying processes, defining differences between the domains of activity and participation, and the ICF’s static nature which does not address change over time. Key findings of Chapter 5: five engagement strategies: 1) creating a physical or virtual hub with updated information or updating current websites to ensure usability and accessibility (e.g. for course selection), 2) hosting “speed dating” events between students and faculty/researchers to enhance communication and knowledge exchange, 3) hosting monthly lectures/workshops/webinars, 4) capacity building via emailing lists for new opportunities, and 5) peer mentoring to connect stakeholders within the University and Hamilton communities. Conclusions: Synthesis of the knowledge from this thesis contributes to the thinking and doing of transition research. Specifically, acculturation theory (a social science and psychology theory) and the International Classification of Functioning, Disability, and Health (ICF) (a bio-psycho-social theory) are offered as complementary conceptual frameworks to inform transition research. Stakeholder involvement in transition research is critical in facilitating knowledge mobilization, however, researchers need to consider the challenges of research partnership with YCHC. It is recommended to explore and assess opportunities for YCHC to have experiences starting in childhood and through adolescence; these experiences can assist in building YCHC’s capacity to assume adult roles and responsibilities for self-management.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Today, one in five Canadian children, adolescents, and young adults live with a chronic physical, developmental, behavioural or emotional condition that impact their developmental trajectories. Youth with chronic health conditions (YCHC) and their families find it difficult to go from pediatric to adult healthcare.  Although the topic of transition is not new, YCHC and parents continue to experience barriers in the adult system for meeting their needs (e.g. fragmented services, accessibility to available services, and biomedical focus of healthcare to name a few). Moreover, research evidence is not reaching the people who need it most, YCHC and their parents, and they are not benefitting optimally from advances in research. Thus, research is needed to carefully examine the process of transition to better understand the underlying processes, to identify current knowledge gaps, and to facilitate knowledge mobilization. The overall aim of this thesis is on the application of theories (acculturation theory) and frameworks (International Classification of Functioning, Disability, and Health-ICF) to provide a new outlook and lens to unraveling the complexities and underlying processes of transition, which has not been examined before. The Knowledge to Action (KTA) framework is used to inform the research process and stakeholder consultation to facilitate knowledge mobilization. The goal is to ultimately produce meaningful and relevant outcomes for YCHC and those involved in the transition process. YCHC and other stakeholders (parents, healthcare providers, community partners, and policymakers) were consulted throughout all of the components of the thesis ensure their voices and needs were heard. Results from this thesis will bring new insights and knowledge to those involved in transition research and practice.


title: The Oxidative Cyclization of Ketone Carbohydrazones and 4-Substituted Semicarbazones. Thermal Decomposition of 5,5-Diaryl-2-Phenylimino-△^3 -1,3,4-Oxadiazolines

contributor:
Warkentin, J.
Chemistry

subject: oxidative, cyclization, ketone, carbohydrazones, semicarbazones, decomposition, reaction

abstract: The reaction of lead tetra-acetate with ketone carbohydrazones and 4-substituted semicarbazones gave a series of 2-(substituted imino)-△^3-1,3,4-oxadiazolines. Spectroscopic and chemical evidence is presented to establish the proposed structure, and the scope of the reaction is described. The thermolysis of the 5,5-diaryl-2-phenylimino-△^3-1,3,4-oxadiazolines was studied in chlorobenzene solution. The results of kinetic experiments (gas evolution and infra-red) are reported, and the mechanism of the decomposition is discussed. A survey of the literature pertaining to related lead tetra-acetate oxidations, and to decomposition of cyclic azo compounds is presented.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Impurity Induced Far-Infrared Absorption in KBr and KCl

subject: impurity, induced, far-infrared, absorption, high resolution, neutron

abstract: High resolution measurements of the far-infrared absorption spectra due to a number of substitutional impurities in KBr and KCl are presented. Several Van Hove singularities of the phonon spectrum of the host lattice are directly observed and found to shift to higher frequencies as the impurity concentration is increased. The first direct experimental evidence for the change of shape or metamorphism of singularities is also presented. The experimental spectra are compared with numerical calculations based on the ordinary shell model for the defect together with phonon data obtained from inelastic neutron scattering experiments. Agreement between experiment and calculation is generally good when impurity resonant modes are absent.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Oxidation Kinetics of Free Falling Iron Droplets

contributor:
Lu, W-K.
Metallurgical Engineering

subject: oxidation, kinetics, free falling, iron droplets, levitation melting

abstract: Levitation melting was used to study the oxidation kinetics of free falling iron droplets. Single droplets of Armco iron were deoxidized and allowed to fall through oxidizing columns of known heights and then quenched in Silicone Oil. The rate of oxygen pick up by a droplet was found to be dependent upon its initial temperature, its size, and the composition of the reacting gas. The proposed mechanism is presented with kinetic data.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Mobile Machine Learning for Real-time Predictive Monitoring of Cardiovascular Disease

contributor:
Doyle, Thomas
Samavi, Reza
Biomedical Engineering

subject:
SVM
MLP
Data Mining
Cardiovascular Disease
Mobile Device
Remote Patient Monitoring
Wearable System
Support Vector Machine
Multilayer Perceptron
Health Records
Machine Learning

abstract:
Chronic cardiovascular disease (CVD) is increasingly becoming a burden for global healthcare systems. This burden can be attributed in part to traditional methods of managing CVD in an aging population that involves periodic meetings between the patient and their healthcare provider. There is growing interest in developing continuous monitoring systems to assist in the management of CVD. Monitoring systems can utilize advances in wearable devices and health records, which provides minimally invasive methods to monitor a patient’s health. Despite these advances, the algorithms deployed to automatically analyze the wearable sensor and health data is considered too computationally expensive to run on the mobile device. Instead, current mobile devices continuously transmit the collected data to a server for analysis at great computational and data transmission expense.
In this thesis a novel mobile system designed for monitoring CVD is presented. Unlike existing systems, the proposed system allows for the continuous monitoring of physiological sensors, data from a patient’s health record and analysis of the data directly on the mobile device using machine learning algorithms (MLA) to predict an individual’s CVD severity level. The system successfully demonstrated that a mobile device can act as a complete monitoring system without requiring constant communication with a server. A comparative analysis between the support vector machine (SVM) and multilayer perceptron (MLP) to explore the effectiveness of each algorithm for monitoring CVD is also discussed. Both models were able to classify CVD risk with the SVM achieving the highest accuracy (63%) and specificity (76%). Finally, unlike current systems the resource requirements for each component in the system was evaluated. The MLP was found to be more efficient when running on the mobile device compared to the SVM. The results of thesis also show that the MLAs complexity was not a barrier to deployment on a mobile device.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: In this thesis, a novel mobile system for monitoring cardiovascular (CVD) disease is presented. The system allows for the continuous monitoring of both physiological sensors, data from a patient’s health record and analysis of the data directly on the mobile device using machine learning algorithms (MLA) to predict an individual’s CVD severity level. The system successfully demonstrated that a mobile device can act as a complete monitoring system without requiring constant communication with a remote server. A comparative analysis between the support vector machine (SVM) and multilayer perceptron (MLP) to explore the effectiveness of each MLA for monitoring CVD is also discussed. Both models were able to classify CVD severity with the SVM achieving the highest accuracy (63%) and specificity (76%). Finally, the resource requirements for each component in the system were evaluated. The results show that the MLAs complexity was not a barrier to deployment on a mobile device.


title: Simulation of III-V Nanowires for Infrared Photodetection

contributor:
LaPierre, Raymond R.
Engineering Physics

subject:
III-V nanowires
nanophotonics
photodetectors
waveguides
photonic crystals
optical simulation
nanoelectronics
multispectral detector
nanoscience
nanotechnology
infrared
MWIR
nanowires
optical coupling
guided modes
leaky modes
radial modes
near field coupling
photonic crystal modes
vertical nw array
InSb
GaAs
InP
InAs

abstract: The absorptance in vertical nanowire (nw) arrays is typically dominated by three optical phenomena: radial mode resonances, near-field evanescent wave coupling, and Fabry–Perot (F-P) mode resonances. The contribution of these optical phenomena to GaAs, InP and InAs nw absorptance was simulated using the finite element method. The study compared the absorptance between finite and semi-infinite nws with varying geometrical parameters, including the nw diameter (D), array period (P), and nw length (L). Simulation results showed that the resonance peak wavelength of the HE1n radial modes linearly red-shifted with increasing D. The absorptance and spectral width of the resonance peaks increased as L increased, with an absorptance plateau for very long nws that depended on D and P. Near-field coupling between neighbouring nanowires (nws) was observed to increase with increasing diameter to period ratio (D/P). The effect of F-P modes was more pronounced for shorter nws and weakly coupled light. Based on the collective observation of the correlation between nw geometry and optical phenomena in GaAs, InP, and InAs nw arrays, a periodic array of vertical InSb nws was designed for photodetectors in the low-atmospheric absorption window (λ = 3-5 μm) within the mid-wavelength infrared (MWIR) spectrum (λ = 3-8 μm). Simulations, using the finite element method, were implemented to optimize the nw array geometrical parameters (D, P, and L) for high optical absorptance (~0.8), which exceeded that of a thin film of equal thickness. The results further showed that the HE1n resonance wavelengths in InSb nw arrays can be tuned by adjusting D and P, thus enabling multispectral absorption throughout the near infrared (NIR) to MWIR region. Optical absorptance was investigated for a practical photodetector consisting of a vertical InSb nw array embedded in bisbenzocyclobutene (BCB) as a support layer for an ultrathin Ni contact layer. Polarization sensitivity of the photodetector was examined. Lastly, how light flux enters the nw top and sidewalls on HE11 resonance was investigated.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: BOUNDING THE DECAY OF P-ADIC OSCILLATORY INTEGRALS WITH A CONSTRUCTIBLE AMPLITUDE FUNCTION AND A SUBANALYTIC PHASE FUNCTION

contributor:
Haskell, Deirdre
Mathematics and Statistics

subject: BOUNDING,DECAY, OF P-ADIC, OSCILLATORY, CONSTRUCTIBLE,  AMPLITUDE,SUBANALYTIC PHASE FUNCTION

abstract: We obtain an upper bound for decay rate of p-adic oscillatory integrals of with analytic phase function and constructible amplitude map.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: WASP: An Algorithm for Ranking College Football Teams

contributor:
McNicholas, Paul
Mathematics and Statistics

subject:
Ranking
Football
Statistics
Principal Component Analysis

abstract: Arrow's Impossibility Theorem outlines the flaws that effect any voting system that attempts to order a set of objects. For its entire history, American college football has been determining its champion based on a voting system. Much of the literature has dealt with why the voting system used is problematic, but there does not appear to be a large collection of work done to create a better, mathematical process. More generally, the inadequacies of ranking in football are a manifestation of the problem of ranking a set of objects. Herein, principal component analysis is used as a tool to provide a solution for the problem, in the context of American college football. To show its value, rankings based on principal component analysis are compared against the rankings used in American college football.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The problem of ranking is a ubiquitous problem, appearing everywhere from Google to ballot boxes. One of the more notable areas where this problem arises is in awarding the championship in American college football. This paper explains why this problem exists in American college football, and presents a bias-free mathematical solution that is compared against how American college football awards their championship.


title: Development of a Vacuum Transfer System for Tokamak Plasma Impurity Studies

contributor:
Robinson, J. E.
Engineering Physics

subject: vacuum transfer system, Tokamak plasma, impurity

abstract: A surface station consisting of a sample manipulator and transfer system was developed to allow the study of plasma - first wall interactions in ALCATOR at M.I.T. A disc shaped probe is located at the plasma edge and rotated past an aperture in a shield to obtain time resolved data. Samples can be analysed in situ or transported under vacuum to McMaster University. The transfer process from the surface station to the 'vacuum suitcase' is accomplished by means of pressure locks.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Effects of Migration Selectivity on the Population of the Atlantic Region

contributor:
Liaw, Kao-Lee
Geography

subject: migration selectivity, population, Atlantic region, education status

abstract:
 The effects of migration selectivity on the population of the Atlantic region are determined by creating six net migration schedules for six personal variables: age, sex,
nativity, education status, mother tongue and marital status. Although the migration schedules were rather complex, selectivity was greatest for young adults and the well educated. The population of the Atlantic region is selective with respect to age and education status. The Atlantic region is losing its young and well educated individuals through the migration process. Furthermore, the Atlantic region had a net inflow of elderly individuals. The effect of the migration selectivity is the loss of young adults, which is interpreted as an important loss of human capital compounding the economic problems of the region. While the increase in elderly population will economically burden the local social and health systems. Using the argument that the migration process is severely hurting the region economically, the Atlantic governments can argue for larger equalization payments to the region.

abstract: Thesis

abstract: Candidate in Philosophy


title: Political Organizing Aroud Housing Issues: A Case Study of Hamilton's Housing Help Centre

contributor:
Chouinard, Vera
Geography

abstract: Title: Political Organizing Around Housing Issues: A Case Study of Hamilton's Housing Help Centre, Author: Sherie L. Willan, Location: Thode

abstract:
This research paper examines political organizing around housing issues and the role of working class backgrounds in the development of alternative approaches to housing. This is done within the context of Hamilton's Housing Help Centre, located at 135 Rebecca Street. It also documents the origin of the Centre up until the development of the Board of Directors. From a theoretical perspective, the study confirms the contribution that Political Economy
theory makes to the understanding of alternative approaches to housing.

Generally, this paper affirms the importance working class backgrounds and views of housing issues played in the development of the Housing Help Centre. In addition, it also identifies the importance of advocacy, as identified by those involved in the Centre's origin. Issues pertaining to the Housing Help Centre that need to be further explored are also identified.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: The Determination of Copper, Manganese and Zinc in Brain Tissue

contributor:
Fritze, K.
Chemistry

subject: copper, manganese, zinc, brain tissue, soluble, metallo-proteins, neutron activation

abstract: This project was undertaken with the aim of studying the distribution of copper, manganese and zinc in brain and to gain same information on the possible presence of soluble metallo-proteins in this tissue. The distribution of copper, manganese and zinc has been determined by neutron activation analysis. Soluble metallo-proteins of these three elements have been identified by the combination of gel chromatography and neutron activation analysis. In addition, in vivo and in vitro radioisotopic labelling techniques have been used occasionally.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Mathematical Modeling and Computer Control of a Two-Phase Permanent-Magnet Stepping Motor

contributor:
Elliott, A. R.
Sinha, N. K.
Electrical Engineering

subject: mathematical modeling, computer control, two-phase, permanent-magnet, stepping motor, loop

abstract:
 The analysis of stepping motors using linear models has been simplified through identifications of the constants. Though the existing nonlinear models assuming a smooth air-gap machine may, in some cases, yield a fairly close prediction of the characteristics of a stepping motor, the models do not represent the actual motors which are essentially salient-pole motors. A new salient-pole nonlinear model is introduced. The analysis of permanent-magnet stepping motors using the nonlinear models has been simplified by assuming constant current sources. Dynamic behaviors of a permanent -magnet stepping motor are shown by phase-plane plots and step by step transient response plots.

 Computer control of stepping motors in both open-loop and closed-loop is discussed. The open-loop control has been demonstrated to be successful and a closed-loop control system using light-sensors as feedback has been designed.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Human Rights and the Dignity of Basic Human Needs

contributor:
Sciaraffa, Stefan
Philosophy

abstract: The inextricability of the concept of dignity from the discourse on human rights suggests that the articulation of rights in terms of human dignity has both a cross-cultural resonance, and an intuitive appeal.  Each of the nine core human rights instruments put forward by the United Nations recognizes the inherent dignity of the human family. In order to determine what kind of guarantees these documents make and the bodies that are responsible for their fulfillment, the concept of dignity requires clarification.  This thesis appeals to the Rawlsian distinction between concept and conception, as well as the notion of reflective equilibrium in order to determine which set of principles ought to form the public conception.  The end toward which this project is oriented is not necessarily one of legal interpretation; rather, it is a normative reconstruction that may or may not be a legal inquiry.  Given the scope of the project, three conceptions of dignity are considered: James Griffin’s personhood-based conception of dignity, Martha Nussbaum’s capabilities-based conception, and David Miller’s needs-based conception.  Appealing to the Concluding Observations of state parties to the Covenant on Economic, Social and Cultural Rights, both personhood and capabilities-based conceptions of dignity are proven inherently exclusionary.  Insofar as it is an intuitively held judgment that human rights ought to be universal, the conceptions which justify the exclusion of certain individuals or demographics from the objects of rights fails to achieve reflective equilibrium.  I argue that a variant of David Miller’s needs-based conception of human dignity that I propose here is the most successful in achieving reflective equilibrium, and for that reason, it ought to inform our conception of human dignity.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: The concept of dignity is inextricable from the discourse on human rights.  This thesis focuses specifically on the concept of dignity within the context of the core international human rights instruments put forward by the United Nations.  In particular, it will demonstrate the importance of establishing a public conception of dignity within this context; one that justifies circumstances that are consistent with commonly held, intuitive judgments about rights.  It will be argued that neither an autonomy or personhood-based conception of dignity, nor a capabilities-based conception achieves this state of affairs.  Instead, this thesis will demonstrate that a needs-based conception of dignity ought to form the public conception.


title: The Fluorosulphuric Acid Solvent System

contributor:
Gillespie, R.J.
Chemistry

abstract: Title: The Fluorosulphuric Acid Solvent System, Author: Robert C. Thompson, Location: Thode

abstract:
A cryoscopic technique for the investigation of solutions in fluorosulphuric acid has been developed, and the cryoscopic constant for the solvent has been determined.

Conductimetric measurements, cryoscopic measurements and n.m.r. spectroscopic studies have been used to determine the mode and extent of ionization of antimony pentafluoride in fluorosulphuric acid. The reactions in fluorosulphuric acid of antimony pentafluoride with sulphur trioxide, and of boron trifluoride with sulphur trioxide have also been investigated.

Solutions of arsenic trifluoride in fluorosulphuric acid have been investigated by conductimetric measurements. Conductimetric and cryoscopic studies have been made on solutions of the supposed compound "2AsF·3S0".

Conductimetric and transport number measurements on solutions of barium fluorosulphate in fluorosulphuric acid have been used to calculate the mobility of the fluorosulphate ion. The mobility of the fluorosulphuric acidium ion has also been determined, and the autoprotolysis constant of fluorosulphuric acid calculated .

In order to obtain information on self-dissociation reactions of fluorosulphuric acid, cryoscopic studies were made on solutions of water, sulphur trioxide, and potassium fluoride.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Manufacturing Structure and Umemployment Rates

contributor:
Anderson, W.P.
Geography

abstract: Title: Manufacturing Structure and Unemployment Rates, Author: Richard G. Wilson, Location: Thode

abstract:
The purpose of this paper is to explain unemployment rates and their variability in nine Census Metroploitan Areas by means of industrial manufacturing structure. The period of analysis is from 1975 to 1983. Basic statistical/mathematical methods and stepwise regression analysis are utilized in the study. Three groups of independent variable measures
are developed: manufacturing subgroup breakdown; area specific
characteristics; and indices of concentration/diversification. The data is selectively pooled by labour force size and by structural similarity to increase the reliability of estimates from the short time series. The structural clustering produces the best results where the most powerful variables explaining unemployment rates are the area's average manufacturing wage and the index of durable goods concentration.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: Admittance Characteristics of Metal-Insulator-Semiconductor (MIS) and Semiconductor-Insulator-Semiconductor (SIS) Structures

contributor:
Shewchun, J.
Physics

subject: admittance, characteristics, metal, insulator, semiconductor, structures, thin film

abstract:
 This work presents theoretical calculations of some of the most important electrical characteristics of thin film, insulator-dominated semiconductor devices. Solutions of prespecified accuracy for an a.c. transmission line model of the semiconductor in such
configurations as the MIS (Metal-Insulator-Semiconductor) structure and the SIS (Semiconductor-Insulator-Semiconductor) structure are given. Together with an accurate solution of the d.c. bias problem, exact C-V (Capacitance-Voltage) and G-V (Conductance-Voltage) characteristics can be found at any frequency. SRH (Shockley-Reed-Hall) impurity centres and surface states have been included in both the d.c. and a.c. solutions. In addition, accurate studies of the low temperature dopant impurity response can be made since the d.c.
solution uses full Fermi integrals over arbitrary densities of states with the impurity dopant band treated like an SRH centre for the a.c. solution.

 In non-equilibrium situations, such as those which occur with the application of light or carrier injection by tunnelling, the a.c. solution requires active elements in the transmission line model but the transmission line can still be solved to a prespecified accuracy provided an accurate solution of the d.c. bias problem can be found. In this thesis the d.c. solution for the case of light-induced pair
production is considered under the assumption of bulk controlled d.c. quasi Fermi level shifts. Thus the accuracy of the related a.c. conductance and capacitance solutions is dependent on the reliability of this assumption.

 The detailed treatment of the a.c. admittance of the MIS structure is justified by its technological importance and fundamental insight gained on impurity centre and surface state effects.

 The other work presented in this thesis is devoted to a study of a new thin film device structure, the SIS diode. First, the a.c. admittance characteristics for the thick insulator case are predicted to a prespecified accuracy. Then a simple treatment for part of the SIS d.c. tunnelling problem is done to qualitatively
predict the effects of such parameters as doping density, temperature and insulator thickness on current-voltage characteristics. Finally, a simple generalization of the a.c. transmission line to include the effects of tunnelling is given which allows accurate solution for the a.c. admittance of tunnelling SIS diodes if the complete d.c. non-equilibrium problem can be accurately solved.

 Practical application of the thick-insulator SIS diode will undoubtedly stem from its wide range of interesting low and high frequency response characteristics. Among the most interesting of these characteristics is a bell-shaped high frequency C-V response previously unobserved in other two terminal devices.

 An interesting negative resistance feature, which partly resembles the negative resistance region of the p-n junction tunnel diode, is analyzed for the degenerate SIS p-i-n thin insulator structure. While the thick insulator SIS device has recently been fabricated and the bell-shaped high frequency response experimentally observed, experimental verification of the tunneling characteristics of the SIS diode has as yet not been fully realized.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Studies on Fraction I Protein

contributor:
McCalla, D. R.
Biology

subject: fraction I, protein, plants, electrophoretic mobilities, amino acid

abstract:
 Studies on the isolation and purification of Fraction I protein from various plants are described. Clear differences in the electrophoretic mobilities of Fr I from various species were observed. The genetic implication of observations on the electrophoretic mobilities of Fr I from wheat, rye and triticales are discussed. It is suggested that a non-chromosomal gene codes for
Fr I. Conclusions are drawn from the fingerprint, N-terminal amino acid, and amino acid analysis studies. The presence of ribulose diphosphate carboxylase activity in Fr I protein is also investigated.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Residual Stresses Produced During Sharp Bending of Wide Sheets

contributor:
Korol, Robert M.
Civil Engineering

subject: residual stresses, sharp bending, wide sheets, plastic metal

abstract:
 Manufacturing processes such as cold-bending flat sheet to a small radius produces a rather complex residual stress state through the thickness of light gauge structural steel sections. When the load-application device is released the sheet exhibits a phenomenon called "spring-back".

 The purpose of this research was to develop an exact method of computing the residual stresses in a wide sheet of ideal plastic metal after spring back and subsequently to study their effect on the behaviour of cold-formed sections. An approximate analysis based on the assumption of elastic spring back is presented for comparison purposes. It is demonstrated that plastic flow occurs within a thin core of sheet below the neutral axis and that the spring back is not completely elastic beyond a certain curvature. Such behaviour
is particularly significant in cases where the radius of bend is of the same order as the thickness. An exact analysis based on a more realistic approach is then performed considering the adjustments in the stress components due to the plastic core. Computer programs have been developed to calculate the residual stresses associated with any given radius of bend.
It is found that the choice of one yield criterion rather than the other does not have any effect on the present analysis and the stress components for Von Mises' material are (2/√3) times the components for Tresca's material. Furthermore, the effect of lateral stretching on the behaviour of cold-formed sections is briefly viewed.

 The purpose of the experimental work in this thesis was to verify the validity of some of the assumptions made in the analysis.

 Conclusions are drawn and suggestions made for further research.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Information Theory and Classification in Geography

contributor:
Webber, M. J.
Geography

subject: information theory, classification, geography

abstract:
 In this paper some fundamental concepts of information theory and their potential for classification construction in geography are discussed. The concepts of information and uncertainty are shown to be equivalent. Three different information measures are discussed
and the particular situations for which each is appropriate are identified. With this background the available literature on the application of information theory to classification is reviewed and reinterpreted. A classification algorithm for objects characterized by multistate ordinal attributes is presented and tested. Recommendations for further research include the consideration of explicitly spatial information measures and the examination of more general information metrics.

abstract: Thesis

abstract: Master of Arts (MA)


title: Body Temperature Regulation During Heat Stress in the Pregnant Rat

contributor:
Stricker, E. M.
Psychology

subject: body temperature, regualtion, heat stress, pregnant rat

abstract:
 Body temperature regulation at high ambient temperatures was compared in pregnant and non-pregnant female albino rats. At an ambient temperature of 40°C, pregnant rats maintained lower body temperatures than non-pregnant rats without added expenditure of moisture for evaporative cooling. This was surprising because of the increased heat load on the
pregnant animal resulting from a large weight gain and increased food intake. The maintenance of lower body temperatures in the heat by pregnant rats was possible because (1) pregnant rats produce less heat; i.e. consume less oxygen during exposure to 40°C than do non-pregnant rats and thus need to dissipate less heat; and (2) pregnant rats have a lower body temperature threshold for increased submaxillary salivary gland output in the heat, which makes more water for evaporative cooling available to them at lower body temperatures.

 The maintenance of lower body temperatures in the heat by pregnant rats suggests that pregnant rats have a need or a preference for lower body
temperatures in the heat. The change in body temperature regulation during pregnancy is likely related to physiological and anatomical changes in the body which accompany pregnancy. Alterations in body temperature regulation to meet the changed physiological state of pregnancy provide another example of the body's remarkable ability to maintain homeostasis.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Evapotranspiration Estimates from the Water Balance and Equilibrium Models

contributor:
Rouse, W. R.
Geography

subject: evapotranspiration, water balance, equilibrium models, soil moisture, heat exchange

abstract:
 This thesis examines the field performance of the water balance and equilibrium evapotranspiration models, and defines the environmental conditions for which they provided accurate estimates of water loss from a corn crop in Southern Ontario.

 It is shown that the water balance model should be used only when surface runoff is measured and drainage is negligible. An error analysis indicated that soil moisture change could be estimated within 10 percent when measurements were conducted at six sites every eight days.

 The equilibrium model predicted daily evapotranspiration within 6 percent when the latent heat exchange utilized between 65 and 80 percent of the available energy, indicating that the model can be applied within temperature limits of 17° and 32°C.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


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

abstract: Title: A Theoretical Analysis of the Velocity Fields in Eccentric Annuli, Author: Norman W. Wilson, Location: Thode

abstract:
A theoretical analysis of the velocity and wall shear stress distributions for fully developed turbulent flow in annular passages is reported in this thesis. The study was carried out for a range of eccentricities from 0 to 80 percent and for Reynolds numbers from 20,000 to
100,000 for a radius ratio of 1/3.5 with an inner radius of 0.25 inches. For the concentric case, the solution was found to be in agreement with experimental fact.

abstract: Thesis

abstract: Master of Engineering (ME)


contributor:
Crocket, J.H.
Geology

abstract: Title: The Protolith of the Carbonate Rich Rocks of the Larder Lake Break, Author: George M. Werniuk, Location: Thode

abstract:
The rocks of the Larder Lake Break at the Misema River road cut are predominantly schists, green carbonates, porphyries, lamprophyres, quartz and an iron formation. The schists and green carbonates have been metamorphosed, altered, and intruded by feldspar rich porphyries, lamprophyres, and quartz veins and stringers. The schists and green
carbonates are komatiitic in composition and are characterized by concentrations of iridium, nickel, and chromium which are similar to known values for relatively unaltered Precambrian ultramafic flows.

The presence of spinifex texture in schists and green carbonates suggests that these rocks were rapidly cooled crystal free ultramafic lavas.

Gold is preferentially concentrated in sulphur rich felsic porphyritic intrusions.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: Making Modern Families: Family Size and Family Planning in Northern Ghana

contributor:
Herring, D. Ann
Anthropology

subject: Medical Anthropology; Family Planning; Contraceptive Use; Ghana; West Africa; Ethnography; Qualitative; Biocitizenship

abstract:
This thesis draws on a political economy of fertility framework and the concept of biocitizenship to analyze changing family size and family planning among women and men in northern Ghana. I draw on a variety of ethnographic sources from eight months of fieldwork conducted under the umbrella of the Navrongo Health Research Centre in 2013 and 2014 in two rural communities in Kassena-Nanakana (K-N) West District in the Upper East region. The primary questions behind this thesis are: 1. How has the desire for smaller families emerged and to what is this transformation linked? 2. What role have family planning programs played in the reduction in family size?  Have they been the most important driver of the transition to smaller families? 3. What are the current ideas about family planning and contraceptives in K-N West? Are they gendered? How have they changed over time? 4. Are local views about family planning and contraceptives in K-N West in keeping with those of public health practitioners? These questions are addressed in this sandwich thesis in three papers, which have been submitted or accepted for publication.
     A major contribution of this thesis is its call for health programmes to pay greater attention to the social context of both women’s and men’s lives where family planning takes place. Contrary to existing public health studies, I argue that while health programming has affected fertility decline, larger social and economic shifts have been some of the most important drivers of women’s and men’s changing practices of family formation and views of contraceptives. In Kassena-Nakana West, the desire for smaller families is linked to processes such as decreasing levels of child mortality and agricultural productivity, as well as parents’ increasing focus on educating their children. In addition, the emerging concepts of responsible manhood and companionate marriage, combined with the decline of polygamy, have helped improve communication between husbands and wives about family planning.
     Narratives of changing family formation from Kassena-Nankana West expand understandings of biocitizenship by illustrating the important role intergenerational relationships play in the construction of “political economies of hope”. When young people adopt family planning, they not only consider the well-being of their own children and the larger community, but make the decision in the context of their aspirations for a more successful life than their parents experienced. Due to larger political-economic shifts, the majority of Kassena women and men today think family planning is beneficial; however, worries about the side effects of contraceptives remain. Women’s ongoing concerns about infertility and the stability of their marriages and men’s conditional acceptance of family planning also reveal that gender inequality persists. I argue that typical policy recommendations, which focus primarily on educating and sensitizing communities to increase the use of contraceptives are problematic in that they often focus on decreasing fertility and are not articulated within a broader, multi-sectoral agenda. Greater attention to local biologies and expanding reproductive rights and freedoms would improve existing family planning programs.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


contributor:
Kramar, J.R.
Geography

abstract: Title: Exchangeable Trace Ions in Lake Erie Sediments, Author: J.P. Witteman, Location: Thode

abstract: Sediment from Lake Erie was leached with distilled water to obtain exchangeable trace elements. Sediment factors considered were organic carbon, pH of leaching and clay composition. Organic carbon decreases with depth in the sediment. The pH remained nearly constant (6.2 - 9.2). Typical concentrations of leached metals are 5 - N50 ppb Zn, 15 - 75 ppb Cd, 6 - 200 ppb Cu, 8 - 34 ppb Cr, and 17 - 100 ppb Ni. The ratio of clay minerals, Kaolinite : Illite : Chlorite = 50 : 40 : 10. In all cores exchangeable trace ions highly correlated with organic carbon and both decrease with depth in the sediment .

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Hamielee, A.E.
Vladchopoulos, J.
Chemical Engineering

abstract: Title: Effect of Stabilizer on the Mechanical Properties of Rigid PVC, Author: Karl K.T. Woo, Location: Thode

abstract:
In this study commercial suspension polymerized polyvinyl chloride resin with different stabilizer contents was first compounded and injuctioned molded into small dumbbell shape specimens. Most of the specimens after annealing were then tested on the Instron Tensile Tester while the rest on iniature Tensile Tester for difference in mechanical properties. Four parameters from the stress-strain curves were of interest in this study: tensile yield stress, tensile modulus, elongation at fracture and ultimate fracture strength. The differences in mechanical properties were explained by the change in molecular structure of polyvinyl
chloride brought about by the reaction between the stabilizer and PVC molecules. In the second part of the experiment, the effects of heat treatment and molecular weight on the mechanical properties of rigid PVC were also investigated.

abstract: Thesis

abstract: Master of Engineering (ME)


contributor:
Crocket, J.H.
Chemistry

abstract: Title: Mn and S34 Partitioning in Sulphides a Comparison of Two Geothermometers, Author: Robert L. Wright, Location: Thode

abstract:
Sulphide samples from high and low temperature environments were used to compare two recently calibrated geothermometers: 1) The distribution of MnS between coexisting galena and sphalerite. 2) ThR fractionation of sulphur isotopes between coexisting
sulphide minerals, The manganese analyses were done by two neutron activation procedures. For the high temperature environment, the MnS temperatures are significantly lower than the sulphur isotope temperatures; these results are reasonable if one accepts an hypothesis of limited subsolidus re-equilibratior of sulphur isotopes, but extensive redistribution of
manganese. The sulphur isotope results for the low temperature deposit are also acceptable, but the manganese temperatures are too high, due to analytic errors (resulting from low concentrations and possible contamination), or to lack of equilibrium in the samples themselves.

The extension of the sulphur isotope geothermometer to low
temperatures (100-200°C) appears to be justified, whereas the results for the MnS geothermometer are inconclusive.

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Duckworth, H.E.
Physics

abstract: Title: Energy Loss in Condensed Matter of H1 and He4 in the energy Range 4<E<30 keV, Author: Arie van Wijngaarden, Location: Thode

abstract:
Measurements are reported of the energy loss suffered by H1 and He4 particles, of 4-30 keV energy, in passing through thin films of carbon, aluminumoxide and VYNS. Only those particles that emerged in the forward direction were studied. Evidence is presented for identifying the stopping cross-sections per atom observed in this way with Se, the electronic
component of the total stopping cross-section per atom. It appears that the calculated energy dependence of Se(∞√E) is somewhat in error, and that the magnitudes of these's for He4 are systematically too small by 10-15%.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: M-Sets and Automata

contributor:
Willis, V.J.
Davison, T.M.K.
Mathematics

abstract: Title: M-Sets and Automata, Author: Richard J. Wood, Location: Thode

abstract:
This thesis attempts to provide a more algebraic foundation for the study of automata. Specifically, a category containing the category of finite state semiautomata is investigated. It is shown that the push down automata of Ginsburg can be treated in a way consistent
with a categorical program, and a new characterization of context-free languages is thus obtained.

abstract: Thesis

abstract: Master of Science (MS)


contributor:
Campbell, C.K.
Electrical Engineering

abstract: Title: Practical Filters Using Distributed RC Structures, Author: Edmund J. Wragg, Location: Thode

abstract:
Theoretical and experimental studies into practical filters using distributed RC structures are described. Various techniques to surmount the transcendental nature of the circuit parameters of such structures are considered and shown to be mostly too clumsy or restricted for practical use. The use of computer-aided analysis together with a sound physical understanding is suggested as an alternative.

Application of the structures to active filters is considered and the experimental development of lowpass and bandpass amplifiers using them described. This leads to the presentation of a general design procedure for bandpass amplifiers using distributed RC null circuits.

It is concluded that distributed RC filters suffer from a number of limitation but have a part to play as a circuit element and are now ready to advance to the stage of practical implementation.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Protein Arginine Methyltransferase Expression, Localization, and Activity During Disuse-induced Skeletal Muscle Plasticity

title: PRMT BIOLOGY DURING SKELETAL MUSCLE DISUSE

contributor:
Ljubicic, Vladimir
Kinesiology

subject:
PRMT
skeletal muscle plasticity
atrophy
Protein Arginine Methyltransferase
disuse

abstract: PRMT biology during skeletal muscle disuse.

abstract:
Protein arginine methyltransferase 1 (PRMT1), PRMT4 (also known as
co-activator-associated arginine methyltransferase 1; CARM1), and PRMT5 are
critical components of a diverse set of intracellular functions. Despite the limited
number of studies in skeletal muscle, evidence strongly suggests that these
enzymes are important players in the regulation of phenotypic plasticity. However,
their role in disuse-induced muscle remodelling is unknown. Thus, we sought to
determine whether denervation-induced muscle disuse alters PRMT expression
and activity in skeletal muscle within the context of early signaling events that
precede muscle atrophy. Mice were subjected to 6, 12, 24, 72, or 168 hours of
unilateral hindlimb denervation. The contralateral limb served as an internal
control. Muscle mass decreased by ~30% following 168 hours of disuse. Prior to
atrophy, the expression of muscle RING finger 1 and muscle atrophy F-box were
significantly elevated. The expression and activities of PRMT1, CARM1, and
PRMT5 displayed differential responses to muscle disuse. Peroxisome
proliferator-activated receptor-γ coactivator-1α, AMP-activated protein kinase
(AMPK), and p38 mitogen-activated protein kinase expression and activation
were altered as early as 6 hours after denervation, suggesting that adaptations in
these molecules are among the earliest signals that precede atrophy. AMPK
activation also predicted changes in PRMT expression and function following
disuse. Our study indicates that PRMTs are important for the mechanisms that
precede, and initiate muscle remodelling in response to neurogenic disuse.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Skeletal muscle is a plastic tissue that is capable of adapting to various
physiological demands. Previous work suggests that protein arginine
methyltransferases (PRMTs) are important players in the regulation of skeletal
muscle remodelling. However, their role in disuse-induced muscle plasticity is
unknown. Therefore, the purpose of this study was to investigate the role of
PRMTs within the context of early, upstream signaling pathways that mediate
disuse-evoked muscle remodelling. We found differential responses of the
PRMTs to muscle denervation, suggesting a unique sensitivity to, or regulation by,
potential upstream signaling pathways. AMP-activated protein kinase (AMPK)
was among the molecules that experienced a rapid change in activity following
disuse. These alterations in AMPK predicted many of the modifications in PRMT
biology during inactivity, suggesting that PRMTs factor into the molecular
mechanisms that precede neurogenic muscle atrophy. This study expands our
understanding of the role of PRMTs in regulating skeletal muscle plasticity.


title: On Fractionally-Supervised Classification: Weight Selection and Extension to the Multivariate t-Distribution

contributor:
McNicholas, Paul D.
Mathematics and Statistics

subject: Fractionally Supervised Classification, Clustering, Discriminant Analysis, Mixture Models

abstract: Recent work on fractionally-supervised classification (FSC), an approach that allows classification to be carried out with a fractional amount of weight given to the unla- belled points, is extended in two important ways. First, and of fundamental impor- tance, the question over how to choose the amount of weight given to the unlabelled points is addressed. Then, the FSC approach is extended to mixtures of multivariate t-distributions. The first extension is essential because it makes FSC more readily applicable to real problems. The second, although less fundamental, demonstrates the efficacy of FSC beyond Gaussian mixture models.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Novel Framework Using Brain Computer Interfacing & EEG Microstates To Characterize Cognitive Functionality

contributor:
Noseworthy, Michael D.
Connolly, John F.
Biomedical Engineering

subject:
Brain Computer Interfacing
Microstates
Resting State Networks
EEG-fMRI
Multimodal

abstract: The rapid advancements in the field of machine learning and artificial intelligence has led to the emergence of technologies like the Brain Computer Interface (BCI), which has revolutionized rehabilitation protocols. However, given the neural basis of BCIs and the dependence of its performance on cognitive factors, BCIs may be used to characterize the functional capacity of the user. A resting state segment can also be considered for characterization of the functional network integrity, creating a two part framework that probes the functional networks and their cognitive manifestations. This thesis explores such a two part framework using a simultaneous EEG-fMRI setup on a healthy population. The BCI accuracies for all subjects increased over the course of the scan and is thought to be due to learning processes on the subject's part. Since such learning processes require cognitive faculties such as attention and working memory, these factors might modulate the BCI performance profile, making it a potential metric for the integrity of such cognitive factors. The resting state analysis identified four EEG Microstates that have been previously found to be associated with verbal, visual, saliency and attention reorientation tasks. The proportion of each microstate that composed the corresponding fMRI resting state networks (RSN) were identified, opening up the potential for predicting fMRI-based RSN information, from EEG microstates alone. The developed protocol can be used to diagnose potential conditions that negatively affect the functional capacity of the user by using the results from this study as healthy control data. This is the first known BCI based system for characterization of the user's functional integrity, opening up the possibility of using BCIs as a metric for diagnosing a neuropathology.

abstract: Thesis

abstract: Master of Applied Science (MASc)


contributor:
Morrison, J.A.
Chemistry

abstract: Title: Orientational Ordering in Solid Methane at Low Temperatures, Author: Mary A. White, Location: Thode

abstract:
The solid isotopic methanes (CHnD4-n, 0 ≤ n ≤ 4) are
known to exist in at least three solid phases, called phases
I, I I and III in order of decreasing temperature domain. There
have been many studies, both experimental and theoretical, of
the properties of solid methane, and the structures of phases
I and II are known. In phase I, the molecules form a face-centered
cubic lattice, and are freely, or nearly freely,
rotating on the lattice sites. In phase II, the solid has a
complex sublattice structure: 3/4 of the molecules arc orientationally
ordered and 1/4 are orientationally disordered. The
structure of phase III is not known, and one of the main aims
of this thesis is to draw conclusions about the orientational
order in this phase.

The heat capacities of isotopically purified CH2D2,
CHD3 and CD4 were measured accurately in the temperature range
0.15K ≤ T ≤ 3.5K where Schottky anomalies were known to occur
in the partially deuterated methanes. From the heat capacity
measurements, the residual entropies at T= 0K of CH2D2 and
CHD3 were determined, and used to deduce that phase III is not
classically orientationally ordered, and that it must contain
at least three different sublattices . The latter conclusion
is in agreement with that of recent theoretical calculations
and optical measurements on solid methane. A model is
presented which accounts for the low temperature thermal
properties of the solids.

Nuclear spin symmetry species conversion is known to
occur in CH4 and CH3D but the present measurements show that
it is not significant in CH2D2 or CHD3. In CD4 on the other
hand, longer thermal relaxation is found and it may be ascribable
to conversion.

The positions and shapes of the Schottky anomalies in
the deuterated methanes are used to ma~e estimates of the tunnel
level splitting these results are compared with those of
recent neutron inelastic scattering experiments for CD4 , and
with theoretical estimates for all of ·the deuterated methanes.

In a different type of experimental investigation, the
relationship between the temperatures of the solid-solid phase
transitions and thermally-stimulated luminescence of electron and
ultraviolet-irradiated methane (CH 4 and CD 4) was probed.
Under certain conditions, a correlation was found to exist
between the phase transition temperatures and sharp peaks in
the glow curves, but thermal gradients in the samples preclude
the use of this method for kinetic analysis of the phase
transitions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Sing, Pan, Code: Enhancing Audience Engagement Through Choral, Algorithmic, and Photographic Crossings

rights: An error occurred getting the license - uri.

subject:
Photography
Choral Music
Mobile Devices
Audience Engagement

abstract: In this project, I explore crossings of panoramic photography, choral music, and mobile device art, through the creation of four interactive artworks: PeaceWeave, Sedimentary, ReptileChoir, and StreetSong. Given an artistic vocabulary of flowing geo-panoramic photography, along with the transparent technical affordances of a networked mobile device platform, audience-performer engagement in choral contexts may be enhanced.


title: Evaluation of Diffuse Reflectance Spectroscopy and Fluorescence Spectroscopy for Detection of Glioma Brain Tumors

contributor:
Fang, Qiyin
Medical Physics

subject: optical properties; diffuse reflectance spectroscopy (DRS); fluorescence spectroscopy; glioblastoma multiform (GBM); low grade glioma (LGG);

abstract:
Imaging instruments are required for accurate tumor resection during neurosurgery, especially in the case of glioblastoma multiforme (GBM) - the most common and aggressive malignant glioma. However, current intraoperative imaging techniques for detection of glioma either suffer low sensitivity and low specificity or require a significant capital cost. Advances in diffuse reflectance spectroscopy and fluorescence spectroscopy have offered high sensitivity and high specificity in differentiating tumors from normal tissues with much lower capital cost. Whereas diffuse reflectance spectroscopy alone and fluorescence spectroscopy alone has been used in limited studies to differentiate normal brain tissues from brain tumors with moderate sensitivity and specificity, low specificity and sensitivity were usually observed when studying high grade glioma (HGG) such as GBM. Furthermore, optical properties and diffuse reflectance signal of HGG and low grade glioma (LGG) have not been observed separately, and thus a relation between optical properties and glioma progression has not been established. Intraoperative differentiation of GBM and LGG can be helpful in making treatment plan at the first surgery.
This thesis focuses on characterizing a previous integrated system of diffuse reflectance spectroscopy and fluorescence spectroscopy to extract optical properties and fluorescence properties of LGG and GBM. First, tissue-simulating phantom models were developed to calibrate the integrated system. The direct method and Mie theory were used to calculate optical scattering of the phantoms while Beer-Lambert’s law was used to calculate optical absorption. Second, an experimental method was introduced to recover intrinsic fluorescence because the measured fluorescence signal is likely distorted by the presence of scatterers and absorbers in tissue (i.e. hemoglobin). Third, an experimental method was developed to recover optical properties of both GBM and LGG. In addition, the sensitivity and specificity of the integrated system was optimized.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Brook, Michael A.
Pelton, Robert H.
Chemical Engineering

abstract: Title: Bioactive Titania Colloidal Particles: Preparation, Characterization and Applications, Author: Lucy Ye, Location: Thode

abstract:
Photocatalytic TiO2, used for oxidizing organic compounds and biological entities, has
been extensively studied. However, biomolecules conjugated to photocatalytic TiO2
colloidal particles and their applications have rarely been reported. In this work, a novel
platform for fabricating biomolecules conjugated to TiO2 using biotin-streptavidin/avidin
bioconjugation and biotin coated photocatalytic TiO2 was developed and the properties
and applications of the biomolecules conjugated photocatalytic TiO2 colloidal particles
were studied. Photocatalytic TiO2 particles were treated with 3-aminopropyltriethoxysilane (APTS)
and then N-hydroxysuccinimidobiotin (NHS-biotin) to give a biotin coating. The
resulting aminosilanized and biotinylated TiO2 particles were characterized by a variety
of methods, including nuclear magnetic resonance spectroscopy (NMR), Fourier
transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM),
electrophoretic mobility, light diffraction, nitrogen adsorption, polyelectrolyte titration,
conductometric titration, biotin assays, X-ray photoelectron spectroscopy (XPS), and
confocal laser scanning microscopy (CLSM), giving insight into the strategies necessary
to control the density of grafted amino groups, organosilane thickness, and surface
charges of the resulting aminosilanized TiO2. Ultimately, the key parameters for
photocatalytic performace relied on the ability to tune the surface modification reaction,
and the conditions for conjugating the biotinylated TiO2 to streptavidin.
The impact of UV irradiation to the aminosilanized cationic TiO2 colloidal particles
was studied. The results show that an oxidization reaction occurs on TiO2 surfaces,
resulting in the removal of the amino groups and the change of surface charge from
positive to negative. A new light-triggered flocculation system was developed based on
this surface charge conversion. Biomolecules conjugated to colloidal titania particles exhibit combined properties of
the biological functions of bound biomolecules and the photocatalytic properties of titania.
Two applications related to biomolecules conjugated photocatalytic TiO2 were studied in
this work. One is the selective binding and killing of bacteria by using antibody coated
photocatalytic TiO2 under UV irradiation. The antibody-TiO2 was prepared by coupling
biotinylated TiO2 particles to biotinylated Escherichia coli (E. coli) antibody with
streptavidin. In a medium containing antibody-TiO2 particles, E. coli, and Pseudomonas
putida (P. putida), when UV irradiation is applied, the selective binding and killing of E.
coli was confirmed by electrophoretic mobility measurement, turbidity tests, optical
microscopy, scanning electron microscopy (SEM), confocal microscopy, and plate
counting. The other application is the immobilization of TiO2 particles on cellulose fibers
with a homogeneous distribution through multi-linker bioconjugation of CBM2a-Streptag
II/streptavidin/biotinylated TiO2. The immobilized TiO2 efficiently decolorizes UV
sensitive dye within about 10 hours, demonstrating the efficiency of photocatalysis of the
resulting TiO2-containing paper.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Exploring the effects of chronic vitamin C deficiency in a mouse model of Her2-positive breast cancer

contributor:
Schellhorn, Herb
Biology

abstract: Vitamin C (VC) is an antioxidant that humans must include in their diet to prevent scurvy. High intake of VC may reduce the incidence of some types of cancer, and high-dose intravenous VC is an alternative cancer therapy. In this study, we used a genetically modified mouse to model the effects of chronic VC deficiency in breast cancer. Mice were fed either a low-dose or normal-dose VC diet, and were monitored for cancer development. We found that there was no difference in tumour characteristics between the mice that received low-dose versus normal VC supplementation. The results of this study suggest that chronic VC deficiency   may not have an effect in this specific type of breast cancer.

abstract: Thesis

abstract: Master of Science (MSc)


title: Solid State Speed Control of a Squirrel-Cage Induction Motor

subject: solid, state, speed control, squirrel-cage, induction motor, variable-frequency

abstract: The speed of a squirrel-cage induction motor is controlled by varying the supply frequency. The design of an SCH controlled inverter, using gating from a logic unit to give a variable-frequency power-level output, is described.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: The  BMI: Measurement, Physician Costs and Distributional Decomposition

contributor:
Sweetman, Arthur
Contoyannis, Paul
Health Policy

subject: BMI, body mass index, measurement, correction, physician costs, distributional decomposition

abstract:
This thesis comprises three chapters involving the analysis of the body mass index (BMI) in
health economics. The first chapter evaluates two correction models that aim to address
measurement error in self-reported (SR) BMI in survey data. This chapter is an addition to the
literature as it utilizes two separate Canadian datasets to evaluate the transportability of these correction equations both over time and across different datasets. Our results indicate that the older method remains competitive and that when BMI is used as an independent variable, correction may even be unnecessary. The second chapter measures the relationship between long-term physician costs and BMI. The results show that obesity is associated with higher longterm physician costs only at older ages for males, but at all ages for females. We find that accounting for existing health conditions that are often associated with obesity does not explain the increase in long-term physician costs as BMI increases. This indicates that there is an underlying relationship between the two that we could not account for in our econometric models. Finally, the third chapter decomposes the differences in BMI distributions of Canada and the US. The results show that the differences between BMI levels, both over time and across countries, are increasing with BMI; meaning the highest difference is observed at the right tail of the two distributions. In analysis comparing two points in time, these differences are solely due to differences in the returns from attributes and the omitted variables that we cannot account for in our models. In cross-country analysis, there is evidence that the differences observed below the mean can be explained by the differences in characteristics of the two populations. The differences observed above the mean are again due to those in returns and the omitted variables.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Distributed Vehicle Routing Approximation

contributor:
Bonakdarpour, Borzoo
Computing and Software

subject: VRP, NP-Complete, Distributed

abstract: Distributed Approximation

abstract:
The classic vehicle routing problem (VRP) is generally concerned with the
optimal design of routes by a fleet of vehicles to service a set of customers by
minimizing the overall cost, usually the travel distance for the whole set of
routes. Although the problem has been extensively studied in the context of
operations research and optimization, there is little research on solving the VRP,
where distributed vehicles need to compute their respective routes in a
decentralized fashion. Our first contribution is a synchronous distributed
approximation algorithm that solves the VRP. Using the duality theorem of
linear programming, we show that the approximation ratio of our algorithm is
$O(n . (\rho)^{1/n} .log(n+m))$, where $\rho$ is the maximum cost of
travel or service in the input VRP instance, $n$ is the size of the graph, and
$m$ is the number of vehicles. We report results of simulations comparing our algorithm results with ILP solutions and a greedy algorithm.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The Open Multi-Depot Vehicle Routing Problem(OMDVRP) problem is solved using an synchronous distributed algorithm and the approximation ratio is found and simulation results comparing the performance of ILP , greedy and the designed algorithm is done.


title: A Data Assimilation Scheme for the One-dimensional Shallow Water Equations

contributor:
Kevlahan, Nicholas
Applied Mathematics

subject: Data assimilation, optimal control, adjoint, initial condition, cost function, noise distortion, amplitude distortion

abstract:
For accurate prediction of tsunami wave propagation, information on the system of PDEs modelling its evolution and full initial and/or boundary data is required. However the latter is not generally fully available, and so the primary objective becomes to find an optimal estimate of these conditions, using available information. Data Assimilation is a methodology used to optimally integrate observed measurements into a mathematical model, to generate a better estimate of some control parameter, such as the initial condition of the wave, or the sea floor bathymetry. In this study, we considered the shallow water equations in both linear and non-linear form as an approximation for ocean wave propagation, and derived a data assimilation scheme based on the calculus of variations, the purpose of  which is to optimise some distorted form of the initial condition to give a prediction closer to the exact initial data. We considered two possible forms of distortion, by adding noise to our initial wave, and by rescaling the wave amplitude. Multiple cases were analysed, with observations measured at different points in our spatial domain, as well as variations in the number of observation points. We found that the error between measurements and observation data was sufficiently minimised across all cases. A relationship was found between the number of measurement points and the error, dependent on the choice of where measurements were taken. In the linear case, since the wave form simply translates a fixed form, multiple measurement points did not necessarily provide more information.
In the nonlinear case, because the waveform changes shape as it translates, adding more measurement points provides more information about the dynamics and the wave shape.  This is reflected in the fact that in the nonlinear case adding more points gave a bigger decrease in error, and much closer convergence of the optimised guess for our initial condition to the exact initial wave profile.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: In ocean wave modelling, information on the system dynamics and full initial and/or boundary data is required. When the latter is not  fully available the primary objective is to find an optimal estimate of these conditions, using available information. Data Assimilation is a methodology used to optimally integrate observed measurements into a mathematical model, to generate a better estimate of some control parameter, such as the initial condition of the wave, or the sea floor bathymetry. In this study, we considered the shallow water equations in both linear and non-linear form as an approximation for ocean wave propagation, and derived a data assimilation scheme to optimise some distorted form of the initial condition to generate predictions converging to the exact initial data. The error between measurements and observation data was sufficiently minimised across all cases. A relationship was found between the number of measurement points and the error, dependent on the choice of where measurements were taken.


title: Self-assembled nanogels of hydrophobized methylcellulose

contributor:
Sheardown, Heather
Biomedical Engineering

abstract:
Topical administration is the most common method to deliver ocular therapeutics. However, the eye is highly resistant to foreign substances and its clearance mechanisms effectively remove drug, significantly limiting the efficiency of common topical formulations. In the search for improved ocular bioavailability, particle based delivery systems have arisen as a promising strategy to overcome these limitations while retaining the patient friendly aspects of topical formulations. Nanoparticles can be formed via the self-assembly of amphiphilic molecules into nano-sized aggregates consisting of hydrophilic networks crosslinked with hydrophobic domains and referred to as “nanogels”. The work presented in this thesis focuses on the design, synthesis and optimization of novel nanogels ultimately intended to improve the efficiency of the delivery of therapeutics to the eye. Methylcellulose, a hydrophilic, non-toxic and biodegradable natural biomaterial, has been extensively investigated for biomedical applications, including ocular applications, and was therefore the polymer of choice for the work. We first describe the synthesis of nanogels via self-assembly of methylcellulose (MC) hydrophobized with side chains of poly(N-tert-butylacrylamide) (MC-g-PNtBAm), and demonstrate that their properties can be tuned by adjusting the degree of hydrophobic grafting (Chapter 2). The results show the formation of stable monodispersed spherical
particles of ~140 nm, presenting good cytocompatibility with human corneal epithelium cells. The impact of the methylcellulose molecular weight on the nanogel properties is investigated and the results demonstrate that the polysaccharide backbone length provides another lever to tailor the performances of the nano-aggregates as drug delivery systems (Chapter 3). These materials show the ability to encapsulate dexamethasone with an efficiency superior to 95% and release their payload for over 30 days. Phenylboronic acid (PBA) functionalization is introduced on the surface of the nanogels to improve their mucoadhesiveness and thereby prolong their residence time on the surface of the eye (Chapter 4). Dexamethasone release from the grafted particles is maintained over 12 days, with the results indicating that the additional PBA layer reduce the initial burst. In terms of mucoadhesion, zeta-potential measurements suggest interaction of some nanogel formulations with mucin. Finally, the surface of the nanogels is covered with chains of poly(ethylene glycol) (PEG) and the effect of PEGylation on the pharmacokinetics and mucoadhesive properties is studied (Chapter 5). PEG functionalization is found to significantly slow the release of dexamethasone phosphate from 1 day to over 8 days, and zeta-potential results also suggest coverage-dependant mucoadhesive properties. These materials show promise for the delivery of drugs to the anterior segment of the eye.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Influence of Hand Position on Prior Entry

contributor:
Shore, David I.
Psychology

subject:
Psychology
prior entry
multisensory perception
crossed-hands

abstract: Attended information is perceived quicker than unattended information. This is known as prior entry. When making judgments on the temporal order of two successive stimuli, performance is influenced based on attention. We were interested in whether this same attentional shift would occur when we adopt a crossed hands posture. Typically when making these tactile temporal order judgments, performance declines when the hands are crossed. This may be due to a greater influence of the external environment in the crossed posture. We investigated this by providing an exogenous visual cue at one or both of the hands prior to making judgments about the temporal order of two successive vibrations. This was completed with the hands crossed and uncrossed. In Experiment 1 responses were to which stimulus occurred first. In Experiment 2 participants responded to which stimulus occurred second. Changing the response requirement did not influence overall performance. In both experiments we observed prior entry that was in the same direction for both crossed and uncrossed postures. The size of the prior entry effect was larger when the hands were crossed. We remap tactile information quickly to external coordinates, however we are less certain of the hand’s location.

abstract: Thesis

abstract: Master of Science (MSc)


contributor:
Tlusty, J.
Mechanical Engineering

abstract: Title: Some Aspects of Tool Wear and Machinability of Free-Machining Steels, Author: K.L. Verma,  Location: Thode

abstract:
Machinability is a key factor for the profitability and is an elusive  variable specially for automatic machining operations. Metallurgists faced with this subjective requirement have nevertheless succeeded in developing a number of modifications to the base alloys that do possess superior machinability. These modified alloys are commonly known as Free-Machining Steels or Free-Cutting Steels.

The report commences with a general description of the mechanism by which three different types of manganese sulphide inclusions are formed in resulphurized steel. Both the selected free-machining steels have globular type of inclusions and probably are of Type I. Lead phase in leaded resulphurized steel exists in association with sulphide inclusions or free lead particles. Tests have shown that the free-machining additives
have a negligible effect on the mechanical properties of steel.

The results on the comparative machinability of plain carbon steel and free-machining steels, under a wide range of cutting conditions, have revealed a clear difference in machinability. Free-machining steels are much superior to unmodified steels. This conclusion is based on the following criteria: tool wear, cutting forces, built up edge, shear angle, contact length, and surface finish produced.

It is evident from the microscopic analysis of the chips produced during the cutting process that the free-machining steels have decreased chip thickness, decreased roughness
at the back of the chip, and decreased wipe-down, than the plain carbon steel. All these factors are in favour of better machinability.

Finally, it is concluded that the leaded resulphurized steel (12L15) is superior than straight resulphurized steel (1215) below a certain critical speed. It is proposed that this critical speed is directly related to the cutting temperature, which is a function of cutting variables.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Synthesis of three carbon homologated unsaturated aldehydes using regioselective Wittig olefination chemistry

contributor:
McNulty, James
Chemistry and Chemical Biology

subject: Organic chemistry

abstract:
Unsaturated aldehydes are widely used in the synthesis of natural products and pharmaceutical molecules.18,19,20 Among various methods available in the literature, carbon homologation is a common reaction employed for the synthesis of unsaturated aldehydes. Wittig reaction has emerged as a very useful method for making homologated unsaturated aldehydes. The use of classical Wittig reaction is not desirable on a commercial scale due to the formation of the by-product triphenylphosphine oxide which is insoluble in water and generally difficult to remove.
Use of alkyl phosphine reagents is one of the research interests in our group. Previously in our group, alkylphosphonium salts were successfully used in the Wittig reaction for the one and two carbon homologations.15 The trialkylphosphine oxide by-product is water soluble and can be easily removed.
In this thesis, the three carbon homologation of aldehydes using (2-(1, 3-dioxolan-2-yl)ethyl)tripropylphosphonium bromide is described. The ylide formation is highly regioselective. A variety of aromatic and hetero aromatic aldehydes are homologated with good stereo selectivity. An attempt to synthesize the cytotoxic natural product (2R,3R,4R)-3,4-dihydro-3,4-dihydroxy-2-(3-methylbut-2-enyl)-1(2H)-naphthalenone using the homologated aldehyde is also illustrated.

Finally, the development of new synthetic routes for tricyclohexylphosphine is described. Tricyclohexylphosphine is used as a ligand in many important complexes which include the olefin metathesis Grubbs' catalyst and the homogeneous hydrogenation Crabtree's catalyst. It is synthesized generally from phosphorus trichloride and cyclohexylmagnesium bromide.  It is also synthesized by hydrogenation of triphenyl phosphine with a niobium catalyst.  Nevertheless, a new commercially viable synthesis possesses greatest advantage in the use of tricyclohexylphosphine.

abstract: Thesis

abstract: Master of Science (MSc)