title: Novel guar crosslinkers for improved ophthalmic solutions

contributor:
Pelton, Robert
Chemical Engineering

subject: Dry Eye, Eye Drop, artificial tear, Hydrophobically modified polymer, Protein, Albumin, Lysozyme, QCM-D, Emulsion, Adsorption, Weak Gelation, Guar

abstract:
In-situ chain extension of polymers used in the formulation of artificial tears and mild gelation are techniques to increase the residence time of eye drops on cornea.  In-situ chain extension also helps to control the stability of ophthalmic emulsions both in the bottle and in the tear film. In this work, the interaction of hydrophobically modified guar and tear proteins as a method of polymer chain extension and mild gelation has been evaluated. Guar and its derivatives have been found to be very effective for ophthalmic applications. The ideal guar gelation agent is the one that turns on the gelation upon introduction onto the eye and that gelation chemistry is biocompatible and biodegradable. Controllable gelation is desirable to have relatively low viscosity eye drops for easy application and the drops form weak gels in the eye.
One recent strategy to cure dry eye disease is to include emulsions in lubricant eye drops.  The idea is to supplement the natural lipid layer on the exterior surface of the tear film. Formulating artificial tear emulsions is relatively complicated and must satisfy conflicting criteria.  Emulsion droplets should be stable over the period of their shelf life without creaming or aggregate formation. On the other hand, in the tear film the emulsion droplets must cream fast enough and deposit onto the water/lipid film interface on the exterior surface of the tear film. Thus, the emulsion must be stable but not too stable. Initially, science-based design rules were proposed for the development of future generations of lubricant eye drops. The effect of guar molecular weight and concentration on emulsion stability was evaluated. According to the concentration-molecular weight plot, polymer solutions can be divided into stable and unstable regions. They are defined based on the critical flocculation concentration (CFC) and critical viscosity concentration (C*). Inverted QCM-D has been proposed as a simple and fast method to define the stability of oil in water emulsion systems. This technique is a promising alternative for time consuming conventional creaming experiments.
Low molecular weight guar can be optimized to out-perform high molecular weight guars without the complications of formulating eye drops with high molecular weight polymers. Hydroxypropyl guar samples were oxidized and modified with linear alkyl amines to give a series of hydrophobically modified guars (MGuars). Lysozyme and human serum albumin (HSA), natural tear proteins, are able to extend the effective chain length of MGuar through polymer/protein complex formation. Hydrophobic modifications on guar enable efficient interaction with proteins, through their mutual hydrophobic characteristics. The interaction of proteins with various alkyl chain lengths, degrees of substitution and a range of molecular weights were examined. Binding and rheological measurements were employed to evaluate the interactions efficiency. Our results suggest that higher degrees of substitution and longer alkyl chain length give higher viscosity values. Lowering molecular weight allows for higher concentration, while keeping the initial viscosity constant. Higher viscosity was achieved as the chain extension occurred. The influence of hydrophobic modification and molecular weight variation on lubrication behavior of MGuars has also been determined. Hydrophobic modification enhanced the lubrication between hydrophobic surfaces. However, saturation of hydrophobes with protein abolished the lubricity.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The impact of recent high-risk coronary artery disease on major vascular complications after non-cardiac surgery

title: HIGH-RISK CAD & VASCULAR OUTCOMES WITH NON-CARDIAC SURGERY

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
perioperative
high-risk CAD
surgery

abstract: Recent high-risk coronary artery disease (CAD), defined as Canadian Cardiovascular Society (CCS) class III or IV angina or acute coronary syndromes (ACS) unstable angina, is independently associated with increased mortality and morbidity following non-cardiac surgery. It remains unclear how the components of high-risk CAD, use of stents and timing of surgery after a high-risk CAD event is associated with risk. This project will address these issues and how they affect current perioperative medicine.

abstract: Thesis

abstract: Master of Science (MSc)


title: THE ROLE OF ATTRIBUTION AND FAIRNESS IN UNDERSTANDING JOB APPLICANT REACTIONS TO SELECTION PROCEDURES AND DECISIONS

contributor:
HACKETT, RICK D.
Business Administration

subject: APPLICANT-ATTRIBUTION-REACTION THEORY, JOB APPLICANT, SELECTION, AART, JOB ACCEPTANCE

abstract: Drawing upon Applicant-Attribution-Reaction Theory (AART) and research in the area ofjob applicant reactions, this study clarifies and underscores the influence of attributions on job applicant perceptions and behavioural reactions to staffing procedures and decisions. Overall, applicant attributions were influenced by: (a) experiencing a staffing process that satisfies/violates procedural justice rules; (b) receiving a favourable (selected) or unfavourable (rejected) selection outcome; and (c) receiving an explanation for a selection decision. Results further suggest that applicant attributions, influence applicant perceptions and behaviours. Consistent with AART's predictions, process fairness perceptions mediated relationships between applicant attributions and each of organizational perceptions, recommendation intentions, litigation intentions, job acceptance intentions, and reapplication intentions. Theoretical and practical implications for these findings are discussed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Sequence Design and Contrast Optimization of Susceptibility Weighted Imaging

contributor:
Haacke, E. Mark
Wong, Max
Electrical and Computer Engineering

subject:
Susceptibility Weighted Imaging
MRI
susceptibility difference
contrast to noice ratio
voxel
imaging parameters

abstract:
Susceptibility Weighted Imaging (SWI) utilizes the susceptibility difference
between tissues to create a new type of imaging contrast in MRI that is different from conventional spin density, T1-, or T2-weighted imaging. The SWI sequence is a high resolution, fully flow compensated gradient echo sequence. High resolution reduces the signal loss caused by local field inhomogeneities yet with relatively long echo time sufficient contrast can be generated between tissues with a susceptibility difference. Contrast between tissues in the phase image is directly proportional to the susceptibility difference and can be used to enhance the contrast in the magnitude image. In this thesis, we optimize the contrast to noise ratio (CNR) in the magnitude image as a function of the multiplication of the phase mask generated from the phase image. We find that a shorter echo time has the advantage of achieving higher CNR efficiency compared with longer echo times. SWI has found numerous clinical applications due to its sensitivity to blood products. Partial volume effects occur when a voxel contains both venous blood and brain parenchyma. We studied the apparent phase of a voxel as a function of
imaging resolution and predict what the best imaging parameters for a specific
clinical application should be. Currently, a long acquisition time is the bottleneck for SWI to be used as a routine protocol in the clinical environment. This thesis evaluates segmented echo planar imaging (SEPI) as an alternative to speed up the acquisition while reducing the artifacts usually associated with other fast imaging methods.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Natural Perversions: Posthuman Economies, Evolutions, and Sexualities

contributor:
Walmsley, Peter
English

subject:
posthumanism
natural perversions
economics
evolutions
sexuality
rationality

abstract: This project examines concepts and theories of the posthuman, or posthumanism, in contemporary popular and theoretical texts. The term "natural perversions" is an apparent paradox, but one that can point to some of the contradictions inherent in humanism; its use here suggests some of the profound challenges posthuman theory presents to exploitative institutions and power structures based on human privilege. Natural perversions is an attempt to naturalize, in a sense, the notion of perversion, but also to turn the nonnative language of perversion back onto dominant humanist institutions and discourses, especially anthropocentric visions of economics, evolution, and sexuality. Economics, evolution and sexuality are implicated in reiterating and supporting each other in their humanist and anthropocentric attitudes and assumptions. Interrogating humanist assumptions in these three areas of knowledge is increasingly necessary, this study contends, in the face of current environmental, economic and political crises such as pollution, peak oil and global warming. Despite their privileging of a human subject, economics, evolution and sexuality can each be considered inhuman systems from a certain point of view, systems that in the words of Elizabeth Grosz "function beyond or above the control of their participants." This project works to problematize human ideals such as reason and rationality, interrogating whether humans can indeed be distinguished from other beings by their rationality and contending that both man-made and natural economies (such as evolution and sexuality) do not function as rationalized and efficient systems in the ways that human thought has generally envisioned. Humans frequently do not behave in their own rational self interest, a foundational assumption of economic theory. The critical theory and popular texts considered here suggest that exuberant, decadent, luxurious, wasteful, and chaotic systems and economies and natural systems may be paradoxically more productive than highly rationalized ones.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Study of Impinging Gas Jets On Liquid Surfaces

contributor:
Irons, Gordon A.
Materials Science and Engineering

subject:
Impinging oxygen jets
steelmaking productivity and stability
momentum transfer
surface instability

abstract:
Impinging oxygen jets are widely used in steelmaking industries. The momentum transfer from the gas to liquid and resulting instability affect the overall productivity and operational stability. The purpose of this research is to understand the surface deformation, its stability and momentum transfer from the gas to the liquid. Video imaging and Particle Image Velocimetry were used along with water modelling techniques. Surface deformations mainly followed the dimensionless relationship of previous researchers. The surface instability was interpreted with Blowing number and Kelvin-Helmholtz instability. Spatial and time oscillation behaviour were analyzed with Power Spectral Density analysis. A new mathematical model with the full stress boundary condition at the surface was developed. The technique combines the Cartesian Cut Cell and Volume of Fluid method and the surface boundary was modelled a a pressure boundary. The numerical code was tested with the Broken Dam and wave instability problems. Both showed good agreement with the reported physical phenomena. Numerical tests of impinging jets showed similar surface depression depth with the water model experiments.
The model was compared with other models. The liquid momentum level
was higher as the gas fiowrate increased and the effects of physical property changes on surface instability and momentum transfer efficiency were investigated with the mathematical model. With observations from the numerical test, momentum transfer mechanisms were proposed. Simulations of momentum transfer at industrial flow rates were also carried out.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Optical Studies of Metamaterials and Bosonic Spectra of High-Tc Superconductors

contributor:
Timusk, T.
Physics and Astronomy

subject: optical spectroscopy

subject: metamaterial

subject: bisonic spectra

abstract:
The optical spectroscopy techniques have been used to investigate left-handed
behavior of metamaterials as well as the electron-bosonic spectral functions (or Bosonic spectra) of high-transition-temperature superconductors (or high-Tc superconductors) in the research work of this thesis. The periodic double-ring split-ring resonator (SRR) array was one of the first proposed magnetic metamaterials which could give rise to a negative magnetic permeability (μ<0). In the traditional design of negative index metamaterials, the SRR arrays were combined with continuous metallic wires that provide a negative electric permittivity (∊<0). However, the requirement of an unbroken electrical connection between unit cells would be challenging in building contoured devices. In our study, we carefully examine the electromagnetic properties of the double-ring SRR arrays on silicon substrates in the mid-infrared frequency regime experimentally and numerically.
For light at normal incidence, we observe that an electric resonance in the
outer ring and a magnetic resonance in the inner ring exist at similar frequencies in one of our samples, which suggests that the double-ring SRR array could have simultaneous a negative permittivity and a negative permeability, or a left-handed behavior. Our conjectures are confirmed by the numerical simulations. We also propose a new left-handed metamaterial composed of two single-ring SRRs in each unit cell. The left-handed behaviors in our designs originate from the SRR structure itself only and therefore, there are no metallic continuous wires involved compared to the conventional left-handed SRR metamaterials. The high-Tc superconductor samples studied here are highly under-doped YBa2Cu3O6.35 (YBCO6.35), nearly optimally doped monolayer HgBa2CuO4+ઠ (Hg1201), Zn- and Ni- doped Bi2Sr2CaCu2O8+ઠ (Bi2212) single crystals. We experimentally determine the optical constants of the samples and numerically extract the electronboson
spectral functions from the optical scattering rate by either an analytic formula
or a maximum entropy inversion technique. We find that the bosonic mode
obtained from the optical data is consistent with a peak in the q-averaged susceptibility seen in the magnetic neutron scattering studies. The comparisons of the bosonic spectra between YBCO6.35 and YBCO6.50, monolayer Hg1201 and trilayer Hg1223 (HgBa2Ca2Cu3O8+ઠ), Zn-doped and Ni-doped Bi2212 characterize the variation of the bosonic spectra with the hole concentration, Tc as well as the magnetic and nonmagnetic atom substitution.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Gas Kinematics of High Mass Star Forming Regions

contributor:
Wilson, C. D.
Astrophysics

subject:
massive star formation
Infrared Hot Core
protostar
accretion
HII region

abstract:
The mechanism by which massive stars form is not nearly as well understood
as it is for lower mass stars. For instance, at the onset of massive star formation, it is still not clear whether the mass for a given massive star comes from the turbulent collapse of a dense core (i.e McKee & Tan, 2003) or whether the star continues to accrete material from the cores environment as it grows (i.e. Bonnell et al., 1998). From this point, it is suggested that the cold, massive core (an Infrared Dar Cloud) begins to heat up and form a Hot Core. Later in its protostellar evolution, an HII region forms from the ionizing radiation being produced by the massive star. How, or even whether, accretion onto the massive protostar can continue in the presence of the large outward thermal and radiation pressures from the star is also quite uncertain. Can the star continue to accrete ionized gas (i.e. Keto & Wood, 2006)? Are the accretion rates high enough early on to account for the final observed masses (i.e. Klaassen et al., 2006)? Or, is there some way of minimizing the radiation pressure affecting the infalling gas (i.e. McKee & Ostriker, 2007, and references therein). Here, we present observations which suggest that there is a statistically significant, although short, period in which rotation and infall of molecular gas (which powers a bipolar outflow) continue after the formation of an HII region. This continued infall of material is seen on both large and small scales, and appears to be continuing to produce outflows in many of the sources observed in this study. That it is not seen in all sources suggests that this stage is short lived.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: UNDERSTANDING AND CHANGING PHYSICAL ACTIVITY AMONG PEOPLE WITH SPINAL CORD INJURY: THE ROLE OF PSYCHOLOGICAL AND ENVIRONMENTAL FACTORS

subject: environmental factors, leisure-time physical activity, (LTPA), spinal cord injury, Geographical Information Systems, mobility disabilities

abstract:
The purpose of this dissertation was to use an integrative theoretical framework to examine the individual and environmental factors associated with leisure-time physical activity (LTPA) for persons living with spinal cord injury (SCI). Using a systematic approach, three studies were conducted to: (1) survey the accessibility and availability of physical activity facilities for Canadians living with mobility disabilities, (2) test an
integrative, theoretical framework for understanding LTPA among people with SCI, and (3) implement a theory-based intervention that focuses on helping beginner exercisers living with SCI cope with salient individual and environmental LTPA barriers.

Study 1 involved two sub-studies. Study lA used a modified version of the
AIMFREE instrument (Rimmer et al., 2004) and provided evidence of the limited accessibility of fitness and recreational facilities (n=44) for persons with mobility disabilities. Study lB applied a geographical technique, Geographical Information Systems (GIS), to develop an objective proximity measure specific to persons with SCI. Results indicated a small, negative association between the objective presence of physical activity facilities and L TPA in a sample of persons with SCI (n=50), suggesting that living in close proximity to a facility which provides adaptive programming and equipment does not necessarily translate into greater LTPA for persons with SCI.

As an extension of Study 1, Study 2 used structural equation modeling to conduct a cross-sectional examination of whether an environmental factor --neighbourhood perceptions--could enhance the Theory of Planned ehaviour's (TPB; Ajzen, 1985) ability to explain LTPA intentions and behaviour in persons with SCI (n=246). Results indicated a small, negative association between perceived wheeling infrastructure and LTPA intentions. However, perceptions of neighbourhood aesthetics and wheeling infrastructure did not explain significant variance in either L TPA intentions or behaviour, beyond that accounted for by the TPB constructs, suggesting that these eighbourhood
factors do not enhance the TPB's ability to explain LTPA behaviour.

Lastly, Study 3 used a randomized, controlled design to examine the effects of a 10-week action and coping planning intervention on enhancing LTPA and coping self efficacy in exercise intenders living with SCI (n=47). Results indicated greater LTPA for participants who formed action plans and coping plans (A+C condition) than for the participants who only formed action plans (A condition). Furthermore, the A+C condition
had greater confidence to schedule their L TPA and overcome L TPA-related barriers than
the A condition. These findings provide evidence of the benefits of supplementing action plans with coping plans for enhancing L TP A and coping self-efficacy beliefs among exercise intenders living with SCI.

Together, these three studies provide a broader understanding of L TPA correlates and determinants in people with SCI, and provide evidence of the efficacy of multiple planning strategics for promoting L TPA in persons with SCI. The results provide an impetus for extending the scope of the research on the physical environment and LTPA towards persons with mobility disabilities. Moreover, the findings demonstrate the value of theory-based research for identifying the multidimensional correlates and determinants
of LTPA, and for designing effective LTPA-enhancing interventions in persons with SCI.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Laminar Natural Convection in Air-Filled Rectangular Cavities With and Without Partitions on Walls

contributor:
Ching, Chan
Mechanical Engineering

subject: laminar, natural convection, air-filled rectangular, cavities,

abstract:
The laminar natural convection in air-filled rectangular cavities with and without a
partition on the wall was experimentally investigated. Temperature measurements
and flow visualizations were performed for cases with heated and cooled vertical
walls (corresponding to global Grashof numbers GrH of approximately 1.4 x 10^8 to
1.8 x 10^8) and non-dimensional top wall temperatures θT of 0.52 (insulated) to 2.3.
In the rectangular cavities without the partition and with aspect ratios of 0.5, 1.0
and 2.0, the heated top wall caused the natural convection boundary layer flow to
separate from either the top wall (for the cases with Or ;S 1.2) or the heated vertical
wall (for the cases with θT >~ 1.2) due to the negative buoyancy force. For the
cases with θT >~ 1.2, there is an anti-clockwise recirculating flow in the upper left
corner region. The extent of the recirculating flow decreased with an increase of the
aspect ratio. The temperature gradient in the core region, dθ∞ /d(y/H), increased
with an increase of θT. For a given aspect ratio, dθ∞/d(y/H) changed more rapidly
with the change in θT for the cases with θT <~ 1.2 compared to the cases with θT >~
1.2. The increase in dθ∞/ d(y/H) was more significant for the smaller aspect ratio
cavity. The temperature profiles predicted from the similarity solutions proposed by
Kulkarni et al. [1] and from the non-similarity model developed by Chen and Eichhorn
[2] for natural convection on an isothermal vertical wall in a stratified environment
were compared to the measurements in the current cases. These models were not able to accurately describe the characteristics of the natural convection flow in the
rectangular cavities.

An aluminium partition with non-dimensional heights Hp/H of 0.0625 and 0.125 was attached either to the heated vertical wall or top wall at y/H = 0.65,
0.95 and x/H = 0.1, 0.2, 0.4 and 0.6 to study the effect of the partition on the
laminar natural convection flow in a square cavity. The blockage and thermal effects
of the partition resulted in changes in the temperature and flow fields, but were
mainly limited in the vicinity of the partition. The effect of the partition changed
with the height and location of the partition. When the partition was attached to the
heated top wall, a recirculating flow was formed between the partition and the heated
vertical wall. For a given partition height, the structure of this recirculating flow was
dependent on the partition location and θT. A thermal boundary layer developed
along the rear surface of the partition due to the thermal effect of the partition. The
ambient temperature outside the boundary layer and Nu near the corner region were
affected by the partition height due to the changes in the recirculating flow and the
rear surface of the partition.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Asymmetric Multiple Quantum Well Light Sources for Optical Coherence Tomography

contributor:
Cassidy, D.T.
Engineering Physics

subject: asymmetric multiple quantum wells (AMQWs), tunable lasers, optical, coherence, tomography

abstract:
Asymmetric multiple quantum wells (AMQWs) can provide broad and flat gain spectra. Broadly tunable diode lasers can be realized with AMQW active regions and without the need for antireflection coatings on cleaved facets.

 This thesis reports the application of AMQW broadly tunable lasers with uncoated facets for Fourier domain and synthesized optical coherence tomography (OCT). A depth resolution of 13 μm in air was obtained with a test bed OCT system that used diffractive optical elements, short external cavities, and AMQW InGaAsP/InP broadly tunable lasers as the light sources for the Fourier domain and the synthesized OCT measurements. The centre wavelengths of the broadly tunable sources were 1550 nm and the tunable ranges were ≤ 117 nm.

The features of broad and flat gain spectra of AMQWs also make AMQWs ideal candidates for broad spectral width superluminescent diodes (SLDs). 1300 nm AMQW InGaAsP/InP SLDs were designed and fabricated for application to time domain OCT. For the design of the active region, it was found by simulation of gain and the comparison of two growths that the transition carrier density (TCD) has to be reasonably high to achieve high power SLDs. A transfer matrix method was used to solve for the modes of planar optical waveguides with arbitrary layers and the thicknesses of these layers were optimized with a Marquardt nonlinear fitting method. With the optimization of the optical waveguide and with AMQWs with high TCDs, the output power of SLDs could reach 2 mW with > 90 nm spectral width. It is shown by time domain OCT measurements that the depth resolution of the OCT measurements could reach 7.85 μmin air with double section SLDs.

Two dimensional OCT images of a glass cover slip were built with the imageSC function in Matlab™. Image enhancement with blind/not-blind deconvolution was performed based on the measured point spread function (PSF) of the OCT setup. A Richardson-Lucy algorithm was used as the blind deconvolution method and a not-blind version of a Jansson-Van Cittert method was used.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: On the Modelling, Analysis, and Mitigation of Distributed Covert Channels

contributor:
Khedri, Ridha
Computing and Software

subject:
distributed covert channels
security
communicating concurrent Kleene algebra
formal methods

abstract: Covert channels are means of communication that allow agents in a system to transfer information in a manner that violates the system’s security policy. Covert channels have been well studied in the constrained and old sense of the term where two agents are communicating through a channel while an intruder interferes to hide the transmission of a message. In an increasingly connected world where modern computer systems consist of broad and heterogeneous communication networks with many interacting agents, distributed covert channels are becoming increasingly available. For these distributed forms of covert channels, there are shortcomings in the science, mathematics, fundamental theory, and tools for risk assessment, and for proposing mechanisms and design solutions for averting these threats. Since current formal methods for specifying concurrent systems do not provide the tools needed to efficiently tackle the problem of distributed covert channels in systems of communicating agents, this thesis proposes Communicating Concurrent Kleene Algebra (C²KA) which is an extension to the algebraic model of concurrent Kleene algebra (CKA) first presented by Hoare et al. C²KA is used to capture and study the behaviour of agents, and description logic is used to capture and study the knowledge of agents. Using this representation of agents in systems of communicating agents, this thesis presents a formulation and verification approach for the necessary conditions for the existence of distributed covert channels in systems of communicating agents. In this way, this thesis establishes a mathematical framework for the modelling, analysis, and mitigation of distributed covert channels in systems of communicating agents. This framework enhances the understanding of covert channels and provides a basis for thinking and reasoning about covert channels in new ways. This can lead to a formal foundation upon which guidelines and mechanisms for designing and implementing systems of communicating agents that are resilient to covert channels can be devised.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Neutron Transport Study of A Beam Port Based Dynamic Neutron Radiography Facility

contributor:
Harvel, Glenn D.
Chang, Jen-Shih
Engineering Physics

subject:
neutron radiography
gas
liquid
density
hydrogen

abstract:
 Neutron radiography has the ability to differentiate between gas and liquid in twophase flow due both to the density difference and the high neutron scattering probability of hydrogen. Previous studies have used dynamic neutron radiography - in both real-time and high-speed - for air-water, steam-water and gas-liquid metal two-phase flow measurements. Radiography with thermal neutrons is straightforward and efficient as thermal neutrons are easier to detect with relatively higher efficiency and can be easily extracted from nuclear reactor beam ports.

 The quality of images obtained using neutron radiography and the imaging speed depend on the neutron beam intensity at the imaging plane. A high quality neutron beam, with thermal neutron intensity greater than 3.0xl06 n/cm2-s and a collimation ratio greater than 100 at the imaging plane, is required for effective dynamic neutron radiography up to 2000 frames per second.

 The primary objectives of this work are: (1) tu optimize a neutron radiography facility for dynamic neutron radiography applications and (2) to investigate a new technique for three-dimensional neutron radiography using information obtained from neutron scattering.

 In this work, neutron transport analysis and experimental validation of a dynamic neutron radiography facility is studied with consideration of real-time and high-speed neutron radiography requirements. A beam port based dynamic neutron radiography facility, for a target thermal neutron flux of l.Oxl07 n/cm2-s, has been analyzed, constructed and experimentally verified at the McMaster Nuclear Reactor.

 The neutron source strength at the beam tube entrance is evaluated experimentally by measuring the thermal and fast neutron fluxes using copper activation flux-mapping technique. The development of different facility components, such as beam tube liner, gamma ray filter, beam shutter and biological shield, is achieved analytically using neutron attenuation and divergence theories. Monte-Carlo simulations (using MCNP-4B code) are conducted to confirm the neutron parameters along the beam path and at the imaging plane. Good agreement between the analytical and the numerical values for the thermal neutron flux at the imaging plane to within 5% has been achieved. The MCNP simulations show that neutron back scattering, due to the presence of the back-wall biological shielding and the beam catcher, have an insignificant effect on the thermal neutron flux at the imaging plane, however, the epithermal and fast neutron fluxes have increased by 4-11 %.

 Experimental results show that the thermal neutron flux is nearly uniform over an imaging area of 20.0-cm diameter. The thermal neutron fl11x ranges from 1.0x 107 - 1.26x10 7 n/ cm2 -s at a reactor operating power of 3. 0 MW. The measured value for the neutron-to-gamma ratio is 6.0x 105 n/cm2-μSv and the Cadmium-ratio is observed to be 1.22. These values promote real-time neutron radiography with relatively high neutron attenuating materials such as light water and high-speed neutron radiography with relatively low neutron attenuating materials such as heavy water and Freon type fluids with a minimal contrast degradation resulting from non-thermal neutron content of the beam.

 A dynamic neutron radiography system has been developed and modified to obtain less neutron damage to the low-light level video camera. The system is used to visualize air-water two-phase flow in a natural-circulation loop to examine the dynamic capabilities of the radiography facility. Measurements of bubble velocity, void fraction, and phase distribution are successfully made. Single frames (-33 ms) of neutron images were captured using the dynamic neutron radiography system for air-water two-phase flow. The system was able to resolve single bubbles interfaces with an image spatial resolution of approximately 0.44 mm.

 Thermal neutron detectors are placed at the periphery of the neutron beam to detect neutrons scattered by a non-flowing two-phase object placed on a turntable to simulate motion of the gas phase. The results show the potential ability to use neutron scattering technique to provide two-dimension neutron radiography with additional information to the third dimension.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: IMPACT OF RESISTANCE AND ENDURANCE EXERCISE AND INGESTION OF VARYING PROTEIN SOURCES ON CHANGES IN HUMAN SKELETAL MUSCLE PROTEIN TURNOVER

contributor:
PHILLIPS, DR. STUART M.
Kinesiology

subject: muscle, protein, synthesis, unilateral model, hypertrophy, myofibrillar, mitochondrial protein, exercise

abstract: Both resistance and endurance exercise elicit an increase in muscle protein synthesis during recovery from exercise. Ingestion of amino acids augments the exercise-induced stimulation of muscle protein synthesis following resistance exercise. Our work showed that 8 wk of unilateral resistance training induced muscle hypertrophy only in the exercised limb. Importantly, using this unilateral model we showed that muscle hypertrophy was confined to the exercised leg and occurred without measurable changes in circulating anabolic hormones. We then went on to use the unilateral leg resistance exercise model to study how animal-derived (milk) and plant-derived (soy) proteins impacted acute post-exercise protein turnover. We observed that ingestion of soy or milk protein resulted in a positive net protein balance following resistance exercise. Moreover, milk promoted a greater net protein balance and muscle protein synthesis than soy protein. In the final study, a key finding was that acute endurance and resistance exercise differentially stimulated myofibrillar and mitochondrial protein synthesis and also differentially affected cellular signaling proteins involved in the regulation of the protein synthetic response. Specifically, the acute, untrained state response showed that resistance exercise stimulated myofibrillar and mitochondrial protein synthesis while endurance exercise stimulated mitochondrial protein synthesis. Following resistance training only myofibrillar protein synthesis increased after exercise, while mitochondrial protein synthesis was unchanged. Endurance exercise training did not affect the acute protein synthetic response and so following training mitochondrial protein synthesis was stimulated as it was acutely, prior to training. In conclusion, the studies within this thesis provided novel insights on the impact of intact dietary proteins and differing modes of exercise on the control skeletal muscle protein metabolism.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A DRAW-BEND FRICTION TEST APPLIED TO MEASUREMENT AND MODELING OF ANISOTROPIC FRICTION ON SHEET METAL

contributor:
JAIN, MUKESH K.
METZGER, DON R.
Mechanical Engineering

subject: metal forming process, friction, velocity, friction model, anistropy, aluminum sheets

abstract:
In sheet metal forming processes, friction has decisive effects on the strain distribution in the deformed sheets and the quality of the final product due to the large surface/thickness ratio of the blank sheets. It is well known that friction in sheet forming operations is dependent on local contact conditions such as surface roughness, contact pressure and sliding velocity. Adding complexity to this frictional behavior, some rolled sheets have oriented surface roughness and show considerable frictional anisotropy. A constant friction model without consideration of these relevant phenomena is regarded as the reason why sheet metal forming simulations often fail to produce satisfying results despite the well developed material models.

To develop a friction model which considers both of the varying conditions of local contact and the frictional anisotropy was the aim of this thesis. For this purpose, the analysis method of the friction test (draw-bend test) had to be examined for the capability to evaluate these parameters independently. Through careful study using finite element simulations, it was found that the conventional method has shortcomings in addressing pressure dependent friction due to the pressure non-uniformity existing in the test. Therefore, a new analysis method, which can evaluate pressure dependency of a friction coefficient, was developed. In the new method, contact pressure maps obtained from simulations were included in the analysis of test data.

The new analysis method was applied to friction measurement of aluminum sheets
with known anisotropic mill finish, and friction coefficients were obtained as functions of
contact pressure, sliding velocity and sliding direction. In the obtained friction model, a
friction coefficient is a continuous surface over the domain of contact pressure and sliding
velocity. Lastly, the new friction model was implemented into a finite element code and
the model was validated through circular cup drawing experiments and simulations. The
comparisons showed good agreements in the aspects of punch force, cup size and failure
location. Thus, the newly developed model can accurately predict the effects of anisotropic friction in sheet metal forming processes.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Meanings and Management of Complementary and Alternative Medicine (CAM) Use in Later Life

contributor:
Bourgeault, Ivy
Sociology

subject: complementary and alternative medicine (CAM), health, later life, management

abstract:
 The purpose of this thesis was to explore why and how seniors used
complementary and alternative medicine (CAM) as well as the meanings they attached to their use of unconventional therapies. To this end, I conducted in-depth, individual interviews with 43 older adults-15 men and 28 women. Based on these data, I found that while all participants recognized the importance of conventional healthcare and continued to use its services, a number of people distrusted and were dissatisfied with medical doctors and treatments as well. Though these negative feelings were not sufficient to push seniors towards CAM, they certainly played a role in their decision making.
What informants particularly valued about unconventional approaches was that they allowed them to assert greater control over their health and, to some extent, their aging process. As a result, they viewed CAM as being an integral part of their aging lifestyles and actively incorporated these therapies into their treatment regimens. These findings overall contribute to the relatively scant, albeit growing, body of research on CAM use in later life, seniors' management of regimens, and older patients' dissatisfaction with and distrust of conventional medicine. Theoretically, the findings of this work demonstrate the importance of meaning in later life and specifically, how
meanings attached to conventional and unconventional care can influence older adults' health-related perceptions and practices.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Agent-Based Collaborative Design of Sheet Metal Parts

contributor:
Nye, T. J.
Mechanical Engineering

subject:
sheet-metal product
agent-based framework
process optimization

abstract:
The key objectives of this research were to develop an integrated design and
analysis methodology for sheet-metal product development based on agent-based technology, feature-based design, optimization and finite element analysis techniques, and to study the performance of prototype systems developed based on such a methodology. To achieve the research objectives, an agent-based framework was proposed for integrating and coordinating activities of participants involved in sheet-metal product
development based on the investigation of the industrial requirements and the procedures of the development of sheet-metal products. Prototype systems were developed based on the proposed framework to answer research problems outlined for the design and implementation of agent-based systems, such as agent encapsulation, system architecture, agent communication and agent coordination. The performance of such prototype
systems demonstrates that communication and coordination among domain agents can facilitate product development and reduce product cost.
An agent-based optimization approach based on an "A-Teams" approach
(Talukdar et al, 1996) was proposed for process optimization in the tooling design stage to combine the utilization of the traditional optimization techniques used to solve sheet-metal forming problems and agent-based approaches. Three test cases were used of varying complexity from a rectangular cup to the NUMISHEET'99 automobile front door panel simulation benchmark for the determination of optimal drawbead restraining forces and blankholder forces when designing draw dies for stamped parts. A network of
software agents, each implementing a different numerical optimization technique, was used in combination with metal forming simulation software to optimize process variables. It was found that the performance of each agent (and optimization technique) depended strongly on the complexity of the problem. For a given amount of computational effort, a network of collaborating agents using different optimization techniques always outperformed agents using a single technique in terms of both the best
solution found and the variance of the collection of best solutions. To provide guidance for the design and implementation of real applications, static and dynamic attributes and metrics of such agent-based collaborative systems, which can be evaluated in the preliminary system design stage and the system implementation stage, were proposed to study the impact of system architectures and coordination strategies on system performance. In addition, real-time system performance was statistically studied based on the data collected by the visualiser agent generated with the agent building toolkit. The results of case studies for system performance evaluation demonstrate the applicability of evaluation strategies proposed and can be used as a reference model for performance and scalability analysis on agent-based sheet-metal product development systems. The proposed evaluation strategies are applicable to general applications for product development by taking into consideration other performance indicators.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Dendronized Polymers and Surfaces: Strategies Toward Novel Therapeutics and Biomaterials

contributor:
Adronov, Alex
Chemistry

subject:
dendronized polymers
Boron Neutron Capture Theory
protein adsorption
cell adhesion

abstract: Combining linear polymers and dendrimers provides numerous advantages such as increased solubility, biodegradability and a large number of functionalizable peripheral moieties. In this work, novel carborane-containing dendronized polymers were designed as potential candidates for Boron Neutron Capture Therapy (BNCT). These polymers were successfully synthesized using two different approaches. The resulting carborane-functionalized polymers were dendronized using a divergent approach to introduce aliphatic polyester dendrons of generation 1-4 grafted from the polymer backbone. Both approaches produced water-soluble dendronized polymers with high molecular weights. The synthetic approach developed in the first part of this work was also applied in the functionalization of poly(ethylene glycol) (PEG)-grafted gold surfaces with hydrophilic dendrons. In this project, the effect of surface dendronization on protein adsorption was investigated. Contrary to our expectation, protein resistance was found to decrease when the surfaces were covalently functionalized with the hydrophilic dendrons despite their improved hydrophilicity. It was postulated that several factors could be responsible for the increased protein adsorption to the dendronized surfaces, including increased surface area, the introduction of hydrogen-bond donor groups, and a decrease in the mobility of the surface-grafted polymers as a result of inter- and intra-molecular hydrogen bonding between the dendrons. To circumvent these confounding phenomena, while maintaining surface hydrophilicity, we have chosen to covalently attach PEG mono-methyl ether (PEG-OMe) chains of various molecular weight to the peripheral hydroxyl groups of first to fourth generation dendronized surfaces. Results showed that protein adsorption was reduced when dendronized surfaces were grafted with PEG-OMe chains. The hydroxyl-terminated G l-G4 dendronized surfaces and PEG-grafted dendronized surfaces were also investigated for cell adhesion and proliferation. These studies showed that little or no cell adhesion occurred on PEG-grafted gold surfaces. However, greater cell affinity for the dendronized surfaces was observed. When dendronized surfaces were coupled with PEG-OMe chains, cell adhesion was significantly diminished.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Methods for Control in the Synthesis of Structured Siloxane Architectures

contributor:
Brook, Michael A.
Chemistry

subject: properties, siloxane, controlled synthesis, structures, functional groups

abstract:
 The advantageous properties of siloxanes find use in a wide range of
applications. Unfortunately, the dynamic nature of silicones which is responsible for these properties is often a limitation in the controlled synthesis and modification of siloxane materials. Gaining greater control over these processes would allow for the synthesis of siloxane materials with more explicit structures, giving them a narrower range of properties and expanding application. Furthermore, the ability to synthesize more siloxane architectures with greater control would allow for an increased understanding of the relationship between structural features and physical properties.

 The synthesis of hydrosilane-rich siloxane elastomers and subsequent
controlled modification, particularly with poly(ethylene oxide), is described. The effect of chain length and functionality (mono- or di-) was found to influence the morphology of grafted polymer. It was also possible to take advantage of the intrinsic properties of siloxanes to sequester hydrophilic moieties to the interior of the elastomer. Utilizing the same hydrosilane rich elastomers, a method for the independent modification of the interior and exterior of hydrosilane rich elastomers is presented. The careful selection of grafting moieties and solvents is used to provide or deny transport to the interior of the elastomer. This method is used to synthesize PEO modified elastomers with various subsequent internal modifications.

 A method for controlled synthesis of silicone-carbohydrate composites is
also described. Utilizing bifunctional silane linkers, protected carbohydrates were functionalized with bulky diisopropyl hydrosilane groups before linkage to short and long silicones. Alternatively, the linker could first be joined to a silicone, followed by silylation of unprotected saccharides using the resultant hindered chlorosilane functional silicone. This method gave preferential silylation at primary hydroxyl groups.

 Finally, a method is presented for the synthesis of explicit branched siloxane architectures. The B(C6F5)3 catalyzed dehydrocarbonative coupling of hydrosilanes with alkoxysilanes was used to construct branched siloxane architectures in a stepwise fashion. High levels of control were available through manipulation of steric parameters: careful selection of starting materials and conditions allowed for the synthesis of explicit alkoxysilane functional branched siloxanes. These could be grafted to hydrosilane functional silicone polymers, or used to assemble explicit branched siloxanes. Further explorations demonstrated that the assembly process was not inhibited by the presence of organohalide- or alkene functional groups, allowing for the synthesis of functional siloxane moieties with explicit structures.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Capacity Deficit and Link Loss in WLAN to Cellular Vertical Handoff

contributor:
Todd, Terence D.
Electrical and Computer Engineering

subject:
wireless LAN (WLAN)
vertical handoff
Vertical Handoff Support Node
bandwidth reservation
cellular communication

abstract:
Mobile handset manufacturers have begun to include wireless LAN (WLAN) interfaces in their cellular handsets. This allows users to access WLAN networks when they are available and to revert to conventional cellular communications otherwise. In this way the handset can dynamically use the "best" available network, by switching connections between the two network interfaces. This switching is referred to as a vertical handoff (VHO). When handling real-time connections, handsets must be capable of performing a
seamless vertical handoff. This occurs when the interface switching does not disrupt the quality of service requirements of the active connections. Vertical handoffs are generally time consuming, and this delay creates a difficult problem since WLAN coverage can be lost very abruptly. In this thesis, we propose and investigate several methods of mitigating this problem. A solution based on using a Vertical Handoff Support Node (VHSN) is proposed.
When the WLAN link is lost, the VHSN is able to quickly redirect packets through the local cellular base-station during the time that handoff is taking place. This approach can eliminate VHO link loss. It is shown that the act of WLAN-to-cellular handoff can result in a severe bandwidth deficit problem on the WLAN. A novel bandwidth reservation and securing mechanism is proposed which overcomes this problem and performs significantly better than schemes based on modified versions of the static guard channel scheme used in cellular networks. The work is characterized by simulation and analytic models which investigate the key performance aspects of this type
of system.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Solid-state NMR Studies of Ion Dynamics in Proton-Conducting Polymers and Composites

contributor:
Goward, G. R.
Chemistry

subject:
proton exchange
proton mobility
Nafion
Sulfonated Polyether Ether Ketones
proton conductivity
NMR

abstract:
High resolution solid state 1H NMR is used to investigate proton mobility of
Nafion, Sulfonated Polyether Ether Ketones(S-PEEK) and their composites, which provides better understanding of their proton conductivities. Proton exchange between sulfonic acid groups and water was observed in these materials. The proton mobility is dependent on both the temperature and the water content. Variable temperature experiments were used to determine the activation energy for proton transportation which generally increases with decrease in hydration level. The preparation of Nafion/SiO2 composites can cause large difference in proton diffusion coefficients and proton conductivities in dried states. This indicates that the amount of dopants needs to be optimized to minimize the blocking of proton diffusion pathways by dopant particles. Detailed information on the control of surface hydroxyl
groups in Nafion/SiO2 is obtained through the combination of 29Si and 1H NMR. Although hydrated Nafion/ZrP composites show reduced proton activation energy, they present lower proton conductivity at 35°C than unmodified Nafion. For composites dried at 160°C, both the conversion of monohydrogen phosphate into pyrophosphate and the protonation of monohydrogen phosphate have been observed, which could be one of reasons for the decreased proton conductivity after rehydration. Under high humidification, a single or multiple sulfonic acid proton environments was observed in S-PEEKs, which explains the small proton conductivity difference
between some of S-PEEKs. However, the observed conductivity difference for
S-PEEKs cast from different solvents was attributed to distinct mobilities of polymer chains. In the crosslinked S-PEEK, not all the crosslinkers of ethylene glycol are fully crosslinked. Proton exchange between residual sulfonic acid and hydroxyls of the crosslinker was observed, which is the primary reason that the crosslinked S-PEEK, with very low residual degree of sulfonation (13 %), still shows proton conductivity comparable to those of S-PEEKs.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: ON-CHIP DEBUG ARCHITECTURES FOR IMPROVING OBSERVABILITY DURING POST-SILICON VALIDATION

contributor:
Nicolici, Nicola
Electrical and Computer Engineering

abstract:
Post-silicon validation has become an essential step in the design flow of system-onchip devices for the purpose of identifying and fixing design errors that have escaped pre-silicon verification. To address the limited observability of the circuits during post-silicon validation, embedded logic analysis techniques are employed in order to probe the internal circuit nodes at-speed and in real-time. In this dissertation, we propose novel on-chip debug architectures and the associated debug methods, which improve observability during at-speed post-silicon validation.

First, we propose a novel embedded debug architecture that enables real-time
lossless data compression in order to extend the observation window of a debug experiment. The proposed architecture is particularly suitable for in-field debugging on application boards that have sources of on-deterministic behavior, such as asynchronous interfaces. To quantify the performance gain from using lossless compression in embedded logic analysis, we present a new compression ratio metric that captures the trade-off between the area overhead and the increase in the observation window.

Second. we propose a novel architecture based on lossy compression. This architecture enables a new debug method where the designer can iteratively zoom only
in the intervals that contain erroneous samples. Thus, it is tailored for the identification of the hard-to-detect functional bugs that occur intermittently over a long execution time. When compared to increasing the size of the trace buffer. the proposed architecture has a small impact on silicon area, while significantly reducing the number of debug sessions. The new debug method is applicable to both automatic test equipment-based debugging, as well as in-field debugging on application boards, so long as the debug experiment can be reproduced synchronously.

Third, we address the problem of the presence of blocking bugs in one erroneous module that inhibit the search for bugs in other parts of the chip that process data received from the erroneous module. We propose a novel embedded debug architecture for bypassing blocking bugs. This architecture enables a hierarchical event detection mechanism to provide correct stimuli from an embedded trace buffer, in order to replace the erroneous samples caused by the blocking bugs.

It is anticipated that the main contributions presented in this dissertation will help further the adoption of embedded logic analyzers, as the main alternative to scan chains for gathering data during post-silicon validation in real-time debug environments.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Artists and Art in Society: Creative Work for Social Change

contributor:
Baines, Donna
Work and Society

subject:
Max Weber
capitalism
economics
starving artists

abstract:
 Abstract: How can artists uphold their creative autonomy from the
dictates of capitalism without compromising their vision for social
change? Max Weber made it clear that the capitalism of to-day, which has to dominate economic life, educates and selects the economic subjects which needs through a process of economic survival of the fittest. (Weber, 1958) Eleven visual artists from the Golden Horseshoe Area and the Greater Toronto Area participated in this qualitative study and provided in-depth interviews their creative work, personal struggles and insights about the current state arts community. The data suggests connections between 'starving artists' and creative autonomy. On one hand, artists who pursued their art outside the formal art market deemed they had greater autonomy but experienced greater economic insecurity and social isolation. On the other hand, artists who practiced their art within the formal art market believed they had better freedom but needed to compromise creative autonomy and their vision for social change. On the whole, both art practices seemed to have lead artists to assume the concept of Art for 'my sake,' an assertion of their self-directed will for their own purpose, reducing artists' creative motivation to produce art society and for social change. While it may be solitary, it may also be a revolutionary strategy that enhances more control and focus on the artists' rather than pursuing society for validation and economic rewards.

abstract: Thesis

abstract: Master of Arts (MA)


title: Design of Ultra Wideband RF IC for Medical Imaging Applications

contributor:
Deen, M. Jamal
Electrical and Computer Engineering

subject:
breast cancer
modern imaging technology

abstract:
 Being the second most important cause of death in women, breast cancer attracted great interest from many research groups in different fields developing techniques to prevent, detect or cure it. Due to the fact that this disease can be treated if it is detected in early stages, many projects in this field have focused on early breast cancer detection. Modern imaging technologies have helped in the detection of this cancer but they still have high false positive or negative rates indicating a great need for more research in early breast cancer detection.

 In 2002 the Federal Communication Commission allowed usage of 3.1 - 10.6 GHz frequency range for short-range medical and personal applications, and this has stimulated much research on one of the most interesting technologies for medical imaging. With the aid of advances in complementary metal-oxide-semiconductor technology as well as wireless communications, this imaging technology has steadily grow, and now, it has it has many attractive characteristics that makes it a perfect substitute for conventional imaging systems.

 This thesis reports on the design of some key circuits for an ultra-wideband transceiver
architecture that can be used for medical imaging and especially for breast cancer detection. In this work, we concentrated on the receiver and two of its major blocks, namely, a low noise amplifier and a mixer are designed, simulated, fabricated and tested. Both of these circuits are designed in 0 .13 μm technology and Cadence tools are used for simulation and layout.

 First, a low noise amplifier is designed based on a common-source configuration with
inductive degeneration and a third order Chebyshev input matching network. Using precise zero-pole analysis, two inductors have been added to the main architecture of amplifier to improve its gain bandwidth product. The designed circuit shows a very good performance in terms of all of design parameters. Voltage gain with a peak value of 18.6 dB and very acceptable flatness is achieved. Also the noise figure of this circuit had an average of 4.7dB and a minimum value of 3.3dB. Input and output impedance matching shows very satisfying performance for the whole range of 3.1 to 10.6 GHz. Moreover, linearity of the circuit shows a very good performance compared with other works with IIP3 of -0.996 dBm. Finally, all of these specifications are achieved while consuming only 4.01 mW and occupying 1.3 mm2 of chip area.

 Second, an ultra-wideband mixer is designed to work as a multiplier in this configuration,
and to perform a critical function in correlation block. The mixer is designed for both super- and sub-threshold modes of MOSFET operation, and in both modes, it shows very acceptable performance. While super-threshold mixer shows much better characteristics in terms of gain, noise and linearity, the very low power consumption of sub-threshold circuit along with its reasonable performance in terms of gain, noise and linearity makes both circuits excellent designs for niche applications. Excellent conversion gain of 22.54dB is achieved for super-threshold circuit together with minimum noise figure of 7.4 dB and IIP3 of 2.67 dBm, while consuming 6.67 mW and having excellent input impedance matching all over the bandwidth. On the other hand, the sub-threshold circuit dissipates only 623 μW, with 13.44 dB of conversion gain and minimum noise figure of 7.67 and IIP3 of -7.47 dBm. This circuit has excellent input matching all over the UWB frequency range.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: THE SEPARATION AND ANALYSIS OF IODOAMINO ACIDS IN HUMAN SERUM

contributor:
TOMLINSON, R. H.
Chemistry

subject: IODOMINO ACIDS, HUMAN SERUM, IODINE, HYPOTHYROID

abstract: This project was undertaken with the aim of developing a method for the assay of iodoamino acids in human serum. The iodoamino acids were separated by an ion exchange technique, and the resulting solutions analyzed for iodine using neutron activation analysis. This analytical system was applied to the analysis.of a number of serum samples from hypothyroid and hyperthyroid subjects. This allowed the division of each of these conditions into a number of classes in terms of the deviation of the individual iodoamino acid concentration from their normal ranges.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Traditional Friendship?

contributor:
Horn, Martin
History

subject:
History
France
Yugoslavia
Cold War

abstract:
This investigation contributes to studies of post-1945 Europe and the Cold War by examining Franco-Yugoslavian relations in the period 1944–1969. In analyzing the diplomatic, economic, military, and cultural relations between the two countries, this dissertation argues that contrary to dominant narratives, neither the destruction wrought by the Second World War nor the ideological divide imposed by the Cold War swept away pre-1945 structures. Rather than jettisoning their “traditional friendship” that had been forged in the First World War, after the defeat of Nazi Germany France and Yugoslavia revived their many forms of cooperation despite the radically changed political landscape. That each sought to exploit the friendship for its own gain was not surprising. While it has been assumed that France quietly retreated from its sphere of influence in Eastern Europe after 1945, this work argues that until 1966 Yugoslavia was an important site for the reclamation of French power and prestige vis-à-vis the British and Americans. Although Yugoslavia’s claim to international status was its leadership of the Non-Aligned Movement, its security concerns remained in Europe. Consequently, it sought to capitalize upon its friendship with France for a variety of purposes, including to facilitate the legitimation of the new regime and its territorial claims against Italy, insurance against German resurgence, and cooperation on the international stage.
	Belgrade’s desire for cooperation with France stemmed from the similarities between “Gaullism” and “Titoism.” The crucial ideologically-derived differences between the two, however, precluded any meaningful form of collaboration. In addition to reintroducing ideology into the realism-dominated field of Cold War studies, the evidence in this dissertation – that both France and Yugoslavia remained invested in the “traditional friendship” – demonstrates that the post-1945 political and ideological division of Europe after was porous.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Tailoring Cellulose Nanocrystal, Polymer and Surfactant Interactions for Gels, Emulsions, and Foams

contributor:
Pelton, Robert
Cranston, Emily
Chemical Engineering

subject:
cellulose nanocrystals
hydrogels
emulsions
foams

abstract:
This thesis describes the investigation of the properties of cellulose nanocrystals (CNCs) in water and at interfaces in the presence of different water-soluble polymers and surfactants. The potential of producing hydrogels, emulsions, and foams using both CNCs and surfactants and polymers is extensively explored herein.
Interactions between CNCs and polymers were studied by measuring adsorption of polymers on CNC-coated surface in quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR) instruments. Hydroxyethyl cellulose, hydroxypropyl guar, and locust bean gum adsorbed onto CNC-coated surfaces, whereas dextran did not adsorb. Gelation of CNC dilute dispersions was found for the samples added with adsorbing polymers, whereas the introduction of non-adsorbing polymers showed no such change of rheological behaviors of CNC dilute dispersions. The further addition of negative surfactant SDS or non-ionic surfactant Triton X-100 disrupted the gels whereas cationic surfactant CTAB did not. These behaviors illustrate the complexities associated with including CNC dispersions in formulated water-based products where polymers and surfactants are commonly used as well.
The adsorption of cationic surfactants on CNC particle surfaces and the associated change of CNC hydrophobicity were investigated. Surfactant-modified CNCs were then employed as emulsifying agents to determine the effects of stabilizing oil-water interface with CNCs after surfactant addition. Emulsion stability was substantially enhanced with the introduction of surfactants. Based on the chemistry of cationic surfactants, and the extent CNC surface hydrophobicity increases after surfactant binding, either oil-in-water or water-in-oil emulsions were successfully produced. This in situ surfactant adsorption method thus offers a simple way of modifying surface hydrophobicity of CNCs and allows fine tuning of CNC-based emulsion properties.
Adsorbing polymers were used together with CNCs to prepare stable emulsions. The introduction of polymers facilitated the production of emulsion droplets with enhanced stability and smaller diameters. Both polymer-coated CNCs and the extra polymers partitioned at the interface and worked as the emulsifiers in a synergistic manner, leading to a reduction in CNC coverage on the emulsion droplet surfaces. Furthermore, reversible thermogelation of the emulsion was obtained when thermosensitive polymers were added. No noticeable emulsion coalescence occurred after multiple cycles of heating and cooling treatments of the emulsion gels. Freeze-drying and air-drying of these emulsion gels produced oil powders containing oil content as high as 94 wt. %.
Finally, highly stable wet foams were successfully produced using CNCs and the water-soluble polymer, methyl cellulose. The effect of CNC and methyl cellulose concentration on the stability of air-water interfaces was elucidated. Both foamability and foam stability were greatly improved by adding CNCs to methyl cellulose solutions. The CNC particles helped to retain fluid in the films and plateau borders between bubbles, increasing bulk viscosity, and impeding water drainage. We also demonstrated that adding various monomers to CNCs- methyl cellulose wet foams did not lead to noticeable foam breaking. The successful production of macroporous structures with tailored chemistry and properties was achieved by subsequent polymerization of the monomers added to the foam.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Infrastructure Power Saving and Quality-Of-Service Provisioning Framework For Wireless LAN Mesh Networks

subject: internet access, networks, mesh, infrastructure, power saving

abstract:
Internet access using IEEE 802.11 wireless local area networks has become very common.
In home and office networks where voice, video and audio will be delivered, quality of service (QoS) support is essential so that customers can be offered video on demand, audio on demand, voice over IP and high-speed Internet access. In addition to the proliferation of WLAN hotspots, WLAN mesh networks are now being used as a cost-effective means for coverage extension and backhaul relaying between IEEE 802.11 access points (APs).

 In conventional IEEE 802.11, APs are always continuously powered using fixed
wired connections. In future WLAN mesh networks however, wired power connections
may not always be readily available, especially in Wi-Fi hotzone installations which
cover expansive outdoor areas. In such cases, fixed power connections can often be
replaced by a battery operated or solar powered design. For this reason, power saving
on the AP is highly desirable for this type of application. Unfortunately, this is not
possible since the existing IEEE 802.11 standard requires that APs remain active at
all times.

 In this thesis, we propose and investigate a comprehensive framework for a power saving QoS-enabled access point (PSQAP), intended for use in solar and low power
IEEE 802.11 infrastructure applications. An energy-efficient media access control protocol
is proposed using the contention-based channel access mode for IEEE 802.11.
When real-time flows are present, a PSQAP schedules its awakening/sleeping pattern
in a manner that satisfies the delay and packet loss requirements for the admitted
real-time flows. A dynamic connection-admission control algorithm is proposed for
efficient management of wireless resources. We show that both background traffic and
the synchronization of stations' transmissions due to AP's alternating between awake
and sleep states can cause excess queuing and packet collision rate. These effects
result in an increase in packet delay and power consumption at the mobile stations in
contention-based channel access mode. We propose and investigate several scheduling
methods for mitigating these effects. It is also shown that voice over IP over WLAN
(VoWLAN) suffers a low capacity problem and high handset/AP power consumption.
A novel adaptive voice packetization scheme is proposed which improves VoIP
capacity and reduces power consumption. The work in this thesis is characterized by analytical models and evaluated through extensive network simulations to study and
analyze the key performance aspects of the proposed framework and the associated
protocols.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Vitamin D Status and Carotid Intima-Media Thickness in Adults Living with HIV Infection

contributor:
Smieja, Marek
Health Care Research Methods

subject:
vitamin D
HIV infection
Intima-medial thickness

abstract:
 Background: Vitamin D activity is important for the functioning of a broad range of body systems. Some of these, including the skeletal, immune, and cardiovascular systems, are particularly relevant in the management of HIV-infection; thus, and in consideration of evidence that factors associated with the scenario of HIV-infection can disrupt vitamin D metabolism, the assessment of vitamin D status in people living with HIV-infection may be particularly important. In this thesis, I address cardiovascular implications of vitamin D status in HIV-infection. More specifically, and based on a growing body of evidence implicating low vitamin D status in the development of cardiovascular disease (CVD), I hypothesized that in HIV-positive adults low 25-hydroxyvitamin D (25(0H)D) concentration would be associated with increased subclinical vascular disease as measured by carotid intima-medial thickness (IMT).

 Methods: Using regression analyses I cross-sectionally studied the relationship between 25(0H)D and carotid IMT in 283 participants of the Canadian HIV Vascular Study, a prospective study of CVD risk among HIV-positive Canadians.

 Results: The prevalence of vitamin D deficiency in the Canadian HIV Vascular study was surprisingly low. Plasma 25(0H)D by quartile was not associated with carotid IMT. However, in restricted cubic spline regression analyses designed to accommodate non-linearity there was evidence of an inverted U-shaped 25(0H)D-carotid IMT relationship. In exploratory regression models restricted to participants comprising the suboptimal range of vitamin D status, lower 25(0H)D concentration was statistically significantly associated
with lower carotid IMT after adjustment for known CVD risk factors and other variables hypothesized to potentially confound a 25(0H)D-carotid IMT association.

 Main implication: While inference from these exploratory findings requires cautious interpretation,
future investigations into the relationship between vitamin D status and vascular disease should consider the problem of non-linearity as a feature of primary analyses; otherwise, such studies might fail to detect a true association.

abstract: Thesis

abstract: Master of Science (MSc)


title: Matching Pursuit and Residual Vector Quantization: Applications in Image Coding

contributor:
Shirani, Shahram
Electrical and Computer Engineering

subject:
region-of-interest image coding
rate-distortion-complexity trade-off
matching pursuit
image quality refinement
joint source-channel

abstract:
In this thesis, novel progressive scalable region-of-interest (ROI) image coding
schemes with rate-distortion-complexity trade-off based on residual vector
quantization (RVQ) and matching pursuit (MP) are developed. RVQ and MP
provide the encoder with multi-resolution signal analysis tools, which are useful for rate-distortion trade-off and can be used to render a selected region
of an image with a specific quality. An image quality refinement strategy is
presented in this thesis, which improves the quality of the ROI in a progressive
manner. The reconstructed image can mimic foveated images in perceptual
image coding context. The systems are unbalanced in the sense that the decoders have less computational requirements than the encoders. The methods also provide interactive way of information refinement for regions of image with receiver 's higher priority. The receiver is free to select multiple regions of interest and change his/her mind and choose alternative regions in the middle of signal transmission. The proposed RVQ and MP based image coding methods in this thesis raise a couple of issues and reveal some capabilities in image coding and communication. In RVQ based image coding, the effects of dictionary size, number of RVQ stages and the size of image blocks on the reconstructed image quality, the resulting bit rate, and the computational complexity are investigated. The progressive nature of the resulting bit-stream makes RVQ and MP based image coding methods suitable platforms for unequal error protection. Researchers have paid lots of attention to joint source-channel ( JSC) coding in recent years. In this popular framework, JSC decoding based on residual redundancy exploitation of a source coder output bit-stream is an interesting bandwidth efficient approach for signal reconstruction. In this thesis, we also addressed JSC decoding and error concealment problem for matching pursuit based coded images transmitted over a noisy memoryless channel. The problem is solved on minimum mean squared error (MMSE) estimation foundation and a suboptimal solution is devised, which yields high quality error concealment with different levels of computational complexity. The proposed decoding and error concealment solution takes advantage of the residual redundancy,
which exists in neighboring image blocks as well as neighboring MP analysis stages, to improve the quality of the images with no increase in the required bandwidth. The effects of different parameters such as MP dictionary size and number of analysis stages on the performance of the proposed soft decoding method have also been investigated.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Modelling Paper Microstructure and its Role in Toner Transfer in Xerographic Printing

contributor:
Provatas, Nikolas
Materials Science and Engineering

subject: paper structure, spatial heterogeneity, toner, transfer, Xerographic, 3D fibre network,

abstract:
This thesis investigates paper structure and how its spatial heterogeneity affects the electrostatic and contact forces responsible for the toner transfer in Xerographic printing. Modeling predictions and experiments are reported which link length scales of variation in toner density distribution in Xerographic printing with certain structural length scales in paper.

A modified 3D fibre network model is introduced, which is used to simulate handsheet paper microstructure. Specific measures addressed by the model include formation, surface roughness and porosity. Simulated (i.e. virtual) handsheet paper structure is compared with that from specially prepared laboratory handsheet, obtaining a good correspondence between theory and experiments.

 An efficient Multigrid Poisson solver is used to simulate the electrostatic fields involved in the Xerographic toner transfer process. The distribution of dielectric property is input into the solver either analytically or from simulated 3D paper webs prepared by the fibre network model of paper. A spectral analysis is used to elucidate the relative importance of spatial variations of paper surface, filler and porosity in establishing spatial variations of the electrostatic field. It is found that only long wavelength variations in either surface height, bulk filler or porosity affect variations in electrostatic toner transfer forces to any relevant degree. Furthermore, it is shown that the long wavelength perturbations of the electrostatic field can be modeled using a new 1D effective capacitor model. Direct use of simulated handsheet paper webs - which are described by several heterogeneous measures - shows that to lowest order it is the paper surface structure not formation is responsible in shaping the electrostatic toner field variations.

 A new platform for modeling toner transfer in Xerographic printing is also introduced. It combines the 3D stochastic fibre network model of paper, the 3D electrostatic field solver, paper compression in the printing nip, and contact adhesion forces acting on toner particles during Xerographic printing. The modeling platform is used to demonstrate that paper-press interactions are critical in shaping the surface of paper, which, in turn, has the greatest influence in controlling both the electrostatic and contact adhesion forces responsible for shaping the distribution of toner transferred to paper during Xerography.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Sedimentologic and taphonomic analysis of a 1945 tsunami deposit in Sur Lagoon, Sultanate of Oman

contributor:
Reinhardt, Eduard
Geography and Earth Sciences

subject: Sultanate of Oman

subject: Sur Lagoon

subject: tsunami

subject: cluster analysis of particle-size distribution

subject: taphonomic analysis

subject: textural analysis

abstract:
The Sultanate of Oman is a rapidly modernizing country with a significant
length of its coastline slated for development. Much of the coastline is still in its natural state and basic studies describing the sedimentary systems need to be conducted in order to plan effectively for their sustainable development and to monitor changes in them with time. For such purposes, sediment samples (surface and sub-surface), elevation data, and serial sediment cores were collected at Sur Lagoon during three field seasons. The research objectives, procedures, results, and analyses for Sur lagoon are presented in three chapters. The first chapter compares textural facies, identified on the basis of particle-size distribution (PSD) of surface sediments from Sur Lagoon and evaluated using multi-variate cluster analysis, for their value in recognizing modem sedimentary environments. Clustering the full PSD size spectrum (0.0375- 1888 μm) shows that facies identification is possible is closely tied to surface elevation, particle-size decreasing with increasing elevation above mean sea level. This analytical technique should be tested under different conditions to assess further its utility. The second chapter discusses the taphonomically distinct and laterally extensive (> 1 km2) bivalve shell bed deposited by a tsunami on November 28th, 1945. Taphonomic characteristics of this unit are compared to those of the shell-rich
tsunamite from Caesarea, Israel, and resulted in the identification of three
generic, tsunamigenic-specific traits in shell beds: 1) thickly bedded and laterally extensive shell deposit, 2) presence of allochthonous articulated bivalves not in life position, and 3) extensive angular fragmentation. When these three traits are found together, a tsunamigenic origin should be considered for the shell bed. The third chapter analyzes the PSD of the tsunamite in eight sediment cores for digested and undigested samples. Cluster analysis of the PSD extended the upper or lower tsunamite contacts in four cores, but in general, the tsunamite thickness is consistent with the previously identified shell beds (Chapter 3). The tsunamigenic processes that resulted in the deposition of the shell bed were complex, and deposition occurred during run-up, flooding, and backwash stages of the tsunami, incorporating marine, lagoonal, and terrestrial (wadi) sediment into the tsunamite. The results of this study provide baseline sedimentological data for an understudied region of the world. New applications of cluster analysis of PSD and taphonomic analysis have the potential to identify previously unknown tsunamites in the geological record, and lithological facies using textural analysis.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Private Interests in the Public Domain: Provacy and Confidentiality in Observational Health Research

contributor:
Gedge, Elisabeth (Boetzkes)
Philosophy

subject:
privacy
confidentiality
health care
observational health research
individual consent

abstract:
The expectation of privacy and confidentiality in health care presents a unique
dilemma for public health interests. A great deal of observational health research such as epidemiological studies, disease surveillance, and quality assurance depends on access and use of personal information in the absence of individual consent. Understandably, this raises concerns about personal privacy since sensitive disclosures of information can result in harm such as stigma, discrimination, and loss of socio-economic goods. However, the issue has been largely framed and discussed as a dichotomy: the privacy interest of the individual versus the social interest in research. to individualist paradigm
informed by a traditional liberal conception of privacy that emphasizes autonomy drives this dichotomy and inevitably leads to an intractable conflict. In this thesis, I attempt to re-frame the issue by moving away from individualism in shifting the focus towards confidentiality which is relational and founded on trust. I argue that confidentiality is broader than the concern for individual privacy and is thus capable of capturing other relevant interests, such as collective and social interests. I advance a broad conception of confidentiality grounded in a mixed deontic-consequentialist moral framework that can account for respect for persons and social interests.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Coded Acquisition of High Speed Videos with Multiple Cameras

contributor:
Wu, Xiaolin
Electrical and Computer Engineering

subject:
Compressive Sensing
High Speed Video
Coded Acquisition
Random Sampling
Sparse Representation
Digital Cameras
Rolling Shutter

abstract:
High frame rate video (HFV) is an important investigational tool in sciences, engineering and military. In ultrahigh speed imaging, the obtainable temporal, spatial and spectral resolutions are limited by the sustainable throughput of in-camera mass memory, the lower bound of exposure time, and illumination conditions. In order to break these bottlenecks, we propose a new coded video acquisition framework that employs K>1 cameras, each of which makes random measurements of the video signal in both temporal and spatial domains. For each of the K cameras, this multi-camera strategy greatly relaxes the stringent requirements in memory speed, shutter speed, and illumination strength. The recovery of HFV from these random measurements is posed and solved as a large scale l1 minimization problem by exploiting joint temporal and spatial sparsities of the 3D signal. Three coded video acquisition techniques of varied trade o s between performance and hardware complexity are developed: frame-wise coded acquisition, pixel-wise coded acquisition, and column-row-wise coded acquisition. The performances of these techniques are analyzed in relation to the sparsity of the underlying video signal.
To make ultra high speed cameras of coded exposure more practical and a fordable, we develop a coded exposure video/image acquisition system by an innovative assembling of multiple rolling shutter cameras. Each of the constituent rolling shutter cameras adopts a random pixel read-out mechanism by simply changing the read out order of pixel rows from sequential to random.
Simulations of these new image/video coded acquisition techniques are carried out and experimental results are reported.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Wisdom in James: An Argument for the Discourse Theme

contributor:
Westfall, Cynthia Long
Christian Studies

subject:
book of James
Systemic Functional Linguistics
discourse theme
wisdom

abstract: There are many debates in the field of interpreting the book of James and there is no consensus among scholars. Some propose that this book is a paraenesis, whereas others argue for its inner coherence. On the basis of these disagreements, however, different scholars propose diverse themes for this book. This work attempts to view the book of Jams has a linguistic approach to identify its cohesion and its discourse theme. After providing a brief introduction to the understanding of cohesion based on the model of Systemic Functional Linguistics, this thesis represents a model of discourse analysis, seeking for the cohesion in this book and arguing that wisdom is the discourse theme of James through an analysis of the cohesive ties between James 3:13-18 and the rest of the discourses.

abstract: Thesis

abstract: Master of Arts (MA)


title: An Examination of Joseph's Enslavement of the Egyptians in Gen 47:13-26 in Light of Relevant Slavery Texts Across the Tanakh

contributor:
Evans, Paul S.
Christian Studies

subject:
Joseph's enslavement of Egyptians
Brueggemann
Child's Canonical Approach
Tanakh

abstract: An examination of scholarly perspectives on the ethicality of Joseph's enslavement of the Egyptians in Gen 47:13-26 reveals a debate over whether Joseph's actions were benevolent or oppressive. The majority of scholars who evaluate Joseph negatively simply ignore the relevant historical data, and Brueggemann's case for its dismissal is unconvincing. However, one area of contention that has gone relatively unexamined is the relevance and implications of later canonical materials relating to slavery. Childs' Canonical Approach is employed in a modified form to honor the canon as the larger context in which a passage should be read. I argue that when examined in light of relevant slavery texts across the Tanakh, Joseph's actions in Gen 47:13-26 are not culpable on the basis of his employment of debt slaver, but can be read as being out of step with the ideal that emerges concerning resource distribution.

abstract: Thesis

abstract: Master of Arts (MA)


title: An Ox and Ass in the Cucumber Field: The Importance of Metaphor to the Exegesis of Meaning, A Frame Semantic Approach to Isaiah 1:2-9

contributor:
Boda, Mark J.
Divinity College

subject: Isa 1:2-9, Frame, Semantic, Metaphor Theory, Exegesis,

abstract: The focus of this thesis is the importance of metaphor to an understanding of Isa 1:2-9. The argument depends on an understanding of metaphor as an imaginative structuring mechanism of cognitive linguistic behaviour, and a concrete mediator of meaning. The work proceeds from the observation that within contemporary scholarship readings of Isa 1 have failed to give sufficient attention to the occasion of its metaphors. The thesis argues that metaphor is essential to the text, and therefore a critical analysis of metaphor is central to its understanding. Using a Frame Semantic approach to contemporary Metaphor Theory, the interpretation of metaphors in Isa 1:2-9 is informed by insight offered from the historical and literary frames of the Ancient Near East and Hebrew Bible. Root metaphors of kinship, body, and land and their conceptual integration are discussed, and rich layers of meaning are revealed.

abstract: Thesis

abstract: Master of Theological Studies (MTS)


title: Church Planting in Niger: A Proposal for Integrating Wesleyan Theology with Church Planting Movements

contributor:
Beach, Lee
Divinity College

subject: Niger, Church planting, theology, Wesleyan

abstract: Despite over eight years of Christian witness, the West African country of Niger is still considered unreached by Christian missiologists. In the face of ongoing ministry challenges in Niger a new perspective is appropriate. Recent trends in missions recommend Church Planting Movements as a model for church-planting ministry in cross-cultural contexts. The church planting movements model may offer some solutions for church planting in Niger but the model tends to suffer from faulty prooftexting and inadequate theology related to the church and mission. Using theological reflection as a guiding model, church-planting-movement theology and practices are compared to John's Wesley's theology and practice. As a practical theologian, Wesley provides an example of how theological reflection can be more adequately integrated into the practice of mission. Through theological reflection and consideration for the Nigerien context, this thesis develops a church-planting ministry plan for the Free Methodist Church in Niger.

abstract: Thesis

abstract: Master of Theological Studies (MTS)


title: Street Youth Voice and Social Art

contributor:
Schormans, Ann Fudge
Social Work

subject:
street youth
art
voice
tools

abstract: This thesis sets out to examine how street youth use art as a mode of voice and what messages they choose to bring forward in their art. To complete this research a critical, post-modern framework was consulted. Alongside this a threeday, art-based research activity was planned and developed for street youth to participate in. Six street youth gathered at a drop-in centre/shelter to work on a collective art piece. Once the art piece was finished, messages from the art were analyzed through interview discussions with the youth, the literature, field notes and my own interpretations of what I was seeing. Findings of the street youth's messages were categorized as follows: public perception of street youth, being ignored/not being heard, expressions of hunger, sadness/pain, and coping/strengths. Art as a tool for voice was explored in the literature, and it was found that it has the ability to send powerful messages that can have consciousness-raising abilities, and even has instances of impacting organizational/structural changes. This research contributes to knowledge in various ways. First the community can learn from street youth voices that were gathered by an alternative medium. Also art-based methods can prove to be a more accessible way of collecting and interpreting data depending on the population you are working with. Finally, in the field of social work, it could be that art-based research is an alternative way to engage communities in research while at the same time challenging dominant knowledge processes.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: The Intention-to-Treat (ITI) Project: A Systematic Review of the Methodological Literature

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
intention to treat
loss to follow up
no consensus
review

abstract:
OBJECTIVES: The primary objective of this systematic review was to illustrate the various definitions authors of methodology articles have offered for intention to treat (ITT) in relation to loss to follow up (LTFU).

 METHODS: We searched MEDLINE® for publications appearing between 1950 to 2008. Eligible papers devoted at least one paragraph to ITT and two other paragraphs to either ITT or LTFU. Investigators independently extracted relevant information from each eligible article. Discrepancies between data extractors were adjudicated. Data was extracted and variables used during data extraction were analyzed using the Landis and Koch guidelines kappa values.

 RESULTS: The MEDLINE® search yielded 1007 articles. One-hundred and ten articles underwent full text screening yielding 66 articles. All kappa's were substantial to near perfect agreement (>0.74). Of the 66 articles, five (8%) did not define ITT, 25 (41%) mentioned LTFU but did not discuss its relationship with ITT, 36 (59%) commented on LTFU in the context of ITT. These 36 articles segregated into three distinctive definitions for ITT: "full-follow-up required" (mentioned 58%), "ITT and LTFU are separate issues" (mentioned 17%), and "ITI involves specific strategy for LTFU" (mentioned 78%). Of the 36 articles, 17 (47%) had multiple definitions for ITT. The most frequent strategies mentioned for handling LTFU were last outcome carried forward (50%), sensitivity analysis (50%), and use of available data to impute (46%). Most articles (81%) specifically excluded complete case analysis under ITI.

 CONCLUSION : The most striking finding of our systematic review is that there is
no meaningful consensus on the definition of ITI. This review, considered alongside previous reviews of RCTs, demonstrates that simply stating a study employed ITT is useless at best and misleading and dangerous at worst. It is the recommendation of this thesis that trialists replace the term ITI with a clear statements about analytic strategies applied to participants who were followed and with those not followed.

abstract: Thesis

abstract: Master of Science (MS)


title: CHANGES WITHIN LAYERED LITHIUM ION BATTERY CATHODE MATERIALS DURING CYCLING DETERMINED BY  6,7Li NMR

contributor:
Goward, Gillian
Chemistry and Chemical Biology

subject: Batteries Lithium Ion Cathodes NMR Nuclear Magnetic Resonance In-Situ

abstract:
The increased demand for electric vehicles in recent years has driven the development of Li ion battery technology, yielding interesting trends in cathode materials. The layered cathode material Li(Ni1/3Mn1/3Co1/3)O2 gives 30% more reversible lithium extraction than the earlier LiCoO2 and the “overlithiated” material Li(Li0.2Mn0.54Ni0.13Co0.13)O2 gives a semi-reversible capacity 25% higher than  Li(Ni1/3Mn1/3Co1/3)O2.1,2 6,7Li MAS NMR and 7Li MATPASS NMR were used to investigate the relation between the lithium ion and metal positions within these materials. It was found that Li(Ni1/3Mn1/3Co1/3)O2 showed a preference for Li ions to associate with Co at high voltages, that Mn4+ and Ni2+ showed some association and that the metals were not highly ordered. Li(Li0.2Mn0.5Ni0.13Co0.13)O2 showed a decrease in transition metal layer lithium upon cycling, in agreement with previous models, an ordering of the metal ions with the reinsertion of the lithium ions and a significant change in structure on deep discharge.3 These results will hopefully lead to more accurate modelling of the materials, understanding of reversibility and to increased reversible capacities in future cathode materials.
	Additionally work was done to enable high rate in-situ NMR spectra in which spectra are obtained from a cell while cycling in the bore of an NMR spectrometer. A Teflon Swagelok-style cell was designed and the effectiveness of solenoid and saddle coils were tested. It was found that for a 6 mm diameter cathode with a Li metal anode, at least half of the signal intensity could be obtained with a saddle coil whereas the signal was not detected when using a solenoid coil.

abstract: Thesis

abstract: Master of Science (MSc)


title: Simulation of Subcritical Experimentsin ZED-2 using G4-STORK

contributor:
Buijs, Adriaan
Engineering Physics

abstract:
In nuclear reactors, transients may happen, for example at the time of refueling, rod
withdrawals or insertions, and during reactor accidents. Transient behavior may result
from changes either in materials or in the geometry of the reactor core components. An
enhanced understanding of these time-dependent changes in reactors may improve the
reactor operation and reduce the probability of accidents. In spite of the importance of
understanding the conditions that lead to transients, there are not many time-dependent
reactor simulation codes available.
This study is focused on modeling the sub-critical reactivity measurements in the ZED-
2 reactor, using the recently developed G4STORK computer code. The ZED-2 experiment
measures the sub-critical state resulting from a step-wise reduction of the moderator
level.
G4-STORK is a time-dependent Monte Carlo code for reactor neutronics calculations
based on the GEANT4 toolkit. G4-STORK has the ability to follow the evolution of
the neutron population in time, including delayed neutrons, and to model the resulting
changes in material and geometric properties of a reactor.
The keff values calculated by G4-STORK were compared with the experimental measurements
and with MCNP results. The comparison shows significant discrepancies
with both MCNP and the experimental measurements. These discrepancies are increasing
as the reactor becomes increasingly subcritical (from ∼20 mk to ∼40 mk). The
recently developed G4-STORK code is still at an early stage of its development, and
needs to be improved further to be used for transient analyses of the reactors. Given the
flexibility of G4-STORK, there are many opportunity to improve and extend this code.

abstract: Thesis

abstract: Master of Applied Science (MASc)