title: Offset-free MPC: A novel design and Application to HVAC Systems

contributor:
Mhaskar, Prashant
Chemical Engineering

subject: Model Predictive Control, energy efficiency, offset-free control, heat pump, vapor compression cycle

abstract:
This thesis considers the problem of implementation of Model Predictive Control (MPC) strategies in the general area of Heating, Ventilation, Air Conditioning (HVAC). Specifically, the contributions utilize the constraint handling and optimality properties of MPC to achieve energy efficient control of many different HVAC systems.
 First, the thesis focuses on a linear offset-free MPC design for a vapor compression cycle. The key contributions include a a sequential tuning method and application to a detailed simulation test-bed, demonstrating superior closed-loop results to that of traditional control strategies in the presence of both disturbances and measurement noise.
 Next, a modified linear offset-free MPC formulation is implemented on a heat pump. The key contribution is the formulation of an optimization problem that recognizes the tradeoff between energy conservation and tracking performance. Simulation results illustrate superior performances as measured through three separate metrics: safety, energy efficiency and tracking. The implementation of MPC formulations to these realistic problems also pointed to a lack of MPC formulations with explicit performance considerations in the control design. Thus, in the final part of the thesis, these observed shortcomings in the standard offset-free linear MPC design are addressed via a new performance specification-based MPC. Desired closed-loop output response is specified and achieved through a tiered optimization formulation that can handle plant model mismatch. Superior closed-loop response, in terms of desired transient behavior and disturbance rejection, relative to standard linear-based and offset-free MPC designs is achieved. Finally, directions for future work are discussed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Perturbed Angular Correlations - 152Sm and 152Gd

contributor:
Cameron, J.A.
Physics

subject: perturbed, angular correlations, 152 Sm, alloys, electron, metallurgical

abstract:
 Using the technique of perturbed angular correlations, the rotation of the 4 + 366 keV 152Sm level and the rotation of the 2 + 344 keV 152Gd level was observed. These nuclei were the daughter nuclei of 152Eu, present in the europium - gadolinium and europium - holmium alloys which were commercially obtained (europium concentration was about 1% in both alloys). Anomolously low fields were obtained for 152Gd in gadolinium and in the holmium which raised doubts as to the homogeneity of the alloys.

 Samples of the alloys were analysed metallurgically. After chemical treatment and microscopic examination the presence of inclusions was detected. Electron microprobe examinations indicated that the inclusions were europium. The metallurgical analysis confirmed the doubts raised by the nuclear experiments showing that the two methods can be employed complementarily for alloy analysis.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Chemical, Thermogravimetric and X-ray Study of Cancrinite

contributor:
Burley, B.J.
Geology

subject:
cancrinite
Ontario
Non-Bragg reflections
main lattice reflections
cancrinite break down reactions
thermogravimetric analyses
sodalite
minerals

abstract:
Cancrinite specimens from Ontario were studied. Chemical
and thermogravimetric analyses were made. Non-Bragg reflections
were observed in x-ray photographs. These reflections have the same symmetry as the main lattice reflections, but the intensities, abundance and the relative positions of them with respect to the main lattice reflections are different from one specimen to another. In the heated specimens, the superstructure reflections decrease in intensities, shift in position and are streaked in a direction parallel to the a*-axis on the a* c* reciprocal lattice plane.
Phase changes in the heated cancrinites show that the sodalite
group of minerals occur as transitional phases in the cancrinite break down reactions. It is shown that the non-Bragg reflections are very similar to the main lattice reflections. There is a probable relation between the non-Bragg reflections in cancrinite and the sodalite group of minerals.

abstract: Thesis

abstract: Master of Science (MSc)


title: Xeroderma Pigmentosum: Sedimentation and Cell Survival Studies Following Ionizing Radiation

contributor:
Skarsgard, L.D.
Biochemistry

subject: molecular, cellular, ionizing, radiation, sedimentation, pigmentosum

abstract:
 In spite of the difficulties involved in molecular and cellular studies of antibiotic-free cultures of primary human cells, investigations of the sedimentation and
survival properties of cell cultures derived from Xeroderma Pigmentosum patients were successfully carried out. Emphasis was on the cellular and molecular effects of
ionizing radiation; however preliminary data for cell survival after exposure to UV was obtained.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Multiloop Control System for Tandem Electrostatic Accelerators

contributor:
Kuehner, J.A.
Physics

subject: multiloop, electrostatic, accelerators, feedback, resonances

abstract: The limitations of the conventional control system due to the corona discharge are discussed. An improved system employing a parallel feedback loop to modulate the terminal stripper is described. Finally an experiment is described whereby the performance of this system is measured and compared with the original system performance.

abstract: Thesis

abstract: Master of Science (MSc)


title: Tidal Propagation in Chesterfield Inlet, N.W.T.

contributor:
James, W.
Civil Engineering

subject: Chesterfield Inlet, Hudson Bay, tidal, water levels,

abstract:
 Chesterfield Inlet drains an area of 290,000 km^2, between Great Slave Lake and northern Hudson Bay, of predominantly continuous permafrost terrain. The 220-kilometre-long inlet may be used as an important navigation link to Baker Lake and potential pipeline sites. The inlet forms a complex network and is characterized by strong tidal
forcing.

 A one-dimensional numerical model, using a weighted, implicit,
finite difference scheme, was modified for application to the network. Sparse matrix techniques were incorporated into the model to speed Gaussian Elimination in the solution of the equations.

 Tidal constituents, derived from admittance calculations, were
used to predict water levels at eight tide gauge locations. Tidal predictions at Sandpiper Island were used as the downstream boundary condition for the numerical model, while tidal predictions at the other gauge locations were used in the model calibration.

 The observed and model-computed water levels are in good agreement over the lower half of the inlet. Appreciable differences between the observed and computed values were encountered in the upper reaches. Although some of these discrepancies are attributable to errors in the upstream boundary condition and schematization of the model, there is evidence to suggest that time and range errors may exist in some of the recorded tidal data.

 The variation in the phase and amplitude of the tide throughout the inlet is determined through an examination of the tidal constituents and the model results. Power spectra of the observed and
model-predicted water levels reveal that nonlinear interactions of the major tidal constituents take place in the upper portion of the inlet.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Globular Cluster Systems in Brightest Cluster Galaxies: Further Definition of the Mass-Metallicity Relation

contributor:
Harris, William E.
Physics and Astronomy

subject: globular clusters, mass-metallicity, galaxies, luminosity, brightest

abstract:
 Globular clusters (GCs) can be divided into two subpopulations when plotted
on a colour-magnitude diagram: one red and metal-rich (MR), and the
other blue and metal-poor (MP). For each subpopulation, any correlation
between colour and luminosity can then be converted into mass-metallicity
relations (MMRs).

 Tracing the MMRs for fifteen GC systems (GCSs) - all around Brightest Cluster Galaxies - we see a nonzero trend for the MP subpopulation but not
the MR. This trend is characterised by p in the relation Z=M^p. We find p ~
0.35 for the MP GCs, and a relation for the MR GCs that is consistent with
zero. When we look at how this trend varies with the host galaxy luminosity,
we extend previous studies (e.g., Mieske et al, 2006b) into the bright end of
the host galaxy sample.

 In addition to previously presented (B-I) photometry for eight GCSs obtained with ACS/WFC on the HST, we present seven more GCSs. Four of
these are newly analysed from HST data, one is previously presented (g-i)
photometry obtained with GMOS on Gemini South, and two are the author's
newly reduced and analysed (g-i) photometry also obtained with GMOS on
Gemini South.

 Interpretation of these results is important for further understanding the formation and evolution of galaxies within the hierarchical-merging picture,
and what process enables the production of two subpopulations.

abstract: Thesis

abstract: Master of Science (MSc)


title: Variations in Morphology of the Brine Shrimp, Artemia in Response to Environment

subject: Artemia, brines, Shrimp, inorganic, organic,

abstract:
 Members of a Californian species of Artemia were raised in brines of four different specific gravities, (1.028, 1.062, 1.090, and 1.120), with the other environmental factors held as constant as possible. Three populations of the shrimp (1.028, 1.090, and 1.120) followed a typical growth curve, while the fourth group (1.062) did not. The dimensions of the mature specimens could be related to the specific gravities of their environments by a formula of the general form y = ax + b

 These results were,
SPECIFIC GRAVITY= 1.19 - .359(±.018)WTHCAF
- .067(±.010)LTHSTE
+.012(±.003)ABDLTH
+.097(±.032)DEPTHU for a mature population.

 An inverse relationship between biomass and specific gravity was determined as was a direct relation between specific gravity of the media, and inorganic residue left after the organic material of the shrimp had been burnt away.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Harmonic and Anharmonic Vibrations in Rubidium Metal

contributor:
Brockhouse, B. N.
Physics

subject:
atomic vibrations
rubidium
phonon frequency distribution
anharmonic vibrations
lattice spacing
neutron diffraction

abstract: No abstract provided.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Scope and contents: The atomic vibrations in rubidium have been studied by the method of slow neutron spectrometry. The results have been analysed to yield atomic force constants which are used to compute the phonon frequency distribution. An interesting effect in the [00ζ]L branch has been examined,
and an explanation of the observations is offered. Anharmonic calculations of frequency shifts and widths are presented, as well as a calculation of the anharmonic heat capacity. The third and fourth derivatives of the real space interatomic potential, which are required for these computations, are estimated in various ways. A determination of the lattice spacing of rubidium by neutron diffraction is described.


title: Rapid Modal Analysis of an Amphibolite by Calibrated X-Ray Diffraction Patterns

subject: amphibolite, modal, minerals, X-ray, diffraction, calibration,

abstract:
 A coarse grained amphibolite from the metamorphosed rim of the Whitestone Anorthosite was prepared in several ways for the purpose of determining the modal abundance of the constituent minerals by calibrated X-ray diffraction. A simple two component amphibolite consisting of plagioclase and amphibole was chosen and five major methods of mounting the specimens for X-ray diffraction were employed.

 It was hoped that a method could be found which would produce randomly oriented, homogeneous samples. A series of such samples each of a different component ratio would then provide a calibration curve from which the mode of a whole rock specimen could be estimated.

 The calibrated X-ray charts were produced on Philips scanning X-ray diffractometers.

 The inconsistencies in the results indicate that better technical procedures are required.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Rhenium β-Ketoenolate Complexes

contributor:
Lock, C.J.L.
Chemistry

subject: reaction, rhenium, β-ketoenols, complexes

abstract:
 The products of the reaction between oxomethoxodichlorobistriphenylphosphinerhenium(V) and acetylacetone are determined, characterized and correlated in terms of a reaction scheme. A series of rhenium(III) compounds, characteristic of reactions analogous to the one mentioned above, with other β-ketoenols is prepared and characterized. The syntheses and properties of tris-1,1,1-5,5,5-hexafluoropentane-2,4-dionatorhenium(III) and trispentane-2,4-dionatorhenium(III) are described. A new nitrido-rhenium complex, nitridochloro-1,1,1-5,5,5-hexafluoropentane-2,4-dionatobistriphenylphosphinerhenium(V) complex is prepared
and characterized. A synthetic route to pyridine-acetylacetonate
complexes of rhenium is described.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Braided River Deposits and their Relationship to the Pleistocene History of the Credit Valley, Ontario

contributor:
Walker, R.G.
Geology

subject: pleistocene, sediments, Credit Valley, Ontario, deposits, braided river, floodplain

abstract:
 The stratigraphy of the Pleistocene sediments of the
Credit Valley of Ontario embraces two large fining-upwards
sequences which correspond to the deposition of glacial debris
during the retreat of the last two glacial periods in south central Ontario. The fining-upwards sequences have a basal gravel unit, a middle cross-stratified sand unit, and an upper unit containing small coarsening-upward sequences. All three of these sedimentary units are the result of deposition of sediment in a braided fluvial system. The basal gravel unit displays mid-channel gravel bars and side channel deposits. The cross-bedded sand unit exhibits incised bed-form deposits such as linguoid bars, dunes and ripples. The upper unit of coarsening-upwards sequences (which in places are interbedded with the cross-stratified sand facies) represents the deposits of bank overflow and consequent reactivation of unused channels on the braided river floodplain.

 During the Halton and Wentworth ice advances, till was deposited on the surrounding plain. With retreat of the ice masses, meltwater and outwash debris built up an alluvial plain in the lower and wider reaches of the Credit Valley near Glen Williams. These alluvial plains or sandurs were built
up by deposition from braided streams. Outwash from the
Halton Ice built a sandur plain on top of one constructed in
Wentworth time. Post glacial drainage has incised these glaciofluvial deposits and leaves them exposed along the banks
of the present Credit River.

abstract: Thesis

abstract: Master of Science (MSc)


title: THE IMPACT OF THE HDL RECEPTOR, SR-B1, ON CARDIOVASCULAR PHENOTYPES IN THE MOUSE.

contributor:
Trigatti, Bernardo
Biochemistry and Biomedical Sciences

subject:
Atherosclerosis
Cholesterol
Lipoproteins
Mouse Models
Myocardial Infarction
Cardiovascular

abstract:
Atherosclerosis is a major cause of cardiovascular disease, which is among the leading causes of death globally. Elevated plasma concentration of low density lipoprotein (LDL) cholesterol is a risk factor for atherosclerosis, while a high plasma level of high density lipoprotein (HDL) cholesterol is considered protective. Uptake of HDL cholesterol by hepatocytes during reverse cholesterol transport, and athero-protective signaling induced by HDL in other cells are mediated by the scavenger receptor class B, type 1 (SR-B1).
SR-B1 deficiency in mice that are susceptible to atherosclerosis results in exacerbation of atherosclerosis, and in mice with mutations in apolipoprotein E (apoE), renders mice uniquely susceptible to occlusive coronary artery (CA) atherosclerosis and myocardial infarction.
In this thesis, the impact of a lack of SR-B1 on the development of atherosclerosis is characterized in otherwise wild type mice, and in mice that also lack the LDL receptor (LDLR). We demonstrate that after prolonged feeding of a high fat, high cholesterol cholate-containing diet, SR-B1 knockout (KO) mice develop similar levels of diet-induced atherosclerosis to LDLR KO mice and apoE KO mice in traditionally susceptible arteries, and significantly more atherosclerosis in arteries that are typically resistant to plaque development, such as the CAs. SR-B1/LDLR double KO mice develop extensive occlusive CA atherosclerosis accompanied by myocardial infarction, and exhibit reduced
iv
survival compared to LDLR KO control mice when fed a variety of atherogenic diets.
In both SR-B1 single KO and SR-BI/LDLR dKO mice, CA atherosclerosis is accompanied by splenomegaly, elevated numbers of circulating leukocytes and increased expression of VCAM-1 in CA endothelium. Interestingly, removal of the spleen has no effect on circulating leukocyte numbers or atherosclerosis in SR-B1/LDLR dKO mice, suggesting the enlarged spleens in SR-B1 deficient mice do not influence atherosclerosis in these animals.
We conclude that SR-B1 is important for the protection against atherosclerosis in mice, particularly in CAs. This is likely through roles in multiple cell types including hepatocytes, endothelial cells and bone marrow-derived cells. Future studies should focus on evaluating the impact of cell-specific SR-B1 activity in different cell types on murine atherosclerotic CA disease.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Modeling Elevator System With Coloured Petri Nets

contributor:
Janicki, Ryszard
Computing and Software

subject:
Formal Specification
Coloured Petri Nets
Software Specification Benchmarks
Elevator System

abstract: A fairly general model of the elevator system is presented. Coloured Petri Nets (CPN) and CPN tools are adopted as modeling tools. The model, which is independent of the number of floors and elevators, covers different stages of the elevator system in substantial detail. The model assists simulation-based analysis of different algorithms and rules which govern real elevator systems. The results prove the compatibility and applicability of this model in various situations and demonstrate the expressive power and convenience of CPN.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Experimental Evaluations of ESF Methods For Neutron Radiographic Image Analysis

contributor:
Harms, A. A.
Ernst, P. C.
Engineering Physics

subject: edge-spread function, ESF, neutron radiographic image fomration, optical density curves, geometric configurations, irradiated reactor fuel elements

abstract: Some experiments designed to test the validity of the edge-spread function (ESF) model for neutron radiographic image formation are described; in addition the experiments are meant to illustrate the application of ESF methods to two areas of practical concern. First, the prediction of optical density curves for specified material and geometric configurations is considered; then, the use of ESF methods in dimensioning irradiated reactor fuel elements is examined. Overall, the results indicate that within the framework of assumptions which ESF theory is based upon, the correlation between theory and experiment is excellent. The results also suggest that in situations which deviate from the theoretical ideal, the ESF method may serve as a good first approximation to more complex models.

abstract: Thesis

abstract: Master of Engineering (ME)


title: PERMEABILITY AND PORE STRUCTURE OF GRANULAR MATERIALS

contributor:
Guo, Peijun
Pietruszczak, Stan
Civil Engineering

abstract:
The influence of the microstructure on the permeability of porous media is very important for various engineering problems in different engineering disciplines. The challenges for research in this area include the characterization and the quantification of microstructure as well as proper involvement of such microstructure measures in mathematical models with clear physical meaning.  This study focuses on the reconstruction of pore structure of porous materials, the quantitative description of pore structure using second-rank fabric tensors, as well as the determination of permeability as a function of microstructural measures via different approaches, including laboratory tests, theoretical analysis and numerical simulations.
This research is centred on the quantification of pore structure of porous materials.  A procedure is established to reconstruct the microstructure of a porous material using 3D CT-scan images. A new algorithm is developed to quantify the internal structure based on the 3D CT-scan images.  More specifically, two fabric descriptors, Mean Intercept Length and Areal Pore Size, are employed to construct fabric tensors as measures for the internal structure. The developed procedure and algorithm are verified for difference scenarios and then used to determine the internal structures of different materials.
An analytical model is developed to describe flow in porous medium with internal structures using the technique of homogenization. With the fluid-solid interaction taking into account on the particle level, the permeability tensor of a porous medium is derived from the macroscopic momentum balance equation of the fluid. The microstructure of the porous media is taken into account using the fabric tensors (based on both the Mean Intercept Length and Areal Pore Size) obtained from 3D microstructure reconstructions. When interpreted in the classical meaning, the two tensors describe the directional dependency of the tortuosity and hydraulic diameter, respectively. The well-known Kozeny-Carmman model is recovered for isotropic materials.
In addition to the directional variation of mean pore sizes, the variation of pore size distribution in different directions also affect the permeability of porous materials.  Pipe Network Models are used to explore the influence of pore size variation on the permeability of granular materials.  A new algorithm is developed to compute the pore size distribution and its variation in different directions in porous media using the CT-scan images. When taking into account the directional variation of pore size distributions, Pipe Network Models can be used to determine the principal permeability of an anisotropic porous material. The success of this approach highly depends on reliable characterization of pore structures
To verify the theoretical and numerical approaches developed in this research, laboratory tests are carried out to obtain the permeability of different materials. To determine the anisotropy of permeability of granular materials with internal structure, a new permeameter is developed to allow the hydraulic conductivity of cohesionless materials to be measured when flow takes place in any direction relative to bedding plane of the specimens. Materials with different type of particle shape and particle size distributions are examined using this permeameter. Good agreements are obtained from comparisons of laboratory test results with theoretical models and numerical simulations.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Development of Pitch Perception Indexed By Infant Mismatch Responses

contributor:
Trainor, Laurel J.
Psychology

subject: hearing, infants, pitch, sounds, speech, music, auditory development, ERPs, even related potentials, EEG, electroencephalogram, maturation, infant mismatch responses, MMRs, frequencies, frequency, stimuli, pitch perception, frontally positive reponses, morphological distributions,  trajectories, tones, MMN, mismatch negativity, single pitch percept

abstract:
 Hearing provides a vital means for infants to discover their environment and communicate with their caregivers. Identifying and discriminating the pitch of sounds is critical for infants in order to acquire information from speech and music. Therefore, how infants process pitch is a fundamental question in research on auditory development. The focus of this dissertation is the use of auditory event related potentials (ERPs) derived from electroencephalogram (EEG) recordings to examine the maturation of pitch perception in early infancy.

 Pitch perception in adults has been extensively studied, but little is known about the development of pitch perception during early infancy. Infant mismatch responses (MMRs) are ERP components that are elicited by infrequent changes in auditory stimuli. MMR is a promising tool to study infant pitch perception because it can be elicited without attention or a behavioural response. However, previous studies on MMRs in infants have reported inconsistent results, some reporting frontally positive responses while others report frontally negative mismatch responses. In Chapter 2, we examined MMRs to simple pitch changes in infants between 2 and 4 months of age and found both types of infant MMRs are present, but the morphological distributions and developmental trajectories are different. In Chapter 3, we reported that both types of infant MMRs are affected similarly by the amplitude of pitch change but only the positive MMR becomes stronger when stimulus presentation rate increases, which suggests different neural mechanisms for the two types of infant MMRs. The studies reported in Chapter 4 found that only the negative MMR can be elicited readily by changes in pitch patterns, suggesting that it may be functionally similar to mismatch negativity (MMN) in adults.

 The experiments in Chapter 5 used MMR as the indication of whether infants automatically integrate the frequency components of a complex tone into a single pitch percept, even when the fundamental frequency component (corresponding to the pitch) is removed. Previous studies show that adult MMN is elicited by a pitch change in such tones missing the fundamental. Previous behavioural studies using a conditioned head tum method show that 7-month-olds also perceive pitch with tones missing the fundamental. The results of the present study indicate that infants as young as 4 months of age integrate components into a single pitch percept, but evidence for this in younger infants could not be found.

 In conclusion, the current dissertation established a promising procedure utilizing infant MMR to study infant pitch perception and contributed to the knowledge of early development of pitch perception by demonstrating dramatic changes in brain response to pitch in harmonic tones in infants between 2 and 4 months old, and to pitch in tones in infants missing the fundamental between 3 and 4 months old .

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CELLULAR AND MOLECULAR MECHANISMS BY WHICH INTERLEUKIN-15 CONTRIBUTES TO ATHEROSCLEROSIS

abstract:
Interleukin-15 is a well known pro-inflammatory cytokine which regulates many activities of immune cells including macrophages, CD8 T, natural killer, and natural killer T cells. All these cell types have been shown to contribute to atherogenesis. Here we report that Interleukin-15 plays a key role in the progression of atherosclerosis in both aortic sinus and coronary arteries. Mice lacking Interleukine-15 had lower levels of atherosclerosis while mice overexpressing Interleukin-15 had increased plaque size. We also showed that this effect on atherosclerosis is partially independent of natural killer, natural killer T, and CD8 T cells. Immunodepletion of NK1.1+ cells led to less atherosclerosis in IL-15+/- ApoE-/- compared with IL-15+/+ ApoE-/- mice. Furthermore the absence of IL-15 in IL15-/- ApoE-/- mice resulted in lower expression of MCP-1 and less presence of CD11b+ cells in plaques compared with ApoE-/- control mice. In addition, in vitro treatment of macrophages with Interleukin-15 increased the expression of inflammatory cytokines, while a soluble Interleukin-15 receptor α suppressed the pro-inflammatory effects of Interleukin-15. These findings are consistent with others’ findings that Interleukine-15 affects macrophages through Interleukin-15 receptor α. To further examine this in vivo, we transplanted bone marrow from wild-type or Interleukin-15 receptor α knockout mice into LDLR-/- recipients. Mice lacking Interleukin-15 receptor α in their bone marrow derived cells developed smaller plaques. Also, we confirmed that Interleukin-15’s pro-inflammatory effect in macrophages isolated from Interleukin-15 receptor α knockout mice was partially suppressed, in comparison with macrophages isolated from wild-type mice.
It has been shown that the absence of HDL receptor (SR-BI) and ApoE in SR-BI/ApoE dKO mice leads to severe coronary artery atherosclerosis and consequently heart attack. We demonstrated that a lack of Interleukin-15 in IL-15/SR-BI/ApoE tKO mice, improved the survival of these mice compared with SR-BI/ApoE dKO control animals and also reduced the levels of atherosclerosis both in aortic sinus and coronary arteries.
In conclusion, these findings indicate that Interleukin-15 promotes atherosclerosis through multiple cellular and molecular mechanisms including monocyte/macrophage activation and survival/maturation of natural killer and CD8 T cells.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Cardiovascular diseases (CVD) are leading causes of death in Canada and among different types of CVD’s, atherosclerosis is the most dominant type. During the progression of this disease, immune cells and cholesterol carrying lipoproteins trespass the wall of arteries where, immune cells such as macrophages engulf cholesterol resulting in narrowing of lumens of arteries. Studies show that elements of our immune system together with other factors such as the levels of lipids in circulation, determine the severity of atherosclerosis development and consequently the occurrence of heart attack and stroke. Our findings demonstrate that Interleukin-15, a protein which regulates many aspects of immune system, plays an important role in atherosclerosis development. Using a variety of biological approaches, we have shown less atherosclerotic plaques in the absence of Interleukin-15 in mouse models, suggesting that this protein can be potentially targeted therapeutically in patients who have high levels of Interleukin-15.


title: The Crystallographic Investigation of a Strontium Labradorite

subject:
precession photography
artificial strontium labradorite
feldspars
cation
crystal symmetry
lattice parameters
crystal system
space group
structure

abstract: Precession photography was used to determine the lattice parameters, the crystal system, the space group and the structure of an artificial Sr-labradorite of composition: Ab27, SrAn73. C= 7.107Å, Ɣ= 90 degrees, β= 115.834 degrees. The crystal system is monoclinic, space group= C2/ m and structure is albite type, reflections being restricted to the 'a' type. The abundance, lithophile characteristics and appropriate ionic radii of elements in Groups IA and IIA are the factors governing their presence as cations of feldspars in nature. The structures of feldspars are discussed as a function of the relative proportion of cations of a charge of +1 and +2. The crystal symmetry (i.e. monoclinicity or triclinicity) is discussed as a function of the ionic radius of the cation.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Factors Affecting the Transition State in Acetate-Catalyzed Enolization. The Influence of Methyl and Bromine Substituents on the Rate of Bromination of Acetone

contributor:
Warkentin, J.
Chemistry

subject: acetate-catalyzed, bromination, enolization, reactions, acid, methyl

abstract:
 The acetate-catalyzed bromination of acetone is shown to occur by an enolization mechanism, although the reactions involved in this process are more complex than
has been supposed.

 A study of the activation parameters for the enolization
of some bromoacetones, and an observed linear free energy relationship between enolization rate constants, and acid ionization constants, shows that the transition state for this process resembles enolate and not enol.

 Bromine substitution in ketones accelerates enolization rates on both sides of the carbonyl group.

 The acetate-catalyzed enolization of 2-butanone favours the methylene group by a factor of nearly two.
This fact is interpreted in terms of methyl groups being inductively electron-withdrawing in their effect in forming an enolate transition state.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Effects of Infection with Adenoviruses on the Chromosomes of Human Cells and Syrian Hamster Cells

contributor:
Stich, H. F.
Biology

subject:
adenovirus
oncogenic
non-oncogenic
human cells
Syrian hamster cells
chromosome damage
replication

abstract: No abstract provided.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Scope and contents: Seven adenoviruses, including oncogenic and nononcogenic serotypes from human and simian hosts, were utilized to investigate their effects upon the chromosomes of human and Syrian hamster cells. Human cells support adenovirus multiplication while hamster cells do not support replication of infectious adenovirus. The chromosome damage induced by adenoviruses in abortive infection of hamster cells was compared with respect to the effect of virus dose upon the incidence and the types of chromosome aberrations. The effect of different adenoviruses upon the amount and types of chromosome damage was also examined. The effect of adenovirus infection upon DNA synthesis of human and hamster cells was examined, and the relevance of adenovirus-induced chromosome aberrations to the etiology of human cancers is discussed.


title: Biosynthesis of Lycopodine

contributor:
Maclean, D.B.
Chemistry

subject: biosynthesis, lycopodine, radioactive acetate, acetoacetate, lysine, pelletierine, lycopodium tristachyum, radioative acetate, biogenetic, Lycopodium alkaloids,  biological processes

abstract:
 The biosynthesis of lycopodine was studied by feeding radioactive acetate, acetoacetato, lysine and pelletierine to Lycopodium tristachyum. Partial degration of the radioactive lycopodine recovered from these experiments revealed specific incorporation of these precursors. The labeling pattern obtained is discussed in the light of the two major blogenetic hypothesis advanced for the Lycopodium alkaloids.

 The results obtained disproved Conroy's polyacetate hypothesis. They are consistent with the hypothesis that regards these alkaloids derived from lysine and acetate.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Study of Farmland Loss in Central Ontario 1951-1971

contributor:
Reeds, L.G.
Geography

subject: loss, farmland,Central Ontario, 1951-1971, socio-economic

abstract: In this investigation, a model is developed to explain the loss of farmland to other uses in Central Ontario in the period 1951-1971. Furthermore, it attempts to identify the socio-economic characteristics of operators involved in the loss of farmland process, as well as ascertaining the factors responsible for the change in land use.

abstract: Thesis

abstract: Master of Arts (MA)


title: Magnetoresistance of Potassium

contributor:
Carbotte, J.P.
Physics

subject: magnetoconductivity, isotropic, anisotropic, torque, potassium

abstract: The semi-classical path-integral method for finding the magnetoconductivity is specialised to cubic one-electron metals having a spherical Fermi surface, isotropic effective mass and anisotropic scattering times. Properties of the conductivity and resistivity tensors are deduced for this special case, in more detail for high magnetic fields. The magnetoconductivity for potassium, and the quantities derived from it - magnetoresistance and induced torque - are calculated as functions of temperature, field strength, impurity concentration and crystal orientation. Comparison is made with experimental results.

abstract: Thesis

abstract: Master of Science (MSc)


title: Hyperglycemia Promotes Accelerated Atherosclerosis and Aberrant Vasa Vasorum Neovascularization

contributor:
Werstuck, Geoff
Medical Sciences

subject:
Atherosclerosis
Diabetes Mellitus
Vasa Vasorum
Angiogenesis

abstract:
Individuals with diabetes mellitus often develop complications that traditionally have been separated into microvascular pathologies, such as retinopathy, nephropathy and neuropathy, or macrovascular pathologies, including cardiovascular disease. Increasing evidence suggests that these micro- and macro-vascular complications may be linked. Our objective is to determine if direct effects of hyperglycemia on a microvascular bed that supplies cells in large arteries, the vasa vasorum, promotes diabetes-associated accelerated atherosclerosis.
Normoglycemic apolipoprotein-E deficient (ApoE-/-) mice showed continuous atherosclerosis progression throughout the study that was directly correlated to increased vasa vasorum density with time. Hyperglycemic ApoE-/- Ins2+/Akita mice and streptozotocin-injected (STZ) ApoE-/- mice also demonstrated progressive plaque growth over time, but had accelerated atherosclerosis at 15 weeks of age compared to normoglycemic controls. The increased
atherosclerosis in hyperglycemic mice correlated with impaired angiogenesis at 10 and 15 weeks of age. These mice showed increased expression for a marker of hypoxia in the atherosclerotic lesions yet decreased expression of vascular endothelial growth factor (VEGF), suggesting disruption of hypoxia-mediated angiogenesis. Cell culture experiments suggested that alternative splicing of an antiangiogenic form of VEGF in macrophages as well as post-translational modifications of macrophages and smooth muscle cells may contribute to
reduced VEGF expression and decreased vasa vasorum neovascularization.  After 25 weeks of age, vasa vasorum expansion plateaued in normoglycemic mice but continued to increase in hyperglycemic ApoE-/- STZ-injected mice. The increase in vasa vasorum neovascularization correlates to increases in plasma cholesterol.
We have shown that hyperglycemia alters the microvascular structure of the vasa vasorum in two distinct mouse models of diabetes. Initially, elevations in glucose correlate to a significant reduction in lesion vascularization that results in increased lesional hypoxia that may promote the development and progression of atherosclerosis. At later time points there appears to be a burst of neovascularization that correlate with increases in cholesterol.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: People with diabetes have elevated glucose levels that affect the vessels that distribute blood in our body. This puts them at higher risk of developing cardiovascular disease and having heart attacks and strokes. One set of vessels, known as the vasa vasorum, delivers blood to the walls of larger vessels. The primary goals of this study are 1) to determine if diabetes affects the vasa vasorum and, 2) to determine if changes to the vasa vasorum increase a person’s risk of developing cardiovascular disease. The results of this study show that diabetes in mice decreases the number of vasa vasorum vessels. The decrease in vasa vasorum blood vessels appears to influence the larger blood vessels they supply which promotes an environment that is more prone to cardiovascular disease. This information could be used in the future to develop drugs that target the vasa vasorum and possibly decrease cardiovascular events.


title: Abelian Monoids

contributor:
Davison, T.M.K.
Mathematics

subject: submonoids, abelian, monoids, factorization,

abstract: This thesis makes a small study of various kinds of submonoids of abelian monoids, of the lattice of submonoids of an abelian monoid, and of the concept of unique factorization in abelian monoids. Also, the main concepts in category theory are examined in the special case of the category of abelian monoids and some of its subcategories.

abstract: Thesis

abstract: Master of Science (MSc)


title: Petrology and Geochemistry of Some Archean Volcanics, Dome Township, Central Red Lake Area, Ontario

contributor:
McNutt, B.
Geology

subject: petrological, geochemical, Archean mafic, felsic volcans, Dome Township, Central Red Lake area, petrographic, chemical investigations, rocks, petrogenesis, TiO2, K2O, SiO2, Na2O

abstract:
 A petrological and geochemical study has been carried out on
some Archean mafic and felsic volcans of Dome Township, Central Red Lake area, Ontario. Included are a discussion on petrographic descriptions along with chemical investigations of the rocks and a discussion concerning the general problem of petrogenesis. Analytical methods used are explained,
and di scussions of the results are included.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: Numerical Investigation of Sloshing Motion Inside Tuned Liquid Dampers With And Without Submerged Screens

contributor:
Hamed, Mohamed S.
Mechanical Engineering

subject: Finite difference, Volume of fluid, Tuned liquid damper, Free surface, Sloshing motion, Deformation, Damping device, Slat screen, TLD, SDOF, single degree of freedom, Duhamel integral method

abstract:
 A numerical algorithm has been developed to solve the sloshing motion of liquid in a Tuned Liquid Damper (TLD) outfitted by slat screens under large and random amplitude of excitation. It is based on the finite-difference method. The free surface has been reconstructed using volume of fluid method. Donor-acceptor technique has been used for tracking the volume fraction field. The effect of slat screen has been included and modeled using the partial cell treatment method.

 The algorithm is an integrated fluid-structure model where the response of the structure is determined considering the effects of TLD. The structure is assumed as a single degree of freedom system (SDOF) and its response is calculated using the Duhamel integral method.

 The algorithm has been validated against experimental data for the cases with and without screens. An excellent agreement was obtained between numerical and experimental results.

 An extensive parametric study has been carried out investigating the effect of slat screens and screen pattern on the TLD performance and on the structure response. A new parameter termed as slat ratio was introduced to characterize the slat screens based on their pattern. Results indicated that screen pattern has a significant effect on the TLD performance and it could lead up to 33 % reduction in structure response. It was found that decreasing the slat ratio will increase the damping effect of a TLD outfitted by slat screen.

The validity of the most commonly used approach, Baines and Peterson model, to
calculate pressure drop of slat screens has been investigated. A conelation factor as a function of Reynolds number and solidity ratio of screen has been proposed to improve the results of this model. A new concept termed as effective solidity ratio has been proposed to account for the physical significant of screen pattern on TLD performance.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Porosity and Cement Development In Pleistocene Key Largo Limestone, Key Largo Florida

contributor:
Risk, Michael J.
Geology

subject: petrographic, Pleistocene Key Largo Limestone Formation, Largo, Key Largo, Florida, 180, 000 years B.P., 125,000 years B.P., cored wells, environment, solution-enhanced interparticle porosity, beachrock

abstract: A detailed petrographic study of the Pleistocene Key Largo Limestone Formation, Key Largo, Florida, was undertaken observing three units of varying ages. From oldest to youngest, these are: Q4A (age unknown); Q4B, (180,000 years B.P.), and Q5, (125, 000 years B.P.). Fifty thin sections from four cored wells were point counted. Porosity remained constant for all three units at 28.5% as did total cements at 27.5%. These are still very porous rocks relative to ancient carbonates, which generally show 0-2% porosity. Q5 is diagenetically less mature than Q4B and Q4A, with the persistence of aragonite (which is being leached) and solution-enhanced interparticle porosity. Q5 has been exposed to a vadose environment. Multiple generation cements in Q4B indicate two periods of vadose exposure coincident with known Pleistocene eustatic sea level fluctuations. Moldic porosity is predominant in Q4B. Vague horizons of macroscopic vuggy porosity act as pathways of directed flow for percolating fluids precipitating late stage cements and stains rich in iron. Q4A has been interpreted as a beachrock in part, deposited at pH's greater than 9, resulting in dissolution of quartz grains. Of special interest in Q4A is the probable exploitation of a quartz substrate by endolithic borers.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: A Longitudinal Evaluation of Bone Erosive Damage in the Metacarpophalangeal Joints of Patients with Rheumatoid Arthritis Using Early Erosions in Rheumatoid Arthritis (EERA) Software

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject: Rheumatoid arthritis, Bone erosion, Metacarpophalangeal joint, Magnetic resonance imaging, Functional ability

abstract:
In this longitudinal pilot study, magnetic resonance imaging (MRI) and Early
Erosions in Rheumatoid Arthritis (EERA) software were used to quantify bone erosive
damage in the metacarpophalangeal (MCP) 2-5 joints of the worst-affected hand (i.e.
greatest swelling and tenderness at baseline) of patients with rheumatoid arthritis (n=35).
Firstly, Spearman’s rho (rs) was used to evaluate the correlation between total change in
sum erosive damage and change in functional ability, as well as the correlation between
rate of change in sum erosive damage and change in functional ability. The rs (p-value)
for total change and rate of change in sum erosive damage was 0.099 (0.585) and 0.104
(0.565), respectively. Therefore, the null hypothesis that neither variable was associated
with change in functional ability could not be rejected. Participants were also classified
into three groups based on total change in sum erosive damage (improvement, stable or
progression) and were examined for possible differences in a variety of measures using an
exploratory, non-statistical approach. Most notably, participants in the improvement
group had more than five times the mean sum erosive damage at baseline compared to the
progression group and also appeared to be the least aggresively medicated of the three
cohorts. This study is the first to apply EERA in a way that helps to address clinically
important questions related to change in erosive damage and functional ability. Future
studies should use the ideas and concepts generated in this pilot study to further explore
the use of this highly reproducible erosion quantification software, with the ultimate goal
of expanding the applications of EERA in both the research and clinical settings.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
In this study, the hands of patients with rheumatoid arthritis (RA) were assessed
using magnetic resonance imaging (MRI) to investigate how erosive damage to the bone
changes over time. Specialized computer software entitled Early Erosions in Rheumatoid
Arthritis (EERA) was used to perform this analysis. Firstly, change in erosive damage
was not found to be related to change in functional ability (e.g. eating, grip, etc.).
Secondly, it appeared that individuals who demonstrated improvement in bone damage
over time had significant damage at the beginning of the study period. Overall, this study
provides new information for researchers and clinicians in terms of how this unique
software can be used to enhance our understanding of RA. Future studies will continue to
explore ways in which this software can be applied to address questions that are important
to RA patients.


title: Approximating Probability Distributions Using Moments

contributor:
Stephens, M. A.
Mathematics and Statistics

subject: approximate significance points of random variables, random variables, approximatae significance, distributions, Pearson curves, Cornish-Fisher, a+bW, chi-squared, degrees of freedom, methods of approximation

abstract:
 We study the problem of finding approximate significance points of random variables whose exact distributions are unknown or extremely complicated . We consider the case where at least the first three moments, and possibly the lower or upper endpoint of the distribution are known.

 The methods of approximation studied include the Johnson system of transformations, Pearson curves, Pearson curves with known lower terminal, Cornish-Fisher expansions and the approximation a+bW, where W is chi-squared with p degrees of freedom . A new three-moment approximation of the form (cW)^k, with W as defined above, is also considered. These methods of approximation are discussed, with special attention to fitting procedures and computer implementation.

 The methods of approximation are compared, with respect to ease of application and accuracy of approximation, over a wide variety of exact distributions. The accuracy of each approximation is discussed and guidelines are given for determining which of several approximations should be used in a particular case.

abstract: Thesis

abstract: Master of Science (MSc)


title: Analysis Of Microtextures On Quartz Sand Grains Of Triassic Age, From The Minas Basin - Cobequid Bay Area (Bay of Fundy), Nova Scotia

contributor:
Middleton, G. V.
Geology

subject: Triassic sandstones, cliffs, eroding, Minas Basin, Nova Scotia, Canadian Geology, sand, intertidal sands, wave, tides, tide, electron microscope, grains, winds, lake

abstract:
 Triassic sandstones form rapidly eroding cliffs around much
of the Minas Basin, Nova Scotia. The sand eroded from these cliffs
is one major source of the modern intertidal sands. Wave erosion of
the cliffs locally produces a small sand beach at the high tide level.

 Eight samples were examined using the Scanning Electron Microscope:
two from the Triassic sandstones, and six from the high-tide
beach below the cliffs. All samples contained rounded, as well as
subrounded and subangular, quartz grains in the 0.5 - 1.00 mm size fraction. As the samples originated in the cliffs, abrasion by strong tidal currents cannot account for the rounded grain shape.

 All grains studied had suffered some degree of diagenesis in
the form of a precipitation coat. This was generally thicker on the
rounded grains than on the more angular ones. The Triassic sandstone grains generally illustrated upturned plates, semiparallel steps,
conchoidal breaks and a fine V-shaped pattern. The high beach grains illustrated upturned plates, V-shaped patterns, conchoidal breaks, greater rounding of featu res present and arc-shaped steps. Wehrfritz (1973) studied quartz grains from intertidal sand bars in the Minas Basin. He concluded that grains were considerably rounded by intertidal processes, and the frequency of V-shapes increased with grain
roundness.

 Although some rounding of the beach sands was inherited, wave and tidal action aided in rounding the features further. The initial rounding of the sand grains within the sandstones may have occurred during periods in the Triassic when they were exposed to wind or reworked in the lakes.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: West Hamilton, A Study In Urban Geography.

contributor:
Reeds, Lloyd George
Wood, H.
Geography

subject: West Hamilton, Land use, urban, rural, Hamilton, railway, subdivison, geography, geographical, Physical Geography, Toronto, Niagara Falls, Mountain, historical development, city, city of Hamilton, residential district, farm, commerical districts, industry, agriculutral, urban services, transportation,

abstract:
No Abstract
Thesis
Bachelor of Arts (BA)


title: A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction

contributor:
Sprung, D.W.L.
Physics

subject: nuclei, density dependent effective inraction, sprung, Banerjee, harmonic variational procedure, Hartree Fock approach, Campi calculations,  nucleon-nucleon force, nuclear shell model

abstract:
 The light even-even nuclei have been studied using the den~ity dependent effective interaction of Sprung and Banerjeee The nuclei were studied initially, using a harmonic variational procedure, to deter mine the most appropriate parameters of t he force for the Hartree Fock study.

 This chosen force was then used in a comparative study of spherical nuclei to d e termine the inadequacies of our Hartn~e Fock approach, as opposed to the spherical basis calculations of Campi. Some deformed nuclei were then examined and our results were compared with those of K. Lassey and A. B. Volkov , and of J. Zofka and G. Ripka.

abstract: Thesis

abstract: Master of Science (MSc)


title: X-Ray Diffraction Studies of Some Polyatomic Cations in the Solid and Liquid State

contributor:
Gillespie, R.J.
Chemistry

subject: polyatomic, cations, X-ray, diffraction, molecular, bond, solid, liquid

abstract:
 In a study of the structures of some polyatomic cations of Group VI and VII, the compound Se4(HS2O7)2 has been prepared and its structure determined by single crystal X-ray diffraction. The bonding in the square planar cation has been discussed in terms of molecular orbital and valence bond theory. The anion geometry has been discussed and
simple rules proposed to predict the changes which occur in bond length and bond angle when one or more oxygen in an SO4 tetrahedron is bonded to another atom or group.

 A θ/θ vertical diffractometer has been constructed, and computer programmes written, so that cation structures could be determined in solution. The structures of the Se4 2+ and Te4 2+ cations have been determined in fluorosulphuric acid, and are shown to be square planar.

 Liquid diffraction studies of 3:1, I2/S2O6F2 solutions have shown
the presence of a cation containing a linear chain of three iodine atoms.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Influence of Mixing and Reaction Kinetics on the Performance of a Biological Reactor

contributor:
Norman, J.D.
Chemical Engineering

subject: pulse response, vessels, kinetics, water flow rate

abstract: The pulse response of a full scale aeration tank is mathematically modelled with an arbitrary network of idealized perfectly mixed and plug flow component vessels. The model is fitted in the frequency domain, then inverse transformed to the time domain. The soluble carbon concentration curve of batch biokinetic run is modelled by a modified logistics equation and a piecewise linear expression. The mixing and kinetic models are combined to predict the degree of conversion assuming the degree of segregation, J, to be one. The pulse responses of a lab scale tank for varying water flow rates are also modelled by the same methods. An attempt is made to correlate the mathematical model parameters to the water flow rate.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Understanding Ribosome Assembly: New Approaches To Determining The Function of Escherichia Coli YjeQ

contributor:
Brown, Eric
Biochemistry and Biomedical Sciences

subject: Ribosome, Biogenesis, Bacteria

abstract:
As the gateway to translation, ribosome biogenesis is a core cellular process that is highly efficient, accurate and regulated. This is made possible in part by a suite of ancillary proteins with diverse but poorly understood functions. One such factor, the Escherichia coli GTPase YjeQ, is suspected of playing a critical role in the assembly of the 30S ribosomal subunit. Here we demonstrate that the absence of this factor in vivo leads to an accumulation of a late-stage immature 30S subunit species. While these precursors lack several ribosomal proteins and feature a number of conformational abnormalities, they are competent for maturation, suggesting that they represent an assembly intermediate.  We further demonstrate that YjeQ accelerates the maturation of these precursors in vivo. In addition, we explore the role of YjeQ through genetic interaction studies and substantiate a functional connection with the putative assembly factor RbfA.
A linear correlation between growth rate and ribosomal content has been observed for multiple wild-type microbes.  We have examined this relationship in the ΔyjeQ strain and found there to be a significant increase in the total cellular ribosomal material in comparison to the wild-type. This phenotype is not wholly exclusive to perturbations in biogenesis. Indeed, linear correlations and elevated levels of ribosomal content are also observed for several translation mutants.  The degree of elevation, however, is marginal in comparison to that seen in the biogenesis mutant. Our work explores this phenomenon and the possibility of exploiting it to identify and further characterize perturbations in the ribosome assembly process.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: In all cells, translation is carried out by ribosomes, large molecules that mediate the interpretation of the genetic code. These cellular interpreters are absolutely required for protein synthesis in bacteria and thus, are necessary for life. Like proteins, ribosomes themselves must also be synthesized, a process known as ribosome biogenesis. The ribosome consists of myriad RNA and protein components and is perhaps the single most complex machine in cells. Nevertheless, cells can build these enormous molecules in less than two minutes. This is made possible by a team of helper proteins, such as the bacterial assembly factor YjeQ. The function of this protein has evaded researchers, but there is growing evidence that it facilitates a key stage in the assembly process. Our work provides new detail into how this protein influences ribosome biogenesis, and how this in turn affects the overall health and proliferation of bacterial cells.


title: Nuclear Magnetic Resonance Studies of Borax, Tincalconite and Ferroelectric Lithium Hydrazinium Sulphate

subject: tensors, borax, tincalconite, nuclear, magnetic, resonance, ferroelectric, lithium

abstract:
The quadrupole coupling tensors at the B11 and Na23 sites in borax and tincalconite, two members of the hydrated sodium tetraborate family have been completely evaluated
using broadline nuclear magnetic resonance (n.m.r.) techniques. The results have enabled deductions to be made concerning the crystal chemistry of boron, the coordinations of the sodium atoms and the crystallographic symmetries. Changes in the Li7 n.m.r. spectrum of ferroelectric lithium hydrazinium sulphate as a function of temperature
were followed in detail. A previously undetected second order phase transition leading to a high temperature polymorph is complete at 164°C, The quadrupole coupling tensors at the Li7 sites have been completely evaluated in the two phases. The second moments or the proton n.m.r. spectrum from powdered lithium hydrazinium sulphate have been determined
within the temperature range -183°C to 225°C, and single crystal data on the protons have been obtained at room temperature. It is shown that the nitrogen and hydrogen atoms
exist in the structure as the hydrazinium ion NH2 and-NH3+. Detailed information is derived concerning the proton-proton vectors and the modes of reorientation of the NH2 and-NH3+
groups at various temperatures. Mechanisms for the ferro-electric switching at room temperature and for the transition to the high temperature polymorph are proposed on the basis of the experimental evidence.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: DETECTION OF NARROW-BAND SONAR SIGNALS ON A RIEMANNIAN MANIFOLD

contributor:
Wong, Kon Max
Electrical and Computer Engineering

subject:
RIEMANNIAN MANIFOLD
NARROW-BAND SONAR SIGNALS DETECTION

abstract: We consider the problem of narrow-band signal detection in a passive sonar environment. The collected signals are passed to a fast Fourier Transform (FFT) delay-sum beamformer. In classical signal detection, the output of the FFT spectrum analyser in each frequency bin is the signal power spectrum which is used as the signal feature for detection. The observed signal power is compared to a locally estimated mean noise power and a log likelihood ratio test (LLRT) can then be established. In this thesis, we propose the use of the power spectral density (PSD) matrix of the spectrum analyser output as the feature for detection due to the additional cross-correlation information contained in such matrices. However, PSD matrices are structurally constrained and therefore form a manifold in the signal space. Thus, to find the distance between two matrices, the measurement must be carried out using Riemannian distance (RD) along the tangent of the manifold, instead of using the common Euclidean distance (ED). In this thesis, we develop methods for measuring the Frechet mean of noise PSD matrices using the RD and weighted RD. Further, we develop an optimum weighting matrix for use in signal detection by RD so as to further enhance the detection performance. These concepts and properties are then used to develop a decision rule for the detection of narrow-band sonar signals using PSD matrices. The results yielded by the new detection method are very encouraging.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Attitudes of Users and Non-Users Toward Public Facilities and Services

contributor:
Dear, M.J.
Geography

subject: public, facilities, services, attitude,

abstract:
 Our study is concerned with the problem of locating public facilities. We suggest that public facilities and the services therein generate locational impacts which can be best elicited through a behavioral approach and more particularly through attitude theory.

  In this framework of analysis, we postulate two alternative hypotheses in an attempt to circumscribe the essential dimensions of impact of public facilities and services. We suggest that either different kinds of externalities are imposed upon the users and the non-users of public goods or the impacts generated by public goods are essentially the same. In the latter case, they are evaluated differently and given different psychological weights. The attitudes developed through the evaluation of public goods are found to be the best indicators of the extent and intensity of their impacts. While attitude formation is a multidimensional process involving tangible and intangible elements we show that the resulting attitudes are largely dependent upon locational factors and distance relationships.

 In order to evaluate the attitudes of users and non-users we develop a Semantic Differential scale relating the characteristics of public services to the attitude system of individuals.

 Finally, we give the attitude score a "utility" interpretation placing the analysis in a planning context: that of environmental satisfaction and conflict situations due to the location of public facilities.

abstract: Thesis

abstract: Master of Arts (MA)


title: Structural and Synthetic Studies on Lycopodium Alkaloids

contributor:
MacLean, David B.
Chemistry

subject: alkaloid, lycopodium, structure, synthetic, compound, purification

abstract:
 An investigation of flabelliformine, an alkaloid obtained from Lycopodium flabelliforme, led to the establishment of its structure.

 A study of the mass spectra of annotine (a minor alkaloid present in Lycopodium annotinum) and several of its derivatives in combination with degradative work gave support to a total structure proposed previously for the alkaloid.

 A synthetic approach to the Lycopodium alkaloids was considered. 1-Carbomethoxy-3-methyl-7-methoxybicyclo [3.3.1] non-3-en-9-one, a compound which appeared suitable as an intermediate in the synthesis, was prepared in low yield. The difficulty encountered in the purification of this compound, coupled with the low yield in which it was obtained, indicated the impracticality of this approach to a total synthesis of a Lycopodium alkaloid.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Experiments With a Vacuum Spark Ion Source

contributor:
Duckworth, H. E.
Physics

subject:
mass spectrometry
relative ionization efficiencies
vacuum spark
solid analysis
ions

abstract: No abstract provided.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Scope and contents:  The principal aim of the present investigation is to extend our knowledge of the merits and demerits of the mass spectroscopic method of solid analysis. This dissertation provides information concerning relative ionization efficiencies for several elements and factors which effect these efficiencies. Secondary purposes of this work are 1) to make an independent determination of the temperature of the vacuum spark, 2) to resolve the current discrepancy concerning the value of the C3+/C2+ ratio from graphite electrodes in a spark and, finally, 3) to provide an accurate value for the Ni58/Ni60 abundance ratio.


title: The Influence of Residual Stress Due to Cold Bending on Thin-Walled Open Sections

contributor:
Korol, R.M.
Civil Engineering

subject: influence, residual stress, cold forming, tension, compression, strains

abstract:
 This thesis deals with the analytical and experimental study of the influence of residual stress due to cold bending on the behaviour of thin-walled open sections. The residual stress distribution caused by cold forming the sections is predicted theoretically. The influence of
this residual stress on the load-displacement characteristic, and load carrying capacity of similarly curved tension and compression specimens is then analyzed. A local buckling
analysis based on the virtual work and incremental theories is performed to predict the collapse load of compression specimens containing residual stresses.

 The experimental work consisted of tests to confirm theoretical elastic springback strains due to cold bending of steel sheet to various radii. Tension and compression tests were then performed on various cold formed sections to observe the effects of residual stress and to confirm analytical predictions.

 Conclusions have been deduced from the theory and from these tests, and suggestions made for further research.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: The Effects of Tenure and Type of Dwelling on Subjective Response to Traffic Noise

contributor:
Taylor, S.M.
Geography

subject:
residential dwelling
tenure status
response to noise
Toronto
traffic noise
noise standards

abstract:
Previous research has suggested that the type of residential dwelling and the tenure status of an individual affects response to noise. However, the effects of these variables has been assumed but not empirically demonstrated. Using questionnaire data collected at selected residential sites, in the Toronto region, this analysis tests the separate and joint effects of dwelling type and tenure, on response to road traffic noise. The results show that tenure status had no effect on a resident's response to traffic noise. There was only a weak dwelling type effect, with detached unit residents being slightly more disturbed than multi-unit
residents by the equivalent noise level. The findings do not support a policy of varying noise standards for different types of residential area.

abstract: Thesis

abstract: Master of Arts (MA)


title: An Analysis of Past, Present and Temporal Changes in Bi-Way's Market Areas for Metropolitan Toronto

contributor:
Reader, Steven
Geography

subject: past, present, temporal changes, Bi-Way's, Toronto, Metropolitan, stores, markets

abstract: This research paper looks at the past, present and temporal changes in Bi-Way's market areas for Metropolitan Toronto. Each of the stores trade or market areas was defined by using Thiessen polygons which gave boundaries in which specific census data was collected and analyzed. The analysis essentially three questions; the first being to see if there are any differences between the trade areas of those stores built in the 1970's and those built in the 1980's, the second was to see if there were any changes between the two groups of stores but in terms of 1981 data, and the third was to see if there were any changes between the groups of stores and their changes between 1971 and 1981. The results showed that for thesis number one it was only the 1980's potential trade areas which revealed any specific market characteristics which could be used to define its target markets. The results from the second hypothesis that both sets of stores showed similar and different trade area characteristics and target markets. The results from the third hypothesis revealed that overall the stores built in the 1970's underwent the most significant changes in its market characteristics. Overall however, it was shown that although some similarities and differences came through for these two sets of stores a more indepth analysis is needed.

abstract: Thesis

abstract: Candidate in Philosophy


title: The Barrier Islands of Kouchibouguac Bay, New Brunswick

contributor:
McCann, S. B.
Geography

subject:
barrier island
Southern Gulf of St. Lawrence
shoreward retreat
dissection
sediment deposit
wave action
stability of the inlets
tidal cycle

abstract: This study is concerned with a 29km long barrier island system along the New Brunswick coast of Kouchibouguac Bay. Over the past 150 years these islands have been retreating shorewards and have been affected by storm wave action. The changes in the island configuration, the characteristics of the island topography and the seasonal variations in the beach profile suggests that these islands are similar to better known ones along the United States coastline.  The sediment characteristics of these islands reveal that there is an interplay of wind and wave processes on the sands, an interplay that is constantly mixing beach, dune and lagoon sands. The dominant southwest winds in summer cause most of the beach and dune sands to take on the characteristics of wind affected sands while the fall and spring storms impart characteristics of wave deposition to the beach sands at these times.  The sediment characteristics revealed seasonal changes in the islands but simulation modelling of the energy distribution of waves in the bay after wave refraction accounts for most of the long term change in the island configuration. This modelling emphasizes field work which revealed that not all parts of the islands are affected by the same storm waves. Nort-northeast waves have a better chance of affecting the southern part of the bay while more easterly approaching waves will only influence the northern part. Over a period of time form 1894 to 1964, wave refraction modelling also shows that much of the change in the configuration of South Beach can be accounted for by wave refraction over a changing offshore bathymetry.  Storm wave action thus accounts for most of the change in island configuration but the change around the inlets is most likely dependent upon the ability of these inlets to maintain stability at all times. Richibucto Inlet has achieved a stable equilibrium between the strength of the tidal currents passing through the inlet and the amount of incoming longshore drift, so that its position has remained static over the last 30 years. It is unlikely that Blacklands Gully or Little Gully have achieved this stability.

abstract: Thesis

abstract: Master of Science (MS)


title: Extensions of a Partially Ordered Set

contributor:
Bruns, G.
Mathematics

subject: partially ordered set, extensions, Boolean, lattices

abstract: In this thesis we introduce the concept of a dense extension of a partially ordered set and study some of the properties of the resulting class of extensions. In particular we study the dense distributive extensions, dense Boolean extensions and dense meet continuous extensions of distributive, Boolean and meet continuous lattices respectively.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Determination of Selenium and Sulphur in Human Tissues by Means of Radioactivation Analysis

contributor:
Tomlinson, R.H.
Chemistry

subject: radioactivation, selenium, sulphur, cells, concentration, human, tissues

abstract:
 A procedure was established for instrumental radioactivation analysis of selenium in biological materials using se77m, and used to determine selenium bound to plasma and cells of blood from 254 normal individuals. Variations with time, age, sex and hematocrit were investigated. Analysis of subfractions of plasma and cells indicated the highest selenium concentration in the plasma alpha and beta globulins. The selenium content of other tissues was determined for two individuals.

 A method was devised for instrumental radioactivation analysis of sulphur in dialyzed biological material using s37. The bound sulphur content of samples of plasma and cells from normal human blood was determined. The method would appear to have application in the instrumental activation analysis for other elements in various matrices.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: THE ROLE OF GLYCOGEN SYNTHASE KINASE-3α/β IN ENDOPLASMIC RETICULUM STRESS AND ATHEROSCLEROSIS

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
GLYCOGEN SYNTHASE KINASE-3α/β
ATHEROSCLEROSIS

abstract:
Atherosclerosis is a multifactorial inflammatory disease of the arterial wall and its clinical manifestations, including myocardial infarction and stroke, are the leading causes of death in western societies. Recent data has suggested that disruption of protein homeostasis in a cell's endoplasmic reticulum (ER), a condition known as ER stress, is associated with the progression of atherosclerosis. Furthermore, signaling by the serine/threonine kinase glycogen synthase kinase (GSK)-3α/β mediates pro-atherogenic processes. This thesis examines the role of ER stress and GSK3α/β signaling in atherosclerosis.
Initially, three apolipoprotein-E deficient (ApoE-/-) mouse models of accelerated atherosclerosis were established. Relative to ApoE-/- mice fed a chow diet, pro-atherogenic conditions promoted hepatic steatosis, atherosclerosis, ER stress and GSK3β activity. A subset of mice from each group were given the GSK3α/β inhibitor valproate. Valproate supplementation suppressed hepatic steatosis, atherosclerosis and GSK3β activity in each mouse model without altering ER stress levels. This study revealed a role for ER stress and GSK3α/β in multiple murine models of atherosclerosis.
Next, we investigated ER stress and GSK3α/β signaling in macrophage foam cell formation. In macrophages, ER stress induced GSK3α/β activity in a protein kinase R-like endoplasmic reticulum kinase (PERK) dependent manor. GSK3α/β inhibition attenuated ER stress induced lipid accumulation and the expression of distal components of the PERK pathway. Overexpression of constitutively active GSK3β induced foam cell formation. In mice, valproate supplementation attenuated PERK signaling in peritoneal macrophages and macrophages within atherosclerotic lesions. Together, these results point to GSK3α/β being a downstream component of the PERK pathway and that PERK-GSK3α/β signaling mediates ER stress induced foam cell formation.
Lastly, we investigated the tissue and homolog specific functions of GSK3α and GSK3β in atherosclerosis. In high fat diet (HFD) fed low-density lipoprotein receptor deficient (LDLR-/-) mice, deletion of GSK3α or GSK3β in hepatocytes did not alter liver lipid content or atherosclerosis. Myeloid cell deletion of GSK3α, but not GSK3β, attenuated HFD induced atherosclerosis. Mechanistically, deletion of GSK3α in macrophages promotes the anti-atherogenic M2 macrophage phenotype by modulating signal transducer and activator of transcription (STAT)-3 and STAT6 phosphorylation and activation.
Together, the data presented in this thesis suggest; 1) GSK3α/β inhibition attenuates atherosclerosis in multiple mouse models, 2) PERK-GSK3α/β signaling regulates macrophage foam cell formation and 3) myeloid cell GSK3α mediates atherosclerosis and macrophage phenotype.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: From Victimization to Transnationalism: A Study of Vietnamese Diaspora Intellectuals in North America

contributor:
McLaughlin, Neil
Sociology

subject: Intellectuals, Identity, Diaspora, Memory and Commemoration, Transnationalism

abstract:
The objective of this thesis is to examine the issue of identity construction among Vietnamese intellectuals in North America.  How is the way in which they construct their identity connected to their position(s) on the Vietnam War, anti-communist community discourse, and memory/commemoration, especially with respect to the contentious debate about which flag represents Vietnam today?  Vietnamese Diaspora Intellectuals (VDI) are an understudied group, and I hope my research will help to fill this gap, at least in part, and also serve as a catalyst for further investigation.
In my attempt to address this neglected area of study, I am bringing together two bodies of literature: diaspora studies and literature on identity formation among intellectuals.  The intersection between these two areas of scholarship has received relatively little attention in the past, and it deserves further consideration, because intellectuals are so often in a position to serve as carriers and disseminators of new ideas, as well as facilitators in conflict resolution. Using a qualitative approach to my data collection, I conducted life history narrative interviews with 32 respondents in Canada and the U.S, as well as some participant observation research of community events.  The majority of my interviewees were academics, but some were also journalists/writers, as well as community activists/representatives.
A key element of diaspora research, as Cohen and Watts have argued, involves an examination of the “victim narrative”.  My project considers the victim narrative in the context of the Vietnamese experience and evaluates the usefulness of such a narrative in terms of community politics and identity formation.  My interviewees were often skeptical about the utility of such a narrative, and in some cases, viewed it as a thinly veiled mechanism of control, which serves the interests of community leaders, but may in fact, hinder the progress of the Vietnamese diaspora population.  They contemplated some possibilities for transcending such a narrative, which could involve the creation of “free spaces”, permitting the expression of other points of view.  As we will see, my interviewees reflected on the irony inherent in this situation.  Many Vietnamese risked their lives in pursuit of the democratic ideal of freedom, but some of my participants discovered that the attempt to impose an overarching narrative – the rejection of communism – in fact led to the very antithesis of that ideal.
In this connection, my research complicates Cohen’s work on diaspora, which assumes that all diasporic communities speak with one voice with regard to defining moments in their history.  Cohen argues that members of such groups, by definition, shared a common past, an agreed-upon way of commemorating that past, and a common destiny.  I argue that Cohen has oversimplified the situation.  My research demonstrates that there is no such thing as unanimity.  Vietnamese diaspora intellectuals do not simply navigate academic “interaction ritual chains” as Randall Collins has asserted, they must navigate several - often competing interaction rituals - which extend to their roles as members of their ethnic community as well.  How do my interviewees deal with the inevitable conflicts and tensions engendered by such competing interaction rituals?
Finally, what are the possibilities of moving forward, of generating a new narrative, which will transcend the rigid and restrictive anticommunist discourse dominant in community politics thus far?  And what role can Vietnamese diaspora intellectuals play in this regard?  My research indicates that they are uniquely qualified to facilitate the process of rapprochement, because the life of intellectuals demands a high degree of reflexivity and thus better enables them to evaluate the merits of conflicting viewpoints.  My hope is to inspire future research – not only in the Vietnamese community, but on and for other diasporic groups as well.  My work extends Neil Gross’ theory of the “intellectual self-concept” (ISC) (which focuses on American academics) by introducing the notion of the diaspora intellectual self-concept (DISC).  Such concept allows us to include analysis of intellectuals with significant transnational connections who are dealing with racial and ethnic tensions in their new homeland while establishing themselves as professionals and citizens in a new cultural and political context.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: The Distribution of Property Tax Assessment Inequities in Hamilton

subject: multivariate, market value, tax assessment, Hamilton,

abstract:
 Multivariate statistical analysis of the ratios of single family dwelling assessed value to current market value or sale price, has been used to evaluate the administration of the property tax assessment function in Hamilton, Ontario. The Hamilton assessment administration has been found to exhibit an unacceptable level of non-uniformity in the assessment of single family dwellings. It is shown that tax burdens will vary substantially within and between price classes of single family dwellings; thus, both horizontal and vertical inequities are attributed to the administration of the assessment function.

 The spatial distribution of property tax assessment inequities in Hamilton is presented. It has been shown that certain districts of the city are overassessed relative to others. The spatial pattern is distinct; the area proximate to the industrial waterfront and the central business district have assessment-sales ratios above the mean ratio determined for the city as a whole, while the peripheral or fringe areas of the city are generally characterized by lower assessment-sales ratios.

abstract: Thesis

abstract: Master of Arts (MA)


title: A Study of Domain Walls in Uniaxial Magnetic Materials

contributor:
Della Torre, E.
Electrical Engineering

subject: domain walls, uniaxial, magnetic materials, energy,

abstract:
 An investigation of domain walls in some uniaxial magnetic materials is reported in this thesis. Firstly, a method for measuring the wall energy anisotropy in orthoferrites, which causes cylindrical magnetic (bubble) domains to be elliptical is described. In Sm0.55Tb0.45FeO3 a measured anisotropy energy of 1.7% of the wall-energy density at room temperature is responsible for eccentricities as large as 0.4 at average bubble radii equal to 85% of the bubble strip-domain transition radius. The relationship between material parameters and wall-energy anisotropy is discussed. The hypothesis that in orthoferrites walls parallel to the a axis are Bloch walls while walls parallel to the b axis are Néel walls is investigated by measuring the wall anisotropy as a function of the quality factor of the material by varying the temperature of the sample. The measurements seem to verify the predicted dependence of wall anisotropy on the quality factor and thus the hypothesis.

 A method for measuring the temperature dependence of the wall-energy
density in orthoferrites and the saturation magnetization in garnets is described. The advantage of the method is that it uses a single isolated bubble domain without the need to destroy the bubble in order to obtain the measurements. This method led to the derivation of
the temperature sensitivities of bubble domains in orthoferrites and garnets in terms of the material parameters. Optimum plate thicknesses to minimize the variation of bubble diameter with temperature are considered. Also, the condition for zero temperature sensitivity of bubbles in some uniaxial materials is derived in terms of the material parameters.

 Finally, a study of the current requirement to cut a bubble domain from a strip domain or another bubble in uniaxial plates is reported in this thesis.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Doctrine of Empirical Consciousness in the Bhoga Kārikā

contributor:
Sivaraman, K.
Religious Studies

subject:
Bhogakārikāvrtti
Bhoga Kārikā
empirical conciousness
bhoga
Śaivism
mala
soul
self
religion
Sanskrit

abstract:
The following dissertation consists of a study of an eighth century A.D. Sanskrit text dealing with the soteriological implications of the nature of "bhoga"- "mundane experience" or, more precisely, "empirical consciousness". The dissertation can be subdivided into two major sections. The first section consists of a critical discussion or the doctrine of bhoga in the Bhogakārikāvrtti; the second section consists of an English translation of the Sanskrit text.  The following study of the Bhoga Kārikā and its commentary has as its major concern the explication of the idea of "bhoga" put forth in the text. According to the school of Śaivism to which the author of the Bhoga Kārikā belongs, souls are by nature possessed of the two "capacities" (śakti) of consciousness and agency. Existing in a beginningless condition in the soul, these two capacities are obfuscated by the defiling power of a cosmic principle described as "mala". Due to this defilement the soul is forced into experiencing things in a limited manner, i.e. solely as an ego-personality whose self-understanding is both defined by and limited to the empirical sphere of experience.  In explicating the doctrine of bhoga expressed by Sadyojyoti and defending his commentator Aghora Śiva, the dissertation takes up a discussion on the various polemics against other systems, such as the Buddhists, Cārvāka, Nyāya and Sāmkhya. As well, an attempt is made to
point out the particular manner in which Sadyojyoti's doctrine of "bhoga"
shares close affiliations with the schools of Mīmāmsā and Sāmkhya-Yoga. The text was translated under the guidance of Dr. S. S. Janaki, the Director of Kuppuswami Sastri Research Institute in Madras. The Sanskrit text of the Bhoga Kārikā consists of 146 verses by a renowned Śaivite author, Sadyojyoti (8th c. A. D.) and a brief commentary by another renowned Śaivite author, Aghora Śiva (14th c. A. D.). Although by themselves the verses are difficult to understand without the aid of the commentary, the commentary itself is written in simple Sanskrit prose. The Bhoga Kārikā is one of a host of Śaivite "manuals" that
systematically define the essential teachings and particular themes of Agamic Śaivism. Aghora Śiva's commentary on the Bhoga Kārikā is typical of the commentaries accompanying most of these manuals: it is brief and polemical. Chapter I of the dissertation deals with the authors Sadyojyoti and Aghora Śiva in relation to the Śaivite tradition; as well, Chapter I treats the basic concepts of "bhoga" and "tattva" employed in the Bhoga Kārikā. Chapter II deals with the doctrine of the subtle and the gross elements, emphasizing the concern of the tattvic doctrine that each tattva is a sine qua non in the event of bhoga. Chapter III treats the sphere of the motor, sense and intellectual organs and the polemics
against the Cārvākas and Nyāya concerning the role of "consciousness" in the sphere of empirical experience. The specific organs of the "antahkarana" , i.e. ,manas, buddhi and ahamkāra, are treated in Chapter IV. More epistemological issues are discussed in Chapter V, most notably the Śaivite doctrine that the soul has intrinsic to the dual capacities (śakti) of consciousness and agency. The last chapter, Chapter VI, deals with the trans-buddhi conditions governing empirical consciousness, and includes a discussion of the soteriological import of māyā and mala. Appendix I consists of the translation of the Bhoga Kārikā Vrtti
while the transliteration of the text appears in Appendix II.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Factors Affecting Evaporation from a Subarctic Tundra, Churchill, Manitoba

contributor:
Rouse, W.R.
Geography

subject: evaporation, subarctic, Churchill, Manitoba, tundra, soli moisture, atmospheric

abstract: Evaporation was calculated for a subarctic beach ridge, near Churchill, Manitoba, using the energy balance approach. Energy balance calculations for the measurement season revealed an average Bowen ratio, β, of 0.68, with a value of 1.00 representing α' (the evaporability parameter). Fifty-seven percent of the net radiation was utilized by the evaporative heat flux over this tundra surface. Regressions were used to determine the most likely combination of environmental variables responsible for the behaviour of evaporation. Surface soil moisture remained relatively constant throughout the summer measurement period and soil temperatures appeared to be unrelated to evaporation. Air temperature proved to be insignificant to the evaporation flux, and net radiation alone could only account for 54% of the variability. The combination of the net radiation and the wet and dry bulb temperature depression at 1 m accounted for 88% of the variability of the evaoorative heat flux. The mean α' for a site is assumed to be controlled by the surface type in simplified variations of the combination model. The conclusion has been drawn from this study that the variability of α' can be accounted for by variable atmospheric humidities as well as net radiation. The importance of this atmospheric control on the rate of evaporation is emphasized.

abstract: Thesis

abstract: Master of Science (MSc)


title: Examination of Surface Morphology and Sub-Surface Crystallographic Changes of Si, Cu, GaP and Ge After Ultrashort Laser Pulse Irradiation

contributor:
Haugen, H. K.
Engineering Physics

subject:
ultrashort laser pulse irradiation
crystallography
laser-induced period surface changes
femtosecond laser micromachining
pulse fluence
silicon
gallium phosphide
germanium
copper
material modification

abstract: This thesis reports the effects of ultrashort laser pulse irradiation of various materials. The morphology after irradiation was examined using several microscopy techniques. Emphasis was placed on the identification of crystallographic changes and the analysis of laser-induced periodic surface structures. Grooves were machined in silicon by translating the target under the focused laser beam. The resulting depths were measured as a function of pulse energy, translation speed, and number of consecutive passes, for 800 and 400nm wavelength irradiation. The wall morphology and a corrugation along the bottom of the grooves were characterized. Various polarization configurations relative to the translation direction were compared. Such characterizations are relevant for the practical application of femtosecond laser micromachining. Silicon and gallium phosphide exhibited periodic structures after irradiation using photon energies less than the bandgap energy, with periods as small as ~20% of the irradiation wavelength. The significantly sub-wavelength periodic structures had a shallow profile on silicon, appearing as fine lines or grids of protrusions and depressions. On gallium phosphide, the surface evolved into planar-like structures with a large aspect ratio, possessing crystalline centers coated with amorphous material. These investigations, along with additional experiments, would help identify the precise physical origins of the short-period structures. On silicon and germanium, the target crystal orientation was shown to affect the formation of certain morphological features. For multiple-pulse irradiation, the (100) and (111) surface orientations exhibited significantly different tendencies for large conical structure formation. A thin layer of defected material coated the conical structures, with some defects present within the periodic structures. The different crystalline orientations did not affect periodic structuring. Cross-sectional transmission electron microscopy of silicon after irradiation by single pulses revealed amorphous material and dislocations in the bulk for sufficiently high pulse fluences. On a sample consisting of a metal layer on thermally-grown oxide on silicon, a range of pulse fluences was found which removed the metal layer without observed thinning of the oxide layer. Within this fluence range, above a particular fluence substantial defects were formed in the underlying silicon. Although ultrashort pulse irradiation of materials is frequently considered to be 'damage-free', attention should be paid to sub-surface modifications not evident from surface imaging. For the drilling of holes in copper foils, the pulse duration did not strongly affect the final morphology for durations under several picoseconds. A photodiode below the foil during drilling recorded transmitted light, indicating the number of pulses required for penetration under a variety of conditions, and characterizing hole evolution during drilling. Periodic surface structuring on the walls of holes depended on the irradiation atmosphere, pulse duration, and laser polarization. These measurements provide insight into the physical processes of material modification, and for the selection of irradiation parameters in practical applications.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Propagation Characteristics of Microstrip Transmission Lines on Intrinsic Germanium Substrates

contributor:
Gunn, M.W.
Chisholm, S.H.
Electrical Engineering

subject: microstrip, transmission line, line capacitance, conductor, intrinsic, substrates, Germanium

abstract:
 The microstrip transmission line has been theoretically analysed using conformal transformation and variational techniques. The variational method has been used to compute the line capacitance, characteristic impedance and guide wavelength of the following microstrip structures:
(i) Microstrip transmission lines having negligible and finite strip conductor thickness.
(ii) Microstrip transmission lines on two layer dielectric substrates having negligible and finite strip conductor thickness.

 The total losses incurred in microstrip lines on semiconductor substrates have been included. An experimental technique (based on the Deschamps method) for measuring the characteristic impedance of microstrip lines through a lossy junction using a high precision microwave reflection bridge has been described. Measurements of the characteristic impedance of microstrip lines on intrinsic germanium substrates have been carried out at 9.38 GHz, and good agreement between the theoretical and experimental results have been obtained.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: ACTION EFFECTS ON THE PERCEPTION OF MULTISENSORY EVENTS

contributor:
Shore, David I.
Psychology

subject:
multisensory
temporal order judgment task
point of subjective simultaneity
just noticeable difference
visuotactile
audiovisual
audiotactile
perceived onset
temporal precision
cognition and perception
cognitive psychology
action

abstract:
Voluntary actions affect subsequent perception. For example, an action that precedes an auditory stimulus is perceived to have occurred later in time than is actually the case, while the auditory stimulus is perceived earlier in time. This effect is known as intentional binding. Current literature regarding action effects focuses on perception of a single sensory modality while the effects on perception of multiple modalities remain largely unknown. The present thesis explored how actions influenced the timing of perceived multisensory events. Additionally, this thesis investigated differences in voluntary compared to involuntary actions on subsequent perception. In Chapter 2, action effects on perceived onsets of visual and tactile stimuli were explored. This question was extended to other bimodal pairs, including audiovisual and audiotactile, in Chapter 3. Lastly, in Chapter 4, action effects on temporal resolution were investigated.
In all the experiments, participants performed a chosen or a fixed button press that followed a bimodal temporal order judgment (TOJ) task. To investigate the influence of spatial proximity between actions and stimuli on binding, in Chapters 2 and 3, each stimulus modality appeared on different sides. In Chapter 4, the critical stimuli appeared at the same location, either close to or far from the preceding action, to explore the effect of action on temporal resolution. The present data provide evidence that actions affect the perceived onsets of multisensory events in an idiosyncratic manner, depending on the subsequent stimuli. Actions appear to preferentially bind to vision, then touch, and lastly, audition, but actions do not always bind to subsequent stimuli. Furthermore, actions degrade temporal resolution of bimodal stimuli. Lastly, the type of action, whether chosen or fixed, did not impact the degree of binding. Together, these data contribute to the action-perception literature, illustrating that our behaviours dynamically affect how we perceive the world.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Comparison Of The Recycling Potential of Hamilton-Wentworth With That of Halton Region

contributor:
Anderson, William P.
Geography

subject: expansion, Third Sector Employment Enterprises, recycling opeartions, Hamilton, Oakville, Burlington, Milton, Halton,  garbage

abstract: This study determines the potential for expansion within Third Sector Employment Enterprises: the recycling operation in Hamilton-Wentworth. Although the company has been in existence since 1977, it has not yet reached the level of viability achieved by other firms established at that time . This study involves a comparison of Third Sector with Halton,s Recycled Resources: the recycling firm in the Region of Halton. The comparison attempts to determine what factors within Third Sector and Hamilton-Wentworth are retarding the growth of the company. A quantitative comparison was used to contrast the net revenues of the two companies, and descriptive data was used to explain and qualify the quantitative findings. The analysis reveals that despite the operational differences between the two companies, it is community participation that makes Halton's Recycled Resources more viable than Third Sector. The concluding remarks make some suggestions as to how community participation, and thus Third Sector's operation can be improved.

abstract: Thesis

abstract: Bachelor of Arts (BA)