title: Role of portal and plasma glucose elevations in taste-to-postingestive consequence learning

contributor:
Weingarten, Harvey P.
Psychology

subject: Psychology Psychology

abstract: Animals are able to associate the taste of a food with its positive nutritive consequences and will modify their feeding behavior when re-exposed to tastes on the basis of this association. However, the specific nutritive consequence(s) that animals detect and associate with a food's taste are unknown. This thesis tested the ability of two postingestive events, elevations of plasma or portal glucose, to support taste-to-postingestive consequence learning. Two strategies were used to evaluate the relevance of elevations in plasma glucose in taste-to-postingestive consequence learning. First, since real, but not sham, feeding supports taste-to-postingestive consequence learning, I recorded plasma glucose levels during sham and real feeding (Experiment 1). For the first 15 minutes of the meal, both sham and real feeding produced similar elevations in plasma glucose. Thereafter, real feeding produced sustained elevations in plasma glucose, whereas sham feeding did not. Next, I paired tastes during sham feeding with a glucose infusion into the jugular vein, calibrated (Experiment 2) to mimick the plasma glucose profile of real feeding. Since rats that experienced tastes paired with plasma glucose elevations characteristic of real feeding, did not demonstrate taste-to-postingestive consequence learning (Experiment 3), plasma glucose elevations must not support taste-to-postingestive consequence learning. In Experiment 4 I also demonstrated that sham feeding produces elevations in plasma glucose because nutrient is absorbed. To assess the relevance of portal elevations in taste-to-postingestive consequence learning, I paired flavoured saccharin or flavoured glucose solutions with glucose infusions in the portal vein (Experiments 6 & 7). Only rats that received portal infusions of glucose paired with flavoured glucose solutions demonstrated taste-to-postingestive consequence learning (Experiment 7). Since oral glucose solutions, alone, elevate glucose levels in the portal vein, portal elevations of glucose may only support taste-to-postingestive consequence learning at suprathreshold levels. Alternatively, signal(s) arising from the stomach or gatrointestinal tract may potentiate the relevance of elevations of portal glucose since oral glucose solutions also stimulate these sites.

abstract: Doctor of Philosophy (PhD)


title: Large System Optimization Using Decomposition With Soft Specifications

contributor:
Siddall, J.N.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract: The problem considered is that of obtaining an optimum solution to large nonlinear engineering system by coordinated optimum solutions of smaller sub-systems. The technique produces a way of displaying graphically and numerically the trade-offs between each sub-system design objective and the sub-system joint design specifications. A nonlinear multi-variable fitting model is developed to represent the trade-off hypersurface. Shape, potential and advantages of the trade-off surfaces also are illustrated.

abstract: Master of Engineering (ME)


title: The optical properties of high-T(c) superconductors grown by pulsed laser deposition

contributor:
Timusk, T.
Physics

subject: Physics Physics

abstract: The discovery of superconductivity at temperatures in excess of 30 K has led to an unprecedented effort in both fundamental and materials research. Four separate projects will be presented here which encompass both types of research. The first two involve the deposition of superconducting thin films by the pulsed laser deposition technique. The final two projects use optical spectroscopy to probe the fundamental excitations which govern these exotic materials. All four projects are summarized below. Superconducting (Pb(0.75}Cu(0.25)Sr₂(Y1-yCay)Cu₂O₇ films were successfully deposited by pulsed laser deposition. The films are grown in situ on (100) LaAlO₃ at the relatively low substrate temperature of 620℃. The films are highly oriented with their c-axis perpendicular to the substrate and exhibit a surface morphology which is unique to the oxide superconductors. The growth procedure used yields relatively sharp superconducting transitions and a maximum Tc that exceeds all other reported values. By substituting Ca for Y it is possible to systematically vary the superconducting transition temperature from 10 K to a maximum of 86 K. The laser deposition system was also used to deposit superconducting Nd(1.85)Ce(0.15)CuO(4+δ) thin films. By carefully controlling the film's oxygen content through high temperature vacuum anneals it is possible to obtain a superconductor with a transition temperature which onsets at 21 K. The high temperature anneal can result in a film surface which is copper deficient. By optimizing the growth parameters we have been able to eliminate this layer resulting in films with superior homogeneity. The films are highly oriented with their c-axis perpendicular to the substrate and show a surface morphology of high quality. The far infrared optical properties of the Nd{1.85}Ce{0.15}CuO{4+δ} films were measured using Michelson interferometry. The reflectance spectra clearly show the presence of a ledge at 420 cm⁻¹ offering further evidence that this feature is common to all the cuprate superconductors. The optical conductivity obtained from Kramers-Kronig analysis can be divided into two components. The first component, which is strongly temperature dependent, is fit to a Drude model. This fit indicates that Nd{1.85}Ce{0.15}CuO{4+δ} has a constant plasma frequency and a temperature dependent scattering rate which closely follows the temperature dependence exhibited by the dc resistivity. The second component shows little temperature dependence and is described by a model which couples phonons to a midinfrared band. Comparisons between the optical conductivity and the structures seen by tunneling and inelastic neutron scattering measurements are made. In the final project, the far infrared reflectance of partially transparent (Pb{0.75}Cu{0.25})Sr₂(Y{0.4}Ca{0.6})Cu₂O₇ films were measured. As was the case for Nd{1.85}Ce{0.15}CuO{4+δ}, the normal state results were described in terms of the two component model. Once again, the Drude component showed a constant plasma frequency and a scattering rate which closely follows the temperature dependence of the dc resistivity while the second component showed only a small change as the temperature was varied. In the superconducting state the reflectance spectra do not exhibit the clean limit behaviour that has been observed in the other oxide superconductors. A measurable fraction of the Drude component's oscillator strength does not condense into the delta function which creates the possibility of observing structure associated with a superconducting energy gap.

abstract: Doctor of Philosophy (PhD)


title: Experimental studies of time-resolved light propagation in turbid media

contributor:
Patterson, Michael S.
Physics

subject: Physics Physics

abstract: The purpose of the work presented here is to determine whether time-resolved remittance spectroscopy can be used to determine noninvasively the optical properties of turbid media such as biological tissue. Knowledge of these properties is important in both therapeutic and diagnostic applications of light in medicine. In all experiments, the propagation of light was modelled as a diffusive process. The thesis consists of three interrelated sections. In the first section, the optical properties of tissue-simulating liquid phantoms were determined using established techniques based on steady-state diffusion theory and Monte Carlo simulations. In the second section, time-resolved experiments were performed in homogeneous liquid phantoms of varying geometries, and the ability of a simple time-dependent diffusion model to predict the remitted (transmitted or reflected) pulse shape and hence the optical properties of the phantoms was determined. In the final section, time-resolved studies were conducted in a homogeneous brain-simulating phantom containing discrete absorbing or scattering objects. Picosecond laser pulses were incident on the inhomogeneous phantom and the remitted pulses were compared to model pulses derived from a finite difference representation of the time-dependent diffusion equation.

abstract: Doctor of Philosophy (PhD)


title: A study of coupled interfacial reactions and diffusion in multi-component metallic/ionic systems

contributor:
Lu, W-K
Materials Engineering

subject:
Materials Science and Engineering
Materials Science and Engineering

abstract: A study consisting of theoretical and experimental work on kinetics of simultaneous interfacial reactions in multi-component metallic/ionic systems has been carried out in the present work. General rate expressions for simultaneous interfacial reactions are proposed based on the application of mass action law to the electrodic half-cell reactions and the constraint of no net electric current. The nature of coupling among interfacial reactions is discussed by defining the coupling factor which is a collective property of the system, contributed by and common to all interfacial reactions. Kinetic behavior of each element can be individually and simultaneously described. Experimental work is conducted in slag/metal system for the study of coupled interfacial reactions and diffusion. Considering interfacial reactions as the boundary conditions for diffusion in both phases, a mathematical model is developed. Computed results, based on thermochemical parameters mostly reported in the literature, are compared with diffusion profiles measured by electron probe microanalysis (EPMA) in silicate slag and Fe-Mn-Si alloy at 1763$\sp\circ$K. Values of reaction rate constants for transfer of iron, manganese and silicon are recommended through curve fitting with the experimental data. The conventional pseudo-binary approach in the formulation of rate equations for interfacial reactions in multi-component slag/metal systems may be deduced from the present theory with simplifying assumptions and as a limiting case.

abstract: Doctor of Philosophy (PhD)


title: Fatty acid uptake in Escherichia coli: Development of a photoaffinity labeling approach for identifying proteins involved in the transmembrane movement of long chain fatty acids

contributor:
Gerber, Gerhard E.
Biochemistry

subject: Biochemistry Biochemistry

abstract: The photoreactive fatty acid 11-m-diazirinophenoxy-[11-³H]-undecanoate was shown to be taken up specifically by the long chain fatty acid transport system expressed in Escherichia coli grown on oleate. This photoreactive fatty acid analogue was therefore used to identify proteins involved in fatty acid uptake in E. coli. The fadL protein, required for fatty acid permeation of the outer membrane of E. coli was labeled by the probe, confirmed to be exclusively in the outer membrane and to exhibit the heat modifiable behaviour typical of outer membrane proteins. The fatty acid uptake activity in E. coli was reduced upon starvation whereas proline uptake was not affected. The inhibitory effect of starvation was rapidly reversed by the addition of D-lactate, L-lactate, succinate or acetate. The stimulatory effect of D-lactate on oleate uptake increased the affinity of the transport system for fatty acid and the maximal rate of uptake, the Kt values being 37.0 and 10.6 μM and the maximal rates being 0.29 and 2.30 nmole/min/mg of protein in the absence and in the presence of D-lactate, respectively. Investigation into the mechanism of regulation of fatty acyl-CoA synthetase showed that D-lactate did not affect the activity of the enzyme directly. It was shown that fatty acyl-CoA synthetase is co-isolated with the inner membrane in the presence of D-lactate but not in its absence; these results suggest that recruitment of the enzyme to the inner membrane by D-lactate results in its activation and consequently in the increased level of fatty acid uptake. The involvement of fatty acyl-CoA synthetase in fatty acid uptake was studied directly using inner membrane vesicles. The vesicles were characterized functionally by assessing proline uptake. The uptake of proline in vesicles prepared from cells grown on oleate, glucose and palmitate was dependent on the state of energization of the membrane, indicating that these vesicles are functionally comparable to those prepared by others. It was determined that vesicles prepared from cells grown on oleate were destabilized by freeze-thawing which is required for trapping CoASH and ATP, while those prepared from glucose and palmitate grown cells were not. Fatty acid uptake in palmitate vesicles containing fatty acyl-CoA synthetase was dependent on exogenously trapped ATP and CoASH. These results demonstrate that fatty acyl-CoA synthetase is directly involved in fatty acid uptake in E. coli and suggest that the observed effects of starvation and D-lactate on oleate uptake in whole cells are related to regulation of fatty acyl-CoA synthetase. This in vitro system will allow for the study of the recruitment of fatty acyl-CoA synthetase to the inner membrane by D-lactate, succinate, L-lactate, acetate and their metabolites. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: The role of cytotoxic T lymphocytes in HIV infection

contributor:
Rosenthal, K.L.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: The acquired immune deficiency syndrome (AIDS) is an incurable disease caused by infection with the human immunodeficiency virus (HIV). In the eight years following identification of HIV as the cause of AIDS, little progress has been made in understanding the complex pathogenesis of AIDS or in developing effective therapies to forestall disease progression. All current strategies to treat HIV infection assume that disease progression is directly related to infection of and replication in CD4⁺ lymphocytes by HIV. Recent theoretical and experimental studies have raised the possibility that the pathogenesis of AIDS depends upon indirect effects of HIV infection; namely the induction of deleterious immune responses. In this study, we examined the effects of HIV infection on cytotoxic T lymphocyte (CTL) activity. Three aspects of CTL activity in HIV infection were examined: the role of anti-HIV CTL in suppressing viral replication and disease progression; the role of autoimmune CTL in CD4⁺ lymphocyte depletion in HIV infection; and changes in the CTL repertoire in HIV infection and the relationship of these changes to progressive CD4⁺ lymphocyte depletion. Although a possible role for circulating anti-HIV CTL in suppressing HIV replication in vivo was seen, there was no evidence that these CTL protect against CD4⁺ lymphocyte depletion. This suggests a dissociation between viral replication and CD4⁺ lymphocyte depletion. Autoimmune CTL that lysed uninfected activated CD4⁺ lymphocytes were found in HIV-infected individuals. The natural history of CD4⁺ lymphocyte depletion suggested a relationship between this CTL activity and in vivo depletion of CD4⁺ lymphocytes. Autoimmune CTL had a conventional phenotype, but were not HLA-restricted. The characteristics of these CTL suggested a mechanism of CD4⁺ lymphocyte depletion involving recognition of CD4⁺ T cell receptor (TCR) idiotypes by the autoimmune CTL. Skewing of the CTL repertoire was also demonstrated in HIV infection. The increased incidence of skewing of TCR variable domain (V) gene usage observed in parallel to CD4⁺ lymphocyte depletion is consistent with an interdependence of the selective expansion of CTL and depletion of CD4⁺ lymphocytes. Results of this thesis suggest that autoimmune CTL play a role in the pathogenesis of AIDS and are rational targets for novel therapeutic approaches to the treatment of HIV infection.

abstract: Doctor of Philosophy (PhD)


title: Modified Ziv-Zakai lower bound on the errors of the estimation of DOA

contributor:
Wong, K.M.
Electrical and Computer Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract: This thesis has been directed toward the problem of deriving a computable tight lower bound on the error of DOA estimation with the array processing. This work is developed based on the logic implied in Ziv-Zakai's idea and the work for Cramer-Rao lower bound (CRLB). A profound understanding of Ziv-Zakai's idea is presented. The lowest bound on the variance of DOA estimate with one incoming signal is derived applying the logic of Ziv and Zakai. Then the modified Ziv-Zakai lower bound (MZLB) on the covariance matrix of the multiple DOA estimates is developed. The theoretic analysis and the simulation results show that MZLB is a tight lower bound over a wide range of signal-noise ratio. It follows the SNR-threshold phenomenon occurring in the performance of the DOA estimation well, and it is easily computable. It is proved that, the maximum-likelihood estimation of DOA parameters based on Data Model(2) discussed in this thesis is asymptotically efficient.

abstract: Doctor of Philosophy (PhD)


title: Poetry of maledictions: A commentary on the "Ibis" of Ovid

contributor:
Kingston, P.
Classics

subject: Classics Classics

abstract: The Ibis of Ovid, an enigmatic poem written during the poet's exile at Tomis, contains a series of violent and allusive imprecations drawn from history and mythology. The purpose of this dissertation is to provide a detailed study of the poem, to aid readers in their understanding and appreciation of the historiae caecae and ambages in which Ovid takes such delight; accordingly, an introductory chapter attempts to outline the historical and literary background to the poem, with particular attention devoted to placing the poem more firmly within the sphere of imprecatory writing in the ancient world. Following this is an explanatory commentary which covers models, parallels for topoi, and explanations of references, meanings, and allusions in the Ibis. Inevitably, this commentary is indebted to the efforts of previous commentators; however, I have endeavoured throughout to suggest additional lines of enquiry and to provide a fresh perspective on a challenging work.

abstract: Doctor of Philosophy (PhD)


title: Finite element analysis of damped vibrations of laminated composite plates

contributor:
Dokainish, M.A.
Mechanical Engineering

abstract: In this thesis, the damped free vibrations of composites are treated from the viewpoint of macromechanical analysis. Two damping models are developed, namely: the Viscoelastic Damping (VED) model and the Specific Damping Capacity (SDC) model. The important symmetry property of the damping matrix is retained in both models. A Modified Modal Strain Energy method is proposed for the evaluation of modal damping in the VED model using a real, instead of a complex, eigenvalue problem solution. Numerical studies of multi degree-of-freedom systems are conducted to illustrate the better accuracy of the method compared to the Modal Strain Energy method. The experimental data reported in the literature for damped free vibrations, in both polymer-matrix and metal-matrix composites, were used in the finite element analysis to test and compare the damping models. The natural frequencies and modal damping were obtained using both the VED and the SDC models. It was shown that the results from both models are in satisfactory agreement with the experimental data. Both models were found to be reasonably accurate for systems with low damping. Parametric studies were conducted to study the effects on damping of the side-to-thickness ratio, the principal moduli ratio, the total number of layers, the ply-angle and boundary conditions.

abstract: Doctor of Philosophy (PhD)


title: Creative Adequation: Merleau-Ponty's Philosophy of Philosophy

contributor:
Madison, Gary B.
Philosophy

subject:
Arts and Humanities
Philosophy
Arts and Humanities

abstract: Phenomenology is oharacteristically assooiated with the motto 'to the things themselves', or even more tellingly, 'back tc the things themselves'. This injunction makes senSe only against the background of the belief that somehow we are at Some remove from 'the things themselves' tc which we are inv i ted to return. In phenomenology, this 'origin' is variously determined as 'experience', 'existence', 'the life-world', and sa on. Much depends upon how we understand thiS return that phenomenology advocates and practises. On one interpretation, phenomenology claims to extricate itself from prejudices, which distort or otherwise falSify 'experience', in favour of achieving a direct and presuppositionless contact with experience, as if there were something like a pristine experience, a raw datum, that could be disclosed in a presuppositionless seeinga Such is how Derrida, for example, interprets phenomenology, and it is on these grounds that he relegates it to the 'metaphysios of presence'. Several commentatorS have argued (and Derrida himself has suggested) that Merleau-Ponty's The Visible and the Invisible breaks with phenomenology in the above Sense a argue that even in hiS Phenomenology of Perception (and to a lesser extent in Husserl's later writings) phenomenology is in fact less naive than Derrida and others would have uS believe. Admittedly, conservative prejudioeS are at work in the Phenomenology, but on the whole the momentum of the text is on the Side of a break with and implicit critique of the metaphysicS of presence. Certain indications to the contrary notwithstanding, Merleau-Ponty attempts to articulate a conception of phenomenology significantly different than the one described above~ a conception that would take into account the fact that phenomenology is itself a point of view and as such mediates the disclosure of lthe things themselves'. Merleau-Ponty focuses this mediation with reference to language, and more preoisely with referenoe to phenomenology as itself an instance of language, Such development as occurS in his philosophy fleshes out, and does not repudiate, the teaching of the Phenomenology concerning language and expression. The phenomenologist neither mirrors nor coincides with experience in the sense of a full presence on the other side of speech. He expresses experience, and hiS expression is necessarily a creative deed. ThiS emphaSiS upon phenomenology's creativity has not received due recognition in the literature on Marleau-Panty. Merleau-Ponty's philosophy, argue, is best characterized as an attempt to reconcile the ideas of adequation and creativity. It embraces both the demand to return to 'the things themselves', the demand to be faithful to experience, and the recognition that, in virtue of its own linguisticality, phenomenology's rendering of experience is neoessarily creative. ThiS tenSion, which traoe throughout Herleau-Ponty's writings, is what is comprehended in the paradOXical expression 'creative adequation'.

abstract: Doctor of Philosophy (PhD)


title: Fabrication and characterization of silicon/silicon(1-x) germanium(x)-based double heterojunction optoelectronic switches (DOES) and heterojunction field effect transistors (HFET)

contributor:
Simmons, J.G.
Jessop, P.E.
Engineering Physics

subject:
Engineering Physics
Engineering Physics

abstract: The fabrication and characterization of the double heterojunction opto-electronic switch (DOES) and the heterojunction field effect transistor (HFET) in the Si/Si_(1-x)Ge_(x) materials system is described. The significant achievements of this work are summarized below. The theory of operation of the DOES and HFET are reviewed. A computer-based, one-dimensional, analytical model is used to calculate the current-voltage characteristics and operational parameters of the DOES. From this, the design of the inversion-channel Si/Si_(1-x)Ge_(x) heterostructure is shown to contain a manifold parameter space. For example, the switching voltage of the DOES is shown to be extremely sensitive to the magnitude of doping in the charge sheet. In the HFET, the threshold voltage is calculated to have a non-linear dependence on the magnitude of the doping in the charge sheet. The measured switching voltages and currents compare well with the calculations of the model. Separately, the effects of illumination and temperature on the dc electrical characteristics of the device are investigated. Illumination is seen to reduce the switching voltage and holding current. With decreasing temperature, the switching voltage and holding current are observed to increase. The effects of illumination and temperature are explained as phenomena related to carrier injection (or the lack thereof). An account of the fabrication of these devices is given in detail. A self-aligned technology for the Si/Si_(1-x)Ge_(x)-based HFET was developed using the aluminum gate as a mask for reactive ion etching and ion implantation procedures. Oscillatory electrical behavior of the DOES is examined. Self-induced oscillations are shown to be correlated to the regime of negative differential resistance. The dc current-voltage characteristics of the DOES are demonstrated to be affected by this oscillatory behavior. In addition, an enhancement in the optical emission over a narrow range of drive currents in the DOES is shown to be a result of device oscillations. Changes in the electrical characteristics of the DOES in response to third terminal current injection are measured for both active layer contact and inversion layer contact. Contact to the inversion layer is shown to be more effective than a third terminal contact to the active layer. These experimental observations are supported by the computer-based model. Concurrent usage of optical and electrical injection to affect the I-V characteristic of the device is demonstrated. Electrical extraction via the third terminal is shown to negate the effect of optical injection. The highest reported transconductance in a Si/SiGe-based metal-semiconductor FET is found in the HFETs reported in this thesis. Peak transconductance of 8mS/mm is measured for a depletion mode device. Subthreshold slope is measured as 720mV/decade and a high frequency 3-dB point for voltage gain is seen to be 1.8GHz. The suitability of this technology for integration is examined by demonstrating a Reset-Set Flip-Flop which is comprised of two HFETs and a three-terminal DOES. The range of operational voltages for the circuit are shown to be determined primarily by the operational characteristics of the DOES. Gate leakage from the HFET is seen to hinder circuit performance.

abstract: Doctor of Philosophy (PhD)


title: Experimental Study of a Cold Flow Radial Turbine

contributor:
T., J. H.
Weaver, D. S.
Mechanical Engineering

abstract:
The experimental study of an inward radial flow turbine is described in this report. Preliminary tests of the turbine by United Aircraft of Canada Ltd. indicated that the isentropic efficiency was some 50% below the design target of 80% efficiency. In an effort to locate problem areas in the turbine design, the unit's response is examined under four different load conditions at speeds ranging from 10,000 to 75,000 RPM and pressure ratios from 1.2 to 2.4. The results of these tests are presented using a series of non-dimensional parameters typically employed in turbine and compressor design. From these parameters it is evident that the poor response of the unit is due to the high degree of exit swirl introduced into the primary diffuser by the "exducerless"turbine blades.

The response characteristics of the unit are examined in the light of the experimental results, and explanations of various phenomena are offered.

abstract: Master of Engineering (ME)


title: A Palaeobiological Approach to Incised Valley-Fills, Alberta Basin (Dunvegan and Viking Alloformations)

contributor:
Walker, Roger G.
Geology

subject:
Earth Sciences
Geology
Earth Sciences

abstract: This study was undertaken to further understand the interrelationships between the endobenthos and sedimentation. Quantification of ichnospecies abundance and diversity are used to interpret their significanceand the ecologicalconditions two sedimentologically different incised valleyfills. This study is based on cores from two incised valley-fills from the Cretaceous Western Interior Seaway (Alberta). The first, the Waskahigan Channel (Shingle Dl) in the Dunvegan Allofonnation (Cenomanian) interpreted as a migrating delta, contains mud and fine-grained sand. The second, the South Willesden Green Channel (Allomember C) in the Viking Allofonnation (Albian) interpreted as a straight incised valley-fill, contains coarser, reworked marine sand and conglomerates. These differences provide a comparative test for the innovative techniques used herein. TInsresearch provided a tool to interpret changes in sea level and the depositional environment by subtle changes observed in the abundance and diversity of ichnofossil communities and ichnofacies. ill the Waskahigan Bottleneck Channel (7-13-64-24W5), estuarine sand flats are distinguished by the such changes. The assemblages' abundance and diversity increased, then decreased and increased again as the channel infilled. In the South Willesden Green Channel, core IO-35-40-7W5 is interpreted as estuarine bay fill deposit. Without quantitative ichnology, the five successive fills recognized herein would be considered one deposit. In both channels, shells and shell fragments are absent as a result of physical weathering and chemical dissolution. This study contributes methods of ichnological quantification and comparison in subsurface core. TI,e subtle details reveal more information about the ecological conditions during the infilling of these Cretaceous depositional environments.

abstract: Master of Science (MS)


title: Sedimentology, Stratigraphy, and Depositional History of the Lower Cretaceous Viking Formation at Willesden Green, Alberta, Canada

contributor:
Walker, R.G.
Geology

subject:
Earth Sciences
Geology
Earth Sciences

abstract: The Lower Cretaceous Viking Formation is a complex stratigraphic unit containing a variety of geographically separated sand bodies of varying orientation, thickness and lithology. Many of these sand bodies are prolific hydrocarbon reservoirs which have been extensively drilled by industry. Despite this fact, their origins and interelationships are largely unknown. Establishment of a Viking Allostratigraphy in the Willesden Green area (1) allows the recognition of distinct allomembers based on bounding discontinuities and facies associations, and (2) determines the exact stratigraphic relationships and depositional histories of the Viking oil and gas fields as defined by basin-wide sea level fluctuations. Detailed core and log correlations indicate that in the Willesden Green area, the Viking Formation is made up of 4 distinct packages of sediment separated by 3 major stratigraphic breaks. The lower most package is regional in extent, and consists of three gradational coarsening-upward cyclic offshore mudstone/siltstone sequences (Members A and B). At Willesden Green, Member B is erosively incised by a major unconformable scour surface (VE2 - Viking Erosion surface 2) filled with conglomerate-rich channel/estuarine sediments (Member C). The VE2 incision was carved during an initial Viking lowstand, and infilled during a temporary stillstand in the ensuing transgression. The top of Member C is erosively truncated by a regionally tracable pebble-mantled ravinement surface (VE3). Member D, a sandying-upward sequence of storm-dominated lower shoreface to transitional offshore sediments, overlies VE3, and records a second major Viking progradational event. This unit thickens southward, and can be traced laterally into correlative upper shoreface and nonmarine sediments at Caroline and Harmattan. The top of Member D is bevelled by a second basin-wide ravinement surface (VE4) which rises in a step-like fashion towards the south. This surface is mantled by a thin veneer of pebbles which locally accumulate to form the elongate shaleencased, conglomeratic shelf sand bodies of Member E. Member E gradationally passes upward into the silty shales of the Colorado Group and records a final transgressive flooding of the Viking basin.

abstract: Master of Science (MS)


title: Anisotropy in the electrical, magnetic and optical properties of lead(2) strontium(2) R copper(3) oxygen(8)

subject: Physics Physics

abstract: The layered structure of the cuprate superconductors leads to a significant anisotropy between ab-plane and c-axis properties which is significantly greater in Bi₂Sr₂CaCu₂O₈ (BSCCO) than in YBa₂Cu₃O_(7-x) (YBCO); likely due to differences in intercalary structure since both systems contain double CuO₂ layers. Pb₂Sr₂(Y/Ca)Cu₃O₈ (PSYCCO) is another system containing double CuO₂ planes which are separated by a PbO-CuO_δ-PbO sequence, the PbO bi-layer analogues to the double BiO sheets in BSCCO and the CuO_δ layer comparable to an oxygen depleted chain layer such as in YBa₂Cu₃O₆. The structural similarities render this material a good candidate for further study. Measurements of anisotropy in the dc-resistivity, magnetization and optical properties of PSYCCO are presented. The magnetization measurements are analyzed to extract both the in-plane and c-axis fundamental superconducting parameters of this material: Tc, the magnetic penetration depth, the coherence length, the upper and lower critical fields, and the upper critical field slope near Tc. The dc-resistivity is an order of magnitude larger than in both YBCO and BSCCO while the optically-derived plasma frequency is considerably smaller than in the other systems. Together with a large penetration depth this suggests that the carrier concentration is unusually small given the high transition temperature (≈ 80 K), and represents a significant deviation from a proposed universal relationship between level of doping and Tc. The extent of the anisotropy in this system is found to be similar to that in YBCO. The low carrier density has facilitated observation of unusual behaviour in the optical properties such as a large finite frequency-centered peak which develops in the optical conductivity upon entry into the superconducting state. The doping dependence of the ab-plane optical properties is investigated via the Ca-free Pb₂Sr₂RCu₃O₈ series, which exhibits a metal/insulator transition as a function of increasing ionic radius of the rare earth. A transfer of spectral weight from the CuO charge transfer band to lower frequencies accompanies the progression to metallic character. As this electronic background develops phonons in the far infrared reflectance of the insulating members become weaker while concurrently there is an appearance of new phonon modes in the 400-600 cm⁻¹ region of the spectrum. These phonons develop an antiresonant-like lineshape at higher doping levels. Examination of several high Tc superconductors with similar structure leads to the hypothesis that these features are due to the coupling of longitudinal c-axis phonons to the ab-plane mid infrared continuum. A surprising consequence, confirmed by experiment, is that due to momentum conservation the ab-properties are different when measured on the ab-plane face and along the a or b directions of a face containing the c-axis.

abstract: Doctor of Philosophy (PhD)


title: Quantum mechanical problems in one, two and three dimensions

contributor:
Bhaduri, Rajat K.
Physics

subject: Physics Physics

abstract: The underlying theme of this thesis is to solve mathematical models related to physical problems in one, two and three spatial dimensions. In some cases, particularly in one spatial dimension, the equations could be solved exactly, while for models in higher dimensions, the solutions were approximate. Although the four separate chapters of the thesis are largely independent, quantum statistics played an important role in the models considered. In the following paragraphs, I briefly summarize the contents of the four chapters. An exactly solvable field theoretical model in one spatial dimension and its classical bound state solution (including the zero mode) are presented in chapter one. The related bosonization and vacuum charge are discussed. In chapter two, a many-anyon system in two dimensional space with a confining potential is solved using the Thomas-Fermi mean-field method. The ground-state energy and spatial distribution are obtained as functions of the statistical parameter. In chapter three, Chern-Simions coupling to fermions in two dimensions is considered. A zero-mode soliton solution is obtained. Classical vortices in fluid mechanics are shown to be mathematically analogous to anyons. Some new results are derived using this analogy. Finally, in three-dimensional space, the vacuum properties of the Nambu-Jona-Lasinio model are studied at both zero and finite temperatures. The vacuum condensation energy per unit volume is calculated and is identified as the MIT bag constant. Some other thermodynamic properties are also calculated, showing striking similarity to the BCS superconductor. A scaling law of the chiral condensation energy density in a nuclear medium is suggested.

abstract: Doctor of Philosophy (PhD)


title: An investigation of polyolefin manufacturing technology: Mathematical modelling of polymerization and polymer modification processes

contributor:
Hamielec, Archie E.
MacGregor, John F.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract: The work described in this thesis can be broken down into two separate parts. The first deals with the mathematical and computer modelling of industrially important methods for the production of polyolefins, specifically: (a) the high pressure tubular reactor process, (b) the high pressure autoclave type reactor process, and (c) the low pressure Ziegler Natta reactor process using heterogeneous catalysts. The second part deals with the chemical modification of these polymers by free radical methods during the extrusion process. Free radical copolymerization of ethylene in high pressure reactors is considered. Kinetic mechanisms to describe the polymerization rate and polymer properties, including copolymer composition, molecular weight, branching frequencies, melt flow index and polymer density, have been proposed. The method of moments is used, in conjunction with pseudo kinetic rate constants to allow for copolymerization, to calculate the molecular weight averages. Based upon this kinetic scheme, a mathematical model has been derived and implemented as computer programs to simulate commercial tubular and autoclave type reactors. The model parameters were fit to steady state data from industrial reactors. The dynamic autoclave reactor model includes the two phase kinetics due to polymer-monomer solubilities and phase separation in the reaction mixture. Gel formation from crosslinking reactions is also analyzed. A mixing model is developed to represent the flow inside the reactor. In the simulation PID control equations are used to maintain operation at the unstable steady state. A sensitivity study is performed on the mixing model parameters and on some of the kinetic parameters. The model is compared to steady state temperature, initiator flow and conversion data from commercial reactors. Many polyolefins are produced using heterogeneous Ziegler Natta catalysts either in gas phase, bulk or slurry type reactors. These properties include broad molecular weight and copolymer composition distributions. A kinetic model has been derived, based upon multiple catalyst sites of differing reactivities, for the Ziegler-Natta copolymerization of olefins. The model predicts the rate of polymerization, the copolymer composition and the molecular weight distribution of the polymer produced as well as accounting for the observed broad copolymer composition and molecular weight distributions. This dissertation deals with the development of mathematical models to relate the molecular modifications, scission, branching, crosslinking and grafting. The models, based upon generally accepted kinetic mechanisms and certain assumptions about the nature of simultaneous scission and crosslinking, can predict the molecular weight averages, degrees of crosslinking, scission and grafting, and the sol/gel ratio. A mathematical formulation to describe simultaneous random scission and crosslinking has been presented in the literature but only solved by assuming that scission and crosslinking occur serially. For this work, an algorithm to numerically solve this equation was developed. The results of these calculations were compared to the classical solutions to this problem and to the experimental data gathered in this project. This model, although applied to polyolefin modification, has applications for other systems where simultaneous random scission and crosslinking of polymers is encountered. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Modelling and measurement of unconfined bubbly two-phase plume flow

contributor:
Irons, G.A.
Materials Science and Engineering

abstract: Bubbly plume flow, which is encountered in many refining processes of the iron and steel making industry, has been studied with a water model ladle and simulated with a novel mathematical model. The main achievements of this project can be summarized as following: (1) A new experimental technique based on the Laser Doppler Anemometry and Electrical Probe has been developed to measure various flow parameters of the plume, such as: mean and turbulent liquid velocities, bubble velocities and distributions of void fraction and bubble frequency. (2) The turbulence feature and bubble behaviour in the gas/liquid two-phase zone has been experimentally studied with the newly developed LDA/EP technique in a water model ladle. It has been found that turbulence in the plume zone is close to an isotropic one and the relative velocity of bubbles is not affected by the void fraction in the plume. (3) A mathematical model based on the modified k-ε turbulence model has been developed to simulate the plume flow. The coefficients of the extra source terms of the modified k-ε model have been determined experimentally. The mathematical model yielded good predictions of both the mean and the turbulent liquid velocities. The behaviour of bubbles in the plume has also been dealt with to produce good predictions of the void fraction distributions.

abstract: Doctor of Philosophy (PhD)


title: Topics in the design, analysis and implementation of feedback control systems

contributor:
MacGregor, J.F.
Wright, J.D.
Chemical Engineering

abstract: This thesis investigates the design, analysis and implementation of feedback control systems. A new definition of robustness for continuous feedback control systems is advanced: the region of the joint allowable variation in the gain and the dead-time of the process. This region is constructed from the open loop system frequency response. The continuous time Proportional-Integral-Derivative (PID), Internal Model Control (IMC) and Linear Quadratic Optimal Control (LQOC) design procedures for a first order plus dead-time process are compared for Integral Square Error (ISE) performance when tuned for the same level of robustness. The order from highest to lowest performance is: PID, IMC, LQOC. The robustness analysis method is used to explain the adverse effects of dead-time compensation on robustness. The continuous ISE performance of the discrete LQOC, and State Deadbeat IMC controllers are compared as the size of the control interval is changed; which one is better is shown to depend on the choice of the control interval. A new modified LQOC controller and a new Extended Horizon controller are proposed. The robustness analysis developed for continuous systems is extended to discrete systems as the region of joint allowable variation in the process gain and quasi dead-time. This region is constructed from the discrete open loop frequency response. The state deadbeat IMC with an augmented filter, and modified LQOC controllers are shown to have better ISE performance than the LQOC controller when tuned for the same level of robustness. A procedure is presented for saturation correction in multivariable one-step optimal controllers. A simultaneous correction is included which adjusts the remaining control inputs if some inputs saturate. The procedure is applicable to all related controllers including IMC. Results on saturation correction for PID controllers are also presented.

abstract: Doctor of Philosophy (PhD)


title: Spectroscopic Studies of Antimony III and V Halide Complexes

contributor:
Birchall, T.
Chemistry

subject: Chemistry Chemistry

abstract:
Antimony-121 Mössbauer spectra have been recorded at liquid-helium temperatures for a number of complex anions derived from SbF₃: M₂[SbF₅] (M₂ = Na₂, K₂, or N₂H₆); NaSbF₄; M[SbClF₃] (M = K or NH₄); Na[SbClF₃]·H₂O; M[Sb₃F₁₀] (M = Na, T1, or NH₄); M[Sb₄F₁₃] (M = K or Cs); and [NH₄]₄[Sb₅F₁₉]. The data were consistent with the known stereo-chemistry of these compounds in which the anitmony 5s electron pair is stereochemically active in a distorted AX₆E environment with a 3:3:1 arrangement or monocapped octahedron, the lone pair in the 1 position.

The ¹²¹Sb Mössbauer spectra of a number of [SbX⁻₄] (X = Cl, Br, or I) and [Sb₂X₉³⁻] (X = F, Cl, Br, or I) salts have been reported. Only [Sb₂F₉³⁻] shows a significantly large quadrupole splitting with the 5s electrons being stereochemically active.

The nature of the compounds of the series SbCl₅₋ᵪFᵪ have been in dispute in the literature for several years, but only SbCl₄F, which has been identified as a cis-fluorine bridged tetramer, and "SbCl₂F₃", which has been shown to exist with the ionic formulation [SbCl₄⁺][Sb₂Cl₂F₉⁻], are well characterized. It was found in this work that a fluorine bridged [SbCl⁺₄][Sb₂Cl₂F₉⁻] species in the solid state is more consistent with the chemistry of this compound. The previously unknown Sb₃Cl₁₀.₇₅F₄.₂₅ was prepared and found from X-ray crystallography to exist as a disordered cis-fluorine bridged trimer in the solid state. SbCl₃F₂ was prepared and characterized as a cis-fluorine bridged tetramer in the solid state. An attempt to prepare SbClF₄ always resulted in the formation of [SbCl⁺₄][Sb₂F₁₁⁻], which previously had been little studied. These SbCl₅₋ᵪFᵪ compounds have been characterized using Mössbauer and Raman spectroscopy, and Mass spectrometry. The reaction of SbCl₄F with strong Lewis acids was also investigated. SbCl₄F was found to form [AsCl₄⁺]-[SbF⁻₆] with AsF₅, [SbCl₄⁺][Sb₂Cl₂F⁻₉] with SbF₅, and a polymeric complex of the type [SbCl₄F.(NbF₅)ᵪ] (x = 1, or 2) with NbF₅.

The reaction of alkali metal halides with antimony(V) halides in liquid SO₂ at room temperature yielded the salts: M[SbCl₆] (M = Na or K); Na[SbCl₄F₂]; Na[SbCl₂F₄]; and M[SbF₆] (M = K or Cs). The variation of ¹²¹Sb Mössbauer isomer shifts and quadrupole coupling constants are discussed in terms of molecular geometry. The salt Na[SbCl₄F₂] has been shown by Raman spectroscopy to exist as the trans isomer in the solid state.

Mössbauer data are reported for pure SbF₅ and SbCl₅, and when intercalated into graphite the spectra show that these halides do not enter the graphite lattice without some reduction to Sb(III) occurring.

Data are reported for a number of SbF₅·X adducts, where X represents SbF₃, AsF₃, or SO₂ at 4ºK. The Mössbauer parameters of SbF₅·SbF₃ (type A), and the SbF₅-SbF₃ 1:1 adduct, [Sb₂F²⁺₄][SbF₆⁻]₂, do not support the contention that these forms are identical.

The complex anions of [Te₂Se₂²⁺][Sb₃F₁₄⁻][SbF₆⁻] and [Te₃.₃Se₀.₇²⁺]-[Sb₃F₁₄⁻][SbF₆⁻] have also been investigated by the Mössbauer method. The magnitude of the n values calculated for the Sb(III) sites are interpreted in terms of the varying asymmetry about the principle axis, which passes through the lone pair of electrons.

abstract: Doctor of Philosophy (PhD)


title: Perceptual manifestations of an analytic structure: The priority of holistic individuation

contributor:
Brooks, L. R.
Psychology

subject: Psychology Psychology

abstract: For many natural categories, there is idiosyncratic information contained in the perceptual stimuli that is not likely to be represented in an analytic description of those stimuli, and thus is likely to be ignored during attempts to establish an abstracted, probabilistic description of the category. This idiosyncratic perceptual information is useful, however, in the identification of distinct individuals within a category and, therefore, will be important in more nonanalytic, exemplar based classification procedures. The present work addresses two such sources of perceptual information: (1) Feature Individuation, the specific manner in which each separate feature is manifested in an individual item, and (2) Holistic Individuation, the manner in which the item's separate features cohere into an individuated gestalt whole. Data from Experiment Sets 1 and 2 indicate that the presence of either source of perceptual information will have an impact on classification behaviour. Furthermore, the extent of this impact is, at least in part, a function of whether subjects are provided with the classification rule prior to training or are expected to induce the classification rule through repeated feedback during training. Data from Experiment Set 3 indicate that if both sources of perceptual information are present, holistic individuation of the stimuli has priority. The presence of individuated features is not sufficient to produce exemplar based transfer if an item's holistic individuality is altered, but will affect responding if the holistic nature of the stimuli is eliminated during the transfer phase of the experiment. Finally, data from Experiment Set 4 indicate that learning about the two types of nonanalytic information does not appear to be incompatible with learning about the analytic information contained in the stimuli. Learning to use these various sources of information for the purposes of classification, however, are somewhat antagonistic.

abstract: Doctor of Philosophy (PhD)


title: Seismic site response of alluvial valleys and effects on a suspension bridge

contributor: Civil Engineering and Engineering Mechanics

subject:
Civil Engineering
Engineering Mechanics
Civil Engineering

abstract: A study has been conducted on the seismic site response of alluvial valleys with limited width and the effects of spatially varying surface motions in these valleys on the response of a suspension bridge. The intent of this investigation is to extend the work carried out by seismologists on the two-dimensional seismic response of alluvial valleys to include the effects of stiffness variation with depth and non-linear behaviour of soils which were mainly considered by engineers in a one-dimensional perspective. One objective is to provide engineers with useful guidelines to predict the valley response at different sites. Another objective is to analyze the potential of soil conditions and subsurface topographic structure in alluvial valleys for producing significant variations in the bridge response to a multiple-support excitation. A simplified engineering model (frame model) has been developed to predict the non-linear seismic response of symmetrical valleys. The proposed model is a one-dimensional model which accounts for the limited horizontal extent of soil in a two-dimensional valley. The frame model provides valuable insight into the dynamic behaviour of the alluvial valley by identifying the vibration modes of significance and their variation in the horizontal and vertical directions. Response results from the frame model show good agreement with those results from the two-dimensional finite-element model of the valley. Effect of the key parameters governing the spatial variations of motions at different sites in the valley has been analyzed. This includes the effect of soil type, valley geometry and control motion characteristics in rock. It is found that the two-dimensional effect from the valley edges extends toward the centre up to a distance after which only one dimension, the depth, governs the response. The soil amplification varies from one soil type to another, depending on the stiffness of soil and the amount of damping existing during excitation. The magnitude of the surface spectral acceleration at a site depends on the proximity of the local-amplification period at site to the dominant period of the input rock record. Finally, the free-field surface motions in a hypothetical valley are applied to the Humber suspension bridge in U.K. It is concluded that the inclusion of the multiple-support excitation case in the analysis is significant when soil conditions and topography produce noticeable variations in the intensity of support motions in the period range of interest for the bridge response.

abstract: Doctor of Philosophy (PhD)


title: The Synthesis and Thermolysis of Triazolines, Triazolinones and Triazolinethiones

contributor:
Warkentin, J.
Chemistry

subject: Chemistry Chemistry

abstract:
The purpose of this work was to synthesize new triazolines utilizing the lead tetraacetate oxidation method, to establish the mechanism of cyclization and to explore thermal and photochemical decompositions of some triazolines.

The first part of this thesis describes the preparation of two new triazolines (3,3-dimethyl-5-imino-Δ¹-1,2,4-triazoline and 3,3-dimethyl-4-phenyl-5-phenylimino-Δ¹,1,2,4-triazoline) achieved by lead tetraacetate oxidation. The mechanism of LTA cyclization is discussed in the relation to the mechanisms of lead tetraacetate oxidations of semi-carbazones. The second part deals with thermal decomposition studies of 3,3-dimethyl-4-phenyl-5-phenylimino-Δ¹-1,2,4-triazoline, 3,3-dimethyl-4-phenyl-Δ¹-1,2,4-triazoline-5-thione and 3,3-dimethyl-4-phenyl-Δ¹,2,4-triazolin-5-one. Possible mechanisms of the decomposition are discussed in the light of a correlation between the rate constants, activation parameters, substituent constants and solvent effects. Exploratory work in the photochemical decomposition of 3,3-dimethy-4-phenyl-Δ¹-1,2,4-triazolin-5-one is presented in the third part.

abstract: Doctor of Philosophy (PhD)


title: Oxyfluoro Compounds of Bromine

contributor:
Gillespie, R.J.
Chemistry

subject: Chemistry Chemistry

abstract:
A number of new oxyfluoro compounds of Br (V) have been prepared and isolated; their structures and some of their reactions have been investigated by ¹⁹F nmr and Raman spectroscopy. The previously reported oxyfluoride BrO₂F has been characterized for the first time, and the preparation and characterization of the previously unknown BrOF₃ is described. Reaction of these oxyfluorides with the Lewis acids BF₃ and AsF₅ has been shown to produce the new cations BrO₂⁺ and BrOF₂⁺. The anions BrO₂F₂⁻ and BrOF₄⁻ have also been prepared for the first time by several methods. These new cations and anions have been characterized by Raman and ¹⁹F nmr spectroscopy. Similar results have been simultaneously reported by other groups, working independently.

Two selenium (IV) anions SeO₂F⁻ and SeO₂F₂²⁻, which are isoelectronic with BrO₂F and BrO₂F₂⁻, respectively, have been investigated. The Raman spectrum of the SeO₂F⁻ anion has been reassigned and evidence for the formation of the SeO₂F₂⁻ anion is presented for the first time.

The ¹⁹F nmr spectrum of the bromine (VII) oxyfluoride BrO₃F has been recorded and interpreted. The Raman spectra of solid and liquid BrO₃F have been obtained and used to support the previously reported assignments of the fundamental bending modes of this molecule. A number of reactions involving the bromine (VII) species BrF₆⁺, BrO₄⁻ and BrO₃F are described. These reactions were carried out in an unsuccessful attempt to prepare the unknown oxyfluorides BrO₂F₃ and BrOF₅.

abstract: Doctor of Philosophy (PhD)


title: Radical Chemistry of α-Azodiphenylcarbinols and of 2-Acetoxy-2-Methyl-5,5-Dialkyl-Δ³-1,3,4-Oxadiazolines

contributor:
Warkentin, John
Chemistry

subject: Chemistry Chemistry

abstract:
A series of new α-azodiphenylcarbinols was synthesized by mild deacetylation (with methyl lithium) of the corresponding azoacetates which, in turn, were prepared by reactions of either lead tetraacetate or bromine with benzophenone monosubstituted hydrazones. The chemistry of these new types of α-azocarbinols was studied in several aspects. Firstly, the kinetics of thermolysis of these compounds in carbon tetrachloride and in benzene solutions are reported, and the mechanism of the decomposition (radical chain, induced) is discussed. The effects of inhibitors on the decomposition is also examined. Secondly, the potential synthetic applicability of these compounds is illustrated by the hydroalkylation of several unsaturated compounds. Thirdly, the catalytic role of phenol in the radical chain reactions is discussed qualitatively. Fourthly, the e.s.r. spectra of nitroxides, resulting from the reactions of these compounds with nitrosobenzene, were obtained at room temperature in degassed benzene solutions. The aN and g values of these nitroxides are reported.

Another part of the thesis describes the synthesis and chemistry of two new 2-acetoxy-2-methyl-5,5-disubstituted-Δ³-1,3,4-oxadiazolines. The thermolysis of these oxadiazolines was investigated, both in nitro-benzene and in benzene solutions. The results of kinetics are presented and a probable mechanism of the decomposition, through diazenyl radical intermediates, is examined.

Radical intermediates are involved in the chemistry of these new azo compounds. α-Azocarbinols decompose by a radical-induced chain mechanism and their synthetic application involves chain addition. The oxadiazolines undergo unimolecular, homolytic cleavage. A review of radical chemistry presented in Chapter I, is therefore appropriate.

abstract: Doctor of Philosophy (PhD)


title: Alternative representations of technological change, learning by use, and energy substitution in Canadian manufacturing industries

contributor:
Denton, F.T.
Spencer, B.G.
Butterfield, D.W.
Economics / Economic Policy

subject: Economics Economics

abstract: Our main focus of interest is the relationship between energy and capital in the Canadian manufacturing industries. The major importance of the energy-capital relationship, from the standpoint of macroeconomic policy, is that various public policy measures designed to economize energy-use, on the one hand, and those designed to provide incentives for increasing capital formation, on the other, can be reconciled only if energy and capital are easily substituted for each other in the long run. A finding of long run energy and capital complementarity makes these policy measures mutually inconsistent and counterproductive. The issue is still unresolved. In this thesis we attempt to underscore the fact that, in the context of production activity, the energy-capital relationship is essentially a technological one. Therefore our modelling effort is directed towards exploring various aspects of the phenomenon of technological change, including (a) dis-embodied and (b) embodied, occurring (i) at an exogenous rate (a vintage view) and (ii) at an endogenous rate (a learning view). In the context of the disembodied characterization of technological change, we use a modified version of the translog cost function that enables us to separately identify various sources of technological change. With an embodied characterization of technological change, on the other hand, we use a Solow-type index of wholly capital-embodied technological change that, unlike the proxy variable time-trend (t), registers an increase only when there is an actual increase in the proportion of investment in the latest vintage of capital. The theme of embodied technological change is carried further into a relatively unexplored dimension. A theory of learning as a kind of meta-technical change is developed that, unlike Arrow's wholly capital embodied "learning by doing", envisages a learning by use that is attributable to the labor input that has been engaged in the use of machinery and equipment over a period of time. We develop a measure of learning by use and empirically implement it in the factor-augmentation framework, for each of the twenty groups of industries which, in the Standard Industrial Classification (SIC), comprise the manufacturing sector of Canada. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: The nature and timing of granitoid plutonism in the Wabigoon volcanicplutonic beit, Northwestern Ontario: Geochemistry, Rb/Sr geochronology, Petrography and Field investigation

contributor:
McNutt, R. H.
Geology

subject: Geology Geology

abstract:
Twelve Archean granitoid plutons, intrusive into greenstones of the Wabigoon volcanic-plutonic belt in the Superior Province were investigated as to their nature and time of emplacement evidenced from field mapping, petrography, X-ray fluorescence for major and trace elements, in situ gamma ray spectrometry for radioelements and mass spectrometry for Sr isotopes.

Despite common tectonic setting, these plutons range from "homogeneous" granodiori tes and porphyries to concentrically zoned or complex plutons of granite-monzonite-monzodiorite. Homogeneity has been tested in one lithologically monotonous pluton by extensive sampling and trend surface analysis. Tenuous textural and petrochemical phases are defined and attributed to subtle magmatic differentiation overprinted by deuteric autometasomatism. The genetic model proposed is one of pulsating diapirism followed by fluid infiltration, diffusion and cation exchange.

Lithologically zoned plutons are multiple intrusives with younger, more felsic cores and discontinuous petrochemical trends. Cores exhibit homogeneity, euteric metasomatism and felsic dyking similar to the monolithologic plutons. The genetic model proposed is multiple diapiric intrusion from multiple sources through a common conduit.

Quartz-feldspar porphyries show petrographlc and geochemical evidence of extensive alteration, cataclasis and metasomatism more indicative of a synvolcanic hypabyssal origin than affinity with phaneritic granitoids.

Binary plots of concentration versus a chemical index compiled for 247 granitoid samples provide rough estimates of element clarkes. Some plutons are anomalous but as a group these granitoids have high Sr, Ba, K/Rb and low Rb/Sr, Th and U. There is no evidence for large scale magma contamination but ubiquitous lensoid mafic enclaves derived from adjacent supercrustals, experienced basification and alkali metasomatism with enrichment in Rb, Nb, Ce and Y and growth of megacrysts.

There is also no chemical evidence in this study to support either a model of secular evolution of Archean granitoids or to demonstrate a chemical distinction between high level and low level plutons.

Seven stocks and a portion of a batholithic canplex have been dated by Rb/Sr whole-rock isochrons sensu stricto (York I, λ = 1.39 x 10⁻¹¹y⁻¹ 20 errors):

[table removed]

Student's-T tests show only Ottertail is distinct. Weighted pooling of isochrons gives: 2616 ± 43 m.y. for seven stocks while a composite 39 point regression yields 2623 ± 35 m.y. These estimates lie median to the Algoman Orogeny (2400 - 2750 m.y.) and are younger than the proposed Kenoran Orogeny (mean age: 2690 m.y.) and suggest coeval vulcanism, batholithic and intra-belt granitic magmatism spanning less than 35 m.y. (68% confidence). A possible southward juvenescence is beyond Rb/Sr resolution. Initial Sr ratios straddle the single-stage, linear mantle growth and suggest a low (⁸⁷Sr/⁸⁶Sr)i provenance.

Aeromagnetic maps suggest that these stocks are upper crust features with dimensions approximated by their surficial exposures.

Regional distribation and emplaceme.nt was controlled by diapirism or polydiapirism from a lower crust or upper mantle source layer. Upwelling was initiated by deep extensions of faults and superbelt interfaces or by downwarping and crustal thinning at paleobasin centers.

abstract: Doctor of Philosophy (PhD)


title: Large deformation finite element analysis for polymer forming processes

abstract: The object of this work is to explore in depth a variety of polymer forming processes and to examine the behavior of polymers during processing by developing large deformation finite element models and computer tools for the numerical simulations of the processes. Thermoforming, one of the major forming processes dealt with in this thesis, is the fabrication of numerous plastic products by use of heat, pressure and mold. Thermoforming is penetrating existing and new product categories due to ease of production, low costs, and the high performance of final products. Axisymmetrical finite element models have been developed that include large deformation, large strain, moving boundaries, contact of polymer with rigid mold, deformation-dependent loading, free surface evolution, and material nonlinearities. The thermoplastics in the forming processes are considered as incompressible, hyperelastic materials, since there is little time for viscous dissipation. The incompressibility condition is accurately incorporated by employing the penalty method. No restriction of sheet thickness is made in the models for thermoforming so that thermoforming of single layer or multilayer composite sheets of finite thickness can be dealt with, as well as plug-assist forming of thick sheet. A simple, efficient method for passing the limit point is established in the finite element formulations, and for the first time the limit point in thermoforming is successfully simulated using this method. Numerical simulations compare well with analytical solutions for simple geometries and experiments for thermoforming, plug-assist forming, combined plug-assist pre-stretching and vacuum forming, and compression forming. The important parameters in the processes which influence processing and products are studied, including the effects of material constants, boundary conditions, and processing sequence. For these processes, information of deformation and stress can be obtained by the developed computer models, such as deformed profile, thickness variation, the relationship between applied loading and deformation, and stress and strain variations at critical areas, which are important in process optimization and damage analysis. The computer modeling and analysis provide a comprehensive understanding of these forming processes and could be valuable for industrial designers in the process of reducing trial-and-error procedures, optimizing their designs, minimizing material and cost, and maximizing product performance.

abstract: Doctor of Philosophy (PhD)


title: The deformation of copper-tungsten composites

contributor:
Embury, J.D.
Materials Science and Engineering

abstract: A series of plane strain compression experiments and finite element method (FEM) calculations were performed on continuous fibre composites to examine the role of volume fraction and fibre arrangement on the mechanical behaviour when the fibre axis was perpendicular to the loading direction. The flow pattern in the matrix was quantified by measuring the shape change of a fine gold grid which had been fabricated on the surface of the sample prior to deformation. It was determined that the pattern of deformation in the matrix was controlled by the spacing and geometric arrangement of the fibres. The damage process (i.e. by fibre cracking or interfacial decohesion) can be understood by the local distribution of stresses (as calculated by FEM) in the fibres and at the fibre matrix interface. The development of the deformation texture in the matrix and the observations of the pattern of subsequent recrystallization events can be related to the flow pattern in the matrix. The combination of careful experiments with finite element method calculations represents a powerful approach to studying problems involving composite materials.

abstract: Doctor of Philosophy (PhD)


title: Explicit Brauer Induction and Shintani descent

contributor:
Snaith, V.
Mathematics

subject: Mathematics Mathematics

abstract: This paper demonstrates an application of Explicit Brauer Induction. Snaith (28), introduced this canonical form for Brauer's induction theorem. An overview of this development is given in chapter one with a new proof of Brauer's theorem. In (29-35) Snaith applied Explicit Brauer Induction, primarily in the construction of invariants of representations of finite groups from invariants of one-dimensional characters. Following (28, 29, 30) Chapter two presents proof that the Grothendieck group R₊(G,S¹) is a ring with properties of induction, restriction, inflation, and Frobenius reciprocity. There exists a ring homomorphism b:R₊(G,S¹) → R(G) which was introduced as a footnote in (26, P. 71). We discuss the map T_G, (30 Pp. 454-469), which is a section to b. Deligne (6, Pp. 501-597) has devised generators for Ker b, in the case for G solvable. We examine the case G = D₈. Boltje (1, 2) has devised another section to the map b, termed a_G. This development and examples are given in Chapter three. In Chapter four, conjugacy classes and character values, for the matrix group GL₂F_q are reviewed for all irreducible representations including the cuspidal case (13, Pp. 122). The main result of this paper is contained in Chapter five. We develop the Explicit Brauer Induction formula for a_G(ρ) where G = GL₂F_q and ρ is an irreducible representation of G. This development is used to describe Shintani descent between the irreducible representations of GL₂Fⁿ_q and the irreducible representations of GL₂F_q. The original derivation of Shintani descent (27, Pp. 396-414), uses norms on character values. In the construction given here, the Shintani norm is not used, but rather, the correspondence is obtained by applying Hilbert Theorem 90 to the maximal one dimensional characters which appear in the expression for a_G(ρ).

abstract: Doctor of Philosophy (PhD)


title: Identification and Decay Kinetics of Photogenerated o-Xylylenes

contributor:
McCullough, J.J.
Chemistry

subject: Chemistry Chemistry

abstract:
The thesis consists of two parts, which have been combined in the Introduction and Discussion sections.

Part A. Isoindenes

Transient isoindenes absorbing in the 400-550 nm range have been observed in the flash photolysis of a series of 1,1-diarylindenes. They have been studied by ultraviolet spectroscopy, low temperature nmr, chemical trapping, and flash photolysis techniques. Irradiation of 1,1,3-triphenyl-indene at 254 nm in cyclopentane at -70ºC gives an orange solution (λ max 478 nm) which contains 1,2,3-triphenylisoindene whose methine and vinylic proton resonances in the nmr occur at 4.45 and 6.80 ppm respectively. Reaction of 1,2,3-triphenylisoindene with 4-phenyl-1,2,4-triazoline-3,5-dione at -70°C, gave a Diels-Alder adduct. The isoindene formed 1,2,3-triphenylindene quantitatively on warming to 20°C. The kinetics of the 1,5-hydrogen shift by which a series of isoindenes rearrange to stable indenes were studied by flash photolysis. The transient decay was first order, and rate constants (deoxygenated hexane, 20°C) are: 1,2-diphenylisoindene, 36 s⁻¹; 1-phenyl-2-p-cyanophenylisoindene, 14 s⁻¹; 1-phenyl-2-p-bromophenylisoindene, 27 s⁻¹; 1-phenyl-2-p-methoxyphenylisoindene, 44 s⁻¹ and 1,2,3-triphenylisoindene, 1.21 s⁻¹. Kinetic isotope effects of kH/kD = 3.7 and 6.5 for the decay of 1,2,3-triphenylisoindene and 1,2-diphenylisoindene (2-H and 2-D) respectively show that the H-shift is rate determining. The 1,5-hydrogen shift in 1,2-diphenylisoindene has Ea = 13.1 kcal/mol and ΔSº† = -9.0 eu, and in 1,2,3-triphenylisoindene has Ea = 11.8 kcal/mol and ΔSº‡= -19.6 eu. The ground state energy of isoindene relative to indene is estimated to be 20 kcal/mol, which is compared with theoretically calculated values.

Part B. o-Xylylenes

o-Xylylene derivatives have been generated in the flash photolysis of four indan-2-ones. Thus, 1,1,3,3-tetramethylindan-2-one gives 7,7,8,8- tetramethyl-o-xylylene while 1,1-dimethylindan-2-one gives 7,7-dimethyl-o-xylylene. Both these transients decay (thermally and photochemically) by a 1,5-hydrogen shift to yield alkyl isopropenylbenzenes. The rates of thermal decay are 0.002 s⁻¹ and 0.038 s⁻¹, for the tetra- and dimethyl compounds respectively, at ca. 20°C in deoxygenated hexane. The decay of tetramethyl-o-xylylene showed a kinetic isotope effect (kH/kD) of 5.4. Activation parameters were: Ea= 19 kcal/mol, ΔSº‡= -7.7 eu (tetramethyl o-xylylene); Ea= 15.5 kcal/mol, ΔSº‡= -13.9 eu (dimethyl-o-xylylene). Low temperature photolysis (-70°C, 254 nm) show absorption maxima at 350nm, for the tetramethyl compound, and 360 nm for the dimethyl compound. Photolysis of 1,1,3,3-tetramethyl-4,5-benzindan-2-one gives the thermally stable 9,9,10,10-tetramethyl-1,2-naphthoquinodimethane, which decays photochemically to 1-isopropenyl-2-isopropylnaphthalene. A transient with a lifetime of about 1 μs could be observed in the flash photolysis of 1,1,3,3-tetramethyl-5-6-benzindan-2-one, which gives two photoproducts, 2-isopropyl-3-isopropenylnaphthalene and 3,3,4,4-tetramethylnaphtho[b]cyclo-butene. The rates of thermal decay of the transients are consistent with thermochemical calculations. Spectroscopic evidence, together with theoretical calculations, indicates that the transients are twisted about the 'essential' single bonds of the non-aromatic ring, and cannot adopt the planar geometry necessary for the allowed suprafacial 1,5-H shift. This together with the photolability of the transients, suggests that the thermal decay maay involve the previously unknown antarafacial 1,5-hydrogen shift.

abstract: Doctor of Philosophy (PhD)


title: Cation Substitution Studies in Some Vanadate-Phosphate Systems

contributor:
Calvo, C.
Ng, H.N.
Chemistry

subject: Chemistry Chemistry

abstract:
Cation substitution studies in several vanadate-phosphate systems have revealed substantial substitution between pentavalent V and P in tetrahedral sites in both ring and chain structures. The phase Zn₃V₀․₅P₁․₅O₈ has been prepared and its structure has been determined and found to be similar to that of α-Zn₃(PO₄)₂. It crystalizes in the space group C2/c with rings of Zn(1)O₄ and (V,P)O₄ tetrahedra sharing corners to form chains, which are linked to neighbouring chains by Zn(2)O₄ tetrahedra. The edge-sharing between Zn tetrahedra which is found in α-Zn₃(PO₄)₂ is absent in Zn₃V₀․₅P₁․₅O₈. There is no evidence of long-range ordering of V⁵⁺ and P⁵⁺ cations in this structure.

Three pyroxene-like phases, related to NaVO₃ and characterized by tetrahedral chains, have been prepared. The NaV⅔P⅓O₃ structure closely resembles that of NaVO₃, and shows no long-range ordering of V⁵⁺ and P⁵⁺. The mixed phases Na․₈₇₅K․₁₂₅VO₃ and Na₀․₅K₀․₅VO₃ were prepared in order to study the effects of M⁺ substitution on the NaVO₃ structure. The structure of Na․₈₇₅K․₁₂₅VO₃ resembles that of NaVO₃ and NaV⅔P⅓O₃, while Na₀․₅K₀․₅VO₃ has the true diopside structure, with Na and K ordered in two nonequivalent sites. All three structures were refined in the space group C2/c and the effects of cation substitution on the configuration of the tetrahedral chains are discussed.

abstract: Master of Science (MS)


title: The Hammett Acidity Function for Hydrofluoric Acid and some related Superacid Systems

subject: Chemistry Chemistry

abstract:
The Hammett acidity function, H₀, has been measured for some superacid systems. These systems include HSO₃F, CF₃SO₃H and HF and their mixtures with some Lewis acids such as NbF₅, TaF₅, AsF₅ and SbF₅. Some base-HF mixtures were also studied for the HF system.

The acidities of these systems were determined by measuring their ability to protonate the very weakly basic nitro aromatic indicators. The protonation behaviour was studied by means of UV-Visible spectrophotometry as well as NMR spectrometry.

The H₀ value for 100% HF was found to be greater than that of 100% H₂SO₄ and was close to that of 100% HSO₃F. The acidities for the acid systems MF₅HF were found to be in the order SbF₅> AsF₅> TaF₅> NbF₅. The H₀ values obtained in the present measurements indicated that the SbF₅HF system is much more acidic than the previously known most highly acidic system, HSO₃F-SbF₅-3SO₃.

The applications of the superacid media in synthetic chemistry has become more important in recent years, for example they have been used as solvents in the presentation of carbonium ions and other highly electrophilic cations.

abstract: Doctor of Philosophy (PhD)


title: Matrix and B*-algebra Eigenfunction Expansions

contributor:
Billingheimer, C.E.
Mathematics

subject: Mathematics Mathematics

abstract:
Let Mn be the set of all n by n complex matrices and [a,b] be a finite real interval. Let L²(a,b;Mn) be the set of all functions f: [a,b]→Mn such that all entry functions belong to L²(a,b). Under the usual addition, scalar multiplication, and inner-product defined by (F,G) = ∫ᵇa π(G*(t)F(t))dt, L²(a,b;Mn) is a Hilbert space. Consider the differential operator L defined by [equation removed], where the superscript (s) denotes s-times differentiation with respect to t, Pi and Y are n by n matrix functions and the domain of L is a linear subspace S of L²(a,b,Mn). Under very general hypotheses on the coefficients Pi, and an appropriate domain S given by end-point conditions, the operator L is symmetric, with finite and equal deficiency indices. The self-adjoint extensions L' of L are explicitly obtained and the following result holds: The self-adjoint operator L' has only a point spectrum, all its eigenvalues are of finite multiplicity, and every finite interval contains only a finite number of them.

The classical Inversion Theorem is also generalized to obtain a unitary mapping from L²(a,b,Mn) onto L²σ, where σ is an appropiate matrix distribution function.

Let now A be an H-algebra, that is a B-algebra for which there exists a positive linear functional π satisfying π(x*x) ≥ 0 and π(x*x) = 0 if and only if x = 0 for all x ε A. Then the following result holds: Let A be an L²-separable H-algebra, [a,b] a finite interval and q(x) an A-valued, continuous function on [a,b] with spectrum σ = σ(q(x)) such that inf {σ(q(x)): x ε [a,b]} is finite. Then the problem y" + (λ - q(x))y = 0, y(a,λ)cosμ - y'(a,λ)sinμ = 0, 0 ≤ μ ≤ π/2, y(b,λ) = 0, has a non-trivial solution for only a countable number of real values λi of λ, and if zi is the solution corresponding to λi, then for any A-valued, twice continuously differentiable function g(x) on [a,b] satisfying the above boundary conditions, we have g(x) = Σi (g,zi)zi(x). An approximation theorem in the singular case for functions on (-∞,∞) is also given.

abstract: Doctor of Philosophy (PhD)


title: The Virial Partitioning Theory and its Applications to Molecular Systems

contributor:
Bader, Richard F. W.
Chemistry

subject: Chemistry Chemistry

abstract:
This thesis is concerned with the application of the theory of virial partitioning of a molecular system and its properties. In this theory the partitioning surfaces are defined in terms of the topographical features of the observable molecular charge distribution, ρ(r). Specifically, ρ(r) is partitioned by those closed surfaces through which the flux of ∇ρ(r) is everywhere zero, i.e.,

∇ρ(r) n(r) = 0 ∀ṟ ε S (ṟ) (A.1)

where n(ṟ) is the vector normal to the surface S(ṟ) at the point ṟ. Equation (A.1) has been derived as a boundary condition through the application of the variational principle in the definition of a quantum subspace. The virial partitioning of a molecular system is obtained by constructing for the system all surfaces which satisfy equation (A.1). This set of surfaces divides a molecule into a set of chemically identifiable atomic-like fragments. Each fragment so defined possess a unique set of quantum properties; the hypervirial and virial theorems are obeyed and all properties of the fragment· including its total energy are rigorously defined. Any property of the total molecular system may be equated to a sum of contributions from the spatially defined fragments. The calculated properties of the fragments, as demonstrated in this thesis, coincide with expectations based on experimental chemistry.

abstract: Doctor of Philosophy (PhD)


title: Photochemistry of Naphthonitrile-Olefin Systerns

subject: Chemistry Chemistry

abstract: The photochemistry of 1- and 2-naphthonitrile with the olefins tetramethylethylene and 1,2-dimethylcyclopentene has been studied in a variety of solvents. In hexane, benzene, and 1,2-dimethoxyethane the major products in the reaction with tetramethylethylene are the cyclobutanes 1-cyano-7,7,8,8-tetramethyl-2,3-benzobicyclo[4.2.0]octa-2,4-diene (from 1-naphthonitrile) and 6-cyano-7,7,8,8-tetramethyl-2,3-benzo-bicyclo[4.2.0]octa-2,4-diene (from 2-naphthonitrile). Reaction with 1,2-dimethylcyclopentene gives cyclobutanes with analogous structures, in genzene and dimethoxyethane. In high polarity solvents, products of photoreduction are formed. 2-Naphthonitrile and tetramethylethylene upon irradiation in 2,2,2-trifluoroethanol give 1-(2'-trifluoroethoxy-1' ,1' ,2' ,2-tetramethyl)-3-cyano-1,4-dihydronaphthalene and 3,4-dihydro-2-naphtho-nitrile. Reactions in other high polarity solvents give complex mixtures of products. Stern-Volmer quenching of 2-naphthonitrile fluorescence by tetramethylethylene increases dramatically as solvent polarity increases from hexane to methanol. The Stern-Volmer constants are 0.50 M⁻¹ and 148 M⁻1 for 2-naphthonitrile fluorescence quenching in hexane and methanol, respectively. Similar, although less dramatic, behaviour is observed for 1-naphthonitrile fluorescence quenching by tetramethylethylene. Lifetimes of the luminescent exciplexes formed from 1-naphthonitrile and the olefins have been measured in the lower polarity solvents. With both teframethyl-ethylene and 1,2-dimethylcyclopente, the exciplex lifetimes increase, level off, and then decrease with increasing solvent polarity. For the 1-naphthonitrile-tetramethylethylene exciplex, the measured lifetimes are 3.75, 10.4, 12.6, 12.7, and 4.7 ns in hexane, benzene, dimethoxyethane, tert-butanol, and iso-propanol, respectively. The photochemistry and photophysics of the naphthonitrile-olfein systems are discussed in terms of a changing quenching mechanism with increasing solvents polarity. It is proposed that quenching in non-polar solvents involves exciplex formation, while in polar media electron transfer occurs. The results are discussed within the context of models for exciplex formation and decay introduced by Weller and Michl.

abstract: Doctor of Philosophy (PhD)


title: The Nuclear Structure of ¹⁶⁶Er

contributor:
Burke, D.G.
Physics

subject: Physics Physics

abstract:
Two-quasiparticle states in ¹⁶⁶Er have been studied using the ¹⁶⁷Er(d,t) ¹⁶⁶Er, ¹⁶⁷Er(³He,α) ¹⁶⁶Er, ¹⁶⁵Ho(³He,d) ¹⁶⁶Er, and ¹⁶⁵Ho(α,t) ¹⁶⁶Er reactions. Beams of 15 MeV deuterons, 24 MeV ³He⁺⁺, and 27 MeV α particles were produced by the McMaster University model FN tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge split-pole magnetic spectrograph and detected with photographic emulsions. Angular distributions were obtained for the (d,t) and (³He,d) reactions at twelve and ten angles, respectively. The data were fitted with a peak finding program to yield peak energies and cross sections up to ~ 2700 keV in excitation energy, although selected peaks were investigated at somewhat higher energies.

The interpretation of the data was performed within the framework of the Unified model, incorporating pairing effects. In the neutron transfer study, two-quasiparticle states formed by removing a particle from the predominantly 7/2⁺[633] ¹⁶⁷Er ground state were investigated, while the proton transfer study dealt with two-quasiparticle states formed by adding a particle to the 7/2⁻[523] ground state of ¹⁶⁵Ho. Several previous assignments have been supported while many new ones are suggested or proposed. In contrast, several other assignments proposed in an earlier proton transfer study have been refuted.

Earlier observations that several states were populated in both the neutron transfer and proton transfer reactions have been confirmed and extended. In addition, the observation in the (d,t) reaction of several states populated by ℓ=0 neutron transfers has been interpreted in terms of a complex mixing scheme involving the 7/2⁺[633]±1/2⁺[400] configurations.

abstract: Doctor of Philosophy (PhD)


title: Topological Algebras with Bases

contributor:
Husain, T.
Mathematics

subject: Mathematics Mathematics

abstract: Let A be a topological algebra. A (Schauder) basis {xn} in A is called an orthogonal basis if xnxm = δnmxn, n,m ε N (δ denotes Kronecker's delta). A basis in A of the form {zⁿ : n=0,1,...}, z ɛ A, is called a cyclic basis. This thesis is concerned with the structure of topological algebras possesing bases of these types. It is shown how the existence of such bases determines algebraic and topological properties of A. An interesting connection between the dense maximal ideals and the topological dual of certain types of topological algebras having unconditional orthogonal bases is explored. These results are used to obtain characterizations of some important F-algebras in terms of the type of bases they possess.

abstract: Doctor of Philosophy (PhD)


title: Photochemical probes of conformational mobility in thermotropic liquid crystals

contributor:
Leigh, William J.
Chemistry

subject: Chemistry Chemistry

abstract: Phenyl ketone photochemistry has been used to probe the effects of thermotropic liquid crystals on the conformational mobility of dissolved solutes. In addition, concentration and temperature dependent deuterium (²H) NMR spectroscopy studies of deuterated analogues of the probe ketones have afforded detailed information on the solubilisation behaviour of the solutes in the nematic and smectic liquid crystalline phases of various mesogens. Results from the ²H NMR studies have allowed for the construction of binary phase diagrams of the solute/solvent mixtures and have provided a method for the accurate determination of the solubility limits of these probes in smectic phases. The Norrish II reactions of butyrophenone (BP), valerophenone (VP), hexanophenone (HP), and γ-cyclohexylbutyrophenone (CHBP) have been carried out at 30℃ as a function of concentration in the isotropic, nematic and smectic liquid crystalline phases of trans,trans-4'-alkyl-[1,1'-bicyclohexyl]-4-carbonitrile (CCH-n) liquid crystals. The distribution of fragmentation and cyclisation products from photolysis of these ketones in the nematic phase is similar to that obtained from photolysis in model isotropic solvents. The product distribution from photolysis of a homogeneous smectic phase solution of BP is also similar to that in the isotropic phase, but the fragmentation/cyclisation ratios from photolysis of homogeneous smectic phase solutions of VP, HP, and CHBP are significantly affected by the ordered environment. For ketone/mesogen mixtures of bulk solute concentration above the solubility limit, the observed effects of the smectic phase on the photochemistry of these solutes is lowered. The rates of intramolecular triplet decay of β-phenyl-4-methoxy-propiophenone (1) in the isotropic and liquid crystalline phases of CCH-n, trans-4-alkylcyclohexyl-trans-4'-alkyl-cyclohexylcarboxylate (OS-nm), and trans,trans-4'-alkyl-[1,1'-bicyclohexyl]-4-alkylether (CCH-nOm) mesogens have been investigated using nanosecond laser flash photolysis techniques. The average triplet lifetimes measured for homogeneous smectic solutions of 1 range from a factor of ca two to four times longer than those in homologous nematic or isotropic phases at the same temperature. The magnitude of the change in lifetime that occurs at the nematic to smectic (N→Sm) phase transition is a function of the relative amount of order associated with each of the smectic phases. A study of the photochemistry of a series of benzoyl- and β-aryl substituted derivatives of 1 in the CCH-n and CCH-nOm mesogens has shown that the nature of the effect on β-phenyl quenching is mainly the result of a change in the equilibrium constant for trans/gauche interconversion in the smectic phase compared to that in the nematic/isotropic phases. This latter study also investigated the effects of solute structure on the ability of thermotropic liquid crystals to control the conformational mobility of this probe. Slight variations in the structure of the alkoxy substituent reduces the ability of the smectic phase to slow triplet deactivation, while substitution at the para-position of the β-phenyl ring magnify the effect of solvent order on the triplet lifetime. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Investigation of the mechanisms of transcription and transactivation by the herpes simplex virus protein Vmw65

contributor:
Capone, John P.
Biochemistry

subject: Biochemistry Biochemistry

abstract: Eukaryotic gene expression is regulated through the assembly of transcription factors into multi-component complexes that interact with cis-acting DNA recognition sites. The herpes simplex virus protein, Vmw65 (also known as VP16, αTIF), stimulates transcription through direct and indirect contacts with specific cellular factors (including the ubiquitous octamer binding protein, Oct-1) and a conserved enhancer-like DNA sequence (consensus TAATGARAT) found upstream of the viral immediate-early (IE) genes. The objective of this project was to utilize this viral system as a model to investigate mechanisms by which eukaryotic gene transcription is regulated. The functional interactions of Vmw65 with the cellular transcription machinery make this a valuable system for the elucidation of the protein-protein and protein-DNA interactions involved in regulation. This thesis describes various strategies that have been utilized to examine the different aspects Vmw65 mediated transactivation. The structure-function profile of Vmw65 was determined through the construction of a series of mutants that were individually assayed for specific activities. An in vivo transient transfection system was utilized to measure the ability of each of the mutants to transactivate an indicator gene, containing a TAATGARAT sequence, relative to the wild type protein. This assay was also utilized to map domains of Vmw65 that are capable of interfering with the wild type transactivation function in a trans-dominant manner. Finally, the mutants were expressed in E. coli as protein A fusion proteins and each was analyzed for its ability to direct the assembly of the Vmw65 dependent complex and to bind directly to DNA in the absence of other factors. To summarize, the transactivation function is highly sensitive to mutations within two distinct internal regions of the protein (corresponding to amino acids 178-215 and 335-379). A region of Vmw65, located between amino acids 141 and 186, is capable of interfering with the wild type transactivation function in vivo and is required for complex assembly in vitro. These results suggest that this domain forms essential contacts with a factor involved in the transactivation function of Vmw65. The transcription activation domain of Vmw65 is not required for complex assembly indicating that Vmw65 is a modular protein consisting of a transcription activation domain and a complex assembly domain. Each of these domains can independently impart its activity to a heterologous protein. Additional cellular components of the Vmw65 dependent complex were identified and characterized using cell fractionation techniques. One factor, designated SF, was shown to specifically stabilize the multi-protein complex. SF has an apparent molecular weight of 1500-3000 Da and is resistant to heat treatment as well as extensive digestions with protease, nuclease and phospholipase. β-glucuronidase digestion did have an effect on SF activity suggesting that this factor may be composed, at least partially, of carbohydrate. Finally, the role of Vmw65 in the herpes simplex virus lytic cycle was investigated through the construction and characterization of a stable cell line (designated BSV65) expressing this transactivator. The cell line was shown to specifically activate viral immediate early genes and was capable of complementing a virus defective for the Vmw65 transactivation function. The transfection of purified HSV-1 DNA into BSV65 cells resulted in a 200 fold increase in virus production relative to the parental cell line. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Synthesis and characterization of polyelectrolytes and aqueous latices

contributor:
Pelton, R.H.
Hamielec, A.E.
Woods, D.R.
Chemical Engineering

abstract: Methods for molecular weight characterization of polyelectrolytes, poly(acrylamide-co-sodium acrylate) by viscometry and gel permeation chromatography have been developed based on the use of fractionated polyacrylamide with known average molecular weights. A set of Mark-Houwink equations for the copolymer with various acrylate content has been established. With the viscosity measurements, these equations can be used to calculate the molecular weights of the copolymer with known composition, and to estimate the acrylate content when the weight average molecular weight of the polymer is known. The universal calibration method has been proven valid for poly(acrylamide-co-sodium acrylate) using nonionic polyacrylamide standards. The correlation of elution volume shift with the content of ionic groups has been found, from which the molecular weight of the copolymer can be estimated by gel permeation chromatography. Heterogeneous free-radical polymerization of N-isopropylacrylamide (NIPAM) and NIPAM with N,N'-methylene bisacrylamide (BAM) has been conducted in aqueous media in the presence of low levels of sodium dodecyl sulfate (SDS). The influence of temperature, BAM level, SDS level, pH and ionic strength on the polymerization rate, particle size and size distribution, and particle concentration has been investigated. Studies on the formation mechanism of latex particles of poly(NIPAM) and poly(NIPAM/BAM) have been carried out by measuring the kinetics of polymerization and the micro-structure of the particles. A mechanism of homogeneous nucleation (dispersant-limited agglomeration) and dispersion polymerization has been proposed. The microstructure of the latex particles has been studied from the swelling extent of the particles at various conversion. It is found that the particles have lowest swelling at early stage and have higher swelling at later stage. This has been interpreted as that the cross-linking density changes along the radius of the particles. In addition to the heterogeneity within the particles, the density distribution among the particles has been observed from the comparison of the particle size distribution by dynamic light scattering and that by disk centrifuge. The interaction of NIPAM polymers with SDS has been investigated by conductometry and turbidimetry. It has been found that the critical micelle concentration (CMC) of SDS increases with the concentration of NIPAM polymers, and that the cloud point of aqueous solutions of NIPAM polymers is elevated in the presence of SDS.

abstract: Doctor of Philosophy (PhD)


title: Arylnitrenes: A synthetic approach towards amino-imino-azepines

contributor:
Bell, Russell Arthur
Chemistry

subject: Chemistry Chemistry

abstract: The chemistry of substituted phenylnitrenes was investigated to discern the mechanism and factors involved in the preparation of 3H-dihydroazepines. Synthetic utility of this phenylnitrene reaction was explored through the photolysis of a series of non-symmetric phenylazides. Phenylnitrene production via the photolysis or thermolysis of phenylazides as well as through the deoxygenation of aryl-nitro compounds was compared. Results indicated the photolysis reaction was superior in yielding azepine products. The intermediates involved in the ring expansion reaction of the phenylnitrenes were computer modelled using a semi-empirical molecular orbital calculation that aided in the prediction of the observed product yields. In addition, the azirine intermediates derived from the photolysis of diamido-phenylazides were chemically trapped in situ confirming their presence in the complicated phenylnitrene mechanism. Kinetic data from the chemical trapping of the intermediates formed from the photolysis of 3-acetamido-4-trifluoroacetamido-phenylazide showed the azirine intermediate was formed directly from the singlet phenylnitrene. The didehydroazepine intermediate was formed from the azirine intermediate and not directly from the singlet phenylnitrene. The computational data were used to determine the substituents necessary to preferentially yield the desired azepine product. Finally, in an attempt to synthesize an amino-imino-azepine, 4,5-substituted 3H-dihydroazepines were synthesized selectively from 3,4-substituted phenylazides. However, attempts at oxidizing and/or deprotecting the 3H-dihydroazepines failed because of the harsh reaction conditions employed.

abstract: Doctor of Philosophy (PhD)


title: Proton Transfer Study of Low-Lying States of ¹³⁶La

contributor:
Summers-Gill, R. G.
Physics

subject: Physics Physics

abstract:
The techniques of charged particle spectroscopy were utilized in studying the low-lying states of ¹³⁶La. Two proton transfer reactions were carried out on isotopically enriched targets of ¹³⁵Ba. Sixty-four energy levels of ¹³⁶La were observed up to an excitation of 1.8 MeV from ¹³⁵Ba(³He,d)¹³⁶La and ¹³⁵Ba(α,t)¹³⁶La reactions. Two methods were used to determine the ℓ-values for some of the states whose cross-sections could easily be obtained. One of the methods was to utilize the ratio of (³He,d) and (α,t) cross-section as an indicator of ℓ-values. The ℓ-values were also obtained from the angular distribution of the cross-sections of some of the multiplets.

The fore hand knowledge of the spin of the ground state made it possible to immediately assign spins to the first two excited states. Spins have also been assigned tentatively to a few other states using the 2J+1 rule.

In the process of this work, the relative Q-values for the ¹³⁴Ba(α,t)¹³⁵La, ¹³⁵Ba(α,t)¹³⁶La and ¹³⁶Ba(α,t)¹³⁷La reactions were also measured. The results show that the presently accepted proton separation energies for these lanthanum isotopes are considerably in error.

abstract: Master of Science (MS)