title: Activation of the endogenous alpha-globin gene in non-erythroid cells by herpes simplex virus

contributor:
Smiley, Jim R.
Biology

subject: Biology Biology

abstract: During lytic infection, herpes simplex virus (HSV) usurps the host cell machineries to facilitate viral gene expression, and executes viral-directed host shutoff activities to strongly inhibit expression of endogenous cellular genes. Our laboratory has previously observed that, in contrast to the fate of the majority of host genes, the α-globin gene in non-erythroid cells is activated upon HSV infection. This finding is intriguing not only because this cellular gene escapes the viral host shutoff functions, but also because this tissue-specific gene is normally repressed in non-erythroid cells. The series of studies presented in this thesis document the characterisation and analysis of this phenomenon. HSV immediate-early proteins ICP0 and ICP4 were each found to be capable of inducing expression of the previously silent α-globin gene in non-erythroid cells. ICP4 was the dominant viral transactivator responsible for transcriptional activation of the α-globin gene during infection, whereas ICP0 may indirectly activate expression of this gene by disrupting its tissue-specific regulation. Efficient accumulation of α-globin transcripts in HSV-infected cells also required the presence of ICP22 which appeared to regulate expression of the α-globin gene at a post-transcriptional level. In addition, ICP27 induced accumulation of unspliced α-globin premRNA. Analysis of the chromatin structure of the endogenous α-globin gene showed that an array of nucleosomes are positioned along the coding region of this gene. Furthermore, activation of the α-globin gene by HSV resulted in subtle alteration of the positioning of the nucleosome located at the TATA box and transcription start site of the gene, suggesting the positioning of this nucleosome may be involved in the repression of this gene in non-erythroid cells. Taken together, the results from this thesis project showed that at least four viral proteins are involved in the activation and expression of the α-globin gene in HSV-infected cells and this activation may be mediated by alteration of the chromatin structure of the endogenous α-globin locus.

abstract: Doctor of Philosophy (PhD)


title: The Accumulation of a Novel Type of Suppressor Cell in the Uterus of the Allopregnant Mice During Successful Pregnancy

contributor:
Clark, David A.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Successful pregnancy involves the accumulation of non-T, FcR-positive cells at the implantation sites of syngenic allogeneic of CTL (cytotoxic T cells) in vitro and in vivo by blocking the response to interleukin 2. It has been shown that xenogeneic embryos can be gestated successfully if enveloped in the trophoblast genotypically compatible with the pseudopregnant recipient (Rossant et al., 1982, J. Emb. Exp. Morph., 69: 141). We have recently demonstarted that the trophoblast plays a critical role in the localization of the deciduaassociated suppressor cell in pseudopregnant mice. We now show that supernatants genereated from trophoblast cell cultures and day 9.5 ectoplacental cone cultures were successful in the recruitment of the non-T, granulated suppressor cell which sediments at 3 ± 0.05 mm/h. These results suggest that the trophoblast elaborates a factor(s) which plays an important role in the accumulation of the deciduaassociated suppressor cells in the decidue which may protect the anti-genic fetus from maternal immue rejection.

abstract: Doctor of Philosophy (PhD)


title: Ion Beam Mixing and Thermoelectric Characteristics of Bi-Sb Thin Film Alloys

contributor:
Thompson, D.A.
Electrical Engineering

subject:
Electrical and Electronics
Electrical and Electronics

abstract:
This thesis is concerned with investigating the production of thin film Bi-Sb alloys by ion beam mixing. Samples were composed of a thin Sb film sandwiched between two Bi layers; the thicknesses of the films were varied to produce composition range from 0 to ~45% Sb. The overall thickness was about 55 nm.

Analysis of the films by Rutherford Backscattering Spectrometry (RBS) and Auger Electron Spectroscopy (AES) indicated that ion beam mixing can produce uniform Bi-Sb alloys with doses of about 2.8X10¹⁵ cmˉ² of 80 KeV Ar⁺ at room temperature. The results of Electron Microscopy showed a grain growth due to ion bombardment.

The mixing was characterized by the increase in the full width at half maximum (FWHM) of the Sb signal in the RBS spectra. It was measured as a function of ion dose, dose rate, mass, and energy. The dependence of mixing on the temperature was also investigated. A square-root dependence of mixing on the dose confirmed a diffusion like mixing process. The rate of mixing per ion dose was found to increase with the elastic energy deposited at the Bi/Sb interface. The mixing is temperature independent in the range of ~40 to ~266 K, i.e., collision cascade mixing dominates. An effective diffusion coefficient, D*, of about 4.9X10ˉ²⁸cm⁴/ion was determined. At temperatures higher than ~266 K, the mixing increases with the temperature. This suggests that a radiation enhanced diffusion mechanism is the dominant mixing process. An effective diffusion coefficient of ~1.7X10ˉ²⁷cm⁴/ion at room temperature was calculated: an activation energy of ~0.15 eV was found.

Thermoelectric characteristics of the alloys were investigated by measuring the thermal voltage, V₃, as a function of the temperature, T, in the range 300-500 K, for alloys with various composition. The thermal voltage was found to have a linear dependence on temperature. The thermoelectric power, dV₃/dT, reaches a maximum of about 70 μV/deg, for Bi₈₇Sb₁₃. The dependence of the thermoelectric power on Sb concentration agrees with the model put forward to explain the transport properties of bulk Bi-Sb alloys. An empirical model has been proposed to relate the state of mixing with the measured thermoelectric power.

abstract: Doctor of Philosophy (PhD)


title: Meaning Dominance and Context in the Processing of Lexical Ambiguities

contributor:
Begg, Ian M.
Psychology

subject: Psychology Psychology

abstract: Homographs can be considered local semantic uncertainties in utterances. As such, a study of how their meanings are resolved can be used to infer the dynamics of retrieval from memory. One view is that resolutions always begins with an exhaustive retrieval of the entire set of meanings, followed by a selection of one, either on the basis of the context, or the amount of experience with a meaning (meaning dominance). In support of this two-stage view, two experiments demonstrated that a homographic primer speeds responses to both subordinate and dominant associates if its presentation time is short, but speeds responses only to a dominant associate if its presentation time is long. Two further experiments also found evidence for exhaustive retrieval by showing that a subordinate associate will selectively interfere with pronunciation of a homograph if it is presented in close temporal proximity. However, whether exhaustive retrieval is the rule for the processing of homographs depends on how immune the initial retrieval is to manipulations of context. Four subsequent experiments demonstrated that if subjects study the actual homographs before employing them as primers, there are conditions in which the critical effects that support exhaustive retrieval are eliminated. Furthermore, across a number of experiments, measures of episodic memory showed a small but replicable selective effects in conditions presumed to reflect only non-selective operations.

abstract: Doctor of Philosophy (PhD)


title: The Effect of Damping on the Seismic Response of Equipment in Buildings

contributor:
Weidebrecht, A.C.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: This thesis studies the effects that nonproportional damping has on the vibrational characteristics of two and three level systems. In additions, error levels in response prediction are estimated for two simplified time history procedures and a response spectrum technique. It is shown that nonproportional damping creates significant changes in the damped frequency, damping ratio and mode shape of each mode of vibration of the system relative to those found for a similar system exhibiting proportional damping. The study of the prediction of the maximum system response to seismic basic motions demonstrates that there exist three regions where different dynamic analysis procedures should be used. A physically uncoupled analysis should be used for large mass ratios. A complex modal analysis should be used if the mass ratio is of an intermediate value. Diagrams are supplied which allow one to readily determine which of the three methods is the most appropriate for a design.

abstract: Doctor of Philosophy (PhD)


title: Techniques for Identifying Search and Rescue Satellite Aided Tracking (SARSAT) Signals

contributor:
Carter, C.R.
Electrical and Computer Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract:
This dissertation studies the problem of identification of the emergency locator transmitter (ELT) signals as related to the Search and Rescue Satellite Aided Tracking (SARSAT) system. The ELT identification is particularly important in order to increase the probability of detection and eliminate sources of interference from the data set.

A set of parameters that uniquely characterizes the ELT signals is selected, namely, the width of the average spectrum sidebands, the ratio of the sideband plateaus of the average spectrum with respect to the carrier peak and the sweep period of the signals. Two methods for estimating the sweep period are developed theoretically. These are the sawtooth and the crosscorrelation methods.

The identification techniques are tested using computer generated signals and real testbed ELT signals recorded by the Communications Research Centre (CRC) in Ottawa.

A study of the different interference sources in the 121.5/243 MHz SARSAT frequency bands is provided. Three different sources of interference are generated and tested using the identification techniques.

The performance of the proposed techniques is further investigated using real data from two different passes of COSPAS satellite CI.

Using the identification techniques presented in this thesis, it is possible to consolidate the number of detections per day from multiple satellites and multiple satellite passes.

abstract: Doctor of Philosophy (PhD)


title: The Effects of Pesticide Use in Apple Orchards On Health and Reproduction of Cavity-nesting Birds

contributor:
Quinn, J.S.
Biology

subject: Biology Biology

abstract: In southern Ontario, Canada during 1988-1997, pesticide exposure and its effects on the immune and endocrine systems and the behaviour and growth of tree swallos (Tachycineta bicolor) and on reproductive success in tree swallos and eastern bluebirds (Sailia sailis) were studied. Birds were exposed in sprayed apple orchards and non-sprayed sites. There were significant effects of pesticides on all of these endpoints. Sprayed tree swallow nestlings had significantly increased blastogenic response to pokeweed mitogen and delayed thymic maturation. Also, some tree swallow immune parameters were correlated to the date chicks were sampled. As the number of mixed sprays applied increased, there was a significant and positive increase in the concentration of the thyroid hormone, tri-iodo-thyronine, in male chicks and some indications of an increasing occurrence of a disrupted sertoli cell population on the seminiferous tubular basement membrane in testes. There were no effects of pesticides on adult swallow incubation times. There were significant increases in hunger signalling by tree swallow chicks after organophosphorus insecticide (OP) spray events in 1996 and 1997 and, after a second OP spray in 1996, there were significant decreases in the number of feeding trips by parent birds. However, weight of chicks did not vary among sites due to pesticide exposure. There was a significant increase in unhatched eggs in eastern bluebirds as organochlorine pesticide residues increased in eggs. At the gradient of contamination in tree swallow eggs, there were no trends between reproduction and organochlorines. With increasing toxicity and exposures to pesticides sprayed during 1988-1994, there were significant declines in egg fertility and daily survival rates of eggs and chicks of tree swallows and eastern bluebirds. Decreased reproductive rates were more often detected in tree swallows than in eastern bluebirds however the possibility that organochlorine chemicals contributed to these effects in bluebirds cannot be discounted.

abstract: Doctor of Philosophy (PhD)


title: Studies of Calcium and Other Storage Minerals in Embryos of Cucurbita Maxima, Cucurbita Andreana and their Reciprocal Hybrids

contributor:
Lott, J.N.A.
Biology

subject: Biology Biology

abstract: Calcium is an essential element in plant and often it is the first nutrient to become limiting during seedling growth. Despite this requirement for CA, embryos have been found to contain low amounts of Ca compared to other macro-nutrients that they store. Cucurbita maxima (squash) and C. andreana (bitter gourd) were selected for the study of calcium storage within embryo tissue because it has already been shown that these two species have a 10-fold difference in see size, a 3-fold difference in Ca level per gram embryo tissue and the reciprocal crosses between them produce visible hybrids. Calcium was analyzed by atomic absorption spectroscopy and the four storage minerals (Mg, K, Ca and P) were analyzed by neutron activations analysis. Atomic absorptions analysis required the destruction of organic matrix of the samples. Dry ashing of cucurbit embryo tissues resulted in the discovery of some unique characteristics of these tissues. When ground embryo samples of less than 0.05 g weight were ashed in porcelain crucibles, the measured Ca levels were abnormally high due to sample-crucible interactions. The apparent enhancement of Ca level occurred because of changes in the K and perhaps Na levels of the samples. Although cucurbit embryo tissues were resistant to complete ashing at temperatures below 550°C, Ca was more easily extracted from the black ash obtained at these temperatures than from carbon-free ash obtained with higher temperature ashing. The Ca binding at the higher ashing temperatures, which occurred because of a low cation-to-P ratio within the cucurbit ash, was not present in other seed tissues with higher cation-to-P ratios. The problems were overcome by ashing samples of at least 0.01 g and by acid digestion of the ash to convert Ca to more soluble forms. Cucurbit embryos contained Mg, K, Ca and P but Ca made up less than 5% of the total mineral reserve while P made up 50%. All four minerals were present in high concentrations in the root-shoot axis than in the cotyledons, but the percent of the total Ca in the axis was higher than that of Mg, K and P. The embryos of C. maxima, the species with the larger sees, stores higher amounts of Ca in the axis than the smaller embryos of C. andreana. The Ca levels were more variable in the large-seeded species and were negatively correlated with embryo size. No correlation between embryo size and Ca level was found for C. andreana. The parent and hybrid embryos differed less in their Mg, K and P levels than in their Ca levels. The Ca levels in the hybrid embryos (C. Maxima X C. andreana and C. Andreana X C. Maxima) were significantly different from the parental Ca levels indicating that the hybrid embryos differed in Ca level from each other and that each hybrid approached the Ca levels of its female parent showed that maternal influences on Ca level were also prominent. In both species mobilization of minerals from cotyledons to the growing axis occurred only in seedlings grown in distilled water. In normal growth conditions with the expanding cotyledons, which became the first photosynthetic leaves, assimilated nutrients from the medium. The assimilation was particularly marked for Ca. This study has contributed toward the understanding of mineral storage in seeds of a group that has not been widely studied to date. The study has also emphasized the difference between the store of Ca and the storage of Mg, K and P.

abstract: Doctor of Philosophy (PhD)


title: Sequence Based Receivers for Bandlimited Nonlinear Channels

contributor:
Taylor, D.P.
Electrical Engineering

abstract:
This thesis examines receiver structures based on maximum likelihood sequence estimation (MLSE) for receiving quaternary phase-shift-keyed (QPSK) signals over bandlimited, non-linear satellite channels, in the presence of additive down link gaussian noise. Two satellite channel models are considered. In the first channel model, the effects of intersymbol interference caused by filtering followed by AM/AM and AM/PM conversions are taken into account while the second channel model includes a post-nonlinearity filter.

An explicit expression for the output of the bandpass nonlinearity (BPNL) for a QPSK signal is obtained in terms of an inphase (1)-quadrature (Q) path memory parameter Pk. The computation of the output of the BPNL requires a knowledge of its transfer characteristic. The transfer characteristics may be specified either analytically or through experimental measurements.

An optimum MLSE receiver structure for bandlimited, non-linear satellite channel is derived and its performance evaluated using computer simulation. Simulating the MLSE receiver in optimum form is too time consuming, so we estimated the I-Q path history parameter pk'S by using a simple procedure analogous to decision feedback processing. Although this method is not theoretically equivalent to an optimum computation, our results show that it performs essentially as well as an optimum computation. For moderate to high SNR, an upperbound on the probability of symbol error is obtained, using the concept of error events. A simplified expression for an upperbound on probability of symbol error, for the case when single-error error events are dominant is also obtained. A sub-optimum receiver structure is then derived using average matched filter responses. The sub-optimum receiver which turns out to be a complex filter followed by a decision device, is a relatively simple structure. The performance of the sub-optimum receiver was estimated for two different uplink filters. The effect of varying the BPNL input drive level was also studied. Our simulation results indicate that the performance of both the MLSE and the sub-optimum receivers approach asymptotically the same optimum performance band.

Finally, we extend our results on an optimum receiver structure for receiving QPSK signals over a digital satellite communications channel, to include the effects of filtering following the non-linear satellite transponder. It is shown that the complexity of the MLSE receiver is primarily determined by the uplink channel memory. The error performance of the receiver at low signal-to-noise ratios is evaluated by computer simulation. An upperbound on the probability of symbol error at moderate to high SNR is also obtained. A sub-optimum receiver similar to the uplink channel filtering case is developed and its performance evaluated using computer simulation. The degradation in performance of the sub-optimum receiver compared to the optimum receiver is found to be small.

abstract: Doctor of Philosophy (PhD)


title: Photonic Bus and Photonic Mesh Networks - Design Techniques in Extremely High Speed Networks

contributor:
Todd, Terence D.
Electrical Engineering

abstract: This work describes two network designs--Photonic Bus Networks and Photonic Mesh Networks. These two designs were developed in order to provide the basis for exploring the possibilities of novel design techniques in future fibre networks. In both cases, attempts are made to take advantage of emerging technologies in the area of fibre optic. The networks were not created to compete with other network designs, athough obvious comparisons with other netorks are possible. Rather, these networks were conceived to create a framework within which to study the behaviour of certain phenomenon that may be present in some future fibre networks. Both simulation studies and analytical modelling were used to improve understanding of the behaviour of the network design techniques. Photonic Bus Networks build upon the emerging IEEE 802.6 network standard by considering a multihop implementation on a physical transmissive optical star topology. Media access techniques are designed to allow for slot reuse at each node, to improve network performance while ensuring fair network access. The combination of the new media access with the broadcast nature of the physical optical network allows for the use of new and novel bandwidth allocation design techniques that would not be possible in IEEE 802.6 networks. Photonic Mesh Networks can be considered a two-dimensional generalization of Photonic Bus Networks. They are topologically regular two-dimensional grid networks that use a novel routing technique known as deflection routing and allow for easy bandwidth allocation. A framework is created for the consideration of traffic processing at a node in a Photonic Mesh Network. Algorithms are defined which consist of three separate but related strategies - the access strategy, the routing strategy and the allocation strategy. Simulation studies indicate that the interaction of these separate strategies affect the performane of the network.

abstract: Doctor of Philosophy (PhD)


title: Blocking and the Prevention of Blocking from the Unconditioned Stimulus in Pavlovian Conditioning

contributor:
Jenkins, H.M.
Psychology

subject: Psychology Psychology

abstract:
Seven experiments are reported which demonstrate and analyze interference with autoshaping from unsignaled USs. In Experiment 1, eight groups of 10 homer pigeons each received conditioning sessions consisting of an 880 s wait followed by a train of USs spaced 10.5 s apart, followed by a second 880 s wait. For all groups except one, one of the USs in the train was signaled by a 10 s red keylight CS. The position of this single trial in the train was varied across these groups; for the remaining group, all the USs were signaled by the CS. Conditioning of the CS was shown to be a function of the position of the CS in the train. Specifically, conditioning was achieved only when the single trial appeared at or near the beginning of the train (referred to as the trial location effect) or, when all USs were signaled by the CS.

The trial location effect was analyzed in Experiments 2 through 4 which showed that the interference from prior USs cannot be explained by any of the currently accepted explanations. Further analysis showed that the source of the interference is blocking of conditioning of the CS by the preceding USs which become established as signals of the next US.

In Experiments 5 - 7 it is shown that blocking from unsignaled USs can be prevented through prior conditioning of the CS. It is argued that this result requires a view of conditioning as producing a long term change in the associability of the CS. A recent model of conditioning which encompasses such a change in associability is reviewed. A preliminary examination of this model shows that it might provide an account for the present results.

abstract: Doctor of Philosophy (PhD)


title: Learned Heart-Rate Control and its Relationship to Accurate Self-Report

contributor:
Roberts, L.E.
Psychology

subject: Psychology Psychology

abstract:
An important debate in visceral learning is whether "awareness" of the response is necessary for learning to occur. Traditional models of visceral learning such as operant conditioning consider awareness of the response unnecessary whereas more recent models such as ideomotor theory, motor skills and problem solving consider it essential. Early research concerning this issue supported the view that awareness of the response was not necessary. However, more recent research has been unable to find instances of heart-rate learning in the absence of accurate self-report. This discrepancy would appear to be due to either inadequate assessment of learning and awareness in the early heart-rate studies, or to procedural differences between early and recent research that affected how or what subjects learned.

Three experiments were conducted to evaluate these two possibilities. Each experiment employed the more thorough assessment methods of the recent research while examining a procedural difference between the early and recent research. In Experiment 1 a group received feedback for increases in heart rate, another group received feedback for decreases in heart rate, and a third group received feedback for both increases and decreases (bidirectional training). Following training, all subjects provided written reports of what they did to produce the response. Average heart rate was found to differ significantly between increase and decrease training conditions and was accompanied by written reports whose contents also differed significantly between these training conditions. Furthermore, there was a significant positive relationship between magnitude of bidirectional control and veridicality of the reports. No differences were found between the groups trained to produce the response in one direction as compared to the bidirectional group. In Experiment 2 subjects were trained either to increase or decrease heart rate, and were or were not forewarned they would eventually have to produce the response without the aid of feedback ("transfer"). No significant differences were obtained between the forewarned and the not-forewarned groups. However, the relation of response awareness and success at learning was well preserved in both forewarning conditions. In Experiment 3, subjects were trained to produce either increases or decreases in heart rate, but were prohibited from using respiratory or somatomotor activity to solve the feedback problems. In addition, half the subjects were encouraged through instructions and electrode placement to use mental means to influence the feedback. Significantly poorer control and less accurate reports were obtained in the increase group given mental instructions compared to the increase group given the standard instructions. However, significant relationships between self-report and bidirectional control were obtained in all groups.

These experiments demonstrate that the positive relationship between heart-rate learning and accurate self-report is a robust association not dependent upon bidirectional training, forewarning of transfer, constraints on behaviour, or a mentalistic task orientation. This result indicates that the discrepancy between the early research and recent research is likely due to inadequate methods of assessing learning and awareness in the early studies. These results also indicate that cognitive considerations are important determinants of visceral learning, and approaches that assign a role to problem-solving activities in learning are appropriate frameworks for study of the visceral learning process.

abstract: Doctor of Philosophy (PhD)


title: The Pattern and Process of Redevelopment: An Empirical Application of a Redevelopment Simulation Model to Kitchener, Ontario

contributor:
Papageorgiou, Y.Y.
Geography

subject: Geography Geography

abstract:
This thesis is an attempt to develop a more comprehensive understanding of the pattern and process of redevelopment through modelling. Conceptually, redevelopment is viewed as a process consisting of a series of individual events related in space and time. The location of redevelopment is influenced by both the relative ability of sites to attract it, as determined by their physical and locational attributes, and chance factors. Based on this conceptual framework, a stochastic simulation model of redevelopment is developed. It is applied to the core area of Kitchener, Ontario and produces a ten-year forecast (1980-1989) of the spatio-temporal pattern of redevelopment therein.

Analysis of the model output indicates that, as of 1980, the sites with the highest redevelopment potential are concentrated in the eastern core. If past trends continue, redevelopment in the early 1980's will occur primarily on the eastern core periphery. However, by the latter half of the decade, the location of redevelopment will have shifted to western core sites, ignoring those in between.

The contribution of this research to the geographic literature is three-fold. Its detailed analysis of redevelopment is a significant supplement to the few existing studies of such an important urban phenomenon. The applicability of the logit model as an alternative functional form in regression analysis under certain conditions is revealed. Finally, the ability of the model to operationalize change and to incorporate a spatio-temporal shift in redevelopment location demonstrates the utility of the simulation approach in dynamic urban modelling.

abstract: Master of Arts (MA)


title: Evaluation of the seismic level of protection of steel moment resisting frame building structures

contributor:
Heidebrecht, A.C.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: A large number of low and medium-rise buildings have steel moment resisting frames as the primary lateral load resisting system. During the past few decades, much confidence has been placed on this type of structural system for resisting seismic loads. However, after recent earthquakes (e.g. Northridge, California, in 1994, and Kobe, Japan, in 1995) the confidence in this system was reduced as a result of various types of damage that moment resisting steel frames suffered. This resulted in a recognition of the need to evaluate the performance criteria on which current provisions are based. While there have not been any major casualties dueu to earthquakes in Canada during the past few decades, in fact there is an actual seismic hazard which affects significant regions of the country, for example, the cities of Victoria, Vancouver, Quebec City, Montreal, and Ottawa. The design peak ground motions in such regions are moderate in comparison with those in California or Japan, however the uncertainties associated with estimating the expected ground motions are such that twice or three times the seismic design level motions are likely to occur. The main objectives of this research study are: (i) to evaluate the seismic level of protection afforded to steel moment resisting frame building structures designed in accordance with the current Canadian provisions (i.e. NBCC (1995) and CAN/CSA-S16. 1-94), and (ii) to investigate the effect of the different design philosophies and seismic hazard design levels on the inelastic dynamic response of multi-storey steel frame structures. Six storey office buildings located in regions of high, intermediate, and low seismic hazard, and a ten storey office building located in a region of intermediate seismic hazard are designed in accordance with the current Canadian provisions using three design philosophies, namely strong-column weak-beam (SCWB), weak-column strong-beam (WCSB), and strong-column weak-panel zone (SCWP). The scope of the research program includes: (a) modelling of the structural elements; (b) nonlinear push over static analyses/inelastic dynamic analyses, and (c) evaluation of the damage potential associated with each design. In the study analytical models are modified and incorporated into the PC-ANSR computer program in order to perform the inelastic dynamic analyses of the frames. The inelastic models take into account the spreading of inelastic deformations in beam-column elements, connection flexibility and panel zone deformations. A cyclic model for the panel zone element is developed and introduced into PC-ANSR. The performance of the frames is evaluated both statically using monotonically increasing lateral load (nonlinear push over static analyses), and dynamically by subjecting the inelastic model to an ensemble of actual strong ground motion records (time-history analyses). The main ensemble of time-histories used in the study consists of twelve earthquake ground motion records selected on the basis of Newmark-Hall design spectra amplification factors. An additional ensemble of time-histories (twelve records) is selected based on the uniform hazard spectrum for Vancouver which describes the new seismic hazard information given by the Geological Survey of Canada. The additional ensemble is used to investigate the implication of the new seismic hazard information on the performance of the six storey frames in the intermediate seismic hazard region. The results of the inelastic dynamic analyses are presented in terms of statistical measures of the maximum response parameters determined during the time-history analyses. Also, the results of the nonlinear push over analyses are presented and compared with those of the dynamic analyses. The performance expectations of the frames are evaluated in order to assess both the overall level of protection provided to the frames and the preferred design philosophy. It is concluded from the analyses that in high and intermediate seismic hazard regions, a well-designed and detailed ductile moment resisting frame (i.e. SCWB or SCWP) can withstand ground motions of twice the design level with a very little likelihood of collapse, while an ill-conditioned designed frame (i.e. WCSB) may develop a collapse mechanism even at the design level excitation. In regions of low seismic hazard activity, the three frame design types perform satisfactorily, and can withstand twice the design level excitations with only a moderate amount of damage.

abstract: Doctor of Philosophy (PhD)


title: The Use of Fluorinated Maleimides as Protein Sulfhydryl Reagents for ¹⁹F-nmr Studies

contributor:
McCarry, Doctor B.E.
Chemistry

subject: Chemistry Chemistry

abstract:
The overall objectives of this work were the development of a) fluorinated maleimides for the specific modification of protein sulfhydryl groups and subsequent ¹⁹F- nmr studies and b) fluorinated phospholipids for the study of protein-lipid interactions by ¹⁹F-nmr. Two fluorinated analogues of N-ethylmaleimide, N-2,2,2-trifluoroethylmaleimide (FEM) and a deuterated analogue N-2,2,2-trifluoro-1,1-dideuteroethyl-maleimide (FEM-d₂) were synthesized from trifluoroacetamide in three steps. A detailed kinetic study showed that FEM reacted at least 10 times faster with thiols than with either other amino acid side chains namely imidazoles amines, alcohols or water. The rates of reaction between FEM and thiols increased ten-fold for each unit increase in pH, in addition, apparent activation parameters were determined for these reactions at pH 6.65. The FEM-thiol adducts were also isolated and fully characterized.

Bovine serum albumin (BSA) on exposure to FEM-d₂ reacted rapidly at the single sulfhydryl residue exclusively. On the other hand, 3-bromo-1,1,1-trifluoropropanone reacted with BSA at the sulfhydryl group and at other sites on the protein to the extent of 20%. The neutral to fast (N-F) transition of BSA was examined by ¹⁹F-NMR following modification of the protein with FEM-d₂ (BSA-FEM-d₂) or Br-TFP (BSA-TFP). Over the pH range 3.0-6.0 at least three distinct ¹⁹F-NMR resonances were observed for both modified proteins; the linewidths, chemical shifts and peak areas of these resonances changed as a function of pH. Circular dichroism and fluorescence spectra of modified and unmodified BSA proteins in the pH 3.0-6.0 range were indistinguishable indicating that the sulfhydryl labels caused little structural perturbation to the protein. At pHs above 8.0, BSA-FEM-d₂ underwent an irreversible chemical reaction; likely opening of the succinimide ring by an amino group of the protein. Chemical shift anisotropy contributions to the ¹⁹F-nmr linewidths for both BSA-FEM-d₂ and BSA-TFP increased linearly on going from 84.66 to 235.36 MHz.

Two phospholipids fluorinated in the acyl chains were synthesized for the purpose of incorporating them into vesicles with lipophilin, an integral membrane protein; bis-8-fluoro, 8-deutero- and bis-12-fluoro, 12-deuterodimyristoylphosphatidyl-choline were synthesized and characterized by ²H-nmr and calorimetric studies. However, ¹⁹F-nmr studies of lipophilin/fluorolipid mixtures showed no evidence for the presence of any immobilized or "boundary lipid" around the protein. In addition, lipophilin was modified with FEM-d₂ but ¹⁹F-nmr experiments provided no information about the environment of the FEM-d₂ labelled cysteine residues of the protein.

abstract: Doctor of Philosophy (PhD)


title: Polymer Reactor Design, Optimization and Control in Latex Production Technology

contributor:
MacGregor, J.F.
Hamielec, A.E.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract:
During continuous emulsion polymerization of many monomers (e.g. vinyl acetate, vinyl chloride), sustained oscillations (limit cycles) occur in conversion and all the latex and polymer properties. This creates severe problems with the commercial application of continuous reactors. As shown by Pollock (1984) advanced control theory is inadequate for controlling these reactors. However, it was shown that the limit cycle behaviour could be eliminated through redesign of the reactor train configuration. The redesigned production train was shown via simulation to be free of oscillations and to offer greatly increased flexibility in controlling particle size and monomer conversion.

In this thesis the mathematical model of Kiparissides (1978) and Pollock (1984), based on a particle age distribution analysis and incorporating detailed chemistry and physics of the polymerization phenomena involved, is modified and is used to simulate the dynamic behaviour of these reactors for different modes of process operation (batch, semi-batch and continuous train) and monomer systems (PVAc, PVc).

Experimental studies which demonstrate the improved dynamic performance of the redesigned reactor system are carried out in a pilot plant stainless steel reactor train with on-line monitoring of monomer conversion with a set of on- line densitometers. Control of the final latex particle size and conversion is achieved through manipulation of the initiator feed rate to the first particle nucleating reactor, and the split of the monomer and water flow rates between the first two reactors of the train.

The effect of monomer arid water soluble impurities on the emulsion polymerization of Case I monomers is further investigated both theoretically and experimentally. Experimental identification and verification of the main source of stochastic disturbances in these systems was thus obtained.

abstract: Doctor of Philosophy (PhD)


title: Photochemical and Thermal E/Z Isomerizations of Some α,β-Unsaturated Iminium Salts

contributor:
Childs, R.F.
Chemistry

subject: Chemistry Chemistry

abstract:
Geometric isomerizations about the C=C and C=N bonds of a series of diaryl α,β-unsaturated iminium salts are investigated in this thesis. These isomerizations are important in several unsaturated iminium ions found in natural systems. The vision process relies on light absorption by the protein rhodopsin followed by Z/E isomerization. A similar reaction is used by certain bacteria to convert light energy into energy the organisms can use for cell functions.

A series of nine iminium salts, N-methyl, N-aryl-3-aryl-2-propenylidene iminium perchlorates, with various electron-withdrawing or electron-donating substituents on the aryl rings were synthesized and characterized. Three methods of isomerization of these molecules were examined--photochemical, electron transfer initiated, and thermal isomerization.

The electronic absorption and emission properties of these iminium salts, and the effect of the substituents on the regioselectivity of photoisomerization, led to some conclusions about the excited states involved in the isomerization. Although the molecules reach an initial excited state where the positive charge of the iminium group has migrated process into the carbon framework of the molecule, the isomerization process is not governed by such an intermediate. It is suggested that the state that governs photoisomerization has biradical character.

E/Z isomerization about the C=N bond of the unsubstituted iminium salt was accomplished by photoinitiated electron transfer from the donor, tris (2,2'-bipyridine)-ruthenium(II)dichloride, the first observation of this reaction.

The iminium salts crystallize as the E,E isomers, but undergo thermal isomerization in solution to produce a mixture of E and Z isomers about the C=N bond. In strong acid media, two mechanisms of isomerization were found. Electron-withdrawing substituted iminium salts isomerize by a nucleophile-catalyzed mechanism, and electron-donating substituents cause isomerization by protonation of the iminium salt.

abstract: Doctor of Philosophy (PhD)


title: The Microcode Level Timeslicing Processor Architecture

contributor:
Szabados, Barna
Electrical Engineering

abstract:
The von Neumann computer model, upon which most of our modern computers are based, is lacking in both parellelism and support for multitasking. One convenient measure of processor-parallelism is the degree to which a processor utilizes its available memory bandwidth for useful work: its Memory Bandwidth Efficiency (MBE). A processor which exhibits an MBE of 100% is operating as fast as possible for its given memory speed.

Conventional processor accelerators like prefetching and pipelining increase parallelism but suffer from the jump problem, in which a taken jump may cause incorrect prefetching. These accelerators are not well adapted to multitasking, although enhancements like selectable register files may be used to reduce context switching overhead. Pipelined multistreaming achieves a high degree of parallelism, avoids the jump problem and supports efficient context switching, but its performance is load dependent and it is awkward to implement. Furthermore, none of these architectures support efficient process resource sharing.

Microcode Level Timeslicing (MLT) is a multistream processor architecture that achieves very high processer MBE, has no-overhead context switching and provides support for resource sharing. Within the processor, process state information is replicated N-fold. Prefetching occurs horizontally across streams, allowing the jump problem to be circumvented. Context switching occurs at microinstruction boundaries, giving no overhead for up to N streams. The fetching and executing mechanisms are controlled by a Stream Control Unit (SCU), which contains task status information for each stream. Efficient process control and resource sharing operations are readily supported in the SCU.

The hardware and software design of a prototype processor demonstrating the MLT principle for up to 16 streams is presented. Process control and syncronization operations are implemented at the microcode level. Two high-level language benchmarks, the Sieve of Eratosthenes and they Dhrystone, are used to evaluate the prototype's performance.

abstract: Doctor of Philosophy (PhD)


title: The Laplacian of the Electronic Charge Distribution

contributor:
W.Bader, R. F.
Chemistry

subject: Chemistry Chemistry

abstract:
The physical basis of chemical concepts are the focal points of this thesis. The chemical concepts of atoms and bonds are equated to real pieces of a molecule and the topology of the electronic charge density which defines their connectivity, respectively. Bader et al's quantum theory of atoms in molecules and topological theory of molecular structure are the theories that justify the above identifications. These theories are reviewed.

The physical basis of the electron pair concept proposed by Lewis is the subject of the original work presented in this thesis. It is reiterated that, in general, the charge distributions of atoms and molecules can not be realistically described as a superposition of the separately localized charge distribution of electronic pairs. The physical basis of the electron pair concept is instead argued to be the topological properties of the Laplacian of the total electronic charge distribution, specifically the local concentrations of charge found in the valence shell charge concentrations of atoms in molecules.

The postulates of Gillespie's VSEPR model of molecular geometry describe the spatial and interactive properties of valence shell electron pairs. All of these postulates are shown to be a prescription of the corresponding properties of the aforementioned local charge concentrations. The observed number, types, locations and shapes of valence shell charge concentrations are in accord with the corresponding elements of Lewis' and Gillespie's models. The interactive properties of these charge concentrations are related to the effect of Fermi correlation on the electron pair distribution function. A pair of electrons with opposite spin is found to be partially localized and maximally separated from other electron pairs when one of the electrons is located at a position of maximum charge concentration. The properties of the charge concentrations as well as the Fermi correlation of reference electrons located at their positions, are shown to be in consonance with the primary postulate of the VSEPR model. This postulate states that molecular geometries minimizing interpair repulsions within the valence shell of the central atom are the most stable.

The relationships between the Laplacion of the electronic charge distribution and the frontier orbital theory of chemical reactivity, as well as the ligand field theory of transition metal complexes, are briefly discussed.

abstract: Doctor of Philosophy (PhD)


title: Factors Which Influence Career Choice and Future Orientations of Females: Implications for Career Education

subject: Education Education

abstract:
The International Women's Year of 1975 was a catalyst in generating interest and stimulating discussion on the status of women in general, but of women in the work force in particular. Despite a discernible increase of women in the job market, occupations continue to be sex-segregated and women are still clustered in certain careers. High status occupations continue to be androcentric and the salary differential between males and females is still widening.

The literature is replete with explanations on the reasons for the constricted career choices of females and the lack of planning for a future which stresses a strong career orientation. In recent years, many efforts have been directed at raising the consciousness of women and sensitizing them to the factors which inhibit their progress. Even though the statistics on the participation of women in the work force are so revealing and the centrality of work in the lives of individuals so well established, many young women continue to be myopic in their career planning. At the other end of the spectrum the influx of ill-prepared, unskilled, "re-entry" women into the workforce amplifies this problem. For an increasing number of women, a productive and self-sustaining life involves a career. Others are trying to make successful integrations of the variety of roles available to them.

With these concerns in mind, the present investigator sought to discover what the future plans of Ontario high school girls were and to elucidate their Career Education needs.

This was an applied study, designed to identify the variables which contribute significantly to the career aspirations, expectations, educations plans and career commitment of Ontario high school girls.

The sample of comprised of 1,167 girls from grades 11, 12 and 13, in both public and private high schools. They were selected in such a manner that the influence of such factors as rural or urban residence, ethnicity, socio-economic status and religious affiliation, could be investigated.

The study was a cross-sectional survey and the major statistical procedure employed was multiple regression analysis. This procedure facilitated the study of the impact of 33 independent variables of a social psychological and demographic nature on the dependant variables previously mentioned. The major findings are summarized below.

1. According to daughters, almost half of their parents wanted them to attend university.

2. As a group the parents had higher educational expectations for their daughters than the daughters had for themselves.

3. Over sixty percent of the girls did not know the occupations their parents wanted them to have. Of those who knew, there were slight differences between the expectations of the two parents. The expectations of the fathers were slightly more non-traditional than those of the mothers.

4. A higher percentage of girls felt that they resembled their mothers in terms of attitudes and expectations than felt that they resembled their fathers.

5. Both parents more often wanted their daughters to combine marriage and a career than for them to become single professionals or to be married without careers.

6. Almost half the girls aspired to upper class occupations. Two out of five aspired to non-tradtional occupations.

7. Less than a third of the girls expected to have an upper class occupation. One girl in four expected to have a non-traditional occupation.

8. Only half the girls stated that they knew at least one woman in the occupation they plan to enter.

9. Just under half of the girls planned to continue their education in a community-college or other post-secondary institution. Slightly more than one-third planned to enter university.

10. Most of the girls had a moderate career commitment. Their plans for career involvement would depend on whether or not they had children. The stage of schooling at which their children were would be very important.

11. More than half of the girls stated that they did not know enough about the occupations available to them to make a well-informed, career choice. However, many felt that they knew themselves (i.e., interests and abilities) quite well.

12. Only sixteen percent of the girls had had a course in which topics related to women were discussed in detail. For the majority, such topics were mentioned but only in a general way. One girl in three had never had the opportunity to discuss such topics.

13. The sex-role ideology of girls was varied with almost an equal proportion of girls falling within the Traditional, Moderate and Liberated categories.

14. In general, the girls in the sample knew very little factual information about women in the work force. They believed many myths about women.

15. The variables which contributed significantly to the dependent variables may be summarized as follows:

a. Career Aspiration (Socio-economic level): Grade level, academic average, position in the family, sex role ideology.

b. Career Aspiration (Traditional, Undifferentiated Non-traditional): Academic average, knowing women in the career, sex-role ideology.

c. Career Expectation (Socio-economic level): Academic average, socio-economic status, occupational category of mother, sex-role ideology.

d. Career Expectation (Traditional, Undifferentiated Non-Traditional): Type of school, academic average, occupational category of mother, occupation of mother, knowing women in the career, sex-role ideology.

e. Educational Plans: Type of school, grade level, academic average, family situation, mother's expectation concerning daughter's education, sex-role ideology.

f. Career commitment: Ethnicity, position in the family, father's education, mother's feelings about employment, parent student wishes to emulate, sex-role ideology, knowledge of women in the workforce.

The results of this study will be of particular interest to counsellors, teachers, educational policy-makers and all those concerned with the career preparation of students. The implications of the major findings for Career Education are discussed and recommendations are made to address the special needs of young women. A review of curriculum models and programs related to Career Education is appended.

abstract: Doctor of Education (EdD)


title: Key Stakeholders' Perceptions of Nursing Human Resource Development in Pakistan: A Situational Analysis

contributor:
Baumann, Andrea
Nursing

subject: Nursing Nursing

abstract: Health human resource development (HHRD), including nursing human resource development (NHRD) is essential for any country, HHRD is an unexplored area of study in Pakistan. In this exploratory study, qualitative methodology was used to obtain the perceptions of key stakeholders on the current situation of nursing human resource development in the Province of Sindh in Pakistan. A conceptual framework organized around the three components of planning, production, and management guided data collection, coding, and analysis. Five year plans (FYPs) (1978-1998) containing national health policies were reviewed to identify issues relating to NHRD. Semi-structured interviews were conducted to elicit key stakeholders' perceptions regarding the current NHRD situation in Pakistan. Individual interviews were held with 34 stakeholders, the majority of whom were from the public sector at the federal, provincial, and local levels. Data were analyzed by generating codes. Nineteen categories emerged from the codes which were clustered under each of the following components: planning, production, and management. Emerging patterns were noted amongst categories and 22 issues within components were identified. The 22 issues were further collapsed into five themes: formulation of policies; planning-implementation gap; supply-requirement imbalance; quality of education; and working environment of nursing personnel. The findings indicated similarities as well as differences in the perceptions of nursing personnel and government officials with respect to the components of HHRD. Homogeneity was found in the perspectives of nursing personnel across levels, with a focus on operational issues. In contrast, divergence was found in perceptions of government officials; the officials at the federal level viewed NHRD from a broad societal perspective, while officials at the local level demonstrated more knowledge and understanding of issues related to NHRD. Findings of this study demonstrated that key stakeholders varied in their understanding of the issues, at both macro and micro levels. The policy review of five year plans indicated clear objectives, but stakeholders identified a policy-implementation gap. This research has implications for studying HHRD in general and for Pakistan in particular. The study confirmed the value of determining the perceptions of key stakeholders as a firs step in HHRD. When selecting key stakeholders, policy makers need to be aware that perceptions differ by level and affiliation of the stakeholder. At the time of policy formulation, input from key stakeholders should be obtained as a means of facilitating implementation of policies. Recommendations for further research were generated from the findings.

abstract: Doctor of Philosophy (PhD)


title: Representation, Truth and Belief in Literature

contributor:
Georgiadis, C.
Philosophy

subject: Philosophy Philosophy

abstract: This work examines interconnected problems concerning representation, truth and belief in literature in the context of a moderate, rather than an absolute, conception of literary autonomy, and a broad, rather than a restrictive, conception of 'the aesthetic'. In Chapter One the different types of representation are categorized and five 'characteristic' features of representation are presented. This analysis is applied to (a) linguistic representation in literature, (b) iconic representation in literature, and (c) symbolic and allegorical representation in literature. Chapter Two explores iconic representation in literature focussing on (i) sound associations, (ii) onomatopoeia, (iii) rhythm, and (iv) visual aspects of the text. The way these interact with linguistic representation is examined and their aesthetic significance is described. Chapter Three is concerned with the ways in which Iiterature may represent or be about the real world, and the ways in which literature may be true to or of reality. Among the topics examined are literary sentences and themes. In analyzing the former we distinguish between literature and purely fictional literature and treat each separately. Sentences in purely fictional literature are not used to make explicit assertions about real phenomena and they are neither true nor false of reality. They represent in an 'internal' (or 'depictive' or 'presentational') sense. Literature, however, includes fictional and non-fictional sentences and may, therefore, contain assertive, referential sentences which represent in an internal and in an external sense, and which may be true (or false) of real phenomena. Arguments against this view are presented and criticized. A different way in which literature (including purely fictional literature) may be about, and be true to, reality, is by having theme. Thematic works are about more than the particular events depicted. In contemplating the work's theme or themes we relate the work to life. Sometimes the work's theme is presented through symbolic or allegorical representation. Chapter Four delineates the essential role which the reader's beliefs (about what is true or false, good or bad) play in 'actualizing' the literary aesthetic object (including its 'world' and its aesthetic form). Chapters Five, Six and Seven explore connections between truth, belief and aesthetic value. In Chapter Five it is argued that, though truth is not a necessary or a sufficient conditions of literary value, it often contributes to literary value by giving depth, power, resonance or wit to a work. Cognitive value sometimes enriches aesthetic value; cognitive judgements are sometimes reasons supporting aesthetic judgements. In Chapter Six we acknowledge the fact that literary works informed by beliefs we do not share often win our 'imaginative consent'. But, we argue, reading literature as literature does not require of us a universal and undiscriminating imaginative acceptance of all beliefs in literature, including the idiotic, the insane, and the horrendously immoral. Some works arouse in us a cognitive or moral dissent that disrupts and impairs the quality of our aesthetic experience. Poor cognitive and moral value judgements can be reasons for aesthetic value; cognitive and moral judgements can be reasons for aesthetic judgements. In Chapter Seven we examine Aristotle's Poetics with interpretative and philosophical aims. We criticize some modern attempts to read Aristotle as an absolute autonomist. We exhibit the connections he posits between truth to reality, 'form', and 'beauty', and also between moral belief and aesthetic emotion. Aristotle's remarks about 'character realism' provide the starting point for a discussion of its aesthetic relevance. We argue that out-of-character actions in literature are often, but not always, an aesthetic flaw, and we attempt to explain why this is so. Fyre's theory of fictional modes is used as a framework for this analysis.

abstract: Doctor of Philosophy (PhD)


title: Doppler Compensation for LEO Satellite Communication Systems

abstract: This thesis investigates the carrier synchronization problem due to Doppler shift encountered in low data rate, low earth orbit (LEO) satellite communication systems. In particular, two new techniques are developed. The first technique which is referred to as the novel technique, is based on the idea of applying a linearly decreasing frequency sweep to the received signal as a method to reduce the Doppler shift to tolerable levels, whereby conventional carrier synchronization may be employed. This method has shown to be better suited for satellites at larger cross track angles. However, for direct overhead satellite pass, improved Doppler compensation is achieved by utilizing the modified novel technique. Simulations have been carried out to explore the performance of the novel technique. Simulations have been carried out to explore the performance of the novel technique and results have shown that it is capable of reducing Doppler shift by at least a factor of two and performs better for satellites at large cross track angles. The second technique of Doppler compensation is based on Maximum Likelihood (ML) estimation of multiple parameters. This algorithm makes use of a model developed for the phase error introduced due to Doppler frequency shift and Doppler rate, and the two implementable solutions investigated are; (1) the grid search, and (2) the ML quadriphase shift keying (QPSK) Doppler compensator. These solutions have been realized by utilizing approximations for low signal to noise ratio (SNR) conditions. The grid search is a non tracking technique and may be used for coarse Doppler compensation. Unfortunately, simulation results have shown that it is computationally intensive. On another note, a block diagram consisting of a phase rotator, matched filtering and two feedback loops has been developed to represent the ML QPSK Doppler compensator. Three digital implementations of this structure have been analyzed, namely; steepest descent, optimized steepest descent and Newton Raphson method. The first two, have two modes of operation; conventional feedback and adaptive feedback. Simulations have shown that the adaptive optimized steepest descent has the best performance, that is, the shortest lockup time. Comparisons to previous work in this area, have shown that the proposed Doppler compensator has superior performance.

abstract: Doctor of Philosophy (PhD)


title: Structural Studies of Tin Compounds in Acid Media

contributor:
Birchall, T.
Chemistry

subject: Chemistry Chemistry

abstract:
Reactions of stannane or methylstannanes (CH₃)₄_nSnHn (n = 1-4) in fluorosulphuric acid at low temperatures (-85°C) produce [(CH₃)₃_nSnHn]⁺ (where n = 0→3) and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy have been used in their characterization. Hydrogen evolution, ¹¹⁹Sn NMR and Mössbauer spectroscopic evidence is presented to show that at higher temperatures these species decompose to Sn²⁺, Sn²⁺ plus (CH₃)₂Sn²⁺ and (CH₃)₂Sn²⁺ depending on the starting hydride. Tin-119 NMR spectra of dialkyltin cationic species in strong acid solutions are field dependent. Relaxation time measurements at three different magnetic fields have established that the dominant spin-lattice relaxation mechanism for these species at higher magnetic field is shielding anisotropy. A comparison of spin-lattice and spin-spin relaxation rates indicates that at ambient temperature a rapid chemical exchange process is occuring. In the case of the (CH₃)₂Sn(SO₃F)₂-HSO₃F system, variable temperature ¹¹⁹Sn NMR spectra reveals the presence of three tin species which are involved in this exchange process.

Tin-119 NMR data for a series of tin(lI) and tin(IV) acid derivatives have been determined. Tin(II) compounds exhibit a wide range of chemical shifts varying from -617 ppm to -1628 ppm, whereas tin(IV) derivatives cover a narrow range around -800 ppm. Stoichiometric mixtures of tin(II) and tin(lV) derivatives of the same acid have been analysed by ¹¹⁹Sn NMR and Mössbauer spectroscopy. Reaction occurs only between Sn(OCOCF₃)₂ and Sn(OCOCF₃)₄ to form a mixed valence tin(II), tin(lV) compound. Partial oxidation of Sn(OCOCF₃)₂ results in the formation of a mixed valence tin compound whose structure has been determined by X-ray crystallography to be [Sn(II)₄Sn(IV)O₂(O₂CCF₃)₈]. This structure consist of discrete noncentrosymmetric units with point group S₄, the central feature of which is a Sn(11)₄Sn(lV)O₂ unit containing two μ₃ oxygen atoms which each form a bridge between a Sn(lV) atom and two symmetry related Sn(lI) atoms. Among the two pairs of Sn(ll) atoms, each pair is bridged by two trifluoroacetates.

A systematic route has been established in the preparation of mixed valence tin compounds by the reaction of SnF₂ with tin(lV) carboxylates. These reactions have been followed by ¹⁹F and ¹¹⁹Sn NMR spectroscopy. In one case an X-ray crystal structure determination showed the compound to be [Sn(lI)₂Sn(lV)₂F₄(O₂CCF₃)₈2CF₃CO₂H]. This consists of eight membered rings with alternating Sn(II) and Sn(IV) atoms bridged by fluorine and trifluoroacetate groups.

abstract: Doctor of Philosophy (PhD)


title: A Novel Electromagnetic Technique for Remote Repositioning of Coolant Tube Spacers In CANDU Nuclear Reactors

contributor:
Findlay, Raymond D.
Electrical and Computer Engineering

abstract:
On August 1, 1983, a sudden failure of a coolant tube, known as a pressure tube, was experienced in one of the CANDU reactors at Pickering 'A' Nuclear Generating Station of Ontario Hydro. A contributing factor to the rupture of the tube was a contact for a period of several years between the tube and an outer coaxial tube, called the calandria tube. The contact between the pressure tube and calandria tube occurred because the annular spacers (garter springs), used to maintain the coaxial configuration when the uranium fuel bundles are loaded inside the pressure tube, had shifted out of their design locations during the construction stage and subsequent hot conditioning of the reactor. The displacement of the spacers was attributed to vibration induced by various sources and was determined to have taken place prior to loading the fuel bundles in the reactor.

Since the garter springs are not directly accessible by mechanical means, extensive dismantling of the fuel channels would have been necessary to reposition the springs in their designated locations. This Thesis describes a novel electromagnetic method to reposition without the garter springs without dismantling the fuel channels. The method consists of inserting an electromagnetic coil into the pressure tube to a location adjacent to the spacer and passing a time-varying electric current in the coil to induce secondary currents in the pressure tube and the spacer. The interaction between the induced current in the spacer and net magnetic field in the spacer region results in an electro-magnetic force having an axial component large enough to displace the spacer in the required direction. In practice, current impulses generated by discharging a large capacitor bank were used to achieve the required garter: spring displacement.

The new method was successfully developed and impIemented to reposition the displaced garter springs in five new CANDU reactors in Ontario. The savings in the reactor repair cost, interest charges and replacement energy costs were in the order of hundreds of millions of dollars. Equally large benefits and savings will be realized if the need to use this technique in commissioned reactors becomes mandatory. The practical aspects of the work including the design of pulse power cables and a coil sufficiently compact to fit in the pressure tube, but strong enough to withstand the stress, were developed by the author at the Ontario Hydro laboratories. The Thesis describes not only this aspect but also develops a model for analysis of the operation and design of the device.

There are a number of other applications of the electromagnetic technique which may also benefit from the analysis, especially for electromagnetic metal forming and fusion technologies.

abstract: Doctor of Philosophy (PhD)


title: Import of Proteins into Mammalian Mitochondria

contributor:
Freeman, K.B.
Biochemistry

subject: Biochemistry Biochemistry

abstract:
Most mitochondrial proteins are encoded in the nuclear genome and imported into mitochondria after their synthesis on cytoplasmic ribosomes. Two rat liver mitochondrial proteins, malate dehydrogenase and the adenine nucleotide carrier, were selected to study the mechanism of importing nuclear coded mitochondrial proteins into the organelle.

Rat liver proteins were synthesized in vitro and the nascent forms of the two proteins were immunoprecipitated by monospecific antibodies against each protein. Size determination by sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that each precursor protein is about 1,500-2,000 daltons larger than its mature monomeric form. In contrast to secretory proteins, both proteins are exclusively synthesized on membrane free polysomes. Molecular mass sieving experiments indicated that both precursor proteins exist as aggregates or complexes after their synthesis. These aggregates or complexes may play a role in transfering the two precursor proteins to the mitochondrial outer membrane.

The import of both precursor proteins into mitochondria was studied with an in vitro system, consisting of the translation mixture and mitochondria isolated from Chinese hamster ovary cells. The precursor of malate dehydrogenase, synthesized in vitro, could be imported into isolated mitochondria in the absence of protein synthesis. The import was accompanied with the conversion of the larger precursor to the mature monomeric size. The newly processed precursor, in mitochondria, was insensitive to externally added protease, suggesting that the protein had been translocated into at least the inter-membrane space, if not the matrix. The proteolytic cleavage was arrested by the chelator, o-phenanthroline, indicating the protease responsible for the conversion requires metallic cations as a cofactor. Time course studies showed that import and processing of the precursor was completed within 10 to 30 min at 30°C and the precursor was converted to the mature size by a single cleavage. Import was found to depend on the electrochemical potential across the inner membrane, as shown by the inhibitory effect of the uncoupler, carbonyl cyanide m-chlorophenylhydrazone.

The same in vitro import system was used to investigate the import of the precursor of the rat liver adenine nucleotide carrier. Although processing of the precursor to its mature size was not observed, there were indications that the precursor was imported into mitochondria: (1) a time-dependent transfer of the precursor from the incubation solution to mitochondria was observed, and the process was greatly reduced in presence of an uncoupler. (2) Unlike the precursor in the incubation solution, the precursor immunoprecipitated from the mitochondrial fraction was protease insensitive. The reasons for the lack of processing of the imported precursor in the in vitro system is not known. However, the results suggest that proteolytic processing of the precursor is not an obligatory step in its import.

The success in establishing an in vitro system in which the processing of the precursor of rat liver malate dehydrogenase occurred, allowed probing of the details of the import process. In the presence of an uncoupler, binding, but not processing, of the precursor to mitochondria was observed. Further experiments showed that the binding process fulfils most of the criteria for a genuine ligand-receptor interaction. It is temperature insensitive and completed very rapidly at 0°C. The binding process is not inhibited by the presence of an uncoupler. The bound precursor is protease sensitive, indicating that its putative receptor is located on the mitochondrial outer membrane. An apparent saturation of the binding sites was observed with a fixed amount of mitochondria and excess amount of in vitro synthesized proteins. Most importantly, it was observed that processing of bound precursor was independent of the volume of reaction mixture, suggesting that bound precursor was directly processed to its mature size. In contrast, processing of unbound precursor was dependent on reaction volume. These results suggest that binding of the precursor of malate dehydrogenase to the mitochondrial outer membrane is an intermediate step in the import process.

Mitochondrial malate dehydrogenase is a NAD⁺-dependent dehydrogenase. The enzyme has been purified to homogeneity from different sources by the affinity column, 5-AMP-Sepharose. However, the precursor of rat liver malate dehydrogenase synthesized in vitro did not bind to the affinity column, indicating the absence of a NAD⁺-binding site on the precursor protein. After conversion to the mature size by isolated mitochondria, the processed protein bound to the affinity column and was eluted with the endogenous enzyme by 40 uM NADH. These results strongly indicate that processing of the precursor to its mature size is followed by conformational changes resulting in the formation of a functional NAD⁺-binding site. This conclusion is supported by studies with antisera prepared against the sodium dodecyl sulphate denatured enzyme, which are conformationally specific. The antiserum recognized only the sodium dodecyl sulphate denatured mature protein and the in vitro processed precursor protein, but not the native functional enzyme. However, the antiserum could immunoprecipitate the precursor protein with or without prior denaturation. The above results suggest that the in vitro imported precursor protein has been converted into a functional enzyme, and indicate that the in vitro import system reflects the process that occurs in vivo.

abstract: Doctor of Philosophy (PhD)


title: Regularized Radial Basis Function Networks: Theory and Applications to Probability Estimation, Classification, and Time Series Prediction

contributor:
Haykin, Simon
Electrical and Computer Engineering

abstract: In this thesis, we study both theoretical and practical aspects of the regularized strict interpolation radial basis function (SIRBFN) estimate or neural network. From a theoretical perspective, we show that the regularized SIRBFN can be globally mean-square (m.s.) consistent whenever the Nadaraya-Watson regression estimate is and the regularization parameter sequence for the SIRBFN is chosen to be asymptotically optimal in the mean-squared fitting error. Hence we prove the Bayes risk consistency of the approximate Bayes decision rules formed from (m.s.-consistent) regularized SIRBFN posterior probability estimates. Similarly, we prove the m.s.-consistency of the regularized SIRBFN predictor for the class of Markovian nonlinear autoregressive time series generated by an i.i.d. noise process. In a one-step-ahead prediction experiment with a phonetically-balanced suite of male and female speech waveforms, the proposed predictor offers an average 2.2dB improvement in predction SNR over corresponding expponentially-weighted RLS predictors. We also show that linearly combining an ensemble of three such proposed predictors via RLS filtering can yield an average 4.2dB improvement over the previous standard RLS predictors, and develop recursive algorithms to update the proposed predictor on-line with reduced computational complexity for certain situations. Two emerging applications areas are then considered. The first is the regression-based approach to nonlinear filtering or state estimation, where the proposed network provides comparable performance to a recurrent MLP-based solution. The second is the dynamic reconstruction of chaotic systems from noisy observational data, where the reconstructed system is shown to generate sequences whose estimated long and short-term dynamical invariants agree closely with those of the original, noise-free system. Taken together, these theoretical and practical results point to the regularized SIRBFN as a principled design choice for RBF neural networks.

abstract: Doctor of Philosophy (PhD)


title: Application of Adaptive Control to a Reciprocating Plate Liquid-Liquid Solvent Extraction Column

contributor:
Baird, Malcolm H.I.
Taylor, P.A.
Chemical Engineering

abstract:
An experimental investigation of the application of direct digital control (DDC) has been carried out with continuous chemical processing equipment, namely a liquid-liquid solvent extraction column. The type of extractor used was the Karr reciprocating plate column.

Steady state simulations of the column were carried out using both a semi-empirical model for studying the hydrodynamics of the column, and a mechanistic model for studying the mass transfer characteristics of the column. The results of these simulations were used to interpret the closed loop response characteristics of the column. Two types of control schemes were studied; (i) an adaptive self tuning regulator (STR), (ii) the Dahlin algorithm.

Though the dispersed phase holdup is not the primary control variable, its control is essential to prevent the hydrodynamic instability. The frequency of reciprocation was used to control the holdup. The relationship between the frequency of reciprocation and the dispersed phase holdup is highly nonlinear therefore an adaptive controller (in this work, a self tuning regulator) has to be used to control this process. Previous work on holdup control has been extended to include a wider, range of operating conditions and prevention of covariance windup by using an empirical discounting factor.

The primary control objective was the control of the extract concentration. This was done in two ways. The first scheme was a cascaded control to manipulate the frequency of reciprocation whereby the inner loop was the holdup control. An STR-STR cascade arrangement was compared with cascade a PI-STR arrangement. It was found that the restrictions imposed on the outer loop meant that the PI-STR arrangement, was as effective as the STR-STR arrangement. The second control scheme manipulated the continuous phase flow rate with (MIMO) and without (SISO) the simultaneous control of the holdup via manipulation of the frequency of reciprocation. A variable dead time Dahlin controller was used to control the extract concentration in this second control scheme. In the MlMO case, decoupling was not necessary since one loop had a positive gain while the other had a negative gain and so the interactions were constructive.

abstract: Doctor of Philosophy (PhD)


title: A Century of Native Leadership: Shingwaukonse and His Heirs

contributor:
Damas, David
Anthropology

subject: Anthropology Anthropology

abstract: Two conflicting schools of thought have arisen regarding proto-Ojibwa society and leadership, as well as social-organizational changes which have taken place within Ojibwa bands during the historic era. Proponents of the first theoretical perspective hold that territorially based clans and clan chiefs existed in the Upper Great Lakes region until social breakdown occurred as a consequence of indirect colonialism and the fur trade. A second view stresses the persistence among the Ojibwa of an ethos of egalitarianism characterized by conceptions of "power" and "control" distinct from Western notions of competitive, self-interested action. Both approaches are examined in the light of oral and historical evidence pertaining to the activities of the noted Ojibwa chief Shingwaukönse and his successors during the nineteenth century. The study concludes that Native leadership underwent substantial elaboration during the colonial period in response to external commercial, government, and missionary agencies, and yet remained sensitive to band goals and aspirations by maintaining a social environment conducive to the preservation of cherished Native values. The tradition of leadership established by Shingwaukönse survived into the twentieth century at Garden River, Ontario, since, with a fair degree of success, chiefs and band have continually sought to protect and develop potentialities inherent in traditional group prerogatives, including a specific interest in land and resources.

abstract: Doctor of Philosophy (PhD)


title: Socio-economic Relations and Urban Spatial Formation

contributor:
Webber, M.J.
Geography

subject: Geography Geography

abstract: This thesis constructs a theoretical framework for the application of Marx's work to urban spatial formation. It is based on Marx's concept of the dialectic as internal relations, examining the concept with regard to the socio-spatial dialectic and the relations of production under capitalism. Marx's theory is applied to urban spatial formation with a focus on the rise of urbanism and suburbanization as manifestations of the inherent relations of the capitalist mode of production. Urbanism, as a set of relations, is discussed through the relations of production, consumption, accumulation, and centralization. The spatial manifestations of urbanization and suburbanization are considered in light of these relations and the inherently spatial moment of production, circulation; with specific emphasis on the spatial expansion of the market and the annihilation of space by time. The study of relations serves to explain more than the mechanisms involved in spatial formation; rather, it explains the dialectical relations between socio-economic and urban spatial formation.

abstract: Master of Arts (MA)


title: The Appearance of Stochastic Control in Fish Communities on Coral Reefs: a Hierarchical Approach to System Organization

contributor:
Kolasa, Jurel
Biology

subject: Biology Biology

abstract: Species membership and population densities of fish communities on coral reefs are highly variable both spatially and temporally across many scales. Several models of stochastic control (i.e., organizing processes that produce these highly variable patterns) have been proposed. These models of stochastic control include: a lottery for available habitat sites, limited recruitment, and opportunistic predation. Although these models of stochastic control differ from each other in their organizing processes, they are similar in that they share two implicit assumptions. First, there is only one level or scale of system organization; second, there is only one significant organizing process. Recent developments in community ecology, however, suggest that the organization of fish communities on coral reefs is complex (i.e., involves multiple levels of system organization). The heuristic value of a multi-level system of organization is that patterns that appear under stochastic control can, at least theoretically, be broken down or decomposed into a series of simpler, non-stochastic patterns. If fish communities on coral reefs are indeed complex as in the above sense, then we need to re-evaluate the supposed single-level stochastic control in these systems. The purpose of this thesis, therefore, is to test the null hypothesis that fish communities on coral reefs are dependent on single-level stochastic processes as has been suggested. The alternative hypothesis is the appearance of stochastic control is a blend of patterns due to multiple levels of system organization. The method I use to test this is conceptually straightforward. The first step is to divide the species membership into several groups. In the second step, for each species group I determine the correlation between species distributions and, for example, some attribute of the habitat template. If the organization of fish communities on coral reefs is dependent on stochastic processes acting within a single level, then independent of how the species are divided into groups, the correlation for all species groups should be similar. I found that: - when the species are divided into groups based on similarities in the number of patch reefs a species is found, then significant differences occur among groups in correlation between species distributions and habitat attributes, - specifically, for each habitat attribute tested there exists a trend of increasing correlation (or decreasing correlation -- depending on the habitat attribute) from species found on most patches to species found on few patches. This suggests that the previous models of single-level stochastic control (e.g., habitat lottery, limited recruitment, and predation) are incomplete because they do not consider consequences due to differences in species' distributions and densities. Instead these results suggest that the structure and organization of fish on coral reefs incorporate a mixture of stochastic and non-stochastic processes that occur (a) simultaneously within the community, and (b) differentially between the species. This implies that fish communities on coral reefs are complex concerning their basic structure, and that unless a community level pattern is decomposed into its component elements, the conclusions made about the nature of these communities can be misleading.

abstract: Doctor of Philosophy (PhD)


title: Design and Modelling of Microwave Circuits Using Optimization Methods

contributor:
Bandler, John W.
Electrical Engineering

abstract:
This thesis addresses itself to the computer-aided design and modelling of microwave circuits using efficient minimax and ℓ₁ optimization techniques.

Recent algorithms for nonlinear minimax and ℓ₁ for the particular applications of this thesis. Efficient gradient approximation techniques applicable to both minimax and ℓ₁ optimization are presented.

A comparative example with ℓ₂ optimization illustrates the robustness of ℓ₁ for the particular applications of this thesis. Efficient gradient approximation techniques applicable to both minimax and ℓ₁ optimization are presented.

A simplified and straightforward treatment of sensitivities for two port networks, cascaded and branched cascaded structures is introduced. The objective is to calculate the sensitivities efficiently, without appealing to the adjoint network concept. A novel proof of a recent result in sensitivity analysis of lossless and reciprocal two-ports is presented.

Design of manifold type waveguide multiplexers has been considered as a major application for both minimax optimization and the theoretical work in branched cascaded network sensitivity analysis. Components of the multiplexer structure and nonideal effects such as dissipation and dispersion are discussed and a step-by-step implementation of an algorithm to calculate particular responses and sensitivities is presented. Examples of the design of 3-, 12- and 16-channel, 12 GHz multiplexers illustrate the practicality of the approach presented.

A new approach to modelling of microwave devices which exploits the theoretical properties of the ℓ₁ norm is presented. The concept of multi-circuit measurements is introduced and its merits in obtaining unique and self-consistent parameters are discussed. The technique is applied to modelling of multi-coupled cavity filters and GaAs FET's. The application of efficient modelling techniques in developing algorithms for postproduction tuning and in establishing the relationship between physical parameters of a device and its equivalent circuit model parameters is discussed.

abstract: Doctor of Philosophy (PhD)


title: Measurement and Modelling of Long Chain Branching

contributor:
Hamielec, A. E.
Chemical Engineering

abstract: The measurement and modelling of long chain branching (LCB) in free-radical chain growth polymerization is examined. A new method, the "instantaneous" property method, is presented for the calculation of the full molecular weight distribution(MWD) of branched polymers when the branching is due to chain transfer to polymer. The method is shown to be accurate and consistent with the method of moments, the method that is generally used to calculate molecular weight averages. The method can give additional detail about the MWD of the various branched families in the polymeric mixture. Such information can be quite useful in correlating processing properties with molecular structure. Two polymers that produce LCB when polymerized were examined. Bulk polymerization of vinyl acetate (VAc) and p-methyl styrene were carried out. Gel permeation chromatography. intrinsic viscosity and low angle laser light scattering measurements were used to measure molecular weight averages and LCB frequencies. Two methods were used to calculate LCB frequencies and they both gave results that were consistent with the method of moments. The "instantaneous" method was applied to the data from the polymerization of PPMS since for this polymer LCB is due to chain transfer to polymer. The predictions from the "instantaneous" method, when compared to the method of moments and the experimental data, were shown to be of acceptable accuracy.

abstract: Doctor of Philosophy (PhD)


title: Kindling and Plasticity of the Hippocampal Inhibitory System

contributor:
Racine, R.J.
Psychology

subject: Psychology Psychology

abstract:
Kindling involves the repeated application of epileptogenic stimulation to certain brain sites until fully generalized behavioral convulsions occur. Input/output relationships (determined by recording responses evoked at different stimulation intensities) and paired-pulse facilitation/depression effects were monitored in the hilus of the hippocampal dentate gyrus as stimulation pulses were applied to the perforant path. These effects were measured before, during and after kindling the perforant path or the hilus of the dentate gyrus.

After kindling was completed, the perforant path-kindled animals showed an increase in population spike height (related to the number of cells firing) at the higher intensities but a decrease at lower intensities. A small increase in the slope of the rising phase of the population EPSP was observed at the higher intensities. The dentate gyrus-kindled animals showed a progressive decrease in population spike height during kindling, while the slope increased in magnitude. All of these kindling-induced effects, except for the increase in slope, appeared to decay towards pre-kindling levels over a 4 week stimulation-free period after the completion of kindling.

Paired-pulse depression of the population spike height was "potentiated" in both groups as a result of kindling. Paired-pulse effects returned towards pre-kindling levels over a 4 week stimulation-free period post-kindling. This decay was especially clear in the perforant path-kindled group.

Kindling the perforant path resulted in a significant increase in number of benzodiazepine receptors. This increase in receptor number is believed to underly the kindling-induced increase in paired-pulse depression. Results indicated that the increase in receptor number may decline with time after kindling is terminated.

It was concluded that almost all kindling-induced effects studied disappear over time after kindling is terminated. They are dependent on the occurrence of epileptogenic stimulation. Characteristics of potentiation of the hippocampal inhibitory system appear to be similar to those of potentiation of the hippocampal excitatory system.

abstract: Doctor of Philosophy (PhD)


title: The Moral Permissibility of Physician Assisted Death

contributor:
Waluchow, W.
Philosophy

subject: Philosophy Philosophy

abstract: This thesis is an investigation of the moral responsibility of physicians in assisted death. I begin with a discussion of the problem that drives the debate concerning end of life decision making. I conclude that the problem faced by those attempting to make decisiosn at the end of life is the bad death. A bad death is marked by a long, debilitating, incapacitating, dying process. Given the problem of the bad death, I discuss what responsibilities the physician might have toward a dying patient. I conclude that the responsibility of a physician is to the wellness of his or her patient, whether that patient is dying or not. For the dying patient, continued existence, or a bad death may count as harm, and a good death as a benefit. Since promoting wellness for a patient means maximizing the benefits and minimizing (or eliminating) the harms, wellness for a dying patient might mean the avoidance of the bad death and the active pursuit of the good death, which I call death management. Since the physician's responsibility is to promote wellness, the physician has a responsibility to promote the good death for a dying patient. Much of my argument hangs on the concept of "dying". I argue for a particular definition of dying and the conceptual distinction between death management and suicide. I defend the claim that physicians have a responsibility to provide death management against the moral difference thesis which holds that it is morally worse to actively kill someone than to merely let that person die. I argue against this thesis and defend instead the moral equivalence thesis which holds that there is no moral difference between bare acts and bare omissions. I also discuss the doctrine of double effect, which represents a potential challenge to my argument. However, I show that the doctrine of double effect is, in fact, not applicable to cases of death management. I condlude with a brief look at some of the concerns should death management become a social policy or legally sanctioned practice. My replies are necessarily brief, but sufficient to show that these concerns are not fatal to the legitimacy of death management.

abstract: Doctor of Philosophy (PhD)


title: Fundamental Analysis for the Processing of Search and Rescue Satellite-Aided Tracking (SARSAT) Signals at Baseband

contributor:
Carter, C.R.
Electrical and Computer Engineering

abstract:
Search and rescue satellite aided tracking (SARSAT) is a method of employing satellites in low polar orbits to relay the emergency signals of distressed aircraft and marine vessels to an earth station. At the earth station, the signals are processed using spectral estimation techniques which permit the calculation of the location of the distressed vehicle. Of considerable importance are the characteristics of the spectrum of the emergency locator transmitter (ELT) signal since the probability of locating the downed aircraft is closely related to the quality of the ELT signal itself.

This thesis analyses and investigates the ELT signal spectra for ranges of different parameter values. A mathematical representation for the variation of the pulse duration across the sweep period for actual real ELT signals has been developed and verified. New models are proposed with nearly ideal spectral properties.

The matched filter performance for detection of the ELT signals has been calculated. Also, the periodogram and averaged periodogram performances for detection of the ELT signals are calculated and verified by computer simulation.

A new processor, called the complex baseband processor, which employs both the periodogram and the maximum entropy method (MEM) is developed. Baseband processing has many advantages over bandpass processing.

This thesis examines the processing of simulated ELT signals, real testbed ELT signals and actual data received from satellite passes using this new baseband processor. It is shown theoretically and by computer simulation that the minimum detectable carrier-to-noise density ratio (CNDR) is approximately 21 dB-Hz when the 512 complex-point FFT is applied to 50 blocks comprising 1 second of data.

A new technique called rate reduction filtering is developed. By applying this technique to the data sequence, improved frequency resolution is obtained along with an increase in signal-to-noise ratio. Further, a new algorithm called "ELT Tracking Algorithm" based on using rate reduction filtering is developed and analysed.

abstract: Doctor of Philosophy (PhD)