title: Attitudes Toward Disabled Children: A New Measure

contributor:
derSpuy, H.I.J. van
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Disabled children are increasingly being integrated into the regular school environment. Poor attitudes of able-bodied peers are a major obstacle to the social success of this process. Our knowledge about the determinants of attitudes and methods of improving attitudes has been hampered by the poor quality of available attitude measures. This thesis describes a new measure to overcome this problem.

The Chedoke-McMaster Attitudes Toward Children with Handicaps (CATCH) scale is a 36-item self-report measure of children's expressed attitude along three dimension; affective response, behavioral intent, and cognitive understanding. CATCH is intended for children in grades four to eight. Over 800 children have been involved in the testing of the first and then the revised draft of CATCH.

Children had no difficulty completing the scale. The items related to their everyday experiences. Descriptive aspects of CATCH were good. Total scores varied from 53 to 143 (possible interval of 0 to 144). The total sample mean was 99.1 with a standard deviation of 16.1. The measure was reliable with a coefficient alpha of .90 for the total score.

Factor analysis of CATCH revealed three factors accounting for 83% of the variance. Factor one and factor three were a mixture of affective and behavioral items and accounted for 62% and 6% of the variance, respectively. Factor two contained primarily cognitive items and accounted for 15% of the variance.

The construct validity of CATCH was established by testing its ability to discriminate groups based on previously hypothesized differences. Girls had significantly more positive attitudes than boys (104.0 versus 94.5; p=.001). Children who had a friend who was disabled; or who had contact with a disabled child in the last week had significantly better attitudes than children without disabled friends or contact. The mean CATCH score for friend was 106.2 versus 95.6 for no friend. For contact the mean score was 108.1 versus 97.0. Children who volunteered for a buddy program or who had previously taken part in a buddy program with a disabled child had significantly higher CATCH scores.

CATCH was used as the primary outcome measure in a randomized controlled trial of a buddy program between able-bodied and disabled children. A criterion score improvement occurred significantly more frequently in buddies than controls (43% versus 18%) p=.05). This intervention also appeared to have a significant effect on parental attitudes with buddy parents having a significant improvement compared to control parents.

These results demonstrate that CATCH is both a reliable and valid measure of children's expressed attitudes. While the limitations of this measure are recognized. CATCH will be extremely valuable in the study of attitude determinants and in the evaluation of interventions to improve attitudes.

abstract: Doctor of Philosophy (PhD)


title: The Energy Levels of ¹³⁴Cs

contributor:
Summers-Gill, R.G.
Physics

subject: Physics Physics

abstract:
The energy levels of ¹³⁴Cs were investigated with single particle transfer reactions, ¹³³Cs (d,p) and ¹³⁵Ba (t,α), and via ϒ-ray spectroscopy studies, ¹³³Cs (d,pϒ) and ¹³⁰Te(⁷Li,³nϒ). The ¹³³Cs(d,p) reaction revealed twentyfive levels up to 936 keV. The ℓ-values and spectroscopic factors were extracted for twenty-three of these levels. Four prominent ℓn = 2 and three prominent ℓn = 0 levels were found. Eleven ℓn = 5 levels were also identified.

The ¹³⁵Ba(t,α) reaction showed nineteen levels up to 1319 keV, but ℓ-values and spectroscopic factors were extracted for only eleven of these levels. Four strong ℓp = 4 and seven ℓp = 2 levels were identified.

High resolution singles and coincidence ϒ-ray studies in the ¹³³Cs(d,pϒ) and ¹³⁰Te(⁷Li:3n) reactions gave data on the de-excitation of the levels in ¹³⁴Cs. The ¹³³Cs(d,pϒ) study provided detailed information on the levels of ¹³⁴cs • These data provided confirmation of some of the (n,ϒ) work of Alexeev et al. (1975, 1978).

A level scheme for ¹³⁴Cs was deduced from the accumulated data. Tentative spin and parity assignments were made for some of the levels. Simple shell model p-n configurations. [πg₇/₂, (νd₃/₂)ˉ¹], [πg₇/₂, (νs₁/₂)ˉ¹], [πg₇/₂, (νb₁₁/₂)ˉ¹] and [πd₅/₂, (νd₃/₂)ˉ¹], were invoked to make the spin assignments. The (d,p) and (t,α) particle data were used to make shell model configuration assignments to some of the energy levels. Poor agreement between the shell model configurations determined in the present study and those assigned by Alexeev et al. (1978) was found.

abstract: Doctor of Philosophy (PhD)


title: Human Lead Metabolism: Chronic Exposure, Bone Lead and Physiological Models

contributor:
Webber, Colin E.
Chettle, David R.
Physics and Astronomy

subject:
Astrophysics and Astronomy
Astrophysics and Astronomy

abstract: Exposure to lead is associated with a variety of detrimental health effects. After ingestion or inhalation, lead may be taken up from the bloodstream and retained by bone tissue. X-ray fluorescence was used to make in vivo measurements of bone lead concentration at the tibia calcaneus for 367 active and 14 retired lead smelter workers. Blood lead levels following a labour disruption were used in conjunction with bone lead readings to examine the endogenous release of lead from bone. Relations between bone lead and a cumulative blood lead index differed depending on time of hiring. This suggests that the transfer of lead from blood to bone has changed over time, possibly as a result of varying exposure conditions. A common polymorphism in the δ-aminolevulinate dehydratase (ALAD) enzyme may influence the distribution of lead in humans. Blood lead levels were higher for smelter workers expressing the more rare ALAD² allele. Bone lead concentrations, however, were not significantly different. This implies that a smaller proportion of lead in blood is distributed to tissue for individuals expressing the ALAD² allele. The O'Flaherty physiological model of lead metabolism was modified slightly and tested with input from the personal exposure histories of smelter workers. The model results were consistent with observation in terms of endogenous exposure to lead and accumulation of lead in cortical bone. Modelling the calcaneus as a trabecular bone site did not reproduce observed trends. Variations in lead metabolism between different trabecular sites may therefore be significant. The model does not incorporate a genetic component, and its output did not reflect observed differences in this respect. This result provides further support for the influence of the ALAD polymorphism on lead metabolism. Experimental trials with a digital spectrometer revealed superior energy resolution and count throughput relative to the conventional x-ray fluorescence system. The associated reduction in the uncertainty of lead measurement has the potential to benefit future surveys and modelling efforts.

abstract: Doctor of Philosophy (PhD)


title: Orchestration of Reactions of Glycoluril Templates

contributor:
Harrison, Paul
Chemistry

subject: Chemistry Chemistry

abstract: Glycoluril 1 has been shown to act as a template, facilitating intramolecular Claisen-type condensations between bound acyl units. Repetitive acylations, condensations, and functional group manipulations allow the synthesis of complex structures from simple starting materials. Thus, the natural product tetradec-2-enoic acid-4,5-epoxide 2 was prepared by condensation on 1 of decanoic acid with two units of acetate. The 1-(3'-oxodecanoyl) glycoluril 3 was prepared from 1 via 4. Conversion to the dodecenoyl derivative 5 (2 steps), followed by a second cycle of acetylation, condensation, reduction and dehydration provided tetradeca-2,4-dienoyl glycoluril 6. Direct cleavage to the carboxylic acid, followed by epoxidation gave 2. Mono- (7) and di-thio (8) analogues of 1 are readily prepared using Lawesson's reagent; this novel application of Lawesson's reagent can be extend to N-acylglycolurils, leading to monacylmonothio derivatives (9) in which thionation occurs at the least hindered urea carbonyl. The thio analogues 7 and 8 are more readily acylated than 1; acylation of 7 occurs exclusively on the NH site adjacent to sulfur to give 10. All diacetylthioglycolurils underwent the Claisen-like condensation reaction to give acetoacetyl thioglycoluril derivatives; 11 undergoes selective deprotonation of the acetyl group adjacent to oxygen to give a mixture of 12 and 13 (2.2:1). Crossed-Claisen condensations of both isomers of acetyl-butanoyl monothioglycoluril (14, 15) afforded 3-ketohexanoyl and 2-ethyl-3-ketobutanoyl thioglycolurils (16 and 17, 18 and 19, respectively). Condensation of 14 led to a highly selective crossed-Claisen condensation (16:17 6:1); while condensation of 15 led to a reversal of regioselectivity (18:19 0.75:1). The x-ray crystallographic structures of key compounds in the glycoluril cycle were compared in order to improve understanding of geometrical factors involved in the condensation reaction. Additionally, several reactions in the cycle, including the first acylation, the condensation, the reduction, and the cleavage reactions were investigated to find conditions which lead to improved yields.

abstract: Doctor of Philosophy (PhD)


title: Sedimentology of the Upper Crataceous (Turonian) Cardium Formation in Outcrop in Southern Alberta

contributor:
Walker, R. G.
Geology

subject: Geology Geology

abstract:
Cardium Formation exposures in Alberta consist of vertically juxtaposed thickening- and coarsening-upward cycles. Shallow-marine deposits exhibiting hummocky cross-stratification (HCS) dominate cycles. Locally, cycles record a marine to non-marine transition; they are interpreted as the deposits of a prograding storm-dominated shoreline. Sands were introduced into the basin by storms, and were transported in the proximal offshore region by seostrophically balanced bottom flows. Sharp contacts between cycles represent transgression surfaces; they display erosionally based, laterally extensive marine conglomerates. Locally, erosional transgressions removed non-marine deposits from the cycle tops over extensive distances normal to shoreline. Conglomerates were transported during transgressions, accumulating within a "hydrodynamic shadow" over the drowned shoreface of the preceding regressive episode.

A technique for paleohydraulic analysis of conglomeratic symmetrical ripples has been discussed, tested, and applied to Cardium occurrences; results suggest that associated examples of HCS were formed in the oscillatory-flow flat-bed field by previously unrecognized low-amplitude, three-dimensional orbital ripples.

abstract: Doctor of Philosophy (PhD)


title: An Extension of Greechie's Atomistic Loop Lemma

contributor:
Burns, G.
Mathematics

subject: Mathematics Mathematics

abstract: One of the major deficiencies of the theory of orthomodular lattices is the lack of accessible examples with which to test and develop conjectures. R. J. Greechie has developed two methods ([1], [2]) of obtaining new orthmodular lattices by "pasting" old ones together. This thesis gives an extension of one of these, the atomistic loop lemma. Briefly, a non-empty set of Boolean lattices with common bounds which either intersect trivially or in disjoint principal sections form an orthocomplemented poset under set-theoretic union. Necessary and sufficient conditions are given for this poset to be orthomodular.

abstract: Master of Science (MS)


title: Comparison of the Metabolic and Behavioral Disturbances following Paraventricular- and Ventromedial-Hypothalamic Lesions

contributor:
Weingarten, H.P.
Psychology

subject: Psychology Psychology

abstract:
Lesions of the ventromedial hypothalamus (VMH) result in an obesity syndrome characterized by metabolic and behavioral disturbances. It has recently been indicated that damage to the paraventricular nucleus of the hypothalamus (PVH) also leads to changes characteristic of obesity. Although deficits following VMH lesions have been characterized extensively, less is known about the consequences of PVH damage. This thesis presents a series of experiments providing a detailed comparison of the two hypothalamic lesion syndromes.

Initially, to assess the basic features of the syndromes, rats underwent VMH, PVH, or sham lesions and were maintained ad libitum for 15 weeks on a series of test diets. Overall, lesion groups gained similar amounts of weight (significantly more than controls) and were equally hyperphagic. However, carcass analyses revealed that although both lesion groups had larger body fat compartments than controls, VMH rats were fatter than PVH animals. Similarly, although insulin levels in both lesion groups were elevated, only VMH rats had a significant hyperinsulinemia.

A defining feature of the VMH obesity is the development of certain disturbances of visceral secretion and excessive adipose stores even in the absence of hyperphagia. To assess whether the PVH obesity shares these characteristics, food intake of PVH and VMH rats were restricted postlesion to control body weights. First, gastric acid secretion was measured to index lesion-induced changes in visceral secretion. VMH rats developed a persisting hypersecretion immediately postlesion; acid secretion levels of PVH rats were normal. In a second experiment, PVH and VMH rats were maintained at control weights for 28 days postlesion by restricted feeding of either a standard pellet or high fat diet. In both diet conditions, VMH rats became obese but PVH rats did not.

Finally, the effects of PVH and VMH lesions on behavioral reactivity to orosensory properties of food were assessed by comparing the sham feeding responses of PVH, VMH and control rats to liquid diets varying in palatability. Control animals increased sham feeding with ascending sucrose concentrations. VMH animals showed disproportionately large increases in consumption with increased sucrose. PVH animals showed sham feeding changes similar to VMH rats.

These data indicate similar effects of PVH and VMH lesions on behavioral measures; specifically, in normal, and sham, feeding. However, these two lesions produce different effects on metabolic and secretion measures. It is concluded that the etiologies of the two obesity are fundamentally different.

abstract: Doctor of Philosophy (PhD)


title: The Phenomenon of Ductile Fracture

contributor:
Sowerby, R.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract:
The topic of this thesis is the phenomenon of ductile fracture, and stems from a government research contract aimed at assessing the utility of different steels designated for cold forging applications.

Recourse has been made to experimental data, available in the published literature, of upsetting tests on certain steels in different heat treated conditions. Some upsetting tests have also been performed as part of the present study, and following earlier work conducted at McMaster University, specimens of different geometry were also investigated. The materials were examined metallographically, before and after deformation.

It was found that in addition to material characteristics the specimen geometry can have a marked effect on the extent of the deformation before surface cracking. The so-called collar specimen resulted in smaller strains to fracture vis à vis the other specimen geometries investigated.

The principal surface strains were determined throughout the course of the upsetting tests by measuring a grid of lines marked on the equatorial free surface of the specimens.

A knowledge of the strain path enables the stress history of a point on the equatorial free surface to be determined using simple plasticity theory. The details are described herein. The upsetting tests were also modelled using a finite element technique based on a rigid, work-hardening material. The predicted and measured strains at the free surface of the specimens showed good agreement, and consequently, the predicted stresses agreed with those determined using simple plasticity theory. However, the finite element technique enables the stress history to be determined at any interior point within the specimens.

A knowledge of the stress history permits an evaluation of certain damage integrals. The ones proposed by Cockcroft and Latham and Oyane were investigated in the present work, but they failed to provide an adequate account of the observed behaviour in the upsetting tests. Failure based on the attainment of a critical shear seemed more appropriate. The experimental data also demonstrated that the fracture strains, i.e. the.hoop, ε₀₀, and axial strains, ε₀₀/ε₂₂ = -1/2, as proposed by Kuhn.

Reliance was also placed on experimental data (gathered by other researchers at McMaster University) from tensile tests performed on spheroidized steels subjected to superimposed hydrostatic pressure. Quantitative metallography had revealed information on certain aspects of void initiation, growth and coalescence as a function of volume fraction of inclusions and hydrostatic pressure.

In the present work the void growth stage was predicted using a void growth model due to McClintock, but modified mutatis mutandis to allow for the continuous nucleation of voids. The model is shown to be capable of describing certain experimental observations regarding void growth.

McClintock's model was also applied to the data gathered from the upsetting tests. Again it appeared capable of predicting the damage rate and damage accumulation in a manner consistent with experimental observations. Furthermore, it was possible to predict a fracture locus, plotted in ε₀₀-ε₂₂ space and based on the attainment of a critical accumulated damage, which correlated very well with the experimental data. McClintock's model is outlined in the thesis, and discussed in the context of other void growth models given in the published literature.

abstract: Doctor of Philosophy (PhD)


title: The Evolution of Sex-related Traits and Speciation in Drosophila

contributor:
Singh, Rama S.
Biology

subject: Biology Biology

abstract: The amount of genetic change associated with species differentiation, and the phenotypic characteristics of such changes between closely related species, are crucial elements to the problem of speciation. This thesis describes an analysis of morphological, protein and DNA sequence divergence between closely related species that show a common pattern of higher interspecific divergence for sex-related traits (i.e. constituents of he genitalia, traits involved in mating, fertilization, or sex differentiation) than non sex-related traits. Proteins expressed in gonodal tissues (testis and ovary) showed a higher interspecific divergence than proteins expressed in nongonodal tissues (brain and malphighian tubule) and a positive significant correlation was found between testis protein divergence and postzygotic isolation when closely related species were compared. An analysis of internal as well as external traits morphology revealed high divergence in testis length and area and genital arch area between species of the melanogaster complex. Similar levels of variation within species and non significant differences in trait asymmetry were found between sex-related and non-sex related traits. The analysis of interspecific hybrid morphology revealed between species allele complementation in non sex-related traits, while sex-related traits displayed signs of disrupted genetic interactions. A preliminary survey of DNA sequence divergence showed a high ratio of nonsynonymous to synonymous substitutions for sex-related genes. Such as elevated ratio proved to be the result of a high proportion of nonsynonymous substitutions between closely related species. Synonymous substitutions did not show any translational selective constraints that may have reduced the proportion of such changes between species.

abstract: Doctor of Philosophy (PhD)


title: The Use of Goal Programming for Resource Assessment, With an Application to Forest Energy Developments in Eastern Ontario

contributor:
Lonergan, S.C.
Smit, B.E.
Geography

subject: Geography Geography

abstract:
This research was primarily concerned with the identification, development and application of methods for the purpose of providing information to assist resource management decisions. The type of information sought was defined by four questions, which essentially relate to the ability to achieve specified development goals and the identification of conflicts amongst goals. Analysis directed at resolving these questions was referred to as resource assessment.

The first major component of the research involved the search for appropriate methods by which to undertake resource assessment analysis. The ability to account for multiple, and possibly conflicting goals, which may be expressed in disparate metrics, was an explicit concern in evaluating the various methods. Multiobjective goal programming was identified as one method well-suitable to resource assessment analysis.

Application of a goal programming model in an assessment of proposed forest energy developments in Eastern Ontario constituted the second major component of the research. This provided an applied context within which to further evaluate the suitability of goal programming for resource assessment. Application of the method was also expected to provided useful insights into the implications for the Eastern region of forest energy developments.

Results suggest that energy plantation developments could make a substantial contribution to the Eastern region of Ontario, through the development of under-utilized land resources, the generation of regional income, the provision of jobs, and the production of energy for local markets and perhaps beyond. The analysis clearly indicates, however, that conflicts exist amongst the specified development goals. Resource allocations which imply favourable results in terms of one development goal may mean relatively poor achievement levels with respect to some of the other goals. This suggests that considerable caution must be exercised in selecting development strategies with respect to a forest energy system.

The research makes an important contribution in a methodological sense, by demonstrating that scientific procedures can be employed to systematically and rigorously address questions of fundamental importance in resource assessment. In particular, this research has shown that it is possible to assess captions in resource use with respect to several, potentially incompatible goals. By providing useful information relating to the possible socio-economic and environmental consequences of forest energy developments in Eastern Ontario, the research also makes an important contribution in all applied sense.

abstract: Doctor of Philosophy (PhD)


title: Large Deformation FEA and Applications for Metal Forming Processes

contributor:
Sklad, Mateusz P.
Mechanical Engineering

abstract: The contents of this thesis reflect a general effort in the endeavour of exploring and developing the effective FEM tools for metal forming analysis. There are three major parts in this work. In chapter 2, an unique mathematical derivation of large deformation equations is presented on the basis of a direct linearization of the "future" virtual work equation without using any pseudo stress tensor and corresponding conjugate strain tensor. A major advantage of this derivation is that a clear physical understanding is carried through the whole mathematical process. Therefore distinctive perception on key fundamentals such as: equilibrium equation, strain measure, constitutive relation, stress rotation and residual force evaluation are presented and discussed on a consistent and integrated basis. The code developed in this part of work forms an independent module for 2D bulk forming analysis, while the methodology is carried through the rest of thesis. A particular effort is described in Chapter 3, which addressed the problem and techniques used in dealing with the frictional contact boundary condition which is common in metal forming processes. A typical ring compression problem is used to show the problem and solution. The algorithm and code developed there is a part of the 2D package. Chapter 4 presents a full description of a 3D degenerated shell element formulation based on the consistent large deformation formulation presented in Chapter 2. Various aspects of techniques used in shell elements to prevent elements from locking have been reviewed. A special penalty method is devised to enforce the Kirchhoff constraint which has been missing in the degenerated shell element discretization. The method has successfully prevented 3-node and 4-node elements from shear locking in analysing the typical cup drawing process. At the end of the thesis, a summary of the thesis is presented. Conclusions and recommendations for further work are provided.

abstract: Doctor of Philosophy (PhD)


title: Canada's Forgotten Poets: Values in Early Twentieth-Century Canadian Poetry in English

contributor:
Shrive, F. N.
English

subject:
English Language and Literature
English Language and Literature

abstract:
Early twentieth-century Canadian poetry has largely been ignored by critics and scholars of Canadian literature. The thesis serves to rectify this omission by concentrating on the values of this poetry, since the period has been neglected due to a negative evaluation of the poetry by the generation of poets who immediately followed those who came to artistic maturity between 1900 and 1936. Rather than imposing yet another evaluation on the period, however, I ask what values early twentieth-century poets chose to express in their verse. From this starting-point, I went on to develop a model of poetic value pertaining to the period in question.

In this first, introductory chapter I discuss values in poetry in general terms, explain the nature of the negative evaluation of the period by reference to critical statements made by A. J. M. Smith and others and conclude with a description of intellectual and social values as they were understood at the time. Chapter Two concerns the verse of Tom MacInnes, Wilson MacDonald, Audrey Brown, G. H. Clarke and Arthur Stringer. Chapter Three is devoted to the work of Marjorie Pickthall and W. W. E. Ross. In chapters two and three I am chiefly concerned with the poetic value of beauty as it is expressed in the poetry. Chapter Four treats the value of prophetic truth as this value emerges in the poetry of F.O. Call, Arthur Bourinot, A.M. Stephen and the poetic and critical writings of Raymond Knister. In the final chapter I discuss a conflict between the values of beauty, truth and order as this conflict appears in the Canadian odes of the time, in a number of highly structured and unusual books of poetry and in the religious poetry of the Reverend Robert Norwood. Chapter Five concludes with a discussion of E. J. Pratt's poetry, in which I maintain that the conflict in values is inevitably resolved in a poetry of order.

In addressing the values of poetry as they were expressed in Canadian poetry in English in the first decades of the century, I render the poetry accessible to contemporary reassessment and re-evaluation. The thesis not only treats a period of literary activity that has been neglected for too long, but also brings forward the question of values in literature and in life.

abstract: Doctor of Philosophy (PhD)


title: Metallocene-Catalyzed Semi-Batch and Continuous Polymerization of Ethylene

contributor:
Hamielec, Archie E.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract: An integrated methodology has been utilized to analyze the factors that affect the activity of metallocene catalysts and the microstructure of the polymers produced under various reaction conditions for both semi-batch and continuous solution polymerization of ethylene. The highly active metallocene catalyst system Cp₂ZrCl₂/MAO was focused on in order to determine the fundamental kinetic rate constants, and a thorough characterization of the polymer microstructure was carried out using high temperature size exclusion chromatography (SEC), carbon-13 nuclear magnetic resonance spectroscopy (¹³C NMR), differential scanning calorimetry (DSC) and shear thinning behaviour as determined by I₁₀/I₂. In the semi-batch polymerization of ethylene in toluene utilizing Cp₂ZrCl₂/MAO, the shape of the polymerization rate-time curves were found to depend on monomer diffusion rates with low ethylene concentrations and poor sparging/mixing impellers giving steady-states while high ethylene concentrations and superior impellers led to decay-type curves/ Increasing temperature increased the catalyst activity with an activation energy for propagation (Ep) of 28.5 kJ/mol while strongly decreasing PE MWs. Several types of commercial and developmental aluminoxanes were studied which indicated that the structure and type of aluminoxane co-catalyst did not influence the MWD of PE although significantly influenced the catalyst activity. Mixing additional TMA with MAO was found not to alter the MWD. For all conditions studied at temperatures between 20-90 ∘C in semi-batch, the PE produced was found to approximate Flory's most probable distribution for a single site-type catalyst. The rate constants for propagation, β-scission and chain transfer to ethylene at 70∘C were found to be kp = 2.7 x 10⁴(M∙s)⁻¹, ktr.β = 0.27 s⁻¹ and ktr.M= 3.8 (M∙s)⁻¹. Long chain branches per 1000 carbons (λN) up to 1.2 were found and the ratio of melt flow indexes indicating shear thinning, I₁₀/I₂, were found up to 15. A high pressure, high temperature CSTR was utilized for the solution polymerization of ethylene at 1500 psig in toluene using the metallocene catalyst system Cp₂ZrCl₂/MAO/TMA. Increasing Cp₂ZrCl₂ concentration led to a decrease in PE MWs while the catalyst activity increased. With increasing temperature between 140-200∘C, the MWs of PE decreased and polydispersities increased while the catalyst activity decreased with an apparent activation energy of -93 kJ/mol. The deactivation of the catalyst is first-order with rate constant kd = 2.1 x 10⁻³ s⁻¹ while kp= 5 x 10³ (M∙s)⁻¹ and ktr.β 3 s⁻¹ at 140∘C. λN's up to 0.6 were found and I₁₀/I₂ were found up to 6.

abstract: Doctor of Philosophy (PhD)


title: The Variations of Che Ju Do Korean Life Styles in Tokyo, Japan

contributor:
Cooper, Matthew O.
Anthropology

subject: Anthropology Anthropology

abstract: This dissertation is an exploratory study of life style variations among Koreans in Tokyo, Japan. The sample of Koreans, whose cultural origin is Che Ju Do, an island located off the southwest coast of South Korea, is classified into three groups: the first-generation which migrated to Japan prior to the end of World War II; the second-generation whose members were all born in Tokyo as offspring of the first group; and the recent migrant group which migrated to Japan since the end of World War II. While the first-generation and the recent migrant groups show similar life styles regardless of their age difference, the second-generation group shows life styles markedly different from the first two groups and discloses a wider variation of life styles within the group than within each of the other two groups. The milieu experienced by Koreans in Japan is bicultural, affecting each of the three groups differently. The first-generation and the recent migrant groups show stable life styles. The Korean cultural referent is a symbol in terms of which they articulate the Korean locus of interpretation and personal and ego identities. Concurrently, Koreans of these groups develop a conceptual and emotional separation from the Japanese domain. As a result, they are unlikely to experience marginality. The same milieu, however, is a constant source of personal trouble for the second-generation group. This is largely due to their ill-defined identification with either the Japanese or the Korean domain. Adopting Korean or Japanese identity and the Korean locus or the Japanese locus of interpretation becomes a serious personal issue. Hence, this group is likely to experience marginality. The theme of this dissertation concerns individuals' subjective interpretations of their sociocultural situations as expressed in the variety of life styles and in the strategies used to maintain them. The theoretical assumptions explain the development and maintenance of the relationships among culture, society, and individuals in terms of the following concepts: life style, ethnic identity, locus of interpretation, passing, marginality, and the bicultural milieu. How these concepts and their properties are inter-connected with particular sociocultural, historical, and politicoeconomic conditions reveal the differences and similarities of the life styles of these three groups.

abstract: Doctor of Philosophy (PhD)


title: High-spin States and Band Structures in ¹¹²ʼ¹¹⁴ʼ¹¹⁶Te

contributor:
Cameron, J.A.
Physics

subject: Physics Physics

abstract:
Excited states in the neutron-deficient transitional nuclei ¹¹²ʼ¹¹⁴ʼ¹¹⁶Te have been studied by means of heavy-ion (H.I.,xnypzα) reactions. Levels up to spin 22n at excitation energies of up to 9 MeV were established using Υ-Υ coincidence, Υ-ray angular distribution, Υ-ray excitation function and, in the case of ¹¹²Te, Υ-Υ-time measurements. In addition, the characteristics of a number of fusion-evaporation reactions leading to residual nuclei in this region have been analyzed and compared to theoretical predictions.

Positive-parity structures above spin 4⁺, 8⁺ and 14⁺ in ¹¹²Te, ¹¹⁴Te and ¹¹⁶Te respectively as well as negative-parity bands based on 8⁽⁻⁾ and 9⁽⁻⁾ states are reported for the first time. Positive- and negative-parity band structures up to spin 16⁺ are compared to the predictions of a number of models usually applied to transitional nuclei, and interpreted in terms of valence single-particle plus collective vibrational degrees of freedom. At higher spins (12n to 22n) no strong evidence for rotational structure is seen.

As part of the data analysis for the present work, a numerical deconvolution method appropriate to Υ-ray spectra is presented in the Appendix.

abstract: Doctor of Philosophy (PhD)


title: Resolving the Free Boundary Problem for Electron-Hole Drops

contributor:
Kirkaldy, J.S.
Physics

subject: Physics Physics

abstract:
The prediction of the stable configuration of a cloud of electron-hole drops involves the resolution of a "free boundary" problem. That is to say, the constraint of steady state relationships is not enough to uniquely determine a stable steady state. There are an infinite number of states which satisfy the boundary conditions. If these stationary states are metastable due to isolation or freedom from large scale fluctuations then different system histories will produce different observable states and hysteresis phenomena. However, if configurational changes can occur through fluctuations, either by creation or annihilation of drops, however slowly, it is necessary to specify an optimizing process to identify a unique stable solution.

In this thesis a simple model is used to describe the cloud, explicitly demonstrating the "free boundary" problem. The optimizing function is taken to the rate of entropy production, the optimum being a maximum in the dissipation. The optimization process leads to linear global and local flux-force relationships and to explicit expressions for drop density and exciton gas density which are in good functional and quantitative accord with experiments.

abstract: Master of Science (MS)


title: Irony and Ideology in Schlegel, de Man, and Rorty

contributor:
Clark, David L.
English

abstract: Why have we spoken about irony so much for so long? What is at stake in the different ways it has been figured and, just as much, what is at stake in the persistence of certain figures through shifting historical contexts? This study attemts a metacritical approach to irony, one which does not so much propose a particular theory of irony or apply a particular understanding of irony to literary or cultural texts as is often done, but which takes as its object of study the discourse on irony. The lengthy history, as well as the continuing proliferation, of critical and theoretical work on irony, not to mention the frequency of its invocation in everyday discourse, invites such an approach. In particular, this work explores the relationship between irony and ideology, two terms that stand in a vexed relationship of interdependence and opposition. What this investigation establishes is that from its modern inception, the critical discourse on irony has been as much a political discourse as an aesthetic or philosophical one. I examine the ideologies underlying and informing three different attempts to theorize, or otherwise invoke and employ, the term irony; those represented by the writings of Friedrich Schlegel, Paul de Man, and Richard Rorty. On the one hand, I argue that the theory of irony partakes inextricably in the philosophy of the self, of the autonomous individual associated with a dominant tradition of liberal thought. To this extent irony can partake in the ideological construction of an imaginary realm of freedom that masks the subject's social and historical domination. On the other hand, I have persistently discovered, and argued for, the resistance to ideological enclosure within the discourse on irony, and the positing of a social and intersubjective character to irony.

abstract: Doctor of Philosophy (PhD)


title: MULTIVARIATE LATENT VARIABLE REGRESSION: MODELLING AND ESTIMATION

contributor:
Viveros-Aguilera, R.
MacGregor, J.F.
Mathematics

subject: Mathematics Mathematics

abstract: The topic of the multivariate latent variable regression model as it applies to practical problems in applied science is investigated. This model is used for sets of data that have been divided into two groups, X and Y, both containing multiple variables and linked by a common latent structure. A detailed statistical model is described for this application. This model is based on models and descriptions found in the literature but is unique in its clear definitions for all of the components. The wide applicability of this model is clearly demonstrated on four real examples taken from both chemistry and chemical engineering. A set of frameworks has been developed for the objective functions satisfied by the estimates of the latent variables in the model. The frameworks encompass the majority of the methods currently used or proposed for use for the multivariate latent variable regression problems. This work provides a basis for research into when each method would be appropriate. Finally, a new method of parameter estimation is developed using the maximum likelihood method on the model with the added assumptions of multivariate normal errors in both spaces with known covariance matrices. This method involves a constraint on the maximization due to the practical nature of the division of the data into X and Y spaces. A special case of this method is used to form a continuum regression that spans several of the existing methods and in particular is shown to be very close to the method used most often in practice, multivariate partial least squares (PLS). This provides some statistical justification for the use of PLS and some guidelines regarding its implementation.

abstract: Doctor of Philosophy (PhD)


title: Finite Element Simulation of Flow in Twin Screw Extruder Mixing Elements

contributor:
Hrymak, A. N.
Wright, J.D.
Chemical Engineering

abstract: In the plastics industry, twin screw extruders are widely used for melting, dispersing and homogenizing polymers. There are a diversity of designs employed throughout the polymer industry, each one having different operating principles and applications. Among the different arrangements of twin screw systems, the intermeshing co-rotating configuration has been found to be one of the most efficient mixers and it is one of the most commonly used pieces of equipment among the continuous mixers due to its self wiping properties. The problem of mixing of polymers involves aspects of fluid dynamics and rheology. Mixing is usually obtained through a combination of mechanical motion of the mixing device and the resulting deformation induced in the flowing material. The quantitative description of the flow patterns is now feasible even in the most complicated geometries through the development of computational fluid dynamics (CFD) tools and the continuous increase in computer resources at lower costs. Intermeshing co-rotating twin screw extruders (ICRTSE) are usually built in a modular fashion to meet the diversity of tasks performed by this type of machine. There are two main types of elements; full flight conveying elements and kneading block mixing elements. The kneading blocks have been the focus of attention for the theoretical analysis of flow due to their significant contribution to the mixing performance of the extruder and the fact that kneading blocks normally work under a fully filled channel condition, which is one of the fundamental assumptions in CFD simulations. The objective of this thesis is to understand the flow mechanisms in the kneading disc section of co-rotating twin screw extruders. This is done by means of the 3D numerical simulation of the flow process within the complex geometry involving intricate passages and continuously moving surfaces. A quasi-steady state finite element model was developed assuming isothermal, non-Newtonian flow. The intricate geometry of the kneading disc section required the development of a tailored finite element mesh generator. An analysis based on particle trajectories, calculated from the obtained velocity field, was carried out to study the effect of geometry on the mixing performance. The approach used for the initial location of the particle tracers was to cover the entire cross section of the kneading blocks. The problem of particles leaving the flow field due to time discretization was addressed by determining the locations where particles crossed the solid surfaces of the discs and reincorporating them into the flow field. The calculation of particle trajectories and deformation history give valuable information about the rapid fluctuations in shear stress experienced by different particles within the flow field. A rigorous examination of the model results was carried out. Comparisons of the 3D model against experimental pressure data in the radial and axial directions are presented. The simulation results were also compared against experimental results of velocity obtained via particle image velocimetry. Results confirmed the ability of the model to predict the flow behaviour. It was determined that inlet and outlet boundary conditions play a significant role in the development of flow patterns in the kneading disc section. The assumption of isothermal flow introduced limitations in the predictions made by the model. Future work should include the addition of the energy equation to the model.

abstract: Doctor of Philosophy (PhD)


title: On Explosions of Extended Stars as Type I Supernovae

contributor:
Sutherland, P. G.
Physics

subject: Physics Physics

abstract:
Despite great theoretical progress the nature of the progenitors of Type I supernovae is still in doubt. In recent years much attention has been focussed on accreting white dwarf models. This thesis examines another class of possible progenitors: extended helium stars. The computer code BOMB was written to hydrodynamically evolve the models.

A total of seventeen models are examined. Five of them resemble R Cor Bor stars which are hydrogen-deficient pulsational variables of roughly 1.5 - 2.0 M₀ named after the archetype R-Corona Borealis. Ten other models are variations on these, used to explore the parameter space of possible models. The remaining two models are of the bare white dwarf type which constitute the current orthodoxy in the field.

It is found that the R Cor Bor stars are not viable as Type I supernova progenitors. The bare white dwarf models fit the available data better than do any of the envelope models, although stars with relatively small, low-mass envelopes could also provide reasonable fits.

abstract: Doctor of Philosophy (PhD)


title: Reflux Condensation Phenomena in Single Vertical Tubes

contributor:
Chang, J.-S.
Nuclear Engineering

subject:
Nuclear Engineering
Nuclear Engineering

abstract:
Reflux condensation in vertical inverted U-tube steam generators forms an important heat removal mechanism for nuclear reactors in certain accidents. Reflux condensation phenomena in single vertical tubes were studied for two well defined boundary conditions to develop an improved understanding of the mechanisms governing heat removal and liquid holdup. A correspondence between an imposed boundary condition and its resulting flow regime has been made where total reflux condensation occurs for an imposed drop across the tube and fill and dump cycling occurs for an imposed steam flow rate at the tube inlet.

Total reflux condensation is characterized by a flow pattern made by a single-phase region oscillating over a two-phase region. This flow region can be maintained indefinitely while the average single-phase and two-phase region lengths remain constant. It is also characterized by the complete condensation of the injected steam with all the condensate flowing back to the tube inlet.

Fill and dump cycling is characterized by a cyclical operation where, during one cycle, the length of the single-phase region increases at the expense of the two-phase region until a point where the system becomes unstable and the single-phase region is ejected from the top of the tube. All the injected steam is condensed and contrary to total reflux condensation, not all the condensate flows back to the tube inlet. Instead, part of the condensate is carried over the condensation length to form the single-phase region. This flow regime could be qualified as dynamic as opposed to quasi-static for total reflux condensation.

Experimental measurements were made in three single vertical tubes with a cooling jacket. These data show fill and dump cycling to be more efficient than total reflux condensation in condensing steam and to allow the condensate not to be trapped in the tube as in total reflux condensation. In addition, the experimental data suggest that total reflux condensation could be well the limiting flow regime for fill and dump cycling as the cycle period becomes very long and consequently it could define conservative lower bounds for the values of total heat removal.

An analysis of counter-current film-wise condensation was conducted to model total reflux condensation, central to this model is an extended Nusselt's model of film-wise condensation, a linearized stability analysis of the condensate film flow and the use of three concepts: critical layer, maximum mechanical energy and transfer and film instability. The agreement between the experimental data and the prediction of total heat removal (via condensation rates) and liquid holdup is satisfactory. Both the present model and the experimental data show that flooding occurs at the tube inlet and plays a key role in defining the heat removal and the distribution of condensate in the tube. In particular, it is shown that for a given inlet cooling water temperature, the flooding flow rates, in terms of the Kutateladze variable, are nearly independent of the tube size and system pressure. In general, for a given tube size and system pressure, the inlet cooling water temperature has a notable influence on the value of the flooding flow rates, except for the smaller tube size, and it does not affect the amount of condensate holdup in the tube.

The results of the present work could be used in small-break LOCA analyses were the present model could estimate the heat removal capabilities of steam generators and the amount of coolant (condensate holdup) trapped in the steam-generator tubes that would be available for core cooling.

abstract: Doctor of Philosophy (PhD)


title: Optical Properties of Strongly-Coupled d-wave Superconductors with an Anisotropic Momentum Dependent Interaction

contributor:
Carbotte, J.P.
Physics

subject: Physics Physics

abstract: We have studied within the Eliashberg framework properties of a two-dimensional d-wave superconductor where the electron-boson interaction leading to pairing in the superconducting state is a highly anisotropic function of momentum. Adding to the momentum anisotropy is an underlying single particle band structure based on a two-dimensional tight-binding model. The convolution of anisotropic interaction and anisotropic energy dispersion leads to a self energy which is strongly k-dependent in the Brillouin zone. Additionally, the boson spectral weight was assumed to extend over a large energy range with significant weight at both high and low frequencies. The study begins with numerical calculations of the self-consistent electronic self energy. Renormalization effects are shown to play an important role in the quasiparticle properties. The effects of strong inelastic scattering on the electronic spectral density in both the normal and superconducting state are investigated. Numerical calculations of the in-plane optical conductivity and electronic Raman scattering cross-sections are made for both the normal and superconducting states. Using a simple model to extract the effective quasiparticle scattering rates and mass renormalization factors, comparison of the optical results are made to the fundamental quasiparticle properties. The effects of momentum space anisotropy and strong electron-boson coupling on the optical scattering rates are discussed. The low frequency behaviour of the various Raman scattering channels in the presence of strong inelastic scattering is investigated. It is shown that both inelastic and elastic scattering can lead to a crossover from ω³ to ω dependence of the low frequency Β₁g spectra in the superconducting state, while the B₂g response remains linear in frequency. An effective boson spectral density, g²x"(ω), is extracted from the the calculated conductivity using a simple model. It is shown that the optical conductivity data may be used to extract the signature of the electron-boson coupling. The effective spectral density is then used in an isotropic model to determine whether or not such a function extracted from the conductivity would capture all the details of the momentum dependent interaction. The effects of resonant impurity scattering on the low frequency conductivity and Raman spectra are also investigated. Numerical calculations confirm the existence of universal values for the zero frequency conductivity and zero frequency slope of the B₂g Raman response in the superconducting state. No such limit is observed in the Raman B₁g spectrum.

abstract: Doctor of Philosophy (PhD)


title: Advection, Diffusion and Settling in the Coastal Boundary Layer of Lake Erie

contributor:
James, W.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract:
Pollution in the coastal zones of the Great Lakes has become more serious in recent years. This is due to increased use of coastal water as a result of population and industrial growth. A substantial portion of the contaminants that enters a lake do so from the shoreline via discharges from sewer overflows, industrial outfaIIs and runoff. Such discharges contain particulates and other materials of density greater than that of lake water. Many heavy metals with toxic components are present in these fractions. The dynamic behavior of these particIes in the coastal and offshore waters is thus of great importance. The principal removal processes for these materials are transport and particle settling. An understanding of the characteristics of nearshore currents, diffusion and temperature patterns is essentiaI to determine their effect on removal processes, and in turn, on coastal biological and chemical processes. This study is limited to the physical fluid mechanics of coastal zones.

The structure of the nearshore flow in the vicinity of Cleveland, Ohio is analyzed in detaiI in this study. The impact of Cleveland, one of the largest urban and industrial agglomerations on the shoreline of Lake Erie, in terms of additional loading is thought to be considerable. A computer program (ADVDIFF) was developed to calculate the mean flow, horizontal turbulent length and time scales, horizontal diffusivities and kinetic energy. ADVDIFF uses filtering techniques, spectral analyses and statistical analyses. Five episodes representing three different flow regimes which may exist in the coastal zone were chosen for special analyses.

To generate the coastal currents, a rigid-lid, channel-type model with fine grid size in the coastal zone was used. A model originally developed by Simons (1983) was modified to incIude nonlinear acceIeration terms and two different forms of the vertical eddy viscosity. Also, a two dimensional x-y model developed by Simons and Lam (1982) was modified and used to expIain some of the observations. Both new modeIs (ERCH, ONELAY) were verified, calibrated and applied to Lake Erie.

A computer program (SEDTRAN) was developed to predict the inflow sediment concentration distribution within the coastaI zone. SEDTRAN soIves numericaIIy the three dimensionaI time-dependent mass transport equation including the settIing term. The modeI uses the currents and diffusivities computed by ERCH and ONELAY and the statistical analyses, respectively. SEDTRAN was verified using several test examples, and partiaIIy vaIidated using the avaiIable data set. The modeI was applied to many cases of settIing activity that may take place in the coastaI zone. The results were used to define a representative influence zone for a pollutant source at CIeveIand.

abstract: Doctor of Philosophy (PhD)


title: A Mechanistic Study of the Reactions 1,1-Diarylsilenes and 1-Silastyrenes

contributor:
Leigh, William J.
Chemistry

subject: Chemistry Chemistry

abstract: The chemistry of 1,1-diarylsilenes, 1-phenylsilene and 1-methyl-1-phenylsilene has been studied using nanosecond laser flash and steady-state photolysis techniques. The silenes were generated by photochemically induced [2+2] cycloreversion of 1,1-diarylsilacyclobutane, 1-phenylsilacyclobutane and 1-methyl-1-phenylsilacyclobutane, respectively. Steady-state photolysis in the presence of alcohols, methoxytrimenthylsilane, water and acetic yields the corresponding alkoxy-, hydroxy-, or acyloxysilane in high yield consistent with the trapping of the silene by ROH or silyl ether. Steady-state photolyses in the presence of acetone afford silyl enol ethers exclusively the product of an ene reaction between the silene and acetone. Nanosecond laser flash photolysis of air saturated hexane, acetonitrile or tetrahydrofuran solutions of the silacyclobuanes leads to readily detectable transient absortions in the 310-330 nm range which have lifetimes of 2-4 μs and have been assigned to the corresponding silenes. Incresing phenyl substitution at the silenic silicon atom results in red-shifts in the silene absorption maxima consistent with increasing conjugation of the chromophore. The transient absorption spectrum of 1,1-diphenylsilene in the THF solution is broadened and red-shifted compared to that in hexane and aceonitrile, consistent with the formation of a silene-THF complex. Absolute rate constants for reaction of the silenes with alcohols, trimethylmethoxysilane, acetic acid and acetone have been determined by NLFP techniques. Silene quenching follows a linear dependence on quencher concentration over the range investigated in all cases and proceeds with the rate constants which vary over the range 10⁷-10⁹ M⁻¹s⁻¹. The absolute rate constants for reaction with alcohols, trimethylmethoxysilane and acetic acid are slightly faster for phenyl- and methylphenysilene than for diphenylsilene. Deuterium kinetic isotope effects for reactions of the 1-silastyrenes (1,1-diphenylsilene, 1-phenylsilene and 1-methyl-1-phenylsilene) with methanol, t-butanol and acetone are consistent with a primary effect and rate determining proton transfer. Acetic acid addition is not subject to a deuterium kinetic isotope effect. Steady-state competition experiments between 1,1-diphenylsilene and variousu alcohols and water have been carried out. The product ratios agree with the corresponding relative constants for water, methanol and ethanol. Those for methanol/t-butanol are significantly different from the rate constant ratio but approach it at very low total alcohol concentrations. Reactions of the 1,1-diarysilenes with alcohols, acetic acid, acetone and trimethylmethoxysilane afford small positive Hammett ρ-values consistent with initial nucleophilic attack by oxygen on silicon. Deuterium isotope effects and arrhenius parameters have been determined for the reactions of 1,1-di-(4-methylphenyl)silene, 1,1-diphenylsilene and 1,1-di-(4-trifluriomethylphenyl)silene with methanol, acetone and acetic acid. Methanol and acetone additions are characterized by negative activation energies, which are suggested to result from entropy dominated proton transfer within a reversibly formed silene-nucleophile complex. The kinetic isotope effects for methanol and acetone addition decrease with increasing electron withdrawing ability of the diaryl substituent and temperature. Acetic acid addition proceeds with a positive activation energy that increases in magnitude with increasing electron withdrawing ability of the substituent. This observation is consistent with a small enthalpic barrier to complex formation. The above results are consistent with a two-step mechanism involving reversible formation of a zwitterionic complex, followed by intramolecular proton (or SiMe₃⁻) transfer. The latter is rate determining in all cases but acetic acid, for which it is proposed that complexation is the rate determining step for reaction. The trends in kinetic isotope, substituent and temperature effects are rationalized in terms of variations in the relative rate constants for reversion of the complex to reactants and proton transfer as a function of substituent and temperature. In the case of alcohol additions, proton transfer from the complex to a second molecule of alcohol competes with the intracomplex proton transfer pathway at high alcohol concentrations, for all cases except t-butanol and acetic acid.

abstract: Doctor of Philosophy (PhD)


title: INDIVIDUALITY AND VALUE IN THE PHILOSOPHY OF ALFRED N. WHITEHEAD

contributor:
DULMAGE, H.A.
Philosophy

subject: WHITEHEAD ACTUALITY FUNCTIONS PROCESS VALUATION INDIVIDUALITY HUMAN Philosophy Philosophy

abstract: Master of Arts (MA)


title: Local Fermi Momentum Dependence in the Effective Nuclear Interaction

contributor:
Sprung, D.W.L.
Physics

subject: Physics Physics

abstract: We have investigated the recently proposed Local Fermi Momentum Approximation's use in the context of the Hartree-Fock model of the nucleus. This suggests the possibility that the effective nuclear potential could depend on the Local Fermi Momentum. It is shown that such a potential derives no rearrangement energy from this dependence. This fact shows why the Density Matrix Expansion Approximation treats the rearrangement energy accurately. In order to produce a rearrangement energy, the effective potential should be chosen to depend on the density as well as on the Local Fermi Momentum. This led to the development of a modified Skyrme-like force in which the density dependence is replaced by a kinetic-energy-density dependence. This force was adjusted to give good fits to observed ground-state properties of closed-shell nuclei, and of infinite nuclear matter. Its use requires that more attention be paid to the numerical solution of the Hartree-Fock problem than for a regular Skyrme force.

abstract: Master of Science (MS)


title: Reliability Evaluation of Large-Scale Power Systems

contributor:
El-Kady, Mohamed A.
Sinhu, Naresh K.
Electrical and Computer Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract: The major effort in this thesis has been directed towards the performance modelling and reliability estimation of large-scale power systems subject to probable single or multiple contingencies. A scheme for performance data pooling is introduced, which overcomes the problems of the limited available performance history and manipulation of large numbers of data sets associated with various components of a power system. A simulation technique which adopts a Monte-Carlo scheme is developed-to estimate component reliability measures and to select the probable contingency states of the system. A combined optimization/reliability formulation is introduced which provides improved reliability figures of the power system. In this formulation the system control parameters are manipulated to simulate practical contingency situations in which suitable system controls are invoked to preserve as much as possible, the continuity of supply. An efficient network partitioning scheme based on Ward equivalence has been developed. Only those parts of the system which are mostly affected by a contingency are retained for detailed analysis while the rest of the system is modelled by network equivalents. It is demonstrated that the use of such a partitioning scheme yields significant reduction in computational time and storage for contingency analysis while maintaining sufficiently accurate solutions. The partitioning scheme is subsequently combined with the optimization/reliability formulation which adds to the efficiency of both approaches. A technique is developed to guide the partitioning scheme via predicting the change in a performance index due to a contingency. The predicted changes are efficiently calculated using either a perturbed matrix inversion scheme or a suitable nth order derivative formulation. Using these predicted changes, a generalized contingency ranking methodology is introduced, for generation and/or transmission contingencies. The contingency ranking scheme is based on an important class of line loading functions representing system security constraints. A novel and computationally efficient technique for fast linear contingency analysis and ranking is introduced. This technique utilizes a bilinear-based formulation to calculate efficiently, the changes of individual bus voltage angles after the occurrence of a transmission contingency. An alternative equivalent formulation of the technique is aIso presented. It adopts reduced gradients of system states and provides the post-contingency exact changes of these states with significantly reduced online computations.

abstract: Doctor of Philosophy (PhD)


title: Topological Algebras with Orthogonal M-bases

contributor:
Husain, T.
Mathematics

subject: Mathematics Mathematics

abstract: An M-basis in a topological vector space is a special case of the extended Markushevich basis, and a generalization of the unconditional basis. We study orthogonal bases and orthogonal M-bases in topological algebras, with emphasis on locally convex algebras. It turns out that an orthogonal basis or an orthogonal M-basis in a topological algebra is necessarily Schauder. We characterize some concrete topological algebras with orthogonal bases or orthogonal M-bases, up to a topological isomorphism. We introduce and study two classes of locally convex algebras: the class of "Φ-algebras" which includes, for example ℂʳ, c₀(r), C*₃(r) and H(D) (with the Hadamard multiplication); and the larger class of "locally convex s-algebras" which also includes - among other examples - ℓp, 1 ≤ p < ∞ and the Arens algebra L^ω[0,1]. A Φ-algebras is not necessarily locally m-convex, and a locally m-convex algebra is not necessarily a locally convex s-algebra. We give two examples of Banach algebras with orthogonal bases which are not unconditional and we prove that an orthogonal basis in a B₀ algebra is unconditional iff the algebra is a locally convex s-algebra. We also study the conversion of a Fréchet space with an unconditional basis into a Fréchet algebra with the basis under consideration as an orthogonal basis and we obtain a necessary and sufficient condition for this to be possible, revising and extending a result of Husain and Watson obtained for Banach spaces.

abstract: Doctor of Philosophy (PhD)


title: Optimal Design of Water and Wastewater Networks

contributor:
Smith, Alan A.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract:
The objective is the development of two reIated mathematical models to provide minimum cost designs of water distribution and waste-water collection networks.

This wealth of literature is classified in terms of problems formation and method of solution. This places individual contributions in perspective and serves to identify the major shortcomings of existing techniques. These are:-

1- Inability to handle large network systems efficiently. 2- lnadequate treatment of the hydraulics of the system. 3- Absence of a satisfactory discrete solution.

The results presented are considered to be more comprehensive than any other technique reported in the literature to the author's knowledge. The major contributions presented are:-

(i) Both problems are formulated in the form of a nonlinear programming problem and in terms of practical engineering variables and solved by application of the MINOS package.

(ii) A standard data format is suggested which allows user input to be defined in a very compact and logical form.

(iii) Pre-and Post-processors are developed which free the user from the complicated and extremely error-prone tasks of creating the necessary input data and interpreting the resultant output files of the MINOS package.

(iv) For distribution networks, a comparison is presented between the explicit use of a network analyser (coupled with an efficient optimization package) and the implicit incorporation of the analysis stage within the linear and nonlinear constraints of a comprehensive nonlinear model. The latter method is shown to have significant advantages.

(v) For collection networks, a model formulation is presented which properly represents the hydraulics of part full flow in circular sewers. The problem size is reduced by the introduction of an equality constraint which correlates velocity and discharge under these conditions. The accuracy of the method is checked by comparison with a more rigorous but significantly more expensive problem formulation.

(vi) Methods are suggested whereby pumps, reservoirs, pressure reducing valves and minor loss devices can be easily and correctly incorporated in a distribution network design.

(vii) Techniques involving variable transformation and the partitioning of basic, nonbasic and superbasic variables are developed which greatly increase the efficiency of solution.

(viii) For both types of network, the models are augmented to allow a very good discrete solution to be obtained in terms of pipe diameter. A heuristic argument is presented which suggests that the solution for distribution networks must be very close to optimal although optimality cannot be rigorously proven. For collection networks it is shown that discretization may frequently be infeasible unless at least one of the constraints is relaxed in the form of a 'soft' constraint.

(ix) Both types of network design are demonstrated using problems of substantial size. For distribution networks a method is demonstrated whereby the analysis or design problem can be solved as special cases of the more general optimization problem.

abstract: Doctor of Philosophy (PhD)


title: Recombinational and Packaging Signals in Herpes Simplex Virus Deoxyribonucleic Acid

contributor:
Smiley, J. R.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Herpes Simplex Virus DNA displays a number of unusual features which have been the subject of intense scrutiny in a number of laboratories. The genome is composed of two segments, each of which is flanked by inverted repeats. These segments invert freely with respect to each other generating equisolar quantities of four different isomers. This phenomenon, called segment inversion, was reputed to be the result of a site specific recombination mechanism operating on the terminal repeat, the 'a' sequence, which is part of the inverted repeats flanking each segment. The 'a' sequence was also implicated as the cleavage/packaging signal utilized by the virus to process viral DNA concatemers. The underlying mechanism of this process was believed to be a double strand break at a specific site between two 'a' sequences. The models of HSV maturation were deficient, however, in explaining several phenomena, namely the tendency of the 'a' sequence to accumulate tandem iterations of itself, the asymmetric distribution of these tandem iterations to one end of the genome, but not to the other, and the ability of defective genomes, which do not have tandemly iterated 'a' sequences, at least initially, to be efficiently packaged. I have shown that the "a" sequence actually contains two signals for cleavage/packaging, not one, that the cleavage occurs it specific distances from these signals, not in specific sequences, and that the cleavage mechanism results in a duplication of the cleavage signal and flanking DNA. Furthermore, I have determined that the 'a' sequence is not a target for site specific recombination, and that there is better evidence to support the idea that segment inversion is accomplished by a number of related, but independent mechanisms, including generalized recombination.

abstract: Doctor of Philosophy (PhD)


title: CD8+ cytotoxic T-lymphocytes in HIV-1 infection and resistance

contributor:
Rosenthal, Kenneth Lee
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Cytotoxic T-lymphocytes (CTL) are important in resistance to HIV-1 infection, and modulate disease progression through various effector functions. Conventional CTL recognizing antigenic peptides in the context of major histocompatibility (MHC) class I molecules eliminate virally-infected cells, and have been shown to modulate the course of disease progression. Other functions of CD8⁺ lymphocytes include non-lytic suppresion of viral transcription and replication, and induction of programmed cell death in activated CD4⁺ cells. In the work presented here, the interactions of CD8⁺ lymphocytes with activated CD4⁺ cells were examined. Lysis of activated CD4⁺ cells was unique for CTL derived from HIV-1 infeced persons, and was not restricted by MHC molecules. The interaction was dependent on target cell activation, correlated with cell proliferation, and was independent of viral replication. Furthermore, the lytic process was biochemically consistent with apoptosis, and resulted in nuclear fragmentation in the target cells. In vitro susceptibility to infection by primary HIV-1 isolates was assessed in a cohort of couples consisting of an infected and an uninfected, but exposed, partner. These findings were correlated with the genetic integrity of the HIV-1 co-receptors, and with the presence of CTL specifically directed against the partner's primary isolate. Individuals with partial or complete resistance to infection were identified, as well as some individuals that had CTL recognizing the partner's viral isolate. The latter results suggested that cellular immune responses comprise a major component of resistance to HIV infection, and that they influence resistance even in individuals lacking the main HIV-1 co-receptor. The later studies were extended by examining the in vitro infectivity of CD4⁺ cells from a group of highly exposed, but persistently uninfected, Kenyan sex workers. No barrier to infection of CD4⁺ lymphocytes with primary Kenyan HIV isolates was identified, however, CD8⁺ cells from these subjects were able to efficiently limit viral replication in autologous CD4⁺ cells. In summary, the broadly different CTL effector functions described in these studies illustrate the importance of the cellular immune system in resistance to HIV infection, and in modulating the disease pathogenesis.

abstract: Doctor of Philosophy (PhD)


title: Copper Sorption on Kaolinite

contributor:
Kramer, J.R.
Geology

subject: Geology Geology

abstract:
In order to improve our ability to predict sorption reactions, the rates of copper sorption on kaolinite were measured to determine the number and type of mechanisms responsible for trace metal sorption on clay minerals. From a theoretical consideration of Cu⁺² chemistry and kaolinite surface properties, it is probable that copper sorption is controlled by several mechanisms, with different sorption rates. These mechanisms include nonspecific coulombic attraction, coordination to one or two surface sites, induced surface precipitation, structural penetration, and sorption induced by kaolinite agglomeration. Cu⁺² sorption on kaolinite, in a 0.05 M KNO₃ medium at pH 6.2, was followed with a specific ion electrode for up to 2.5 weeks. The kinetic data revealed an instantaneous sorption, occurring within the first 1 to 5 seconds, followed by four concurrent first-order reactions. The mean rate constants of the first-order reactions are 0.7 ± 0.7, (8 ± 4) * 10⁻³, (14 ± 6) * 10⁻⁴, and (9 ± 6) * 10⁻⁵ (min.⁻¹).

In order to characterize and identify the apparent mechanisms resolved by kinetics, experiments were designed to test the properties of Cu sorbed on kaolinite. These tests included (1)varying the salt concentration (2)changing the pH, (3)measuring the H⁺/Cu⁺² exchange ratio, and (4)desorbing Cu⁺² with water, Sr⁺², ⁶⁴Cu⁺², nitric acid and cyanide. The results of these tests indicate that the instantaneous sorption is caused by complexation to surface sites, with a small amount of nonspecific sorption. The first-order reactions are attributed to surface induced precipitation, coordination to two surface sites, and Cu fixation in the kaolinite structure. Copper sorption induced by centrifuging suggests that when clays are agglomerated, as in a clay floc, metal sorption may be enhanced. Sorption mechanisms observed on kaolinite may be applied to other clays, if differences in surface properties are taken into consideration.

abstract: Doctor of Philosophy (PhD)


title: Modelling Solar Radiation Transmission in Cloudy Atmospheres

contributor:
Davies, J.A.
Geography

subject: Geography Geography

abstract:
The transmission of solar radiation through cloudy atmospheres was examined using nine years of continuous hourly radiation and meteorological records. Transmittances of clouds were empirically determined using data from five stations in southern Canada. Statistical parameters were evaluated for exponential, linear and constant expressions for transmittance of global irradiances after correcting for multiple reflection between the surface and atmosphere. Exponential and linear uncorrected results compared well with previous work, however marked differences were noted in comparisons of constant transmittance values for Canada with those calculated for Hamburg, Germany and those for Blue Hill, Massachusetts. Multiple reflection effects were shown to enhance the surface irradiance by as much as 30%. Results of regression analysis indicated transmittance to be effectively independent of zenith angle.

Several expressions for estimating direct beam transmittance were tested in a numerical model using data from three stations in eastern Canada. Results showed the present form, the product of global radiation and one minus the total cloud opacity, performed best thereby justifying its further usage.

Results of direct beam and cloud transmittance analyses were combined to estimate direct, diffuse and global surface irradiances. Results were compared with measured fluxes for hourly, daily, monthly and monthly mean hourly time periods. Correcting for multiple reflection underestimated surface irradiances. No improvement in performance was obtained in models using uncorrected Canadian-derived parameters over existing parameters determined for Blue Hill. Underestimation of transmittance by the corrected parameters was attributed to the presence of undetected overlying cloud above the overcast deck. Although mean bias error values are better for global irradiances determined using the original Blue Hill parameters, it is shown that differences in model estimates which used Canadian data are within the range of uncertainties on the calculated values of the solar constant, aerosol transmission and surface albedo.

abstract: Master of Science (MS)


title: LONG-TERM OPTIMAL OPERATION OF HYDRO-THERMAL POWER SYSTEMS

contributor:
Syed, M. A.
Smith, Alan A.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: When new construction projects are postponed or cancelled because of socio-economic concerns, greater emphasis is placed on enhanced operational planning -- to get the most at the least cost, from the existing projects. Of the approaches that made significant improvement in the operation of energy production systems is the co-ordination between hydro and thermal power plants. In this research, the problem of "Long-term Optimal Operation of Hydro-Thermal Power Systems" is addressed. Considering the uncertainty in reservoir in flows, the problem is defined as a "two-stage stochastic linear network programming with recourse". To avoid dimensionality problem generally associated with the employment of dynamic programming in large scale applications, Bender's decomposition approach is employed as the solution algorithm basis for the defined problem. Using the "General Algebraic Modelling System", a modelling code, the "Hydro-Thermal Co-ordinating Model (HTCOM)" is developed. In HTCOM, each sequence of hydrologic inflows generates a subproblem which is solved deterministically. The solutions of all subproblems are next co-ordinated by a master problem to determine a single feasible optimal policy for the original problem. This policy includes optimal reservoirs releases as well as allocation of energy generation at different power plants in the subsequent time period. The objective minimizes the expected total cost of meeting the energy demands while satisfying the system constraints over the long-term horizon of one to three years. To demonstrate the applicability of HTCOM, a real world case study named the "Khozestan Water and Power Authority (KWPA)" in Iran is employed as a system of two multipurpose reservoirs with five hydro-thermal power plants and transactions of energy. The KWPA system components are operating policies are stimulated as the network flow model and an integrated solution procedure is planned to determine the optimal operation policies. This procedure included the development of three specialized models: - HTCOM-I: to investigate the potential improvements of the current system; -HTCOM-II: to provide the required confidence in using the model in future simulations by evaluating the actual savings; and -HTCOM-III: to simulate the system operation under uncertainty, and determining the optimal operation policies for the next month. The results of employing all three cods in the KWPA system conclude that the selected approach for formulating the problem, the adopted algorithm based on Benders' decomposition technique, and the models (developed in the GAMS environment) are suitable, capable to handle stochasticity of inflows, and considerably cost-efficient.

abstract: Doctor of Philosophy (PhD)


title: A Measurement of T₂₀ for the ¹H(đ,ϒ)³He Reaction and D-State Effects in ³He

contributor:
Kuehner, J.A.
Physics

subject: Physics Physics

abstract: The tensor analysing power T₂₀ for the radiative capture reaction ¹H(đ,ϒ)³He has been measured in order to test new three-body wave functions. This observable arises from the D-state of ³He. An effective two-body direct radiative capture calculation, which was previously shown to fit the a₂ coefficient of a Legendre polynomial expansion of the differential cross-section, is found to give a good description of the present data. A range of 5% to 9% is deduced for the D-state probability in the ³He ground state wave function. A value of -0.032 ± 0.014 for the asymptotic D/S state ratio is extracted from the data although it is found to be model dependent.

abstract: Doctor of Philosophy (PhD)


title: The Imagery of Morality in Seneca's Prose-Works

contributor:
Paul, G.M.
Classics

subject: Classics Classics

abstract:
The persuasiveness of Seneca's paraenetic prose-works is owed, in large measure, as Seneca himself is aware (Ep.59.6), to the use of imagery - metaphor, analogy, and simile. As such, this stylistic device suggests itself as an important subject of enquiry. Its significance, however, extends further: in so far as many of Seneca's images are demonstrably traditional, they help in defining the tradition to which these prose-works may belong. In particular, they bear on the question of the relationship of Seneca's prose-works to the so-called 'diatribe', in the paraenetic effect of which imagery plays an important part.

D. Steyns (Gand, 1907) and C.S. Smith (Baltimore, 1910), have made limited lists of Senecan prose-imagery without consideration of its sources. F. Husner (Leipzig, 1924) has investigated the sources of Seneca's imagery within the confines of a narrow topic, while appreciating their implications for definition of the tradition of Seneca's moral prose-works. In the present work I apply the same approach in greater depth to the topic of central analysis of the moral prose-works: the state of the Stoic sapiens, of his antithesis - the sinner- and that of the proficiens between them.

Part I collects by category of allusion the relevant extended images in the moral prose-works, excluding the fragments. Part II investigates their sources. It is shown that, while the possibility of Seneca's originality cannot be discounted, precedents for his images can be found in the vast majority of cases; that Plato frequently provides an ultimate source, and that some of Seneca's imagery was also used by the Old and Middle Stoa. It is clear, however, that a stock of imagery is shared and passed on between 'diatribists', and that it is primarily from these - mainly via the philosophical schools of contemporary Rome -- that Seneca draws the images of his moral prose-works.

abstract: Doctor of Philosophy (PhD)


title: On the Numerical Solution of Nonlinear Problems in Continuum Mechanics

contributor:
Dokainish, M.A.
Mechanical Engineering

abstract:
A critical discussion of the formulation methods for the finite clement analysis of nonlinear problems is given, which includes the Lagrangian, the updated Lagrangian, and the Eulerian formulation. It is shown that each formulation is suitable for a specific class of nonlinear problems. In the literature many authors treat updated Lagrangian formulation as an Eulerian formulation. Therefore, the basic differences between the two formulations are critically discussed.

Consistent Lagrangian and updated Lagrangian formulation are derived from the virtual work principle expressed in current configuration, then transformed to the proper reference configuration. A detailed Eulerian formulation in the current configuration is derived by means of the virtual work principle. Explicit forms for the stiffness matrices contributing to the total nonlinear stiffness matrix, for the mass matrix, and for the load increments are presented in each case. Differences between the presented Lagrangian and the updated Lagrangian formulations and similar formulations in the literature are found to exist in the number of the stiffness matrices in the final incremental equilibrium equations as well as in the definition of the load increments. These differences as well as those between the existing formulations in the literature are assessed within the framework of the basic equations of the continuum mechanics. Specific forms of constitutive equations for elastic and elasto-plastic response of the materials are presented. A discussion on the use of the stress rates to derive acceptable constitutive equations is also given.

For the Lagrangian and the updated Lagrangian formulation two example problems have been solved to demonstrate the applicability of the presented formulations and the effect of the individual stiffness matrices as well as the definition of the follower load which results from the consistent formulation. These problems are elastic, large deformation static analysis of a cantilever under uniformly distributed load and elastic-perfectly plastic dynamic analysis of a pipe-whip problem.

To assess the presented Eulerian formulation and to show the effectiveness of the Eulerian finite element analysis using fixed mesh in space: a metal-extrusion problem has been solved. In this approach, the mesh is maintained fixed in space and the increment of stress tensors for a forward incremental step are added to a set of interpolated stress tensors. Then these stresses are interpolated back to obtain the state of stress of the body-points momentarily occupying the fixed integration points of the mesh.

abstract: Doctor of Philosophy (PhD)


title: Sigmatropic and Haptrotropic Shifts In Complexes of Cyclopental[ℓ]phenanthrene

contributor:
McGlinchey, M.J.
Bain, Alex D.
Chemistry

subject: Chemistry Chemistry

abstract: In a calculational study at the unrestricted Hartree-Fock (UHF) level of theory, it has been predicted that strategically incorporating an aromatic ring onto indenyltrimethylsilane would lower the barrier for [1,5]-sigmatropic shifts of silicon around the five-membered ring through retention of aromatic character in the transition state and in the intermediate iso-indene. In this thesis, the synthesis and dynamic behavior of the tricyclic system angular trimethylsilylbenzindene, 50, and also the tetracycle trimethylsilylcyclopental[ℓ]phenanthrene, 53, are reported. Incorporation of one aromatic ring onto the indenyl ligand does lower the barrier for [1,5]-silatropic shifts to 21.9 ± 0.5 kcal/mol, compared to 24 kcal/mol for the indenyl system. Addition of a second aromatic ring further lowers the barrier to 17.6 ± 0.2 kcal/mol, in good agreement with calculations. The intermediate iso-indenes for both systems have been trapped as their Diels-Alder adducts with tetracyanoethylene. In an attempt to study the migration of transition metals over the surface of cyclopenta[ℓ]phenanthrene, 55, a series of complexes have been synthesized in which the metals are bonded to the 5-membered ring in an η⁵-fashion. It seemed reasonable that the ligand might behave as a "super-indenyl" in that a transition state in a ligand substitution reaction would be stabilized by two aromatic rings compared to the single aromatic ring in the indenyl system. The experimental data revealed that haptotropic shifts, in which a metal migrates from a five-membered ring to a six-membered ring have a high barrier and are not observed. Moreover, it was not possible to substitute ligands such as phosphines for carbonyls or ethylene. One can conclude that the ligand is behaving as a cyclopentadienyl ligand rather than an indenyl unit. We hypothesized that we might be able to induce haptotropic shifts in complexes in which the transition-metal is bound to a six-membered ring of cyclopental[ℓ]phenanthrene, by deprotonating such complexes. However, attempts to bond transition-metals to a six-membered ring of the ligand were unsuccessful. When the ligand was not carefully dried, the result was to hydrogenate the double bond of the five-membered ring and yield a complex with Cr(CO)₃ attached to a terminal six-membered ring. This molecule, (cyclopental[ℓ]phenanthrene)Cr(CO)₃, 88, was characterized by X-ray crystallography. In an attempt to bond Cr(CO)₃ to a six-membered ring by using carefully dried ligand, we isolated the Diels-Alder dimer, 94, of the ligand cyclopental[ℓ]phenanthrene. It was also possible to synthesize this molecule by heating it under reflux in n-butyl ether, and we obtained an X-ray crystal structure of the molecule. Of course, it is well-known that cyclopentadiene dimerizes at relatively low temperature; in contrast, indene itself does not dimerize, but instead yields a styrene-type polymer. Theoretical studies on indene itself does not dimerize, but instead yields a styrene-type polymer. Theoretical studies on indene and cyclopental[ℓ]phenanthrene revealed that both have a high barrier (= 43 kcal/mol for cyclopental[ℓ]phenanthrene and 46 kcal/mol for indene) to hydrogen migration, but that the iso-indene type structure for cyclopental[ℓ]phenanthrene is only 4.3 kcal/mol above the ground state, while the intermediate structure for cyclopental[ℓ]phenanthrene is only 4.3 kcal/mol above the ground state, while the intermediate for indene is 9.0 kcal/mol above the ground state.

abstract: Doctor of Philosophy (PhD)


title: Influence of Pressure on the Cyclotron Mass of Potassium and Hole Fermi Surface of Antimony

contributor:
Datars, W.R.
Physics

subject: Physics Physics

abstract:
Detailed investigations of the hydrostatic pressure dependences of the hole Fermi surface of antimony and the cyclotron effective masses of antimony and potassium were made in the pressure range from 1 bar to 4.4 kbar, by means of the de Haas-van Alphen (dHvA) effect. Solid helium was used as a pressure transmitting medium. These measurements were made using the field modulation measuring technique, modified to optimize the sensitivity and selectivity of the dHvA spectrometer action. The effect of pressure on the anisotropy of the entire hole Fermi surface in the trigonal-bisectrix crystallographic plane was determined in detail. The pressure derivatives of the extremal cross-sectional areas of the surface were found to differ in sign and magnitude for various field directions. The total departure of the hole Fermi surface from a perfect ellipsoid in this crystallographic plane was accurately calculated at standard atmospheric pressure (1 bar) and at a pressure of 1.08 kbar, using the ellipsoidal-parabolic approximation. It was found that the anisotropy and shape of the surface are greatly influenced by pressure. The tilt angle was found to be insensitive to pressure within quoted experimental error.

The cyclotron effective masses were derived from the temperature dependence of the dHvA amplitude. In potassium, the logarithmic pressure derivative, (1/m*)dm*/dP, was found to be -(0.71±0.12)x10⁻² kbar⁻¹, and the standard atmospheric pressure cyclotron effective mass was determined to be (1.211±0.005) m₀, where m₀ is the free electron mass. The observed decrease of the quasiparticle mass with increasing pressure was analyzed and explained in terms of changes of the band structure effects and many-body effects with pressure. In antimony, the cyclotron effective mass associated with the minimum section of the hole Fermi surface was determined to be (0.0637±0.0005) m₀ at standard atmospheric pressure, in agreement with the calculated band structure mass of Pospelov and Grachev of 0.06 m₀. The cyclotron mass was found to be nearly insensitive to pressure with (l/m*)dm*/dP = + (0.16=0.39)xl0⁻² kbar⁻¹. The study of the pressure dependence of m* in these elements along with a theory proposed by Trofimenkoff and Carbotte for the pressure dependence of the electron-phonon mass enhancement parameter, λep, permits the magnitudes of the changes of the band structure mass and λep with pressure to be deduced in these elements.

abstract: Doctor of Philosophy (PhD)


title: Adsorption of Copper on Particulates along a Salinity Gradient

contributor:
Kramer, James R.
Geology

subject: Geology Geology

abstract:
The scavenging or Cu was studied along a salinity gradient using a reference clay mineral (SiIver HiII Illite. 1Mt-1) and sediments from La Have estuary (Nova Scotia). Experiments were conducted in progressive (Sal inograd) and batch mixing systems. The adsorption of Cu in the Salinograd is not significantly different from that in the batch system. The higher values in the Salinograd probably reflect experimental artifacts resulting from the inclusion or dialysis membrane to retain suspended particles in each mixing tank or the Salinograd.

The measured adsorption (distribution coefficient, Kd) of Cu in the laboratory experiments decreased drastically in the low salinity regime. This suggests a dilution phenomena of Cu along an estuarine profile. Field measurements or particulate Cu and other trace metals support this hypothesis.

The distribution coefficient varies inversely with sediment concentrations (100-1000 mg/L). The experimental data fit the O'Connor & ConnolIy (1980) Power law function: Kd = β/mc at salinities of 2.9-11.0°/oo, where α, and β are empirical coefficients and m is the sediment concentration. It appears however, that this inverse relations is strongIy dependent on salinity ( i.e. α and β are the salinity parameters in the Power law function).

The explanation to this inverse relationship can be related partIy to "radiocolloid" formation which tends to increase the metal concentration in the particulate phase. The effects of these colloids are more important at the lower solid concentrations than at the higher concentration. An additional or possibly more important contributor to the decrease in Kd as particle concentration increases is inter-particle association. This particle-particle interaction tends to block adsorption sites as particle come closer, colIide and aggregate at large sediment concentration and higher ionic strength.

The adsorption or Cu prior to and after chemical extractions or the particulates, indicates that the organic phase is the most important "sink" for Cu. The order of importance or the different phases in iIlite (IMt-1) and La Have sediments is:

Organic > Fe-Mn oxide >>>> Clay mineraI (Illite)

abstract: Doctor of Philosophy (PhD)


title: Carbon, Oxygen and Strontium Isotopic Composition Of Diagenetic Calcite And Siderite From The Upper Cretaceous Cardium Formation Of Western Alberta

contributor:
Schwarcz, H.P
McNutt, R.H.
Geology

subject: Geology Geology

abstract: The Upper Cretaceous (Turonian) Cardium Formation of western Alberta consists of a sequence of interbedded mudstones, sandstones and some conglomerates. Siderite is a common mineral constituent in the Cardium Formation and occurs as an early pore-filling cementing phase in marine conglomerates (Carrot Creek) and as concretions in marine mudstones and brackish/continental (Kakwa) sediments. Diagenetically later calcite cements are also common in the conglomerate and sandstone units. Petrographic investigation of the diagenetic mineral phases defines the sequence of mineral precipitation to be pyrite, siderite, calcite, quartz, kaolinite, fracture-filling calcite. The siderites precipitated below the sediment seawater interface under reducing conditions in porewaters depleted in sulphate via sulphate reduction and sulphide precipitation. The reduction of organic rich matter and Fe³⁺ by bacterial processes increased the DIC and Fe/Ca ratio of the porewaters so that siderite precipitated preferentially over calcite. Sedimentary siderites have a high clay content and an analytical procedure was established to prevent contamination from the interlocked, highly radiogenic clays Sr. Marine siderite concretions are distinguishable from their brackish/continental counterparts by their Sr and O isotopic composition. Brackish/continental siderites have lighter oxygen isotopic values and a more radiogenic strontium composition compared to the marine equivalents. Sr and O isotopic composition of the calcites reveals that they precipitated at a later stage, following meteoric water encroachment into the basin.

abstract: Doctor of Philosophy (PhD)


title: Simulation Analysis of The Alternative Life-Cycle Models

contributor:
Denton, F.T.
Burbidge, J.B.
Spencer, B.G.
Economics

subject: Economics Economics

abstract:
This thesis deals with the important issue of the elasticity of saving with respect to the interest rate. Michael Boskin, and more recently, Lawrence Summers, have argued that saving is much more interest-elastic than economists have generally believed, and as a consequence, that the dynamic efficiency losses from capital income taxation are much higher than they were previously thought to be. In Summers' life-cycle simulation model an increase in the interest rate depresses the present value of future labour income and this leads to declines in the consumption of younger cohorts, more saving, and a higher capital stock. These results are established with a CES utility function. I argue that it is reasonable to introduce minimum consumption levels into the model and that when this is done, younger cohorts do not decrease their consumption by as much in response to an interest rate increase. I show that the interest elasticity of saving is significantly reduced and may even be negative.

In his analysis, Summers assumed an inelastic labour supply. I have relaxed this assumption by allowing both consumption and leisure to be decision variables of the individual. For a Cobb-Douglas utility function, I find the interest elasticity of saving to be 0.008, compared to 3.36 reported by Summers. Moreover, when a lower bound is imposed on consumption, the interest elasticity becomes negative.

abstract: Doctor of Philosophy (PhD)