title: Sediment Transport and Deposition Under Upper Flow Regime Plane Bed Conditions

contributor:
Middleton, G.V.
Geology

subject: Geology Geology

abstract:
Upper plane bed is a stable bedform which develops on mobile sand beds and results in the formation of horizontal laminae. An investigation of some characteristics of upper plane bed and its deposits is described in the thesis.

"Heavy mineral shadows" are described for the first time and defined as: irrregular patches of heavy minerals, on bedding plane exposures of sandstones (or sands) deposited on an upper plane bed, which are characterized by the presence of an abrupt upstream boundary, with adjacent lighter minerals, and a gradual transition into the lighter minerals in the downstream direction. The directional significance of shadows is shown with examples from an ancient sandstone and from a flume. Flume experiments also showed that shadows wash out with increasing flow strength, suggesting their possible use in paleohydraulic interpretations.

Horizontal laminae formed under upper plane bed conditions are precisely described by a detailed examination of textural variations through laminated sands and sandstones as seen in thin section. The data show two types of structure: (1) "textural laminae", including both fining-upward (F.U.) and coarsening-upward (C.U.) laminae less than 1 mm thick, occuring in random sequence and extending generally less than 40 mm in the direction normal to the depositing flow, and (2) laterally extensive "heavy mineral sheets", consisting of layers (often only a few grain diameters thick) in which opaque heavy minerals are abundant in or making up coarsening-upward laminae. The characteristics of textural laminae are proposed to result from their formation by bursts (forming F.U. laminae) and sweeps (forming C.U. laminae) in the flow near the bed. Heavy minerals in sheets, however, are thought to move in patches (shadows?) on the bed largely in response to large eddies in the outer flow. Local erosion of the patches by sweeps incorporates the heavy minerals into C.U. laminae while the patches are resistant to the effects of bursts, so that heavy minerals are absent in F.U. laminae.

abstract: Doctor of Philosophy (PhD)


title: The Mode of Production, Social Classes and the State in Colonial India, 1757-1947: A Case of the Process of Dependent Capitalist Development

contributor:
Levitt, Cyril
Sociology

subject: Sociology Sociology

abstract:
Sociological studies of Indian social change are hard to come by. Only a few concerned sociologists have justly studied social change in India, and they have done so from the traditional methodological and theoretical standpoint of the Sociology of Modernization. None of them, however, focussed on social change in colonial India per se; neither did they adequately point out and illustrate the immense historical significance and specificity of colonial social change.

The present study seeks to remedy these deficiencies. It is argued, first, that the historical significance of Indian social change consists in the dependent (i.e. retarded) development of capitalism in India during the period of colonialism (1757-1947). The growth of dependent capitalism is what precisely makes colonial social change both unique and historically specific social change, i.e. alterations in the economic, class and political structures which the Indian social formation experienced in its movement from Mughal feudalism to colonial capitalism. From this point of view, this work is a case study of the historical formations of the capitalist mode of production, the capitalist class structure and the capitalist state as three major and specific dimensions of colonial social change.

Second, this work seeks to demonstrate dependent capitalist development in colonial India from an alternative methodological and theoretical standpoint. In contrast to the approach adopted by the few sociologists who have studied social change in terms of "modernization" of the Indian social structure, this work focusses on colonial social change from the conflict orientation as based upon the methodological and theoretical principles of Marxist Sociology. It is argued that dependent capitalist development in colonial India is a dialectical outcome of the historical interaction between British and Indian social formations or between metropolitan and indigenous forces of determination. This objective is pursued in terms of three theses. First, it is argued that the country that is more developed (Britain) industrially only shows, to the less developed (India), the image of its own future. The second thesis states that the country that is more developed industrially does not necessarily show, to the less developed, the image of its own future. Though apparently contradictory, these theses are meant to deal precisely with the contradictory role of metropolitan capital in colonial India. Given, this role, the third thesis illustrates that colonial capitalist development, i.e. the historical formations of the capitalist mode of production, the capitalist class structure, and the capitalist state, is the end product of an interplay between external and internal forces of determination within the contexts of global capitalism.

Finally, by undertaking the examination of the nature of, and the processes involved in, dependent capitalist development, this case study seeks to redirect Indian sociological concerns to the need for further research on Indian social change from the standpoint of the Sociology of Development. It is sincerely desired that this work will succeed to raise and stimulate further debate on the past, present and future roles of capitalism in the Indian social formation from the developmental sociological perspective.

abstract: Doctor of Philosophy (PhD)


title: Spatiotemporal activity patterns of Merriam kangaroo rats (Dipodomys merriami)

contributor:
Daly, Martin
Psychology

subject: Psychology Psychology

abstract:
Using radiotelemetry, the spatiotemporal surface activity patterns of the Merriam kangaroo rat (pipodomys merriami) were studied in relation to several physiological and ecological factors. It was found that males were more active than females during the breeding season but not otherwise. Females' surface activity varied in relation to reproductive condition with estrous females most active, pregnant and lactating females intermediate, and anestrous females least active. D. merriami home range sizes were sexually monomorphic in all seasons and ranged in size from 0.03 to 1.16 ha. The majority of activity, however, was restricted to an area of about 0.03 ha. Animals exhibited substantial range overlap with females overlapping males more than other females. No difference was apparent for males. Ranges remained relatively stable in location with only a few animals making substantial shifts. Day burrows, of which animals used several, were regularly distributed so that nearest-neighbors tended to be at maximal distances. As with spatial overlap, females' nearest-neighbors tended to be males.

These findings contribute to the natural history of D. merriami and to the study of small mammal social systems. These findings also suggest that this species may have a more complex social structure than heretofore thought.

abstract: Doctor of Philosophy (PhD)


title: Homoenolization and Rearrangement of Bicyclic Monoketones and Diketones

contributor:
Werstiuk, N.H.
Chemistry

subject: Chemistry Chemistry

abstract:
The H-D exchange and rearrangement of 3,3,6,6-tetramethyl[2.2.1]-heptane-2,5-dione (63a), 3,3,6,6-tetramethylbicyclo[2.2.1]heptan-2-one (63d) and 1,3,3-trimethylbicyclo[2:2.2]octane-2,5-dione (64) in 0.7 -1.3 M K⁺ṯ-BuŌ/ṯ-BuOD(H) at 175°C were examined. Preliminary work on the dithione 63b and monothiomonoketone 63c has also been carried out.

The substrates 3,3,6,6-tetramethylbicyclo[2.2.1]heptan-2-one (63d), 3,3,6,6-tetramethylbicyclo[2.2.1]heptane-2,5-dithione (63c), and 3,3,6,6- tetramethylbicyclo[2.2.1]heptane-2,5-dithione(63b), which have not been reported in the literature previously, were synthesized.

Approximate pseudo-first-order rate constants for the exchange at different sites were calculated from the H-D exchange data. The results suggested that the effect of the second carbonyl group in the exchange of the diones under homoenolization conditions, appeared to be due largely to an inductive and field effect, with small homoconjugative participation.

In addition, homoenolization of 3,3,6,6-tetramethylbicyclo[2.2.1]-heptane-2,5-dione (63a) resulted in rearrangement to 1,3,3-trimethylbicyclo-[2.2.2]octane-2,5-dione (64), via a novel β-homoenolate switch. This is the first report of such a rearrangement when the homoenolate is generated by deprotonation of a ketone. When dione 64 was treated under homoenolization conditions, it underwent unusually rapid H-D exchange of the hydrogens of the bridgehead methyl group. The facile exchange can be explained if a carbon analogue of the acyloin rearrangement is invoked, the first example of such a rearrangement in a non-aromatic system. Monoketone 63d underwent H-D exchange at the bridgehead and the syn-H-7 position as well as at the hydrogens of the C-3 methyl group and the hydrogens of the endo-11-methyl group. It was also found that 1,3,3-trimethylbicyclo[2.2.1)heptan-2-one, (fenchone), (29), previously studied by others, also underwent exchange at the syn-7-position.

abstract: Doctor of Philosophy (PhD)


title: Enhancement of the Finite Difference Time Domain Technique and its Application to Microwave Devices.

contributor:
Georgieva, N.
Jessop, P.
Smith, P.
Electrical and Computer Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract: Most intriguing and complicated scientific problems are solved with the aid of high-speed computers. Advancements in computer technology in conjunction with lower cost of computers have tremendously contributed to this effort. In this thesis, adopting the same philosophy, we explore the solutions to electromagnetic problems using a numerical technique, namely the Finite Difference Time Domain technique. This technique requires large computer resources: specifically, fast computing and large amount of computer memory. Therefore, our developments of this numerical technique focus on reducing both the computational time and computer memory requirements. A unique line-of-sight (LoS) approximation to the equivalence principle, which is a far more efficient alternative to the standard equivalence principle, is introduced. This includes the theory associated with the LoS equivalence, the examination of the error due to the approximation, and the verification with simulations and measurements. The FDTD method is formulated by discretizing Maxwell's curl equations over a finite volume and approximating the derivatives with central difference approximations. The error due to this approximation depends directly on the method of implementation such as the non-uniform mesh. An experimental investigation of the numerical error due to the non-uniform FDTD technique is presented. In the area of active and passive microwave devices, a unique method of incorporating the device equations into the FDTD algorithm is presented. The measurement and simulation results verify this method. In addition to device analysis, new antennas for the use in Personal Communication Systems are presented. The finale to the thesis is an electromagnetic simulation software package that incorporates all the new techniques developed in the course of this work.

abstract: Doctor of Philosophy (PhD)


title: "Ta'n Teli-Ktlamsītasimk (Ways of Believing)": Mi'kmaw Religion in Eskasoni, Nova Scotia

contributor:
Badone, Ellen E.F.
Religious Studies

subject: Religion Religion

abstract: The residents of Eskasoni make up the largest Mi'kmaw community in eastern Canada, the majority of whom claim Roman Catholicism as a primary religious affiliation. However, to describe the Mi'kmaq of Eskasoni as Roman Catholics belies the diversity and complexity of religious belief and expression practiced in the community. This ethnography contributes to the growing body of literature that includes Native views on the role of religion in Aboriginal societies. Drawing upon fieldwork conducted in a number of Mi'kmaw communities in Cape Breton, Nova Scotia, this ethnography is concerned with three specific aspects of Mi'kmaw Catholicism. First, I elucidate the reciprocal nature of the exchange between Roman Catholicism and "traditional" Mi'kmaw beliefs and values, and the multiplicity of religious orientations that emerge from this exchange. Second, I address claims to authenticity by neo-Traditionalists, Mi'kmaw Catholics and Catholic-Traditionalists, paying particular attention to the various cultural markers, especially religious or spiritual motifs, beliefs and values that individuals may either invoke or subvert in the process of constructing positive Mi'kmaw personal and social identities. Third, I look at the role that religion and spirituality plays in the day-to-day lives of the Mi'kmaw people. Taken together, these three aspects of religion and spirituality highlight the distinctive local quality and significance of Roman Catholicism among the Mi'kmaq.

abstract: Doctor of Philosophy (PhD)


title: Bubble Growth Dynamics in Boiling

contributor:
Judd, R. L.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract: This dissertation details a fundamental study of bubble growth dynamics for both spherical vapour bubbles in a uniform temperature field and hemispherical bubbles on a heated plane surface in a non-uniform temperature field in microgravity. The governing equations were solved numerically in order that accurate predictions of bubble growth could be generated for a wide range of system conditions for two fluids, water and R113. One dimensional spherically symmetric bubble growth in an initially uniformly superheated liquid was investigated by first developing grid and time step independent solutions on a computational grid with uniform spacing between adjacent nodes. These solutions were utilized as benchmark solutions for subsequent bubble growth models. A clustered grid arrangement was then implemented to reduce the computational time with insignificant loss of accuracy. The numerical predictions of the uniform and clustered grid arrangements predict the available analytic theories and experimental data with sufficient accuracy. The mechanisms which govern the growth of a spherical vapour bubble in an unbounded liquid were exposed by investigating the complex interaction between the heat transfer and the fluid flow surrounding a bubble as it grows from inception, through the various growth stages, to diffusion controlled growth. The influence of system pressure and liquid superheat were also investigated. Utilizing similar physical arguments, the model developed for spherically symmetric growth was extended to simulate hemispherical growth at a heated plane surface in microgravity. The theory was able to accommodate both spatial and temporal variations in the temperature and velocity fields in the liquid surrounding the bubble as it grows. Utilizing the present theory, the complicated thermal and hydrodynamic interactions between the vapour, liquid and solid have been manifested for a single isolated bubble growing on a heated plane surface from inception.

abstract: Doctor of Philosophy (PhD)


title: CHARACTERIZATION OF MEMBRANE-BINDING BY FTSY, THE PROKARYOTE SRP RECEPTOR

contributor:
Andrews, David W.
Biochemistry

subject: Biochemistry Biochemistry

abstract: The signal recognition particle pathway cotranslationally targets polytopic proteins to the inner membrane of Escherichia coli. FtsY is the receptor that is recognized by the ribosome-nascent chain-bound signal recognition particle in the bacterial targeting reaction. At the outset of this work a major unresolved issue, and current issue of some contention is the mechanism of Fts Y assembly on the E. coli inner membrane. To clarify the nature of this process, this thesis describes the region of FtsY that binds the membrane and a site-specific cleavage event that defines this region upon membrane binding. The involvement of a specific lipid, phosphatidylethanolamine and an as-yet unidentified inner membrane protein in FtsY membrane targeting are also addressed. With this understanding of the mechanisms ofFtsY membrane assembly in E. coli, additional investigations demonstrate divergent species-specific interactions with the membrane for FtsY homologues from Bacillus subtilis and Streptomyces coelicolor. Finally, the unique amino- erminal region was determined to be essential for the function of FtsY in E. coli.

abstract: Doctor of Philosophy (PhD)


title: Frail Elderly Home Care Clients: the Effects and Expense of Adding Nursing Health Promotion and Preventive Care to Personal Support Services

contributor:
Browne, Gina B.
Nursing

subject: Nursing Nursing

abstract: Objectives: • Develop, implement and evaluate a new model for delivering services to frail seniors, focusing on health promotion and preventive care provided by a Registered Nurse within the context of home care services. • Provide information on the health outcomes and costs associated with existing policies regarding the provision of preventive home care services for frail seniors living at home. • Provide scientific support for the role of a Registered Nurse in health promotion and preventive care within the context of home care services. Intervention: Proactive health promotion and preventive care provided by a Registered Nurse for frail elderly home care clients eligible for personal support services. The intervention consisted of a minimum of one contact (primarily home visits) per month by an RN over a 6-month period. Research Design: Randomized controlled trial with baseline (pre-randomization) and 6 month follow-up and outcome assessment. Sample and Setting: 94 individuals (44 experimental, 50 controls) 75 years and older newly referred to and eligible for personal support services through a home care programme in Southern Ontario, Canada. Results: Clinically and statistically significant improvements in physical and mental health functioning and increased level of perceived social support for clients was associated with the study intervention at no additional expense from a societal perspective. There was an economically important difference in the use of acute hospitalization in the intervention group compared to usual care which translates into an annual cost saving of $200,879 within 1 year for every 100 elderly home care clients. Implications: Under the current home care delivery system, this study demonstrates that it is more effective and no more expensive to provide proactive RN health promotion to a general population of frail seniors than to provide professional services on a reactive and piecemeal basis.

abstract: Doctor of Philosophy (PhD)


title: Synthesis, Characterization, Thermomechanical and Rheological Properties of Long Chain Branched Metallocene Polyolefins

contributor:
Zhu, Shiping
Hamielec, Archie E.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract: The objectives of this research were to prepare model long chain branched polyolefin samples with controlled molecular weights and chain structural properties, and to elucidate the effects of long chain branching on the rheological and mechanical properties of polyethylene and polypropylene using a variety of synthesis and characterization techniques. Significant long chain branch (LCB) formation was found by ¹³C NMR measurements in polyethylene (PE) samples produced using the homogeneous catalyst bis(cyclopentadienyl) zirconium dichloride in a semi-batch slurry polymerization. Enhanced levels of LCB were attributed to the in-situ reaction of ethylene macromonomer and the encapsulation of active centres by precipitated polymer chains. PE samples with controlled levels of LCB were synthesized using a two-stage polymerization process. Narrowly dispersed poly( ethylene-co-propylene) (EPR) macromonomer was first produced in a continuous stirred tank reactor (CSTR). The macromonomer was subsequently copolymerized with ethylene in a semi-batch reactor using the constrained geometry catalyst (CGC-Ti). The two-stage reaction process was also employed to synthesize polypropylene (PP) with EPR long chain branches using the catalyst system rac-dimethylsilylenebis(2-ethylbenz[e]indenyl)zirconium dichloride / MMAO. It was found that the stoichiometry of the macromonomer could be used to efficiently control the long chain branch frequency (LCBF) of the copolymers without greatly influencing the copolymer molecular weight. It was also possible to control the long chain branch length by varying the molecular weight of the macromonomer. The rheological properties of various long chain branched polyolefins were measured. These polymers exhibited significantly higher zero shear viscosities (110) and displayed greater shear thinning than linear polymers with similar molecular weights. It was observed that the branch MN had to be greater than 7000 g/mol in order to form sufficient entanglements to significantly influence the rheological responses. The 110 was found to be a sensitive indicator of branch frequency and branch length. Increasing the branch MN led to enhanced values of 110, improved shear-thinning, and elevated flow activation energies. Long chain branching played a significant role in the dynamic mechanical behaviour of polyolefins. Increasing the frequency of branching increased the stiffness of polyethylene, as reflected by the storage modulus. Long chain branching also served to enhance the damping or energy dissipation of PE, shown by increased values of the loss modulus. The dynamic mechanical behaviour of polypropylenes with EPR long chain branches was also characterized. There appeared to be a critical EPR branch length at a MN of approximately 6000 g/mol. When the branch length was below this critical MN, a homogenous system resulted. If this critical MN was exceeded, a two-phase system developed, with fine rubbery domains dispersed in a PP matrix. When a two-phase system developed, it enhanced the loss modulus of the copolymer in a manner similar to impact modified PP.

abstract: Doctor of Philosophy (PhD)


title: Northrop Frye and the Phenomenology of Myth

contributor:
Lee, Alvin A.
English

subject:
English Language and Literature
English Language and Literature

abstract: This study examines the contributions of the Canadian literary theorist Northrop Frye (1912-1991) to the study and understanding of myth in the modem and postmodem periods. The specific mythographic context in which Frye's work is situated is not merely the study of the ancient religious narratives that conventionally structure literature, but the study of myth as phenomenological; which is to say, as a theory or mode of consciousness that informs the very perception of reality, and which, therefore, has profound existential, moral, and cultural implications. The study's introduction positions Frye in relation to three of his contemporaries, the most influential mythographers of the modem era, whose theories have tended to overshadow his, despite their questionable assumptions and conclusions about the phenomenological nature of myth. Chapter I examines the theories of the Romanian historian of religions Mircea Eliade (1907-1986), and demonstrates that their metaphysical basis abrogates an understanding of myth as phenomenological. Chapter Il surveys the work of Swiss psychologist C.G. Jung (1875-1961), whose theory of the collective unconscious is similarly problematic. Chapter III explores the ideas of popular American mythologist Joseph Campbell (1904-1987), which possess some phenomenological elements but settle ultimately upon a metaphysical ontology. Chapter IV is a detailed consideration of the apocalyptic potential of the phenomenology of myth which Frye develops out of the mythopoetics of William Blake and puts forth in his book Fearful Symmetry. Illuminated by the work of philosopher Maurice Merleau-Ponty, Frye's theories of archetype and anagogy are shown to involve the recreation of perceived reality. The study concludes with an examination of the revisions that Frye made to his phenomenology of myth for the context of postmodemism in his book Words with Power; there Frye introduces his theory of kerygma, an apocalyptic phenomenology of mythic language with extraordinary ethical and social ramifications.

abstract: Doctor of Philosophy (PhD)


title: Real-Time Rainfall Estimation and Prediction

contributor:
Tsanis, LK.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: In this study the two problems of rainfall estimation and forecasting using data from weather radars and rain-gauges are studied. A GIS multi-component interface is developed for the analysis of weather radar precipitation data. This interface performs different operations, such as loading and redelivering radar and satellite data, projecting geographical features into the radar coordinate system, and overlaying data from multi-sensor into a common coordinate system. Additional features include accumulating radar rainfall depths, radar comparison with rain-gauge data, animating storm evolution on top of geographical features, and tracking and forecasting rainfall fields. Accurate measurements of rainfall duration, timing, location, and intensity are important for different water resources applications. Weather radars can provide valuable information on the space-time variations of rainfall. However, there are uncertainties in the radar measurements of precipitation. Thus rain-gauges are used to calibrate Z-R relations, which are used to convert from radar reflectivity Z to rainfall rate R. Sampling errors cause differences between rainfall estimated by radar and that estimated by rain-gauges. These errors constitute a limitation for use of radar data for high resolution applications such as urban applications. A methodology is developed to address and correct the effects of these errors. The results prove that correction for these errors reduces the variation between the two sensors. In addition, given that the radar is properly calibrated, correction for sampling errors can provide temporally detailed radar rainfall fields that can be used for high resolution hydrological applications. The comparisons between two Canadian radars (King City and Exeter) show that there is good agreement between rainfall fields estimated by the two radars. The comparisons between radar rainfall intensities estimated by the two radars and the corresponding rain-gauge intensities show that the classical Z-R equation used by the National Canadian Radar Network is biased and can lead to serious underestimation of rainfall. An optimum Z-R relation is calibrated using surface rain-gauge data to be used for unbiased rainfall estimation by the two radars. A new radar-based model is developed for quantitative short-term forecasting of rainfall fields. The new model is called the AARS (Automated Adaptive Rainfall Simulator). The AARS model employs an optimization strategy for performing the cross-correlation analysis that reduces the run time significantly and makes the technique attractive for real-time applications. In addition, the model tracks and forecasts the changes in rainfall intensities in space and time and produces forecasted rainfall fields for the specified lead time. The AARS model employs the adaptive exponential smoothing algorithm for real-time parameters estimation. Performance comparisons between the AARS model and the Canadian short-term prediction model SHARP (Short-Term Automated Radar Prediction) show that the AARS is superior in terms of tracking run time and slightly better in terms of accuracy for forecasting lead times up to 30 minutes. The application of the AARS model for rainfall forecasting in Hamilton-Wentworth Region shows promising results for forecasting lead times less than 60 minutes.

abstract: Doctor of Philosophy (PhD)


title: Molecular Abnormalities in Postmortem Brains of Subjects with Mood Disorders

contributor:
Young, Trevor L.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Biochemical and structural abnormalities have been reported in postmortem brain tissue from patients with mood disorders. Studies of the molecular pharmacology of drugs used in the treatment of mood disorders have led to a reinterpretation of earlier models of neuropathology in these diseases. Noradrenergic and serotonergic hypotheses have been expanded to include postsynaptic intracellular signal transduction pathways, regulation of gene expression, and synaptic plasticity. Because much of this evidence was obtained from postmortem brain, the experiments in this study also used postmortem tissue to examine the neuropathology of mood disorders. Human postmortem brain tissue was obtained from the Stanley Consortium Neuropathology Foundation and consisted of pieces of temporal and occipital cortex, and slices of prefrontal cortex and hippocampus from patients with bipolar affective disorder (BD), major depressive disorder (MDD), schizophrenia (SCZ) and controls (N = 15 per group). Components of the cAMP system were examined, as were potential target transcription and neurotrophic factors. Morphological consequences arising from altered cAMP signalling such as sprouting and DNA fragmentation were also investigated. There was a trend towards blunted temporal cortex adenylyl cyclase activity in subjects with mood disorders, and decreased occipital cortex Gas in lithium-treated BD subjects. Temporal cortex CREB level~ were decreased in antidepressant-untreated MDD subjects compared to controls, and normal in those subjects treated by antidepressants at the time of death. Temporal cortex CREB levels were decreased in BD patients treated with anticonvulsants relative to those not treated by anticonvulsants at the time of death. When assessing the effect of suicide on cAMP signalling, subjects who died as a result of suicide had lower temporal cortex CREB levels and CRE-binding than subjects who died of other causes. This effect was most evident in the MDD group. In hippocampus, BDNF levels were increased in subjects treated by antidepressants compared to subjects not treated by these medications at the time of death. This finding was more pronounced in the MDD group. Hippocampal studies also showed that BD subjects had increased mossy fibre staining relative to controls and other diagnoses, suggesting increased sprouting of the dentate gyrus axons. These postmortem findings are consistent with recent animal and cell models of antidepressant and mood stabilizer pharmacology. The changes in post-receptor signalling and hippocampal sprouting are also consistent with current conceptualizations of the neurobiology of mood disorders. These studies support the use of postmortem brain tissue as a clinically relevant research model, and add to the growing literature elucidating the pathophysiology of mood disorders and the molecular pharmacology of their treatments.

abstract: Doctor of Philosophy (PhD)


title: A New Procedure for Determining Bond Orders in Polar Molecules, with Applications to Phosphorus and Nitrogen Containing Systems

contributor:
W., R. F.
Chemistry

subject: Chemistry Chemistry

abstract: This thesis introduces a newly discovered relationship between calculated values of the delocalization index and Lewis bond orders, for polar bonds. Using the methods of the Theory of Atoms in Molecules, properties of individual atoms - defined as regions of real space - can be calculated from numerical molecular wavefunctions. In addition to determining the number of electrons in an atom, and thus the atomic charge, one can also calculate the extent to which the charge density on a given atom is delocalized to the each of the other atoms in the molecule. This property is known as the de localization index. F or a non-polar bond (equal sharing of electrons), the delocalization index calculated from a Hartree-Fock wavefunction is found to correspond closely with the bond order predicted by the Lewis model of chemical bonding. The delocalization index decreases, however, as the bond polarity increases. The relationship between the decreasing delocalization index and the increasing atomic charges is quantified in this work. A simple quadratic relationship is observed between the delocalization index, 8(A,H) and the charge transfer, q(H), across the A-H bond in a series of hydrides, AHn • The same relationship, 5 = 1-q2, is shown to be derived from the Hartree-Fock expressions for the delocalization index and the atomic charges and can be generalized to more than one pair of electrons. The same derivation applies to two other definitions of bond order proposed by other workers. A method for employing these correlations, along with other calculated properties, to establish the Lewis bond order for a series of related molecules, with differently polarized bonds, is presented. The method is applied to seven series of phosphorus containing molecules and three series of nitrogen containing molecules. The octet rule is found to be more important for the nitrogen systems than for the phosphorus systems.

abstract: Doctor of Philosophy (PhD)


title: A Genetic Dissection of the Role of the ErbB2 IN eu Receptor Tyrosine Kinase in Development and Tumorigenesis in Transgenic Mice.

contributor:
Muller, W.J.
Biology

subject: Biology Biology

abstract: Amplification and overexpression of Neu (HER2, ErbB2) has been observed in a significant proportion of human breast cancers. Consistent with this, overexpression of various neu alleles in the mammary epithelium of transgenic mice resulted in the formation of mammary adenocarcinomas. However, these mouse models have relied upon a hormonally responsive strong viral promoter to direct transgene expression and therefore may not accurately model the human condition. In this thesis I demonstrate that endogenously regulated expressIon of the activated neuNT allele in the mammary gland resulted in increased lateral branching and ductal escape from the fat pad. Upon amplification and overexpression of neuNT, these mice developed adenocarcinomas which shared several similarities with the human disease. I also created a line of mice that express neuNT under the control of the endogenous promoter in the germline. Surprisingly, this did not result in tumor formation, although these mice expressed neuNT at levels equal to the mammary specific activation. I have also examined the role of Neu in the mammary gland through a mammary specific deletion and observed delayed ductal outgrowth. In addition to examining the function ofNeu in the mammary gland, I have also described mice with a conditional deletion of Neu in the skeletal muscle. These mice have profound defects in proprioception due to a lack of muscle spindles, and have a deficiency in muscle regeneration and differentiation. Taken together, these results illustrate the role of Neu in tumorigenesis and in the normal development of numerous other tissues.

abstract: Doctor of Philosophy (PhD)


title: Pain assessment in the elderly: a psychometric evaluation of self-report and behavioral methods.

contributor:
Crook, Joan
Nursing

subject: Nursing Nursing

abstract: Limited research has been done that examines appropriate and reliable methods to assess for pain in the elderly population. For the cognitively impaired elderly, pain assessment is further complicated by their limited communication abilities. Reliable and clinically feasible methods are desperately needed to assess pain so that it can be managed appropriately. The purpose of this study was to examine the psychometric properties (Le., testretest and interrater reliability, criterion concurrent validity) of three verbal pain assessment tools (i.e., Faces scale, numerical rating scale, present pain intensity scale) and a behavioural pain assessment scale within the elderly population. This measurement study used a repeated measures design to examine the reliability and validity of these pain assessment tools across four groups of elderly participants: 1) cognitively intact, 2) mildly cognitively impaired, 3) moderately cognitively impaired, and 4) extremely cognitively impaired, using a nonrandom stratified sample of 130 elderly residents who live in long term care. The findings support the test-retest and interrater reliability of the behavioural pain assessment tool across all four groups of the elderly whereas the same measures of reliability for the verbal pain assessment tools decrease with increasing cognitive impairment. However, the majority of elderly with mild to moderate cognitive impairment were able to complete at least one of the verbal pain assessment tools. The Present Pain Intensity scale had the strongest criterion concurrent validity for the elderly with moderate cognitive impairment (r=0.64, p=O.OOl). The findings are discussed in relation to its clinical and research implications.

abstract: Doctor of Philosophy (PhD)


title: The influence of response priming, competition, and inhibition on movement trajectories.

contributor:
Elliott, Digby
Kinesiology

subject: Kinesiology Kinesiology

abstract: Fundamental to the theories of action-based attention is the notion that response-producing processes are automatically initiated when an object receives attention. In support of action-based theories, movement trajectories have been found to deviate in the presence of non-target stimuli even when the stimuli do not present a physical barrier to the movement (Howard & Tipper, 1997; Welsh, Elliott, & Weeks, 1999). A model of response activation has been proposed to explain these deviations. Predictions based on the model are that, if a response is active at the moment of response activation, then the response will contain characteristics of both the target and non-target response. If the non-target response is inhibited at the time of response initiation, then the response will contain characteristics that are opposite to the non-target response. The five experiments reported in this dissertation were designed to test this model. In the first experiment, it was found that the trajectories of the rapid-aiming movement to a target location deviated towards the location of a simultaneously presented non-target stimulus. This finding replicated earlier work (Welsh et aI., 1999). The results of the second experiment supported the hypothesis that movement deviation away from the location of the non-target stimulus was the result of inhibition of the response to that stimulus. In the third experiment, the target location was precued to examine the effects of response priming on selective action. Consistent with predictions, when the target response was validly cued, no significant distractor interference was observed. On the other hand, if the distractor was presented at the cued location while the target was presented elsewhere, then the movement veered towards the location of the distractor. A similar precuing methodology was employed in the fourth experiment to explore the effects that response priming and inhibition associated with valid and invalid cues have on the trajectory of the target movement when the target is presented in isolation (without a simultaneously presented non-target stimulus). The results of this experiment were generally congruent with the model of response activation. The final study was designed to examine how inhibitory processes, hypothesized to be associated with negative priming and inhibition of return, would affect movement preparation and execution. Consistent with previous work, the presence of the distractor in the prime trials caused deviations in the movement trajectories towards the location of the non-target stimulus. Inhibition of return and negative priming effects, however, were not found. Facilitation effects associated with colour repetition and the lack of competition in the probe trials were the likely causes underlying these latter null effects. Overall, the results of the present series of studies suggest that the model of response activation is able to predict deviations in the path of aiming movements under competitive conditions. Development of the model in terms of the interaction between perception and action systems is required to enable it to account for all effects associated with selective attention.

abstract: Doctor of Philosophy (PhD)


title: Electromagnetic Modal Analysis of Circular-Rectangular Waveguide Structures for Combline Filter Design

contributor:
Litva, J.
Wu, K.
Electrical and Computer Engineering

abstract: The rapid growth in mobile and satellite communications has intensified the requirements for good performance, compact structure, high quality and low cost waveguide filters and diplexers. This dissertation is devoted to the full wave analysis and modeling of various circular-rectangular (C-R) coaxial waveguide structures which are commonly used to develop combline filters and diplexers. Specifically, models that can be cascaded to simulate the system performance of the filters and diplexers are being sought in the dissertation. The research includes three parts: (1) modal analysis of the higher-order modes in the C-R waveguide; (2) modal analysis of the TEM mode in the CR waveguide; and (3) the scattering characteristics of the right-angle bend and the T waveguide junctions loaded with a generic post. A rigorous analysis, which combines the orthogonal expansion method and the Galerkin method, is performed to obtain the higher-order eigenmodes in the C-R waveguide. The Bessel-Fourier series is employed to merge the circular and rectangular coordinate systems used in the analysis. The cutoff frequencies of the higher-order modes are determined using the singular value decomposition (SVD) technique. The modal solution of the TEM mode in the C-R waveguide is obtained by superposition of the resonant modes in an equivalent rectangular cavity loaded with a conducting post. The characteristic impedance and attenuation coefficient of the waveguide are derived from the solution of the TEM mode. Analytic models of the right-angle bend and T -junctions loaded with posts of varying heights are derived. A novel technique of the extended eigen mode functions is developed to deal with the complex boundary conditions in the junction structures. The general scattering matrices of the right-angle bend and T - junctions are obtained.

abstract: Doctor of Philosophy (PhD)


title: Styrene-Maleic Anhydride and Styrene-Ma1eimide Based Copolymers as Building Blocks in Microencapsulation Procedures

contributor:
Stover, H. D.
Chemistry

subject: Chemistry Chemistry

abstract: This thesis addresses the formation and properties of capsule walls formed from new types of wall-former materials such as styrene-maleic anhydride and styrenemaleimide based preformed hydrophobic polymers. During the course of this study two new methods of encapsulation were developed: interfacial encapsulation based on the cross-linking reaction between oil-soluble styrene-maleic anhydride (SMA) copolymer and a water-soluble polyamine, or alternatively the hydrolysis reaction of tertbutyl styrene-maleic anhydride copolymers to produce non-cross-linked microcapsules, and photoinduced phase-separation encapsulation. The internal morphologies of the produced SMA microcapsules were found to depend primarily upon polymer/core-solvent interactions and rate of amine addition. Thus, the transition from matrix structures to hollow particles was observed with increasing volume fraction of hydrophobic non-solvent, dodecyl acetate, or alternatively by slowing the rate of polyamine addition. The effect of polymer loading, type of polymer and polyamine, and molecular weight of the preformed polymer on the observed morphologies was also investigated. The interfacial reaction between styrene-maleic anhydride type of copolymers and polyamines was shown to be fast in order of minutes. Hydrolysis, as the side reaction, was not found to play a significant role in the interfacial encapsulation reaction between SMA copolymers and amines. Styrene-maleimide based capsules were prepared by photo stimulated precipitation of azobenzene-functionalized copolymers dissolved in an oil phase and dispersed in a continuous phase. This microencapsulation process was found to be irreversible, and the resulting microcapsule walls were permanent even during storage in the dark, or irradiation with visible light.

abstract: Doctor of Philosophy (PhD)


title: Contributions to Parametric and Nonparametric Inference in Life Testing

contributor:
Balakrishnan, Narayanaswamy
Mathematics

subject: Mathematics Mathematics

abstract: In this thesis, we consider both nonparametric and parametric inference in life-testing. Under nonparametric inference, we study the nonparametric precedence test and some alternatives. We first introduce a general maximal precedence test for testing the hypothesis that two distribution functions are equal, which is a variation of the precedence life-test discussed earlier in the literature. Next, we introduce three Wilcoxon-type rank-sum precedence tests, which in fact generalize the classical Wilcoxon rank-sum test for Type-II censored data. We propose the use of Edgeworth expansion to approximate the null distributions of these test statistics. Finally, we introduce another generalization of the precedence and maximal precedence tests, viz., weighted precedence and maximal precedence tests, by giving weights to the precedence failures. We also extend these tests to the case of progressive Type-II censoring. We examine the power properties of these test statistics and compare them with those of the precedence and maximal precedence tests under Lehmann alternative as well as the location-shift alternative. Under parametric inference, we first propose the use of EM-algorithm to determine maximum likelihood estimators (MLE's) when the data are progressively Type-II censored. We explain how one could obtain the variances and covariances as well as the standard errors of the MLEs by using the missing information principle. Next, we discuss point and interval estimation for the normal distribution under progressive censoring. Then, we concentrate on the Wei bull lifetime model under progressive censoring and discuss the determination of optimal censoring schemes. Finally, construction of progressively-sensored reliability sampling plans is discussed. Next, we discuss goodness-of-fit tests based on spacings under progressive censoring. We propose a test for exponentiality based on spacings from a progressively Type-II censored sample. We then generalize this test to a general location-scale family of distributions. We use a simulation study to investigate the power of this test under several different alternatives. Finally, we study the estimation of the parameters of a two-parameter BirnbaumSaunders distribution based on complete and Type-II censored samples. For the complete sample situation, we study the MLE's and propose and study modified moment estimators, simple bias-corrected estimators, and jackknifed estimators, and all their asymptotic distributions. For the Type-II censored sample situation, we discuss the MLE and derive the asymptotic variance-covariance matrix of the MLE's. A Monte Carlo EM-algorithm for the determination of the MLE's is discussed. We also propose a simple bias correction technique. Asymptotic confidence intervals based on these estimators and their probability coverages are examined.

abstract: Doctor of Philosophy (PhD)


title: Protein Kinases in Streptomyces: Involvement in Growth, Glycopeptide Production and Resistance.

contributor:
Wright, G.D.
Biochemistry

subject: Biochemistry Biochemistry

abstract: With the recent crisis in hospital-acquired infections, a renewed sense of urgency for studying bacterial species carrying antibiotic resistance determinants has developed. Much of the focus has been centered on the glycopeptide antibiotics including vancomycin, which represent the last main line of defense against many hospital-acquired infections. These clinically pivotal antibiotics are produced by filamentous bacteria in the order Actinomycetes including the genus Streptomyces. The investigations presented in this thesis were undertaken to address fundamental questions of glycopeptide production and resistance in the glycopeptide-producing Streptomyces toyocaensis NRRL 15009 and non-producing Streptomyces coeficolor A3(2). Specifically, questions with respect to the regulation of antibiotic production and resistance have been addressed in light of the relatively recent isolation of protein kinase genes with high similarity to those of eukaryotic origin. A link between glycopeptide production, resistance and protein phosphorylation in S. toyocaensis NRRL 15009 is presented as a basis for a subsequent degenerate PCR strategy to clone putative protein kinase genes from this organism. Using the PCR strategy four putative protein kinase gene fragments were cloned and one of these, stoPK-1 was isolated in its entirety and characterized by biochemical and genetic methods. Analysis of StoPK-1 revealed a bona fide serine/threonine protein kinase with localization to membrane fractions. Disruption of the genomic stoPK-1 gene in S. toyocaensis NRRL 15009 brought about an increased sensitivity to oxidative stress which could be reversed by supplying stoPK-l in trans, but not with a catalytically dead mutant, suggesting a role for the active kinase in responding to oxidative stress in S. toyocaensis NRRL 15009. Additionally, studies examining glycopeptide resistance were undertaken through genomic gene disruption and complementation on the previously isolated vancomycin resistance gene cluster (vanHAX), supporting a role for this cluster in Streptomyces similar to its function in yancomycin resistant gnterococcus (VRE). Furthermore, analysis of Streptomyces DNA sequences revealed putative two component regulatory systems composed of histidine kinase and response regulator pairs associated with the vanHAX genes in S. coelicolor A3(2) and the glycopeptide biosynthesis genes in S. toyocaensis NRRL 15009. These putative VanRS systems share homology to proteins shown to be critical for inducible resistance in VRE, and these observations encouraged an assessment of the response regulator (VanR) homologue in regulating resistance in S. coelicolor A3(2). The results of these studies support the conclusion that the regulation of vancomycin resistance in Streptomyces is similar to Enterococcus and provide further evidence that these soil-born bacteria may be the original source of the clinically important resistance genes.

abstract: Doctor of Philosophy (PhD)


title: The Treatment Of Missing Measurements In PCA And PLS Models

contributor:
Taylor, P. A.
MacGregor, J. F.
Chemical Engineering

abstract: This thesis investigates the building and application of principal components analysis (PCA) and projection to latent structures (PLS) models when some objects in the data set have missing measurements. Score calculation is treated first, followed by model application to prediction and monitoring. Model building is explored in the final part of the thesis. The first problem treated in this work is that of estimating scores from an existing PCA or PLS model when new observation vectors are incomplete. Several methods for estimating scores from data with missing measurements are presented and analysed, including a novel method involving data replacement by the conditional mean. Expressions are developed for the error in the scores calculated by each method and the factors that lead to error are drawn from these expressions. The error analysis is illustrated using simulated data sets designed to highlight problem situations. A larger industrial data set and a simulated process data set are also used to compare the approaches. In general, all the methods perform reasonably well with moderate amounts of missing data (up to 20% of the measurements). However, in extreme cases where critical combinations of measurements are missing, the novel method is generally superior to the other approaches. Uncertainty intervals arising from missing measurements are then developed for the squared prediction error (SPE), Hotelling T2, PLS predictions and their contributions. These uncertainty intervals provide performance measures and diagnostics when measurements are missing in process monitoring and prediction. The uncertainty intervals derived agree well with the values calculated from the complete objects and give valuable information about the true level of knowledge about the process. The uncertainty in the contributions is used to correctly diagnose which missing measurement in a set gives the greatest reduction in uncertainty when it is recovered. Insight gained in the analysis of score estimation and model application is applied to model building with the nonlinear iterative partial least squares (NlPALS), maximum likelihood principal components analysis (MLPCA), expectation maximisation (EM) and iterative replacement algorithms. Challenges unique to model building and factors that lead to error in individual steps of each model building algorithm are examined. Recommendations are made to improve the quality of the models obtained, and a procedure is proposed to screen data for objects and variables with missing measurements that would have an adverse effect on a model built using missing measurements.

abstract: Doctor of Philosophy (PhD)


title: A Qualitative Evaluation of Healthy and Sustainable Community Initiatives in Hamilton and Sudbury, Ontario

contributor:
Eyles, John D.
Geography

subject: Geography Geography

abstract: In an effort to ameliorate some of the current problems facing cities (e.g., social, health, environmental, etc.), a number of locales in Canada and throughout the world have engaged in healthy and sustainable community initiatives. In essence, these initiatives represent an effort to fundamentally change the culture of local decision-making to explicitly include concerns for "health" and "sustainability" (broadly defined). While the popularity of these initiatives continues to rise, little is known in terms of their ability to effect significant change. Most evaluative efforts to date have centred on the development and use of quantitative indicators of community health outcomes. These methods are unable to capture the kinds of subtle and locally contingent changes taking place. In an effort to address this deficiency, this dissertation presents the results of an interpretive process/impact evaluation of healthy and sustainable community initiatives in Hamilton and Sudbury, Ontario. Interviews with key informants in Hamilton (n=20) and Sudbury (n=15) suggest that despite contrasting approaches to implementation, the initiatives in both communities have experienced significant barriers in operationalizing the concepts into practice. A combination of institutional inertia and a lack of political will has meant that implementation has been incremental at best, and the initiatives' agenda status has remained low. In both communities, the initiatives have been interpreted as policy mechanisms to assist in the re-imaging of these post-industrial cities. As such, despite the "radical" rhetoric put forth by its original proponents, the abstract and highly malleable nature of the concepts has led to their narrow interpretation by local elites as policy mechanisms to facilitate traditional economic growth. The implications of these findings for theory and policy, along with the future prospects of the initiatives are explored.

abstract: Doctor of Philosophy (PhD)


title: Branchial and renal urea transport mechanisms in three teleost fish

contributor:
Wood, Chris M.
Biology

subject: Biology Biology

abstract: Physiological and pharmacological approaches were used to characterize the pulsatile, facilitated diffusion urea transport mechanism (tUT) known from molecular evidence to be present in the gills of the facultatively ureotelic gulf toadfish (Opsanus beta). Using those findings, potential urea transport mechanisms in the kidney of the toadfish and in both excretory organs of the ammoniotelic plainfin midshipman (Porichthys notatus), closely related to the toadfish, and the ammoniotelic freshwater rainbow trout (Oncorhynchus mykiss), distantly related to the toadfish, were investigated. With respect to the gulf toadfish, the measured branchial permeabilities to urea and the urea analogues, acetamide and thiourea, were similar in the periods between pulses when tUT was not activated. During pulsatile excretion (when tUT was activated), the permeabilities of all three substances increased, however urea permeability was significantly greater than analogue permeability. This translated to a branchial clearance of urea > acetamide >> thiourea. Midshipmen and trout displayed a similar pattern of branchial urea and analogue handling, suggesting a facilitated diffusion urea transport mechanism like that of the gulf toadfish. In all three species, the movement of urea into the kidney tubule was against an apparent concentration gradient, suggesting the presence of an active transport mechanism. The secretion clearance rate (SCR) of urea, acetamide and thiourea in toadfish and midshipmen displayed a pattern where SCRthiourea > SCRurea > SCRacetamide. In contrast, the pattern of renal handling of these substances in trout was SCRurea = SCRacetamide > SCRthiourea. The difference between trout and batrachoidid fish is likely a combination of different urea transport mechanisms and different kidney morphology; the handling of urea in batrachoidid fish was not correlated with Na+ as observed in trout, and the kidneys of toadfish and midshipmen are aglomerular while the kidney of the trout is glomerular. Based on the different patterns of urea and analogue handling observed in the kidney and gill in all three species, plus the fact that urea is moving against a concentration gradient in the kidney, it is unlikely that the urea transport mechanisms in the two organs are the same. When infused with consecutive exogenous urea loads, initial plasma and urine urea concentrations steadily increased in toadfish and midshipmen. In the toadfish, there was no change in pulse frequency and only a very weak relationship between pulse size (measured as branchial excretion during pulsatile excretion of urea) and plasma urea concentration, suggesting that the branchial excretion mechanism was already saturated at normal plasma urea concentrations. In contrast, the branchial excretion rate of urea in midshipmen was linearly correlated with plasma urea concentration with no observable transport maximum. In both toadfish and midshipmen, renal urea secretion rate maintained a strong linear relationship to plasma urea levels with no observable transport maximum, suggesting that the renal secretory transport mechanism could not be saturated even at plasma levels well above normal. Further characterization of the branchial urea excretion mechanism in the trout was achieved by using an in vitro membrane vesicle preparation, isolating the basolateral membrane of the gill. Basolateral membrane vesicles (BLMV) demonstrated urea uptake with a saturable component (Km = 1.17 ± 0.43 mmol·1⁻¹; Vmax = 0.42 ± 0.08 μmol·mg protein⁻¹·h⁻¹) at low, physiologically relevant urea concentrations and a non-saturable component at urea concentrations of up to 17.5 mmol·1⁻¹ . Uptake of urea by BLMV was inhibited by the presence of the urea analogue, thiourea, was sensitive to phloretin, a potent blocker of UT-type urea transport mechanisms, and altered by temperatures above and below the temperature of acclimation. Cortisol and glucocorticoid receptors appear to be involved in the regulation of urea production in the ammoniotelic rainbow trout (Oncorhynchus mykiss). Fish implanted with cortisol alone had 3-fold greater plasma and urine urea concentrations relative to fish of all other groups, including fish with similarly high cortisol levels but implanted with RU486. In addition, a positive correlation was observed between plasma cortisol and plasma urea concentration in cortisol-implanted fish that was abolished in fish implanted with cortisol + RU486. Compared to sham-implanted fish, cortisol-treated fish had significantly elevated branchial (two-fold higher) and urinary (three-fold higher) excretion rates of urea but not ammonia. However, as branchial and renal urea clearance were unaffected, there appears to be no stimulation or inhibition of urea excretion mechanisms in the gill or kidney separate from effects due to changes in plasma urea concentrations.

abstract: Doctor of Philosophy (PhD)


title: The Vertical Mosaic Within: Class, Gender and Nativity within Ethnicity

contributor:
Davies, Scott
Levitt, Cyril
Sociology

subject: Sociology Sociology

abstract: Historically, many studies of social inequality in Canada have tended to focus upon its ethnic dimension. Since the time of Porter (1965), most studies have been preoccupied with either supporting or refuting his Vertical Mosaic thesis. Research results are mixed. Some social scientists have found that, over the years, there has been a convergence in the earnings of ethnic groups; others have maintained that ethnic earnings inequality is persistent. Recently, proponents of the "visibility" thesis have argued that "colour" has replaced ethnicity in the structure of social inequality in Canada. Since the mid-1980s, the gender and nativity dimensions of ethnic inequality have been incorporated into the analysis of earnings differentials among ethnic/"visible"groups. There has been, however, a relative silence on the importance of class in this analysis. Even intersectionalist analyses that claim to interconnect class and gender with ethnicity are mostly qualitative, usually focus on small groups, often conflate "race" and class or examine only one class, gender and nativity group (immigrant women of "colour"). The present study is based upon the Public Use Microdata File on Individuals drawn from the 1996 Census of Canada. The class dimension is re-introduced and earnings differentials are examined, not only across, but also within ethnic groups, in terms of their class, gender and nativity segments. Evidence shows that the ethnic groups examined are not homogeneous or monolithic entities. They vary in terms of sex, nativity and class compositions. It is argued that despite the noticeable earnmgs differentials across ethnic groups, they have, with the exception of Jewish-descent respondents, similar class structures. The class and gender earnings differentials within them are greater than the ethnic earnings differentials among them. In addition, when class is introduced into the gender and nativity dimensions of ethnic earnings, the image of social inequality becomes more complex. The "visibility" thesis does not provide a completely accurate earnings picture. The earnings differentials within ethnic/"visible" groups are greater than those among them. The regression models show that human capital variables like schooling, labour market/production variables like class, weeks worked and industrial sectors, and the ascriptive variable sex, explain more of the variation in earnings than ethnicity or "visibility".

abstract: Doctor of Philosophy (PhD)


title: The Control of a Plasticating Extruder with Flight Noise and Pressure Surging

contributor:
Taylor, P.A.
Wright, J.D.
Chemical Engineering

abstract:
Dynamic models for a plasticating extruder melt pressure are formed from steady state, step test and time series analysis data. The extruder pressure response to steps in screw speed is modelled by a first order transfer function with a time constant of approximately 0.2 s. The noise associated with the extruder pressure consists of a pressure surging at 0.125 Hz frequency and a longer term drift associated with the die temperature controller. This drift has a period of approximately 3.0 min. The pressure also has a signal noise at the same frequency as the screw rotation caused by the screw flight passing the tip of the pressure transducer.

The digital PI and the self-tuning regulator control algorithms are used to control the extruder. These controllers are implemented in combination with various filters which remove the flight noise. The most successful controller/filter combination is a digital PI controller used with a filter constructed from 2 poles and 2 zeroes.

The dynamic response of a disturbance caused by changing the input polymer quality is also examined. The use of Box and Jenkins seasonal time series models as bandstop filters is studied and it is concluded that they have little practicality as filters. Another topic covered by the thesis is the effect that including filters in the forward transfer function part of a process has on the self-tuning regulator algorithm.

abstract: Master of Engineering (ME)


title: Mathematical Modeling of the Pressure- Driven Performance of McMaster Porefilled Membranes

contributor:
Dickson, James M.
Chemical Engineering

abstract: The McMaster Pore-filled (MacPF) membranes are a new class of nanofiltration membranes prepared by co-polymerizing a polyelectrolyte (PEL) gel into a microporous substrate. The PEL gives unique characteristics to the MacPF membranes that make them suitable for water softening and fractionation. The main objective of this investigation is to develop a procedure that can be used to design MacPF membranes for specific applications from theory a priori. This procedure involves the combination of two mechanistic models. The first model (gel model) predicts the physicochemical structure (i.e., membrane parameters) of the pore-filling gel (Mika and Childs, 2001). The second model (transport model) can be used in combination with the parameters predicted by the gel model to predict the pressure-driven transport of the MacPF membranes. The transport model is developed in this dissertation. The design procedure and mathematical models outlined in here would be the first time a membrane design is attempted using only theoretical arguments. The membrane transport model is a pseudo 2-dimensional transport model that consists of the extended Nemst-Planck equation (viscous flow and frictional model), a modified Poisson Boltzmann equation, and hydrodynamic calculations to relate the frictional and steric forces to the membrane structure. The model has three fitting parameters that describe four structural properties of the membrane:pore radius, pure water permeability, surface charge density and the ratio of effective membrane thickness to water content. The model successfully predicts and explains the performance of the MacPF membranes as well as one commercial thin-film composite membrane tested simultaneously. The model parameters estimated here are statistically significant and are comparable to previous results (Garcia-Aleman, 1998). A comparison of the performance of the commercial and MacPF membrane was performed using experimental data and the transport model. This analysis shows that the rejection and transport mechanisms are the same in the commercial and MacPF membranes. Convection, diffusion and electromigration are the main mechanisms of solute transport. However, their contribution is different for each type of membrane. Solute rejection in NF membranes is determined primarily by steric and electrostatic effects. For the MacPF membranes separation and selectivity are primarily determined by the latter. The contribution of steric effects to rejection is significantly smaller compared to commercial membranes. Additionally, the membrane parameters were estimated using both the gel and transport models. At this point, the results obtained separately from the two models show similar parameter estimates and separation. However, additional work has to be done to improve the agreement between the models before the procedure outline here can be used to truly tailor-make the MacPF membranes.

abstract: Doctor of Philosophy (PhD)


title: Cloning and characterization of PHIP, a novel protein ligand of the PH domain of IRS-1

contributor:
Rozakis-Adcock, Maria
Biology

subject: Biology Biology

abstract: Insulin receptor substrate- I (IRS-I) protein is a major substrate of the insulin receptor tyrosine kinase and is essential for transducing many of the biological effects of insulin including mitogenesis, gene expression and glucose transport. The N-terrninus of IRS-1 contains a pleckstrin homology (PH) domain, followed by a phosphotyrosine-binding (PTB) domain that have been shown to co-operatively contribute in mediating productive receptor/substrate interactions. The PH domain is critical for recognition and subsequent phosphorylation of lRS-1 by the activated insulin receptor. In this thesis, the cloning and biochemical characterization of a novel protein, named PHIP (PH-interacting protein), has been described. PHIP binds selectively to the PH domain of lRS-1 in vitro, and stably associates with IRS-l ill vivo. Importantly, mutants of the IRS-1 PH domain that disrupt the PH fold fail to bind to PHIP. Anti-phosphotyrosine immunoblots of PHIP revealed no discernible insulin receptor-regulated phosphorylation, suggesting that PHIP is not itself a substrate of the insulin receptor. By contrast to full-length PHIP, overexpression of the PH-binding region of PHIP has a pronounced inhibitory effect on insulin-induced IRS-1 tyrosine phosphorylation levels. Moreover, expression of this dominant-negative PHIP mutant (DN/PHIP) leads to a marked attenuation of insulin-stimulated mitogen activated protein (MAP) kinase activity. Furthermore, overexpression of PHIP enhances insulin-induced transcriptional responses in a MAP Kinase-dependent manner. By contrast, DN/PHIP mutants specifically block mitogenic signals elicited by insulin and not serum.In addition, DN/PHIP mutant proteins also inhibit insulin-triggered GLUT4 translocation to the cell surface as well as actin assembly. It is therefore concluded that PHIP represents a physiological ligand of the IRS-1 PH domain which plays a critical role in insulin-stimulated biological responses mediated by IRS-1.

abstract: Doctor of Philosophy (PhD)


title: Letter Processing in Children with Naming Speed Deficits

contributor:
Levy, Betty Ann
Psychology

subject: Psychology Psychology

abstract: Research has clearly established that naming speed on a rapid automatized naming (RAN) task is related to reading. However, the nature of this relationship is unclear. Debate continues as to the underlying process or processes that are indexed by the RAN task. The present thesis addressed this issue by exploring the nature of the deficit(s) exhibited by children with slow naming speed on the RAN task. Both orthographic and letter processing skills were examined. The first three experiments used a probe task to examine the letter processing abilities of children with slow naming speed. Levels of orthographic knowledge were also measured. All three experiments indicated that children with slow naming speed on the RAN task are characterized by deficits in orthographic knowledge and in processing individual letters in a sequence. Results suggest that these two deficits may be independent, as difficulties in processing individual letters in a sequence were observed whether or not orthographic structure was present (Experiment 1 and 2). In addition, children with naming speed deficits were able to use the orthographic structure present in a string to aid processing (Experiments 2 and 3b). The processing difficulties exhibited by children with naming speed deficits were not a result of inadequate processing time alone (Experiment 3a and 3b). Providing longer time for these children to encode a letter string did not alleviate the problem. A more fundamental problem in representing individual letters may result in poor or slow processing of letter strings. It is this underlying problem that needs to be corrected in order for letter processing speed to improve. A training study (Experiment 4) illustrated the importance of orthographic pattern recognition training for children with naming speed deficits. Training children to recognize orthographic units within a word facilitated learning of these words, and enabled them to read new words that shared the same orthographic units. Orthographic training also had an impact on the speed with which children identified individual letters in a sequence. Training to increase the speed ofletter identification was successful only when it was preceded by training in orthographic pattern recognition. Training children to recognize larger orthographic units within words may foster an awareness that orthographic consistencies exist within words. When searching for these consistencies within a letter string, children may process the internal elements more efficiently, resulting in an increase in the speed of letter identification when letters are presented in a sequence. Therefore, orthographic training may be beneficial not only in its own right, by addressing the orthographic deficits of children with slow RAN performance, but orthographic pattern recognition training may also be the route through which we can improve processing of individual letters.

abstract: Doctor of Philosophy (PhD)


title: Multivariate Image Analysis and Regression for Industrial Process Monitoring and Product Quality Control

contributor:
MacGregor, John F.
Chemical Engineering

abstract: On-line Multivariate Image Analysis (MIA) and Multivariate Image Regression (MIR) methods are developed for purposes of on-line monitoring and feedback control of industrial processes that are equipped with vision systems. The thesis progresses via three main investigative studies through applications of the proposed methods in the steel manufacturing and forest products industries. These studies are concerned with (i) vision based automatic grading of softwood lumber; (ii) empirical modeling of pulp and paper characteristics using multi-spectral imaging sensors; and (iii) texture based classification of steel surface samples with image texture analysis. The first industrial application study addresses the problem of automatic quality grading (classification) of sawn softwood lumber based on visually identifying the severity and distribution of common defects. An extended MIA approach for on-line monitoring of true color (RGB) image representations of lumber boards is proposed, which provides both qualitative and quantitative measures of lumber defects. The proposed approach involves developing a robust MIA model on typical defects commonly found in lumber. These defects are then monitored using the MIA model on lumber boards being imaged by an on-line RGB imaging sensor. The Near-Infrared (NIR) wavelength region (900 nm - 1700 nm) of the electromagnetic spectrum is also investigated for lumber defect analysis using MIA of multi-spectral NIR images. Advantages and shortcomings of using NIR imaging spectroscopy versus RGB cameras for lumber grading are highlighted. The second industrial application involves empirical model based prediction of the properties of finished dry pulp sheets and the classification of paper samples having different compositions. In the pulp study a novel MIR technique extracts relevant feature information from multi-spectral images of the samples acquired through NIR imaging spectroscopy, and uses Partial Least Squares (PLS) regression to relate the extracted NIR feature space to the corresponding (non-image) quality data measured via laboratory analysis. The proposed MIR scheme is successfully used to monitor pulp quality variations in an at-line mode on an industrial pulp process during several grade changes. In the paper classification problem the feature space, extracted from NIR spectroscopic images, is further interrogated using Principal Component Analysis (PCA) to classify the finished samples based on their chemical ingredient information. The third industrial application addresses the problem of classifying steel sheet samples based on their overall surface roughness characteristics. A novel MIA based image texture analysis technique has been proposed, which extracts textural features from grayscale, color, or multi-spectral images in the latent variable space of PCA. The proposed method enables interactive texture analysis of individual images using visual MIA tools. Furthermore, a MIA model can be developed to monitor textural features from various images for the purpose of image classification. The scheme is illustrated on a set of steel surface images with varying degrees of roughness characteristics. Image classification achieved by the proposed technique is compared with that obtained by other classical multivariate statistical methods and conventional texture analysis approaches.

abstract: Doctor of Philosophy (PhD)


title: The Women of Red Clydeside: Women Munitions Workers in the West of Scotland during the First World War.

contributor:
Rempel, R.A.
History

subject: History History

abstract: During World War One, the Clydeside region became one of the most important centres of war production in Britain. It also had one of the most volatile male workforces, earning it the reputation 'Red' Clydeside. Previous historical accounts have focussed on the skilled workers, debating the extent to which they were red-hot revolutionaries or narrow craft conservatives. To date, there has been no study of the region's large, capable, hard-working female workforce. This thesis traces the experience of the tens of thousands of women employed in the Clydeside munitions industry, paying particular attention to the working conditions in local factories. This thesis contributes to the long-standing historiographical arguments over the nature of Red Clydeside by offering a new view of the dilution crisis which stands at the epicentre of the debate. It finds more cooperation between male and female munitions workers than has previously been recognized, and suggests that class confrontation, not craft conservatism, was at the root of the deportation of the shop steward leaders in March 1916. Although women did not participate in industrial disputes to the extent of the male workforce, they nevertheless contributed to the industrial unrest on the Clyde by joining trade unions and engaging in spontaneous strike activity. In addition, the significant presence of middle class women in positions of authority within the factories generated class hostility, turning munitions factories into breeding grounds of class tension. This study offers a further contribution to the historical knowledge of women workers in the First World War by conducting a searching investigation into the oppressive working conditions in munitions factories and their impact on the health of the female workforce. It disputes the view that munitions women were healthy, robust creatures, arguing that working conditions were particularly harsh in Clydeside factories, with women working longer hours and undertaking heavier work than women in other industrial areas of Britain. In addition, the much-lauded new welfare measures in the factories had little impact in mitigating the debilitating effects of munitions work on women's health.

abstract: Doctor of Philosophy (PhD)


title: Cellular Instability in Binary Solidification

contributor:
Kirkaldy, J.S.
Metallurgy

subject: Metallurgy Metallurgy

abstract: The steady-state growth of cells in binary alloy single phase solidification is examined theoretically and experimentally. The failure of the marginal-stability calculations to predict and describe the growth of stable cells indicates a theoretical gap in this field. The Zener-Hillert type model for cellular solidification proposed by Kirkaldy is discussed. In this theory the physics of cell growth demands that the interface be a non-equilibrium interface stabilized by Kinetic and crystallographic effects. A quantitative model following this line is advanced for the steady-state growth of two-dimensional cells. The solution to the free boundary diffusion problem requires, in addition to the boundary conditions, two extra constraints. A principle of minimum cell root radius, surrogate to the principle of minimum rate of entropy production, is used to provide the additional conditions. Cell growth in the succinonitrile-salol system was studied experimentally. For a given set of growth conditions the cells have a unique steadystate spacing and length. Perturbation experiments about the steady-state support the validity of the optimization procedure used in the calculations. Quantitative predictions on steady-state growth are verified by the experiments.

abstract: Doctor of Philosophy (PhD)


title: The Synthesis of Alcohols from Carbon Monoxide and Hydrogen

contributor:
Anderson, R.B.
Chemical Engineering

abstract:
The synthesis of alcohols from carbon monoxide and hydrogen on a commercial Cu/ZnO catalyst, promoted with K₂CO₃ for the synthesis of higher alcohols, particularly 2-methyl-1-propanol, has been investigated.

Discrimination of rate equations for the methanol synthesis, derived from published proposals for the reaction mechanism, was achieved using sequential experimental design. The optimum equation assumed the hydrogenation of a CH₂O surface intermediate as the rate determining step, consistent with proposals from adsorption and isotope studies. Rate equations derived from mechanisms, assuming the hydrogenation of hydroxycarbene or methoxy intermediates as the rate determining step, failed to describe the measured kinetics. The temperature dependence of the parameters for the optimum equation was also determined.

The optimum promoter concentration for the Cu/ZnO catalyst was 0.5% K₂CO₃ by weight. The promotion effect was related to the CO and CO₂ chemisorption uptakes relative to the N₂ monolayer volume, the maximum effect occurring when these were equal. The intrinsic activity of the Cu/ZnO catalyst permitted less severe operating conditions than has previously been reported for the 2-methyl-1-propanol synthesis. The H₂/CO feed ratio was important in determining the higher alcohol selectivity; increasing CO and decreasing H₂ favoured higher alcohol production. At low H₂/CO ratios, the increased butanol selectivity with increased conversions were explained by a decreased hydrogenation of the methanol precursor and increased concentration of the higher alcohol precursors. The reaction temperature was limited by low butanol selectivities below 260°C and catalyst instability above 300°C.

A chain growth scheme which quantitatively described the observed alcohol distribution for a range of operating conditions, is also presented. Growth was assumed to occur at the α- or β- carbon atoms of the adsorbed precursor. The rate of growth varied as the CO partial pressure and the rate of termination as the H₂ partial pressure. The assumed growth rules are consistent with increased alcohol yields observed with the addition of alcohols to the feed gas. • .' " increased alcohols . growth ~ied as. the CO par~~~ of terminat~on as the H2 partial growth rules are consistent with II with the adAition of

abstract: Doctor of Philosophy (PhD)


title: Uncertainty and Allocative Behaviour in Peasant Agriculture: A Study of Small-Holding Farmers in Bangladesh

contributor:
Butterfield, D.W.
Economics / Economic Policy

subject: Economics Economics

abstract:
Knowledge of farmers' decision making behaviour constitutes an essential element in the formulation of appropriate policies for agricultural development in low-income countries. Since agricultural production is inherently a risky process in which farmers are exposed to numerous sources of uncertainty, any study of farmers' decision making behaviour should explicitly consider the role of risk. This study analyses farmer behaviour in Bangladesh, focussing on the effects that risk has on resource allocation decisions. The key issues explored in this context are: (a) analysis of peasant behaviour towards risk in terms of subsistence requirements and income earning potential of the farm family; and (b) investigation of allocative efficiency in the presence of risk for the small-holding farmers in Bangladesh.

In peasant agriculture where the farms are extremely small and cultivation is dependent upon highly variable rainfall, the farm family may be preoccupied not with maximising income but with maximising their chances of survival. Safety-first models of decision making are based upon this notion of disaster-avoidance and this study specifically employs Roy's Safety Principle under which the decision maker attempts to minimise the probability that income falls below a certain level. Based on the allocative efficiency conditions derived from our safety-first model, alternative testable hypotheses are developed to ascertain whether the small-holding farmers in Bangladesh efficiently allocate their resources to various crops in the presence of risk. A comparison of resource allocation behaviour under two rival criterion for analysing decision making under uncertainty shows that it is possible to analyse the risk preferences of the farm household in a safety first model much in the same way as in an expected utility model. The interpretation of the risk coefficient, however, will be somewhat different for the safety-first model. Emphasizing the farmer's behaviour towards risk, the safety-first approach attempts to explain, in terms of subsistence needs and income generating capacity of the farm households, whether the household is 'forced to gamble' or 'allowed to accept less risk' in their choice of crop portfolio.

The model was estimated using field survey data collected in four different regions in Bangladesh. In particular, data on minimum consumption needs were directly elicited from each farm household in the sample. Our estimates of the risk coefficients in each region show that while most of the farm households in Sylhet should display 'gambling type' behaviour, which occurs when the subsistence needs of the farm family exceeds their income earning potential from farming activities, the situation for the farm households in the other three regions is not so desperate. For most of these households, the minimum consumption needs were less than their income earning capacity, thereby allowing them to undertake less risky activities. Attempts were then made to establish a systematic relationship between our coefficients capturing peasant behaviour towards risk and a number of socio-economics variables characterising the peasant households and their access to income-earning opportunities. Our regression results show that although the explanatory power of the risk-predictive equations are not very high, major explanatory variables such as family size, farm size and off-farm income have the expected signs in most case and are statistically significant. We are thus able in our study to identify some specific determinants of peasant behaviour towards risk and also to quantify their impact on decision making.

Our empirical results indicate that in general the safety-first model outperforms the expected profit maximisation model in our sample. This tends to validate the hypothesis that in subsistence agriculture like that in Bangladesh, peasant households are preoccupied with their security and survival, and therefore, are very likely to follow some sort of safety-first behaviour in their resource allocation decisions. There were, however, considerable regional variations in resource allocation behaviour. Such observed differences in the behaviour pattern across the four regions examined in Bangladesh are explained in terms of a disaster-avoidance motive which is ultimately traced to the capacity of the farm households to generate sufficient income to meet their subsistence needs.

abstract: Doctor of Philosophy (PhD)


title: Synthesis and Testing of Neurological Produgs for the Gamma-Aminobutyric Acid System

contributor:
McCarry, Doctor B.E.
Chemistry

subject: Chemistry Chemistry

abstract:
The purpose of this work was to synthesize derivatives of a GABA agonist to be used as prodrugs. These compounds would be chemically liable and thus would not depend on enzymatic activation to release the parent drug.

Two of the most potent GABA agonists, muscimoi and isoguvacine, were synthesized in 19% and 29% overall yield from propargyl chloride and isonicotinic acid, respectively. A series of prodrugs of muscimol, phenyl carbamate derivatives, were synthesized in 42-66% yields from the corresponding chloroformates. Depending on the substituents on the aromatic ring, a wide range of hydrolysis rates (2.8 to 380 mins) and partition coefficients (0.05 to over 15) were observed for these carbamates. These prodrugs were evaluated as sedatives and anticonvulsants. All carbamates with partition coefficients greater than 0.1 induced dose-dependent sedation which was found to increase with increasing partition coefficient and with increasing hydrolysis rate. Sedation times as long as 12 hours were observed in mice. While one of these carbamates, the p-carboethoxyphenyl carbamate, showed no inhibition of seizures induced by GABA antagonists, a significant delay (about 80%) in the onset of these seizures was observed. Muscimol itseIf had no effect on these antagonist-induced seizures.

Some carbamates radiolabelled in the muscimol portion were administered to mice i.p. and the amount of free [³H]-muscimol in the brain was determined after 1 hour. The amounts of muscimol found ranged from 2.3 to 10.5 nmols/brain. These quantities paralleled the amount of sedation produced by these carbamates.

A phenyl acetamide of muscimol with a partition coefficient identical to a sedative carbamate was prepared, as a non-labile counter-part to the labile carbamate. No sedation was observed for this acetamide even at high doses. Thus it appears that intact carbamates are not responsible for the sedative effects. • However, seven per cent of a radiolabelled form of this acetamide was found in the brain, indicating that agents with similar partition coefficients have ready access to the brain by passive diffusion.

abstract: Doctor of Philosophy (PhD)


title: Farm Household Decision-Making: Theory and Evidence from a Rural Economy

subject: Economics Economics

abstract:
Policy interventions into the rural sectors of developing countries are urgently needed in order to alleviate poverty and foster economic growth. The applicability of a farm household model that combines the farm household's production and consumption decisions to the evaluation of policy measures has been explored in this study. A model incorporating the farm household's decisions regarding resource allocation, family size, schooling and participation in income earning activities is developed and its predictions are tested with farm household data from Bangladesh.

The data analysis reveals that in rural Bangladesh there exist close relationships between farm size, family size, child schooling and income. The size of the family labour force, which is determined by family size and child schooling rates, appears to be an important determinant of farm household participation in income earning activities. Farm households are found to maximize profit, to respond to price incentives and to be allocatively efficient, given the technology and resources available. On the consumption side, a linear expenditure system that contains a set of household demand functions for goods, including household produced goods, family size and child schooling, and labour supply functions has been estimated. Household response elasticities with respect to some selected variables are calculated first on the assumption that consumption is independent of production decisions. The results show that the household's demand for farm goods is income inelastic while demand for non-farm goods is income elastic. It also suggests that the demand for child quantity and child quality are income inelastic but that a trade-off exists between quantity and quality of minor children.

To the extent that the farm household's consumption decisions depend on production decisions, an analysis of the interaction between production and consumption behaviour is undertaken. The major finding of this analysis is that farm households are responsive to prices, income and technical change, both in production and consumption. Any change that may occur in production, following exogeneous changes through some policy variables, also affects household consumption behaviour. This suggests that a model of farm household decision-making that incorporates the interaction of production and consumption behaviour can be of particular importance for policy evaluation.

abstract: Doctor of Philosophy (PhD)


title: The Coral Reef at Cahuita, Costa Rica, a Reef Under Stress

contributor:
Risk, M. J.
Geology

subject: Geology Geology

abstract:
The coral reef at Parque Nacional Cahuita, Limón, Costa Rica, is a reef under stress due to siltation. The amount of suspended sediments is high: 7.4 mg/l (0.1 to 212.7 mg/l), resuspension of bottom sediments is also high: 30 to 360 mg/cm²/day. As a consequence, growth rates of corals are low: 5.3 mm/year (3.7±0.8 to 7.7±0.4 mm/year), live coral coverage is low: 40% (4 to 80%), and coral diversity is low: H'=1.443 (0.038 to 1.602). Coral colonies are generally larger than in other areas studied, and recruitment of coral planulae seems to be low. Most of the corals present are good at rejecting sediments. Morphologies of some corals change to resist better the sediments (vertical fronds of Agaricia agaricites) or to receive more light (shingles of Montastrea annularis and Porites astreoides).

Analysis of the currents and the type of minerals present in the non-carbonate fraction (illite, montmorillonite, feldspar and kaolinite) of the sediments at the reef, point to Río La Estrella as the source of sediments. The amount of sediments carried by this river has probably increased recently as a result of watershed deforestation. The problem of siltation in reef environments is bound to increase as new areas in the tropics are being developed.

Sediments affect both the individual coral and the coral community. It can be determined if a reef is (or was) under stress due to siltation, by analysing the following: growth rates of the corals, amount of trapped sediments in the coral skeletons, live coral coverage, species composition and diversity, and coral morphologies.

abstract: Master of Science (MS)


title: Bounded Noetherian Prime Rings of Injective Dimension One

contributor:
Mueller, B. J.
Mathematics

subject: Mathematics Mathematics

abstract:
This thesis studies the maximal ideals and minimal overrings of the rings of the title. It is shown that then maximal ideals are segregated into projective and non-projectives with no interplay between these classes. Moreover, the projective maximal ideals behave as though the ring were hereditary.

The maximal spectrum of minimal equivalent orders is calculated in terms of that of R. This enables a comparison of their link-graphs (they are almost the same) and a characterization of when a minimal equivalent order also has the attributes of the title. This inductive property is shown to be preserved by the "cycle map" as well as passing up to the minimal equivalent order itself.

abstract: Doctor of Philosophy (PhD)


title: Identification, Modelling and Modification of Mechanical Structures from Modal Analysis Testing

contributor:
Tlusty, J.
Mechanical Engineering

abstract:
One important field of "Structural Dynamics" is "Modal Analysis Testing". This field, concerns the modes of vibration which constitute the link between experimental and analytical methods, like Finite Elements.

The present work deals with the use of the experimental data obtained from Modal Analysis Testing in building a mathematical model of the structure, identifying its parameters and predicting the effects of possible design changes on its dynamics. It also deals with the use of these experimental data in predicting the behaviour of the structure according to a certain criterion. In this work, in particular, machine tool structures are considered.

A systematic formulation of identifying the structural parameters from the Modal Analysis Testing is presented. It depends basically on the accessibility of the relevant coordinates for measurement. If all these coordinates are accessible then the formulation based on the equation of motion of the system and on the orthogonality relationships leads to linear equations. On the other hand if some of the relevant coordinates are missing, like coordinates on the bearings inside a headstock, then nonlinear optimization is used to minimize the errors between experimental and estimated modal parameters. These identification formulations are applied here to theoretical structures as well as actual machine tools.

As a special exercise a procedure is suggested to be used in predicting the dynamics of a lathe with different workpieces using the modal data measured on a single workpiece. Such a procedure can help estimate the limit of stability against machining chatter beforehand and consequently could be implemented in the postprocessors of Numerically Controlled Turning Centers.

The thesis deals also with further development of the theory of machining chatter. For the first time digital simulation in the time domain of the cutting process including chatter is carried out using mathematical models of machine tools established through Modal Analysis Testing. Cutting tests carried out in this work have shown that the digital simulation approach to machining chatter represents the reality very closely. Thus it could be used in formulating acceptance test procedures of machine tools as well as in designing the cutters to achieve higher metal removal rates.

abstract: Doctor of Philosophy (PhD)