title: Optimal level schedules for mixed-model, Just-in-Time assembly systems

contributor:
Steiner, George
Business Administration

subject: Business Administration, Management, and Operations

abstract: The usage problem which occurs in the scheduling of mixed-model assembly processes operating under Just-In-Time (JIT) methods is examined. A minimax objective function, which has not been considered previously for use with mixed-model JIT systems, is introduced to control these processes. A general integer programming model of the problem is developed with the goal being to determine optimal sequencing methods for various formulations of this model. It is shown that the single-level, unweighted version of the model can be solved to optimum using an algorithm which is polynomial in the total product demand. A graph theoretic representation of the problem permits the calculation of bounds on the objective value. Of particular significance is the upper bound which demonstrates that a feasible sequence always exists for each copy of every product in which the actual level of production never deviates from the ideal level by more than 1 unit. Symmetries within the problem are shown to exist which substantially reduce the computational effort. Extensions to weighted single-level problems are made. A dynamic programming (DP) algorithm is presented for optimizing the multi-level problem formulations. The time and space requirements of this DP are demonstrated. Tests of the DP's performance capabilities, characteristics and limitations are performed. As the growth of the DP's state space could severely restrict the problem size if all of the states are generated, a necessary screening method, employing simple heuristics, is used. The results of the testing indicate that the size of the problems which can be optimized is constrained by the solution time. Conversely, the size of the problems that could be optimized never became constrained by the storage requirements since the simple heuristics acted as highly efficient screening mechanisms. The experimentation also uncovered certain inherent solution characteristics.

abstract: Doctor of Philosophy (PhD)


title: The role of expiratory muscle activity in ventilation during exercise

contributor:
Killian, K.J.
Campbell, E.J.M.
Physiology and Pharmacology

subject: Pharmacology Physiology Pharmacology

abstract: The purpose of this thesis is to investigate the partitioning of work performed by the expiratory muscles between controlling operating lung volume and increasing expiratory flow, as well as the importance of the expiratory work in determining maximal ventilation during exercise. Healthy subjects were studied at rest and six levels of exercise, including maximum exercise (WRmax). Esophageal and gastric pressure (Pes and Pga) were measured using standard balloon catheter systems. Lung volume was measured using inductance plethysmography, calibrated at each exercise work rate with inert gas dilution and spirometric volumes. The static effects of lung and chest wall recoil on esophageal pressure (Pes-stat and Pel,w respectively) were measured at rest (Pel,w was estimated for some subjects). Work of breathing was measured for both inspiratory and expiratory muscle activity and further partitioned into elastic and resistive work. During the transition from rest to mild exercise (50W), end-expiratory lung volume fell from 53.0 ± 3.7 to 47.6 ± 3.6 (M ± SE) percent of total lung capacity, there was a further significant decrease with 100W exercise to 44.0 ± 3.8 %TLC, at maximal exercise, end-expiratory volume was 40.3 ± 2.5 %TLC. During exercise, expiratory flow was greater than that which could be achieved passively (i.e. due to the combined elastic recoil of the lung and chest wall). At maximal exercise, approximately half of the measured expiratory flow was due to expiratory muscle activity. The extent to which expiratory flow was dependent on expiratory muscle activity was greatest at low lung volumes, where the combined elastic recoil of the lung and chest wall was relatively small. Expiratory esophageal pressure progressively increased during the course of exercise. This increase in pressure was associated with significant increases in expiratory flow at all work rates, including maximal exercise. Expiratory pressure remained effective throughout the majority of expiration (i.e. it did not exceed the point at which starling type resistance prevents further increases in expiratory flow). Transient ineffective pressure toward end expiration may have occurred during maximal exercise. The total work of breathing at a given level of ventilation was in agreement with studies reported in the literature. At rest all work was performed by inspiratory muscles. During mild exercise (50W), expiratory muscle work was significant, accounting for 10.5 ± 2.1 % of the total work of breathing (p < 0.05). During mild to moderate exercise (50-150W) the expiratory work used to lower end-expiratory volume below functional residual capacity exceeded that used for increasing expiratory flow (p < 0.05). At maximal exercise however, the work performed increasing expiratory flow accounted for 71 ± 9.2 % of the total expiratory work and was significantly greater than the work used to lower end-expiratory volume (p < 0.05). Ventilation during maximal exercise could not be achieved without expiratory muscle activity, illustrating the importance of these muscles in lowering end-expiratory lung volume and increasing expiratory flow. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: The determinants of Canadian defence policy-making within NORAD: A theoretical and case study approach

contributor:
Richardson, Jack
Sociology

subject: Sociology Sociology

abstract: Since 1958, Canada and the United States have cooperated in the air/aerospace defence of the North American continent under the terms of the North American Aerospace Defence Agreement (NORAD). This thesis examines Canadian defence policy as it pertains to NORAD and NORAD-related defence programs, and uses the findings to test the assumptions of two international relations theoretical perspectives, the realist paradigm and Immanuel Wallerstein's capitalist world-economy model. On the basis of the case study, the thesis argues that the Canadian military, in its professional cooperative association with the U.S. military, develops a defence agenda which reflects the U.S. military's defence policy preferences for Canada, an agenda that often runs counter to the Canadian government's defence policy positions and/or its expressed policy preferences. In addition, the Canadian defence production industry, organized, like the military, both within Canada and across the Canadian/U.S. border, has economic interests in the defence policy positions taken by Canada. Both actors have the means to exercise significantly their influence on the policy formulation process. In mediating the interests of these two actors, as well as its own political, strategic and economic interests, the Canadian government often finds its political/strategic interests compromised, and hence the making of "strategic miscalculations" in defence policy as it relates to NORAD. In applying the assumptions of the two theoretical perspectives to these findings, the thesis argues that the major assumptions of the realist paradigm have to be relaxed in order to explain Canada's defence policy positions in the international realm as they pertain to NORAD, while the assumptions of Wallerstein's model require two correctives in order to perform well as a theoretical guide to explaining Canada's position within the NORAD defence alliance.

abstract: Doctor of Philosophy (PhD)


title: Short-external-cavity near-infrared diode lasers for use in molecular spectroscopy

contributor:
Cassidy, D.T.
Reid, J.
Engineering Physics

subject:
Engineering Physics
Engineering Physics

abstract: InGaAsP and AlGaAs near-IR laser diodes with a short external cavity (SXC) were characterized and used as single-mode radiation sources for molecular spectroscopy. A module for extended temperature-tuning of the lasers was tested to evaluate their single-mode frequency tuning range. AlGaAs SXC lasers operating at 0.76 μm tuned up to 400 cm⁻¹ in a single mode, a few wavenumbers at a time, with no gaps in frequency coverage. InGaAsP SXC lasers operating at 1.3-1.55 μm tuned up to 200 cm⁻¹ in a similar fashion. A technique was developed to control the behaviour of the longitudinal modes and enhance laser operation. The technique employed interference fringes in the laser output intensity distribution to produce a discriminating signal used in an electrical feedback loop to maintain the external cavity at the optimum length for single-mode operation. Control theory was used to optimize the operation of this feedback loop. The SXC lasers were used in a high-sensitivity absorption spectrometer. The noise sources of the spectrometer were assessed, and the sensitivity obtained with SXC lasers was compared with that obtained with distributed feedback lasers. Both lasers yielded sensitivities of ≈3x10⁻⁶ in units of equivalent absorbance in an equivalent noise bandwidth of 1.25 Hz. The sensitivity was limited by etalon fringes produced by optical components in the detection path. The SXC laser spectrometer was employed to monitor the relative abundance of H₂O/HDO and ¹²CO₂/¹³CO₂. Changes in the relative abundance as small as 1% could be observed. The crystal-field and impurity splitting of the W₁₋₀(0) transition of solid hydrogen were observed with the spectrometer. Finally, frequency measurements were made of the 3v₂← 0 ro-vibrational band of the H₃⁺ molecular ion.

abstract: Doctor of Philosophy (PhD)


title: Hosszú's Functional Equation

contributor:
K., T. M.
Mathematics

subject: Mathematics Mathematics

abstract:
In this thesis we make an extensive study of the algebraic solutions of the functional equation

[equation removed]

where the unknown function [equation removed] maps a ring to an abelian group G.

After proving some general results about the solutions of the equation, we study it over rings generated by their units, over number rings, and over polynomial rings. We find that over a large class of rings, the equation is equivalent to Cauchy's functional equation, and we give ideal-theoretic criteria to specify when it is not.

Our methods involve a wide variety of techniques and results from algebra and algebraic number

We complete our study with an a class of functional equations which generalizes the above equation.

abstract: Doctor of Philosophy (PhD)


title: Lewis Acid Chemistry of Some Sulphur-Nitrogen Compounds

contributor:
Gillespie, R.J.
Chemistry

subject: Chemistry Chemistry

abstract:
The compound S₄N₄ has been shown to react with the Lewis acids SbCl₅, SbF₅ and AsF₅ to produce the previously unreported cyclotetra-thiazyl dication, S₄N₄²⁺, in the form of the salts S₄N₄(SbCl₆)₂, S₄N₄(SbF₆)₂, S₄N₄(AsF₆)₂.xSO₂ and S₄N₄(Sb₃F₁₄)(SbF₆). A reaction sequence for the preparation of S₄N₄(SbCl₆)₂ has been suggested and the infrared and Raman spectra for each of the salts is reported as well as the crystal structures of the S₄N₄(SbCl₆)₂ and S₄N₄(Sb₃F₁₄)(SbF₆) salts.

A brief investigation of the reaction of S₄N₄ with the Lewis acids PF₅ and PCl₅ produced in the S₄N₄/PF₅ system the new molecular adduct, S₄N₄PF₅, whereas the reaction of S₄N₄ with PCl₅ yielded a complex mixture of products, composed of phosphonitrilic chlorides.

The chemistry of trichlorocyclotrithiazene with SbCl₅ has been studied. It has been determined for the first time that S₃H₃Cl₃ when oxidized by SbCl₅ produces the S₄N₄(SbCl₆)₂ salt with the compounds S₄N₄ SbCl₅ and S₅N₅ (SbCl₆) isolated as intermediates formed during the production of the S₄N₄²⁺ dication. The crystal structures of both Si₄N₄ SbCl₅ and S₅N₅(SbCl₆) are reported in this thesis.

In contrast, the fluoride, trifluorocyclotrithiazene, S₃N₃F₃, when combined with the Lewis acids SbF₅, AsF₅ and SO₃ was not oxidized but rather simple fluoride ion abstraction occurred to yield the thiazyl salts SN(Sb₂F₁₁), SN(AsF₆) and SN(SO₃F).

For the first time, the chemistry of the sulphur imides with Lewis acids of oxidative capability has been studied.

Cyclotetrasulphurtetraimide, S₄N₄H₄, reacted readily with SbCl₅ to yield the S₄N₄²⁺ salt, S₄N₄(SbCl₆)₂. The compound S₄N₄ SbCl₅ has been shown to be an intermediate formed during the oxidation of S₄N₄H₄ with SbCl₅.

Cycloheptasulphurimide, S₇NH, and 1,4-cyclohexasulphurdiimide, 1,4-S₆N₂H₂, produced the previously unknown dithionitronium ion, S₂N⁺, when treated with SbCl₅. Infrared and Raman spectra for the S₂N(SbCl₆) are reported as well as the crystal structure.

In a limited investigation, the compound Cl₃PNPCl₃(PCl₆), has been isolated from the reaction of S₇NH with PCl₅. The crystal structure of the trichlorp[(trichlorophosphoranylidene)amino] phosphorus (V) hexachlorophosphate is reported in this work.

abstract: Doctor of Philosophy (PhD)


title: K, Rb AND Tl DISTRIBUTIONS BETWEEN COEXISTING NATURAL AND SYNTHETIC ROCK-FORMING MINERALS

contributor:
Shaw, Denis M.
Geology

subject: Geology Geology

abstract:
Distributions of K, Rb and TL in alkali feldspar measured for different systems of alkali feldspar-vapour, alkali feldspar-phlogopite-vapour and alkali feldspar-phlogopite-amphibole-plagioclase-rhyolite- vapour at PH₂O = 1.5 Kbar depend strongly on the composition but also vary with the structure and previous thermal history of the alkali feldspar. Such variations can be reduced by initial heating of the capsule at high temperature (900ºC) to fuse the feIdspar so that it recrystallizes into a homogeneous high sanidine. The following results, measured for one or more of the above-mentioned systems appear to be consistent with results obtained for natural materials and also with previously reported experimental results.

[chart removed]

For natural minerals, the following eseries of decreasing element concentrations and ratios together with the corresponding D and KD values for adjacent pairs of minerals are observed:

[equations removed]

Observed Tl concentrations for natural sulfides and oxides are generally lower than those for potassic silicates but higher than those for non-potassic silicates.

In a normal fractionation sequence of rocks the later crystallates will be enriched in Rb and Tl, due to the early crystallization of mafic minerals and calcic plagioclase, and if alkali feldspar crystalizes at high temperatures, will have lower K/Rb and K/T1 ratios. Formation of rocks of lower ratios will be favoured by low temperature crystallization of K-minerals, particularly micas, and incorporation of vapour. On the other hand, Rb/Tl ratios are more constant in silicate minerals but can be fractionated by sulfides and oxides, leading to lower Rb/Tl ratios.

abstract: Doctor of Philosophy (PhD)


title: The tectonic and petrogenetic history of Archean rocks from the Kenora Area, English River Subprovince, northwest Ontario

contributor:
Clifford, Paul M.
Geology

subject: Geology Geology

abstract:
A detailed study of the tectonic and petrogenetic history of Archean rocks at Kenora has unravelled a complex deformational/intrusive history. This is integrated with previous work into a tectonic evolutionary model for the English River Subprovince.

The earliest Kenora Area rocks were mafic volcanics, cogenetic sills and minor ultramafic, intermediate and sedimentary rocks. The mafic rocks are tholeiitic with island arc/ocean floor characteristics. Compositional data are compatible with shallow level fractionation from a peridotite source.

Biotite tonalite gneisses and the more homogeneous Melick Tonalite, for which a sedimentary protolith is rejected are interpreted as plutonic rocks emplaced into the supracrustal sequence. Rb-Sr ages are,

[table removed]

REE patterns in the tonalitic rocks are modelled by 10% melting of a two-pyroxene garnet granulite of tholeiitic composition.

Granitic pegmatoid gneisses are interpreted as deformed pegmatites injected into tonalitic gneiss and amphibolite. Bulk compositional data are compatible with fractionation from a tonalitic magma, but unusual LREE-depleted REE patterns accessory phases precipitate before residual liquid crystallizes.

A suite of calc-alkaline mafic/mafelsic dikes were injected, over an extended period, into the gneisses and some granitic plutons. Overlapping time of emplacement and calcalkaline affinities indicates a link with the granitic plutons.

The Dalles Granodiorite, the only granitic pluton studied in detail, consists of intergradational pink and grey phases which together define an Rb-Sr age of 2630 ± 10 Ma, initial ratio 0.7014 ± 1. REE patterns in the grey phase can be modelled by 10% melting of hornblende-bearing garnet granulite or, ignoring a model positive Eu anomaly, quartz eclogite. The pink phase is modelled by 70% fractional crystallization of the grey phase under conditions of high fO₂.

A severe compression ( ), now recorded as intrafolial, rootless isoclinal folds, post-dates the tonalitic rocks. Subsequent injection and further deformation (D₂) produced a well-banded gneissic rock. Major F₂ folds can be delineated from the geometry of minor F₂ structures. During deformation the area was subjected to upper amphibolite grade metamorphism (650-750ºC, 0.4-0.7 GPa) with K-feldspar megacrysts and garnet developing in the deeper levels. Major F₂ folds are refolded in a rim synform (D₃) which developed synchronously with the emplacement of the Dalles Granodiorite, an event which also accentuated tonalite gneissosity and created a plunge culmination uplifting part of the deeper K-feldspar megacryst/garnet structural level. D₄ deformation produced open, upright folds and caused buckling of dioritic dikes and pegmatites. D₅ and D₆ deformations invoIve minor faulting and joint development.

The tectonic model formulated for the English River Subprovince is divisible into five parts:

(i) Volcanic-plutonic cycle I (not present at Kenora). Tonalitic gneisses from Lac Seul (ca. 3050 Ma) and undated gneisses at Cedar Lake were formed. Amphibolite enclaves may be the only surviving relics of a pre-existing supracrustal sequence.

(ii) Volcanic-plutonic cycle II. The Kenora Area supracrustal remnants and tonalitic gneisses (2760 Ma) and the undated Clay Lake Granitoid Suite, Twilight (metasedimentary) Gneisses and supracrustal rocks at Cedar Lake and a trondhjemite-granodiorite unit at Lac Seul (2780 Ma) were generated during this cycle, as were the Ear Falls - Manigotagan Gneiss Belt metasediments.

(iii) Major tectonothermal event (2680 Ma). Regional metamorphism resulted in upper amphibolite to granulite mineral assemblages. An intense layer normal compression event at Cedar Lake caused tectonic interleaving of the Cedar Lake Gneiss 'basement' and the Twilight Gneiss 'cover' sequence.

(iv) Diapiric granite event (2650 Ma). The Dalles Granodiorite (2630 Mal at Kenora and the undated Cliff Lake Granodiorite at Cedar Lake are local representatives of this event. Sialic material at the present erosion level was doubled and the English River Subprovince was elevated relative to the adjoining Wabigoon Subprovince.

(v) Late events (2550 Ma). Sporadic injection of minor intrusions and weak deformation conclude the tectonic evolution of the English River Subprovince.

abstract: Doctor of Philosophy (PhD)


title: The Role Of Platelet-Derived Materials In Mural Thrombogenesis

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
Medical Sciences
Medical Sciences

abstract:
Washed human platelet suspensions were used to study platelet-surface interactions in tubes at wall shear rates between 80 s⁻¹ and 640 s⁻¹ and exposure times up to 900 s. Radiolabeled platelets were used to measure platelet accumulation and release from accumulated platelets as a function of time, shear rate, distance from the inlet of a tube, surface composition and drug treatments of platelets. These empirical data were used in a calculation procedure based upon diffusion and convection, designed to yield the maximum interfacial fluid concentration (IFC) for each of the materials which are liberated from platelets during platelet accumulation upon surfaces. Substances such as AMP, ATP, serotonin, pyrophosphate, PGG₂ and PGH₂ were found not to be present in sufficient quantity to produce IFC's which could affect platelet aggregation. A second set of materials, von Willebrand factor, fibronectin, and calcium had IFC's less than the concentrations normally found in plasma. A third group, ADP, PGD₂, and TA₂ had IFC's close to those known to affect platelet aggregation. These last materials, along with materials formed by a vessel wall or in plasma are most likely to determine the rate of thrombus growth on subendothelium or on a blood-contacting biomaterial.

As well, epi-fluorescent video microscopy was used to monitor platelet-surface interactions with different surfaces giving different spectrums of results.

[table removed]

Aspirin, sulfinpyrazone, indomethacin and PGE₁ treatment of platelets inhibited aggregate formation on a collagen surface but not platelet adhesion. Heparin, hirudin, imipramine, mepacrine, adenosine triphosphate, creatine phosphate/creatine phosphokinase treatment of platelets had no or little effect on adhesion, release or aggregate formation. Modification of platelet functions using pharmacological and suspension modification techniques demonstrated mural aggregate formation was independent of release of adenosine diphosphate by adherent platelets but dependent on prostaglandin and thromboxane formation.

abstract: Doctor of Philosophy (PhD)


title: Transformation and Perturbation of Subspaces of a Banach Space

contributor:
Kovarik, Z.V.
Mathematics

subject: Mathematics Mathematics

abstract: An n-frame on a Banach space X is E=(E₁,...,En) where the Ej's are bounded linear operators on X such that Ej≠0, ∑ Ej=I and EjEk=δjkEk (j,k=1,2,...,n). This with the study of pairs of such n-frames. It is shown that if two n-frames are close to each other then they are similar. A particular similarity, the direct rotation comes naturally in connection with the geodesic arc connecting the two frames when the set of n-frames in regarded as a Banach manifold. For a pair of 2-frames, the direct rotation is characterized. Another similarity, the balanced transformation which realizes the equivalence of the two frames is locally characterized and its closeness to the direct rotation is investigated. These results are used to obtain an error bound on invariant subspaces under perturbation. Our study, which is based on a functional calculus approach, involves techniques and results from operator theory, perturbation theory, and differential geometry. Some of the results are relevant to numerical spectral analysis.

abstract: Doctor of Philosophy (PhD)


title: Theory and Application of Self-Tuning Regulators

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

subject:
Chemical Engineering
Chemical Engineering

abstract:
The theory of self-tuning regulators and related topics in linear stochastic control theory have been examined. A unifying treatment of the theory of self-tuning regulators has been presented, and an attempt made to clarify the confusion surrounding certain aspects of these regulators. The notation is that of Box and Jenkins (1970).

Self-tuning control of a steam jacketed stirred tank was successfully implemented. The experimental program was designed to illustrate points from the theory that have caused confusion in previous industrial and pilot plant implementations.

abstract: Master of Engineering (ME)


title: Classical and quantum chaos in the wedge billiard

contributor:
Goodings, David A.
Physics

subject: Physics Physics

abstract: We examine the relationship between the classical mechanics and the quantum eigenvalues of the wedge billiard. Special emphasis is placed on applications of the periodic orbit theory developed by Gutzwiller (1971) and recently modified by others. Evidence is presented suggesting that words formed from a two letter alphabet, consisting of T and V, uniquely label all periodic orbits. The periodic orbits are found (for several different wedge angles) using a two-dimensional Newton method and their actions, periods, stability exponents, and Maslov indices calculated. It is found that the periodic orbits are heavily pruned at all wedge angles. Families of non-isolated periodic orbits and their implications for the Gutzwiller trace formula are discussed. The scaling properties of the classical periodic orbits are also examined. A large matrix diagonalization was used to accurately calculate the first 200 and 300 quantum eigenvalues for the 60° and 49° wedges respectively. A theory is developed which allows one to use the quantum eigenvalues to obtain information about the classical periodic orbits. This theory is tested on the 49° and 60° wedges and shows that the quantum eigenvalues 'know' about the classical periodic orbits. Several quantization schemes derived from the Gutzwiller periodic orbit theory are presented and then tested for the 49° and 60° wedges. Eigenvalues computed using the classical periodic orbits as input are compared to the 'exact' eigenvalues from the matrix diagonalization. A functional relation which uses the dynamical zeta function expressed as a product gives the best results.

abstract: Doctor of Philosophy (PhD)


title: Galanin receptors in canine small intestine

contributor:
Daniel, Edwin E.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Galanin, a 29 amino acid polypeptide, is widely distributed in enteric nerves of the gastrointestinal tract (GIT) in mammals. Previous functional studies demonstrated that galanin may function as neurotransmitter and neuromodulator in GIT. In canine small intestine, galanin induces TTX-insensitive inhibition of small intestinal circular muscle motility in vivo and in vitro, suggesting a direct smooth muscle action of galanin (Fox et al, 1986). Intraarterial infusion of galanin inhibits vasoactive intestinal polypeptide release from isolated perfused canine small intestinal circular muscle, indicating a neuronal action of galanin (Fox et al, 1988). We used ¹²⁵I-porcine galanin as a ligand to study the galanin receptors in the circular muscle and deep muscular plexus from the canine small intestine. The separation, purification and characterization of nerve and muscle membranes were carried out using the technique developed in our laboratory by Ahmad et al (1988). Specific binding sites for galanin were found in both nerve and smooth muscle membranes. The galanin receptor on synaptosomes showed some similar characteristics to that on smooth muscle membranes: (1) The equilibrium binding analysis showed a high affinity and high capacity binding sites in nerve (Kd = 1.1 nM, Bmax = 244 fmol/mg) and in muscle (Kd = 0.58 nM, Bmax = 389 fmol/mg); (2) The specific binding of ¹²⁵I-galanin was inhibited by galanin or N-terminal galanin fragments (galanin 1-16, 1-15, 1-11), but not inhibited by C-terminal fragment galanin 15-29, suggesting a crucial role of the N-terminal region of the galanin molecule in receptor recognition. Computer analysis suggested a two-site model of galanin receptor; (3) The receptor-bound ¹²⁵I-galanin was only partially dissociated by addition of excess (1 μM) unlabelled galanin. However, in the presence of a GTP analog, GTPγS, the dissociation of bound ¹²⁵I-galanin was accelerated and completed, implicating involvement of G proteins in binding of galanin to a two-site receptor. This was supported by the observation that GTPγS abolished the high affinity galanin binding site, leaving only a low affinity binding site in competition studies; (4) Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of cross-linked galanin-receptor complexes from synaptosomes and smooth muscle membranes revealed a similar radioactive band at an approximate molecular mass of 50,000 dalton. Although, the neuronal and muscular galanin receptors have the similar properties, studies on characterizing the G proteins involved in these two groups of receptors using bacterial toxins indicated that galanin-receptor interaction in nerves involves a pertussis toxin-sensitive G protein, while the receptor in smooth muscle plasma membranes is coupled to a cholera toxin-sensitive, pertussis toxin-insensitive G protein. We conclude that, in canine small intestine, galanin may act as a neurotransmitter and/or neuromodulator by interacting with a specific receptor subtype coupled by distinct G proteins on smooth muscle membrane as well as synaptosomes.

abstract: Doctor of Philosophy (PhD)


title: Synthesis and NMR spectroscopy of N,N'-bis(2-thioethanoyl)-2,3-diaminopropanoic acid derived carrier chelants for technetium radioimaging

contributor:
Bell, Russell Arthur
Chemistry

subject: Chemistry Chemistry

abstract: Because of its availability and favorable disintegration characteristics, there has been interest in recent years to bind technetium-99m (⁹⁹ᵐTc) to carrier molecules for use as tissue-specific diagnostic radiopharmaceuticals. In contribution to this effort, this thesis describes some investigations into the synthesis and NMR spectroscopy of novel bifunctional chelants for Tc radioimaging. Using bifunctional chelate strategies, a series of diamide disulfur (DADS) ligand conjugates of biologically active, carrier compounds were prepared for development into prospective myocardial and gastroenterological imaging agents. Carrier molecules of the intended myocardial agents included cardioactive compounds, such as C₁₁ and C₁₆ long chain fatty acids and the cardenolide aglycone digitoxigenin. DADS ligand derivatives of cholic acid, taurine and β-cyclodextrin were also synthesized in an effort to determine their potential utility as gastroenterological technetium imaging agents. The conjugation of ligands to steroidal molecules represents a new approach towards the production of ⁹⁹ᵐTc-based radiopharmaceuticals. The 10-membered heterocycle, N,N'-[dimethyl-(2,2'-dithiobisethanoyl)] ethylenediamine (40), was prepared to aid in the interpretation of the complex NMR spectral characteristics observed in many of the DADS ligands. It exists in solution as a mixture of two Z,Z and on Z,E disulfide and amide ring conformers and has been characterized by NOE, ¹H-¹H, ¹H-¹³C shift correlated NMR and molecular modelling studies. Among the Z,Z ring conformers, Z,Z₁ and Z,Z₂, the former predominates and interconverts with the latter isomer by rotation about the S-S bond with an apparent activation energy of 14.5 ± 1.3 kcal/mol. Coalescence of N-CH₃ signals occurred at about 127℃ at 500 MHz, which corresponded to an approximate barrier to amide rotation of 19.3 kcal/mol. Aromatic solvent induced shifts (ASIS) in C₆D₆ have corroborated molecular mechanics and NOE predictions of stereochemistry. The structure of the Z,E stereoisomer of 40 has been determined by single crystal X-ray diffraction at 296 K. A large geminal N-CH₂ inequivalence (>2 ppm in CDCl₃) was seen in the Z,Z conformers. Based on empirical calculations of chemical shifts, roughly one-half of the observed splitting was rationalized in terms of nearly equal contributions from magnetic anisotropy and electric field shielding mechanisms of the amide carbonyl groups. An implication of these results is the possibility of using α-CH (and eventually -CH) shifts to probe the local conformational space in structured proteins and other complex amides.

abstract: Doctor of Philosophy (PhD)


title: The performance of a tuned liquid damper equipped with inclined and oscillating damping screens

contributor:
Tait, Michael J.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract:
ABSTRACT

The first application of the tuned liquid damper (TLD) to mitigate the

dynamic vibrations of structures was only around 20 years ago and has just been

recently applied in North America. TLDs are partially fluid filled tanks (usually

water) with a fundamental sloshing frequency tuned close to the frequency of the

dynamic mode of structural vibration to be suppressed. Water alone is

insufficient to achieve the level of damping typically required for design.

Damping devices are often submerged in the water to greatly increase the inherent

TLD damping. The damping device investigated in this study is a thin sharpedged

horizontal-slat screen. TLDs with such screens of a particular solidity are

designed for one target amplitude of structural response and have limited

efficiency over a range of structural response. To increase the efficiency, the

concept of smart screens is introduced in this study.

Smart screens is the name given to a damping screen that alters its fluid

pressure-loss characteristics at differing levels of excitation, (ideally) in a passive

state of control. Symmetric fixed-angle screens and oscillating (rotating) parallellinked

screens are experimentally investigated inside a rectangular TLD on a

shake-table under sinusoidal motion in this study.

TLDs have similar principles to common tuned mass dampers (TMD) and

are analyzed accordingly. The TLD equipped with fixed-angle screens is

modelled with linear numerical fluid models to simulate the TLD performance for preliminary design purposes. An inclined screen alters the pressure-loss

characteristics from its typical vertical position, which in turn changes the

inherent TLD damping, allowing damping to be controlled by simple screen

rotation. The analytical models, including the utilization of a pressure-loss

coefficient for an inclined horizontal-slat screen in oscillatory flow developed in

this study, are compared with experimental results to verify their accuracy and

ascertain limitations.

Oscillating smart screens are investigated mainly for their practical

consideration in a preferred passive mode of control. The screens rotate

automatically with changes in fluid velocity (or excitation amplitude). Their

ability to maintain a near-constant amount of TLD damping (or resonant energy

dissipation) is examined. Other implementations of (passive) smart screens are

possible and suggestions for future study are recommended.

A TLD equipped with the mathematically modelled symmetric fixed-angle

screens is theoretically investigated in a hypothetical structure-TLD system. This

system demonstrates the ability of a smart screen to change its damping

characteristics-altering the angle of inclination in this study-over a range of

structural response thereby maintaining an optimal level of efficiency over a

range of structural response accelerations.

abstract: Master of Applied Science (MASc)


title: Specificity and immunosuppression of human cytotoxic T lymphocyte responses to herpes simplex virus

contributor:
Rosenthal, Kenneth L.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Cytotoxic T lymphocytes (CTL) are important in controlling a number of viral infections including those caused by members of the herpesvirus family. Many studies have focussed on the phenotype of human CTL specific for herpes simplex virus (HSV) although few studies address their specificity. HSV glycoproteins B (gB) and D (gD) can serve as target antigens for CD4⁺ and CD8⁺ anti-HSV CTL clones generated by repeated stimulation of peripheral blood mononuclear cells (PBMC) with HSV antigens or HSV-infected cells. In the present study, the presence of gB- and gD-specific CTL in polyclonal cultures of anti-HSV CTL stimulated with a single in vitro exposure to HSV-1 was examined using autologous EBV-transformed B-lymphoblastoid cell lines (LCL) infected with recombinant vaccinia virus or adenovirus vectors encoding gB (vgB11, AdgB) or gD (vgD52, AdgD). Of six HSV seropositive donors tested, only one individual generated CD4⁺ and CD8⁺ T cells capable of lysing LCL infected with HSV, vgB11 or vgD52. Anti-HSV CTL from the remaining five HSV seropositive donors lysed HSV-infected LCL only. Therefore, gB and gD can serve as target antigens for polyclonal cultures of human anti-HSV CTL although the majority of the bulk CTL response in most patients is directed at HSV antigens other than gB and gD. LCL infected with recombinant adenoviruses were not recognized by gB- and gD-specific CTL due to the restricted expression of the inserted gene product. Since LCL infected with recombinant adenoviruses were not lysed by human anti-HSV CTL, human fibroblasts, which are permissive to adenovirus infection, were chosen as potential target cells. However, human fibroblasts infected with HSV-1 (HSV-FB) were not lysed by human anti-HSV CTL or human allo-antigen specific CTL (allo-CTL). HSV-FB were not only resistant to lysis by human CTL, but exposure of CTL to HSV-FB rendered the CTL unable to lyse its normally sensitive target cell. Studies concerning the mechanism of this inhibition suggested that there were two distinct mechanisms of inhibition of CTL lysis. The first involved FB infected with HSV-1 for 2 hours and required the expression of ICP4, an immediate-early protein of HSV-1, but not infectious virus or virus-induced shut-off of host protein synthesis. The second mechanism of inhibition occurred later in the HSV replication cycle and involved the infection of CTL via cell-to-cell spread of HSV-1 from FB infected for 20 hours. The elucidation of mechanisms involved in HSV-induced immunosuppression may foster the development of preventative or therapeutic strategies aimed at controlling these pathogens in humans.

abstract: Doctor of Philosophy (PhD)


title: Investigations of a discharge-excited short-pulse xenon monochloride laser

contributor:
Ballik, E.A.
Physics

subject: Physics Physics

abstract: Experimental and theoretical investigations have been carried out for a compact, UV-preionized, discharge-excited, short-pulse XeCl laser. A comprehensive description of the molecular states and the potential-energy curves for XeCl is provided. The possible radiative transitions are determined according to the selection rules for electric-dipole transitions. An electron-jump model, based on the pseudo-crossings of the potential-energy curves of the ionic states and Rydberg states, is developed to calculate the formation rate-coefficient of the exciplex XeCl*. The results from this model are in good agreement with the results of earlier models discussed in the literature. Furthermore, this model suggests two additional important channels for the formation of XeCl*. As well, the model can be used to evaluate the rate-coefficients for each individual dissociative channel for XeCl*. The compact laser system has an active discharge volume of ≈1 cm³, providing ≈1 mJ output energy in a pulse duration of ≈1 ns. This corresponds to a peak output power of ≈1 MW. Until very recently, this was the shortest duration pulse produced directly in a discharge-excited excimer laser. The typical operation of the laser employed a 0.8%Xe/0.3%HCl/He gas mixture at a total gas pressure in the range from 350 kPa to 450 kPa, and a capacitor charging voltage of 15 kV. Discharge voltage waveforms were measured by using a fast-response Pockels cell. The time resolution for these measurements was better than 1 ns. Discharge current waveforms were measured using a fast-response Rogowski coil. These waveform data were used to evaluate parameters such as inductance and resistance in the excitation circuit, and for comparison with the results from the model. The model, which is self-consistent and concise, combines the models for both the kinetic processes and for the excitation circuit. In the kinetic model for the discharge, only 40 kinetic processes involving 13 chemical species, plus photons and electrons, are required. These 40 processes, chosen from a much larger number of possible processes, are the only ones with sufficiently large rate-coefficients to influence a short-duration discharge. For the model, use is made of the Boltzmann equation for a spatially-homogeneous medium to solve the electron energy distribution. The validity of the model is demonstrated by the good agreement between the calculated and measured waveform data for discharge voltage, current and resistance, and for laser output in terms of waveform, peak power, total energy, and delay time to the onset of laser emission. This model is very useful for the analysis of the kinetics for short-pulse XeCl lasers, and for optimizing the performance of these lasers.

abstract: Doctor of Philosophy (PhD)


title: High-resolution stratigraphy, reservoir geometry, and facies characterization of Cretaceous and Tertiary turbidites from Brazilian passive margin basins

contributor:
Walker, R.G
Geology

subject: Geology Geology

abstract: Two canyon-filling, coarse-grained turbidite systems have been studied, essentially at the oil-field scale, in immature passive margin basins of eastern Brazil. Three oil fields were chosen for detailed study from a group of over 120 turbidite oil fields distributed along the eastern Brazilian margin; Carapeba and Pargo fields (tabular or lobate reservoirs, Coniacian/Santonian to early Maastrichtian, Campos basin), and Lagoa Parda field (channelized reservoirs, early Eocene, Espirito Santo basin). The three oil fields combined contain 162 wells (20 cored), with average spacing of 200-500 m. The Carapeba/Pargo turbidite system contains 181-198 coarse-grained turbidites, each with a thickness in the 0.5-12 m range. There are eight facies successions, 27-140 m thick. Each succession contains between 7 and 58 turbidites. Most of these successions become finer-grained upward and downcanyon, and their younger or more distal turbidites tend to become thinner-bedded and more discontinuous. The Carapeba/Pargo turbidite successions form 1-12 km wide, non-channelized, tabular or lobate sandstone bodies. They were stacked in an overall retrogradational pattern for at least 20 km, recording the backfilling of the Carapeba/Pargo canyon. The Lagoa Parda turbidite system contains unstratified, coarse-grained turbidites up to 6 m thick, with interbedded bioturbated mudstones and thin-bedded ($<$70 cm), stratified, fine-grained sandstones. The coarse-grained facies fill 38 deeply-incised channels; these channel fills are 9 - $>$ 50 m thick, 210 - $>$ 1,050 m wide, and $>$1 km long. The finer- grained facies build asymmetrical levees that are higher and thicker on the left side (looking downstream) of their associated channels. Nine levee successions (up to 50 m thick) are associated with the 20 youngest channels. The overall Lagoa Parda turbidite system is characterized by channel fills that become narrower, thinner, and finer-grained upward. As a result of the common amalgamation of channel fills, and the partial preservation of levee deposits between channel fills, Lagoa Parda reservoirs show a complicated, multi-storied sand body geometry. Coarse-grained turbidite successions that fill canyons were developed in the eastern Brazilian margin during relative sea level falls that punctuated the overall transgressive setting of the late Cretaceous and early Tertiary. Only a few of the turbidite successions studied here can be correlated with global, eustatic sea level curves. Most of the relative sea level falls probably resulted from increased sediment supply, which, in turn, would have responded to tectonic reactivation in the source area and basin margin, and/or to climatically-controlled denudation rates in the source area.

abstract: Doctor of Philosophy (PhD)


title: Single selective inversion dynamic NMR applied to complex organometallic exchange

contributor:
Bain, Alex D.
Chemistry

subject: Chemistry Chemistry

abstract: Organometallic species often participate in complex multi-exchange processes. The existing dynamic Nuclear Magnetic Resonance (NMR) spectroscopic methods are of limited use in complex systems. The classical line-shape method generally cannot provide mechanistic detail, and the actual data analysis may well be intractable if multi-exchange processes are occurring. Spin relaxation methods are more appealing for complex systems as they can also provide mechanistic information. The one-dimensional selective inversion relaxation experiment is inherently more precise than the corresponding two-dimensional method, but was thought to be impractial for multi-site systems as a separate experiment is required for each site. A one-dimensional selective inversion experiment in which all of the exchange processes are probed in a single experiment regardless of the number of sites was designed and tested for complex organometallic systems of the type M₂(CO)₆(μ-PPh₂)(μ₂-η¹η²-CCR) where M = Fe or Ru and R = -HC=CH₂ or −C≡CPrⁱ. Three potential exchange processes occur with these systems: trigonal carbonyl rotation on each metal atom and σ to π interconversion of the μ₂-η¹:η²-CCR ligand between the two metal atoms. The single selective inversion method successfully determined the temperature dependence of the chemical exchange rates for these processes in the chemical systems under study. In all cases, the line-shape data were in agreement with the single selective inversion values. The strengths and weaknesses of each of the dynamic NMR methods are complementary in complex exchanging systems and it appears that in many cases the optimal experiment is a combination of the available methods. A recommended combination strategy incorporating the single selective inversion methodology with both 2D-EXSY and line-shape analysis is outlined. Preliminary exchange studies on OS₃(CO)₉(μ-PPh₂)(μ₃-η¹:η²:η²-C≡C-t-Bu) with qualitative 2D-ESXY experiments permitted the detection of (1) a minor isomer in exchange with the major isomer at low temperature (233 K) and (2) both delocalized and localized carbonyl exchange processes at higher temperature (253 K). The chemical exchange process of the μ₂-η¹:η²-HC=CH₂ ligand in Fe₂(CO)₆(μ-PPh₂)(μ₂-η¹:η²-HC=CH₂) exhibited an interconversion barrier of 71 ± 6 kJ mol⁻¹. This was higher than expected, as most other vinyl and all acetylide complexes exhibit a barrier in the range of 42 to 55 kJ mol⁻¹. The use of two structural features to predict the barrier is proposed: (1) strength of the π interaction as determined by the difference in M-Cα and M-Cᵦ bond distances and (2) asymmetry in the electronic donation to each metal as determined through the metal to ligand distances. Application of these two criteria have so far allowed prediction of the barrier in all cases found in the literature to date.

abstract: Doctor of Philosophy (PhD)


title: Haptotropic rearrangements in metal complexes of 4H-cyclopenta(def)phenanthrene

contributor:
McGlinchey, M.J.
Chemistry

subject: Chemistry Chemistry

abstract: Transition-metal complexes of the tetracyclic system 4H-cyclopenta[def]phenanthrene (cppH) have been prepared for a series of metals, i.e. (η⁶-cppH)Cr(CO)₃, (η⁶-cppH)Mn(CO)₃⁺ and (η⁶-cppH)Fe(C₅H₅)⁺; in all cases the metal is bonded to a terminal six-membered ring. Upon deprotonation, the corresponding (η⁶-cpp) species can be trapped at low temperatures. Raising the temperature results in a η⁶- to η⁵-haptotropic shift, in the case of the Cr(CO)₃ complex at temperatures above -30℃ and +20℃ for the Mn(CO)₃ complex. However, heating of a sample of (η⁶-cpp)Fe(C₅H₅) did not result in a haptotropic rearrangement. The corresponding 8,9-dihydro-cpp derivatives (η⁶-H₂-cppH)Cr(CO)₃ and [(η⁶-H₂cppH)Mn(CO)₃] PF₆ have also been prepared. Deprotonation of the Mn(CO)₃ complex yielded the thermally stable compound (η⁶-H₂ccp)Mn(CO)₃ which only undergoes an η⁶- to η⁵-haptotropic shift upon heating to 60℃ for one hour. The relative ease of haptotropic shifts in the cpp complexes can be rationalized in terms of a transition state in which the migrating organometallic fragment is η³-bonded to the polycyclic ligand in which a 10π (naphthalene like) system is retained. EHMO calculations predict that the barriers to migration in case of the (cpp)FeCp system can be expected to be some 4.5 kcal mol⁻¹ lower than in the corresponding fluorenide system. Furthermore, calculations for the system (cpp)Mn(CO)₃ reveal that the barriers to migration can be expected to be much lower than in the analogous (cpp)Fe(C₅H₅) system. The barriers were calculated to be 17.5 kcal mol⁻¹ and 30.0 kcal mol⁻¹ respectively. Reactions have been carried out to prove the existence of the proposed η³-transition state. In the course of these studies, the complexes (η¹-cpp)Fe(C₅H₅) and (η¹-cpp)Mn(CO)₃(P(C₂H₅)₃)₂ have been synthesized, both of which were found to be unexpectedly stable.

abstract: Doctor of Philosophy (PhD)


title: The Aerodynamic Performance of a High Turning Angle Turbine Blade Profile

contributor:
T., J. H.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract:
The continuous emphasis placed on obtaining higher work outputs from Gas Turbines has led to the design of turbine blades having large turning angles.

As part of a research program co-sponsored by the National Research Council and Pratt and Whitney of Canada Ltd., this work examined the aerodynamic behaviour of the root section of the highly curved turbine blade under investigation.

An intermittant blow-down wind tunnel was used to test a two dimensional cascade of high turning angle turbine blades. The tunnel was modified to allow improved flow control at the desired operating conditions.

A computerized scheme was developed whereby the two dimensional potential flow solutions could be obtained by merely specifying the cascade geometry and inlet flow. This allowed the direct comparison of theoretical and experimental blade surface pressure distributions. The effect of overall pressure ratio on the variation of exit gas angle and total head loss coefficient was also investigated experimentally.

abstract: Master of Engineering (ME)


title: Effects of intentionally introduced mismatch strain on the operating characteristics and temperature performance of indium gallium arsenic phosphide/indium phosphide long wavelength semiconductor lasers

contributor:
Simmons, J.G.
Thompson, D.A.
Engineering Physics

subject:
Engineering Physics
Engineering Physics

abstract: An investigation into the effects of material strain on the temperature sensitivity and operating characteristics of InGaAsP/InP strained-layer multiple-quantum-well (MQW) ridge-waveguide lasers is reported. This thesis contains the first comparison between the performance of strained and unstrained all quaternary MQW lasers having, not only similar emission wavelength, but also identical quantum well thicknesses. Results show that significant improvements in device performance can be obtained through the application of strain. These improvements include: a substantial reduction in the temperature sensitivity of laser threshold current, Ith; a reduction in Ith; an increase in maximum output power; an increase in the maximum operating temperature; and, an increase in the internal device efficiency, η. From investigations into the effects of strain, and QW width on the temperature performance of InGaAsP/InP lasers, the root of the temperature sensitivity of Ith is found to be much more complicated than can be explained by a single dominant physical process, as proposed by other authors. In addition the exponential relationship proposed by Pankove in 1968, which is commonly used to describe the Ith-T sensitivity in terms of the parameter, To, is found to be inappropriate. A new, relationship to describe the variation of Ith with temperature for InGaAsP/InP based lasers is proposed, and the parameter To is replaced by the parameter Tmax which represents the lasers' maximum operating temperature. In addition an expression relating Tmax to adjustable device parameters, such as: cavity length; facet reflectivity; optical confinement factor; internal efficiency; and transparency current density, is derived mathematically from an empirically determined relationship between the temperature rate of change of the threshold current density, ∇TJth, and the threshold current density, Jth. Achieved are the highest reported maximum operating temperature (140℃) and largest characteristic temperature (To = 88 K) for InGaAsP based lasers.

abstract: Doctor of Philosophy (PhD)


title: Multiple-user communications with nonorthogonal signalling

contributor:
Taylor, Desmond P.
Electrical and Computer Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract: Channel sharing by orthogonal separation is fundamental to the designs of an extremely wide variety of multiple-user communications systems. Popular examples in digital communications include TDMA, FDMA, CDMA, and the temporary channel that exists during successful transmission in random-access channels. These engineering solutions have been so successful in practice that it may not be recognized that they were limited by the existing technology. Orthogonality is not, in general, a criterion of optimality. For example, in the additive multiple-user AWGN channel, performance is largely determined by the minimum Euclidean distance between signals at the receiver. Yet, there appears to be no signal design work based on maximizing the minimum Euclidean distance in the overall summed set of signals. The symbol-synchronous linearly-additive multi-user channel is considered in the first part of this work. Rules are presented to realize multi-user coded signals that do not lose minimum Euclidean distance in the receive space. In particular, superposition onto BPSK streams with unit symbol-energy is considered. A trellis code based on 4-dimensional unit-energy signals is constructed which allows a second user to transmit. 3 bits every 4 BPSK intervals without reducing the minimum Euclidean distance in the superposed signal. This design obtains a greater summed rate than previous two-user codes. Furthermore. less energy per bit is required for a given minimum distance. The collision event of the random-access channel is also reconsidered. It is shown that overlapping collisions are often separable by the proper processing algorithm. A generalization of ALOHA is given where 'slot'-collisions are replaced by 'subslot'-collisions, where, in general, there is more than one subslot per slot, with one subslot being equivalent to slotted-ALOHA. Throughputs obtained depend on the complexity available. For example, relative to a single user continuously transmitting, 91% throughput is achieved with 4 subslots, which requires an 8-state Verdu-Viterbi trellis detection algorithm, while 159% throughput is achieved with 10 subslots. requiring 512 states. Potentially, systems with K-subslots obtain K carrier-sense channels when carrier-sensing is available for each subslot. Although it was not the goal of this work, some results may have application to single-user communications. For example, the trellis-coded component of the multi-user constructions may be useful for low-rate, low-SNR signalling. Less anticipated is the result that, for certain values of K, a single-user may send K binary symbols separated in time by T/K, using raised-cosine time-domain pulses limited to duration T, with higher spectral-efficiency than M = 2ᵏ level PAM signalling with raised-cosine frequency-domain pulses at rate 1/T. This particular result appears to be unknown, nevertheless it is less relevant today in light of the more substantial gains that have been achieved with (single-user) trellis-coded modulations. Future investigations and other possible directions of research stemming from this work are discussed throughout and in the concluding chapter.

abstract: Doctor of Philosophy (PhD)


title: Molecular aspects of nickel genotoxicity

contributor:
Nieboer, Evert
Biochemistry

subject: Biochemistry Biochemistry

abstract: The experimental approach adopted had three components. The first involved an examination of the effects of the Ni(II) ion on simple DNA and synthetic polydeoxynucleotides of defined sequence and base composition. In the second part, the interaction of the Ni(II) ion with chromosomes in intact nuclei was investigated. A final component assessed the genotoxic effects of a variety of nickel compounds in a mammalian cell line (AS52) by the characterization of damage at a specific gene locus. A comparison of the effects of Ni(II) to those of other metal ions suggested that the interaction of the Ni(II) ion with DNA or polydeoxynucleotides is to some extent base (or basepair) and sequence-context specific. A clear affinity for G/C bases was evident, which was also reflected in the magnitude of the binding constants. All DNAs and polydeoxynucleotides examined featured two binding sites, differing in affinity by approximately two orders of magnitude. The interaction of the Ni(II) ion with chromosomes in intact nuclei was assessed utilizing UV/visible spectroscopy, resistance to nuclease digestion and electron microscopy. As monitored by spectroscopic techniques, the Ni(II) ion induced a chromosomal condensation which was nickel specific and observable even when Mg(II) ions were present in the buffer. Susceptibility to nuclease digestion decreased in a concentration-dependent manner following an incubation for 96 h with Ni(II). By contrast, no decrease was observed following incubations of 2 or 24 h duration. Ultrastructural changes in chromosome structure were also observed in electron micrographs for the longer exposures. Molecular analysis of the AS52 cell line identified and characterized two independent sites of integration of a bacterial gpt gene insert. Sequence analysis revealed that the locus designated as the pseudogene (gpt') shared homology with the 5' and 3' ends of the gpt gene but also involved a unique insert, part of which derived from the β-lactamase gene of the parent transformation plasmid (pSV₂gpt). The pseudogene was not transcribed as deduced from reverse transcriptase (RT) PCR and Northern hybridization analysis. Analysis of nickel-generated mutants yielded three empirically distinct PCR profiles: (1) amplification of both the gpt and gpt' loci; (2) absence of the gpt band (no amplification); and (3) absence of both the gpt and gpt' bands. The illustrated ability of the Ni(II) ion to induce conformational changes in DNA and chromosomal condensations in nuclei, and its recognized capability of generating oxygen-derived chemicals clearly point to its potential involvement in epigenetic pathways of carcinogenesis. The confirmation by PCR analysis that nickel compounds are mutagenic and can induce point mutations and apparent loci deletions indicates that genotoxic mechanisms are also plausible. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Quality control and improvement based on grouped data

contributor:
Wesolowsky, G.O.
Management Science/Systems

subject: Management Science/Systems

abstract: This thesis develops quality control and improvement techniques based on grouped data. Grouped data occur frequently in industry. However, in the past, most techniques have failed to directly take this grouping into account, and as a result do not perform well in many circumstances. Two major areas of application are considered. First, acceptance sampling plans, acceptance control charts, and Shewhart control charts based on grouped data are developed. These forms of statistical process control have broad application and are in use widely. The design and implementation methodology is derived assuming either a normal or Weibull process, but is easily adapted to any other underlying distribution. A number of design approaches are presented and their relative advantages and disadvantages are discussed. The second application involves estimating the correlation between destructively measured strength properties. This problem arises in the area of structural design. To obtain an estimate of the correlation censoring of the strength data is required. The censoring or proof-testing results in grouped data. A number of simple estimation procedures are presented and compared.

abstract: Doctor of Philosophy (PhD)


title: Etale K-theory and Iwasawa theory of number fields

contributor:
Kolster, M.
Mathematics

subject: Mathematics Mathematics

abstract: Results of W. G. Dwyer and E. M. Friedlander on étale K-theory of the S-integers O^s_E in a number field E are used to express the higher étale tame and wild kernel in terms of arithmetical invariants in the cyclotomic Z_l-extension of F = E(ζ_l). Furthermore, properties of these groups are discussed, such as higher rank formulas and Galois descent.

abstract: Doctor of Philosophy (PhD)


title: In-plane behaviour of grouted concrete masonry under biaxial states of stress

contributor: Civil Engineering and Engineering Mechanics

subject:
Civil Engineering
Engineering Mechanics
Civil Engineering

abstract: The available literature on the in-plane behaviour of masonry was categorized and reviewed under one of three research approaches; experimental testing of masonry shear walls, microscopic modelling, and macroscopic modelling. The significant differences found in the results obtained from different research programs may leave a wrong impression about the potential of masonry as a structural material. The literature review also pointed out the lack of experimental data on the macro-behaviour of grouted concrete masonry, particularly for reinforced assemblages. Accordingly, the reported investigation provides explanations of behaviours which lead to an improved understanding of the in-plane behaviour of grouted concrete masonry. The experimental part provides a body of test data for North American conditions (practice and material) to form the basis of a macro-behaviour model. The experimental program in this investigation included two major parts; biaxial tests and auxiliary tests. The biaxial tests involved a total of 36 full scale unreinforced or reinforced panels tested under uniform states of biaxial tension-compression. A biaxial test rig was specially devised to perform these tests. The variables considered covered the bed joint orientation θ, the ratio between principal stresses σ₁/σ₂, and the percentages of reinforcement used parallel and normal to the bed joints. The auxiliary tests comprised 33 prisms tested under uniaxial compression, 27 prisms tested under uniaxial tension, and 15 couples tested under direct shear. In addition, a large number of component material tests were performed to determine the physical and mechanical properties of each material used. These also served as control tests. A macro-model was proposed to predict the in-plane behaviour of grouted concrete masonry. In this model, the masonry assemblage was replaced by an "equivalent material" which consisted of a homogenous medium intersected by two sets of planes of weakness (along the head joint and bed joint planes) and two sets of reinforcement. The macro-behaviour of the "equivalent material" was determined by smearing the influence of these sets, which provided a means for modelling the inherent part of the anisotropic characteristics of masonry assemblages. On the other hand, the behaviour of the homogeneous medium was described by an orthotropic model to account for the induced part of the anisotropic characteristics. The reliability of the proposed model was confirmed using the experimental results from this investigation and others. The model was also used to fill the gaps in the available test results and to provide a more complete picture of the in-plane behaviour of grouted masonry.

abstract: Doctor of Philosophy (PhD)


title: The photochemistry of aryldisilanes and the reactivity of transient silenes

contributor:
Leigh, William J.
Chemistry

subject: Chemistry Chemistry

abstract: The photochemistry of a homologous series of aryldisilanes (9, 12, 34, and 35) has been studied in detail by steady state and nanosecond laser flash photolysis (NLFP) techniques. Direct irradiation in hydrocarbon or acetonitrile solution results in competitive formation of the corresponding transient simple silenes by concerted dehydrosilylation, 1,3,5-(1-sila)hexatrienes (silatrienes) by [1,3]-silyl migration, and silyl free radicals by Si-Si bond homolysis. Simple silenes and silatrienes are derived from rearrangements in the disilane lowest excited singlet state and are the major products in hydrocarbon solvents. Silyl free radicals are triplet-derived and are the major products in polar solvents such as acetonitrile. Steady-state photolysis in the presence of acetone affords two products consistent with addition of acetone to the corresponding silatriene: a silyl ether (56) from a formal ene reaction, and a 1,2-siloxetane (57) from formal [2+2]-cycloaddition. Product consistent with ene reaction of the corresponding simple silenes with acetone are also detected. Aryldisilane photolysis in the presence of 2,3-dimethyl-1,3-butadiene (DMB) affords both formal ene- and [2+2]- or [2+4]- addition products of the corresponding silatrienes, while irradiation of oxygen-saturated disilane solutions results in the formation of phenyltrimethylsilane and silanone oligomers. Steady-state photolysis in the presence of methanol affords complex mixtures of at least five primary products, four of which are isometric products consistent with addition of the trapping reagent to the corresponding silatriene, while the other is the simple-silene adduct. Analogous complex product mixtures are obtained upon photolysis in the presence of a series of other alcohols and methoxytrimethylsilane. Nanosecond laser flash photolysis of deoxygenated acetonitrile (ACN), isooctane (OCT), or tetrahydrofuran (THF) solutions of aryldisilanes affords readily detectable transient absorptions in the 300-340 and 400-540nm ranged which have been assigned to the corresponding silyl radicals (and simple silenes in some cases), and silatrienes, respectively. Silyl radical absorptions are significantly more intense in polar solvents such as ACN compared to hydrocarbons. Simple Silenes, silyl radicals, and silatrienes can be detected selectively by the addition of the appropriate combination of trapping reagents to the disilane solutions. Increasing phenyl substitution at the silenic silicon atom results in red-shifts in the silatriene absorption maxima consistent with increasing conjugation in the chromophore. The silatrienes form complexes with THF solvent molecules; the equilibrium constant for complex formation is dependent upon the degree of phenyl substitution in the chromophore. Absolute rate constants for reactions of several silatrienes with carbonyl compounds, alkenes, dienes, oxygen, alkyl halides, dimethyl sulfoxide, and alcohols have been determined by NLFP techniques. Silatriene reactions with acetone, DMB, and oxygen occur via stepwise mechanisms involving rate-determining formation of biradical intermediates which undergo subsequent decomposition to afford the detected products. Silatriene quenching by water, methanol, ethanol, tert-butanol, 1-pentanol, and ethylene glycol affords curved quenching plots, while the analogous plots for quenching by 2,2,2-trifluorethanol, acetic acid, and 1,3-propanediol are linear. The addition of water and methanol are subject to deuterium kinetic isotope effects (KIE's) of 1.7 and 1.9, respectively, while silatriene quenching by acetic acid-Od does not exhibit an observable KIE. These results are consistent with a mechanism which involves rapid, reversible formation of an alcohol/silatriene complex followed by competing, rate-determining, intra- and intermolecular proton transfer. Direct photolysis of 1,2-di-tert-butyl-1,1,2,2-tetraphenyldisilane (40) affords tert-butyldiphenylsilyl radicals (41) exclusively. Bimolecular rate constants for the reactions of tert-butyldiphenylsilyl radicals with a variety of alkyl halides, alkenes, dimethyl sulfoxide, and acetone have been determined.

abstract: Doctor of Philosophy (PhD)


title: The transformation of the Bassa: A study in culture, identity and social change, 1830-1987

contributor:
Matthews, David Ralph
Anthropology

subject:
Social structure
Cultural anthropology
Anthropology
Social and Cultural Anthropology
Anthropology

abstract: The conventional study of social change had tended to perceive the values, attitudes, and cultural institutions of non-Western peoples as "obstacles" to the "rational" organization of society. Policy makers, "modernizing" states and "development" agencies have sought to create institutions which would supposedly diffuse values needed to promote rationality. Though this Modernist position has been severely criticized in the last two and a half decades by Dependency, Underdevelopment and Marxist theorists, the critics themselves have not departed from some of the fundamentally Eurocentric premises of Modernism. Despite the recognition of the role played by the historical linkages between the Western Europe, Africa, Asia and Latin America in precipitating the condition described as "underdevelopment", it is taken for granted that the desired goal of "development" is the creation of Western type "advanced" societies. The case of the Bassa indicates the dreams and aspirations of the targets of "development", may differ fundamentally from the agendas of governments and development agencies. People in rural communities like the Bassa have their "development" agenda, an agenda informed by priorities derived from their unique historical experiences. Their case suggests that some of the questions development planners and theorists must start addressing are: What do the people themselves want? What are their dreams? What are their visions of the "good life"? In what context(s) are these aspirations formed? Can these be legislated or thought for them by planners and experts? The Bassa case shows that historical experiences are processed and reconstructed through cultural reference points and go on to inform a community's sense of "Who we are" "What is good for us" and "What we want". As communities transform their consciousness and behaviour patterns, new identities emerge. These identities become the instrument for the bestowal of roles in relation to the definition of their sense of "our problems". For the Bassa, struggling for power with their neighbours has involved reformulating the meaning of being "Bassa" in the late 20th century. Assailing "community-powerlessness" has meant developing new definitions for age-old institutions and reinterpreting the value of formal education. Their story shows culture is not the "iron-caged debris" of bygone ages. Rather, culture is as alive as the human beings who create it and for whom it is a reference point for action. The Bassa experience suggests culture is a dynamic sense of collective history and "group consciousness" which is transformed as new challenges to survival emerge.

abstract: Doctor of Philosophy (PhD)


title: Eosinophils and cytokines in mild asthma and allergen-induced asthma

contributor:
O`Byrne, P.M.
Physiology and Pharmacology

subject: Pharmacology Physiology Pharmacology

abstract: Asthma is a chronic respiratory disease, characterized by variable airflow obstruction, airway hyperresponsiveness and airway inflammation. Prior to starting this thesis, information on the role of inflammatory cells and cytokines in asthma was limited. The aim of this thesis was to determine the roles of eosinophils, an inflammatory cell believed to be important in asthma, and GM-CSF and IL-3, cytokines shown to regulate eosinophils in vitro, in mild and allergen-induced asthma. Fiberoptic bronchoscopy was performed on each subject and blood, bronchoalveolar lavage and bronchial biopsy samples were obtained. In comparison to non-asthmatics, eosinophil number and activity and GM-CSF levels were increased in asthmatics. GM-CSF levels correlated with eosinophil number and activity and airway responsiveness correlated with eosinophil number and activity and GM-CSF levels. IL-3 was detected in both asthmatics and non-asthmatics, with no difference apparent between the groups. These findings indicate that eosinophils, potentially regulated in vivo by GM-CSF, contribute to airway inflammation in mild asthma. In comparison to the control diluent inhalation, allergen inhalation caused increases in eosinophil number and activity and GM-CSF levels. IL-3 levels did not change after allergen. Eosinophil number and activity correlated with GM-CSF and the severity of the late asthmatic response correlated with the number and activity of eosinophils. These findings indicate that an increase in eosinophil number and activity, possibly due to GM-CSF, contributes to allergen-induced asthma. This thesis has demonstrated cellular and cytokine involvement in mild and allergen-induced asthma. For the first time, the presence of GM-CSF and IL-3 cytokines, at the protein level, have been demonstrated in the airways of subjects with mild and allergen-induced asthma. Eosinophils, potentially regulated by GM-CSF, appear to play an important role in the disordered airway function associated with asthma.

abstract: Doctor of Philosophy (PhD)


title: Farmer efficiency: The frontier approach applied to rice farming in Bangladesh

contributor:
Denton, Frank T.
Economics / Economic Policy

subject: Economics Economics

abstract: In this study, we have attempted to empirically assess the efficiency of a sample of Bangladeshi farmers in the civilization of rice, the most important crop in the country. That sample is drawn from Khilghati, a village lying about 95 miles north of the capital city of Dhaka. Our empirical analysis is based on survey data collected by Khandker (1982) for the 1981-82 crop year. The importance of farmer efficiency in Bangladeshi architecture cannot be overstated given the predominance of agriculture in the economy, low crop yields and limited land supplies relative to population. While the adoption of "Green Revolution" technologies involving the use of more production seed varieties and fertilizer inputs are undoubtedly important for increasing yields, and while progress has been made in that direction, attention also needs to be paid to improving the efficiency of farmers within the framework of any technology, be it of the traditional or more modern kind. the data for Khilghati provides an opportunity to examine this question. In particular, we construct indices to assess the efficiency of Khilghati farmers in the cultivation of the traditional, wet-season "Aman" and "Aus" rice crops, and the dry season, new technology "Boro" rice crop. Several efficiency indices are estimated for each crop. Thus, we construct multi-factor indices of technical and allocative efficiency, as well as factor-specific efficiency indices which are indicators of the efficiency of individual factor usage. Technical efficiency refers to the efficiency of factor use in the physical sense and is an attribute of the production function, while allocative efficiency is a cost concept and is associated with the question of whether a firm utilizes inputs in the "right" (that is cost-minimizing) proportions. Technical and allocative efficiency can be modeled and estimated in different ways [Schmidt (1986)]. In this study, given the nature of the data available, the efficiency indices are constructed from deterministic and stochastic Cobb-Douglas production frontiers. In the deterministic case, all departures from the frontier are taken to represent inefficiency, while stochastic frontiers frontiers additionally allow for statistical noise. The estimation of the production frontier generally (though not always) involves assumptions about the distribution of the technical inefficiency term in the deterministic case, and additionally statistical noise in the stochastic case. To examine the sensitivity of the estimates, we consider two alternative assumptions about the technical inefficiency term - one, that it follows a half-normal distribution and two, that it follows an exponential distribution. These distributions imply that technical inefficiency places the firm on or below the deterministic/stochastic frontier. In the stochastic case, we assume that the disturbance term reflecting statistical noise is normally distributed with zero mean and constant variance. The deterministic frontier is estimated by two versions of the corrected least squares (COLS) as well as by linear and quadratic programming techniques, while the stochastic frontier is estimated by the COLS and maximum likelihood methods. The distributional assumptions stated earlier are critical aspects of the estimation strategy, particularly in the stochastic case where they are needed in order to separate technical inefficiency from statistical noise. Our results indicate that the efficiency estimates are somewhat sensitive to estimation method and distributional assumptions, though primarily in the deterministic case. More importantly, we find that the relative ranking of farmers along the technical or allocative efficiency sprectrum is largely independent of estimation method and distributional assumptions under the deterministic and stochastic approaches. The major difference between the two approaches is that, under the latter, the average level of technical efficiency is clearly higher, with statistical noise being an important reason for departures from the deterministic kernel. This points to the importance of allowing for statistical noise. The following discussion deals with estimates obtained from the stochastic frontier, unless noted otherwise. The estimates of technical efficiency suggests that Khilghati farmers are highly efficient in the cultivation of all crops, with at least 70 percent of farmers having a technical efficiency index in excess of 80 percent. Average technical efficiency is about 90 percent in Aman, and about 85 percent in Aus and Boro cultivation. In allocative terms, farmers are markedly less efficient, and the inter-crop variation is also greater. Thus, average allocative efficiency is in the 70-75 percent range for Aman and Boro, but only about 50 percent for Aus. Alternative distributional assumptions have only a minor impact on the allocative efficiency estimates and a somewhat larger impact on the technical efficiency estimates. We used our estimates of technical and allocative efficiency to examine a number of issue. Thus, correlation analysis provides limited evidence to indicate that a farm household's technical (allocative) efficiency indices are related across crops, indicating perhaps that efficient cultivation practices related across crops, indicating perhaps that efficient cultivation practices are crop specific, and that farmers' growing experience and/or learning by doing also vary across crops. We also found little evidence to support the view that technically more efficient farmers are also allocatively more efficient. In addition, we examined the widely held view that better educated farmers are relatively more efficient in the technical and/or allocative senses, in a regression context. Only allocative efficiency in Aman cultivation and technical efficiency in Boro cultivation were found to bear a statistically significant positive relationship with farmer education. Our factor-specific estimates of efficiency suggest that farmers are least efficient, in the physical sense, in the use of labour (the relatively abundant factor), and generally most efficient in the use of land (the relatively scarce factor). The inefficiency of labour usage is substantial; however, the greatest gain (in terms of cost saving) would be realized through the elimination of inefficiency in land or other inputs, and not labour. Several implications follow from our findings. Farmers appear to be as efficient in the new-technology Boro crop as in the traditional Aman and Aus crops. A policy of encouraging the adoption of such HYV crops is thus well-founded. However, attention clearly needs to be paid to improving farmer skills within the existing crops. For instance, rural development policies could be geared to improving allocative skills, perhaps through rural education, and more effective management of extension services and rural co-operatives. our estimates point to a substantial cost saving via such an improvement. Those policies would probably have to take account of possible differences in efficient cultivation practices across crops.Policies aimed at improving the efficiency of highly scarce inputs such as land could also go a long way towards improving the overall efficiency of farmers. In fact, since the relative price of land can be expected to increase over time, the cost reductions by improving the efficiency of land use could be substantial. Finally, it may be that institutional constraints on individual behaviour foster, inefficiency. For example, the lack of access of smaller farmers may lead them to make inefficient choices. Ensuring greater access to those farmers could be important in promoting greater efficiency.

abstract: Doctor of Philosophy (PhD)


title: Eosinophils and bone marrow progenitors in allergen-induced airway hyperresponsiveness in dogs

subject: Pharmacology Physiology Pharmacology

abstract: The pathogenesis of airway hyperresponsiveness, a characteristic feature of asthma, is uncertain. Current evidence suggests a pathogenic role for immature (progenitors) and mature inflammatory cells, particularly eosinophils. The aim of this thesis was to examine the role of eosinophils and bone marrow progenitors in the development of allergen-induced airway hyperresponsiveness in dogs. Random source mongrel dogs demonstrating skin test reactivity to Ascaris suum allergen were studied. Acetylcholine airway responsiveness was measured before and 24 hours after inhalation of Ascaris allergen. For the second and third studies, dogs were pre-treated with inhaled budesonide twice daily for one week prior to allergen challenge. Airway eosinophils were enumerated from bronchoalveolar lavage samples and eosinophil activation was assessed by measurement of eosinophil peroxidase levels in bronchoalveolar lavage fluid. Bone marrow was obtained 24 hours after allergen inhalation with progenitors counted after 8 days in culture. In the first study, dogs that developed airway hyperresponsiveness were found to have a greater number of and more activated airway eosinophils before allergen inhalation than dogs that did not develop airway hyperresponsiveness. In the second study, pre-treatment with inhaled budesonide reduced the number of eosinophils present in the airways before allergen inhalation. This reduction was associated with an attenuation of allergen-induced airway hyperresponsiveness. In the third study, allergen inhalation increased bone marrow progenitor production in dogs that developed allergen-induced airway hyperresponsiveness. Furthermore, the increases in progenitors and airway hyperresponsiveness were reduced by pre-treatment with inhaled budesonide. These results suggest that pre-existing airway eosinophilia influences the development of airway hyperresponsiveness after allergen inhalation. In addition, the results from this thesis provide the first direct evidence that allergen inhalation can increase bone marrow progenitor production and suggest that such increases may contribute to the development of airway hyperresponsiveness in asthma.

abstract: Doctor of Philosophy (PhD)


title: Simultaneous sulfur dioxide absorption and hydrogen sulfide generation in an aqueous solution of sodium sulfide

contributor:
Lu, W-K.
Engineering

subject: Engineering Engineering

abstract: In recovering flue gas desulfurization (FGD) processes, sulfur dioxide is removed from the flue gas and converted into useful products, typically, sulfuric acid, liquid sulfur dioxide or elemental sulfur. For sulfur dioxide producers located far from their customers of sulfur-containing products, elemental sulfur is desirable since it is easy to ship and to store, and is the raw material of many sulfur consuming processes. The existing technologies for elemental sulfur production from sulfur dioxide in flue gas are mainly limited by high capital and operating costs due to the complexity of process. To overcome this limitation, a new process based on aqueous Na$\sb2$S solution has been proposed by Lu and co-workers at McMaster University, in which SO$\sb2$ absorbed by Na$\sb2$S solution lowers the pH of solution and hydrogen sulfide is generated from the acidified solution. For the purpose of converting SO$\sb2$ in the flue gas to H$\sb2$S, and then to elemental sulfur, thermodynamics and kinetics of Na$\sb2$S$\sb{\rm (aq)}$-SO-H$\sb2$S$\sb2$-H$\sb2$S reacting system have been studied, both experimentally and theoretically. Based on experimental and computed results obtained in the present work, it is concluded that aqueous solution of sodium sulfide may be used to absorb sulfur dioxide and to generate hydrogen sulfide simultaneously by acid-base reactions. Recommendation has been made towards further development of this new technology for its commercialization.

abstract: Doctor of Philosophy (PhD)


title: Human embryonic zeta-globin gene expression in mouse-human hybrid erythroid cell lines

contributor:
Chui, David H.K.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Human hemoglobin (Hb) is composed of two pairs of globin chains, each of them contains a heme group. One pair of globin chain is encoded by a gene on the street arm of human chromosome 16 within the α-globin gene cluster and another pair encoded by a gene on the short arm of human chromosome 11 within the β-globin gene cluster. During human embryonic and fetal development, there are orderly changes of Hbs from embryonic to fetal, and later to adult Hbs, which are referred to as hemoglobin switching. These alterations are due to sequential activation of the globin genes in the order of their locations in chromosomes. Embryonic α-globin chains are present in abundance during the first five to six weeks of gestation. Subsequently, ζ-globin chains are supplanted by the expression of α-globin chains (Peschle et al 1985). In infants older than 3 months of age and in normal adults, ζ-globin chains are not detected by sensitive radioimmunoassays. However, exceptions were observed in a subgroup of α-thalassemia-1 carriers with a deletion of two adjacent α-globin genes while the ζ-globin gene in cis to the deletion remains intact, e.g., (--^(SEA)/) α-thalassemia-1. In adult carriers with this --^(SEA) deletion, embryonic ζ-globin chains are persistently present at a low level in their erythrocytes (Chung et al 1984, Chui et al 1986). In order to understand the mechanism leading to ζ-globin gene expression in the adult carriers with the --^(SEA) deletion, we constructed stable mouse-human somatic cell hybrids with APRT deficient murine ertythroleukemia cells bearing human chromosome 16 with either the --^(SEA) deletion or the normal α-globin gene cluster. The results showed that the human ζ-globin gene was constituitively expressed at higher levels in hybrids containing human chromosome 16 with --^(SEA) deletion than that in hybrids with the normal human chromosome 16. These observations indicate that the DNA sequences within the deletion may have a role in regulating ζ-globin gene expression. Moreover, expression of the human ζ-globin gene in cis to the deletion was readily induced by DMSO and HMBA but not butyrate, in parallel with the induction of endogenous mouse α-globin gene expression. These observations are consistent with the hypothesis that ζ-globin gene expression in the adult carriers is linked to the (--^(SRA)) deletional human chromosome 16. The ζ-globin gene in the cis to the --^(SRA) deletion can be activated by adult regulatory factors in the mouse erythroleukemia cells. It is conceivable that the ζ-globin gene is normally suppressed in the adult erythroid cells by the DNA sequences within the --^(SRA) deletion.

abstract: Doctor of Philosophy (PhD)


title: Ineffability Properties of Pkλ

contributor:
Pelletier, D.H.
Mathematics

subject: Mathematics Mathematics

abstract:
We first use some results of Menas to prove that every normal filter on PKλ extends the cub filter on PKλ thereby settling a basic question in the structure theory of filters on PKλ.

Then we investigate ideal-theoretic and other aspects of ineffability properties of PKλ with particular emphasis on those which can be viewed as PKλ generalizations of weak compactness.

In the course of these studies, we came to view mild λ-ineffability as a PKλ generalization of weak compactness in an ideal-theoretically weak sense, and sought a PKλ generalization of weak compactness in an ideal-theoretically stronger sense.

To this end, we define the λ-Shelah property, a new ineffability property of PKλ between mild λ-ineffability and almost λ-ineffability, and prove results which support the contention that this is the property we sought.

These results include characterizations of the λ-Shelah property in terms of a normal ideal on PKλ and if λ K.

abstract: Doctor of Philosophy (PhD)


title: Li Ch 'un-fu and His Discussions of the "Collected Plaints on Tao"

contributor:
Jan, Y.-h.
Religious Studies

subject: Religion Religion

abstract:
This thesis is an analysis of Li Ch'un-fu's ([characters removed]) chief extant work, the Ming-tao-chi shuo ([characters removed] Discussions of the "Collected Plaints on Tao") Two foci have arisen from this book. The first is the defence of Buddhism from Neo-Confucian criticisms. The second is a theory of harmonization of the Three Teachings. Li's involvement with the first earned him the more widely known reputation of being a defender of Buddhism while his contribution to harmonization has often been neglected. Our study has shown that Li's life-work had been harmonization and that the defence of Buddhism should be regarded as an intermediate step towards the identity of the Three Teachings.

The chief accusation of Neo-Confucianists is that Buddhism neglects involvement with worldly affairs, customs and human relationships. Li's reply is that from the point of view of Mahayana, one should not and could not make a distinction between religious practice and worldly affairs, between the Absolute and the phenomenal, between Nirvāna and samsāra. Hence, the Buddhist does not neglect worldly affairs. Then, Li turns around and say that this Buddhist truth is exactly what Confucianism and Taoism teach originally. In order to substantiate his claim, he draws parallels of the main philosophical and cultivational concepts from each tradition. The guiding principles of interpretation of these parallels have often been taken from Buddhism. Among these principles, the most important has been the identity of the Absolute Truth and the worldly truth. Thus, the Mahāyāna teaching of Truth provides the structure on which Li maps out Chinese concepts and from this mapping an identity of the Three Teachings comes into view. Compared to previous theories of harmonization, Li's is the most elaborate and provides a most outstanding example of how an harmonizer attempts to find an intellectual unity among the divergent traditions he has inherited.

abstract: Doctor of Philosophy (PhD)


title: Determination of the Thermodynamic Properties of Rare Earth-Oxygen-Sulfur Systems at High Temperatures

contributor:
Kay, D.A.R.
Metallurgy

subject: Metallurgy Metallurgy

abstract:
The thermodynamics of rare earth-oxygen-sulfur systems was studied at high temperatures using the following four types of oxygen concentration cells.

Type I Cells:

[equation removed]

Type II Cells:

[equation removed]

Type III Cells:

[equation removed]

Type IV Cells:

[equation removed]

Type I and II cells were used to yield the standard free energy changes corresponding to the reaction

[equation removed]

at two different sulfur partial pressures. Type III cells were used to determine the standard free energy changes for the reaction.

[equation removed]

Type IV cells were used to determine the standard free energy changes for the reaction

[equation removed]

Combining the experimental results for the above three-reactions with the values of ΔGfº for Cu₂S and Ag₂S, the standard free energies of formation of La₂O₂SO₄, Pr₂O₂SO₄, Nd₂O₂SO₄, Sm₂O₂SO₄, Eu₂O₂SO₄, Gd₂O₂SO₄, La₂O₂S, Pr₂O₂S, Nd₂O₂S, Sm₂O₂,S, Eu₂O₂S, Gd₂O₂S, Y₂O₂S and Ce₂O₂S were determined at high temperatures. In addition, the standard free energy changes for oxidation of Tb₂O₂S and Dy₂O₂S to Tb₂O₂SO₄ and Dy₂O₂SO₄ were determined.

The above data were used to construct the phase stability diagrams for the rare earth-oxygen-sulfur systems at high temperatures.

abstract: Doctor of Philosophy (PhD)


title: Cu(₁₋y)AgyInS₂(₁₋ᵪ)Se₂ᵪ as a Prototype of the Pentenary Chalcopyrite Semiconductor Systems

contributor:
Garside, B.K.
Physics

subject: Physics Physics

abstract:
The group Ill-V alloy quarternary semiconductors, such as Ga(₁₋y)InyAs(₁₋ᵪ)Pᵪ have been extensively employed in lattice matching different semiconducting layers (at specific bandgaps) to form heterojunction electro-optical devices. However, these cover only a limited set of direct bandgap/lattice constant combinations. The analogous pentenary alloys, consisting of the ternary chalcopyrite groups l-lll-VI₂ and II-IV-V₂, have the potential of similar applications as they cover a even wider band/lattice range. As, a prototype of such alloys, samples the pentenary Cu(₁₋y)AgyInS₂(₁₋ᵪ)Se₂ᵪ have been synthesize and studied.

Samples were prepared by reacting stoichimetric powder mixtures at about 900ºC. X-ray diffractometry tests suggest the compounds maintained complete powder solid solubility throughout the system in the chalcopyrite crystal structure. The intrinsic conductivity type of the alloys appear to follow a trend towards n-type for silver and sulfur rich compounds, while forming p-type for copper and selenium rich materials.

The bandgap of these samples were measured using cathodoluminescence techniques, which generally have some ambiguity in their resulting estimates. To generate better values of the band parameters extensive computer modeling for emission spectra from heavily doped direct bandgap materials was done. The effect of band tails and Gaussian impurity states on the luminescence spectra was studied for changes in doping densities, temperature and carrier injection levels. Formulae were derived from these models to obtain better estimates of the bandgap and impurity activation levels. Algorithms were developed to obtain the impurity spreading energy of a tailed or Gaussian band, and the quasi-Fermi energy levels for injected current in a material with a specific band structure.

Cathodoluminescence measurements were made at 300 and 77 K on the samples. As predicted by the models, it was found easier to generate good estimates from the 300 K results due to the obscuring effects of the impurity bands at cooler temperatures. Using these band estimates least squares fits were made on the data to generate the topological bandgap/lattice constant versus compositional value maps for the studied alloy.

abstract: Doctor of Philosophy (PhD)


title: Adsorption Behaviour of Delta-Manganese Dioxide in Relation to its Use as a Resin in Trace Metal Speciation Studies

contributor:
Kramer, James R.
Snodgrass, William J.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract:
The accuracy of the δ-MnO₂ method in determining Conditional Stability Constants (CSC's) for trace metal - organic complexes depends on the precise modeling of trace metal uptake by δ-MnO₂. Accordingly, characteristics of δ-MnO₂ and its adsorption behaviour for Cu were studied.

Laboratory preparation of δ-MnO₂ is influenced by pH. A neutral redox process and an acid reduction of Mn⁺⁷ yield δ-MnO₂, but an alkaline oxidation of Mn²⁺ does not produce δ-MnO₂. Positive identification of MnOᵪ as δ-MnO₂ includes confirmation of characteristics such as x > 1.9, an adsorption capacity (ɼmax) ≥ 0.25 mol Cu/mol MnO₂, an amorphous XRD pattern, a specific TEM morphology and 1 < pHzpc < 2.

Natural and simulated aging of δ-MnO₂ depends on temperature, pH and K content of the solid, and causes reduction of surface area and adsorption capacity by a factor 1.5 (natural) to 7 (simulated).

Adsorption of trace metals onto δ-MnO₂ is described almost exclusively by a linearized Single Langmuir isotherm in the literature. This study found that Cu adsorption on δ-MnO₂ deviates from Langmuir linearity at low surface coverages. Explanations include the existence of two adsorption sites (Double Langmuir model) and non-constant activity of surface groups. The Implicit Langmuir expression is derived from surface complexation theory to model the latter, and has the form:

[equation removed]

where ɼads (= mol Cu adsorbed/mol MnO₂) and the free Cu²⁺ concentration in solution are measured. r ,B and n are the adsorption parameters. This model predicts the observed deviation from linearity. The bindings energy depends on the pH, the H⁺/Cu²⁺ exchange ratio (n), the surface coverage (ɼads/ɼmax) and a constant B.

Adsorption isotherms were obtained over a pH range of 6 to 8.5, and a Cutotal range of 1 - 40 μM with glycine added to prevent precipitation of Cu. Adsorption results were fitted to Single, Double and Implicit Langmuir models, and compared. The Implicit Langmuir model describes Cu uptake by δ-MnO₂ most accurately, and CSC's for Cu-NTA and Cu-glycine complexes were readily determined using this model.

¹⁴C studies indicated that NTA, glycine and aspartic acid do not adsorb on δ-MnO₂.

abstract: Doctor of Philosophy (PhD)


title: A Comparison of the Effect of Reinforcement, Cost and Mixed Token Programs on the Attending Behaviour and Arithmetic Performance of "Learning Disabled" Children

contributor:
Clarke, C.
Psychology

subject: Psychology Psychology

abstract: Eight children in a classroom for "learning disabled" children were used as subjects in an experiment designed to compare the relative effectiveness of a reinforcement token program, a response cost token program and a mixed token program. The effects of the three token programs were assessed by a within-subject comparison divided into three phases: i) baseline; ii) training; iii) withdrawal of tokens. The eight subjects were separated into a control group of two subjects who received only the mixed procedure throughout the training phase and an experimental composed of six subjects who received a counterbalanced sequence of all three of the conditioning procedures. It was found that, although the token programs as a whole increased the attending behaviour and academic performance of the subjects, there was no difference in effectiveness between the three conditioning procedures. Explanations for the findings were explored by examining the assumptions concerning possible mechanisms underlying reinforcement and punishment.

abstract: Master of Arts (MA)