McGill University Thèses et mémoires publiés en 1988

In the vicinity of the point of minimum critical shear of a quasi-geostrophic two-level model on the $ beta$-plane, the weakly nonlinear dynamics of developing baroclinic vortices can be described in terms of a nonlinear critical layer problem which, in the inviscid case, can be solved analytically. When the supercritical shear $ delta$ is such that 0 $<$ $ delta$ $ ll$ 1 and the initial conditions are sufficiently small, finite amplitude equilibration occurs even though the potential vorticity field in the bottom layer Q(X,Y,t) remains transient, the potential enstrophy being transferred to smaller and smaller scales. It is shown …  Read more

Seventy-five workers exposed to styrene in four reinforced plastics plants in the Montreal area have taken part in this study. All subjects were tested for peripheral nervous system functioning during a period of continuous exposure; 12 were re-evaluated after a lay-off period without exposure. During the period of continuous exposure, a dose-response relationship between the environmental exposure and the sensory nerve conduction velocity (NCV) was demonstrated. Almost all workers exposed for at least one month to levels of styrene above 100 ppm had a nerve conduction deficit. The effects observed were not related to cumulated exposure. After a period of …  Read more

This dissertation addresses the issue of cost subadditivity of two Canadian telecommunications carriers, Bell Canada and Alberta Government Telephones (AGT). Multi-output, multi-input models of the production structure of Bell Canada and AGT are estimated under various alternative hypotheses. Subadditivity tests are conducted for both these companies in order to increase understanding of the issues concerning the deregulation of the Canadian telecommunications network and to assist policy makers in their decisions. The hypothesis that both Bell Canada and AGT are natural monopolies cannot be rejected. Important cost savings are realized from having each of these firms alone in their respective markets …  Read more

A nonlinear wave equation invariant with respect to unitary representations of the Lorentz group is considered in an attempt to describe extended particles with spin and positive definite energy by means of a self-confined classical field. The wave function has an infinite number of components and, in the specific representations used, the corresponding internal degree of freedom is identified with the spin. A fractional power of the scalar bilinear invariant appears as an appropriate choice for the nonlinearity in order that all the stationary states be localized. Two approximation methods are proposed and both lead to results that bear a …  Read more

The effect of planting date on yield was studied in Parana State, Brazil where five tropical hybrids of maize were planted at 14 planting dates over three growing seasons at five locations. Soil water holding characteristics and meteorological variables were measured at each location. The water release curve for each soil was determined, using a power function. Corn heat units were calculated and used to measure the phenological development of each hybrid. This information, along with meteorological data, was used in a mathematical model to simulate plant growth over each growing period. Meteorological data from 1976 to 1986 were employed …  Read more

Glycosyl transferases in membranes or tissue slices from growing regions of etiolated Pisum sativum seedlings transferred [14C]-glucose from either UDP-glucose or GDP-glucose to endogenous acceptors to form products that were partIy water-soluble and insoluble. The products that contained l,4-beta-linked glucose readily dissolved in dimethyl sulfoxide-paraformaldehyde and fractionated on controlled pore glass bead columns. The average size of the products synthesized from UDP-glucose ranged from the fractionation equivalent of dextrans with molecular weights between 40K and 100K, white the products synthesized from GDP-glucose ranged from 1K to 40K. The latter were not precursors for glucomannan biosynthesis when GDP-mannose was included in …  Read more

This thesis presents an extensive study of the kinematics of parallel manipulators. The latter are considered here as a subset of a more general class of kinematic chains called complex kinematic chains which are defined as chains in which there exists at least one link having a degree of connectivity greater than or equal to three. The degree of connectivity of a link is defined here as the number of rigid bodies that are directly attached to this link by kinematic pairs. The first portion of the thesis is devoted to the study of simple kinematic chains which are the …  Read more

In this study, it was shown that improvements in the quality of continuously cast steel billets, similar to those which can be achieved by electromagnetic stirring (EMS) of the liquid pool during solidification, can be obtained if casting superheats can be consistently controlled at low levels. A lack of casting temperature control is not only detrimental to the quality of the cast product, but also to a shop's overall productivity. The important variables for temperature control in the ladle, tundish and mould were quantified and possible methods of controlling these variables were proposed. The thermal state of the ladle lining …  Read more

"Seven measures of nutritive value were determined for 11 plant species browsed by deer in the Hill Head yard (Québec). Diet quality was monitored throughout winter from periodic browse surveys and fecal analyses. Digestibility varied most among species, while gross energy was the most constant. Red maple, sugar maple and striped maple had the highest digestibility values. Lignin content and digestibility were the most commonly used variables to link browse species on a nutritive basis. amount of energy available in the Throughout winter, the diet was below the threshold required to maintain body weight. The high proportion of lignin in …  Read more

Using a barotropic model, some aspects of the theory of multiple equilibria were investigated, namely, the genesis of multiple equilibria via bent resonance, and the properties of some of the linearly unstable low index solutions. These studies were conducted using numerical models with a truncated spectral representation of the dependent variables, truncation that was determined in terms of its capacity to allow for nonlinear interactions. By means of a continuation algorithm, the stationary solutions of the potential vorticity equation were calculated for a number of regions of parameter space, allowing us to study the dependence of the steady solutions on …  Read more

This thesis focuses upon the algorithms of the so-called conservative methodology for distributed discrete-event simulation. In the first approach, a network of fully distributed processes, and severely restricted memory are assumed. In this environment, a look-ahead, deadlock-breaking algorithm called Pseudosimulation, is developed. A lower bound on memory requirements for distributed simulation is established. In the second approach, a scenario where several processes are mapped to the same processor is investigated. The Time-of-Next-Event algorithm, created for this purpose, computes the greatest lower bound of time stamps of the events to arrive at all empty inter-process links located in the same processor. …  Read more

The present work is divided in two parts: the first part contains analysis of some writings from Feria d'agosto among which "Il nome", narration that opens the series in the book, has retained our particular attention and its analysis brings us to discover "classic" origins not yet identified by critics. "Il nome" is the key to finding out about the essence of Pavese's poetics. In the second part we approach the Croce-Pavese's affinities. The relation arises from Pavese's controversial writing on Proust. We also give an idea of reviews which reflected various tendencies of the Arts during the 20th century. …  Read more

We have studied spontaneous mutations in a chromosomally-located, single copy HSV-1 thymidine kinase (TK) gene in a human AK 143 TK$ sp-$ cell line. We have used three anti HSV-1 thymidine kinase nucleotide analogues, namely Trifluorothymidine (TFT), Acyclovir (ACV) and DHPG (9-(1,3-dihydroxy-2-propoxy-methyl)guanine), to select for $TK sp-$ mutants. The spontaneous mutation rate for the TK gene was very high in this system. The mutation frequency was 5 $ times$ 10$ sp{-3}$ per cell per generation when Acyclovir (ACV) was used as a selective agent and 5 $ times$ 10$ sp{-4}$ per cell per generation when Trifluorothymidine (TFT) was used. The …  Read more

The effect of CO$ sb2$ on sympathetic preganglionic neuron (SPN) activity and hindlimb neurogenic vascular resistance (HVR) was investigated in cats. Both variables increased as continuous functions of systemic arterial PCO$ sb2$, from hypocapnia to hypercapnia. Eucapnic PCO$ sb2$ was responsible for a significant component of SPN background activity and HVR. The carotid body chemoreceptors were shown to contribute to the CO$ sb2$ response of SPNs, since section of the carotid sinus nerves, after prior section of the aortic nerves, reduced the CO$ sb2$ response of SPNs. A significant ventral medullary contribution to this CO$ sb2$ relationship was demonstrated, since …  Read more

The aim of this study was to develop norms for the Movement Assessment of Infants (MAI) and to investigate the concurrent validity of this measure. Sixty-three full-term, low-risk, four-month-old infants were tested according to the MAI, the Bayley Motor Scale and the Wolanski Motor Development Scale. Infants were scored according to the four-month Risk Profile (RP) of the MAI and the Study Population Profile (SPP) which was developed from the behaviours of the infants on the MAI. Risk scores of the infants on the RP were significantly higher than risk scores on the SPP. This difference was attributed to the …  Read more

This thesis is an investigation of the place and function of repentance in the theology of Paul as determined by the critical application of the categories "getting-in" and staying-in" to the passages where the term is used and to passages where the concept may be implied. It contains an exegesis of those passages and an analysis of Paul's conversion experience. Consideration is also given to the implications this study has for other areas of New Testament study. The main theses are that repentance was used by Paul in a variety of ways and played a more important role for him …  Read more

Habermas rejects a class-specific approach to social analysis and political practice and, in renewing the social theory of Marx, he turns primarily to a reconstruction of the work of Max Weber. The conceptualization of society is approached from the interrelated themes of rationalization, bureaucratization and reification. But Habermas seeks to overcome the instrumentalist implications of Weber's one-sided view of rationalization and related rejection of a cognitivist ethics by an expanded framework of rationality that introduces the concept of communicative action and, with it, the promise of clarifying the normative foundations of a critical theory of society. Against contrary views of …  Read more

This research concerns the alternate melting and freezing of a phase change material (PCM) to simulate cyclic operation of phase change energy storage systems. A one-dimensional conduction-controlled phase change model was derived for a PCM slab. One surface of the slab is subjected to successive periods of constant temperature above and below the fusion temperature while the other surface is adiabatic. A front-tracking, self-marching finite-difference scheme was developed to solve the resulting multiple moving boundary problem. Temperature fields within each solid and liquid region were decoupled with an explicit treatment of the interfacial energy balances. Temperatures at all grid points …  Read more

The objective of this study was to determine whether formal, primary education could increase the level of ethnicity in children. One hundred Jewish children completing grade 6, and their parents, were measured on a series of instruments designed to evaluate their level of ethnic identity. Half the children had received their full education in private, parochial schools, while the other half had attended public, secular schools. The two samples were further sub-divided so that each sample consisted of 25 children of Ashkenazi descent and 25 of Sephardi descent. The data were subjected to a multivariate analysis of covariance wherein the …  Read more

The reaction of a series of 1,1-disubstituted-1-silacyclo-3-pentenes with butyllithium reagents was studied. This reaction depends critically on the substituent at silicon. 1,1-Dimethyl- or 1,1-diphenyl-1-silacyclo-3-pentene has the propensity to undergo anionic polymerization whereas 1,1-bis(4-tert-butylphenyl)-1-silacyclo-3-pentene was metalated cleanly to give the anion derived from proton abstraction on the cyclopentenyl ring. The regioselectivity of the reaction of the silacyclopentenyl anion with electrophiles was examined and found to be influenced by the steric size of the electrophile. Small electrophiles favor $ alpha$-selection while larger ones show slight $ gamma$-preference. The regiochemistry of reactions of $ alpha$-silylallyl lithium with alkyl halides can be controlled with …  Read more

Direct lympho-stromal interactions constitutes an intrinsic part of T-cell differentiation. However the precise role of cellular complexes is far from clear. The objective of the present work was to gain an insight into this question. An in vitro model was previously developed in the laboratory, which detects the adherence of thymocytes to a thymic stromal cell line, E-5. Using this model, we describe here a novel lympho-stromal interaction involving L3T4$ sp+$/Ly-2$ sp+$ "cortical type" thymocytes and medullary epithelial cell. These adherent thymocytes appear at day 16 of murine gestation and their number vary during ontogenesis and leukemogenesis. After contact with …  Read more

This thesis analyzes and tests some new solution techniques for the optimal power flow problem. This new methodology exploits a parametric technique, called the continuation method, which is applied to different tasks in the solution procedure. In a first application, the continuation method solves the quadratic subproblems generated sequentially by the optimal power flow's nonlinear program. It first creates a simple subproblem, which is easy to solve, and then links it to the subproblem we wish to solve. Starting at the solution of the simple problem, it generates optimal solution trajectories for the intermediate problems, leading to the desired optimal …  Read more

Cette thèse étudie des méthodes expérimentales de détermination des coefficients de diffraction, en tant qu'outils pour la théorie géométrique de la diffraction (TGD). Un système original de mesure des micro-ondes en bande X a été conçu, construit et employé pour mesurer le champ diffuse par des objets physiques, dans le but d'étudier la diffraction des champs. Le système est capable de mesurer le champ ponctuel à n'importe de quel point à l'intérieur d'un volume de 1m3 . L’emploi du problème du demi-plan conducteur comme référence nous permet de· démontrer que dans certains cas I l'on peut extraire les composants diffractés …  Read more

Testing VLSI circuits is a complex task that requires enormous amounts of resources. To decrease testing costs, testing issues are considered earlier in the design process. This is known as "design for testability" (DFT). Built-in Self Test (BIST) is one proposed DFT approach. BIST generally consists of incorporating additional circuitry on the chip to generate test patterns and compact the response of the circuit under test (CUT) into a reference signature. Compaction implies an information loss, introducing the possibility that a faulty circuit declares itself as good. Such errors are known as aliasing errors. Several BIST schemes have been proposed, …  Read more