McGill University Thèses et mémoires publiés en 2000

Spinal adaptive response in the frontal plane was investigated in relationship to pelvic unleveling during gait. Kinematic data were collected from 10 healthy adult subjects (5 male, 5 female) for walking and running on the treadmill at self-selected speeds. Spine and pelvic kinematic patterns and ranges of motion (ROM) were investigated with gender, speed and slope as factors. Speed and slope had the greatest impact on changes in the amplitude of the spine's kinematic patterns. Interaction effects were seen for speed and slope for the ROM, particularly of the greater trochanter (p < .047), PSIS (p < .011) and for …  Lire la suite

This thesis presents a method based on the velocity singularities for the analysis of oscillating airfoils. The method of velocity singularities has been originally developed by Mateescu for the analysis of the steady flows past airfoils. This method makes use of special singularities associated to the leading edge and ridges that directly represent the complex perturbation velocity. Closed form solutions were derived for the pressure distributions and for the aerodynamic forces and moments acting on the oscillating airfoils with or without oscillating ailerons. The solutions obtained with the velocity singularity method for steady flows past airfoils were found to be …  Lire la suite

Defatted soybean was subjected to isolation procedures as follows: NaOH extraction/acid precipitation (NaOH-IE); water extraction/acid precipitation (H2O-IE); NaOH extraction/cryoprecipitation (NaOH-CP) and citric acid extraction/cryoprecipitation (CA-CP). NaOH-CP and CA-CP each resulted in precipitation of one protein mainly consisting of glycinin and beta-conglycinin, respectively. The proteins were subjected to polyacrylamide gel electrophoresis (PAGE), SDS-PAGE, size exclusion-chromatography (SEC) and differential scanning calorimetry (DSC) for characterization. PAGE, SDS-PAGE, SEC and DSC confirmed the homogeneity of NaOH-CP. The gelation properties and structural characteristics of NaOH-CP were investigated; the minimum protein concentration required for formation of a thermally-induced gel from NaOH-CP was 8%. With cold-set gelation, …  Lire la suite

In the present thesis, we study the change in structural properties induced by ion beam irradiation of Ni/Fe and Co/Cu bilayers using various x-ray scattering techniques. These bilayers exhibit interesting GMR and magnetotransport properties. We show that an N-step model is useful in simulating any given electron density profile. We test four different interface profile functions in fitting the reflectivity and conclude that the error-function profile best describes our samples. Different types of interfaces are introduced, namely graded and rough interfaces, together with a discussion of their representation and their effect on both specular reflectivity and non-specular x-ray intensity. We …  Lire la suite

Neuronal networks are specified by unique wiring patterns, however, it is not clear how these patterns are encoded into topographic maps of synaptic connections. We found networks in vitro and in vivo , where multiple-neurites converge and intersect at single sites non-randomly. At these sites, the density and activity of axonal terminals increased exponentially with the number of converging neurites. Multiple-neurite intersections were formed by a directed growth of neurites toward neurite intersections, they facilitated target switching by axons, and their frequency was elevated by activity through NMDA and AMPA glutamate receptors. Thus, clustering and strengthening of synaptic connections by …  Lire la suite

Shifting cultivation is considered to be a key cause of deforestation in the tropics as agriculturalists transform the rain forest into cropland and later allow for its regeneration through fallowing. Forest fallows strongly influence the ecological and economic potential of shifting cultivation, yet, secondary forest management among shifting cultivators remains poorly understood. This study focuses on secondary forest management among peasant households in a land-abundant ejido, near the Calakmul Biosphere Reserve of Mexico. Data were gathered through in-depth household interviews and field visits with 44 households, accounting for more than 450 fields. Striking differences were found in fallowing practices in …  Lire la suite

McGilvray, Jim (Supervisor)  Lire la suite

We describe a general formalism for computing scattering rates of weak probes in macroscopic systems, based on a density matrix formalism. We show that weak probes in general scatter off fluctuations in the medium. In the limit that the neutrino wavelength is much larger than the lengthscale of the fluctuations, we show that the scattering rate can be calculated from knowledge of the equation of state of the medium through which the neutrinos travel. Using radial profiles of a post-bounce, shocked supernova core and a well-established equation of state for nuclear matter we compute these scattering rates for various times …  Lire la suite

Gagnon, Claude (Supervisor)  Lire la suite

A melt extraction process with a new approach to making ceramic fibers was used to produce amorphous fibers in the Y2O3-Al 2O3 system within the 20--30 micron size range. Three different compositions were studied, E1, Y3A5 and E2 with 79, 62.5 and 57.5 mol% Al2O3, respectively. Such fibers were X-ray amorphous and transparent, regardless of composition in the as-produced state, and showed all the principal characteristics of the fibers made by this process: a cross section which is almost circular, a line of contact with the wheel and a clean and defect-free surface. However, the quality of the fibers was …  Lire la suite

The goal of this study is to present the empirical results of a design experiment that validates the Integrated Learning Model (ILM). The study also explores the contribution of multiple Web-tools that facilitate specific learning outcomes. Using a multiple paradigmatic approach that blends the best of both cognitive and situative perspectives in an open-learning constructivist environment, three broad constructs were used to identify variables that influence learning. These constructs include (1) knowledge acquisition strategies ; (2) cognitive tools that support practice and (3) assessment components that capture artifacts of learning. In addition, the ILM uses expertise, pedagogical content knowledge and …  Lire la suite

Enameling steel, used in a vast range of applications, can suffer from a surface defect resembling fish scale. In this study, the effects of several microstructural, physical and coating factors on the hydrogen diffusion in low carbon steel were investigated using an electrochemical permeation apparatus, to find out the way to prevent the surface defects on the enamel coatings. A new mechanism explaining the formation of the surface defects on the enameling steel was proposed after summarizing the experimental results. Then, the effects of porosity, dislocation density, the surface roughness of a steel substrate, oxide passive layer and Pd coating …  Lire la suite

This dissertation deals with Ibn Taymiyya's theory of the unity of God and of creation, or, as Muslim philosophers have posited the question, the relation between the oneness of God and the diversity that has come out of it. Indeed, Ibn Taymiyya (d. 728/1328) responded to the same ontological question that earlier Muslim philosophers were concerned to answer. Although Ibn Taymiyya was a theologian, he did not encounter quite the same questions as the early kalam theologian whose concern it was to prove the existence of God. The dissertation discusses the forms this question took. The introduction reviews Ibn Taymiyya's …  Lire la suite

This study is an exploration of the relationship between spirituality and the career-transition process in middle-aged women's lives. The sample of this study consisted of 20 women who were in or went through a career-transition process. The research data were collected through in-depth interviews. Grounded theory methodology (Strauss & Corbin, 1990) was used to analyse the data and to generate frameworks for the interaction between the career-transition process and spirituality. The results indicated three different frameworks to explain the interaction between the two research variables for three different patterns of career-transition process. These frameworks included five major themes related to …  Lire la suite

The susceptibility of steels to transverse cracking during continuous casting depends, in part, on the hot ductility of the steel. In the past, hot ductility has been measured in the laboratory by tensile testing specimens reheated to a high temperature (preferably melted), and then cooled down to the desired test temperature before isothermally testing to fracture. More recently, isothermal tensile testing has been performed after imposing different thermal histories prior to reaching the test temperature. The most relevant thermal history is that of the solidifying strand surface. Such thermal histories have been found to be quite complex, and invariably involve …  Lire la suite

A need exists for developing a drying technique for heat-sensitive materials as the conventional heat-based drying methods often produce changes in their physico-chemical properties. This thesis presents a non-thermal electrohydrodynamic (EHD) drying technique that may be used to dry both heat-sensitive and viscous materials. A single point-to-plate EHD system was used in de-watering sugar solutions and glycerin-water mixtures having viscosity between 2 and 22 mPa s. The EHD and forced air (2.5 m s-1) each produced 3 to 5 times higher evaporation rate than the control, which was at ambient temperature and relative humidity. The vapor flux decreased considerably and …  Lire la suite

In trying to solve nonlinear partial differential equations with time dependence using the Galerkin method, one ends up with solving nonlinear systems of ordinary differential equations, which are not easily solved. In this thesis we introduce a new iterative method based on eigenfunction expansion to deal with the finite non-linear systems sequentially. We apply the new method to integrate the semi-linear parabolic equation ut=12u+fu ,x∈D with homogeneous Dirichlet or Robin boundary conditions. We prove the convergence of the new iterative method, and use it to find the multiple solutions of the system, which are difficult to obtain using the Galerkin …  Lire la suite

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals are often present together at contaminated sites. These sites are considered difficult to clean-up using bioremediation technologies because of the toxicity of heavy metals to microorganisms. Laboratory experiments were conducted to verify if biodegradation of a model PAH, naphthalene, could be sustained over a long time-period (weeks) in the presence of a common heavy metal contaminant, Cr (VI). Complete reduction of Cr (VI) at concentrations up to 6.3 mg/L was achieved by Pseudomonas putida ATCC 17484 in the presence of naphthalene that was continuously released from an immiscible organic liquid, 2,2,4,4,6,8,8-heptamethylnonane (HMN). The …  Lire la suite

A total of twenty-eight Bacillus spp. isolated from value-added surimi nuggets and their raw ingredients, were tested against each other and selected reference strains of Bacillus and Clostridium for their production of inhibitory substances using the deferred antagonism assay plating method. The isolated Bacillus strains showed inhibitory activity against all Bacillus strains, with the exception of the producer strain, as well as being effective against various strains of C. botulinum (type A, B and E). Subsequent studies showed that the inhibitory activity was detected in the culture supernatant in the late stationary phase of growth prior to sporulation. The inhibitory …  Lire la suite

Shih, I.  Lire la suite

Parallel computing can take many forms. From a user's perspective, it is important to consider the advantages and disadvantages of each methodology. The following project attempts to provide some perspective on the methods of parallel computing and indicate where the tradeoffs lie along the continuum. Problems that are parallelizable enable researchers to maximize the computing resources available for a problem, and thus push the limits of the problems that can be solved. Solving any particular problem in parallel will require some very important design decisions to be made. These decisions may dramatically affect portability, performance, and cost of implementing a …  Lire la suite

This thesis examines the custom of child marriage in Islamic law and its practice in Muslim society. It also gives an overview of the history of child marriage from ancient to modern times. The focus of this research is the status of child marriage in the modern Muslim world as a continuation of ancient tradition and the role historical interpretations of Islamic law play in its perpetuation. Child marriage was once a globally accepted and practiced phenomenon. Over the centuries its practice has diminished considerably. Today, although child marriage is viewed as an offensive act and discouraged by the majority …  Lire la suite

The use of ordinary perturbation theory is ubiquitous in modern physics. However, it violates probability conservation, one of the fundamental laws of physics. In this thesis a unitarized perturbation theory is briefly described and its predictions for the behaviour of a number of simple systems are compared with those of ordinary perturbation theory. It is found that the new technique performs just as well as the usual perturbative approach in the regime where the latter is valid and provides improved results where perturbation theory fails. In particular, in the cases studied, the new method is found to reproduce the exact …  Lire la suite

Kirmayer, Laurence (Supervisor)  Lire la suite

In this thesis, we provide a system level design methodology aimed for the design of embedded systems. Our methodology is geared towards the concurrent design of hardware components and software agents. Our choice of tool/language pair is CoWare N2C design tool and SystemC specification language. Our design flow is completed with a high performance hardware synthesis methodology relying behavioral synthesis. A case study, the design of an ATM switch, is carried out to illustrate the proposed ideas.  Lire la suite

According to Chapter XV of the Chicago Convention, the Joint Financing Aid has been successfully applied in the North Atlantic Region since 1948. The Agreement on the Joint Financing of Certain Air Navigation Services in Iceland, the main topic of this thesis, has ensured the availability of the service and facilities in the Reykjavik Flight Information Region, in accordance with the Standards and recommended practices of the Annexes to the Chicago Convention. The services were at first financed by the participating States, but later on user charges were gradually introduced and, since 1981, they became the principal means of services …  Lire la suite

Gunjal, Kisan R.  Lire la suite

This research program consists of laboratory studies of the corrosion phenomenon and field study of the deterioration due to corrosion of the Dickson Bridge. The laboratory studies examined the influence of increasing levels of corrosion on the progressive deterioration of bond between the steel and concrete and determined the extent to which the various cements and mix proportions influence the corrosion of the reinforcement as well as the chloride ion penetration. The corrosion resistance of the fly ash concrete is examined and compared with that of plain concrete to determine the effects of cement type, w/c ratio, cover thickness, and …  Lire la suite

Heat transfer characteristics under a single turbulent confined slot jet were determined experimentally. New enhancement techniques for the impingement heat transfer rate are proposed and tested experimentally. The results from each enhancement technique are compared with those for a smooth slot nozzle configuration with the same apparatus. The impingement heat transfer rate was observed to increase due to internal finning of the slot nozzles. Both rectangular and triangular fins were tested. The fins acted as roughness elements. Experimental results with the "rough" nozzle show that the stagnation and average heat transfer rates can be enhanced by up to 15% and …  Lire la suite

In the electrophysiological evaluation of neuromuscular disorders, the number of active motor units in a muscle is considered one of the most important indicators of the physiological state of peripheral nerve/muscle systems. Electrophysiological techniques have been designed to estimate this number but, despite considerable effort, they only provide an approximation of the exact number. To assist further development in this field, the specific problem of the classification of stimulus-evoked potentials was investigated. Over 1300 series of signals were recorded from four subjects over a five-week period. From these data sets, those having clearly separable unique responses were selected and unsupervised …  Lire la suite

The importance of fossils to phylogenetic reconstruction is well established. However, analyses of fossil data sets are confounded by problems related to the incomplete nature of the specimens. Taxa that are incompletely known are problematic because of the uncertainty of their placement within a tree, leading to a proliferation of most parsimonious solutions because of wild card behavior. Problematic taxa are commonly deleted based on a priori criteria of completeness. Paradoxically, a taxon's problematic behavior is tree dependent, and levels of completeness are not necessarily associated with problematic behavior. Exclusion of taxa based on completeness eliminates real character conflict and, …  Lire la suite

Although more and more women are present in university, feminist scholars contend that we have been and often still are viewed as "other" in this context. This position of "outsider" can problematize academic discourse for women writers. This qualitative study explores the search for authority as academic writers among twelve re-entry women graduate students. This quest is explored as a social process within the university setting. The study argues that re-entry graduate women encounter the problem of "authority" at several levels: in their experience of self as academics; in their experience of the academic milieu; and in their relation to …  Lire la suite

Signalling the beginning of a new era to international civil aviation, the concept of the CNS/ATM systems came into being as the result of joint efforts of the international community, under the aegis of ICAO, in search for a solution to the limitations of the ground-based air navigation systems, which would otherwise inhibit further development of air transport on a global scale. Employing digital and satellite technologies in support of a seamless air traffic management system, it will bring improvements upon the present levels of safety, efficiency and accuracy, as well as increased capacity and economic benefits. An analysis of …  Lire la suite

The PDQ-39 is a health-related quality of life questionnaire with 39 items describing eight dimensions in Parkinson's disease (PD). The original English version of PDQ-39 showed excellent psychometric properties. The present study was aimed at assessing the construct validity, internal consistency, and test-retest reliability of the PDQ-39 French version as well as the degree of agreement between PD patients and their proxy respondents when completing the scale. One neurologist and two psychologists using standardized clinical scales of PD severity and depression rated 126 PD non-demented patients, attending a neurological clinic. Then, patients and their 110 proxies completed the PDQ-39 and …  Lire la suite

Gavzleski, John (Supervisor)  Lire la suite

In the modeling of piezoelectric vibrators, one of the universally used assumptions is that the exterior electroquasistatic field due to the electric flux leakage through the piezoelectric-air interface can be neglected. This approximation, valid for materials with large dielectric constants, can introduce a significant error in the simulation of piezoelectric crystals whose permittivity is comparable with that of free space. Because models that take into account the electric flux leakage are virtually non-existent, the objective of this thesis is to develop a solution of the three-dimensional piezoelectric problem which is referred to, by analogy with electromagnetics, as electrically unbounded. To …  Lire la suite

Ten trained male track athletes (VO2max = 64.7 ml·kg·min -1) performed three workouts (conditions) with repeated 400-m runs. The intensity and number of repetitions varied among conditions. Condition 1 consisted of two all-out 400-m runs. Condition 2 was 4 x 400-m runs with the first three reps performed 4 s slower than condition 1 and the 4 th rep was all-out. Condition 3 consisted of 8 x 400-m runs with the first seven reps performed 8 s slower than condition 1 and the 8th rep was all-out. Dependent variables were HR, blood lactate and run time for the final rep …  Lire la suite

The present dissertation is a multi-disciplinary project that examines the relationship between human rights and development in Africa, with specific focus on Ghana. The proposition, which is expressed in a theory of community emancipation, is that human rights hold the key to the attainment of sustainable holistic development. The theory of community emancipation represents the Akan notion of rights which speak to the lived experiences (traditional, colonial and post-colonial) of Akan peoples. It is offered as a contribution to the evolution of distinct African notions of rights. The Akan perspective on rights aims at making human rights a more accessible …  Lire la suite

"The goal of this thesis was to develop a framework that could integrate and analyse industry-wide information for the support of on-farm decision-making in dairy-cattle breeding. Specific objectives included (i) describing a dairy breeding information system (DBIS); (ii) examining how the Internet could be exploited to improve the DBIS and its functioning; (iii) describing a process for implementing a unified data model to facilitate integrated user access to information in the DBIS; and (iv) developing software to support decision-making by facilitating access to a unified data model when implemented as a database management software. The first objective was achieved by …  Lire la suite

Forty years (1958-97) of observed and four simulations of Arctic sea-ice concentration (SIC) data are compared to document and better understand Arctic sea-ice variability. The four simulations result from four different forcings, and they are used in an attempt to quantify the relative importance of thermodynamic and dynamic forcings in the Arctic and its peripheral seas. The four runs (A through D) are forced as follows: Run A is forced with monthly varying monthly mean wind stresses and monthly varying climatological air temperatures, Run B is forced monthly varying monthly mean wind stresses and monthly varying monthly mean air temperatures, …  Lire la suite

To facilitate proper recognition of a human's action from a video sequence, several key features must first be determined. Initially, the person performing the action must be isolated from the background scene. This information is then used to decipher pertinent action attributes that may include the center of mass, contours, and regions of motion. It is these characteristics that will become the feature elements in the recognition of a person's actions. This thesis will investigate the various image processing tools available to obtain the aforementioned action attributes. The applicability of filters, background removal techniques, skin-tone matching, and contouring schemes will …  Lire la suite

This thesis deals with the image of the prostitute in four films: Klute (1971) Pretty Baby (1978) McCabe and Mrs. Miller (1972) and American Gigolo (1980). It includes a review of the image of the prostitute in art and literature in the eighteenth and nineteenth centuries. These earlier images are compared and contrasted with the images presented in the four films and used to analyze how women are represented through the role of the prostitute in Klute, Pretty Baby and McCabe and Mrs. Miller. American Gigolo presents male prostitution in a manner conventional to prostitution, but unconventional in terms of …  Lire la suite

The application of haptic devices to surgery simulation presents many exciting opportunities. For example, medical students could practise surgery without using animals and surgeons could evaluate and plan surgical procedures before making a single real incision. An integral component of these surgical simulator systems is haptic feedback. There are many engineering challenges that must be addressed in order to successfully integrate haptics with the environmental characteristics found in surgery. The most fundamental of these challenges is to achieve update rates of solid nonlinear deformable objects that are acceptable to the human haptic system. This thesis presents a software architecture that …  Lire la suite

The continuing advances in silicon integrated circuit technology in accordance with Moore's Law have fueled the constant performance improvement of computing systems. At the same time, the deployment of networks of workstations with high-speed processors has driven the need to increase bandwidth capacities in networked environments. Electrical interconnect technologies are plagued by substantial physical problems at high frequencies, that limit their data transmission capacities. With increasing clock rates, high-bandwidth computing and communication architectures become more difficult to implement using electrical interconnects, and therefore creates a strong motivation for exploring both free-space and fiber-based optical interconnect technologies. In this thesis, the …  Lire la suite

First, the set of G-representations of a finitely generated group is described. This set of functions endowed with the compact-open topology will be used to prove some results in combinatorial group theory. Then we will see that the set of SL2( C )-representations may be viewed as an algebraic set. This new structure will allow some more applications in group theory. Finally, we will describe the set of characters of a finitely generated group and we will show that the set of characters associated to SL2( C )-representations also inherits an algebraic set structure.  Lire la suite

Chaoborus americanus larvae were used in laboratory experiments to assess their efficiency at decreasing mosquito larval populations. Third and fourth instar Chaoborus americanus larvae were independently fed assemblages of single prey species to test hunger and several prey species to test preference. Prey species included Daphnia and the four Aedes aegypti larval instars. The results show that Chaoborus americanus larvae will choose early instar mosquito larvae over Daphnia, however, this preference decreases as the mosquito larvae become older. Third instar Chaoborus americanus larvae will choose first instar mosquito larvae over Daphnia 76% of the time, whereas they will select third …  Lire la suite

Using mandibular 2-Implant overdentures is an alternative therapy for edentulous patients. Several studies have been conducted to evaluate the efficacy of this treatment modality compared to conventional dentures. However, most of these studies have emphasized the evaluation of the clinical aspects of the prostheses or did not use standardized specific patient based-outcomes. Therefore, the main objectives of this research was to investigate the effect of using mandibular 2-implant supported prostheses and conventional dentures on oral health related quality of life, using a randomised controlled clinical trial design. The secondary objectives were to assess the factors that explained patients' satisfaction with …  Lire la suite

Wonsley, Keith (Supervisor)  Lire la suite

Experiments were conducted in 1997, 1998 and 1999 to determine the effects of mulch/mini-tunnel and thermal-water tube combinations on daily carbon dioxide (CO2) concentration, air, soil temperatures and early growth of muskmelons (var. Earligold) during the vegetative phase. Treatments consisted of mulched plot covered with a clear perforated, a clear non-perforated or a non-perforated infrared polyethylene mini-tunnel with the absence or the presence of a thermal-water tube compared with control treatments. Additional treatments consisting of the ventilation non-perforated clear and infrared tunnels containing no tube were used in 1998 and 1999. The non-perforated tunnels significantly increased CO2 concentrations, air and …  Lire la suite

Ingram, Grant (Supervisor)  Lire la suite