McGill University Thèses et mémoires par auteur commençant par R

In order to elucidate the propagation mechanism of detonations, the failure mechanism of detonations propagating in tubes with porous walls is investigated experimentally. Two distinct failure mechanisms were identified depending on the type of detonating mixture. Experiments in mixtures characterized by piecewise laminar reaction zone structures with weak three-dimensional effects revealed that the attenuation and failure is caused by the global mass divergence to the porous, permeable walls. The limits observed in these mixtures agreed very well with the theoretical limiting conditions for the existence of curved ZND detonations subjected to lateral expansions. Experiments were also conducted in a second …  Read more

Initiation of detonation in the cylindrical geometry is important in validating a general theory of initiation, and has particular significance to the interaction of high velocity projectiles with combustible gas. In the present study, an experimental investigation of the direct initiation of gaseous detonations by a line source of condensed explosives (detonating cord) is presented. Due to the high velocity of detonation in the condensed explosive cord (6--7 km/s), the rapid chemical energy release along its length generates a quasi-cylindrical blast wave in the surrounding combustible mixture. For a sufficiently strong detonating cord, the generated blast wave is observed to …  Read more

Most Romanian national heroes lived while the Ottoman Empire dominated the Balkans. History bears witness to their doings, yet certain figures have become almost mythical thanks to the powerful impact of the nationalistic literature. Mihai Eminescu, the Romanian national poet par excellence, whose writings were merely tolerated by the Communists, exerted a strong influence despite his passionate involvement and he managed to create historical confusion lasting for generations. After 1989, Romanian history books changed. In my thesis, I seek to modify the myth of invincible Romanian heroes and to understand the reason why Romanian principalities enjoyed a special treatment during …  Read more

La corrosion du cuivre dans les tours de refroidissement, potentiellement accentuée par une chimie agressive de l’eau ou une activité microbienne, entraîne des inefficacités opérationnelles et des risques environnementaux. Bien que les inhibiteurs à base d’azoles comme la benzotriazole (BTA) et la tolyltriazole (TTA) soient efficaces, leur faible biodégradabilité et leur toxicité aquatique soulèvent des préoccupations en matière de durabilité. Cependant, peu d’études ont évalué des alternatives plus écologiques dans des conditions représentatives des tours de refroidissement. Ce mémoire évalue des composés organiques biodégradables, sans phosphate et à faible toxicité comme candidats potentiels pour inhiber la corrosion du cuivre thermiquement …  Read more

The beginning of the twentieth century in Russia, especially the years around 1905, was a period of deep, severe economical and political crisis. It was heightened by the lost war against Japan in 1904-1905 and the violent social disturbances of 1904-1907. It was also a period of great social, political and ideological upheaval. Efforts were made to save and preserve the economical, social and political system, to reform it, to change it profoundly as well as to overthrow it through revolution. Those years can be described as a turning point in Russia's history, an era of struggle about the future …  Read more

The political rhetoric and theory of Abdullah Öcalan (What I call Apocular thought, after the early name for the group which would one day become the PKK) has influenced millions of people across the middle east and the Kurdish diaspora to support his organization, the Kurdistan Worker’s Party (PKK). PKK militants have conducted a guerilla war on-and-off against the Turkish republic from 1984 to present, with their Syrian branch, the PYD, controlling significant territory in northern Syria since the start of the Syrian civil war. Despite its influence, this branch of political theory remains understudied in the English-speaking world. This …  Read more

Engle-Warnick, James (Supervisor2)  Read more

Effects of growth environment (E) on carbon isotope discrimination (Delta), water-use efficiency (WUE), leaf movement (LM) and nutrition of bush bean were examined. Environments in greenhouse (GR), open air (E0), perforated (E1) and non-perforated (E2) plastic covers in combination with well-watered (W0), moderately-watered (W 1), and water-stressed (W2) plants were used. Soil water content (WC), E, and E x WC interaction significantly affected Delta, WUE, dry matter (DM) and water use. WUE, photosynthetic rate, and leaf nitrogen increased; while Delta, DM, and transpiration decreased with water stress in GR, and E0. WUE in E2 either decreased or remained almost constant …  Read more

An isoenzyme survey of several taxa within the genus Lotus was undertaken to provide markers for genetic research and to test hypotheses concerning the phylogenetic origin of Lotus corniculatus L. A preliminary study identified seven enzyme systems PGI, TPI, PGM, MDH, IDH, 6-PGDH and ME, that produced consistent clear phenotypes in L. uliginosus Schkuhr. Variation in phenotype with tissue type and stage of development suggested the presence of several isozyme zones in the phenotypes. Enzyme phenotype was constant for shoot tissue of plants older than six weeks. A second study examined recombination and segregation of isoenzyme phenotypes in interspecific hybrids, …  Read more

Attempts to design a novel mannosylation were carried, unsuccessfully, on in situ generated 3,4,6-tri-O-benzyl-$ beta$-D-mannose-1,2-sulfite, and on 3,4,6-tri-O-benzyl-$ beta$-D-mannose-1,2-carbonate, with sequential treatments with bromotrimethylsilane and with glycosyl acceptors in the presence of a base. Trials were then conducted on Lewis acid catalysed mannosylations with the two above compounds, and the use of the in situ generated 3,4,6-tri-O-benzyl-$ beta$-D-mannose-1,2-sulfite with a mixture of chlorotrimethylsilane and zinc triflate in glycosylating simple alcohols was successfully demonstrated. However this activation was insufficient to build disaccharides using 1,3,4,6-tetra-O-benzyl-$ alpha$-D-manno-pyranose, methyl-2,3,4-tri-O-benzyl-$ alpha$-D-glucopyranoside and methyl-2,3,6-tri-O-benzyl-$ alpha$-D-glucopyranoside as acceptors. A mannosylating agent, namely 2-O-acetyl-3,4,6-tri-O-benzyl-$ alpha$-D-mannopyranosyl trichloacetimidate, designed for …  Read more

La génération des nombreux types de cellules qui sont spécifiés pendant le développement requiert un nombre étonnement petit de signalisations cellulaires, cela implique qu’un même signal peut avoir deux issues différentes selon le contexte. Nous utilisons l’épithélium folliculaire de l’ovaire de la Drosophile comme modèle. Dans ce tissu, l’activation localisée du récepteur du facteur de croissance épidermique (EGFR) mène à deux issues différentes selon le moment et la localisation du signal. Dans les premières phases de l’ovogenèse, l’activation de l’EGFR dans le domaine postérieur induit l’expression des facteurs de transcription Midline (Mid) et H15. Ensuite, EGFR est activé dans le …  Read more

Les machines thermoacoustiques convertissent l’énergie mécanique présente dans des ondes acoustiques stationnaires en chaleur pompée, ou vice-versa. Le rendement des machines thermoacoustiques produites à ce jour est limité en raison de pertes thermiques associées à différents mécanismes. Entre autre, les écoulements moyens redressés produits par des phénomènes physiques non linéaires résultant des interactions entre l’empilement et les ondes stationnaires produisent des échanges de chaleur importants. Le but de la présente étude était de quantifier ces échanges de chaleur dans des résonateurs acoustiques sans obstacles, et obstrués en partie par des plaques orientées dans la direction de l’écoulement, simulant des plaques …  Read more

La plupart des structures en béton qui existent aujourd'hui ont été construites il y a plus de 50 ans. Ces structures, en particulier les ponts sont soumis à différents processus de détérioration. À Montréal, les ponts sont principalement exposés aux sels de déglaçage durant l'hiver. Les sels de déglaçage sont l'une des principales sources de corrosion dans les armatures d'acier qui sont incorporés dans le béton. La corrosion provoque de graves dommages aux ponts et ces dommages requièrent des ressources important les réparer ou remplacer les ponts.. L'objectif principal de cette thèse est d'optimiser la modélisation de la pénétration des …  Read more

The societal burden of autoimmune diseases and donor organ transplant rejection in developed countries reflects the lack of effective immune suppressive drugs. The main objective of my thesis was to develop novel fusion proteins targeting receptors linked to autoimmunity; strategies that will allow the suppression of autoreactive cells while sparing resting lymphocytes. Interleukin (IL) 15 has been demonstrated to exert its effects mainly on activated T-cells triggered via their T-cell receptor (TCR). Since we found that the fusion of granulocyte-macrophage colony stimulating factor (GMCSF) to IL15 - aka GIFT15 - paradoxically leads to aberrant signalling downstream of the IL15R and …  Read more

Le forage et le dynamitage sont deux tâches principales dans les mines à ciel ouvert. A l'heure ou l'industrie minière s'automatise et augmente l'efficacité de sa production, une surveillance efficace de l'état des forages est essentielle. La condition du bit affecte de manière significative les performances de forage, et par conséquent le cout total d'exploitation. Déterminer le temps nécessaire pour changer le bit est une question difficile. Une panne de bit au cours de l'opération à la suite d'une usure progressive entrainera des couts ultérieurs pour la société minière. Ainsi, la présente étude développe une nouvelle approche pour surveiller l’état …  Read more

In Victorian England George Eliot “must needs occupy a central place. Probably no English writer of the time, and certainly no novelist, more fully epitomizes the century.” Many, including William Hale White and Lord Acton, have considered her the greatest Victorian. G. M. Young makes the reason for such tributes clear. George Eliot was, he says, “a light to thousands who had learnt from her that, in the darkness deepening over all ancient faiths, the star of duty shone clearer than ever. Grave and wise men thought that George Eliot had, single-handed, by her ethical teaching, saved us from the …  Read more

The exploration and discontinuity of Melville's early life are reflected in his writing career. Before settling into silent conventionality, he wrote remarkably diverse prose. His aesthetics were individualistic: the page was an arena in which to deploy experimental strategies. The novels from Typee to Moby-Dick can be regarded as action of mind as it explores ways of seeing and describing reality. But these experiments proved that vision is inevitably guided by the well-stocked mind and that Nature is an everchanging subjective construct. In Pierre, The Piazza Tales, and The Confidence-Man--the fiction that immediately followed these discoveries--the action is externalized. Melville …  Read more

Les particules d’aérosols sont omniprésentes dans l’atmosphère et contribuentactuellement à une grande incertitude dans les modèles climatiques. Une partiedes efforts pour réduire cette incertitude consiste à améliorer notre compréhensiondes aérosols au niveau microphysique, ce qui permet ainsi aux processus chimiqueset physiques d’être représentés plus précisément dans les modèles à plus grandeéchelle. En plus des efforts de modélisation, nous sommes amenés á développerde nouveaux instruments et méthodologies pour interroger les propriétés physicochimiquesdes aérosols. Ce travail présente le développement et l’application d’unnouvel outil puissant pour étudier les particules d’aérosols uniques: le piège optiqueà double faisceau. Comme son nom l’indique, le piège utilise …  Read more

Spatialization as a compositional parameter in multi-speaker environments opens many new opportunities in music research while simultaneously highlighting several important questions. How can space be used as an effective compositional tool? On a technical level, in which manner will the spatialization be implemented in a space? How would one capture an acoustic space in a recording that would emulate an environment accurately? How can we reimagine a performance space to enhance the experience of contemporary music? These were the questions driving the composition 'structured cell'. The piece was written for 10 performers, a 22.2 speaker dome surrounding the musicians performed …  Read more

Since the end of the Cold War, the central puzzle of alliance theory is no longer why or how do alliances form, but (1) why do some alliances persist beyond the conditions in which they were created and (2) of these, why do some evolve in new directions ? Traditional realist scholarship cannot account for the persistence or evolution of military alliances when threats recede. This dissertation devises a model of alliance institutionalization and norm formation to explain and predict these processes. When multidimensional threats exist, states facing a common threat ally, but they formalize and institutionalize the alliance so …  Read more

Introduction: The use of wearable technology for ambulatory physiological monitoring has become increasingly popular in recent years. However, only about five percent of these wearable devices have been formally validated in healthy adults, let alone in people with chronic obstructive pulmonary disease (COPD). Objectives: To assess (a) the validity of the Hexoskin biometric smart shirt for measuring cardiopulmonary parameters at rest and during exercise in people with COPD and (b) the responsiveness of the Hexoskin biometric smart shirt to detect changes in minute ventilation (V’E), tidal volume (VT), respiratory rate (RR), heart rate (HR), inspiratory capacity (IC) and inspiratory reserve …  Read more

The addition of frother in flotation has two main functions, to help reduce bubble size and help produce a stable froth. A role of frother on bubble behavior in pulp zone is usually not considered. A previous study showed that as frother type was changed the same gas holdup was given by different size bubbles. This implies that bubble rise velocity depends on the nature of the surfactant (frother type). A study using bubble swarms appears to support the frother type effect but bubble interactions are a possible confounding factor. This study resolved the question by measuring terminal rise velocity …  Read more

Le cancer de la prostate est une des formes les plus répandues de cancer et la cinquième cause de décès liés au cancer chez les hommes dans le monde entier. La morbidité et la mortalité associée au cancer de la prostate peuvent souvent être attribués aux conséquences de la propagation métastatique des cellules cancéreuses à des organes éloignés, le plus souvent les os. Suite à la métastase, les options thérapeutiques, ne sont que modérément efficaces. Malgré des recherches intensives pour comprendre les métastases osseuses, cette maladie complexe reste incurable. Les études présentées dans cette thèse cherchent à clarifier les mécanismes …  Read more

The survival of breast cancer patients declines when tumors are invasive and have an increased possibility of metastasizing to distal sites. Transforming Growth Factor-beta (TGF-beta) suppresses breast cancer formation by preventing cell cycle progression in mammary epithelial cells. However, at late stage of mammary carcinogenesis, due to genetic and epigenetic alterations, TGF-beta loses its cytostatic actions, and contributes to tumor invasion by promoting cell proliferation, Actin cytoskeletal reorganization, as well as Epithelial to Mesenchymal Transition (EMT). Despite the key role of TGF-beta1 in tumor suppression as well as tumor progression, the molecular mechanisms underlying the conversion of TGF-beta form an …  Read more

L'ADN et les polypeptides sont tous deux des polymères naturels à séquence définie qui jouent un rôle essentiel dans l'existence et la propagation de la vie. Leurs rôles diversifiés en biologie sont déterminés par la nature de leurs éléments constitutifs. L'ADN repose sur l'appariement de deux paires de bases nucléiques complémentaires et sert principalement à stocker et à transmettre l'information génétique, tandis que les polypeptides utilisent une multitude d'interactions non covalentes issues de leurs vingt acides aminés constitutifs possibles et forment des assemblages hiérarchiques d'ordre supérieur – les protéines – qui sous-tendent la structure et la fonction des organismes vivants. …  Read more

The plasma and urinary corticosteroids, haemoglobin, blood urea nitrogen and plasma creatinine were determined in CF1 female mice before, during and after exposure to -10°C. Plasma corticosterone levels increased significantly soon after exposure, remained significantly elevated even in comatose animals and tor an hour during recovery in the warmth, and returned to normal levels a day after the stress. The pattern of change was similar in mice exposed twice, though the deviations from the control levels were less. Urinary corticosteroids were depressed the first day following each exposure, and more so following the second one, with the values tending to …  Read more

The injection molding process, due to its versatility, cost effectiveness, and ability to produce precise complex articles is widely used in plastics processing. Mold cavity pressure is a good indicator of the processes taking place in the cavity and plays an important role in determining the quality of the molded articles. The dynamic modeling and control of cavity pressure, based on a physically-based approach, is studied in this research project. The work deals with the filling and packing phases. A lumped physically-based model was developed in order to study the behavior of the system. The model is derived from conservation …  Read more

AbstractThe language of the film screen is ubiquitous. Hollywood’s wide release feature films, like The Godfather (1972) or Wonder Woman ( 2017), are experienced by millions of people all over the world. However, before a movie makes it on screen, it has to make it as a screenplay, the blue print of a movie. With films costing 10’s of millions of dollars to produce, it helps to have the best blueprint possible. Increasingly, computers are capable of linguistic analysis at scale. “It is the work of humanities scholars to trace patterns in language, in narratives, in art, and other cultural …  Read more

This thesis treats some of the problems related to the good drawings D$ sb{ rm n}$ of the complete graph K$ sb{ rm n}$. The first of these problems is obtaining all the non-isomorphic good drawings D$ sb{ rm n}$ of K$ sb{ rm n}$. After conjecturing that any good drawing D$ sb{ rm n}$ of K$ sb{ rm n}$ has at least one crossing-free Hamiltonian Circuit, an algorithm generating all the non-isomorphic good drawings D$ sb{ rm n}$ of K$ sb{ rm n}$ is developed. The second problem, determining the existence of a rectilinear drawing D$ sb{ rm n}$ …  Read more

A large demand for bandwidth, both for voice and data communication, has increased the need for high-speed systems. Specifically, a wireless revolution is establishing renewed standards and design requirements, such as higher operation frequencies and higher levels of integration. The improved performance of traditional technologies, such as CMOS, which used to be geared towards digital circuits running at lower frequencies, makes them now suitable for Radio-Frequency applications. The challenge is not only to design RF systems, but also to establish design methodologies for their building-blocks. This thesis is concerned with one of those building blocks, namely the low noise amplifier, …  Read more

The case study examines the process of change undergone by the McGill Institute for Learning in Retirement (McGill ILR), a volunteered organization. ILRs have emerged across North America in the past 15 years and their success is attributed to the congenial participatory learning environment and the fact that members volunteer to administer the program activities in collaboration with a host university. Four years after it was founded, leaders sensed the need to evaluate McGill ILR's strengths and weaknesses. Under the aegis of McGill Centre for Continuing Education, a Planning Committee designed and implemented an organizational self-assessment to provide recommendations for …  Read more

Springback is a phenomenon that occurs when nonhomogeneous elastic and plastic deformation occurs throughout a component during forming processes. Since the elastic deformation is recovered when the forming load is removed, geometrical changes occur. Springback is particularly important in sheet forming; therefore, in order to provide formed parts of close tolerances it is essential to first have a good understanding of the factors which affect springback and to be able to determine the extent those factors have. It is also important to be able to predict springback under different conditions so that it can either be minimized or properly accounted …  Read more

A numerical study is carried out to predict 3-D fluid flow and heat transfer of confined turbulent single and twin slot jets in the presence of a crossflow. The low Reynolds number k-$ sigma$ turbulence (Launder and Sharma (17)) model was used to calculate the Reynolds stress and the turbulent heat flux. In the present work the following cases were studied: (1) Case I considers an impingement surface heated by a single turbulent slot jet. (2) Case II considers an impingement surface cooled by twin turbulent slot jets. In the latter case the buoyancy effect has been taken into consideration …  Read more

A three-dimensional mathematical model for the simulation of vertical direct chill (DC) slab casting of aluminum alloys has been developed. The model is based on the solution of the 3D time-averaged turbulent momentum (Navier-Stokes) and energy equations. The momentum equations are modified with a Darcy-type source term to simulate motion of the melt in the mushy region. The buoyancy force term is implemented in the model through the Boussinesq approximation. The low Reynolds number k-ε turbulence model of Launder and Sharma is used to calculate the Reynolds stresses and the turbulent heat fluxes. A variable heat transfer coefficient is used …  Read more

Wallis, Faith (Supervisor2)  Read more

This thesis attempts to analyse the problem of national integration in the Sudan. The study presents an analysis of the Addis Ababa Agreement (1972), which had facilitated the cessation of a civil war that had lasted for seventeen years. In spite of its ultimate breakdown, theAgreement illustrated the premise that the north-south conflict in the Sudan was not completely without a solution. This study examines the extent to which economic development of the south and the promise of equal access to the scarce resources of the state formed substitute arrangements for 'national integration' in the sense of creating a homogenous …  Read more

Oligodendrocytes, the cells that produce and maintain myelin in the central nervous system (CNS), express several muscarinic acetylcholine (ACh) receptor (mAChR) subtypes. Carbachol (CCh), a stable analogue of ACh, stimulates various intracellular signals through mAChRs, including p42-mitogen-activated protein kinase (p42mapk) activation and c-fos gene expression. The present study examined the mAChR subtype(s) and the signaling pathway(s) involved in both responses using purified cultures of oligodendrocyte progenitors from newborn rats. The M3 mAChR selective antagonist 4-DAMP and its irreversible analogue 4-DAMP-mustard, but not pirenzepine (M1) or methoctramine (M2/M4), prevented p42mapk activation and c-fos mRNA expression. Pretreatment with a phospholipase C (PLC) …  Read more

The importance of removing the epicardium for myocardial revascularization was recognized by Beck in 1935. Beek and Tichy (1935) recommended removal of the epicardium irrespective of the graft or material used, be it talc powder, pericardium, pericardial fat, mediastinal tissue, pleura, etc. Beck believed that the epicardium was a barrier to the development of extra-coronary vessels. Further, he stated that a pressure differential was necessary to promote anastomoses between the cardiac and extra-cardiac vascular beds.  Read more

The past half-decade has seen progress in methodology and reusable components available to designers of music authoring tools. This thesis examines currently prevalent architectures for music making software and applies currently available technical means to update design methodology and architectural patterns for the next-generation of tools. It aims to map the various categories of advances and the manner in which they relate to each other, to the problem of building these tools. The focus is on conceptualization. The thesis aims to understand, from historical perspectives, as well as from perspectives provided by other domains, the fundamental problems encountered in the …  Read more

In Part I we investigate the thermodynamic consistency problem and a closure for the Ornstein-Zernike relation. A thermodynamically consistent closure is deduced from the grand canonical ensemble theory. When applied to a hard sphere fluid, the closure yields analytic expressions for the equation of state and the excess chemical potential, which turn out to be identical with those of the scaled particle theory as well as those calculated via the compressibility route in the Percus-Yevick theory. In Part II we study the bulk viscosity etab of simple liquids and the shear viscosities eta of simple and molecular liquids, respectively. We …  Read more

Cette recherche avait comme objectif de déterminer si des expositions répétées à un auditoire virtuel (réalité virtuelle) pouvait désensibiliser des musiciens souffrant d'anxiété de performance à jouer devant un auditoire réel. Seize étudiants en musique de niveau universitaire ont participé à la recherche. Ils ont participé à deux concerts devant des auditoires réels, à titre de prétest et de postest. Chaque participant fut assigné soit au groupe de contrôle ou au groupe exposé à l'auditoire virtuel. Les étudiants exposés à la réalité virtuelle ont joué une fois semaine pour un total de cinq sessions durant lesquelles les fréquences cardiaques et …  Read more

International school counsellors struggle with developing a coherent School Counselling Professional Identity (SCPI) (Alvarez et al., 2013; Foxx et al., 2016), through which professionals understand their roles and make professional decisions (Remley & Herlihy, 2014). Much of the SCPI research (e.g., Darcy & Al-Faghri, 2013; Heled & Davidovitch, 2020; Woo et al., 2017) has focused on professional components in School Counselling (SC) that crystallize SCPI, overlooking sociocultural impact on SC knowledge, students’ needs, and a school counsellor’s personal identity. Foucault (1977; 1978/1990) asserts that individuals’ identities and educational and mental health disciplines are shaped by historical-cultural contexts and power gaps …  Read more

Mouse bone marrow was shown to contain a population of null lymphocytes which lack molecular markers of both B and T lineages ($ mu sp-,$ B220$ sp-,$ Thyl$ sp-).$ Null cells represent 12-14% of all bone marrow small lymphocytes. Studies on population dynamics have revealed that these null cells turnover rapidly with a production rate almost 1/3 as great as that of B lymphocytes. Some newly-formed null lymphocytes express natural killer (NK) cell-associated markers, including NK1.1. Some small lymphocytes in the bone marrow express low intensities of Thyl. These Thyl$ sp{ rm lo}$ cells are also rapidly renewing and some …  Read more

Agus Sasmito (Supervisor1)  Read more

DNA is the molecule that encodes our genetic information. DNA nanotechnology is the field that uses the information given by DNA to build materials in the nanoscale. Through Watson-Crick base pairing, a wide range of DNA-based geometrical motifs self-assemble into programmable and well-defined one-, two- and three-dimensional nanostructures. The remarkable accuracy provided by DNA had an impressive impact on the field of nanotechnology and has been utilized by biologists, chemists, physicists and engineers. However, the generation of higher-order DNA nanostructures remains challenging and often requires hundreds of DNA strands. This thesis tackles this limitation using three approaches. (i) In the …  Read more