Cette thèse présente une analyse approfondie et comparative des résultats de mesures µ-XRD et µ-XAS sur des combustibles UO2 standard, dopé au sesquioxyde de chrome (Cr2O3) et MOX, irradiés ou non. Elle présente également l'interprétation des résultats en regard des effets induits par le chrome en tant que dopant ainsi que par la présence de plusieurs produits de fission. Les paramètres de maille de l’UO2 et les paramètres de densité d'énergie de déformation élastique dans les matériaux irradiés ou non ont été mesurés et quantifiés. Les données de µ-XRD ont en outre permis l'évaluation de la taille des domaines cristallins, ainsi que l’étude de la formation de sous-grains à différentes positions au sein des pastilles de combustibles irradiés. Le paramètre de maille et l'environnement atomique local du chrome dans des précipités d’oxyde de chrome présents dans les pastilles de combustible non-irradié ont également été déterminés. La structure locale du Cr dans la matrice du combustible dopé et l'influence de l'irradiation sur l'état du chrome dans la matrice de combustible ont été étudiées. Enfin, pour une comparaison du comportement des gaz de fission et du phénomène de re-solution induite par l'irradiation dans l’UO2 standard ou dopé, la dernière partie de ce travail propose une tentative d'analyse de l’environnement atomique du Kr dans ces deux combustibles irradiés. Le travail effectué par micro-faisceau XAS sur ce gaz de fission a permis la détermination des distances du Kr avec ses proches voisins, une estimation des densités atomiques des gaz de fission dans les agrégats et des pressions internes apparentes dans ces nano-phases de gaz inertes. / This thesis work reports in depth analyses of measured µ-XRD and µ-XAS data from standard UO2, chromia (Cr2O3) doped UO2 and MOX fuels, and interpretation of the results considering the role of chromium as a dopant as well as several fission product elements. The lattice parameters of UO2 in fresh and irradiated samples and elastic strain energy densities in the irradiated UO2 samples have been measured and quantified. The µ-XRD patterns have further allowed the evaluation of the crystalline domain size and sub-grain formation at different locations of the irradiated fuel pellets. Attempts have been made to determine lattice parameter and next neighbor atomic environment in chromia-precipitates found in fresh chromia-doped fuel pellets. The local structure around Cr in as-fabricated chromia-doped UO2 matrix and the influence of irradiation on the state of chromium in irradiated fuel matrix have been addressed. Finally, for a comparative understanding of fission gases behavior and irradiation induced re-solution phenomenon in standard and chromia-doped UO2, the last part of the present work tries to clarify the fission gas Kr atomic environment in these irradiated fuels. The work performed on Kr, by micro-beam XAS, comprises the determination of Kr next neighbor distances, an estimation of gas atom densities in the aggregates, and apparent internal pressures in the gas bubbles.

A study was conducted to evaluate the properties and processes influencing the rate and magnitude of volume decrease and strength gain for oil sand fine tailings resulting from a change in bitumen extraction process (caustic versus non-caustic) and the effect of adding a coagulant to caustic fine tailings. Laboratory flume deposition tests were carried out with the objective to hydraulically deposit oil sand tailings and compare the effects of extraction processes on the nature of beach deposits in terms of geometry, particle size distribution, and density. A good correlation exists between flume deposition tests results using oil sand tailings and the various other tailings materials. These comparisons show the reliability and effectiveness of flume deposition tests in terms of establishing general relationships and can serve as a guide to predict beach slopes. Fine tailings were collected from the various flume tests and a comprehensive description of physical and chemical characteristics of the different fine tailings was carried out. The characteristics of the fine tailings is presented in terms of index properties, mineralogy, specific surface area, water chemistry, liquid limits, particle size distribution and structure. The influence of these fundamental properties on the compressibility, hydraulic conductivity and shear strength properties of the fine tailings was assessed. Fourteen two meter and one meter high standpipe tests were instrumented to monitor the rate and magnitude of self-weight consolidation of the different fine tailings materials. Consolidation tests using slurry consolidometers were carried out to determine consolidation properties, namely compressibility and hydraulic conductivity, as well as the effect of adding a coagulant (calcium sulphate [CaSO4]) to caustic fine tailings. The thixotropic strength of the fine tailings was examined by measuring shear strength over time using a vane shear apparatus. A difference in water chemistry during bitumen extraction was concluded to be the cause of substantial differences in particle size distributions and degree of dispersion of the comparable caustic and non-caustic fine tailings. The degree of dispersion was consistent with predictions for dispersed clays established by the sodium adsorption ratio (SAR) values for these materials. The biggest advantage of non-caustic fine tailings and treating caustic fine tailings with coagulant is an increased initial settlement rate and slightly increased hydraulic conductivity at higher void ratios. Thereafter, compressibility and hydraulic conductivity are governed by effective stress. The chemical characteristics of fine tailings (water chemistry, degree of dispersion) do not have a significant impact on their compressibility behaviour and have only a small influence at high void ratio (low effective stress). Fine tailings from a caustic based extraction process had relatively higher shear strengths than comparable non-caustic fine tailings at equivalent void ratios. However, shear strength differences were small and the overall impact on consolidation behaviour, which also depends on compressibility and hydraulic conductivity, is not expected to be significant.

This thesis brings together for the first time, in an organised account, Saskatchewans search for a pulp industry. This thesis will show that, in a fundamental tension between goals of fiscal prudence and of economic growth, fiscal prudence won out again and again, to the point that the CCF governments could be characterised as risk-averse where pulp production was concerned. The cautious approach is in contradiction both to the activist reputation of the CCF governments and to their aggressive development of other resources, notably mining. Pulp offers an example of the contradictions that plagued the CCF governments and their policies for the north, contradictions that included disagreements between moderates and radicals over the roles of public and multinational enterprise, colonial attitudes towards the north, and risk aversion despite bold rhetoric and announcements.<p>The methodology used in this thesis has generally maintained an economic policy and political discourse, and incorporates mostly a top-down governmental approach. The personal papers of Tommy Douglas and Woodrow Lloyd provided CCF government correspondence and departmental memos that included premiers, ministers, deputy ministers, and departmental directors involved with the Department of Natural Resources, the Timber Board, the Industrial Development Office, and the Economic Advisory and Planning Board, and with pulp company officials. Furthermore, pulp reports, surveys, and studies helped contextualise all of the interrelated correspondences. To supplement government discourse I utilised the Prince Albert Daily Herald to gain an understanding of what issues the public was debating and found to be most important.

This thesis brings together for the first time, in an organised account, Saskatchewans search for a pulp industry. This thesis will show that, in a fundamental tension between goals of fiscal prudence and of economic growth, fiscal prudence won out again and again, to the point that the CCF governments could be characterised as risk-averse where pulp production was concerned. The cautious approach is in contradiction both to the activist reputation of the CCF governments and to their aggressive development of other resources, notably mining. Pulp offers an example of the contradictions that plagued the CCF governments and their policies for the north, contradictions that included disagreements between moderates and radicals over the roles of public and multinational enterprise, colonial attitudes towards the north, and risk aversion despite bold rhetoric and announcements.<p>The methodology used in this thesis has generally maintained an economic policy and political discourse, and incorporates mostly a top-down governmental approach. The personal papers of Tommy Douglas and Woodrow Lloyd provided CCF government correspondence and departmental memos that included premiers, ministers, deputy ministers, and departmental directors involved with the Department of Natural Resources, the Timber Board, the Industrial Development Office, and the Economic Advisory and Planning Board, and with pulp company officials. Furthermore, pulp reports, surveys, and studies helped contextualise all of the interrelated correspondences. To supplement government discourse I utilised the Prince Albert Daily Herald to gain an understanding of what issues the public was debating and found to be most important.

No description available.

La presente tesis doctoral tiene como propósito el estudio del fenómeno sociopragmático llamado atenuación retórica (hedging en inglés) en dos géneros distintos del discurso médico escrito: los artículos de investigación científica y los informes de caso o casos médicos. Con este fin se examina un corpus de ambos géneros escritos en español y en inglés (L2) por científicos españoles y publicados en revistas científicas de prestigio en el campo de la biomedicina . Se comparan los resultados obtenidos del análisis del corpus con los obtenidos por otros autores con muestras lingüísticas escritas en inglés. El trabajo, pues, consiste en un análisis interlingüístico e intergenérico de la atenuación retórica en el discurso médico. Un interés particular que presenta la tesis reside en las aplicaciones pedagógicas que tiene para los profesores de enseñanza de idiomas con fines específicos (LFE). / La present tesi doctoral té com a objectiu l'estudi del fenòmen sociopragmàtic anomenat atenuació retòrica (hedging en anglès) en dos gèneres diferents del discurs mèdic escrit: els articles d' investigació científica i els informes de cas o casos mèdics. Amb aquesta finalitat s' examina un corpus en ambdós gèneres escrits en espanyol i en anglès (L2) per cientifics espanyols i publicats en revistes científiques de prestigi en el camp de la biomedicina . Es comparen els resultats obtinguts de l'anàlisis del corpus amb els obtinguts per altres autors amb mostres lingüístiques escrites en anglès. El treball, doncs, consisteix en una anàlisi interlingüística i intergenèrica de la atenuació retòrica en el discurs mèdic. Un interès particular que presenta la tesis resideix en les aplicacions pedagògiques que té pels professors d' ensenyament d' idiomes per a finalitats específiques (LFE). / This PhD aims at studying the sociopragmatic phenomenon called hedging in two different genres of the written medical discourse: the research article and the case report. Therefore, a corpus of these two genres is examined both in Spanish and in English (L2). Being all texts written by Spanish scientists and published in scientific journals of prestige in the biomedical field . The results obtained in the corpus analysis are then compared to the ones obtained by other authors with similar linguistic samples written in English. This thesis, hence, consists of itergeneric and interlinguistic analyses of hedging in medical disourse. A special interest of this research project may lay in the pedagogical applications for teachers of languages for specific purposes (LSP).

The impact of the law on the lives of homeless people in Queensland has, to date, remained largely unexplored by legal academics and researchers. This is despite the fact that homeless people experience a number of legal difficulties that seriously affect their lives. This thesis by published papers aims to make a significant and original contribution to filling this gap in the research evidence by presenting the results of analyses of the legal, theoretical and practical issues that arise in the context of homeless persons' interactions with the legal system in Queensland. Most notably, it is comprised of three pieces of empirical research which identify those areas of law that impact most on homeless people in Queensland and explore the consequences of the operation of these laws on their lives. In sum, this thesis examines the extent of the law's influence on the lives of homeless people in Queensland, and finds that the consequences of the law's operation on homeless people in Queensland are serious. The thesis first examines the effect on Queensland's homeless people of laws which regulate behaviour conducted in public space. The criminal offences of vagrancy, begging and public nuisance are analysed; their historical origins, the reasons for their retention on modern statute books, and arguments in favour of their repeal are discussed. The impact of 'public space law' on homeless people in Queensland is also explored through a survey of 30 homeless people residing in inner-city Brisbane. This part of the thesis concludes that public space law in Queensland results in breaches of homeless persons' human rights, as well as the contravention of rule of law principles. The thesis then explores the impact of the law on homeless persons' experiences of citizenship. Empirical research and theoretical analysis demonstrate that the application of various laws, particularly public space laws, social security laws and electoral laws, encroaches on homeless persons' citizenship rights. The thesis then reports on the results of a unique survey of Queensland's homelessness service providers. This survey is the most extensive piece of empirical research ever conducted on the extent to which various laws impact on homeless people. Respondents were asked to indicate which areas of law impact most adversely on their homeless clients. Based on the research findings outlined above, the hypothesis was that criminal law issues, particularly public space offences, would be proven to impact particularly adversely on homeless people in Queensland. Somewhat unexpectedly, the findings of the survey indicated that fines law, debt law and family law difficulties are those legal difficulties most often encountered by homeless people in Queensland. Difficulties produced by criminal laws, social security laws and electoral laws, while still generally relevant, rated less highly. However, the survey did demonstrate that experiences differ between sub-groups within the homeless population, for example Indigenous homeless people were reported to be most affected by criminal law issues, while young homeless people were reported to be most affected by social security law issues. Together, the five papers which comprise this thesis make an original and substantial contribution to knowledge by identifying empirically for the first time the various laws that have a significant impact on the lives of homeless people in Queensland, and analysing the consequences of this in terms of their effect on homeless persons' citizenship rights, human rights and rule of law entitlements.

Les matériaux constitutifs des digues sont souvent des sables silteux dont le comportement mécanique peut manifester une « instabilité » à des états de contraintes situés bien avant la limite de plasticité de Mohr-Coulomb. Ce mécanisme de rupture pourrait expliquer plusieurs brèches dont l'occurrence n'a pas été attribuée aux mécanismes classiques de rupture de digues telle que l'érosion interne. L'objectif de cette thèse est de mieux comprendre, au regard de ce phénomène d'instabilité, le comportement mécanique d'un sable silteux provenant de la zone adjacente à une brèche de digue du Rhône lors de la crue de 2003, à l'aide d'essais triaxiaux.Les résultats sur le sable propre montrent que le matériau étudié est très sensible au phénomène d'instabilité. Ce dernier peut être prédit par une courbe d'instabilité reliant, au déclenchement de l'instabilité, le rapport des contraintes au paramètre d'état. L'analyse de ces résultats suggère qu'une forte contractance du matériau est la condition nécessaire pour que l'instabilité du sable lâche ait lieu et qu'une direction appropriée du vecteur d'incrément de contraintes est la condition suffisante.Les résultats sur les mélanges constitués du sable avec des fines montrent qu'un départ de fines, causé par exemple une érosion de type suffusion, favorise l'occurrence de l'instabilité dans les digues. Par ailleurs, ces résultats révèlent que l'indice des vides équivalent est un paramètre pertinent dans l'analyse du comportement du sable silteux. Le calcul de l'indice des vides équivalent nécessite la détermination du paramètre b pour lequel une nouvelle formule a été proposée. / The constitutive materials of dikes are often silty sands whose mechanical behavior can become unstable at stress states located well under the Mohr-Coulomb plasticity limit criterion. This failure mechanism could explain several dike breaches whose occurrence has not been assigned to conventional mechanisms of dike failure such as internal erosion. The objective of this thesis is to better understand, with respect to the instability phenomenon, the mechanical behavior of a silty sand which is collected in the area adjacent of a breach of the Rhone embankment dike during the flood of 2003, by means of triaxial tests.The test results obtained on clean sand show that this material is very sensitive to the instability phenomenon. The occurrence of the latter can be predicted by an instability curve relating, at the onset of instability, the stress ratio to the state parameter. The analysis of these results suggests that a strong contractiveness of the material is the necessary condition for instability of loose sand and an appropriate direction of stress increment vector is the sufficient condition.The test results obtained on mixtures of sand with fines show that a removal of fine particles caused by an erosion, such as suffusion for example, favors the occurrence of instability in the dikes. Moreover, these results indicate that the equivalent void ratio is a relevant parameter in analyzing the behavior of silty sand. The calculation of the equivalent void ratio requires the determination of the parameter b for which a new formula has been proposed.

Le travail illustré par ce manuscrit de thèse présente l'étude structurale d'hétéro-structures semi-conductrices à base de nitrures d'éléments III avec l'un des outils les plus puissants de la recherche scientifique: le rayonnement synchrotron. La cartographie haute résolution de l'espace réciproque, la diffraction anomale multi-longueur d'onde, la spectroscopie d'absorption X et la spectroscopie en condition de diffraction nous ont permis de caractériser la structure à l'échelle atomique de différentes régions d'un même système. Dans un premier temps, nous montrons que les nanofils GaN sur Si(111) ont une polarité N et proposons un mécanisme de nucléation. Dans un second temps, nous mettons en évidence un phénomène d'inter-diffusion stimulée par la contrainte dans les boîtes quantiques GaN / AlN recuites à haute température. Enfin, nous observons la présence d'un ordre local à courte distance dans les nanofils coeur-coquille InGaN / GaN. Cette organisation atomique pourrait être induite par la présence de contrainte, nous avons initié une étude de l'anisotropie de l'ordre à courte distance pour explorer cette hypothèse. / The work presented in this manuscript deals with the structural investigation of III-nitrides semiconductor heterostructures with one of the most powerful tools of materials science: the synchrotron radiation. We used high resolution reciprocal space mapping, multi-wavelenght anomalous diffraction, x-rays absorption spectroscopy and diffraction anomalous fine structure to characterize the structure at the atomic scale of complex nano-structured systems. First, we show that GaN nanowires on Si(111) are N-polar and we suggest a nucleation mecanism. Then, we highlight a strain assited inter-diffusion phenomenon in the GaN / AlN quantum dots annealed at high temperature. Finally, we observe the presence of short-range order in InGaN / GaN core-shell nanowires. This atomic organization could be induced by the presence of stress and we have begun a study of the anisotropic ordering to explore this hypothesis.

Ces travaux de recherche portent sur le développement d'un système original de fusion de données de diffusion électromagnétique et optique par des milieux denses et complexes. La méthode, à la fois théorique, numérique et expérimentale, permet la fusion des signatures de diffusion hyperspectrales, polarimétriques et angulaires d'un milieu d'étude. Un système expérimental multi-capteurs comprenant une source laser supercontinuum est présenté pour mesurer les signatures de diffusion de différentes cibles. Des modèles directs de simulation physique ont aussi été développés via : (i) une approche dite « top-down » qui modélise les signatures à partir de paramètres macroscopiques (ex. rugosité, indices optiques effectifs) ou (ii) une approche dite « bottom-up » qui modélise les signatures à partir de paramètres microscopiques (ex. distribution en taille, géométrie, concentration, indices optiques et structuration des diffuseurs) en résolvant soit l'équation de transfert radiatif ou directement les équations de Maxwell. Des méthodes inverses appliquées sur les signatures mesurées sont développées pour retrouver simultanément les paramètres d’intérêt du milieu analysé. Les avancées de ces travaux permettent une amélioration de la compréhension des phénomènes de diffusion électromagnétiques et optiques par des milieux denses et complexes tels que les surfaces rugueuses, les revêtements, les nanomatériaux, les suspensions colloïdales ou les agrégats fractals d'aérosols ultrafins. Les domaines d'applications de ces travaux sont l'aéronautique (ex. peintures d'aéronefs), l'imagerie aéroportée ou satellite (ex. imagerie active hyperspectrale ou polarimétrique), la sécurité et la défense (ex. matériaux pour la furtivité) ou bien les sciences de l'atmosphère (ex. systèmes LiDAR, suivi de pollution, suies), l'industrie chimique (ex. suspensions colloïdales) ou le biomédical (ex. diagnostic de tumeurs et mélanomes). / This work reports the development of an original data fusion system dedicated to electromagnetic and light scattering by dense and complex media. The dissertation encompasses the theoretical, numerical and experimental studies. The output of the data fusion system is a fused hyperspectral, polarimetric and angular scattering signature. An experimental multi-sensor and supercontinuum laser-based system is presented to measure the scattering signatures for various targets. Direct physical simulation models were developed using a two-level modelling scheme: (i) a top-down approach is used to model signatures from macro-physical parameters, e.g. the surface roughness or the effective refractive index and, (ii) a bottom-up approach is used to model signatures from microphysical parameters, e.g. the size distribution, the geometry, the concentration, the refractive index and the structuration of the scatterers, by solving the radiative transfer equation or directly the Maxwell's equations. Inversion schemes are deployed to retrieve these parameters by inverting the experimental signatures. The advancements described throughout this dissertation will serve to improve understanding of electromagnetic and light scattering by dense and complex media such as rough surfaces, coatings, nanomaterials, colloidal suspension and fractal aggregates of ultrafine aerosols. This study has relevant applications in fields as diverse as aeronautics (e.g. aircraft paint coatings), remote-sensing (e.g. hyperspectral, polarimetric, active or passive imaging), security and defense (e.g. furtive materials), atmospheric science (e.g. black carbon or soot characterization, LiDAR systems), chemical engineering (e.g. colloidal suspensions), or biomedical (e.g. tumor and melanoma diagnostic).