Canada is a predominantly urbanized and urbanizing country, with consistent expansion in recent decades in its major cities‘ populations and geographic size. Major cities have been advancing claims for, or have already been granted by their provincial governments, greater autonomy in the responsibilities assigned to them under provincial legislation. Urban municipalities‘ legislative frameworks are gradually becoming more permissive, making urban governments and governance structures a highly relevant topic, particularly given the trend of amalgamation that occurred in some major cities in the 1990s which significantly altered municipal governance structures. The Halifax Regional Municipality (HRM), amalgamated in 1996, has commenced a mandatory Governance and District Boundary Review Process to be completed by the end of 2010. The thesis develops a necessarily flexible set of criteria of good democratic governance for the municipal level through consulting the literature on urban governance in Canada and the trends that characterize the experience and consequences of municipal restructuring, particularly amalgamation. A case study of the HRM‘s unique context and governance structure challenges results in the following reform recommendations: should the HRM seek greater effectiveness in decision making and clearer lines of accountability, regional council should be significantly reduced in size, community councils should be granted greater formal authority to set rates and make decisions beyond land-use issues, and the formal executive power of the office of the mayor should be significantly strengthened.

<p>The novel method of this thesis work is based on using quadrature filters to estimate an orientation tensor and to use the advantage of tensor information to control 3D adaptive filters. The adaptive filters are applied to enhance the Magnetic Resonance Angiography (MRA) images. The tubular structures are extracted from the volume dataset by using the quadrature filters. The idea of developing adaptive filtering in this thesis work is to enhance the volume dataset and suppress the image noise. Then the output of the adaptive filtering can be a clean dataset for segmentation of blood vessel structures to get appropriate volume visualization.</p><p>The local tensors are used to create the control tensor which is used to control adaptive filters. By evaluation of the tensor eigenvalues combination, the local structures like tubular structures and stenosis structures are extracted from the dataset. The method has been evaluated with synthetic objects, which are vessel models (for segmentation), and onion like synthetic object (for enhancement). The experimental results are shown on clinical images to validate the proposed method as well.</p>

There is a well-known connection between the structure and dynamics that is present in molecular and colloidal systems. Using this connection as a guide we are able to design interparticle potentials that optimizes the diffusivity of a single particle. While structure-dynamic correlations provide the insight that diffusion could be enhanced, the effect of this enhancement on the dynamics of neighboring particles is more difficult to quantify. A novel method for calculating position-dependent dynamics is introduced that can be easily implemented into existing simulation protocols. The computational requirements are very low compared to existing methods and this technique can also be applied to a wide variety of systems, including experiments where particle trajectories can be determined. Using this method, the position-dependent diffusivity of solvent particles in the vicinity of a tracer particle can be measured. This information allows for determination of the microscopic changes that take place as a result of the optimization discussed above. To study the effect of a non-continuum solvent, we design a system that eliminates inhomogeneous structuring near an interface. Hydrodynamic theory can predict the position-dependent diffusivity of a sphere in continuum solvent. Comparing these systems not only highlights the difference in position-dependent dynamics for continuum and non-continuum solvents, but is a starting point to study what happens to dynamics when structure is reintroduced. This allows us to answer many other questions about the relationships between structure and dynamics. While these connections have been studied extensively for average properties, they have not been explored for their position-dependent counterparts. For bulk fluids, the insertion probability and two-body excess entropy has proven useful for predicting average dynamic properties. We develop expressions for the position-dependent versions of both of these quantities. We show that when using the appropriate reference state the position-dependent diffusivity can be qualitatively related to the insertion probability. / text

The novel method of this thesis work is based on using quadrature filters to estimate an orientation tensor and to use the advantage of tensor information to control 3D adaptive filters. The adaptive filters are applied to enhance the Magnetic Resonance Angiography (MRA) images. The tubular structures are extracted from the volume dataset by using the quadrature filters. The idea of developing adaptive filtering in this thesis work is to enhance the volume dataset and suppress the image noise. Then the output of the adaptive filtering can be a clean dataset for segmentation of blood vessel structures to get appropriate volume visualization. The local tensors are used to create the control tensor which is used to control adaptive filters. By evaluation of the tensor eigenvalues combination, the local structures like tubular structures and stenosis structures are extracted from the dataset. The method has been evaluated with synthetic objects, which are vessel models (for segmentation), and onion like synthetic object (for enhancement). The experimental results are shown on clinical images to validate the proposed method as well.

The simple cubic ReO₃-type framework has all of the key features required for negative thermal expansion (NTE) arising from the transverse thermal motion of bridging atoms and rotation of rigid polyhedra. Although ReO₃ itself only displays low NTE below ambient temperature, there is a potentially large family of isostructural fluorides and oxyfluorides that could display NTE. However, the coefficients of thermal expansion (CTE) of ReO₃-type materials range from strongly positive to strongly negative. Through extensive use of in situ synchrotron diffraction, this thesis examines the thermal expansion of several ReO₃-type fluorides and oxyfluorides, demonstrating the effects on CTE and related properties of both cation and anion substitution and the disorder produced by these structural changes.

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第19817号 / 人博第788号 / 新制||人||189(附属図書館) / 27||人博||788(吉田南総合図書館) / 32853 / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 田部 勢津久, 教授 吉田 寿雄 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

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L'élucidation du mécanisme de formation de divers verres naturels peut aider à comprendre la dynamique de la Terre car ces matériaux retiennent l'état de formation dans leurs structures. La spectroscopie XAFS appliquée aux matériaux amorphes issue des météorites fournit des informations sur les changements structuraux locaux des éléments présents. En effectuant des analyses dans la phase de verre des météorites et dans les verres issus de l'impact météoritiques des informations sur les conditions de formation des ces matériaux peuvent être obtenues. Dans cette thèse, l'analyse de la structure locale d’éléments de transition (Ti, Zr) dans les minéraux et les verres naturels a été réalisée par la XAFS. Des expériences de chauffage au laser à haute température et de flux gazeux sur zircon ont également été effectuées pour observer les changements structuraux à haute température dans les phases cristallines qui accompagnent le verre météoritique. La structure locale de ces matériaux est semblable à celle du Zr dans les sédiments de la limite Crétacé – Paléogène (K-Pg). Ce dernier ne montre aucune influence de diagenèse ou d'altération, ce qui suggère que les sédiments Cependant, l'abondance de Zr dans les sédiments n'est pas toujours suffisante pour obtenir des informations fiables sur la structure locale du Zr. Nous nous sommes ainsi intéressés à la structure local du Ti, qui appartient au même groupe que le Zr. Les conditions d'impact des météorites sur Mars et du passage des météorites à travers l'atmosphère peuvent être estimées par l'analyse de la structure locale de Zr dans la partie vitrifiée des météorites. L'analyse de la structure locale du Zr dans la météorite martienne de Tissint montre la croûte de fusion de cette météorite est semblable à celle des tectites et du verre d'impact qui les accompagne, alors que la partie intérieure vitreuse de Tissint est similaire à celle de la baddeleyite et de la fulgurite. Cette dernière aurait subi une vitrification pendant le passage à travers l'atmosphère. Afin de confirmer le changement structurel de Zr à haute température, nous avons effectué des expériences de chauffage du zircon, ainsi qu’une expérience de diffraction des rayons X sur poudre pendant le chauffage. L'analyse chimique dans le MEB a montré l'évaporation de la composante SiO2. Nous avons aussi obtenu un nouveau digramme de phase ZrO2-SiO2 dans lequel la région d’immiscibilité liquide proposée auparavant n’a pas pu être confirmée / Elucidation of the formation mechanism of various natural glasses can help to understand the dynamics of the Earth because these materials record the formation condition in their structures. XAFS applied to natural meteorite-related glasses provides information about the local structural changes of elements therein. By performing high-accuracy XAFS analyses for trace elements and their local structure in sedimentary rocks, in the glass phase of meteorites and in the meteorite impact-related glasses such as tektite and impact glass, information on the formation condition of these materials can be obtained. We have performed local structure analysis of IVb transition metal elements (Ti, Zr) in natural minerals and glasses K-edge XANES and EXAFS as well as high-temperature laser heating and gas flow experiments on zircon, to observe structural changes at high temperature in the crystalline phases that accompany the meteoric glass. The local structure of these materials is similar to that of of Zr in K-Pg sediments, which do not show any influence from diagenesis and weathering, suggesting that K-Pg sediments maintain the thermal quenching history of the meteorite impact. However, the low abundance of Zr in sediments prompted us to study Ti, which belongs to the same group as Zr and is much more abundant. Combination of the information about the local structures of Ti and Zr allows a higher reliability for the estimation of meteorite impact event. The local structure of Zr in the fusion crust and inner glassy part of the Martian meteorite of Tissint are similar, respectively, to that in tektite and accompanying impact glass and to that in baddeleyite and fulgurite. The latter was likely vitrified part during the passage through the atmosphere. It should be possible to estimate the conditions of meteorite impact on Mars and the passage of meteorites through the Earth’s atmosphere through the analysis of the local structure of Zr in the glassy part of meteorites. In order to confirm this hypothesis, we performed heating experiments of zircon with in-situ powder X-ray diffraction experiment was performed for ZrSiO4 and ZrO2. SEM analysis confirmed evaporation of the SiO2 component. We have obtained a new ZrO2-SiO2 phase diagram where the liquid-immiscible region proposed earlier does not appear.

Developing greener, more efficient, and less energy-intensive processes will lead the chemical industry into a more sustainable future. Gas-expanded liquids (GXLs) form a unique class of environmentally benign and tunable solvents that can be used in a variety of applications. Through the series of studies presented in this thesis, we have investigated both the properties and applications of GXLs. We have developed a more complete understanding of the interactions between the gas, the organic liquid, and solutes at the molecular level through kinetic and solvatochromic experiments. We have examined a Diels-Alder reaction and an SN2 reaction and have described the kinetic results in terms of intermolecular interactions and local composition enhancement. We have also demonstrated the use of Organic-Aqueous Tunable Solvents, a special case of GXLs, to recycle homogeneous hydroformylation catalysts. The results of this research can be used to guide future applications of GXLs as green reaction solvents.

Nous étudions dans cette thèse divers aspects du transport optimal martingale en dimension plus grande que un, de la dualité à la structure locale, puis nous proposons finalement des méthodes d’approximation numérique.On prouve d’abord l’existence de composantes irréductibles intrinsèques aux transports martingales entre deux mesures données, ainsi que la canonicité de ces composantes. Nous avons ensuite prouvé un résultat de dualité pour le transport optimal martingale en dimension quelconque, la dualité point par point n’est plus vraie mais une forme de dualité quasi-sûre est démontrée. Cette dualité permet de démontrer la possibilité de décomposer le transport optimal quasi-sûre en une série de sous-problèmes de transports optimaux point par point sur chaque composante irréductible. On utilise enfin cette dualité pour démontrer un principe de monotonie martingale, analogue au célèbre principe de monotonie du transport optimal classique. Nous étudions ensuite la structure locale des transports optimaux, déduite de considérations différentielles. On obtient ainsi une caractérisation de cette structure en utilisant des outils de géométrie algébrique réelle. On en déduit la structure des transports optimaux martingales dans le cas des coûts puissances de la norme euclidienne, ce qui permet de résoudre une conjecture qui date de 2015. Finalement, nous avons comparé les méthodes numériques existantes et proposé une nouvelle méthode qui s’avère plus efficace et permet de traiter un problème intrinsèque de la contrainte martingale qu’est le défaut d’ordre convexe. On donne également des techniques pour gérer en pratique les problèmes numériques. / In this thesis, we study various aspects of martingale optimal transport in dimension greater than one, from duality to local structure, and finally we propose numerical approximation methods.We first prove the existence of irreducible intrinsic components to martingal transport between two given measurements, as well as the canonicity of these components. We have then proved a duality result for optimal martingale transport in any dimension, point by-point duality is no longer true but a form of quasi safe duality is demonstrated. This duality makes it possible to demonstrate the possibility of decomposing the quasi-safe optimal transport into a series of optimal transport subproblems point by point on each irreducible component. Finally, this duality is used to demonstrate a principle of martingale monotony, analogous to the famous monotonic principle of classical optimal transport. We then study the local structure of optimal transport, deduced from differential considerations. We thus obtain a characterization of this structure using tools of real algebraic geometry. We deduce the optimal martingal transport structure in the case of the power costs of the Euclidean norm, which makes it possible to solve a conjecture that dates from 2015. Finally, we compared the existingnumerical methods and proposed a new method which proves more efficient and allows to treat an intrinsic problem of the martingale constraint which is the defect of convex order. Techniques are also provided to manage digital problems in practice.