Existing travel patterns in Windhoek are influenced by the past land use policy of restricted urban development in the former townships ofKatutura and Khomasdal. Thus residents in these townships are faced with longer distances to reach quality urban servtces. This thesis examined the impact on travel demand of changes in land use policies aimed at stimulating growth in the two areas using the HLFM computer model. The results showed that, policy induced land use changes may stimulate population and employment growth in the neglected areas, but with no effects on the present travel patterns. The model needs to be refined to fit the peculiarity of the study area. Nevertheless, information provided in the thesis could be used in assessing areas where development trends will go if any ofthe land use policy tested in the study is adopted. / Geography / M.A. (Geography)

This thesis performed within the Collaborative Research Center 799 describes a development of the metal-ceramic thermodynamic databases as applied to the design of the TRIP-Matrix-Composite materials. A wide range of theoretical and experimental investigations have been carried out in the relevant systems of Fe–Mg–Zr–O, Mg–Ti–Zr–O and Mg–Mn–Zr–O. Thermodynamic data were obtained using experimental methods of calorimetry and ab-initio calculations. Phase relations in the constituent binary and ternary systems have been studied using different types of static and dynamic methods. The obtained results allowed an assessment of thermodynamic parameters of the aforementioned systems using CALPHAD approach. The thermodynamic calculations have been performed to predict interfacial reactions within the composite material as well as to made recommendations for the design and further development of production processes for TRIP-Matrix-Composite materials.

Die verformungsinduzierten Phasenumwandlungen und die Zwillingsbildung wurden in drei metastabilen austenitischen Cr-Mn-Ni-Stählen mit unterschiedlichem Nickelgehalt im breiten Temperaturbereich untersucht. Die entwickelten STU- und DTU-Diagramme fassen die gewonnenen Erkenntnisse zusammen und charakterisieren die verformungsinduzierten Gefügeänderungsprozesse in Abhängigkeit von der Spannung und der Temperatur. Die thermodynamischen Berechnungen bestätigen die Unterschiede in der chemischen Triebkraft für die Martensitumwandlung zwischen den Stählen und erklären unterschiedliches Werkstoffverhalten. Ein thermodynamisch-mechanisches Modell der verformungsinduzierten α‘-Martensitbildung wurde entwickelt. Der maximale α‘-Martensitanteil wird als Funktion der Gesamttriebkraft und der Temperatur mit einer guten Genauigkeit beschrieben. Des Weiteren wurde ein Modell der Umwandlungsplastizität mit Berücksichtigung der Plastizitätsverringerung infolge der isothermen oder spannungsinduzierten Martensitbildung entwickelt. Außerdem wurde der Einfluss von Mikroseigerungen auf die verformungsinduzierte Martensitbildung anhand drei Modellstähle untersucht und bestätigt.

Inert gas atomization is one of the main sources for production of metal powder forpowder metallurgy and additive manufacturing. The obtained final powder size distribution iscontrolled by various technological parameters: gas flow rate and pressure, liquid metal flowrate, gas type, temperature of spraying, configuration of nozzles, etc. This work explores anotherdimension of the atomization process control: modifications of the liquid metal properties andtheir effect on the obtained powder size. Series of double-alloyed Cr-Mn-Ni steels with sulfur andphosphorus were atomized with argon at 1600◦C. The results indicate that surface tension andviscosity modifications lead to yielding finer powder fractions. The obtained correlation is comparedwith the individual modification of surface tension with S and Se and modification of viscosity withphosphorus. Discrepancy of the results is discussed. Additives of surfactants and viscosity modifierscan be a useful measure for powder fractions control.

Cette thèse porte sur l'analyse d'un phénomène particulièrement important dérivant des conséquences mécaniques des transformations de phases solide-solide dans les aciers : la plasticité de transformation ou TRIP (Transformation Induced Plasticity) et son interaction avec la plasticité classique. Ce sujet est abordé à la fois par des investigations expérimentales et par une approche de modélisation numérique, pour les transformations martensitiques. / This thesis concerned with the analysis of a particularly important phenomenon which corresponds to one of the mechanical consequences of solid-solid phase transformations in steels: the transformation plasticity or TRIP (TRansformation Induced Plasticity) and its interaction with classical plasticity. This subject is addressed from the point of view of experimental investigations as well as with a nuimerical modelling approach, concerning martensitic transformations.

Pour répondre à la demande croissante d’allègement des véhicules automobiles, les aciéristes développent une nouvelle gamme d’aciers à Très Haute Résistance (THR), dite de troisième génération. Cette thèse, inscrite dans le projet ANR MATETPRO « MeMnAl Steels », s’intéresse plus particulièrement à deux nouvelles familles d’aciers THR Fe-C-Mn-Al, produites par ArcelorMittal et potentielles candidates pour la caisse en blanc des futurs véhicules. Elle vise à mieux cerner les paramètres microstructuraux permettant de contrôler et optimiser le comportement à rupture de ces aciers.Pour représenter les deux familles d’aciers, deux matériaux modèles ont été élaborés par laminage puis recuit intercritique, conduisant à une microstructure duplex : austénite retenue (γr, pouvant se transformer en martensite par effet TRIP) et ferrite. La microstructure du premier acier, dite UFG, est ultrafine (grains de taille inférieure au micromètre) tandis que celle du second est bimodale, mêlant gros grains de ferrite δ et régions à grains fins de ferrite α et d’austénite retenue γr.Les propriétés mécaniques de la microstructure UFG dépendent fortement de la température de recuit, en raison des variations de stabilité de l’austénite retenue. A l’inverse, la microstructure bimodale est très robuste vis-à-vis de la température de recuit mais très sensible à la température d’essai. L’endommagement en traction et en résilience est très peu développé pour ces deux familles. Il est localisé aux interfaces ferrite-martensite (formée pendant l’essai). Le lien entre les modes de rupture et la microstructure bimodale, étudié à l’aide d’essais Charpy, a montré l’existence de deux transitions distinctes de mode de rupture : une transition entre rupture ductile à grandes cupules et clivage pour les gros grains de ferrite δ et une transition entre rupture interfaciale et rupture ductile à fines cupules pour les zones à grains fins {α + γr}. La rupture de la microstructure UFG est ductile à température ambiante et interfaciale à plus basse température. Cette microstructure UFG peut être vue comme un matériau modèle représentant les régions à grains fins {α + γr} de la microstructure bimodale.Pour les deux familles d’aciers, le comportement élastoplastique comme le comportement à rupture semblent dominés par la stabilité de l’austénite retenue. / To fulfil the increasing demand on lightweighting automotive vehicles, steelmakers are developing a third generation of Advanced High Strength Steels (AHSS). This work, part of the ANR project MATETPRO “MeMnAl Steels”, addressed two new families of third generation AHSS produced by ArcelorMittal which may be used for the body in white of upcoming cars. It aimed at improving our current understanding of the microstructural features allowing controlling and optimizing the fracture behavior of this steel family.Two model materials were manufactured by hot and cold rolling followed by intercritical annealing. The resulting, so-called duplex microstructure is a mixture of ferrite and retained austenite (γr, which can transform into martensite by TRIP effect). The microstructure of the first steel was made of ultra-fine grains (UFG) of ferrite and retained austenite (grain size below one micrometer), while the second steel possessed a bimodal microstructure made of coarse δ-ferrite grains and fine-grained regions of α-ferrite and retained austenite γr.The mechanical properties of the UFG microstructure were strongly sensitive to the annealing temperature, due to variations in the stability of retained austenite. On the contrary, the bimodal microstructure was very robust regarding the annealing temperature but very sensitive to the test temperature. For these two families, damage development is scarce and mainly located at ferrite-martensite interfaces. Charpy impact tests on steels with the bimodal microstructure showed that each microstructural region presents its own fracture mechanisms and a specific ductile-to-brittle transition. A transition from brittle cleavage to large-dimpled, ductile fracture was observed for coarse δ-ferrite grains, while fined-grained regions presented a transition from interfacial fracture to fine-dimpled, ductile fracture. Fracture of the UFG microstructure was ductile at room temperature and interfacial at lower temperatures. This UFG microstructure can be interpreted as a model material embodying the behavior of the fine-grained {α + γr} regions in the bimodal microstructure.For both two steels, the constitutive and fracture behavior seem to be dominated by the stability of retained austenite.

Neste trabalho é proposto um modelo para estimar a geração e a distribuição de viagens intraurbanas baseado em agentes, denominado Modelo GDA. Neste modelo foram aplicadas simulações em Sistemas Multiagentes (SMA), nas quais foram usadas, como dados de entrada, informações relativas ao morador e ao uso do solo. Na estimativa da geração de viagens, a simulação SMA foi usada para estimar uma população sintética baseada nas informações sociodemográficas dos moradores e para obter um plano de atividades associado a cada morador. Na estimativa da distribuição de viagens, a simulação SMA foi usada para obter uma matriz Origem-Destino (OD) com base no plano de atividades dos moradores e nos atributos do uso do solo. Para definir os critérios da distribuição de viagens, foram testadas teorias alternativas à força gravitacional, como a teoria das redes livres de escala e o conceito de path dependence. Foi feita uma aplicação do Modelo GDA na cidade de São Carlos (SP), cujos resultados estimados foram comparados aos resultados observados, provenientes da pesquisa Origem-Destino (OD), e aos resultados estimados obtidos pela aplicação de modelos gravitacionais nesta cidade. Os resultados mostraram que os resultados estimados obtidos pelo Modelo GDA são tão acurados quanto aos do modelo gravitacional. Conclui-se que o Modelo GDA, comparativamente ao modelo gravitacional, possui vantagens quanto à sua aplicabilidade, pois em vez de serem utilizados pelo modelo dados provenientes de pesquisas de tráfego, geralmente onerosos e de difícil aquisição; são empregados dados acerca do morador e do uso do solo, de fácil coleta e atualização periódica. / In this work, an agent-based model in order to estimate trip generation and trip distribution in an intra-urban context (GDA model) is proposed. Simulations using Multiagent Systems (MAS), with input data concerning dwellers and land use were applied in this model. To estimate the trip generation, the MAS simulation was used to elaborate a synthetic population based on sociodemographic information of the dwellers and to obtain an activity plan of each dweller. To estimate the trip distribution, the MAS simulation was used to obtain an Origin-Destiny (OD) matrix based on the dwellers activity plans and the land use characteristics. To define the trip distribution rules, alternative theories to gravitational force like free scale networks and path dependence theories were tested. The GDA model was applied in the urban area of São Carlos (Brazil), whose estimates was compared to the observed data from the OD survey and the estimate data from the Gravity model applied in this same area. The results showed that the estimates from the GDA Model are as accurate as from the Gravity Model. It was observed that the GDA Model presents advantages in relation to the Gravity Model because instead of using traffic survey data, which often is expensive and difficult to get, it uses dwellers and land use information, which is periodically collected from government researches, making it easy for government agencies to obtain this information.

This thesis deals with organization of a long-term school trip, which means organization of a sojourn for primary school pupils in surrounding which is beneficial to pupils' health while their education is not interrupted. The theoretical part of this thesis is focused on those law regulations, which have to be followed in the process of organizing a long-term school trip and during the time the event is taking place. Basic concepts dealing with the organization of a long-term school trip are also defined in the theoretical part of this thesis. The practical part of this thesis is based on collecting data through a survey and dialogues with teachers. The aim of the survey and those dialogues is to find out the interest of primary school teachers who teach at schools located in Prague 1 and in Prague 2 in organizing a long- term school trip and to detect their experience which they have acquired by organizing long- school trips. KEYWORDS: organization, long-term school trip, administration, interest, pupil of primary school age, younger school age, sojourn, primary school

Estudou-se a cinética das transformações de fase em resfriamento contínuo e em tratamentos isotérmicos de cinco ligas de aços TRIP microligados com Nb, contendo teores variáveis de Mn e Si, através de ensaios dilatométricos, de caracterização morfológica dos produtos de transformação e de cálculos termodinâmicos e simulações numéricas usando os programas Thermocalc ® e Dictra®. Foram determinados os diagramas RC para a transformação da austenita, e foi estudada a influência da precipitação de ferrita pró-eutetóide e de bainita na fração volumétrica de austenita retida. Através dos diagramas de resfriamento contínuo foi possível delimitar a extensão do campo intercrítico dos cinco aços analisados, com determinação da janela de resfriamento e seus intervalos de temperaturas. Isso permitiu projetar os ciclos de resfriamento controlado a serem aplicados durante o processamento termomecânico dos Aços TRIP-D, TRIP-E e TRIP-H. Os cálculos pelo modelo numérico de redistribuição de carbono e de elementos substitucionais na interface ferrita/austenita, bem como as medidas de microanálise química por WDS e EDS permitiram verificar que a taxa de crescimento da ferrita pró-eutetóide é controlada pela difusão do carbono na austenita. Para tempos curtos de tratamento, o modelo de crescimento que melhor se ajusta é o do equilíbrio local com partição negligível de soluto. Verificou-se através de tratamentos isotérmicos no campo bainítico, que o silício atrasa a precipitação de carbonetos durante a reação bainítica, o que justifica o aumento da estabilidade da austenita retida no aço de maior Si (TRIP-H), quando comparado com o aço de menor Si (TRIP-E). Baseado nos resultados dos estudos das transformações de fase por resfriamento contínuo foram selecionadas as ligas TRIP-D, TRIP-E e TRIP-H, para simular dois esquemas de laminação controlada por meio de ensaios de torção a quente. Nesses ensaios foram variados o grau de deformação e a temperatura de acabamento, de modo a estudar os efeitos dos parâmetros de deformação mecânica na fração transformada dos diferentes constituintes microestruturais, e em particular na fração volumétrica de austenita retida. O primeiro ensaio refere-se à laminação controlada por recristalização estática (LCRE) e o segundo à laminação convencional (LCC), com temperatura de acabamento de 1030°C e 850°C, respectivamente. O resfriamento consistiu em dois tratamentos isotérmicos consecutivos: o primeiro no campo intercrítico (austenita + ferrita), e o segundo no campo bainítico. O aumento do grau de deformação na simulação por torção a quente da laminação controlada por recristalização estática, levou a um aumento da porcentagem de austenita retida obtida durante o resfriamento controlado (de 9 a 14,0 %). O acúmulo de energia de deformação abaixo da TNR na simulação do processo de laminação controlada convencional provocou uma diminuição da fração volumétrica de austenita retida bem como da concentração de carbono contido nela. Os perfis de Mn e C obtidos a partir de análises químicas com EDS e WDS em amostras do aço TRIP-E, deformadas com deformação total de 2,1 e deformação total de 2,8, mostram a contribuição do refinamento de grão para a difusão destes elementos na frente da interface ferrita/austenita, durante a precipitação de ferrita pró-eutetóide. / The phase transformation kinetics of five Nb microalloyed Si-Mn TRIP steels was studied under continuous cooling and isothermal treatments, using dilatometric techniques, morphologic characterization, Thermocalc computational thermodynamics and Dictra numerical simulation. WDS and EDS X-ray microanalysis and Dictra numerical modeling of C, Mn and Si distribution during transformation showed that the reaction is carbon diffusion controlled and growth occurs under local equilibrium with negligible partition. CCT diagrams for austenite transformation were determined and the effect of the amount of proeutectoid ferrite and bainite precipitation on the volume fraction of retained austenite was also estimated. The CCT diagrams allowed determining the boundaries of the critical zone and the processing window to obtain bainite plus austenite microstructures. Based on this information cooling cycles were selected to perform thermomechanical treatments. Three TRIP steels were selected to simulate, in a hot torsion testing machine, two different controlled rolling sequences: Recrystallization Controlled Rolling and Conventional Controlled Rolling. The influence of the degree of deformation and the finishing temperature on the amount of retained austenite was studied. After rolling the cooling cycle comprised two isothermal treatments, one in the austenite + ferrite field and the other in the bainitic field. Increasing the strain during simulation of Recrystallization Controlled Rolling led to an increase in the volume fraction of retained austenite to the range 9 to 14 %. The energy stored during simulation bellow TNR of the Conventional Controlled Rolling led to a decrease in the volume fraction and in the carbon content of retained austenite. The Mn and C contents measured by EDS and WDS analysis of TRIP-E steel, showed that grain refinement due to recrystallization contributes to diffusion of these elements in front of the ferrite/austenite interface during precipitation.

Les mythes américains génèrent des symboles et des stéréotypes fréquents dans l’imaginaire collectif. Leur usage dans la littérature québécoise exclut toute idéologie, privilégiant l’acte fondateur d’une nouvelle mythologie. Les mythes québécois se sont d’abord distingués de ceux de l’Amérique. Ils ont porté un regard critique sur la globalisation que peut susciter le territoire américain. En élaborant leur littérature nationale, les auteurs québécois de la Révolution tranquille ont formulé d’autres pistes interprétatives autour des mythes américains. L’américanité offre des perspectives anthropologiques fluides à l’adaptation du mythe au cinéma et en littérature. Le mythe tel que le définit Roland Barthes permet une interprétation contemporaine de chaque mythe québécois présenté dans cette étude. Le corpus est donc composé d’œuvres québécoises et étatsuniennes, de films de Denys Arcand et Clint Eastwood, de romans et textes argumentatifs de notre auteur tranquille référent, Jacques Godbout mais aussi de Jacques Poulin, Philippe Aubert de Gaspé, Antonine Maillet, Anne Hébert, Jack Kerouac. / American myths generate recurring symbols and stereotypes in the collective imagination. In Quebec literature, the use of these myths ignores ideology, favouring the founding act of a new mythology. Quebec myths firstly distinguished themselves from American myths, carrying with them a critical perspective on the globalising process driven by the American territory. In developing their national literature, Quebec authors from the Quiet Revolution shaped new interpretations of American myths. Americanness offers changing anthropological perspectives for the adaptation of myths into film and literature. The myth as Roland Barthes defines it, enables a contemporary interpretation of each Quebec myth you can find in this study. Thus, the corpus in my dissertation is made up of Quebec and American works, movies directed by Denys Arcand and Clint Eastwood and novels or argumentative essays by the quiet author who is the subject of this dissertation, Jacques Godbout as well as Jacques Poulin, Philippe Aubert de Gaspé, Antonine Maillet, Anne Hébert and Jack Kerouac.