The growth of population and business during the rapid urbanization process in the twentieth century has generated significant demand for transportation. As the demands have grown, road and air transportation are suffering from significant congestion and delays. Continuing expansion of highways and airports has become both expensive and difficult, along with not being able to provide adequate solutions to the growing congestion. One alternative, which is being pursued by many countries, is to invest in efficient high-speed rail networks to meet the pressing demand for mass passenger transportation. This alternative is also one that may have beneficial impacts by reducing energy consumption and alleviating some of the environmental concerns. But to make these infrastructure investments, governments need to make difficult decisions due to the complexity of the industry and technologies involved. This thesis examines decision making by government for such investments. In order to carefully study the industry, we use a two part approach. First, we examine the HSR industry supply-chain. We create a detailed taxonomy of the industry supply-chain and highlight various aspects of the advanced technologies being used, the sophisticated multiproduct nature of the firms, and the diverse international location of the companies. Second, we gather information on all the international HSR contracts between 2001-2011. These contracts enable us to examine business strategies pursued by the major HSR trainset suppliers and component manufacturers, insights into the size of the orders and type of trainsets being delivered, and the formation of partnerships and collaborations to meet the complex demands imposed by Governments when they invite bids for these expensive projects. A detailed examination of the supply-chain shows that the core technologies and competencies are highly concentrated in those countries which historically have had high demand for high-speed rail. Germany, Japan, France, for example, have the highest number of trainset and component suppliers. In more recent years, South Korea and China have emerged as the new frontiers of trainset and components suppliers. This implies that countries who are outside of this group are highly dependent on either importing these technologies and investments or make a concerted effort to develop them via partnerships and technology transfer agreements. Our examination of contracts shows that the size of HSR investment order is important for both business and government strategy. The order size determines the extent of domestic content and production. While many components will inevitably be imported, a larger order size may allow for various components to be manufactured domestically. Order size also appears to influence the nature of partnerships among the firms in the industry. We observe a growing number of HSR investment partnerships among trainset suppliers over time, possibly due to the need to pool risk in these highly complex and uncertain investments, as well as the changing competitive dynamic of HSR markets.

This Master's Thesis deals with high-speed rail in the Czech Republic. The theoretical part describes the history, the evolution and the present of high-speed rail and presents the successful foreign high-speed rail systems. Furthermore this part presents the high-speed railway tracks which are planned in the Czech Republic. The practical part researches the perception of high-speed rail by passengers. Based on the result of the survey, which was realized via the questionnaire, it analyses the criteria that passengers consider important in the choice of means of transport and it looks into passenger willingness to accept higher fare for shorten of travel time. With using the result of the survey it also deals with competitiveness of high-speed rail compared with other modes of transport. The aim of the Thesis is determine whether high-speed rail is attractive from the perspective of passengers and whether it is able to compete with other modes of transport.

One of the most important electrical requirements in high performance electronic systems or high speed integrated circuits, is to process larger numbers of electrical signals at much higher speeds. Signal propagation delay must be minimized in order to maximize signal velocities. Therefore, material with low dielectric constant and low dissipation factor is being sought. In this thesis research measurements of dielectric constant and dissipation factor were performed on commercially available polyimides that are used in multilayer interconnect structures. Capacitor structures with a polyimide dielectric were measured up to a 1GHz frequency and 220°C temperature. Polyimides were concluded to be compatible for use in high performance systems such as multilayer interconnect structures.

<p>Within the gas turbine industry, turbofan engines are widely implemented to enhance engine efficiency, specific thrust, and specific fuel consumption. However, these turbofans have yet to be widely implemented into microgas turbine engines. As turbofans become implemented into smaller engines, the need to design engine intakes for high-speed mission becomes more vital. In this work, a design procedure for compact, highly diffusive engine intakes for high subsonic speed applications is set about. The aerodynamic tradeoffs between cruise and takeoff flights are discussed and methods to enhance takeoff performance without negatively impacting high-speed cruise performance is discussed. Intake performance is integrated into overall engine analysis to help guide future mission analyses. Finally, an experimental model for engine intakes is developed for application to linear wind tunnels; allowing future designers to effectively validate numerical results.<br></p> <p>A multi-objective optimization routine is performed for compact engine intakes at a Mach number of 0.9. This optimization routine yielded a family of related curves that maximize intake diffusive capability and minimize intake pressure losses. Design recommendations to create such optimal intakes are discussed in this work so that future designers do not need to perform an optimization. Due to high diffusion rate of the intake, the intake performance at takeoff suffers greatly (as measured by massflow ingestion). Methods to enhance takeoff performance, from designing a variable geometry intake, to creating slots, to sliding intake components are evaluated and ranked for future designers to get an order of magnitude understanding of the types of massflow enhancements possible. Then, off-design performance of the intake is considered: with different Mach number flights, non-axial flow conditions, various altitudes, and unsteady engine operation considered. These off-design effects are evaluated to generate an intake map across a wide engine operational envelope. This map is then inputted into an engine model to generate a performance map of an engine; which allows for mission planning analysis. Finally, various methods to replicate intake flow physics in a linear wind tunnel are considered. It is shown that replicating diffuser curvature in a linear wind tunnel allows for best replication of flow physics. Additionally, a method to non-dimesnsionalize intake performance for application to a wind tunnel is developed. </p> <p>This work can be utilized by future engine intake designers in a variety of ways. The results shown here can help guide future designers create highly compact diffuser technology, capable of operating across a wide breadth of conditions. Methods to assess intake performance effects on overall engine performance are demonstrated; and an experimental approach to intake analysis is developed.</p>

Neste trabalho aços rápidos ao molibdênio AISI M3:2 obtidos por diferentes processos de fabricação, submetidos ao mesmo procedimento de tratamento térmico, foram avaliados no que concerne às propriedades mecânicas de resistência à ruptura transversal e dureza. Os materiais em questão constaram dos aços rápidos comerciais Sinter 23 obtido por metalurgia do pó, o aço rápido VWM3C obtido pelo processo convencional e o aço rápido M3:2 obtido por uma técnica de metalurgia do pó que consiste de compactação uniaxial a frio de pós atomizados a água com e sem a adição de uma pequena quantidade de carbono na forma de grafite (0,3% em massa) e sinterização a vácuo com fase líquida. Esses aços rápidos foram avaliados através da comparação de suas propriedades. O aço rápido M3:2 foi sinterizado a vácuo podendo vir a se constituir numa alternativa economicamente mais viável do que o aço rápido MP Sinter 23 obtido por uma técnica de sinterização por compactação isostática a quente e com propriedades similares ao aço rápido processado pela rota convencional. A caracterização do aço rápido sinterizado a vácuo consistiu de medidas de densidades do compactado e após a sinterização. A sinterização produziu uma microestrutura aceitável e densidades próximas da densidade teórica desse aço rápido. A resistência à ruptura transversal foi avaliada através de ensaios de flexão em três pontos e a dureza através de medidas de dureza Rockwell C e Vickers. Os aços rápidos foram avaliados no que tange à microestrutura por uma técnica de microscopia eletrônica de varredura (MEV). Estabeleceu-se assim uma relação entre a microestrutura e a resistência à ruptura transversal desses aços após o tratamento térmico. Uma técnica de difração de raios X foi utilizada para a determinação das fases presentes e detecção da austenita retida. A contribuíção desse trabalho consiste na avaliação da relação microestrutura / propriedades mecânicas desses aços rápidos bem como na viabilização do aço rápido sinterizado a vácuo. / In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the adition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vaccum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstruture and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic mycroscopy (SEM) was used to evaluate the microstruture and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels.

Neste trabalho aços rápidos ao molibdênio AISI M3:2 obtidos por diferentes processos de fabricação, submetidos ao mesmo procedimento de tratamento térmico, foram avaliados no que concerne às propriedades mecânicas de resistência à ruptura transversal e dureza. Os materiais em questão constaram dos aços rápidos comerciais Sinter 23 obtido por metalurgia do pó, o aço rápido VWM3C obtido pelo processo convencional e o aço rápido M3:2 obtido por uma técnica de metalurgia do pó que consiste de compactação uniaxial a frio de pós atomizados a água com e sem a adição de uma pequena quantidade de carbono na forma de grafite (0,3% em massa) e sinterização a vácuo com fase líquida. Esses aços rápidos foram avaliados através da comparação de suas propriedades. O aço rápido M3:2 foi sinterizado a vácuo podendo vir a se constituir numa alternativa economicamente mais viável do que o aço rápido MP Sinter 23 obtido por uma técnica de sinterização por compactação isostática a quente e com propriedades similares ao aço rápido processado pela rota convencional. A caracterização do aço rápido sinterizado a vácuo consistiu de medidas de densidades do compactado e após a sinterização. A sinterização produziu uma microestrutura aceitável e densidades próximas da densidade teórica desse aço rápido. A resistência à ruptura transversal foi avaliada através de ensaios de flexão em três pontos e a dureza através de medidas de dureza Rockwell C e Vickers. Os aços rápidos foram avaliados no que tange à microestrutura por uma técnica de microscopia eletrônica de varredura (MEV). Estabeleceu-se assim uma relação entre a microestrutura e a resistência à ruptura transversal desses aços após o tratamento térmico. Uma técnica de difração de raios X foi utilizada para a determinação das fases presentes e detecção da austenita retida. A contribuíção desse trabalho consiste na avaliação da relação microestrutura / propriedades mecânicas desses aços rápidos bem como na viabilização do aço rápido sinterizado a vácuo. / In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the adition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vaccum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstruture and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic mycroscopy (SEM) was used to evaluate the microstruture and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels.

L’étude des seuils de tolérance du corps humain aux impacts requiert des expérimentations sur des sujets humains vivants ou post-mortem, ce qui soulève naturellement des questions d’éthique. Pour pallier à ces limitations, le développement des outils numériques a conduit, au fil des dernières années à la mise en place des mannequins numériques plus ou moins capables de reproduire fidèlement le comportement mécanique du corps humain lorsqu’ils sont soumis à divers types de sollicitations. C’est dans ce contexte que le modèle de mannequin numérique HUByx (Hermaphrodite Biomechanics yx-model) a été développé au sein du département de recherche COMM du laboratoire ICB à l’UTBM. Ce travail de thèse a pour but la validation et l’amélioration de la biofidélité de la partie thoracique du modèle HUByx, et vise à comprendre les mécanismes de lésions et à rechercher des critères de prédiction des lésions thoraciques à travers la reconstruction numérique des chargements violents dans des contextes civils et militaires. Des simulations numériques ont été réalisées dans le cadres des études de chutes libres de personnes, des impacts balistiques non-pénétrants de projectiles non létaux et dans le cadre du phénomène de l’explosion. De bonnes corrélations ont été obtenues entre les résultats numériques et expérimentaux, contribuant ainsi à renforcer la capacité du modèle HUByx à répondre de manière biofidèle aux différentes sollicitations auxquelles il est soumis. Mots-clés : Biomécanique d’impacts, éléments finis, blessures thoraciques, critère visqueux, reconstruction d’accident, chutes libres, balistique, explosion. / The study of human tolerance thresholds to impacts requires experiments on living or post mortem human subjects, which naturally raises ethical questions. To overcome these limitations, the development of numerical tools has led over the last few years to the implementation of numerical models more or less capable to accurately reproduce the mechanical behavior of the human body when subjected to various types of stresses. It is in this context that the numerical model HUByx (Hermaphrodite Biomechanics yx-model) has been developed within the research department COMM of the ICB lab at UTBM. This PhD work aims at validating and improving the biofidelity of the thoracic part of the HUByx model and also aims to understand the mechanisms of lesions and to seek criteria for the thoracic injury prediction through the numerical reconstruction of violent loadings in civil and military contexts. Numerical simulations were carried out in the framework of human free falls studies, non-penetrating ballistic impacts of non-lethal projectiles and finally in the context of explosion phenomenon. Good correlations were obtained between the numerical and experimental results, thus contributing to reinforce the capacity of the HUByx model to respond in a biofidelic manner to the different stresses to which it is subjected. Keywords : Impact biomechanics, finite elements, thoracic injuries, viscous criterion, accident reconstruction, free falls, ballistics, explosion.

After decades of standstill in intercity passenger rail in the United States, the Obama administration recently started major initiatives to implement high-speed ground transportation projects that are expected to improve the nation's transportation system significantly, addressing most prevailing issues like congestion and energy prices while having positive effects on the economy. This study evaluates and compares two high-speed ground transportation systems that have the potential to improve intercity passenger transportation in the United States significantly: the wheel-on-rail high-speed system and the high-speed maglev system. Both high-speed ground transportation systems were evaluated with respect to 58 characteristics organized into 7 categories associated with technology, environmental impacts, economic considerations, user-friendliness, operations, political factors, and safety. Based on the performance of each system in each of the 58 characteristics, benefit values were assigned. In order to weight the relative importance of the different characteristics, a survey was conducted with transportation departments and transportation professionals. The survey produced weighting factors scoring each of the 58 characteristics and the 7 categories. Applying a multi-criteria decision making (MCDM) approach, the overall utility values for either system were calculated based on the benefit values from the systems comparison and the weighting factors from the survey. It was shown that the high-speed maglev system is generally slightly superior over the wheel-on-rail high-speed system. Because the magnitude of the difference in the overall performance of both transportation systems is not very big, it is recommended that every project in the high-speed intercity passenger transportation market consider both HSGT systems equally.

One of the most important additives in High Speed Steels (HSS) is cobalt, mainly for its effect on the hot properties. Based on statistic data about the increased price of cobalt and its negative effect on human health, an ethical and financial barrier in the steel industry have occurred. In order to solve the problem, it is of great importance to examine the future cobalt price and accessibility, as well as examine the possibility of finding alternative substitutes to cobalt. The purpose of this project was therefore to examine alternatives to cobalt as an alloying element in HSS. A qualitative literature study was performed by analyzing the economy of cobalt, studying the main reasons for cobalts tendency to improve the hot properties of the steel and finding alternative elements to replace, or at least reduce, cobalt in HSS without degrading the hot properties. Cobalt is used both in the chemical and metallurgical business. But the demand of cobalt is largely driven by chemical purposes with the focus on its rechargeable battery applications. The analysis shows that there is nothing pointing at a significant decrease of the price of cobalt. Lithium ion batteries stands for about 50% of current cobalt supply, which is why the price has surged the recent years. The market for electric vehicles and rechargeable batteries has skyrocketed. To decrease the price of cobalt, a substitute for cobalt in rechargeable batteries would need to be found, which is not very likely for the time being. The effect of cobalt in HSS is mainly on the red hardness and tempering resistance. Cobalt increases the bonding strength in the steel matrix and changes the microstructure of the finer secondary carbides. Also the growth rate and coalescence rate of the carbides decreases. This causes the red hardness and the tempering resistance to increase. To replace cobalt, several alternative alloying elements have been researched. Among the most promising are niobium, nitrogen and aluminium, where niobium were found to be of most interest, due to the broad support of relevant articles in the field of powder metallurgical processing. The positive effect of niobium could be regarded as three-fold. The first contribution is the refinement of grain size and homogeneity of the primary carbides, which increases the overall hardness. The second effect is that the addition of niobium shifts the phase equilibria in such a way that the precipitation of primary carbides mainly will be in the form of hard and stable NbC. The majority of the other alloying elements will hence be precipitated as secondary carbides during tempering. The final effect is an increase in secondary hardness, as a consequence of the large amounts of vanadium and smaller amounts of niobium that is being precipitated during tempering to the secondary carbides. This enables a high matrix hardening potential in the optimal state of tempering.

La thèse a pour objet l’analyse de mécanismes d’assemblage permettant la création de structures auto-assemblées à base d’ADN, fonctionnalisées par des protéines. Les PDNA sont des molécules synthétiques associant de manière covalente une séquence d’ADN et un module protéique. Basés sur le domaine hèmique du cytochrome b5, les PDNA présentent des propriétés d’absorption optique dépendant de l’état d’oxydoréduction. Pour comparer leurs propriétés d’assemblage à celles des ADN correspondants, différentes briques ont été assemblées en ensembles finis ou ouverts. Un premier chapitre développe des approches expérimentales et de modélisation pour caractériser les paramètres contrôlant ces assemblages dans le cas des ADN. Un second chapitre transpose ces approches aux assemblages de PDNA afin de mettre en évidence l’influence des domaines protéiques. Dans les deux cas, les travaux sont menés à la fois à un niveau macroscopique et de molécule unique par AFM classique ou à haute vitesse. Une troisième partie vise à comprendre comment ces assemblages peuvent être multiplexés sur des puces au sein de matrices poreuses de dextran. Nous avons modélisé l’influence de la matrice sur l’assemblage et utilisé ces modèles pour définir les relations entre observables et paramètres microscopiques. Une dernière partie vise à lever les limitations (pièges d’assemblages) mises en évidence dans les réactions sous contrôle cinétique. Nous avons développé des assemblages dans des conditions douces et contrôlées par le pH impliquant des structures ADN en motifs-i. Leur mécanisme de formation et de polymérisation en suprastructures a été étudié en combinant biochimie et analyse structurale par AFM. / The work aimed at the analysis of assembly mechanisms allowing the creation of DNA-based self-assembled structures functionalized with proteins. PDNA are synthetic molecules covalently associating a DNA strand to a protein domain. The ones based on the heme binding domain of cytochrome b5 feature optic properties that depend on oxydoreduction state. In order to compare self-assembly properties of PDNA and corresponding DNA, different building blocks were assembled into converging or open ensembles. A first part develops experimental and modeling approaches to characterize parameters controlling such assemblies of DNA blocks. A second part extends these approaches to PDNA assemblies, bringing in evidence the influence of the protein domain on nucleic parts. Studies were both performed at macroscopic and single molecule levels using conventional and high-speed AFM. A third part describes how chip multiplexing of those assemblies onto a porous dextran matrix influences behaviors. Modeling the matrix influence on assembly allowed defining relations between experimental and macroscopic parameters. A last part aims at bypassing bottlenecks related to the formation of trapped structures when reactions are kinetically driven. We developed i-motif based DNA structures that can be assembled into mild, pH controlled conditions. Their mechanism of formation and polymerization into supramolecular structures were studied combining physico-chemical and structural analyses using AFM.