Aluminium-silicon alloys have gained increasing market share in the automotive and aerospace industry because of increased environmental demands. These alloys have a high strength-to-weight ratio, good corrosion resistance, castability and recycling potential. However, variations in properties and limited performance at elevated temperature are restricting these alloys from use at elevated temperatures. During the last decades, researchers have investigated ways to improve the properties at elevated temperatures. However, the effect of some transition elements is not well understood. The aim of this work is to investigate the aluminium-silicon alloys with addition of cobalt and nickel for high temperature applications. Tensile testing and hardness testing were conducted on samples produced by directional solidification in a Bridgman furnace with condition generating a microstructure corresponding to that obtained in high pressure die casting, i.e. SDAS ~ 10 µm. The results show that cobalt and nickel improve the tensile properties up to 230 °C.

La biogéochimie de l’Océan austral joue un rôle crucial dans la régulation de la production primaire marine globale en contrôlant la disponibilité des nutriments dans les eaux de surface des basses latitudes. Les variations du cycle du silicium (Si) sont nombreuses et son couplage avec les autres éléments n’est pas encore bien compris dans cet océan. Les résultats issus de deux approches isotopiques différentes suggèrent qu’une pompe de Si active est rapidement initiée au printemps par la transition d’un mode de production de silice biogénique régénéré à une production dite « nouvelle ». L’évolution saisonnière de la composition isotopique naturelle du Si (δ30Si) est principalement contrôlée par l’équilibre entre les rapports « dissolution/production » et « Si-supply/Si-uptake » qui découplent la dynamique isotopique des réservoirs de Si dissout et particulaire (respectivement DSi et BSi). Nous avons également utilisé les mesures de δ30Si pour retracer les flux saisonniers de BSi vers l’océan profond. Ces résultats confirment que le δ30Si n’est pas altéré durant la sédimentation des particules. L’évolution saisonnière du δ30Si a permis de quantifier pour la première fois certains processus contrôlant la production des diatomées et leur devenir, tels que les évènements de mélange alimentant la ML en nutriments, ou l’évolution saisonnière de la vitesse de sédimentation des particules. Ces résultats confirment que le δ30Si du DSi et de la BSi, combinés aux techniques isotopiques de mesure des flux dans la ML, sont des outils prometteurs dans l’amélioration de nos connaissances du cycle du Si et apportent des informations nouvelles à intégrer aux modèles biogéochimiques. / Southern Ocean biogeochemistry plays a crucial role on global marine primary production by impacting the nutrient availability even in low latitude surface water. Variations in the silicon (Si) cycle are large and its coupling to other nutrient biogeochemical cycles is still not well understood in this ocean. Results of two different isotopic approaches suggested that a strong silicon pump was quickly initiated in spring by a switch from regenerated to new biogenic silica production. The seasonal evolution of natural Si isotopic composition (δ30Si) was mainly driven by the balance between the “dissolution to production” and “Si-supply to Si-uptake” ratios that decoupled the isotopic dynamics of particulate and dissolved Si-pools (DSi and BSi, repectively). We also used δ30Si measurements to track seasonal flows of BSi to the deep sea with. These results confirmed that the δ30Si is well preserved during particles settling. The seasonal evolution of δ30Si signal allows for the first time to quantify important features about the processes controlling the diatoms’ productivity and its fate, such as mixing events that bring nutrient in the ML or the seasonal evolution of particles sinking velocities. These insights confirm that the δ30Si of DSi and BSi, combined to isotopic technics to measure Si fluxes in the ML, are promising tools to improve our understanding on the Si-biogeochemical cycle and provide new constraints for application to biogeochemical models.

The field of crystallography has recently been expanded to include the science of quasicrystals, crystalline structures lacking unit cells and conventional periodicity. This resulted in a paradigm shift in the field, opening up for a whole new branch on the subject of structural chemistry. Despite this, not much is known about the abilities of quasicrystalline and approximant materials. Quasicrystalline approximants in the RE-Au-SM system have previously shown promising results regarding magnetic properties. To explore and discover properties like this is key to further improve the understanding of quasicrystalline materials.   The scope of the project was to explore the Gd-Au-Si system with compositions theoretically calculated to yield possible quasicrystals. In three batches with varying composition ratios, crystals were synthesised, using an arc-melting self-flux method. These were then analysed with powder X-ray diffraction, single crystal X-ray diffraction and electron dispersive spectroscopy (EDS) to characterise the synthesised compounds using diffraction data and composition data respectively. The resulting crystals were determined to be of a ternary composition close to what was theoretically calculated. The phase synthesised is yet to be found in any previous work or database, possibly marking it out as a new phase, albeit the structure not being quasicrystalline in nature. Thus, the exploratory study yielded a so for unobserved composition in the Gd-Au-Si system.

[pt] Este trabalho tem como objetivo investigar os significados e funções que vêm assumindo os blogs pessoais para seus autores, como espaços para a escrita de si. Para isso foi realizado primeiramente um levantamento bibliográfico de outras formas de auto-relatos escritos, inaugurados em diferentes períodos da História, desde a Antigüidade. Num segundo momento desenvolveu-se uma pesquisa qualitativa na qual foram analisados os discursos contidos em dez blogs pessoais, de autoria feminina. A partir desta análise chegou-se a algumas categorias para discussão, relacionadas às funções que parecem estar os blogs exercendo para suas autoras, aos destinos das mensagens publicadas e, ainda, aos diferentes níveis de explicitação de si presentes nos mesmos. Os resultados desta pesquisa revelaram serem os blogs um gênero híbrido de escrita de si, que reúnem algumas características dos diários pessoais, outras comumente típicas das correspondências íntimas e, ainda, certas características das formas de escrita de si destinadas à publicação. / [en] The present work aims at investigating meanings and functions personal blogs have been performing; the personal ones, for their own authors - as some space for self- writing. Towards that, a bibliography research of other forms of written self-account was initially carried out, inaugurated in different periods of History, since Antiquity. Subsequently, a qualitative research was developed, in which ten speeches, extracted from blogs written by women, were analized. This analysis led to some categories to be further discussed, related to the functions the blogs in reference apparently perform for their authors, to the destinations of the posted messages and, still, to the different levels of self-expliciting present in them. The results of this research revel the blogs to be an hybrid type of selfwriting, which gathers some characteristics depicted in personal diaries, others, commonly found in intimate correspondence and, finally, some characteristics of self-writing forms, destined to posting.

Due to governmental requirements on low exhaust gas emissions and the drivers request of fast response, it is important to be able to control the gas flow in a spark ignited engine accurately. The air into the cylinder is directly related to the torque generated by the engine. The technique with recirculation of exhaust gases (EGR) affect the air flow into the cylinder and increase the complexity of the control problem. In this thesis a mean value model for a spark ignited engine has been created. The basis was a diesel model from Linköping University that has been modified and parameterized with data from a test cell. The model has been used to study the gas exchange system with respect to the dynamic behaviors and nonlinearities that occur when the three actuators (throttle, wastegate and EGR-valve) are changed. Based on this analysis, some different control strategies have been developed and tested on the model. The presented results show that different control strategies give different behaviors and there is a trade-off between fast torque response and high precision for controlling the EGR-ratio. A control strategy is proposed containing two main feedback loops, prefiltering of the reference signal and a feedforward part.

This thesis wants to analyze the media service of the Empresa Media group during the three-day visit of chinese president Xi Jinping in the Czech Republic in march of 2016. At that time 49 percent share of Empresa Media was owned by chinese company CEFC. The visit was covered with a very high importance in all of the czech media. And not only in connection with the official schedule. Series of demonstration took place in Prague and also some fights occured between supporters of the chinese presindent and his opponents. However, media of the Empresa Media group almost without any exception ignored these events. Any manifestations of disagreement with the finese presindent's visit or China's politics is missing from its coverage. It results from analyzing magazine Tyden, its online version Tyden.cz, evening news of TV Barrandov and online coverage provided by Tyden.cz. This fact stands out even more when compared to some other important czech media.

Cette thèse porte sur le développement des méthodes d'analyse structurale de la couche mince de GaP epitaxiées sur le substrat de silicium par l'épitaxie par jets moléculaires (MBE), basées sur la diffraction des rayons X (ORX) et combinées à des techniques complémentaires telles que la microscopie électronique en transmission (TEM), la microscopie à force atomique (AFM) et la microscopie à effet tunnel (STM). Le travail est centré sur la caractérisation quantitative de la densité des défauts cristallins comme les micro-macles et les domaines d'inversion présents dans la couche ainsi que l'évaluation de la qualité de surface et l'interface. L'objectif ultime est d'obtenir une plate-forme GaP/Si parfaitement cristallisée sans défaut, via l'optimisation des paramètres de croissance. Nous avons mis en place et utilisé deux méthodes de quantification des micro-macles par la diffraction des rayons X en condition de laboratoire : les figures de pôles pour la visualisation rapide et l'évaluation de la densité des micro-macles et les « rocking-curves » permettent une extraction précise de la faction volumique de domaine maclé. Les propriétés structurales de la plate-forme de GaP/Si ont été considérablement améliorées, après une procédure d'optimisation impliquant la température de croissance, une procédure de croissance alternée (MEE) et une séquence de croissance en deux étapes. Un échantillon quasiment sans micro-macles a été obtenu par le dépôt de 40 monocouches de GaP par MEE à 350 •c suivi d'une surcroissance de 40 nm de GaP par MBE continue, à 500 •c. La surface de l'échantillon est lisse avec une rugosité de 0.3 nm. L'évaluation des domaines d'inversion par la ORX a été effectuée sur les cartographies de l'espace réciproque centrées sur les réflexions GaP de type (OOL), en laboratoire et sur une ligne synchrotron. Les balayages « transverses » extrait à partir des cartographies de l'espace réciproque sont analysés via une méthode dite "Williamson-Hall like", afin d'obtenir la "mosaïcité" qui est reliée à la micro-désorientation des petits domaines cristallins et la longueur de corrélation latérale correspondant à ces petits domaines. La distance moyenne entre parois de domaines d'inversion et ensuite estimé à partir de cette mesure. En utilisant cette méthode d'analyse et les techniques microscopiques, une optimisation plus poussée a été effectuée sur la dose de Ga au stade initial de croissance, l'utilisation de couches de marqueur AIGaP et l'homoépitaxie d'une couche de silicium avant le GaP. Enfin, nous avons obtenu un échantillon ne présentant pas de signal de micro-macle détectable en conditions standard de laboratoire, et une très faible densité de domaine d'inversion. Nous avons aussi observé une interface de GaP/Si visiblement présentant des bi-marches atomiques très régulières, sur un échantillon avec une couche de silicium déposée avant la croissance du GaP. / This thesis deals with the development of structural analysis methods of the GaP thin layers heterogeneously grown on the Si substrate by Molecular Beam Epixay (MBE), based on X-ray diffraction (XRD) analyses, combined with complementary techniques such as transmission electron microscopy (TEM), atomic force microscopy techniques (AFM) and scanning tunneling microscope (STM). The main work is centered on the quantitative characterization of crystalline defect such as micro-twins and the anti-phase domains, and the evaluation of the surface and interface quality. The ultimate goal is to achieve a perfectly crystallized GaP/Si platform without any defect, through the optimization of the growth conditions. We have applied two micro-twin quantification methods using a XRD lab setup. Pole figure method for fast visualization and evaluation of micro-twin density and rocking curves integration for a more precise absolute quantification of the micro-twin volume fraction. The GaP/Si platform structural properties have been significantly improved, after an optimization procedure involving growth temperature, MEE (Migration Enhanced Epitaxy) growth procedure and a twostep growth sequence. GaP layers quasi-free of MTs are obtained, with a r.m.s. roughness of only 0.3 nm. The APD evaluation by XRD has been performed on reciprocal space maps (RSM) centered on the (OOL) GaP reciprocal space lattice point either in lab setup or on synchrotron. Analysis of the transverse scans extracted from such RSM through the "Willamson-Hall like" method permits obtaining the "mosaicity" that is related to the micro-orientation of the small crystalline domains in the GaP layer, and the lateral correlation length which is considered to be related to the mean distance between two APBs, provided that this distance is approximately homogenous and corresponding to the mean APD size, and the density of other defects are very weak so that their influence can be neglected. Using this analytical method and the microscopic techniques, further optimization has been carried out on Ga amount at the initial growth stage, the use of AIGaP marker layers and the homoepitaxie of Si buffer layer. Finally, sample with none MT signal and very low density of APD has been achieved. Moreover, an abrupt GaP/Si interface displaying regular and double atomic steppes is observed on sample with a Si buffer layer prior to the GaP growth.

Small Intestinal Neuroendocrine Tumors (SI-NETs) are indolent neoplasms with an increasing annual incidence of approximately 1/100 000 people. They are often diagnosed at a late stage, restricting treatment efficacy. The aim of this thesis was to investigate clinical aspects of patients with advanced and/or disseminated disease with regard to clinical signs and management of abdominal fibrosis, the role of locoregional surgery and liver transplantation, as well as the ex vivo sensitivity of tumor samples to cytotoxic and targeted agents. Additionally, novel serum biomarkers for the diagnosis and prognosis of SI-NETs were investigated. In Paper I, abdominal fibrosis induced by serotonin and other cytokines from tumor cells, was associated with clinically significant symptoms of intestinal ischemia and/or obstructive uropathy, and was linked to advanced disease. Prompt recognition and minimally invasive intervention with superior mesenteric vein stenting and/or percutaneous nephrostomy and J stent treatment were effective in disease palliation. Paper II challenged the role of prophylactic, upfront locoregional surgery in Stage IV, which conferred no survival advantage in asymptomatic SI-NET patients. The option of delayed surgery as needed seemed to be comparable in all the outcomes examined, whilst also offering the advantage of fewer re-operations for intestinal obstruction in patients with already disseminated disease. Paper III confirmed that most young patients (<65 years) with SI-NET and liver metastases had a favorable survival with standardized multimodality treatment and that survival figures reported after liver transplantation for NETs do not surpass these figures. In Paper IV, 145 biomarkers were analyzed in blood serum using two different multiplex proximity assays. Subsequent ELISA and immunohistochemical analyses identified DcR3, TFF3 and midkine as novel serum biomarkers for SI-NETs. In Paper V, SI-NET samples were profiled with respect to sensitivity ex vivo to a panel of standard chemotherapeutics and targeted agents using a short-term total cell kill assay. SI-NETs exhibited variable but generally intermediate sensitivity ex vivo compared with other cancer diagnoses, calling for individualized selection of therapy.

Recent development in portable electronics and electric vehicles have increased the demand for high performance lithium ion batteries. However, it is still challenging to produce high energy and high power lithium ion batteries. The major objective of this research is to fabricate advanced electrode materials with enhanced power density and energy density. Porous Li4Ti5O12 (LTO) and its nanocomposites (with Si and reduced graphene oxide (rGO)) synthesized by electrostatic spray deposition (ESD) technique were mainly studied and promising electrochemical performance was achieved. In chapter 3, porous LTO thin film electrode was synthesized by ESD to solve the low energy density and low power density issues by providing good ionic and electronic conductivities. Electrochemical test results showed that it had a large specific capacity of 357 mAh g-1 at 0.15 A g-1, which was even higher than its theoretical capacity. It also exhibited very high rate capability of 98 mAh g-1 at 6 A g-1. The improved electrochemical performance was due to the advantage of ESD generated porous structures. In order to further enhance the power density of LTO, ESD derived LTO/rGO composite electrodes were studied in chapter 4. In chapter 5, high energy density component Si was introduced viii into LTO composite. The synergistic effect between commercial LTO and Si powder was studied. Then, ESD derived LTO/Si/rGO composite was prepared and evaluated. At 0.15 A g-1, a stable capacity of 624 mAh g-1 was observed, which was much higher than the capacities of LTO and LTO/rGO electrodes. In addition, effect of activation process on electrochemical performance of carbon nanofibers (ACNFs) and feasibility of ion intercalation into 2D MMT montmorillonite clay (MMT) were studied and discussed in chapter 6. In summary, we have successfully synthesized various LTO based electrodes by ESD. Both high energy and high power density were achieved as compared to commercial LTO electrode. Through electrochemical characterization and charge storage distribution analysis, origins of the high rate capability were proposed. This work demonstrates ESD as a powerful tool for fabricating high performance porous structures and nanocomposite electrode materials.

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