Numerical simulation of mold filling in low pressure die casting is considered in this study. The physical model includes modeling of free surface flow, heat transfer with phase change, surface tension, natural convection together with effect of trapped air in the mold. The governing equations are discretized by control volume finite difference method. The pressure field is computed by two-step projection method and the free surface is tracked by PLIC-VOF method. Water analog model is used for the validation purpose. Good agreement between numerical and experimental results is observed which supports the feasibility of the presented method.

The use of function has been recognized as an important part of the design process over last two decades, especially at the conceptual design stage, due to its critical role in determining the final product’s functionality. Although there are now some general methodologies dealing with functions or reasoning about functions, virtually no commercial CAD system can support conceptual design process due to their focus on geometrical modeling but not functional modeling. This paper presents a functional modeling approach to guide conceptual die design through functional reasoning steps including functional decomposition, functional supportive synthesis and function-structure mapping. The formed functional model provides a good basis to generate various die structures at the conceptual design stage, because function is a higher level of abstraction than structure, and helps to capture the designer’s intent. The functional modeling process has been implemented in a computerized design environment to expedite the conceptual die design process. / Singapore-MIT Alliance (SMA)

This paper presents an intelligent, hybrid system for stamping process planning in progressive die design. The system combines the flexibility of blackboard architecture with case-based reasoning. The hybrid system has the advantage that it can use past knowledge and experience for case-based reasoning when it exists, and other reasoning approaches when it doesn’t exist. A prototype system has been implemented in CLIPS and interfaced with Solid Edge CAD system. An example is included to demonstrate the approach. / Singapore-MIT Alliance (SMA)

The role of water and volatiles in the solar system is of critical interest in planetary science. Evidence for the past action of water or direct observation of water on a planetary body can indicate the potential to harbor life and is critical to human exploration of the solar system. We study two very different remote sensing techniques that address the issue of identifying water-related processes on the surface of other planetary bodies, and in particular, Mars. The first technique, combined thermal infrared and visible imaging, has been used extensively on Mars for determining the thermal inertia of surface materials. In the second part of this dissertation, we develop a technique that combines remote thermophysical and visible data sets with ground-based field investigations for the identification of sedimentary features at the surfaces of alluvial fans. Several methods for remotely identifying sedimentary features will be explored using thermal and visible images. We combine results from pre-existing ground-based studies with thermal images and ground-based field investigations to develop a robust technique to be used on a variety of alluvial fans. In the third part, we characterize the remote thermophysical and visible properties of specific classes of sedimentary features on alluvial fans using the technique developed in part two. The second remote sensing technique, neutron spectroscopy, has been used on many planetary spacecraft missions for the identification of hydrogen on planetary surfaces. The Dynamic Albedo of Neutrons (DAN) instrument on the upcoming Mars Science Laboratory rover mission represents a new type of neutron detector for planetary spacecraft, with the neutron detectors mounted to a rover on the Martian surface (as opposed to in orbit around the planetary body) and neutron counts that are binned by time, energy, and location (as opposed to just by energy and location). In chapter four, we model expected neutron energies and arrival times for geologic settings where water has altered the chemistry of the near surface using available geochemical data from the Mars Exploration Rovers (MER). Particle transport models are used to determine the sensitivity of neutron detection techniques to the variations in hydrogen abundance, hydrogen layering and chemical composition measured by MER.

Diese Publikation einer Masterarbeit leistet einen Beitrag, die bestehende Forschungslücke hinsichtlich der Rolle rechtspopulistischer Parteien in Regierungsbildungsprozessen zu füllen. Warum haben sich etablierte Parteien und Rechtspopulisten für eine bestimmte Konstellation entschieden? Welche Probleme traten durch den spezifisch rechtspopulistischen Charakter bei der Regierungsbildung auf? Welche Alternativen gibt es? Mittels eines vergleichenden Ansatzes werden dabei als Fallbeispiele die Regierungsbildungsprozesse nach drei Wahlen zu nationalen Parlamenten im Jahr 2010 in Belgien, den Niederlanden und Schweden analysiert.

No description available.

Aluminum alloys are widely used in many manufacturing areas due to good castability, lightness and mechanical properties. The purpose of this research is to investigate copper’s influence on an Al-Si-Mg alloy (A356). Copper in the range of 0.6 – 1.6 wt. % has been used in an A356 aluminum based alloy. In this work a simulation of three different casting processes, sand-, die- and high pressure die-casting has been employed with the help of gradient solidification equipment. The microstructure of the samples has been studied by optical and scanning electron microscopy. Materials in both as-cast and heat treated states have been investigated through tensile test bars  to get the mechanical properties of the different conditions.   Questions that have been subjected to answer are what influence does copper have on the plastic deformation and on fracture behavior and whether there is a relationship between the content of copper and increased porosity or not; and in that case explore this relationship  between the amount of copper and the mechanical behaviour.   It has been analyzed that a peak of mechanical properties is obtained with a content about 1.6 wt. % copper. The increment of copper seems to have a remarkable impact on the mechanical properties and especially after the aging process showing a large raise on the ultimate tensile strength and yield strength. Relationship between the copper content and increased porosity could not be found.

Microbial contamination of drinking water poses an important health risk which causes severe illnesses and epidemics. In order to improve surface and drinking water quality, the understanding of fecal pathogen contamination processes including their prevention and control needs to be enhanced. The watershed model soil water assessment tool (SWAT) is commonly used to simulate the complex hydrological, meteorological, erosion, land management and pollution processes within river basins. In recent years, it has been increasingly applied to simulate microbial contamination transport at the watershed scale. SWAT is used in this study to simulate Escherichia coli (E.coli) and fecal coliform densities for the agriculturally dominated Payne River Basin in Ontario, Canada. Unprecedented extensive monitoring data that consist of 30 years of daily hydrological data and 5 years of bi-weekly nutrient data have been used to calibrate and validate the presented model here. The calibration and validation of the streamflow and nutrients indicate that the model represent these processes well. The model performs well for periods of lower E. coli and fecal coliform loadings. On the other hand, frequency and magnitude of higher microbial loads are not always accurately represented by the model.

Microbial contamination of drinking water poses an important health risk which causes severe illnesses and epidemics. In order to improve surface and drinking water quality, the understanding of fecal pathogen contamination processes including their prevention and control needs to be enhanced. The watershed model soil water assessment tool (SWAT) is commonly used to simulate the complex hydrological, meteorological, erosion, land management and pollution processes within river basins. In recent years, it has been increasingly applied to simulate microbial contamination transport at the watershed scale. SWAT is used in this study to simulate Escherichia coli (E.coli) and fecal coliform densities for the agriculturally dominated Payne River Basin in Ontario, Canada. Unprecedented extensive monitoring data that consist of 30 years of daily hydrological data and 5 years of bi-weekly nutrient data have been used to calibrate and validate the presented model here. The calibration and validation of the streamflow and nutrients indicate that the model represent these processes well. The model performs well for periods of lower E. coli and fecal coliform loadings. On the other hand, frequency and magnitude of higher microbial loads are not always accurately represented by the model.

Le Tambour de Günter Grass peut être lu comme la mise en fiction du roman familial du personnage et narrateur, Oscar Matzerath, qui rédige ses mémoires dans la maison de santé où il est interné. L'objet de ce mémoire est précisément l'analyse de l'écriture d'Oscar comme invention d'une généalogie mythique et fantasme des origines. Ce narrateur indique dès le début de ses mémoires que « nul ne devrait décrire sa vie » sans d'abord « commémorer une bonne moitié de ses grands-parents ». Ce besoin de reconstituer l'origine et de l'interroger se déploie dans le récit à travers, notamment, le fantasme du retour au sein maternel (dont le tambour et l'écriture constituent en quelque sorte les moyens) qui se traduit par la reconstitution d'une généalogie sur les modes mythique et théologique. Ce mémoire s'intéresse donc d'abord aux mécanismes qui régissent l'écriture « oscarienne » dans sa cohésion interne, c'est-à-dire en fonction des fantasmes du personnage et des réseaux symboliques et signifiants qui le construisent dans le texte et qui constituent son style propre. La question de l'origine convoque celles de la filiation et du mythe, autant d'éléments à mettre en réseau pour éclairer la construction généalogique fantasmée par le narrateur. Sur ce plan, l'approche psychanalytique ouvre une perspective de recherche appropriée pour repérer les mécanismes du fantasme dans l'écriture d'Oscar, c'est pourquoi nous opterons pour une lecture orientée en ce sens. Il s'agit de voir comment, sur les plans de l'énonciation, de la mémoire et du mythe, le roman construit une filiation matrilinéaire au service d'une toute-puissance narrative qui permet d'échapper au temps et à la mort. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Günter Grass, Le Tambour, Fantasme de l'origine, Généalogie matrilinéaire, Mythe.