40 research outputs found

    Modélisation et simulation de l'atelier de régénération de l'usine Kraft

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    L atelier de régénération d une usine kraft permet d extraire des liqueurs noires les élémentschimiques nécessaires à la cuisson du bois et de les régénérer sous leur forme active, ainsi quede valoriser la fraction organique dissoute sous forme de chaleur. Les opérations unitaires enoeuvre sont nombreuses, complexes, et souvent mal décrites. Ce travail vise à permettre unemeilleure compréhension de la régénération, par la réalisation de modÚles fiables décrivant lesphénomÚnes et processus dans chaque opération unitaire, leur implémentation algorithmiqueet leur exploitation par la simulation du procédé global.Chemical recovery at the kraft mill is the process whereby the valuable inorganic elements areextracted from spent kraft liquors and regenerated under their form effective to the cooking ofthe wood and energy is producted from the dissolved organic fraction. Many unit operations areinvolved, often poorly described. This work aims at a better understanding of the recovery processes.Reliable models describing the physical phenomena were proposed for each operation andimplemented as a computer algorithm. The whole chemical recovery unit was then simulated.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

    The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description

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    On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds

    Contribution à l'étude des luxations congénitales de l'épaule

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    ThÚse : Médecine : Université de Bordeaux : 1901N° d'ordre : 6

    Modélisation et simulation de l'atelier de régénération de l'usine Kraft

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    Chemical recovery at the kraft mill is the process whereby the valuable inorganic elements areextracted from spent kraft liquors and regenerated under their form effective to the cooking ofthe wood and energy is producted from the dissolved organic fraction. Many unit operations areinvolved, often poorly described. This work aims at a better understanding of the recovery processes.Reliable models describing the physical phenomena were proposed for each operation andimplemented as a computer algorithm. The whole chemical recovery unit was then simulated.L’atelier de rĂ©gĂ©nĂ©ration d’une usine kraft permet d’extraire des liqueurs noires les Ă©lĂ©mentschimiques nĂ©cessaires Ă  la cuisson du bois et de les rĂ©gĂ©nĂ©rer sous leur forme active, ainsi quede valoriser la fraction organique dissoute sous forme de chaleur. Les opĂ©rations unitaires enoeuvre sont nombreuses, complexes, et souvent mal dĂ©crites. Ce travail vise Ă  permettre unemeilleure comprĂ©hension de la rĂ©gĂ©nĂ©ration, par la rĂ©alisation de modĂšles fiables dĂ©crivant lesphĂ©nomĂšnes et processus dans chaque opĂ©ration unitaire, leur implĂ©mentation algorithmiqueet leur exploitation par la simulation du procĂ©dĂ© global

    Modelling and simulation of the recovery in a kraft pulp mill.

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    L’atelier de rĂ©gĂ©nĂ©ration d’une usine kraft permet d’extraire des liqueurs noires les Ă©lĂ©mentschimiques nĂ©cessaires Ă  la cuisson du bois et de les rĂ©gĂ©nĂ©rer sous leur forme active, ainsi quede valoriser la fraction organique dissoute sous forme de chaleur. Les opĂ©rations unitaires enoeuvre sont nombreuses, complexes, et souvent mal dĂ©crites. Ce travail vise Ă  permettre unemeilleure comprĂ©hension de la rĂ©gĂ©nĂ©ration, par la rĂ©alisation de modĂšles fiables dĂ©crivant lesphĂ©nomĂšnes et processus dans chaque opĂ©ration unitaire, leur implĂ©mentation algorithmiqueet leur exploitation par la simulation du procĂ©dĂ© global.Chemical recovery at the kraft mill is the process whereby the valuable inorganic elements areextracted from spent kraft liquors and regenerated under their form effective to the cooking ofthe wood and energy is producted from the dissolved organic fraction. Many unit operations areinvolved, often poorly described. This work aims at a better understanding of the recovery processes.Reliable models describing the physical phenomena were proposed for each operation andimplemented as a computer algorithm. The whole chemical recovery unit was then simulated

    Des images claires dans des piÚces obscures. Les représentations du Jātakamālā au Tibet oriental (1450-1550)

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    International audienc

    The Minyak Jigsaw: Spreading, Shuffling and Reordering an Iconography

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    International audienc

    Des images sous la boue: les chapelles peintes du Minyak (Tibet oriental)

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    International audienc

    Geometric and numerical techniques in optimal control of the two and three-body problems

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    The objective of this article is to present geometric and numerical techniques developed to study the orbit transfer between Keplerian elliptic orbits in the two-body problem or between quasi-Keplerian orbits in the Earth-Moon transfer when low propulsion is used. We concentrate our study on the energy minimization problem. From Pontryagin's maximum principle, the optimal solution can be found solving the shooting equation for smooth Hamiltonian dynamics. A first step in the analysis is to find in the Kepler case an analytical solution for the averaged Hamiltonian, which corresponds to a Riemannian metric. This will allow to compute the solution for the original Kepler problem, using a numerical continuation method where the smoothness of the path is related to the conjugate point condition. Similarly, the solution of the Earth-Moon transfer is computed using geometric and numerical continuation techniques
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