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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Un nouveau regard sur la Structure interne et l'évolution des planètes géantes solaires et extrasolaires / A new vision on (Extrasolar) Giant Planets Internal Structure and Evolution

Leconte, Jérémy 05 October 2011 (has links)
La détection et la caractérisation d'exoplanètes apparaissent clairement comme des thèmes centraux de l'observation astronomique pour les années à venir. Les projets spatiaux ou au sol sont nombreux (HARPS, CoRoT, Kepler, JWST, SPHERE...), mais les études théoriques visant à l'analyse et à la compréhension des données recueillies et à venir sont nécessaires. Durant cette thèse j'ai étudié divers processus physiques affectant la structure interne et l'évolution des planètes géantes, aussi bien au sein, qu'à l'extérieur de notre système solaire. J'ai notamment modélisé en détail: -L'impact de l'irradiation intense émise par l'étoile sur l'atmosphère d'une planète à faible distance orbitale, et l'effet induit sur l'évolution interne de cette planète. -Le couplage par dissipation de marée de l'évolution orbitale et thermique d'une planète interagissant avec sa proche étoile parente. -L'effet de la déformation due aux marées sur les paramètres observables d'une planète en transit grâce au suivi photométrique de son passage devant l'étoile. -L'incidence sur la structure et l'évolution d'une diminution de l'efficacité du transport de chaleur par convection due à un gradient d'éléments lourd dans l'enveloppe gazeuse d'une planète géante, conduisant au phénomène de convection double-diffusive. A travers l'étude des ces divers processus, j'ai développé différents modèles analytiques et codes numériques qui sont à la fois flexibles et robustes, et qui permettent maintenant d'étudier certaines propriétés des nouveaux objets substellaires détectés à mesure qu'ils sont découverts. / The detection and characterization of extrasolar planets clearly appears as one of the main goals of observational astronomy for the coming years. Space and ground project are numerous, but theoretical studies aimed at analyzing and understanding available and future data are needed. During this thesis, I study various physical processes affecting the internal structure and evolution of both solar, and extrasolar giant planets. In particular I investigate : -the impact of the intense stellar irradiation received by a close in planet on its subsequent internal evolution. This allows me to quantify the radius anomaly of bloated Hot Jupiters and to constrain their internal composition. -the tidal and centrifugal distortion of a fluid planet. By using both analytical and numerical models, I show how non-sphericity of the planet affects transit measurements, yielding an underestimation of its radius. -how the presence of double-diffusive convection caused by a heavy elements gradient in the gaseous envelope of a planet can decrease the efficiency of its internal heat transport, and affect its structure and evolution. -the coupling between the orbital and the thermal evolution of a planet arising from the strong star-planet tidal interaction. Subsequently, I find that tidal heating alone is not a viable explanation for the observed radius anomaly of transiting planets. Through these different studies, I developed various analytical models and numerical codes that are both flexible and robust, and which now allow one to study the properties of new extrasolar planets and brown dwarfs as they are discovered.
132

Diffusion de la lumière par des agrégats irréguliers: simulations numériques et expérimentales, applications aux petits corps dans le système solaire

Lasue, Jérémie A.F. 29 September 2006 (has links)
Les particules cométaires sont des témoins de l’évolution du système solaire, dont les caractéristiques peuvent être estimées à partir de la lumière qu’elles diffusent et émettent.<p>Je montre qu’un modèle de diffusion lumineuse par un nuage d’agrégats fractals et de sphéroïdes permet d’interpréter, en fonction de la distribution en taille et des matériaux constitutifs, des observations polarimétriques en angle de phase et longueur d'onde. Le modèle est en particulier appliqué à la comète Hale-Bopp, et au milieu interplanétaire en modélisant aussi les observations thermiques.<p>Je développe des outils de diffusion lumineuse (numériques et expérimentaux) pour analyser des agrégats analogues aux particules protoplanétaires qui seront formés avec ICAPS à bord de l’ISS. De façon complémentaire, une simulation expérimentale en vol parabolique avec PROGRA2 me permet de déterminer les propriétés physiques de microparticules d’intérêt astrophysique par des mesures polarimétriques.<p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
133

The use of technology in meeting science reform criteria: Can web-based instruction promote scientific literacy?

Vogt, Karen Fay 01 January 1999 (has links)
Science educators are currently facing the challenge of reforming the practices of science education. Publications of various science and educational organizations have established new criteria for accomplishing this goal. The new goal of science educators is scientific literacy for all.
134

Analýza tepelné spotřeby objektu / Analysis of Heat Energy Consumption of Buildings

Houzar, Tomáš January 2017 (has links)
Master’s thesis is focused on analysis of thermal consumption in the buiding. This work describes current state of family house and possible suggestions for heating and water heating. Part of solution is created program, which supposed to serve as universal calculation program for design and economic evaluation of suggested solar systém and allows a comparison between commonly used sources for heating and water heating.
135

Měření a regulace počítačem řízených solárních systémů: Vizualizace energetických systémů / Measuring and regulation of computer controlled solar systems: Vizualization of energetic systems

Vlčnovská Kotlíková, Silvie January 2008 (has links)
This work is oriented on study and evaluation of performance of real operating solar system. There was made analysis of actual technological unit and there was suggested mode of measuring of nodal parameters. There was made interconnection between the head operating unit of the solar system and the web server. And there was prepared software for grafical image of time and temperature dependence and for data transfer to ready web application. It primarily talks about increase of efficiency of real technological unit through regulating of parameter that is using up of accumulated energy.
136

Vyhodnocení ekonomické efektivnosti solárního systému / Analysis of the economic efficiency of a solar system

Mikl, Antonín January 2009 (has links)
The Master’s thesis deals with the processing of solar thermal systems for heating hot water, outdoor swimming pool and heating selected house. Introduces us how we can use the sun for the production of thermal energy through solar collectors. Furthermore, the basic components of the solar system and the types of collectors used. After this summary on the present state be the calculation of the system and fixing the price of the investment. The economic part of the evaluate if this system to invest, eventually appoint a return on investment.
137

Energetické hodnocení obytných budov / Energy Evaluation of Residential Buildings

Fojtů, Pavel January 2013 (has links)
This master thesis offers two cost-saving measures to reduce the energy consumption of a residential building. These measure include insulation of the building envelope, domestic hot water by solar colectors and heat recovery.
138

Návrh otopného systému pro nízkoenergetický rodinný dům / Design of heating system for low-energy family house

Kytýrová, Zdeňka January 2008 (has links)
This diploma thesis deals with the design of a heating system for a "low-energy" house. It is conceived as a low temperature system using a combination of radiators and underfloor heating. The design is supplemented with a calculation of heat loss, a proposal of needed components, a scheme of the system and means of regulation. The second part solves the heat source selection. A solar system with vacuum tubes is used as the primary source. The second one is an electrical water heater located in the accumulation reservoir for the hot domestic water. Necessary calculations for the design of the solar system, together with a scheme and means of regulation, are enclosed in this section.
139

Návrh solárního ohřevu vody a solárního přitápění v rodinném domě / Design of a solar space and DHW heating system for a detached dwelling

Čukat, Stanislav January 2012 (has links)
The master’s thesis deals with the design of solar assisted space heating and domestic hot water (DHW) heating in a detached single family dwelling. The thesis contains the heating load calculations as well as the calculation of the energy consumption for space and DHW heating. The thesis also contains the actual design and sizing of the heating system including the drawings. A simulation of solar heating was carried out with the use of the TRNSYS simulation tool in order to assess the yield of the solar heating system.
140

Heating of building with almost zero energy consumption / Heating of building with almost zero energy consumption

Kubátová, Anna January 2012 (has links)
The aim of the thesis is to model energetic needs for heating and temperatures progress in the building with almost zero energy consumption. The part of the work is the economical and energetic comparison. Proposed systems are based on a knowledge of active houses.

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