Search results for "thèse"
showing 10 items of 68 documents
Télécollaboration asymétrique en réalité virtuelle
2016
National audience; Nous présentons une première étude de combinaison de deux systèmes asymétriques de réalité virtuelle dans un contexte de travail collaboratif : un système de type CAVE et un casque immersif. L’architecture, de type serveur-client, permet une collaboration entre plusieurs utilisateurs. Les expériences sur une tâche de construction de puzzles en un temps limité, seul et en collaboration, montrent que l’utilisation combinée de systèmes asymétriques CAVE et casques permet d’améliorer les performances des utilisateurs. Par ailleurs les utilisateurs préfèrent le travail en collaboration et sont plus efficaces ensemble. Ces résultats ouvrent des perspectives intéressantes de com…
« La faucille après le marteau ». L’Internationale communiste et la paysannerie
2020
International audience
L’interaction agglomération-croissance en économie géographique
1999
International audience
Electrochemical reactivity of magnesium porphine : functionalization, oligo-polymerization and application to the synthesis of porphyrins and multi-p…
2012
This work deals with the redox reactivity of magnesium porphine, the study of its electropolymerization and resulting materials, of its functionalization by nucleophiles as well as the mechanistic investigation of the C-C oxidative coupling on a tris-meso-substituted porphyrin model.The electrochemical oxidation of magnesium porphine to its cation radical leads to oligomers in solution and polymers on the electrode, which molecular structure depends on the imposed potential. The reactivity of the cation radical has also been exploited by adding sufficient amount of nucleophiles (pyridine and triphenylphosphine) in the reactional in order to inhibit the oligomerization/polymerization process…
Le problème du réalisme des hypothèses en économie politique
2010
This is a version, slightly corrected in 2010 with regard to form, of a working paper produced in 1968. Its subject is the problem of the realism of assumptions in economics. It offers an interpretation of Milton Friedman's famous essay of 1953 in which, contrary to most discussions, Friedman's solution to the problem does make sense. Under that interpretation, Friedman does not assert that one should test the consequences of a theory but not its assumptions, that one can predict but not explain, or that individuals behave as if they were rational and firms as if they maximized profits. Such assertions do not make sense and ascribing them to Friedman makes criticism of his position much too…
Los museos etnológicos como instrumentos de formación ciudadana para hacer frente a los problemas que la humanidad tiene planteados
2017
Desde hace algunas décadas se viene llamando la atención desde diferentes ámbitos acerca de la insostenible situación de auténtica emergencia socioambiental planetaria en la que estamos inmersos y de la necesidad de contribuir a la formación de una ciudadanía consciente de dicha situación y preparada para participar en la toma de decisiones fundamentadas para hacer frente a la misma. Esta investigación responde a los llamamientos por Naciones Unidas a los educadores de todos los niveles, áreas y contextos, tanto de la educación formal como de la no reglada, con ese propósito de convertir la educación para la Sostenibilidad en una componente fundamental de la formación ciudadana. El objeto d…
PI-Extension of porphyrins via intramolecular aromatic oxidative C-N coupling
2019
Π-extension of porphyrins has been performed via intramolecular oxidative C-N coupling of peripheral pyridinyl fragment(s) with the porphyrin core. These fusion reactions lead to the formation of C-N bond(s) between the substituent(s) and the porphyrin. The precursors were functionnalized with 2-mercaptopyridine, 8-hydoxyquinoline and 2-picoline at their meso or β-pyrrolic positions via aromatic nucleophlic substitution, cross-coupling reaction or reaction of the macrocycle with organolithium reagents. Voltametric analyses revealed some marked differences on the reactivity of the porphyrins depending on their substitution pattern and metalation (nickel(II) or zinc(II)). Chemical and electro…
Synthèse in situ de fluorophores organiques : formation de liaisons covalentes par déclenchement enzymatique et applications en biodétection
2017
Fluorescence imaging is a growing field of biology over the past decades. Intensive works mainly focused on instrumental developments and chemistry of contrast agents (probes), were already done to improve such bioanalytical technique. The main goal of this Ph. D. thesis was to explore various fluorogenic molecular platforms responsive to various (bio)chemical stimuli and capable of releasing organic fluorophores in the biological medium to analyze. This approach named "in-situsynthesis" is based on domino reactions belonging to the repertoire of "covalent chemistry", triggered by the target (bio)analyte. This kind of process should provide advanced fluorogenic probes with high signal-to-no…
Vers des systèmes viticoles économes en pesticides
2022
L’utilisation de produits phytosanitaires (cuivre, soufre et produits de synthèses) est à ce jour le moyen de lutte le plus efficace pour garantir une vendange qualitative et quantitative (Pujol, 2017). Face aux préoccupations sociétales croissantes concernant l’impact des pesticides sur l’environnement et la santé, la viticulture se doit pourtant de réduire sa dépendance aux produits phytosanitaires. Une transition agroécologique est ainsi nécessaire et implique de changer les pratiques afin de parvenir à diminuer l’utilisation des produits phytosanitaires. Le réseau DEPHY-Ferme a été créé en 2010 afin d’initier et stimuler cette transition agroécologique et répondre aux enjeux ambitieux i…
Integration of thermal building simulation and VR techniques for sustainable building projects
2013
Déjà présent sur HAL mais sans le fichier pdf; The importance of energy efficiency and integration of advances in building design and VR technology have led this research to focus on thermal simulation results visualized in a virtual environment to optimize building design. This paper combines the principle of integration for thermal calculation and scientific visualization in VR. The method is to use CAD models (extensively used in architectural design) to analyze a building's thermal performance and visualize it, as well as simulating it through VR technology. Interaction between users and objects in a virtual world are certainly through techniques of visualization metaphors. The object o…