La viticulture sud-africaine : un équilibre entre Europe et « nouveau monde »

Le vignoble sud-africain a été créé en 1659 par Jan van Riebeeck ; la viticulture sud africaine a souffert jusqu’en 1994 d’une mauvaise réputation sur le plan international. Cela était dû à des produits de qualité médiocre et à un embargo sur les exportations qui résultait du régime d’apartheid. Aujourd’hui avec un vignoble de 110 200 hectares  et une production de 712 661 millions de litres 1, l’Afrique du Sud est le sixième producteur mondial (fig. 1). Ce revirement de situation est dû à pl..

Tectono-thermal history of an exhumed thrust-sheet-top basin : an example from the south Pyrenean thrust belt

This paper presents a new balanced structural cross-section of the Jaca thrust-sheet-top basin of the southern Pyrenees combined with paleo-thermometry and apatite fission track (AFT) thermochronology data. The cross-section, based on field data and interpretation of industrial seismic reflection profiles, allows refinement of previous interpretations of the south-directed thrust system, involving the identification of new thrust faults, and of the kinematic relationships between basement and cover thrusts from the middle Eocene to the early Miocene. AFT analysis shows a southward decrease in the level of fission track resetting, from totally reset Paleozoic rocks and lower Eocene turbidites (indicative of heating to Tmax>~120°C), to partially reset middle Eocene turbidites and no/very weak resetting in the upper Eocene-lower Oligocene molasse (Tmax<~60°C). AFT results indicate a late Oligocene-early Miocene cooling event throughout the Axial Zone and Jaca Basin. Paleo-maximum temperatures determined by vitrinite reflectance measurements and Raman spectroscopy of carbonaceous material reach up to ~240°C at the base of the turbidite succession. Inverse modelling of AFT and vitrinite reflectance data with the QTQt software for key samples show compatibility between vitrinite-derived Tmax and the AFT reset level for most of the samples. However, they also suggest that the highest temperatures determined in the lowermost turbidites correspond to a thermal anomaly rather than burial heating, possibly due to fluid circulation during thrust activity. From these results, we propose a new sequential restoration of the south Pyrenean thrust system propagation and related basin evolution

Fiabilité des amplificateurs optiques à semiconducteur 1,55 um pour des applications de télécommunication (étude expérimentale et modélisation physique)

Ces travaux de thèse décrivent le développement et la mise en œuvre d'un protocole expérimental pour estimer la fiabilité d'une technologie "bulk" d'amplificateur optique à semiconducteur (AOS) 1,55æm de couche active InGaAsP épitaxiée sur substrat InP. Il est basé sur l'analyse des paramètres électriques et optiques (puissance optique, pseudo-courant de seuil, gain, figure de bruit, puissance de saturation, ) suivis lors de différents tests de vieillissement sous différents facteurs d'accélération (courant-température). Ces études expérimentales, confortées par des simulations physiques 2D par éléments finis en introduisant un grand nombre de paramètres physiques extraits de caractérisations expérimentales, ont permis de mettre en évidence trois signatures de défaillance distinctes. Une première prédiction de distribution des durées de vie d'un AOS est également proposée à partir d'une approche statistique basée sur la méthode Monte-Carlo appliquée dans le cadre d'une faible population de composants et d'une faible dérive des paramètres.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF

Inferring New Information from a Knowledge Graph in Crisis Management: A Case Study

KEOD is part of IC3K : International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge ManagementInternational audienceNatural crises are dangerous events that can threaten lives and lead to severe damages. Crisis-related data can be heterogeneous and be provided from multiple data sources. These data can be formally described using ontologies and then integrated and structured forming knowledge graphs. Inferring new information from knowledge graphs can strongly assist in the various phases of the crisis management process. Different approaches exist in the literature for inferring new information from knowledge graphs. In this paper, we present a case study of a flood crisis where we discuss three approaches for inferring flood-related information, and we experimentally evaluate these approaches using real flood-related data and synthetic data for further analysis. We discuss the interest of using each of these approaches and detail its advantages as well as its limitations

Enhancing Interoperability and Inferring Evacuation Priorities in Flood Disaster Response

International audienceDisaster management is a crucial process that aims at limiting the consequences of a natural disaster. Disaster-related data, that are heterogeneous and multi-source, should be shared among different actors involved in the management process to enhance the interoperability. In addition, they can be used for inferring new information that helps in decision making. The evacuation process of flood victims during a flood disaster is critical and should be simple, rapid and efficient to ensure the victims’ safety. In this paper, we present an ontology that allows integrating and sharing flood-related data to various involved actors and updating these data in real time throughout the flood. Furthermore, we propose using the ontology to infer new information representing evacuation priorities of places impacted by the flood using semantic reasoning to assist in the disaster management process. The evaluation results show that it is efficient for enhancing information interoperability as well as for inferring evacuation priorities

Captage du CO₂ par formation d'hydrates de gaz : aspects thermodynamiques et cinétiques

National audienceLe captage du CO2 par la formation d'hydrates de gaz est envisagé dans la lutte contre les émissions de gaz à effet de serre. L'étude des équilibres tri phasiques Gaz, Liquide et Hydrate du mélange CO2- CH4 a montré la faisabilité d'une telle technique avec une phase hydrate majoritairement composée de CO2. Les résultats thermodynamiques ont été confrontés au modèle hermodynamique de Van der Waals et Platteeuw et nous observons une bonne concordance. L'aspect cinétique de la séparation de ces deux gaz a été aussi étudié afin de déterminer les vitesses relatives de capture des gaz. Nous remarquons une consommation très importante de CO2 dans les premiers instants de la cristallisation. Ce résultat a été interprété grâce au modèle cinétique élaboré. Ce modèle cinétique montre des comportements différents des deux gaz. Concernant le CH4, la consommation de gaz est limitée par le transfert gaz/liquide comme l'avaient prédit Skovborg et Rasmussen. Pour le CO2, la consommation de gaz est limitée par la diffusion de gaz à travers la couche limitante entourant les particules d'hydrates et la réaction d'incorporation

An Ontology and a reasoning approach for Evacuation in Flood Disaster Response

International audienceManaging flood-related data to assist in the disaster management is a critical process of high importance during a flood disaster. These data are heterogeneous and can be provided from different data sources, and integrating them is a challenging task which allows to infer new information that helps in limiting the consequences of a flood. In this paper, we propose a novel approach that manages heterogeneous flood-related data based on semantic web techniques and helps in limiting the damage caused by floods. We first propose an ontology that is used to formally describe the flood-related data, and we build our knowledge graph through integrating heterogeneous data using the proposed ontology. Then, we propose a reasoning approach using SHACL rules to infer new information that helps in managing the flood disaster or in anticipating future events. The experimental evaluations of our proposed approach are conducted on a real case study in the frame of flood disaster management with the aim of generatingevacuation priorities. The results show that it succeeds in managing heterogeneous flood-related data and generating evacuation priorities in a very short time

An Ontology and a Reasoning Approach for Evacuation in Flood Disaster Response

International audienceManaging flood-related data to assist in the disaster management is a critical process of high importance during a flood disaster. These data are heterogeneous and can be provided from different data sources, and integrating them is a challenging task which allows inferring new information that helps in limiting the consequences of a flood. In this paper, we propose a novel approach that manages heterogeneous flood-related data based on semantic web techniques and helps in limiting the damage caused by floods. We first propose an ontology that is used to formally describe the flood-related data, and we construct our knowledge graph through integrating heterogeneous data using the proposed ontology. Then, we propose a reasoning approach using SHACL rules to infer new information that helps manage the flood disaster or anticipate future events. The experimental evaluations of our proposed approach are conducted on a real case study in flood disaster management with the aim of generating evacuation priorities. The results show that the proposed approach succeeds in managing heterogeneous flood-related data and in generating evacuation priorities in a very short time

Réduire les pesticides, un peu, beaucoup, résolument

National audienceLa France s’est engagée depuis le Grenelle de l’environnement en 2008 dans une politique de réduction de l’usage des pesticides de synthèse, avec des avancées certaines, mais qui restent en deçà des ambitions initiales. Le Pacte vert européen fixe à son tour des objectifs ambitieux qui impliquent une reconception profonde des systèmes agricoles et alimentaires. Analyse des verrous qui freinent le changement et des leviers à actionner pour l’enclencher