Cipières – Église Saint-Mayeul

Identifiant de l'opération archéologique : 8119 et 8187 Date de l'opération : 2007 (SU) Inventeur(s) : Blanc Fabien (AUT) L’église paroissiale de Cipières fait l’objet, depuis plusieurs années déjà, de projets de restauration à l’initiative de la municipalité suite à un état général de dégradation de l’édifice. La première tranche de restauration concernait les sols qui présentaient à plusieurs endroits des déformations dues à la présence sous-jacente de plusieurs caveaux alors scellés par un..

Strains Induced by Point Defects in Graphene on a Metal

Strains strongly affect the properties of low-dimensional materials, such as graphene. By combining in situ, in operando, reflection high energy electron diffraction experiments with first-principles calculations, we show that large strains, above 2%, are present in graphene during its growth by chemical vapor deposition on Ir(111) and when it is subjected to oxygen etching and ion bombardment. Our results unravel the microscopic relationship between point defects and strains in epitaxial graphene and suggest new avenues for graphene nanostructuring and engineering its properties through introduction of defects and intercalation of atoms and molecules between graphene and its metal substrate

Secure migration of virtual SDN topologies

International audienceWith the emergence of Software Defined Networks (SDN), new virtualization techniques have appeared (e.g., FlowVi-sor [14]). Traditional hypervision has attracted a lot of attention with respect to resource sharing and multi-tenancy. Cloud providers have usually a solid knowledge on how to manage computing , memory and storage resources, but often lack the ability to properly manage network resources. Thanks to OpenFlow, a widespread SDN southbound interface protocol, virtualizing the network infrastructure has become possible. However, network virtualization also comes with its own security issues ([5], [6]). In this paper, we focus on the security aspects related to the migration of virtual networks. After providing a brief overview of the technological scope of our work, we review the state of the art of the migration of virtual resources. Finally, we conclude with our current results and the prospective outcomes we expect to obtain

Sainte-Agnès – Château

Identifiant de l'opération archéologique : 8217 Date de l'opération : 2007 (FP) Inventeur(s) : Lapasset Michel (EDU) ; Blanc Fabien (EDU) La campagne 2007 sur le site de Sainte-Agnès (Alpes-Maritimes) est la poursuite du travail entamé sur le corps castral (BSR PACA, 2006 : 93-94). Après avoir étudié l’évolution des accès au bloc central l’année précédente, c’est la tour maîtresse qui a été fouillée (Fig. n°1 : Vue de la tour maîtresse de Sainte-Agnès). Une première campagne avait déjà été e..

Optimizing resource allocation for secure SDN-based virtual network migration

International audienceRecent evolutions in cloud infrastructures allowed service providers to tailor new services for demanding customers. Providing these services confronts the infrastructure providers with costs and constraints considerations. In particular, security constraints are a major concern for today's businesses as the leak of personal information would tarnish their reputation. Recent works provide examples on how an attacker may leverage the infrastructure's weaknesses to steal sensitive information from the users. Specifically, an attacker can leverage maintenance processes inside the infrastructure to conduct an attack. In this paper, we consider the migration of a virtual network as the maintenance process. Then we determine the optimal monitoring resources allocation in this context with a Markov Decision Process. This model takes into account the impact of monitoring the infrastructure, the migration process and finally how the attacker may chose particular targets in the infrastructure. We provide a working prototype implemented in Python

Validating Meteosat-derived surface solar irradiance in Mozambique

International audiencehe solar radiation reaching the ground level on horizontal surfaces is of interest to many domains. The database HelioClim-1 contains daily values of radiation for 21 years: 1985-2005. It has been derived from Meteosat images and covers Europe, Africa and Atlantic Ocean. It is compared to ground-based measurements in Mozambique collected from the World Radiation Data Center. The quality of HelioClim-1 is good: the root mean square difference is approximately 30 W/m², and the correlation coefficient is greater than 0.85. These results are similar to those obtained by previous studies for Europe. HelioClim-1 is freely available through the SoDa Service and offers a reliable and accurate knowledge of the solar radiation and its daily, seasonal and annual variations over recent years

Topography of the graphene/Ir(111) moiré studied by surface x-ray diffraction

International audienceThe structure of a graphene monolayer on Ir(111) has been investigated {\it in situ} in the growth chamber by surface x-ray diffraction including the specular rod, which allows disentangling the effect of the sample roughness from that of the nanorippling of graphene and iridium along the moiré-like pattern between graphene and Ir(111). Accordingly we are able to provide precise estimates of the undulation associated with this nanorippling, which is small in this weakly interacting graphene/metal system and thus proved difficult to assess in the past. The nanoripplings of graphene and iridium are found in phase, i.e. the in-plane position of their height maxima coincide, but the amplitude of the height modulation is much larger for graphene ($0.379 \pm 0.044$ \AA) than, {\it e.g.}, for the topmost Ir layer ($0.017 \pm 0.002$ \AA). The average graphene-Ir distance is found to be $3.38 \pm 0.04$ \AA

Séranon – Chapelle Notre-Dame de Gratemoine

Identifiant de l'opération archéologique : 8413 Date de l'opération : 2007 (SU) Inventeur(s) : Blanc Fabien (EDU) ; Cavanna Émilie (EDU) ; Georget Gwenhaël (EDU) ; Suméra Franck (SRA) ; Tzortzis Stefan (SRA) La chapelle Notre-Dame de Gratemoine devait recevoir un éclairage extérieur destiné à sa mise en valeur. L’installation des éclairages impliquaient la réalisation de tranchées tout autour de l’édifice parfois à moins de 1 m de distance. La présence d’une zone funéraire à proximité de l’ab..

Fast detection and structural identification of carbocations on zeolites by dynamic nuclear polarization enhanced solid-state NMR

Acidic zeolites are porous aluminosilicates used in a wide range of industrial processes such as adsorption and catalysis. The formation of carbocation intermediates plays a key role in reactivity, selectivity and deactivation in heterogeneous catalytic processes. However, the observation and determination of carbocations remain a significant challenge in heterogeneous catalysis due to the lack of selective techniques of sufficient sensitivity to detect their low concentrations. Here, we combine 13C isotopic enrichment and efficient dynamic nuclear polarization magic angle spinning nuclear magnetic resonance spectroscopy to detect carbocations in zeolites. We use two dimensional 13C–13C through-bond correlations to establish their structures and 29Si–13C through-space experiments to quantitatively probe the interaction between multiple surface sites of the zeolites and the confined hydrocarbon pool species. We show that a range of various membered ring carbocations are intermediates in the methanol to hydrocarbons reaction catalysed by different microstructural β-zeolites and highlight that different reaction routes for the formation of both targeted hydrocarbon products and coke exist. These species have strong van der Waals interaction with the zeolite framework demonstrating that their accumulation in the channels of the zeolites leads to deactivation. These results enable understanding of deactivation pathways and open up opportunities for the design of catalysts with improved performances