The inequality level-set approach to handle contact: membrane case

International audienceBackground: Contact mechanics involves models governed by inequality constraints. Even for the simplest contact problem, inequalities arise from the lack of information on the contact zone position. In addition to increasing the difficulty to solve such problems, an unknown contact zone makes it difficult to use an appropriate mesh and to represent efficiently phenomena on the contact zone boundary. Nevertheless these phenomena are often crucial to have an accurate representation of the problem such as weak discontinuity of the displacement.Methods: In this paper, we propose a method specifically designed to solve inequality constraint problems linked to an unknown domain without remeshing. In order to do so, level sets coupled with X-FEM is used to define the unknown domain and take into account the specific behavior at the contact zone boundary. The key idea of the method is to split the problem involving inequality constraints into two problems. In the first problem, the unknown domain is set and therefore it only involves equalities. Nevertheless, the constraints might be violated, meaning the set domain has to be changed. Then, the other problem is a shape optimization of this domain and leads to an updated set domain. These two problems are iterated up to convergence of the algorithm. Moreover, the addition of adhesion to the problem will be considered.Results: The studied case in this paper is a membrane in the context of small deformations. First, a 1D example will be given to illustrate the method with and without adhesion. Then 2D cases will be studied. Finally an example with an evolving load will be given. Comparison will be made with a classical active-set method.Conclusions: The ILS is proved to be an efficient method giving a convincing accuracy for the contact boundary without need of re-meshing. It is also able to naturally handle adhesion

La Tolérance des religions de Henri Basnage de Beauval (1684)

Lorsque la Tolérance des Religions sort des presses de Hollande, le protestantisme français est à l’agonie. Ce traité est le fruit d’une réaction désespérée de la part d’un huguenot, Henri Basnage de Beauval (1656-1710), qui s’inquiète pour l’avenir de sa communauté confessionnelle. Il y dénonce les persécutions orchestrées par une Église catholique corrompue et rebelle à l’autorité légitime des Bourbons sur la Couronne de France. Ce texte est aussi un appel, de la part d’un protestant profondément attaché à la monarchie absolue, au « bon vouloir » de Louis XIV. L’auteur réclame en effet la mise en place d’une tolérance civile qui, selon lui, est nécessaire à la préservation de la paix dans le royaume et à « l’émulation positive des religions concurrentes ». Cette tolérance des plus pragmatiques n’est autre qu’un retour à l’édit de Nantes des origines, purifié de toute interprétation rigoriste. Son application devrait contribuer à la gloire du Roi-Soleil en Europe, l’érigeant en monarque soucieux du bonheur de ses sujets. Le sieur de Beauval justifie cette demande par l’idée que les huguenots sont de bons chrétiens mais surtout de bons français qui méritent d’être récompensés pour leur loyauté. Si ce traité est le premier d’un ensemble de textes dédiés à la tolérance qui apparaissent dans le sillage de l’édit de Fontainebleau de 1685, il ne peut être considéré comme complètement innovant. Il construit effectivement sa théorie à partir de ses propres lectures de théologiens protestants aussi bien que catholiques. Influencé par des auteurs comme Castellion, Locke ou encore Bayle, il propose cependant des arguments originaux qui, à leur tour, sont pris en compte par d’autres théoriciens de la tolérance.The Tolérance des Religions was published in 1684, when French Protestantism was dying. This treaty was the result of a desperate reaction by Henri Basnage de Beauval (1656-1710), a Huguenot who had to confront the dark future of his religious community. He denounced the persecutions orchestrated by a corrupt Catholic Church, which betrayed the legitimate dynasty of France. This text is also a call, by a Protestant deeply attached to the political system of absolute monarchy, to “le bon vouloir” of his king. Indeed, Basnage de Beauval wanted civil toleration, for his country. According to him, it was the only manner of finding peace in the kingdom and creating a “positive emulation of competing religions”. This pragmatic toleration was, in reality, a return to an unadulterated edict of Nantes, free from rigorous interpretations. Its application should glorify the Sun King in Europe, showing that he respected his subjects and sought to make them happy. This request was legitimised by the fact that Huguenots were good Christians but above all good Frenchmen who deserved to be rewarded for their loyalty. This treaty was the first of several others about toleration published after the edict of Fontainebleau of 1685. However, it was not completely innovative as Basnage de Beauval constructed his theory from his own knowledge of theological literature (Protestant and Catholic). He was influenced by authors such as Castellion, Locke or Bayle, but he also created his own original arguments which were then taken into consideration by other toleration theorists

DALLE POLITICHE LINGUISTICHE ALLA PRATICA PROFESSIONALE IN CLASSE: L’ESPERIENZA FRANCESE

Il nodo della presente riflessione nasce dalla doppia postura in cui mi trovo : sono docente di francese lingua due (FLS) in una scuola superiore di secondo grado in Francia ; in parallelo, nella mia tesi di dottorato, cerco di definire cosa devo insegnare in questo dispositivo. Infatti, non esiste nessun curriculum di francese per gli alunni allofoni. Cercherò di mostrare che la politica attuale del Ministero della Pubblica istruzione ha molte conseguenze pratiche per gli alunni con bisogni educativi speciali : l’inclusione degli alunni allofoni non è più una priorità ; il loro plurilinguismo è poco valorizzato ; la scelta istituzionale di non scrivere programmi di studio per l’UPE2A (unità pedagogica per gli alunni allofoni recentemente arrivati) crea difficoltà per i docenti.   From language policies to professional classroom practice: the French experience As a teacher trained in French as Second Language (FSL), I have taught foreign high school students since 2016. It is important to note that French curricula don’t consider the linguistic needs of foreign high school students, compared with primary and middle school students. These students are no longer subject to compulsory education: could this be the reason for the lack of research? This leads us to the following questions: is the concept of inclusion accounted for in Special Needs Education? What are the possible connections between the national linguistic policy and multilingualism at school? And more pragmatically, how can FSL theory be applied in high school classrooms with non-Francophone students

Documents, données et méta-données : une approche mixte pour un système de veille

International audienceMots clefs : sources d'information, informations textuelles, données structurées, méta-données, analyse et conception d'un système de veille Keywords: information sources, textual information, structured data, metadata, watch system modeling and design Palabras clave : fuentes de información, información textual, datos estructurados, méta datos, métodos de diseño y diseño de los sistemas de vigilancia Résumé L'exploitation de grandes masses documentaires pour l'élaboration d'un dossier de veille technique nécessite la mise en oeuvre d'un système d'information adapté à la compilation de données multisources. Le retour d'expérience sur l'utilisation du système de veille SILURE au Centre Technique des Systèmes Navals, système présenté dans nos précédentes contributions [Gra97,BG98], nous conduit à étendre la modélisation initiale pour une meilleure prise en compte du contexte documentaire d'où sont extraites les données sélectionnées. L'originalité de cette double approche (« orientée donnée » et « orientée document ») repose sur l'emploi de méta-données relatives à la qualité des données stockées et à celle de leurs sources (intérêt, fiabilité, complétude, fraîcheur). L'exploitation combinée de ces méta-données permet notamment d'affecter les priorités de traitement sur une collection de documents qui va, par une structuration sélective semi-automatique, assurer l'alimentation en données factuelles et référentielles de la base au coeur du système de gestion des informations du domaine ciblé par la démarche de veille

Sand, salt, and models : The legacy of Bruno Vendeville

Acknowledgements We are grateful for the support of numerous colleagues who contributed, either materially or simply with encouragement, to putting together this memorial to our friend Bruno. The important task of reviewing and editing manuscripts was carried out by the co-editors along with Jürgen Adam, Ian Davison, Tim Dooley, Carl Fiduk, Pablo Granado, Geoffroy Mohn, Webster Mohriak, Van Mount, Josep Anton Muñoz, Thierry Nalpas, Fabrizio Storti, Gabor Tari, Lei Wu, and 16 reviewers who chose to remain anonymous. And of course, this volume would not have happened without the hard work and persistence of the many authors and coauthors who contributed their manuscripts. We also thank Lorna Stewart and other staff at the Journal of Structural Geology for their help and guidance, as well as Tim Dooley for supplying original versions of the figures used here.Peer reviewe

Neogene uplift of the Tian Shan Mountains observed in the magnetic record of the Jingou River section (northwest China)

The Tian Shan Mountains constitute central Asia's longest and highest mountain range. Understanding their Cenozoic uplift history thus bears on mountain building processes in general, and on how deformation has occurred under the influence of the India-Asia collision in particular. In order to help decipher the uplift history of the Tian Shan, we collected 970 samples for magnetostratigraphic analysis along a 4571-m-thick section at the Jingou River (Xinjiang Province, China). Stepwise alternating field and thermal demagnetization isolate a linear magnetization component that is interpreted as primary. From this component, a magnetostratigraphic column composed of 67 polarity chrons are correlated with the reference geomagnetic polarity timescale between ∼1 Ma and ∼23.6 Ma, with some uncertainty below ∼21 Ma. This correlation places precise temporal control on the Neogene stratigraphy of the southern Junggar Basin and provides evidence for two significant stepwise increases in sediment accumulation rate at ∼16–15 Ma and ∼11–10 Ma. Rock magnetic parameters also undergo important changes at ∼16–15 Ma and ∼11–10 Ma that correlate with changes in sedimentary depositional environments. Together with previous work, we conclude that growth history of the modern Tian Shan Mountains includes two pulses of uplift and erosion at ∼16–15 Ma and ∼11–10 Ma. Middle to upper Tertiary rocks around the Tian Shan record very young (<∼5 Ma) counterclockwise paleomagnetic rotations, on the order of 15° to 20°, which are interpreted as because of strain partitioning with a component of sinistral shear that localized rotations in the piedmont

The in vitro effects of resistin on the innate immune signaling pathway in isolated human subcutaneous adipocytes

Context: Obesity-associated inflammation is a contributory factor in the pathogenesis of type 2 diabetes mellitus (T2DM); the mechanisms underlying the progression to T2DM are unclear. The adipokine resistin has demonstrated pro-inflammatory properties in relation to obesity and T2DM. Objective: To characterize resistin expression in human obesity and address the role of resistin in the innate immune pathway. Furthermore, examine the influence of lipopolysaccharide, recombinant human resistin (rhResistin), insulin and rosiglitazone in human adipocytes. Finally, analyze the effect of rhResistin on the expression of components of the NF-κB pathway and insulin signaling cascade. Methods: Abdominal subcutaneous adipose tissue was obtained from patients undergoing elective liposuction surgery (n = 35, aged: 36-49 yr; BMI: 26.5 ± 5.9 kg/m2). Isolated adipocytes were cultured with rhResistin (10-50 ng/ml). The level of cytokine secretion from isolated adipocytes was examined by ELISA. The effect of rhResistin on protein expression of components of the innate immune pathway was examined by Western blot. Results: In-vitro studies demonstrated that antigenic stimuli increase resistin secretion (P < 0.001) from isolated adipocytes. Pro-inflammatory cytokine levels were increased in response to rhResistin (P < 0.001); this was attenuated by rosiglitazone (P < 0.01). When examining components of the innate immune pathway, rhResistin stimulated Toll-like receptor-2 protein expression. Similarly, mediators of the insulin signaling pathway, phosphospecific JNK1 and JNK2, were upregulated in response to rhResistin. Conclusion: Resistin may participate in more than one mechanism to influence pro-inflammatory cytokine release from human adipocytes; potentially via the integration of NF-κB and JNK signaling pathways