A piecewise-linear reduced-order model of squeeze-film damping for deformable structures including large displacement effects

This paper presents a reduced-order model for the Reynolds equation for deformable structure and large displacements. It is based on the model established in [11] which is piece-wise linearized using two different methods. The advantages and drawbacks of each method are pointed out. The pull-in time of a microswitch is determined and compared to experimental and other simulation data.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Manipulation of subcortical and deep cortical activity in the primate brain using transcranial focused ultrasound stimulation

Publisher’s embargo period: Embargo set on 04.03.2019 by SR (TIS).The causal role of an area within a neural network can be determined by interfering with its activity and measuring the impact. Many current reversible manipulation techniques have limitations preventing their application, particularly in deep areas of the primate brain. Here, we demonstrate that a focused transcranial ultrasound stimulation (TUS) protocol impacts activity even in deep brain areas: a subcortical brain structure, the amygdala (experiment 1), and a deep cortical region, the anterior cingulate cortex (ACC, experiment 2), in macaques. TUS neuromodulatory effects were measured by examining relationships between activity in each area and the rest of the brain using functional magnetic resonance imaging (fMRI). In control conditions without sonication, activity in a given area is related to activity in interconnected regions, but such relationships are reduced after sonication, specifically for the targeted areas. Dissociable and focal effects on neural activity could not be explained by auditory confounds

Bond and charge density waves in the isotropic interacting two-dimensional quarter-filled band and the insulating state proximate to organic superconductivity

We report two surprising results regarding the nature of the spatial broken symmetries in the two-dimensional (2D), quarter-filled band with strong electron-electron interactions. First, in direct contradiction to the predictions of one-electron theory, we find a coexisting ``bond-order and charge density wave'' (BCDW) insulating ground state in the 2D rectangular lattice for all anisotropies, including the isotropic limit. Second, we find that the BCDW further coexists with a spin-density wave (SDW) in the range of large anisotropy. Further, in contrast to the interacting half-filled band, in the interacting quarter-filled band there are two transitions: first, a similar singlet-to-AFM/SDW transition for large anisotropy and second, an AFM/SDW-to-singlet transition at smaller anisotropy. We discuss how these theoretical results apply to the insulating states that are proximate to the superconducting states of 2:1 cationic charge-transfer solids (CTS). An important consequence of this work is the suggestion that organic superconductivity is related to the proximate Coulomb-induced BCDW, with the SDW that coexists for large anisotropies being also a consequence of the BCDW, rather than the driver of superconductivity.Comment: 29 pages, 18 eps figures. Revised with new appendices; to appear in Phys. Rev. B 62, Nov 15, 200

Procédés d'insertion de dopants dans poudre industrielle INCO718 = ODS (Oxide Dispersion Strengthened,) pour fabrication LPBF (SLM) pour des applications nucléaires

International audienceLes alliages à base de Ni sont des matériaux prometteurs pour le nucléaire en raison de leur excellente résistance mécanique sous haute température et de leur bon comportement dans des environnements corrosifs ou oxydants. Cependant, en raison de la complexité de ses composants, les techniques de traitements conventionnelles sont limitées. De nouvelles technologies, élaboration à base de poudre métalliques, permettent d'élargir les possibilités de conception, de s'affranchir des problèmes de soudabilité, en particulier la fusion laser en lit de poudre (LPBF). Les performances mécaniques remarquables de l'Inconel 718 sont obtenues par le renforcement de la phase de matrice γ en solution solide, la précipitation γ' et γ''. Cependant l'ajout d'oxyde peuvent permettre d'augmenter les performances des matériaux. Dans cette étude nous nous sommes intéressés à l'influence de l'ajout d'Y2O3 sur la microstructure de l'Inconel 718. L'intégration de particules d'oxyde nanométriques dans une matrice relativement ductile n'est pas facile à réaliser. Afin de résoudre ce problème, divers procédés d'insertion ont été essayés, notamment le procédé MA (mécanosynthèse), le mélange par turbula et le dépôt d'oxyde par PVD. De plus, l'ajout d'oxyde nécessite une adaptation des paramètres du procédé LPBF. Les principaux paramètres tels que la vitesse du processus, la puissance du laser, la distance de hachage et les stratégies de balayage sont pris en compte pour chaque processus d'insertion d'oxyde. Enfin, les macro et microstructures sont analysées et des conclusions sont données sur les potentialités et les limites de chaque condition de fabrication

From fault creep to slow and fast earthquakes in carbonates

A major part of the seismicity striking the Mediterranean area and other regions worldwide is hosted in carbonate rocks. Recent examples are the destructive earthquakes of L'Aquila (M-w 6.1) in 2009 and Norcia (M-w 6.5) in 2016 in central Italy. Surprisingly, within this region, fast (approximate to 3 km/s) and destructive seismic ruptures coexist with slow (<= 10 m/s) and nondestructive rupture phenomena. Despite its relevance for seismic hazard studies, the transition from fault creep to slow and fast seismic rupture propagation is still poorly constrained by seismological and laboratory observations. Here, we reproduced in the laboratory the complete spectrum of natural faulting on samples of dolostones representative of the seismogenic layer in the region. The transitions from fault creep to slow ruptures and from slow to fast ruptures were obtained by increasing both confining pressure (P) and temperature (T) up to conditions encountered at 3-5 km depth (i.e., P = 100 MPa and T = 100 degrees C), which corresponds to the hypocentral location of slow earthquake swarms and the onset of seismicity in central Italy. The transition from slow to fast rupture is explained by an increase in the ambient temperature, which enhances the elastic loading stiffness of the fault, i.e., the slip velocities during nucleation, allowing flash weakening and, in turn, the propagation of fast ruptures radiating intense high-frequency seismic waves

Rational Choice of Antibiotics and Media for Mycobacterium avium Complex Drug Susceptibility Testing

International audienceThe Clinical and Laboratory Standards Institute recommends the use of Mueller Hinton (MH) medium to perform drug susceptibility testing (DST) of Mycobacterium avium complex (MAC) using the microdilution method. For MAC, there has been no study on the impact of media on the determination of minimum inhibitory concentrations (MICs) of antibiotics other than clarithromycin. This study aimed at determining the impact of two media used for DST of MAC and at augmenting the number of pertinent MICs for MAC species encountered in clinical practice. MICs of antibiotics used for the treatment of MAC infections were determined for 158 clinical MAC isolates (80 M. avium, 40 M. intracellulare, 35 M. chimaera, two M. yongonense and one M. timonense) in MH and 7H9 broths using the SLOMYCO SensititreTM system (TREK Diagnostic Systems, East Grinstead, United Kingdom). The modal MICs determined in both media were the same for linezolid, moxifloxacin, rifabutin and amikacin but not for clarithromycin, rifampin and ethambutol. The kappa test for MICs converted to susceptibility categories showed an excellent agreement for clarithromycin, a moderate agreement for linezolid and a weak agreement for moxifloxacin and amikacin. For amikacin, 7H9 allowed a better distinction (fewer intermediate strains) of wild-type populations than MH. Existing breakpoints for linezolid and moxifloxacin are spread through the distribution of MICs for wild-type populations. The only breakpoints that can be used rationally are those for amikacin and clarithromycin. For amikacin, 7H9 performs better than MH, whereas both media perform equally for clarithromycin. Given that testing in 7H9, as opposed to MH, allows easier MIC measurements and yields greater reproducibility, we propose the use of 7H9 medium for DST of MAC

La maison d'arrêt de Briey : détenus politiques par Fanny Lebigot

Photo Ministère de la Justice Située en ville à 80km de Nancy, dans les hauts de Briey, la prison a été construite en 1906. Elle a été une maison d’arrêt jusqu’en 1974 puis un Quartier de Haute Sécurité (QHS) jusqu’en 1982 (date de fermeture de ce type d’établissement). Par la suite, elle redevient maison d’arrêt. Depuis 1990, l’établissement fait office de Centre de Semi-Liberté. En 1996, sa capacité d’accueil est passée de 15 à 25 personnes. Enfin depuis 2004, le CSL est habilité pour écrou..