Three-dimensional CFD simulations with large displacement of the geometries using a connectivity-change moving mesh approach

This paper deals with three-dimensional (3D) numerical simulations involving 3D moving geometries with large displacements on unstructured meshes. Such simulations are of great value to industry, but remain very time-consuming. A robust moving mesh algorithm coupling an elasticity-like mesh deformation solution and mesh optimizations was proposed in previous works, which removes the need for global remeshing when performing large displacements. The optimizations, and in particular generalized edge/face swapping, preserve the initial quality of the mesh throughout the simulation. We propose to integrate an Arbitrary Lagrangian Eulerian compressible flow solver into this process to demonstrate its capabilities in a full CFD computation context. This solver relies on a local enforcement of the discrete geometric conservation law to preserve the order of accuracy of the time integration. The displacement of the geometries is either imposed, or driven by fluid–structure interaction (FSI). In the latter case, the six degrees of freedom approach for rigid bodies is considered. Finally, several 3D imposed-motion and FSI examples are given to validate the proposed approach, both in academic and industrial configurations

Evaluation de l'alternance de l'onde T par la méthode de la variabilité (à propos de 48 cas)

POITIERS-BU Médecine pharmacie (861942103) / SudocSudocFranceF

Intérêt de la spectrométrie de masse par désorption-ionisation laser assistée par matrice dans la comparaison de souches de staphylocoques à coagulase négative

Les staphylocoques à coagulase négative (SCN) sont les espèces majoritaires de la flore commensale cutanée. Dans des situations d immuno-dépression ou en présence de matériels étrangers, les SCN sont à l origine d infections caractérisées par une morbidité et une mortalité importantes. La distinction entre les situations de contamination et celles d infections n est pas toujours aisée et seule la mise en évidence d un lien de clonalité entre les souches est en faveur d une infection. Pour cela, les techniques de biologie moléculaire, dont la méthodologie est lourde et coûteuse, sont souvent utilisées. Récemment, la spectrométrie de masse par Désorption/Ionisation assistée par matrice (MALDI-TOF) a été utilisée comme méthode d identification bactérienne. Dans notre étude, nous avons évalué la capacité de cette technique à comparer les souches de SCN provenant de patients hospitalisés à l hôpital Necker entre 2005 et 2006 et les résultats ont été confrontés à ceux de l électrophorèse en champ pulsé, technique génotypique de comparaison des souches. Les résultats ont montré qu il est possible par MALDI-TOF de différencier les souches génotypiquement liées des autres. Néanmoins, ces résultats nécessitent l analyse d une plus grande série de souches de SCN. Répondre rapidement au clinicien à la question de l existence d un lien de clonalité entre les souches de SCN et donc à la question d une infection éventuelle peut contribuer à améliorer la prise en charge thérapeutique des patientsPARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Nb-Ta, Nb-Mo and Nb-V oxides prepared from hybrid organic-inorganic precursors

New hybrid organic-inorganic materials based on group 5 elements and a well-defined polymeric matrix have been prepared and used as precursors for Nb-Ta and Nb-Mo mixed oxides. In this non-conventional but easily accessible route to multimetallic oxides, a copolymer of N,N-diallyl-N-hexylamine and maleic acid was synthesised and used as matrix to stabilise inorganic species generated in solution from (NH4)(6)Mo7O24-4H(2)O, NH4VO3, (gu)(3)[Nb(O-2)(4)] and (gu)(3)[Ta(O-2)(4)]. Solid-state studies indicate that the homogeneity of the blends can be kept up to about 0.5 mol Nb-v and Ta-v and 0.25 mol V-v per mol of repeat units of the copolymer. The calcination conditions of these homogeneous hybrid precursors were optimised to produce Nb-Mo, Nb-Ta and Nb-V oxides. While the thermal treatment of the Nb-V hybrid blends led only to a mixture of different phases, the characterisation of the final phases by X-ray diffraction (XRD) proved the formation of pure Nb2MO3O14 and showed that Nb-Ta oxides could be synthesised as single phases corresponding to a continuous series of solid solutions. (c) 2007 Elsevier Inc. All rights reserved

The Impact of Backward and Forward Causal Connectives on Text Comprehension

n

Accurate identification of S. pneumoniae using MALDI-TOF mass spectrometry, still a challenge for clinical laboratories?

International audienc

Patients with community-acquired bacteremia of unknown origin: clinical characteristics and usefulness of microbiological results for therapeutic issues: a single-center cohort study

Abstract Bacteremia of unknown origin (BUO) are associated with increased mortality compared to those with identified sources. Microbiological data of those patients could help to characterize an appropriate empirical antibiotic treatment before bloodcultures results are available during sepsis of unknown origin. Based on the dashboard of our ward that prospectively records several parameters from each hospitalization, we report 101 community-acquired BUO selected among 1989 bacteremic patients from July 2005 to April 2016, BUO being defined by the absence of clinical and paraclinical infectious focus and no other microbiological samples retrieving the bacteria isolated from blood cultures. The in-hospital mortality rate was 9%. We retrospectively tested two antibiotic associations: amoxicillin–clavulanic acid + gentamicin (AMC/GM) and 3rd generation cephalosporin + gentamicin (3GC/GM) considered as active if the causative bacteria was susceptible to at least one of the two drugs. The mean age was 71 years with 67% of male, 31 (31%) were immunocompromised and 52 (51%) had severe sepsis. Eleven patients had polymicrobial infections. The leading bacterial species involved were Escherichia coli 25/115 (22%), group D Streptococci 12/115 (10%), viridans Streptococci 12/115 (10%) and Staphylococcus aureus 11/115 (9%). AMC/GM displayed a higher rate of effectiveness compared to 3GC/GM: 100/101 (99%) vs 94/101 (93%) (p = 0.04): one Enterococcus faecium strain impaired the first association, Bacteroides spp. and Enterococcus spp. the second. In case of community-acquired sepsis of unknown origin, AMC + GM should be considered