144 research outputs found

    Influence of constructive options on the vibro-acoustic behavior of a wooden lightweight structure

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    This paper aims to present the influence of several constructive options on the vibro-acoustic behavior of a wooden lightweight structure. The experiemental protocol, which was optimised and described in an preceeding paper, allows us to quantify the influence of these constructive options in terms of acoustic level and isolation, eigenfrequencies and vibration mode shapes of the different parts of the structure. The results of this work are coherent and confirmed that the experimental test protocol is functional and repeatable

    Rayonnement acoustique de structures de type ossature bois : comparaison entre méthode éléments finis et formulation intégrale

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    Un des points délicats de la construction bois se situe au niveau de l'isolation acoustique des planchers bois. L'objectif de cette article est de déterminer le rayonnement acoustique de ce type de structures (légÚres et nervurées). Deux méthodes sont présentés, l'une modélisant, par éléments finis, le domaine global (structure in-vivo) et son couplage, l'autre exploitant une méthode combinée (élément finis et formulation intégrale) sur la structure in-vacuo. Un code éléments finis sous licence libre (FreeFem++) est employé dans cette étude en comparaison avec un des codes commerciaux

    Fluorescent core-shell alloy nanoparticles for cell targeting applications

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    ABSTRACT: RÉSUMÉ: ABSTRACT

    Haut parleur tout aimant guidé sur joint ferrofluide : caractérisation dynamique du guidage

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    Une étude expérimentale sur le comportement visqueux de ferrofluides, au sein d'une goutte insérée entre deux plans parallÚles, en condition de cisaillement oscillatoire et sous champ magnétique homogÚne et stationnaire, permet d'alimenter un modÚle pour les pertes d'un haut-parleur tout aimant guidé sur joint ferrofluide. Ces joints sont localisés dans les zones de fort gradient de champs magnétique. Le modÚle de perte, fonction du volume, de la viscosité et de la saturation magnétique du ferrofluide, est alors validé par confrontation avec une expérience

    ‘Citizens’ Attitudes Under Covid19’, a cross-country panel survey of public opinion in 11 advanced democracies

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    This article introduces data collected in the Citizens’ Attitudes Under Covid-19 Project (CAUCP), which surveyed public opinion throughout the Covid-19 pandemic in 11 democracies between March and December 2020. In this paper, we present a unique cross-country panel survey of citizens’ attitudes and behaviors during a worldwide unprecedented health, governance, and economic crisis. This dataset investigates the behavioral and attitudinal consequences of multifaceted Covid19 crisis across time and contexts. In this paper, we describe the design of the CAUCP and the descriptive features of the dataset; we also present promising research prospects

    The Chloroplast Genome of the Green Alga Schizomeris leibleinii (Chlorophyceae) Provides Evidence for Bidirectional DNA Replication from a Single Origin in the Chaetophorales

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    In the Chlorophyceae, the chloroplast genome is extraordinarily fluid in architecture and displays unique features relative to other groups of green algae. For the Chaetophorales, 1 of the 5 major lineages of the Chlorophyceae, it has been shown that the distinctive architecture of the 223,902-bp genome of Stigeoclonium helveticum is consistent with bidirectional DNA replication from a single origin. Here, we report the 182,759-bp chloroplast genome sequence of Schizomeris leibleinii, a member of the earliest diverging lineage of the Chaetophorales. Like its Stigeoclonium homolog, the Schizomeris genome lacks a large inverted repeat encoding the rRNA operon and displays a striking bias in coding regions that is associated with a bias in base composition along each strand. Our results support the notion that these two chaetophoralean genomes replicate bidirectionally from a putative origin located in the vicinity of the small subunit ribosomal RNA gene. Their shared structural characteristics were most probably inherited from the common ancestor of all chaetophoralean algae. Short dispersed repeats account for most of the 41-kb size variation between the Schizomeris and Stigeoclonium genomes, and there is no indication that homologous recombination between these repeated elements led to the observed gene rearrangements. A comparison of the extent of variation sustained by the Stigeoclonium and Schizomeris chloroplast DNAs (cpDNAs) with that observed for the cpDNAs of the chlamydomonadalean Chlamydomonas and Volvox suggests that gene rearrangements as well as changes in the abundance of intergenic and intron sequences occurred at a slower pace in the Chaetophorales than in the Chlamydomonadales
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