Advances in martensitic transformations in Cu-based shape memory alloys achieved by in situ neutron and synchrotron X-ray diffraction methods

This article deals with the application of several X-ray and neutron diffraction methods to investigate the mechanics of a stress induced martensitic transformation in Cu-based shape memory alloy polycrystals. It puts experimental results obtained by two different research groups on different length scales into context with the mechanics of stress induced martensitic transformation in polycrystalline environment

Cyclic Loading and Fabric Evolution in Sand: A Constitutive Investigation

An anisotropic plasticity model is proposed to describe the effect of fabric and fabric evolution on the cyclic behaviour of sand within the framework of anisotropic critical state theory. The model employs a cone-shaped bounding surface in the deviatoric stress space and a yield cap perpendicular to the mean stress axis to describe sand behaviour in constant-mean-stress shear and constant-stress-ratio compression, respectively. The model considers a fabric tensor characterizing the internal structure of sand associated with the void space system which evolves with plastic deformation. The fabric evolution law is assumed to render the fabric tensor to become co-directional with the loading direction tensor and to reach a constant magnitude of unit at the critical state. In constant-stress-ratio compres-sion, the final degree of anisotropy is proportional to a normalized stress ratio. An anisotropic variable defined by a joint invariant of the fabric tensor and the loading direction tensor is employed to describe the fabric effect on sand behaviour in constant-mean-stress monotonic and cyclic shear. Good comparison is found between the model simulations and test results on Toyoura sand in both monotonic and cyclic loadings with a single set of parameters

The Origins of la vie neutre:Nicolas Caussin's Influence on the Writings of Gabrielle Suchon

This article examines the influence of Nicolas Caussin's writing on secular celibacy (vie neutre) — and especially of his Vie de Sainte Isabelle (1643) — on Gabrielle Suchon's Traité de la morale et de la politique (1693) and Du célibat volontaire, ou la vie sans engagement (1700). I argue that this overlooked source played a considerable part in shaping Suchon's theories regarding the subordination of women and the usefulness of a celibate life in the secular world. In order to establish this source's importance, Caussin's influence is considered in relation to Suchon's other known sources as well as in the context of the Querelle des femmes. The similarities between the two authors' works are considered in terms of vocabulary, rhetorical issues and theological positions in order to prove that Suchon uses a number of ideas originally found in Caussin as a springboard for a far more extensive and complex argument. Unlike him, she does not take the notion of secular celibacy for granted but examines the obstacles put in the way of those who would choose it (especially women), analyses dominant discourse on the place of women in society and offers counterarguments and practical advice for potential neutralistes

La contrainte Increasing NValue

National audienceCet article introduit la contrainte Increasing NValue, qui restreint le nombre de valeurs distinctes affectées à une séquence de variables, de sorte que chaque variable de la séquence soit inférieure ou égale à la variable la succédant immédiatement. Cette contrainte est une spécialisation de la contrainte NValue, motivée par le besoin de casser des symétries. Il est bien connu que propager la contrainte NValue est un problème NP-Difficile. Nous montrons que la spécialisation au cas d'une séquence ordonnée de variables rend le problème polynomial. Nous proposons un algorithme d'arc-consistance ayant une complexité temporelle en O(sum D), où sum D est la somme des tailles des domaines. Cet algorithme est une amélioration significative, en termes de complexité, des algorithmes issus d'une représentation de la contrainte Increasing NValue à l'aide d'automates ou de la contrainte SLIDE. Nous utilisons notre contrainte dans le cadre d'un problème d'allocation de ressources

Using NLP to build the hypertextuel network of a back-of-the-book index

Relying on the idea that back-of-the-book indexes are traditional devices for navigation through large documents, we have developed a method to build a hypertextual network that helps the navigation in a document. Building such an hypertextual network requires selecting a list of descriptors, identifying the relevant text segments to associate with each descriptor and finally ranking the descriptors and reference segments by relevance order. We propose a specific document segmentation method and a relevance measure for information ranking. The algorithms are tested on 4 corpora (of different types and domains) without human intervention or any semantic knowledge

Contrainte

National audienc

Strain monitoring of tapestries: results of a three-year research project

The outcomes of an interdisciplinary research project between conservators and engineers investigating the strain experienced by different areas of a tapestry are described. Two techniques were used: full-field monitoring using digital image correlation (DIC) and point measurements using optical fibre sensors. Results showed that it is possible to quantify the global strain across a discrete area of a tapestry using DIC; optical fibre and other sensors were used to validate the DIC. Strain maps created by the DIC depict areas of high and low strain and can be overlaid on images of the tapestry, creating a useful visual tool for conservators, custodians and the general public. DIC identifies areas of high strain not obvious to the naked eye. The equipment can be used in situ in a historic house. In addition the work demonstrated the close relationship between relative humidity and strain

Rheological study of sludge of membranes bioreactors for water treatment: protocol, limitations and link with the filtration

The submerged membranes bio-reactors (sMBR) are more and more visible in the field of waste water treatment. The membrane fouling, that causes a drastic fall of the performances, can be limited by the application of a swarm of bubbles close to the membrane surfaces. This aeration as a major factor of the energetic expense of these processes, lets numerous studies to focus on the understanding of the mechanisms linking the bubbles swarm with fouling.. In this background, the rheological tools appeared to be useful to understand the behaviour of sludge under shear stress. In order to be sure to get significant results, we used three types of rheological measurements: i) the influence of shear rate on shear stress; ii) the influence of upward then downward stages of shear stress on viscosity; iii) the influence of the alternation of two stages of shear stress with implementation times identical to those of sMBR aeration. Besides a viscoplastic behaviour previously observed, a phenomenon of hysteresis appeared. The transparent upper plan used on the rheometer exhibited formations of aggregative structures “in roll”. Sludges of a sMBR using different sequencing of aeration are compared: the developed protocols enabled to differentiate those sludges, with characteristic results depending on mechanical applications. The aim of this work is, eventually, to propose some correlations between usual characteristics of the process and aeration operating parameters, in order to propose an aeration policy improving energetic performances

Génératrice à aimants permanents à flux axial à grand diamètre avec entrefer immergé

Cette étude propose une méthode de modélisation et de conception adaptée aux machines à flux axial et à Double Stator (poly-entrefer) destinée à être intégrée comme génératrice pour une hydrolienne RIM-DRIVEN de grande puissance. La particularité du concept RIM-DRIVEN ou à entrainement circonférentiel réside dans le fait que la machine électrique se situe sur la périphérie de l’hélice. De plus, dans cette étude, l’entrefer de la machine est considéré immergé dans l’eau de mer. Les particularités du système imposent de mettre au point des modèles de dimensionnement adaptés. Ainsi, un modèle électromagnétique analytique 2D inversé permettant le calcul des dimensions géométriques principales est présenté. De même, un modèle thermique spécifique aux machines à entrefer immergé est décrit. Ces modèles permettent d’estimer la masse et le coût des parties actives. Cette machine à flux axial est comparée en termes de coûts matières, masses et comportement thermique avec une machine à flux radial à aimants permanents dimensionnée pour un même cahier des charges. Il en ressort clairement que la machine à flux axial double stator est thermiquement moins contrainte que les machines à simple stator