Current-driven magnetization decrease in single crystalline ferromagnetic manganese oxide

The electrical and magnetic response to a bias current has been investigated in a singlecrystalline ferromagnetic manganese oxide $\Pr_{0.8}$Ca$_{0.2}$MnO$_3$ . A significant decrease of the magnetization is observed at the same threshold current where a non-linearity of V-I characteristics appears. Such a behavior cannot be understood in the framework of the filamentary picture usually invoked for the non linearity of the other manganese oxides. Instead, an analogy with spintronic features might be useful and experimental signatures seem to be in agreement with excitations of spin waves by an electric current. This provides an example of a bulk system in which the spin polarized current induces a macroscopic change in the magnetization.Comment: 3 pages, 4 figure

Conditions de stabilité des détonations multiphasiques et calcul de leur structure interne.

La stabilité des détonations monophasiques est connue depuis plus d'un siècle. En revanche, les conditions de stabilité des ondes de détonation multiphasiques et leur structure interne sont restées inconnues, par manque de modèle d'écoulement plausible et en raison de l'absence de relations de saut au choc. Sur la base d'un modèle d'écoulement à une seule vitesse et une seule pression (mais plusieurs températures), et de relations de saut appropriées, la détermination de cette structure est désormais possible. Dans ce rapport, on se propose de mettre en place une méthodologie d'analyse et de résolution, en rappelant les deux principaux modèles existant pour le calcul de la structure interne des ondes de détonation monophasiques. Dans le cas particulier où le fluide obéit à une loi des gaz parfaits, on explicite sa solution analytique, et l'on propose un algorithme numérique donnant une solution approchée. Cette méthode sert de base a l'élaboration de celui que l'on utilise pour un fluide multiphasique. Dans ce rapport, nous proposons une détermination de la structure interne des ondes de détonations multiphasiques. Des tests numériques sont effectués pour valider et évaluer à la fois le modèle et le solveur proposés

Situation awareness and ability in coalitions

This paper proposes a discussion on the formal links between the Situation Calculus and the semantics of interpreted systems as far as they relate to Higher-Level Information Fusion tasks. Among these tasks Situation Analysis require to be able to reason about the decision processes of coalitions. Indeed in higher levels of information fusion, one not only need to know that a certain proposition is true (or that it has a certain numerical measure attached), but rather needs to model the circumstances under which this validity holds as well as agents' properties and constraints. In a previous paper the authors have proposed to use the Interpreted System semantics as a potential candidate for the unification of all levels of information fusion. In the present work we show how the proposed framework allow to bind reasoning about courses of action and Situation Awareness. We propose in this paper a (1) model of coalition, (2) a model of ability in the situation calculus language and (3) a model of situation awareness in the interpreted systems semantics. Combining the advantages of both Situation Calculus and the Interpreted Systems semantics, we show how the Situation Calculus can be framed into the Interpreted Systems semantics. We illustrate on the example of RAP compilation in a coalition context, how ability and situation awareness interact and what benefit is gained. Finally, we conclude this study with a discussion on possible future works

Donne vittime di violenza da parte del partner: quali strade per chidere aiuto?

La ricerca di sostegno sociale ha un ruolo centrale nell’uscita dalla violenza; avere figli (nel testo verrà utilizzato il sostantivo “figli” per indicare l’insieme dei figli e delle figlie delle donne) e divenire consapevoli degli effetti che la violenza ha su di loro è spesso l’elemento chiave che spinge le donne a ricercare aiuto. Questo studio ha l’obiettivo di indagare quali fonti di aiuto le donne contattano prima di rivolgersi ad un Centro Antiviolenza (CAV) e di analizzare le circostanze in cui lo fanno. A tal fine è stato condotto uno studio trasversale in cinque CAV del Nord Italia. Centocinquantuno donne hanno compilato autonomamente un questionario anonimo. Le donne hanno riportato elevati livelli di tutte le tipologie di violenza; i figli erano, nella maggior parte dei casi, direttamente coinvolti nelle violenze. Il 33% delle donne ha riferito di aver contattato 4 o più fonti di aiuto prima di arrivare al CAV. Il coinvolgimento dei figli nelle violenze ha portato le donne a rivolgersi a più fonti di aiuto rispetto alle situazioni in cui i figli non erano coinvolti. I risultati sottolineano l’importanza di formare tutti i professionisti e le professioniste che potrebbero incontrare nel loro percorso professionale delle donne che hanno subito o che stanno subendo violenza. La demande d’aide et de soutien joue un rôle central pour mettre fin à la violence du partenaire et pour marquer le tournant dans le processus concernant la prise de conscience des effets de la violence sur les enfants. Cette étude vise à examiner les sources d’assistance que les femmes ont contactées avant d’arriver au centre anti-violence et à analyser les circonstances concrètes des cas de figure. Une étude transversale a été menée sur les femmes qui se sont adressées à un centre antiviolence en Italie. Cent cinquante et une femmes ont rempli un questionnaire auto-administré. Elles ont signalé des niveaux élevés de toutes les typologies de violence entre partenaires intimes ; les enfants étaient étroitement associés à la violence. Avant d’arriver au centre anti-violence, 33,1 % de l’échantillon a contacté au moins quatre sources d’assistance. Lorsque les enfants étaient impliqués dans la violence, les sources activées étaient plus nombreuses que si les enfants ne l’étaient pas. L’étude rappelle toute l’importance d’améliorer la capacité des professionnels à reconnaître la violence et à soutenir les victimes. Looking for help and support has a central role in the process of putting an end to partner violence and an important turning-point in the process of deciding to seek help is having children and becoming aware of the effects of the violence on them. This study aims to investigate which sources of help women contacted before arriving at an Anti-violence Centre(AVC), and to analyse the circumstances in which they contacted them. A cross-sectional study was conducted among women arriving at an Anti-violence Centre in Italy. One hundred and fifty-one women filled in a self-administered questionnaire. The women reported high levels of all typologies of IPV (Intimate Partner Violence); the children were closely involved in the violence. Before arriving to the AVC, 33.1% of the sample contacted four or more sources. When children were involved in violence, more sources were activated, than in cases in which children were not involved. This study points to the importance of improving practitioners’ ability to recognize violence and support the victims

TaMaris Project : Interpretation of detected suspect vessel events

International audienceAs we face varied unlawful activities and other threats, innovative solution shall be set up to permanently track and monitor all type of ship traffics, in vulnerable trading lanes and country border zones in order to detect abnormal vessel behaviour, to understand suspicious event and to early identify threatening situation. TaMaris on going development is a technical capability grouping analysis tools and operational procedures, operated from state of art human machine interface (HMI), to support experts group in understanding suspicious event, early identify threat and generating argued electronic report. Reports required for keeping continuously informed decisional authority ..

Liquid and liquid-gas flows at all speeds : Reference solutions and numerical schemes

This paper present some reference solutions to be used in order to validate and improve numerical schemes for multiphase flows. We address here exact one-dimensional liquid and liquid-gas compressible flows solutions in nozzles. The exact solution is first derived for the compressible single liquid phase Euler equations and extends the well known ideal gas dynamic nozzle flow solutions.The all Mach number scheme is then derived. A preconditioned Riemann solver is built and embedded into the Godunov explicit scheme. It is shown that this method converges to exact solutions but needs too small time steps to be efficient. An implicit version is then derived, in one dimension first and second in the frame of 3D unstructured meshes

Le sanctuaire laténien de Semoine, "Voie Palon" (Aube)

National audienceA rescue excavation in 2003 resulted in the discovery of a building on piles, constructed between two sections of ditch, of which the one on the north side has an entrance. The chronological data of the building and two ditches match and demonstrate the existence of cults during La Tène C2. Evidence of the cults is given by a small quantity of deliberately mutilated weapons, as has been found in other La Tène sanctuaries. Dating the creation of the enclosure is problematicaln but it probably derives from La Tène C1. Although sections of the site remained unexcavated, the stratigraphy of the ditches reveals the brevity and limited and unusual nature of the practices. This study links them to the very particular geographical context of the place, which lies on the watershed between the Aube and Marne rivers. During the Second Iron Age, this watershed was part of the area of influence of one or the other of the two populations living respectively in one of the two hydrographic basins, and it probably allowed the Augustinian administration to fix the frontier between the Remi and Senones. The transformations that took place during the La Tène C, therefore, may have led to the erection of a short-lived place of worship linked with the frontier.En 2003, une fouille préventive a permis de découvrir un bâtiment sur poteaux installé entre deux tronçons de fossé, dont celui du côté nord est muni d'une entrée. Les données chronologiques de ces trois éléments sont homogènes et démontrent le déroulement de cultes durant La Tène C2. Ceux-ci se manifestent par une quantité modeste d'armes volontairement mutilées, comme sur d'autres sanctuaires laténiens. La date de création de l'enclos pose encore problème, mais doit se situer à La Tène C1. Malgré les parties du site restées en dehors de la fouille, la stratigraphie des fossés étudiés prouve la brièveté et la modestie des cultes pratiqués, très singulières par rapport aux comparaisons disponibles. Cet exposé propose de les imputer à la particularité géographique du lieu, sur lequel passe la ligne de partage des eaux de l'Aube et de la Marne. Au deuxième Âge du Fer, cette ligne de crête est intégrée à l'aire d'influence de l'une ou l'autre des populations concentrées sur les deux bassins hydrographiques, et elle permet probablement à l'administration augustéenne de fixer la frontière commune aux Rèmes et aux Sénons. Les mutations de La Tène C conduisent donc peut-être à dresser un lieu de culte éphémère, lié à des événements frontaliers

A simple phase transition relaxation solver for liquid-vapor flows

International audienceDetermining liquid-vapor phase equilibrium is often required in multiphase flow computations. Existing equilibrium solvers are either accurate but computationally expensive, or cheap but inaccurate. The present paper aims at building a fast and accurate specific phase equilibrium solver, specifically devoted to unsteady multiphase flow computations. Moreover, the solver is efficient at phase diagram bounds, where non-equilibrium pure liquid and pure gas are present. It is systematically validated against solutions based on an accurate (but expensive) solver. Its capability to deal with cavitating, evaporating and condensing two-phase flows is highlighted on severe test problems both 1D and 2D