Porous silica beads produced by nanofluid emulsion freezing

It is shown that porous spherical particles can be obtained via the freezing of silica nanoparticle aqueous suspensions emulsified in a continuous oil phase. After two freeze-thaw cycles, nanoparticles turn aggregated into flocculated objects with microstructure that depends upon emulsion volume fraction and droplet size. For low volume fractions, regular microspheres are produced while for large ones, irregular beads with several tens of micrometer radius are formed. Electronic microscopy, mercury porosimetry and nitrogen adsorption are used to get insights into these porous particles typical radius, pore size distribution, surface area and pore network structure. All exhibit mesopores that result from inter-nanoparticle spacing after flocculation. An unexpected macroporous domain appears which is not observed when drying non-emulsified suspensions. This macroporosity is interpreted as the signature of dendrite formation during the undercooled period, right before freezing occurs. Beside this additional macroporosity, the protocols presented in this article constitute also promising emulsion-based routes for porous material synthesis with original geometry, chemical composition and porosity.Comment: 20 pages, 8 figure

Multi-Objective Design Optimization of the Leg Mechanism for a Piping Inspection Robot

This paper addresses the dimensional synthesis of an adaptive mechanism of contact points ie a leg mechanism of a piping inspection robot operating in an irradiated area as a nuclear power plant. This studied mechanism is the leading part of the robot sub-system responsible of the locomotion. Firstly, three architectures are chosen from the literature and their properties are described. Then, a method using a multi-objective optimization is proposed to determine the best architecture and the optimal geometric parameters of a leg taking into account environmental and design constraints. In this context, the objective functions are the minimization of the mechanism size and the maximization of the transmission force factor. Representations of the Pareto front versus the objective functions and the design parameters are given. Finally, the CAD model of several solutions located on the Pareto front are presented and discussed.Comment: Proceedings of the ASME 2014 International Design Engineering Technical Conferences \& Computers and Information in Engineering Conference, Buffalo : United States (2014

Towards an automatic animal diseases surveillance system based on textual media analysis

La veille en santé animale, et notamment la détection précoce d'émergence au niveau mondial d'agents pathogènes, est l'un des moyens permettant de prévenir ou d'anticiper l'introduction de dangers sanitaires en France. Dans le cadre de la Veille Sanitaire Internationale (VSI) de la plateforme nationale d'épidémiosurveillance en santé animale (ESA), un outil dédié à la veille automatique des dépêches issues des médias électroniques a été développé (PADI-web : Platform for Automated Extraction of Animal Disease Information from the Web). Son objectif est de compléter voire d'anticiper les données produites par les sources de notification de référence en santé animales telles que l'OIE ou la FAO. Le fonctionnement de PADI-web repose sur une méthode de fouille de texte pour la détection, la collecte, la catégorisation et l'extraction de l'information sanitaire à partir des données textuelles non structurées publiées sur le web. Une évaluation de l'outil a été effectuée à partir d'un cas d'étude sur une maladie animale d'intérêt (la fièvre aphteuse) en Afrique. Cette évaluation a mis en évidence des performances quantitatives de détection d'événements variables selon les pays, et une forte plus-value qualitative en terme de complémentarité d'informations. Les verrous méthodologiques identifiés (ambiguités géographiques, extraction d'événements pertinents en particulier) font l'objet des développements de cette thèse

How to combine spatio-temporal and thematic features in online news for enhanced animal disease surveillance?

Early detection of outbreaks of emerging and exotic pathogens is one of the means of preventing the introduction of infectious diseases into unaffected territories. In that context, since 2016, the French Animal Health Epidemic Intelligence team (Veille Sanitaire Internationale, VSI) monitors the online news sources through a designated Platform for Automated extraction of Disease Information from the web (PADI-web). The tool automatically detects, categorizes, and extracts information from online news reports. We focus on the combination of epidemiological features (locations, dates, diseases and hosts) extracted from free text of the news in order to automatically find similarity between different news reports. We describe an original approach based on text mining and data fusion methods and evaluate its performance on a specialized corpus

Exploiting textual source information for epidemiosurveillance

In recent years as a complement to the traditional surveillance reporting systems there is a great interest in developing methodologies for early detection of potential health threats from unstructured text present on the Internet. In this context, we examined the relevance of the combination of expert knowledge and automatic term extraction in the creation of appropriate Internet search queries for the acquisition of disease outbreak news. We propose a measure that is the number of relevant disease outbreak news detected in function of the terms automatically extracted from a set of example Google and PubMED corpora. Due to the recent emergence we have used the African swine fever as a disease example. (Résumé d'auteur

Une analyse des écrits sur les impacts du jeu sur l’apprentissage

Cet article présente une synthèse des publications récentes (1998-2005) qui traitent des impacts du jeu, en tant que formule pédagogique, sur l’apprentissage. Constatant une grande variété d’approches, une certaine disparité dans la manière de présenter et d’interpréter les résultats, et souhaitant vérifier si les jeux éducatifs ont un impact réel sur l’apprentissage, les auteurs ont procédé à une recension des écrits sur le sujet à partir d’une grille d’analyse validée. Ces impacts sont détaillés après un résumé des attributs essentiels du jeu, attributs sur lesquels cette recherche a été fondée pour être menée à bien. L’analyse des écrits montre que le jeu a des impacts positifs sur l’apprentissage.This article presents a synthesis of recent (1998-2005) publications on the impact of play, as a pedagogical technique, on learning. While confirming that there are a great number of approaches, a certain disparity in the way of presenting and interpreting results, and hoping to verify if educational games have a real impact on learning, the authors used a validated analysis grid to produce a review of the literature in this area. The authors present a summary of the essential attributes of games, these attributes being used to frame this research, as well as details regarding the impacts noted. The analysis shows that play has positive impacts on learning.Este artículo presenta una síntesis de las publicaciones recientes (1998-2005) que tratan de los impactos del juego, como formula pedagógica, sobre el aprendizaje. Al observar una gran variedad de enfoques, una cierta disparidad en la manera de presentar y de interpretar los resultados, y con el deseo de comprobar si los juegos educativos tienen un real impacto sobre el aprendizaje, los autores procedieron a una recensión de los escritos sobre el tema a partir de una matriz de análisis validada. Estos impactos se detallan a continuación de un resumen de los atributos esenciales del juego, atributos que fundamentaron esta investigación para poder llevarla a cabo. El análisis de los escritos muestra que el juego tiene impactos positivos sobre el aprendizaje

eISP: a Programmable Processing Architecture for Smart Phone Image Enhancement

4 pagesToday's smart phones, with their embedded high-resolution video sensors, require computing capacities that are too high to easily meet stringent silicon area and power consumption requirements (some one and a half square millimeters and half a watt) especially when programmable components are used. To develop such capacities, integrators still rely on dedicated low resolution video processing components, whose drawback is low flexibility. With this in mind, our paper presents eISP {--} a new, fully programmable Embedded Image Signal Processor architecture, now validated in {TSMC 65nm} technology to achieve a capacity of {16.8 GOPs} at {233 MHz}, for {1.5 mm$^2$} of silicon area and a power consumption of {250 mW}. Its resulting efficiency ({67 MOPs/mW}), has made eISP the leading programmable architecture for signal processing, especially for {HD 1080p} video processing on embedded devices such as smart phone

Monitoring disease outbreak events on the web using text-mining approach and domain expert knowledge

Timeliness and precision for detection of infectious animal disease outbreaks from the information published on the web is crucial for prevention against their spread. We propose a generic method to enrich and extend the use of different expressions as queries in order to improve the acquisition of relevant disease related pages on the web. Our method combines a text mining approach to extract terms from corpora of relevant disease outbreak documents, and domain expert elicitation (Delphi method) to propose expressions and to select relevant combinations between terms obtained with text mining. In this paper we evaluated the performance as queries of a number of expressions obtained with text mining and validated by a domain expert and expressions proposed by a panel of 21 domain experts. We used African swine fever as an infectious animal disease model. The expressions obtained with text mining outperformed as queries the expressions proposed by domain experts. However, domain experts proposed expressions not extracted automatically. Our method is simple to conduct and flexible to adapt to any other animal infectious disease and even in the public health domain. (Résumé d'auteur

Simulation of morphological plasticity of Acacia tortilis in response to herbivore attacks

International audienceUnderstanding tree architectural plasticity is a major challenge. Functional-structural models can be of great interest to quantify the allocation patterns and their changes according to environment. In this paper, we focus on Acacia tortilis trees in savanna to understand their responses to herbivore attacks both in terms of architecture and allocation pattern. Measurements were carried out in Hwange National Park (Zimbabwe) in 2008. Architectural and biomass data were analysed to quantify the effects of herbivore attacks on plant morphogenesis, and trees were gathered in two groups depending on the intensity of herbivore attacks they suffered. Based on these results, a simple model of herbivore attacks has been implemented and parameters have been estimated in the framework of the GreenLab model and we simulate different realistic behaviours according to the intensity of herbivore attacks