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Sustainable Development and the SDGs: Revealing Engineering Academics, Students and Employer Viewpoints
No full textInternational audienceAs the world’s focus turns to the future and not the present, the engineering profession must respond to the ever increasing need to bring about a sustainable future. The objective of this paper is to support the reform of engineering education by acknowledging and building upon the current awareness and understanding of sustainable development held by key stakeholders in the process. This paper presents the outcomes of a study involving twelve focus groups with Academics, Employers and Students in four European countries (Denmark, Finland, France and Ireland) as part of the A-STEP 2030 European Project. Based on the findings, it is clear that the key stakeholders closely associate the theme of the environment with Sustainable Development. There is also mention of the pillar of economy, but less so, that of society. The findings also reveal differences in the awareness of specific Sustainable Development Goals (SDGs), with SDG 13 (Climate Action) being most widely noted. The findings allow educators to engage in discussion with students to build a more complete understanding of aspects of sustainable development and to act in redesigning curricula to ensure engineers can contribute to a sustainable future
Apports de l'imagerie qualitative infrarouge pour la caractérisation thermomécanique et le dimensionnement en fatigue de composites tissés 3D
No full textThis work focuses on the thermomecanical characterisation and design against fatigue of a woven composite that is produced for research purposes by the Safran Group. The experimental characterisation is based mainly on the analyses of infrared measurements. The experimental protocols, used for generating the experimental database, are based on the heat build-up protocol, which seeks to relate the temperature variations measured under cyclic loadings to different heat sources. In order to fully exploit the experimental data, different postprocessing tools that enable to highlight mechanisms characteristic to woven composites were developed (thermal event detection, frequency analyses, ...). This experimental characterisation is then complemented by results coming from simulation/experiment comparisons. The latter enable to identify dissipative mechanisms activated under relatively low cyclic loadings. Furthermore, this dissipative mechanism description was used to introduce a rapid fatigue characterisation method that identifies an S-N curve model based on the results of tensile tests and heat build-up experiments.Les travaux de cette thèse portent sur la caractérisation thermomécanique et le dimensionnement en fatigue d’un composite tissé 3D qui est fabriqué par le groupe Safran à des fins de recherche. La caractérisation expérimentale repose principalement sur des analyses des mesures infrarouges. Les protocoles expérimentaux, utilisés pour la génération des bases de données expérimentales, se basent sur le protocole d’auto-échauffement, qui cherche à relier les variations de température mesurées sous chargements cycliques aux différentes sources thermiques. Pour exploiter au mieux les données expérimentales obtenues, plusieurs outils de post-traitement, permettant de mettre en évidence les mécanismes caractéristiques aux composites tissés, ont été mis en place (détection des événements thermiques, génération des cartographies des amplitudes à 2×f, . . .). Cette caractérisation expérimentale est complétée par des comparaisons issues d’un dialogue essai/calculs. Ce dernier représente une complémentarité aux mesures expérimentales, notamment, parce qu’il permet d’identifier les mécanismes dissipatifs activés sous chargements cycliques relativement faibles. En s’appuyant sur la description des mécanismes dissipatifs, une méthode de caractérisation rapide en fatigue, qui cherche à identifier un critère de dimensionnement à partir des résultats des essais de traction et d’auto-échauffement, a été proposée
L’apport combiné de deux algorithmes d’IA à l’optimisation des parcours d’apprentissage dans le projet Adaptiv'Math
No full textNational audienceLes algorithmes employant des techniques d'intelligence artificielle se retrouvent de plus en plus dans des solutions à destination des élèves et enseignants, mais il s'agit toutefois généralement de briques isolées. L'objectif de ce travail est de montrer comment deux algorithmes peuvent avoir des apports complémentaires dans le cadre d'une solution d'apprentissage des mathématiques en cycle 2. D'une part, un algorithme utilisant l'apprentissage par renforcement (ZPDES) personnalise le parcours de chaque élève, en suivant en temps réel sa progression et en lui proposant les exercices qui lui sont les plus adaptés. D'autre part, un algorithme de regroupement de profils (SACCOM) définit des groupes homogènes d'élèves autour de critères donnés (réussite à un exercice, nature des erreurs, …), facilitant la mise en place de pratiques pédagogiques différenciées et compensant la divergence des activités des élèves avec les parcours personnalisés. Le projet Adaptiv'Math combine ces deux approches, proposant ainsi des phases d'apprentissage en autonomie et des interventions pédagogiques de l'enseignant en petits groupes
Spatio-temporal characterization of attosecond pulses from plasma mirrors
No full textInternational audienceReaching light intensities above 1025 W cm−2 and up to the Schwinger limit of order 1029 W cm−2 would enable the testing of fundamental predictions of quantum electrodynamics. A promising—yet challenging—approach to achieve such extreme fields consists in reflecting a high-power femtosecond laser pulse off a curved relativistic mirror. This enhances the intensity of the reflected beam by simultaneously compressing it in time down to the attosecond range, and focusing it to submicrometre focal spots. Here we show that such curved relativistic mirrors can be produced when an ultra-intense laser pulse ionizes a solid target and creates a dense plasma that specularly reflects the incident light. This is evidenced by measuring the temporal and spatial effects induced on the reflected beam by this so-called plasma mirror. The all-optical measurement technique demonstrated here will be instrumental for the use of relativistic plasma mirrors with the upcoming generation of petawatt lasers that recently reached intensities of 5 × 1022 W cm−2, and therefore constitutes a viable experimental path to the Schwinger limit
The effect of antoxidant additives on the physicochemical properties of a surrogate gasoline system
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Modal analysis of composite nozzle for an optimal design of a tidal current turbine
No full textInternational audienceMonitoring of structural vibrations and operational modal analysis are clearly essential to effectively control structural safety and the operational behavior of tidal current turbines. In order to satisfy industrial requirements, generally related to a mass gain problem, hybridization provides an excellent method to improve the breaking strength of composite materials, while keeping adequate mechanical performance for marine renewable energy applications. In this context, this work aims to study the structural modal analysis of a tidal turbine nozzle and the effect of hybrid materials (carbon/Glass) on the natural frequencies and corresponding mode shapes of the three laminates. The modal analysis was calculated by the Finite Element Method using ABAQUS software. According to the results, the stacking sequence has a considerable impact on the natural frequency of the nozzle. Furthermore, it is also found that the resonance effect does not appear for the three laminates under investigation
A progressive damage model for pressurized filament-wound hybrid composite pipe under low-velocity impact
No full textInternational audiencePressurized hybrid composite pipe structures, produced by filament wound subjected to impact loads, were numerically investigated. A combined 3D-FE Model based on the use of interlaminar and intralaminar damage models is established. Intralaminar damages such as matrix cracking and fibre failures are predicted using 3D Hashin criteria, whereas interlaminar damage (delamination) was evaluated using cohesive zone elements. The damage model was coded and implemented as a user-defined material subroutine (VUMAT) for Abaqus/Explicit. Numerical results in the form of contact force, displacement and energy dissipated compare well with the experimental results. Predicted matrix damage in each cross-ply of hybrid composite pipe and delamination onset were also presented in this paper. The ability of this new 3D model to simulate the damage evolution in the full-scale pressurized hybrid composite pipe under low-velocity impact events were demonstrated throughout comparison with existing experimental results published
Identifying Functions and Behaviours of Social Robots for In-Class Learning Activities: Teachers’ Perspective
No full textInternational audienceWith advances in artificial intelligence, research is increasingly exploring the potential functions that social robots can play in education. As teachers are a critical stakeholder in the use and application of educational technologies, we conducted a study to understand teachers' perspectives on how a social robot could support a variety of learning activities in the classroom. Through interviews, robot puppeteering, and group brainstorming sessions with five elementary and middle school teachers, we take a sociotechnical perspective to conceptualize possible robot functions and behaviours, and the effects they may have on the current way learning activities are designed, planned, and executed. Using activity theory to analyze learning activities as an activity system illustrated a number of tensions that currently exist between the components of the system. Overall, the teachers responded positively to the idea of introducing a social robot as a technological tool for learning activities, envisioning differences in usage for teacher-robot and student-robot interactions. We discuss the fine-grained functions and behaviours envisioned by teachers, and how they address the current tensions-providing suggestions for improving the design of social robots for learning activities
2020 roadmap on plasma accelerators
No full textInternational audiencePlasma-based accelerators use the strong electromagnetic fields that can be supported by plasmas to accelerate charged particles to high energies. Accelerating field structures in plasma can be generated by powerful laser pulses or charged particle beams. This research field has recently transitioned from involving a few small-scale efforts to the development of national and international networks of scientists supported by substantial investment in large-scale research infrastructure. In this New Journal of Physics 2020 Plasma Accelerator Roadmap, perspectives from experts in this field provide a summary overview of the field and insights into the research needs and developments for an international audience of scientists, including graduate students and researchers entering the field
Interval Extended Kalman Filter - Application to Underwater Localization and Control
No full textInternational audienceThe extended Kalman filter has been shown to be a precise method for nonlinear state estimation and is the facto standard in navigation systems. However, if the initial estimated state is far from the true one, the filter may diverge, mainly due to an inconsistent linearization. Moreover, interval filters guarantee a robust and reliable, yet unprecise and discontinuous localization. This paper proposes to choose a point estimated by an interval method, as a linearization point of the extended Kalman filter. We will show that this combination allows us to get a higher level of integrity of the extended Kalman filter