Search results for "Electronique"
showing 10 items of 15 documents
Reliable diagnostics using wireless sensor networks
2019
International audience; Monitoring activities in industry may require the use of wireless sensor networks, for instance due to difficult access or hostile environment. But it is well known that this type of networks has various limitations like the amount of disposable energy. Indeed, once a sensor node exhausts its resources, it will be dropped from the network, stopping so to forward information about maybe relevant features towards the sink. This will result in broken links and data loss which impacts the diagnostic accuracy at the sink level. It is therefore important to keep the network's monitoring service as long as possible by preserving the energy held by the nodes. As packet trans…
Induction Heating Technology and Its Applications: Past Developments, Current Technology, and Future Challenges
2013
International audience; Induction heating technology is nowadays the heating technology of choice in many industrial, domestic, and medical applications due to its advantages regarding efficiency, fast heating, safety, cleanness, and accurate control. Advances in key technologies, i.e. power electronics, control techniques, and magnetic component design, have allowed the development of highly reliable and cost-effective systems, making this technology readily available and ubiquitous. This papers reviews induction heating technology summarizing the main milestones in its development, and analyzing the current state-of-art of induction heating systems in industrial, domestic and medical appl…
Radiation effects on optical frequency domain reflectometry fiber-based sensor
2015
International audience; We investigate the radiation effects on germanosilicate optical fiber acting as the sensing element of optical frequency domain reflectometry devices. Thanks to a new setup permitting to control temperature during irradiation, we evaluate the changes induced by 10 keV x rays on their Rayleigh response up to 1 MGy in a temperature range from −40°C up to 75°C. Irradiation at fixed temperature points out that its measure is reliable during both irradiation and the recovery process. Mixed temperature and radiation measurements show that changing irradiation temperature leads to an error in distributed measurements that depends on the calibration procedure. These results …
Radiation Characterization of Optical Frequency Domain Reflectometry Fiber-Based Distributed Sensors
2016
International audience; We studied the responses of fiber-basedtemperature and strain sensors related to Optical FrequencyDomain Reflectometry (OFDR) and exposed to high γ-ray dosesup to 10 MGy. Three different commercial fiber classes areused to investigate the evolution of OFDR parameters withdose, thermal treatment and fiber core/cladding composition.We find that the fiber coating is affected by both thermal andradiation treatments and this modification results in anevolution of the internal stress distribution inside the fiber that influences its temperature and strain Rayleigh coefficients. These two environmental parameters introduce a relative error up to 5% on temperature and strain…
Radiation Hardened Optical Frequency Domain Reflectometry Distributed Temperature Fiber-Based Sensors
2015
International audience; We study the performance of Optical Frequency Domain Reflectometry (OFDR) distributed temperature sensors using radiation resistant single-mode optical fibers. In situ experiments under 10 keV X-rays exposure up to 1 MGy( SiO 2 ) were carried out with an original setup that allows to investigate combined temperature and radiation effects on the sensors within a temperature range from 30 ° C to 250 ° C. Obtained results demonstrate that optical fiber sensors based on Rayleigh technique are almost unaffected by radiation up to the explored doses. We show that a pre-thermal treatment stabilize the sensor performance increasing the accuracy on temperature measurement fro…
Vulnerability of OFDR-based distributed sensors to high γ-ray doses
2015
Vulnerability of Optical Frequency Domain Reflectometry (OFDR) based sensors to high γ-ray doses (up to 10 MGy) is evaluated with a specific issue of a radiation-hardened temperature and strain monitoring system for nuclear industry. For this, we characterize the main radiation effects that are expected to degrade the sensor performances in such applicative domain: the radiation-induced attenuation (RIA), the possible evolution with the dose of the Rayleigh scattering phenomenon as well as its dependence on temperature and strain. This preliminary investigation is done after the irradiation and for five different optical fiber types covering the range from radiation-hardened fibers to highl…
Radiation Response of OFDR Distributed Sensors Based on Microstructured Pure Silica Optical Fibers
2015
International audience; Temperature sensors based on microstructured pure silica optical fibers are investigated by OFDR and RIA performed during X-ray irradiation up to 50kGy dose. The results evidence that the temperature measures are poorly influenced by irradiation (the error being less than 0.3°C). Such a radiation tolerance is relevant for the use of these Rayleigh based sensors in harsh environments.
Les courses alimentaires à l'heure des drives : nouvelles pratiques, nouvelles mobilités ?
2017
Commerce et Changements Urbains, Paris, France, 18-/01/2017 - 20/01/2017; Avec le développement du commerce électronique, les pratiques d'achats des consommateurs et les infrastructures physiques du commerce de détail connaissent des transformations profondes, en particulier dans le domaine de l'alimentation. Même si le succès du e-commerce concerne d'autres produits, les achats alimentaires sont en progression : entre 2007 et 2011, la part des Français ayant acheté de la nourriture ou de l'épicerie sur Internet est passée de 3 % à un peu plus de 6 % (Gombault, 2013). Cette tendance s'accompagne d'une diversification des produits alimentaires disponibles sur Internet, du développement de no…
Achats en ligne et proximités périurbaines
2015
National audience; En considérant Internet comme partie prenante et entière de l'espace d'approvisionnement des ménages, on peut se demander plus précisément comment ces derniers le mobilisent au quotidien et en quoi il change en pratique leurs habitudes de consommation, la localisation de leurs achats et leur rapport à leur espace d'approvisionnement. L'enjeu est d'autant plus important selon les territoires de vie des ménages, notamment les moins denses ou les plus éloignés des aménités. Pour les territoires les plus dépendants de l'automobile par l'absence de commerces et de services, Internet et ses modes de récupération associés (livraison à domicile, points relais ou intermédiaires) p…
La durabilité du périurbain dépendant de l'automobile au regard des pratiques d'achat en ligne des ménages
2014
ASRDLF2014 - 51ème colloque de l'Association de Science Régionale de Langue Française : Métropolisation, cohésion et performances : quels futurs pour nos territoires ?, CHAMPS-SUR-MARNE, FRANCE, 07-/07/2014 - 09/07/2014; International audience; La dépendance automobile des territoires périurbains liée à une absence de commerces et de services pose la question de leur soutenabilité, voire de leur durabilité à l'aube probable d'une augmentation importante et continue des prix des carburants. Internet et plus particulièrement la vente en ligne sont en mesure de fournir une alternative propice au maintien des ménages dans ces territoires. En effet, grâce au e-commerce, les ménages n'auraient pl…