Influence of fillers on mechanical properties of ATH filled EPDM during ageing by gamma irradiation

International audienceThe presence of a significant content of fillers accelerates the degradation of ATH filled EPDM subjected to gamma irradiation at room temperature. Above the melting temperature of the EPDM, this induces a decrease in the apparent mechanical reinforcement of the fillers. This also promotes de-cohesion mechanisms which leads to an increase in the strain at break with irradiation dose. It is not clear whether the use of a filler treatment attenuates this accelerating effect or not; however, part of this treatment remains efficient at a high dose and seems also to delay but not suppress the occurrence of de-cohesion mechanisms at large strain. Moreover, at room temperature, i.e. below the melting temperature, all the consequences of ageing by gamma irradiation are strongly attenuated by the presence of a semicrystalline microstructure, the morphology of which is not too strongly modified by irradiation. (C) 2010 Elsevier Ltd. All rights reserved

The phenotypic and genotypic spectrum of individuals with mono- or biallelic ANK3 variants

ANK3 encodes ankyrin-G, a protein involved in neuronal development and signaling. Alternative splicing gives rise to three ankyrin-G isoforms comprising different domains with distinct expression patterns. Mono- or biallelic ANK3 variants are associated with non-specific syndromic intellectual disability in 14 individuals (seven with monoallelic and seven with biallelic variants). In this study, we describe the clinical features of 13 additional individuals and review the data on a total of 27 individuals (16 individuals with monoallelic and 11 with biallelic ANK3 variants) and demonstrate that the phenotype for biallelic variants is more severe. The phenotypic features include language delay (92%), autism spectrum disorder (76%), intellectual disability (78%), hypotonia (65%), motor delay (68%), attention deficit disorder (ADD) or attention deficit hyperactivity disorder (ADHD) (57%), sleep disturbances (50%), aggressivity/self-injury (37.5%), and epilepsy (35%). A notable phenotypic difference was presence of ataxia in three individuals with biallelic variants, but in none of the individuals with monoallelic variants. While the majority of the monoallelic variants are predicted to result in a truncated protein, biallelic variants are almost exclusively missense. Moreover, mono- and biallelic variants appear to be localized differently across the three different ankyrin-G isoforms, suggesting isoform-specific pathological mechanisms.</p

Performances des capteurs à fibres optiques basés sur les diffusions Brillouin, Rayleigh et Raman en environnement sévère

This thesis was carried out in collaboration between Andra (The National Agency for the Management of Radioactive Waste) and the Hubert Curien laboratory (Joint Research Unit CNRS 5516) of the Jean Monnet University of Saint-Étienne.In this work, I evaluated the performance of fiber optic sensors for monitoring the geological disposal site of long-lived radioactive waste (Cigéo project). This application requires regular, remote and distributed monitoring of the evolution of different quantities of interest such as: temperature, deformation and the presence of hydrogen (as well as their combinations) in a severe radiative environment. The proposed solution is based on the follow-up of optical signatures evolution of these wave-guides via backscatter studies: Brillouin, Rayleigh, and Raman.In order to answer this problem, several interrogation systems have been tested (used). According to their specificities, they are differentiated by: their types of analysis, their spatial resolutions, their optical budgets and scopes...The selection of the studied optical fibers is a key element for this type of application as they have to withstand these extreme environments over long periods of time. In this work, I studied the responses of optical fibers containing different dopants, in particular Ge and F. I quantified the effects of gamma radiation, temperature, deformation and the presence of hydrogen on the quality (sensitivitiy) of the distributed measures.My work has identified the optical fiber type to be used for these harsh environments. The interrogators’ responses are driven by these fiber types as well as their lengths and, consequently, make it possible to clearly define the dimensions of the areas to be monitored. The qualities of the measurement are governed by the choice of several parameters and in particular: the pulse duration, the power injected into the fiber, the frequency steps, the measurement duration ... these elements have a direct impact on the final resolutions (spatial and frequency) of measured quantities. Particular attention must be attached to these criteria.Cette thèse a été réalisée en collaboration entre l'Andra (L’Agence Nationale pour la Gestion des Déchets Radioactifs) et le laboratoire Hubert Curien (Unité Mixte de Recherche CNRS 5516) de l’Université Jean Monnet de Saint-Étienne. Dans ce travail, j’ai évalué les performances de capteurs à fibre optique pour la surveillance du site de stockage géologique de déchets radioactifs à vie longue (projet Cigéo). Cette application demande un suivi régulier, déporté et réparti de l’évolution de différentes grandeurs d’intérêt telles que : la température, la déformation et la présence d’hydrogène (ainsi que leurs combinaisons) en environnement radiatif sévère. La solution proposée repose sur les suivis des évolutions des signatures optiques de ces guides via des études en rétrodiffusion : Brillouin, Rayleigh et Raman. Afin de répondre à cette problématique, plusieurs systèmes d’interrogations ont été testés (utilisés). Selon leurs spécificités, ils se différencient par leurs types d’analyses, leurs résolutions spatiales, leurs budget optique et portées…. La sélection des fibres optiques d’étude est un élément clés pour ce type d’applications car elles doivent résister à ces environnements extrêmes sur de longues durées. Dans ce travail, j’ai étudié les réponses de fibres optiques contenant différents dopants, en particulier Ge et F. J’ai quantifié les effets des rayonnements gamma, de la température, de la déformation et de la présence d'hydrogène sur la qualité des mesures réparties. En conclusion, mon travail a cerné le type de fibre optique à utiliser pour ces environnements sévères. Les interrogateurs conditionnent le type de fibre à utiliser ainsi que leurs longueurs et, par conséquent, permettent de bien cerner les dimensions des zones à surveiller. Les qualités des résultats de mesures sont gouvernées par les choix de plusieurs paramètres et notamment : la durée de l’impulsion, la puissance injectée dans la fibre, les pas fréquentiels, la durée de la mesure…qui se répercutent directement sur les résolutions finales (spatiales et fréquentielles) des grandeurs mesurées. Une attention particulière doit être attachée à ces critères

Performances of Brillouin, Rayleigh and Raman fiber-based sensing of temperature and strain in harsh environment

Cette thèse a été réalisée en collaboration entre l'Andra (L’Agence Nationale pour la Gestion des Déchets Radioactifs) et le laboratoire Hubert Curien (Unité Mixte de Recherche CNRS 5516) de l’Université Jean Monnet de Saint-Étienne. Dans ce travail, j’ai évalué les performances de capteurs à fibre optique pour la surveillance du site de stockage géologique de déchets radioactifs à vie longue (projet Cigéo). Cette application demande un suivi régulier, déporté et réparti de l’évolution de différentes grandeurs d’intérêt telles que : la température, la déformation et la présence d’hydrogène (ainsi que leurs combinaisons) en environnement radiatif sévère. La solution proposée repose sur les suivis des évolutions des signatures optiques de ces guides via des études en rétrodiffusion : Brillouin, Rayleigh et Raman. Afin de répondre à cette problématique, plusieurs systèmes d’interrogations ont été testés (utilisés). Selon leurs spécificités, ils se différencient par leurs types d’analyses, leurs résolutions spatiales, leurs budget optique et portées…. La sélection des fibres optiques d’étude est un élément clés pour ce type d’applications car elles doivent résister à ces environnements extrêmes sur de longues durées. Dans ce travail, j’ai étudié les réponses de fibres optiques contenant différents dopants, en particulier Ge et F. J’ai quantifié les effets des rayonnements gamma, de la température, de la déformation et de la présence d'hydrogène sur la qualité des mesures réparties. En conclusion, mon travail a cerné le type de fibre optique à utiliser pour ces environnements sévères. Les interrogateurs conditionnent le type de fibre à utiliser ainsi que leurs longueurs et, par conséquent, permettent de bien cerner les dimensions des zones à surveiller. Les qualités des résultats de mesures sont gouvernées par les choix de plusieurs paramètres et notamment : la durée de l’impulsion, la puissance injectée dans la fibre, les pas fréquentiels, la durée de la mesure…qui se répercutent directement sur les résolutions finales (spatiales et fréquentielles) des grandeurs mesurées. Une attention particulière doit être attachée à ces critères.This thesis was carried out in collaboration between Andra (The National Agency for the Management of Radioactive Waste) and the Hubert Curien laboratory (Joint Research Unit CNRS 5516) of the Jean Monnet University of Saint-Étienne.In this work, I evaluated the performance of fiber optic sensors for monitoring the geological disposal site of long-lived radioactive waste (Cigéo project). This application requires regular, remote and distributed monitoring of the evolution of different quantities of interest such as: temperature, deformation and the presence of hydrogen (as well as their combinations) in a severe radiative environment. The proposed solution is based on the follow-up of optical signatures evolution of these wave-guides via backscatter studies: Brillouin, Rayleigh, and Raman.In order to answer this problem, several interrogation systems have been tested (used). According to their specificities, they are differentiated by: their types of analysis, their spatial resolutions, their optical budgets and scopes...The selection of the studied optical fibers is a key element for this type of application as they have to withstand these extreme environments over long periods of time. In this work, I studied the responses of optical fibers containing different dopants, in particular Ge and F. I quantified the effects of gamma radiation, temperature, deformation and the presence of hydrogen on the quality (sensitivitiy) of the distributed measures.My work has identified the optical fiber type to be used for these harsh environments. The interrogators’ responses are driven by these fiber types as well as their lengths and, consequently, make it possible to clearly define the dimensions of the areas to be monitored. The qualities of the measurement are governed by the choice of several parameters and in particular: the pulse duration, the power injected into the fiber, the frequency steps, the measurement duration ... these elements have a direct impact on the final resolutions (spatial and frequency) of measured quantities. Particular attention must be attached to these criteria

Steady γ-Ray Effects on the Performance of PPP-BOTDA and TW-COTDR Fiber Sensing

We investigated the evolution of the performances of Pulse Pre Pump-Brillouin Time Domain Analysis (PPP-BOTDA) and Tunable Wavelength Coherent Optical Time Domain Reflectometry (TW-COTDR) fiber-based temperature and strain sensors when the sensing optical fiber is exposed to two γ-ray irradiation conditions: (i) at room temperature and a dose rate of 370 Gy(SiO2)/h up to a total ionizing dose (TID) of 56 kGy; (ii) at room temperature and a dose rate of 25 kGy(SiO2)/h up to a TID of 10 MGy. Two main different classes of single-mode optical fibers have been tested in situ, radiation-tolerant ones: fluorine-doped or nitrogen-doped core fibers, as well as Telecom-grade germanosilicate ones. Brillouin and Rayleigh Sensitivities of N-Doped fibers were not reported yet, and these characterizations pave the way for a novel and alternative sensing scheme. Moreover, in these harsh conditions, our results showed that the main parameter affecting the sensor sensitivity remains the Radiation Induced Attenuation (RIA) at its operation wavelength of 1550 nm. RIA limits the maximal sensing range but does not influence the measurement uncertainty. F-doped fiber is the most tolerant against RIA with induced losses below 8 dB/km after a 56 kGy accumulated dose whereas the excess losses of other fibers exceed 22 dB/km. Both Rayleigh and Brillouin signatures that are exploited by the PPP-BOTDA and the TW-COTDR remain unchanged (within our experimental uncertainties). The strain and temperature coefficients of the various fibers under test are not modified by radiations, at these dose/dose rate levels. Consequently, this enables the design of a robust strain and temperature sensing architecture for the monitoring of radioactive waste disposals

Influence des charges sur les propriétés mécaniques des élastomères lors de leur vieillissement par irradiation

National audienc

Influence des charges sur les propriétés mécaniques des élastomères lors de leur vieillissement par irradiation

National audienc

Etude de la fibre standard Corning SMF28 par réflectométrie PP-BOTDA et TW-COTDR

International audienceL'objectif du présent article est de valider la méthodologie de traitement des données issues du Neubrescope, qui effectue des mesures de type réflectométrie PP-BOTDA et TW-COTDR sur la fibre standard SMF28. Les coefficients de température et de contrainte de la fibre de référence SMF28 donnés par cet outil sont comparés avec les valeurs de la littératur

Study of γ-ray radiation effects on TW-COTDR optical fiber sensors

International audienceRadiation effects on the performances of TW-COTDR (Tunable Wavelength - Coherent Optical Time Domain Reflectometry) optical fiber sensors based on Rayleigh scattering have been studied online for Ge-doped and F-doped fibers. We confirm that the Rayleigh response is not affected by low radiation (dose ∼55 kGy). However we observed using the TW-COTDR technology, a radiation induced frequency shift increasing at higher radiation (dose ∼ 10MGy): up to 96 GHz for Ge-doped fiber and up to 25.5 GHz for F-doped fiber

Steady γ-Ray Effects on the Performance of PPP-BOTDA and TW-COTDR Fiber Sensing

International audienceWe investigated the evolution of the performances of Pulse Pre Pump-Brillouin Time Domain Analysis (PPP-BOTDA) and Tunable Wavelength Coherent Optical Time Domain Reflectometry (TW-COTDR) fiber-based temperature and strain sensors when the sensing optical fiber is exposed to two γ-ray irradiation conditions: (i) at room temperature and a dose rate of 370 Gy(SiO2)/h up to a total ionizing dose (TID) of 56 kGy; (ii) at room temperature and a dose rate of 25 kGy(SiO2)/h up to a TID of 10 MGy. Two main different classes of single-mode optical fibers have been tested in situ, radiation-tolerant ones: fluorine-doped or nitrogen-doped core fibers, as well as Telecom-grade germanosilicate ones. Brillouin and Rayleigh Sensitivities of N-Doped fibers were not reported yet, and these characterizations pave the way for a novel and alternative sensing scheme. Moreover, in these harsh conditions, our results showed that the main parameter affecting the sensor sensitivity remains the Radiation Induced Attenuation (RIA) at its operation wavelength of 1550 nm. RIA limits the maximal sensing range but does not influence the measurement uncertainty. F-doped fiber is the most tolerant against RIA with induced losses below 8 dB/km after a 56 kGy accumulated dose whereas the excess losses of other fibers exceed 22 dB/km. Both Rayleigh and Brillouin signatures that are exploited by the PPP-BOTDA and the TW-COTDR remain unchanged (within our experimental uncertainties). The strain and temperature coefficients of the various fibers under test are not modified by radiations, at these dose/dose rate levels. Consequently, this enables the design of a robust strain and temperature sensing architecture for the monitoring of radioactive waste disposal