18 research outputs found
Développement d'un capteur pour mesurer en continu et in situ les teneurs en fer (III) et fer (II) ainsi que d'autres métaux dans les eaux d'exhaure des anciens sites miniers
ette thèse s'inscrit dans une thématique de surveillance des effluents miniers. Elle a été cofinancée par le Bureau de Recherches Géologiques et Minières et le Ministère de la Recherche dans le cadre du projet Fer_On_Line, issu du réseau de Recherche et d'Innovation Technologique sur l'Eau. L'objectif de ce projet était de mettre au point un capteur électrochimique instrumenté afin de mesurer en continu et in situ les teneurs en fer(II) et fer(III) ainsi que celles d'autres éléments dans les eaux d'exhaure d'anciens sites miniers et de les transmettre par télétransmission. Le suivi de ces éléments " marqueurs " renseigne sur l'évolution d'ensemble des effluents miniers d'un site donné. Il a été montré que la mesure de la concentration du fer [fer(II) et/ou fer(III)] dans les effluents miniers de deux anciens sites (Chessy et Carnoulès) était possible par détection ampérométrique, en même temps que celle du cuivre(II) [Chessy]. Une autre espèce, l'arsenic(III) [Carnoulès], a pu être détectée mais non quantifiée. Une cellule électrochimique à jet noyé adaptée aux mesures in situ et à un environnement comme celui des eaux issues du drainage minier acide a été conçue et réalisée, ainsi que l'électronique associée. Le prototype constitué de la cellule incluant le capteur ampérométrique et du dispositif de mesure a été implanté sur le site de Carnoulès où le suivi de la concentration du fer(II) a été effectué pendant 7 jours. Les résultats ont montré d'une part une très bonne concordance entre les valeurs déterminées par ampérométrie et celles obtenues par colorimétrie et d'autre part, une durée de vie du capteur ampérométrique très prometteuse pour la suite de l'étude.This thesis deals with mining effluents monitoring. It has been cofinanced by the Office of Geological and Mining Research and the Ministry of Research within the scope of the Fer_On_Line project, resulting from the network of Research and Technological Innovation on Water. The purpose of this project was to develop an electrochemical sensor for the continuous and in situ determination of iron(II) and iron(III) levels, as well as other elements, in acid mine drainage waters from abandoned mining sites and to transmit them by telemetry. The follow-up of these elements "markers" informs about the overall evolution of the mining effluents from a given site. It has been shown that the concentration measurement of iron [iron(I) and/or iron(III)] in the mining effluents from two abandoned sites (Chessy and Carnoulès) was possible by amperometric detection, as well as copper(II) measurement [Chessy]. Another species, such as arsenic(III) [Carnoulès], could be detected but not quantified. An electrochemical cell using impinging jet flow adapted for in situ measurements of acid mine drainage waters has been designed and carried out, as well as associated electronics. The prototype composed of the cell including the amperometric sensor and the measurement instrument has been established on the site of Carnoulès where continuous and in situ measurements of iron(II) level has been carried out during 7 days. The results showed not only a very good agreement between the values determined by amperometry and those obtained by colorimetry but also a good life time of the amperometric sensor. Thus, the continuation of the study is very promising.CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF
SmartRight: A Copy Protection System for Digital Home Networks
This paper describes the rationales supporting the design of a Copy Protection System. It reflects the experience of the Security Laboratory of Thomson in the development of SmartRight. This paper does not only account the chosen technical solutions. It also explores less technical but highly important issues such as the social, legal and commercial aspects. Hence, while carefully developing our motivations, some light is shed on the very peculiar problems raised by the enforcement of copy protection. It gives then an overview of the global SmartRight system and some technical details on its main innovative features
Investigation on the injection of the Arronax Cyclotron 70XP
International audienceA 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation
Study of Injection Line of the Cyclotrons C70XP of Arronax
International audienceThe cyclotron C70XP is an accelerator built for the production of non-conventional radionuclides for nuclear medicine, research in physics, radio-chemistry and biology. Its injection section has been designed for 4 types of ions (HH⁺, D-, He2+ & H⁻), 3 types of ions reach the end of the beamline (H⁺, He2+ & D⁺) at the maximum energy of 70 MeV (H⁻ & He2+). It is important that regular and standard runs provide similar beam features with a good emittance quality. An investigation, focused on the beam in the injection, cover beam measurements and potential beam geometry constraints. The beam transverse characteristics in the injection line has been studied with an Allison-type emittance meter and a simple instrumented collimator installed inside the injection line *. With these 2 devices, it is scrutinized how the beam emittance evolves as a function of settings of the injection magnets and the source parameters **. Dependencies found between the emittance, beam hotspots and tunings are discussed, as well as the protection performed by the collimator. Future of this work with a potential collimator design is introduced
Characterization of the Achromobacter xylosoxidans Type VI Secretion System and Its Implication in Cystic Fibrosis
International audienceBacteria of the genus Achromobacter are environmental germs, with an unknown reservoir. It can become opportunistic pathogens in immunocompromised patients, causing bacteremia, meningitis, pneumonia, or peritonitis. In recent years, Achromobacter xylosoxidans has emerged with increasing incidence in patients with cystic fibrosis (CF). Recent studies showed that A. xylosoxidans is involved in the degradation of the respiratory function of patients with CF. The respiratory ecosystem of patients with CF is colonized by bacterial species that constantly fight for space and access to nutrients. The type VI secretion system (T6SS) empowers this constant bacterial antagonism, and it is used as a virulence factor in several pathogenic bacteria. This study aimed to investigate the prevalence of the T6SS genes in A. xylosoxidans isolated in patients with CF. We also evaluated clinical and molecular characteristics of T6SS-positive A. xylosoxidans strains. We showed that A. xylosoxidans possesses a T6SS gene cluster and that some environmental and clinical isolates assemble a functional T6SS nanomachine . A. xylosoxidans T6SS is used to target competing bacteria, including other CF-specific pathogens. Finally, we demonstrated the importance of the T6SS in the internalization of A. xylosoxidans in lung epithelial cells and that the T6SS protein Hcp is detected in the sputum of patients with CF. Altogether, these results suggest for the first time a role of T6SS in CF-lung colonization by A. xylosoxidans and opens promising perspective to target this virulence determinant as innovative theranostic options for CF management
The Injection and Chopper-Based System at Arronax C70XP Cyclotron
International audienceThe multi-particle cyclotron of the Arronax Public Interest Group (GIP) is used to perform irradiation up to hundreds of µA on various experiments and targets. To support low and high average intensity usage and adapt the beam time structure required for high peak intensity operation and experiments such as pulsed experiments studies, it has been devised a pulsing system in the injection of the cyclotron. This system combines the use of a chopper, low frequency switch, and a control system based on the new extended EPICS network. This paper details the pulsing system adopted at Arronax, updates and results for various intensity experimental studies performed with alpha and proton beams. Updated work on the simulation of the injection is also shown, specifically towards high intensity future irradiation
Installation, Use and Follow-Up of an Emittance-Meter at the Arronax Cyclotron 70XP
International audienceThe 70 MeV cyclotron group of the Arronax GIP (Interest Public Group), France, foresees to increase its beam intensity on target. For this, several beam studies are being performed in the various sections of the accelerator including the injection. Thus, an Allison-type emittance-meter has been installed in this section above the cyclotron and downstream a quadrupole triplet. Installation and the first results of a campaign of measurements are presented including high intensity runs, up to 1 mA for 40 keV H⁻ ions. The emittance-meter is expected to be used with several accelerators throughout the world. Therefore, a strategy on the follow-up of the activation of sample materials used in the equipment is being established and is described in the paper
Beam Instrumentation, Challenging Tools for Demanding Projects –– a Snapshot from the French Assigned Network
International audienceParticle accelerators are thrusting the exploration of beam production towards several demanding territories, that is beam high intensity, high energy, short time and geometry precision or small size. Accelerators have thus more and more stringent characteristics that need to be measured. Beam diagnostics accompany these trends with a diversity of capacities and technologies that can encompass compactness, radiation hardness, low beam perturbation, or fast response and have a crucial role in the validation of the various operation phases. Their developments also call for specialized knowledge, expertise and technical resources. A snapshot from the French CNRS/IN2P3 beam instrumentation network is proposed. It aims to promote exchanges between the experts and facilitate the realization of project within the field. The network and several beam diagnostic technologies will be exposed. It includes developments of system with low beam interaction characteristics such as PEPITES, fast response detector such as the diamond-based by DIAMMONI, highly dedicated BPM for GANIL-SPIRAL2, emittance-meters which deals with high intensity beams and development for MYRRHA, SPIRAL2-DESIR and NEWGAIN