42 research outputs found

    Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower RhĂŽne Valley, France

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    On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower RhĂŽne Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional CĂ©venne fault system in a context of present-day compressional tectonics

    Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

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    RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≄60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Experimental study of aerosol behavior and their deposits in a bucket elevator : impact on carry-over of micro-ingredients in animal feed industry

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    La problĂ©matique des contaminations croisĂ©es (transfert inter-lots de micro-ingrĂ©dients : additifs et/ou produits mĂ©dicamenteux) dans le secteur de l'alimentation animale est entrĂ©e, depuis quelques dĂ©cennies, au cƓur des prĂ©occupations de la profession. Ce phĂ©nomĂšne se dĂ©compose en 2 phases : le dĂ©pĂŽt de particules par un lot de fabrication et sa rĂ©cupĂ©ration par le/les lot(s) suivant(s). Plusieurs Ă©tudes expĂ©rimentales, ont incriminĂ© l’élĂ©vateur Ă  godets post-mĂ©langeur dans l’augmentation du niveau de contamination d’une ligne de fabrication. Cet appareil de manutention achemine verticalement des mĂ©langes pulvĂ©rulents de diverses matiĂšres premiĂšres, pouvant contenir, en particulier, des additifs ou des produits mĂ©dicamenteux. L’objectif de ces travaux est de comprendre dans quelles mesures cet appareil est source de transfert inter-lots, et quels paramĂštres liĂ©s au procĂ©dĂ© entrent en jeu. Plusieurs outils ont Ă©tĂ© mis en place et la rĂ©alisation d'un plan d’expĂ©riences a permis de mettre en lumiĂšre l’impact de certains facteurs sur la contamination croisĂ©e :d’une part, le mode de vidange (liĂ© Ă  la vitesse de la sangle) en tĂȘte de l’élĂ©vateur et l’angle de la bavette de jetĂ©e agissent sur la quantitĂ© de micro-ingrĂ©dient dĂ©posĂ©e lors du passage d’un lot, et d’autre part, l’espace autour des godets, modifie la capacitĂ© du lot suivant Ă  collecter les reliquats.Ces informations dĂ©finissent une position optimale des paramĂštres de l’élĂ©vateur qui, sur pilote, rĂ©duit le niveau de contaminations croisĂ©es de 9 Ă  7 %. Enfin, des observations des champs de vitesses pendant la jetĂ©e du produit ont apportĂ© de Ă©lĂ©ments de comprĂ©hension sur mouvements d'air et d'aĂ©rosols Ă  l'origine des contaminations.Carry-over of additives and/or medicated products is a common issue in feed industry and, by extension in most of powder handling industries. Currently carry-over rate of a production line can be accurately defined but the causes are not identified yet. It can be broken into 2 phases : firstly, particle deposit during one batch processing and then, their collecting during the following batches. Experimental studies, carried out on industrial sites or on test benches, charged the bucket elevator situated just after the mixer to be responsible for a significant increase of cross contamination rate of industrial feed production lines. Therefore this work focuses on this handling device. It transfers mixing of several raw materials in powdery forms, which may contain micro-ingredients, especially additives or medicated products. The aim of this study is to understand how process operations affect cross contamination rates during bucket elevator handling. A test bench of this handling device, a reference product and laboratory methods have been setup. Moreover, an experimental fractional factorial design highlights the effects of several process parameters : on one hand the discharge phase on elevator head (linked to belt velocity) and the discharge spout angle act on microingredients deposit mass. On the other hand, spacing between buckets and the leg’s inner surface influences micro-ingredients collected mass. Furthermore, ideal position of process parameters has been defined. By this way, cross contamination rate on the test bench has been decreased from 9 to 7 percent. Finally, velocity fields observations during the discharge phase leads to better understanding of how these process parameters influence cross contamination rate

    Etude expérimentale du comportement des aérosols et de leurs dépÎts dans un élévateur à godets : impact sur la contamination croisée en alimentation animale

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    Carry-over of additives and/or medicated products is a common issue in feed industry and, by extension in most of powder handling industries. Currently carry-over rate of a production line can be accurately defined but the causes are not identified yet. It can be broken into 2 phases : firstly, particle deposit during one batch processing and then, their collecting during the following batches. Experimental studies, carried out on industrial sites or on test benches, charged the bucket elevator situated just after the mixer to be responsible for a significant increase of cross contamination rate of industrial feed production lines. Therefore this work focuses on this handling device. It transfers mixing of several raw materials in powdery forms, which may contain micro-ingredients, especially additives or medicated products. The aim of this study is to understand how process operations affect cross contamination rates during bucket elevator handling. A test bench of this handling device, a reference product and laboratory methods have been setup. Moreover, an experimental fractional factorial design highlights the effects of several process parameters : on one hand the discharge phase on elevator head (linked to belt velocity) and the discharge spout angle act on microingredients deposit mass. On the other hand, spacing between buckets and the leg’s inner surface influences micro-ingredients collected mass. Furthermore, ideal position of process parameters has been defined. By this way, cross contamination rate on the test bench has been decreased from 9 to 7 percent. Finally, velocity fields observations during the discharge phase leads to better understanding of how these process parameters influence cross contamination rate.La problĂ©matique des contaminations croisĂ©es (transfert inter-lots de micro-ingrĂ©dients : additifs et/ou produits mĂ©dicamenteux) dans le secteur de l'alimentation animale est entrĂ©e, depuis quelques dĂ©cennies, au cƓur des prĂ©occupations de la profession. Ce phĂ©nomĂšne se dĂ©compose en 2 phases : le dĂ©pĂŽt de particules par un lot de fabrication et sa rĂ©cupĂ©ration par le/les lot(s) suivant(s). Plusieurs Ă©tudes expĂ©rimentales, ont incriminĂ© l’élĂ©vateur Ă  godets post-mĂ©langeur dans l’augmentation du niveau de contamination d’une ligne de fabrication. Cet appareil de manutention achemine verticalement des mĂ©langes pulvĂ©rulents de diverses matiĂšres premiĂšres, pouvant contenir, en particulier, des additifs ou des produits mĂ©dicamenteux. L’objectif de ces travaux est de comprendre dans quelles mesures cet appareil est source de transfert inter-lots, et quels paramĂštres liĂ©s au procĂ©dĂ© entrent en jeu. Plusieurs outils ont Ă©tĂ© mis en place et la rĂ©alisation d'un plan d’expĂ©riences a permis de mettre en lumiĂšre l’impact de certains facteurs sur la contamination croisĂ©e :d’une part, le mode de vidange (liĂ© Ă  la vitesse de la sangle) en tĂȘte de l’élĂ©vateur et l’angle de la bavette de jetĂ©e agissent sur la quantitĂ© de micro-ingrĂ©dient dĂ©posĂ©e lors du passage d’un lot, et d’autre part, l’espace autour des godets, modifie la capacitĂ© du lot suivant Ă  collecter les reliquats.Ces informations dĂ©finissent une position optimale des paramĂštres de l’élĂ©vateur qui, sur pilote, rĂ©duit le niveau de contaminations croisĂ©es de 9 Ă  7 %. Enfin, des observations des champs de vitesses pendant la jetĂ©e du produit ont apportĂ© de Ă©lĂ©ments de comprĂ©hension sur mouvements d'air et d'aĂ©rosols Ă  l'origine des contaminations

    Etude expérimentale du comportement des aérosols et de leurs dépÎts dans un élévateur à godets (impact sur la contamination croisée en alimentation animale)

    No full text
    La problĂ©matique des contaminations croisĂ©es (transfert inter-lots de micro-ingrĂ©dients : additifs et/ou produits mĂ©dicamenteux) dans le secteur de l'alimentation animale est entrĂ©e, depuis quelques dĂ©cennies, au cƓur des prĂ©occupations de la profession. Ce phĂ©nomĂšne se dĂ©compose en 2 phases : le dĂ©pĂŽt de particules par un lot de fabrication et sa rĂ©cupĂ©ration par le/les lot(s) suivant(s). Plusieurs Ă©tudes expĂ©rimentales, ont incriminĂ© l Ă©lĂ©vateur Ă  godets post-mĂ©langeur dans l augmentation du niveau de contamination d une ligne de fabrication. Cet appareil de manutention achemine verticalement des mĂ©langes pulvĂ©rulents de diverses matiĂšres premiĂšres, pouvant contenir, en particulier, des additifs ou des produits mĂ©dicamenteux. L objectif de ces travaux est de comprendre dans quelles mesures cet appareil est source de transfert inter-lots, et quels paramĂštres liĂ©s au procĂ©dĂ© entrent en jeu. Plusieurs outils ont Ă©tĂ© mis en place et la rĂ©alisation d'un plan d expĂ©riences a permis de mettre en lumiĂšre l impact de certains facteurs sur la contamination croisĂ©e :d une part, le mode de vidange (liĂ© Ă  la vitesse de la sangle) en tĂȘte de l Ă©lĂ©vateur et l angle de la bavette de jetĂ©e agissent sur la quantitĂ© de micro-ingrĂ©dient dĂ©posĂ©e lors du passage d un lot, et d autre part, l espace autour des godets, modifie la capacitĂ© du lot suivant Ă  collecter les reliquats.Ces informations dĂ©finissent une position optimale des paramĂštres de l Ă©lĂ©vateur qui, sur pilote, rĂ©duit le niveau de contaminations croisĂ©es de 9 Ă  7 %. Enfin, des observations des champs de vitesses pendant la jetĂ©e du produit ont apportĂ© de Ă©lĂ©ments de comprĂ©hension sur mouvements d'air et d'aĂ©rosols Ă  l'origine des contaminations.Carry-over of additives and/or medicated products is a common issue in feed industry and, by extension in most of powder handling industries. Currently carry-over rate of a production line can be accurately defined but the causes are not identified yet. It can be broken into 2 phases : firstly, particle deposit during one batch processing and then, their collecting during the following batches. Experimental studies, carried out on industrial sites or on test benches, charged the bucket elevator situated just after the mixer to be responsible for a significant increase of cross contamination rate of industrial feed production lines. Therefore this work focuses on this handling device. It transfers mixing of several raw materials in powdery forms, which may contain micro-ingredients, especially additives or medicated products. The aim of this study is to understand how process operations affect cross contamination rates during bucket elevator handling. A test bench of this handling device, a reference product and laboratory methods have been setup. Moreover, an experimental fractional factorial design highlights the effects of several process parameters : on one hand the discharge phase on elevator head (linked to belt velocity) and the discharge spout angle act on microingredients deposit mass. On the other hand, spacing between buckets and the leg s inner surface influences micro-ingredients collected mass. Furthermore, ideal position of process parameters has been defined. By this way, cross contamination rate on the test bench has been decreased from 9 to 7 percent. Finally, velocity fields observations during the discharge phase leads to better understanding of how these process parameters influence cross contamination rate.NANTES-ENS Mines (441092314) / SudocSudocFranceF

    Micro-Ingredients Carry-Over During Bucket Elevator Handling in Feed Industry: Influence of Process Parameters

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    WOS:000325088000013International audienceCurrently, carry-over level of feed production lines can be accurately defined, but the causes are not identified yet because of a misunderstanding of this phenomenon. On-site studies charged conveying equipment between mixer and pelleting press, and especially bucket elevator, to be responsible for carry-over level increasing. A series of experiments has been carried out on a bucket elevator test bench in order to determine how process parameters influence carry-over phenomenon. Product deposits on equipment walls represent, on average, 3.0% of the initial batch mass and contain about 0.2% of micro-ingredient after one tracer batch passing and 0.1% after flushing batch passing. Experimental design results showed that parameters acting on micro-ingredient deposited are different from those influencing collected product. Therefore, optimal position of tested process parameters will depend on the batch objective regarding its position in the production schedule. Practical ApplicationsThis work allows a new approach of understanding carry-over phenomenon at pilot scale. Indeed, process parameters acting on micro-ingredient deposits by a batch n have been differentiated from those acting on micro-ingredient gathering by a batch n+1. By this way, the results of this experimental study brought industrial solutions to control micro-ingredient transfer, considering the batch position in the whole sequencing
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