59 research outputs found

    Lieu de liens, lieu de vie : oser le rĂ©seau comme alternative Ă  la vulnĂ©rabilitĂ© : le cas des demandeurs d’asile Ă  Projet Refuge (MontrĂ©al)

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    La vulnĂ©rabilitĂ© est l’attribut fondamental justifiant le passage des frontiĂšres du refuge canadien (Rousseau et al., 2002 ; ClĂ©ment et Bolduc, 2004). Elle est preuve d’insĂ©curitĂ© pour la victime requĂ©rant l’asile ; elle est aussi porteuse d’espĂ©rance de sĂ©curitĂ© en terre hospitaliĂšre. Elle est pourtant potentiel rĂ©actualisĂ© dans l’insĂ©curitĂ© d’un statut incertain en terre d’accueil (Agamben, 1997 ; D’Halluin, 2004). Violente immersion. En attendant que les preuves de sa vulnĂ©rabilitĂ© originelle soient validĂ©es, le demandeur d’asile se retrouve dans un entre-deux a-territorial et atemporel (Agier, 2002 ; Le Blanc, 2010) et dans une prĂ©caritĂ© tout aussi dangereuse (Ouimet et al., 2009). Des besoins Ă©mergent en cette terre inconnue, or l’accĂšs aux soins de santĂ© lui est limitĂ© par des textes de lois ambigus et leurs interprĂ©tations maladroites (Harris et Zuberi, 2015). Ainsi lorsqu’il se heurte Ă  des barriĂšres Ă©rigĂ©es par une transmission d’informations dĂ©fectueuse, sa prĂ©caritĂ© ne fait qu’empirer. Tel un boomerang, ce paradoxe cultive leur vulnĂ©rabilitĂ©. Alors que les recherches interrogent les divers intervenants en santĂ© (Asgary et Smith, 2013), j’ai choisi de donner la parole aux premiers concernĂ©s et de relayer leur vĂ©cu par rapport Ă  leur propre personne. Deux objectifs principaux guident la recherche : documenter dans un premier temps leur parcours de quĂȘte de soins Ă  partir de la circulation des informations formelles et informelles dans le but de sonder leur avis sur la vulnĂ©rabilitĂ© qui leur est attribuĂ©e ; documenter dans un second temps leur parcours migratoire de quĂȘte de soi afin de mettre en lumiĂšre les stratĂ©gies alternatives d’entrĂ©e en contact avec la sociĂ©tĂ© d’accueil pour nĂ©gocier voire rejeter cette identitĂ© vulnĂ©rable. J’ai rencontrĂ© pour cela des demandeurs d’asile lors d’un terrain de huit mois au sein d’un organisme communautaire d’hĂ©bergement Ă  MontrĂ©al. Dans ce contexte d’accompagnement et de stabilitĂ© spatiale, accalmie bienvenue au terme d’un itinĂ©raire semĂ© d’embĂ»ches, les ressources informationnelles sont Ă  leur disposition et la reconnaissance sociale est Ă  l’honneur. En parallĂšle, beaucoup tĂ©moignent de la diminution de leurs besoins de soins de santĂ©. En cette communautĂ© thĂ©rapeutique (Pocreau, 2005), vĂ©ritable tremplin vers la sociĂ©tĂ© d’accueil en attendant un statut reconnu, ils bĂ©nĂ©ficient d’une possibilitĂ© de participation sociale et d’un sentiment d’appartenance valorisant. Si des conditions prĂ©caires peuvent aggraver la vulnĂ©rabilitĂ©, le bricolage de conditions positives favorise la rĂ©silience (Cleveland et al., 2014), crĂ©ant un environnement revitalisant qui leur permet de rebondir.Vulnerability is a fundamental attribute which justifies the crossing of the Canadian refuge borders (Rousseau et al., 2002 ; ClĂ©ment et Bolduc, 2004). It is a proof of insecurity for the victim who requires asylum ; it also bears hope of security in the land of hospitality. However it is an updated potential of insecurity about an uncertain status in the host country (Agamben, 1997 ; D’Halluin, 2004). Violent immersion. Until the proofs of his original vulnerability are validated, the asylum seeker lies in an “in-between” with no defined territoriality or temporality (Agier, 2002 ; Le Blanc, 2010); and in a precariousness just as dangerous (Ouimet et al., 2009). Needs arise in this unknown land, yet the access to healthcare is limited by ambiguous laws and their inappropriate interpretation (Harris et Zuberi, 2015). So when he faces barriers erected by an erroneous transmission of information, his precariousness only spirals down. As a boomerang, this paradox maintains his vulnerability. While researches have focused on the perceptions of various health practitioners (Asgary et Smith, 2013), I chose to let the concerned patient speak, and to relay their actual experience. Two key objectives are guiding my research : first, to examine their quest for health care with formal and informal information sources, aiming to sound out their feelings about the vulnerability ; secondly, to document their migratory path for their self in order to lighten the alternative strategies to create contact with the host society, negotiating or fully rejecting this vulnerable identity. To accomplish this research, I met asylum seekers during an eight months ethnographic fieldwork in a community organization of accommodation in Montreal. In that context of support and spatial stability, a welcomed respite at the end of a bumpy route, the informational resources are at their disposal and they at last encounter some social recognition. Meanwhile, many of the participants felt a lesser need for healthcare. In this therapeutic community (Pocreau, 2005), which is a real springboard to the host society while waiting for an accepted status, they enjoy an opportunity for social participation and a growing sense of belonging. Precarious conditions can exacerbate the vulnerability, however the tinkering of positive conditions favors resiliency (Cleveland et al., 2014) by creating a revitalizing environment which allows them to rebound

    Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

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    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    Refroidissement radiatif et texturation de surfaces pour condenseurs de rosée à haut rendement

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    This work is a contribution to the development of passive condensation and dew water harvesting. In the first part, we report a study on rough surfaces developed by a simple surface treatment (sand-blasting). Results obtained show that roughness of surface favors droplet shedding compared to the original smooth substrate, provided that sand-blasting does not increase too much the surface roughness. This process enhances the density of nucleation sites and the coalescences events at a sub-micron scale, thus lowering the lag-time to obtain drop sliding during condensation. Experiments show that combining sand-blasting and edge effects can thus increase substantially the passive collection by gravity from a substrate. Gains about 30% when compared to the same smooth substrate are obtained. In a second part, a laboratory radiative chamber is developed, which carries out radiative exchanges between a centimeter-sized object and a cold source. This device makes it possible to study the radiative properties of different materials on the performance of passive dew condensers. In a humid environment, condensation is obtained on objects of various geometries, including geometries for which contact cooling is very inefficient. An important result was obtained with the device : the beginning of the condensation process is highly dependent on the emissivity of the surface; but it is no longer so when the surface is covered with water drops. A simplified model of radiative exchanges between a water drops on a planar surface and its environment is proposed to establish an expression for the average emissivity of a surface covered with condensed water drops.Ce travail est une contribution Ă  l’amĂ©lioration de la condensation et de la collecte passive de l’eau de rosĂ©e. Dans une premiĂšre partie, une surface traitĂ©e par sablage est utilisĂ©e pour la condensation en laboratoire. Sur cette surface rugueuse, refroidie par contact, les gouttes condensĂ©es se dĂ©tachent plus vite que sur la surface non-traitĂ©e, et la collecte passive par gravitĂ© des gouttes est augmentĂ©e. Les expĂ©riences montrent que la combinaison du sablage et des effets de bord peut augmenter considĂ©rablement la collecte passive par gravitĂ© Ă  partir d'un substrat. Des gains d'environ 30% par rapport au mĂȘme support lisse sont obtenus. Dans une deuxiĂšme partie, un dispositif original de refroidissement radiatif en laboratoire est dĂ©veloppĂ©, qui rĂ©alise des Ă©changes radiatifs entre un objet de petite taille et une source froide. Ce dispositif permet d’étudier de maniĂšre contrĂŽlĂ©e l’influence des propriĂ©tĂ©s radiatives des matĂ©riaux sur les performances des condenseurs passifs de rosĂ©e. En environnement humide, la condensation est obtenue sur des objets de gĂ©omĂ©tries variĂ©es, y compris des gĂ©omĂ©tries peu compactes et/ou de faibles conductivitĂ©s thermiques pour lesquelles le refroidissement par contact est peu efficace. Un rĂ©sultat important a Ă©tĂ© obtenu par cette technique : l’émissivitĂ© de la surface de condensation ne joue un rĂŽle important qu'au dĂ©but de la condensation, puis la surface se couvre de gouttes condensĂ©es qui dĂ©terminent son Ă©missivitĂ© globale. Un modĂšle simple des Ă©changes radiatifs entre une goutte posĂ©e sur une surface plane et son environnement est proposĂ© afin d'Ă©tablir une expression de l'Ă©missivitĂ© moyenne d'une surface couverte de gouttes

    Radiative cooling and surface texturing for high-efficiency dew condensers

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    Ce travail est une contribution Ă  l’amĂ©lioration de la condensation et de la collecte passive de l’eau de rosĂ©e. Dans une premiĂšre partie, une surface traitĂ©e par sablage est utilisĂ©e pour la condensation en laboratoire. Sur cette surface rugueuse, refroidie par contact, les gouttes condensĂ©es se dĂ©tachent plus vite que sur la surface non-traitĂ©e, et la collecte passive par gravitĂ© des gouttes est augmentĂ©e. Les expĂ©riences montrent que la combinaison du sablage et des effets de bord peut augmenter considĂ©rablement la collecte passive par gravitĂ© Ă  partir d'un substrat. Des gains d'environ 30% par rapport au mĂȘme support lisse sont obtenus. Dans une deuxiĂšme partie, un dispositif original de refroidissement radiatif en laboratoire est dĂ©veloppĂ©, qui rĂ©alise des Ă©changes radiatifs entre un objet de petite taille et une source froide. Ce dispositif permet d’étudier de maniĂšre contrĂŽlĂ©e l’influence des propriĂ©tĂ©s radiatives des matĂ©riaux sur les performances des condenseurs passifs de rosĂ©e. En environnement humide, la condensation est obtenue sur des objets de gĂ©omĂ©tries variĂ©es, y compris des gĂ©omĂ©tries peu compactes et/ou de faibles conductivitĂ©s thermiques pour lesquelles le refroidissement par contact est peu efficace. Un rĂ©sultat important a Ă©tĂ© obtenu par cette technique : l’émissivitĂ© de la surface de condensation ne joue un rĂŽle important qu'au dĂ©but de la condensation, puis la surface se couvre de gouttes condensĂ©es qui dĂ©terminent son Ă©missivitĂ© globale. Un modĂšle simple des Ă©changes radiatifs entre une goutte posĂ©e sur une surface plane et son environnement est proposĂ© afin d'Ă©tablir une expression de l'Ă©missivitĂ© moyenne d'une surface couverte de gouttes.This work is a contribution to the development of passive condensation and dew water harvesting. In the first part, we report a study on rough surfaces developed by a simple surface treatment (sand-blasting). Results obtained show that roughness of surface favors droplet shedding compared to the original smooth substrate, provided that sand-blasting does not increase too much the surface roughness. This process enhances the density of nucleation sites and the coalescences events at a sub-micron scale, thus lowering the lag-time to obtain drop sliding during condensation. Experiments show that combining sand-blasting and edge effects can thus increase substantially the passive collection by gravity from a substrate. Gains about 30% when compared to the same smooth substrate are obtained. In a second part, a laboratory radiative chamber is developed, which carries out radiative exchanges between a centimeter-sized object and a cold source. This device makes it possible to study the radiative properties of different materials on the performance of passive dew condensers. In a humid environment, condensation is obtained on objects of various geometries, including geometries for which contact cooling is very inefficient. An important result was obtained with the device : the beginning of the condensation process is highly dependent on the emissivity of the surface; but it is no longer so when the surface is covered with water drops. A simplified model of radiative exchanges between a water drops on a planar surface and its environment is proposed to establish an expression for the average emissivity of a surface covered with condensed water drops
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