By definition, energetic materials can deliver a huge amount of gas and cause different kinds of phenomena, such as: burning, deflagration or detonation. These materials are mainly used in the automotive industry (airbag deployment), military devices (missiles, ammunition) and space launchers (Ariane 5 boosters and pyrotechnic devices). The manufacturing process, although well controlled by the historical "batch" process, presents several challenges when it is transferred to the continuous mixing process, using a twin-screw mixer device. Indeed, this last device induces extreme evolutions of pressure gradients and shearing gradients (reduced air-gap.). Plus, the energetic material is composed of fluid components and different diameters of solid components that can ignite by shearing. Consequently, tribological conditions leading to the ignition of an energetic material, a solid propellant, are studied during its manufacturing in a twin-screw mixer. Unfortunately, because of the industrial confidentiality on solid propellants, the bibliography on the solid propellants tribology is limited. However it appears that too few studies have effectively dealt with the tribological behaviour of this third body. By nature, this last is a composite material; therefore it is necessary to understand internal flows that evolve from tribological stresses. Thus, a coupled approach experimental and numerical is chosen in order to reproduce the mechanical elementary stresses applied by the two first bodies (top of screw thread and bore of the barrel element), and undergone by the third body during its manufacturing in a twin-screw mixer (compression and shearing). This approach consists of the instrumentation of a security test that shears the solid propellant and a discrete element simulation of the tribological triplet (inferior and superior first bodies, and the third body). The distinctive tribological behaviour of this third body appears obvious: different types of component segregations lead to a three superposed layer ...
This paper, rooted in my studies of the historiography of the French Revolution and of the War of Vendée, discuss the relationships between History, Memory, and Oblivion as social uses of the Past. History and Memory could be seen as « Siamese twins » due to their opposite prospects and méthodes, the first devoted to the universal and the criticism, the second linked to communautaries relationships and affective feelings. Both are however unseparable and dependant as it could be seen in the creation of historiographies, of historical schools and cultural identities, and due to the necessity to elaborate narration on the Past. History and Memory must be assigned to their right places, in their necessary cooperation to deal with the Past. Oblivion could be seen as the horizon line of these proceedings, reassuring the obligation to incorporate the Past in every body and in every social group.
By definition, energetic materials can deliver a huge amount of gas and cause different kinds of phenomena, such as: burning, deflagration or detonation. These materials are mainly used in the automotive industry (airbag deployment), military devices (missiles, ammunition) and space launchers (Ariane 5 boosters and pyrotechnic devices). The manufacturing process, although well controlled by the historical "batch" process, presents several challenges when it is transferred to the continuous mixing process, using a twin-screw mixer device. Indeed, this last device induces extreme evolutions of pressure gradients and shearing gradients (reduced air-gap.). Plus, the energetic material is composed of fluid components and different diameters of solid components that can ignite by shearing. Consequently, tribological conditions leading to the ignition of an energetic material, a solid propellant, are studied during its manufacturing in a twin-screw mixer. Unfortunately, because of the industrial confidentiality on solid propellants, the bibliography on the solid propellants tribology is limited. However it appears that too few studies have effectively dealt with the tribological behaviour of this third body. By nature, this last is a composite material; therefore it is necessary to understand internal flows that evolve from tribological stresses. Thus, a coupled approach experimental and numerical is chosen in order to reproduce the mechanical elementary stresses applied by the two first bodies (top of screw thread and bore of the barrel element), and undergone by the third body during its manufacturing in a twin-screw mixer (compression and shearing). This approach consists of the instrumentation of a security test that shears the solid propellant and a discrete element simulation of the tribological triplet (inferior and superior first bodies, and the third body). The distinctive tribological behaviour of this third body appears obvious: different types of component segregations lead to a three superposed layer arrangement of the solid propellant thickness. These segregations come from the creation of internal component flows, specific to the nature and the geometry of the third body components. These flows select the components that remain within the contact area and also establish the tribological conditions that favour the third body ignition (gradient of mobility between solid components, draining of the third body thickness, localization of the efforts applied to the third body…). Ultimately, this study rebuilds the ignition tribological circuit(s) of a solid propellant and offers technical solutions to prevent the materialisation of unfavourable conditions to a safe solid propellant manufacturing in a twin-screw mixer. ; Les matériaux énergétiques sont, par définition, des matériaux susceptibles de dégager un volume important de gaz, en se décomposant via les phénomènes suivants : combustion, déflagration ou détonation. Ils sont notamment utilisés dans les secteurs industriels de l'automobile (déploiement d'airbag), du militaire (propulsion de missiles tactiques et stratégiques, munitions) et du spatial (boosters de lanceurs spatiaux type Ariane 5). La maîtrise de leur fabrication nécessite que soient vérifiées certaines contraintes spécifiques rencontrées lors de leur mise en œuvre dans un malaxeur bivis. En effet, ce procédé de malaxage en continu induit de fortes évolutions de gradients de pression et de cisaillement au sein du matériau énergétique (entrefers réduits.) qui peuvent initier les constituants fluides et solides. Par conséquent, dans un souci de parfaite maîtrise des risques industriels, les conditions tribologiques menant à l'initiation d'un matériau énergétique, ici le propergol, lors de sa fabrication, doivent être étudiées. Malheureusement, à cause de la confidentialité industrielle liée à ce secteur d'activité, la bibliographie de la tribologie des propergols est limitée. Il apparait toutefois que peu d'études portent effectivement sur le comportement tribologique du troisième corps, c'est à dire le propergol. Ce dernier étant hétérogène (mélange de constituants fluides et de solides), il est donc nécessaire d'appréhender les écoulements internes qui l'animent sous sollicitations tribologiques. Ainsi, pour reproduire les sollicitations mécaniques élémentaires (compression et cisaillement) appliquées par les deux premiers corps que sont les vis et le fourreau, et subies par le troisième corps lors du malaxage, il a été choisi d'utiliser une approche couplée expérimentale et numérique. Cette dernière s'organise autour de l'instrumentation d'un dispositif de sécurité permettant la sollicitation par frottement du propergol et de la modélisation par éléments discrets du triplet tribologique (parois supérieure et inférieure des premiers corps, et troisième corps). Il est ainsi apparu un comportement tribologique caractéristique du troisième corps : des ségrégations entre les constituants mènent à un arrangement selon trois couches superposées dans l'épaisseur du troisième corps. Ces ségrégations sont issues de la mise en place de débits internes, spécifiques à chaque nature et géométrie de constituants. Ces débits sélectionnent les constituants présents dans l'aire de contact et favorisent l'existence de conditions tribologiques favorables à l'initiation du troisième corps (assèchement de l'épaisseur, localisation des efforts appliqués au troisième corps .). L'ensemble de ces débits permet de reconstituer un circuit tribologique d'initiation d'un propergol et ainsi d'envisager des solutions techniques permettant d'endiguer la mise en place des conditions défavorables à la fabrication en sécurité d'un propergol dans un malaxeur bivis.
This PhD dissertation studies the impact of number of children and of social interactions on mothers' labour supply. To determine the extent to which the link between number of children and mothers' labour supply is causal, we use two random events that affect the number of children: having same sex eldest siblings and twin births at the second pregnancy. Results suggest that having more than two children reduces mothers' participation in the labour market by 20 percentage points and the number of hours worked by employed mothers by 2 hours per week. We then analyze how the institutional context alters the effect of the number of children on mothers 'participation in the labour market. First, we find that before 1994, when the Allocation parentale d'éducation was intended for parents of three children or more, having more than two children decreases significantly mothers' activity. After the extension of the benefit to mothers with two children, this is not the case anymore and the negative effect of having a second child on their activity is stronger. Second, our results indicate that in departments where the access of two-year-old children to pre-elementary public schools is low, having more than two children has a significant negative impact on mothers' activity. On the contrary, the effect is insignificant in departments where this access is high. We finally examine the effect of neighbourhood social interactions on mothers' activity. Mobilzing different exogenous sources of variation of close neighbours' activity, we find that neighbours' activity positively affects a mother's individual participation. ; Cette thèse porte sur l'impact du nombre d'enfants et des interactions sociales de voisinage sur l'offre de travail des mères de famille. Nous proposons d'abord une étude sur la nature du lien entre nombre d'enfants et offre de travail des mères. Pour déterminer si cette relation est causale, nous utilisons deux évènements qui affectent aléatoirement le nombre d'enfants : le fait d'avoir deux aînés de même ...
International audience ; The US automakers are likely to crumble like the twin towers of the World Trade Center unless a vigorous and costly state intervention takes place sooner rather than later. Their disappearance would have the same effect on the 'real economy' as Lehman Bothers' bankruptcy had on the financial sphere. After all, the Big 3 still account for one-quarter of global automobile output, two-thirds of which they produce out of North America. The fallout would be extremely painful to their suppliers and to competitors who get their inputs from these same sources, leading to the elimination of hundreds of thousands of additional jobs. Then there are all the financed sales and leasing operations that the Big Three have developed in recent years, plus the way a large part of their receivables portfolios has been transformed into derivative products. Lastly, their property holdings did not benefit from the same subprime facilities as other sectors did.The conditions underlying the American auto- mobile firms' current situation have their origins in the distant past. It should be noted, however, that these companies also had many opportunities to escape the trap set for them by the form of capitalism that progressively took shape in the United States following Richard Nixon's 1971 decision to let the Dollar float.
International audience ; The US automakers are likely to crumble like the twin towers of the World Trade Center unless a vigorous and costly state intervention takes place sooner rather than later. Their disappearance would have the same effect on the 'real economy' as Lehman Bothers' bankruptcy had on the financial sphere. After all, the Big 3 still account for one-quarter of global automobile output, two-thirds of which they produce out of North America. The fallout would be extremely painful to their suppliers and to competitors who get their inputs from these same sources, leading to the elimination of hundreds of thousands of additional jobs. Then there are all the financed sales and leasing operations that the Big Three have developed in recent years, plus the way a large part of their receivables portfolios has been transformed into derivative products. Lastly, their property holdings did not benefit from the same subprime facilities as other sectors did.The conditions underlying the American auto- mobile firms' current situation have their origins in the distant past. It should be noted, however, that these companies also had many opportunities to escape the trap set for them by the form of capitalism that progressively took shape in the United States following Richard Nixon's 1971 decision to let the Dollar float.
International audience ; The US automakers are likely to crumble like the twin towers of the World Trade Center unless a vigorous and costly state intervention takes place sooner rather than later. Their disappearance would have the same effect on the 'real economy' as Lehman Bothers' bankruptcy had on the financial sphere. After all, the Big 3 still account for one-quarter of global automobile output, two-thirds of which they produce out of North America. The fallout would be extremely painful to their suppliers and to competitors who get their inputs from these same sources, leading to the elimination of hundreds of thousands of additional jobs. Then there are all the financed sales and leasing operations that the Big Three have developed in recent years, plus the way a large part of their receivables portfolios has been transformed into derivative products. Lastly, their property holdings did not benefit from the same subprime facilities as other sectors did.The conditions underlying the American auto- mobile firms' current situation have their origins in the distant past. It should be noted, however, that these companies also had many opportunities to escape the trap set for them by the form of capitalism that progressively took shape in the United States following Richard Nixon's 1971 decision to let the Dollar float.
Dreaming of the Avant-Garde: Georges Bataille, Nathalie Sarraute, Pierre Michon, Agnès VardabyMaia Lea Beyler-NoilyDoctor of Philosophy in FrenchDesignated Emphasis in Film StudiesUniversity of California, BerkeleyProfessor Michael Lucey and Professor Jean-François Louette, Co-ChairsThis dissertation focuses on the ways in which the avant-garde proposes new models for the community throughout the twentieth century in France, specifically in the works of writers Georges Bataille, Nathalie Sarraute and Pierre Michon, and filmmaker Agnès Varda. This research was spurred by a turn-of-the century sociology obsessed with the supposed decay of community and the necessity to revitalize it. According to sociology's forefather, Emile Durkheim, if the traditional community is rooted in religion, a secular and individualistic modernity ignores the very notion of community, leaving a dangerous vacuum too easily filled by totalitarian systems of thought. This work argues that the avant-garde is simultaneously critical of the traditional community, deemed closed and exclusive, and of modern secularism, characterized by individualism and mercantilism. Hence, rejecting both traditional community and modern society, the avant-garde attempts to imagine new, open alternatives. However, by following a party line, be it political or aesthetic, the avant-garde becomes susceptible to the same pitfalls of exclusivity and authority as the traditional community. As such, the artists upon which this dissertation focuses cannot be affiliated with any specific avant-garde movement. Rather, they remain in the avant-garde's margins, keeping their distance, i.e. their freedom, from it: Bataille in regard to surrealism, Sarraute in regard to the Nouveau Roman, Michon in regard to Tel Quel, and Varda in regard to the New Wave. Bataille's twin philosophical notions of sovereignty-servility shed light on what these marginal avant-garde artists are gesturing towards: on the one hand, they are attempting to break away from the traditional and hierarchical, that is the servile community, and on the other, they are innovating by imagining a free and equal community, i.e. one that is sovereign. However, the question asked throughout this research is whether these dreams of communities, here featured in novels, short stories and films, could, or even should, be turned into concrete realities.Chapter One focuses on the avant-garde writers' novels and their attempt to bring about a sovereign community through their criticism of traditional Judeo-Christian morals. Rejecting Christian and fascistic communities, as well modern secularism, Bataille's Julie imagines an erotic community made up of perverts and lunatics. It seems that only an erotic community could achieve sovereignty by being unredeemable, that is by stubbornly resisting all political and aesthetic re-appropriation. In Sarraute's Martereau, a new community can come about through the suspicion of all our preconceived notions of identity. Only the anxiety-ridden search for the community, never its establishment, can lead to sovereignty. Michon's La Grande Beune, an implicit tribute to Bataille, can be read in dialogue with the avant-garde. However, while paying homage to his fiercely antireligious predecessor, Michon imagines a sovereign community that might find a way to be in relation, however tentative, with Christianity.The second chapter of this work explores both the avant-garde's attacks against a visual culture deemed authoritative and dictatorial, and the communities born from these attacks. Bataille's Histoire de l'oeil strikingly illustrates the avant-garde's desire to defile and literally deface the human image. The sovereign community here imagined by Bataille is one of felons and outlaws that could never be corralled into a well-functioning society. Showcasing a face-off between a fervent collector and his snide children, Sarraute's Vous les entendez? ridicules the ways that art takes over religion in the twentieth century. Refusing to adore literal and figurative images, Sarraute imagines a community of people who never settle for answers, but keep searching for them. Michon's Maîtres et Serviteurs and Corps du roi are meditations on painting and photography, respectively. Here, Michon succeeds in conjuring a community of lovers of the visual arts that remembers the avant-garde's wariness towards them, but refuses to indict all representation once and for all.Chapter Three explores modern literature's compulsion to self-sabotage and the communities brought about by this self-destruction. Bataille's L'Abbé C. points an accusing finger at Literature as another model for authoritative, exclusive communities. Self-combusting through haphazard writing and self-plagiarism, L'Abbé C. attempts to challenge the authority of its writer and avoid any future co-optations, but, in turn, leaves its readers stranded. Sarraute's Le Mensonge similarly disowns Literature, and Literature's authoritative tendencies, by writing for the radio-waves. The radio seems to short-circuit Literature's normative bent and to give way to a sovereign community. Michon's Mythologies d'hiver similarly alludes to the avant-garde's hostility towards a narrative accused of bringing together the traditional, i.e. religious, community. While constantly throwing his enterprise into self-doubt, Michon paradoxically reintroduces both the narrative and the possibility of Christian faith as potential ways to a sovereign community. Featuring a behind-the-scenes look at a globalized economy, Varda's film, Les Glaneurs et la glaneuse, focuses on what happens to unproductive, i.e. sovereign, things and beings. Chapter Four of this dissertation looks at how Varda's marginals, who live off of the system without any political inklings, successfully dodge all political re-appropriation while, through solidarity, offering alternative models for sovereign communities.Having looked at how these four artists on the margins of the avant-garde, Bataille, Sarraute, Michon and Varda, reject the traditional, that is the religious and servile community and try to image new, sovereign ones, this work concludes by asking whether they accomplished what they set out to do. While some call their attempts to imagine new communities irrelevant, since these communities could never be put into effect without betraying themselves, this analysis argues that it is those very attempts that in fact allow the avant-garde to continue dreaming of and arguing over what could be.
L'étude du domaine international, très souvent orientée vers les relations interétatiques, trouve dans cette thèse un débouché à un autre niveau : celui des relations interlocales. À l'ombre des hypothétiques projets de transferts massifs d'eau existent ce que nous avons qualifié d'approvisionnements transfrontaliers locaux en eau potable, soit des adductions destinées à l'approvisionnement en eau entre communautés jumelles situées le long de la frontière entre le Canada et les États-Unis. Il s'agit des seuls transferts d'eau en vrac existants entre les deux pays à l'heure actuelle. Compte tenu de l'absence d'études approfondies sur le sujet, une meilleure compréhension de ce phénomène se révèle essentielle. La thèse s'articule autour de deux questions de recherche principales. Comment ces échanges sont-ils spatialement structurés ? Quelles sont leurs caractéristiques et leurs conséquences juridiques dans le contexte de l'ALÉNA ? Le premier chapitre présente le cadre normativo-institutionnel d'une recherche s'inscrivant dans le domaine international selon une perspective interdisciplinaire conciliant la géographie et le droit. Le deuxième chapitre énonce le cadre conceptuel de la thèse et sa contribution à l'étude des transferts d'eau, de la pénurie d'eau en tant que construit social et du concept de cycle hydrosocial. Le troisième chapitre expose la méthodologie, laquelle conjugue les méthodes qualitatives et juridiques; recension exhaustive des approvisionnements transfrontaliers locaux, analyse des documents juridiques, sélection d'études de cas et réalisation de séjours sur le terrain et d'entrevues semi-dirigées. Le quatrième chapitre présente les résultats de la recherche en quatre sections. La première consiste en une base de données dévoilant et qualifiant les onze types d'approvisionnements transfrontaliers recensés. La deuxième section développe en profondeur trois études de cas. La troisième section porte sur le cycle hydrosocial et l'apport de l'approche géo-légale. La quatrième section situe la perception des acteurs. Le cinquième chapitre explore les implications juridiques de ces transferts pour le Canada. Il est montré que ceux-ci ne constituent pas une menace pour le Canada dans le cadre de l'ALÉNA. Dans l'éventualité où les pouvoirs publics souhaiteraient mieux encadrer ces transferts, il est ensuite précisé au chapitre 6 ce que pourrait constituer une politique publique des approvisionnements transfrontaliers locaux. ; While studies within international fields are often dedicated to understanding the nature of interstate relationships, this research is devoted to the interlocal scale. In the shadow of hypothetical, continental water transfers, there exist transboundary local freshwater supplies, or water adductions apportioned to supply water between twin communities located along the border between Canada and the United States. These constitute the only contemporary, bulk water transfers between the two countries. A better understanding of this phenomenon is needed in the absence of any in-depth studies focusing on these local water transfers. This dissertation is organized around two main research questions: How are these transfers spatially organized ? What are the legal characteristics and consequences of these transfers within the context of NAFTA ? The first chapter begins by introducing the normative-institutional frame of the study, which is both international in scope and interdisciplinary, bringing together geography and law. The conceptual frame of this research and its contribution to the study of water transfers, water scarcity as social construction, and the concept of hydrosocial cycle comprise the second chapter. The third chapter explores the methodology located at the interface between geography and law. It includes an exhaustive survey of local transboundary water supplies, an analysis of legal documents, case studies, fieldwork, and semi-structured interviews. The results of this research are presented in the fourth chapter and divided into four sections. The first section represents a database describing the eleven local transboundary water supplies surveyed, followed by an in-depth analysis of three case studies. The third section relates to the hydrosocial cycle and the contribution of the geo-legal perspective while the fourth builds upon local and national actors' perceptions. The fifth chapter explores the legal consequences of these transfers for Canada, arguing that these transfers do not constitute any potential threat for Canada within the context of NAFTA. The final chapter elucidates what a public policy of local transboundary water supplies could look like if public authorities (i.e. federal and provincial governments) chose to assert more control over these transfers.
This PhD dissertation studies the impact of number of children and of social interactions on mothers' labour supply. To determine the extent to which the link between number of children and mothers' labour supply is causal, we use two random events that affect the number of children: having same sex eldest siblings and twin births at the second pregnancy. Results suggest that having more than two children reduces mothers' participation in the labour market by 20 percentage points and the number of hours worked by employed mothers by 2 hours per week. We then analyze how the institutional context alters the effect of the number of children on mothers 'participation in the labour market. First, we find that before 1994, when the Allocation parentale d'éducation was intended for parents of three children or more, having more than two children decreases significantly mothers' activity. After the extension of the benefit to mothers with two children, this is not the case anymore and the negative effect of having a second child on their activity is stronger. Second, our results indicate that in departments where the access of two-year-old children to pre-elementary public schools is low, having more than two children has a significant negative impact on mothers' activity. On the contrary, the effect is insignificant in departments where this access is high. We finally examine the effect of neighbourhood social interactions on mothers' activity. Mobilzing different exogenous sources of variation of close neighbours' activity, we find that neighbours' activity positively affects a mother's individual participation. ; Cette thèse porte sur l'impact du nombre d'enfants et des interactions sociales de voisinage sur l'offre de travail des mères de famille. Nous proposons d'abord une étude sur la nature du lien entre nombre d'enfants et offre de travail des mères. Pour déterminer si cette relation est causale, nous utilisons deux évènements qui affectent aléatoirement le nombre d'enfants : le fait d'avoir deux aînés de même sexe et les naissances gémellaires de rang deux. Les résultats suggèrent qu'avoir plus de deux enfants diminue la participation des mères au marché du travail d'environ 20 points et le nombre d'heures travaillées par semaine d'environ 2 heures lorsqu'elles sont en emploi. Nous trouvons également que l'effet négatif du nombre d'enfants sur l'activité des mères est particulièrement marqué pour les mères peu diplômées. Nous affinons ensuite cette étude en étudiant comment le contexte institutionnel altère l'effet du nombre d'enfants sur la participation des mères au marché du travail. Premièrement, nous testons l'impact de l'extension de l'Allocation parentale d'éducation aux parents de deux enfants en juillet 1994 sur les termes de l'arbitrage entre fécondité et activité. Nous trouvons que lorsque l'Allocation parentale d'éducation est destinée aux parents ayant au moins trois enfants (avant la réforme), le passage de deux à trois enfants réduit significativement la participation des mères au marché du travail. Lorsque les mères de deux enfants sont éligibles (après la réforme), l'effet négatif d'avoir un deuxième enfant sur la participation des mères au marché du travail est accru, tandis qu'avoir plus de deux enfants n'a plus d'effet négatif sur la probabilité d'activité des mères. Deuxièmement, nous utilisons la variabilité des taux de scolarisation à deux ans en maternelle entre les différents départements pour identifier l'impact des possibilités de garde gratuite pour les enfants de moins de trois ans sur l'élasticité de l'activité des mères au nombre d'enfants. Les résultats indiquent que dans les départements où l'accès des enfants de deux ans à la maternelle est faible, avoir plus de deux enfants a un effet significativement négatif sur la participation des mères au marché du travail. Au contraire, dans les départements où l'accès des enfants de deux ans à la maternelle est élevé, avoir plus de deux enfants a un effet non significatif sur la participation des mères au marché du travail. Nous examinons ensuite l'effet des interactions sociales de voisinage sur la participation des mères au marché du travail. Nous utilisons différentes sources de variation exogène de la participation des proches voisines au marché du travail : le sexe de leurs aînés, le trimestre de naissance de leur deuxième enfant et la différence d'âge entre leurs deux aînés. Nous trouvons que la participation des voisines au marché du travail a un effet positif et significatif sur la participation individuelle d'une mère.
