Investigation of a superthermal ultracold neutron source based on a solid deuterium converter for the TRIGA Mainz reactor

Research in fundamental physics with the free neutron is one of the key tools for testing the Standard Model at low energies. Most prominent goals in this field are the search for a neutron electric dipole moment (EDM) and the measurement of the neutron lifetime. Significant improvements of the experimental performance using ultracold neutrons (UCN) require reduction of both systematic and statistical errors.rnThe development and construction of new UCN sources based on the superthermal concept is therefore an important step for the success of future fundamental physics with ultracold neutrons. rnSignificant enhancement of today available UCN densities strongly correlates with an efficient use of an UCN converter material. The UCN converter here is to be understood as a medium which reduces the velocity of cold neutrons (CN, velocity of about 600 m/s) to the velocity of UCN (velocity of about 6 m/s).rnSeveral big research centers around the world are presently planning or constructing new superthermal UCN sources, which are mainly based on the use of either solid deuterium or superfluid helium as UCN converter.rnThanks to the idea of Yu.Pokotilovsky, there exists the opportunity to build competitive UCN sources also at small research reactors of the TRIGA type. Of course these smaller facilities don't promise high UCN densities of several 1000 UCN/cm³, but they are able to provide densities around 100 UCN/cm³ for experiments.rnIn the context of this thesis, it was possible to demonstrate succesfully the feasibility of a superthermal UCN source at the tangential beamport C of the research reactor TRIGA Mainz. Based on a prototype for the future UCN source at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRMII) in munich, which was planned and built in collaboration with the Technical University of Munich, further investigations and improvements were done and are presented in this thesis. rnIn parallel, a second UCN source for the radial beamport D was designed and built. The comissioning of this new source is foreseen in spring 2010.rnAt beamport D with its higher thermal neutron flux, it should be possible to increase the available UCN densities of 4 UCN/cm³ by minimum one order of magnitude.

Die lateinische Epigraphie Hispaniens als Quelle für die keltische Gesell-schaft und Religion

Presentado en el III Workshop F.E.R.C.A.N (Fontes Epigraphici Religionum Celticarum Aantiquarum)

Traitement de la schistosomiase à S. mansoni : quelle alternative au praziquantel ?

Les schistosomiases sont des maladies parasitaires causées par des helminthes du genre Schistosoma (S.) qui touchent 200 millions de personnes dans le monde, mais restent rares chez le voyageur. Contrairement à S. heamatobium, agent de la bilharziose urinaire, S. mansoni, présent en Afrique subsaharienne, en Egypte ainsi qu'aux Antilles, au Surinam et dans le nordest du Brésil, est responsable des formes hépato-intestinales de la maladie. Les larves, vivant en eaux douces contaminées par des selles infectées, peuvent pénétrer la peau des baigneurs sans que l'individu ne s'en rende compte. Les parasites adultes s'établissent dans le système veineux digestif où ils se reproduisent et excrètent des oeufs qui migreront dans la lumière intestinale. Cette revue systématique évalue les effets des médicaments antibilharziens, utilisés seuls ou en association, pour traiter l'infection à S. mansoni.

La controverse avant le film : quelle politique pour Good Night, And Good Luck ?

This article aims to explain how newspapers commented on the movie Good Night, and Good Luck before its release. The media coverage anticipated George Clooney's film as a partisan attack launched against George W. Bush's policy since 9/11. Clooney advocates another reading: the historic confrontation between journalist Edward Murrow and Senator Joseph McCarty permits to reflect on the crucial role that the media play for democracy. Such reflection tries to prevent the dividing of the public sphere into antagonistic camps opposing "friends" to "foes," a division that undermines the possibility of a true pluralism. Our socio-semiotic analysis will focus on the critical work accomplished by the media, and on the way that work determines the collective meaning of a cultural object. Simultaneously, we will discuss the necessary conditions for pluralism in a public sphere.

Quelle famille pour le XXIe siècle ? Perspectives québécoises

L'auteur, autour du thème de l'avenir de la famille, explore deux manifestations de ce qu'il appelle «l'objectivation» de celle-ci. Ce phénomène, issu d'une pluralisation des modes de vi, s'illuste en un premier temps par l'éclatement de la filiation du à une certaine réification de la personne. D'un modèle binaire et sexué, copié de la nature, on accepte aujourd'hui tant la filiation unilinéaire qu'homosexuelle et on se rapproche d'une possible filiation trilinéaire. En ce sens, l'éclatement du modèle semble consommé. En un second temps, cette «objectivisation» de la famille découle de la pluralité des types d'unions. L'auteur, tout en présentant sommairement la réglementation actuelle du mariage et de la récente union civile, soulève la question d'une éventuelle extension de l'«union de droit» dans la législation québécoise.