Discovery of a very weak magnetic field on the Am star Alhena

Alhena ($\gamma$ Gem) was observed in the frame of the BRITE (BRIght Target Explorer) spectropolarimetric survey, which gathers high resolution, high signal-to-noise, high sensitivity, spectropolarimetric observations of all stars brighter than V=4 to combine seismic and spectropolarimetric studies of bright stars. We present here the discovery of a very weak magnetic field \textbf{on} the Am star Alhena, thanks to very high signal-to-noise spectropolarimetric data obtained with Narval at T\'elescope Bernard Lyot (TBL). All previously studied Am stars show the presence of ultra-weak (sub-Gauss) fields with Zeeman signatures with an unexpected prominent positive lobe. However, Alhena presents a slightly stronger (but still very weak, only a few Gauss) field with normal Zeeman signatures with a positive and negative lobe, as found in stronger field (hundreds or thousands of Gauss) stars. It is the first detection of a normal magnetic signature in an Am star. Alhena is thus a very interesting object, which might provide the clue to understanding the peculiar shapes of the magnetic signatures of the other Am stars.Comment: letter accepted by MNRA

France and Germany nuclear energy policies revisited: A veblenian appraisal

Nuclear energy policy should have been a major area of cooperation for France and Germany, playing a lead role in the energy policy of the EU. Yet they have retained different options, especially regarding nuclear energy while the EU energy policy remained very indicative. These two “coordinated economies” should have been able to cooperate more closely on this issue. While the reasons for this difference in behavior have much to do with the specificities of the nuclear energy, they are more precisely related to the continuously rising level of security requirements, a learning process in which the magnitude of risks and time lengths appeared, even before Fukushima, to go beyond rational boundaries on which cooperation (as well as market) ventures could be based. This raises the issue in the present state of the technologies of the possibility of an international governance of this nuclear industry

Indice des prix : des tensions révélatrices de nouveaux modes de régulation

Contribution au rapport du Conseil d'analyse Stratégique sur le pouvoir d'achat (Rochefort/Miotti)La mesure de l'indice des prix à la consommation a toujours été un enjeu conflictuel. C'est un élément clé dans la régulation de la distribution des revenus et ceci explique cela. Même si les indexations de salaires ne sont plus systématiques depuis le début des années 80, l'indice reste une référence première dans les négociations salariales comme dans l'évolution des rentes et pensions.Si les controverses contemporaines s'inscrivent dans une longue série de tensions entre groupes d'intérêt opposés, elles n'en possèdent pas moins leur spécificité qu'il est utile de connaître, ne serait ce que partiellement, pour mieux saisir en quoi les tensions actuelles peuvent en parti différer des précédentes et réclamer d'autres suites, d'autres transformations que celles que pourraient donner les seules instances statistiques responsables de la construction des dits indices

Investissements directs étrangers et intégration régionale en Asie de l'Est

On cherche dans ce chapitre à caractériser le processus de régionalisation en Asie de l'Est, en tenat compte des dimensions économiques mais aussi politiques te citoyennes. On apprécie l'ampleur des processu de rattrappage en faisant référence au schéma d'intégration qu'implique la division régionale hiérarchisée du travail impulsée par les grandes firmes multinationales en particulier japonaises. Une partie prospective évalue l'impact du choc financier de 1997 sur cette dynamique d'intégration

Rising Inequalities and Reconstruction of Labour Capital Compromises

The so-called golden years of capitalism took place under the auspices of a broad political consensus that labour should be protected and benefit from economic growth. This compromise eroded in the 1980s and 1990s as shown by the rise in income inequalities and in unemployment. At the turn of the century, it became clear that the sustainability of the global economy was at stake. It is useful in this perspective to assess, as this chapter attempts to do, both the conditions in which the old compromise of the welfare states collapsed and how then the discussions on the sustainable development goals can be implemented and play the role of a new capital labour compromise at world level

Investissements directs étrangers et intégration régionale en Asie de l'Est

On cherche dans ce chapitre à caractériser le processus de régionalisation en Asie de l'Est, en tenat compte des dimensions économiques mais aussi politiques te citoyennes. On apprécie l'ampleur des processu de rattrappage en faisant référence au schéma d'intégration qu'implique la division régionale hiérarchisée du travail impulsée par les grandes firmes multinationales en particulier japonaises. Une partie prospective évalue l'impact du choc financier de 1997 sur cette dynamique d'intégration.Intégration régionale, Asie de l'Est, multinationales japonaises

Inauguration de la bibliothèque en open access au Centre for Information and Library de l’Université agronomique n°1 de Hanoï

Aboutissement du projet open acces lancé en mars 2005 avec le soutien de la CUD, le libre accès des collections de la Bibliothèque centrale de l’UAh a été inauguré le 11 octobre dernier. Un cap supplémentaire franchi en matière d’accès à la connaissance et à ses modes d’appropriation

Static spectropolarimeter concept adapted to space conditions and wide spectrum constraints

The issues related to moving elements in space and instruments working in broader wavelength ranges lead to a need for robust polarimeters, efficient on a wide spectral domain, and adapted to space conditions. As part of the UVMag consortium, created to develop spectropolarimetric UV facilities in space, such as the Arago mission project, we present an innovative concept of static spectropolarimetry. We studied a static and polychromatic method for spectropolarimetry, applicable to stellar physics. Instead of modulating the polarization information temporally, as usually done in spectropolarimeters, the modulation is performed in a spatial direction, orthogonal to the spectral one. Thanks to the proportionality between phase retardance imposed by a birefringent material and its thickness, birefringent wedges can be used to create this spatial modulation. The light is then spectrally cross-dispersed, and a full-Stokes determination of the polarization over the whole spectrum can be obtained with a single-shot measurement. The use of Magnesium Fluoride wedges, for example, could lead to a compact, static polarimeter working at wavelengths from 0.115 mm up to 7 mm. We present the theory and simulations of this concept, as well as laboratory validation and a practical application to Arago.Comment: Article accepted for publication in Applied Optics on 20 July 201