Effect of varying conditions of exposure to an aggressive medium on the corrosion behavior of the 2050 Al--Cu--Li alloy

The corrosion behavior of aluminum alloy 2050 was studied as a function of varying conditions of exposure to an aqueous NaCl solution. Two metallurgical states were considered, i.e., an as-received alloy (NHT) and aged samples (HT). After continuous immersion tests, the NHT samples were susceptible to intergranular corrosion, whereas intragranular corrosion was observed for the HT samples. For the NHT samples, cyclic corrosion tests, with alternate immersion – emersion periods, induced subgrain boundary dissolution, and for the HT samples, grain and/or subgrain boundary sensibilization was induced. Hydrogen content measurements suggested a hydrogen enrichment of the alloy under cyclic corrosion tests

Corrosion-fatigue lifetime of Aluminium–Copper–Lithium alloy 2050 in chloride solution

The fatigue behaviour of Aluminium–Copper–Lithium 2050 alloy under two metallurgical states (T34 and T84) was studied in air for healthy and pre-corroded samples in a 0.7 NaCl solution. The results were compared to those obtained during fatigue–corrosion tests performed in a similar chloride medium. Preliminary corrosion tests demonstrated that the T34 metallurgical state was susceptible to intergranular corrosion, while the T84 metallurgical state was susceptible to intragranular corrosion. Fatigue life tests in air on pre-corroded samples revealed a significant decrease in fatigue life related to the presence of corrosion defects before the cyclic solicitation. A strong effect of the first minutes of immersion in corrosive media was evidenced on fatigue life behaviour. The fatigue–corrosion tests revealed that the T34 metallurgical state was more affected by fatigue–corrosion in terms of fatigue life than the T84 metallurgical state. This observation can be explained by the increased propagation of intergranular corrosion enhanced by the cyclic solicitation

Effect of the microstructure and environmental exposure conditions on the corrosion behaviour of the 2050 alloy

Alternate immersion-emersion tests were performed for a 2050 aluminium alloy to characterize its corrosion resistance with exposure conditions representative of in serviceconditions. Tests were performed for T34 samples and aged samples. After continuous immersion tests, T34 samples exhibited intergranular corrosion while intragranular corrosion was observed for aged samples. The alternate immersion-emersion tests led to a corrosion extension to the subgrain boundaries, for both T34 and aged samples, as shown by electron backscattered diffraction analysis

AMELIS, étude des usages d’un calendrier électronique mural par des personnes âgées et leurs aidants

National audienceLa France et le Canada font l'expérience d'un vieillissement de la population dans le cadre duquel les technologies comme le calendrier électronique Amelis, pourraient représenter des instruments intéressants d' accompagnement des aînés et de leurs aidants. Les théories de l' activité médiatisée par des instruments et de l ' acceptation des technologies nous apprennent cependant que l ' appropriation d ' une technologie par des utilisateurs est un processus situé influencé par de multiples facteurs. L ' objectif de cette recherche est d ' étudier ce processus afin d ' analyser comment les usages du calendrier Amelis pourront se développer dans l ' activité quotidienne de personnes âgées françaises et québecoises. Une première phase de recherche fera évoluer le calendrier Amelis de sa version actuelle à une version co-­‐conçue par des personnes âgées et l ' équipe de recherche. Ensuite , cette technologie sera implantée au domicile de personnes âgées volontaires. La mise à l ' épreuve du calendrier avec le réel permettra ainsi d ' analyser le développement des usages en contexte

Identification of the metallurgical parameters explaining the corrosion susceptibility in a 2050 aluminium alloy

The corrosion behaviour of a 2050 aluminium alloy was studied in a NaCl solution. The structure ofprecipitation did not fully explain the susceptibility to intergranular (in the -T34 state) and intragran-ular corrosion for the aged state (the -T8 state). A relationship between the nature of interfaces, thegrains characteristics (size, internal misorientation and orientation according to the plane exposed tothe electrolyte) on one hand and the corrosion susceptibility of the alloy on the other hand was clearlyestablished. Galvanic coupling between grains with different internal misorientations helped to explainthe intergranular corrosion susceptibility of the -T34 state

Associer des itinéraires techniques de niveau d'intrants variés à des variétés rustiques de blé tendre : évaluation économique, environnementale et énergétique

International audienceL’impact de l’utilisation des engrais azotés et des pesticides (Aubertot et al., 2005) sur l’environnement ainsi que l’instabilité des prix de vente des céréales ont suscité un certain nombre de réflexions sur de nouvelles manières de produire du blé tendre d’hiver, en prenant notamment appui sur le progrès variétal. Ainsi, à partir de 1999, l’INRA, l’ITCF (puis ARVALIS-Institut du végétal), les sélectionneurs du GIE Club des Cinq et les chambres d’agriculture d’Indre-et-Loire et du Morbihan ont engagé une collaboration afin d’évaluer l’intérêt des variétés rustiques conduites avec des itinéraires techniques à niveaux d’intrants réduits. Ces variétés ont été choisies parmi celles présentant des caractères de multirésistance aux maladies et à la verse, tout en s’assurant d’un niveau de rendement comparable aux autres cultivars du catalogue. Le réseau expérimental multilocal mis en place de 2000 à 2002 a révélé des performances économiques satisfaisantes de ces itinéraires techniques au regard des recommandations locales, et ce pour le prix de vente moyen de cette période, à savoir 100 € par tonne (Loyce et al., 2001 ; Félix et al., 2002 ; Rolland et al., 2003 ; Loyce et al., accepté)

Use of the 3D radon transform to examine the properties of oceanic Rossby waves

One of the most successful applications of satellite-borne radar altimeter data over the oceans in recent years has been the extraction of information about long-wavelength baroclinic Rossby (or planetary) waves, which play a significant role in ocean circulation and climate dynamics. These waves cross ocean basins from east to west at speeds of few centimetres per second at mid-latitudes. The cross-basin propagation time may therefore be several months or even years and an accurate estimation of the speed of the waves is important. We review the methods for obtaining information on Rossby wave velocity from altimetry data, particularly the two-dimensional Radon transform. Unfortunately the use of longitude-time plots, although it allows the estimation of the zonal phase speeds, does not give any information on the speed vector when the propagation of the waves is not purely zonal (east-west). We show how the two-dimensional Radon Transform can be generalised to three dimensions, enabling not only the true propagation velocity component to be determined, but also the direction of the waves and thus any deviation from the pure-westward case. As examples of the application of this extended technique, we show maps of direction, speed and energy of Rossby waves in the North Atlantic Ocean

Estimation des taux de recombinaison entre les locus Phi et Pgd et le complexe SLA chez le porc

International audienc

Theranostic 64Cu-DOTHA2-PSMA allows low toxicity radioligand therapy in mice prostate cancer model

IntroductionWe have previously shown that copper-64 (64Cu)-DOTHA2-PSMA can be used for positron emission tomography (PET) imaging of prostate cancer. Owing to the long-lasting, high tumoral uptake of 64Cu-DOTHA2-PSMA, the objective of the current study was to evaluate the therapeutic potential of 64Cu-DOTHA2-PSMA in vivo.MethodsLNCaP tumor-bearing NOD-Rag1nullIL2rgnull (NRG) mice were treated with an intraveinous single-dose of 64Cu-DOTHA2-PSMA at maximal tolerated injected activity, natCu-DOTHA2-PSMA at equimolar amount (control) or lutetium-177 (177Lu)-PSMA-617 at 120 MBq to assess their impact on survival. Weight, well-being and tumor size were followed until mice reached 62 days post-injection or ethical limits. Toxicity was assessed through weight, red blood cells (RBCs) counts, pathology and dosimetry calculations.ResultsSurvival was longer with 64Cu-DOTHA2-PSMA than with natCu-DOTHA2-PSMA (p < 0.001). Likewise, survival was also longer when compared to 177Lu-PSMA-617, although it did not reach statistical significance (p = 0.09). RBCs counts remained within normal range for the 64Cu-DOTHA2-PSMA group. 64Cu-DOTHA2-PSMA treated mice showed non-pathological fibrosis and no other signs of radiation injury. Human extrapolation of dosimetry yielded an effective dose of 3.14 × 10-2 mSv/MBq, with highest organs doses to gastrointestinal tract and liver.DiscussionCollectively, our data showed that 64Cu-DOTHA2-PSMA-directed radioligand therapy was effective for the treatment of LNCaP tumor-bearing NRG mice with acceptable toxicity and dosimetry. The main potential challenge is the hepatic and gastrointestinal irradiation