Protective action of spermine and spermidine against photoinhibition of photosystem I in isolated thylakoid membranes

10.1371/journal.pone.0112893PLoS ONE911e11289

Nouveau modèle empirique du gonflement libre des sols argileux

Le gonflement des sols argileux est un phénomène très complexe et fortement influencé par les propriétés chimiques, minéralogiques et hydriques. Ce phénomène provoque l'instabilité des fondations construites sur ce type de sols, en provoquant par la suite leur détérioration. La modélisation permet une meilleure compréhension du comportement hydromécanique de ces sols argileux lorsqu’ils sont soumis à différents paramètres (teneur en eau, succion, degré de saturation, humidité etc…). Différents modèles, reposant essentiellement sur des concepts hydro-thermomécanique et la théorie double couche diffuse, sont proposées dans les littératures [1-4]. Dans le présent travail nous proposerons un modèle simplifié du gonflement des sols argileux dans un milieu non saturé en fonction du temps. Pour le valider, nous allons comparer ses résultats avec les résultats expérimentaux obtenus dans notre laboratoire par la nouvelle technique optique basée sur l'interférométrie laser ainsi qu’avec ceux obtenue par le modèle de Vayassade [5]

PSCF and CWT methods as a tool to identify potential sources of 7Be and 210Pb aerosols in Granada, Spain

This research is focused on studying the preferred source regions and the pathways of the air masses with high particulate concentrations impacting on the activity concentrations of 7Be and 210Pb aerosols in Granada atmosphere. For this purpose, three different source-receptor methods have been used: Cluster Analysis, Potential Source Contribution Function (PSCF), and Concentration Weighted Trajectory (CWT). Air filter samples were weekly collected and analysed in Granada university (Spain 37.177N, 3.598 W, 687m a.s.l.) during 12 years (2006–2017) for the activity concentration of 7Be, and during 5 years (2010–2014) for the one of 210Pb. The time series of the collected data indicate that the concentration of both radiotracers present a cyclical and seasonal pattern, in association with their origins and atmospheric conditions. Clustering analysis showed that the air masses arriving to Granada can be classified as: (1) tropical continental air masses coming from the Mediterranean Sea, (2) tropical and warm polar maritime air masses produced over the Atlantic Ocean, and (3) continental air masses originated over Europe and Northern Africa. The PSCF and CWT methods confirmed that the main source areas of 7Be are located in the Atlantic coast of southern Morocco, and Northern Africa. On the other hand, southern France and the Algerian desert were found to be the main region sources of 210Pb. In addition, the Mediterranean Basin has been postulated as a strong source region for 7Be and 210Pb. Furthermore, the PSCF and CWT models show that the regions with larger 7Be/210Pb ratios are located in the Atlantic Ocean, due to frequent stratospheric intrusions specially during the winter months

Antipodal Vivaldi antennas dedicated to in-situ broadband microwave permittivity measurements

In the context of the ESA's SMOS and the ESA's BIOMASS space mission, the data processing algorithms require precise permittivity models of the different wood species. To develop the models, in situ sensors that could be easily deployed on the site dedicated to calibration/validation studies would be truly relevant. Microwave volume analysis can be a very useful tool to monitor material properties. There are very few commercial equipment dedicated to in-situ measurements and none of them is developed in order to leave the instrument on site for automatic measurements with specific constraints such as communication, low power consumption, frequency broadband, non-invasive measurement and cheap price. The main objective of the study presented is to develop an equipment to meet these challenges. In this article we will present the study that we conducted to design the broadband antennas needed by the device to perform efficient in situ measurements. Preliminary results on a concrete structure demonstrate the possibility to perform quality B scan despite the strict imposed specifications