This project is articulated around to directions: semi-classical limit, and long time behavior, for nonlinear Schrödinfer equations. The first direction is subdivided into supercritical WKB regime (need of a new model beyond singularities for the Euler equation), critical WKB regime (and link with the Cauchy problem on the one hand, and Physics on the other hand), the propagation of wave packets, and instabilities. The second direction is concerned with dynamical properties of the nonlinear scattering operator, the role of geometry, vortex filaments, and solitons for the Gross-Pitaevskii equation.

The main objective of the proposal is to design and produce porous membranes having non-fluoro super-hydrophobic surface. To achieve this goal we propose a strategy bio-inspired from the lotus leaf effect. The surface of lotus leaves displays a hierarchical morphology based on the combination of nano- and micro-structures. The roughness developed by this unique feature gives rise to high water-repellency and self-cleaning properties without any fluorinated compounds. The purpose is to reach the control of the surface energy by mastering the fabrication process to obtain such hierarchical structures. The design and producing capability of porous membranes having controlled surface hierarchical morphology require the in-depth understanding of interplay between mass transfer operating during the processing and structure, surface properties and permeation functionalities. Surface hierarchical structures will be generated according to two different approaches: (i) during the fabrication process using vapour induced phase separation (VIPS) and (ii) by post-treatment of pre-formed porous membranes using plasma techniques. In the former method, VIPS will be used to generate the micro-scale structure and polymer crystallization and block copolymer additives for the nano-scale structure, forming the hierarchical structure. In the latter method, plasma etching and anarchical growth under unusual PECVD conditions will be investigated. Feasibility of both methods to produce the desired structure in a spatially controlled uniform surface area and with stable surface properties will be evaluated for a scaling-up capability. The novelty of the proposal lies in association between hierarchical micro- and nano- binary organisation and membrane material having a specified porosity controlled by the fabrication process. This approach is completely novel and the prepared membrane new since no report describes such fluorine-less material till now. Development of the above-mentioned fabrication processes will be carried out by using some recent methods described to turn surface super-hydrophobic. Another novelty concerns the understanding of mechanisms controlling the formation of such micro- nano- assembly to monitor uniformity and defect generation by the fabrication process. The understanding of structure-processing-property relationship is required to address questions about: (i) the spatial placement and length scale distribution of hierarchical structures and (ii) the tolerance limit for defects. This point is especially critical to envision the scaling-up stage. Beyond this proposal, the long term ambition of this project is to develop a fundamental understanding of the morphology control of membrane at multi-scaled length from nano to micro to macro. The aim is to design and manufacture membrane materials with the exact properties needed. This requires the development and validation of coupled modelling mass transfer-structure formation during the membrane processing enabling the prediction of membrane morphology.

The wavelength range spanning from 2 to 4 µm is of particular interest for spectroscopy. Many molecules of industrial interest exhibit in that spectral region intense absorption lines, and lasers and detectors to mesure them work cw at room temperature, thus enabling industrial applications. However, the emitting lasers must exhibit some specific features, such as a single frequency emission and some wavelength tuning capacities. This project aims to realise for the first time single frequency tunable laser diodes using photonic crystals and emitting in the mid-infrared, for spectroscopy applications in the 2 to 4 µm wavelength range. IES will grow by molecular beam epitaxy on GaSb the GaInAsSb/AlGaAsSb quantum well heterostructures constituting of the device. Based on the large expertise of IES on GaInAsSb/AlGaAsSb structures emitting around 2.3 µm, an important step will be the first quantum wells lasers working cw at room temperature beyond 3 µm. They will be studied and realised using type I active zone with GaInAsSb quantum wells and AlGaInAsSb quinary barriers. A full technological workflow on GaSb will be developed at LAAS-CNRS to realise a waveguide surrounded by photonic crystals. The full laser cavity is inspired from cleaved coupled cavities geometry (C3) and uses photonic crystals to optimize and stabilize the spectral filtering of these cavities. This technique should make lasers single mode and tunable over the whole gain spectral range, a highly regarded property for spectroscopy. These devices will be the first lasers using photonic crystals on GaSb. Fully characterized devices will be tested at LSP for cavity ring down spectroscopy (CRDS) experiments to measure sub ppm traces of methane, carbon monoxide and ammonia.

Ce projet étudiera l'expression génique (production des ARN messagers) dans les cellules du dinoflagellé phytoplanctonique Alexandrium catenella pendant la phase d'initiation de son développement. Cette approche totalement nouvelle pour comprendre la dynamique de la formation des floraisons algales toxiques, utilisera les méthodes de biologie moléculaire les plus en pointe actuellement. Ce projet sera effectué en coordination avec d'autres programmes écologiques et océanographiques en cours dans les équipes demandeuses. La variation de l'expression génique dans les cellules (la quantité d'ARNm) sera analysée dans différentes conditions. Cette variation sera étudiée entre les phases du développement en culture, en particulier pendant la phase de latence (avant que les cellules ne commencent à se diviser) et le début de phase exponentielle de croissance (les premiers cycles de division), deux périodes pendant lesquelles on s'attend à mesurer une grande quantité d'ARNm par cellule. Des facteurs environnementaux physico-chimiques et nutritifs seront variés en culture afin de déterminer leur influence sur l'expression génique, en affectant son intensité ou le temps de réponse entre l'application du facteur et le pic d'expression génique. Les variations de l'expression génique seront mesurées par transcription inverse et PCR quantitative pour deux gènes cibles choisis : un gène représentatif de l'activité métabolique codant l'enzyme RubisCO (fixation du CO2) et un gène indicatif de la dynamique prolifératrice des cellules codant pour la protéine PCNA (proliferating cell nuclear antigen) intervenant dans le processus de division cellulaire. Dans le cadre du suivi in situ des floraisons d'A. catenella, la quantification de ces deux ARNm cibles sera effectuée et rapportée aux densités de cellules estimées par le comptage sous microscope. En début de période favorable aux floraisons, même en présence de faibles densités d'A. catenella, on s'attend à mesurer des quantités d'ARNm relativement élevées révélant des cellules dans une phase de multiplication intense. Cette situation pourra être vérifiée avec le développement ultérieur des floraisons. Ceci permettra donc de déterminer quels sont les facteurs environnementaux régnant pendant la phase d'initiation des floraisons. En outre, une librairie d'expression (Expressed sequence tag, EST) sera générée à partir de cellules prises en tout début de développement. Ces séquences EST seront comparées avec celles d'autres dinoflagellés, dont l'espèce voisine A. tamarense, qui ont été obtenues à partir de cellules en fin de croissance, pour mettre en évidence des gènes exprimés plus spécifiquement dans les cellules proliférantes. Ceci ouvrira de nouvelles voies pour l'analyse des mécanismes moléculaires d'initiation des floraisons, et pour la détection des floraisons toxiques.

Today, our energy needs are in large part satisfied by fossil fuels. In the future, renewable energies will play an ever increasing role. For transportation, a renewable fuel will be needed, except for battery vehicles with limited driving range. Hydrogen produced from water and renewable energies could be that fuel. In this respect, H2/air polymer electrolyte fuel cells (PEFCs) are interesting due to their twice higher energy efficiency compared to a H2-combustion engine. A major drawback of today’s PEFCs is their dependence on platinum, a rare and expensive metal, for catalyzing the PEFC-reactions: hydrogen-oxidation and air-reduction. The latter reaction is by far the slowest and 90 % of the platinum in such a fuel cell is used at the air-reducing cathodes. Based on today’s price for platinum, studies have shown that 40-50% of the material’s cost of a PEFC-stack would be ascribed to the raw platinum metal. Therefore, eliminating platinum from the cathode would drastically reduce the cost of PEFCs and allow a massive utilization of this technology. Recently, several breakthroughs have been reported in the field of non-precious-metal catalysts (NPMCs) made from iron (cobalt), nitrogen and carbon. Their activity for the oxygen reduction has been increased tremendously, making them suddenly interesting catalysts from a performance standpoint. Other less active NPMC catalysts have been reported to be stable for 700 h. In order to bring these NPMCs into real PEFC stacks, the highest activity reported for recent NPMCs will have to be combined with a stable behaviour for thousands of hours in an operating PEFC, as required for transportation application. The aim of the present proposal is to investigate innovative approaches to obtain more durable NPMCs and simultaneously advance the science on the various degradation mechanisms that are specific to these catalysts in fuel-cell environment. Two novel approaches will be investigated. The first will consist in synthesizing new NPMCs by replacing the microporous carbon support by other microporous supports. The second will consist in modifying the surface of pre-existing NPMCs by various methods, in order to strengthen the resistance of Fe-based catalytic sites to demetallation, oxidative attack or anion adsorption. Simultaneously, an experimental methodology will be developed to quantify the importance and rate of each of these degradation mechanisms. Long fuel cell tests under controlled conditions will be coupled with advanced characterization techniques such as X-ray photoelectron spectroscopy, Mössbauer spectroscopy and on-line mass spectroscopy.