LEFOG LEad-Free Oxides for Gas detection Developing portable or fixed instrument systems compatible with the RoHS directive (restriction of dangerous substances) to monitor our environment is one objective of OLDHAM SAS. This company, which is a subsidiary of the ISC (Industrial Scientific Corporation) group, is ISO 14001 certified since 2009 and is therefore one of the European leaders in matters of ecology. Nowadays gas detection uses mainly optical sensors, lead-based electrochemical sensors and catalytic sensors based on platinum/palladium. This is a very fast growing (10% / year) and promising market (estimated at 3 billion €). Medium-term tensions on the platinum market, increasing prohibitions of use of lead on account of its toxicity and the need for new systems of instrumentation dedicated to the monitoring of the interior air quality and to the detection of dangerous substances require the study and development of new sensors compatible with the environmental (RoHS, REACH) and economics stakes (low cost materials, reliable and cheap manufacturing techniques, high lifetime). The OSPÉGAZ project aims at developing innovative integrated systems of instrumentation dedicated to the characterization of the various environmental exposures in link in particular with the actions recommended within the framework of the PNSE2 for the proven medical impacts. This apparatus which will integrate new gas sensors containing lead free oxides will be dedicated to the detection of flammable gases, protection against toxic risks and air quality monitoring. The preliminary work on lead-free ferroelectric oxides enabled us to optimize the conditions of thin films manufacturing. The properties of these pyroelectric oxides should also permit other applications such as the gas detection with optoelectronics cells. Catalytic demonstrators made from BaxSr1-xTiO3 (BST) films gave some very encouraging results. These lead free oxides will thus enable us to develop a new generation of innovating gas sensors of various technologies (catalytic passive sensors and optoelectronic cells integrating a pyroelectric sensor, optical sensors). These technologies open us vast opportunities of study and research on the same material, including the detection of a larger panel of gases. For the proposed gas sensors, the multiple requirements related to the characteristics of thin films (adjustable film composition, various substrates, thickness, variable structure and microstructure) and industrial purpose (technology transfer to industry, low-cost) led us to use several techniques of deposit for the realization of thick and thin films. OSPÉGAZ project aims therefore at: - replacing the current lead containing gas sensors (for example, OLDHAM uses 1-2 tons of lead per year for its sensors) by lead free oxides sensors - producing catalytic sensors without platinum (cost reduction and need for developing an alternative technology before the exhaustion of the platinum resources) - demonstrating that ferroelectric oxides based pyroelectric sensors open new prospects when applied to the gas detection (high sensitivity and wide range of detection) - developing new sensors in agreement with the PNSE2 health plan which aims at reducing the aqueous and atmospheric emissions of priority substances (benzene, HAP aromatic hydrocarbons polycyclic, chlorinated solvents…). By controlling the power consumption of the new sensors, we hope to show that it will be then possible to transfer these new technologies of sensors into OLDHAM SAS instruments. We also wish to quantify the effectiveness of these new sensors on an extended list of gas to include the requirements of PNSE2.

Improvised explosive devices (IED), also known as roadside bombs are causing increased losses of troops and are also widely used for terrorist attacks too. Such devices use various kinds of explosives and due to the difficulty to detect them they are extremely effective. A large range of detection solutions are being evaluated. Optical spectroscopy techniques have without doubt great potential. Among this panel, we propose to use THz radiation, located between the microwaves and infrared bands. THz Spectroscopy is an excellent alternative completing or even to improve traditional approaches for the detection pyrotechnic compounds. Indeed, THz spectroscopy is characterized by an excellent molecular selectivity, with rotational lines of small polar molecules and/or low frequency vibrational signatures of bigger molecular systems. THz spectroscopy is a breakthrough technique for detection, analysis and quantification of a wide variety of molecular compounds . The potentiality of this technique is considered in the context of the detection of chemical agents involved in military programs. While gases has been studied for a long time in the THz domain for fundamental science, the interaction of the THz radiation with explosives substances has only recently been started to be examined. THz Time Domain Spectroscopy (THz TDS) has removed many technological difficulties to initiate those first studies in this spectral gap. Now, many data are available on these types of compounds. However the data contain substantial discrepancies probably due to various experimental conditions measurements (pure or diluted, the use of matrix or not…). Moreover, the additives can modify and so complicate the recognition of prohibited substance present in a mixture. We can also legitimately question the feasibility of identifying an individual compounds whien its spectrum is not attributed to any isolated spectral lines. Some explosives and their derivatives have significant vapour pressure which can be use for the detection with a high degree of discrimination. However, these relatively heavy compounds are not very volatile, and therefore require very high sensitivity spectrometers, especially as additives further decrease their volatility. Such approaches have great potential, but require an extensive and fundamental study of the spectral signatures. To the best of our knowledge, THz gas phase spectra of the most volatile explosives are not available. The objective of this proposal is to record and fully interpret the THz and Far Infrared spectra of the vapour pressures of some target explosives and /or their derivative compounds. Without doubt, these new data provide information about the potential of this spectral band to detect such substances in the gas phase. So, the industrial partner will propose several approaches towards studies or experimental development at higher TRL levels.

Satellite remote sensing now allows for the collection of various physical and biological parameters at regional and global scales and at different temporal resolutions which are not accessible to other sampling methods. The first objective of the present project is to assess and analyse the seasonal, inter-annual, and decadal evolution of the global coastal waters in terms of biogeochemical composition as revealed from satellite ocean colour observations, for the very first time. Basic (inherent optical properties (IOPs), chlorophyll a (Chl), as a proxy for phytoplankton biomass and suspended particulate matter (SPM) concentrations) as well as more innovative products (particulate and dissolved organic carbon POC and DOC) will be assessed from new approaches developed in the frame of GlobCoast. In the second part of the project, time series for the latter biogeochemical parameters will be analysed conjointly with various physical forcing parameters as obtained from remote sensing, in situ measurements, and modelling. This will help to gain a better understanding of the origins of the temporal variability of biogeochemical parameters over the coastal ocean. This part will be preferentially performed over three highly contrasted areas covering a great variety of environmental, biological and bio-optical conditions encountered in coastal areas: the English Channel and the North Sea, some major coastal upwelling systems, and the Amazon-influenced coast (mainly French Guiana). Besides its fundamental role in marine biogeochemical cycles, phytoplankton, which is at the basis of the marine food web, transfers energy to higher trophic levels and its dynamics influences directly and indirectly the biodiversity of some trophic groups such as zooplankton, fishes and marine mammals. The third main objective of this project is to analyse the potential link between the variability of the environmental parameters as assessed in the first parts of the project, and the variance in the recruitment and stocks of higher trophic level organisms (fishes). While fishing pressure has a strong impact on recruitment and stocks, the contribution of environmental fluctuations to the variability in recruitment is now clearly demonstrated, especially thanks to remotely sensed data from satellite. This last part will be performed over the English Channel and the North Sea, and some major coastal upwelling systems.