Une Russie plurielle: Confins et profondeurs

International audienc

Influence du diabète non insulino dépendant expérimental et du vieillissement sur la biosynthèse des acides gras à longues chaînes chez le rat spontanément hypertendu

CORTE-BU (200962101) / SudocSudocFranceF

High power 2.5D integrated thermoelectric generators combined with microchannels technology

International audienceWe have developed high power integrated thermoelectric generators (µTEGs). These µTEGs are CMOS compatible, i.e. based on polycristalline SiGe materials. These µTEGs have been processed directly on a silicon interposer. Even if poly-SiGe exhibits low thermoelectric performances at room temperature, the specific design and proposed architecture enable µTEGs to deliver up to 680 µW for a temperature difference at 15.5 K. To reach such high power, an original 2.5D structure has been developed and µchannels technology has been associated, below the µTEG, to dissipate heat coming from the hot side. µTEGs have been tested in real environment, located below a hot test chip. Such µTEG performances overtake those from similar state-of-the-art CMOS compatible devices, and pave the way for a potential use in different applications such as sensors power supply or battery charger

Spatial and temporal distribution of current-use pesticides in ambient air of Provence-Alpes-Côte-d’Azur Region and Corsica, France

International audienc

Organic aerosol molecular composition and gas–particle partitioning coefficients at a Mediterranean site (Corsica)

International audienceMolecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry (GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3–C7), mono and di-carboxylic acids (C3–C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached

Organic aerosol molecular composition and gas–particle partitioning coefficients at a Mediterranean site (Corsica)

International audienceMolecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry (GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3–C7), mono and di-carboxylic acids (C3–C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached

The project ChArMEx - Chemistry Aerosol Mediterranean Experiment.

ChArMEx is a new regional project on tropospheric chemistry and aerosols in the Mediterranean proposed by the French community, calling for international cooperation. ChArMEx proposes an integrated modelling and observational approach to study budgets of species, chemical and dynamical processes, intense events, trends, and impacts. The objectives include an assessment of the recent past, present and future states of the atmospheric chemistry and of related impacts on air quality, regional climate and marine biogeochemistry.The experimental strategy includes long-term monitoring, 2 years of enhanced surface observations, and summer intensive campaigns with research aircrafts and drifting balloons to study the aging of continental air masses over the basin when pollutants and desert dusts are at their maximum and likely impact the regional climate. Focus is presently put on the western basin. Synergies are built with other Mediterranean projects on the hydrological cycle (HyMEx) and marine ecosystems (MERMEX)