Characterization Study of CO2, CH4, and CO2/CH4 Hydroquinone Clathrates Formed by Gas–Solid Reaction

Hydroquinone (HQ) is known to form organic clathrates with some gaseous species such as CO2 and CH4. This work presents spectroscopic data, surface and internal morphologies, gas storage capacities, guest release temperatures, and structural transition temperatures for HQ clathrates obtained from pure CO2, pure CH4, and an equimolar CO2/CH4 mixture. All analyses are performed on clathrates formed by direct gas–solid reaction after 1 month’s reaction at ambient temperature conditions and under a pressure of 3.0 MPa. A collection of spectroscopic data (Raman, FT-IR, and 13C NMR) is presented, and the results confirm total conversion of the native HQ (α-HQ) into HQ clathrates (β-HQ) at the end of the reaction. Optical microscopy and SEM analyses reveal morphology changes after the enclathration reaction, such as the presence of surface asperities. Gas porosimetry measurements show that HQ clathrates and native HQ are neither micro- nor mesoporous materials. However, as highlighted by TEM analyses and X-ray tomography, α- and β-HQ contain unsuspected macroscopic voids and channels, which create a macroporosity inside the crystals that decreases due to the enclathration reaction. TGA and in situ Raman spectroscopy give the guest release temperatures as well as the structural transition temperatures from β-HQ to α-HQ. The gas storage capacity of the clathrates is also quantified by means of different types of gravimetric analyses (mass balance and TGA). After having been formed under pressure, the characterized clathrates exhibit exceptional metastability: the gases remain in the clathrate structure at ambient conditions over time scales of more than 1 month. Consequently, HQ gas clathrates display very interesting properties for gas storage and sequestration applications

CATHY : une plateforme expérimentale multi-échelles pour l'étude et la CAracTérisation d'HYdrates de gaz

Les hydrates de gaz sont des structures cristallines, composées d’un réseau tridimensionnel de molécules d’eau pouvant emprisonner sous certaines conditions de pression et température des molécules de gaz comme par exemple le méthane ou le dioxyde de carbone (CO2). Les recherches menées sur ces composés ont de nombreuses applications pratiques à fort impact économique dans les domaines du flow-assurance (prévention de la formation d'hydrates de gaz pour assurer la production de gaz ou de pétrole), du captage/stockage du CO2 (traitement et/ou stockage de gaz sous pression), de l’environnement (production d'énergie propre, transport et stockage de gaz), de l’énergie (exploitation des dépôts naturels d’hydrates représentant une source colossale de gaz naturel), et de l’industrie du froid (utilisation en tant que nouveaux Matériaux à Changement de Phase (MCP)). La plateforme CATHY met en synergie trois laboratoires (le LFC-R, le LaTEP et l’IPREM-ECP) de l’Université de Pau et des Pays de l’Adour (UPPA) pour l’étude et la caractérisation expérimentale des hydrates de gaz par plusieurs techniques complémentaires, mises en œuvre à différentes échelles, dans les domaines suivants : - micro et macro spectroscopie RAMAN pour l’analyse cinétique et structurale in-situ; - synthèse d’hydrates à échelle pilote et à l’échelle de la goutte ; - micro et macro calorimétrie (un brevet déposé) sous pression pour la détermination de propriétés thermodynamiques (diagrammes d’équilibre de phases, enthalpies, etc). Les différents équipements de la plateforme ainsi que des résultats expérimentaux caractéristiques de chaque technique seront illustrés et présentés pour l’hydrate de CO2

The Euclid Science Ground Segment Distributed Infrastructure: System Integration and Challenges

The Science Ground Segment (SGS) of the Euclid mission provides distributed and redundant data storage and processing, federating nine Science Data Centres (SDCs) and a Science Operations Centre. The SGS reference architecture is based on loosely coupled systems and services, broadly organized into a common infrastructure of transverse software components and the scientific data Processing Functions. The SGS common infrastructure includes: 1) the Euclid Archive System (EAS), a central metadata repository which inventories, indexes and localizes the huge amount of distributed data; 2) a Distributed Storage System of EAS, providing a unified view of the SDCs storage systems and supporting several transfer protocols; 3) an Infrastructure Abstraction Layer, isolating the scientific data processing software from the underlying IT infrastructure and providing a common, lightweight workflow management system; 4) a Common Orchestration System, performing a balanced distribution of data and processing among the SDCs. Virtualization is another key element of the SGS infrastructure. We present the status of the Euclid SGS software infrastructure, the prototypes developed and the continuous system integration and testing performed through the Euclid “SGS Challenges”

Efficacité du transfert de gènes du TIMP-2, de l'IL-10 et de leur association dans la thérapie anti-angiogénique et anti-cancéreuse

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Prevalence of Cyprinid herpesvirus 3 and ORF150 genomic variations in carp populations of Indonesia

Cyprinid herpesvirus-3 (CyHV-3) is the etiological agent of koi herpesvirus disease (KHVD) in common and koi carp farming. This highly contagious pathogen has a 295-kb genome that harbours 156 open reading frames. Recent in vitro experimental evolution studies highlighted strong dynamics of genomic structural variations (SVs), in particular in the region of ORF150, an ORF potentially involved in virus multiplication and host inflammatory response. Among these SVs, a 1363-bp deletion could be associated with a loss of virulence. The present study aimed at investigating the genomic variations in the ORF150 region, and especially the deletion, in viruses isolated from carp populations of Indonesia. A screening of 236 fish from 43 different farms revealed a high prevalence of CyHV-3 (nearly 70%), both in symptomatic and asymptomatic common carp. However, in contrast with the results obtained in vitro, long read sequencing of the ORF150 region revealed a low level of genetic variations and the absence of the 1363-pb deletion. The complex interactions between the virus, the environment and the host, particularly the immune system, probably play an important role in this reduced variability

Cu2ZnSn(S1−xSex)4 based solar cell produced by selenization of vacuum deposited precursors

International audienc

Analyse de la spermatogenèse

Un des enjeux de la réglementation européenne REACH est l’amélioration des connaissances des propriétés chimiques, toxiques et écotoxiques des substances utilisées dans la vie courante. Concernant la toxicité testiculaire, nous manquons de modèles pertinents et les rares modèles in vivo utilisés ne sont pas toujours appropriés pour des études mécanistiques. Notre laboratoire a développé des systèmes de culture des cellules germinales mâles, en chambre bicamérale, qui reproduisent une barrière hématotesticulaire et permettent d’étudier le mécanisme d’action des régulateurs physiologiques et les effets d’une substance toxique sur la spermatogenèse, tout en réduisant le nombre d’animaux requis

InGaN/GaN multiple-quantum well heterostructures for solar cells grown by MOVPE: case studies

International audienceWe investigate the influence of growth temperature, p ‐doping with bis‐cyclopentadienyl magnesium (Cp2Mg) and number N of multi‐quantum wells on the surface morphology, the electrical and optical properties of InGaN‐based solar cells grown by metal‐organic vapour phase epitaxy. Atomic force microscopy measurements show no influence of multiple‐quantum well number on the surface morphology, but a smoothing with the increase of the Cp2Mg flow. Electrochemical capacitance‐voltage profiling exhibits an increase of the Na‐Nd concentration when increasing the Cp2Mg flow from 250 to 700 sccm. X‐ray diffraction analysis and transmission electron microscopy measurements confirm completely strained quantum wells with similar superlattice period for N=5 to 30. Finally, first solar cells have been demonstrated with a maximum external quantum efficiency of 38% at 380 nm wavelength for N=30