29 research outputs found
Implementing the FAIR principles of findability and interoperability for data from the French OZCAR critical observatory network: the Theia/OZCAR information system
International audienc
Implementing the FAIR principles of findability and interoperability for data from the French OZCAR critical observatory network: the Theia/OZCAR information system
International audienc
Implementing the FAIR principles of findability and interoperability for data from the French OZCAR critical observatory network: the Theia/OZCAR information system
International audienc
Implementing FAIR principles for dissemination of data from the French OZCAR Critical Observatory network: the Theia/OZCAR information system
International audienceOZCAR-RI, the French Critical Zone Research Infrastructure gathers 20 observatories sampling various compartments of the Critical Zone, and having historically developed their own data management and distribution systems. However, these efforts have generally been conducted independently. This has led to a very heterogeneous situation, with different levels of development and maturity of the systems and a general lack of visibility of data from the entire OZCAR-RI community. To overcome this difficulty, a common Information System (Theia/OZCAR IS) was built to make these in situ observation FAIR (Findable, Accessible, Interoperable, Reusable) and that will allow the data to be visible in the European eLTER-RI (European Long Term Ecosystem Research) Research Infrastructure to which OZCAR-RI contributes. The IS architecture was designed after consultation of the users, data producers and IT teams involved in data management. A common data model including all the requested information and based on several metadata standards was defined to set up information fluxes between observatories IS and the Theia/OZCAR IS. Controlled vocabularies were defined to develop a data discovery web portal offering a faceted search with various criteria, including variables names and categories that were harmonized in a thesaurus published on the web. The communication will describe the IS architecture, the pivot data model and open source solutions used to implement the data portal that allows data discovery. The communication will also present future steps to implement data downloading and interoperability services that will allow a full implementation of these FAIR principles
Theia/OZCAR Thesaurus: a terminology service to facilitate the discovery, interoperability and reuse of data from continental surfaces and critical zone science in interdisciplinary research
International audienc
Le thĂ©saurus Theia/OZCAR : un service terminologique pour faciliter la dĂ©couverte, lâinteropĂ©rabilitĂ© et la rĂ©utilisation des donnĂ©es du systĂšme dâinformation sur les surfaces continentales
International audienceLe systĂšme d'information Theia/OZCAR a pour objectif de Faciliter la dĂ©couverte, de rendre Accessible, InteropĂ©rable et RĂ©utilisable (FAIR), les donnĂ©es in-situ des surfaces continentales collectĂ©s par les organismes de recherche Français et leurs partenaires Ă©trangers (1). Les observatoires qui produisent les donnĂ©es prĂ©sentent des pratiques de description des donnĂ©es hĂ©tĂ©rogĂšnes et des noms de variables qui peuvent ĂȘtre diffĂ©rents pour la mĂȘme variable (i.e. : « soil moisture », « soil water content », « humiditĂ© des sols », etc.). Il n'est pas possible de dĂ©duire simplement les similaritĂ©s entre des variables mesurĂ©es par diffĂ©rents observatoires. Afin d'identifier ces similaritĂ©s et d'implĂ©menter dans le systĂšme dâinformation des fonctionnalitĂ©s de dĂ©couverte des donnĂ©es sur ces dimensions, le thĂ©saurus de variable Theia/OZCAR (2) a Ă©tĂ© crĂ©Ă©. Pour permettre lâinteropĂ©rabilitĂ© technique du thĂ©saurus, celui-ci est publiĂ© sur le web Ă l'aide du standard de description de vocabulaire SKOS (3). D'autres thĂ©saurus utilisĂ©s en sciences de l'environnement en Europe et dans le monde ont Ă©tĂ© identifiĂ©s et la dĂ©finition de relations associatives avec ces vocabulaires garantit l'interopĂ©rabilitĂ© sĂ©mantique du thĂ©saurus Theia/OZCAR. Cependant, il est assez commun que les noms de variables utilisĂ©s pour les dimensions de recherches restent gĂ©nĂ©ralistes (i.e. « soil moisture ») et ne soient pas assez spĂ©cifiques pour que l'utilisateur final interprĂšte exactement ce qui a Ă©tĂ© mesurĂ© (i.e. « soil moisture at 10 cm depth measured by TDR probe »). C'est pourquoi, pour amĂ©liorer la rĂ©utilisation et lâinteropĂ©rabilitĂ© des donnĂ©es, le thĂ©saurus suit maintenant une recommandation de la Research Data Alliance et implĂ©mente le framework I-ADOPT (4) pour dĂ©crire plus prĂ©cisĂ©ment les variables. Chaque variable est composĂ©e et dĂ©crite par des relations avec des concepts atomiques dont la dĂ©finition est prĂ©cisĂ©e. (1) Braud, Isabelle, et al. "Building the information system of the French Critical Zone Observatories network: Theia/OZCAR-IS." Hydrological Sciences Journal (2020): 1-19. 10.1080/02626667.2020.1764568(2) ThĂ©saurus Theia/OZCAR: https://w3id.org/ozcar-theia(3) Miles, Alistair, and Sean Bechhofer. âSKOS simple knowledge organization system reference.â W3C recommendation (2009).(4) Magagna, Barbara, MoncoiffĂ©, GwenaĂ«lle, Devaraju, Anusuriya, Stoica, Maria, Schindler, Sirko, Pamment, Alison, & RDA I-ADOPT WG. (2022). InteroperAble Descriptions of Observable Property Terminologies (I-ADOPT) WG Outputs and Recommendations (1.1.0). https://doi.org/10.15497/RDA0007
Tm3+ codoping for mid-infrared laser applications of Dy3+ doped CaF2 crystals
International audienceWe report here on a spectroscopic study of Dy3+-doped and Tm3+-Dy3+ doped CaF2 as promising candidates to develop crystalline waveguide laser sources around 3 ÎŒm. The advantages of Tm3+ ions as sensitizers to improve the excitation of Dy3+ ions in CaF2 is demonstrated: an energy transfer efficiency from Tm3+ to Dy3+ ions of 99.6% has been reached for Dy3+ concentration as high as 2 at.%, by considering a Tm3+ ratio set at 5 at.%. Moreover, the behavior of such doped crystals in a laser waveguide configuration has been modeled and the modeling results show that it seems possible to achieve promising laser perspectives around 3 ÎŒm, with laser thresholds in the watt level for singly doped Dy3+:CaF2 and around 0.2â0.3 W for codoped Tm3+-Dy3+:CaF2, presenting both laser efficiencies in the order of 30%. Finally, the saturation of the absorption which is observed in the modeling for such codoped Tm3+-Dy3+:CaF2 waveguide at Dy3+ concentration below 1% is discussed and its origin is explained
Close look on cubic Tm:KY 3 F 10 crystal for highly efficient lasing on the 3 H 4 â 3 H 5 transition
International audienceWe report on Czochralski growth, detailed ground- and excited-state absorption and emission spectroscopy and highly-efficient mid-infrared (âŒ2.3 ”m) laser operation of a cubic potassium yttrium fluoride crystal, Tm:KY3F10. The peak stimulated-emission cross-section for the 3H4 â 3H5 transition is 0.34Ă10â20 cm2 at 2345 nm with an emission bandwidth exceeding 50 nm. The excited-state absorption spectra for the 3F4 â 3F2,3 and 3F4 â 3H4 transitions are measured and the cross-relaxation is quantified. A continuous-wave 5 at.% Tm:KY3F10 laser generated 0.84 W at 2331-2346 nm by pumping at 773 nm, with a record-high slope efficiency of 47.7% (versus the incident pump power) owing to the efficient action of energy-transfer upconversion leading to a pump quantum efficiency approaching 2. The first Tm:KY3F10 laser with ESA-assisted upconversion pumping (at 1048 nm) is also demonstrated. Due to its broadband emission properties, Tm:KY3F10 is promising for ultrashort pulse generation at âŒ2.3-2.4 ”m
CHARACTERIZATION OF A FLOW SEPARATION SENSOR ON A HYDROFOIL: THE HYDRO E-TELLTALE
The performance of lifting bodies such as hydrofoils is determined by the flow state and particular attention should be paid to flow separation, as this greatly affects the generated lift and drag. Sailors are used to look at telltales (woolies) to trim their sails or steer their yacht. A French company developed an electronic telltale for sails based on a strain gauge activated by a silicon strand, with the appropriate signal processing to deliver the same information as a classical wool-made telltale, basically attached or separated flow. This new sensor proved useful when woolies are not visible or to deliver a signal to feed a control system, such as the autopilot for example. It was also applied to wind turbines to control the blade pitch. Mer AgitĂ©e is now developing an equivalent hydrodynamic e-Telltale to be used on hydrofoils and rudders to help trimming and controlling. The present work presents the investigation of a foil section fitted with this new sensor in a water tunnel, combining force and PIV measurements with the sensor signal, on a wide range of angle of attack. Results show that the hydro e-Telltale enables detecting the flow separation and anticipate stall, and possibly allows for detecting the boundary layer transition to turbulence. The feedback from this new sensor could be used for example in a control loop to make an âAnti-Stall Systemâ on a rudder or a foil