Suchergebnisse

The research has been supported by the Project ERANET RUS_ST#2017-051(Latvia) and #18-52-76002 (Russia). The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework, Program H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2. ; Indium (0.038 at.%) and gallium (0.042 at.%) doped ZnO ceramics were prepared by hot pressing. Ceramics were investigated to determine their structural and mechanical characteristics for the prospective use in scintillators. Based on results of nanoindentation, atom force and scanning electron microscopy as well as energy dispersive X-ray spectra measurements, loca-tions of gallium within grain, indium at grain boundaries (GBs) and their different effect on the mechanical properties of ZnO ceramics were detected. Doping of gallium led to the increased modulus of elasticity in grain, decreased hardness near GBs, stabilization of micropores and brittle intercrystalline fracture mode. ZnO:In ceramic has modulus of elasticity and hardness values close to ZnO characteristics, the increased fracture toughness and some plasticity near GBs. Differences in the micromechanical properties of the ceramics correlate with the location of dopants. Results demonstrate that the ZnO:In ceramic has a greater stress relaxation potential than the ZnO:Ga. ---//---This work is licensed under a CC BY 4.0 license. ; Project ERANET RUS_ST#2017-051(Latvia) and #18-52-76002 (Russia); The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework, Program H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2.

Transparent ZnO ceramics are of interest for use as material for high-efficiency fast scintillators. Doping ZnO ceramics in order to improve complex of their properties is a promising direction. In the present research, the role of indium in the ZnO nanopowders surface interactions and in the change of microstructures and photoluminescence (PL) characteristics of sintered cera-mics is considered. Undoped and 0.13 wt% In doped ZnO ceramics are obtained by hot pressing sintering. It has been found that indium leads to the transition of initially faceted ZnO particles to rounded, contributing to good sintering with formation of diffusion active grain boundaries (GBs). Unlike ZnO ceramics, ZnO:In ceramics microstructure is characterised by the trans-crystalline mode of fracture, faceted GBs with places of zig-zag forms and predominant distribution of In at the GBs. Such indium induced modifications of GBs promote removal of point defects and reduce PL parameter α = I def /I exc in comparison with the undoped ceramics. Results characterise ZnO:In cera-mics with improved GBs properties as a prospective material for scintillators. ; The present research has been supported by the Project ERANET RUS_ ST#2017-051(Latvia) and #18-52-76002 (Russia); Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Pelagic habitats are a policy priority below Descriptor 1 (Biodiversity) of the Marine Strategy Framework Directive (MSFD). They are addressed under the D1C6 criterion, stating "the condition of the habitat type, including its biotic and abiotic structure and its functions…, is not adversely affected due to anthropogenic pressures". The evaluation of pelagic habitats status is challenged by the functional and structural characteristics of pelagic habitat diversity and processes. To date, pelagic habitats assessments are lacking in common criteria and methodologies that characterize the habitat while accounting for the effects of anthropogenic pressures to achieve the Good Environmental Status (GES). It is therefore necessary to prioritise communication between scientific and policy communities and frame pelagic research to agree on common methods and approaches at regional or EU scale. This is key for achieving harmonised and comparable pelagic assessments for the MSFD. This report summarizes the outcomes on the assessment workflow of pelagic habitats of the JRC "MSFD pelagic habitats" workshop (9th and 10th March 2021), and the need for coordinated evaluations of the scientific challenges of policy relevance. Recommendations on the MSFD implementation of D1C6, that were generated from the experts during the workshop, will be communicated to the MSFD policy groups and the EU Member States competent authorities to support future harmonised assessment of pelagic habitats. ; Publications Office of the European Union