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ISTerre is part of Labex OSUG@2020. Use of the Geochem- istry–Mineralogy platform at ISTerre is acknowledged. The authors wish to aknowledge the ESRF for provision of beam time (MA4498). We are also thankful to Dr Pierre-Olivier Autran for useful insights on tomographic reconstructions and Dr Marta Majkut for discussions on grain orientation calcu- lations. The authors also thank Dr Irina Snigireva and Dr Nathaniel Findling for SEM characterization of the samples and Dr Catherine Dejoie for complementary high-resolution powder diffraction data from the ID22 beamline of the ESRF., The mechanism of hydration of calcium sulfate hemihydrate (CaSO4 0.5H2O) to form gypsum (CaSO4 2H2O) was studied by combining scanning 3D X-ray diffraction (s3DXRD) and phase contrast tomography (PCT) to determine in situ the spatial and crystallographic relationship between these two phases. From s3DXRD measurements, the crystallographic structure, orientation and position of the crystalline grains in the sample during the hydration reaction were obtained, while the PCT reconstructions allowed visualization of the 3D shapes of the crystals during the reaction. This multi-scale study unfolds structural and morphological evidence of the dissolution–precipitation process of the gypsum plaster system, providing insights into the reactivity of specific crystallographic facets of the hemihydrate. In this work, epitaxial growth of gypsum crystals on the hemihydrate grains was not observed.

This topic presents the effect of water temperature on benthic invertebrate growth and assemblages at downstream site of the Dam in winter, in Japan. The surface layer water of dam was released, and the temperature was always 3-5 degrees higher than the upstream. This was because of tentative manipulation of dam. Life cycles of dominated species were faster and their body size were all larger in the downstream than the upstream. Kamimuria tibialis (Perlidae) as a predator grew faster. Also, its body weight was much heavier than in the upstream, even its body length is the same in the upstream. Periphyton biomass was also much higher, especially, filamentous species were dominated at slow current site in the downstream. Regardless of abundance of periphyton, Heptageniidae as a grazer were not increased compared with the upstream. Besides discharge control, water temperature changes invertebrate assemblages quickly. This result implies that restrict of the movement of species is need to consideration.

The growing problem of hydrogen sulfide resulting from the disposal of waste gypsum boards has yet to find an effective solution. Recent years have brought urgent calls for a means of recycling waste gypsum boards. This study focused on applications in floors, which among major structural parts are subject to particularly severe conditions. The author examined the form of gypsum after pouring, as well as the formwork and pouring methods, employing the properties of gypsum hemihydrate recycled from waste gypsum boards. The study has established specifications that overcome the problem of afterflame following a fire involving wooden fireproof construction.

The growing problem of hydrogen sulfide resulting from the disposal of waste gypsum boards has yet to find an effective solution. Recent years have brought urgent calls for a means of recycling waste gypsum boards. This study focused on applications for thermal mitigation in roof, wall, and road in urban area. The author examined the form of gypsum after pouring, as well as the formwork and pouring methods, employing the properties of gypsum hemihydrate recycled from waste gypsum boards. The study has established specifications that overcome the problem of urban heat island.