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Abstract Chlorinated solvents contaminated soils and aquifers are a widespread problem in industrialized countries and many require clean-up due to the risk of contaminant flow into groundwater systems. Clean-up is costly and often invasive, thus there is high interest in stimulating natural attenuation processes. For this, first an assessment of the type and extent of natural attenuation present at the site is required. Here, we present chemical, isotopic and microbial analyses of waters collected at a chlorinated ethene contaminated site in Denmark to give insights into natural attenuation processes. The data gives indication of complete reductive dechlorination by microbial communities but their extent varies greatly across short distances and between the different geological layers. The data further indicates that overall, chlorinated ethene degradation through natural attenuation is small at this site but near surface degradation due to aerobic co-metabolism or abiotic geochemical reduction could potentially play a role.

‘Green rust’ intercalated with aromatic sulfonates can potentially be effective materials for the treatment of soil and groundwater polluted with chlorinated benzenes. We investigated the potential intercalation of benzene sulfonate (BzS) and 1,3-benzene disulfonate (BzDS) into green rust sulfate (GRSO4) via ion exchange. The GRSO4 reacted with various concentrations of sulfonates were characterized by X-ray diffraction, X-ray scattering and transmission electron microscopy. GR interacted with BzDS did not result in intercalation due to stearic hindrance and electrostatic repulsion. For BzS, mixtures of GRSO4 and GR-BzS (d001 = 14.3 Å) were obtained at molar equivalents of ion exchange capacity >5. The intercalation of BzS in the GR structure is limited (~18% intercalation) since BzS cannot fully replace SO42-. The BzS molecules are likely arranged in the interlayer as a dehydrated monolayer with the –SO3 groups facing away in alternate directions.

AbstractBiogenic volatile organic compound (BVOC) emissions from subarctic ecosystems have shown to increase drastically in response to a long‐term temperature increase of only 2°C. We assessed whether this increase takes place already after 3 years of warming and how the increase changes over time. To test this, we measured BVOC emissions and CO2 fluxes in a field experiment on a subarctic wet heath, where ecosystem plots were subjected to passive warming by open top chambers for 3 (OTC3) or 13 years (OTC13) or were kept as unmanipulated controls. Already after 3 years of moderate temperature increase of 1–2°C, warming increased the emissions of isoprene (five‐ to sixfold) and monoterpenes (three‐ to fourfold) from the subarctic heath. The several‐fold higher BVOC emissions in the warmed plots are likely a result of increased vegetation biomass and altered vegetation composition as a shift in the species coverage was observed already after 3 years of warming. Warming also increased gross ecosystem production and ecosystem respiration, but the increases were much lower than those for BVOCs. Our results demonstrate that the strong BVOC responses to warming already appeared after 3 years, and the BVOC and CO2 fluxes had acclimated to this warming after 3 years, showing no differences with another 10 years of warming. This finding has important implications for predicting CO2 and BVOC fluxes in subarctic ecosystems.

An overtopping model specifically suited for Wave Dragon is needed in order to improve the reliability of its performance estimates. The model shall be comprehensive of all relevant physical processes that affect overtopping and flexible to adapt to any local conditions and device configuration. An experimental investigation is carried out to update an existing formulation suited for 2D draft-limited, low-crested structures, in order to include the effects on the overtopping flow of the wave steepness, the 3D geometry of Wave Dragon, the wing reflectors, the device motions and the non-rigid connection between platform and reflectors. The study is carried out in four phases, each of them specifically targeted at quantifying one of these effects through a sensitivity analysis and at modeling it through custom-made parameters. These are depending on features of the wave or the device configuration, all of which can be measured in real-time. Instead of using new fitting coefficients, this approach allows a broader applicability of the model beyond the Wave Dragon case, to any overtopping WEC or structure within the range of tested conditions. Predictions reliability of overtopping over Wave Dragon increased, as the updated model allows improved accuracy and precision respect to the former version.

Some molecular photoisomers can be isomerized to a metastable high-energy state by exposure to light. These molecules can then be thermally or catalytically converted back to their initial state, releasing heat in the process. Such a reversible photochemical process has been considered for developing molecular solar thermal (MOST) systems. In this review, we introduce the concept, criteria, and state-of-the-art of MOST systems, with an emphasis on the three most promising molecular systems: norbornadiene/quadricyclane, E/Z-azobenzene, and dihydroazulene/vinylheptafulvene. After discussing the fundamental working principles, we focus on molecular design strategies for improving solar energy storage performance, remaining challenges, and potential focus areas. Finally, we summarize the current molecular incorporation into functional devices and conclude with a perspective on challenges and future directions. Z.W. and K.M.-P. would like to thank the financial support from K. & A. Wallenberg foundation, the Swedish Foundation for Strategic Research, the Swedish research foundation FORMAS, and the European Union’s Horizon 2020 research and innovation program under grant agreement No. 951801. K.M.-P. acknowledges support from the Catalan Institution for Research and Advanced Studies. P.E. thanks the K. & A. Wallenberg foundation (2014.0226) and the Swedish Research Council (2020-04935). T.L. and Z.-Y.Z. thank the financial support from National Key Research and Development Program of China (2017YFA0207500), National Natural Science Foundation of China (22022507, 51973111), and Beijing National Laboratory for Molecular Sciences (BNLMS202004). D.S. thanks the financial support from MINECO/FEDER (CTQ2017-87372-P). O.B., J.L., and H.A.W. thank the Deutsche Forschungsgemeinschaft (DFG, project 392607742, 62201757). Additional support by the DFG is acknowledged through the Research Unit FOR 1878 “funCOS – Functional Molecular Structures on Complex Oxide Surfaces.” J.L. and O.B. acknowledge the cooperation with the groups of Julien Bachmann, Christian Papp, Andreas Hirsch, Andreas Görling, and Hans-Peter Steinrück in the framework of the studies described in this review. M.B.N. thanks the University of Copenhagen for financial support. With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S). Peer reviewed

AbstractThe capability of Pleistocene hominins to successfully adapt to different types of tropical forested environments has long been debated. In order to investigate environmental changes in Southeast Asia during a critical period for the turnover of hominin species, we analysed palaeoenvironmental proxies from five late Middle to Late Pleistocene faunas. Human teeth discoveries have been reported at Duoi U’Oi, Vietnam (70–60 ka) and Nam Lot, Laos (86–72 ka). However, the use of palaeoproteomics allowed us to discard the latter, and, to date, no human remains older than ~ 70 ka are documented in the area. Our findings indicate that tropical rainforests were highly sensitive to climatic changes over that period, with significant fluctuations of the canopy forests. Locally, large-bodied faunas were resilient to these fluctuations until the cooling period of the Marine Isotope Stage 4 (MIS 4; 74–59 ka) that transformed the overall biotope. Then, under strong selective pressures, populations with new phenotypic characteristics emerged while some other species disappeared.We argue that this climate-driven shift offered new foraging opportunities for hominins in a novel rainforest environment and was most likely a key factor in the settlement and dispersal of our species during MIS 4 in SE Asia.