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The onshore–offshore correlation of sedimentary successions is a common problem in basin analysis, but it becomes critical for the full understanding of the Messinian salinity crisis (MSC), a complex array of palaeoenvironmental events which affected the Mediterranean basin at the end of the Miocene. The outcrop records show that the Messinian stratigraphic architectures may be highly complex as the deposits of the different MSC evolutionary stages can be lithologically similar and separated by erosional surfaces and/or morphostructural highs. The correct definition of the nature and stratigraphic position of Messinian deposits in offshore areas through seismic data may be almost impossible, especially where core data are sparse. To bridge the gap between onshore and offshore records, we have built synthetic seismic sections from well‐constrained outcrop successions. Our results provide useful insights and warnings for the interpretation of offshore data, pointing out that MSC units having different age, nature and depositional settings, may show similar seismic facies and geometries. Conversely, the same deposit may result in different seismic facies, either with parallel and high‐amplitude reflections or even transparent or chaotic due to interference patterns of seismic reflections related to dominant frequency. It follows that a correct interpretation of the nature and age of deep‐seated Messinian deposits can only be obtained through the integration of seismic and core data, and considering the onshore record. The application of our approach to the Balearic Promontory results in an alternative interpretation with respect to previous models. We show that this offshore area has good analogues in the onshore of the Betic Cordillera and includes both shallow and intermediate depth sub‐basins that underwent a strong post‐Messinian subsidence. [ABSTRACT FROM AUTHOR]

Polymer electrolyte fuel cells (PEFC), although a promising technology for carbon free production of electricity, are penalized by system complexity, partly due to cooling and humidifying systems. These systems are necessary to avoid the heating up and drying of the membrane, which stop the electrochemical reaction. Here, we present an evaporative cooling concept for PEFC developed at Paul Scherrer Institute (PSI). Unlike other concepts, our approach does not require any additional layer in the cell structure. Water flows through dedicated anode flowfield channels, parallel to the gas channels, and is distributed over the cell area thanks to a modified gas diffusion layer (GDL). A synthesis method developed at Paul Scherrer Institut (PSI) transforms some portions of the GDL into hydrophilic patterns, which wick the water from the supply channels at low capillary pressure. These hydrophilic areas, parallel and equally spaced, define pathways for liquid water separated from the gases, which avoids flooding. A test cell was built to investigate both water transport with the help of neutron radiography and heat transport thanks to integrated heat flux sensors. Here, we will present how the evaporation can be controlled by the mass flow rates, temperatures, pressures of gases, and the geometry of the hydrophilic lines. [ABSTRACT FROM AUTHOR]

Earth scientists have searched for signs of microscopic life in ancient samples of permafrost, ice, deep-sea sediments, amber, salt and chert. Until now, evidence of cyanobacteria has not been reported in any studies of ancient DNA older than a few thousand years. Here, we investigate morphologically, biochemically and genetically primary evaporites deposited in situ during the late Miocene (Messinian) Salinity Crisis from the north-eastern Apennines of Italy. The evaporites contain fossilized bacterial structures having identical morphological forms as modern microbes. We successfully extracted and amplified genetic material belonging to ancient cyanobacteria from gypsum crystals dating back to 5.910–5.816 Ma, when the Mediterranean became a giant hypersaline brine pool. This finding represents the oldest ancient cyanobacterial DNA to date. Our clone library and its phylogenetic comparison with present cyanobacterial populations point to a marine origin for the depositional basin. This investigation opens the possibility of including fossil cyanobacterial DNA into the palaeo-reconstruction of various environments and could also be used to quantify the ecological importance of cyanobacteria through geological time. These genetic markers serve as biosignatures providing important clues about ancient life and begin a new discussion concerning the debate on the origin of late Miocene evaporites in the Mediterranean. [ABSTRACT FROM AUTHOR]

This study shows the results obtained during the starting-up evaluation of an UASB reactor treating domestic sewage. It is located in the municipality of Ginebra, Valle del Cauca region in Colombia. Its design flow is 7.5 l/s with a maximum capacity of 10 l/s. The reactor was seeded with a deficient quality inoculum which accounted for 20% of the total reactor volume. The starting-up methodology comprised the sequential washing of the sludge (inoculum) by applying three different upflow velocities. This procedure resembles what other authors term the "selective pressure method". Once the sludge was washed, the reactor was started-up with an initial hydraulic retention time (HRT) of 24.9 hours, which was steadily reduced down to 6.7 hours in the final stage. Along the starting-up phase, there was a positive evolution in terms of quantity, quality and spatial distribution of the sludge. Consequently, there was a positive evolution in organic matter removal mechanisms. For HRT above 14 hours, the removal mechanisms were mainly physical whilst for HRT below 9 hours the removal mechanisms were mostly biological. Based on the above considerations and on the water quality parameters measured, it may be concluded that the start-up of an UASB reactor for domestic sewage treatment seeded with a low quality inoculum can be done with HRT as low as 15 or 12 hours. In this way, it is possible to reduce the starting-up period of these reactors down to 4 to 6 weeks, provided that the starting-up methodology is properly applied. [ABSTRACT FROM AUTHOR]

The biogeochemistry of hypersaline environments is strongly influenced by changes in biological processes and physicochemical parameters. Although massive evaporation events have occurred repeatedly throughout Earth history, their biogeochemical cycles and global impact remain poorly understood. Here, we provide the first nitrogen isotopic data for nutrients and chloropigments from modern shallow hypersaline environments (solar salterns, Trapani, Italy) and apply the obtained insights to δ15N signatures of the Messinian salinity crisis (MSC) in the late Miocene. Concentrations and δ15N of chlorophyll a, bacteriochlorophyll a, nitrate, and ammonium in benthic microbial mats indicate that inhibition of nitrification suppresses denitrification and anammox, resulting in efficient ammonium recycling within the mats and high primary productivity. We also suggest that the release of 15N-depleted NH3(gas) with increasing salinity enriches ammonium 15N in surface brine (≈34.0‰). Such elevated δ15N is also recorded in geoporphyrins isolated from sediments of the MSC peak (≈20‰), reflecting ammonium supply sufficient for sustaining phototrophic primary production. We propose that efficient nutrient supply combined with frequent bottom-water anoxia and capping of organic-rich sediments by evaporites of the Mediterranean MSC could have contributed to atmospheric CO2 reduction during the late Miocene. [ABSTRACT FROM AUTHOR]