35 research outputs found

    Applying Topological and Economical Principles in Catalyst Design: New Alumina–Cobalt Core–Shell Catalysts

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    Designing new and effective catalysts may be an art, but its consequences are very real and pragmatic. That said, chemists often build designs on ideal systems, whereas the manufg. of chems. requires catalysts that withstand varied feeds, harsh conditions and long exposure times. Moreover, economical considerations are often underestimated at the catalyst design stage. Here we discuss the inclusion of economical and topol. considerations early on in the catalyst design process, giving as an example the synthesis and testing of a new type of alumina​/cobalt Fischer-​Tropsch catalysts

    Population Genomics on the Fly: Recent Advances in Drosophila

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    Drosophila melanogaster, a small dipteran of African origin, represents one of the best-studied model organisms. Early work in this system has uniquely shed light on the basic principles of genetics and resulted in a versatile collection of genetic tools that allow to uncover mechanistic links between genotype and phenotype. Moreover, given its worldwide distribution in diverse habitats and its moderate genome-size, Drosophila has proven very powerful for population genetics inference and was one of the first eukaryotes whose genome was fully sequenced. In this book chapter, we provide a brief historical overview of research in Drosophila and then focus on recent advances during the genomic era. After describing different types and sources of genomic data, we discuss mechanisms of neutral evolution including the demographic history of Drosophila and the effects of recombination and biased gene conversion. Then, we review recent advances in detecting genome-wide signals of selection, such as soft and hard selective sweeps. We further provide a brief introduction to background selection, selection of noncoding DNA and codon usage and focus on the role of structural variants, such as transposable elements and chromosomal inversions, during the adaptive process. Finally, we discuss how genomic data helps to dissect neutral and adaptive evolutionary mechanisms that shape genetic and phenotypic variation in natural populations along environmental gradients. In summary, this book chapter serves as a starting point to Drosophila population genomics and provides an introduction to the system and an overview to data sources, important population genetic concepts and recent advances in the field

    Numerical simulation of basaltic lava flows in the Auckland Volcanic Field, New Zealand—implication for volcanic hazard assessment

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    Monogenetic volcanic fields, such as the Auckland Volcanic Field (AVF), New Zealand, are common on the Earth’s surface and are typically dominated by basaltic lava flows up to 10 s of km long. In monogenetic volcanic fields located in close proximity to human population and infrastructure, lava flows are a significant threat. In this study, lava flow emplacement conditions for some basaltic eruptions of the AVF were reconstructed using the thermo-rheological MAGFLOW model. Eight existing lava flows in the AVF were simulated using MAGFLOW and eruptive volumes measured from Light Detection and Ranging (LiDAR)-derived digital terrain models (DTMs). Fitting the simulations to the dimensions of actual lava flows provides insight into their emplacement mechanisms and conditions, such as effusion rate, and probable eruption durations. By looking at emplacement in different settings, the likely magma ascent rate for studied AVF eruptions is calculated to have been on the order of 0.1 m/s. In the AVF, the typical estimated duration of past lava flows was from a minimum of 2 days for small volume flows, such as Little Rangitoto (0.0015 km3), up to 83 days for large volume flows, such as Three Kings (0.078 km3). The three best-fitting simulations were used to establish eruption scenarios for future volcanic hazard mapping for the AVF. Inferences of eruption duration that will be useful for developing realistic emergency management plans and recovery scenarios for this densely populated volcanic field are also provided.Published8793V. Dinamiche e scenari eruttiviJCR Journalrestricte
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