Using the third state of matter: high harmonic generation from liquid targets

High harmonic generation on solid and gaseous targets has been proven to be a powerful platform for the generation of attosecond pulses. Here we demonstrate a novel technique for the XUV generation on a smooth liquid surface target in vacuum, which circumvents the problem of low repetition rate and limited shot numbers associated with solid targets, while it maintains some of its merits. We employed atomically smooth, continuous liquid jets of water, aqueous salt solutions and ethanol that allow uninterrupted high harmonic generation due to the coherent wake emission mechanism for over 8 h. It has been found that the mechanism of plasma generation is very similar to that for smooth solid target surfaces. The vapor pressure around the liquid target in our setup has been found to be very low such that the presence of the gas phase around the liquid jet could be neglected

Harmonic generation from relativistically oscillating plasma surfaces

[Abstract unavailable

A Biomedically Enriched Collection of 7000 Human ORF Clones

We report the production and availability of over 7000 fully sequence verified plasmid ORF clones representing over 3400 unique human genes. These ORF clones were derived using the human MGC collection as template and were produced in two formats: with and without stop codons. Thus, this collection supports the production of either native protein or proteins with fusion tags added to either or both ends. The template clones used to generate this collection were enriched in three ways. First, gene redundancy was removed. Second, clones were selected to represent the best available GenBank reference sequence. Finally, a literature-based software tool was used to evaluate the list of target genes to ensure that it broadly reflected biomedical research interests. The target gene list was compared with 4000 human diseases and over 8500 biological and chemical MeSH classes in ∼15 Million publications recorded in PubMed at the time of analysis. The outcome of this analysis revealed that relative to the genome and the MGC collection, this collection is enriched for the presence of genes with published associations with a wide range of diseases and biomedical terms without displaying a particular bias towards any single disease or concept. Thus, this collection is likely to be a powerful resource for researchers who wish to study protein function in a set of genes with documented biomedical significance

Human and mouse essentiality screens as a resource for disease gene discovery.

The identification of causal variants in sequencing studies remains a considerable challenge that can be partially addressed by new gene-specific knowledge. Here, we integrate measures of how essential a gene is to supporting life, as inferred from viability and phenotyping screens performed on knockout mice by the International Mouse Phenotyping Consortium and essentiality screens carried out on human cell lines. We propose a cross-species gene classification across the Full Spectrum of Intolerance to Loss-of-function (FUSIL) and demonstrate that genes in five mutually exclusive FUSIL categories have differing biological properties. Most notably, Mendelian disease genes, particularly those associated with developmental disorders, are highly overrepresented among genes non-essential for cell survival but required for organism development. After screening developmental disorder cases from three independent disease sequencing consortia, we identify potentially pathogenic variants in genes not previously associated with rare diseases. We therefore propose FUSIL as an efficient approach for disease gene discovery

Development and Characterisation of Solid Oxide Electrolyser Cells (SOEC)

A reliable energy supply which is based on increasing shares of sustainable and renewable energy sources, such as wind power and solar energy, requires appropriate storage technologies. Hydrogen as energy carrier, produced by water electrolysis using electric current from regenerative energy sources, offers a high potential in this respect. A very efficient option to produce hydrogen in this way is high-temperature steam electrolysis based on solid oxide electrolyser cells (SOEC). This technology requires operating temperatures in the range of 700-1000 °C and offers some additional advantages compared to low temperature electrolysis techniques. The higher operating temperature results in faster reaction kinetics thus enabling potentially high energy efficiency. From a thermodynamic point of view, part of the energy demand for the endothermic water splitting reaction can be obtained from heat produced within the cell. The electric energy demand can be further significantly reduced if high temperature heat from renewable energy sources such as geothermal or solar thermal power or waste heat from industrial processes is available. Furthermore, it is possible with high temperature electrolysis to not only split water but also carbon dioxide or a mixture of both to produce synthesis gas (syngas) or other energy carriers such as methane or methanol by subsequent catalytic conversion. For a further development of this promising technology, development work on materials and cells as well as extensive operational experience is still needed. A main objective is to develop highly efficient and long-term stable cells and stacks using novel electrode materials and to improve the degradation behaviour by elucidating the relevant degradation mechanisms.To this aim, German Aerospace Center (DLR) and Forschungszentrum Jülich (JÜLICH) who have both long experience in the development of SOFC/SOEC technology [1-3] started a joint project in the frame of the “Helmholtz Energy Alliance” on electrochemical energy storage and conversion. Cathode-supported cells containing novel perovskite-type air electrodes were fabricated by ceramic processing and sintering for electrochemical characterisation in electrolysis operating mode. The selection and preparation of electrode materials and the process of cell manufacturing is described. A new test bench has been installed which allows measuring polarisation curves of 4 cells simultaneously under relevant SOFC and SOEC conditions as well as performing long-term durability measurements. The experimental setup for electrochemical cell characterisation is described and results of electrochemical measurements performed at different operational conditions, such as different steam content and operating temperature, are presented. After operation the cells were investigated by post-test analytical methods; hereby special emphasis is put on the detailed investigation of degradation phenomena and mechanisms [4] by applying numerous characterisation techniques as well as the elaboration of mitigation strategies for the degradation processes. References1. Schiller G., Ansar A., Lang M., Patz O., 2009, J. Appl. Electrochem.,vol. 39: pp. 293-3012. Schiller G., Ansar A., Patz O., 2010, Advances in Science and Technology, vol. 72: pp. 135-1433. Tietz F., Buchkremer H.-P., Stöver D., 2002, Solid State Ionics, vol. 152-153: pp. 373-3814. Tietz F., Sebold D., Brisse A., Schefold J., 2013, J. Power Sources, vol. 223: pp. 129-13

Systematic Parameter Study on the Influence of Humidification and Current Density on SOEC Degradation

Within a joint project of German Aerospace Center (DLR) and Forschungszentrum JÜLICH solid oxide fuel cells have been electrochemically characterized and the influence of the current density and fuel gas humidity on the long-term stability of electrolysis operation have been investigated. In order to observe the time- dependent change in electrochemical behaviour of the fuel electrode supported cells, in-situ analysis with a special focus on impedance spectroscopy was utilized. DRT-analysis was applied to validate assumptions made for equivalent circuit fitting and to improve fitting quality and reliability. Four rate limiting processes (electrolyte, cathode, anode and mass transport) could be separated and it was possible to track their development during the 1000 h experiments, showing their individual degradation behaviour under the applied operating conditions. This information was used for a dependence study, while additionally post mortem analysis methods were applied.</jats:p