Polygeneration-Annex: Integrating hydrogen into syngas-based gasoline production

As a result of the rising share of renewable energy in Germany, suitable energy storage solutions are needed. At the same time, existing base-load lignite-fired power plants suffer from low capacity utilization and frequent load changes. In combination with a Coal-to-Liquids (CTL) facility, the power generation utilization might increase. By using the existing power plant infrastructure, investment costs for the CTL facility can be reduced. Such combined polygeneration concepts, called ’Annex’, have been developed at TU Bergakademie Freiberg. Previously, polygeneration concepts based on Methanol - to - Gasoline (MTG), Methanol - to - Olefins and Fischer - Tropsch synthesis have been analyzed. In addition, the Annex CTL plant can be used to store energy by incorporating renewable hydrogen from electrolysis into the synthesis step. Such a concept offers the advantage to lower CO₂ emissions and could be used to store renewable excess power. In the current study, concepts based on entrained-flow gasification and MTG synthesis are analyzed. This concept is compared to a stand-alone synthesis route. Linking a 52 MW_el alkaline water electrolysis to the synthesis plant, hydrogen can be integrated in the CTL plant. Four different concepts for hydrogen integration are investigated. Fluctuations in hydrogen supply could be counter-balanced through storage tanks or Demand Side Management in the CTL Annex plant. A techno-economic study is conducted using the commercial software package Aspen Plus. An analysis of efficiencies, carbon emissions and production costs is provided. An overall system efficiency of 36.5–37.6% is determined.     

Eine „typische“ hydrogeologische Systembeschreibung für den Buntsandstein

On the site of a former ammunition factory in Hessisch-Lichtenau/Hirschhagen in northern Hesse, a large number of boreholes and groundwater monitoring wells were installed as part of a remediation and containment plan. Hydraulic testing over a period of 20 years has significantly improved the understanding of the hydrogeological system. The alternating sandstone, siltstone and claystone formations of the Middle Buntsandstein at the site constitute a succession of aquifers, semi-pervious layers and aquicludes. The subsurface is fractured by step faults and is also permeated by tectonic faults and fissures. This results in a heterogeneous, anisotropic system in which water circulates primarily through permeable fault zones. The aquifer consists of three different zones that are connected through preferential pathways along fault lines. The Upper Zone (Hirschhagen) and the Intermediate Zone are perched aquifers that enable groundwater seepage to lower aquifers. In all three zones, preferential flow paths were observed along north-south striking fault lines.     

Die Kontrolle des Umsetzungsgrades des Zugangs- und Zugriffsschutzes

Rechtlich verpflichtende Datenschutzkontrollen im Cloud-Umfeld stellen den Cloud-Nutzer vor eine große Herausforderung. Zusammen mit der Verantwortlichkeit für die in der Cloud verarbeiteten Daten und den immer noch weitverbreiteten Datenschutzbedenken gegen Cloud-Dienste, stellen diese einen Hemmschuh für die Nutzung von Cloud-Diensten dar. Teilautomatisierte Datenschutzkontrollen, die dem Cloud-Nutzer im laufenden Betrieb den Umsetzungsgrad von Datenschutzzielen anzeigen, können dieser Barriere begegnen. Dieser Beitrag schlägt ein Vorgehen für eine teilautomatisierte Messung der Datenschutzziele des Zugangs- und Zugriffsschutzes vor.     

Biosynthesis of Nudicaulins: A 13CO2‐Pulse/Chase Labeling Study with Papaver nudicaule

Nudicaulins are unique alkaloids responsible for the yellow color of the petals of some papaveraceaous plants. To elucidate the unknown biosynthetic origin of the skeleton, a ¹³CO₂‐pulse/chase experiment was performed with growing Papaver nudicaule plants. ¹³C NMR analysis revealed more than 20 multiple ¹³C‐enriched isotopologues in nudicaulins from the petals of ¹³CO₂‐labeled plants. The complex labeling pattern was compared with the isotopologue composition of a kaempferol derivative that was isolated from petals of the same ¹³CO₂‐labeled plants. The deconvolution of the labeling profiles indicated that the nudicaulin scaffold is assembled from products or intermediates of indole metabolism, the phenylpropanoid pathway, and the polyketide biosynthesis. Naringenin‐type compounds and tryptophan/tryptamine are potential substrates for the condensation reaction finally generating the aglycone skeleton of nudicaulins.     

On the intrinsic complexity of point finding in real singular hypersurfaces

In previous work we designed an efficient procedure that finds an algebraic sample point for each connected component of a smooth real complete intersection variety. This procedure exploits geometric properties of generic polar varieties and its complexity is intrinsic with respect to the problem. In the present paper we introduce a natural construction that allows to tackle the case of a non-smooth real hypersurface by means of a reduction to a smooth complete intersection.     

Biomimetic Architectures for the Impedimetric Discrimination of Influenza Virus Phenotypes

Rapid discrimination of avian vs. human phenotypes of emerging influenza A virus isolates with pandemic potential is an important issue in pathogenesis and epidemiology studies of the infection. In this work, functional architectures are tailored on the surface of a gold electrode, introducing receptor molecules as a sensing entity that mimics those found in the membrane of target cells of the influenza A virus and with the aim of developing an impedimetric‐based detector for influenza A virus phenotyping. In a bottom‐up approach, the artificial receptors are built by sequential assembly of a 1‐octanethiol/octyl‐galactoside hybrid bilayer, followed by an enzyme‐mediated functionalization of the terminal galactoside groups with sialic acid molecules. The detection mechanism relies hence on the specific affinity between the sialic acid‐galactose receptor moieties anchored on the modified electrode surface and the hemagglutinin (HA) viral surface protein. By using the appropriate type of sialyltransferase enzyme, sialylation of galactose residues is made through α‐2,3 or α‐2,6 linkages. This permits the envisaged impedimetric detector to discriminate rapidly between avian vs. human strains of influenza A virus with the absence of elaborate sample preparation steps. In contrast to immunosensors based on antibodies as bioreceptor, the sialylated modified gold electrode is also able to distinguish among influenza phenotypes, which could make the here presented detector a reagentless, label‐free diagnostic device for influenza phenotyping.