Erkenntnisse aus der Individualmarkierung im Wanderfalken-Baumbrüterprojekt

Das Wanderfalken-Baumbrüterprojekt wurde 1990 in Brandenburg begonnen, ab 1995 vom Landesjagdverband auch in Mecklenburg-Vorpommern und ab 2001 in Sachsen-Anhalt durchgeführt. Ziel ist es, den ehemals von Baumbrütern des Wanderfalken besiedelten Raum von der Weser bis Zentralrussland durch Auswilderung von auf Baumbrut geprägten Vögeln wieder für diese Art zu erschließen. Eine spontane Wiederbesiedlung durch Wanderfalken aus Fels- und Gebäudebruten ist aufgrund der Sonderstellung der Baumbrut bei dieser Art nicht zu erwarten

Waste-heat recovery and power generation with reciprocating motion

The utilization of renewable and waste heat from industrial processes is an important step towards the reduction of emissions and the increase in the efficiency of energy systems. This heat is available at different and mostly low grade temperatures (ca 100 °C to 550 °C) and various mass flow rates. The current work focuses on the understanding of the most important parameters that determine the potential efficiency of generalised heat engines from a technology agnostic perspective, followed by the development of modelling frameworks that correspond to two specific engines that can make use of heat sources at low temperature levels. The efficiency and power output of generalised heat engines when optimising different objective functions have been examined. These are the power output and the ecological- criterion value. The efficiency remains within upper and lower bounds, when varying the heat capacity of the heat source and heat sink, as well as the contact time between the external heat reservoirs and the working fluid. The corresponding power output variations are considerably higher than those observed for the efficiency. The power output reaches a maximum for values of the heat capacity of the heat source or sink larger than those of the working fluid or for contact times of the heat-exchange processes that are short or of approximately equal length. From these technology-agnostic considerations and the resulting limits that are imposed on the expected performance of real engines, we proceed to consider two specific technologies in the context of waste-heat recovery and power generation. The common feature of these technologies is that they involve reciprocating motion, either as part of a dedicated component (i.e., expander) or inherently as part of the overall operation of the entire device. The first engine, called Up-THERM, is a two-phase thermofluidic oscillator with low investment costs. A dynamic non-linear model framework of the Up-THERM has been developed. The dominant fluid or thermal effect in each engine component is described by a first-order differential equation. The temperature profile along the heat-exchanger walls has been validated experimentally. After the validation a parametric study has been performed examining the effects of five geometric parameters and the heat-source temperature on the engine’s performance. It is found that the heat-source temperature should be high for high power outputs, the volume of the gas spring small and the diameterof the displacer cylinder should be at its nominal value or somewhat larger. The Up- THERM engine has been compared with organic Rankine cycle (ORC) engines in terms of technical and economical performance. While for low temperature heat-sources the ORC engines have a higher power output, for higher heat-source temperatures this becomes comparable between the two engines. Due to the lower investment costs, the costs per unit power become lower for the Up-THERM engine at high heat-source temperatures. The second engine is an open cycle hot air Ericsson engine. It uses two reciprocating- piston cylinders as compressor and expander, inter-linked by a heat exchanger. It is particularly suitable for heat-sources at higher temperatures with small mass flow rates. The engine is described by a system of 12 equations. Pressure losses across valves, heat losses in the cylinders, friction and mass leakage are considered as loss mechanisms. Pres- sure losses and heat losses together account for 99% of the total losses. An optimisation using neural networks has been performed at five different heat-source conditions. Three operational and four geometric parameters are varied to maximise the power output of the engine. The net power output scales nearly linearly with the mass flow rate of the heat source. The thermal efficiency is constant at around 15% for a heat-source tem- perature of 350 °C and mass flow rates between 0.025 kg/s and 0.1 kg/s. The exergy efficiency increases with decreasing mass flow rate from 3.1% to 6.4%. For a heat-source mass flow rate of 0.1 kg/s the net power output increases from 1.9 kW at 250 °C to 7.2 kW at 350 °C and 48 kW at 450 °C. Higher heat-source temperatures also result in higher thermal efficiencies, but lower exergy efficiencies. Comparing the Ericsson to an equivalent ORC engine, which is a mature waste-heat recovery technology, reveals that the former can operate at lower thermal heat inputs, which allows operation over a wider range of applications with different heat-source mass flow rates. For comparable heat inputs and heat-source temperatures the power output and thermal efficiency of the Ericsson engine are higher than those of the ORC engine. Therefore, the Ericsson engine is an attractive alternative to existing waste-heat recovery technologies.Open Acces

Benchmarking whole exome sequencing in the German Network for Personalized Medicine

Introduction Whole Exome Sequencing (WES) has emerged as an efficient tool in clinical cancer diagnostics to broaden the scope from panel-based diagnostics to screening of all genes and enabling robust determination of complex biomarkers in a single analysis. Methods To assess concordance, six formalin-fixed paraffin-embedded (FFPE) tissue specimens and four commercial reference standards were analyzed by WES as matched tumor-normal DNA at 21 NGS centers in Germany, each employing local wet-lab and bioinformatics investigating somatic and germline variants, copy-number alteration (CNA), and different complex biomarkers. Somatic variant calling was performed in 494 diagnostically relevant cancer genes. In addition, all raw data were re-analyzed with a central bioinformatic pipeline to separate wet- and dry-lab variability. Results The mean positive percentage agreement (PPA) of somatic variant calling was 76% and positive predictive value (PPV) 89% compared a consensus list of variants found by at least five centers. Variant filtering was identified as the main cause for divergent variant calls. Adjusting filter criteria and re-analysis increased the PPA to 88% for all and 97% for clinically relevant variants. CNA calls were concordant for 82% of genomic regions. Calls of homologous recombination deficiency (HRD), tumor mutational burden (TMB), and microsatellite instability (MSI) status were concordant for 94%, 93%, and 93% respectively. Variability of CNAs and complex biomarkers did not increase considerably using the central pipeline and was hence attributed to wet-lab differences. Conclusion Continuous optimization of bioinformatic workflows and participating in round robin tests are recommend

Approaches to Destabilized 7-Norbornyl Cations

2-Oxo-7-norbornyl cations and l-eyano-7-norbornyl cations have been generated from various precursors, mostly derivatives of bicyclo[3.2.0]hep- tane. Whereas 2-bromobicyclo[3.2.0]heptan-3-one (17) solvolyzed exclusively with formation of 2-methoxybicyclo[3.2.0]heptan-3-ones (19,20), the analogous diazonium ion rearranged in part to give syn-7-methoxynorbornan-2-one (29). The epimeric 2-brosyloxybicyclo[3.2.0]heptane-2-carbonitriles (34,35) solvolyzed with predominant migration of C-7, yielding l-cyano-7-norbomyl derivatives without significant anti -*syn leakage. Similarly, the decomposition of 5-cyanobicyclo[3.2.0]heptane-2-diazonium ions (47) led to 7-hydroxynor- bornane-l-carbonitrile (38) in a stereospecific manner. Slightly lower stereoselectivity (ca 90%) was observed in solvolyses of labeled l-cyano-7-norbornyl triflate (39). While the stereochemical data conform with those of the parent system, the lack of bridge flipping (40242) points to graded destabilization of bridged and open ions