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The present study deals with the simulation of the filling process in injection molding using Ansys CFX and its experimental validation. For this purpose, the filling process of an exemplary mold is investigated numerically as well as experimentally at different time steps. For the numerical investigation, a suitable model is elaborated in Ansys CFX, which enables such a comparison. In particular, the representation of a suitable viscosity model for polymers is not common in Ansys CFX. Therefore, the Carreau-WLF viscosity model is adapted for the considered polymer Schulamind 66 SK 1000 and integrated into Ansys CFX. The contribution focuses on the comparison of the numerically calculated flow front contour and the respective filling levels of the melt from experiments. Furthermore, a detailed numerical analysis of temperature and viscosity profiles is included in order to illustrate the effect of shear-induced temperature changes and the interplay between the temperature field and the viscosity of the injected polymer. In conclusion, the numerical model nicely fits the experimental results despite some slight deviations in the early filling stages.

A modern concept of producing nitriles involves aldoxime dehydratases, which are capable of dehydrating aldoximes to the corresponding nitriles without need of a cofactor. Aldoximes as the starting material for nitrile synthesis are easily prepared by condensation of hydroxylamine with the corresponding aldehydes. In this contribution we present chemoenzymatic cascade reactions toward nitriles consisting of an initial nitroxyl radical-catalyzed oxidation of aliphatic alcohols to aldehydes using sodium hypochlorite as the oxidation agent, subsequent condensation of the aldehyde with hydroxylamine, and a biocatalytic dehydration using aldoxime dehydratases to the corresponding nitriles without isolation of intermediates and using the product nitrile as a solvent. These formal "solvent-free" cascades open up the possibility to use biorenewable sources, namely fatty acids, as the starting material for a chemoenzymatic nitrile synthesis. We were also able to apply this cascade concept for the synthesis of aliphatic dinitriles, which are used as, e.g., a precursor for polymer building blocks. Overall yields without isolation of intermediates of up to 70% with very simple product isolation were achieved.

ZusammenfassungDer Beitrag setzt sich aus Teilnehmendensicht mit dem Modellprogramm „Karrierewege FH-Professur“ auseinander, das 2016 bis 2020 in NRW durchgeführt wurde und gibt Anregungen zu dessen Fort- und Weiterentwicklung.

The TEMPO‐catalyzed oxidation of alcohols to aldehydes has emerged to one of the most widely applied methodologies for such transformations. Advantages are the utilization of sodium hypochlorite, a component of household bleach, as an oxidation agent and the use of water as a co‐solvent. However, a major drawback of this method is the often occurring strict limitation to use dichloromethane as an organic solvent in a biphasic reaction medium with water. Previous studies show that dichloromethane cannot easily be substituted because a decrease of selectivity or inhibition of the reaction is observed by using alternative organic solvents. Thus, up to now, only a few examples are known in which after a tedious optimization of the reaction dichloromethane could be replaced. In order to overcome the current limitations, we were interested in finding a TEMPO‐oxidation method in alternative organic solvents, which is applicable for various alcohol oxidations. As a result, we found a method for N‐oxyl radical‐catalyzed oxidation using sodium hypochlorite as an oxidation agent in nitriles as an organic solvent component instead of dichloromethane. Besides the oxidation of aromatic primary alcohols also aliphatic primary alcohols, secondary alcohols as well as dialcohols were successfully converted when using this method, showing high selectivity towards the carbonyl compound and low amounts of the acid side‐product.

Peer support approaches are gaining increasing importance within the mental health sector as an effective way to assist people with mental and addictive disorders. This article explores peer support volunteers’ motives for voluntary engagement in a model project in Germany. It aims to gain a deeper understanding of peer support approaches and their underlying motivations in an innovative context. Twenty-three qualitative interviews with peer support volunteers were analyzed according to Mayring’s qualitative content analysis. Results showed that voluntary engagement fulfills a heterogeneous range of functions for peer support volunteers. Alongside “typical” volunteers’ motives, there were peer-specific functions such as motivation due to own personal experiences and the objective of changing societal attitudes toward mental health. Furthermore, the context of employment promotion played a motivational role: Many interview partners aimed to transform counseling structures within the institutions they had experienced as clients themselves.

Alcohol dehydrogenases catalyse the conversion of a large variety of ketone substrates to the corresponding chiral products. Due to their high regio- and stereospecificity, they are key components in a wide range of industrial applications. A novel alcohol dehydrogenase from Comamonas testosteroni (CtADH) was identified in silico, recombinantly expressed and purified, enzymatically and biochemically investigated as well as structurally characterized. These studies revealed a broad pH profile and an extended substrate spectrum with the highest activity for compounds containing halogens as substituents and a moderate activity for bulky–bulky ketones. Biotransformations with selected ketones—performed with a coupled regeneration system for the co-substrate NADPH—resulted in conversions of more than 99% with all tested substrates and with excellent enantioselectivity for the corresponding S-alcohol products. CtADH/NADPH/substrate complexes modelled on the basis of crystal structures of CtADH and its closest homologue suggested preliminary hints to rationalize the enzyme’s substrate preferences

Immobilization of biocatalysts is a current topic in research enabling the easy recovery of catalysts from the reaction medium after the reaction, and it is often accompanied by a stabilization of the catalysts, which enables recycling. Within our ongoing research on the utilization of aldoxime dehydratases in the cyanide-free synthesis of nitriles through dehydration of readily available aldoximes, a screening of different immobilization methods for free enzymes was performed. The applied immobilization methods are based on covalent binding and hydrophobic interactions of the enzyme with the carrier material and whole-cell immobilization in calcium alginate beads with and without subsequent coating. In our study, we found that the immobilization with purified free aldoxime dehydratases from OxdRE (Rhodococcus erythropolis) and OxdB (Bacillus sp. strain OxB-1) leads to high immobilization efficiencies, but also to a strong loss of activity with a residual activity of

Das Soziale ist der wesentliche Ort, der Identitaten und Praktiken von Menschen reguliert und koordiniert. Es stellt gleichermasen eine Tatsache und eine politisch-normative Arena dar, die den zentralen Bezugspunkt Sozialer Arbeit markiert. Dabei erscheint das, was ‚das Soziale‘ ist und was soziale Burgerschaft ausmacht, starker denn je mit dem verknupft, was die Soziale Arbeit praktisch tut.

Empirical evidence on the relationship between social support and post-disaster mental health provides support for a general beneficial effect of social support (main-effect model; Wheaton, 1985). From a theoretical perspective, a buffering effect of social support on the relationship between disaster-related stress and mental health also seems plausible (stress-buffering-model; ibid.). Previous studies however a) have paid less attention to the buffering effect of social support and b) they have mainly relied on interpersonal support (but not collective-level support such as community resilience) when investigating this issue. This work might has underestimated the effect of support on post-disaster mental health. Building on a sample of residents in Germany recently affected by flooding (N = 118), we show that community resilience to flooding (but not general interpersonal social support) buffered against the negative effects of flooding on post-disaster mental health. The results support the stress-buffering model and call for a more detailed look at the relationship between support/resilience and post-disaster adjustment, including collective-level variables.