The simultaneous addition of styrene maleic anhydride copolymer and multiwall carbon nanotubes during melt‐mixing on the morphology of binary blends of polyamide6 and acrylonitrile butadiene styrene copolymer

The effect of simultaneous addition of multiwall carbon nanotubes (MWNTs) and a reactive compatibilizer (styrene maleic anhydride copolymer, SMA) during melt‐mixing on the phase morphology of 80/20 (wt/wt) PA6/ABS blend has been investigated. Morphological analysis through scanning and transmission electron microscopic analysis revealed finer morphology of the blends in presence of SMA + MWNTs. Fourier transform infrared spectroscopic analysis indicated the formation of imide bonds during melt‐mixing. Non‐isothermal crystallization studies exhibited the presence of a majority faction of MWNTs in the PA6 phase of 80/20 (wt/wt) PA6/ABS blend in presence of SMA + MWNTs. Rheological analysis, dynamic mechanical thermal analysis, and thermogravimetric analysis have demonstrated the compatibilization action of simultaneous addition of a reactive compatibilizer (SMA copolymer) and MWNTs in PA6/ABS blends. An attempt has been made to investigate the role of simultaneous addition of SMA copolymer and MWNTs on the morphology of 80/20 (wt/wt) PA6/ABS blend through various characterization techniques. POLYM. ENG. SCI., 55:457–465, 2015. © 2014 Society of Plastics Engineers     

Aryl Bis‐Sulfonamide Inhibitors of IspF from Arabidopsis thaliana and Plasmodium falciparum

2‐Methylerythritol 2,4‐cyclodiphosphate synthase (IspF) is an essential enzyme for the biosynthesis of isoprenoid precursors in plants and many human pathogens. The protein is an attractive target for the development of anti‐infectives and herbicides. Using a photometric assay, a screen of 40 000 compounds on IspF from Arabidopsis thaliana afforded symmetrical aryl bis‐sulfonamides that inhibit IspF from A. thaliana (AtIspF) and Plasmodium falciparum (PfIspF) with IC₅₀ values in the micromolar range. The ortho‐bis‐sulfonamide structural motif is essential for inhibitory activity. The best derivatives obtained by parallel synthesis showed IC₅₀ values of 1.4 μm against PfIspF and 240 nm against AtIspF. Substantial herbicidal activity was observed at a dose of 2 kg ha^?1. Molecular modeling studies served as the basis for an in silico search targeted at the discovery of novel, non‐symmetrical sulfonamide IspF inhibitors. The designed compounds were found to exhibit inhibitory activities in the double‐digit micromolar IC₅₀ range.     

Stochastic modeling of grain wear in geometric physically-based grinding simulations

Grinding processes can be optimized by simulating the influence of individual grains on process forces and surface topographies. However, the process results are significantly influenced by tool wear. Simulating this effect allows, e.g., the prediction of necessary tool changes when manufacturing large forming tools. Therefore, a new point-based approach for modeling arbitrarily shaped grains in different states of tool wear was developed. Based on a small amount of representative wear investigations, a flexible tool model was defined, which can be used for various tool shapes without further experiments. This model can be applied for grinding processes with varying engagement situations.     

Zur Feuchteproblematik in Eissporthallen

Aufgrund vieler Untersuchungen zur Standsicherheit von Eissporthallen wurde festgestellt, dass diese in unterschiedlichem Maße saniert werden müssen. Die Holzfeuchtigkeit der Tragkonstruktionen betrug meistens langanhaltend über 20 %. Daher wurden Untersuchungen zu den Ursachen hoher Holzfeuchten in Eissporthallen durchgeführt. Eine der Ursachen liegt in dem Strahlungsaustausch zwischen der Hallendecke und der Eisfläche. Zu dieser Problematik wurden Versuche durchgeführt und daraus mögliche Verbesserungsvorschläge für Eissporthallen abgeleitet. About the humidity problem in ice rinks. After expertising the structural safety of several ice rinks, it was detected that the constructions of several buildings have to be redeveloped. The long lasting wood moisture of the main structure was predominantly over 20 %. Therefore research into the reason of high wood moisture in ice rinks was made. One fact is the exchange of radiation between the ceiling and the ice. This problem was analysed in tests and suggestions for improvement are made.     

Physiological relevance of food grade microcapsules: Impact of milk protein based microcapsules on inflammation in mouse models for inflammatory bowel diseases

In order to increase beneficial effects of bioactive compounds in functional food and dietary supplements, enormous efforts are put in the technological development of microcapsules. Although these products are often tailor‐made for disease susceptible consumer, the physiological impact of microcapsule uptake on the respective target consumer has never been addressed. The present study aimed to assess the relevance of this aspect by analyzing the impact of milk protein based microcapsules on experimental inflammatory bowel disease. Long‐term feeding of sodium caseinate or rennet gel microcapsules resulted in significant alterations in the intestinal microbiota of healthy mice. In TNFΔARE/wt mice, a model for chronic ileal inflammation, rennet gel microcapsules resulted in further increased splenomegaly, whereas ileal inflammation was unchanged. In IL10^?/? mice, a model for chronic colitis, both types of microcapsules induced a local increase of the intestinal inflammation. The present study is the first to demonstrate that, independent of their cargo, microcapsules have the potential to affect the intestinal microbiota and to exert unprecedented detrimental effects on disease‐susceptible individuals. In conclusion, the impact of microcapsule uptake on the respective target consumer groups should be thoroughly investigated in advance to their commercial use in functional food or dietary supplements.     

A method for determination of length distributions of multiwalled carbon nanotubes before and after melt processing

A relatively simple method to determine the length distribution of carbon nanotubes (CNTs) before and after melt processing was developed. This involves the selection of a suitable solvent for dispersing pristine CNTs as well as to dissolve the matrix of melt mixed composites and the choice of an appropriate nanotube concentration. The length of suitably individualized CNTs was visualized using transmission electron microscopy and length distributions were measured using image analysis. Examples are shown for Baytubes® C150HP and Nanocyl™ NC7000 and their melt mixed composites with polycarbonate where the same procedure was applied to both, measuring the initial length distribution and the distribution after recovering from the composites. These results indicated a significant shortening after melt processing up to 30% of the initial length.