Computational engineering of metallic nanostructures and nanomachines

Small structures with dimensions in the nanometer regime play an important role within a lot of modern technological branches like, for example, genetics, chip fabrication, material science, medicine, or chemistry. While highly sophisticated characterization methods would be necessary to study such nanostructures, computational methods and models have made their entrance into the field of nanotechnology. The present work gives an overview of the problems connected with quantum mechanics, many-particle systems, and nanophysical models. Further, the application of molecular dynamics (MD)--a typical computational method suitable for modelling at the nanolevel--is introduced and outlined. The setup and use of specific MD models, advanced computation techniques, and efficient algorithms are discussed, while the focus is laid on the subjects nanodesign and nanoengineering which are demonstrated for the example of metallic nanostructures. Finally, the introduced techniques and methods are applied to stability studies of theoretical nanomachines.     

Untersuchung des betriebsähnlichen Hochtemperaturdehnwechselverhaltens des Stahles 28 CrMoNiV 4 9

Dehnwechselversuche mit betriebsähnlich schematisiertem Beanspruchungsverlauf bis rd. 7 000 h Dauer an einer Schmelze des Turbinenwellenstahles 28 CrMoNiV 4 9. Untersuchung betriebsähnlicher anisothermer, vergleichbarer isothermer und paketierter Zyklen. Vergleich der Ergebnisse mit denen aus Standarddehnwechselversuchen. Analyse von Spannungs-Dehnungs-Hysteresisschleifen. Gültigkeit der verallgemeinerten Schadensakkumulationsregel.     

Effect of chemical composition on the response of zwitterionic glucose sensitive hydrogels studied by design of experiments

A stimuli‐responsive hydrogel that contains the anionic monomer 3‐acrylamidophenylboronic acid and the cationic monomer N‐[3‐(dimethylamino)propyl]acrylamide binds with cis‐diol groups of glucose molecules selectively and reversibly. Even though such hydrogels have good selectivity for glucose, there are still remaining thresholds that should be overcome to enhance the sensitivity (swelling pressure response magnitude) and to reduce the response time (inverse of 1st order rate constant). In this study, the sensitivity and response time of zwitterionic glucose sensitive hydrogels (GSHs) were studied with three factor DOE analysis. The DOE results show that the molar ratio of 3‐acrylamidophenylboronic acid/N‐[3‐(dimethylamino)propyl]acrylamide and the wt % of monomer in the pregel solution are the most important factors for enhancing the hydrogel sensitivity. In addition, fast response times can best be achieved by decreasing the molar ratio of cross‐linker. The results of this study will be useful as guidelines for the optimal synthesis of glucose sensitive hydrogels. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40667.