Supramolecular discrimination of carbon nanotubes according to their helicity

Adsorption of specifically designed and geometrically constrained polyaromatic amphiphiles on single-walled carbon nanotubes (SWNTs) was found to be selective of the nanotube helicity angle. Starting from the same SWNT mixture, photoluminescence and resonant Raman spectroscopies show that a pentacenic-based amphiphile leads to the solubilization of armchair SWNTs and that a quaterrylene-based amphiphile leads to the solubilization of zigzag SWNTs. The results were predicted by the design of the two amphiphiles and are consistent with a supramolecular recognition of the nanotube graphene-type atomic structure by the aromatic part of the molecules through optimized pi-pi-stacking interactions.     

Extended arrays of vertically aligned sub-10 nm diameter [100] Si nanowires by metal-assisted chemical etching

Large-area high density silicon nanowire (SiNW) arrays were fabricated by metal-assisted chemical etching of silicon, utilizing anodic aluminum oxide (AAO) as a patterning mask of a thin metallic film on a Si (100) substrate. Both the diameter of the pores in the AAO mask and the thickness of the metal film affected the diameter of SiNWs. The diameter of the SiNWs decreased with an increase of thickness of the metal film. Large-area SiNWs with average diameters of 20 nm down to 8 nm and wire densities as high as 10 (10) wires/cm (2) were accomplished. These SiNWs were single crystalline and vertically aligned to the (100) substrate. It was revealed by transmission electron microscopy that the SiNWs were of high crystalline quality and showed a smooth surface.     

Studies on uptake and distribution of antibiotics in red cabbage

A large source of antibiotic active compounds and resistant bacteria is livestock waste, distributed as fertilizer on fields, used for vegetable cultivation. Frequently consumed vegetable, contaminated by low levels of antibiotics, may contribute to the development of bacterial antibiotic resistance. The objective of this work was to estimate the possible role of red cabbage as reservoir and carrier of antibiotic contaminants into the food chain. Red cabbage was exposed to antibiotics in hydroponic cultures and farming conditions. Enrofloxacin (ENR), chlortetracycline (CTC), monensin (MON) and amoxicillin (AMO) were separately added to nutrient solutions. Analysed by sequential extraction and LC–MS/MS methods, the plants revealed a remarkable uptake of CTC and in particular ENR (old leaves 0.22 mg/kg fresh weight (fw) CTC, 6.0 mg/kg fw ENR; roots up to 215.0 mg/kg fw CTC, 14.6 mg/kg fw ENR). The uptake of MON was significantly lower and AMO was not detectable. Red cabbage was also grown on manure-fertilized plots. The pig manure contained defined amounts of CTC and ENR (50 and 150 mg/kg). At harvest the edible parts of cabbage had between 9.2 to 16.9 µg/kg fw ENR, while there was no evidence obtained for the uptake of CTC. Finally, production steps of canned red cabbage were examined for carry over effects. Traces of tetracycline (16.4–19.2 µg/kg fw) were detected in supplies of freshly harvested vegetable, grown conventionally, but not in the marketable final product.     

WattsApp in Multiphase Systems by Gravity-Driven Buoyancy and Settling

Power and energy balances are described for simplified gravity-driven multiphase flows. It is emphasized that the power (→ Watts) or energy input by gravity impulse must be found back as the sum of all power or energy consumptions from the flow processes (→ Application). Examples are given for bubble columns and for batch liquid-liquid separation processes, based on simplified assumptions regarding the flow behavior. For large-scale apparatus, the flow characteristic of the involved phases is more complex and needs to be modeled more precisely. That is still a key challenge for scaling-up multiphase systems. Computational fluid dynamics is an adequate instrument but needs to be further developed and enhanced for multiphase flows in large-scale processes. And of course, any rigorous model must then be verifiable by a power balance.     

Efficient Automation Engineering of Modular Process Equipment Assemblies Using the Digital Twin

Modular process plants are a promising approach to accelerate the engineering of greenfield process plants. This is achieved by the combination of pre-engineered process equipment assemblies (PEAs) with a standardized interface for the integration in process control systems, the module type package (MTP). This standardized interface can be integrated in the engineering process to further improve the potential. In this paper existing standards are used to generate aspects of the MTP. For this purpose, the engineering process of conventional plants is adapted for the engineering of PEAs. Therefore, similarities and potential of the described aspects have been analyzed regarding shared fundamental standards and characterized by their location in the asset life cycle. To describe the interconnections of the different standards, exemplary rules are proposed, which can be used for a transformation.     

Integrierte Versuchsmethode zur Analyse des Matrizenfüllprozesses beim uniaxialen Trockenpressen

Die filling during dry compaction shaping operations is one important process step, which influences quality and complexity of the compacts as well as the processing speed. A method for characterizing the die filling behavior under process‐oriented conditions will be presented. By the use of a self‐constructed filling device, the filling progress can be visualized and quantified via image processing. The density structure of the resulting bulk in the die is analyzed using computer tomography. On the basis of experiments with ceramic granules the potential of the new method is shown.     

Semantics-aware detection of targeted attacks: a survey

In today’s interconnected digital world, targeted attacks have become a serious threat to conventional computer systems and critical infrastructure alike. Many researchers contribute to the fight against network intrusions or malicious software by proposing novel detection systems or analysis methods. However, few of these solutions have a particular focus on Advanced Persistent Threats or similarly sophisticated multi-stage attacks. This turns finding domain-appropriate methodologies or developing new approaches into a major research challenge. To overcome these obstacles, we present a structured review of semantics-aware works that have a high potential for contributing to the analysis or detection of targeted attacks. We introduce a detailed literature evaluation schema in addition to a highly granular model for article categorization. Out of 123 identified papers, 60 were found to be relevant in the context of this study. The selected articles are comprehensively reviewed and assessed in accordance to Kitchenham’s guidelines for systematic literature reviews. In conclusion, we combine new insights and the status quo of current research into the concept of an ideal systemic approach capable of semantically processing and evaluating information from different observation points.