A fast and robust hybrid method for block‐structured mesh deformation with emphasis on FSI‐LES applications

The present work introduces an efficient technique for the deformation of block‐structured grids occurring in simulations of fluid–structure interaction (FSI) problems relying on large‐eddy simulation (LES). The proposed hybrid approach combines the advantages of the inverse distance weighting (IDW) interpolation with the simplicity and low computational effort of transfinite interpolation (TFI), while preserving the mesh quality in boundary layers. It is an improvement over the state‐of‐the‐art currently in use. To reach this objective, in a first step, three elementary mesh deformation methods (TFI, IDW, and radial basis functions) are investigated based on several test cases of different complexities analyzing not only their capabilities but also their computational costs. That not only allows to point out the advantages of each method but also demonstrates their drawbacks. Based on these specific properties of the different methods, a hybrid methodology is suggested that splits the entire grid deformation into two steps: first, the movement of the block‐boundaries of the block‐structured grid and second, the deformation of each block of the grid. Both steps rely on different methodologies, which allows to work out the most appropriate method for each step leading to a reasonable compromise between the grid quality achieved and the computational effort required. Finally, a hybrid IDW‐TFI methodology is suggested that best fits to the specific requirements of coupled FSI‐LES applications. This hybrid procedure is then applied to a real‐life FSI‐LES case. Copyright © 2016 John Wiley & Sons, Ltd.     

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Ohne Zusammenfassung VDI     

In-house and interlaboratory validation of a method for the extraction of DNA from pollen in honey

In this work, the in-house and interlaboratory validation of a DNA extraction method from pollen in an unifloral rape honey as well as several multifloral honeys is described. The amplifiability of plant and rape DNA amplifiable by real-time PCR was used as a parameter for the evaluation of the method. The practical (i.e., relative) limit of detection was used as a tool for assessing the suitability of the extraction method for further GMO analysis. In a collaborative study with 14 participating labs the results of the in-house validation could be confirmed. The amount of amplifiable plant and rape DNA varied depending on the type of honey. For rape honey, a mean practical LOD of 0.12?% was obtained.     

A formal nethod (a networked formal method)

A year-long trial has seen a large lightweight verification problem treated by an ad hoc distributed network of identical solvers. The trialled problem is the semantic analysis of the C code in the Linux kernel to exclude a common deadlock possibility. The aim of the programme behind the experiment is to develop a viable loosely coupled distributed formal method which a community of interested part-time helpers on the net can lend their computing cycles to as they will, or send their own verification problems to for solving.     

Experimental detection of laminar‐turbulent transition on a rotating wind turbine blade in the free atmosphere

This paper discusses the findings from a measurement campaign on a rotating wind turbine blade operating in the free atmosphere under realistic conditions. A total of 40 pressure sensors together with an array of 23 usable hot‐film sensors (based on constant temperature anemometry) were used to study the behavior of the boundary layer within a specific zone on the suction side of a 30 m diameter wind turbine at different operational states. A set of several hundreds of data sequences were recorded. Some of them show that under certain circumstances, the flow may be regarded as not fully turbulent. Accompanying Computational Fluid Mechanics (CFD) simulations suggest the view that a classical transition scenario according to the growth of so‐called Tollmien–Schlichting did not apply. Copyright © 2016 John Wiley & Sons, Ltd.     

A review of copper cyanide recovery technologies for the cyanidation of copper containing gold ores

Many gold producers are today processing gold ores containing significant amount of cyanide soluble copper. Typically, cyanide destruction is used to prevent the discharge of copper cyanide into tailings storage facilities. This imposes a significant financial cost to producers from the additional cyanide used to solubilize the copper and the cost of cyanide destruction reagents. Therefore, the recovery of copper as a valuable by-product and the recycle of cyanide to the leach circuit have the potential for significant economic and environmental benefits. This includes enabling the treatment of gold ores with even higher soluble copper. Over the years, a variety of processes have been developed or proposed to recover the copper and/or cyanide including acidification based technologies such as AVR and SART, direct electrowinning, activated carbon, ion exchange resins, solvent extraction, polychelating polymers, and membrane technologies. In this paper, these processes are critically reviewed and compared, with particular focus on the advantages and limitations, and the separation of copper from cyanide. Ultimately, there is no universal process solution and the choice is highly dependent on the nature of the stream to be treated and integration with the whole processing plant.     

Amorphous ternary rare-earth gate oxides for future integration in MOSFETs

In this contribution we present results on the structural and electrical properties of amorphous REScO₃ (RE = La, Gd, Tb, Sm) and LaLuO₃ thin films. The study reveals that these oxides are potential candidates for so-called higher-k dielectrics for forthcoming MOSFET generations. High dielectric constants up to 32, low leakage currents and low interface trap densities are determined for amorphous thin films prepared by pulsed-laser deposition, molecular beam deposition and e-gun evaporation. Moreover, we show that LaLuO₃ gate stacks annealed up to 1050 °C maintain low leakage current densities without substantial EOT increase. Finally, promising results for n-MOSFETs with GdScO₃ as gate dielectric processed on strained silicon-on-insulator substrates are also shown.