The virtual production simulation platform: from collaborative distributed simulation to integrated visual analysis

Computational simulations are used for the optimization of production processes in order to significantly reduce the need for costly experimental optimization approaches. Yet individual simulations can rarely describe more than a single production step. A set of simulations has to be coupled to each other to form a contiguous representation of a process chain. Eventually, simulated results have to be analyzed by domain experts to gather insight from the preformed computations. In this paper, we propose an IT infrastructure and software tools that aim at a rather non-intrusive way of coupling resources and domain expert’s knowledge to enable the collaborative setup, execution and analysis of distributed simulation chains. We illustrate the approach in the domain of materials processing. Beyond means originating from the domain of GRID computing for resource management, a data integration component assures semantic data integrity between the simulation steps and stores simulation data in an application independent way. Thus, we can transform this data into native formats for each simulation tool, and finally into a format that allows for contiguous visualizations and an intuitive, comprehensive analysis of complete simulated process chains.     

Application of Gate Turn-Off Thyristors in 460-V 7.5-250-hp AC Motor Drives

A 7.5-250-hp range of variable-frequency ac motor drives has been under development at the Westinghouse R & D Center since early in 1981. Design and performance details for prototype equipment rated for 10, 20, and 50 hp will be discussed. The drive system comprises a three-phase thyristor controlled ac/dc converter in conjunction with a dc/ac adjustable-frequency inverter using gate turn-off thyristors (GTO's). The output of the inverter is a six-step voltage wave in the range of 6-120 Hz, suitable for driving three-phase ac induction or synchronous motors. Details of the inverter design, including means to protect the gate turn-off thyristors from output line-to-line or line-to-ground short circuits, will be given special attention.     

Weidmüller Ein-Bolzen-Klemme

ProdukteW-Reihe Gem?ss en 50 124-1

Weidmüller Ein-Bolzen-Klemme     

Multigrid Convergence of Calculated Features in Image Analysis

This paper informs about number-theoretical and geometrical estimates of worst-case bounds for quantization errors in calculating features such as moments, moment based features, or perimeters in image analysis, and about probability-theoretical estimates of error bounds (e.g. standard deviations) for such digital approximations. New estimates (with proofs) and a review of previously known results are provided.     

Untersuchungen zur Wirksamkeit von Benzyl-n-propyl-sulfid als Korrosionsinhibitor in sauren Lösungen

Investigations into the efficiency of benzyl-n-propyl sulfide as a corrosion inhibitor in acid solutions Investigations made so far into thioethers have shown that benzyl and phenyl sulfides, though being comparable from a structural point of views, may have very different inhibiting effects in the system iron-mineral acid. An attempt has therefore been undertaken to obtain further information about sorption and inhibition processes by using benzyl-n-propyl sulfide labelled with 35S. The protective effect of benzyl-n-propyl sulfide has been determined in sulfuric and hydrochloric acids under varying conditions of concentration, time, temperature and anions present, and the amount of inhibitor adsorbed to the metal surface was simultaneously measured. Other measurements were concerned with the adsorption of labelled anions from pickling acids with and without inhibitor.     

Single-bonded cubic form of nitrogen

Nitrogen usually consists of molecules where two atoms are strongly triple-bonded. Here, we report on an allotropic form of nitrogen where all atoms are connected with single covalent bonds, similar to carbon atoms in diamond. The compound was synthesized directly from molecular nitrogen at temperatures above 2,000 K and pressures above 110 GPa using a laser-heated diamond cell. From X-ray and Raman scattering we have identified this as the long-sought-after polymeric nitrogen with the theoretically predicted cubic gauche structure (cg-N). This cubic phase has not been observed previously in any element. The phase is a stiff substance with bulk modulus >or=300 GPa, characteristic of strong covalent solids. The polymeric nitrogen is metastable, and contrasts with previously reported amorphous non-molecular nitrogen, which is most likely a mixture of small clusters of non-molecular phases. The cg-N represents a new class of single-bonded nitrogen materials with unique properties such as energy capacity: more than five times that of the most powerfully energetic materials.