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 Time-Resolved Fluorescence Spectroscopy on the Analysis of PAH-Coated Aerosols

A fiberoptic sensor system was developed for the detection of PAH-coated aerosols. It incorporates a pulsed nitrogen laser for excitation and a monochromator, a photomultiplier and a digital storage oscilloscope for recording of fluorescence decay curves. With a software-realized photon counting technique detection limits less than 100 ng/m³ for most of the PAHs investigated were achieved with NaCl as a substrate (e.g., 20 ng/m³ for benzo(e)pyrene on NaCl). The sensitivity of the system decreased dramatically when PAH adsorbed on carbon aerosol were analyzed. With pyrene on polydisperse NaCl aerosol the formation of excimers was observed and the formation kinetic could be analyzed. With benzo(e)pyrene on NaCl under similar conditions excimer fluorescence was observed but not the formation kinetic. This indicates the formation of micro-crystals of PAHs on aerosol surfaces even at surface coverages Θ ?1. Due to the observed matrix effects experiments were carried out, at which the PAHs were thermally desorbed in advance of the analysis. By this PAH fluorescence was measurable with carbon as matrix.     

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.     

Platinentechnologie auf dem Vormarsch

ProdukteHeraeus Sensor-Nite

Platinentechnologie auf dem Vormarsch     

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.     

Hautbr?unung und Lichtschutz -Grundlagen, Wirkstoffe und analytische Aspekte

Ohne Zusammenfassung

---

Skin tanning and light protection - theory, agents and analytical aspects

     

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.