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Alexander Burkov, Evgenii Krasilnikyants and Alexander Smirnov

The Model of Nonstationary Rotor Magnetic Field Observer in the Induction Motor

This article is devoted to the questions, associated with observer construction for monitoring the values of rotor magnetic vector magnitude and angular deflection of induction motor oriented on bidimensional convolution on temporal and spatial actual parameters. The interrelation of induction motor breakdown torque and rotor characteristic time and transportation lag is shown. The system of rotor running stream observer on the basis of gage rotor position and stator current is put forward.

Open access

Alexander Smirnov, Jaroslav Pršek and Martin Chovan

Mineralogy and Geochemistry of the Nižná Boca Sb-Au Hydrothermal Ore Deposit (Western Carpathians, Slovakia)

Samples from hydrothermal Sb-Au mineralization in the area SE of Nižná Boca village in the N&iAzke Tatry Mountains were investigated using a variety of geochemical and mineralogical methods. Ore minerals typically occur in N-S striking quartz-carbonate veins hosted by an I-type biotite granodiorite to tonalite of Variscan Age (the Ďumbier Type). Paragenetic associations in the deposit are comparable to other mineralizations of the same type in the Ďumbierske Nízke Tatry Mountains. A quartz-arsenopyrite, pyrite stage of mineralization is the oldest with a calculated temperature of formation of about 445°C. It is followed by a quartz-carbonate-stibnite, zinkenite stage and, in turn, a quartz-carbonate-sphalerite-galena, boulangerite-gold stage. The gold typically contains between 9-18 wt.% Ag regardless of mineral association. No evidence for further generations of gold was found although it is possible that some gold was remobilized from the structure of the auriferous arsenopyrite. The Au and Ag content of the bulk ore ranges from 0.53 g.t-1 to 20.2 g.t-1 and from 0.9 g.t-1 to 31.2 g.t-1, respectively. A tetrahedrite-chalcopyrite stage is followed by a barite-hematite stage - the youngest assemblage in the deposit. Fluid inclusions from the first mineralization stage are usually less than 3 μm in size and contain less than 3.6 wt.% CO2; salinity, density and homogenization temperature range from 2.7-16.3 wt.% NaCl(eq), 0.85-1.03 g.cm-1 and 128-280°C, respectively.

Open access

Alexander Burkov, Evgenii Krasilnikyants, Alexander Smirnov and Georgy Bouldukan

Abstract

Wide use of induction motor drives makes the problems related to induction motors very topical. One of such problems is the maximal utilization of torque and velocity of induction motors. In this regard the use and accurate adjustment of rotor magnetic flux observers may be helpful. The technique of observer adjustment is subject of special interest. This technique can be regarded as optimal if it ensures constant acceleration that, in turn, corresponds to constant magnitude of active and magnetizing components of stator current. In contrast, nonoptimal tuning of the magnetic flux observer creates a transient response caused by variation of magnetic and active components of the stator current resulting in changing acceleration of the motor. However, the parameters of non-optimal process can be used for fine tuning of the observer which considers the variation of the time constants obtained analyzing the drive's magnetic circuit saturation. It is possible to conclude that implementation of fine adjustment of rotor magnetic flux observer is of critical importance for induction motor torque and velocity maximum utilization.

Open access

Jaroslav Prşek, Emil Makovicy, Martin Chovan and Alexander Smirnov

A Note on the Chemical Composition of Nuffieldite Solid-Solution From Sulphide Mineralizations in the Western Carpathians, Slovakia

The chemistry of the rare sulphosalt nuffieldite from three localities in Slovakia is examined. Nuffieldite is a part of a complex association of Bi sulphosalts accompanying tetrahedrite mineralization in some sulphide deposits in the Western Carpathians. Cu + Pb = (Bi, Sb) + vac. substitution in nuffieldite and the general formula Cu1+xPb2Bi2(PbxSbyBi1-x-y)S7 where 0 < x < 0.34; and 0.32 < y < 0.45 are confirmed. Decreasing Sb content with increasing copper content indicates a predominant substitution of Bi by Sb in nuffieldite.

Open access

Kurt Sandkuhl, Ulf Seigerroth, Alexander Smirnov, Tatiana Levashova and Nikolay Shilov

Abstract

This work investigates the use of enterprise models for service configuration with a focus on knowledge related to organizational roles. Starting from an industrial case, it presents an approach to extract a role’s information demand from an enterprise model and to use this as initial configuration for agent-based services. In addition to the meta-model included in the enterprise modeling language, the use of a common ontology is proposed which captures both, the perspective of information demand and services. The architecture of the agentbased services is following the idea to characterize all actors by their roles and to represent them by sets of services. This approach facilitates self-organization in the service level. The main contributions of the paper are (1) to show that a role’s information demand is relevant for service configuration, (2) to present a way of extracting information demand from enterprise models, and (3) to extend an approach for SOA-based enterprise representation with information demand.