Hitherto existing investigations concerning the ceramic filter use in the steel making processes (both of laboratory and industrial scale) have given good results. The obtained results of filtration (in the industrial) have proved that this method may be used as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location in consideration of limiting the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters.
Influence of Slenderness Ratios of a Multi-Hole Ceramic Filters at the Effectiveness of Process of Filtration of Non-Metallic Inclusions from Liquid Steel
The paper presents the results of investigations of the process of filtration of solid non-metallic inclusions from liquid steel with use of multi-hole ceramic filters (filtrating surfaces) characterised by a varying slenderness ratios. In order to eliminate the negative influence of the ambient air atmosphere the investigations have been carried out under a protective argon atmosphere. The experimental results obtained have proved earlier suggestions of papers [9-12] about the negative influence of ambient air atmosphere, as well as the essential influence of slenderness ratio of the used multi-hole ceramic filter at the increase of effectiveness of the liquid steel refining processes carried out through steel filtration.
K. Zawirski, D. Janiszewski and R. Muszynski
This paper describes a study and the experimental verification of sensorless control of permanent magnet synchronous motors using Kalman filters. There are proposed two structures, extended and unscented Kalman filters, which use only the measurement of the motor current for on-line estimation of speed, rotor position and load torque reconstruction. The Kalman filter is an optimal state estimator and is usually applied to a dynamic system that involves a random noise environment. These structures are described in detail, starting with the selection of the variables state vector, the filters structure, and ending with in-depth laboratory tests. It has become possible, without using position and torque sensors, to apply these control structures as a cost-effective solution. Experimental results confirm the validity of the proposed estimation techniques.
J. Willner, A. Fornalczyk, J. Cebulski and K. Janiszewski
Automotive catalytic converters have a limited life time, after which the catalyst must be replaced or regenerated. The spent catalytic converters contain small amount of precious metals. Recovery of these metals is essential for environmental and economic reasons. The waste electronic equipment is also an attractive source for recovery of precious metals. Precious metals in electronic scraps are concentrated mainly in printed circuits and integrated circuits - so generally in elements that are the most diverse in their composition. Material heterogeneity of these elements is the reason why there is no universal method for processing this type of scrap. Methods used in the world for recovery of precious metals from spent auto catalytic coverters and electronic wastes by pyrometallurgical and hydrometallurgical methods were mentioned in this paper. The results of simultaneous melting of electronic waste with spent automotive catalysts were presented. The printed circuit boards were used as the carrier and as a source of copper. The precious metals present in the catalyst were collected in copper.
K. Śmietanka, Z. Minta, R. Włodarczyk, K. Wyrostek, M. Jóźwiak, M. Olszewska, P. Minias, K. Kaczmarek, T. Janiszewski and A. Kleszcz
Avian influenza viruses in wild birds at the Jeziorsko reservoir in Poland in 2008-2010
During a 3-year surveillance study for avian influenza virus (AIV) infections at the Jeziorsko reservoir in central Poland, 549 oropharyngeal or cloacal swabs from 366 birds of 14 species belonging to 3 orders (Anseriformes, Charadriiformes and Gruiformes) were tested. AIV was detected in 14 birds (3.8%): Common Teals (12x), Mallard (1x) and Garganey (1x). Three potentially dangerous H5 AIV were detected in Common Teals (2x) and Garganey (1x) but all of them revealed a low pathogenic pathotype. A unique cleavage site amino acid motif PQREIR*GLF was found in one H5 isolate from a Garganey.