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Kraków, Poland

Dybiec H.,al. Mickiewicza
Physica Status Solidi (A) Applications and Materials Science | Year: 2010

Rapid crystallization is a well-known method for production of ultrafine-grained metallic materials using the overcooling effect. Unfortunately, this method provides material in dispersed form with very limited dimensions of individual particles, which must be consolidated to bulk form for engineering use. To prevent destabilization of ultrafine-grain structure of polycrystalline particles the consolidation process should to be quick enough and must be conducted at reasonably low temperatures. Such reasons suggest the process of plastic consolidation. In this process plastic deformation of individual particles develops new surfaces in status nascendi, which is able to create strong bonds between collectively deformed particles of dispersed materials and converts the powder to the bulk form. The plastic consolidation by isothermal extrusion is the agglomeration process of plastically deformable particles without involving diffusion effects. Bulk materials with no measurable porosity are the product of this process, in which the character of interaction among individual particles of powder shows similar character to interaction at grain boundaries in polycrystalline metals. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Lupa M.,al. Mickiewicza | Koziol K.,AGH University of Science and Technology | Lesniak A.,al. Mickiewicza
Communications in Computer and Information Science | Year: 2015

The paper presents a method for the simplification of building objects in multiresolution databases. The authors present a theoretical foundation, practical ways to implement the method, examples of results, as well as a comparison with currently available generalization methods in commercial software. This algorithm allows the verifiability and reproducibility of results to be kept while minimising graphic conflicts, which are a major problem during the automatic generalisation process. These results are achieved by defining the shape of buildings, employing classification rules and adopting minimum measures of recognition on a digital map. Solutions included in this paper are universal and can successfully be used as a component in any automated cartographic generalisation process. Moreover, these methods will help to get closer to full automation of the data generalisation process and hence the automatic production of digital maps. © Springer International Publishing Switzerland 2015. Source

Florkowska B.,al. Mickiewicza | Florkowski M.,ABB | Furgal J.,al. Mickiewicza | Pajak P.,al. Mickiewicza | And 2 more authors.
Przeglad Elektrotechniczny | Year: 2010

In-service stresses cause degradation of high voltage insulating systems. The assessment of the intensity and dynamics of these processes,being a consequence of local, working electric field strength is considered mainly at the sinusoidal voltage. However in applications where power electronics converters are used the voltage stress usually has a form of fast switching pulses composed of repetitive sequences. Such pulse trains usually pose a modulated width and fast rise- and fall-times. Such conditions have essential influence on inception and development of partial discharges in insulating systems subjected to a non-sinusoidal stimulus. The insulation degradation mechanism is especially important to cables and electrical machines subjected to non-sinusoidal waveforms. The paper presents the simulation results and experimental investigations of fast overvoltages at the electrical machines and influence of a fast switching stimulus on electrical insulation systems of electric machines, including partial discharge measurements and analysis. Source

Kamisinski A.,al. Mickiewicza | Cholda P.,al. Mickiewicza | Jajszczyk A.,al. Mickiewicza
ACM Computing Surveys | Year: 2015

In this tutorial, 17 structural complexity indices are presented and compared, each representing one of the following categories: adjacency- and distance-based metrics, Shannon entropy-based metrics, product measures, subgraph-based metrics, and path- and walk-based metrics. The applicability of these indices to computer and communication networks is evaluated with the aid of different elementary, specifically designed, random, and real network topologies. On the grounds of the evaluation study, advantages and disadvantages of particular metrics are identified. In addition, their general properties and runtimes are assessed, and a general view on the structural network complexity is presented. © 2015 ACM. Source

Grabowski K.,al. Mickiewicza | Zbyrad P.,al. Mickiewicza | Uhl T.,al. Mickiewicza
Key Engineering Materials | Year: 2014

In this paper there wasdevelopeda CNT based sensor applied to the tested material and integrated with it. MWCNTs weremixed with polymer and then applied to the materials (fiber glass composites)with the use of screen printing. The surface and the inner part of the sensing material were investigated using SEM. The most importantand noticeable thing was dispersion of CNTs in epoxy.Moreover, the sensors were tested under the different loads. There were three runs for the same compositions of CNT/epoxy. Results from the test runs were compared to the images from SEM and discussed. Screen printing technique has shown promising results for the application and integration of the sensors on the base materials leading to the conclusion to do more research for the screen printing technique for application of CNT/epoxy sensors for large area appliaction and variant environments. Copyright © 2014 Trans Tech Publications Ltd, Switzerland. Source

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