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Andrzej Sikora and Ewa Niewiadomska-Szynkiewicz

A Federated Approach to Parallel and Distributed Simulation of Complex Systems

The paper describes a Java-based framework called ASimJava that can be used to develop parallel and distributed simulators of complex real-life systems. Some important issues associated with the implementation of parallel and distributed simulations are discussed. Two principal paradigms for constructing simulations today are considered. Particular attention is paid to an approach for federating parallel and distributed simulators. We describe the design, performance and applications of the ASimJava framework. Two practical examples, namely, a simple manufacturing system and computer network simulations are provided to illustrate the effectiveness and range of applications of the presented software tool.

Open access

Maciej Kaliski, Marcin Krupa and Andrzej Sikora

Abstract

The paper addresses the problem of the forecasting and possible development of gas production from unconventional plays in Poland. As authors underline the potential of Polish shale gas is quite similar to US shales. Due to geological conditions, stage of development, size and location in more urban areas some experts compare Polish shale plays to Marcellus even. Document stated that from geographical and infrastructural points of view one can identify five different directions for export of natural gas surplus from Poland. It is important to notice that currently none of those routes physically exists - it means, that at present there are no infrastructure (or access to such infrastructure) for exporting of the Polish natural gas.

Open access

Andrzej Sikora, Łukasz Bednarz, Tomasz Fałat, Marek Wałecki and Maria Adamowska

Abstract

In this paper we present the results of investigation of micro- and nanoscale degradation of a sheet moulded composite exposed to simulated solar radiation. Utilization of high resolution methods such as atomic force microscopy, optical profilometry and microcomputer tomography allowed us to provide the evidence of significant deterioration of the surface as well as the material few microns in depth. Additionally, the typically used macroscopic investigations, such as wettability and flexural strength, were performed to observe the impact of weathering process. It was also shown that high resolution techniques provide superior sensitivity of the material degradation detection. The particular effectiveness of the applied approach was related to the structure of investigated material, as due to its degradation, a number of voids appeared, causing a significant roughness increase. In addition, the impact of light radiation could be compared to other environmental conditions maintained in the climatic chamber. It should be underlined, that according to our knowledge, such a study has not been performed so far.

Open access

Magdalena Moczała, Miriam Karpińska, Monika Poznar, Piotr Dobryszycki and Andrzej Sikora

Abstract

This paper presents utilization of argon plasma for gradual etching of calcium carbonate crystals. The plasma treatment has been chosen as it appears to be the technique that enables removal of following material layers, thus, the access to the inside of crystals is possible. Examples of investigations of the morphology and mechanical properties of surfaces of calcium carbonate crystals are presented. The impact of plasma treatment has been verified in terms of roughness and volume changes investigated using atomic force microscopy technique in a multi-step experiment. Therefore, we were able to observe the crystal degradation process, revealing the spatial inhomogeneity of the calcium carbonate crystals resulting from their core-shell structure.

Open access

Andrzej Araźny, Krzysztof Migała, Sebastian Sikora and Tomasz Budzik

Meteorological and biometeorological conditions in the Hornsund area (Spitsbergen) during the warm season

Meteorological and biometeorological conditions during the warm seasons (June-September) of 1979-2008 are described for the Hornsund area, Spitsbergen. The measurements were taken at four sites: at Hornsund, at the Hans Glacier (at its equilibrium line and in the firn section) and at the summit of Fugleberget. The variation of meteorological and biometeorological conditions was analysed in relation to altitude, distance from the sea and the ground type. In warm seasons, the air temperature at Hornsund was 2.2 °C higher on average than at the Hans Glacier (central section) and by 2.8 °C than at the Hans Glacier (firn section) and at Fugleberget. The average wind speed recorded at Hornsund was higher (0.6 m s-1) than at the Hans Glacier and lower (0.9 m s-1) than at Fugleberget. Four biometeorological indices were used: wind chill index (WCI), predicted insulation of clothing (Iclp), cooling power (H) and subjective temperature index (STI). The strongest thermal stimuli were observed on the Hans Glacier and in the upper mountain areas. The study has found a considerable degree of spatial variation between the meteorological elements investigated and the biometeorological indices in the Hornsund area. The impact of atmospheric circulation on meteorological elements and biometeorological indices is also presented. The mildest biometeorological conditions of the warm season found at Hornsund were associated with air masses arriving from the southwest and west.

Open access

Lidia Gawlik, Maciej Kaliski, Jacek Kamiński, Andrzej P. Sikora and Adam Szurlej

Abstract

This paper reviews the coal policy of Poland. It analyzes the forecasts of production and consumption of hard coal, the size of exports and imports and its importance for the energy sector on the basis of strategic documents. The main aim of the article is to show the role of hard coal in the fuel - energy balance of Poland until 2050. The adoption of appropriate assumptions for each scenario, including the maximum supply of hard coal from domestic mines, coal price curves, CO2 emission allowances and several calculations performed allowed to obtain certain results on the basis of which the future role of hard coal was determined.

Open access

Andrzej Danilewicz and Zbigniew Sikora

Abstract

A theoretical base of SPH method, including the governing equations, discussion of importance of the smoothing function length, contact formulation, boundary treatment and finally utilization in hydrocode simulations are presented. An application of SPH to a real case of large penetrations (crater creating) into the soil caused by falling mass in Dynamic Replacement Method is discussed. An influence of particles spacing on method accuracy is presented. An example calculated by LS-DYNA software is discussed. Chronological development of Smooth Particle Hydrodynamics is presented. Theoretical basics of SPH method stability and consistency in SPH formulation, artificial viscosity and boundary treatment are discussed. Time integration techniques with stability conditions, SPH+FEM coupling, constitutive equation and equation of state (EOS) are presented as well.

Open access

Maciej Kaliski, Marcin Krupa, Stanisław Rychlicki, Jakub Siemek and Andrzej P. Sikora

Streszczenie

Artykuł poświęcony jest przeglądowi metod i sposobów estymacji kosztów otworów wiertniczych stoso- wanych na rynkach międzynarodowych (głównie na rynku północnoamerykańskim) oraz zawiera próbę aplikacji wybranej metody lub metod dla dostępnych danych odnośnie tego typu kosztów w basenach geologicznych w Polsce. Autorzy zajmują się wstępnym oszacowaniem przydatności tego typu estymacji dla modelowania i benchmarkingu efektywności prac poszukiwawczych i wydobywczych w Polsce. Na poziomie poszczególnych przedsiębiorstw poszukiwawczo-wydobywczych benchmarking i planowanie kosztowe są z reguły oparte na wypracowanych na różnorodnych złożach doświadczeniach i próbach optymalizacji technicznej i kosztowej całości procesu. W artykule zaproponowano i opisano wstępny algorytm do wyliczeń tych kosztów. Autorzy zwracają uwagę, że przydatność utworzonego na bazie równania (4) modelu do estymacji kosztów wierceń na podstawie głębokości docelowych formacji w Polsce jest mniejsza niż w na rynku amerykańskim, ale nadal bardzo wysoka. W przypadku analiz wykonywanych poza przedsiębiorstwami prowadzącymi prace poszukiwawczo- -wydob>|vcze może to być jedyne dostępne narzędzie do szacunkowych obliczeń kosztów otworów wiertniczych dla poszczególnych basenów geologicznych i docelowych głębokości.