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Godyn K.,Instytut Mechaniki Gorotworu Polskiej Akademii Nauk
Biuletyn - Panstwowego Instytutu Geologicznego | Year: 2011

Lower Carboniferous rocks of Western Pomerania are interesting in terms of petrographic composition containing fragments of volcanic rock (called volcaniclasts). This unique volcanic material is abundant in Lower Carboniferous sandstones. However, the volcanic clasts are present in all types of Lower Carboniferous sedimentary rocks of this zone. The paper presents an attempt of classification of clasts in volcanic rocks from the Koszalin-Chojnice zone. The volcaniclasts are divided into three main groups. Clasts were divided mainly according to their structural features. Some clasts have been indentified as parts of holocrystalline - felsitic rocks with the attributes of granophyric, poikilitic and spherolitic structures, and as grains of semi-crystalline rock structures with dendritic development. There are also some clasts showing different structural types combined. Parent rocks for the volcaniclasts were acidic igneous rocks from the quartz porphyry and quartz-free porphyry group (rhyolite-dacite series).

Kesek D.,Instytut Mechaniki Gorotworu Polskiej Akademii Nauk | Rachalski A.,Instytut Mechaniki Gorotworu Polskiej Akademii Nauk
Przeglad Elektrotechniczny | Year: 2014

This paper presents the method of simultanous measurement of low flow air velocity and thermal diffusivity. the idea of measurement consist of spectral analysis of thermal wave signal. As a wave source the themal MBS signal was applied. Some results of measurements for air flow of range 10-80 cm/s were presented. © 2014, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.

The petrographic features of hard coal coming from the Upper Silesian Coal Basin (USCB) coal seams are very different. Additionally some differences among them are associated with the influence of external tectonic factors on these formations. The coal with specific, "altered" structure appears very often near tectonic disturbances. This "altered" and in consequence structure-weakened coal creates seams of elevated risk of mine gases migration, and - due to their high porosity - increased gas capacity. Therefore, in such locations there is a higher risk of some dangerous dynamic phenomena like outbursts. Coal material which was analyzed came from three so called "outburst" mines from the USCB: Pniówek, Borynia- Zofiówka and Brzeszcze. The tested coal pieces were sampled from seams where local tectonic discontinuities occurred. A quantitative and qualitative description of the coal samples were performed by means of microscopic analysis. In the description maceral groups and type and degree of destruction of coal structure were taken into account. In the paper some preliminary results are presented with special consideration to the effect of maceral composition on the vulnerability of the coal formation and deformability of coal structure.

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