Petřvald is a typical mining town in the Czech part of the Upper Silesian Basin. Since the Petřvald sub-basin is limited by significant tectonic structures, its development was to a great extent independent from other areas of the basin and can serve as an example of the influence of the geological structure on the development of mining and residential communities. In the first phase of mining development (ca 1830 to 1844) first claims begin to occur in the area. Thick coal seams were available in shallow depths. Due to missing railway connection, the demand for coal was not very large and the village economy was focused on agriculture. In the second phase (1844 to 1871), the first underground mines start to operate in the area. They were situated in favorable areas with thin overburden. Also, the connection to the railway improved the sale opportunities and a significant share of the local population worked in the mines. The third phase of mining (1871 to 1963) brought still increasing demand for coal, which resulted in establishing new coal mines in geologically less favorable areas (thicker overburden, water-bearing horizons). From the 1930s to the end of the 1950s the extraction peaked, which coincided with the urbanistic and cultural climax. New housing was provided for miners and their families by the companies. The final stage of mining development (1963 to 1998) is connected with the steady decline of production and phase-out of mining. The reason was a lack of economically recoverable coal reserves connected to unfavorable geological conditions. We conclude that the results of studies concerning specific geological parameters of coal deposits can be used for more detailed analyses regarding the development of urbanism, or to explain its causes.

This article presents an overview of land use mapping work carried out in Poland. The authors discuss major early 20th-century publications and then review projects undertaken since WWII, pointing out the use of satellite imagery as a new source of data for land use mapping. They also discuss contemporary land use mapping programs pursued by international organizations in Europe, including in Poland. The outcome of work performed in Poland under the COR1NE Land Cover program is presented, and also the Land Cover Classification System developed by the FAO for the purposes of land use mapping is discusse

The aim of this paper is to examine individual social remittances in the sphere of employment, against the background of the changing employment patterns and flexibilisation of work. Through an analysis of life stories of post-accession return migrants from the UK to Poland, it investigates the way in which returnees’ work experience gathered abroad impacts on their perception of employment standards in general. The revealed differences are understood as ‘potential social remittances’, i.e. the discrepancies acknowledged by returnees between the realities experienced during emigration and after their return (in this case to Poland). It is argued that the actualisation of the ‘potential social remittances’ depends on return migrants’ coping strategies as well as on the institutional and structural settings in returnees’ home country. The four main distinguished strategies are: re-emigration, activism, adaptation and en-trepreneurship.

The paper presents a plane model of articulated vehicles worked out for the analysis of their dynamics. The dAlambert principle was used for derivation of motion equations for this system. The forces and moments acting on wheels were formulated on the basis of the Dugoff-Uffelmann tyre model. The system consists of any number of vehicles connected by kinematic pair of the 5th class (non friction joint of pivot-bush type) and the fifth wheel (with dry fricton). Since crash calculations usually take into account the impulse of crash force only, and since it is not appropriate for articulated vehicles, a new approach to crash calculation is presented in this paper. The authors propose to calculate the force in crash point both as a function of the relative velocity of vehicles and the stiffness of their bodies. Simulation results of articulated lorry crashes and the attempt to verify the performed simulation are presented in the article.

The paper presents a method of choosing parameters of a mathematical model for simulation of a working cycle of compression-ignition engine on the basis of experimental measurements. In order to choose the parameters of the model, the Nelder-Mead method has been used. As a result of such an approach, a simplified mathematical model with very good numerical effectiveness can be used for simulation of the working cycle of the engine, while very good compatibility of numerical results and experimental measurements is ensured. Suitable algorithms and results of calculations are presented.

Underground structures have gained importance in recent times all over the globe. Successful completion of such ventures hinges on accurate and realistic design which is neither optimistic nor conservative, and a balanced design is the need of the hour. The present work shows a comparative study on support design, such as Terzhagi’s load theory and quantitative methods of Rock mass quality (Q), Rock Mass Rating of Bieniawski, and PLAXIS-2D Numerical modeling. The results obtained show that final support measures such as shotcreting, thickness, rock bolting, length, frequency, and requirements of steel supports are better. Based on engineering judgment and analytical approaches, realistic support measures were obtained for an access tunnel to be excavated in Nilagiri, Tamil Nadu.

The paper provides a comparison of minimum air temperature (TN), maximum air temperature (TX), mean air temperature (T _mean) and a few derived temperature indices for Herschel Island (Qikiqtaruk) in the Yukon Territory, Canada for the periods 1899–1905 and 2008–2014. A significant increase in the TN was noted at +4.2°C, which was a larger increase than that for both T _mean (+3.7°C) and TX (+3.5°C). Air temperature increased the most in October, November, and December. In addition, the length of the frost-free season increased by 26 days and the length of the growing season increased by 25 days from the early 20th century to the early 21st century. The increase in the TN also triggered a change in the plant hardiness zone where Herschel Island is located. However, the daily air temperature range declined over the course of the study period as well as the annual total of heating degree days and the number of exceptionally cold days. No statistically significant change in the number of freeze-thaw days was found for the studied periods.

The author analyzes attitudes to the phenomenon of sexuality on the basis of two theoretical perspectives, the evolutionary and the feminist, between which there has long been conflict. In his opinion, however, they are only seemingly contrary. The main texts of both trends of thought concern entirely different problems and at the substantive level there is basically no contradiction between them. It is important that evolutionary theory often undermines existing cultural schemas, although this is rarely perceived by proponents of feminist theories. Evolutionists, in turn, rather too often identify feminism with radical social constructivism. Another extreme is a view that could be described as evolutionary sexism, consisting in justifying the gender status quo by reference to biological essentialism. After elimination of the extreme approaches, which are rare in any case, it is possible to use the results of evolutionary research in the debate over gender equality and to transform the two monologues into a cohesive dialogue; this, in the author’s opinion, is an important task for empirically oriented social theory.

This paper presents a unique case study and methodology for measurements of the bedload transport in the two, newly created troughs at the forefield of the Baranowski Glacier: Fosa and Siodło creeks. The weather conditions and the granulometric analysis are presented and discussed briefly. Rating curves for the Fosa and Siodło creeks are presented for the first time for this region. Changes of the bedload transport as well as water discharge and water velocity at both creeks are investigated. The hysteresis for the relationships between rate of bedload transport and water discharges were identified showing that for both creeks for the higher water levels a figure of eight loop may be easily recognized. Moreover, a new method for the calculation of bedload transport rate, based on the weighted arithmetic mean instead of the arithmetic mean, is proposed.