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Number of results: 8
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Abstract

We propose a class of m-crane control systems, that generalizes two- and three-dimensional crane systems. We prove that each representant of the described class is feedback equivalent to the second order chained form with drift. In consequence, we prove that it is differentially flat. Then we investigate its control properties and derive a control law for tracking control problem.
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Abstract

Luminescence dating is based mainly on the dosimetric properties of quartz and feldspar. These minerals are among the most popular found on Earth, resulting in the possibility of using luminescence methods in practically any environment. Currently, quartz remains the best recognized mineral in terms of dosimetric properties, particularly with regards to results obtained for quartz grains, which are regarded as being the most reliable in luminescence dating. Supporters of luminescence methods are constantly growing, however, these groups do not always have sufficient knowledge to avoid even the most basic of issues that may be encountered overall – from the process of sampling through to the awareness of what a single luminescence result represents. The present paper provides an overview of several practical aspects of luminescence dating such as correct sampling procedures and all necessary information regarding the calculation of the dose rate and equivalent dose with particular reference to potential problems that occur when the age of the sample is being determined. All these aspects are crucial for obtaining a reliable dating result, on the other hand, they remain a potential source of uncertainty.
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Abstract

The article offers a discourse-analytic examination of original (English) and interpreted (Polish) versions of several extracts from plenary speeches by three Members of the European Parliament (Janusz Korwin-Mikke, Nigel Farage and Guy Verhofstadt). Controversial statements that have met with adverse reactions of the audience and/or the media are selected for analysis. The author endeavours to assess the degree to which pragmatic equivalence has been achieved by Polish interpreters. Another pertinent question is whether the identifi ed shifts are due to some systemic differences between the pragmatics of the source and target languages or to other factors, such as the constraints typical for simultaneous interpreting or specific, local problems.
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Abstract

The paper analyzes the monthly day equivalent levels, Lday (06–22 h) and night equivalent levels, Lnight (22–06 h) values observed in year 2015 and 2016 for the 70 locations whereby continuous noise monitoring is conducted under the National Ambient Noise Monitoring Network (NANMN). The study exclusively analyzes the ambient noise data acquired for 25 locations in commercial zone, 12 in industrial, 16 in residential and 17 in silence zones. The analysis of (Lday–Lnight) for 70 locations under observations reveals that 10 dB night time adjustment in day-night average sound level descriptor is not appropriate in such a scenario and as such it is recommended to use day-night average sound level and day-eveningnight average sound level descriptors without any 10 dB night time adjustment or 5 dB evening time adjustments. The analysis and conclusions of the present study shall be very useful for developing single value noise descriptor correlating the noise annoyance and health effects in Indian perspectives.
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Abstract

The article discusses changes in Polish regulations concerning assessment of the climate hazard in underground mines. Currently, the main empirical index representing the heat strain, used in qualification of the workplace to one of the climate hazard levels in Poland is the equivalent climate temperature. This simple heat index allows easy and quick assessment of the climate hazard. To a major extent, simple heat indices have simplifications and are developed for a specific working environments. Currently, the best methods used in evaluation of microclimate conditions in the workplace are those based on the theory of human thermal balance, where the physiological parameters characterising heat strain are body water loss and internal core temperature of the human body. The article describes the results of research on usage of equivalent climate temperature to heat strain evaluation in underground mining excavations. For this purpose, the numerical model of heat exchange between man and his environment was used, taken from PN-EN ISO 7933:2005. The research discussed in this paper has been carried out considering working conditions and clothing insulation in use in underground mines. The analyses performed in the study allowed formulation of conclusions concerning application of the equivalent climate temperature as a criterion of assessment of climate hazards in underground mines.
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Abstract

The “Sulmierzyce-Odolanów” study area analyzed in the present paper constitutes an example of the presence of deep Zechstein metallic mineralization in the Fore-Sudetic Monocline. Unlike the shallow deposits which are being mined nowadays, these types of areas were not previously considered in terms of their possible extraction. However, in recent years, due to the development of modern mining technologies, this situation has changed and these areas have become prospective for the future documenting of mineral deposits. The threshold parameters delimiting an ore deposit, recommended for use when preparing geological documentation and not compulsory, have been established by the regulation of the Minister of Environment. In the case of stratabound Zechstein deposits they take the equivalent percentage and productivity of only two metals, i.e. copper, as the main useful component, and silver into account. This leads to the underestimation of the resources of ore which also contains other metals, including zinc and lead, which is particularly disadvantageous in the case of deep deposits, which from an economic standpoint, it is advisable to focus on their richest parts and to document, and in the future to extract all the useful metals. Also, the regulation of the Minister of Environment does not take into account the fluctuations of the market prices of metals over time, the impact of which on the equivalent content and productivity of these elements in the deposit is considerable. This paper presents the authors’ own formulas intended to calculate polymetallic equivalent content and productivity taking the share of four elements in the ore into account: copper, silver, zinc and lead. They also enable determining these values for arbitrarily selected time intervals and tracing their changes over time. Apart from the quality parameters it is also possible to calculate the value of mineral resources in the deposit expressed in American dollars per one square meter of its area for each selected time interval. The calculations used the results of chemical analyses of historical drill cores originating from the studied area. A total of 135 historical holes located within its boundaries were analyzed. Based on the obtained figures, the time-varying resources of the polymetallic equivalent (Cu-Ag-Zn-Pb) were estimated along with their market value expressed in American dollars for each year in the time interval of 2012–2016.
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Abstract

Results of a research on influence of chromium, molybdenum and aluminium on structure and selected mechanical properties of Ni-Mn-Cu cast iron in the as-cast and heat-treated conditions are presented. All raw castings showed austenitic matrix with relatively low hardness, making the material machinable. Additions of chromium and molybdenum resulted in higher inclination to hard spots. However, a small addition of aluminium slightly limited this tendency. Heat treatment consisting in soaking the castings at 500 °C for 4 h resulted in partial transformation of austenite to acicular, carbon-supersaturated ferrite, similar to the bainitic ferrite. A degree of this transformation depended not only on the nickel equivalent value (its lower value resulted in higher transformation degree), but also on concentrations of Cr and Mo (transformation degree increased with increasing total concentration of both elements). The castings with the highest hard spots degree showed the highest hardness, while hardness increase, caused by heat treatment, was the largest in the castings with the highest austenite transformation degree. Addition of Cr and Mo resulted in lower thermodynamic stability of austenite, so it appeared a favourable solution. For this reason, the castings containing the highest total amount of Cr and Mo with an addition of 0.4% Al (to reduce hard spots tendency) showed the highest tensile strength.
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