This article presents a comparison of the real amount of structural bending of a traditional residential building on curved mining ground with the bending results from an elastic model of the system: building + ground. Thanks to surveying measurements conducted during the exploitation front, the relationship between the curvature of the building and the curvature of the area in its direct vicinity was determined. The measurement work lasted one and a half years. Observation results collected in nature verify the deformation results of the modelled structure in the approach proposed by the guidelines for designing buildings in mining areas in Poland. Building Research Institute Instructions, Guidelines, Guidance 416 (2006) allows the adoption of an elastic model for the structure, and for the ground, it allows the adoption of linear elastic features characteristic of Winkler elastic ground. The main purpose of the work was to determine the overestimation of stress in the modelled building resulting from the use of a simplified, computational engineering approach.

The problem of of the use of fly ash still constitutes a research and exploration area for scientists. This is due to the fact that, 6,000,000 Mg of coal combustion by-products (CCB) are storage on landfills yearly in Poland alone. One of the potential directions of using fly ash is to use it as a substrate in hydrothermal syntheses of mesoporous materials (synthetic zeolites). Zeolites are aluminosilicates with a spatial structure. Due to their specific structure they are characterized by a number of specific properties among others molecular-sieve, ion-exchange and catalytic that can be used in engineering and environmental protection. So far, the synthesis has been carried out using coal combustion by-products such as fly ash or microsphere. The article analyzes whether separation from the fly ash of the appropriate fraction (below 63 μm) will affect the formation of zeolite grains. The syntheses were carried out using class F fly ash and the fraction separated from it, which was obtained by sieving the ash through a 63 μm sieve. Chemical (XRF) and mineralogical (XRD, SEM-EDS) analyzes were carried out for substrates as well as the obtained reaction products. In the case of substrates, the analysis did not show any significant differences between the ash and the separated fraction. However, in products after synthesis (Na-X zeolite with a small amount of Na-P1 zeolite, and small amounts of quartz and unreacted aluminosilicate glass - mullite) higher aluminum and sodium contents were observed from the separated fraction, with a lower calcium and potassium content. A small proportion of illite was observed on the diffraction curve of the zeolite from the fraction. Observations of grain morphology showed no differences in formation. Based on the conducted analyzes, it can be stated that, considering the economics of the synthesis process, the separation of fine fractions from the fly ash does not affect the quality of the synthesis process.

The article tackles the problem of weak definite descriptions, i.e., it attempts to explain the mysterious uses of definite descriptions which do not meet Russell’s uniqueness condition. The author discusses theories of weak definite descriptions offered in relevant literature and proposes an original solution to the problem which she presents in terms of modern type‑theoretical semantics.