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In this study, high-performance liquid chromatography (HPLC) methods were utilised to identify and quantify C21–C33 n-alkanes in permafrost peatlands located within the Eastern European and Western Siberian cryolithozone. The total content of n-alkanes in Europe is 7.4 times higher compared to Siberian permafrost peatlands, and was estimated at 282 ± 145 (range from 74 to 709) μg/kg and 38 ± 12 (10–66) μg/kg, respectively. In the European cryolithozone, CPI alkane 9.5 ± 2.4 (3.7–18.6) and HPA 0.10 ± 0.03 (0.05–0.23) indicate a relatively higher share of higher plants and a higher stage of peat decomposition decree, with 6.9 ± 2.1 (3.1–12.9) and 0.15 ± 0.05 (0.06–0.29) in the Siberian region. In contrast, the Western Siberian peat plateaus were formed under conditions of constant excess moisture, a distinction from the Eastern European peatlands, where moisture and permafrost conditions were subject to constant change. This is further corroborated by the values of Paq, C23/C29 and C23(C27 + C31), which are 0.90 ± 0.05 (0.69–0.99); 11.1 ± 8.9 (0.84–61.6); 1.53 ± 0.80 (0.21–4.72) and 0.47 ± 0.12 (0.08–0.71); 0.64 ± 0.32 (0.08–1.48); and 0.43 ± 0.21 (0.04–1.26), respectively. The n-alkanes and peat physicochemical properties show no significant correlation. In the European part, permafrost degradation occurred repeatedly during the warming periods. Nevertheless, only slight subsidence of the permafrost table was observed, and peat continued to accumulate (up to 0.1 mm/year) in the West Siberian peat plateaus. Consequently, the variation in the quantitative and qualitative composition of n-alkanes in permafrost peatlands is determined not only by the different botanical composition of the plant remains forming the peat strata, but also by the consequence of lower mean annual temperatures in Western Siberia compared to the European nNortheast, and such a climatic difference persisted throughout the Holocene. [ABSTRACT FROM AUTHOR]

The purpose of the research is to study and systematize the solutions of facade structures for prefabricated and precast-monolithic construction. The article considers single-layer, two-layer and three-layer external wall panels. An analysis of design solutions was carried out in terms of ensuring energy efficiency requirements. Possible options for finishing buildings with external walls made of large-sized elements were analyzed, taking into account their design solutions. The scientific novelty of the article lies in considering the issue of facade decoration both from the point of view of architectural expressiveness and energy efficiency. It also compares the most common types of external wall panels based on the thermal characteristics and geometric dimensions of the materials used and, as a result, their economic feasibility. As a result of the analysis, it can be concluded that modern solutions for prefabricated external walls have great importance for the implementation of design solutions and finishing the facade of buildings from large-size prefabricated elements. The best indicators of all the options considered are the two-layer hinged and three-layer external wall panels.

The article developed a methodological basis for implementing automatic diagnostics based on thermal analysis of bearing assemblies. The diagnostic criteria of the technical operation condition and the procedure for determining the temperature ratio inside and outside the bearing unit based on the finite element analysis (FEA) of stable thermal conductivity have proven to be justified. Method of simulation of stable thermal conductivity of bearing units using KOMPAS-3D software and APM FEM finite element analysis module is proposed. The developed method was tested in practice and verified based on the results of theoretical and experimental studies. The developed method enables the determination of the relationship between the observed temperature on the surface of the bearing units and the friction temperature in the wear zone. [ABSTRACT FROM AUTHOR]