A B S T R A C T This paper deals with the research of friction coefficient in tribopairs

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In the context of urbanization of territories and the intensification of agriculture, the biological diversity of animals and plants in their habitats is degrading. The purpose of the study is to determine the edaphic factors affecting the growth of Populus diversifolia Schrenk and Populus pruinosa Schrenk, as well as anthropogenic factors affecting their conservation in the Syr-Darya valley (Kazakhstan). For identifying the range of edaphic growing conditions, the analysis of soil samples gathered in different phytocenoses with the dominance or participation of Turanga was carried out. The following results were presented: Physical and chemical analyses of soil samples for the content of humus, mobile forms of easily hydrolyzable nitrogen, phosphorus, and potassium; pH aqueous solution; type, and degree of salinization. Among the 6 sections studied, 4 belong to alluvial-meadow tugai salt marsh soils, 1-to meadow salt marshes, and 1-to alluvial-meadow strongly salt marsh soils. Populus diversifolia has been found to prefer mild (sandy) and fewer saline conditions than Populus pruinosa. Among the negative anthropogenic impacts on the Turanga groves were: Regulation of the runoff of the Syr-Darya, felling of trees, fires, and grazing. The identified cenoflora was represented by 103 species of higher vascular plants. Among them, Chenopodiaceae (18), Asteraceae (18), and Brassicaceae (12) were leading. The indicative role of Turanga was based on its connection to the places of groundwater occurrence.

In this paper, the tensile tests were carried out for the samples made of polylactic acid (PLA) with the use of fused deposition modeling (FDM) with various filling factors. The results of the study showed that the ultimate strength of 3D-printed parts non-linearly depends on the filling factor. In addition, the thermal analysis of the 3D printing process using a thermal camera was performed. The obtained results could be used for medical purposes, e.g. PLA parts can be used as implants in maxillofacial surgery. That kind of temporary implants should have cellular structure and enough strength to sustain external and internal loads.

The necessity of creating the collection of wild relatives of fat and oil crops (WRFOC) of Kazakhstan is presented in the article. To achieve this an overview of international experience in studying the role of polyunsaturated fatty acids (PUFA) contained in plants was compiled. These PUFAs are essential fatty acids (EFA) entering the animals’ and humans’ bodies only with food. It is noted that countries possessing the marine wealth use marine fish for production of dietary supplements containing PUFA, but the plant world wealth should be also taken into account. In sufficient quantities EFAs are present in vegetable oils and in small quantities in animal tissues. The participation of EFAs in transcription regulation of certain genes was highlighted. Their role in development of animal and human organisms was noted. The role of the seed bank of Kazakhstan natural flora in ongoing work for creating the various plant species’ collections with great value for the country’s economy, in particular the WRFOC collection of Kazakhstan natural flora was emphasized. The rationale for financing and maintaining works (collecting and preserving seed material, studying seed behavior before and after storage, seed germinating, studying the chemical composition of different plants’ parts) for creating and research this collection is given.