Факультет митної справи, матеріалів, технологій та гостинності
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Item type:Наукова стаття, Design of biocomposites based on a glutinous matrix with a combined content of wood flour and chopped stalks of grain crops(Kharkiv: TECHNOLOGY CENTER, 2026) Sadova, Oksana; Kashytskyi, Vitalii; Tkachuk, ValentynaThis study considers biocomposite materials based on a glutinous matrix and fillers of plant origin. Waste from the woodworking industry and the agricultural sector is a promising raw material for obtaining fillers for biocomposite materials, which are characterized by a high degree of environmental safety and renewable raw material base. The task addressed is to optimize the amount of technological additive (water) in the glutinous composition, which contributes to the formation of a dense structure of the biocomposite material with a compact arrangement of particles of the combined mixture of fillers. In the process of research, the effectiveness of using fillers of different granulometric composition against the effect of mechanical loads was determined. The complex effect of fillers of plant origin on the mechanical characteristics of biocomposite materials was studied, which made it possible to define the optimal composition of the biocomposite. An analysis of the effect of the amount of moisture in the composition on the formation of the structure and the resistance of the biocomposite material to the effect of static and dynamic loads was carried out. The maximum values of the ultimate compressive strength (115–120 MPa) were obtained for biocomposites containing a mixture of fillers of different granulometric composition (40–80% of cereal stalk particles, the remaining particles of wood flour) provided that 30% of moisture is removed from the composition. The maximum impact strength (13.8 kJ/m2) was established for biocomposites containing 100% of crushed cereal stalks provided that 10% of moisture is removed from the composition. The designed materials could be used to manufacture packaging elements that are disposed of after operation by recycling or through safe decomposition at landfills without harm to the environment.Item type:Наукова стаття, Designing tribotechnical epoxy composite materials reinforced with chopped fibers and modified with silicon organic varnish(Kharkiv: Technological center, 2024) Sadova, Oksana; Kashytskyi, Vitalii; Tkachuk, Valentyna; Shehynskyi, Oleh; Parfentyeva, InnaThe object of research is modified epoxy composite materials containing fibrous fillers treated in physical fields. The technological features of the development of tribotechnical epoxy composites, which must withstand the effects of elevated temperatures, have been considered. In this case, it is necessary to modify the structure of the epoxy polymer matrix, which is achieved as a result of the introduction of heat-resistant organosilicon varnish. Organosilicon varnishes and chopped fibers contain technological additives, which complicates the process of structuring epoxy composites and leads to the appearance of structural defects. Removal of technological additives and cleaning the surface of the aramid and glass fibers from lubricants is possible as a result of processing the components of the composition in physical fields. There is a need to study the influence of physical fields on the structuring processes of the epoxy system and the formation of the structure of epoxy composites with specified properties. Modified epoxy composites contain chopped aramid and glass fibers treated with ultrasound. The tribotechnical characteristics of epoxy composites were studied at a sliding speed of V=1.0 m/s with a change in specific load from 0.5 MPa to 1.5 MPa. The temperature in the tribocontact zone during frictional interaction rises to 100 °C with an increase in the specific load. An increase in the density of the surface layer of tribocontact of epoxy composites with fillers treated in physical fields was revealed. The practical recommendations have been compiled for the implementation of the treatment technology of components in physical fields, which ensures structuring of epoxy composites with high tribotechnical characteristicsItem type:Наукова стаття, Impact of war and geopolitical factors on foreign trade(Kyiv, 2025-08) Peredriy, Oksana; Pakholiuk, Olena; Dziubynskyi, Andrii; Shehynsky, Oleg; Rechun, Oksana; Shehynskyi, VolodymyrIn the context of the current geopolitical transformations caused by the war in Ukraine, world trade is undergoing significant changes that emphasize the need to analyze the new geoeconomic reality. The war in Ukraine has become a catalyst for the restructuring of global trade chains, intensifying de-globalization processes that are shaping a sustainable preference for political loyalty over economic efficiency. The purpose of the article is to analyze the impact of the war in Ukraine and geopolitical factors on the dynamics of world foreign trade in 2016-2024, with a focus on structural changes in Ukraine's trade flows. The study applies an econometric panel regression model to estimate trade turnover, exports, imports, and their percentage changes, taking into account commodity prices, macroeconomic conditions, exchange rate, and time effects. The econometric model found that the war-induced rise in commodity prices significantly increased the turnover of commodity groups, particularly mineral products. Hryvnia devaluation stimulated exports, while global GDP growth had a weaker effect. Fuel and energy products showed low growth due to import restrictions. The model confirmed a high explanatory power (R² > 0.8) for trade turnover and emphasized the vulnerability of trade to geopolitical shocks that could hinder the recovery in 2024. Further research should focus on analyzing the long-term effects of the war and sanctions, including detailed data on logistical constraints and sanctions pressure, and assessing the impact of trade agreements with the EU on Ukrainian exports. Expanding the model to analyze trade in services and regional blocs will help develop strategies for adapting to the new geopolitical reality