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The work used a model of severe hypobaric hypoxia (SH) – a three-hour session of rats staying at 180 mmHg (5% O2) and an attempt was made to evaluate the possibility of its use for muscle tissue by determining biomarkers of cardiac muscle and skeletal muscles damage in the blood plasma. To assess the effect of HIF1, we used the HIF-1α translation inhibitor, topotecan, which was administered intraperitoneally (5 mg/kg body weight) in a DMSO–0.09% NaCl mixture 10 min before hypoxia. For postconditioning (PostC), moderate hypobaric hypoxia was used [1]. A significant increase in the level of cardiac biomarker troponin I in the blood plasma of rats subjected to TH was shown, which indicated myocardial damage after SH. The blood level of the nonspecific muscle biomarker myoglobin did not change significantly after SH. However, when the HIF-1α inhibitor topotecan was used before SH, the amount of myoglobin in the blood plasma of rats one day after the SH session was significantly lower than in the absence of the inhibitor. Thus, it can be assumed that inhibition of the transcription factor HIF-1α before SH reduces skeletal muscle damage. Topotecan can be proposed as a means to reduce damage to injured muscles.

To determine the fatigue life of the tail rotor blade of a helicopter made of polymer composite materials (CM), a method of fatigue testing of the specimens of the blade with accompanied numerical modeling of the deformed state has been developed. The tests are carried out on a resonant vibration set-up, with simultaneous reproduction of a forcing harmonic transverse force and a constant longitudinal tensile force. The tests are carried out by a vibration loading mode equivalent in fatigue damage, which includes one level of variable load in the thrust plane and in the plane of rotation. The equivalent mode is formed based on the variable loading spectrum of the blade, which is obtained from the results of flight measurements of the loads on the tail rotor, as well as the repeatability of the expected operating conditions of the helicopter. The tests are accompanied by computational and experimental studies, which include finite element calculation of the stress state and modal analysis of the standard blade and the test specimen, as well as the strain measuring of the structure. According to the results of the research, the vibration loading modes are corrected.

This study demonstrates the possibility of crop rotation selection based on the assessment of productivity and sustainability of crop production under different atmospheric moisture conditions. The study considers 8 crop rotations oriented to grain production. The data obtained in long-term field experiments in the forest-steppe of the Novosibirsk region were used. As a result of the implementation of the decision tree (CART) and the use of ensemble algorithm (Random Forest) the construction of a model characterized by a fairly high predictive ability was performed. Standardized Precipitation Index was chosen as the main predictor characterizing atmospheric moistening in different periods of vegetation. The most stable from the point of view of stability of crop yield – grain-fallow with winter rye, grain-fallow with legumes (vetch-oats), in conditions of manifestation of atmospheric drought of different severity were selected. The possibility of using machine learning methods (CART, Random Forest) as effective tools in the selection of crop rotation for sustainable grain production without the use of chemicalization in soil and climatic conditions of Siberia, as well as the assessment of possible risks in the transition of crop production to organic technologies were scientifically substantiated.

The aim of the study was the selection of effective modes of rosehip sublimation dehydration. An Iney-6M unit was used for freeze drying. The selection of the duration of the sublimation stage and the final drying temperature was carried out. At the same time, such indicators as the duration of drying, organoleptic assessment and the preservation of vitamin C were analyzed. The duration of freeze drying of rose hips with a period of sublimation of 4, 5, 6 and 7 hours was 6, 7, 8 and 8.5 hours, respectively. It was found that with a decrease in the duration of the sublimation stage, a decrease in the quality characteristics of dry rose hips is observed. It was found that when the drying temperature changes from 70 to 40 °C, the drying time increases from 6.5 to 9.5 hours. At the same time, the loss of vitamin C also decreases. Based on the research, the most favorable modes of sublimation dehydration of rose hips have been determined - the final drying temperature is 50 °C and the duration of the sublimation stage is 5 hours. Under these modes, the duration of lyophilization is 8 hours, the total organoleptic assessment is 18.25 points out of 20, and the preservation of vitamin C is 27%. Lyophilized rose hips can be used as an independent product, or ground into powder for adding to other products - confectionery, dairy, bakery products, as well as biologically active additives and functional food.

Enrichment of food products with proteins, minerals and dietary fiber is possible by introducing grinding products of some cereal crops into wheat flour, i.e. obtaining composite flour mixtures. To date, there is a need to enrich food products with essential fatty acids, especially Linolenic acid (w-3), the deficiency of which leads to serious disruptions in functioning of the human body. Analysis of the lipid composition of various oilseed crops shows that the composition of flaxseed oil as a source of w-3 demonstrates an absolute advantage. The solution to the problem of flour enrichment with essential fatty acids is currently being solved by using crushed flaxseed cake. However, the use of flaxseed cake has several disadvantages. First of all, as studies have shown, the amount of such flaxseed flour in the composition of the composite mixture should be 15-20% to ensure the required amount in essential fatty acids, which significantly impairs the consumer properties of bread. The use of flax seeds directly will significantly reduce their proportion in the composition of the composite mixture.

A mathematical model is presented for determining the rational machining conditions for flat grinding operations by the rim of a wheel on machines with a rectangular table consisting of a linear objective function and linear inequality constraints. As the objective function, the equation, determining the main machining time, was used. And constraints which are related to the functional parameters and parameters determining the machining quality and the kinematic capabilities of the machine were used as inequality constraints.

A mathematical model has been introduced for determining the most advantageous conditions for parts formation when end milling operations. This model consists of a linear objective function and linear inequality constraints and takes into account the kinetics of thermal processes in the cutting zone. The equation determines the processing time was used as the objective function and constraint inequalities are related with the functional parameters and the parameters of the milling process and determines the quality of the machining.