The foliar feeding of soil-grown plants with essential elements such as molybdate can restore their Nitrate reductase activity. However, the activity of nitrate reductase under the foliar feeding of plants with molybdate and nitrate in hydroponic conditions has not been investigated. Thus, we wanted to investigate the effect of the foliar feeding of molybdate and nitrate on the nitrate reductase activity in the leaves of lemon balm plants under hydroponic conditions. Nitrate and molybdate solutions were applied by spraying the leaves of lemon balm plants and the nitrate reductase activity was determined by the colorimetric method. The results of our study demonstrated that the application of molybdate and KNO₃ solution enhanced the nitrate reductase activity in the leaves of lemon balm plants. Importantly, our results indicate that foliar fertilization with nitrate and molybdate can improve nitrogen metabolism and carbon fixation in the leaves of lemon balm plants under hydroponic conditions.

In the global economy there is a significant increase in the scale of traffic, the implementation of which directly depends on the quality of transport equipment. Therefore, the work considers new technologies for hardening by modifying the working surfaces of parts of transport machines.The most effective ion-beam nitriding and thermodiffusion carbonitriding were selected for the modification of sputtered steel coatings. Experiments have shown that as the temperature of the nitriding process increases, the depth of the modified layer increases, and the microhardness of the layer also increases. The main phases are nitrides. The increased wear resistance of the nitrided layer is revealed. Carbonation leads to the formation of a modified layer with a thickness of 150-200 μm and a microhardness of 6500-7000 MPa. The main phase is carbonitrides. To regulate the depth and hardness of the layer, the technology of nitrocarburization has been changed by increasing the temperature and changing the composition of the medium. High adhesion strength was obtained.

Due to the fact that the increase in the efficiency of transportation processes directly depends on the reliability of transport equipment, this article discusses the method of hardening the surfaces of parts of transport machines with a new efficient oxidation technology. The process of obtaining multilayer composite systems by combining supersonic gas-flame spraying of an aluminum coating with subsequent microplasma oxidation to obtain oxide-ceramics was studied. The structure and composition of the treated coating was studied. An increase in the porosity and microhardness over the depth of the layer was revealed.