The object of research is the process of using a hydrogen fuel cell to generate and accumulate electricity. The study highlights the feasibility of using a hydrogen fuel cell to provide electrical load. The potential of using hydrogen as an alternative energy source was evaluated. SWOT analysis was used as a research method, based on the results of which recommendations were developed. The proposed measures could be taken to increase the use of hydrogen energy as an alternative to traditional energy sources. The use of hydrogen technologies in an administrative building connected to an existing electrical network was analyzed. The economic and environmental aspects of the use of hydrogen fuel cells to meet the demand for electrical load were investigated. Six schemes of energy supply of the building and comparing them to select the optimal solution have been developed. In the study, the assessment tool was the Hybrid Optimization of Multiple Energy Resources (HOMER) software. The considered schemes were evaluated in accordance with a single generalized indicator. As a result, it was determined that the use of a hydrogen fuel cell could increase the efficiency of the traditional system by 85 %. For renewable energy systems, there was an increase in efficiency of 7 % (for the wind generator) and 10 % (for the photocell). The practical use of the results will contribute to the efficiency of the process of electricity production by equalizing the stability of energy supply in hybrid systems. The economic and environmental assessment conducted demonstrates the prospects of using a hydrogen fuel cell. This assessment is designed to strengthen consumer confidence in the use of hydrogen fuel cells and hydrogen in general

The object of this study is the processes of shielding electromagnetic radiation by building and facing materials. The research is aimed at solving the problem of ensuring the electromagnetic safety of people by improving the composition and structures of building and facing materials. Means for improving the electromagnetic safety of people under industrial and domestic conditions using non-homogeneous building materials have been determined. The shielding properties of reinforced concrete structures were studied. A methodology for increasing their efficiency depending on the amplitude-frequency characteristics of the radiation that needs shielding has been devised. The efficiency of electromagnetic radiation shielding by heterogeneous dielectric building materials based on cement concrete and basalt fibers was determined. It was established that shielding through the refraction of electromagnetic waves on inhomogeneities does not give an acceptable effect. The expediency of covering basalt fibers with a conductive substance to increase the protective properties of materials was substantiated. The protective properties of flat facing material with carbonyl iron content were studied. It has been shown that the properties of materials can be effectively controlled by adjusting the filler. The material's transmission coefficient of ultra-high frequency electromagnetic radiation does not exceed 0.40, and the reflection coefficient – 0.25 with a filler content in the base of 14–15 % by volume. This makes it possible to simultaneously ensure the electromagnetic safety of people and the stable functioning of wireless communication devices. The advantage of the material is the low coefficients of reflection of electromagnetic waves, which does not lead to deterioration of the electromagnetic situation in other areas where people stay. It has been established that the addition of boron nitride to the facing material significantly increases the thermal insulation characteristics of the coating and contributes to the solution of energy saving problems. Adding a layer containing boron nitride to the material provides thermal conductivity coefficients of 0.030–0.031 W/m·K, which is better than known analogs

Development of environmentally safe technological water disposal scheme of aviation enterprise

Conventional process schemes of municipal sewage water treatment, advantages, and disadvantages of the methods applied when removing biogenic elements were considered. It was shown that the existing shortcomings cause additional explicit costs and difficulties when disposing of the resulting waste. Low efficiency of the removal processes themselves causing residual concentrations of biogenic elements in the treated sewage water was also shown. A process scheme for treating municipal sewage water was proposed. It includes the use of a photobioreactor of a proposed design for the removal of biogenic elements due to the metabolism of microalgae. It was experimentally shown that the use of Euglena gracilis strain for removal of phosphates in initial concentrations of 4, 7, and 14 mg/dm³ from sewage water is the most efficient way. It makes it possible to reduce these concentrations to residual 0…0.55 mg/dm³ in four days. A 3.75…5.58 times increment of microalgae biomass during this period was also shown. A mathematical model was constructed for calculating the time of staying the sewage water and microalgae mixture in a photobioreactor to achieve the required degree of removal of biogenic elements. Based on the proposed model and experimental studies, the required time of staying in the rector working area was calculated. It was shown that with the use of Euglena gracilis strain but without removal of biogenic elements at previous purification stages (process schemes including only mechanical purification), the time of mixture staying in the working zone was 37.81 hrs. With partial removal of biogenic elements at the stage of biological treatment (0.55 mg/dm³ total nitrogen, 0.91 mg/dm³ ammonium nitrogen, 0.44 mg/dm³ phosphates), this time was reduced to 26.66 hrs. It was found that the use of Euglena gracilis strain instead of Chlorella vulgaris (FC-16) in the removal of phosphates results in a 2-time increase in the process efficiency and a 50 % decrease in time of mixture staying in the working zone. Recommendations for calculating geometric parameters of photobioreactors of the proposed design were given for use in the process schemes