The paper investigates the state-of-the-art architecture of photovoltaic systems (PVS) by evaluating the performance of the developed maximum power point tracking (MPPT) algorithm of fuzzy particle swarm optimization (FPSO) for temperate continental latitudes. The material of the paper gives an evaluation of traditional MPPT algorithms in relation to the state-of-the-art FPSO algorithm. The paper summaries the experience of observations of climatic factors and solar resources on the example of the Russian Federation. Thus, in 2023, the average winter temperature exceeded the norm by 4,7 ºC, and the average summer temperature exceeded the norm by 4,9 ºC compared to 2022. The paper analyses the level of insolation, which increased by 0,03 kWh/m² by regions of Russia for the period 2022-2023. The experimental part of the work was carried out at the solar power plant (SPP) «Kalmykskaya» with coordinates 53,422832 north latitude and 55,266895 east longitude. The watt-volt field characteristic of photovoltaic modules (PVM) connected to the inverter was obtained experimentally. When compared, the correlation coefficient between the experimental power (P) and voltage (U) of the panels was found to be higher than that of the ideal panels, 0,933 versus 0,914. The correlation coefficient between the ideal P(U) function and the experimental one is (-0,475). The data for calculating the coefficient of performance (COP) of the implemented MPPT algorithm was also obtained experimentally, which was about 98,7%. The reliability of the data used in the calculations was confirmed by two independent means of measurement, the difference of the obtained results was less than 1%. In the last part of the experiment of this study, the dependence of insolation in a given geographical point on the generated PV field power was evaluated. The correlation coefficient was 0,47, while the inverter output voltage was maintained in the nominal range of (600 ± 20%) V. Thus, the authors of the study experimentally proved the efficiency of using MPPT on FPSO in temperate continental climate with duration of sunshine T = 1850 hours per year. The effectiveness of the FPSO algorithm under the conditions of inverter distance from the common point of the DC switching cabinet (DCSC) has been confirmed. The effectiveness of the MPPT algorithm based on FPSO under conditions of partial shading, increased cloud cover and increased air temperature is concluded. Using the description of the current architecture of On-Grid SPP, the authors draw attention to the impossibility of operation of such systems without the presence of voltage in the reference network. In addition, the impossibility of the system operation at the value of PVM power over 1500 kW and at the voltage of panels less than 900 V is noted. To modernize the existing PVS architecture, for the first time, the use of a DCSC and an inverter with implemented MPPT on the FPSO in combination with a hydrogen (H₂) production unit and nickel-hydrogen (Ni-H₂) batteries is proposed. The researchers propose that when the PVM field voltage is below 900 V and when the PVM field power exceeds 1500 kW, energy can be diverted to H₂ generation or to charge Ni-H₂ batteries via a DCSC controller. Such an architecture will improve the continuity and efficiency of the PVS, reduce the carbon footprint, and allow the PVS to be used as an industrial uninterruptible power supply (UPS). The authors see the lack of standardization of implemented projects based on the ESG principle as the main problem of alternative energy development.

This article describes the properties of yeast strains used in the production of bioethanol by processing grape waste, and their effect on raw materials. Methods for producing second-generation biofuels are one of the most relevant topics of our time. The production of biofuels from food waste helps to solve two problems that arise simultaneously. Firstly, the negative impact on the environment is reduced through the disposal of food waste. Secondly, as a result of economic and demographic growth, the increasing demand for energy resources is being met. during the study, a strain of yeast belonging to the Saccharomyces class was compared with each other and recommended for the production of bioethanol in relation to the results of the study.

The safety of nuclear installations is largely determined by the tightness of the fuel element shells. As shown by the accident at the Fukushima-1 nuclear power plant, the main task in case of loss of power supply is to ensure reliable removal of residual heat from the holding pool with irradiated fuel assemblies. It is possible to increase the reliability of the heat sink in case of loss of power supply using passive heat removal systems.

In accordance with NP-033-11 «General provisions for ensuring the safety of research nuclear installations», the purpose of ensuring the safety of nuclear power plants is to limit the radiation effects of nuclear power plants on workers (personnel), the public and the environment during normal operation and violations of normal operation, including accidents.

The paper describes an experimental passive heat removal system developed based on the design features of the storage shaft of the IVV-2M research nuclear reactor. Its complete design is given, as well as its constituent elements.

The system consists of three parts, an evaporative, a condensing and a lifting and lowering path. The operation of the system is described in two modes:

1. Liquid-liquid – corresponds to the normal operation mode of the holding pool, in which the temperature of the coolant does not exceed the boiling point of alcohol 78,3 °C;
2. Liquid-two-phase – corresponds to the mode of heat dissipation in case of violation of normal operating conditions, in which ethyl alcohol boils in the circulation circuit.

Theoretical formulas for determining the heat output from the installation and the dependence of the expansion of a low-boiling coolant (alcohol) in the circuit during heating are presented.

To remove the parameters of the system circuit, thermocouples of the THA, evaporative module, heater and tank were used, the values of which were transmitted via ADAM 4014 converters to a computer. ADAMView and GenieDAQ software were used to output the readings.

In the course of the work, the results obtained on changes in temperatures in the circulation circuit of the system and the dynamics of changes in heat sink power, temperatures in the circuit, and the flow rate of the working fluid in the cooling mode are presented.

The introduction of passive heat sink systems for use in research facilities not only increases the safety of the installation itself, but also competitiveness in the market (when analyzing the literature, no analogues were found). At the moment, a significant number of nuclear research centers are being built not only in Russia, but also abroad. The proposed system of passive removal of residual heat emissions increases the competitiveness of new nuclear power plants, and can also be implemented in already operating installations.

Currently, software packages such as COMSOL Multiphysics and Solid Works Flow Simulation are actively used for modelling processes occurring in the equipment of nuclear power plants. Computer modelling allows to represent many thermal-hydrodynamic processes in NPP equipment, to estimate their efficiency and to reduce expenses on manufacturing of mock-ups and samples, to find the most optimal variant of medium flow, which will reduce time for NPP equipment design.

The study of sodium phase transition processes in the drainage pipeline is especially important for optimisation of NPP heat-mechanical equipment operation during scheduled preventive maintenance (SPM), as the SPM duration significantly affects the economic component of the power project. Computer modelling in the computational package COMSOL Multiphysics [4] is able to find methods that allow to determine the most effective way of solving problems associated with the duration of PPM, in particular, the cooling of elements of nuclear plant equipment.

The article presents the results of computer modeling of the influence of external factors on the processes occurring in thermal mechanical equipment used at nuclear power plants.

The sodium drainage pipeline of the steam generator PGN-200M of the BN-600 reactor unit was chosen as the object of modelling. The influence of the cooling air temperature on the intensity of thermal processes in the equipment was investigated and the contribution of the pipeline thermal insulation to the rate of processes was evaluated.

The results of the study showed that decrease of cooling air temperature by 8 оС leads to decrease of sodium crystallisation time by 14,5%. Removal of thermal insulation leads to reduction of time interval from the beginning of cooling process to the beginning of crystallisation by 84%, but the considered method does not meet the requirements of federal norms and rules in the field of labour protection.

Inverter-driven generation units (IDGUs) based on renewable energy sources (RES) are actively integrated into electric power systems (EPSs) as a part of carbon neutrality development vector. RES units based on solar energy (photovoltaic power plants (PvPPs)) connected to hydrogen-based electric energy storage system (EESS) have been being actively introduced recently. For connection of modern PvPPs and hydrogen-based EESS (HESS) to grid electric power converters (EPC) are used. Large-scale implementation of these devices causes changes of EPS dynamic properties due to properties of inverting EPCs and their automatic control systems. To study and analyze these properties mathematical modelling can be used. Software on calculation of electromechanical transients is usually used for modelling transient processes. In such soft-ware generic mathematical models are developed and used to calculate transients in EPSs with PvPPs and HESSs. These models have a number of features due to which the full range of processes accompanying implementation of PvPPs and HESSs into weak grids cannot be simulated. The paper proposes an alternative all-mode variant to model these units in EPS.

Fuel cells (FCs) have attracted significant interest due to their versatile applications, but modeling their nonlinear behavior is challenging. This research proposes an Enhanced Artificial Hummingbird Algorithm (EAHA) to identify the seven unknown parameters of proton exchange membrane fuel cell (PEMFC) stacks using their experimental data. The goal is to accurately predict the current/voltage (I/V) curves by minimizing a cost function defined as the sum of squared differences between measured data points and model estimates. The EAHA combines several territorial foraging techniques with a linear regulation mechanism. Its performance is compared to the conventional Artificial Hummingbird Algorithm (AHA) using three common PEMFC modules. Additionally, a comparative analysis is performed against previously published methods and newly developed optimizers like Particle Swarm Optimizer (PSO), Grasshopper Optimization Algorithm (GOA), Atom Search Optimization (ASO), Grey Wolf Optimizer (GWO), and parental algorithm i.e., Artificial Hummingbird Algorithm (AHA). The findings showcase the proposed approach’s efficacy relative to existing methods and state-of-the-art optimizers. The two models are taken for the checking of reliability and performance of the PEMFC. The results are also compared with the Non-Parametric tests and it is concluded that the proposed algorithm is far better than the rest of the compared algorithms in both the models.

The use of NiTi as a material for implants is possible due to its bioinertness. But at the same time, it is necessary to provide it, firstly, with additional protection, since when interacting with living tissues, NiTi undergoes corrosion, and secondly, to enhance the bioactivity of the surface in order to accelerate the regeneration of damaged tissue. Therefore, to solve this problem, a two-layer coating was produced using magnetron and plasma-assisted RF sputtering, one part of which prevents corrosion, and the second increases bioactivity. It has been established that the formed calcium phosphate coating has a dense and pore-free structure, and the coating itself includes elements of calcium, phosphorus and oxygen. Data on the elemental composition correlate well with the data of X-ray diffraction analysis, according to which the coating consists of hydroxyapatite of the hexagonal system. The MTT test conducted with groups of samples without and with calcium phosphate coating showed that the percentage of dead cells was 11 ± 4% and 12 ± 3%, respectively. Preliminary in vitro studies support the osteogenic activity of the coated samples. The results obtained show that in the future these materials can be used for the manufacture of bone implants, since the formed hydroxyapatite is most similar to biological one. At the same time, it is necessary to further expand studies of osteogenesis on these coatings to ensure their ability to positively influence the process of bone tissue formation.