A number of factors affecting the interaction of iodides in the melt are considered. For eutectic systems, the deviations of the experimental liquidus curves from the ideal curves calculated by the Schroeder equation are analyzed. The relationship between double iodide systems has been established. The position is substantiated that an important factor influencing the formation of compounds containing a complex iodide ion is the difference in the polarizing effect of cations. The proximity of the sizes of cations and the similarity of crystal structures contributes to the formation of solid solutions, and the difference in the structure of melts leads to delamination.

In this paper, various types and modifications of solar cells manufactured by plasma deposition are considered. Some parameters of thin films of a a-Si_1-x C_x:H, a-C:H, and nc-Si bilayer solar cell (where each layer consists of a p-i-n structure of a single-layer p-i-n junctions and heterojunctions in which the n⁺ layer was made of a-C:H and nc-Si) are studied. It is found that when illuminated with light of 85 mW/cm² and an element area of 0,9 cm², the highest efficiency value of bilayer solar cells is 9,6%. The results of measuring some physical parameters show that more stable elements are manufactured on the basis of a-C:H, which are associated with mechanical stress stability and radiation resistance.

This article explores three current natural lighting solutions for dimly lit underground buildings. It analyzes the advantages, disadvantages, and influencing factors of each method, including skylight illumination, light tube systems, and fiber optic systems. The paper also outlines the ideal applications for each approach, providing a foundational understanding of natural lighting solutions for underground structures.

In the article, within the framework of solving the problem of providing NPPs with a base load due to combination with a hydrogen complex, a new principle of ensuring the safety of hydrogen use during overheating of the working fluid in the steam turbine cycle of NPPs is substantiated. For the first time, a system for removing unreacted hydrogen from the vapor phase of the working fluid of the steam turbine cycle of NPPs has been developed based on a catalytic hydrogen recombiner and magnetic separation with underground placement of the main equipment of the hydrogen complex. A detailed review is given on the experience of using catalytic recombiners in power engineering, as well as magnetic field technologies for gas separation and in obtaining hydrogen by water electrolysis, which proves the practical mastery of these technologies in the world. The principle of underground placement of the main equipment of the hydrogen complex is presented. A methodology for assessing the risk of fire and explosion of hydrogen when mixing with an oxidizer in the event of an emergency is given. Based on the developed system for removing unreacted hydrogen, new indicators have been obtained for reducing the likelihood of an explosion or fire when mixing hydrogen with an oxidizer. New results have been obtained for assessing the overall risk of explosion or fire when mixing hydrogen with an oxidizer in the event of an accident.

The contact of saltier and fresher water forms a salinity gradient, which is an unconventional source of renewable energy. A promising method of extracting this energy is reverse electrodialysis using hydrogen generation. The conditions required for hydrogen generation by this method can be achieved by a variety of approaches including microbial cell and electrolysis. This paper reviews the works reporting hydrogen generation in the reverse electrodialysis process, reports the competitiveness of this method compared to conventional electrode reactions, and concludes that it is promising to use dimensionless criteria to compare the amount of hydrogen and specific power generated using different approaches.

The use of hydrogen technologies in metallurgy, especially in the process of melting steel from metal waste and granular iron, is becoming more and more relevant. Hydrogen can replace carbon as a reducing agent, which significantly reduces carbon dioxide emissions and makes the process more environmentally friendly.

The main advantages of hydrogen use include:

1. Reducing of CO2 emissions: Hydrogen, unlike carbon, emits water, not carbon dioxide, which helps reduce the carbon trace of steel production.
2. Improving efficiency: hydrogen technologies can improve the energy efficiency of the melting process, since hydrogen has high heat intensive ability.
3. The use of secondary resources: metal waste and granular iron can be effectively processed using hydrogen, which contributes to saving natural resources and reducing the cost of raw materials.

These technologies are at the stage of active development and implementation, and many companies are already beginning to use hydrogen in their production processes to achieve a more sustainable and environmentally friendly production of steel.

The article examines the issue of improving the efficiency of the melting process in steel production by using hot briquetted iron (HBI) in the charge, which mainly consists of metallic waste. An analysis of the characteristics of the melting process when using a complex charge composition has been conducted. To activate the boiling of the metal bath, it is recommended to introduce carbon-containing raw materials, such as steel scrap, in a volume of more than 80%. It has been established that the use of HBI practically does not reduce the yield of usable metal, which is due to the high content of metallic waste in the charge composition.

At the same time, an analysis is carried out on the influence of silicon and manganese oxidation processes on the purification of liquid steel during the melting of alloyed waste in an electric arc furnace, where they are used as charge materials. Graphs are presented showing the equilibrium concentrations of oxygen and silicon at different temperatures in the Fe–Si–O system. Additionally, a graph is created illustrating the dependence of manganese oxidation products in liquid iron on temperature and manganese concentration in the MnO–FeO alloy. The equilibrium concentrations of oxygen and silicon are determined, considering the liquefying effect of carbon in both the liquid silicate region and the solid SiO₂ region.

Effective oxidation of silicon and manganese during the melting of steel from metallic waste and hot briquetted iron (HBI) contributes to the maximum purification of liquid steel through metal-slag or metal-gas phases. It has been established that during electric steel production, the silicon content is reduced to minimal levels. Therefore, when metallic waste and HBI are used as charge components in the steelmaking process, the silicon oxidation reaction does not reach equilibrium. In the case of an acidic process, silicon oxidation may be followed by silicon reduction at higher temperatures due to the heat of the electric arc (the silicon reduction process), provided that equilibrium oxidation conditions are achieved.

It is recommended to conduct the primary melting process of the charge, which includes metallic waste and hot briquetted iron, in an electric arc furnace. During this period, the melting process focuses on metal purification, sulfur removal, achieving the required chemical composition of steel, and regulating the process temperature. All these tasks are performed simultaneously throughout the entire refining period. After the complete removal of oxide slag, slag-forming mixtures with fluxes are added to the furnace, introducing new slag (carbide or white slag). As the temperature in the furnace bath increases, the equilibrium constant of manganese decreases. Consequently, in the absence of ferromanganese addition to the bath during the final stage of melting, the interaction of manganese in the bath can be used to assess the metal temperature.

The use of hydrogen technologies in the process of smelting steel we will show in detail in the English version of the article, which will be published in the International Scientific Journal of Hydrogen Energy – IJHE.

Achieving energy security of a federal state is impossible without achieving energy security of each of the constituent entities. Regional energy security has its own peculiarities related to the criteria of its achievement, which allow assessing the prospects of using renewable and hydrogen energy to achieve it. If the energy security of federation as a whole is aimed at protecting the economy and population of the country from threats to national security in the field of energy and fulfillment of export contracts and international obligations, regional energy security is aimed at protecting the fuel and energy complex of the region from threats that lead to termination or sharp reduction in the quality of supply to consumers and to disruption of technological processes. Most regions do not need to achieve absolute energy autonomy, it is enough to have generating capacities and accumulated energy that would allow to ensure operation of consumers of the first category of reliability and comfortable living standards of the population until the factor interrupting the connection with the main energy system of the country is eliminated. For regions whose climatic characteristics allow efficient use of power plants based on at least two different renewable energy sources and which have a sufficient number of small and medium-sized consumers remote from central transmission lines the transition to distributed generation based on renewable energy power plants supplemented by modern methods of energy storage using hydrogen energy, seems to be the most feasible way to achieve this goal.

A power grid designed in this way is more resilient to natural disasters, targeted negative anthropogenic impacts, requires fewer resources to maintain security, and has a lower risk of severe consequences if generating facilities or transmission lines fail.

This article discusses the operation of auxiliary equipment in a stress-strain state. When using hydrogen in the energy industry, it is necessary to take into account and evaluate not only the high energy properties of hydrogen fuel during use, but also its effect on auxiliary equipment. Hydrogen must be stored at high pressure (at gas stations, the pressure can reach 70 MPa). Special attention should be paid to the complete condition of the hydrogen fuel storage receiver – welding points and welds are most susceptible to damage. The finite element method can be one of the ways to analyze the operation and then predict the condition of auxiliary equipment. Based on the finite element method, a calculation scheme was constructed that made it possible to predict the design change over time under the influence of internal forces. The conducted research will make it possible to identify defects at an earlier stage of operation and obtain the results of a numerical analysis of the stress-strain state. At the moment, GOST 24755-89 is the main standard in the Russian Federation that defines the norms and methods of strength calculation. This standard establishes norms and methods for calculating the strength of strengthening holes in shells, transitions and convex bottoms of vessels and apparatuses used in chemical oil refining and related industries operating under the influence of internal or external pressure. As a result of the research, the permissible values of geometric parameters have been determined to ensure the vital activity and strength of the hydrogen receiver housing for design pressures and possible fluctuations, wall temperature, permissible prolongation of service life, and operating time.

Even for short space flights, such as manned flights to the Moon back in the 60s, it became extremely obvious that electric batteries are completely unsuitable because of their huge mass needed to store the required supply of onboard energy. Therefore, already in the 60s of the last century, the USA and the USSR took the path of using a hydrogen storage system using hydrogen fuel cells.

Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen. The article presents too the result of the development of a solar-hydrogen power supply system for spacecraft, the onboard network of which provides slow and fast processes. This paper delves into designing digital control systems for power conditioning devices on the example of charging-discharging device based on a boost DC-DC converter. The device was implemented to condition a storage battery by properly charging and discharging it. A technique for constructing a small signal model of the converter has been developed. This involves constructing a block diagram using the discontinuous switching functions and analog models of electrical circuit components. The transfer functions of the analog controllers for the two-loop subordinate control system were derived. Then the procedure of a bilinear z-transform to the given transfer functions was applied. As a result, the discrete transfer functions of the digital controllers were obtained. Realization both analog and digital controllers in Matlab Simulink confirmed their identical behavior and stability within the power converter. Experimental studies of the static and dynamic waveforms of the digital control system showed controllability and stability of the charging-discharging device for the storage battery in typical operating modes. Thus, the method of synthesizing digital control systems for energy converters is proved valid and applicable for designing new power conditioning devices within modern power supplies.