This paper examines the effect of hydrogen gas on the quality of the casting during the liquefaction of aluminum alloy. In addition, the technology for the separation of aluminum from Al₂O₃ oxide, depending on the liquefaction temperature during the liquefaction of aluminum alloy.

The rapid depletion of fossil fuels and the steady increase in human energy consumption, leading to environmental pollution, are creating a situation characterized as an energy-environmental degradation. For this reason, extensive research is being conducted to address the problem of reducing the consumption of non-renewable energy sources and pollution of the environment with toxic waste. In such cases, the concept of hydrogen energy, ie the use of hydrogen as a source of energy on a large industrial scale and in road transport, is important. The prospects for the use of hydrogen for automobile engines can be summarized as follows. First of all, environmental friendliness, renewability and unrestricted raw material reserves, as well as unique engine performance; these allow hydrogen to be used without drastic changes to modern engine designs.

The article defines the types of public buildings that provide the rural population with a full range of cultural and social services. Also, when designing these buildings, 5 design methods were chosen and their functional and economic efficiency was taken into account.  Design using these techniques can save community resources as well as provide equal services to rural and urban populations.

The development of the transport communications and the improvement of their use  one of the most pressing tasks in the development of the economy. The share of highways in the national freight traffic in the country shows that highways are one of the key factors in the development of the country's economy.

This article describes the quality and cost-effectiveness of converting steels by melting them in electric arc furnaces. In addition, the technology of continuous casting of cast products in the furnace with the help of ferroalloys, followed by various equipment.

In this article, tannins are substances that change the physicochemical and mechanical properties of the skin when exposed to it and turn the skin into leather. Vegetable tannins are commonly referred to as tannins. Both abroad and in our country, plant extracts are mainly used to soothe thick leather on the soles of shoes, technical leather, leather of belts and seams, leather of high boots and leather.

The article provides a substantiation of the relevance of the development of highly efficient extraction equipment, shows the ways of intensification of liquid extraction processes, shows the device and principle of operation of the bubbling extractor developed by the authors, and the results of experimental studies of new designs of extractors at industrial enterprises.

The article presents the prospects for the growth of construction volumes in the Republic of Uzbekistan, as a consequence of the need for load-handling devices (LHD) made of synthetic woven belts and ropes (STLK). The results of experimental work are presented, where the wear of textile materials after exposure to light weather is characterized by a change in mechanical properties, which affects the reliability of products during operation.

In this article, the importance of carrying out production based on the legal framework of the organization, the relative physical loads of employees employed in the production, along with the lights of the employee's negative impact on labor productivity, as well as methods of preservation of health are presented. Recommendations were made to make the work process taking into account the energy consumption of the employees employed in the production.

The article examines the main factors that affect the nature of the manifestation of mountain pressure. The physical and mechanical properties of rocks are the main factor determining the nature of the manifestation of rock pressure, their stability and their tendency to self-collapse.

This article claims that robotics has enormous potential to improve all aspects of human life. While these advantages are restricted to highly specialized environments such as factories, robotic technology has advanced to the point that it can now be used in the human environment on a daily basis. However, without a thorough understanding of how humans and robots communicate, this integration would fail.

If the surface temperature of any building material drops sharply without changing the humidity and the surface temperature is lower than the dew point temperature, dew-like water droplets are formed on the surface of this material. This condition is called condensing humidity condition. Condensation moisture formed on the surfaces of building materials and external barriers is slowly absorbed into the body of building materials over time, increasing the relative humidity of this structure. Condensation moisture can be observed when the temperature of the surfaces of external barrier structures drops sharply. This condition can be observed everywhere where the basement is connected to the outer walls of the basement. The article deals with the issue of thermal insulation and calculation of basement walls of modern energy-efficient buildings, which are widely used in the country and abroad.

In this paper the issues like preprocessing of medical data, reclassification of the training sets and determining the importance of classes, formation of reference tables, selection of an informative features set that differentiate between class objects, formed by medical professionals are discussed and solved. Mainly in the most studied references [5-8, 11-13] the Fisher's criterion is used to obtain solutions to problems/tasks. Also for solving problems, the algorithms for an estimate calculation as well as the related software programs are used. For all cases, algorithms and software programs are suggested.

The study consists of two important steps. The first step is to build a reference table, based on the importance of the features and objects as well as their contribution to the classes [1-4, 9, 10]; the second step is concerned with the choice of the most useful characteristic features set to be investigated. This corresponds to solving the issue of selection of set of informative features from a given table, their visualization, and the determination of the contribution of the features set to the formation of classes [1-13].

In this article methodological potential of Wiki technology in teaching English is considered. Moreover, didactic features, advantages and implementation methods of this technology in English classroom are examined.

The foundation of knowledge is the school threshold, the school is closely connected with the future. The motto of the President of the Republic of Uzbekistan “The threshold of a new Uzbekistan begins at school” is a unique initiative of the XXI century, which serves to make the future of the population and all young people a great and strong state. This initiative gives architects spiritual strength. This means that each building must be clearly visible to the public in terms of its appearance.

In article the new algorithm of a digital signature in composition of the existing difficulties is developed: discrete logarithming in a final field, decomposition of rather large natural number on simple multipliers, additions of points with rational coordinates of an elliptic curve. On the basis of a combination of difficulties of discrete logarithming on a final field with the characteristic of large number, decomposition of rather large odd number on simple multipliers and additions of points of an elliptic curve develops algorithm of a digital signature for formation. The conventional scheme (model) of a digital signature covers three processes: generation of keys of EDS; formation of EDS; check (authenticity confirmation) of EDS. The idea of a design of the offered algorithm allows modifying and increasing crypto stability with addition to other computing difficulties. It is intended for use in systems of information processing of different function during forming and confirmation of authenticity of digital signature.

The technological properties of cement stone modified with a plasticizing complex chemical additive KDj-3CHMB have been studied. The influence of the additive on the basic properties of the cement stone has been investigated. The results of the research are given, indicating the active participation of improving the performance of concrete, as well as the possibility of reducing the amount of cement to 10-15%. The content of the additive KDj-3CHMB in the composition of the cement stone leads to an increase in its density by 7-10% and prismatic strength by 40% in comparison with the control samples. At the same time, the complex chemical additive KDj-3CHMB increases the indicators of mobility and frost resistance of cement stone

The article considers the ways of ensuring the safety of athletes and the problems of studying the compliance of an educational institution with the safety standards of a gym, an open sports ground, as well as sports equipment and additional equipment. In addition to studying the causes of injuries among people working in the sports industry, materials on the main areas of their labor protection were analyzed.

The article calculates the thermal energy required for the correct choice of a heat pump and solar collector, which is part of a combined heating system, and the choice of their type and quantity based on the calculations performed and the profitability of water-based solar collectors, which are part of combined heating systems.

Asynchronous motors require its study not only in stationary modes, but also in dynamic ones. At the same time, this makes it possible to formulate the corresponding requirements for automatic control devices of a regulated IM, the implementation of which will ensure the optimal course of transient processes in the electric drive system; it requires its study not only in stationary modes, but also in dynamic ones. This simultaneously makes it possible to formulate the corresponding requirements for automatic control devices of variable IM, the implementation of which will ensure the optimal course of transient processes in the electric drive system.

The study of electromechanical transient modes requires a joint consideration and solution of the equations of equilibrium of electrical quantities in the windings of the machine and the equations of motion of an electric drive.

The article analyzes the peculiarities of the process of designing the production of body details. In addition, the necessary recommendations are given in the design of the production of body details.