Theoretically, the combustion stability of solid fuel, which during the combustion process is decomposed according to the "solid phase-liquid phase-gas" scheme, is investigated. The physical and mathematical models for the propagation of small perturbations of combustion are constructed. The medium in all areas of combustion and in combustion products is assumed to be incompressible, and the viscosity of the fuel in the liquid phase is taken into account. Thus, perturbations of hydrodynamic parameters are considered not only in the two-phase gasification zone, but also in the combustion products area and the geometric perturbation of the instantaneous combustion front (flame), distorting the shape of its surface, is also specified. That is the characteristic feature of the presented physical model. The mathematical eigenvalue problem is set and solved. This problem is reduced to an algebraic characteristic equation for a dimensionless complex eigenvalue, which positivity determines the instability. It is proved that in the limiting case of the absence of a liquid phase, absolute instability takes place. At the other limiting case-for perturbations with infinite wavelength-a transition to stability takes place. The latter fact indicates that the presence of a viscous liquid film and changes in the length of the gasification zone under the influence of perturbations have a significant stabilizing effect on solid fuel combustion. In the general case, a sufficient condition for the instability of the roots of the characteristic equation is analytically determined. The physical interpretation of the mathematical results explains the processes of autoturbulization of solid fuel combustion and the possible transition of combustion to deflagration explosion or detonation. The results of the study are in qualitative agreement with experimental data and can additionally be used for theoretical analysis of the stability of the liquid fuel combustion process in the combustion chamber

The article is concerned with the increasing importance of computer technologies and the need to educatean engineer at the level of modern advances in science and technology. New methods and technologies of learning based on the training of competitive engineers are considered. The teaching and methodological support of the didactic process of the professional training for the engineering students is presented and characterized: the motivation tasks for laboratory training and for calculating-and-graphic assignments, the individual card for the organization of the student's work, the methodical guidances. Examples of motivational tasks used for laboratory training are provided: the solution of the search tasks of linear programming, the simulation modeling of the optimal tax rates. The most effective ways to organize learning process using computer technologies for the vocational training of engineering students are indicated.

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In modern conditions of the development of public relations and political life, criminal activity in Ukraine is changing and transforming. In such transformational conditions, the commission of political crimes by members of informal youth groups is becoming more widespread. Given the above, the need to analyze political crimes committed by members of informal youth groups, methods, and means of combating such crimes, including foreign positive experience, becomes especially relevant. The work aims to analyze the means and methods of combating political crimes committed by members of such groups. The object of the research is the fight against political crimes committed by members of informal youth groups. The subject of the study is the social relations that arise, change, and end during the fight against political crimes committed by members of these groups. The research methodology is a set of different scientific methods, including observation, analysis, synthesis, extrapolation, generalization, comparison, dialectical method. The empirical basis of the study was the materials of the investigation of crimes committed by members of informal youth groups. As a result of the study, some issues of combating political crimes committed by members of informal youth groups were considered. Three main reasons for the participation of informal youth groups in political confrontations are highlighted, and certain issues of investigation of this type of criminal activity are considered.