SELECTIION OF THE SWIRLER’S ANGLE AND DIAMETER OF DILUTION HOLES OF THE COMBUSTION CHAMBER BASED OF NUMERICAL MODELING OF COMBUSTION PROCESSES

One of the most important tasks at the design stage of the combustion chamber is to determine its environmental characteristics. There are several methods for determining the degree of influence of factors on the characteristics of combustion chamber, one of which is the three-dimensional modeling of processes in the combustion chamber. The factors are divided into constructive and regime ones. In this paper, the influence of structural design parameters of the front device and the flame tube on the characteristics of the combustion chamber is considered. The studies were carried out on a three-dimensional model of the combustion chamber of the gas turbine power plant; methane gas was used as the fuel. To study the effect of the geometry of the axial swirler on the pollutant emission, two variants of the swirler’s angle are chosen: w= 55° and w = 45°. In order to take into account the effect of the amount of air drawn into the combustion zone, geometric models are constructed with a different diameter of the dilution holes in the range from 0 to 7 mm. As a result, the recommended parameters of the front device elements are determined: 1) the recommended swirler’s angle b = 55 °; 2) the recommended range of dilution holes of the liner is d = 3 ... 4 mm. The results obtained in this paper are based on a series of calculations of combustion processes in a three-dimensional stationary formulation

ESTIMATION ОF THE ЕFFЕСТ ОF FINITE-VOLUME MESH PARAMETERS ON THE SIMULATION OF THE WORKING PROCESS OF AXIAL TURBINES

The paper gives recommendations on the creation of numerical models of the working process in axial turbines. The recommendations are based on the comparison between the flow structure and the model parameters: the 3D-mesh parameters and turbulence models. The recommendations make it possible to improve the efficiency of gas-dynamic design and development of aviation uncooled turbines

Scattering theory and ground-state energy of Dirac fermions in graphene with two Coulomb impurities

We study the physics of Dirac fermions in a gapped graphene monolayer containing two Coulomb impurities. For the case of equal impurity charges, we discuss the ground-state energy using the linear combination of atomic orbitals (LCAO) approach. For opposite charges of the Coulomb centers, an electric dipole potential results at large distances. We provide a nonperturbative analysis of the corresponding low-energy scattering problem

Microbial landscape of wounds in patients with purulent inflammatory diseases of the hand

Interpreting the results of bacteriological examination of material from wounds is a complex and crucial task for the surgeon. Detecting a pathogen in the wound does not confirm its pathogenic role, and the clinical picture of the disease often does not correspond to the obtained microbiological result. The research presents treatment data for 205 patients with purulent diseases of the hand who underwent surgery with biological samples taken for microbiological examination of the wound microflora. In Group 1 (n = 100), the microbial agent was studied by the traditional biochemical method. In Group 2 (n = 105), the combined polymerase chain reaction – mass spectrometry (PCR-MS) diagnostic method was used. In Group 1, the obtained results on the microbial flora structure of a purulent wound were comparable with published data. In Group 2, the combined PCR-MS diagnostic method allowed identifying pathogens in a shorter time, and the revealed structural features showed the predominance of gram-negative flora and fungi. © 2020, Institute of Advanced Scientific Research, Inc.. All rights reserved

Quality criteria of specialists training within the context of competencydevelopment approach

Introduction. The on-going changes in the Russian Federation have revealed a severe lack of specialists who have expertise and experience in taking decisions under the conditions of market economy, which causes an increased need in such specialists. The solution is possible if there is continuous economic education within the system of professional education. Research Methodology. In the course of the research, a competence-development teaching package has been worked out as a methodological support of continuous economic education, which is now being practically used. The package takes into account the educational level and the educational program specialization, which facilitates an individual's participation in the real economic activity. Research results.In specialists' economic skills development, it is prudent to use both traditional and innovative educational methods and technologies, which will enable to integrate pedagogical science and practice of continuous economic education and consider the succession of professional education levels and sublevels. The diversity of educational techniques will allow a teacher to realize educational goals and objectives. Discussion. The level of students' economic competencesdevelopment was measured in accordance with three criteria: the cognitive criterion, personal motivational criterion and creative activity criterion. Each of the criteria reveals through a system of empirical indexes which reflect the degree to which a particular component is developed. Conclusion. Continuous economic education is an obligatory part of continuous professional education, which is focused on developing a competitive, economically competent specialist, who is in demand in the labor market. © 2018

Quality criteria of specialists training within the context of competencydevelopment approach

Introduction. The on-going changes in the Russian Federation have revealed a severe lack of specialists who have expertise and experience in taking decisions under the conditions of market economy, which causes an increased need in such specialists. The solution is possible if there is continuous economic education within the system of professional education. Research Methodology. In the course of the research, a competence-development teaching package has been worked out as a methodological support of continuous economic education, which is now being practically used. The package takes into account the educational level and the educational program specialization, which facilitates an individual's participation in the real economic activity. Research results.In specialists' economic skills development, it is prudent to use both traditional and innovative educational methods and technologies, which will enable to integrate pedagogical science and practice of continuous economic education and consider the succession of professional education levels and sublevels. The diversity of educational techniques will allow a teacher to realize educational goals and objectives. Discussion. The level of students' economic competencesdevelopment was measured in accordance with three criteria: the cognitive criterion, personal motivational criterion and creative activity criterion. Each of the criteria reveals through a system of empirical indexes which reflect the degree to which a particular component is developed. Conclusion. Continuous economic education is an obligatory part of continuous professional education, which is focused on developing a competitive, economically competent specialist, who is in demand in the labor market. © 2018

Designing a comfortable educational environment

Introduction. The problem of maintaining the physical health of teachers in educational organizations is discussed in the article in the context of professional "burnout" and conflict prevention. Research methodology. When studying the content and essence of a comfortable educational environment, we were interested in the works that provided for an understanding of the nature of human interaction and reflected the interdependence and communication style of people in direct contact with each other. Research results. The most important factor of external and internal order, determining the content, direction and intensity of work activity, has always been a special atmosphere in the team, which in scientific and social discourse was defined by various terms such as: "microclimate", "moral and psychological microclimate", "sociological microclimate", "comfortable educational environment". Discussion. Designing refers to the category of innovative creative activity, since it primarily involves a purposeful transformation of reality, the need for which arises whenever there is an awareness of the necessity to move to a prognostic model of an educational or upbringing system. The main purpose of such "educational changes" consists in the possibility for a person himself/herself to learn and self-change during life, to apply knowledge in solving professional tasks. Conclusion. The term "comfortable educational environment" is used to denote a special atmosphere in the team that determines the content, direction and intensity of work activity and manifests itself in such group effects as team members' mood and opinion, individual well-being, assessment of the person's living and working conditions in the team. This special atmosphere is regarded on the whole as a result of people's joint activity, their interpersonal interaction. © 2018 Authors

The research of pricing mechanisms of public procurement system in the Russian Federation

This article presents the main results of research on the topic of the research of the pricing mechanisms within the public procurement system in the Russian Federation. The goal of this article is to estimate the effect of the pricing mechanism on the efficiency of public procurement system in the Russian Federation. This research examines the initial maximum contract price (IMCP) mechanism as one possible reason for persistent inefficiency of the public procurement system. The authors discuss composite auctions (in which the winner is selected based on more than just price criteria) in the procurement of the results of research and development (R&D) work in Russia. It is found that unscrupulous customers can collude with suppliers to manipulate (overstate) the IMCP and restrict competition, which results in a higher final contract price and losses to the state budget. Using the metric of interaction frequency, we identified suppliers potentially affiliated with the customers. The results of econometric modeling suggest that potentially affiliated suppliers win the auctions with bids closer to the initial maximum contract price (IMCP) than independent suppliers. This result is observed regardless of specification changes and different evaluation methods. Potentially affiliated bidders have higher quality scores in contests with potentially affiliated organizers. At the same time, independent participants receive lower scores in such auctions. Therefore, a potentially affiliated bidder can set a higher price, winning due to overstated quality criteri

Combined vaccines in the national prevention immunization schedules for the children in Belarus, Kazakhstan, Russia and Ukraine

Еhe announcement of the east European expert group for vaccine prevention presents position of the leading specialists of Russia, Belarus, Ukraine and Kazakhstan on key issues of the national pre vention immunization schedule. the authors examine in detail the aspects of vaccination against hepatitis type b, including optimal term of injection of the first vaccine dose, vaccination tactics for the premature and low weight newborns, safety of recombinant vaccines against hepatitis type в. based on the analysis of the morbidity of h. influenzae type b invasive forms along with the methods recommended by who (HIB RAT), experts recommend introduction of the vaccine against this infection into the prevention immunization schedule. The experts believe the basis for the combined vaccines in pediatrics to be the vaccines with cellfree pertussis component. This class of vaccines allows introducing the additional booster dose of pertussis vaccines for immunization of the preschool children into the immunization schedule, which is dictated by the present epidemic situation with due account for this infection. The experts note the importance of application of the combined vaccines in pediatrics, whose wide implementation into healthcare system practices is in the interests of the parents, medical officers and society.Key words: hepatitis type в, h. influenzae type b, HIB RAT, pertussis, diphteria and tetanus toxoids and pertussis vaccine, poliovaccines, combined vaccines, prevention immunization schedule, children