Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan

About: Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan is a education organization based out in Dnipro, Ukraine. It is known for research contribution in the topics: Track (rail transport) & Bogie. The organization has 736 authors who have published 655 publications receiving 1468 citations. The organization is also known as: Institute of Railway Transport Engineers.

Prediction of atmosphere pollution in case of emissions from main mine fans

Abstract: Purpose. Emissions from mine ventilation system can create intensive atmosphere air pollution. As a rule, a huge amount of dust from mine fan enters atmosphere low layers. An important task is the development of methods to assess levels of the atmosphere pollution near mines and settlements. To solve this problem it is important to have physically proved mathematical models. Nowadays to predict the atmosphere pollution near settlements which are effected by mine fan the empirical model OND–86 is used. This model does not take into account many important physical factors. So, the purpose of this study is the development of quick computing mathematical model to predict the atmosphere pollution in case of dust emissions from mine fan. Methodology. To predict levels of the atmosphere pollution in case of mine fan work 3D equation of dust convective – diffusive flow was used. This equation takes into account gravity fallout, wind velocity, atmosphere turbulent diffusion, location of dust emission source. To sole modeling equation the implicit difference scheme of splitting was used. Findings . Developed mathematical model allows quick prediction of the level of atmosphere pollution in case of dust emissions from mine ventilation fan. The models allow to obtain zones of contamination near settlements which are situated in vicinity of mine. Originality . The developed mathematical model takes into account a number of physical factors, which at the present time are not considered on the days when prediction of the atmosphere pollution in settlements near mine is carried out. Practical value . On the basis of the developed mathematical model program code was created. This code can be used for evaluation of atmosphere pollution in settlements which are effected mine fan emissions.

Complex of programs for assessment of air environment pollution level

Abstract: Purpose . The work involves the development of numerical models for assessing the level of air pollution in the case of emergencies. Methodology . To describe the process of dispersing in the atmosphere of chemically hazardous substances emitted in emergency situations, we use the three-dimensional equation of the mass transfer of pollutants in the atmospheric air. For the express calculation two-dimensional mass transfer equation is used. Equations of mass transfer take into account the field of wind speed, atmospheric diffusion, the intensity of release of chemically hazardous substances into the atmosphere. For numerical integration of the mass transfer equations, implicit difference schemes are used. The developed complex of programs was created for solving the problems of forecasting the level of atmospheric pollution taking into account the influence of buildings on the formation of pollution zones. In order to take into account the influence of buildings on the formation of pollution zones, the calculation of the velocity field of the wind stream is based on the model of potential flow. Application of this model makes it possible to quickly calculate this field in the presence of obstacles. Findings . The developed mathematical models form the basis of the programs complex and can be applied for carrying out operative calculations of the sizes, intensity of pollution zones, which are formed in the atmosphere during the release of chemical substances in the case of emergency situations on chemically dangerous objects and transport. The developed complex of programs can be realized on computers of small and average power, which allows it to be widely used for solving problems that arise during the development of PLES (plan for liquidation of emergency situations). For practical application of the developed complex of programs, standard input information is required. Originality. The complex of programs for the estimation of the level of air pollution during the release of chemically hazardous substances into the atmosphere is proposed. The program complex can be used to assess the impact of emissions on the risk of chemical damage to people both on the territory of the industrial facility and in the residential area. The basis of the developed complex of programs are numerical models for calculating aerodynamics and mass transfer. Practical value . The developed complex of programs makes it possible to solve the applied problems that arise during the development of PLES for chemically hazardous objects.

Experimental investigations of interaction of track and rolling stock on crossovers

Abstract: Purpose. Recently on the Ukrainian railways network more attention is paid to the cases of violations in the maintenance of crossovers, which may lead to deterioration of the train traffic safety conditions. As a rule, such violations occur as a result of inaccuracies during crossover pegging and laying, as well as are the consequence of impact of rolling stock and thermal forces. The appearance of geometrical irregularities can also be triggered by violation of the scheme of layout of concrete sleepers in the crossover turnout curve with intertrack spaces of less than 5.3 m. Therefore, we have decided to analyze the impact of the presence of deviations from the layout scheme of the sleepers and geometric irregularities on the conditions of track and rolling stock interaction based on the results of experimental investigations. It was also decided to establish a connection between the stress-strain states of the track and the presence of short sleepers. Methodology. The effect of deviations from the layout scheme of the sleepers and geometric irregularities on the interaction conditions of track and rolling stock was studied by means of theoretical calculations and experimental research. The experimental research covered the area on the non-public railway tracks that meets the required conditions for scientific and research work on the territory of «Transinvestservice» company. Findings. The distribution of stresses and forces acting on a railway track depending on speed movement of experienced rolling stock was obtained. In addition we obtained the data on the influence of the sleeper geometric parameters on its stress-strain state. Originality. For the first time the paper assessed the impact of rolling stock in the presence of geometrical irregularities and asymmetrically truncated sleepers within the crossover connection part on the stress-strain state of track in this zone. In addition, we compared the results for the area with common and shortened sleepers. Practical value. The obtained experimental data allowed determining that the stress-strain state of the track structure in the crossover turnout curve at rolling stock speeds of up to 40 km/h fulfills the conditions of strength and stability. These results can be used to test mathematical models and theoretical studies on the development of standards for the maintenance of crossovers. The level of the obtained vertical, lateral forces and stresses practically does not depend on the presence of the truncated part of the sleepers, which are stacked in crossovers.

Simulation and prediction of the process based on the general logistic mapping

Abstract: Purpose . The aim of the research is to build a model of the generalzed logistic mapping and assessment of the possibilities of its use for the formation of the mathematical description, as well as operational forecasts of parameters of complex dynamic processes described by the time series. Method ology . The research results are obtained on the basis of mathematical modeling and simulation of nonlinear systems using the tools of chaotic dynamics. Findings . A model of the generalized logistic mapping, which is used to interpret the characteristics of dynamic processes was proposed. We consider some examples of representations of processes based on enhanced logistic mapping varying the values of model parameters. The procedures of modeling and interpretation of the data on the investigated processes, represented by the time series, as well as the operational forecasting of parameters using the generalized model of logistic mapping were proposed. Originality . The paper proposes an improved mathematical model, generalized logistic mapping, designed for the study of nonlinear discrete dynamic processes. Practical value . The carried out research using the generalized logistic mapping of railway transport processes, in particular, according to assessment of the parameters of traffic volumes, indicate the great potential of its application in practice for solving problems of analysis, modeling and forecasting complex nonlinear discrete dynamical processes. The proposed model can be used, taking into account the conditions of uncertainty, irregularity, the manifestations of the chaotic nature of the technical, economic and other processes, including the railway ones.

Metaphysical revolution of descartes and transformation of the anthropological project

Abstract: The purpose is to reveal and comprehend forms of influence metaphysical' revolution for a way of interpretation of the anthropological project by Descartes on the basis of investigations of modern dekartes's researchers, that is the recognition of a fundamental role of metaphysics. Methodology. As methodological base modern investigations of dekartes's researchers accenting a fundamental role of metaphysics and expediency of unbiassed judgment of heritage of the great thinker are used. The scientific novelty. The transformation of the anthropological project is outlined as manifestation of metaphysical revolution. It is about a transcendencecy of naive anthropology (as an embodiment of reductive mindset), that is interpretations of human nature as its corporality and transition to metaphysical anthropology which consists in upholding of unconditional priority of human thinking as associated with God. As result of transition concentration of attention on intense human nature, that is at tension between sensuality and intelligence, aspiration to truth and tendency to delusion, between Life and Nothing, etc. Conclusions. The appeal to the incomplete anthropological project of Descartes on the basis of innovative researches allows proving the thesis about influence of metaphysical revolution on a way of its interpretation. The main forms of oriented to science ideals of naive anthropology, trust in evidence of the senses, atheism, interpretation of science as the main form of detection rationality of human nature, which Descartes tends constructively to overcome in the text of "meditation", are highlighted. During creation of metaphysical anthropology the attention of the thinker is drawn by the fact of impossibility of comprehension of human nature by means of natural-science rationality and expediency of the appeal to metaphysics. The subject of attention of the thinker is the tension between sensuality and intelligence, need for truth and tendency to delusion, ontologic tension between Life and Nothing etc.