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.

Mathematical model of unsteady heat transfer of passenger car with heating system

Abstract: Purpose . The existing mathematical models of unsteady heat processes in a passenger car do not fully reflect the thermal processes, occurring in the car wits a heating system. In addition, unsteady heat processes are often studied in steady regime, when the heat fluxes and the parameters of the thermal circuit are constant and do not depend on time. In connection with the emergence of more effective technical solutions to the life support system there is a need for creating a new mathematical apparatus, which would allow taking into account these features and their influence on the course of unsteady heat processes throughout the travel time. The purpose of this work is to create a mathematical model of the heat regime of a passenger car with a heating system that takes into account the unsteady heat processes. Methodology . To achieve this task the author composed a system of differential equations, describing unsteady heat processes during the heating of a passenger car. For the solution of the composed system of equations, the author used the method of elementary balances. Findings . The paper presents the developed numerical algorithm and computer program for simulation of transitional heat processes in a locomotive traction passenger car, which allows taking into account the various constructive solutions of the life support system of passenger cars and to simulate unsteady heat processes at any stage of the trip. Originality . For the first time the author developed a mathematical model of heat processes in a car with a heating system, that unlike existing models, allows to investigate the unsteady heat engineering performance in the cabin of the car under different operating conditions and compare the work of various life support systems from the point of view their constructive solutions. Practical value . The work presented the developed mathematical model of the unsteady heat regime of the passenger car with a heating system to estimate the efficiency of unsteady, transitional temperature states in passenger cars, taking into account the design features of the heating system and the regulatory requirements. This allows the development and implementation of optimal technical characteristics of heating appliances and the construction of an algorithm for controlling their operation in accordance with operating conditions, taking into account the thermal inertia of the car in the transitional modes of heating, on the basis of mathematical modeling.

Water cleaning from residues of medicinal preparations

Abstract: Цель. Основная цель статьи – проанализировать наличие в воде Украины и мира остаточных количеств лекарственных препаратов, а также на основании мирового и собственного опыта предложить методы очистки вод от лекарств. Методика. Исследования выполнены на основании анализа научных источников и отчетных данных о наличии лекарств в воде Украины, европейских стран, США (1999–2017 гг.). Результаты. Проанализированные источники свидетельствуют, что основной экологической угрозой мирового масштаба является наличие лекарств в питьевой воде. Очистные сооружения не приспособлены для обнаружения и разложения лекарственных средств. Во всем мире не предусмотрена борьба с данными веществами. Авторы представляют результаты комплексного рассмотрения вопросов, связанных с определением наличия лекарств в различных водах, их концентраций и наиболее опасных лекарственных препаратов-токсикантов. Медикаменты могут накапливаться не только в организме людей и животных, но и в морской и речной рыбе и т. под. Воздействие даже следовых количеств некоторых лекарств (наркотики, гормональные средства) может оказывать негативное влияние на здоровье более уязвимых слоев населения, особенно детей. Установлено, что главным виновником гормонального загрязнения воды является сельское хозяйство, а именно животноводство. Научная новизна. В работе обобщены имеющиеся и представлены новые методы и технологии очистки воды, такие как: электрохимический, мембранный, адсорбция на основе активированного угля, ультразвуковая обработка в присутствии катализаторов, обработка вод ферментами и персульфатами. Как второй путь снижения количества лекарств в воде предложено создание экологически чистых лекарств. Практическая значимость. Водные проблемы являются главными во всем мире и в Украине в том числе. Нужно предусмотреть дополнительное финансирование для решения проблемы очистки воды от лекарственных препаратов не по остаточному принципу, а по основному финансированию, учитывая то, что вода – это основа жизни на земле, и от качества воды зависит здоровье и жизнь человечества.

Simulation of subgrade embankment on weak base

Abstract: Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.

Assessment of the railway influence on the heavy metal accumulation in soil

Abstract: Purpose. The scientific paper aims at analyzing the current state of the railway infrastructure soil contamination with heavy metals (HM), namely, the three stations of Prydniprovska railway: Kamianske-Pasazhyrske, Zaporizhzhia-Kamianske and Trytuzna. Methodology. The research object is the soil of the above mentioned railway stations, the research subject is the total content of HM. Sampling was carried out every 15 m between and outside both rails up to the end of railway ties. The total area of the investigated sites is 600 m 2 . The total form of Fe, Pb, Zn, Cu, Ni, Cd and Mn concentration was determined by the atomic absorption spectrometry method. The obtained data were compared with the background concentration of HM for Dnipropetrovsk oblast and the results of analyzing the reference control located at a distance of 250 m from the railway stations. Findings. It is found out that rail transport is a source of HM emission into soil. The findings indicate that the soil state of the Kamianske-Pasazhyrske station corresponds to a low ecological risk and a low degree of pollution, since the station is a passenger one only and pollution occurs mostly due to the friction of wheels and rails and that of the pantograph and overhead system, as well as the pesticide use. The soil contamination of the Zaporizhzhia-Kamianske station is characterized by a considerable potential environmental risk and a very high degree of pollution. This station is a cargo-passenger one, and this pollution level is mainly due to loading and unloading processes. The soil of the Trytuzna station is characterized by an average potential ecological risk and a moderate degree of pollution. Although this station is mainly used for the freight trains reformation, but due to the transportation of large volumes of bulk ore cargoes HM fall into soil. Besides, the station is not electrified. Recommendations for assessment of the soil pollution levels are given. Originality. For the first time the potential ecological risk of soil contamination was determined on the basis of the physical and chemical analysis of the HM content in the soil of the above-mentioned stations. Practical value. The results of the study can be used as a justification of the reasonability of introducing the environmental monitoring programs for the railway land, the environmental protection measures for the soil treatment from HM, correcting the railway exclusion zone, as well as protection of adjacent territories from the propagation and accumulation of the mentioned pollutants. The necessity and urgency of the constant control of the HM content in the railway soil and the relevance of the research continuation in this scientific direction are confirmed on the basis of the received data.

The basis of mathematical description for wave model of stresses propagation in railway track

Abstract: Purpose. Modern scientific research has repeatedly cited practical examples of the dynamic effects of railway track operation that go beyond the static calculation schemes. For the track sections where the train speed is approaching to the velocity of wave propagation in the slab track layers such issues are of particular relevance. An adequate tool for the study of such issues can be the use of the wave theory of stress propagation. The purpose of the article is the creation of a mathematical description of the basic principles of the stress propagation wave model in the railway track, which can be used as a basis for the practical development of the relevant calculation system. Methodology. The model of stress-strain states of the railway track on the basis of the stress wave propagation theory is to bring together the equations of the geometry of the outline of the space systems that is involved in the interaction at a given time, and the dynamic equilibrium equations of deformation. The solution is based on the use of the laws of the theory of elasticity. The wave front is described by an ellipsoid equation. When determining the variation in time of the surface position of the ellipsoid a vector approach is used. Findings. The geometry equations of the wave motion determine the volumes of material layers of the slab track involved in the interaction at a given time. The dynamic equilibrium determination of the deformed condition of the space bounded by the wave front makes it possible to calculate both the stresses and strains, and their changes during the time of the load perception. Thus, mathematical descriptions of the processes that occur in the perception of the load by the elements of railway track at high speeds were obtained. Originality. The simulation tasks of the track and rolling stock interaction, in particular taking into account the dynamic deflection of slab track were further developed. For the first time the article presents the basics of the mathematical description of the wave stress propagation model in the railroad track, which can be used to perform practical calculations. Practical value. The obtained data can be used to justify the track construction or establishing appropriate values of permissible speeds for the introduction of train motion with high speeds.