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.

Electromagnetic Compatibility and Power Quality of Traction and Non-Traction Consumers

Abstract: The energy efficiency of power traction system and the power quality of the electric grid are estimated. The electromagnetic compatibility (EMC) traction and non-traction consumers are investigated. The propagation of traction current is studied as well as the third harmonic. The coefficient of harmonics is accorded the standards on the 110 kV buses.

Elastic deformations impact in elements of the rail fastening, type кпп-5 on a size of pressing force of the rail to the subrail basis

Abstract: Purpose. The railway transport is one of the most important links in economy of Ukraine, and it is a basis of its transport system. As the majority of freight transportation of coal and metallurgical industry is conducted by railway transport, its effective use is a necessary condition of stabilization and development in economy of Ukraine. One of the strategic works connected with implementation of high-speed train service in Ukraine is the reliable work ensuring of connection of intermediate rail fastening during operation. For engineering works, according to the contents and repair of fastenings the considerable share of labor expenses during operation of a way is necessary. One of domestic intermediate fastenings which after long operational supervision has implemented into continuous operation is the fastening, type КПП-5. This fastening is a prototype of the Polish rail fastening type SB-3. After the long operation in fastenings, type KПП-5, a number of the shortcomings connected with premature refusal of its elements was revealed. This in generally is connected with intensive reduction of size of pressing force of a rail to the subrail basis. Therefore the purpose is the development of a technique and practical control devices concerning a condition of work of a rail fastening knot, type KПП-5 at operation. Methodology. The assessment of various factors impact at a size of pressing force of a rail to the subrail basis in the knot of a rail fastening, type KПП-5 at operation is the foundation of the research method. Findings. By means of the developed technique and practical control devices it was established: the general reduction of pressing force of a rail to the subrail basis during one mill. tons gross ., taking into account influence of various factors, may constitute kN . Originality. Accordingly to the obtained results the author firstly described and expressed by empirical dependence the process of change of pressing force of a rail to a subrail basis in a fastening, type KПП-5 after the admission of T, one mill. tons gross . Practical value. The device design is developed for control of elastic properties and a numerical assessment of pressing force decrease of the terminal to a rail depending on the passed tonnage.

Territorial risk assesment after terrorist act: express model

Abstract: Purpose. The paper involves the development of a method to assess the territorial risk in the event of a terrorist attack using a chemical agent. Methodology. To describe the process of chemical agent scattering in the atmosphere, ejected in the event of a terrorist attack, the equation of mass transfer of an impurity in atmospheric air is used. The equation takes into account the velocity of the wind flow, atmospheric diffusion, the intensity of chemical agent emission, the presence of buildings near the site of the emission of a chemically hazardous substance. For numerical integration of the modeling equation, a finite difference method is used. A feature of the developed numerical model is the possibility of assessing the territorial risk in the event of a terrorist attack under different weather conditions and the presence of buildings. Findings. A specialized numerical model and software package has been developed that can be used to assess the territorial risk, both in the case of terrorist attacks, with the use of chemical agents, and in case of extreme situations at chemically hazardous facilities and transport. The method can be implemented on small and medium-sized computers, which allows it to be widely used for solving the problems of the class under consideration. The results of a computational experiment are presented that allow estimating possibilities of the proposed method for assessing the territorial risk in the event of a terrorist attack using a chemical agent. Originality. An effective method of assessing the territorial risk in the event of a terrorist attack using a chemically hazardous substance is proposed. The method can be used to assess the territorial risk in an urban environment, which allows you to obtain adequate data on possible damage areas. The method is based on the numerical integration of the fundamental mass transfer equation, which expresses the law of conservation of mass in a liquid medium. Practical value. The proposed method for assessing the territorial risk in the event of a terrorist attack using a chemical agent can be used to calculate the affected areas near administrative buildings, centers and other socially significant facilities.

Increased controllability of the distributed traction system in emergency mode

Abstract: The puprose of the work is to improve approaches to the controllability of power consumption in distributed power systems of electric rolling stock using modern technologies and equipment. Unequal energy consumption on the shoulders of the power supply causes additional losses in the system and makes the voltage mode worse on the current collectors of electric locomotives. To increase the controllability of operation modes, is proposed to use feeder volt-additional converters with arcless commutation of short-circuit currents. Using such converters allow to stabilize the voltage on the current collectors of electric locomotives and reduce the switching-off time. Variant calculations using the proposed circuit engineering of traction substations on the simulation model prove that the power losses from the equalizing currents are significantly reduced

Structure and Properties of Composite Nickel Coatings Deposited by Means of Programmable Pulsed Current under Laser Irradiation

Abstract: A method for the formation of composite electrolytic coatings in the process of electrodeposition in an electrolyte with ultradisperse diamond (UDD) particles in the programmable pulsed current regime under simultaneous laser irradiation has been developed. This method provides the layer-by-layer deposition of gradient nickel coatings 15–20 µm in thickness with a variable content of UDD particles along their depth. The amount of UDD particles is minimal (0.10–0.13 at %) in the layers deposited in the initial period of this process, whereas the concentration of UDD particles in the layers formed at the later process stages grows to 0.19–0.26 at %. The concentration gradient of UDD particles along the depth improves the adhesion properties and wear resistance of coatings and provides a 16% decrease in the consumption of UDD particles with a local increase in the concentration of UDD particles in a coating to 0.32 at %.