http://elar.nung.edu.ua/handle/123456789/7353 The scientific journal Sun, 05 Apr 2026 15:34:22 GMT 2026-04-05T15:34:22Z http://elar.nung.edu.ua:80/retrieve/27641/2018-5.jpg http://elar.nung.edu.ua/handle/123456789/7353 http://elar.nung.edu.ua/handle/123456789/7360 Title: Method of evaluating the rhythm structure of a cyclic signal through defining the additional countdowns of a discrete function of rhythm Authors: Lytvynenko, I. V. Abstract: The method of evaluation of additional countdowns of a discrete function of rhythm is being considered by taking into account single-phase values of the countdowns of the simulated cyclic signal, which is rhythmically related to the studied one. Considering the equality of the attributes of cyclicity, additional isomorphic countdowns are chosen in a simulated cyclic signal at all segment-cycles and segment-zones. Then the rhythmic structure is evaluated taking into account the defined additional countdowns. The obtained additional countdowns of the rhythmic structure provide the possibility to evaluate the behaviour of a discrete rhythm function between the countdowns’ limits of the segmental structure. The developed method can be used in automated digital processing systems (of diagnostics and forecasting) of cyclic data: cardiac signals of different physical nature, cyclical economic processes, processes of gas, water and power consumption, processes of surface formations of modern materials for evaluating the countdowns of the rhythmic structure that provides the information relating to the rhythm (pace) escalation in time of the magnitude of time intervals (distances) between single-phase values of the cyclic signal. The developed method allows solving the problem of evaluating the countdowns of the rhythmic structure through obtaining a rhythmically coupled cyclic signal from a simulated implementation with the initial, studied additional countdowns that correspond to single-phase values in all segments of the cyclic signal. In further research, it is planned to use the obtained information for developing a method for choosing an optimal interpolation polynomial for adaptive interpolation of a discrete function of rhythm on the corresponding segment-cycles or segment-zones. Mon, 01 Jan 2018 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/7360 2018-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/7359 Title: Pecularities of calculation of throughput capacity and energy consumption of oil pipeline at parallel operation of pumping units Authors: Serediuk, M. D. Abstract: The peculiarities of hydrodynamic processes in the case of parallel operation of centrifugal pumps on the pipeline are established. The method and software for determining the throughput capacity and energy efficiency of the main oil pipeline for the use of multi-type pumps operating at oil pumping stations are developed. It has been proved by calculations that, under certain conditions, a parallel operation of the pumps can have advantages over the traditional sequential scheme of their operation. Mon, 01 Jan 2018 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/7359 2018-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/7358 Title: Non-stationary processes in the gas transmission systems at compressor stations shut-down Authors: Grudz, V. Ya.; Grudz, Ya.V.; Zapukhlyak, V.B.; Kyzymyshyn, Ya. V. Abstract: There are presented results of analytical studies of the nature and duration of non-stationary processes in complex gas transmission systems caused by the shut-down mode of individual compressor stations. A mathematical model of the gas pipeline has been made, taking into account the influence of compressor stations on the basis of classical gas flow and continuity equations using the Dirac source functions. Realization of the created mathematical model by application of the Fourier and Laplace integral transforms allowed to obtain a dependence in the analytical form, reflecting the nature of the oscillation in time of the mass flow of gas in the initial and final sections of the gas pipeline. The constructed graphical dependences of the trend in the performance of the gas transportation system at its beginning and at the end showed the effect of placing the compressor station in the gas transportation system, in particular its serial number on the route number, on the nature of the non-stationary process caused by its stop, in particular, the duration of non-stationarity. The results obtained and the final conclusions will be useful in forecasting the operating modes of gas transmission systems, especially when they are not fully loaded. Mon, 01 Jan 2018 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/7358 2018-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/7357 Title: Influence of nanoparticles on the physical and mechanical properties of modified epoxy-composite coatings Authors: Stukhlyak, D. P.; Yakushchenko, S. V. Abstract: In the work, to form a composite material with increased physical and mechanical properties, an epoxy diane oligomer ED-20, a hardener polyethylene polyamine PEPA and a modifier 2,4 diaminotoluene were used as a binder. The dependence of the nanoparticle content as a mixture of nanodispersed compounds on the physicomechanical properties of epoxy composites was studied. To form a protective coating with increased cohesive properties, the optimal content of nanoparticles is q = 0.5 pts.wt. by 100 parts by weight of epoxy oligomer ED-20, which provides an increase in the ability of the developed material to resist static, dynamic, and shock loads. The adsorption and catalytic activity of nanofillers has been proved by optical spectroscopy, which provides interaction with the side chains of the epoxy oligomer chain, as a result of which the cohesive strength of the materials increases. Mon, 01 Jan 2018 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/7357 2018-01-01T00:00:00Z