Факультет "Промислове та цивільне будівництво" (ДІІТ)

Permanent URI for this communityhttp://crust.ust.edu.ua/handle/123456789/47

ENG: Faculty "Industrial and Civil Construction"

Browse

Now showing 1 - 40 of 1027

10 лет отечественной отрасли пассажирского вагоностроения: история, сегодняшний день, перспективы развития
(ТОВ ЦІТУ, м. Харків, 2011) Приходько, Владимир Иванович; Хворост, Е. Ф.; Лутонин, Сергей Витальевич; Шкабров, Олег Анатольевич; Пшинько, Александр Николаевич; Мямлин, Сергей Витальевич; Донченко, Анатолий Владимирович
RU: Статья посвящена десятилетию отечественной отрасли пассажирского вагоностроения. История, сегодняшний день, перспективы развития.
3D Modeling of Biological Wastewater Treatment in Aeration Tank
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2020) Biliaiev, Mykola M.; Lemesh, Maksym V.; Gunko, Olena Y.; Zadoia, Viacheslav O.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
ENG: Purpose. The main purpose of the article is to develop a 3D CFD model for modeling the process of biological wastewater treatment in an aeration tank. Methodology. For mathematical modeling of the process of biological wastewater treatment in the reactor, taking into account the flow hydrodynamics, geometric shape of the aeration tank, convective-diffusion transfer of the substrate and activated sludge, a 3D CFD model was built. The model is based on the three-dimensional equation of motion of an ideal liquid and the equation of mass conservation for the substrate, activated sludge. The field of sewage flow rate in the aeration tank is calculated based on the velocity potential equation. The process of biological transformation of the substrate is calculated on the basis of the Monod model. The splitting scheme was used for numerical integration of the equations of convective-diffusion transfer of activated sludge and substrate. The splitting is carried out in such a way to take into account the transfer of substrate (activated sludge) in only one direction at each step of splitting. The calculation of the unknown value of the substrate (activated sludge) concentration is carried out according to an explicit scheme. The Richardson method is used to numerically integrate the three-dimensional equation for the velocity potential, and the unknown value of the velocity potential is calculated by an explicit formula. Euler's method is used for numerical integration of equations describing the process of substrate transformation and change in activated sludge concentration (Monod model). Findings. The software implementation of the constructed 3D CFD model is carried out. A description of the structure of the developed software package is provided. The results of a computer experiment to study the process of wastewater treatment in an aeration tank with additional elements are presented. Originality. A new multifactor 3D CFD model has been developed, which allows quick assessing the efficiency of biological treatment in an aeration tank. Practical value. The constructed 3D CFD model can be used to analyze the efficiency of the aeration tank under different operating conditions at the stage of sketch design of wastewater treatment systems.
3D численная модель для оценки территориального риска при теракте
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Беляев, Николай Николаевич; Калашников, Иван Владимирович; Клименко, Ирина Владимировна; Козачина, Виталий Анатольевич
RU: Цель. Работа предполагает разработку 3D численной модели для оценки территориального риска в случае теракта с использованием химического агента. Методика. Для описания процесса рассеивания в атмосфере химического агента, выброшенного в случае теракта, используется трехмерное уравнение массопереноса примеси в атмосферном воздухе. Уравнение учитывает поле скорости ветрового потока, атмосферную диффузию, интенсивность эмиссии химического агента, наличие зданий возле места выброса химически опасного вещества. Для численного интегрирования моделирующего уравнения используется конечноразностный метод. Особенностью разработанной численной модели является возможность оценки территориального риска в случае теракта при различных метеоусловиях и наличии зданий. Для расчета поля скорости ветрового потока в условиях застройки применяется трехмерное уравнение для потенциала скорости. Результаты. Разработанная численная модель и пакет программ могут быть использованы для оценки территориального риска как в случае терактов с применением химических агентов, так и в случае экстремальных ситуаций на химически опасных объектах и транспорте. Построенная численная модель может быть реализована на компьютерах малой и средней мощности, что позволяет широко использовать ее для решения задач рассматриваемого класса, при разработке плана ликвидации аварийной ситуации. Представлены результаты вычислительного эксперимента, позволяющие оценить возможности предложенного метода оценки территориального риска в случае теракта с использованием химического агента. Научная новизна. Предложена эффективная численная модель для оценки территориального риска в случае теракта с применением химически опасного вещества. Метод может быть использован для оценки территориального риска в условиях городской застройки, что позволяет получать адекватные данные о возможных зонах поражения. Метод основан на численном интегрировании фундаментального уравнения массопереноса, выражающего закон сохранения массы в жидкой среде. Практическая значимость. Предложенный метод оценки территориального риска в случае теракта с применением химического агента может быть использован для расчета зон поражения возле административных зданий, центров и других социально значимых объектов.
3D-розрахунок вертикального відстійника на базі CFD-моделі
(Вінницький національний технічний університет, 2012) Біляєв, Микола Миколайович; Нагорна, Олена Костянтинівна
UK: Розглянуто побудову чисельної моделі масопереносу у вертикальному відстійнику. Моделювання здійснено на основі тривимірного рівняння переносу домішки і моделі потенціального руху. Для чисельного інтегрування використано неявні різницеві схеми. Наведено результати обчислювального експерименту.
Air Pollution in Ukraine from Space
(Arnika – Citizen Support Centre, Prague, Czech Republic, 2020) Bočková, Simona; Bohovic, Roman; Hrnčiar, Matúš; Muroň, Mikuláš; Filippovová, Pavlína; Skalský, Martin; Soroka, Maksym L.; Labohý, Jan
EN: Purpose. This study presents the results of the analysis of air pollution in Ukraine, based on satellite data Copernicus Sentinel 5p and the Copernicus Atmospheric Monitoring Service. The authors of this study present the spatial and temporal distribution of the content of the PM2.5, PM10, NO2, CO and H2CO in Ukraine. Methodology. Satellite data from Sentinel-5P is obtained via the Sentinel Hub (SH) operated by Sinergise. The Sentinel Hub supports Sentinel-5P level 2 (L2) data products which are geolocated, primarily preprocessed, and contain a “qa_value”. SP5 satellite data products are mostly measured and provided in mol/m2 units. For the purpose of the analysis presented here, the surface level concentrations of PM2.5 and PM10 were obtained through the Atmosphere Data Store (ADS) – a distributed data and information system which provides access to all CAMS datasets through unified web and API interfaces. In order to keep the observation time in line with the values monitored by the S5P satellite, daily concentrations modelled for 13:00 UTC have been used. As the database of CAMS data offered through the ADS consists of three years of the most recent data (termed a rolling archive), our analysis of PM2.5 and PM10 concentrations covers the period from 15 July 2017 to 14 July 2020. Results. According to the results of the study, areas of increased air pollution were identified, which include industrial agglomerations of Dnipropetrovsk, Donetsk, Kyiv, Luhansk and Zaporizhia regions of Ukraine. Producing real data and evidence and their use must be a priority for achieving real improvements in air quality while also maintaining cost-effectiveness. Therefore, the connection of all existing ground monitoring systems and extension of the network is a necessity, especially in places that have been identified as air pollution hotspots. According to the experience of the EU countries, building a unified system operated by one authority on a national level, which also performs validation of data, seems to be the best option. This system should also be independent of external and political influences. It is advisable to use all available data on air quality, including public air monitoring systems and the results of independent scientific research, after their additional evaluation. Disclaimer. This study was financed from the Transition Promotion Program of the Ministry of Foreign Affairs of the Czech Republic and National Endowment for Democracy (USA). The donors are not responsible for the opinions presented in the study.
Analysis of Temperature Field in the Transport Compartment of the Launch Vehicle
(Kaunas University of Technology, Kaunas, 2022) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Semenenko, Pavlo
ENG: The development of satellite linkage systems is based on the satellite’s transportation in space. The transportation of a satellite into orbit is carried out by a launch vehicle. The satellite is located in the transport compartment inside the main fairing. At the stage of the pre-launch preparation, it is necessary to fulfill very strict environment conditions inside the main fairing. Namely, it is very important to predict temperature field in the transport compartment inside the main fairing during its forced ventilation at the stage of pre-launch preparation. To calculate the temperature field formed by the ventilation of the transport compartment and release of heat from different elements of the satellite, the energy equation was used. This equation took into account the intensity of heat release from different parts of satellite, air flow pattern over the satellite, heat transfer in the transport compartment. The non-uniform field of the air flow velocity in the transport compartment was calculated on the basis of the potential flow model. The finite difference schemes were used for numerical integration of modeling equations. The computer code has been developed that implements the proposed numerical model. The results of computational experiments to estimate the temperature regime in the main fairing of the launch vehicle for different satellites is presented.
Analysis of the Causes of Accidents of Steel Capacitive Structures for Bulk Materials
(Ukrmetallurginform "STA" Ltd., 2011) Bannikov, Dmytro O.
ENG: The data collected by the author regarding the accident rate of steel capacitive structures for the storage of bulk materials are presented. The materials include both the information written in the specialized literature, the results of the reports of practical structure investigation and review of the causes of accidents and the author's own developments, compiled on the basis of the research results. The presentation is illustrated by photographs of damages and accidents of the investigated structures.
Analytical Method for Compiling and Applying a Ballast Map for the Traction Unit PE2U
(НВП ПП «Технологічний Центр», м. Харків; Українська державна академія залізничного транспорту, м. Харків, 2019) Bannikov, Dmytro O.; Radkevich, Anatolii V.
ENG: Under practical operation, electric locomotive traction units of series PE2U quite often require, especially in recent decades, various kinds of repair, necessitating the restoration of fleet of these machines that are rather worn-out. That changes the most important indicator in the work of the machine ‒ the distribution of masses; the resulting imbalance of the machine can reach 30 %. Further operation of such a locomotive leads to a decrease in its traction by 40‒100 kN, shortens the service life of the undercarriage by 8‒10 years on average, as well as requires that the speed of the machine during operation should be reduced by 10‒15 km/h. Given the lack of an appropriate regulatory framework and of recommendations in the specialized literature, such balancing operations are actually performed iteratively, with an arbitrary arrangement of ballast elements, which often delays the duration of operations and leads to their poor quality. One of the possible solutions to resolve this issue is the development and implementation of a special theoretical method that would make it possible to analytically substantiate the proposed structural-technological solutions related to the arrangement of a ballast at the electric locomotive traction unit PE2U. In this case, the ballast is composed of individual small-size elements that are stacked in rows into existing structural cavities in a bearing frame. The result is a compiled so-called individual ballast map for each machine. The proposed approach includes two stages of calculations and makes it possible to not only obtain practically acceptable ballast location diagrams, but to also significantly reduce the number of weighings required for the machine. The approach has been tested on several machines at electric locomotive traction units of PE2U over 2010‒2012 and could be officially used in the specialized regulatory documentation. Its practical error does not exceed 3 % and is mainly predetermined by technological factors.
Anti-Crisis Management of Passenger Transport as a Factor of Increasing Railway Competitiveness
(Національний технічний університет «Дніпровська політехніка», Дніпро, 2020) Pshinko, Oleksandr M.; Orlovskaya, Oleksandra V.; Charkina, Tetiana Yu.; Carra, A. O.
ENG: Methods. To conduct research, the following methods were used: competition, SWOT analysis, mathematical analysis, marketing models, the PEST analysis method, the decision-making method, the Kaizen approach to achieve a high degree of quality of a product or service, as well as systems approach. Results. The article proves the expediency of applying anti-crisis management of passenger transportation as a factor of increasing the competitiveness of the railway. The analysis of the development of the transport services market has shown that rail transport is gradually losing its passengers, in favor of air and road transport. The management of «Ukrzaliznytsia» has recently made many steps to improve the competitiveness of railway passenger transportation in the domestic market of transport services, but these measures are not sufficient today to restore the lost positions that the railway had before. In order to increase the level of competitiveness of railway passenger transportation, as well as to develop a larger segment in the transport services market, the following tasks are identified: to conduct research and analysis of factors affecting the current situation in the service market, to analyze the advantages of existing potential competitors in the transport services market, to analyze the experience of passenger transportation in the European Union, to develop measures that can be proposed to «Ukrzaliznytsia» to improve the efficiency of passenger services and generate additional profit. Novelty. Areas of crisis management to improve the efficiency of passenger transport are proposed, namely: the development of railway tourism, the introduction of a system of discounts «bonus ticket», the creation of a railway hub, implementation of Kaizen approach to achieve a high level of quality services, the organization of multimodal passenger transport by «travel card». Practical value. The implementation of the proposed measures and strategies will allow «Ukrzaliznytsia» to identify promising mechanisms for managing the passenger complex in the context of an escalating crisis. All these measures will help «Ukrzaliznytsia» to get out of the crisis and get additional profit for the passenger industry.
Anti-Terror Engineering in the Case of Possible Terrorist Attacks with Chemical Agents
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Biliaev, Nikolai N.; Berlov, Oleksandr V.; Kalashnikov, Ivan V.; Kozachyna, Vitalii A.
ENG: Purpose. This work aims to develop a method of local outdoor reduction of the concentration of a chemically hazardous substance, which entered the atmosphere through a cafe roof vent. It also involves the creation of a numerical model for calculating the chemical contamination zone that allows assessing the effectiveness of the screens used to minimize its level. Methodology. To solve this problem, we used the velocity potential equation that al-lowed to determine the air flow velocity field, and the equation of convective diffusion dispersion of a chemically hazardous agent in the atmospheric air emitted through the ventilation system in case of a terrorist attack. The simulation took into account the uneven velocity field of the wind flow, atmospheric diffusion, emission rate of a chemically hazardous agent. In the numerical integration of the velocity potential equation, we used the Liebmann method. For the numerical solution of the equation of convective diffusion dispersion of the impurity, an implicit alternate-triangular difference splitting scheme was used. Findings. The developed numerical model allowed assessing the effectiveness of building screens used to reduce the concentration of a hazardous substance and minimize the risk of toxic damage to people outdoor during an initiated emission of a chemical agent. The constructed numerical model can be implemented on computers of low and medium power, which allows it to be widely used for solving problems of the class under consideration when developing an anti-terror engineering strategy. Originality. An effective numerical model for calculating the outdoor chemical contamination zone during a possible terrorist attack using a chemical (biological) agent has been proposed. The model can also be applied to assess the effectiveness of some protective measures aimed at reducing the air pollution level during a terrorist attack. Practical value. The developed numerical model can be used to organize protective actions near social objects of a possible chemical attack by a terrorist.
Application of Local Exhaust Systems to Reduce Pollution Concentration Near the Road
(Silesian University of Technology, Katowice, Poland, 2020) Biliaiev, Mykola M.; Pshinko, Oleksandr M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Sładkowski, Aleksander
EN: In this study, the methodological foundations of the technology for the local reduction of chemical pollution from vehicles were improved through the use of twolevel suction units and guide plates of various lengths installed on the nozzles of the suction devices. A program has been developed for the numerical calculation of the carbon monoxide concentration field for evaluating the efficiency of using two-level exhaust systems with different lengths of guide plates on the gas flow selection pipes. The solution of the equations of hydrodynamics and mass transfer is carried out on the basis of finite-difference methods. A number of physical and computational experiments have been carried out; it has been established that the concentration of carbon monoxide in the zone of two-level suctions location decreases by 46-68%.
Application Prospects of Threaded Joint of Armature
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2014) Radkevych, Anatolii V.; Netesa, Andrii M.
ENG: Purpose. One of the main technological operations of buildings construction on the basis of monolithic frame systems is the production of mesh reinforcement. The current interest is the new ways specification of advanced bonding armature techniques without reliability weakness and design of the building in whole, as well as the finding of use prospects of screw-threaded joint of armature as the most technological and economic method of re-bars joints. Methodology. Advantages and disadvantages analysis of existing rebar compound technologies was implemented by couplings of different types and constructions. The most promising vertical constructions for the vertical bars joints in frameworks were determined. Findings. Researches of existing technologies of rebar joints by the couplings of different construction were carried out. The installation method of mesh reinforcement of vertical structural elements with the use of the special catching devices was developed. It allows considerably accelerating installation of mesh reinforcement. Originality. Regularity of labor intensiveness change of mesh reinforcement installation of columns at armature joint in vertical position by threaded couplings with the help of catching devices using special construction was determined. This allows substantially reducing the labor expenditures during installation of these elements. Dependency of labor intensiveness and cost of lap welding armature joints, by tub-seam welding and by thread coupling depending on its diameter was designated. Regularity of labor intensiveness changes of installation at armature joints by different methods taking into account preparatory works was defined. Practical value. The analysis of mechanical armature joints techniques was conducted. It will allow selecting methods of armature joints to increase the speed of construction works more economical and effective.
Aspects Definition of Reliability Evaluation Facade Systems From the View Point of Eurocode
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Radkevych, Anatolii V.; Netesa, Kostiantyn M.
ENG: Purpose. This paper is devoted to the definition of the most rational technique of reliability evaluation of facade systems of multistoried residential buildings with using the experience of buildings construction and operation abroad. The subject is also focused on defining the parameters of materials and facade systems, the improvement of which can increase the reliability and durability of facade systems of multistoried residential buildings, as well as cut the cost of their operation. Methodology. A comparative analysis of the operating experience of various types of facade systems in Ukraine and abroad based on the data of different authors was conducted. The analysis of the impact of external factors on facade systems with the subsequent comparison of methods for assessing the reliability of facades according to the criteria stated in the Eurocode was carried out as well as the selection of parameters that determine the reliability and durability of facade systems. Findings. Authors have performed researches of valuation methods of organizational and technological reliability and durability of modern facade systems. It was identified the cause of the failure of facade systems. It is offered the ways of materials improvement of facade systems, and constructional and organization-technological decisions on the structure of facade systems. Methods of increase of reliability and durability of front systems were defined. Originality. The most rational technique of reliability evaluation of facade systems considering requirements of Eurocode in questions structural design was defined. Practical value. Improvement of evaluating methods for organizational-technological reliability of facade systems of multistoried residential buildings will predict more accurately the lifetime of enclosures. Using the methods described in the Eurocodes, to determine the reliability and durability of the facade systems will provide the general criteria for the building structures design in Ukraine and Europe, as well as facilitate the exchange of experience in the construction and operation of buildings between the countries of Europe. An analysis of the causes of failures of facades enables to determine the directions of improving the properties of the materials used for the manufacture of facade elements structures as well as engineering and technological solutions of applied facade systems.
Assesment of the Railway Influence on the Heavy Metal Accumulation in Soil
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Samarska, Alla V.; Zelenko, Yuliya V.
EN: 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 m2 . 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 Assessment of Negative Impact of Oil Products on Railroad Track and Rolling Stock Constructions
(Kaunas Univ. of Technology, Lithuania, 2019) Zelenko, Yuliya V.; Lunys, O.; Neduzha, Larysa O.; Steišūnas, S.
EN: Abstract In order to ensure the reliability of metal elements in structures of railway infrastructure, the influence of solutions is investigated that contain oil products on the degree of corrosive changes of steels of grade 3, 5, RSt37-2, 09G2D and grey cast iron 21-40. On the basis of experimental data that were obtained using R-5126 polarization resistance indicator, potentiostat P-5827 mathematical relations of the influence of various fractions of oil products on the rate of metal corrosion are introduced. The obtained data can be used for non-destructive control of basic elements of structures, the choice of effective inhibitors for reducing the corrosive aggressiveness of the environment and the protection of structural elements.
Atmosphere Pollution Modeling in the Case of Accident During Rocket Propellant Transportation by Trains
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Gunko, Olena Yu.; Chernyatyeva, Kateryna
EN: Abstract. At present time, in Ukraine the intensive development of solid-propellant missiles takes place. These missiles are called «Grim», «Grim-2», etc. Transportation of rocket propellant very often is carried out by trains. In the case of accident during such transportation great amount of toxic chemicals may be emitted into atmosphere. It is very important to predict the atmosphere pollution level near railways transport corridors to obtain the realistic information about the size of possible zones of hitting. To forecast the atmosphere pollution in the case of rocket propellant burning in railway wagon numerical models have been developed. These models are developed to predict the atmosphere pollution in two scales. The first scale is the simulation of the atmosphere pollution near the railway tracks (so called “local scale”). The second scale is the simulation of the atmosphere pollution on the territory which is adjacent to the railway tracks («urban scale»). The forecast is based on the Lagrangian model of toxic chemical dispersion. The models allow also to predict acid rain formation in the case of solid propellant burning products dispersion into atmosphere. To solve the governing equations we used difference schemes of splitting. The results of numerical experiments are presented.
Atmosphere Protection in Case of Emergency During Transportation of Dangerous Cargo
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2016) Berlov, Oleksandr V.
EN: Purpose. The paper highlights the development of numerical models for prediction of atmospheric pollution in case of burning of the solid rocket propellant in a railway car, situated near the building on railway territory. These models can be used in predicting the effectiveness of neutralization upon the atmosphere protection for this type of accidents. Methodology. To solve this problem the numerical models based on the use of Navier-Stokes equations, to determine the velocity field of the wind flow near cars and buildings, and contaminants-transfer equations in the atmosphere were developed. For the numerical integration of pollutant transport equation was used implicit «change – triangle» difference scheme. When constructing a difference scheme physical and geometric cleavage of the transfer equation is carried out in four steps. Unknown value of pollutant concentration at each step of cleavage is determined by the explicit scheme – the method of «point-to-point computation». For the numerical integration of the Navier-Stokes equations are used implicit difference schemes. When carrying out computing experiment also takes into account: the velocity profile of wind flow; interaction between the building and the wind flow and flame jet of solid rocket propellant; the presence of a railroad car; inside which there is a source of pollution; instability of pollutant emissions. On the basis of constructed numerical models was performed the computer experiment for assessing the level of air pollution at dangerous cargo rail transportation in case of emergency at railway territory.The application calculations for the timely combustion products neutralization of solid rocket propellant were carried out. Findings. The numerical models that let promptly calculate air contamination in case of emergency during solid rocket propellant transportation, as well as calculate the rational parameters of pollutant neutralization process were developed by the researcher. These models can be used for routine calculations of various accident scenarios simulation. Originality. Numerical models were developed; they take into account significant factors, influencing the pollutant dispersion process in the atmosphere. On their base a pollutant neutralization method was offered in emergency situations on the railway transport. Practical value. Efficient numerical models, so called «diagnostic models» were considered for the rapid calculation of the air pollution level and air protection technology in emergency situations, in particular, in the case of railway transportation the solid rocket propellant.
Calculation of «Vulnerability» Zone in Case of Terrorist Attack with Chemical Agents
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Kalashnikov, Ivan V.; Kozachyna, Vitalii A.
EN: Purpose. The work involves the development of a numerical model for calculating the «vulnerability» zone of a possible terrorist attack objective with the use of a chemical agent in a builtup environment. The «vulnerability» zone is a territory near the attack objective, where the emission of a chemical agent during the attack will lead to undesirable consequences. The emission of a chemical agent outside the «vulnerability» zone will not create a dangerous concentration near the attack objective. Methodology. To solve this problem, we use the equation for the velocity potential, on the basis of which we determine the wind stream velocity field, and the equation adjoint to the equation of mass transfer in the atmospheric air of the chemical agent emitted in the event of a terrorist attack. During simulation, we take into account the uneven wind stream velocity field, atmospheric diffusion and the rate of emission of a chemically hazardous substance. For the numerical integration of the velocity potential equation, we use the method of A. A. Samarsky. For numerical solution of the adjoint equation, we introduce new variables and use an implicit difference splitting scheme. The peculiarity of the developed numerical model is the possibility of operative estimation of the «vulnerability» zone near a possible attack objective. Findings. The developed numerical model and computer program can be used for scientifically grounded assessment of the «vulnerability» zone near significant facilities in the event of possible attacks with the use of chemical (biological) agents. The constructed numerical model can be implemented on computers of small and medium power, which allows it to be widely used to solve the problems of this class when developing the emergency response plan. The results of the computational experiment are presented, which allow us to evaluate the possibilities of the proposed numerical model. Originality. An effective numerical model is proposed for calculating the «vulnerability» zone near the facility, which may be the target of a terrorist attack with the use of a chemical agent. The model is based on the numerical integration of the velocity potential equation and the equation adjoint to the equation of mass transfer of a chemically dangerous substance in the atmosphere. Practical value. The developed model can be used to organize protective actions near the target facility of a possible chemical attack by terrorists.
Calculation of the Efficiency of the Horisontal Settler with Baffles
(Саратов, 2014) Biliaiev, Nikolay N.; Kozachyna, Vitalii A.; Polubinskaja, E. V.
EN: The main purpose of this paper is development of the effective CFD model which can be used for computation speed field of the flow in the horizontal settlers which takes into account the geometrical form of the settler.
Carbon Materials for Electrically Conductive Concrete
(EDP Sciences - Web of Conferences, France, 2024) Savytskyi, Mykola V.; Sukhyy, Kostyantyn M.; Savytskyi, Oleksandr M.; Babenko, Maryna; Shevchenko, Tetyana
ENG: In recent decades, the direction of building materials science related to the creation of Smart Concretes has been rapidly developing. Smart Concretes, in addition to the functions of a structural material, also perform other functions that are related to their new properties. Among the large number of Smart Concretes, it is necessary to highlight Electrically Conductive Smart Concrete. This type of concrete is obtained by adding conductive fillers to the concrete mixture. Among them, carbon materials are the most promising in terms of their properties. Despite the large number of conducted studies of conductive fillers and conductive concrete, there is still no generalization and systematization of them. In addition, there are no standards for testing the conductive properties of both fillers and concretes. Therefore, the authors aimed to systematize data on Electrically Conductive Smart Concrete, as well as electrically conductive carbon fillers. A method for testing the electrical conductivity of Carbon Nanomaterials (CNMs) as fillers for Electrically Conductive Concrete is proposed. Approbation of the proposed method was carried out by determining the electrotechnical indicators of carbon fillers, such as coke breeze and carbon black.
CFD моделирование аэроионного режима в рабочих зонах в условиях искусcтвенной ионизации воздуха
(Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, Днипропетровск, 2016) Беляев, Николай Николаевич; Цыганкова, Светлана Григорьевна
RU: Цель. Работа предполагает создание CFD модели расчета аэроионного режима в помещениях и в рабочих зонах при искусственной ионизации воздуха путем установки ионизатора внутри помещения с учетом наиболее существенных физических факторов, оказывающих влияние на формирование концентрационного поля аэроионов. Методика. Предложенная CFD модель расчета аэроионного режима в рабочих зонах при искусственной ионизации воздуха путем установки ионизатора внутри помещения основана на применении уравнений аэродинамики, электростатики и массопереноса. Уравнение массопереноса учитывает взаимодействие ионов различной полярности друг с другом и с частицами пыли. Расчет скорости движения воздушных потоков в помещении осуществлялся на основе модели потенциального течения, для чего было использовано уравнение Лапласа для функции тока. Для расчета дрейфа заряженных частиц под действием электрического поля использовалось уравнение Пуассона для электрического потенциала. При моделировании учитывались: 1) влияние геометрических характеристик рабочей зоны; 2) местоположение отверстий приточно-вытяжной вентиляции; 3) расстановка мебели и оборудования; 4) режим воздухообмена в помещении; 5) наличие препятствий в процессе рассеивания аэроионов; 6) конкретное место эмиссии частиц пыли и ионов различной полярности и их взаимодействие в помещении и в рабочих зонах. Результаты. Разработанная CFD модель позволяет определить концентрацию отрицательных ионов в помещении и в зоне расположения органов дыхания человека. Распределение концентрации отрицательных аэроионов представлено в виде изолиний концентрационного поля. Научная новизна. Авторами создана 2D CFD модель для расчета аэроионного режима в рабочих зонах, предоставляющая возможность определять концентрационное поле аэроионов в заданном месте в помещении. Предложенная модель разработана с учетом: размещения мебели и оборудования в помещении; геометрических характеристик помещения; местоположения источников эмиссии пыли и ионов различной полярности; физических процессов, влияющих на формирование концентрационного поля аэроионов. Практическая значимость. Полученная 2D CFD модель для расчета аэроионного режима в рабочих зонах позволит рассчитывать концентрацию аэроионов в месте расположения дыхательных органов человека с учетом основных физических факторов, определяющих формирование концентрационных полей аэроионов. Это даст возможность рационально расположить ионизаторы в рабочих помещениях для создания комфортных условий работы персонала.
CFD модель для оценки территориального риска и уровня загрязнения воздушной среды при эмиссии химического агента
(Национальный горный университет, Днепр, 2018) Беляев, Николай Николаевич; Калашников, Иван Владимирович; Берлов, Александр Викторович
RU: Предложен метод расчета распространения опасных веществ в условиях застройки, который позволяет осуществлять оценку территориального риска. Численное моделирование осуществляется на базе модели аэродинамики и распространения примеси в атмосферном воздухе. Численная модель ориентирована на проведение экспресс расчетов. Приведено описание алгоритма решения задачи по оценке территориального риска при эмиссии химически опасного вещества при экстремальной ситуации на промышленном объекте. Представлены результаты вычислительного эксперимента.
CFD моделювання в аналізі ефективності систем захисту довкілля та працівників на робочих місцях
(Журфонд, Дніпро, 2022) Біляєв, Микола Миколайович; Біляєва, Вікторія Віталіївна; Берлов, Олександр Вікторович; Козачина, Віталій Анатолійович
UKR: У моноrрафії розrлянуто питання розробки та оцінки ефективності систем захисту довкілля та працівників на робочих місцях від хімічноrо, шумовоrо, пиловоrо забруднень. Велику увагу приділено розробці математичних моделей для оцінки ефективності використання засобів захисту від пилового забруднення робочих зон біля транспортних маrістралей та на об'єктах rірничого комплексу. Представлено результати розрахунку процесу дифракції ударної хвилі після вибуху на залізнничній станції та забруднення атмосферноrо повітря при горінні ракетного палива.
Choice of STFT and WT Parameters for Monitoring of EMI in Track Circuits
(Institute of Electrical and Electronics Engineers, 2023) Havryliuk, Volodymyr I.; Nibaruta, Regis; Radkevych, Anatolii V.
ENG: The article considers the problem of the correct choice of the parameters of the short-time Fourier transform and the continuous wavelet transform to ensure monitoring of electromagnetic interference in rails in order to ensure the electromagnetic compatibility of traction current with track circuits. The problem of correct choice of parameters for the time-frequency analysis of currents in track circuits lies in the strict requirements of the standards for the accuracy of measuring the magnitude, frequency, and duration of disturbances, as well as in the specifics of the measured current parameters and in restrictions inherent in the short-time Fourier transform and continuous wavelet transforms on the accuracy of measuring harmonic parameters. The specificity of currents in rails is associated with a large dynamic range of harmonics, a wide frequency range and the proximity of harmonics in the spectrum to each other, which makes it difficult to distinguish weak harmonics against the background of more powerful ones, as well as in the non-periodic and random nature of current. The paper considers the technology of the correct choice of parameters of the short-time Fourier transform and the continuous wavelet transforms. The results of the work were approved during testing of new types of trains.
Clean Air for Ukraine: Roadmap for Reducing Industrial Air Pollution in Ukrainian Cities
(Arnika – Citizen Support Centre, Prague, Czech Republic, 2020) Havránková, Šárka; Yaroshchuk, Oleksandr; Soroka, Maksym L.
EN: This study overview about necessary components of functional air pollution management in Ukraine, such as centralized, accessible and reliable monitoring, public participation in decision making, a clear process for issuing permits, strict pollution limits and thorough control. The authors of the study suggest overview of Ukrainian environmental legislation and environmental policy options and recommendations to effectively reduce industrial air pollution in Ukrainian cities. Disclaimer. This study was financed from the Transition Promotion Program of the Ministry of Foreign Affairs of the Czech Republic and National Endowment for Democracy (USA). The donors are not responsible for the opinions presented in the study.
Comparative Analysis of Calculation Results of Supporting Structure of Soil-Cement Piles
(Kaunas University of Technology, Kaunas, 2019) Pshinko, Oleksandr M.; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Hubar, Oleksіy V.; Ihnatenko, Dmytro Yu.; Markul, Ruslan V.
ENG: Abstract. The article presents the results of comparison of the stress-strain state of 4 models of a retaining wall structure of soil-cement piles on a landslide-prone slope. This study compares the changes in the stress distribution and displacements in the model elements of the retaining structure of soil-cement piles depending on the design parameters and the method of piles location in the body of the soil mass. The comparison of models of supporting structures of soil-cement piles on a landslide-prone slope allowed obtaining: –the comparative analysis of the quality work of individual elements of the supporting structure for strength and deformation in a three-dimensional representation; –the comparative assessment of the performance of the supporting structure of soil-cement piles on a landslide-prone slope; – histograms of dependences of changes in the angle of piles inclination to the vertical axis of their holding force, strength and deformation of the slope;
Comparative Analysis of the Parameters of the Strength of the Subgrade at the Transition to the Higher Axial Loading up to 25 t
(IOP Publishing, Kharkiv, 2019) Radkevych, Anatolii V.; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Mukhina, Nataliya
ENG: Abstract. A review of the scientific and technical literature on the re-alignment of the route during the transition to high axial load from the accepted today (23.5 t / axis) to the perspective (25 t / axis) shows that in the stage of preliminary researches imitation modeling of the earth web by the finite element method (ITU) as the most convenient, accurate and illustrative of the known numerical methods. In order to provide recommendations on the strength of the subgrade when moving to a higher axial load up to 25 t / axis, an analysis was conducted, the essence of which was to compare the stress-strain state of the subgrade at two loads per axis: 23.5 t / axis (existing ) and 25 (perspective). All the geometric and deformation characteristics of the formation are taken from data on a two-track section with a height of embankment of 3. The deformation characteristics are chosen so that the working material of the formation is in accordance with the average indices of deformation capacity of the railways used. The ITU train load calculus makes it possible to obtain all the factors of VAT in it, which is the main purpose of the study of the strength of the earth cloth, and allows to forecast their development in the future.
The Comparative Analysis of the Stress-Strain State of the Support of the Escalator Tunnel Constructed in Weak Soils by the NATM
(IOP Publishing Ltd, 2022) Radkevych, Anatolii V.; Tiutkin, Oleksii L.; Kuprii, Volodymyr; Bielikova, Sofiia
ENG: The construction of underground objects of the subway is always associated with building of structures connecting the surface. For subways, such structures are escalator tunnels. During the construction of the Dnipro Metro, these underground structures are built using a new technology that forms a multilayered support. This technology is the New Austrian tunneling method. A special feature of its application under the conditions of the Dnipro city is the existence of weak rocks in the upper part of the escalator tunnel. To ensure their stability, various special operational techniques are used that impact the rock massif. The basic techniques include artificial freezing, which was the dominant strengthening technology, and chemical strengthening (cementation), which is more consistent with the New Austrian tunneling method. To elucidate the effectiveness of the two strengthening techniques, a finiteelement model of the Dnipro Metro escalator tunnel has been built. The numerical calculation of two variants for the strengthening of weak soils yielded results for a comparative analysis of the stress-strain state. The result of the comparative analysis is the conclusion of greater cementation efficiency when strengthening weak soils of the massif in which the escalator tunnel is constructed using New Austrian tunneling method.
Complex of Numerical Models for Computation of Air Ion Concentration in Premises
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Biliaiev, Mykola M.; Tsygankova, Svetlana G.
EN: Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which is based on numerical 2D CFD model and balance model, are presented. Practical value. A numerical CFD model and balance model for the computation of air ion regime allow calculating the ions concentration in the premises in the conditions of artificial air ionization taking into account the main physical factors determining the formation of ions concentration fields.
Comprehensive Study of the Microclimate Parameters in the Residential Building
(Sciendo, Poland, 2021) Yurchenko, Yevhen; Kuznetsov, Valeriy; Radkevich, Anatolij V.; Koval, Olena; Skrzyniarz, Marek; Kruczek, Włodzimierz; Mike, Kamil; Mroczkowski, Łukasz
ENG: The relevance of the research lies in the development of the current question about the influence of microclimate quality on the efficiency of residential units. The aim of the study is to examine how the microclimate parameters affect the efficiency of residential buildings. Findings. The results obtained are essential for the design of energyefficient and comfortable residential buildings. The scientific novelty and practical importance of research resides in the thorough study of microclimate in low-rise residential buildings. Microclimate deviation charts for residential buildings have been produced.
Computer Modeling of Air Pollution in Case of Dust Cloud Movement in Open Pit Mine
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Berlov, Oleksandr V.; Gabrіnets, Volodymyr O.; Horiachkin, Vadym M.
ENG: Purpose. Explosions in open pits lead to the formation of dust clouds. These clouds lead to intense air pollution. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during ex-plosions in open pits. The purpose of this work is development of a numerical model to predict atmosphere pollution after explosion in open mine pit. The task is to develop a numerical model that would allow for the calculation to take into account the geometrical shape of the open pit mine, the parameters of the meteorological situation (wind speed, atmosphere), the shape of the dust cloud that is formed in the open pit mine at the site of the explosion. Methodology. Mathematical modeling of dust cloud dispersion during an explosion in an open pit mine is based on the use of fundamental equations of aerodynamics and mass transfer. The airflow velocity field in the open pit mine is modeled using the Laplace equation for the velocity potential. The formation of the concentration field of dust is mod-eled on the basis of the equation of convective-diffusion dispersion of an impurity. For numerical integration of model-ing equations, difference schemes are used. The Laplace equation for the velocity potential is numerically integrated using the Richardson method. For the numerical integration of the convective-diffusion dispersion equation for an im-purity, an implicit difference splitting scheme is used. Findings. A CFD model has been developed that allows you to calculate the formation of pollution zones during the movement of a dust cloud in the open pit mine. A feature of the developed model is the speed of calculation. For practical use of the developed model, standard input information is required. Originality. In contrast to the existing models in Ukraine, the developed numerical model allows taking into account the geometrical shape of the open pit mine and the geometrical shape of the dust cloud when making predictive calculations to assess the level of air pollution caused by explosions in open pits. Practical value. The developed nu-merical model can be implemented on computers of low and medium power. For practical use of the numerical model, standard information on meteorological conditions in open pit mine is required. The numerical model can be used for environmental assessment of the effect of explosions in open pit mine on environmental pollution and work areas.
Computer Simulation of Biological Wastewater Treatment Processes in Aerotanks With Plates
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2020) Biliaiev, Mykola M.; Lemesh, Maksym V.; Biliaieva, Viktoriia V.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
EN: Purpose. Efficiency determination of the aeration tank at the stage of design or reconstruction of bioreactors in which biological wastewater treatment is carried out requires the use of special mathematical models and calculation methods. The main purpose of the article is to develop CFD models for evaluating the operation efficiency of aeration tanks. Methodology. A numerical model has been developed for the computer calculation of the biological wastewater treatment process in aerotanks, taking into account hydrodynamics. The model is based on two-level mass conservation equations for the substrate and activated sludge and the velocity potential equation. The process of biological transformation of the substrate is calculated based on the Monod model. For the numerical integration of the mass transfer equations of activated sludge and substrate, the alternating-triangular difference splitting scheme is used. In this case, the basic equations are divided into two equations of a more simplified form. For the numerical integration of the equations for the velocity potential, it is split into two one-dimensional equations. Further, each equation is solved according to explicit scheme. For the numerical integration of equations that describe the process of substrate transformation based on the Monod model, the Euler method is used. Findings. The software implementation of the constructed numerical model has been carried out. The results of a computational experiment on the study of the wastewater treatment process in an aeration tank with plates are presented. This leads to the conclusion that the quality control of wastewater treatment in aeration tanks is possible with the help of plates. Originality. A multivariate CFD model has been developed, which makes it possible to quickly assess the efficiency of the aeration tank. A feature of the model is the ability to evaluate the operation of the aeration tank, taking into account its geometric shape and location of additional plates in the construction. Practical value. The constructed numerical model can be used during calculations in the case of designing aeration tanks, or in determining the efficiency of wastewater treatment under new operating conditions.
Computer Simulation of Dead-End Mine Working Ventilation
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Gunko, Olena Y.; Bondarenko, Iryna O.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
ENG: Purpose. The important problem in the field of ecological safety and industrial safety is providing of normal microclimate in dead-end mine working. In these regions of the mine methane gas can be accumulated and as a result explosion may take place. So, to avoid these accidents it is important to ventilate appropriately dead-end mine working. The purpose of the work is development of quick computing mathematical model to obtain information about dead-end mine working ventilation process. Methodology. The process of dead-end mine working ventilation computing is separated in two stages. At the first stage the velocity flow field is computed in the dead-end mine working. We consider the situation when the suction tube is situated in this region. To solve this problem the fluid dynamics model of inviscid gas flow was used. At the second stage of the computational modeling the convective-diffusive equation of admixture transfer was used. The equation takes into account non-uniform flow field in the dead end mine workings. Findings. The developed numerical model was coded using FORTRAN language. The developed computer code allows to perform numerical experiment to assess the efficiency of suction tube imple-mentation to decrease methane gas concentration in dead-end mine working. Originality. The developed numerical model takes into account physical factors, which are not considered nowadays in the empirical models, which are used for solving the problems of dead-end mine working ventilation. It allows taking into account the geometrical form of the dead-end mine working. Practical value. The developed computer program allows to perform calculations to assess the efficiency of suction system used for the ventilation of the dead-end mine working.
Computing Model for Simulation of the Pollution Dispersion Near the Road with Solid Barriers
(Silesian University of Technology, Gliwice, Poland, 2021) Biliaiev, Mykola M.; Pshinko, Oleksandr M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Sładkowski, Aleksander
ENG: In this study, a numerical model is proposed for calculating pollution zones near the road, taking into account the geometry of the automobile transport, meteorological conditions, the location of the barriers and their height, and the chemical transformation of nitrogen oxides in the atmospheric air. The numerical solution is based on the integration of the mass transfer equations using the finite-difference method. To determine the components of the air flow velocity vector, a two-dimensional model of the potential flow is used, where the Laplace equation for the velocity potential is the modeling equation. Based on this numerical model, a software package has been developed that allows computational experiments and does not require large expenditures of computer time. Based on the results obtained, an assessment was made of the effectiveness of the use of barriers to reduce the level of air pollution near highways. It has been established that the use of barriers of different heights reduces the level of pollution behind the road by approximately 20-50%.
Concrete Properties Improvement of Slab Tracks Using Chemical Additives
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Pristinskaya, Victoria V.
EN: Purpose. On the Railways of Ukraine a very large number of slab tracks are operated with cracks. Many scientific works of previous years are dedicated to improving the design of slab tracks. The main causes of defects are: poor exploitation of the track; insufficient physic-mechanical characteristics of concrete; poor quality of initial materials. It is therefore necessary to develop an optimum concrete mix for the manufacture of these concrete products. Methodology. To assess the impact of individual factors and effects of their interactions on properties of concrete mix and concrete method of experimental and statistical modeling was used. At this, methodological fundamentals of mathematical experiment planning in concrete technology and modern methods of optimization of composite materials were taking into account. Based on the obtained data during the planned experiment conducting, including 15 studies and using the computer program MathCad, were obtained the regression equations, which describe the relevant physical and mechanical properties of concrete. On the basis of the equations with the help of computer program MATLAB R2012b the graphs were drawn, illustrating the dependences of system response from the changes of two factors at a fixed value of the third factor. Findings. Firstly was the analysis of cracks that occur in the process of operation in the constructions of slab tracks. Further reasons of possible occurrence of these cracks were presented. In the process of the conducted research the author has concluded that for rational concrete mix development it is necessary to conduct the planned experiment with the use of quality materials. It was established that to increase the strength, chemical additives should be added in to concrete mix, it will let reduce cement amount. Originality. Experiments proved the usage of modern chemical additives in order to improve the properties of concrete. Models were developed, reflecting characteristics of concrete strength. With their help one can optimize concrete composition. Practical value. Research proved that the usage of more sustainable concrete mix for production of slab tracks will increase their strength, and with it the reliability of these designs mechanical properties.
Constructing a Method for Assessing the Effectiveness of Using Protective Barriers Near Highways to Decrease the Level of Air Pollution
(ПП ТЕХНОЛОГІЧНИЙ ЦЕНТР, Харків, 2021) Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Biliaieva, Viktoriia V.; Rusakova, Tetiana I.; Berlov, Oleksandr V.; Mala, Yuliia
ENG: Highways are an intensive source of environmental pollution. Atmospheric air is exposed to the fastest anthropogenic influence. Therefore, a particularly important task is to minimize the level of air pollution near the highway. An effective method for solving this problem is the use of protective barriers of various shapes installed near highways. At the stage of designing these protective structures, an important task arises to assess their effectiveness. Estimation of the effectiveness of protective barriers by the method of the physical experiment takes considerable time to set up and conduct an experiment, as well as analyze the results of hysical modeling. This method is not always convenient during design work. An alternative method is the method of mathematical modeling. For the designer, it is very important to have mathematical models that make it possible to quickly obtain a predictive result and take into consideration a set of important factors on which the effectiveness of the protective barrier depends. A method has been devised that makes it possible to assess the effectiveness of using protective barriers to reduce the level of air pollution near the highway. It was found that an increase in barrier height by 80 % leads to a 22 % decrease in the concentration of impurities behind the barrier. It was established that applying a barrier with a height of 1.5 m leads to a 26 % decrease in the concentration of impurities in buildings adjacent to the highway. A method has been devised to assess the effectiveness of using absorbent "TX Active" surfaces on the protective barrier located near the highway. This study's result revealed that the application of a barrier with one "TX Active" surface leads to a decrease in the concentration of NO behind the barrier by an average of 43 %. When using a barrier with two "TX Active" surfaces, a decrease in the NO concentration behind the barrier is 85 % on average.
Constructional Features of Shearwalls Stiffness in a Lightweight Steel Framing Buildings
(De Gruyter Poland, Warsaw, 2019) Zinkevych, Oksana G.; Savytskyi, Mykola V.; Zinkevych, Andrii M.
EN: Abstract. For low-rise buildings frame technologies using lightweight thin-wall steel constructions have become significantly widespread. The main influence on a building’s spatial rigidity under lateral forces is taken by shearwalls. The necessary stiffness can be accomplished by setting definite constructional parameters that are selected according to the design approach. The purposes of the work are to receive the dependencies of the influence of the constructional features on the stiffness of the shearwalls (using FEM models) and to set the value of the stiffness of the shearwall of any configuration by linking its parameters with the corresponding parameters of a standard shearwall through the established dependencies. The received dependencies of the effect of the main constructional factors and design approach for the stiffness of shearwalls can be used to provide spatial rigidity. A simplified design approach for estimating the influence of the main constructional features of shearwalls on their rigidity has been developed.
Contemporary Principles for Solving the Problem in Noise Reduction from Railway Rolling Stock
(IOP Publishing, 2020) Zelenko, Yuliia V.; Zelenko, Dariia; Neduzha, Larysa O.
EN: The statistical and monitoring data confirm the significant impact of the operational mode on the most important noise and vibration parameters, which is relevant for ensuring the efficiency and quality of the operational process with regard to ergonomic and environmental requirements. The article analyzes the acoustic parameters of rolling stock of the railway, emphasizes the peculiarities of noise emission from various elements of rolling stock and a track. Existing approaches towards solving the problem in the organization of railway noise control are outlined. On the basis of existing modern methods for measurement and analysis of acoustic parameters, the authors propose conceptual approaches toward monitoring the acoustic parameters, predicting noise characteristics and constructing the noise maps of railways. The algorithm of the developed acoustic model for the operational monitoring of noise load and the possibility to compile a case of noise maps for Ukrzaliznytsia is presented. The proposed algorithm allows at given basic design parameters and speed of rolling stock, known sound-absorbing and dissipative characteristics of all elements to carry out a rational selection of noise-protective measures in accordance with the sanitary noise regulations for a specific receptive facility.
Controlling the Dynamic Characteristics of Steel Bunker Containers for Bulk Materials
(IOP Conference Series: Earth and Environmental Science, 2024) Bannikov, Dmytro O.; Tiutkin, Oleksii L.; Hezentsvei, Yukhym; Muntian, Antonina O.
ENG: The article presents the main results of research devoted to the definition and analysis of the dynamic characteristics of steel small-sized bunker containers for storing bulk materials. All studies were carried out using the finite element method with the use computer complex SCAD. The object of research was a bunker of a bypass track for feeding bulk materials with a total volume of up to 70 m3. The study analysed the natural partial frequency spectrum and the partial oscillation modes of individual load-bearing elements of the bunker. Based on the results of the data analysis, a rather high quantitative density of the natural frequency spectrum was determined. At the same time, its lower limit is about 25-30 Hz for an empty bunker capacity and decreases to 3-5 Hz when the bunker is fully loaded, which is dangerous from the point of view of the possibility of resonance phenomena. In order to qualitatively and quantitatively control the dynamic characteristics, it was proposed to change the steel strength of the structure, which made it possible to change the natural frequencies by about 15% for every 100 MPa change in steel strength for the bunker containers of the considered type.
Costs of the Human Capital and Development of the Social Potential in Accounting System for Central and Eastern Europe
(Oxford University Press, 2020) Pshynko, Alexander N.; Golovkova, Lyudmila S.; Kolomiiets, Viktoriia M.; Dobryk, Liliia O.
EN: Nowadays, human capital and social potential become the most valuable resource for the harmonious development of the national economy. Expenditure on human capital and social development should occupy a significant part in the state budgets of countries. Therefore, accounting of such expenses is extremely important. The purpose of the study is to reveal the possibility of accounting for expenditures on the human capital and social potential development in the accounting system of the Central and Eastern Europe, provide recommendations for the current accounting system. The research revealed the plurality and ambiguity of the interpretation for the categories «human capital» and «social potential». The regulatory and legislative uncertainty complicates the accounting of the human capital costs and development of the social potential. These categories must be defined by law. As per normative and methodological basis for the accounting of the human capital, it would be better to apply the International Financial Reporting Standards. The absence or misrepresentation of information about available human capital are contrary to IFRS requirements and reduces or exaggerates the value of the organization. It is offered in IFRS, to provide a comprehensive accounting of the cost for the human capital and developing social capacity. The budget of the Central and Eastern European countries includes only the costs of social protection, health, education, recreation, culture, religion. After the budget analysis was conducted, the authors proposed to develop new objects of accounting (human capital, social potential), accounting standards for it. A part of the GDP expenses should be directed to the financing of the human capital expenditures and social potential development.