The article highlights the proposed algorithm for evaluating the reliability of steel frames. In ... more The article highlights the proposed algorithm for evaluating the reliability of steel frames. In particular, it is possible to analyze the reliability of the most likely failure mechanism. Separate assumptions that determine the sequence of application of the limit equilibrium method are presented. A method for determining the reliability of statically indeterminate steel frames in the plastic stage is presented. This method provides an opportunity to determine the probable mechanism of destruction. The ultimate equilibrium method is used to calculate the forces at the final stage of destruction. In the work, the real mechanism of destruction is understood as a mechanism for which the work of external forces to create it is the least. It is revealed that the real mechanism of destruction is approaching the beam or floor elementary mechanism.
The article proposes to using Ocean Thermal Energy Conversion (OTEC) to increase the energy effic... more The article proposes to using Ocean Thermal Energy Conversion (OTEC) to increase the energy efficiency mining of methane from deposits subaquatic gas hydrates on the gas hydrate cycle (GHET), that will allow not to spend 10-15% of the extracted methane for power supply of a gas-producing complex (GPC). The circuit-technological solution GPC is described, according to which carbon dioxide is introduced into the gas hydrate layer to extract methane from gas hydrates. To improve the kinetics of the process of replacement of methane with carbon dioxide in gas hydrates, it is proposed do recirculation part of CO2. The scheme and cycle of gas-hydrate energy-technological installation GHET are given, which operates using OTEC and generates together with electricity for GPC, fresh water and cold. Based on the method proposed in this paper, a comparative thermodynamic analysis of installations using OTEC for Black Sea conditions was performed. by GHET and Anderson cycles and it is shown that the specific useful work obtained in the GHET cycle, approximately 3 times more, and energetic efficiency 1.5 times more.
One of the most perspective non-traditional sources of hydrocarbon raw materials and energy is ga... more One of the most perspective non-traditional sources of hydrocarbon raw materials and energy is gas hydrates (GH), which stimulates their large-scale study in many laboratories and scientific centers around the world. The interest in the GH is related to the possibility of their industrial application. The use of technologies for storage and transportation of natural gas in the form of GH requires fundamental kinetic studies of the hydration process at atmospheric pressure in the presence of chemical impurities (catalysts, surfactants, etc.). During the research, an increase in the rate of gas hydrates formation was discovered at the expense of activated impurities and composite compounds obtained on their basis, which lead to changes in the hydrochemical and hydrodynamical modes of systems. It was established that the process of GH formation occurs due to the binding of methane macromolecules and other chemical impurities, which contribute to increase the number of moles of gaseous methane, due to the flow of exchange processes between the polymer matrix and water soluble salts, as well as a result of the change in the hydrodynamics of the water system. The purpose of this work is to investigate the effect of polyelectrolytes solutions hydrodynamic properties on the GH formation. We used a number of ionenes based on polymeric quaternary ammonium salts, side aliphatic radicals of different lengths contained in the acyl fragment.
Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas... more Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas-hydrated technologies, suitable for energy-efficient transportation of natural gas, the separation of gas mixtures, production and storage of cold, desalinating of seawater, etc. Hydrate formation is one of the main processes of gas-hydrate technological installations. In the article a model is proposed that describes the kinetics of the formation of hydrate in disperse systems, which are characteristic for real conditions of operation of gas-hydrate installations, on the basis of a stochastic approach using Markov chains. An example of numerical calculations is presented on the basis of the proposed model of the dynamics of the total mass of gas hydrates, and changes in the velocity of their formation and size distribution at different values of the nucleation constants and growth rate of the gas hydrates, and results of these calculations are analyzed. It is shown that the rate of formation of hydrate has a maximum value in half the time period of the whole process. The obtained results of the calculations of the dynamics the total mass of gas hydrates are in good agreement with the results of calculations by the equation of kinetics Kolmogorov-Avrami. The proposed model can be applied to the inverse problem: the determination of the nucleation constants and the rate of growth of gas hydrates by the results of the dynamics of the formation of hydrate and the changes in the fractional composition of the generated gas hydrates.
The article considers a scheme and cycle for the gas-hydrate energo-technological (GHET) plant to... more The article considers a scheme and cycle for the gas-hydrate energo-technological (GHET) plant to produce electricity, fresh water and cold using ocean thermal energy conversion (OTEC). It is shown that in the cycle of the plant GHET can obtain approximately 3 times more work from 1 kg of working fluid than in the Anderson steam cycle, which is similar to the Rankine cycle. On the basis of the proposed method a comparative analysis of energy indices of these the plants is made using the Anderson cycle and GHET under conditions found in the Black Sea.
IOP Conference Series: Materials Science and Engineering, 2021
Innovative ways of using furnace dust to improve the strength of soil-cement are analyzed. It is ... more Innovative ways of using furnace dust to improve the strength of soil-cement are analyzed. It is proposed to solve the environmental problem of utilization of this material, when using the addition of furnace dust during the construction of soil-cement elements. The samples were kept immersed in water for 28 days in order to gain strength, until laboratory tests. The removal ash before the experiment was sieved on a 4 mm sieve. Strength of soil-cement samples with the addition of furnace dust and pellet ash (with the main content of sunflower husk with a percentage of 5% by weight of cement) was studied. It is established that the average compressive strength of the samples with the addition of Mykolaiv CHP furnace dust with a fraction of inclusions up to 4 mm in the amount of 5 % increases the compressive strength by 30%. It was found that the content of organic matter (ash from burning sunflower husks) in soil-cement reduces its strength.
Purpose. To analyze Australian methane hydrate resources, exploration, and production, its curren... more Purpose. To analyze Australian methane hydrate resources, exploration, and production, its current state and future potential. Methods. Analysis of data published in different sources concerned with geological surveys and government reports related to Australian natural gas reserves, production and consumption of gas in Australia. Analysis of theoretical and experimental research into methane hydrates properties and prevention of gas hydrate deposits formation in pipes during production and transportation of natural gas. Findings. The study of gross figures associated with the present state of gas production in Australia testified that enough gas is extracted to meet the current needs. Increase in natural gas consumption in future creates good chances for developing gas production from unconventional deposits, specifically getting methane from gas hydrates deposits. While predicting main trends in the efficient exploration and use of methane hydrates resources it is necessary to consider their possible impact on the environment. Originality. On the basis of the conducted analysis, the current state of methane hydrates research in Australia is examined. For its gas industry, it is critical to estimate their reserves and assess methane extraction from gas hydrates deposits in the near future. Practical implications. The obtained results can be used to evaluate the investment attractiveness of future exploration of methane hydrates resources in Australia.
International Conference on Modern Problems of Radio Engineering, Telecommunications and Computer Science, Feb 1, 2008
... for at a particular point in time in the market [1]. The importance of the ... paper the ana... more ... for at a particular point in time in the market [1]. The importance of the ... paper the analysis of new methods of forecasting the residual value of hardware products is ... Manatakis, PA Drakatos, New method for the analysis of operating costs of construction equipment, International ...
One of the most acute thematic areas in discussions at international forums at various levels are... more One of the most acute thematic areas in discussions at international forums at various levels are the issues of improving the environmental performance and increasing the energy efficiency of the merchant marine vessels, both in international maritime and inland navigation. This article discusses the results of the practical application of analytical methods for processing the indication data of internal combustion engines of the Danube pusher under operating conditions, as well as some aspects of the application of the results of analytical synchronization of the data obtained to further substantiate the optimal operating modes of such vessels. The results are applicable to determine the possible range of variation in energy efficiency and environmental friendliness. When determining the energy efficiency indices, various forms of pushed caravans, most often operating in the Danube shipping, are taken into account. Further steps have also been taken to substantiate the concept of p...
Central Ukrainian Scientific Bulletin. Technical Sciences
The production of biofuel pellets requires significant energy consumption during their production... more The production of biofuel pellets requires significant energy consumption during their production. At the primary technological stage of production: grinding of solid vegetable waste (SVW), electricity costs can be, depending on the physical and mechanical characteristics of SVW, 40… 60% of the total electricity consumed for the production of pellets. Significant losses of electric energy are observed during grinding due to uneven loading of the shredder and operation of the electric motor of its drive in constantly changing modes. This is especially true for small productions when downloading is done manually. This paper proposes a method and algorithm for determining the maximum values of the energy efficiency of the SRW grinding system for the production of biofuel pellets as a function of the load factor of the electric motor of the working machine at different values of applied voltage. As a result of research of an asynchronous electric motor with a nominal power of 4 kW SVW s...
У статті розглядається проблема підвищення ефективності роботи автомобільної газонаповнювальної ... more У статті розглядається проблема підвищення ефективності роботи автомобільної газонаповнювальної компресорної станції (АГНКС) в умовах наявності пікових навантажень внаслідок нерівномірного надходження на заправку автомобільного транспорту на протязі доби. Для підвищення ефективності використання обладнання АГНКС в умовах нерівномірної добової заправки автомобільного транспорту стиснутим природним газом (СПГ-CNG) запропоновано застосовувати газогідратний акумулятор (ГА). В ГА реалізуються процеси утворення газогідратів природного газу при низькому тиску, їх накопичення і зберігання та наступне плавлення з виділенням стиснутого природного газу при тиску 25 МПа, достатньому для повної заправки автомобільного транспорту. Процес утворення газогідрату відбувається з виділенням теплоти, а його розкладання з поглинанням теплоти. Відводити теплоту процесу гідратоутворення пропонується пропановою холодильною машиною (ХМ). Однак при температурі довкілля ≤ 1 °С процес утворення газогідраті...
ABSTRACT We examine the influence of the charge density along a polyelectrolyte chain on the buil... more ABSTRACT We examine the influence of the charge density along a polyelectrolyte chain on the buildup of multilayer films formed by the sequential adsorption of alternating layers of polyanions and polycations (the layer-by-layer technique). Model random copolymers of diallyldimethylammonium chloride (DADMAC) and N-methyl-N-vinylacetamide (NMVA) having matched molecular weights and varying percentages (24-100%) of the cationic DADMAC component are alternated with polyanionic polystyrene sulfonate (PSS). Multilayer buildup is monitored by UV-vis and FTIR spectroscopies, and with a quartz crystal microbalance (QCM) and is correlated with structural information obtained using atomic force microscopy. When films are deposited from polyelectrolyte. solutions containing added salt, a critical charge density limit (between 75% and 53%), below which no significant layer growth is possible, becomes apparent. Below the critical charge density, addition of the polyanion leads to almost complete removal of the previously deposited cationic copolymer and vice versa, and thus multilayers cannot grow. Above the critical charge density, the rate of film growth and the film morphology are strongly influenced by the solution structure of the adsorbing polyelectrolytes: thicker and rougher films are produced with increased salt concentration in the adsorption solutions.
The article highlights the proposed algorithm for evaluating the reliability of steel frames. In ... more The article highlights the proposed algorithm for evaluating the reliability of steel frames. In particular, it is possible to analyze the reliability of the most likely failure mechanism. Separate assumptions that determine the sequence of application of the limit equilibrium method are presented. A method for determining the reliability of statically indeterminate steel frames in the plastic stage is presented. This method provides an opportunity to determine the probable mechanism of destruction. The ultimate equilibrium method is used to calculate the forces at the final stage of destruction. In the work, the real mechanism of destruction is understood as a mechanism for which the work of external forces to create it is the least. It is revealed that the real mechanism of destruction is approaching the beam or floor elementary mechanism.
The article proposes to using Ocean Thermal Energy Conversion (OTEC) to increase the energy effic... more The article proposes to using Ocean Thermal Energy Conversion (OTEC) to increase the energy efficiency mining of methane from deposits subaquatic gas hydrates on the gas hydrate cycle (GHET), that will allow not to spend 10-15% of the extracted methane for power supply of a gas-producing complex (GPC). The circuit-technological solution GPC is described, according to which carbon dioxide is introduced into the gas hydrate layer to extract methane from gas hydrates. To improve the kinetics of the process of replacement of methane with carbon dioxide in gas hydrates, it is proposed do recirculation part of CO2. The scheme and cycle of gas-hydrate energy-technological installation GHET are given, which operates using OTEC and generates together with electricity for GPC, fresh water and cold. Based on the method proposed in this paper, a comparative thermodynamic analysis of installations using OTEC for Black Sea conditions was performed. by GHET and Anderson cycles and it is shown that the specific useful work obtained in the GHET cycle, approximately 3 times more, and energetic efficiency 1.5 times more.
One of the most perspective non-traditional sources of hydrocarbon raw materials and energy is ga... more One of the most perspective non-traditional sources of hydrocarbon raw materials and energy is gas hydrates (GH), which stimulates their large-scale study in many laboratories and scientific centers around the world. The interest in the GH is related to the possibility of their industrial application. The use of technologies for storage and transportation of natural gas in the form of GH requires fundamental kinetic studies of the hydration process at atmospheric pressure in the presence of chemical impurities (catalysts, surfactants, etc.). During the research, an increase in the rate of gas hydrates formation was discovered at the expense of activated impurities and composite compounds obtained on their basis, which lead to changes in the hydrochemical and hydrodynamical modes of systems. It was established that the process of GH formation occurs due to the binding of methane macromolecules and other chemical impurities, which contribute to increase the number of moles of gaseous methane, due to the flow of exchange processes between the polymer matrix and water soluble salts, as well as a result of the change in the hydrodynamics of the water system. The purpose of this work is to investigate the effect of polyelectrolytes solutions hydrodynamic properties on the GH formation. We used a number of ionenes based on polymeric quaternary ammonium salts, side aliphatic radicals of different lengths contained in the acyl fragment.
Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas... more Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas-hydrated technologies, suitable for energy-efficient transportation of natural gas, the separation of gas mixtures, production and storage of cold, desalinating of seawater, etc. Hydrate formation is one of the main processes of gas-hydrate technological installations. In the article a model is proposed that describes the kinetics of the formation of hydrate in disperse systems, which are characteristic for real conditions of operation of gas-hydrate installations, on the basis of a stochastic approach using Markov chains. An example of numerical calculations is presented on the basis of the proposed model of the dynamics of the total mass of gas hydrates, and changes in the velocity of their formation and size distribution at different values of the nucleation constants and growth rate of the gas hydrates, and results of these calculations are analyzed. It is shown that the rate of formation of hydrate has a maximum value in half the time period of the whole process. The obtained results of the calculations of the dynamics the total mass of gas hydrates are in good agreement with the results of calculations by the equation of kinetics Kolmogorov-Avrami. The proposed model can be applied to the inverse problem: the determination of the nucleation constants and the rate of growth of gas hydrates by the results of the dynamics of the formation of hydrate and the changes in the fractional composition of the generated gas hydrates.
The article considers a scheme and cycle for the gas-hydrate energo-technological (GHET) plant to... more The article considers a scheme and cycle for the gas-hydrate energo-technological (GHET) plant to produce electricity, fresh water and cold using ocean thermal energy conversion (OTEC). It is shown that in the cycle of the plant GHET can obtain approximately 3 times more work from 1 kg of working fluid than in the Anderson steam cycle, which is similar to the Rankine cycle. On the basis of the proposed method a comparative analysis of energy indices of these the plants is made using the Anderson cycle and GHET under conditions found in the Black Sea.
IOP Conference Series: Materials Science and Engineering, 2021
Innovative ways of using furnace dust to improve the strength of soil-cement are analyzed. It is ... more Innovative ways of using furnace dust to improve the strength of soil-cement are analyzed. It is proposed to solve the environmental problem of utilization of this material, when using the addition of furnace dust during the construction of soil-cement elements. The samples were kept immersed in water for 28 days in order to gain strength, until laboratory tests. The removal ash before the experiment was sieved on a 4 mm sieve. Strength of soil-cement samples with the addition of furnace dust and pellet ash (with the main content of sunflower husk with a percentage of 5% by weight of cement) was studied. It is established that the average compressive strength of the samples with the addition of Mykolaiv CHP furnace dust with a fraction of inclusions up to 4 mm in the amount of 5 % increases the compressive strength by 30%. It was found that the content of organic matter (ash from burning sunflower husks) in soil-cement reduces its strength.
Purpose. To analyze Australian methane hydrate resources, exploration, and production, its curren... more Purpose. To analyze Australian methane hydrate resources, exploration, and production, its current state and future potential. Methods. Analysis of data published in different sources concerned with geological surveys and government reports related to Australian natural gas reserves, production and consumption of gas in Australia. Analysis of theoretical and experimental research into methane hydrates properties and prevention of gas hydrate deposits formation in pipes during production and transportation of natural gas. Findings. The study of gross figures associated with the present state of gas production in Australia testified that enough gas is extracted to meet the current needs. Increase in natural gas consumption in future creates good chances for developing gas production from unconventional deposits, specifically getting methane from gas hydrates deposits. While predicting main trends in the efficient exploration and use of methane hydrates resources it is necessary to consider their possible impact on the environment. Originality. On the basis of the conducted analysis, the current state of methane hydrates research in Australia is examined. For its gas industry, it is critical to estimate their reserves and assess methane extraction from gas hydrates deposits in the near future. Practical implications. The obtained results can be used to evaluate the investment attractiveness of future exploration of methane hydrates resources in Australia.
International Conference on Modern Problems of Radio Engineering, Telecommunications and Computer Science, Feb 1, 2008
... for at a particular point in time in the market [1]. The importance of the ... paper the ana... more ... for at a particular point in time in the market [1]. The importance of the ... paper the analysis of new methods of forecasting the residual value of hardware products is ... Manatakis, PA Drakatos, New method for the analysis of operating costs of construction equipment, International ...
One of the most acute thematic areas in discussions at international forums at various levels are... more One of the most acute thematic areas in discussions at international forums at various levels are the issues of improving the environmental performance and increasing the energy efficiency of the merchant marine vessels, both in international maritime and inland navigation. This article discusses the results of the practical application of analytical methods for processing the indication data of internal combustion engines of the Danube pusher under operating conditions, as well as some aspects of the application of the results of analytical synchronization of the data obtained to further substantiate the optimal operating modes of such vessels. The results are applicable to determine the possible range of variation in energy efficiency and environmental friendliness. When determining the energy efficiency indices, various forms of pushed caravans, most often operating in the Danube shipping, are taken into account. Further steps have also been taken to substantiate the concept of p...
Central Ukrainian Scientific Bulletin. Technical Sciences
The production of biofuel pellets requires significant energy consumption during their production... more The production of biofuel pellets requires significant energy consumption during their production. At the primary technological stage of production: grinding of solid vegetable waste (SVW), electricity costs can be, depending on the physical and mechanical characteristics of SVW, 40… 60% of the total electricity consumed for the production of pellets. Significant losses of electric energy are observed during grinding due to uneven loading of the shredder and operation of the electric motor of its drive in constantly changing modes. This is especially true for small productions when downloading is done manually. This paper proposes a method and algorithm for determining the maximum values of the energy efficiency of the SRW grinding system for the production of biofuel pellets as a function of the load factor of the electric motor of the working machine at different values of applied voltage. As a result of research of an asynchronous electric motor with a nominal power of 4 kW SVW s...
У статті розглядається проблема підвищення ефективності роботи автомобільної газонаповнювальної ... more У статті розглядається проблема підвищення ефективності роботи автомобільної газонаповнювальної компресорної станції (АГНКС) в умовах наявності пікових навантажень внаслідок нерівномірного надходження на заправку автомобільного транспорту на протязі доби. Для підвищення ефективності використання обладнання АГНКС в умовах нерівномірної добової заправки автомобільного транспорту стиснутим природним газом (СПГ-CNG) запропоновано застосовувати газогідратний акумулятор (ГА). В ГА реалізуються процеси утворення газогідратів природного газу при низькому тиску, їх накопичення і зберігання та наступне плавлення з виділенням стиснутого природного газу при тиску 25 МПа, достатньому для повної заправки автомобільного транспорту. Процес утворення газогідрату відбувається з виділенням теплоти, а його розкладання з поглинанням теплоти. Відводити теплоту процесу гідратоутворення пропонується пропановою холодильною машиною (ХМ). Однак при температурі довкілля ≤ 1 °С процес утворення газогідраті...
ABSTRACT We examine the influence of the charge density along a polyelectrolyte chain on the buil... more ABSTRACT We examine the influence of the charge density along a polyelectrolyte chain on the buildup of multilayer films formed by the sequential adsorption of alternating layers of polyanions and polycations (the layer-by-layer technique). Model random copolymers of diallyldimethylammonium chloride (DADMAC) and N-methyl-N-vinylacetamide (NMVA) having matched molecular weights and varying percentages (24-100%) of the cationic DADMAC component are alternated with polyanionic polystyrene sulfonate (PSS). Multilayer buildup is monitored by UV-vis and FTIR spectroscopies, and with a quartz crystal microbalance (QCM) and is correlated with structural information obtained using atomic force microscopy. When films are deposited from polyelectrolyte. solutions containing added salt, a critical charge density limit (between 75% and 53%), below which no significant layer growth is possible, becomes apparent. Below the critical charge density, addition of the polyanion leads to almost complete removal of the previously deposited cationic copolymer and vice versa, and thus multilayers cannot grow. Above the critical charge density, the rate of film growth and the film morphology are strongly influenced by the solution structure of the adsorbing polyelectrolytes: thicker and rougher films are produced with increased salt concentration in the adsorption solutions.
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Papers by Vasyl Klymenko