Pub Date : 2022-07-18DOI: 10.15407/knit2022.03.029
V. Lyalko, M. Popov, O. Sedlerova, A. Khyzhniak
The paper was prepared in connection with the 30th anniversary of the “State Institution Scientific Centre for Aerospace Research of the Earth IGS NAS of Ukraine”. The article briefly describes the history of the development of aerospace exploration of the Earth in Ukraine and the role of the Centre in remote sensing research provided by institutions of the National Academy of Sciences of Ukraine. The history of the Centre, its scientific academic schools, and main areas of research are presented, and the prospects for further development are outlined. We describe the current organizational structure of the Scientific Centre for Aerospace Research of the Earth and the achievements of the scientific team. The analysis of the contribution of its employees to the development of aerospace research in Ukraine and international activities of the Centre are presented. Further prospects and plans for the development of scientific research at the Centre, which cover the basic principles of the development of world society determined by the UN decisions on sustainable development, are considered.
{"title":"Scientific Centre for Aerospace Research of the Earth of the Institute of Geological Sciences of the National Academy of Sciences of UkraineE: A 30-year-Old Road","authors":"V. Lyalko, M. Popov, O. Sedlerova, A. Khyzhniak","doi":"10.15407/knit2022.03.029","DOIUrl":"https://doi.org/10.15407/knit2022.03.029","url":null,"abstract":"The paper was prepared in connection with the 30th anniversary of the “State Institution Scientific Centre for Aerospace Research of the Earth IGS NAS of Ukraine”. The article briefly describes the history of the development of aerospace exploration of the Earth in Ukraine and the role of the Centre in remote sensing research provided by institutions of the National Academy of Sciences of Ukraine. The history of the Centre, its scientific academic schools, and main areas of research are presented, and the prospects for further development are outlined. We describe the current organizational structure of the Scientific Centre for Aerospace Research of the Earth and the achievements of the scientific team. The analysis of the contribution of its employees to the development of aerospace research in Ukraine and international activities of the Centre are presented. Further prospects and plans for the development of scientific research at the Centre, which cover the basic principles of the development of world society determined by the UN decisions on sustainable development, are considered.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48627485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-18DOI: 10.15407/knit2022.03.062
Y. Luo, L. Chernogor, Y. Zhdanko
Ionospheric effects accompanying launches and maneuvering system thruster firings of large rockets have been studied for about 60 years. Fairly complete and adequate models of generation and propagation of disturbances, which are caused by launches and maneuvering system thruster firings of large rockets in the Earth–atmosphere–ionosphere–magnetosphere (EAIM) system, are absent at present. It turns out a number of physical effects during ionospheric storms and rocket launches are similar. Therefore, the presence of ionospheric storm significantly complicates the search for the ionospheric response to the spacecraft launches. The aim of this study is to describe the results of observation of the ionospheric processes that accompanied rocket launches and maneuvering system thruster firings against the background of ionospheric storms. To analyze the measurements, observational data of the state of the ionosphere before, at the time, and after Soyuz and Proton rocket launches from the Baikonur cosmodrome (the Republic of Kazakhstan) were used. Observations were made at the Radiophysical Observatory of V. N. Karazin Kharkiv National University (near Kharkiv city, Ukraine). The Doppler vertical sounding radar was used for the measurements. Observations were made during solar cycle 24 (2009—2021). The number of the Soyuz rocket launches is 81, and 53 launches of the Proton rocket. Identification of the ionospheric response to the launch and maneuvering system thruster firings of a large rocket 2000 km away from the observation site against the background of a geospace storm by the Doppler method is usually possible at Kpmax 5, and at its larger values is very complicated or even impossible. In a number of cases, even though Kpmax = 4 the determination of the ionospheric response is complicated. To increase the detection reliability of the response to the launch and maneuvering system thruster firings of the rocket, the Doppler radar has to operate on a number of frequencies in the frequency range from 1.5...2 to 4…6 MHz. The existence of several groups of horizontal apparent speeds of disturbance propagation is confirmed: 1.7...3 km and more, 700...1000, 300...700, 150...260 m/s.
{"title":"Ionospheric effects from rocket launches against the background of geospace storms","authors":"Y. Luo, L. Chernogor, Y. Zhdanko","doi":"10.15407/knit2022.03.062","DOIUrl":"https://doi.org/10.15407/knit2022.03.062","url":null,"abstract":"Ionospheric effects accompanying launches and maneuvering system thruster firings of large rockets have been studied for about 60 years. Fairly complete and adequate models of generation and propagation of disturbances, which are caused by launches and maneuvering system thruster firings of large rockets in the Earth–atmosphere–ionosphere–magnetosphere (EAIM) system, are absent at present. It turns out a number of physical effects during ionospheric storms and rocket launches are similar. Therefore, the presence of ionospheric storm significantly complicates the search for the ionospheric response to the spacecraft launches. The aim of this study is to describe the results of observation of the ionospheric processes that accompanied rocket launches and maneuvering system thruster firings against the background of ionospheric storms. To analyze the measurements, observational data of the state of the ionosphere before, at the time, and after Soyuz and Proton rocket launches from the Baikonur cosmodrome (the Republic of Kazakhstan) were used. Observations were made at the Radiophysical Observatory of V. N. Karazin Kharkiv National University (near Kharkiv city, Ukraine). The Doppler vertical sounding radar was used for the measurements. Observations were made during solar cycle 24 (2009—2021). The number of the Soyuz rocket launches is 81, and 53 launches of the Proton rocket. Identification of the ionospheric response to the launch and maneuvering system thruster firings of a large rocket 2000 km away from the observation site against the background of a geospace storm by the Doppler method is usually possible at Kpmax 5, and at its larger values is very complicated or even impossible. In a number of cases, even though Kpmax = 4 the determination of the ionospheric response is complicated. To increase the detection reliability of the response to the launch and maneuvering system thruster firings of the rocket, the Doppler radar has to operate on a number of frequencies in the frequency range from 1.5...2 to 4…6 MHz. The existence of several groups of horizontal apparent speeds of disturbance propagation is confirmed: 1.7...3 km and more, 700...1000, 300...700, 150...260 m/s.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-18DOI: 10.15407/knit2022.03.086
A. Sohor, P. Zazuliak
The condition and composition of air in Lviv are influenced by two main factors: the introduction of pollutants into the atmosphere through various sources and harmful physical effects on it. The latter includes radiation, sound vibrations, noise, and so on. These and other factors disrupt the optimal conditions of the air, which negatively affects human health and the condition and development of animals and plants. The main sources of pollutants in the air of Lviv are as follows: dust — vehicles, woodworking and building materials industry; sulfur dioxide — industrial enterprises, carbon monoxide — vehicles, thermal power plants; nitrogen dioxide — heat power companies; formaldehyde — motor transport, woodworking industry. Today, emissions from mobile sources are the biggest air pollutants in the city. The chemical composition of emissions from mobile sources of pollution is characterized by the predominance of carbon monoxide (up to 74 %), nitrogen compounds, and hydrocarbons (12 % and 11 %, respectively). Today the state of atmospheric air in large cities of Ukraine and, in particular, in the city of Lviv is at an unsatisfactory level. The main problems in this area are the progressive nature of the negative impact on the ecological state of the environment and human health. As there is currently no interactive cartographic material that can visualize the problem of environmental pollution, the main purpose of this work was to create an interactive web map of the quality of life of the population of Lviv in terms of air pollution. To achieve this goal, we collected and systematized geospatial statistical cartographic materials on the ecological conditions of the air in Lviv. The necessary software for the development of an interactive map of air pollution has been selected, and its possibilities have been studied. An algorithm for loading geospatial data into the created web resource has been developed. A template of applications for creating web maps of air pollution in Lviv was selected according to the indicators of 2020, which were measured at 30 crossroads of the city. Thus, two interactive web maps of air pollution in Lviv were developed in the environment «Google My Maps» and «ArcGIS Online».
{"title":"Mapping of enviromental pollution of air in Lviv","authors":"A. Sohor, P. Zazuliak","doi":"10.15407/knit2022.03.086","DOIUrl":"https://doi.org/10.15407/knit2022.03.086","url":null,"abstract":"The condition and composition of air in Lviv are influenced by two main factors: the introduction of pollutants into the atmosphere through various sources and harmful physical effects on it. The latter includes radiation, sound vibrations, noise, and so on. These and other factors disrupt the optimal conditions of the air, which negatively affects human health and the condition and development of animals and plants. The main sources of pollutants in the air of Lviv are as follows: dust — vehicles, woodworking and building materials industry; sulfur dioxide — industrial enterprises, carbon monoxide — vehicles, thermal power plants; nitrogen dioxide — heat power companies; formaldehyde — motor transport, woodworking industry. Today, emissions from mobile sources are the biggest air pollutants in the city. The chemical composition of emissions from mobile sources of pollution is characterized by the predominance of carbon monoxide (up to 74 %), nitrogen compounds, and hydrocarbons (12 % and 11 %, respectively). Today the state of atmospheric air in large cities of Ukraine and, in particular, in the city of Lviv is at an unsatisfactory level. The main problems in this area are the progressive nature of the negative impact on the ecological state of the environment and human health. As there is currently no interactive cartographic material that can visualize the problem of environmental pollution, the main purpose of this work was to create an interactive web map of the quality of life of the population of Lviv in terms of air pollution. To achieve this goal, we collected and systematized geospatial statistical cartographic materials on the ecological conditions of the air in Lviv. The necessary software for the development of an interactive map of air pollution has been selected, and its possibilities have been studied. An algorithm for loading geospatial data into the created web resource has been developed. A template of applications for creating web maps of air pollution in Lviv was selected according to the indicators of 2020, which were measured at 30 crossroads of the city. Thus, two interactive web maps of air pollution in Lviv were developed in the environment «Google My Maps» and «ArcGIS Online».","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-18DOI: 10.15407/knit2022.03.043
S. Piltyay, А. Bulashenko, А. V. Polishchuk, О. V. Bulashenko
The volumes of information transmitted in modern satellite telecommunication systems are constantly increasing. Antennas with signal polarization processing, which is performed by polarizers, are the fundamental elements of such systems. Therefore, the development of methods for the analysis of new polarizers is an important problem. From a technological point of view, polarizers based on waveguides with irises are the simplest. Analysis and optimization of electromagnetic characteristics of a polarizer based on a square waveguide with irises are the goals of the presented research. To solve this optimization problem, we have created a new mathematical model, which allows investigating the influence of the design parameters of the polarizer on its electromagnetic characteristics. A mathematical model of the waveguide polarizer with irises was created by the method of decomposition using wave transmission and scattering matrices. Besides, the new mathematical model takes into account the thickness of the irises using their equivalent T- and П-shaped substitution circuits. The general wave scattering matrix is the basis of a new mathematical model of a waveguide polarizer. This matrix was determined using the theory of microwave circuits. The main characteristics of the waveguide polarizer were determined through the elements of this matrix. Here, we perform the optimization of the polarizer characteristics in the Ku-band 10.7–12.8 GHz. The developed new mathematical model of a waveguide polarizer with irises makes it possible to take into account the heights of the irises, distances between them and their thickness. The new mathematical model determines the electromagnetic characteristics of the polarizer in a simpler and faster way compared to the finite integration technique, which is often used for the analysis of microwave devices for various purposes
{"title":"Microwave waveguide polarizer for satellite communication antennas with circular polarization","authors":"S. Piltyay, А. Bulashenko, А. V. Polishchuk, О. V. Bulashenko","doi":"10.15407/knit2022.03.043","DOIUrl":"https://doi.org/10.15407/knit2022.03.043","url":null,"abstract":"The volumes of information transmitted in modern satellite telecommunication systems are constantly increasing. Antennas with signal polarization processing, which is performed by polarizers, are the fundamental elements of such systems. Therefore, the development of methods for the analysis of new polarizers is an important problem. From a technological point of view, polarizers based on waveguides with irises are the simplest. Analysis and optimization of electromagnetic characteristics of a polarizer based on a square waveguide with irises are the goals of the presented research. To solve this optimization problem, we have created a new mathematical model, which allows investigating the influence of the design parameters of the polarizer on its electromagnetic characteristics. A mathematical model of the waveguide polarizer with irises was created by the method of decomposition using wave transmission and scattering matrices. Besides, the new mathematical model takes into account the thickness of the irises using their equivalent T- and П-shaped substitution circuits. The general wave scattering matrix is the basis of a new mathematical model of a waveguide polarizer. This matrix was determined using the theory of microwave circuits. The main characteristics of the waveguide polarizer were determined through the elements of this matrix. Here, we perform the optimization of the polarizer characteristics in the Ku-band 10.7–12.8 GHz. The developed new mathematical model of a waveguide polarizer with irises makes it possible to take into account the heights of the irises, distances between them and their thickness. The new mathematical model determines the electromagnetic characteristics of the polarizer in a simpler and faster way compared to the finite integration technique, which is often used for the analysis of microwave devices for various purposes","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-18DOI: 10.15407/knit2022.03.017
K. H. Bilousov, М. V. Nechyporuk, V. S. Khoroshylov, D. Svynarenko, D. Mozgovoy, V. M. Popel'
An alternative method of automated correction of instrumental distortions of the ETM + scanner on Landsat-7 multispectral satellite images is proposed. The method is based on the application of filtering in the field of spatial frequencies using fast Fourier transform and spectral masks. The parameters of the mask are determined by a known spatial period of interference or experimentally by the results of the filtration. To filter the area of spatial frequencies to be removed, a filtering mask is applied, consisting of pixels with zero values. Periodic components whose spatial period corresponds to the spatial frequencies filtered on the Fourier image will be removed from the filtered image. The quality of filtration is determined by the mask used. When using multispectral images, a filter mask based on the Fourier image of one of the spectral channels is applied to filter other channels. The results of visual analysis of the processed images showed a fairly high-quality correction and elimination of instrumental distortions of the ETM + scanner in comparison with other methods. The main advantages of the proposed method are the next: the ability to work without the use of metadata and masks of instrumental distortion; work with single-channel and multispectral images; ability to work with small fragments of the scene; minimum number of manual settings for processing procedures; possibility to work without additional pictures for other dates; high stability of the used algorithms when using images from different satellites; fairly good repeatability of the results on satellite images taken in different seasons and for different areas. Experimental testing of the proposed method on a large number of images also confirmed the good repeatability and high stability of the algorithms used. It is expected that the developed technology will also be successfully used to cor
{"title":"METHOD OF AUTOMATED CORRECTION OF INSTRUMENT DISTORTIONS ON LANDSAT-7 MULTISPECTRAL SATELLITE IMAGES","authors":"K. H. Bilousov, М. V. Nechyporuk, V. S. Khoroshylov, D. Svynarenko, D. Mozgovoy, V. M. Popel'","doi":"10.15407/knit2022.03.017","DOIUrl":"https://doi.org/10.15407/knit2022.03.017","url":null,"abstract":"An alternative method of automated correction of instrumental distortions of the ETM + scanner on Landsat-7 multispectral satellite images is proposed. The method is based on the application of filtering in the field of spatial frequencies using fast Fourier transform and spectral masks. The parameters of the mask are determined by a known spatial period of interference or experimentally by the results of the filtration. To filter the area of spatial frequencies to be removed, a filtering mask is applied, consisting of pixels with zero values. Periodic components whose spatial period corresponds to the spatial frequencies filtered on the Fourier image will be removed from the filtered image. The quality of filtration is determined by the mask used. When using multispectral images, a filter mask based on the Fourier image of one of the spectral channels is applied to filter other channels. The results of visual analysis of the processed images showed a fairly high-quality correction and elimination of instrumental distortions of the ETM + scanner in comparison with other methods. The main advantages of the proposed method are the next: the ability to work without the use of metadata and masks of instrumental distortion; work with single-channel and multispectral images; ability to work with small fragments of the scene; minimum number of manual settings for processing procedures; possibility to work without additional pictures for other dates; high stability of the used algorithms when using images from different satellites; fairly good repeatability of the results on satellite images taken in different seasons and for different areas. Experimental testing of the proposed method on a large number of images also confirmed the good repeatability and high stability of the algorithms used. It is expected that the developed technology will also be successfully used to cor","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47820936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-29DOI: 10.15407/knit2022.02.003
O. Haidachuk, A. Kondratiev, A.V. Nabokina
The technological process of composite products’ molding consists in giving them non-a reversible shape using shape-generating molding tools through polymerization of the binder at a certain temperature and pressure varying in time. The paper deals with the research of technological parameters of the most common practical method of molding products made of polymeric composite materials, pre-formed of prepregs. The mathematical model of filling with a binder of inter-fiber space of the reinforcing material for the polymeric composite material with the varying fiber packing densities, from quadratic to hexagonal one, depending on the type of reinforcing material, has been further developed. A new method for optimization of the pressure and time of composite products’ molding at the temperature of the minimum binder viscosity has been developed. The method is implemented by analytical dependencies, which establish the optimal time intervals and pressure of molding on the section of the temperature and time diagram, associated with the ability of the operating equipment (oven, autoclave) to provide the maximum possible rate of temperature rise in order to “soften” the binder in prepreg to its minimum viscosity. It is shown that energy consumption for the re-formation of the tetragonal structure of the polymeric composite material into hexagonal one is ten times higher than the costs for the tetragonal structure formation. For example, re-formation of the tetragonal structure at volume content of the binder of 0.4 into dense hexagonal structure requires 66.7 times increase in pressure. Obtained results allow establishing the economically feasible level of pressure and time of composite products’ molding while ensuring their specified quality.
{"title":"Optimization of pressure and time of composite products molding at the temperature of minimum binder viscosity","authors":"O. Haidachuk, A. Kondratiev, A.V. Nabokina","doi":"10.15407/knit2022.02.003","DOIUrl":"https://doi.org/10.15407/knit2022.02.003","url":null,"abstract":"The technological process of composite products’ molding consists in giving them non-a reversible shape using shape-generating molding tools through polymerization of the binder at a certain temperature and pressure varying in time. The paper deals with the research of technological parameters of the most common practical method of molding products made of polymeric composite materials, pre-formed of prepregs. The mathematical model of filling with a binder of inter-fiber space of the reinforcing material for the polymeric composite material with the varying fiber packing densities, from quadratic to hexagonal one, depending on the type of reinforcing material, has been further developed. A new method for optimization of the pressure and time of composite products’ molding at the temperature of the minimum binder viscosity has been developed. The method is implemented by analytical dependencies, which establish the optimal time intervals and pressure of molding on the section of the temperature and time diagram, associated with the ability of the operating equipment (oven, autoclave) to provide the maximum possible rate of temperature rise in order to “soften” the binder in prepreg to its minimum viscosity. It is shown that energy consumption for the re-formation of the tetragonal structure of the polymeric composite material into hexagonal one is ten times higher than the costs for the tetragonal structure formation. For example, re-formation of the tetragonal structure at volume content of the binder of 0.4 into dense hexagonal structure requires 66.7 times increase in pressure. Obtained results allow establishing the economically feasible level of pressure and time of composite products’ molding while ensuring their specified quality.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48044922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-29DOI: 10.15407/knit2022.02.014
L. Nyrkova, T. Labur, E. I. Shevtsov, O. Nazarenko, A. Dorofeev, S. Osadchuk, M. Yavorska, A. Poklyatsky, V. Fedorchuk
A complex of properties of aluminium alloy 2219 welded joint, made by single-pass welding with a non-fusible electrode along and across the rolled product, and heat-treated to the state T62, in liquid amyl and its vapors at a temperature of 50 °C for 45 days was investigated. Characteristics of plasticity and strength of 2219 alloy welded joints are as follows: in the longitudinal (D) direction – yield strength of the welded joint is (301–317) MPa, of the base metal (295—297) MPa, strength limit of the welded joint (409–415) MPa, of the base metal (422–425) MPa, elongation is (4.0–5.8)% and (17.6–19.1)%, respectively; in the transverse (P) direction – the yield strength of the welded joint is (309–331) MPa, of the base metal (304–307) MPa, the yield strength of the welded joint (392–414) MPa, of the base metal (428–433) MPa, elongation is (2.1–3.3)% and (12.6–15.0)%, respectively. The strength coefficient of welded joints in the longitudinal direction is 0.96, in the transverse – 0.94. Welded joints in the above environment are resistant to corrosion cracking and intergranular corrosion, resistance against exfoliating corrosion is evaluated by grade 2. Resistance of 2219 alloy in T62 state in amyl corresponds to the resistance group «stable», in amyl vapors – the group “highly resistant”. After aging in amyl and amyl vapors, the strength grades of the base metal samples and welded joints in both directions are almost unchanged, the plasticity parameters change ambiguously: the yield strength of the base metal increases by ~ (5–6)%, of welded joints decreases by ~ (6–7)%, the relative elongation of the base metal is reduced by ~ (5–16)%, of welded joints by about ~ 20 %. Independently of the direction of welding relative to metal’s rolling, samples’ fractures are mostly viscous. After the exposing in amyl, the coefficient of the strength of welded joints in the longitudinal and transverse directions is the same and equal to 0.91, after the influence of amyl vapors, it is 0.95 in the longitudinal direction and 0.96 in the transverse direction.
{"title":"Complex of properties of 2219 alloy weld joint in T62 state under modeling operating conditions","authors":"L. Nyrkova, T. Labur, E. I. Shevtsov, O. Nazarenko, A. Dorofeev, S. Osadchuk, M. Yavorska, A. Poklyatsky, V. Fedorchuk","doi":"10.15407/knit2022.02.014","DOIUrl":"https://doi.org/10.15407/knit2022.02.014","url":null,"abstract":"A complex of properties of aluminium alloy 2219 welded joint, made by single-pass welding with a non-fusible electrode along and across the rolled product, and heat-treated to the state T62, in liquid amyl and its vapors at a temperature of 50 °C for 45 days was investigated. Characteristics of plasticity and strength of 2219 alloy welded joints are as follows: in the longitudinal (D) direction – yield strength of the welded joint is (301–317) MPa, of the base metal (295—297) MPa, strength limit of the welded joint (409–415) MPa, of the base metal (422–425) MPa, elongation is (4.0–5.8)% and (17.6–19.1)%, respectively; in the transverse (P) direction – the yield strength of the welded joint is (309–331) MPa, of the base metal (304–307) MPa, the yield strength of the welded joint (392–414) MPa, of the base metal (428–433) MPa, elongation is (2.1–3.3)% and (12.6–15.0)%, respectively. The strength coefficient of welded joints in the longitudinal direction is 0.96, in the transverse – 0.94. Welded joints in the above environment are resistant to corrosion cracking and intergranular corrosion, resistance against exfoliating corrosion is evaluated by grade 2. Resistance of 2219 alloy in T62 state in amyl corresponds to the resistance group «stable», in amyl vapors – the group “highly resistant”. After aging in amyl and amyl vapors, the strength grades of the base metal samples and welded joints in both directions are almost unchanged, the plasticity parameters change ambiguously: the yield strength of the base metal increases by ~ (5–6)%, of welded joints decreases by ~ (6–7)%, the relative elongation of the base metal is reduced by ~ (5–16)%, of welded joints by about ~ 20 %. Independently of the direction of welding relative to metal’s rolling, samples’ fractures are mostly viscous. After the exposing in amyl, the coefficient of the strength of welded joints in the longitudinal and transverse directions is the same and equal to 0.91, after the influence of amyl vapors, it is 0.95 in the longitudinal direction and 0.96 in the transverse direction.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48072374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-29DOI: 10.15407/knit2022.02.039
O. Ben Bahri
Space technology is becoming increasingly important in modern society. It participates in the construction of the future and the welfare of humanity through many applications in daily life. These factors lead to the need for training, research, and development in this area of space exploration. This paper reviews the use of small satellites to acquire basic knowledge of the space sector. Further development of this knowledge leads to the creation of space missions, which, in turn, ensure the progress of the space technology readiness level (TRL), defined by the international measurement scale. It is able to estimate technological maturity. The review concludes that the use of low-cost or didactic satellites could contribute to space mission development and demonstration. We reckon that embedded components with functions similar to smartphones can be used to achieve this goal. Two types of embedded components are discussed to demonstrate their efficacy in space engineering.
{"title":"Impact of Didactic Satellite in Space Maturity Improvement: A Review Paper","authors":"O. Ben Bahri","doi":"10.15407/knit2022.02.039","DOIUrl":"https://doi.org/10.15407/knit2022.02.039","url":null,"abstract":"Space technology is becoming increasingly important in modern society. It participates in the construction of the future and the welfare of humanity through many applications in daily life. These factors lead to the need for training, research, and development in this area of space exploration. This paper reviews the use of small satellites to acquire basic knowledge of the space sector. Further development of this knowledge leads to the creation of space missions, which, in turn, ensure the progress of the space technology readiness level (TRL), defined by the international measurement scale. It is able to estimate technological maturity. The review concludes that the use of low-cost or didactic satellites could contribute to space mission development and demonstration. We reckon that embedded components with functions similar to smartphones can be used to achieve this goal. Two types of embedded components are discussed to demonstrate their efficacy in space engineering.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47489185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-29DOI: 10.15407/knit2022.02.030
M.O. Yemelyanov, A. Shelestov, H. Yailymova, L. Shumilo
In this work, a statistical analysis of the time series of areas of majoritarian crops for 20 years (from 1998 to 2020) is carried out, and the influence of agro-climatic zones on the area of cultivation of major crops is analyzed. Climate change is acutely felt in the southern regions of Ukraine, increasing the production risk in the agricultural sector through changes in temperature, precipitation, and other extreme weather events. Historical climatic data indicate an increase in temperature on the territory of Ukraine, and climate forecasts suggest further warming, especially in the south of Ukraine. Using satellite and statistical data, changes in the earth’s surface are investigated for certain areas, which are characterized by the greatest changes in crop areas for the main types of crops. To analyze the dynamics of cultivated areas in relation to climatic zones, we used national statistical data for 1998—2019, maps of the classification of land cover from 2016—2020, data on climatic zones on the territory of Ukraine for 2000 and 2020, as well as the contours of administrative units of the NUTS2 level. Since statistical data for many districts are not available for the period 2019—2020 due to the reform of territorial boundaries, we used instead cultivated areas obtained from open satellite records. As additional and alternative information for the analysis of acreage, crop classification maps for 2016—2020 were used, obtained by specialists of the Space Research Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine from their own in-depth training technologies. We used classification maps obtained using open satellite data of the Copernicus program: SAR Sentinel-1 and Sentinel-2 with a spatial resolution of 10 m. A comparison of statistical data and crop areas obtained from satellite data was carried out by applying the metric of statistical analysis of the correlation coefficient (r). To assess the accuracy, the coefficient of determination R2 between the statistical area of the main crops and the area according to satellite data was also applied
{"title":"Impact of climate change on the area of major crops","authors":"M.O. Yemelyanov, A. Shelestov, H. Yailymova, L. Shumilo","doi":"10.15407/knit2022.02.030","DOIUrl":"https://doi.org/10.15407/knit2022.02.030","url":null,"abstract":"In this work, a statistical analysis of the time series of areas of majoritarian crops for 20 years (from 1998 to 2020) is carried out, and the influence of agro-climatic zones on the area of cultivation of major crops is analyzed. Climate change is acutely felt in the southern regions of Ukraine, increasing the production risk in the agricultural sector through changes in temperature, precipitation, and other extreme weather events. Historical climatic data indicate an increase in temperature on the territory of Ukraine, and climate forecasts suggest further warming, especially in the south of Ukraine. Using satellite and statistical data, changes in the earth’s surface are investigated for certain areas, which are characterized by the greatest changes in crop areas for the main types of crops. To analyze the dynamics of cultivated areas in relation to climatic zones, we used national statistical data for 1998—2019, maps of the classification of land cover from 2016—2020, data on climatic zones on the territory of Ukraine for 2000 and 2020, as well as the contours of administrative units of the NUTS2 level. Since statistical data for many districts are not available for the period 2019—2020 due to the reform of territorial boundaries, we used instead cultivated areas obtained from open satellite records. As additional and alternative information for the analysis of acreage, crop classification maps for 2016—2020 were used, obtained by specialists of the Space Research Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine from their own in-depth training technologies. We used classification maps obtained using open satellite data of the Copernicus program: SAR Sentinel-1 and Sentinel-2 with a spatial resolution of 10 m. A comparison of statistical data and crop areas obtained from satellite data was carried out by applying the metric of statistical analysis of the correlation coefficient (r). To assess the accuracy, the coefficient of determination R2 between the statistical area of the main crops and the area according to satellite data was also applied","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-29DOI: 10.15407/knit2022.02.054
Y. Vovchyk, А.І. Bilinsky, K. Martynyuk-Lototskyy, N. Virun, І.Ya. Pidsryhach, R.T. Nohach
Space debris is becoming an increasing threat to near space services, including satellite communications, the launching of new satellites, as well as navigation and timekeeping programs. It affects even observations of the Earth. As space around us becomes more congested, the need to track space objects and provide information about space activities is becoming increasingly critical and urgent in helping to prevent collisions or damage caused by space debris. Among the methods of tracking artificial objects are optical methods, which can provide information about the position of the selected object (positional observations), distance to the object (laser observations), as well as about the behavior of the object in orbit and its shape (photometric observations). The Astronomical Observatory of Lviv National University is equipped with a special hardware complex and software for the implementation of observations of artificial objects and can provide relevant information.
{"title":"Optical observations of the artificial objects at the Lviv Astronomical Observatory","authors":"Y. Vovchyk, А.І. Bilinsky, K. Martynyuk-Lototskyy, N. Virun, І.Ya. Pidsryhach, R.T. Nohach","doi":"10.15407/knit2022.02.054","DOIUrl":"https://doi.org/10.15407/knit2022.02.054","url":null,"abstract":"Space debris is becoming an increasing threat to near space services, including satellite communications, the launching of new satellites, as well as navigation and timekeeping programs. It affects even observations of the Earth. As space around us becomes more congested, the need to track space objects and provide information about space activities is becoming increasingly critical and urgent in helping to prevent collisions or damage caused by space debris. Among the methods of tracking artificial objects are optical methods, which can provide information about the position of the selected object (positional observations), distance to the object (laser observations), as well as about the behavior of the object in orbit and its shape (photometric observations). The Astronomical Observatory of Lviv National University is equipped with a special hardware complex and software for the implementation of observations of artificial objects and can provide relevant information.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47033181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：