Pub Date : 2022-05-25DOI: 10.22616/erdev.2022.21.tf119
M. Cerpinska, J. Viba, Ivo Vaicis
The research presents the mathematical model of non-stationary movement of an object in the air, considering that the wind flow might not be constant, as in the example of the vertical wind tunnel. The air flow rate might change its direction and magnitude over time, having variable velocity – a problem not solvable using conventional methods of aerodynamics, drag and lift force. Instead, the air flow around the object is divided into pressure and suction zones, and the angle of attack is variable. A thin flat plate is chosen as the moving object to allow the object not only translational movement, but also one rotational degree of freedom. Differential equations corresponding to a system with three degrees of freedom are presented in the article. Differential-integral equations are obtained and solved numerically using MathCAD software and explicit Euler step integration method. The developed method of motion analysis has been used for solving specific tasks: 1) vertical free fall of the plate in variable wind flow; 2) oscillations of the plate around a stationary base if additional elastic forces of the suspension reaction are applied. In addition, the case of a flapping wing structure in which energy is extracted from the air flow is considered. The obtained results can be used in practice to reduce or increase the interaction of other similar surface objects with air, for example, for sports equipment in competitions and everyday vehicles, as well as for obtaining energy from variable air flow in wind generators.
{"title":"Dynamics of flat plate complete motion in air flow with variable velocity","authors":"M. Cerpinska, J. Viba, Ivo Vaicis","doi":"10.22616/erdev.2022.21.tf119","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf119","url":null,"abstract":"The research presents the mathematical model of non-stationary movement of an object in the air, considering that the wind flow might not be constant, as in the example of the vertical wind tunnel. The air flow rate might change its direction and magnitude over time, having variable velocity – a problem not solvable using conventional methods of aerodynamics, drag and lift force. Instead, the air flow around the object is divided into pressure and suction zones, and the angle of attack is variable. A thin flat plate is chosen as the moving object to allow the object not only translational movement, but also one rotational degree of freedom. Differential equations corresponding to a system with three degrees of freedom are presented in the article. Differential-integral equations are obtained and solved numerically using MathCAD software and explicit Euler step integration method. The developed method of motion analysis has been used for solving specific tasks: 1) vertical free fall of the plate in variable wind flow; 2) oscillations of the plate around a stationary base if additional elastic forces of the suspension reaction are applied. In addition, the case of a flapping wing structure in which energy is extracted from the air flow is considered. The obtained results can be used in practice to reduce or increase the interaction of other similar surface objects with air, for example, for sports equipment in competitions and everyday vehicles, as well as for obtaining energy from variable air flow in wind generators.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121265192","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf290
I. Rogovskii, L. Titova, R. Shatrov, O. Bannyi, O. Nadtochiy
The article presents the results of experimental studies of the process of digging seedlings, which confirm the interaction of the working bodies with the soil slice and the reinforced root system of seedlings. The authors confirmed that the root system of seedlings grown on vegetative rootstocks is much more compact and has a fibrous structure, and therefore, their excavation requires less effort compared to seedlings grown on seed rootstocks. Plants are mainly planted in the first field of the fruit nursery with rows between 0.7 and 1 m that the maximum depth of excavation of biennial seedlings on clonal rootstocks is 0.30-0.35 m, and the width of the excavation soil is about 0.50 m. The results of the study showed that the energy intensity of machine technological operations was 30.8 GJ, which is more per 1 ha of land per year (permissible load of 15 GJ per 1 ha). The construction scheme and kinematic parameters of the working body of the machine are substantiated, which should consist of two elements: passive digging bracket and active shaker. The working part of the bracket should be formed by a cylinder with the radius about 0.34 m and have a width of 0.18-0.24 m, and its spatial location should provide the angle of attack about 10 degrees. The ripper must be active, namely oscillating, and the amplitude of its oscillations must increase from the minimum at the inlet of the roll to the maximum at its output. The range of changes in the amplitude and frequency of oscillations should be in the range of 0.01-0.03 m and 5.5-6.2 s, respectively.
{"title":"Technological effectiveness of machine for digging seedlings in nursery grown on vegetative rootstocks","authors":"I. Rogovskii, L. Titova, R. Shatrov, O. Bannyi, O. Nadtochiy","doi":"10.22616/erdev.2022.21.tf290","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf290","url":null,"abstract":"The article presents the results of experimental studies of the process of digging seedlings, which confirm the interaction of the working bodies with the soil slice and the reinforced root system of seedlings. The authors confirmed that the root system of seedlings grown on vegetative rootstocks is much more compact and has a fibrous structure, and therefore, their excavation requires less effort compared to seedlings grown on seed rootstocks. Plants are mainly planted in the first field of the fruit nursery with rows between 0.7 and 1 m that the maximum depth of excavation of biennial seedlings on clonal rootstocks is 0.30-0.35 m, and the width of the excavation soil is about 0.50 m. The results of the study showed that the energy intensity of machine technological operations was 30.8 GJ, which is more per 1 ha of land per year (permissible load of 15 GJ per 1 ha). The construction scheme and kinematic parameters of the working body of the machine are substantiated, which should consist of two elements: passive digging bracket and active shaker. The working part of the bracket should be formed by a cylinder with the radius about 0.34 m and have a width of 0.18-0.24 m, and its spatial location should provide the angle of attack about 10 degrees. The ripper must be active, namely oscillating, and the amplitude of its oscillations must increase from the minimum at the inlet of the roll to the maximum at its output. The range of changes in the amplitude and frequency of oscillations should be in the range of 0.01-0.03 m and 5.5-6.2 s, respectively.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132627159","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf022
Ketvara Sittichok
Thailand is located in Southeast Asia where it is indicated as highly vulnerable to climate change. This country will likely be one of the countries that have experienced negative impacts of climate change. To reduce the impact of climate change on drought and flood, a water management plan under climate change needs to be prepared. The changes of future rainfalls under climate change emission scenarios play an important role and need to be investigated. This study aims to describe projected rainfall characteristics under AR6 climate change scenarios. Rainfalls generated from 10 GCMs were downscaled to a basin scale at the Pasak River Basin using the quantile mapping method. After the downscaling process simulated precipitation significantly improved in both magnitude and volume compared to the observed data using the Nash-Sutcliff coefficient and volume error methods. Slight differences between downscaled and observed precipitation were found with acceptable results using the coefficient of determination. Variabilities of future precipitation under four scenarios (SSP1-2.6, SSP24.5, SSP3-7.0 and SSP5-8.5) of each model were revealed. Annual average of projected rainfalls was slightly different between the models, but large variation compared to others could be found in INM-CM5. The standardized anomaly index was then calculated for historical and two future periods: the near-term (2015-2050) and the long-term (2051-2100), and the frequencies of wet and dry incidents were presented. Very-extremely wet and dry years often occurred in 2051-2100 under SSP2-4.5 and SSP1-2.6 respectively. Finally, the increments in annual rainfalls were obviously seen in SSP2-4.5, SSP3-7.0 and SSP5-8.5 for the near-term and in all scenarios of the long-term. Slight decreasing trend was only found in the near-term under SSP1-2.6.
{"title":"Future rainfall characteristics under AR6 climate change scenarios, case study of pasak river basin, Thailand","authors":"Ketvara Sittichok","doi":"10.22616/erdev.2022.21.tf022","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf022","url":null,"abstract":"Thailand is located in Southeast Asia where it is indicated as highly vulnerable to climate change. This country will likely be one of the countries that have experienced negative impacts of climate change. To reduce the impact of climate change on drought and flood, a water management plan under climate change needs to be prepared. The changes of future rainfalls under climate change emission scenarios play an important role and need to be investigated. This study aims to describe projected rainfall characteristics under AR6 climate change scenarios. Rainfalls generated from 10 GCMs were downscaled to a basin scale at the Pasak River Basin using the quantile mapping method. After the downscaling process simulated precipitation significantly improved in both magnitude and volume compared to the observed data using the Nash-Sutcliff coefficient and volume error methods. Slight differences between downscaled and observed precipitation were found with acceptable results using the coefficient of determination. Variabilities of future precipitation under four scenarios (SSP1-2.6, SSP24.5, SSP3-7.0 and SSP5-8.5) of each model were revealed. Annual average of projected rainfalls was slightly different between the models, but large variation compared to others could be found in INM-CM5. The standardized anomaly index was then calculated for historical and two future periods: the near-term (2015-2050) and the long-term (2051-2100), and the frequencies of wet and dry incidents were presented. Very-extremely wet and dry years often occurred in 2051-2100 under SSP2-4.5 and SSP1-2.6 respectively. Finally, the increments in annual rainfalls were obviously seen in SSP2-4.5, SSP3-7.0 and SSP5-8.5 for the near-term and in all scenarios of the long-term. Slight decreasing trend was only found in the near-term under SSP1-2.6.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117238706","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf227
J. Sanchaniya, S. Kanukuntla, Shino Simon, A. Geriņa-Ancāne
The methods of deposition of nanofibers on a rotating drum and a stationary plate, as well as analysis of mechanical properties of the nanofibers from both collectors, are proposed in this article. The deposition of nanofibers on collectors is crucial, as it is the successful development of nanofibers with various types of collectors, as well as the evaluation and demonstration of their strength and other mechanical properties. The most popular method for producing continuous nanofibers is electro spinning, which involves jetting polymer solutions in high electric fields to produce continuous nanofibers with diameters ranging from 200 to 600 nm. These results were compared using ANSYS, and the material behavior of biaxial nanofibers collected from the spinning collector was identified. The rotating drum collector’s spinning speed causes the fibers to stretch, resulting in alignment and a decrease in diameter. The rotating drum collector adds force to the strong shear and elongation forces that arrange the chains and align the lamellae in the fiber axis direction during the electro-spinning process. As a result, the nanofibers on the rotating drum are aligned uniaxial. It indicates that by altering the collector design, the alignment and mechanical properties of nanofibers can be improved. The results showed that the nanofibers collected from the spinning drum were more consistently aligned (biaxial arrangement) than those obtained from the stationary plate and had Young’s modulus of composite 5.01 GPa and 4.4 GPa respectively, ~9% more strength than the nanofibers collected from flat plate.
{"title":"Analysis of mechanical properties of composite nanofibers constructed on rotating drum and collector plate","authors":"J. Sanchaniya, S. Kanukuntla, Shino Simon, A. Geriņa-Ancāne","doi":"10.22616/erdev.2022.21.tf227","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf227","url":null,"abstract":"The methods of deposition of nanofibers on a rotating drum and a stationary plate, as well as analysis of mechanical properties of the nanofibers from both collectors, are proposed in this article. The deposition of nanofibers on collectors is crucial, as it is the successful development of nanofibers with various types of collectors, as well as the evaluation and demonstration of their strength and other mechanical properties. The most popular method for producing continuous nanofibers is electro spinning, which involves jetting polymer solutions in high electric fields to produce continuous nanofibers with diameters ranging from 200 to 600 nm. These results were compared using ANSYS, and the material behavior of biaxial nanofibers collected from the spinning collector was identified. The rotating drum collector’s spinning speed causes the fibers to stretch, resulting in alignment and a decrease in diameter. The rotating drum collector adds force to the strong shear and elongation forces that arrange the chains and align the lamellae in the fiber axis direction during the electro-spinning process. As a result, the nanofibers on the rotating drum are aligned uniaxial. It indicates that by altering the collector design, the alignment and mechanical properties of nanofibers can be improved. The results showed that the nanofibers collected from the spinning drum were more consistently aligned (biaxial arrangement) than those obtained from the stationary plate and had Young’s modulus of composite 5.01 GPa and 4.4 GPa respectively, ~9% more strength than the nanofibers collected from flat plate.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"418 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132520774","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf057
A. Jaunzems, I. Balode
The goal of the research is to carry out the comparative dynamic Input-Output analysis of economics of the industry “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials” (C16) in the Baltic States and Finland. The information for the study is the National Input-Output Tables for the period 2000-2014 as part of the World Input-Output Database. The theoretical basis in the general sense is the Input-Output analysis and linear algebra as well. The investigation tool is the original version of the Input-Output model elaborated by the authors according to the structure of the National Input-Output Tables. The purpose of the work is the dynamic comparative Input-Output analysis of industry’s C16 operating as an economic unit in the Baltic States and Finland in order to highlight the differences in the sales and purchases structures as factors for industry’s value added creation and industry’s influence to the national economy as a whole. The investigations concern the gross output sales structure, intermediate consumption structure, Leontief inverse, Ghosh inverse, direct and total backward linkages, direct and total forward linkages of the industry C16. Comparison the industry’s C16 operating in Estonia, Finland, Latvia and Lithuania in the dynamic aspect allows us to discover the cost and revenue factors of the industry’s “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials” value added creation efficiency in the referred countries. All indicators calculated with help of the Input-Output model contain the pithy information for the managers of the industry “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials”. Our results are original because of the specific object of current research and the dynamic comparative Input-Output investigation method employed by us.
{"title":"Comparative dynamic analysis of value added created by industry \"\"manufacture of wood and of products of wood and cork, Except furniture; Manufacture of articles of straw and plaiting materials\"\" in baltic states and finland","authors":"A. Jaunzems, I. Balode","doi":"10.22616/erdev.2022.21.tf057","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf057","url":null,"abstract":"The goal of the research is to carry out the comparative dynamic Input-Output analysis of economics of the industry “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials” (C16) in the Baltic States and Finland. The information for the study is the National Input-Output Tables for the period 2000-2014 as part of the World Input-Output Database. The theoretical basis in the general sense is the Input-Output analysis and linear algebra as well. The investigation tool is the original version of the Input-Output model elaborated by the authors according to the structure of the National Input-Output Tables. The purpose of the work is the dynamic comparative Input-Output analysis of industry’s C16 operating as an economic unit in the Baltic States and Finland in order to highlight the differences in the sales and purchases structures as factors for industry’s value added creation and industry’s influence to the national economy as a whole. The investigations concern the gross output sales structure, intermediate consumption structure, Leontief inverse, Ghosh inverse, direct and total backward linkages, direct and total forward linkages of the industry C16. Comparison the industry’s C16 operating in Estonia, Finland, Latvia and Lithuania in the dynamic aspect allows us to discover the cost and revenue factors of the industry’s “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials” value added creation efficiency in the referred countries. All indicators calculated with help of the Input-Output model contain the pithy information for the managers of the industry “Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials”. Our results are original because of the specific object of current research and the dynamic comparative Input-Output investigation method employed by us.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116955861","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf030
M. Mangalis, J. Priekulis, M. Mangale
The article discusses the experience of Latvian dairy farms in keeping cows in cubicle beds. It has been found that the number of cows kept in this way in the country is increasing every year. If in 2010 about 35% of the total number of dairy cows were kept in the cubicles, now it exceeds 50%. In addition, both high and deep cubicles are common. It was found that the highest milk yields and high milk quality (based on SCC) were obtained using deep cubicle beds in which the cows’ beds were filled with sand. If high cubicle beds or deep cubicle beds with other bedding are used, the milk yield of cows is on average 15% lower. The number of SCC, on the other hand, increases by 50% with high cubicle beds and increases by 40% with deep cubicle beds with other bedding. However, this figure depends to a large extent on the frequency of cleaning the cubicle and the frequency of refilling the bedding material.
{"title":"Studies of cubicle bed design in latvian dairy farms","authors":"M. Mangalis, J. Priekulis, M. Mangale","doi":"10.22616/erdev.2022.21.tf030","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf030","url":null,"abstract":"The article discusses the experience of Latvian dairy farms in keeping cows in cubicle beds. It has been found that the number of cows kept in this way in the country is increasing every year. If in 2010 about 35% of the total number of dairy cows were kept in the cubicles, now it exceeds 50%. In addition, both high and deep cubicles are common. It was found that the highest milk yields and high milk quality (based on SCC) were obtained using deep cubicle beds in which the cows’ beds were filled with sand. If high cubicle beds or deep cubicle beds with other bedding are used, the milk yield of cows is on average 15% lower. The number of SCC, on the other hand, increases by 50% with high cubicle beds and increases by 40% with deep cubicle beds with other bedding. However, this figure depends to a large extent on the frequency of cleaning the cubicle and the frequency of refilling the bedding material.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"187 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117274769","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf291
E. Aruvee, A. Vintere
Several studies suggest that industrial infrastructure and education need to be adapted in line with the 4 Industrial Revolution. In education, on the one hand, schools, training and university programs need to be adoptive and, on the other hand, an entrepreneurial approach is needed to increase the information technologies and innovation skills of the workforce. To sustain economic growth, emerging economies need education and training programs to develop skills, especially digital, which are increasingly in demand in the labour market. Digital competence is not just the ability to surf the Internet, it can be broken down into many smaller components. It should be also noted that digital competence, can be seen also as a transversal competence, it also helps develop other essential skills, such as communication, language skills or basic knowledge in mathematics or science. The European Commission has developed the Digital Competences Framework for Europeans (DigComp), which is divided into five areas: information and data literacy; communication and cooperation; digital content creation; safety; and problem solving. The empirical part of the study includes a comparative analysis of the use of technology in mathematics studies at the Latvia University of Life Sciences and Technologies and the Estonian University of Life Sciences, and a student survey to assess the development of digital competencies in mathematics studies at the university by five components identified in DigComp, as well as to identify which e-learning tools (informative and interactive) and internet resources looking for specific information or using other mathematics software besides MatLab or MathCad are included in the course. The analysis of students’ digital skills shows that these are quite good. However, the biggest problems for students were solving problems, such as storing files in the cloud, editing videos/photos, solving technical problems related to studying mathematics, and solving security problems.
{"title":"Use of ict in mathematics studies to develop digital skills of undergraduate engineering students","authors":"E. Aruvee, A. Vintere","doi":"10.22616/erdev.2022.21.tf291","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf291","url":null,"abstract":"Several studies suggest that industrial infrastructure and education need to be adapted in line with the 4 Industrial Revolution. In education, on the one hand, schools, training and university programs need to be adoptive and, on the other hand, an entrepreneurial approach is needed to increase the information technologies and innovation skills of the workforce. To sustain economic growth, emerging economies need education and training programs to develop skills, especially digital, which are increasingly in demand in the labour market. Digital competence is not just the ability to surf the Internet, it can be broken down into many smaller components. It should be also noted that digital competence, can be seen also as a transversal competence, it also helps develop other essential skills, such as communication, language skills or basic knowledge in mathematics or science. The European Commission has developed the Digital Competences Framework for Europeans (DigComp), which is divided into five areas: information and data literacy; communication and cooperation; digital content creation; safety; and problem solving. The empirical part of the study includes a comparative analysis of the use of technology in mathematics studies at the Latvia University of Life Sciences and Technologies and the Estonian University of Life Sciences, and a student survey to assess the development of digital competencies in mathematics studies at the university by five components identified in DigComp, as well as to identify which e-learning tools (informative and interactive) and internet resources looking for specific information or using other mathematics software besides MatLab or MathCad are included in the course. The analysis of students’ digital skills shows that these are quite good. However, the biggest problems for students were solving problems, such as storing files in the cloud, editing videos/photos, solving technical problems related to studying mathematics, and solving security problems.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115472636","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf026
Tonggang Shen, Y. Inagaki, Hiroki Koike, Ranjusha Vaddake Pariyarath, M. Komori, Y. Sakakibara
Sulfamethoxazole (SMX) is one of the most frequently used antibiotics. The capacity of conventional wastewater treatment plants to remove such antibiotics is limited, posing a risk of antibiotic resistance genes spreading into the environment. In this study, to carry out biological Fenton reaction under neutral conditions, an anaerobic and aerobic sequencing batch reactor (SBR) supplemented with magnetite was proposed. This process aims to enhance the treatment of antibiotics in addition to organic pollutants such as chemical oxygen demand (COD) without external addition of hydrogen peroxide (H2O2). Mixed anaerobic and aerobic sludge was exposed to alternative anaerobic and aerobic conditions in two identical SBRs with and without magnetite to treat the synthetic wastewater containing 1 mg·L sulfamethoxazole. The experimental results showed that the H2O2 level increased to 34.9 μM under aerobic conditions in the system with magnetite, and similar COD removal was observed in both SBRs. Moreover, enhanced SMX treatment was observed in the SBR with magnetite, while removal efficiencies of SMX gradually decreased in the SBR without magnetite. The experimental results demonstrate that H2O2 generation under aerobic conditions and biological Fenton reaction that can produce hydroxyl radicals led to the enhanced treatment of SMX in the SBR with magnetite. Magnetite as the catalyst was not dissolved during the redox process, indicating the possibility of its reusability. Further studies are needed to analyse the reaction mechanisms and the kinetics in the proposed SBR.
{"title":"Enhanced sulfamethoxazole removal using anaerobic and aerobic sequencing batch reactor with magnetite","authors":"Tonggang Shen, Y. Inagaki, Hiroki Koike, Ranjusha Vaddake Pariyarath, M. Komori, Y. Sakakibara","doi":"10.22616/erdev.2022.21.tf026","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf026","url":null,"abstract":"Sulfamethoxazole (SMX) is one of the most frequently used antibiotics. The capacity of conventional wastewater treatment plants to remove such antibiotics is limited, posing a risk of antibiotic resistance genes spreading into the environment. In this study, to carry out biological Fenton reaction under neutral conditions, an anaerobic and aerobic sequencing batch reactor (SBR) supplemented with magnetite was proposed. This process aims to enhance the treatment of antibiotics in addition to organic pollutants such as chemical oxygen demand (COD) without external addition of hydrogen peroxide (H2O2). Mixed anaerobic and aerobic sludge was exposed to alternative anaerobic and aerobic conditions in two identical SBRs with and without magnetite to treat the synthetic wastewater containing 1 mg·L sulfamethoxazole. The experimental results showed that the H2O2 level increased to 34.9 μM under aerobic conditions in the system with magnetite, and similar COD removal was observed in both SBRs. Moreover, enhanced SMX treatment was observed in the SBR with magnetite, while removal efficiencies of SMX gradually decreased in the SBR without magnetite. The experimental results demonstrate that H2O2 generation under aerobic conditions and biological Fenton reaction that can produce hydroxyl radicals led to the enhanced treatment of SMX in the SBR with magnetite. Magnetite as the catalyst was not dissolved during the redox process, indicating the possibility of its reusability. Further studies are needed to analyse the reaction mechanisms and the kinetics in the proposed SBR.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116076548","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 : 2022-05-25DOI: 10.22616/erdev.2022.21.tf181
A. Zimelis, G. Spalva
The aim of the study is to evaluate the productivity and potential reduction of greenhouse gas (GHG) emissions due to use of the compact class Malwa harvester 560H and forwarder 560F in thinning of aspen hybrid plantations as well as to indicate the production cost and to analyse the possibility to use forest machines of this class in aspen plantations and to definite the quality of thinning, including the damage to the remaining trees, width of strip-roads, as well as to provide recommendations for the further development of the technology. These parameters have significant effect on productivity, fuel consumption and the vitality of the remaining trees. The productivity and cost are affected by tree dimensions, if the average harvested stem diameter is 12.2 cm, the productivity is 8.63 m per productive hour and the harvesting cost is 12.24 EUR·m, but in average productivity gives a big impact on the cost – 10.96 m per productive hour and harvesting cost – 10.04 EUR·m. The average forwarder load in the study is 4.03 m, forwarding productivity 5.1 m per productive hour and total harvesting and forwarding cost – 21.04 EUR·m. Harvesting related GHG emissions in aspen plantations are 4.12 kg CO2·m, including harvester related emissions – 49% and forwarding – 51%. According to the study results the harvesting GHG emissions using the Malwa harvester and forwarder are significantly smaller than of a middle-class forest machines due to smaller fuel consumption and high productivity values; besides, maintenance and investment costs of compact class machines are significantly smaller. The mechanical damage to roots and stems of the remaining trees during logging is inevitable. This is ensured by the use of recommended working methods setting special attention to the felling direction and the distance between the remaining trees in the stand, as well as avoiding unnecessary movements with the manipulator.
本研究的目的是评估由于使用紧凑型Malwa收割机560H和转发器560F在杨树杂交林间伐中产生的生产力和减少温室气体(GHG)排放的潜力，并指出生产成本，分析在杨树人工林中使用这类森林机器的可能性，并确定间伐的质量，包括对剩余树木的损害，带状道路的宽度，并为该技术的进一步发展提供建议。这些参数对剩余树木的生产力、燃料消耗和活力有显著影响。生产效率和成本受树木尺寸的影响，如果平均采伐茎粗为12.2 cm，生产效率为8.63 m /生产小时，采伐成本为12.24 EUR·m，但平均生产效率对成本的影响较大，为10.96 m /生产小时，采伐成本为10.04 EUR·m。研究中货代的平均载重为4.03米，每生产小时的货代生产率为5.1米，总收获和货代成本为21.04欧元·米。在杨树人工林中，与采伐相关的温室气体排放量为4.12 kg CO2·m，其中与采伐相关的排放量为49%，与运输相关的排放量为51%。研究结果表明，由于燃料消耗小，生产率值高，使用马尔瓦收割机和转运机的采伐温室气体排放量明显小于中等规模的森林机械;此外，紧凑型机器的维护和投资成本明显更小。在采伐过程中，对剩余树木的根和茎造成机械损伤是不可避免的。这是通过使用推荐的工作方法来确保的，特别注意砍伐方向和林内剩余树木之间的距离，以及避免使用机械手进行不必要的运动。
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Pub Date : 2022-05-25DOI: 10.22616/erdev.2022.21.tf067
V. Dubrovskis, I. Plume, I. Straume
Noticeable climate change around the world has led to the search for more and more low-carbon technologies. Biogas is also produced in Latvia and is used to produce electricity and heat. The use of biomethane in transport needs to be further developed to replace diesel and petrol engines more quickly. In the spring, biogas producers sometimes have difficulty securing good quality raw materials. The raw materials procured in the previous year are not always left in sufficient quantities. It happens that long-term storage of raw materials also breaks down. The amount of manure, which is mainly used by Latvian biogas plants, cannot usually be increased. There is a shortage of raw materials and gas yields are falling. Biomethane yields can be increased by substances that catalyze the anaerobic fermentation process. They can also be found in spring plants. The use of spring plants such as dandelions (taraxacum), which grow over large areas, could improve the situation. The methane potential of dandelions and three other plants was investigated in this study. Plants such as celandine (Chelidonium majus), European twist (Cuscuta europaea) and elderberry (Sambucus nigra) have specific effects. Elderberry and celandine have a healing effect, but the European twist is a parasitic plant. Therefore, it seemed interesting to find out whether these plants will somehow specifically affect the activity of bacteria in the process of anaerobic fermentation. Fourteen bioreactors were filled with fresh plants collected in the field and in the garden on the same day. The two bioreactors were filled with inoculum only. Anaerobic fermentation took place at 38C and lasted from 10.05 to 7.06. The methane potential was 0.486 L·gDOM for dandelions, 0.440 L·gDOM for elderberry leaves, 0.488 L·gDOM for European twist and 0.403 L·gDOM for celandine. All the plants tested are very useful as feedstocks for methane production in anaerobic fermentation. However, expectations that Sambucus nigra, Chelidonium majus and Cuscuta europaea will show some catalytic properties for anaerobic fermentation were not met.
{"title":"Anaerobic fermentation of spring fresh wild plants","authors":"V. Dubrovskis, I. Plume, I. Straume","doi":"10.22616/erdev.2022.21.tf067","DOIUrl":"https://doi.org/10.22616/erdev.2022.21.tf067","url":null,"abstract":"Noticeable climate change around the world has led to the search for more and more low-carbon technologies. Biogas is also produced in Latvia and is used to produce electricity and heat. The use of biomethane in transport needs to be further developed to replace diesel and petrol engines more quickly. In the spring, biogas producers sometimes have difficulty securing good quality raw materials. The raw materials procured in the previous year are not always left in sufficient quantities. It happens that long-term storage of raw materials also breaks down. The amount of manure, which is mainly used by Latvian biogas plants, cannot usually be increased. There is a shortage of raw materials and gas yields are falling. Biomethane yields can be increased by substances that catalyze the anaerobic fermentation process. They can also be found in spring plants. The use of spring plants such as dandelions (taraxacum), which grow over large areas, could improve the situation. The methane potential of dandelions and three other plants was investigated in this study. Plants such as celandine (Chelidonium majus), European twist (Cuscuta europaea) and elderberry (Sambucus nigra) have specific effects. Elderberry and celandine have a healing effect, but the European twist is a parasitic plant. Therefore, it seemed interesting to find out whether these plants will somehow specifically affect the activity of bacteria in the process of anaerobic fermentation. Fourteen bioreactors were filled with fresh plants collected in the field and in the garden on the same day. The two bioreactors were filled with inoculum only. Anaerobic fermentation took place at 38C and lasted from 10.05 to 7.06. The methane potential was 0.486 L·gDOM for dandelions, 0.440 L·gDOM for elderberry leaves, 0.488 L·gDOM for European twist and 0.403 L·gDOM for celandine. All the plants tested are very useful as feedstocks for methane production in anaerobic fermentation. However, expectations that Sambucus nigra, Chelidonium majus and Cuscuta europaea will show some catalytic properties for anaerobic fermentation were not met.","PeriodicalId":244107,"journal":{"name":"21st International Scientific Conference Engineering for Rural Development Proceedings","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126371666","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}
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