Pub Date : 2021-03-31DOI: 10.4236/JEMAA.2021.133003
S. Peden, Ronald C. Bradbury, D. Lamb, M. Hedley
Assessing plant water status is important for monitoring plant physiology. Radio signals are attenuated when passing through vegetation. Both analytical and empirical models developed for radio frequency (RF) loss through vegetation have been dependent on experimental measurements and those measurements have been completed in specific situations. However, for models to be more broadly applicable across a broad range of vegetation types and constructs, basic electrical properties of the vegetation need to be characterised. Radio waves are affected especially by water and the relationship between water content in vegetation expressed as effective water path (EWP) in mm and measured RF loss (dB) at 2.4 GHz was investigated in this work. The EWP of eucalyptus leaves of varying amounts of leaf moisture (0% - 41.5%) ranged from 0 - 14 mm, respectively. When the model was compared with the actual RF loss there was a systematic offset equivalent to a residual leaf moisture content of 6.5% that was unaccounted for in the leaf moisture content determination (oven drying). This was attributed to bound water. When the model was adjusted for this amount of additional leaf water, the average RMSE in predicted RF loss was ±2.2 dB and was found to explain 89% of the variance in measured RF loss.
{"title":"A Model for RF Loss through Vegetation with Varying Water Content","authors":"S. Peden, Ronald C. Bradbury, D. Lamb, M. Hedley","doi":"10.4236/JEMAA.2021.133003","DOIUrl":"https://doi.org/10.4236/JEMAA.2021.133003","url":null,"abstract":"Assessing plant water status is important for monitoring plant physiology. Radio signals are attenuated when passing through vegetation. Both analytical and empirical models developed for radio frequency (RF) loss through vegetation have been dependent on experimental measurements and those measurements have been completed in specific situations. However, for models to be more broadly applicable across a broad range of vegetation types and constructs, basic electrical properties of the vegetation need to be characterised. Radio waves are affected especially by water and the relationship between water content in vegetation expressed as effective water path (EWP) in mm and measured RF loss (dB) at 2.4 GHz was investigated in this work. The EWP of eucalyptus leaves of varying amounts of leaf moisture (0% - 41.5%) ranged from 0 - 14 mm, respectively. When the model was compared with the actual RF loss there was a systematic offset equivalent to a residual leaf moisture content of 6.5% that was unaccounted for in the leaf moisture content determination (oven drying). This was attributed to bound water. When the model was adjusted for this amount of additional leaf water, the average RMSE in predicted RF loss was ±2.2 dB and was found to explain 89% of the variance in measured RF loss.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70292803","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 : 2021-02-28DOI: 10.4236/JEMAA.2021.132002
Genquan Xie, Xingpeng Song, Xiao Xiao
A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.
{"title":"Bulk Waves in the Infinite Electric-Magnetic-Elastic Plate with Mixed Boundary Conditions","authors":"Genquan Xie, Xingpeng Song, Xiao Xiao","doi":"10.4236/JEMAA.2021.132002","DOIUrl":"https://doi.org/10.4236/JEMAA.2021.132002","url":null,"abstract":"A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"13 1","pages":"21-39"},"PeriodicalIF":0.0,"publicationDate":"2021-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47006246","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 : 2021-01-28DOI: 10.4236/JEMAA.2021.131001
Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado
The paper describes a simulated experiment that focuses on the numeric computation of magnetic loss in the laminated core of a single-phase power transformer. The students’ laboratory work is part of the library of experiments of the Electrical Machines virtual laboratory and makes use of the two-dimensional open-access electromagnetic field analysis software Finite Element Method Magnetics. The idea of the simulated exercise is to demonstrate how the magnetic loss caused by time-varying excitations affects the magnetic permeability, μ, of the laminated core and the terminal quantities of the energizing winding. A parametric analysis employing different values for the electrical conductivity and maximum hysteresis-induced angle of the laminated material yields five different field problems with increasing magnetic loss. Electric circuits characterized by the (I-V) operating point and reflected impedance of the energizing winding provide the information required to compute the changes in real power ΔP, reactive power ΔQ and magnetically stored energy ΔWm between successive problems characterized by increasing magnetic loss. The concept of reflected impedance helps to explain the physical meaning of the changes in power dissipation and energy storage in the laminated core.
{"title":"Finite Element CAD Experiments on the Effect of Magnetic Loss in Power Transformers with Laminated Cores","authors":"Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado","doi":"10.4236/JEMAA.2021.131001","DOIUrl":"https://doi.org/10.4236/JEMAA.2021.131001","url":null,"abstract":"The paper describes a simulated experiment that focuses on the numeric computation of magnetic loss in the laminated core of a single-phase power transformer. The students’ laboratory work is part of the library of experiments of the Electrical Machines virtual laboratory and makes use of the two-dimensional open-access electromagnetic field analysis software Finite Element Method Magnetics. The idea of the simulated exercise is to demonstrate how the magnetic loss caused by time-varying excitations affects the magnetic permeability, μ, of the laminated core and the terminal quantities of the energizing winding. A parametric analysis employing different values for the electrical conductivity and maximum hysteresis-induced angle of the laminated material yields five different field problems with increasing magnetic loss. Electric circuits characterized by the (I-V) operating point and reflected impedance of the energizing winding provide the information required to compute the changes in real power ΔP, reactive power ΔQ and magnetically stored energy ΔWm between successive problems characterized by increasing magnetic loss. The concept of reflected impedance helps to explain the physical meaning of the changes in power dissipation and energy storage in the laminated core.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"13 1","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44597987","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 : 2021-01-01DOI: 10.4236/jemaa.2020.1311011
Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado
{"title":"An Introductory Note on Finite Element Problems Based on the Eddy Current Testing Approach","authors":"Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado","doi":"10.4236/jemaa.2020.1311011","DOIUrl":"https://doi.org/10.4236/jemaa.2020.1311011","url":null,"abstract":"","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70292731","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 : 2021-01-01DOI: 10.4236/jemaa.2021.1312012
K. Sakai
Today, the sun is a very useful source of energy because it continuously radiates energy. An electron is radiating energy continuously, too. A new electrostatic generating method using this electric field energy from electrons as a driving force of charge carriers was invented, and its success was presented on ESA 2017 and ESA 2019. This new electrostatic generator was realized by asymmetric electrostatic force, which is a new phenomenon. Unfortunately, its experimental success rate was rare. Therefore, the cause was searched by many experiments. Finally, it became apparent that the acceleration force of the charge carrier was not stronger than the deceleration force of the charge carrier with this experimental equipment. Therefore, the electrode arrangement of this equipment was improved. As a result, the acceleration force was increased, and the deceleration force was decreased. Then, the experimental success rate became 100%.
{"title":"A New Electrostatic Generator Driven by Only an Electric Field of an Electret","authors":"K. Sakai","doi":"10.4236/jemaa.2021.1312012","DOIUrl":"https://doi.org/10.4236/jemaa.2021.1312012","url":null,"abstract":"Today, the sun is a very useful source of energy because it continuously radiates energy. An electron is radiating energy continuously, too. A new electrostatic generating method using this electric field energy from electrons as a driving force of charge carriers was invented, and its success was presented on ESA 2017 and ESA 2019. This new electrostatic generator was realized by asymmetric electrostatic force, which is a new phenomenon. Unfortunately, its experimental success rate was rare. Therefore, the cause was searched by many experiments. Finally, it became apparent that the acceleration force of the charge carrier was not stronger than the deceleration force of the charge carrier with this experimental equipment. Therefore, the electrode arrangement of this equipment was improved. As a result, the acceleration force was increased, and the deceleration force was decreased. Then, the experimental success rate became 100%.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70292787","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 : 2020-12-30DOI: 10.4236/jemaa.2020.1212014
S. Kühn
In this article, we investigate the physical consequences that would result if electromagnetic field quanta were emitted at random speeds by a source and if the receiver could only perceive the fraction of the quantum field that is slower than the speed of light in its individual rest frame. The analysis shows that this plausible hypothesis eliminates the weak points of conventional emission theories and that both postulates of special relativity are fulfilled. Furthermore, the results demonstrate that this theory can explain numerous experiments that are usually interpreted using different aspects of special relativity. However, the resulting quantum field theory is not equivalent to the special theory of relativity and requires neither spacetime nor Lorentz transformation. Furthermore, this approach offers a starting point for interpreting quantum effects and effects that contradict the special theory of relativity.
{"title":"Analysis of a Stochastic Emission Theory Regarding Its Ability to Explain the Effects of Special Relativity","authors":"S. Kühn","doi":"10.4236/jemaa.2020.1212014","DOIUrl":"https://doi.org/10.4236/jemaa.2020.1212014","url":null,"abstract":"In this article, we investigate the physical consequences that would result if electromagnetic field quanta were emitted at random speeds by a source and if the receiver could only perceive the fraction of the quantum field that is slower than the speed of light in its individual rest frame. The analysis shows that this plausible hypothesis eliminates the weak points of conventional emission theories and that both postulates of special relativity are fulfilled. Furthermore, the results demonstrate that this theory can explain numerous experiments that are usually interpreted using different aspects of special relativity. However, the resulting quantum field theory is not equivalent to the special theory of relativity and requires neither spacetime nor Lorentz transformation. Furthermore, this approach offers a starting point for interpreting quantum effects and effects that contradict the special theory of relativity.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"12 1","pages":"169-187"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48669124","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 : 2020-12-11DOI: 10.4236/jemaa.2020.1211013
J. Escobedo-Alatorre, V. Grimalsky, S. Koshevaya, M. Tecpoyotl-Torres
The superheterodyne amplification of electromagnetic waves is investigated when the resonant three-wave interaction of two electromagnetic waves with the space charge wave occurs in the waveguides nitride n-GaN, n-InN films-dielectric. The amplification of SCW waves due to the negative differential conductivity is investigated in nitride n-GaN, n-InN films at the frequencies f ≤ 400 GHz in the lower part of the terahertz (THz) range. The electromagnetic waves are either in the upper part of THz range or in the optical range. The superheterodyne amplification is considered in two geometries, the collinear one in which the three interacting waves travel in the same direction and the anti-collinear geometry where the second electromagnetic wave propagates in the opposite direction. The preferences and drawbacks of each geometry are pointed out. The finite width of space charge waves leads to decrease of increments of amplification.
{"title":"Different Geometries of Superheterodyne Amplification of Electromagnetic Beams in Waveguides Nitride-Dielectric","authors":"J. Escobedo-Alatorre, V. Grimalsky, S. Koshevaya, M. Tecpoyotl-Torres","doi":"10.4236/jemaa.2020.1211013","DOIUrl":"https://doi.org/10.4236/jemaa.2020.1211013","url":null,"abstract":"The superheterodyne amplification of electromagnetic waves is investigated when the resonant three-wave interaction of two electromagnetic waves with the space charge wave occurs in the waveguides nitride n-GaN, n-InN films-dielectric. The amplification of SCW waves due to the negative differential conductivity is investigated in nitride n-GaN, n-InN films at the frequencies f ≤ 400 GHz in the lower part of the terahertz (THz) range. The electromagnetic waves are either in the upper part of THz range or in the optical range. The superheterodyne amplification is considered in two geometries, the collinear one in which the three interacting waves travel in the same direction and the anti-collinear geometry where the second electromagnetic wave propagates in the opposite direction. The preferences and drawbacks of each geometry are pointed out. The finite width of space charge waves leads to decrease of increments of amplification.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"12 1","pages":"159-168"},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44707798","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 : 2020-10-30DOI: 10.4236/jemaa.2020.1210012
A. Ndiaye, S. Gueye, Mame Faty Mbaye Fall, G. Diop, Amadou Mamour Ba, Mamadou Lamine Ba, Ibrahima Diatta, Lemrabott Habiboullah, G. Sissoko
The modelling and determination of the geometric parameters of a solar cell are important data, which influence the evaluation of its performance under specific operating conditions, as well as its industrial development for a low cost. In this work, an n+/p/p+ crystalline silicon solar cell is studied under monochromatic illumination in modulation and placed in a constant magnetic field. The minority carriers’ diffusion coefficient (D(ω, B), in the (p) base leads to maximum values (Dmax) at resonance frequencies (ωr). These values are used in expressions of AC minority carriers recombination velocity (Sb(Dmax, H)) in the rear of the base, to extract the optimum thickness while solar cell is subjected to these specific conditions. Optimum thickness modelling relationships, depending respectively on Dmax, ωr and B, are then established, and will be data for industrial development of low-cost solar cells for specific use.
{"title":"Diffusion Coefficient at Resonance Frequency as Applied to n+/p/p+ Silicon Solar Cell Optimum Base Thickness Determination","authors":"A. Ndiaye, S. Gueye, Mame Faty Mbaye Fall, G. Diop, Amadou Mamour Ba, Mamadou Lamine Ba, Ibrahima Diatta, Lemrabott Habiboullah, G. Sissoko","doi":"10.4236/jemaa.2020.1210012","DOIUrl":"https://doi.org/10.4236/jemaa.2020.1210012","url":null,"abstract":"The modelling and determination of the geometric parameters of a solar cell are important data, which influence the evaluation of its performance under specific operating conditions, as well as its industrial development for a low cost. In this work, an n+/p/p+ crystalline silicon solar cell is studied under monochromatic illumination in modulation and placed in a constant magnetic field. The minority carriers’ diffusion coefficient (D(ω, B), in the (p) base leads to maximum values (Dmax) at resonance frequencies (ωr). These values are used in expressions of AC minority carriers recombination velocity (Sb(Dmax, H)) in the rear of the base, to extract the optimum thickness while solar cell is subjected to these specific conditions. Optimum thickness modelling relationships, depending respectively on Dmax, ωr and B, are then established, and will be data for industrial development of low-cost solar cells for specific use.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46126489","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 : 2020-09-30DOI: 10.4236/jemaa.2020.129011
F. Z. Boudara, M. Rivaletto, L. Pécastaing, A. Ferron, S. Paquet, J. Brasile
Highly Resonant Power Transfer (HRPT) technology is currently receiving very significant attention from the industry and the smart power grid distribution community in particular. This technology ensures electrical power transmission between two points while controlling the level of transmitted power and ensures the immediate shutdown of the transmitted power in the event of a problem. This paper reviews the inductive power transfer method and describes the design of an ultra-compact PLA core electromagnetic coupler. The proposed architecture confines the magnetic field in a toroidal PLA core transformer, and by avoiding the use of heavy and bulky shielding plates, reduces magnetic losses and avoids the Curie point. As a result, the overall unit has a weight of 5 kg and a volume of only 0.013 m3. The electromagnetic coupler is capable of transferring a peak power of 150 kW with an operating frequency of 193 kHz, giving a satisfactory efficiency of 95%. The proposed novel system was first investigated through CST 3D numerical modelling to determine the electrical parameters of the coupler’s equivalent circuit and its efficiency, to verify its compatibility with the ICNIRP 2010 standard and to evaluate its temperature rise with an air-cooling system. Afterwards, the designed coupler was built with a 3D printing device and finally tested experimentally. Simulation and experimental results are compared and show a good agreement.
{"title":"Design and Development of High Efficiency 150 kW Very Compact PLA Core Electromagnetic Coupler for Highly Resonant Power Transfer Technology","authors":"F. Z. Boudara, M. Rivaletto, L. Pécastaing, A. Ferron, S. Paquet, J. Brasile","doi":"10.4236/jemaa.2020.129011","DOIUrl":"https://doi.org/10.4236/jemaa.2020.129011","url":null,"abstract":"Highly Resonant Power Transfer (HRPT) technology is currently receiving very significant attention from the industry and the smart power grid distribution community in particular. This technology ensures electrical power transmission between two points while controlling the level of transmitted power and ensures the immediate shutdown of the transmitted power in the event of a problem. This paper reviews the inductive power transfer method and describes the design of an ultra-compact PLA core electromagnetic coupler. The proposed architecture confines the magnetic field in a toroidal PLA core transformer, and by avoiding the use of heavy and bulky shielding plates, reduces magnetic losses and avoids the Curie point. As a result, the overall unit has a weight of 5 kg and a volume of only 0.013 m3. The electromagnetic coupler is capable of transferring a peak power of 150 kW with an operating frequency of 193 kHz, giving a satisfactory efficiency of 95%. The proposed novel system was first investigated through CST 3D numerical modelling to determine the electrical parameters of the coupler’s equivalent circuit and its efficiency, to verify its compatibility with the ICNIRP 2010 standard and to evaluate its temperature rise with an air-cooling system. Afterwards, the designed coupler was built with a 3D printing device and finally tested experimentally. Simulation and experimental results are compared and show a good agreement.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45529643","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 : 2020-07-16DOI: 10.4236/jemaa.2020.127008
Ronda Silvia, Martinez Oibar, Oliver Clara, Marquez Patricia, M. Miguel
This paper presents a study of the soil electrical resistivity of El Roque de los Muchachos Observatory, located in La Palma Island (Spain). This work is mainly motivated by the current plans of building an array of Cherenkov Telescopes (CTA) as well as other scientific installations, which demand low earth resistances for the operation of sensitive instruments, prevention of damage due to electrostatic discharges and protection against lightning strikes. Despite the top quality of the sky, the terrain is mostly filled of hard rocks and materials with high resistivity and hardness. No reliable data of resistivities could be found in available literature, therefore a dedicated resistivity survey onsite like the one presented here is essential to optimize the earth resistance of future installations. In this work, we present measurements done in six different locations of an area covering around 250 m × 275 m and centered on coordinates 28˚45'42.9"N, 17˚53'28.5"W. Low resistivity (Ωm) layers have been found at specific places and depths. The resistivity at the sites has been simulated with COMSOL Multiphysics software using two different models: a simple single layer model and a three-layer model. Agreement with measurements within 10% discrepancies was obtained in all cases. The main contributions of this work are the presentation of reliable values of soil resistivity at ORM, together with the accurate simulation of the soil profiles.
本文介绍了位于西班牙拉帕尔马岛的El Roque de los Muchachos天文台的土壤电阻率研究。这项工作的主要动机是目前计划建造一系列切伦科夫望远镜(CTA)以及其他科学装置，这些装置需要低接地电阻来操作敏感仪器，防止静电放电造成的损坏和防止雷击。尽管天空质量最好，但地形大多是坚硬的岩石和高电阻率和硬度的材料。在现有文献中找不到可靠的电阻率数据，因此在现场进行专门的电阻率调查对于优化未来安装的接地电阻至关重要。在这项工作中，我们介绍了在一个面积约250米× 275米的区域的六个不同位置进行的测量，以坐标28˚45'42.9"N, 17˚53'28.5"W为中心。在特定的地方和深度发现了低电阻率层(Ωm)。利用COMSOL Multiphysics软件，采用简单的单层模型和三层模型，对各测点的电阻率进行了模拟。在所有情况下，测量结果在10%的误差范围内一致。这项工作的主要贡献是提供了可靠的ORM土壤电阻率值，以及对土壤剖面的精确模拟。
{"title":"Finite Element Analysis and Experimental Characterization of Soil Electrical Resistivity at El Roque de los Muchachos Observatory","authors":"Ronda Silvia, Martinez Oibar, Oliver Clara, Marquez Patricia, M. Miguel","doi":"10.4236/jemaa.2020.127008","DOIUrl":"https://doi.org/10.4236/jemaa.2020.127008","url":null,"abstract":"This paper presents a study of the soil electrical resistivity of El Roque de los Muchachos Observatory, located in La Palma Island (Spain). This work is mainly motivated by the current plans of building an array of Cherenkov Telescopes (CTA) as well as other scientific installations, which demand low earth resistances for the operation of sensitive instruments, prevention of damage due to electrostatic discharges and protection against lightning strikes. Despite the top quality of the sky, the terrain is mostly filled of hard rocks and materials with high resistivity and hardness. No reliable data of resistivities could be found in available literature, therefore a dedicated resistivity survey onsite like the one presented here is essential to optimize the earth resistance of future installations. In this work, we present measurements done in six different locations of an area covering around 250 m × 275 m and centered on coordinates 28˚45'42.9\"N, 17˚53'28.5\"W. Low resistivity (Ωm) layers have been found at specific places and depths. The resistivity at the sites has been simulated with COMSOL Multiphysics software using two different models: a simple single layer model and a three-layer model. Agreement with measurements within 10% discrepancies was obtained in all cases. The main contributions of this work are the presentation of reliable values of soil resistivity at ORM, together with the accurate simulation of the soil profiles.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44346357","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：