American Journal of Electromagnetics and Applications最新文献

{"title":"Characterization of Rectangular Waveguides Loaded E-Plane Dielectrics Using the Newton-Raphson Method","authors":"C. Moukengue, Conrad Tsahat, Conscet Gakosso, Haroun Labane","doi":"10.11648/j.ajea.20241201.11","DOIUrl":"https://doi.org/10.11648/j.ajea.20241201.11","url":null,"abstract":"Homogeneous metallic waveguides have long been used to carry high powers. They are often filled with inhomogeneous, isotropic dielectrics to reduce their size and cut-off frequencies. To characterize these inhomogeneous rectangular waveguides made of homogeneous and isotropic media, the Newton-Raphson method is used in this article. Frequency of cutoff, attenuation, and power flow distribution are all properties of the EM wave that are highly dependent on the physical structure and composition within the guide. This article presents the characterization of an inhomogeneous and isotropic rectangular guide. The analysis of this type of guide is based on the Borgnis potential method for determining the components of the electric field E and the magnetic field H, to obtain the guide's dispersion equations. The modes that were found to exist in these waveguides are hybrid, meaning that they have both axial E- and H-fields. Numerical resolution of these equations using the Newton-Raphson method obtains the guide's propagation constants. A MATLAB program is used to plot these dispersion curves. The propagation constant increases as a function of frequency, and the d/a ratio influences the dispersion curves. Increasing the relative permittivity of the dielectric leads to an increase in the ratio of the propagation constant in the z direction to the wave number.\u0000","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991871","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}

{"title":"Determining the Permittivity of a High-Loss Liquid by Resonant Method in Ka-Waveband","authors":"O. Kogut, Serhii Nosatiuk, Yuriy Prokopenko, I. Kuzmichev, Yevgen Ostryzhnyi, M. Ilchenko, Teodor Narytnyk, Hleb Avdieienko, Mohammed El Bakkali","doi":"10.11648/j.ajea.20231101.11","DOIUrl":"https://doi.org/10.11648/j.ajea.20231101.11","url":null,"abstract":"","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"21 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139263893","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}

{"title":"Estimation of the Parameters of Focused Beams at Short Distances for Antennas of Diffraction Radiation at the Millimeter-Wave Band","authors":"S. Provalov, Yuriy Sydorenko, S. Shylo","doi":"10.11648/j.ajea.20221002.11","DOIUrl":"https://doi.org/10.11648/j.ajea.20221002.11","url":null,"abstract":"","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132926822","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}

{"title":"Electromagnetic Problems Modeling Using Algebraic Topological Method","authors":"Vikram Reddy Anapana, Venkata Kowshik Sivva, P. Sai, Venkatesh Gongolu, Lanka Mithin Chakravarthy","doi":"10.11648/J.AJEA.20210902.11","DOIUrl":"https://doi.org/10.11648/J.AJEA.20210902.11","url":null,"abstract":"We can solve electromagnetic problems using two main mathematical tools: vector calculus and differential equations. These tools command the computational electromagnetic domain. However, these tools are not always needed for the realistic modeling of electromagnetic problems. In reality, we are interested in the measurement of scalar quantities in electromagnetics, not vector quantities. Conventional electromagnetic simulation approaches are proving to be more mathematical than physical. Furthermore, the use of differential equations leads us along a different route for modeling fundamental physics. Since computers need discrete formulations, we can’t directly transform continuous differential equations into numerical algorithms. The algebraic topological method is a direct discrete and computationally ambitious technique that uses only physically measurable scalar quantities. This paper simulates a parallel plate capacitor using global variables and calculating and comparing the potentials with the analytical method. The measured results show a good agreement between the analytical and the algebraic topological methods.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134337886","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}

{"title":"Machine Learning Algorithms and Wireless Sensor Network Applied to Medical Diagnosis: A Systematic Review","authors":"Ibrahim Goni","doi":"10.11648/J.AJEA.20190702.13","DOIUrl":"https://doi.org/10.11648/J.AJEA.20190702.13","url":null,"abstract":"In this research work systematic approach were used to conduct a survey on recent contributions of the authors that applied Machine learning algorithms or computational intelligence, Artificial intelligence and soft computing techniques such as Artificial Neural Network, Fuzzy logic Genetic algorithm, Artificial Immune System Swarm intelligence among others or any combination of these techniques Neuro-fuzzy, Adaptive Neuro-fuzzy, Neuro-genetic, fuzzy-genetic, and so on that is soft computing to medical diagnosis and also a systematic review on the application of wireless sensor network, wireless sensor is a veritable embedded system with a wireless communication function, and that is capable to: Collect physical quantities such as heat, humidity, temperature, vibration, radiation, sound, light, movement, etc. Convert them into digital values which are sent as sensed data to a remote processing station or base station (WSN) to medical and health care delivery. However the survey believed that combining wireless sensor network with soft computing techniques, artificial intelligence techniques can perform well in providing health care services compare to one technique because any of these techniques has certain limitations but together perhaps they two or three techniques connected together would reduce error to a minimum level.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132562634","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}

{"title":"On the Periodicity of a Max-type Fuzzy Difference Equations","authors":"Changyou Wang, Wei Wei, Qiangqiang Yang, Yonghong Li","doi":"10.11648/J.AJEA.20190702.11","DOIUrl":"https://doi.org/10.11648/J.AJEA.20190702.11","url":null,"abstract":"Our aim in this paper is to discuss the periodicity and boundedness of a max-type fuzzy difference equation. When studying the periodicity of the solution to the max-fuzzy difference equation, the equation is first converted into a difference system composed of two related difference equations through the cut set theory of the fuzzy number, then the periodicity of each solution sequence in the system is obtained by means of inequality technique, mathematical induction and other theoretical methods, thus the periodicity of the solution is proved. As researching the boundedness of the solution for the fuzzy difference equation, the difference system is also obtained through the cut set theory of the fuzzy number, then analyze the boundedness to each solution sequence according to the periodicity with the solution sequence, through examining the value of the finite subsequence in each solution sequence, the boundedness with these subsequences can be obtained, and then the boundedness for each solution sequence made up of complete subsequences can be known, thus the boundedness of the solution is proved. Finally, the results obtained in this paper are simulated by using the software package MATLAB 2016, the numerical results not only show the dynamic behavior of the solutions to the fuzzy difference systems, but also verify the effectiveness of the theoretical results.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132942392","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}

{"title":"New Magnetics Observations with a Random Exchange Interaction","authors":"A. Diouf, Souleymane Sene, B. Lo","doi":"10.11648/J.AJEA.20190702.12","DOIUrl":"https://doi.org/10.11648/J.AJEA.20190702.12","url":null,"abstract":"The aim of this paper is to investigate a new type of magnetic material, which has a permanent random exchange interaction. The ferromagnetic properties (magnetizations) of an Ising nanostructure are investigated using the effective field theory with correlations. The system has consisted from spin-1/2 atoms with a random exchange interaction Jij. The value of Jij is randomly distributed by a random function. A specific investigation about the special effects of the random core exchange interaction on the magnetization and the critical temperature has been studied. For the appropriate value of the system parameter new descriptions and phenomena of the magnetizations in 3D have been obtained. The results show that it is possible to get the same ferromagnetic behavior observed with a constant exchange interaction by using a permanent random exchange interaction. Moreover, the results found can be as well displayed in three dimensions (3D) with the same behavior observed in 2D. The results are well detailed in the paper.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"217 0 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124224420","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}

{"title":"Dynamics of Two-level Atom Interaction with Single-mode Field","authors":"S. Eshete, Yimenu Yeshiwas","doi":"10.11648/J.AJEA.20190702.14","DOIUrl":"https://doi.org/10.11648/J.AJEA.20190702.14","url":null,"abstract":"In this paper, the dynamics of fluorescent light emitted by a two-level atom interacts with squeezed vacuum reservoir is studied wisely using two-time correlation function fundamentals. The mathematical analysis shows the fluorescent spectrum of light emitted by the atom is turned out to be a single peak at a Lorentz's frequency. On the other hand, the squeezed vacuum reservoir input is responsible to the stimulated emission of photon from the atom. Moreover, it is identified that thermal reservoir is more efficient than squeezed vacuum reservoir to have valuable power spectrum.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125874126","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}

{"title":"Earth's Electromagnetic Forces and Their Participation in the Creation of Tornadoes","authors":"Y. Pivovarenko","doi":"10.11648/j.ajea.20190701.12","DOIUrl":"https://doi.org/10.11648/j.ajea.20190701.12","url":null,"abstract":"Both in the earth’s atmosphere and on the earth’s surface, electromagnetic forces of a understandable nature act. Despite the fact that these forces are quite substantial, their participation in the phenomena occurring on the Earth’s surface and in the Earth’s atmosphere is traditionally ignored. Such a tradition does not allow explaining the nature of a number of phenomena occurring both in the Earth’s atmosphere and on the Earth’s surface, for example, the distribution of charges in the direction perpendicular to the Earth’s surface, in particular, the distribution of charges existing between the Earth’s surface and the upper atmosphere. In particular, such a tradition, thanks to which a tornado is considered solely as a result of mechanical interactions, does not allow us to understand its true nature and, as a result, to suggest ways of its destruction. Since this may have worldview significance, this article is intended to draw attention to electromagnetic forces that act in the Earth’s atmosphere and on the Earth’s surface.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126755481","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}

{"title":"Comparative Studies on the Effect of Noise and Electromagnetic Fields on Rabbit Blood","authors":"K. Elwasife, Ismail I. Abdel Aziz, M. Shabat","doi":"10.11648/J.AJEA.20190701.11","DOIUrl":"https://doi.org/10.11648/J.AJEA.20190701.11","url":null,"abstract":"This study have shown the comparison between the effect exposure to the noise and electromagnetic waves radiation on rabbit. Environmental noise and electromagnetic fields are a known stressful factor that induces alterations of various physiological responses in the exposed individuals. The electromagnetic field applied was generated by using an antenna installed at the laboratory of Islamic University of Gaza. The mobile system used in Gaza is GSM with frequency equals 900 MHz. The antenna place at 20 cm away from the animals such that the whole body exposed to the electromagnetic field on the days of the test the rabbits were brought to the laboratory. The experiment was conducted at Gaza strip laboratory. Twenty two adult male rabbit were used throughout the study. Rabbits were randomly divided into three groups. The first group consists of ten rabbits (w1000-1200gm) served as the control group. During the course of the study the animals were housed in pairs in the animal house with food and water and kept under standard environmental conditions for light (12: 12 h light: dark cycle) temperature (27°C). The second group was subjected to the noise levels (60-70 dB) for 18 days. The animals were exposed to noise product from generator with 1KW and dimension of 1200 mmx1100 mmx1300 mm. They exposure for 3-4 hour in each day. The third one of animals were exposed to split dose of electromagnetic field with constant power in the range from (1.4–4.7) mw/cm2 and electric field with the range (60-130) V/m. The treated animals were subjected to electromagnetic field for eight hours then rest eight hours without exposure. The process of exposure and rest for the same time interval were repeated for two weeks. Animals from both control and experimental groups were decapitated at the end of the experiment. Blood samples were collected in 10 ml plain tubes for serum preparation. The effect of electromagnetic exposure is greater than noise one in urea, uric acid, creatinine, Alpha., AST, ALT and PLT. Exposure to noise caused increase triglycerides, white blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. It was found to be directly related to the duration of exposure, the intensity and the characteristics of the noise with loud intermittent noise and longer duration of exposure producing more analgesia.","PeriodicalId":430478,"journal":{"name":"American Journal of Electromagnetics and Applications","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127941547","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}