期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Simulation of Propagation Loss Models and Antenna Designs for Naval Troposcatter and Tropospheric Duct Communications
1
作者 Nikos J.Farsaris Peter P.Stavroulakis 《China Communications》 SCIE CSCD 2007年第3期63-68,共6页
Tropospheric Scattering(Troposcatter) and Tropospheric Ducting are two different mechanisms due to in-homogenoueties in the lower part of the Earths atmosphere.Their common influence in propagation of microwaves is st... Tropospheric Scattering(Troposcatter) and Tropospheric Ducting are two different mechanisms due to in-homogenoueties in the lower part of the Earths atmosphere.Their common influence in propagation of microwaves is studied here in order to achieve a feasible naval communication system.Although not new,Troposcatter together with Tropospheric Ducting communications are regaining popularity in current military and civil applications such as isolated islands and oil extraction facilities in the open sea.The innovation proposed here is the application of such systems in naval communications where at least one of the stations is mobile.Several propagation together with fading models are simulated using appropriate programs and scientific simulation packets in order to predict maximum range of such communication systems in each dominant mode of operation.Then appropriate antenna design proposals are given to overcome the high propagation loss and minimize possible interferences. 展开更多
关键词 naval COMMUNICATIONS TROPOSPHERIC SCATTERING TROPOSPHERIC ducting
在线阅读 下载PDF
Solving the Three-Neutrino Problem as One of the Three-Body Problems in Physics
2
作者 Zoran B. Todorovic 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期197-227,共31页
By using the standard PMNS (Pontecorvo-Maki-Nakagawa-Sakata) mixing matrix and applying the rule for the sum of the oscillation probabilities of three neutrinos, the equations of motion were derived in which the Dirac... By using the standard PMNS (Pontecorvo-Maki-Nakagawa-Sakata) mixing matrix and applying the rule for the sum of the oscillation probabilities of three neutrinos, the equations of motion were derived in which the Dirac CP violating phase appeared as an unknown quantity. The equations of motion were separately derived for each of the three possible transitions for flavor-neutrino oscillations. Two roots of those equations were obtained in the form of two formulas for the Dirac CP violating phase with opposite signs. In the mathematical sense, the connection between those formulas was established in order to maintain the continuous process of oscillation of three neutrinos. This made it possible to calculate the numerical value for the Dirac CP violating phase, the Jarlskog invariant and to write the general form of the PMNS mixing matrix in the final form in which all its elements are defined with explicit numerical values. 展开更多
关键词 Ordinary Neutrino PMNS Matrix Dirac CPV Phase Jarlskog Invariant
在线阅读 下载PDF
Analysis of the instability growth rate during the jet-background interaction in a magnetic field
3
作者 Miroslav Horky Petr Kulhnek 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第6期687-694,共8页
The two-stream instability is common, responsible for many observed phe- nomena in nature, especially the interaction of jets of various origins with the back- ground plasma (e.g. extragalactic jet interacting with t... The two-stream instability is common, responsible for many observed phe- nomena in nature, especially the interaction of jets of various origins with the back- ground plasma (e.g. extragalactic jet interacting with the cosmic background). The dispersion relation that does not consider magnetic fields is described by the well- known Buneman relation. In 2011, Bohata, Bren and Kulhanek derived the relation for the two-stream instability without the cold limit, with the general orientation of a magnetic field, and arbitrary stream directions. The maximum value of the imaginary part of the individual dispersion branches ωn(k) is of interest from a physical point of view. It represents the instability growth rate which is responsible for the onset of turbulence mode and subsequent reconnection on the scale of the ion radius accom- panied by a strong plasma thermalization. The paper presented here is focused on the non-relativistic instability growth rate and its dependence on various input parameters, such as magnitude and direction of magnetic field, sound velocity, plasma frequency of the jet and direction of the wave vector during the jet - intergalactic medium in- teraction. The results are presented in plots and can be used for determination of the plasma parameter values close to which the strong energy transfer and thermalization between the jet and the background plasma occur. 展开更多
关键词 plasmas -- methods: numerical -- instabilities -- turbulence -- waves-- MHD
在线阅读 下载PDF
Testing the Results of Measurements of Neutrino Parameters Using the Dirac CPV Phase Formula
4
作者 Zoran B. Todorovic 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1283-1310,共28页
Essentially the main intention of this paper was to test the formula for the Dirac CPV phase and see if it can reflect the results of experimental measurements of neutrino parameters. By knowing the mathematical formu... Essentially the main intention of this paper was to test the formula for the Dirac CPV phase and see if it can reflect the results of experimental measurements of neutrino parameters. By knowing the mathematical formula for the Dirac CPV phase, a connection was established with some of the residual symmetry groups, which made it possible to develop a procedure for directly determining the range in which the numerical value for the Dirac CPV phase could be found. In this sense, two different sources of information containing measured data for neutrinos were used for the corresponding calculations, and then a comparative overview of the calculated results was presented. It is particularly emphasized that the formula for the Dirac CPV phase does not depend on the mixing angles that are incorporated into the PMNS matrix, but only on the ratio between the corresponding squares of the neutrino mass difference. All the numerous results obtained from the corresponding calculations for the Dirac CPV phase point to the justified introduction of the theory that is related to three neutrinos, and thus the agreement of our results with the STEREO experiment is justified, so that the hypothesis of the possible existence of a sterile neutrino in nature should be excluded. 展开更多
关键词 Ordinary Neutrino PMNS Matrix Dirac CPV Phase Jarlskog Invariant Residual Discrete Symmetry Group
在线阅读 下载PDF
Determining the Neutrino Mass Eigenstates and the Effective Majorana Mass 被引量:1
5
作者 Zoran B. Todorovic 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2022年第3期593-622,共30页
This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), th... This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), the Majorana matrix and the absolute value of the effective Majorana neutrino mass. In the research presented in this paper, we have shown that the precise definition of the mass splittings between neutrino mass eigenstates, done in the latest analysis of experimental data, can be of crucial importance for defining the nature of neutrino mass hierarchy. The Standard Model has three generations of fundamental matter particles. Three generations of the charged lepton mass show a hierarchical structure: m<sub>τ</sub> > m<sub>μ</sub> > m<sub>e</sub>. Owing to that, there is a belief and it is considered that neutrinos may follow such hierarchical structure. In our calculations, we have also included the latest data obtained, based on the processing of measurement results, which showed that even with such data, obtained results favor the normal neutrino mass hierarchy. As for the individual neutrino mass calculated in this paper, in today’s neutrino physics it is only known that neutrino mass scale is bounded only from above, and both the Dirac and the Majorana character of neutrinos are compatible with all observations. Among some of the questions resolved in this paper, which are related to the properties of neutrinos, a positive answer was also given to the question of whether light neutrinos are self-conjugate particles or not. 展开更多
关键词 Special Relativity LEPTONS Ordinary Neutrino Neutrino Mass and Mixing PMNS Matrix Jarlskog Invariant Majorana Mass
在线阅读 下载PDF
A Compact Size 5G Hairpin Bandpass Filter with Multilayer Coupled Line
6
作者 Qazwan Abdullah Ömer Aydogdu +5 位作者 Adeeb Salh Nabil Farah Md Hairul Nizam Talib Taha Sadeq Mohammed A.A.Al-Mekhalfi Abdu Saif 《Computers, Materials & Continua》 SCIE EI 2021年第12期4025-4042,共18页
The multilayer structure is a promising technique used to minimize the size of planar microstrip filters.In the flexible design and incorporation of other microwave components,multilayer band-pass filter results in be... The multilayer structure is a promising technique used to minimize the size of planar microstrip filters.In the flexible design and incorporation of other microwave components,multilayer band-pass filter results in better and enhanced dimensions.This paper introduces a microstrip fifth-generation(5G)low-frequency band of 2.52–2.65 GHz using a parallel-coupled line(PCL)Bandpass filter and multilayer(ML)hairpin Bandpass filter.The targeted four-pole resonator has a center frequency of 2.585 GHz with a bandwidth of 130 MHz.The filters are designed with a 0.1 dB passband ripple with a Chebyshev response.The hairpin-line offers compact filter design structures.Theoretically,they can be obtained by bending half-wavelength resonator resonators with parallel couplings into a“U”shape.The proposed configuration of the parllel-coupled line resonator is used to design the ML band-pass filter.The FR4 substrate with a dielectric constant(Er)of 4.3 and 1.6 mm thickness was used.A comparative analysis between the simulated insertion loss and the reflection cofficient of substrates RO3003 and FR4 was performed to validate the eficiency of the proposed filter design.Simulation of PCL filter is accom-plished using computer simulation technology(CST)and an advanced design system(ADS)software.The PCL Bandpass filter was experimentally validated and a total tally between simulation results and measured results were achieved demonstrating a well-measured reflection coefficient.The simulated results obtained by the hairpin ML bandpass filter show that the circuit performs well in terms of Scattering(S)parameters and the filter size is significantly reduced. 展开更多
关键词 Band-pass filter 5G hairpin multi-layer size reduction parallelcoupled line
在线阅读 下载PDF
Three Neutrinos and the Formula for the Dirac CP Violation Phase
7
作者 Zoran B. Todorovic 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1259-1282,共24页
Based on the derived equations of three neutrinos, especially for motion through a physical vacuum and for space with a constant density of matter, the same formula for Dirac’s CP-violating phase was obtained. The ma... Based on the derived equations of three neutrinos, especially for motion through a physical vacuum and for space with a constant density of matter, the same formula for Dirac’s CP-violating phase was obtained. The main property of this formula is that it does not depend on mixing angles θ<sub>12</sub>, θ<sub>13</sub>, θ<sub>23</sub> and remains unchanged for the spaces through which the neutrino beam moves. Using that formula, the final form for the Jarlskog invariant formula was formed. Knowing the Dirac CPV phase would have the following consequences: 1) By obtaining an explicit mathematical formula for the Dirac CPV phase, it would no longer be necessary to perform computer simulations to draw areas where it could be found. 2) At the same time, the Dirac CPV phase does not depend on the mixing angles θ<sub>12</sub>, θ<sub>13</sub>, θ<sub>23</sub> that make up the elements of the PMNS matrix, but depends only on the ratio of the corresponding differences of the squares of the neutrino masses. 展开更多
关键词 Ordinary Neutrino PMNS Matrix Dirac CPV Phase Jarlskog Invariant
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部