Time-Varying Electromagnetic Field

2017 ◽  
pp. 139-214
Author(s):  
Branislav M. Notaroš
Keyword(s):  
Electromagnetic Field ◽  
Time Varying

scholarly journals Time-varying metamaterials and metasurfaces for antennas and propagation applications

2021 ◽  
Vol 2015 (1) ◽  
pp. 012121
Author(s):  
D. Ramaccia ◽  
A. Toscano ◽  
F. Bilotti
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Scattering ◽  
Surface Impedance ◽  
Frequency Conversion ◽  
External Control ◽  
Anomalous Scattering ◽  
Time Varying ◽  
Excitation Signal ◽  
Constitutive Parameters ◽  
Antenna Systems

Abstract In this contribution we present the most recent results from our group about the opportunities offered by time-varying metamaterials and metasurfaces for conceiving antenna systems and devices exhibiting artificial non-reciprocity, frequency conversion, energy accumulation and temporal electromagnetic scattering. Such artificial metastructures are characterized by constitutive parameters (permittivity, permeability and/or surface impedance) that are modulated in time through an external control or requires modulated excitation signal for enabling anomalous scattering behaviour. Here, we briefly describe the physical insights of the unusual interaction arising between the electromagnetic field and such metamaterials and metasurfaces, and then we present some antennas and propagation applications, showing the performances of non-reciprocal antenna systems, magnet-less isolators, Doppler cloaks, temporal devices and metasurface-based virtual absorbers.

Effect of Extremely Low Power Time‐Varying Electromagnetic Field on Germination and Other Characteristics in Foxtail Millet ( Setaria italica ) Seeds

2020 ◽  
Vol 41 (7) ◽  
pp. 526-539
Author(s):  
Balasubramanian Ramesh ◽  
Govindababu Kavitha ◽  
Sendurpandi Gokiladevi ◽  
Rajagopal K. Balachandar ◽  
Kuppuswamy Kavitha ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Low Power ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Time Varying

Calculation and analysis of the loss and heat on damper bars in large tubular hydro-generator

2013 ◽  
Vol 62 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Yong Liao ◽  
Zhen-Nan Fan ◽  
Li Han ◽  
Li-Dan Xie
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Heat Conduction ◽  
Heat Dissipation ◽  
Operating Conditions ◽  
Fe Model ◽  
Time Varying ◽  
Rotor Core ◽  
Anisotropic Heat Conduction ◽  
Generator Design

Abstract In order to research the losses and heat of damper bars thoroughly, a multislice moving electromagnetic field-circuit coupling FE model of tubular hydro-generator and a 3D temperature field FE model of the rotor are built respectively. The factors such as rotor motion and non-linearity of the time-varying electromagnetic field, the stator slots skew, the anisotropic heat conduction of the rotor core lamination and different heat dissipation conditions on the windward and lee side of the poles are considered. Furthermore, according to the different operating conditions, different rotor structures and materials, compositive calculations about the losses and temperatures of the damper bars of a 36 MW generator are carried out, and the data are compared with the test. The results show that the computation precision is satisfied and the generator design is reasonable.

New Method of Determiner of the Position of Lightning Stroke Point by Using Dynamic Analysis

2014 ◽  
Vol 675-677 ◽  
pp. 253-256
Author(s):  
Hao Wu ◽  
Yong Huang ◽  
Yu Sheng Quan ◽  
Pu Xin Shi
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Analytical Method ◽  
Simulation Analysis ◽  
New Method ◽  
Time Varying ◽  
Lightning Stroke ◽  
Exponential Form ◽  
Dynamic Potential ◽  
The Magnetic Field

This paper summarize the existing method that can explain the lightning shield failing and put forward a new method to analyze the development of the leader and the upward leader. By using time-varying electromagnetic field analytical method. Solve the dynamic potential at the streamer zone in the bottom of leader. Give a simulation analysis for the dynamic potential and find the trend grow in exponential form. Deduce the electric field and the magnetic field from the dynamic potential in time-varying electromagnetic field.

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