Search results for "electromagnetic wave"
showing 10 items of 26 documents
The Brain, Mind and Electromagnetic Waves
2021
The functions of electromagnetic waves both as an information carrier and energy field in the impact on the human body have been discussed. Possible consequences of the effect of electromagnetic fields of different frequencies on the human brain and body have been addressed and commented on. The complex nature of electromagnetic phenomena revealed in interactions between humans and the environment, featuring the most relevant hazards, was demonstrated.
Ag11(SG)7 : A New Cluster Identified by Mass Spectrometry and Optical Spectroscopy
2014
We report a one-step and high yield synthesis of a red-luminescent silver cluster with the molecular formula, Ag11(SG)7 (SG: glutathionate) via reduction of silver ions by sodium borohydride in the presence of the tripeptide, glutathione (GSH). The as-prepared cluster shows prominent absorption features at 485 and 625 nm in its UV-vis absorption spectrum. Aging of the as-prepared cluster solution led to the disappearance of the 625 nm peak, followed by broadening of the 485 nm peak to give three maxima at ?487, 437, and 393 nm in its absorption spectrum. These peaks remain unchanged even after polyacrylamide gel electrophoresis (PAGE), where a single band was observed confirming high purity…
Influence of the electro-optical properties of an a-Si:H single layer on the performances of a pin solar cell
2012
We analyze the results of an extensive characterization study involving electrical and optical measurements carried out on hydrogenated amorphous silicon (α-Si:H) thin film materials fabricated under a wide range of deposition conditions. By adjusting the synthesis parameters, we evidenced how conductivity, activation energy, electrical transport and optical absorption of an α-Si:H layer can be modified and optimized. We analyzed the activation energy and the pre-exponential factor of the dark conductivity by varying the dopant-to-silane gas flow ratio. Optical measurements allowed to extract the absorption spectra and the optical bandgap. Additionally, we report on the temperature dependen…
Modulational instability and generation of self-induced transparency solitons in resonant optical fibers
2009
International audience; We consider continuous-wave propagation through a fiber doped with two-level resonant atoms, which is described by a system of nonlinear Schrodinger-Maxwell-Bloch (NLS-MB) equations. We identify the modulational instability (MI) conditions required for the generation of ultrashort pulses, in cases of both anomalous and normal GVD (group-velocity dispersion). It is shown that the self-induced transparency (SIT) induces non-conventional MI sidebands. The main result is a prediction of the existence of both bright and dark SIT solitons in the anomalous and normal GVD regimes.
A Mesh-free Particle Method for Transient Full-wave Simulation
2007
A mesh-free particle method is presented for electromagnetic (EM) transient simulation. The basic idea is to obtain numerical solutions for the partial differential equations describing the EM problem in time domain, by using a set of particles, considered as spatial interpolation points of the field variables, arbitrarily placed in the problem domain and by avoiding the use of a regular mesh. Irregular problems geometry with diffused non-homogeneous media can be modeled only with an initial set of arbitrarily distributed particles. The time dependence is accounted for with an explicit finite difference scheme. Moreover the particle discretization can be improved during the process time ste…
Generation of even harmonics of sub-THz radiation in bulk GaAs in the presence of a static electric field
2007
The static electric field effects on nonlinear carrier dynamics in low-doped GaAs bulk under the influence of an intense sub-terahertz field are studied by a three-dimensional multivalleys Monte Carlo simulation. The conversion efficiency is calculated by using the appropriate Maxwell equation for the propagation of an electromagnetic wave along a given direction in the medium. Production of odd and even harmonics due to the nonlinearity of the velocity-field relation is investigated.
Observation of Poincaré-Andronov-Hopf Bifurcation in Cyclotron Maser Emission from a Magnetic Plasma Trap
2018
We report the first experimental evidence of a controlled transition from the generation of periodic bursts of electromagnetic radiation into the continuous-wave regime of a cyclotron maser formed in magnetically confined nonequilibrium plasma. The kinetic cyclotron instability of the extraordinary wave of weakly inhomogeneous magnetized plasma is driven by the anisotropic electron population resulting from electron cyclotron plasma heating in a MHD-stable minimum-B open magnetic trap. peerReviewed
FDTD simulation for electromagnetic radiated emissions in 42 V vehicle electrical systems
2005
In this paper a full 3D approach, based on finite difference time domain method, is used to predict the electromagnetic radiated emissions from 42 V vehicle electrical loads. An experimental set-up has been arranged on purpose. A comparative analysis among measured and computed results is performed. The good agreement obtained among simulated and measured data enables to validate the numerical scheme. The proposed methodology contributes to predict electromagnetic emissions in the automotive environment since the design stage. Moreover, the proposed numerical tool can be used to define, for new vehicle electrical architectures, low cost test methods for electromagnetic compatibility and sui…
Electric Power Quality Evaluation in the Presence of Electromagnetic Emissions
2013
The measurements for the assessment of the electric power quality are often carried out in hostile electromagnetic environments. The aim of the paper is analyzing if and how both radiated and conducted electromagnetic emissions can disturb the measurement system used to quantify these disturbances. To achieve the target, an experimental approach is proposed, which, by means of a simple and fast test, allows establishing if the real electromagnetic environment, where power quality analysis is performed, can alter the measurements. © 2013 IEEE.
On new ways of group methods for reduction of evolution-type equations
2005
AbstractNew exact solutions of the evolution-type equations are constructed by means of a non-point (contact) symmetries. Also we analyzed the discrete symmetries of Maxwell equations in vacuum and decoupled ones to the four independent equations that can be solved independently.