1,720,962 research outputs found
A Numerically Efficient Technique to Evaluate Specific Absorption Rate in Exposures to Pulsed Electromagnetic Fields
No full textA Numerical Investigation of SAR Uniformity in Exposed Cultures for in Vitro Experiments
No full textNumerical Analysis of the Electric Field Distribution within Complex Cell Structures
No full textThis paper shows the importance of using realistic cell shapes with the proper geometry and orientation to study the mechanism of direct cellular effects from RF exposure. For this purpose, the electric field distribution is computed, using the FDTD technique, in realistic cell models exposed to a linearly polarized plane wave of frequencies 900 MHz and 2.45 GHz. Furthermore, an insight on the mutual interactions between erythrocyte cell models shows that polarizing effects significantly affect the values of field intensity within the cell. © 2008 EuMA
RF Coils for MRI Applications: a Design Procedure
No full textA design procedure for radio frequency (RF) coils to be used in magnetic resonance imaging (MRI) applications is presented. The analysis is carried out by resorting to a full-wave numerical code based on the method of moments (MoM). Indeed, at the increasing of the operating frequency quasi-static solutions are no longer valid and more accurate electromagnetic tools are needed. The optimization is based on an iterative procedure that has been implemented by using a genetic algorithm (GA). The GA is used to determine the geometry of the coil by imposing the homogeneity of the RF magnetic field amplitude in a volume inside the coil at the resonance frequency. Some preliminary numerical results have been obtained for a volume coil with cylindrical shape and resonating at 190 MH
Interazione dei Campi Elettromagnetici con i Tessuti Biologici: Metodi e Modelli Numerici per la Valutazione Dosimetrica
No full textEvaluation of electromagnetic field level emitted by Medium Frequency AM broadcast stations
No full textOn the Influence of a Glass Slide on the SAR Distribution in Petri Dishes for In Vitro Exposure to 2.45 GHz EM Fields
No full textDynamic Particle Swarm Optimization for the Design of Loaded Wire Antennas
No full textA modified particle swarm optimisation (PSO) algorithm, the dynamic PSO, is proposed to obtain a better convergence rate, thus increasing the overall efficiency of the algorithm. To prove the effectiveness of the method, wire antennas operating over a wide frequency range have been optimised and tested
Design of Magnetic Resonance Imaging (MRI) RF Coils by Using the Method of Moments
Full text linkAbstract - A Method of Moments (MoM) technique is employed, to design RF coils for Magnetic Resonance Imaging (MRI) applications. In particular a full wave simulator has been usefully applied to determine the principal characteristics of the antennas used for this kind of application, i.e. the resonant modes, the Q factor and the uniformity of the magnetic field radiated by the sensor. Indeed, at the increasing of the operating frequency, magneto-static models are no longer valid and more sophisticated electromagnetic tools are needed. Some examples relevant to the design of different kind of birdcage coils are presented to demonstrate the effectiveness of the method
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