In this paper, for the first time, effects of external Electromagnetic Fields on a coplanar waveguide (CPW) are numerically studied by means of the method of finite elements. Two CPW lines with different geometry and dielectric substrate permittivity are considered. Both lines have characteristic impedance of 50 Ω . Induced electric and magnetic Fields on the two CPW lines are analyzed by illuminating the structure with a plane wave. The uniform plane wave with fixed frequency at 3 GHz is considered as the incident Field. The influences of the incidence angle and dielectric substrate permittivity are investigated. For this purpose, two incidence planes are considered and, for each case, two polarizations, parallel and perpendicular, for incidence electric Field relative to incidence planes are studied. According to the results, for the two CPW lines terminated with their characteristic impedance at both ends and the incident plane wave with electric-Field intensity of 1 V/m at f = 3 GHz with incidence angles of 22. 5˚ and 45˚ , maximum peaks of the induced Field occur and also, depending on the incidence plane, incidence angle and E-Field polarization, even or odd quasi-TEM mode of the CPW line can be propagated.

Summary: Spectral Induced Polarization (SIP) is widely used for environmental and hydrogeophysics, but one major limitation concerns the Electromagnetic (EM) Coupling effect. In this study, an overview of the mutual impedance of a polarizable multilayered homogeneous half-space is done (it consist both of Electromagnetic Coupling and the Spectral Induced Polarization effects). Then, the effect of electrode array parameters and the subsurface electrical resistivity on mutual impedance response is investigated. The results show the EM Coupling effect can be seen at frequencies less than 10 Hz. It will increase with increasing frequency of excitation current and the conductivity. So by choosing the optimal arrangement for current cable, SIP can be surveyed using electrode arrays such as Schlumberger electrode array (with higher signal to noise ratio) and the EM Coupling effect is also reduced as much as possible. Introduction: Induced polarization (IP) is the main geophysical method in mineral deposits prospecting. Spectral induced polarization (SIP), an extension of the IP method, in the past few decades has been used extensively in mineral prospecting and increasingly in environmental investigations, hydro-geophysics, archaeo-geophysics, bio-geophysics. SIP measurements are very sensitive to the low frequency capacitive properties of rocks and soils. One of the major limitations of SIP method is the EM Coupling effect. In SIP method, the amplitude and phase components of the earth’s resistivity are measured in a frequency range (typically 0.001 Hz to 10 kHz). At low frequencies, the inductive Coupling effect may affect the spectrum ohmic responses and normal polarization effect of the subsurface material. In SIP, there are three types of the EM Coupling effect: the first is the removal of the EM Coupling effect from SIP Field data. In the second type, the mutual impedance of the earth is calculated using Cole-Cole equation as IP dispersion of the earth. SIP data and mutual impedance are compared using an inversion algorithm in order to recover the earth IP parameters. In this method, since the SIP method employs alternative Fields using grounded wires, it should be characterized as an EM method. The third uses a current cable arrangement in order to reduce the EM Coupling effects from SIP data. Due to the increasing application of SIP method during the recent years, investigating and finding solutions to its limits is necessary. Because in this method, time-varying current signal is used, Electromagnetic Coupling occurs between the Earth, current cable and potential cable and electrical response affected by this phenomenon. So the calculation of earth's mutual impedance response and the separation of earth's electrical and Electromagnetic responses are necessary. Methodology and Approaches: In this study, an overview of the Electromagnetic Coupling effect on the Spectral Induced Polarization data and calculating this effect on the total response using linear dipole-dipole electrode array with dipole arbitrary length on a polarizable multilayered homogeneous half-space is done. Then, the effect of electrode array parameters and the subsurface electrical resistivity on mutual impedance response is investigated. We used CR1D mod code in order to calculate the mutual impedance of the earth (it consists both of SIP and Electromagnetic response of the earth). At the end, the effect of current cable arrangement on Electromagnetic Coupling and mutual impedance response is investigated.Results and Conclusions: The results show that the Electromagnetic Coupling effect can be seen at frequencies less than 10 Hertz. The induced impedance response will increase by increasing the survey's dipoles length as well as increasing the distance between the two consecutive dipoles. So we can conclude, when electrode array is pole-dipole, pole-dipole and linear Schlumbeger, the Electromagnetic Coupling effect will be much larger when electrode array is dipole-dipole; if the rectangular arrangement is chosen for current cable, the Schlumberger electrode array with low signal to noise ratio is used for SIP survey. On the other hand, the EM Coupling effect will increase with increasing frequency of excitation current and the conductivity. So by choosing the optimal arrangement for current cable, SIP can be surveyed using electrode arrays such as Schlumberger electrode array and the EM Coupling effect is also reduced as much as possible.

Purpose: Cell experiments are vitally dependent on CO2 incubators. The heating system of usual incubators result in undesirable induction of Electromagnetic (EM) Fields on cells that result in decreased accuracy in bio-Electromagnetic tests. EM shields can cause a considerable decrease in the stray Fields and eliminate the undesirable induction. Materials and Methods: CST-2019 is used for simulations. five different shielding systems have been examined in this paper. We try to modify shape and material used for shielding to achieve better result. (Iron, Mu-Metal, steel). Results: We introduce a simple practical design, together with variations of previously reported ones, and numerical evaluation of their magnetic Field attenuation. Conclusion: The targeted design decreases the Field within the shield to about 0. 03 times of the incident magnetic Field, while having holes for air and CO2 exchange.

Induced polarization (IP) method is a main geophysical method in deposits exploration. As an extension of the IP method, the spectral induced polarization (SIP) has been used extensively in mineral prospecting and increasingly in environmental investigations, hydro-geophysics, archaeo-geophysics, bio-geophysics. The reason for this extensive use is that SIP measurements are sensitive to the low-frequency capacitive properties of rocks and soils. One major limitation of SIP method is Electromagnetic (EM) Coupling effect. In SIP method, the amplitude and phase components of the earth’s resistivity are measured in a frequency range typically from 0.001 Hz to 10 kHz. At low frequencies, the inductive Coupling effects impact the spectrum Ohmic responses and normal polarization effect of the subsurface material. In SIP literature, there are three types of the EM Coupling effects: the first is the EM Coupling effect removal methods from SIP Field data. In the second method, the mutual impedance of the earth is calculated using the Cole-Cole equation as IP dispersion of the earth. SIP data and mutual impedance are compared using an inversion algorithm in order to recover the earth IP parameters. Since the SIP method employs alternating Fields using grounded wires, this method should be characterized as an EM method. The third method uses a current cable arrangement in order to reduce the EM Coupling effects from SIP data. Many different models have been proposed for the description of the dispersive behavior of the IP. However, the most widely used model is the Cole–Cole model. This model describes the resistivity dispersion observed in the Field data from areas with metallic mineral content. It is also used to estimate various subsurface properties of nonmetallic soil and rocks in IP frequency domain investigations (SIP). A multiple Cole–Cole model is typically a more general and proper model than a single Cole–Cole model for describing IP data with various dispersion ranges caused either by multiple-length scales in sediments or by Coupling effects in the IP measurements. The Cole–Cole model parameters are widely used to interpret both time- and frequency-domain induced polarization data. Among many studies in which the Cole–Cole parameters are estimated from the SIP measurements on soils and rocks, a majority of them use least squares (deterministic) methods. The previous studies have shown that the geometry of an array such as electrode spacing (e.g., dipole–dipole electrode array) has an important effect on mutual impedance. In this study, by using the dipole–dipole array on a homogeneous polarizable half-space, the Electromagnetic Coupling effect on mutual impedance is investigated. The aim of this work is an investigation of the Cole–Cole parameters effects on the mutual impedance of a polarizable half-space. Since Sunde’s mutual impedance equation is widely used for an impolarizable earth (real resistivity), the effect of a polarizable earth has been less investigated. We use the Nyquist plot to show the mutual impedance response of theoretical and Field data. The results show that if the Cole–Cole parameters including time constant (τ), frequency constant (c) or chargeability (m) of the half-space are small, the IP response is very small compared with the EM Coupling response and thus the Cole–Cole parameters recovered from the inversion algorithms are less reliable. In practice, the above-mentioned terms occur when there are small particles of ore, extended grain size distribution of ore or low-grade ore in porphyry deposit. It is worth mentioning that the chargeability of the earth in environmental investigations also has a small value.

Laplacian equation in fractional space describes complex phenomena of physics. With this view, potential of charge distribution in fractional space is derived using Gegenbauer polynomials. Multipoles and magnetic Field of charges in fractional space have been obtained. (C) 2008 Elsevier Ltd. All rights reserved. 

Background and Aim: It is known that prolonged exposure to low intensity Electromagnetic Field (EMF) is hazardous for biological systems. However, the effect of EMF on human being is controversial. Several epidemiologic and experimental studies have shown that EMF has a harmful effect on central nervous system of animals. Previous research works in our laboratory, using light microscopes have shown that EMF could produce morphological changes in Cerebellum. The aim of the present study is to investigate ultrastructural changes of Cerebellum in EMF-exposed rats.Materials and Methods: 30 wistar rats were exposed to 3 mT EMF for 4 hours/day in a period of 4 months. After the experimental period rats in control and experimental groups were killed and tissue samples from their Cerebella were prepared for electron microscopic studies. Statistical analysis was performed by means of SPSS software and Hest. p<0.05 was regarded significant. Results: The results of this study clearly demonstrated that the number and size of purkinje cells in EMF-exposed rats were decreased significantly (p<0.01). Other changes included: condensation of nuclei, dilatation of endoplasmic reticulum, vacuolization of cytoplasm, breakdown and disappearance of crista in mitochondria in the purkinje cells of Cerebellum. Conclusion: These findings indicated that long-term exposure to EMF had detrimental effects at cellular level on central nervous system of the rats.