Electromagnetic Field Variations Research Articles

"On the Effect of the Variable Electromagnetic Field on the Movement of Red Blood Cells on the Circulatory System"

"On the Effect of the Variable Electromagnetic Field on the Movement of Red Blood Cells on the Circulatory System"

A modelling evaluation of electromagnetic fields emitted by buried subsea power cables and encountered by marine animals: Considerations for marine renewable energy development

The expanding marine renewable energy industry will increase the prevalence of electromagnetic fields (EMFs) from power cables in coastal waters. Assessments of environmental impacts are required within licensing/permitting processes and increased prevalence of cables will increase questions concerning EMF emissions and potential cumulative impacts. It is presumed that protecting a cable by burial, may also mitigate EMF emissions and potential impacts on species. Focussing on a bundled high voltage direct current (HVDC) transmission cable, we use computational and interpretive models to explore the influence of cable properties and burial depth on the DC magnetic field (DC-MF) potentially encountered by receptive species. Greater cable pair separation increased the deviations from the geomagnetic field and while deeper burial reduced the deviations, the DC-MF was present at intensities perceivable by receptive species. An animal moving along a cable route may be exposed to variable EMFs due to varied burial depth and that combined with an animal's position in the water column determines the distance from source and EMF exposure. Modelling contextually realistic scenarios would improve assessments of potential effects. We suggest developers and cable industries make cable properties and energy transmission data available, enabling realistic modelling and environmental assessment supporting future developments.

Interference caused by electromagnetic interactions

We consider interference fluxes of energy, momentum and angular momentum, describing the interaction of electric charges with constant and variable electromagnetic fields. Absorption and stimulated emission of atoms in the field of free and evanescent waves are described. It is shown that in the case of interaction with reactive fields, the momentum of an atom during absorption and stimulated emission does not change. A wave derivation of Planck’s formula based on the interference of the fields of classical thermal radiation and quantum zero-point oscillations is presented.

Perfectly Matched Layer Formulation of the INBC-FDTD Algorithm for Electromagnetic Analysis of Thin Film Materials

The impedance network boundary condition (INBC)-based finite-difference time-domain (FDTD) method has been widely used for electromagnetic analysis of highly conductive thin film materials. In the INBC-FDTD formulation, the electromagnetic field variations inside the thin film material are taken into account mathematically and thus extremely small FDTD grids are not necessary for the FDTD modeling of the material. Therefore, computational efficiency of the INBC-FDTD formulation is significantly better than other FDTD formulations. Albeit with this great advantage, the INBC-FDTD formulation cannot be fully employed for thin film materials because the corresponding perfectly matched layer (PML) formulation has not been reported in literature. In this work, we propose a PML formulation suitable for the INBC-FDTD algorithm. Numerical examples illustrate that the proposed PML-INBC-FDTD formulation can yield good absorption performance and also it can improve computational efficiency while maintaining numerical accuracy.

МЕТОДЫ И РЕЗУЛЬТАТЫ ЭКОЛОГИЧЕСКОГО МОНИТОРИНГА НЕКОТОРЫХ ФИЗИЧЕСКИХ ЗАГРЯЗНЕНИЙ ОКРУЖАЮЩЕЙ СРЕДЫ НА ПРИМЕРЕ ТЕРРИТОРИИ ГОРОДСКИХ ОКРУГОВ САМАРСКОЙ ОБЛАСТИ

The paper is devoted to the problem of ecological monitoring of physical pollutions of environment of urban territories on the example of the territory of city districts of Samara region. Methods of carrying out of researches of physical pollutions are considered. In framework of researches measurements of levels of physical pollutions were carried out: ambient dose equivalent power of gamma radiation, external sources of variable electromagnetic fields of industrial (electrical and magnetic components) and radio frequency range (electrical and magnetic components and energy low density), sound and infrasound levels (equivalent, octave and third octave). Zones of the territory of Samara region with increasing of admissible levels were determined. In total results of researches and it comparison with results of previous measurements of physical pollutions on the territory of Samara region are showing that the level of negative impact of physical pollutions is increasing.

Some Results of the Study of Variations of Electromagnetic Fields Caused by Different-Rank Seismogeodynamic Processes and the Mode of Operation of Man-Made Objects

The data of the analysis of long-term studies of variations of electromagnetic fields on the territories of geodynamic polygons and technogenic objects are presented. It is revealed that local anomalies of the geomagnetic field in technogenic objects are associated with the operation mode and with the combined manifestation of different-rank geodynamic processes and seismicity.

On the Effect of The Variable Electromagnetic Field on The Movement of Red Blood Cells on The Circulatory System

SO Gladkov* Author Affiliations Moscow Aviation Institute (National Research University) (MAI), Russia Received: November 16, 2020| Published: November 24, 2020 Corresponding author:S O Gladkov, Moscow Aviation Institute (National Research University) (MAI), Russia DOI: 10.26717/BJSTR.2020.32.005208

Enhanced Spatial Light Confinement of All Inorganic Perovskite Photodetectors Based on Hybrid Plasmonic Nanostructures.

3D incident light confinement by radical electromagnetic fields offers a facile and novel way to break through the performance limit of inorganic perovskite CsPbBr3 quantum dots (QDs). Herein, metallic nanoparticles decorated anodic aluminum oxide (AAO) hybrid plasmonic nanostructures with geometric control are first proposed for cyclic light utilization of perovskite photodetectors, enabled by spatially extended light confinement. The drastic multiple interference induced by plasmonic coupling within AAO matrixes are generated as a function of pore sizes, which can effectively collect the transmitted photons back to the surface. In addition, the self-assembled metallic nanoparticles simultaneously concentrate the incident and reflected light beams into the CsPbBr3 QD layers. The light confinement inherently stems from the metallic nanoparticles due to the variation of the near surface electromagnetic fields. As a result, perovskite photodetectors based on Al nanoparticles/AAO hybrid plasmonic nanostructures with a pore size of 220nm exhibit enhanced photoresponse behavior with remarkably increased photocurrent by ≈43× and maintain low dark current under 490nm light illumination at 1V.

Bioelectromagnetic Uncertainty Analysis Using Geometrically Stochastic FDFD Method

In this work, a novel frequency-domain stochastic numerical method named the geometrically stochastic finite-difference frequency domain (GS-FDFD) is proposed to study the variation in electromagnetic fields caused by random geometric changes in the model. The delta method approximation is employed to extract the 1-D and 2-D GS-FDFD equations. Two bioelectromagnetic examples are studied. First, a 1-D multilayered body tissue with size variation is analyzed to calculate electromagnetic field variations. Second, the influence of size variation in a 2-D slice of an anatomical head model on specific absorption rate (SAR) is investigated. In both examples, the GS-FDFD results compare well with the benchmark Monte Carlo results.

The influence of the ionospheric disturbance on the ground based VLF transmitter signal recorded by LEO satellite – Insight from full wave simulation

The earthquakes could induce ionospheric electron density disturbance at D/E, F layer and even topside of ionosphere. Subsequently the ionospheric disturbance would change the electromagnetic field from the ground based VLF transmitter. Nowadays, the electromagnetic field recorded by Low earth orbit (LEO) satellite have been used to study the possible seismic anomalies frequently. It is essential to study systematically how the ionospheric disturbance influences the electromagnetic field at the altitude of LEO satellite theoretically. In this paper, we construct a full wave model to simulate the influence of the amplitude, altitude, and scale of the ionospheric disturbance on the electromagnetic field in the ionosphere from the ground based VLF transmitter. The result shows the electromagnetic field at the altitude of satellite changes obviously when the wave encounters an ionospheric disturbance in the D/E layer. The variation of the electromagnetic field increases with the amplitude and scale of the ionospheric disturbance. However, the influence of the ionospheric disturbance in the F layer just has a local effect on the electromagnetic field. The influence of ionospheric disturbance in the nighttime on the variation of electromagnetic field is smaller compared with it in the daytime. These conclusions can improve our understanding of using electromagnetic field observed by satellite to study seismic anomalies.

Static stability analysis of smart nonlocal thermo-piezo-magnetic plates via a quasi-3D formulation

By employing a quasi-3D plate formulation, the present research studies static stability of magneto-electro-thermoelastic functional grading (METE-FG) nano-sized plates. Accordingly, influences of shear deformations as well as thickness stretching have been incorporated. The gradation of piezo-magnetic and elastic properties of the nano-sized plate have been described based on power-law functions. The size-dependent formulation for the nano-sized plate is provided in the context of nonlocal elasticity theory. The governing equations are established with the usage of Hamilton's rule and then analytically solved for diverse magnetic-electric intensities. Obtained findings demonstrate that buckling behavior of considered nanoplate relies on the variation of material exponent, electro-magnetic field, nonlocal coefficient and boundary conditions.

Empirical study on influences of electromagnetic field on Hall Effect sensor for analysing oil lubricant deterioration

This study aims to present the procedure developed for detecting deterioration of oil lubricant under variation of electromagnetic field which was generated by a ferrite-core solenoid coil. The overall diameter of coil was 18.5 mm and the inductance was 22.421 mH from direct current stimulation. The results were then compared to those from frequency stimulation. The optimal efficiency of measurement systems was then assessed by real-time analyzing the metal particle contamination of 3 oil lubricants categorized by grade namely ISO 32, ISO 46 and ISO 68 as well as the viscosity under specific conditions which were flow rate and temperature ranging from 25 °C to 100 °C. The analysis was performed to compare the results from experiments of unused and used (approximately 6 months) oil lubricants. From experiments, the viscosity of oil lubricant was reduced when the temperature exceeded 50 °C. However, the stimulation of coil using 0.9 A direct current could clearly distinguish the difference between the unused and used oil lubricants with metal particle contamination comparing to other values of direct currents applied with 0.42 % of error. Also, the 0.5 kHz of frequency would be the most appropriate value for frequency stimulation with 0.38 % of error.

Solving procedure for the dynamics of charged particle in variable (time-dependent) electromagnetic field

In this challenging analytic survey, we present a new approach for solving equations of the dynamics of a charged particle (describing its motion in variable, time-dependent electromagnetic field) which has been applied earlier in various fields of mechanics for solving equations of hydrodynamics, Euler–Poisson equations of rigid body rotation and even in celestial mechanics (solution of equations of small body’s motion in the CR3BP problem near librations points): a new type of the solving procedure is implemented in all of these equations as well as in case of solving momentum equation for the aforementioned dynamics of a charged particle, determined by Lorentz force in non-relativistic case. Meanwhile, in each case the system of momentum equations has been successfully solved analytically. The main result of the current research should be formulated as follows: the analytic algorithm is pointed out for solving momentum equation, which has been reduced to the analytical solution of three nonlinear ODEs with respect to the components of velocity of the particle. Moreover, absolutely new partial analytical solutions have been obtained for the special cases of magnetic field (with zero electric field’s components). In addition to this, we conclude that system of Lorentz momentum equations for dynamics of a charged particle has not the analytical presentation of solution in case of nonzero, time-dependent electric field.

Health-Related Electromagnetic Field Assessment in the Proximity of High Voltage Power Equipment

With respect to health issues, this paperpresents the results of an electromagnetic field (EMF) assessment in the proximity of a high voltage power station located in South Transylvania, Romania. The main parameters taken into account are, according to all standards and recommendations, the RMS (Root Mean Square) value of low frequency (0–300 Hz) electrical field strength E (in kV/m) and magnetic flux density B (in µT). Measurements were performed near all critical pieces of equipment (transformers, switches, busbars, overhead lines), according to the EMF European Directive. Some measurements were made as a function of distance from the HV (high-voltage) equipment, others as a time variation. The main objective was to verify that specific limits are met and, if necessary, to identify protective measures. Finally, safe exposure times for personnel operating at these sites were determined. In the future, detailed maps of EMF variations will be made available to the power companies.

Методика побудови розв’язку двовимірної задачі електродинаміки для електропровідного тіла з плоскопаралельними межами за дії зов-нішнього нестаціонарного електромагнітного поля

A two-dimensional initial-boundary value problem of electrodynamics for an electroconductive non-ferromagnetic body with planar-parallel boundaries is formulated under the action of an external non-stationary electromagnetic field. The electromagnetic field is given by the values of the inhomogeneous longitudinal coordinate of the component of the magnetic field intensity vector at its bases. To construct a general solution of the formulated initial boundary value problem under such electromagnetic action, a cubic approximation by thickness coordinate and an integral Fourier transform along a longitudinal coordinate was used for a key function — a given component of the magnetic field intensity vector. As a result, the initial two-dimensional initial boundary value problem for the key function is reduced to the one-dimensional initial boundary value problem. This initial boundary value problem is on the integral key function. These characteristics are the functions of time variable and the thickness coordinate. The coefficients of the polynomial approximating the key function are given by the transformants of the integral characteristics of the key function and given its values on the bases of the body as corresponding functions of time and longitudinal coordinate. The general solutions of the one-dimensional initial boundary value problem are obtained as a convolution of functions. These functions describe homogeneous solutions and key function boundary values on the bases of the body. Using the inverse Fourier transforms, the solution of the original electrodynamics problem under the action of an arbitrary variable in time and by the longitudinal coordinate of a non-stationary electromagnetic field is written. On the basis of such a common solution, as a partial case, we also write the solutions of the original two-dimensional initial boundary value problem under the action of a stationary harmonic in time variable electromagnetic field. In order to improve the accuracy of the approximate solution of the problem under consideration, an independent approximation of the corresponding component of the electric field intensity vector along the thickness coordinate is proposed. Systems of equations are formulated to determine the integral characteristics of this component, both under the action of an arbitrary variable in time and for a longitudinal coordinate non-stationary and the stationary electromagnetic field.

One-Dimensional Non-Uniform Dielectric Structure as Tunable Resonator

The paper presents research on the composite dielectric resonators. This type of resonator consists of dielectric parts, which can move with respect to each other using an external actuator. The air discontinuity between dielectric parts perturbs the electromagnetic field of the resonator and as a result, shifts resonance frequency. As an analytical solution for this kind of structure does not exist, most practical techniques resort to approximate numerical solutions. The electromagnetic field problem for an inhomogeneous dielectric structure consisting of two infinite plates separated by a dielectric layer with a different dielectric constant is solved rigorously. The problem is reduced to a nonlinear eigenvalues and vectors problem. The eigenvalues determine the resonant frequencies, and the vectors represent the electromagnetic field of the resonance structure. It is shown, that the resonant frequency of the basic LM -mode has a high sensitivity to the change of the air layer between dielectric plates. Displacement of the plates in a few percent of its thickness leads to a change in the resonant frequency by tens of percent, depending on the dielectric constant of the plate. The sensitivity of the resonant frequency shift and the tuning range increases as the dielectric constant grows up and the plate thickness decreases. Another factor affected on resonant frequency tuning sensitivity and range is the distribution of the electromagnetic field along the dielectric plate plane. The increase of the electromagnetic field variation in such directions leads to growing sensitivity but reducing the tuning range. Resonant frequencies of LE -mode are less sensitive to a displacement of resonator's parts. The main reason for such a difference is the direction of E -field in inhomogeneity regions. E -field of LM -modes is directed normally to the border between the dialectic plate and air, but the E -field of LE -modes is located parallel to the border. The correlation characteristics of the tuning with the geometric and electrophysical parameters of the plates were established. It has been shown, that resonance frequency tuning occurs without degradation of the resonator's unloaded Q -factor. Moreover, the Q -factor increases due to the redistribution of electromagnetic field energy into the air region where the loss is almost absent. It has been demonstrated, that the regularities for a one-dimensional inhomogeneous structure are valid for inhomogeneous cylindrical dielectric resonators.

Experimental Research of Electromagnetic Field Influence on Digital Temperature Sensors with Single-Wire Lines to Study Possibility of Their Use in NPP Control Systems

Issues related to the introduction of new control technologies and temperature monitoring at NPPs are being considered, since NPP longterm operation depends on the reliability of process control means. It is promising to build instrumentation and control complexes using one-wire technologies, since the operation information removal and transmission means should be carried out under the conditions of spatial constraints on the location of cabling. One-wire technologies make it easy to build a measurement network of the most complex topology. It is proposed to use DS18B20 universal digital primary measuring transducers as NPP testing equipment. In this regard, scientific and technical interest is a new approach to the measurement of temperature fields based on 1-Wire technology.
 It was proposed to use UR-1 demagnetizer as a source of a variable electromagnetic field imitating NPP equipment operating conditions. The paper also presents a study for visualization of the generated electromagnetic fields. A Hall sensor is used for measuring the fields under consideration.
 The proposed method can be used to conduct other similar studies to assess the response of temperature sensors (or other digital sensors) to an external magnetic field. A visualization method is used to evaluate the informational function and a conclusion is made about the applicability of such sensors in the systems of metrological control and monitoring of NPP auxiliary equipment.

Комплексний магнітоваріаційний та тектономагнітний моніторинг сучасної геодинаміки західного схилу Антарктичного півострова

Aim – investigations of effectiveness and information value of tectonomagnetic and magnetic-variations monitoring complex to study the recent geodynamics of Antarctic Peninsula in the location of Akademik Vernadsky station. Methodology. The methodology provides long-term magnetic variations observations on the Akademik Vernadsky station. On the base of observations electromagnetic induction vector components (Wise vector) are processing in the range 2.5—60 min. Series of this parameters temporal variations are developing. Tectonomagnetic observations are performed on the stationary network of observational points on the Antarctic geodynamic polygon and then, tectonomagnetic anomalies (increasing of a local magnetic field among observational epochs-total magnetic field vector module) is defined. The nature of tectonomagnetic anomalies usually is connected with variations of tectonic tensions. Compounding of magnetic variations and tectonomagnetic observations allows to upgrade certainty of tectonophysic interpretation of geophysical and geological data for investigations of Antarctic Peninsula recent geodynamics. Results. The results of tectonomagnetic and magnetic variations observations on the Akademik Vernadsky station in the location of Antarctic tectonomagnetic polygon during 1998—2017 yrs. were analyzed and generalized. Temporal variations of Wise electromagnetic induction vectors and local geomagnetic field variations were investigated. Anomalous effects in tectonomagnetic variations and Wise vectors temporal variations, caused by seismotectonic processes in the region’s lithosphere were defined. Comparative analyses of tectonomagnetic and magnetic variations data was done. Also was justified possibility their complex for monitoring of recent seismotectonic processes in the location of Akademik Vernadsky station. Conclusions. Complex analyses of long-term tectonomagnetic field and magnetic variations parameters on the Akademik Vernadsky station was done. Correlation between tectonomagnetic effects on the Antarctic geodynamic polygon and anomalous effects in Wise vectors temporal series was defined. Such complex of tectonomagnetic and magnetic variations monitoring is organic and allows to obtain reliable information about Antarctic Peninsula geodynamics in connection with seismic and other geophysical methods.

Some Aspects of Mathematical Modeling of the Electromagnetic Field Influence on the Human Brain

Background. One of lacks of the use of high technologies is the megascopic level of unfavorable electromagnetic smog. Therefore, the study of influencing of the external electromagnetic field (EMF) is actual, within the limits of wide row of frequencies, on man's organs and brain. Objective. Modeling of influences on the brain of electric induction arising up at penetration of the EMF of a different frequency in the reserved sphere. Methods. A mathematical model of the EMF influence on human brain is considered. Namely, the model of a multi stratified sphere as an approximation of a human head is proposed. This sphere embedded into the unlimited nonconductive space (σ 0 = 0) of the dielectric constant e 0 . Skin and bones of head have a magnetic permeability of vacuum μ 0 . Influences on a brain are given as induction of the electric field, arising up at penetration of the variable electromagnetic field in the reserved sphere. Results. The results of numerical calculations for the three-layered model of head showed that induced of the electric field in the layer of brain has increased on the frequencies 10 7 –10 8 Hz of external EMF. Distributions on the sphere of electromagnetic fields with f ≤ 10 6 Hz leave their amplitudes by unchanged regardless of depth of penetration. Fading of amplitudes shows up only for frequencies 10 7 and 10 8 Hz. Conclusions. Exposed in a model changes of electromagnetic waves on the frequencies 10 7 –10 8 Hz can activate the parameters central nervous system and brain, that substantially will affect of man's activity. Will allow the further study of influencing of the electromagnetic field of a different frequency to identify to extent of brain activity, and also stress, positive and negative influencing of external EMF.

Regulation of spatial fields in wireless power transfer with artificial magnetic conductor

In order to improve the efficiency of wireless power transfer (WPT) system, the spatial fields are regulated on a two-non-resonant-coil WPT system by hexagon artificial magnetic conductors (AMC). In our configuration, the AMC is located by the side of the two-non-resonant-coil WPT system and close to the transmitter coil. The AMC structure consists of small hexagon copper patches periodically arranged on the dielectric substrate. Each patch is grounded by a via passing through its center hole. Chip capacitors are soldered in the gaps between the adjacent patches. We can design the working frequency of WPT system through the capacitance of these chip capacitors. The results show that the electromagnetic fields are changed between the transmitter coil and the receiver coil in WPT system due to the introducing of the AMC structure. There are two main reasons. First, many resonant modes are excited by near magnetic fields on the AMC structure. Second, near magnetic fields are shielded by the AMC structure. The variation of space electromagnetic field improves the transmission efficiency of WPT system. When the working frequency is 27 MHz and the transmission distance is 3 cm, the experiment verifies that the transmission efficiency increases by 22% in the WPT system with the AMC structure compared with the WPT system without the AMC structure. Simultaneously, the transmission efficiency is raised by 25% at different transmission distances. The simulation results are almost consistent with the experimental results. There is a little difference that the number of resonant modes is different between the simulation and the experiment due to the resistance loss of the chip capacitors in experiment. Therefore, we correct the simulation results under consideration of resistive loss. In addition, the excited multiple resonant modes can supply multiple and adjustable working frequencies in the WPT system with the AMC structure. In practical applications, AMC is low in cost and easy to implement.