Electric And Magnetic Fields Research Articles

Graviton–photon conversions in Euler–Heisenberg nonlinear electrodynamics

We study graviton–photon conversions in an environment of the uniform and constant magnetic field considering Euler–Köckel–Heisenberg-type nonlinear corrections in electrodynamics. We take the transverse-tracefree gauge for gravitons and employ both the field potential and the electric and magnetic (EM) fields for photons. The nonlinear correction causes parity violating (chiral) graviton propagation equations, which depend on the two treatments for photons. Thus, the medium becomes effectively birefringent for two polarizations of gravitational waves similar to the photon birefringence, a characteristic of the nonlinear correction. In the presence of gravity, due to the nontrivial relation between the potential and EM fields, it is important to present the result using the EM fields.

On graviton–photon conversions in magnetic environments

Graviton–photon conversions in a given external electric or magnetic field, known as the Gertsenshtein mechanism, are usually treated using the four-potential for photons. In terms of the electric and magnetic (EM) fields, however, proper identification of the fields in curved spacetime is important. By misidentifying the fields in Minkowski form, as is often practiced in the literature, we show that the final equation for photon conversion is correct in transverse-tracefree gauge only for planar gravitational waves in a uniform and constant external field. Even in the former method, to recover the EM fields from the four-potential in curved spacetime, one should properly take into account the metric involved in the relation. By including the metric perturbation in the graviton conversion equation, we show that a magnetic environment can cause tachyonic instability term in gravitational wave equation.

Maxwell equations in curved spacetime

In curved spacetime, Maxwell’s equations can be expressed in forms valid in Minkowski background, with the effect of the metric (gravity) appearing as effective polarizations and magnetizations. The electric and magnetic (EM) fields depend on the observer’s frame four-vector. We derive Maxwell’s equations valid in general curved spacetime using the fields defined in the normal frame, the coordinate frame, and two other non-covariant methods used in the literature. By analyzing the case in the generic frame we show that the EM fields, as well as the charge and current densities, defined in non-covariant ways do not correspond to physical ones measured by an observer. We show that modification of the homogeneous part is inevitable to any observer, and such a modification is difficult to interpret as the effective medium property. The normal frame is the relevant one to use as it gives the EM fields measured by an Eulerian observer.

A New Intelligent Estimation Method Based on the Cascade-Forward Neural Network for the Electric and Magnetic Fields in the Vicinity of the High Voltage Overhead Transmission Lines

The evaluation and estimation of the electric and magnetic field (EMF) intensity in the vicinity of overhead transmission lines (OHTL) is of paramount importance for residents’ healthcare and industrial monitoring purposes. Using artificial intelligence (AI) techniques makes researchers able to estimate EMF with extremely high accuracy in a significantly short time. In this paper, two models based on the Artificial Neural Network (ANN) have been developed for estimating electric and magnetic fields, i.e., feed-forward neural network (FFNN) and cascade-forward neural network (CFNN). By performing the sensitivity analysis on controlling/hyper-parameters of these two ANN models, the best setup resulting in the highest possible accuracy considering their response time has been chosen. Overall, the CFNN achieved a significant 56% reduction in Root Mean Squared Error (RMSE) for the electric field and a 5% reduction for the magnetic field, compared to the FFNN. This indicates that the CFNN model provided more accurate predictions, particularly for the electric field than the proposed methods in other recent works, making it a promising choice for this application. When the model is trained, it will be tested by a different dataset. Then, the accuracy and response time of the model for new data points of that layout will be evaluated through this process. The model can predict the fields with an accuracy near 99.999% of the actual values in times under 10 ms. Also, the results of sensitivity analysis indicated that the CFNN models with triple and double hidden layers are the best options for the electric and magnetic field estimation, respectively.

EMEMI: An interference-free mini-incubator with integrated electric and magnetic field exposure for real-time microscopic imaging of field effects.

Uninterrupted microscopic observation and real-time imaging of cell behavior during exposure to the stimulus, for example, electric and/or magnetic fields, especially for periods of several days, has been a challenge in experimental bioelectromagnetics due to a lack of proper gas/temperature conditions outside the incubator. Conventional mini-incubators might suffer from stray fields produced by heating elements. We report an in vitro electric and magnetic fields (EMF) exposure system embedded inside a novel under-the-microscope mini-CO2 -incubator with a unique design to avoid electromagnetic interference from the heating and circulation functions while ensuring the requisite temperature. A unique, reconfigurable array of electrodes and/or coils excited by calculated current distributions among array elements is designed to provide excellent field uniformity and controllable linear or circular polarization (even at very low frequencies) of the EMF within the cell culture. Using standard biochemical assays, long-term cell viability has been verified and compared with a conventional incubator. Cell orientation/migration in three-dimensional culture made of collagen-hydrogels has been successfully observed in vitro, in long-term, and in real-time under the influence of DC electric fields with the device.

Joint Uplink and Downlink EMF Exposure: Performance Analysis and Design Insights

Installing more base stations (BSs) into the existing cellular infrastructure is an essential way to provide greater network capacity and higher data rate in the 5th-generation cellular networks (5G). However, a non-negligible amount of population is concerned that such network densification will generate a notable increase in exposure to electric and magnetic fields (EMF) over the territory. In this paper, we analyze the downlink, uplink, and joint downlink&uplink exposure induced by the radiation from BSs and personal user equipment (UE), respectively, in terms of the received power density and exposure index. In our analysis, we consider the EMF restrictions set by the regulatory authorities such as the minimum distance between restricted areas (e.g., schools and hospitals) and BSs, and the maximum permitted exposure. Exploiting tools from stochastic geometry, mathematical expressions for the coverage probability and statistical EMF exposure are derived and validated. Tuning the system parameters such as the BS density and the minimum distance from a BS to restricted areas, we show a trade-off between reducing the population's exposure to EMF and enhancing the network coverage performance. Then, we formulate optimization problems to maximize the performance of the EMF-aware cellular network while ensuring that the EMF exposure complies with the standard regulation limits with high probability. For instance, the exposure from BSs is two orders of magnitude less than the maximum permissible level when the density of BSs is less than 20 BSs/km2.

Measuring and assessing the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on blood parameters and liver enzymes of personnel working in high voltage power stations in a petrochemical industry

IntroductionExposure to electric and magnetic fields (EMF) is a phenomenon that has always been present. In the last two decades, there have been numerous worries about the possible effects of extremely low-frequency (ELF) fields on human health. Consequently, this study aims to measure and evaluate the effect of ELF fields on blood parameters and liver enzymes of personnel working in high-voltage power stations in the petrochemical industry. MethodsThis cross-sectional, descriptive-analytical study was done in a petrochemical industry in southern Iran in 2021. Two groups of 50 people were selected to attain the research goals and classify jobs with the risk of exposure to extremely low-frequency electromagnetic fields (ELF-EMF) and the time spent on work. One group was exposed to ELF-EMF, and the other was regarded as the control group. Electromagnetic fields were measured using the HI-3604 device and the standard method of IEEE 1994-644. The workers' demographic data, blood parameters, and liver enzymes were also obtained from the workers’ medical records. The course of changes in each of the blood parameters and liver enzymes and demographic variables in the control and case groups were then examined. In the last stage, the effect of the electric field and magnetic field on the blood parameters and liver enzymes of the two control and subject groups was conducted using the multiple regression model. ResultsThe measured points in all stations are 200, and the minimum and maximum values of the magnetic field was 0.8 and 2019 mG, respectively. The minimum and maximum values of the electric field intensity was 0.003 and 215 V/m, respectively. The average results of the demographic variables and blood and liver indices in the control and case groups from 2018 to 2020 revealed that the average variables were not significantly different in the case and control groups (p-value>0.05). Moreover, workers' exposure to ELF-EMF was below the permissible limit. ConclusionBased on the results of the present study, ELF-EMF does not have any significant effects on demographic factors, blood parameters, and liver enzymes.

Some thoughts on the possible health effects of electric and magnetic fields and exposure guidelines.

Concerns about the possible health effects from exposure to weak electric and magnetic (EM) fields have been debated since the early 1960s. It is now well established that biological systems respond to exposure to weak EM fields at energy levels well below the current safety guidelines which result in modification of their functionality without significant changes in temperature. These observations are adding to the debate over what should be done to protect the users of cellular telecommunications systems. Experimental results showing both increases and decreases in cancer cell growth rates and concentration of reactive oxygen species for exposure to nano-Tesla magnetic fields at both radio frequencies (RF) and extra low frequencies (ELF) are cited in this paper. Some theoretical models on how variations in EM exposure can lead to different biological outcomes and how feedback and repair processes often mitigate potential health effects due to long-term exposure to low-level EM energy sources are presented. Of particular interest are the application of the radical pair mechanisms that affect polarization of electrons, and nuclear spins and the importance of time-delayed feedback loops and the timing of perturbations to oscillations in biological systems. These models help account for some of the apparently conflicting experimental results reported and suggest further investigation. These observations are discussed with particular emphasis on setting future safety guidelines for exposure to electromagnetic fields in cellular telecommunications systems. The papers cited are a very small fraction of those in the literature showing both biological effects and no effects from weak electric and magnetic fields.

EMF-Aware Cellular Networks in RIS-Assisted Environments

The deployment of the 5th-generation cellular networks (5G) and beyond has triggered health concerns due to the electric and magnetic fields (EMF) exposure. In this letter, we propose a novel architecture to minimize the population exposure to EMF by considering a smart radio environment with a reconfigurable intelligent surface (RIS). Then, we optimize the RIS phases to minimize the exposure in terms of the exposure index (EI) while maintaining a minimum target quality of service. The proposed scheme achieves up to 20% reduction in EI compared to schemes without RISs.

Could Electromagnetic Field Exposure Contribute to “Zoom Fatigue”?

The article discusses potential exposure sources to workers during remote teleconferencing and discusses measures to reduce exposure and prevent potential harms. Topics discussed include demonstrated that electric and magnetic field (EMF) from RF sources results in electric, magnetic, and associated currents that permeate into tissues of the body from the surrounding areas;and Regarding personal exposure levels, there are two primary factors that determine the magnitude of current.

The Unexplained Negative Electromagnetic Radiation and its Reduction effect on Human by Electromagnetic seed Rudraksha

Electric and magnetic fields (EMFs) are indefinable regions of energy that are often referred to as Radiation and are linked to the use of electricity as well as various natural and man-made phenomena. Due to continuous exposure to Unexplained and negative EMF, people experienced stress, anxiety, Hypoxia, and even long-term exposure result in Cancer to patients. On the other hand, Rudraksha seeds are globally known as electromagnetic seeds due to their positive electromagnetic healing effect. This research was conducted to find the consequence of the Negative EMF effect on human pulse rate and Oxygen carrying capacity in blood and the use of Rudraksha to study cut off harmful effect of negative EMF by this Electromagnetic property. This topic constitutes a new domain with the largely unstudied potential of Rudraksha seeds shielding effect on Unexplained Negative Electromagnetic Radiation.
 Keywords: EMF, Rudraksha, electromagnetic seeds, human pulse rate, Oxygen carrying capacity, Negative Electromagnetic Radiation.

Benchmark of Acceleware vs XFdtd for Field Simulations of Microstrip Patch Antenna

We benchmark the accuracy and the speed of the Acceleware FDTD library vs XFdtd in simulating a microstrip patch antenna. The benchmark is based on the sampled electric and magnetic fields. The results show that Acceleware performs almost three times faster than XFdtd. The relative mean error is less than 2.0%.

Marmara Üniversitesi Başıbüyük Kampüsü'ndeki Elektromanyetik Alan Kirliliğinin Farklı Hava Koşullarına Göre Gaz Boşalım Görselleştirmesi Tekniği Kullanılarak Analizi ve Değerlendirilmesi

The continuous development of technology and, accordingly, people's interest in technological devices is increasing. Electric powered devices generate electricity and magnetic fields. The intensity of electric and magnetic fields is restricted by international organizations and limit values by Turkey's Information Technologies and Communication Authority (BTK). The values of the electromagnetic field generated by the base stations are monitored by the BTK. The limit values determined by the BTK are more stringent than those set by international organizations. The intensity of the electromagnetic field varies according to the distance and power to the system. In this study, electromagnetic field pollution in Marmara University Başıbüyük Campus was analyzed periodically and according to different weather conditions. Measurements were performed at 19 different points and the results were mapped. SRM 3006 model selective radiation meter was used in the measurement. Measurement results were compared with international limit values and evaluated. The limit value determined by international organizations for the environment is 61 V/m and the limit value determined by BTK is 42 V/m. 12-day average electric field is 1.53 V/m for periodical measurements. The average electric field in sunny weather is 1.9 V/m, 1.28V/m in rainy weather and 1.39V/m in cloudy weather. Gas Discharge Visualization technique was used to observe the possible changes in the energy and stress situation of the different electromagnetic field points within the campus. Energy and stress measurement with this technique was performed with Bio-well device. According to the measurement results, no change in stress and energy status was observed

Field-only surface integral equations: scattering from a dielectric body.

An efficient field-only nonsingular surface integral method to solve Maxwell's equations for the components of the electric field on the surface of a dielectric scatterer is introduced. In this method, both the vector wave equation and the divergence-free constraint are satisfied inside and outside the scatterer. The divergence-free condition is replaced by an equivalent boundary condition that relates the normal derivatives of the electric field across the surface of the scatterer. Also, the continuity and jump conditions on the electric and magnetic fields are expressed in terms of the electric field across the surface of the scatterer. Together with these boundary conditions, the scalar Helmholtz equation for the components of the electric field inside and outside the scatterer is solved by a fully desingularized surface integral method. Compared with the most popular surface integral methods based on the Stratton-Chu formulation or the Poggio-Miller-Chew-Harrington-Wu-Tsai (PMCHWT) formulation, our method is conceptually simpler and numerically straightforward because there is no need to introduce intermediate quantities such as surface currents, and the use of complicated vector basis functions can be avoided altogether. Also, our method is not affected by numerical issues such as the zero-frequency catastrophe and does not contain integrals with (strong) singularities. To illustrate the robustness and versatility of our method, we show examples in the Rayleigh, Mie, and geometrical optics scattering regimes. Given the symmetry between the electric field and the magnetic field, our theoretical framework can also be used to solve for the magnetic field.

The Impact of the Treatment Method of Root Crops on Micro flora during their Storage

The study aims at determining the effect of the treatment method of root crops before storage, as well as storage parameters, on the dynamics of their microflora, namely, the quantity of bacterial microflora, mesophilic aerobic and optionally anaerobic microorganisms (MAaOAM), as well as molds. When storing garden carrot at t = +(2±1) °C (during 56 days), the amount of bacterial microflora of the samples subjected to integrated treatment decreased by 2.5 times by the end of storage; the number of mold fungi decreased twice compared to the control. When storing garden carrot at t = +(25±1) °C (for 21 days) the amount of bacterial microflora in the samples treated by electromagnetic fields of extremely low frequencies (with the following parameters: frequency – 28 Hz, the treatment time – 5 min, the magnetic induction – 12 mTl), and by Vitaplan biologic preparation (at the concentration of 106 CFU/g, and in the amount of 2.5 ml/kg), decreased by 2.1 times, while the number of mold fungi reduced by 1.5 times. When storing garden beet at t = +(2±1) °C for 56 days, the amount of bacterial microflora of samples, subjected to integrated treatment for 5 min at a frequency of 15, 24, and 30 Hz, and magnetic induction of 9 mTl, as well as treatment with Bactofit biological preparation (at the concentration of 106 CFU/g in amount of 2.5 ml/kg), decreased by 1.5 times compared to the control, while the number of mold fungi decreased by 2.3 times. When storing garden beet at t = +(25±1) °C (for 21 days), the quantity of bacterial microflora of samples, subjected to integrated treatment, was by 2.8 times lower compared to the control, while the number of mold fungi reduced by 1.8 times. It has been revealed that the integrated treatment of root crops with biopreparations and extremely low frequency (ELF) electric and magnetic fields (EMF) more effectively inhibits the development of pathogenic microflora compared to treatment only with biopreparations or treatment only by ELF-EMF. Significant retardation of growth rates was revealed in both bacterial and fungal pathogenic microflora during storage of root crops at different temperatures.

TOPICALITY OF MONITORING OF INDUSTRIAL FREQUENCY MAGNETIC FIELDS OF 50 HZ IN RESIDENTIAL AND PUBLIC BUILDINGS

The problem of ensuring safety of electric and magnetic fields (EMF) of extremely low frequencies (ELF) is resulted from the development of the first low-frequency generators producing penetrating effect and causing negative biological outcomes. World power resources are doubling every 10 years, and ELF EMF are generated around by such sources. The number of sources on the scale of application, power and design diversity significantly exceeds those generating EMF in other frequency ranges. The population is exposed to 50 Hz ELF at work, in electric transport, in residential and public buildings, in residential areas. ELF EMF was found both to “pollute” the environment, be an environmental health risk factor, and affect negatively the health with potential long-term outcomes. Development of various methods and means of protection against the effect of ELF EMF remains relevant today. Limitation (regulation) of the effect of the factor both in terms of intensity and exposure is the most effective protection. Epidemiological studies to identify the relationship between exposure to ELF magnetic fields (MF) and carcinogenesis are on-going. A task panel group of research experts, established by WHO in 2005, conducted a routine procedure to assess health risks resulting from exposure to ELF MFs and, in particular, cancer and considered them to lack evidence. However, the significance of the data obtained was noted to be reduced due to procedural problems, potential systematic error of assessment. The problem remains unsolved. Research using various types of monitoring: social and hygienic, sanitary and epidemiological, is going on. Spatio-temporal monitoring of 50 Hz ELF MF in enclosed spaces of residential and public buildings, where a variety of equipment, devices, power supply systems, generating different MF levels, is an important area. The population is exposed to these conditions most of the day. Monitoring will allow assessing electromagnetic load at short-term and long-term exposures.

Risk hidden in plain sight: Explaining homeowner perceptions of electricity transmission infrastructure

This project probes perceptions of long-standing concern about high voltage electricity overhead transmission lines (HVOTL). Psychometric, cultural and broader risk analysis frameworks permit close examination of homeowners' worries about relevant externalities. Investigated via a telephone survey in Queensland, Australia, the most significant perceptions are hypothesized to relate to technologically-infused risks. Visual effects and noise are the key externalities but shield deeper qualms relating to electric and magnetic fields (EMFs). Safety, environmental damage and property impacts are less feared. Regression analysis indicates that prior knowledge about HVOTLs and a person's residential locale influence risk perception, along with gender and age. The research supports the underlying precepts of a ‘risk society’ while offering significant policy guidelines for infrastructure and associated agencies.

Enhanced anaerobic fermentation of dairy manure by microelectrolysis in electric and magnetic fields

The degradation rate of lignocellulose and methane (CH4) content must be improved through anaerobic fermentation process engineering in order to promote the proper operation of anaerobic organic waste removal without secondary pollution and low cost. The present study investigates mesophilic anaerobic fermentation of dairy manure (DM) under weak magnetic and low operation voltage (0.3–0.8 V). The results showed that the effect of electric and magnetic fields (EMF) can significantly enhance the fermentation, and improve the CH4 content of biogas and accelerate the degradation rate of lignocellulose. Fe-C microelectrolysis intensified the anaerobic fermentation of DM, the highest CH4 content was 87%, the cellulose degradation rate was 36%, increased by 125%, and the lignin degradation rate was 23%, increased by 203%, under loading 0.5 V voltage and weak magnetic field. Metagenome sequence results showed that EMF and Fe-C microelectrolysis can not only promote the microbial diversity, but also increase the abundance of functional microorganisms at various stages. This finding provides theoretical support and foundation for the extraordinary efficiency degradation of lignocellulose and the electric and magnetic regulation of anaerobic fermentation microorganism system.

THE IMPACT OF ELECTROMAGNETIC RADIATION OF MOBILE PHONE FOR LYMPHOCYTE ACTIVATION IN VITRO

The character of the influence of the electromagnetic radiation (EMR) of mobile phone on the activation of lymphocytes in vitro was investigated. This is important, since modern human is exposed to a complex combination of electric and magnetic fields (EMF) of different frequencies. The object of the study were whole venous blood and lymphocytes isolated from 21 adult donors (aged of from 20 to 55 years) - 10 were healthy donors and 11 were healthy persons 7 days after their vaccination with meningococcal polysaccharide vaccine. In the study the influence of phone’s EMR on the functional activity of peripheral blood lymphocytes was determined by the flow cytometry method with the use of monoclonal antibodies of Beckman Coulter company (by the identification and calculation the number of basic and activated lymphocyte subpopulations). The changes of cytokines production by blood cells exposed to mobile phone electromagnetic radiation were determined in supernatants by measuring their concentration using EIA kits produced by JSC “Vector-Best” (Russia) and LLC “cytokine” (Russia). The results of the study of the effects of electromagnetic radiation of mobile phone on blood cells revealed changes in the percentage of lymphocytes carrying the early activation marker CD69 significantly to be more frequently and were observed with greater intensity in the group of donors which were vaccinated compared to healthy donors. Under the influence of phone’s EMR mean values of cytokine production determined in the supernatants samples did not changed in both groups, but in the group of healthy donors mean values of cytokines production were 1,5 - 2 times higher than in the group of persons following immunization. The increase or decrease in cytokine production under the influence of phone’s EMR occurred regardless of the initial level of its production in the surveyed donor. The changes of the cytokine production (IFNγ, TNFα, IL-6 and IL-8) by blood cells under the influence of phone’s EMR happen individually; this should be considered when deciding on the presence or absence of phone’s EMR impact on the status of lymphocytes.

Scoping Review of the Potential Health Effects of Exposure to Extremely Low-Frequency Electric and Magnetic Fields.

Previous studies suggest that extremely low-frequency (ELF) electric and magnetic fields (EMFs) may impact human health. However, epidemiologic studies have provided inconsistent results on the association between exposure to ELF EMFs and various health outcomes. This scoping review reports on primary investigations that were published during the ten-year period of 2007-2017 on the association between ELF EMFs and cancer, cardiovascular disease (CVD), reproductive health effects, and neurodegenerative diseases. We identified a total of 361 articles from two bibliographic databases (PubMed and EMBASE). Of these, 39 articles (19 cancer studies, two CVD studies, nine reproductive health studies, and ten neurodegenerative disease studies [with one repeated for two outcomes]) met inclusion criteria. Articles identified in this study focus on three different types of exposure: occupational (22 studies), residential (15 studies), and electric blanket (two studies). This review suggests that ELF EMFs may be associated with neurodegenerative diseases, specifically Alzheimer's disease; however, limited evidence was found to suggest that ELF EMFs are associated with several types of cancer, CVD, and reproductive outcomes. Additional epidemiological studies in large study populations with improved exposure assessments are needed to clarify current inconclusive relationships.