Natural Electromagnetic Field Research Articles

Identification of Sub-Fault Zone Using Magnetotelluric Inversion (Case Study: Ketaun Fault, Lemeu Village, Lebong Regency)

Lemeu Village, Lebong Regency, borders the Bukit Barisan Mountain range and is crossed by the Ketaun Fault, which causes a high level of seismic activity, so it is necessary to conduct research on the potential existence of the Ketaun sub-fault as one of the efforts to mitigate natural disasters such as earthquakes. The Magnetotelluric method utilises the earth's natural electromagnetic field, which is used to determine the distribution of resistivity in the subsurface using the ADU-07e Magnetotelluric tool with two horizontal electrical sensors (Ex, Ey) and three horizontal (Hx, Hy) and vertical (Hz) magnetic sensors and uses seven research points with an interval of 1 km. Data processing uses MAPROS software to convert data from the time domain to the frequency domain and ZONDMT2D to obtain subsurface resistivity values. The results obtained from this study are 2D magnetotelluric cross sections showing a zone with low resistivity values between research points P4 and P5 which is thought to be a new fault zone with resistivity values ranging from 1.3 – 6.1 Ωm from a depth of 2.5 km to a depth of 10 km. The zone is assumed to be a new fault that is a branch of the Ketaun fault.

Delineating leachate-groundwater interaction at Gyadi-Gyadi dumpsite, Kano, using natural electromagnetic (EM) field detector and Vertical Electrical Sounding (VES)

Geophysical investigations are mostly used for hydrogeological studies, mining, geotechnical investigation and environmental surveys. Geophysical investigation of groundwater within the dumpsite is highly critical because the extent of interaction between leachate plume/contaminated zone and aquifer zones could significantly reduce groundwater quality. The textural complexity and clay content of soils could change their electrical properties, thus reflecting inconsistent resistivity values using the resistivity method. This research investigates the extent of leachate infiltration from waste dumpsite into groundwater at Gyadi-Gyadi Kano State, using natural Electromagnetic (EM) field and Vertical Electrical Sounding (VES) methods. Six natural EM profiles were obtained in various locations within the study area using PQWT-TC 150 model. Six VES data points were occupied along the EM profile lines using SAS 1000 ABEM resistivity meter. The two techniques employed revealed some intercalations of low resistivity (conductive) as well as very low electrical potential differences in the study area. The low resistivity media are mixtures of leachates into groundwater units, thereby creating formations from the surface to a depth of about 40 m. The first and second layers have experience leachate-aquifer interaction in the northern, southern and eastern parts of the study area to about 40 m depth, and the leachate-aquifer interaction has extended to the deep aquifer of about 70 m depth at the western part. Shallow aquifer has not been infiltrated by leachate at about >100 m away from the waste dumpsite. Therefore, for potable groundwater exploitation in this area, it is advised that boreholes should be sited >100 m away from the dumpsite, where leachate-aquifer interaction has attenuated. The natural EM field detector is evidently constrained by issues of over-generalization and summation of potential values, probably due to its relatively low resolution. Hence it might not be capable of precisely delineating varying geological units. In contrast, the resistivity method is able to delineate and discretize the subsurface into sub-units of different resistive zones. This implies that VES is better suited for accurately defining the true subsurface geology, while the NEF detector is effective for determining the extent of a leachate plume.

Comparison of anomalies in the VLF spectrum of the natural electromagnetic field with data from the seismometer in a landslide-affected area

The data from a permanent monitoring station, based on a sound card as an AD/DA converter and a magnetic loop antenna for continuous recording of electromagnetic field intensities in the Very Low Frequency (VLF) range, were recorded and compared with data from a seismic station based on Raspberry Pi located in a landslide-affected area. The stations operated 24/7 and were placed in a room below ground level. Correlations were observed between seismic signals in the frequency spectrum from 0.1 Hz to 10 Hz (some extending beyond 20 Hz) and anomalies in the electromagnetic field in the VLF range. These anomalies are likely associated with micro-fracturing, piezo-electromagnetic, and triboelectric phenomena within the landslide body, producing relatively weak VLF emissions and a faint seismic signal. A single-component 4.5 Hz 395 Ohm vertical Racotech RGI-20DX geophone with electronic extension to lower frequencies (< 1 Hz) was used with a sampling rate of 100 sps (samples per second). VLF emissions cover almost the entire spectrum from 6 kHz with a peak at 14 kHz to 18 kHz. The received spectrum was divided into following sections: VLF band 4 kHz – 6 kHz; 6 kHz – 8 kHz; 8 kHz – 10 kHz; 10 kHz – 12 kHz; 12 kHz – 14 kHz; 14 kHz – 16 kHz; 16 kHz – 18 kHz. Simultaneously, there were changes in these sections analysed and compared with the seismic record within the same time interval.

Detecting and recovering critical mineral resource systems using broadband total-field airborne natural source audio frequency magnetotellurics measurements

Airborne geophysical methods offer a substantial advantage compared to ground-based techniques in exploring territories of different sizes, ranging from entire metallogenic provinces to the deposit scale, including those hosting critical minerals. An airborne method with measurements of natural magnetic field variations, known as audio frequency magnetotellurics (a passive field method), significantly increases the depth of investigation and expands the resistivity detection range compared with some controlled-source primary-field methods. We describe the technical solutions used in an airborne electromagnetic passive system with a mobile sensor of the total magnetic field variations and the stationary sensor of electric field variations, and its applications to recovering the complex geology of hydrothermal-magmatic systems often associated with critical minerals. The system’s ability to explore depths, typically beginning from the near-surface and down to 1–2 km, by recording responses in three orthogonal inductive coils over a broad bandwidth from 22 Hz to 21,000 Hz allows for mapping resistivities across a broad range. This capability is crucial for obtaining more comprehensive exploration models. Field case studies of the natural field system include application in exploring for unconformity uranium mineralization, along with other associated minerals, epithermal gold and polymetallic-bearing structures, and ferromanganese and polymetallic deposits formed in a continental rift valley. An extra case study involving kimberlites was incorporated as a proven example of the natural field system’s capability in conducting near-surface and deep investigations. The case histories illustrate the airborne natural electromagnetic field technology capabilities in recovering geoelectric models and their specific patterns.

Hydrogeological conditions in the recharge area of the Glava Panega spring

Hydrogeological conditions in karst areas reflect the high velocities of groundwater movement in open or material-filled channels. Usually they remain hidden under the ground, and only high flow rates of the flowing underground water reveal them. An example is one of the largest karst springs in Bulgaria – Glava Panega in the village of Zlatna Panega. There are two hydraulically connected lakes close to the spring head. The purpose of the present study is to establish this relationship, as well as to provide a more accurate information of groundwater discharge zones in the lake near the source of groundwater. The methods used include analyzing specific information from speleological studies, combined with conducted on field geophysical studies. Profiling was carried out using the method of the self potential, as well as research with the determination of the values of the natural electromagnetic field. The obtained results support the understanding of the behavior of the karst system in the area of the Glava Panega spring.

Application of frequency selection and geoelectrical sounding methods for mapping of leachate’s pathways in an active dumpsite

Contamination of surrounding environments is one of the threats to the proper maintenance of municipal waste sites in developing nations. This study integrates natural electromagnetic (EM) field and geoelectrical sounding methods to assess the leachate’s pathways in the near-surface layers and groundwater system in and around an active dumpsite. Five natural EM traverses were obtained in varying orientations using PQWT-TC 150 model. Fifteen vertical electrical sounding (VES) data points were randomly occupied using SAS 4000 ABEM resistivity meter. The two techniques revealed some intercalations of conductive and resistive media in the study area. The conductive media are composed of mixtures of leachates into clay and groundwater units, thereby creating zones of very low electrical potential differences from the surface to a depth beyond 30 m. A zone of leachate-aquifer’s interphase exists between the third layer and the fourth layer. The directions of the fluid flow are in the S–N and SE–NW trends, which could be linked to the fault towards the northwestern part of the study area. The fluid dynamics, however, justified the reason for the thick conductive materials being mapped at the northwestern and northern parts of the study area.

Magnetotelluric Power Line Noise Removal Using Temporally Varying Sinusoidal Subtraction of the Grid Utility Frequency

The magnetotelluric method relies on variations of natural electromagnetic fields, which in the vicinity of human settlements are persistently distorted by anthropogenic electromagnetic noise. A large source of noise to the magnetotelluric response is caused by the harmonic oscillations of the power network utility frequency centered on 50/60 Hz along with the associated higher harmonics. Removing this type of noise is essential for high frequency magnetotelluric measurements used for shallow surveys. There are a large number of approaches for how to treat power line noise in magnetotelluric signals, however, commonly used methods do not take into account time variations/instabilities of the utility frequency. That is not serious problem in vicinity of well balanced grid networks, but can cause issues in regions with larger utility frequency variations. Under such conditions, commonly used methods loose more of the natural signal, which is undesirable especially in case of very noisy datasets. Hence, we adopted approach for removing of power line noise with respect to time variations of the utility frequency and applied it to magnetotelluric signals to preserve more of natural signal. The method is based on modelling of the grid network harmonic oscillations by the optimum utility frequency and its integer multiples. The resulting sum of sinusoidal signals is subsequently subtracted from recorded data and only particular noise frequencies are removed from the original signal with high precision, while frequency ranges around power line harmonics are cleaned.

Вивчення малоамплітудної тектоніки вугільних родовищ геофізичними методами

An analysis was made as to the usage of geological-geophysical methods for studying of low-amplitude tectonic dislocations in coal-enclosing massifs. As a result of geophysical researches conducted at coal fields, mine fields and mine workings of the Lviv-Volyn Coal Basin, the methods of field observations by means of natural electromagnetic and electric fields were worked and their results were processed for prediction and diagnostics of tectonic dislocations with a break of continuity and zones of unstressed state. To raise the efficiency of the methods of electromagnetic fields it is recommended to carry out measurements at wide frequency range (from 5 to 50 hz) with orientation of the antenna according to the world sides (azimuthal surveying) and at narrow frequency range (5; 12.5; 17 khz) with the southern orientation of the antenna (frequency sensing). According to azimuthal surveying one can calculate the vector of maximum intensity of electromagnetic radiation. It was ascertained that over distinctive dislocation one can observe the variation in the direction and absolute value of vectors. Displacement of the anomaly of electromagnetic radiation intensity at different frequency range by profile indicates the direction of dipping of the area of displacement of dislocations with a break of continuity. The method of natural electromagnetic impulse field of the Earth fixes both the dislocations, distinguishes by geological-geophysical methods before, and new low-amplitude dislocations and stressed zones.Tectonic dislocations, that are displayed only in Paleozoic deposits, are distinguished by contrast anomalies of electromagnetic radiation in electromagnetic field, but dislocations with a break of continuity that cut the Mesozoic thickness and in most cases are accompanied by zones of rock fracturing in the Cretaceous deposits: by wide destructive anomalies. Plots over worked-out lavas with stressed deformational state are characterized by strongly differential abnormal values of the intensity of natural impulse electromagnetic field of the Earth. The method of natural electric field allows us to detect zones with water-bearing fracturing rocks in the upper part of the geological section. Methods of natural impulse electromagnetic field of the Earth and natural electric field may be used both independently and in the complex with other geophysical methods for detection and tracing of tectonic dislocations and dynamically-unstressed zones. Thus, the optimum apparatus-methodical complex for detection and diagnostics of low-amplitude dislocations with a break of continuity of coal-enclosing series by electromagnetic methods (NIEMF, NEF) was formed and effective methods of field observations, processinf and interpretation of data were developed.

Review of rationales for the introduction of the “Geophysical electrodynamics” term

Background. The article provides arguments for the introduction of the “geophysical electrodynamics” term.Aim. To justify the introduction of a new term “geophysical electrodynamics”.Methods of substantiation. The limits of the applicability of Maxwell’s equations are studied. Additionally, some concepts are introduced, in particular, about a new paradigm in electrodynamics, about new equations in geophysical electrodynamics, about the differences between new electrodynamics and Maxwell’s electrodynamics, about the sources of toroidal and poloidal electromagnetic fields, about toroidal currents in Maxwell’s equations, about non-power electromagnetic fields, about the quantum effect in non-power electromagnetic fields, toroidal fields in the core of the Earth, mathematical achievements in the new paradigm, about the reproduction of sources of the electromagnetic field of the Earth, and effects in classical electrodynamics explained by geophysical electrodynamics.Results. Responses to the above justifications were received.Conclusion. Physical and mathematical justifications for the introduction of the term “geophysical electrodynamics” find confirmation both in the natural electromagnetic field of the Earth, and in a number of long-known classical effects in the standard Maxwell’s electrodynamics. Small but fundamental differences of one electrodynamics from another will reduce the number of effects unexplained from the standpoint of Maxwell’s equations, encountered in both theory and experiments on Earth.

Natural Field Airborne Electromagnetics—History of Development and Current Exploration Capabilities

The mineral resources exploration industry continuously expands the efficiency requirements for geophysical technologies. Due to their relatively inexpensive nature, coupled with the ability to rapidly acquire data over large areas, airborne electromagnetic technologies have been used for decades in subsurface exploration. Limitations on the depth of investigation of airborne platforms with controlled primary field sources is the main obstacle for using these systems in many geoelectrical conditions and geographical terrains. In addition, systems based on the time-domain principle are limited in applications requiring differentiations in a high resistivity range of the mapping parameter and suffer from parasitic electromagnetic non inductive natural effects in specific near surface conditions. Methods exploiting natural electromagnetic fields in the audio frequency range significantly increase depth of investigation and sensitivity to a wide range of resistivity contrasts including in the range of thousands of ohm-ms. A brief history of the development of the natural field airborne technology is provided accompanied by a comparison of the systems technical specifications. Field examples from the latest development in the airborne electromagnetic natural fields’ domain, MobileMT, demonstrate its exploration capabilities in both conductive and resistive environments, sensitivity to any direction of geoelectrical boundary, and detectability of near-surface discrete targets along with deeper structures.

Improving the system of technical diagnostics and environmentally safe operation of soil hydraulic structures on small rivers

This paper reports the results of studying soil hydraulic structures (SHS) of the CC1 class of consequences on small rivers. The representativeness of the results for the domestic and world practice of further operation of such structures is ensured by the typical technical and technological approaches to the construction, materials, and conditions of their work. Dams are built of soil materials and operated over significant time periods while their standard service life has been exhausted, which increases the environmental and technical danger of their further operation. Visual surveys were conducted and the technical condition was instrumentally diagnosed by the geophysical method of the earth's natural pulsed electromagnetic field (ENPEMF); observational data were mathematically treated. The possibility of arranging areas of increased water filtration through the SHS body was substantiated, as well as watering, loosening, and suffusion; potentially dangerous zones prone to landslides, cracks, and collapse were determined. The probability of risk of an accident on dams was estimated at their cascading arrangement as a result of filtration deformations of the body and the base of the structure. Under current operating conditions, the possibility of letting the normative and excess (forced) water volumes through water discharge facilities due to precipitation or a breakthrough of the structure located upstream was estimated. The proposed approach makes it possible to manage the cascade of hydraulic structures at different stages of operation: planned, operational decision-making, forecasting. This allows diagnostic examinations to be performed in order to identify structures that require priority in raising funds for repair and restoration work or demolition (dismantling)

The Impact of Electromagnetic Pollution on Human Health and Environment: Recommendation for an Effective Regulatory Framework in Bangladesh

In this era of modern technologies, our social life is surrounded by various electronic devices and pieces of equipment. These generated electromagnetic fields and cause electromagnetic radiation. As a result, modern technologies are one of the major sources of electromagnetic pollution. Human-made electromagnetic pollution is far greater and powerful than the radiation made from any natural electromagnetic fields source. Electromagnetic pollution is becoming more serious by the day, due to the rapid advancement of electronic technology and especially by the mobile phone base transmitter stations (BTS). As a result, many countries have paid attention to it, and it has been added to the list of public hazards that must be addressed through an effective regulatory framework. In that context, the objective of this paper is to find the cause of electromagnetic pollution in Bangladesh, measuring the impact and providing recommendation for effective regulation to mitigate the pollution.

Low Intensity Microwave Fields and Radiation and Their Interaction with the Human Body

Sources of low-intensity microwave signals formation, which affect the metabolism processes when they interact with human body, are considered in the article. It’s noticed that increasing intensity level of the technogenic signals in environment significantly exceeds natural electromagnetic fields and radiation (EMR). The peculiarities of the registration and measurement of low-intensity signals parameters of the microwave range are considered. The processes of the interaction of the microwave signals and human organism are analyzed. Formation mechanisms of the positive and negative microwave flows of the electromagnetic radiation are revealed. Particularly, possible formation mechanism of the microwave EMR fluxes of implants in the human body. The results of the experimental study of the EMR signals levels of the objects contacting with human body, partly materials for bone defects replacement and soft tissues regeneration so as materials for physiotherapy, are given. The use of the term “electromagnetic compatibility” for materials which contacting the human body, is proposed. The expediency of its use is proven. Microwave properties of materials for clothes, minerals and building materials, which can affect the human body and environment, have been also studied.

Creation of a system for automatic monitoring of electromagnetic effects on biological and technical systems

Using a digital “twin” of a convergent biological and technical supersystem of a certain region to develop measures to ensure environmental safety is because of the need to analyze and predict processes and the level of electromagnetic pollution of the environment because of geomagnetic storms in interaction with the operation of electric power facilities. The article proposes modeling a digital “twin” using indicators of the taxonomy of the identified functional relationships about the influence of natural and man-made electromagnetic fields. The study aims to develop fresh approaches to the development of methods for analyzing the influence of electromagnetic factors on people, animals, plants and technical systems using general and special technologies for recording the levels of pulsed electromagnetic effects. The authors use methods of management theory, expert decision-making methods, principles and approaches of international standards and recommendations in management, ecology and informatics. The article proposes an analysis and identification of the reactions of the digital “twin” of a convergent biological and technical supersystem of a certain region to different categories of signals (information) about the effect of a complex of electromagnetic pollutants, with the determination of indicators of environmental safety and critical electromagnetic effects. The new technology provides for the study of the amplitude of electromagnetic pulses in a wide frequency range, their interpretation, analysis and development of recommendations for maintaining the required modes of environmental monitoring. The necessity of creating new cyber-physical environmental monitoring systems based on the operation of the automatic monitoring system of electromagnetic influences based on noise-resistant sensors for registering the levels of pulsed electromagnetic influences is substantiated.

О свойствах силы Лоренца в естественном магнитном поле Земли

The properties of the Lorentz force in the natural electromagnetic field of the Earth are considered. Theorems of the existence of toroidal non-forceful magnetic fields modulating the Lorentz force are formulated and proved. The sources of these fields are indicated, the initial equations of geophysical electrodynamics are written taking into account force and non-force electromagnetic fields on Earth.

Three-Dimensional Inversion of Borehole-Surface Resistivity Method Based on the Unstructured Finite Element

The electromagnetic wave signal from the electromagnetic field source generates induction signals after reaching the target geological body through the underground medium. The time and spatial distribution rules of the artificial or the natural electromagnetic fields are obtained for the exploration of mineral resources of the subsurface and determining the geological structure of the subsurface to solve the geological problems. The goal of electromagnetic data processing is to suppress the noise and improve the signal-to-noise ratio and the inversion of resistivity data. Inversion has always been the focus of research in the field of electromagnetic methods. In this paper, the three-dimensional borehole-surface resistivity method is explored based on the principle of geometric sounding, and the three-dimensional inversion algorithm of the borehole-surface resistivity method in arbitrary surface topography is proposed. The forward simulation and calculation start from the partial differential equation and the boundary conditions of the total potential of the three-dimensional point current source field are satisfied. Then the unstructured tetrahedral grids are used to discretely subdivide the calculation area that can well fit the complex structure of subsurface and undulating surface topography. The accuracy of the numerical solution is low due to the rapid attenuation of the electric field at the point current source and the nearby positions and sharply varying potential gradients. Therefore, the mesh density is defined at the local area, that is, the vicinity of the source electrode and the measuring electrode. The mesh refinement can effectively reduce the influence of the source point and its vicinity and improve the accuracy of the numerical solution. The stiffness matrix is stored with Compressed Row Storage (CSR) format, and the final large linear equations are solved using the Super Symmetric Over Relaxation Preconditioned Conjugate Gradient (SSOR-PCG) method. The quasi-Newton method with limited memory (L_BFGS) is used to optimize the objective function in the inversion calculation, and a double-loop recursive method is used to solve the normal equation obtained at each iteration in order to avoid computing and storing the sensitivity matrix explicitly and reduce the amount of calculation. The comprehensive application of the above methods makes the 3D inversion algorithm efficient, accurate, and stable. The three-dimensional inversion test is performed on the synthetic data of multiple theoretical geoelectric models with topography (a single anomaly model under valley and a single anomaly model under mountain) to verify the effectiveness of the proposed algorithm.

Magnetotelluric Data Analysis Using Phase Tensor and Tipper Strike to Determine Geoelectrical Strike in “DKH” Geothermal Field

The magnetotelluric (MT) method is passive geophysical method that measures natural electromagnetic field to estimate the subsurface resistivity structure. Before conducting 2D MT data inversion, data analysis, dimensionality, including determining the direction of the geoelectrical strike must be performed. It is needed to fulfill the assumption of 2D MT modeling. 2D modeling of magnetotelluric data is an important part because the results can determine the quality of the subsurface interpretation. Therefore, this paper describes the determination of the dimensonality and geoelectrical strike using the phase tensor and tipper strike parameters. The invariant parameters of phase tensor including skew angle (β) and ellipticity are used to get the information about the dimensionality and geoelectrical strike. The results from the phase tensor are plotted in a rose diagram to determine the main direction of the geoelectrical strike. The phase tensor analysis contains ambiguity 90°, therefore tipper strike used to validate the analysis. From the analysis, the result shows the 1D or 2D structures of the MT data in high frequency, meanwhile the lower frequency, the majority of the data show 3D structures. The dominant geoelectrical strike is around N15°E and it is confirmed with the regional structure of the area. Determination of dimensionality and geoelectrical strike are applied to MT data from the geothermal field.

ОСОБЕННОСТИ РАЗВИТИЯ DROSOPHILA MELANOGASTER В УСЛОВИЯХ ДЕЙСТВИЯ УМЕРЕННОГО ФЕРРОМАГНИТНОГО ЭКРАНИРОВАНИЯ И РЕНТГЕНОВСКОГО ИЗЛУЧЕНИЯ

The question of the biological role of weakened electromagnetic fields (EMF) is relevant due to the fact that in modern life, organisms of varying degrees of complexity often face conditions in which the natural EMF can be shielded or distorted. And the study of the influence of ionizing radiation on life expectancy has been conducted for several decades in various laboratories around the world. The main component in determining the effects of radiation exposure is induced genetic instability, against the background of which it is possible to implement a variety of radiobiological reactions that lead to both stimulation and significant suppression of vital functions of the cell or body. In this regard, the aim of the study was to investigate the effect of moderate ferromagnetic shielding and 40 Gy X-ray radiation on the development of Drosophila melanogaster. Two series of experiments were carried out to achieve the goal. Initially, the nutrient medium prepared from yeast, sugar, semolina, propionic acid, water, and agar-agar was placed in the test tube. In groups there were 10 test tubes each, in which adult flies in number of 1 female and 1 male were placed. In the experiment, tubes with daily egg-laying were used (after the daily content of parent flies were removed from the tubes). Clutches were observed: from the appearance of the first pupae to the end of adults’ release. All groups of insects were kept in special thermoboxes (without light access). In the first series of the experiment the air temperature was 22 °C, in the second series of the experiment – 18 °C. The development of Drosophila melanogaster depends on t° air, with its decrease from 22 ° C to 18 ° C, the intensity of pupation of larvae and the yield of adults decreases by 45 % (p<0,05) and 50 % (p<0,05), respectively, and slows down by two days. In conditions of moderate ferromagnetic shielding in the first series of the experiment no reliable changes were found, while in the second series at t = 18 °C EME stimulates the process of pupation of larvae on the 8th day by 21 % (p<0,05), and the yield of adults on the 16th day by 30 % (p<0,05) in contrast to the development of Drosophila melanogaster in the control group. However, in both series EMEs do not affect the total number of pupated larvae and the yield of adults. In the first series of the experiment, X-ray irradiation with 40 Gy absorbed dose and 5-minute exposure leads to 28 % (p<0,05) and 55 % (p<0,05) decrease in the number of pupated larvae on the 6th and 7th days of development, respectively, and to 86 % (p<0,05) and 30 % (p<0,05) decrease in adults appearance on the 12th and 13th days, respectively, in comparison with the control group data. Whereas, in the second series of the experiment the number of pupated larvae decreased by 85 % (p<0,05) and 50 % (p<0,05) respectively on the 7th and 9th days, and the number of adults decreased by 85 % (p<0,05) relatively to the control data. Also X-ray irradiation causes delay in time of pupation of larvae and formation of adults.

The Effects of Electromagnetic Fields on Human Health: Recent Advances and Future

The potential of electromagnetic fields (EMFs) for disease treatment and health enhancement has been actively pursued over the recent decades. This review first provides a general introduction about natural EMFs and related biological effects. Then the recent progress on the EMF treatment of some common diseases (such as cancer, diabetes, wound healing and neurological diseases, etc.) has been carefully reviewed and summarized. Yet, the blindness on the selection of therapeutic EMF parameters still hinders the broad application of EMF therapy. Moreover, the unclear mechanism of EMF function and poor reproducibility of experimental results also remain big challenges in the field of bioelectromagnetics. Bionics is a useful methodology that gains inspiration from nature to serve human life and industry. We have discussed the feasibility of applying bionic approach on the selection of therapeutic EMFs, which is based on the findings of natural EMFs. Finally, we advocate that the detailed information of EMFs and biological samples should be thoroughly recorded in future research and reported in publications. In addition, the publication of studies with negative results should also be allowed.

Analysis of seismoelectric effects via tank experimental observations

The purpose of the present research is to experimentally confirm the seismoelectric effects of the second type on the physical model, which is represented by a tank filled with sand (2.1 x 1.32 x 3.2 m). Analysis of the current state in the field of hydrocarbon search using seismoelectric effects was carried out. Physical modeling of microseismic and natural electromagnetic field was performed applying acoustic emitter and grounded electrodes at the tank edges; registration was carried out with the help of three axial seismic receivers manufactured by GS and grounded dipole using non-polarizing electrodes of VIRG design. The results show that the maximum of the cross-correlation function is highly noisy, and recording seismoelectric effects on physical models of such sizes using the existing element base is not possible, thus, it is necessary to either increase the sensitivity of the receiving equipment along with an increase in the size of physical models or increase the signal accumulation time from 20 minutes or more.