Extremely Low Frequency Research Articles

Amplitude variations of ELF radio waves in the Earth–ionosphere cavity with the day–night non-uniformity

The real structure of lower ionosphere should be taken into account when modeling the sub–ionospheric radio propagation in the extremely low frequency (ELF) band and studying the global electromagnetic (Schumann) resonance of the Earth–ionosphere cavity. In the present work we use the 2D (two dimensional) telegraph equations (2DTE) for evaluating the effect of the ionosphere day-night non-uniformity on the electromagnetic field amplitude at the Schumann resonance and higher frequencies. Properties of the cavity upper boundary were taken into account by the full wave solution technique for realistic vertical profiles of atmosphere conductivity in the ambient day and ambient night conditions. We solved the electromagnetic problem in a cavity with the day–night non-uniformity by using the 2DTE technique. Initially, the testing of the 2DTE solution was performed in the model of the sharp day–night interface. The further computations were carried out in the model of the smooth day–night transition. The major attention was directed to the effects at propagation paths "perpendicular" or "parallel" to the solar terminator line. Data were computed for a series of frequencies, the comparison of the results was made and interpretation was given to the observed effects.

Electronic Transmission of Antibacterial Property Into Water at Extremely Low Frequency Range: A Preliminary Study.

The aim of this study was to assess the possibility of transmitting the "ampicillin" growth inhibitory property to pure sterile water. Three control groups were designed as references of bacterial maximal growth (MG). Different concentrations of ampicillin and pure sterile water used as "positive" and "negative" controls, respectively, and the bacterial cultures supplemented with water that merely exposed to the background carrier waves were set as "sham control." The electronic characteristic of the ampicillin solution relayed to the water and then it was added to the bacterial culture medium. By this treatment, water received both the carrier wave and ampicillin electronic properties at 1-105 Hz range. When the MG of the "treated water" and "positive control" dilutions is getting normalized against either sham or negative control, the treated water competently imitates ampicillin in a way that there is no significant difference with the positive control. These results will be affected to some extent by the time of electronic transmission and the inoculation concentration of bacterial culture. Comparison of electromagnetic signal patterns of "treated water" with the "positive control" shows that they are more similar to each other rather than negative control. It is believed that the extremely low frequencies can facilitate electronic transmission of ampicillin supramolecular chemistry into water. Imprinting such a property in water could be the result of durable structural configuration in treated water.

Radiation from Different Parts of Laptops

Radiation from laptop cannot be seen by the naked eyes, but it can pose real dangers to our health. If only we are a few feet away to our laptops, otherwise when laptops are placed and used directly on our laps, it exposes us to quite more intense radiation that are harmful. It has been said that the amount of radiation emitted by desktop computers is generally higher than that which is emitted from Laptop or notebook computers. And the use of small-sized components, a Light Emitting Diode (LED) or Liquid Crystal Display (LCD) are some of the main reasons why that is so. Furthermore, since these laptops are battery operated and this plays a major role in reducing the rate of radiation emitted from these portable computers. But internal parts of laptop heat up and radiate. There is a generation of Extremely Low Frequency (ELF)by laptop from storage and computing processing. Placing the laptop on the lap make to be very close to the genitals, skin and muscles. Prolonged exposure to this radiation may produce biological effects on human health. This work used Cell Sensor manufactured by Action Electronic, USA to detect ELF from fourteen (14) laptops and mini laptops. It was found that the keyboard of the laptop emitted highest value of ELF radiation while the back of the laptop had the lowest ELF radiation. The highest ELF at 0 cm for different parts measured are 5 mG, 5 mG,3.5 mG and 0.7 mG for laptop keyboard, mouse pad, fan and screen respectively. There is no ELF measured at the back of the laptops except in AMP with ELF of 0.1 mG at 0 cm. Mini laptops were observed emit less ELF radiation than laptops of size ranging from 14 inches – 17 inches. Therefore, the study suggested that less often the laptops are placed on the laps the more the health and safety of the users are guaranteed.

Improved Endurance Gain in BALB / C Mice by a Nanotechnology Medical Device

The main finding of the present study was the improved gain in BALB / C mice, following the application of a patch (T-NES®-HIT Tech.), enriched with an active central pad, based on micronized silver. In order to transfer very thin Extremely Low Frequency (ELF) magnetoelectric signals, the pad contains a nanotechnological material (silver micronized by plasma vaporization) that is appropriately activated with optical, magnetic, electrical, and acoustic signals. It has been reported previously that the ELF magnetic field, induces an action on cellular glycocalics, fundamental for cellular communication and recognition, and a direct activation of protons and ionic fluxes. The treated animals underwent exercises with Rotarod and several parameters were evaluated and compared with untreated control mice. The following parameters were measured: steady state generic training, long slow distance, high intensity endurance and steady state split session training. The ELF magnetic field of T-NES®-HIT Tech. micronized silver patch device, applied to BALB / C mice, markedly improved their gain performance as evidenced by the increase of their aerobic capacity, maximum heart rate and maximum aerobic speed.

Reduction by a Nanotechnology Device of Serum Lactate Levels and Heart Rate in Athletes Undergoing to Resistance Exercises

The aim of the present study was to demonstrate the effect of the T-NES®-HiT Tech patch system, on serum lactate levels and on the heart rate, of 60 triathletes, subjected to a resistance test. The active central portion of the patch contains a nanotechnological material (silver micronized with plasma vaporization) that is appropriately activated with a technology device, which uses optical radiation, magnetic fields, electric fields and acoustic waves specially sequenced. The patch transfers an Extremely Low Frequency (ELF) magneto-electric pulse by ion exchange. The ELF signal emitted by the device, increases the electromagnetic coherence of the systemic cellular electrical signals, which shows a better management of the muscular contraction, both bilaterally and between the agonist and antagonist districts and also a better management of oxygen and lactate, elements that lead to increased proprioception. The final result is manifested in the activation of the transmembrane ion channels, thus providing sufficient energy to the phosphate groups of the ADP, avoiding the deprotonation of excess lactic acid, present in the blood stream and therefore qualitatively improving the work of muscle contraction and aerobic capacity. Following these effects the T-NES®-HiT Tech patch system has led to a significant decrease in heart rate and serum lactate production in the athletes examined.

Evaluation of Cytotoxic and Genotoxic Effects of Extremely Low-frequency Electromagnetic Field on Mesenchymal Stromal Cells.

BackgroundInterest in the use of extremely low-frequency (ELF) electromagnetic field (EMF) for the treatment of pain and inflammation is increasing due to the ability of this promising therapy to compete with pharmaceuticals without the adverse effects caused by drugs. However, there continues to be concerns regarding cytotoxic and genotoxic effects that may occur as a result of exposure to EMF.ObjectiveTo investigate this concern, we tested the effect of our known therapeutic 5 Hz, 0.4 milliTesla (mT) EMF on a human mesenchymal stromal cell (hMSC) line to determine whether ELF-EMF exposure would cause cytotoxic or genotoxic effects.MethodsTreated samples along with controls were exposed to 5 Hz, 0.4 mT ELF-EMF for 20 min/day, 3×/week for 2 weeks and then assayed for cell viability, proliferation rates, and chromosome breaks.ResultsCytogenetic analysis of the viability and proliferation rates along with analysis of morphological genome stability showed no cytotoxicity, and no chromosome breaks per karyotype analysis—therefore no genotoxicity.ConclusionExposure to an ELF-EMF of 5 Hz, 0.4 mT for 20 min/day, 3×/week for 2 weeks does not cause cytotoxic or genotoxic effects in hMSCs.

Effects of A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study.

Humans are surrounded by sources of daily exposure to power-frequency (60 Hz in North America) magnetic fields (MFs). Such time-varying MFs induce electric fields and currents in living structures which possibly lead to biological effects. The present pilot study examined possible extremely low frequency (ELF) MF effects on human neuromotor control in general, and physiological postural tremor and electroencephalography (EEG) in particular. Since the EEG cortical mu-rhythm (8–12 Hz) from the primary motor cortex and physiological tremor are related, it was hypothesized that a 60 Hz MF exposure focused on this cortical region could acutely modulate human physiological tremor. Ten healthy volunteers (age: 23.8 ± 4 SD) were fitted with a MRI-compatible EEG cap while exposed to 11 MF conditions (60 Hz, 0 to 50 mTrms, 5 mTrms increments). Simultaneously, physiological tremor (recorded from the contralateral index finger) and EEG (from associated motor and somatosensory brain regions) were measured. Results showed no significant main effect of MF exposure conditions on any of the analyzed physiological tremor characteristics. In terms of EEG, no significant effects of the MF were observed for C1, C3, C5 and CP1 electrodes. However, a significant main effect was found for CP3 and CP5 electrodes, both suggesting a decreased mu-rhythm spectral power with increasing MF flux density. This is however not confirmed by Bonferroni corrected pairwise comparisons. Considering both EEG and tremor findings, no effect of the MF exposure on human motor control was observed. However, MF exposure had a subtle effect on the mu-rhythm amplitude in the brain region involved in tactile perception. Current findings are to be considered with caution due to the small size of this pilot work, but they provide preliminary insights to international agencies establishing guidelines regarding electromagnetic field exposure with new experimental data acquired in humans exposed to high mT-range MFs.

Power density optimization for MEMS piezoelectric micro power generator below 100 Hz applications

In piezoelectric based micro-power generator (PMPG), electrical energy is generated from mechanical vibration by gaining on the piezoelectric effects. This study concentrates on optimization of the output power density of PMPG at an extremely low frequency (ELF) range below 100 Hz. Taguchi method with eight control parameters and signal-to-noise ratios are utilized in design optimization, COMSOL Multiphysics ver. 4.2 was used for PMPG simulation at optimized parameter. Both Taguchi and S/N ratio analyses show that piezoelectric material selected and its dimensions have the most influence on the generated electric energy density. The simulated PMPG resulting output root mean square voltage was 2.47 V, and power density was 0.376 W/cm3. The PMPG design was fabricated with MEMS technology producing 0.29 W/cm3 power density and supplying 2.19 V DC to the final load. The modeling, simulation and fabricated design show that the PMPG is capable of replacing traditional Lithium Iodide (Li-Ion) batteries powering small electronic gadgets, such as biomedical implant and wearable electronics in frequency range of 25–27 Hz.

Applied Engineering Using Schumann Resonance for Earthquakes Monitoring

For populations that may be affected, the risks of earthquakes and tsunamis are a major concern worldwide. Therefore, early detection of an event of this type in good time is of the highest priority. The observatories that are capable of detecting Extremely Low Frequency (ELF) waves (<300 Hz) today represent a breakthrough in the early detection and study of such phenomena. In this work, all earthquakes with tsunami associated in history and all existing ELF wave observatories currently located worldwide are represented. It was also noticed how the southern hemisphere lacks coverage in this matter. In this work, the most suitable locations are proposed to cover these geographical areas. Also, ELF data processed obtained from the observatory of the University of Almeria in Calar Alto, Spain are shown. This is a contribution to help protect against natural disasters such as those caused by earthquakes and tsunamis.

Influence of extremely low frequency electromagnetic field on antioxidant system and change of volatile composites in Pinus sylvestris L.

The present study investigated the effect of extremely low frequency electromagnetic fields (ELF - EMFs) from high voltage power line on the antioxidant balance and inducible volatile emissions of Pinus sylvestris L. needles. The samples were collected from pines just below power line (P0, 50.66 mG) and 10 meter away from same power line. They were then categorized as P0 (just below power line) and 10 meter away from the same power line (P10, 6.30 mG). ELF - EMFs inhibited superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX), but increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents in needles of P0 plants. Therefore, volatile components of needles were investigated by GC-MS. The total rate of the volatile components for P0 and P10 plants was determined as 93.39% and 95.11%, respectively. α-pinene (20.74%), cyclohexene (9.20%), caryophyllene (9.10%) and bornylacetate (8.13%) were identified as main components in needles of P0 plants, and α-pinene (17.40%), bornylacetate (17.33%), cyclohexene (14.98%) and β-pinene (13.24%) in needles of P10 plants. Consequently, our findings suggest that Pine trees are sensitive to ELF - EMFs emitted from power line due to cause oxidative damage and alter the rate of volatile components in pine.

On the Modeling of ELF Electric Fields for Space Mission Equipment

The majority of the space missions carry measuring instruments that are sensitive to electric fields and require stringent electromagnetic cleanliness. Therefore, the time variations of electric fields produced from spacecraft equipment have to be characterized, measured, and modeled. In this paper, a novel methodology is proposed, employing equivalent dipole modeling to describe the extremely low frequency (ELF) electric field spectral dependence. Each spectral component of the measured field is considered isolated and produced by one electric dipole. An iteration of this process over the whole frequency range yields the complete ELF model of the equipment under test, which consists of one electric dipole per frequency. In order to validate the accuracy of the proposed methodology, various ELF signals in different distances are studied.

The Accuracy of Radio Direction Finding in the Extremely Low Frequency Range

AbstractIn this work, we study the accuracy of direction finding in the extremely low frequency (ELF) range using a newly installed broadband receiver equipped with two active magnetic antennas. The main natural source of ELF radio waves is lightning. In this work, we analyzed 1000 atmospheric discharges at distances of up to 5000 km from the receiver. We identified the most important factors influencing the accuracy of the angle of arrival: the deviation of the radio waves propagating through the day‐night terminator zone and the signal‐to‐noise ratio resulting from local electromagnetic noise and Schumann resonance background. The obtained results clearly show that the accuracy of estimating the direction of arrival is very high (an average error of 0.1° with the standard deviation of 2.3°) when the signal‐to‐noise ratio is large (the amplitude of the magnetic field component above 100 pT), except for short periods in the local morning and evening, when the day‐night terminator is present on the propagation path of the direct wave. For the day‐night propagation paths, the refraction angle was larger than the incidence angle, and for the night‐day propagation paths, the refraction angle was smaller than the incidence angle, which is consistent with theory. Using our analytical ELF radio propagation model allowed us to explain the obtained results.

High-performance magnetic shielding solution for extremely low frequency (ELF) sources

Some particular aspects related to open shields with high performance are presented. The magnetic flux density targets related to the protection of sensitive devices are quite low, <0.2 μT. The problem to reach high magnetic field attenuation is more complicated by the fact that open shields have to be adopted instead of closed solutions. After some general considerations about open shields two practical examples are presented and discussed.

Effects of extremely low frequency (ELF) and radio-frequency (RF) on melatonin and cortisol, two markers of the circadian rhythms

Effects of extremely low frequency (ELF) and radio-frequency (RF) on melatonin and cortisol, two markers of the circadian rhythms

The propagation model and characteristics for extremely low frequency electromagnetic wave in Earth-ionosphere system and its application in geophysics prospecting

This paper employs the finite-difference time-domain method (FDTD) to model and study the propagation characteristics and distribution features for extremely low frequency (ELF) in Earth-ionosphere (EI) system. For electromagnetic pulse source whose bandwidth is 10 Hz, the ELF electromagnetic wave forms standing wave. When the bandwidth is 100 Hz, there exists 180° phase reversals. Due to EI system, the electromagnetic field generated by horizontal dipole antenna is mainly vertical electric field and horizontal magnetic field when the receiver is away from the source antenna and locates on the surface of the earth. The distribution is mainly determined by the polarization direction of the source antenna other than the topographic feature and the conductivity. The ELF electromagnetic field can be used as incident field to detect conductivity anomaly underground. Thus, this paper may provide valuable information for long distance and large-scale underground detection, showing potential applications in geophysics prospecting.

Statistical Study of the Magnetic Noise in a Model Describing the Effect of Solar Activity on the Ionosphere

The study of the electromagnetic (EM) anomaly occurring in the ionosphere prior to earthquakes has attracted researchers’ interest during the past couple of decades. Similar to other parameters of the ionosphere, the EM waves in the ionosphere can be considered as a precursor of earthquake although it is influenced more by solar than seismic activities such as earthquake. Therefore, modeling of the EM waves variation caused by solar activities is necessary for prediction of earthquakes. In this study, the magnetic data obtained from the instrument magnetic search coil (IMSC) experiment onboard the detection of electromagnetic emissions transmitted from earthquake regions (DEMETER) satellite have been used to estimate the parameters of the proposed model. Since the effect of solar on the ionosphere depends on the geographic location, the analyses are limited to the data above Iran and the parameters of proposed model are only computed in this region. The main purpose of this article is to derive the statistical distribution of the noise added to the model describing the solar effect on the magnetic waves in the ionosphere at an extremely low frequency (ELF) band ranging from a few Hz up to 10 kHz. The results show that this noise can be considered as a zero-mean Gaussian distribution with known variance.

СОПОСТАВЛЕНИЕ ВАРИАЦИЙ ТЕМПЕРАТУРЫ ВОЗДУХА НА АФРИКАНСКОМ КОНТИНЕНТЕ И ИНТЕНСИВНОСТИ ШУМАНОВСКОГО РЕЗОНАНСА ПО ДОЛГОВРЕМЕННЫМ НАБЛЮДЕНИЯМ В AНТАРКТИКЕ

СОПОСТАВЛЕНИЕ ВАРИАЦИЙ ТЕМПЕРАТУРЫ ВОЗДУХА НА АФРИКАНСКОМ КОНТИНЕНТЕ И ИНТЕНСИВНОСТИ ШУМАНОВСКОГО РЕЗОНАНСА ПО ДОЛГОВРЕМЕННЫМ НАБЛЮДЕНИЯМ В AНТАРКТИКЕ

A Novel Detection Method for Underwater Moving Targets by Measuring Their ELF Emissions with Inductive Sensors.

In this article, we propose a novel detection method for underwater moving targets by detecting their extremely low frequency (ELF) emissions with inductive sensors. The ELF field source of the targets is modeled by a horizontal electric dipole at distances more than several times of the targets’ length. The formulas for the fields produced in air are derived with a three-layer model (air, seawater and seafloor) and are evaluated with a complementary numerical integration technique. A proof of concept measurement is presented. The ELF emissions from a surface ship were detected by inductive electronic and magnetic sensors as the ship was leaving a harbor. ELF signals are of substantial strength and have typical characteristic of harmonic line spectrum, and the fundamental frequency has a direct relationship with the ship’s speed. Due to the high sensitivity and low noise level of our sensors, it is capable of resolving weak ELF signals at long distance. In our experiment, a detection distance of 1300 m from the surface ship above the sea surface was realized, which shows that this method would be an appealing complement to the usual acoustic detection and magnetic anomaly detection capability.

Effect of Underwater Ambient Noise on Quadraphase Phase-shift Keying Acoustic Sensor Network Links in Extremely Low Frequency Band

This study evaluates the impact of underwater ambient noise using seven real noise samples; Dolphin, Rain, Ferry, Sonar, Bubbles, Lightning, and Outboard Motor in three frequency ranges in extremely low frequency (ELF) band. The ELF band is the most significant bandwidth for underwater long-range communication. ELF band which is extended from 3 to 3000 Hz clearly, faces bandwidth limitation. Measuring the impact of noises that are imposed on this bandwidth, based on center frequency employment is highly regarded. This measurement optimizes detection process and assists the design of more reliable underwater communication systems and will improve network quality of service (QoS). In this investigation, Quadraphase Phase-shift Keying (QPSK) acoustic communication nodes are designed in MATLAB and real noise samples are added to network link. Three frequency bands are defined (0-1600), (400-2000) and (1600-3200) Hz, then the impact of noise samples on phase is measured. Next, ( ) ratio for every bandwidth (BW) is simulated. The result demonstrates 0 to 1600 Hz band is the nosiest part of the ELF band. This study discovered the Bubble noise sample from the environmental noise; Ferry from man-made noise and the Dolphin in mammal’s noise have the greatest impact on 0 to 1600 Hz bandwidth.

Effect of electromagnetic fields on some biomechanical and biochemical properties of rat’s blood

In order to study the effect of electromagnetic fields (0.3 mT, 50 Hz) on some biomechanical and biochemical properties of rats’ blood, healthy thirty male albino rats of 150 ± 10 g were divided into three equal groups namely A, B1, B2. Group A used as a control group, group B1 was continuously exposed to a magnetic field of (0.3 mT, 50 Hz) for a period of 21 days for direct effect studies. Group B2 was continuously exposed to the same magnetic field for the same period of time, then was housed away from the magnetic field for a period of 45 days for delayed effects studies. After examination, the results indicated that the apparent viscosity and the consistency index increased significantly and very high significantly for groub B1 and B2 compared to control at P<0.05. Red blood cell counts (RBCs) membrane elasticity had significantly and very high significantly decreased for groups B1 and B2. Moreover, delayed effects studies indicated that there is deterioration in the bone marrow functions. These results are supported by the blood film image, where irregularities and deformations in the RBCs membranes had been occurred. We conclude that the cell membrane properties are highly affected by the extremely low frequency (ELF) magnetic fields, which proved to be biologically toxic.