Emission Of Electromagnetic Radiation Research Articles

Effects of Electromagnetic Radiation of Mobile Phones on Hematological and Biochemical Parameters in Male Albino Rats

The widespread usage of mobile phones in recent years has raised concern for potential dangers and subsequent research activities. Many have tried to determine the effects of the emitted electromagnetic radiation of mobile phones. The present study was aimed at evaluating the effects of EMR from mobile phones on behavior, some hematological (RBC, MCV, WBC, HGB, MCH, MCHC, LYM, LYM %) and biochemical parameters (AST, ALT and ALP) in experimental rats. The results indicated that there is increase in mean weight of animals exposed to low EMR but the increment was less as the exposure period increases. No changes were observed in terms of their behavior. The values of RBC, HGB and MCH in 100% of the experimental animals in all groups of low and high EMR have exceeded that of the control. However, the values of WBC in 100% of experimental animals have not exceeded that of the control group. The mean values of AST and ALT in 30% of high EMR exposed rats has exceeded the control groups. There is no significant difference between high and low EMR exposed rats in terms of hematological parameters (RBC, MCV, WBC, HGB, MCH, MCHC, LYM, LYM %) and biochemical parameters (ALT, AST and ALP) (P>0.05).

Suppression of a Certain Vehicle Electrical Field and Magnetic Field Radiation Resonance Point

The pulse-width-modulation-controlled inverter and the permanent-magnet synchronous motor are the key electrical components of the electric vehicle (EV). The electromagnetic radiation emission of the motor drive system has a great influence on the electromagnetic radiation emission of the vehicle to a certain extent. Different motor drive systems may have significant differences in the design of the inverter electromagnetic compatibility, the length, and the direction of the cable, which resulting in a significant difference in the radiation emission of the motor drive system. At present, there are many researches on the conduction emission, electromagnetic interference (EMI) modeling, and EMI suppression of the inverter and the motor, but the research on the radiation emission of the motor drive system and its relationship with radiation emission of the vehicle is relatively little. In this paper, a certain EV is taken as an example to analyze the reason why the electric motor drive system is the source of the high emission amplitude in the frequency range from 0.50 to 3 MHz and the resonance point. Also, it is proved that it is feasible to add Y capacitor at inverter's dc terminal. It is effective to reduce the radiation emission of the vehicle in the above frequency range particularly, and a simplified vehicle common-mode interference model is established. Finally, the availability of the model is verified on multiple models.

Investigation of Electromagnetic Radiation Emission during Sheet Metal Incremental Micro Forming

Edge dislocations within the plastic zone ahead of a crack tip form accelerated electric line dipoles which give rise to the electromagnetic radiation (EMR) emissions in metal and alloys. This paper reports an experimental investigation to determine EMR radiation during incremental microforming of a thin aluminum sheet. The EMR signals emit from aluminum grade Al3003 during deformation under unrestricted quasi-static micro-deformation is reported. The EMR emission characteristics are influenced by the microstructural changes rather than forming parametric conditions. The EMR emissions are followed by micro-deformation locally in predetermined loci in continuous deformation pattern through a rotating tool with two different depths. The nature, amplitude and frequency of the observed EMR emissions are in conformity with the predictions of the theoretical model developed by the Misra and co-authors.24-29

Study of EMR and AE during Coal Fracture under Quasi-static Uniaxial Compression Load

A quasi-static uniaxial compression experiment was designed to simulate creep damage in coal. During the experiment, electromagnetic radiation (EMR) and acoustic emission (AE) signals were synchronously acquired. The energy of EMR and AE signals were subsequently calculated after the background noise from the equipment and the environment were filtered out. We then analyzed the change in signal energy associated with the sample strength, loading time and other factors. The results showed that as the loading time increases, the frequency of the periodic signal in the EMR energy also increases. In addition, the dominant AE signal energy release occurs only in the final stage of sample failure. However, intermittent AE pulse clusters were recorded during the entire loading cycle. The analysis of data provided a strong correlation between the change in the AE signal energy and the expansion of micro-cracks in the materials, which is manifested as an irreversible deformation of the material at the macroscopic scale.

A kilonova as the electromagnetic counterpart to a gravitational-wave source.

Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.

LIGO’s “GW150914 signal” reproduced under YARK theory of gravity

The widely publicized “GW150914 event” that was recently detected by the LIGO Scientific Collaboration is given as confirmation of gravitational waves (GWs) predicted by Albert Einstein in his general theory of relativity (GTR), although the extremely weak intensity of this signal does not allow confirmation of all of the specific properties of GWs predicted in GTR. In the present contribution, we provide an alternative explanation of the LIGO signal without GWs under the framework of Yarman–Arik–Kholmetskii (YARK) gravitation theory, which has garnered considerable success during the past years in accounting for landmark astrophysical observations so far thought to confirm GTR, as well as recent laboratory-scale experiments that were shown to be at odds with GTR. According to YARK, the coalescence of super-massive bodies in a distant binary system would induce a related alteration of the wavelength of the laser beam used in the LIGO Michelson–Morley interferometer, as well as the emergence of mechanical stresses in the suspended mirrors. We show that the latter effect turns out to be negligible, and thus, the variation of the phase alone of the laser beam in the output of the Michelson–Morley interferometer suffices to describe the amplitude and the shape of the observed LIGO signal. In addition, the binary merger necessitates a rest mass decrease in YARK (which we calculated to be about 3.1 solar masses on the whole) that we predict should be released via electromagnetic radiation emission according to our theory. We point out that electromagnetic radiation of exactly the same kind is in fact responsible, instead of GWs, for the energy loss in the Hulse–Taylor binary system. Our numerical results thus well match the GW150914 interference pattern without involving any GWs hypothesis.

Electromagnetic Differential Measuring Method: Application in Microstrip Sensors Developing.

Electromagnetic radiation is energy that interacts with matter. The interaction process is of great importance to the sensing applications that characterize material media. Parameters like constant dielectric represent matter characteristics and they are identified using emission, interaction and reception of electromagnetic radiation in adapted environmental conditions. How the electromagnetic wave responds when it interacts with the material media depends on the range of frequency used and the medium parameters. Different disciplines use this interaction and provides non-intrusive applications with clear benefits, remote sensing, earth sciences (geology, atmosphere, hydrosphere), biological or medical disciplines use this interaction and provides non-intrusive applications with clear benefits. Electromagnetic waves are transmitted and analyzed in the receiver to determine the interaction produced. In this work a method based in differential measurement technique is proposed as a novel way of detecting and characterizing electromagnetic matter characteristics using sensors based on a microstrip patch. The experimental results, based on simulations, show that it is possible to obtain benefits from the behavior of the wave-medium interaction using differential measurement on reception of electromagnetic waves at different frequencies or environmental conditions. Differential method introduce advantages in measure processes and promote new sensors development. A new microstrip sensor that uses differential time measures is proposed to show the possibilities of this method.

Phase-controlled propagation of surface plasmons

Directional emission of electromagnetic radiation can be achieved using a properly shaped single antenna or a phased array of individual antennas. Control of the individual phases within an array enables scanning or other manipulations of the emission, and it is this property of phased arrays that makes them attractive in modern systems. Likewise, the propagation of surface plasmons at the interface between metal films and dielectric materials can be determined by shaping the individual surface nanostructures or via the phase control of individual elements in an array of such structures. Here, we demonstrate control of the propagation of surface plasmons within a linear array of nanostructures. The generic situation of plasmonic surface propagation that is different on both sides of a metal film provides a unique opportunity for such control: plasmons propagating on the slower side feed into the side with the faster propagation, creating a phased array of interfering antennas and thus controlling the directionality of the wake fields. We further show that by shaping the individual nanoantennas, we can generate an asymmetric propagation geometry.

Experimental realization of a terahertz all-dielectric metasurface absorber.

Metamaterial absorbers consisting of metal, metal-dielectric, or dielectric materials have been realized across much of the electromagnetic spectrum and have demonstrated novel properties and applications. However, most absorbers utilize metals and thus are limited in applicability due to their low melting point, high Ohmic loss and high thermal conductivity. Other approaches rely on large dielectric structures and / or a supporting dielectric substrate as a loss mechanism, thereby realizing large absorption volumes. Here we present a terahertz (THz) all dielectric metasurface absorber based on hybrid dielectric waveguide resonances. We tune the metasurface geometry in order to overlap electric and magnetic dipole resonances at the same frequency, thus achieving an experimental absorption of 97.5%. A simulated dielectric metasurface achieves a total absorption coefficient enhancement factor of FT=140, with a small absorption volume. Our experimental results are well described by theory and simulations and not limited to the THz range, but may be extended to microwave, infrared and optical frequencies. The concept of an all-dielectric metasurface absorber offers a new route for control of the emission and absorption of electromagnetic radiation from surfaces with potential applications in energy harvesting, imaging, and sensing.

Laser Technologies in Spintronics and Nanoelectronics as the Method of Changing the Structure and Magnetic Characteristics of Thin Films

In the present article we want to consider some features of not thermal influence of laser pulses on multilayer heterogeneous nanofilms to present the results of our experimental researches of change of the roughness of a surface and magnetic characteristics of permalloy films after their irradiation nanosecond laser pulses and the results of measurement of dynamics of magnetic reversal of magnetic tunnel nanostructures with one and two magnetic nanolayers. It is shown that the photon drag effect of electrons can not only generate an electric potential difference between the input and output surfaces in a semiconductor, but may also lead to a drift of the impurities. The results of our research show that in the thin CdS single crystals can be obtained stimulated emission of electromagnetic radiation in the terahertz frequency range.

Generalization of the Force Approach to Radiation Reaction

A new approach to radiation reaction for the correction of the linear and circular motion of a charged particle takes into account the emission of electromagnetic radiation due to its acceleration. This new formulation was based on expressing the radiation reaction force in terms of the external force rather than the acceleration of the charge. In this paper, a generalization of the radiation reaction force in terms of the external force approach is formulated for any arbitrary motion of the charged particle. This generalization includes the linear and circular acceleration cases previously investigated.

On the diversity of compact objects within supernova remnants – II. Energy-loss mechanisms

Energy losses from isolated neutron stars are commonly attributed to the emission of electromagnetic radiation from a rotating point-like magnetic dipole in vacuum. This emission mechanism predicts a braking index $n=3$, which is not observed in highly magnetized neutron stars. Despite this fact, the assumptions of a dipole field and rapid early rotation are often assumed a priori, typically causing a discrepancy between the characteristic age and the associated supernova remnant (SNR) age. We focus on neutron stars with `anomalous' magnetic fields that have established SNR associations and known ages. Anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) are usually described in terms of the magnetar model, which posits a large magnetic field established by dynamo action. The high magnetic field pulsars (HBPs) have extremely large magnetic fields just above QED scale (but below that of the AXPs and SGRs), and central compact objects (CCOs) may have buried fields that will emerge in the future as nascent magnetars. In the first part of this series we examined magnetic field growth as a method of uniting the CCOs with HBPs and X-ray dim isolated neutron stars (XDINSs) through evolution. In this work we constrain the characteristic age of these neutron stars using the related SNR age for a variety of energy loss mechanisms and allowing for arbitrary initial spin periods. In addition to the SNR age, we also make use of the observed braking indices and X-ray luminosities to constrain the models.

Brownian Emitters

A Brownian harmonic oscillator, which dissipates energy either by friction or via emission of electromagnetic radiation, is considered. This Brownian emitter is driven by the surrounding thermo-quantum fluctuations, which are theoretically described by the fluctuation–dissipation theorem. It is shown how the Abraham–Lorentz force leads to dependence of the half-width on the peak frequency of the oscillator amplitude spectral density. It is found that for the case of a charged particle moving in vacuum at zero temperature, its root-mean-square velocity fluctuation is a universal constant, equal to roughly 1/18 of the speed of light. The relevant Fokker–Planck and Smoluchowski equations are also derived.

Enhancing Automatic Maritime Surveillance Systems With Visual Information

Automatic surveillance systems for the maritime domain are becoming more and more important due to a constant increase of naval traffic and to the simultaneous reduction of crews on decks. However, available technology still provides only a limited support to this kind of applications. In this paper, a modular system for intelligent maritime surveillance, capable of fusing information from heterogeneous sources, is described. The system is designed to enhance the functions of the existing vessel traffic services systems and to be deployable in populated areas, where radar-based systems cannot be used due to the high electromagnetic radiation emissions. A quantitative evaluation of the proposed approach has been carried out on a large and publicly available data set of images and videos, which are collected from multiple real sites, with different light, weather, and traffic conditions.

Feasibility of an electromagnetic compatibility method for MRgFUS using a wire mesh screen

This study evaluated an electromagnetic compatibility method for high-intensity focused ultrasound (HIFU) and magnetic resonance (MR) imaging in an MR-guided focused ultrasound surgery using a conductive wire mesh screen. This screen has a good ultrasound transmission and shielding effectiveness. A hybrid acoustic simulation method was developed to analyze the effects of mesh parameters and the HIFU working frequency on the acoustic field. Experiments were performed to measure both acoustic pressure profile and radiated electromagnetic noise. With the proposed mesh screen, the electromagnetic radiation emission was reduced by 14dB at 128MHz while the acoustic focal intensity was reduced by less than 11% using one screen. This shielding method is easy to implement and requires no additional phase correction method. This method also improves the quality of MR images.

Effect of Peierls stress and strain-hardening parameters on EMR emission in metals and alloys during progressive plastic deformation

Abstract The article deals with the development of a theoretical model to predict the nature (amplitude and shape) of deformation-induced electromagnetic radiation (EMR) in metals and alloys during progressive plastic deformation. The model explicitly embraces the effect of Peierls stress and strain hardening to envisage the nature of EMR in materials with relatively large Peierls stress. The theoretical results were evaluated for 0.15 % plain carbon steel and compared with experimental results. The signals obtained from the model were found to be exponential in shape and are in good agreement with the experimental observations. The results suggest that inclusion of strain hardening parameters in the earlier model is necessary for determining deformation induced EMR in bcc metals and alloys during progressive plastic deformation.

Effects of a new device to guide venous puncture in elderly critically ill patients: results of a pilot randomized study.

Novel devices based on the emission of near-infrared electromagnetic radiation (NIR) have been developed to minimize venous puncture failures. These instruments produce an "augmented reality" image, in which subcutaneous veins are depicted on a LCD display. We compared the new technique with standard venipuncture in a population of elderly patients. Patients admitted in Intensive Care Unit were randomized to standard or to NIR assisted procedure. In the 103 enrolled patients (age 74±12years; standard venipuncture-N=56; NIR-N=47), no differences were found in procedure length, number of attempts, and referred pain. With NIR there was a lower incidence of hematomas and fewer anxiety and depressive symptoms. The use of the novel NIR-based device is safer and more psychologically tolerable, and it is not associated to an increase of procedure length or number of attempts.

Detection of electromagnetic radiation in ferroelectric ceramics for non-contact sensing applications

This paper presents some preliminary investigation of electromagnetic radiation (EMR) emissions from (1-x)(Bi0.5Na0.5TiO3)–x(BaTiO3) (x = 0.04, 0.05, 0.06, 0.07 & 0.08) lead-free piezoelectric ceramics. Compositions near the morphotropic phase boundary 0.94(Bi0.5Na0.5TiO3)–0.06(BaTiO3) (BNT-6BT) are studied. The electromagnetic radiations were detected with the help of non–contacting loop antenna placed around the sample. EMR voltage detection was done simultaneously when the piezoelectric material was subjected to alternating electric field. Digital storage oscilloscope was used to measure the EMR voltage. At highest applied alternating electric field of 5.8 kV/cm EMR Signal of 17.6 V was detected for 0.95(Bi0.5Na0.5TiO3)–0.05(BaTiO3) (BNT-5BT). Higher frequency of the electric field leads to the higher acceleration of the dipoles of the piezoelectric material and thus leads to the higher amplitude of EMR. The EMR Voltage is observed to be proportional to the polarization and this can lead to the development of new technique of measuring extent of polarization. Also the EMR phenomenon can be used to develop sensors for non-contact excessive deformation measurement.

Energetic electrons generated during solar flares

The Sun is a giant particle accelerator. During solar flares, magnetic field energy stored in the corona is suddenly released and transferred to local heating of the coronal plasma, mass motions (e.g. jets) and the generation of energetic particles, i.e. electrons, protons and heavy ions. Basically, a flare occurs as a local enhancement of the emission of electromagnetic radiation from the radio up to the ${\it\gamma}$-ray range on the Sun. That indicates the production of energetic electrons during flares. NASA’s RHESSI mission has the aim to investigate electron acceleration processes by studying the Sun’s X-ray and ${\it\gamma}$-ray emission with high spatial, temporal and spectral resolution, i.e. by means of imaging spectroscopy. A substantial part of the energy released during a flare is carried by these energetic electrons. Apart from them, solar energetic particles, i.e. protons and heavy ions, and coronal mass ejections play an important role in the energy budget of a flare. Here, we focus on electron acceleration. The way in which $10^{36}$ electrons are accelerated up to energies beyond 30 keV is one of the open questions in solar physics. A flare is considered as the manifestation of magnetic reconnection in the solar corona. Which mechanisms lead to the production of energetic electrons in the magnetic reconnection region is discussed in this paper. Two of them are described in more detail.

Condition monitoring of high voltage transformers using Fiber Bragg Grating Sensor

High voltage (HV) power apparatus determines the stability of any electrical power system. Failure of such apparatus is mainly due to damage of insulation normally caused by the Partial Discharge (PD). Therefore PD measurements are globally considered as most essential and favored testing procedure for most of the HV power apparatus. Online condition monitoring may help to take proper corrective action at proper time, which reduces unscheduled downtime and can save money for electrical supply utilities.HV power transformers are being considered as heart of any electrical system and they have received much attention in recent years. In HV transformers, PD is one of the main reasons for degradation of insulation quality. Therefore its detection can provide early indication of the insulation failures of transformers. PD can be traced through direct measurement of current, electromagnetic radiation, chemical changes or acoustic emission. Electrical, acoustic, chemical and optical methods of PD measurement are the popularly accepted methods of PD detection in the high voltage (HV) power transformers. Over the past decades various PD sensors have been developed, most of these require electrical connections closed to measurement site and electrical wirings and amplifiers for transmission of measured signals. Placing electrical components and wirings closer to HV terminals is difficult for installation of such sensors; moreover, due to proximity of HV terminals these sensors suffer from electromagnetic interference (EMI).In this context, development of optical fiber based PD sensor can be promising as the optical fibers are made of dielectric material so can be easily placed inside the equipment without any additional insulation arrangements. On the other hand, it has very low transmission loss; therefore, the measured signal can be transmitted to the sub-station control room without use of any electrical amplification system and it is free from EMI. In this work, a Fiber Bragg Grating (FBG) based optical PD sensor has been developed for online detection of PD within HV power transformer. The shift in wavelength of FBG due to impulsive acoustic pressure generated during PD event has been used for the detection. The performance of the developed FBG based sensor has been validated experimentally with standard electrical (IEC60270) PD measurement system. Experimental results show that the developed sensor is a suitable substitute for conventional PD measuring system and it can be placed inside the apparatus.