Electromagnetic Energy Transfer Research Articles

Peculiarities of Transfer and Heat Losses of Electromagnetic Energy in the Two-Wire Overhead Line with Alternating Electric Conduction Current

Peculiarities of Transfer and Heat Losses of Electromagnetic Energy in the Two-Wire Overhead Line with Alternating Electric Conduction Current

Research on the mechanism of electromagnetic ultrasonic energy transfer based on dynamic multi-magnetic vector coupling

The traditional electromagnetic acoustic transducer (EMAT) in steel plate inspection has a problem of suboptimal energy transfer efficiency due to fixed static sensitivity. The dynamic sensitivity detection method with multi-magnetic vector coupling is proposed based on the principle of mutual conversion of electromagnetic fields inside and outside the workpiece. The conversion relationship of multi-magnetic vector coupling was analyzed, and then a mathematical model of rotational wave displacement between wave displacement and magnetic parameters was established. This approach theoretically guides the modeling, simulation, and design optimization of high energy conversion efficiency EMATs. The experiment shows that under the action of rotating magnetic field, different rotating directions and deflection angles have varied detection effects. The optimal energy transfer efficiency of the transducer under the dynamic multi-magnetic vector coupling mechanism is effectively improved compared with the static traditional form. The optimal signal amplitude of the dynamic sensitivity detection method is 3.73 times that of traditional detection signals. The electromagnetic ultrasonic dynamic multi-magnetic vector coupling detection method explores new ideas for the mechanism analysis from static to dynamic and guarantees high sensitivity detection and evaluation of steel plates.

Broadband electromagnetic wave absorption performance of CuS-biomass carbon composites derived from moss

The absorption performance of broadband electromagnetic waves is of utmost importance in safeguarding diverse electronic equipment against electromagnetic wave pollution, necessitating materials with low density, thin thickness, and cost-effectiveness to be employed. This study presents the successful synthesis of biomass-derived carbon (BC) composites via the hydrothermal method, utilizing moss coated with flower-like CuS. The CuS was uniformly dispersed on BC matrix, contribute to dipole polarization relaxation. The formation of heterogeneous interfaces between CuS and the BC phase resulted in significant polarization loss. Additionally, the wrinkled BC and flower like CuS constructed by nanosheets boosted scattering of electromagnetic wave due to its large specific surface area, which can provide additional channels for charge transfer and avail dissipation of electromagnetic wave energy. With an efficient absorption bandwidth (EAB) that encompasses the whole X band, the electromagnetic waves absorption (EMA) performance of CuS/BC composites was able to reach a minimum reflection loss of − 28.8 dB.

Electromagnetic energy transfer processes in effective electro-magneto dynamics of axions

Oscillating and dissipative energy exchange between the electromagnetic and axion fields is investigated in an effective electro-magneto dynamical (EEMD) model theory, implying the coexistence of axions with hypothetic magnetic charges. An exact formula is presented for the energy transfer between the electromagnetic and axionic sectors. In a first example, we compute analytically the homogeneously oscillating electric and magnetic field configurations generated by the combined action of a constant static magnetic field and a periodically oscillating axion condensate. In the second example, the electromagnetic radiative energy loss of a gravitationally bound axion configuration is computed in the EEMD model. As a result, an asymptotic [Formula: see text] temporal increase of the clump size is found also in EEMD.

Near-Field Matching and Universal Limits on Electromagnetic Energy Transfer

This article introduces the concept of near-field (NF) matching as a continuum-mode generalization of port matching in circuit theory suitable for field-theoretic electromagnetic energy transfer scenarios, with a focus on spatio-frequency processes in coupled systems. The concept is rigorously formulated using the full electromagnetic Green’s function of a generic receiving surface interacting with arbitrary illumination fields where the Riemannian structure and the electromagnetic boundary condition of the problem are encoded into the tensor structure of a Green’s function on a manifold. After a carefully selected combination of proper function spaces for the various field quantities involved, we utilize exact methods to estimate the sizes of various operator quantities using the appropriate function space norms. A field-theoretic measure of power transfer efficiency in generalized NF matching scenarios is introduced, and exact upper bounds on this efficiency are derived using Young’s inequality for integral kernel operators. This theoretical study complements and generalizes the largely empirical and problem-specific literature on wireless energy transfer by providing an exact and rigorous mathematical framework that can guide and inform future optimization and design processes.

Faraday rotation enhancement due to proximity effect of surface plasmon resonance in magnetoplasmonic colloidal mixtures

The modification of Magneto-optic Faraday Rotation (MFR) based on Surface Plasmon Resonance (SPR) of noble metal nanoparticles (NP) has been an exciting field of research. The underlying physical mechanisms are intriguing and correspond to various observation patterns in composite magnetoplasmonic systems. Exploiting the immense potential of SPR phenomenon for excellent electromagnetic field confinement and energy transfer to a wide variety of dimensionally different nanostructures, we report MFR measurements in typical magnetoplasmonic colloidal mixtures of separately synthesized cobalt ferrite (CoFe2O4) and gold (Au) NP at wavelength of 532 nm where we have observed a spectacular possibility for “proximity effect” based plasmonic enhancement of MFR, for the very first time. The Langevin-type MFR patterns show a strong dependence on the concentrations of participating systems, where a typical optimum concentration produced a significant enhancement in MFR. For both the entities present in the liquid, a mutually dependent optimum concentration was necessary to obtain the Langevin pattern as well as MFR enhancement, confirming the influence from SPR due to the proximity effect. The observations open up exciting possibilities to apply SPR to discover novel magnetoplasmonic phenomena underlined by proximity effects, in addition to eluding constrained procedures to synthesize composite magnetoplasmonic systems.

Bright and Stable Perovskite Nanocrystals Lighted Up Remotely by Means of Wireless Power Transfer

AbstractHalide perovskite nanocrystals (NCs) are an emerging family of low‐cost and high‐efficiency luminescent nanomaterials. They offer a broad gamut of emitted light colors owing to the broad bandgap tunability of the perovskite via anion variation. Previously, to lighten up perovskite NCs, they were placed between two electrodes to inject charge carriers or were integrated with commercial blue light‐emitting diodes powered by electric contacts. However, the opportunities for remote lighting of perovskite NCs have not been explored yet. In this work, the principles of wireless power transfer of electromagnetic energy are applied to light up perovskite NCs encapsulated into a polymer matrix. The photoluminescence and absorption spectra of the CsPbBr3 NCs in a polymer matrix on incident laser power density are experimentally studied. As a proof of concept, chess pieces are created consisting of the perovskite NCs and charge from a chessboard with an integrated metasurface‐based resonator that provides quasi‐homogeneous power distribution. The efficient lighting of the chess pieces with encapsulated NCs is demonstrated over the whole area of the chessboard at various heights up to ≈10 cm. The results of the study open the door for potential applications of perovskite NCs with remote lighting capability.

Синхронный многофазный электропривод с управлением по основному энергетическому каналу

One of the options to improve the technical and economic characteristics of a synchronous electric drive is to design it based on an actuating motor with an increased number of phases. However, the characteristics of m-phase (m > 3) synchronous motor associated with the transfer of electromagnetic energy by a whole spectrum of spatial harmonic fields sets the task to develop an automatic control system that considers these features. The method to calculate the characteristics of an m-phase synchronous motor in quasi-stationary modes based on the use of spectral vectors of electromagnetic parameters for its individual substructures as a control object is used. The authors have proposed an approach to study and calculate energy characteristics of m-phase synchronous motor for different control laws implemented on the basis of equations of its design equivalent circuit. The results of the study of the main energy characteristics of the engine for various control laws along the main energy channel are presented. To implement the advantages of a multiphase synchronous motor, it is necessary to force the required mutual arrangement of the flux linkage vectors and stator current for higher spatial harmonics. It can be implemented based on the multi-channel principle of control system design.

Effect of non-thermal ultraviolet and ultrasound technologies on disinfection of meat preparation equipment in catering industry.

In recent years, ultraviolet and ultrasound treatments are gaining attraction as promising green decontamination technologies to ensure microbial safety in food industry. Decontamination by ultraviolet light is a physical process defined by the transfer of electromagnetic energy from a light source to an organism's cellular material and depended on the emission of radiation in the ultraviolet region (100-400 nm), specifically the UV-C region (200-280 nm) which has been demonstrated to be germicidal. Ultrasound technology is defined as sound waves with high and low frequency beyond the limit of human hearing and shows a decontamination effect that occurs as a consequence of cavitation at high power (low frequency) in general. In the present study, it was aimed to determine the effectiveness of ultraviolet light (254 nm, 10 min) and high frequency ultrasound techniques (40 kHz, 10 min) in reducing total aerobic mesophilic bacteria, yeast and mold, Esherichia coli/coliform and Salmonella spp. on the equipment surfaces used in the catering facility. For this purpose, the equipment (cutting knife, meat grinder knife, knife sharpener, cut-proof glove) used in the meat preparation department of catering facility were selected for the treatments. According to the results, appreciable reductions were achieved in total aerobic mesophilic bacterial counts of the ultraviolet treated samples (maximum difference 2.61 log cfu/cm2) and the ultrasound treated samples (maximum difference 4.07 log cfu/cm2). After ultraviolet treatment, Salmonella spp. were totally inhibited on the contaminated surfaces. Furthermore, Escherichia coli/coliform was not detected in the samples after both treatments whereas it was detected before the treatments. It has been concluded that the techniques are effective in reducing microbiological load and also ultraviolet treatment is effective on pathogenic microorganisms on food contact surfaces. As a result, the ultraviolet and ultrasound techniques are effective treatments for equipment disinfection in the catering sector and can be used industrially as it gives successful results.

Applications of Microwaves in Medicine

Advances and updates in medical applications utilizing microwave techniques and technologies are reviewed in this paper. The article aims to provide an overview of enablers for microwave medical applications and their recent progress. The emphasis focuses on the applications of microwaves, in the following order, for 1) signal and data communication for implants and wearables through the human body, 2) electromagnetic energy transfer through tissues, 3) noninvasive, remote or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> physical and biochemical sensing, and 4) therapeutic purposes by changing tissue properties with controlled thermal effects. For signal and data communication and wireless power transfer, implant and wearable applications are discussed in the categories of pacemakers, endoscopic capsules, brain interfaces, intraocular, cardiac and intracranial pressure sensors, neurostimulators, endoluminal implants, artificial retina, smart lenses, and cochlear implants. For noninvasive sensing, remote vital sign radar, biological cell probing, magnetic resonance and microwave imaging, biochemical, blood glucose, hydration and biomarker sensing applications are introduced. For therapeutic uses, the developments of microwave ablation, balloon angioplasty, and hyperthermia applications are reviewed. The scopes of this article mainly concentrate on the research and development efforts in the past 20 years. Recent review articles on specific topics are cited with accomplishment highlights and trends deliberated. At the end of this article, a brief history of the IEEE Microwave Theory and Techniques Society (MTT-S) Biological Effects and Medical Applications committee and the contributions by its members to the promotion and advancement of microwave technologies in medical fields are chronicled.

Ultra-Wide Band Polarization Converter Based on Ultra-Thin Bi-Layer Slot Structures

An ultrathin linear-to-linear polarization converter exhibiting a high polarization conversion ratio (PCR) in an ultrawide bandwidth is fabricated on a printed circuit board (PCB). It is based on a bilayer slot structure that is electrically connected by via holes. Front- and back-sided slot structures are arranged in mutually orthogonal directions and function as receivers and radiators, respectively. The via holes provide a route for the transfer of electromagnetic energy received by the front-sided slot structures to the back-sided slot structures and radiate an electromagnetic wave having polarization orthogonal to that of the input electromagnetic wave. Moreover, two slots are employed for each unit cell design, and the locations of the via holes are carefully determined to achieve broadband polarization conversion. The via-hole positions that change the surface current distribution around the slot apertures enable the control of multiple resonance frequencies. Via holes are positioned to make first and second resonance frequencies that are blue-shifted toward the third resonance frequency, which broadens the operational band of the perfect polarization conversion. The 0.8 mm thick polarization converter exhibits PCR greater than 99% in the frequency band from 24.5 to 47 GHz.

Moiré-driven reconstitution on electromagnetic energy transfer

The past decade has witnessed an explosion in the field of twistronics concepts, opening the door to numerous extraordinary physical phenomena such as weak ferroelectric charge transfer, superconductivity, topologically protected states, and so on. Here, inspired by the twistronics concepts, we take a moiré three-body system consisting of three metasurfaces supporting highly confined hyperbolic surface plasmons as an example, introducing an analogous concept into the study of near-field electromagnetic energy transfer within three-body system. We demonstrate the possible existence of the moiré transistor effect induced by the twisted hyperbolic repeater in the polariton coupling system (source and drain parallel to each other), where the near-field electromagnetic energy transfer exchanged between the source and the drain can be reversibly switched, amplified, and modulated by action on moiré patterns. Moreover, we point out that for the symmetry-breaking situations (source and drain not parallel to each other), there is also a magic angle in this system and demonstrate that the twisted hyperbolic repeater can act as a moiré compensation effect at this magic angle, mitigating to a certain extent the electromagnetic energy attenuation caused by the malposition between source and drain. Our findings may open new opportunities for the development of near-field thermal energy transport, enabling new perspectives concerning thermal management at the nanoscale, near-field energy conversion, and infrared spectroscopy.

Metamaterial engineering for optimized photon absorption in unipolar quantum devices.

Metamaterials have played a major role in the development of optoelectronic devices due to their capability of coupling free-space radiation with active materials at the nanometer scale. In particular, unipolar photodetectors display highly improved performances when implemented into patch-antenna arrays. We study light-coupling and absorption in patch-antenna metamaterials by combining an experimental investigation, an analytical approach based on coupled mode theory and numerical simulations in order to understand how the geometrical parameters influence the electromagnetic energy transfer from the free-space to the active material. Our findings are applied to the design of optimized unipolar photodetectors with improved quantum efficiency.

Electromagnetic Energy Transfer in the Atmosphere Ionized by Laser Radiation

Electromagnetic Energy Transfer in the Atmosphere Ionized by Laser Radiation

ФИЗИЧЕСКИЕ ПРОЦЕССЫ В ИОНИЗОВАННОЙ ЛАЗЕРНЫМ ИЗЛУЧЕНИЕМ АТМОСФЕРЕ ПРИ СОЗДАНИИ ЛИНИИ РАДИОСВЯЗИ

The results of studies of ionization processes in the atmosphere that occur under the action of laser radiation make it possible to consider the possibility of using directed laser beams for location or formation of a communication channel. To do this, with the help of laser radiation in the atmosphere, a channel with a weakly ionized wall is formed, into which radio emission is introduced. The mini mum electron concentration Ne in the ionized channel, which ensures the reflection of the transmitted electromagnetic wave, depends on its frequency. If the frequency of electromagnetic radiation propagating in the channel is less than the frequency of plasma oscillations in the medium, then the waves are completely reflected from the ionized layer. In the range of long waves (1000-3000 m), the effect of self-radiation of plasma centers can be used to transmit information. By changing the dimensions of the plasma source in space, by modulating the laser radiation, it is possible to vary the frequency and amplitude of the emitted electromagnetic waves in a given range. The main mechanisms of creation of weak ionization channels in the atmosphere by laser radiation are considered. A scheme for the transmission of electromagnetic energy is proposed and its parameters are calculated. A variant of electromagnetic energy transfer by creating a plasma mirror in the atmosphere is considered. The frequency, duration, and energy of laser pulses necessary to create weak ionization channels in the atmosphere and ionosphere are estimated. The calculations and experiments carried out showed that an IR laser sub nanosecond radiation source with a pulse repetition rate of 108 Hz and providing a breakdown or pre-breakdown ionization mode can be used to transfer electromagnetic microwave energy in the atmosphere. It has been established that in the atmosphere it is possible to use both the breakdown mode and the pre-breakdown mode for generating and transmitting long-wave and microwave electromagnetic radiation. It is shown that in the pre-breakdown mode of aerosol ionization, anomalous scattering on plasma particle halos may occur due to the formation of plasmons, which increase the scattering intensity by 2-3 orders of magnitude.

Seasonal and Solar Cycle Dependence of Energy Transfer Rates in the Auroral E‐Region

AbstractWe report one of the first comprehensive ground‐based investigations of energy transfer rates in the E‐region ionosphere compared relative to geomagnetic activity, seasonal effects, and solar activity level using nearly continuously sampled data collected with the Poker Flat Incoherent Scatter Radar (PFISR) between 2010 and 2019. We quantified the integrated electromagnetic (EM) energy transfer rate and the integrated Joule heating rate in the E‐region between 90 and 130 km, which includes the contribution from the neutral winds. We find that (a) the median Joule heating rate and EM energy transfer rate in the evening sector are larger in the winter versus the summer and have similar magnitudes in the spring and fall for the same solar activity and geomagnetic conditions. (b) The seasonal dependence of the energy transfer rates is closely associated with the seasonal variations of the electric fields. Our analysis shows that the larger EM energy transfer and Joule heating rates in disturbed conditions in the winter versus the summer are associated with the combined effects of both the electric field and Pedersen conductance with the electric field playing a dominant role. Given that the Pedersen conductance in the evening sector is closely related to the particle precipitation and field aligned currents in the auroral region, this study provides complementary ionospheric evidence of the winter‐summer asymmetry of the intensity and density of field‐aligned currents (e.g., Ohtani et al., 2009, https://doi.org/10.1029/2009ja014115). (c) The geomagnetic activity level has the most significant impact on the magnitude of the energy transfer rates, followed by seasonal variations, and last the solar activity level.

An Investigation of Auroral E Region Energy Exchange Using Poker Flat Incoherent Scatter Radar Observations During Fall Equinox Conditions

AbstractWe present new results using data collected by the Poker Flat Incoherent Scatter Radar (PFISR) of energy transfer rates, which include the effects from neutral winds in the high latitude E‐region ionosphere‐thermosphere (IT) during Fall 2015. The purpose of our investigation is to understand the magnetic local time (MLT) dependence of the peak energy transfer, which occurs asymmetrically in the morning‐evening (dawn‐dusk) MLT sector. The statistical characteristics of both altitude‐resolved and altitude‐integrated energy transfer rates in the auroral E region local to PFISR during different geomagnetic conditions are quantified. Our analysis shows that the geomagnetic activity level has large impacts on the energy transfer rates. In contrast with previous investigations, we find both the altitude integrated electromagnetic (EM) energy transfer rate and Joule heating rate are larger in the evening sector than in the morning sector during all geomagnetic activity conditions. We also observe a non‐negligible negative EM energy transfer rates below 110 km in the morning sector during active conditions, which is associated with neutral winds during this MLT interval. The statistical results show that the neutral winds tend to increase the Joule heating rate in a narrow altitude range in the morning sector and impact a broader region with respect to altitude and time in the evening sector in the E region under moderate and active conditions. We find that during quiet conditions that the neutral winds have a significant contribution to the Joule heating and contribute up to 75% of the Joule heating. However, during active conditions the enhanced electric fields are a dominant driver of Joule heating, while the neutral wind effects can reduce the Joule heating rates by 25% or more relative to the passive heating rates.

Asymmetric coupling coefficients induced amplified spontaneous emission in planar coupled waveguides

We demonstrate the role of coupling coefficients in asymmetric coupled waveguides towards delivering a low threshold amplified spontaneous emission (ASE). A theoretical investigation in four different coupled waveguides possessing varying order of symmetry that arises from the bounding media refractive indices shows that the coupling coefficient carries the asymmetry in accordance with the nature of symmetry of the investigating structure. That is, a symmetric coupled waveguide is characterized with identical and asymmetric coupled waveguides, with, unlike coupling coefficients. The effect of unequal coefficients designating the electromagnetic energy transfer from one waveguide to the other and vice versa are experimentally demonstrated on the ASE of the acceptor (Rhodamine 640) by flipping the positions of the donor [[2-[2-[4-(dimethylamino) phenyl] ethenyl]-6-methyl-4H-pyran-4-ylidene]-propanedinitrile (DCM) and acceptor molecules that exist in the opposite waveguides of an asymmetric coupled waveguide. We also correlate the value of the coupling coefficient with the observed threshold of the acceptor ASE towards the optimization of a coupled waveguide as an efficient optical amplifier.

Ultracompact Energy Transfer in Anapole-based Metachains.

Realization of electromagnetic energy confinement beyond the diffraction limit is crucial for high-performance on-chip devices. Herein we construct an array of nonradiative anapoles that originate from the destructive far-field interference of electric and toroidal dipole modes to achieve ultracompact and high-efficiency electromagnetic energy transfer without the coupler. We experimentally investigate the proposed metachain at mid-infrared frequencies and give the first near-field experimental evidence of anapole-based energy transfer, in which the spatial profile of the anapole mode is also unambiguously identified on the nanoscale. We further demonstrate that the metachain is intrinsically lossless and scalable at infrared wavelengths, realizing a 90° bending loss down to 0.32 dB at the optical communication wavelength. The present scheme bridges the gap between the energy confinement and the transfer of anapoles and opens a new gate for more compactly integrated photonic and energy devices, which can operate in a broad spectral range.

Statistical Survey of Collisionless Dissipation in the Terrestrial Magnetosheath

AbstractKinetic dissipation of turbulence is an important physical process occurring in collisionless plasmas. Using in‐situ data from the Magnetospheric Multiscale (MMS) Mission, we investigate the statistical distribution of kinetic dissipation in the terrestrial magnetosheath. We make use of an analysis of the Vlasov–Maxwell equations that provides a general description of transfer of internal energy, fluid‐flow energy, and electromagnetic energy in collisionless plasma, including both spatial transport and conversion between forms. In particular, we focus on the channels that separately produce proton and electron internal energies. Applying those results to MMS burst‐mode data obtained in the weakly collisional, turbulent magnetosheath plasma, it is possible to quantify contributions to dissipation from the compressive pressure‐dilatation channel, and from the incompressive pressure‐strain channel, for both plasma species. We also employ a simple spatial filtering approach as a first step to quantifying plasma heating at large and small scales. The analysis is carried out for 50 selected turbulent data intervals, and statistical distributions of the results are presented.