High-power Electromagnetic Field Research Articles

STUDY OF TRANSMISSION PARAMETERS AND MUTUAL INFLUENCE OF SIGNAL-BLOCKING CABLES WITH CURRENT-CONDUCTIVE CORES WITH INCREASED FLEXIBILITY

In recent years, the intensive development of passenger high-speed and freight heavy traffic сreated increased demands on the organization and provision of transportation, the development and implementation of new, primarily infocommunication technical means and technologies of the track complex. Russian Railways is implementing a number of significant infrastructure projects, several of which have obtained federal status. One of the main directions of of the railway network development is its widespread electrification, development and implementation of innovative infocommunication technical means and technologies for the railway infrastructure of the track complex. During the operation of electrified railways, generted high-power electromagnetic fields posing a serious problem related to electromagnetic compatibility of equipment. Therefore, requirements are placed on the quality of cables of signaling, centralization and blocking systems of railways are rather high. The article observes the transmission parameters and mutual influence of signal-blocking cables and current-carrying cores with high-flexibility.

An Experimental Investigation of the Heating Effects of 900 MHz Cell Phones on Brain Phantom in terms of Public Health

Investigation of the effect of mobile phones in the terms of human health is getting more important position in the literature due to the increased public concern. An experimentally efficient setup was established to determine the thermal effects caused by mobile phones in the brain. Temperature increasing in the brain during exposing the mobile phone is investigated in a brain equivalent liquid (phantom). In the proposed experimental setup, mobile phone which operates at 900 MHz frequency was represented with a radio frequency (RF) generator which has a half-dipole antenna and this system is applied to phantom at different distances. Thermal absorptions were observed by sensitive temperature sensors at different depths. Effects of electromagnetic fields are usually investigated via numerical methods and simulations in the literature. In this study, an experimental analysis of temperature distributions in the human brain phantom exposed to mobile phone radiation at 900 MHz is presented. All experiments were conducted in an anechoic chamber where temperature variation is about 0.009oC. Additionally, high-power electromagnetic fields are used such as 4W, 7W and 10W which are not implemented till now in the literature for GSM frequencies. Different temperature distribution in the phantoms was observed by systematically changed distances and power options. In this last case, maximum temperature elevation was observed as 0.403oC. While the temperature elevation increases with increasing applied power, removing the mobile phone from the phantom reduce the temperature elevation in the phantom.

Denaturation of the SARS-CoV-2 spike protein under non-thermal microwave radiation

SARS-CoV-2, the virus that causes COVID-19, is still a widespread threat to society. The spike protein of this virus facilitates viral entry into the host cell. Here, the denaturation of the S1 subunit of this spike protein by 2.45 GHz electromagnetic radiation was studied quantitatively. The study only pertains to the pure electromagnetic effects by eliminating the bulk heating effect of the microwave radiation in an innovative setup that is capable of controlling the temperature of the sample at any desired intensity of the electromagnetic field. This study was performed at the internal human body temperature, 37 °C, for a relatively short amount of time under a high-power electromagnetic field. The results showed that irradiating the protein with a 700 W, 2.45 GHz electromagnetic field for 2 min can denature the protein to around 95%. In comparison, this is comparable to thermal denaturation at 75 °C for 40 min. Electromagnetic denaturation of the proteins of the virus may open doors to potential therapeutic or sanitation applications.

Maximizing Radiated High-Power Electromagnetic Threat to Transmission Line System Under the Constraints of Bounded Bandwidth and Amplitude

This article aims at identifying the worst-case waveform of a radiated high-power electromagnetic (HPEM) for maximizing threats to the victim electric system. In contrast to the previous analysis where constraint on energy-density of the HPEM field is imposed, the proposed analysis considers an upper bound constraint for the amplitude of the electrical waveform, which appears to be a more concerned restriction for practical radiation system. In this connection, evolutionary algorithms, i.e., genetic algorithm, stud-genetic algorithm (StudGA), and particle swarm optimization, are resorted to for solving the problem. In particular, it is found that StudGA outperforms the other two approaches for solving the proposed problem. The results demonstrate an optimized wideband HPEM is only marginally more threatening to the victim system than an attentively tuned continuous-wave/narrowband interference, and it is a fairly good compromise to apply these fields for the worst-case immunity assessment, especially when the difficulty in generating wideband HPEM of complex waveform details is considered.

Simulation analysis of passive intermodulation mechanism of transceiver link

The electromagnetic environment of modern battle-field is complex and the interference intensity is large. Under the influence of high field electromagnetic interference, airborne RF equipment becomes the short board of electromagnetic environment adaptability of aircraft. Because of the wide application of military aircraft platform, the external climate and electromagnetic environment are very complex. At the same time, the interior space of military aircraft is narrow and there are many high-power frequency equipment, which lead to a very complex electromagnetic environment inside the aircraft. Under the irradiation of high-power electromagnetic field, passive intermodulation products will be produced in the receiving antenna, transmission line, connector, filter and even some non-metallic conductive materials and aircraft skin under certain conditions. The passive intermodulation products will cause great interference to the airborne high sensitivity receiving equipment, and even burn the receiving equipment in extreme conditions. Therefore, the research on passive intermodulation products of airborne equipment is very urgent.

철근 콘크리트 구조 내 포설 케이블의 HEMP 결합 근사 해석 방법

High-power electromagnetic fields, which are used as one of the core weapon systems in electronic warfare, can cause malfunctions in communication and power systems. Therefore, it is necessary to study their effects on civil and military facilities. In this paper, an approximated method for analyzing the voltage induced in a cable, placed inside a building, by HEMP was proposed. To calculate the electric field penetrating into the building, an equivalent medium for a multilayer reinforced concrete structure was implemented, and its transmission and reflection characteristics were obtained. The penetration level of the E1 pulse and the load voltage of the cable for unit voltage sources at each load were calculated. Subsequently, the coupling voltage was obtained and verified.

Moving flux quanta cool superconductors by a microwave breath

Almost any use of a superconductor implies a non-equilibrium state. Remarkably, while a sufficiently high-power electromagnetic field of GHz frequency can stimulate superconductivity, fast motion of magnetic flux quanta (Abrikosov vortices) can trigger an instability abruptly quenching the superconducting state. Here, we show that such dynamical quenching of the vortex state in Nb thin films can be advanced or delayed by tuning the power and frequency of the microwave ac stimulus added to a dc bias current. The experimental findings are supported by time-dependent Ginzburg-Landau simulations and they can be explained, qualitatively, based on a model of “breathing mobile hot spots”, implying a competition of heating and cooling of quasiparticles along the trajectories of moving fluxons whose core sizes vary in time. In addition, we demonstrate universality of the stimulation effect on the thermodynamic and transport properties of type II superconductors.

Three-Dimensional Numerical Model of the Interaction of Laser Radiation with the Plasma of a Plastic Target

The effect of generation of high-energy protons and carbon nuclei is identified in the threedimensional model of the interaction of a high-power electromagnetic field with plasma with supercritical density by the numerical solution of the Vlasov–Maxwell equations. The effect was first discovered in 2000 in experiments carried out at the Lawrence Livermore National Laboratory (United States) using the petawatt laser.

Dissipative variational analysis for bounded dark solitons of electromagnetically induced transparency

Electromagnetically-controlled precision is one of novel topics in the electromagnetics. To realize the precision controlling of the electromagnetically complicated phenomenon, the systematic characteristics of medium environment needs considering. Based on the cancellation of interference caused by quantum coherence in the systematic environment of material, the electromagnetically-induced transparency (EIT) can be achieved. For this nonlinear phenomenon, due to the advancement of quantum spot and well, the controlling of the bounded sate of quantum in various dimensions of semiconductor can be operated. So the solid system presents a clear superiority of controlling EIT. High power electromagnetic field excites the dynamic characteristics in solid material, which is the result of systematic reaction between field and material. Under the excitation of electromagnetic pulse, because of quantum coherence, the dual-well semiconductor has the ability to induce the dark state of solitons. In the study of the complicated system of multiple physical fields, two aspects need investigating further. Firstly, in the induction process of electromagnetic filed and solid material, the features of high dispersion and nonlinear reaction appear increasingly. Thus, due to the environmental restriction on dispersion and nonlinear reaction, electromagnetic dissipation is a crucial point, which needs considering in the electromagnetically-controlled precision of the EIT. Secondly, compared with the formation of soliton, the coupling reaction of solitons under co-sate is much complicated. The relation among these factors is necessary to be investigated in the formulation of soliton excitation. Therefore, a dual-well semiconductor is employed as solid environment to analyze the dynamic characteristics of dark solitons in the EIT. In order to achieve the controlling of precision and regulating of the effect, the environmental features of solid materials ought to be systematically considered. Accordingly, the variational method is utilized, through which the bounded action of dissipation and nonlinear coherence is effectively studied for the dark solitons under co-sate, and under the condition of exciting dark soliton in the system of EIT. Using the density matrix and electric polarization, the spectrum of dynamic transmission deviation of EIT is calculated in the solid environment. With the assistance of relevant action principle, the bounded relation of dark solitons under co-state is practically investigated in the dissipative environment of solid system. In addition, the space-time trajectory is analyzed in the applicable region of characteristic equations of dark solution. The deduced result indicates that the systematical balance between dissipative weakening and coherent coupling supports the valuable approach to controlling the space-time evolution of dark solitons in precision. The results also show that the special effect has the potential applications in electromagnetically-controlled precision in the quantum information, ray sensor, controllable environment, etc.

The process for making low density LAS surfactant detergent agglomerates using microwave heating

The internal structure of detergent surfactant agglomerates is modified using electromagnetic heating to produce a lower bulk density final product. The agglomerates are heated in a 1.8KW microwave waveguide heating applicator operating at license-free ISM frequency band of 2450MHz. The density of the agglomerates reduces significantly when exposed to high power electromagnetic fields. The effect of number of process variables such as input power initial moisture content over bulk density of detergent particles is studied. Three different input power levels (500W, 1KW & 1.6KW) are applied to the agglomerates and it has been observed that higher input powers raise the temperature of the agglomerates very quickly, hence reducing the required residence time of the sample. Agglomerates exposed to the highest input power (1.6KW) had the lowest bulk density. The temperature profile and residence time of the agglomerates during heating was continuously recorded. Experimental results obtained in the lab-based process will be used to design a full scale continuous mode applicator.

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

Субтераваттные фемтосекундные импульсы среднего инфракрасного диапазона: новые эффекты пространственно-временной динамики мощных электромагнитных полей

On an anomaly of the thermal filamentation mechanism in a high-power electromagnetic field of a strongly collisional plasma

It is shown that, under the conditions when the mean free path of electrons in a fully ionized plasma is small compared with the London plasma length, the thermal mechanism of inverse bremsstrahlung absorption and electronic conductivity has a stabilizing action on filamentation instability of high-power electromagnetic radiation, in contrast to the known case of comparatively low-intensity radiation. This new nonlinear property of a plasma is shown to be determined by a decrease in the effectiveness of plasma heating in a heating pumping field with increasing the intensity of radiation if electron oscillations have above-thermal rates.

強光子場下におけるクラスターのイオン化のシミュレーション

The ionization of argon clusters by an intense, femtosecond laser pulse has been studied using classical particle dynamics simulations. The time evolution of electrons and ions in a high power electro-magnetic field is described. These simulations show that it takes only a few tens of femtoseconds until many electrons leave from the clusters.

Interface enhanced Raman scattering of thin SiC layers at the graphite/silicon boundary

Carbon atoms were deposited on Si(100) substrates by plasma glow discharge of a gas mixture of H 2 + CH 4 in a high power electromagnetic field. A thin SiC compound of about 20 Å thick is formed at the interface of the Si substrate and the deposited graphite. This thin layer clearly exhibits the Raman bands of the optical phonon modes of the wurtzite SiC crystal at almost the same vibrational frequencies as the bulk, which indicates that the Raman scattering is enhanced by a factor of 170 at the interface. This is a new type of enhanced Raman scattering. The enhancement mechanism is tentatively concluded to be due to an enhancement of the spatial derivative of the polarizability in a strong electric field induced at the boundaries.

Theory of the heating of dielectrics by high-power electromagnetic fields

The self-consistent problem of determining the interacting electromagnetic and temperature fields in a semi-infinite medium when a plane electromagnetic wave is incident normally on it is solved in the adiabatic approximation. The parameters of the medium are arbitrary functions of the temperature, thus enabling the WKB method to be used.