Source Of Microwave Radiation Research Articles

Annular Beam Driven Metamaterial Backward Wave Oscillator

Metamaterials (MTMs) are synthetic materials designed to have characteristics that "may not be readily available in nature," such as negative permittivity, reversed Doppler Effect, reversed Cherenkov Effect, and negative Refractive Index. These characteristics have motivated researchers to analyze and investigate the use of MTMs for modelling high-power microwave (HPM) radiation sources. One of the most potential HPM sources is an annular beam-driven Backward-Wave Oscillator (BWO) based on the Cerenkov mechanism. The devices that use the Cerenkov mechanism are preferred due to their larger bandwidth. Its high output power and repetition operations make it a promising source. In this paper, an annular beam-loaded metamaterial BWO is simulated in order to investigate and comment on the possibility of metamaterial or metamaterial-inspired structures replacing the slow-wave structures (SWSs) in vacuum tube devices. Performance parameters of several BWO configurations loaded with different metamaterial-inspired conductor rings are compared to rippled SWS-based BWOs. The results suggest that fewer metamaterial rings with solid cross-section (CS) inside the BWO lead to a closer match in generated output power and frequency with the output power generated using a rippled SWS.

Properties of Indium Antimonide Nanocrystals as Nanoelectronic Elements

By measurements on single nanocrystals of indium antimonide in the interelectrode nanogap of a scanning probe microscope, current-voltage characteristics with quasiperiodic current pulsations, are explained in the model of Bloch oscillations in a perfect nanocrystal, and individual sharp peaks - conductivity resonances, explained in the model of quantum-size limitation of the wave process of electron transport in a deep potential hole. The mutual influence of radiation from two statistical ensembles of nanocrystals from the same batch was experimentally studied and established. It is assumed that this radiation is entangled photons. It is proposed to use nanocrystals in nanoelectronics as a single-electron memristor, a single-photon bolometer, and a source of microwave radiation.

Bright ultraviolet knots as possible sources of coherent microwave radiation

A distinctive feature of the September 6, 2012 event was that sources of narrow-band (2–4 GHz) sub-second pulses (SSP) were observed in small areas of flare loops with so-called bright ultraviolet knots with high plasma density up to 1011 10¹¹ cm⁻³. Time profiles of hard X-rays of the flare, although similar to microwave light curves, do not have structures corresponding to SSP. Analysis of microwave, X-ray, and ultraviolet data has shown that the observable pulses of microwave radiation with a narrow spectral band are coherent in nature and are generated by electrons with energies of several tens of kiloelectronvolt in bright knots at a double plasma frequency. The results of the observations suggest that the appearance of bright knots is associated with local processes of energy release due to interaction of flare loops.

Role of Cx43 in iPSC-CM Damage Induced by Microwave Radiation.

The heart is one of the major organs affected by microwave radiation, and these effects have been extensively studied. Previous studies have shown that microwave-radiation-induced heart injury might be related to the abnormal expression and distribution of Cx43. In order to make the research model closer to humans, we used iPSC-CMs as the cell injury model to investigate the biological effect and mechanism of iPSC-CM injury after microwave radiation. To model the damage, iPSC-CMs were separated into four groups and exposed to single or composite S-band (2.856 GHz) and X-band (9.375 GHz) microwave radiation sources with an average power density of 30 mW/cm2. After that, FCM was used to detect cell activity, and ELISA was used to detect the contents of myocardial enzymes and injury markers in the culture medium, and it was discovered that cell activity decreased and the contents increased after radiation. TEM and SEM showed that the ultrastructure of the cell membrane, mitochondria, and ID was damaged. Mitochondrial function was aberrant, and glycolytic capacity decreased after exposure. The electrical conduction function of iPSC-CM was abnormal; the conduction velocity was decreased, and the pulsation amplitude was reduced. Wb, qRT-PCR, and IF detections showed that the expression of Cx43 was decreased and the distribution of Cx43 at the gap junction was disordered. Single or composite exposure to S- and X-band microwave radiation caused damage to the structure and function of iPSC-CMs, primarily affecting the cell membrane, mitochondria, and ID. The composite exposure group was more severely harmed than the single exposure group. These abnormalities in structure and function were related to the decreased expression and disordered distribution of Cx43.

Electrodeless Source of UV Radiation Based on Low-Pressure Microwave Mercury Discharge

An experimental study of the radiation, temperature, and electrical parameters of an electrodeless UV source with two mercury-argon (рAr ≈ 7.5∙10–1 Torr, рHg ≈ 0.01–0.06 Torr) quartz lamps based on a coaxial microwave discharge has been carried out. The design of a germicidal (185–280) nm spectral range UV irradiator with its disinfection of the air-aqueous environment and its main parameters are proposed. A magnetron for household microwave ovens (2.45 GHz, 1 kW) was used as a source of microwave radiation. The maximum UV radiation flux (87.2 W) was achieved at the power consumed by the magnetron from the mains Pel = 687 W. It has been established that with water cooled burners (twater = 15 °C), the power range of Pel, at which the maximum energy efficiency of the lamp and irradiator is achieved, in the indicated wavelength range is wider (up to 13 %) in range (490–720) W, than with air (tair = 23 °C) cooling with power range (490–550) W.

Studying the Radiative and Spectral Characteristics of UV Radiation Sources Based on Coaxial Microwave Discharges in Low-pressure Mercury Vapor

The radiative and spectral characteristics of the authors’ proprietary model of an electrodeless optical radiation source with two mercury-argon (p(Ar) » 0.75 Torr, p(Hg) » 0.01 – 0.06 Torr) lamps based on a coaxial microwave discharge are experimentally studied. An industrial magnetron (f = 2.45 GHz) was used as a microwave radiation source. The experimental results have shown that about 53% of the microwave power is converted into UV radiation, which is in good agreement with the results of electron temperature measurements in the low pressure region, p(Hg) < 0.08 Torr.

Design and Cold Test on the Slow Wave Structure of a Wide-Voltage Tuned and High-Power Extended Interaction Oscillator in W-Band

In order to obtain continuously tunable high-power output in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$</tex-math> </inline-formula> -band, the slow wave structure (SWS) of a wide tuned and high-power extended interaction oscillator (EIO) was designed and studied in this article. The structure of the designed circuit was described while the operating characteristics were analyzed. The SWS not only has high power output capability but also operates near standing waves with a wide electronic tuning range. The EIO can operate over an electronic tuning range of 1.36 GHz in ensuring the output power no less than 1.6 kW, where the maximum output power over 4.5 kW is obtained at 43.8 kV and 2 A from the simulation. The wide tuning range and the high output power are achieved by increasing the number of periods with offsetting the coupling hole and beam voltage and current in order to match with high impedance modes near to 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $</tex-math> </inline-formula> . The SWS was processed and cold tested, and its S-parameter distribution was close to the simulation result. The designed 94-GHz extended interaction oscillation can be effectively used to generate wide tuned and high-power microwave radiation sources in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$</tex-math> </inline-formula> -band.

A wideband high-power microwave radiation source based on gyromagnetic nonlinear transmission line and Vlasov antenna.

The gyromagnetic nonlinear transmission line (GNLTL) is a special kind of coaxial transmission line partially loaded with the ferrite material. A GNLTL system can modulate the input high-power pulses into wideband high-power microwaves without relying on the electron beam and confining magnetic field. The unique working mechanism gives the GNLTL system the potential to be a small portable wideband high-power microwave radiation source. In this study, a wideband high-power microwave radiation source based on a GNLTL system is designed and constructed. In order to effectively radiate the wideband microwaves into the air, a high-power wideband Vlasov antenna and a special absorption high-pass filter are developed. The designs of key subsystems and high-power radiation experiments have been introduced and discussed in detail. In the test experiments, a radiated pulse with a peak electric field strength of 23 kV/m was measured at 20m away from the transmitting antenna and the effective potential of radiation is 460 kV/m. The pulse width of the radiation pulse is about 4ns, the center frequency is about 2.25GHz, and the highest repetition rate can reach 25Hz.

Numerical study of microwave impact on gas hydrate plugs in a pipeline

Purpose. Development of a technique for the numerical study on the decomposition of gas hydrate plugs in deep-water pipelines under microwave radiation using a coaxial source. Theoretical efficiency evaluation of using such an impact to unblock the pipelines. Methodology. Mathematical modeling and computational experiment. Findings. An original mathematical model is proposed to describe heat transfer processes during the decomposition of gas hydrates in a pipeline under the action of heat sources distributed over the volume. The non-stationary problem of heat transfer was considered in a one-dimensional formulation. An algorithm for numerical computation is proposed. A mathematical expression is obtained for distributed heat sources generated by the microwave radiation from a coaxially located SHF antenna. Parametric numerical studies on temperature fields and decomposition dynamics of a gas hydrate plug are performed for specified parameters of pipe and microwave radiation power. The boundaries of the decomposition area and the dynamics of change in this area are determined. The decomposition time of a gas hydrate plug with a diameter of 0.3 m was determined using a 300 W microwave source. The complete decomposition took approximately 40 hours. Originality. The task of thermal decomposition of a cylindrical gas hydrate plug in a pipeline due to microwave heating using a coaxial microwave power source has been considered for the first time. The process is viewed as a sequence of several stages: heating, heating and decomposition, decomposition after complete heating of the gas hydrate layer. To model the volumetric dissociation of gas hydrate, it was proposed to use special functions that characterize the amount of decomposed gas hydrate. The introduction of such functions makes it possible to construct an efficient computational algorithm taking into account the action of volumetric sources in the decomposition area. The known models mainly consider only surface thermal effect or microwave impact on gas hydrate in porous mediums. The presented model allows describing the decomposition during volumetric heating of a solid hydrate adequately. Practical value. Blocking plugs may occur due to hydrate formation when transporting gas through deep-water pipelines or through pipelines in cold environments. The elimination of such complications is a complex technical task. In particular, a special source of microwave radiation, which was proposed by the authors in previous works, can be used to unblock the pipeline. The device that makes the microwave radiation is located along the pipe axis. The results of this work allow us to evaluate the effectiveness of the microwave method for eliminating the gas hydrate plug. The mathematical model and computational method can be used in the development of appropriate technologies using a coaxial microwave heating source.

A Tunable Dual-Frequency Microwave Radiation Source Based on a Gyroklystron in the Beat Mode with an Input Signal

A Tunable Dual-Frequency Microwave Radiation Source Based on a Gyroklystron in the Beat Mode with an Input Signal

On the Origin of Persistent Radio and X-ray Emission from Brown Dwarf TVLM 513-46546

We study the origin of unusually persistent microwave and X-ray radiation from the ultracool dwarf TVLM 513-46546. It is shown that the source of ≈1 keV X-ray emission is not the entire corona of the brown dwarf, but a population of several hundreds of coronal magnetic loops, with 10 MK plasma heated upon dissipation of the electric current generated by the photospheric convection. Unlike models, which assume a large-scale magnetic structure of the microwave source, our model suggests that the microwave radiation comes from hundreds of magnetic loops quasi-uniformly distributed over the dwarf’s surface. We propose a long-term operating mechanism of acceleration of electrons generating gyrosynchrotron radio emission caused by oscillations of electric current in the magnetic loops as an equivalent RLC circuit. The second population of magnetic loops—the sources of microwave radiation, is at the same time a source of softer (≈0.2 keV) X-ray emission.

Intensity correlation functions of microwave maser sources

Abstract Astrophysical sources of microwave radiation with extremely high spectral brightness are interpreted as masers. But by itself, the information about high brightness of radiation does not make it possible to establish whether the radiation is thermal or maser. This can be determined only on the basis of the analysis of high-order correlation functions. A possible measurement procedure for the second-order autocorrelation function (the bunching parameter) for these sources is proposed.

Basics of the Development of Microwave Intensification of Upstream on the Example of &lt;i&gt;Escherichia coli&lt;/i&gt;

Introduction. E. coli strains are the main microorganisms used for the production of a number of important biopharmaceutical products. There are no natural sources of microwave radiation on Earth, as it is absorbed by the upper atmosphere. No one doubts the importance of studying the biological effect of microwave radiation. The number of publications devoted to this problem is growing every year, and new ideas for the use of microwaves in drug production technology are emerging.Aim. Reveal the main effects of microwave irradiation and develop a technology for microwave intensification of E. coli culture growth.Materials and methods. This study presents the results of atomic force microscopy, refractometry, NMR relaxometry, turbidimetry, and lumimetry, demonstrating the possibility of microwave intensification of the cultivation process.Results and discussion. It was found that microwave irradiation leads to changes in the mobility of protons and the adsorption of water molecules on biopolymers and cells. These are the main links in the mechanism of "non-thermal" microwave action. A single microwave irradiation, depending on a number of parameters, can decrease or increase the growth of biomass. Studies of the bioluminescence of the E. coli strain with the lux-operon have shown that the optimal processing conditions do not negatively affect the luciferase production and metabolic activity of cells. Conclusion. The intensification procedure using microwave radiation can be considered a promising method and can provide new ideas for various applications in biotechnology.

Artificial radio lighting with sources of microwave dynamic chaos.

Application of dynamic chaos for the illumination of the surrounding space by artificial incoherent sources of microwave radiation with the purpose of its subsequent observation using special receiving equipment is considered. An incoherent broadband microwave radiation field is provided by "radio light lamps" based on dynamic chaos generators. The radio light is received with specially designed sensitive elements that combine the properties of an envelope detector in communication systems and a radiometer. It is shown that with the help of directional antennas connected to these sensitive elements, it is possible to create receivers with spatial resolution for visualizing a part of the surrounding space in artificial radio light. Radio light images of a room have been obtained. The possibility to detect changes associated with the emergence of new objects on these images is demonstrated.

Highly efficient and selective heterogeneous catalytic reduction of 2-nitroaniline by cerium oxide nanocatalyst under microwave irradiation

ABSTRACT Efficient nanocatalyst with incredible performance is highly demanding in a heterogeneous catalysis system. Herein, we report the facile fabrication of uniform and highly stable Cerium Oxide nanoparticles (CeO2 NPs), through chemical precipitation method using sodium hydroxide as reducing agent. The synthesized material is characterized through highly sophisticated techniques including UV-Visible, FT-IR, SEM, AFM, XRD, and Zeta Sizer- Potential to check the particle formation, surface morphology, topography, crystalline nature, size, and surface potential. The heterogeneous catalytic performance of CeO2 NPs has been accomplished for the reduction of 2-nitroaniline from the aqueous media. The CeO2 nanocatalyst displayed excellent reusability, while the reduction in several repetitive catalytic cycles against 2-nitroaniline under optimized conditions. The CeO2 nanocatalyst shows 99.12% efficiency within 60s reaction time under a greener source of microwave radiation.

Contrast‐enhanced ultrasound combined with augmented reality medical technology in the treatment of rabbit liver cancer with high‐energy focused knife

AbstractAugmented reality technology can enhance people's perception and interactive experience of real scenes due to its characteristics of fusion of virtual and real, and has become a popular technology in the field of computer science. This article mainly studies the application of contrast‐enhanced ultrasound combined with augmented reality medical technology in the treatment of rabbit liver cancer with high‐energy focused knife. Sixty healthy male New Zealand white rabbits were used in this study. Seldinger's method was used to superselective embolize the artery supplying tumor with the help of hepatic angiography, which can kill tumor cells to the greatest extent and reduce the damage to normal liver cells. At the same time, another assistant under the guidance of ultrasound inserted the temperature probe into the position 1 cm away from the microwave radiation source, and then started the microwave ablation (MWA) treatment. High intensity focused ultrasound (HIFU) treatment is carried out under general anesthesia, the breathing rhythm of patients is controlled by ventilator, the proper position is set before operation, the real‐time monitoring is carried out by ultrasound monitoring mediated by medium water, and the HIFU three‐dimensional scanning treatment system is used to accurately cover all tumor treatment areas from point to line and from line to surface, so as to kill tumor cells to the greatest extent. The data of each group were processed by SPSS17.0 statistical software, and the measurement data were expressed as mean ± SD. ANOVA analysis of variance was used to compare the differences among the groups, and LSD method was used to make pairwise comparison within the group. p &lt; 0.05 was considered as having statistical difference. The growth rate of tumor was 56.1% and 60.3%, respectively. Contrast‐enhanced ultrasound combined with augmented reality medical technology provides a new way for the treatment of rabbit liver cancer.

The foam concrete temperature measuring during its microwave heat treatment

The actual problem of accelerating and reducing the energy costs of the foam concrete slabs heat treatment technological process is considered. It is shown that to solve this problem, it is advisable to use the microwave radiation energy as a heat source. The main advantages of the microwave method of foam concrete slabs heat treatment in comparison with traditional methods are considered. The design of a microwave installation for the foam concrete slabs heat treatment has been developed. The installed microwave radiation sources have energy outputs in the form of a rectangular waveguide openings, which are used as radiating antennas. Huygens-Kirchhoff method was used to calculate the temperature distribution on the foam concrete slab surface; the method of loaded long lines was used to calculate the temperature distribution over the foam concrete slab thickness. A method for measuring the foam concrete slab temperature distribution is proposed. The results of theoretical and experimental temperature distribution studies on the surface and the cross-section of foam concrete slab with a width of 1500 mm, a height of 1000 mm and a thickness of 200 mm, a density of 1000 kg/m3 on the electromagnetic fields oscillation frequency of 2450 MHz are shown. The obtained experimental results showed a high efficiency of using microwave radiation for the foam concrete slabs heat treatment technological processes. Microwave technologies can be used for heat treatment of products made of concrete, reinforced concrete and polymer composite materials.

Features of decomposition of gas hydrate when exposed to microwave radiation

The article summarizes the results of numerical monitoring of the decomposition of gas hydrates in a high frequency electromagnetic field. The results of the numerical experience of the decay process are summarized. In addition, the distribution of temperature and pressure is presented, but in addition, the relationship with the coefficient of permeability. In this article, the features of decomposition of methane hydrate under the influence of microwave radiation are studied. It is shown that the values of temperature and pressure in the reservoir decrease with time and distance from the source of microwave radiation. The dependence of the expansion front coordinate on time for different values of the permeability coefficient is presented.

Experimental and computational study on the microwave energy based regeneration in diesel particulate filter for exhaust emission control

The uncontrolled combustion and early-life failure of the Diesel Particulate Filter substrate during fuel-based regeneration has raised the requirement for an alternate regeneration technique. The Latest emission norms have made it a mandatory requirement to retrofit the Diesel Particulate Filtration system in the exhaust line of CI engines to bring down the Particulate emissions. In this work, a novel technique through application of microwave energy has been developed for active regeneration of soot particles accumulated in the filter channel. Modelling of soot layer formation and microwave regeneration were carried out using CFD software (COMSOL MULTIPHYSICS). Performance and emission characteristics of multi-cylinder CI engine were evaluated after retrofitting the developed after-treatment system comprising of Diesel Oxidation Catalysis (DOC) and microwave regeneration based Diesel Particulate Filtration (DPF) systems. Soot accumulation rate and regeneration rate were experimentally investigated at different engine loads and magnetron (microwave radiation source) power levels. The experimental results showed that the developed after-treatment system has an average filtration efficiency of 90% for brake specific particle number emissions and 55% for hydrocarbon emissions. The regeneration rate was observed to be a maximum of 0.21 g/min at 50% power levels owing to the non-linear behaviour of magnetron. Energy consumption pattern of other regeneration techniques has been compared with the developed microwave regeneration system. The effect of soot accumulation and regeneration on the morphology, microstructure, chemical composition and particle size of DPF substrate were examined using characterization studies like Scanning Electron Microscopy – Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infra-Red spectroscopy (FTIR), Particle Size Analysis (PSA) and microscopic imaging.

Length Dependence on Broadband Microwave Emission From Laser-Generated Plasmas

A high-power ultrashort laser pulse focused in air generates a plasma that radiates broadband electromagnetic waves. The transient current source responsible for the radiation remains an open area of study. To better understand how the laser drives currents in the plasma, we investigate the dependence of radiation at microwave frequencies on the length of the plasma column. Radiation patterns of the microwaves are consistent with currents that flow longitudinally (in the direction of laser propagation). We measure the angular dependence of the microwave frequency spectrum to determine the microwave radiation source characteristics. We also model the plasma evolution using a PIC code to provide initial conditions for a finite-difference time domain (FDTD) simulation of the plasma currents responsible for the microwaves. The experiments and simulations show that the plasma length determines the shape of the radiation pattern, and also weakly influences the microwave frequency content. Our research demonstrates that the radiation mechanism is coupled with variation in the current along the entire plasma length.