Electromagnetic Heating Research Articles

The analysis of electromagnetic maxwell nanofluid flow over an axisymmetric cylindrical surface using artificial neural networks for active and passive control

ABSTRACT This work presents a novel approach to active and passive control of fluid flow on a stretching cylinder, considering the collective effects of electromagnetism, and chemical reactivity. The Maxwell fluid flow over the stretched surface of a cylinder is responsible for the improvement in heat transfer. The proposed methodology leverages the power of Artificial Neural Networks (ANN) to effectively manipulate and optimize fluid flow behavior in this complex system. By integrating ANN into the control strategy, we achieve enhanced propulsion system design and optimization capabilities, enabling improved performance around cylinders. Additionally, insights into the interconnection of electromagnetic effects and heat sources provide valuable implications for thermal management systems, where understanding and controlling fluid flow behavior are essential for efficient heat transfer. The design approach for addressing different aspects of the fluid problem consists of a sequence of operations, which encompass training, testing, and validation using a reference dataset. Furthermore, visual representations are employed to portray the flow model parameters concerning momentum, energy, and concentration profiles, effectively illustrating the results of the investigation, all of which are closely aligned with each other on average 10−8.

A novel flexible catheter with integrated magnetic variable stiffness and actuation

Flexible instruments offer significant advantages over traditional rigid instruments in ophthalmic surgery, because they can achieve larger working space and minimize the risk of damage caused by contact with eye tissues. However, it also needs to be rigid to achieve sufficient surgical operation force and stability. In this study, we propose a novel flexible catheter with integrated magnetic variable stiffness and actuation, based on electromagnetic induction heating and phase change alloy. The experimental results show that the catheter can switch from rigid to flexible modes in 11 s, and it takes 10 s to switch from flexible to rigid modes in room temperature. The bending stiffness of the catheter is 930.23°N mm2 in rigid mode and 74.42°N mm2 in flexible mode. In addition, the catheter can limit the axial force below 0.08°N in flexible mode, while withstand a force greater than 1.08°N in rigid mode. The catheter is equipped with a magnetic tip that can safely navigate in flexible mode with maximum bending angle of 106 degrees. The phantom experimental results demonstrated the potential clinical value of the proposed catheter.

Solar Induction Cooker

There is no available power grid in the rural areas in many countries in South America, Asia and Africa. st places, Fossil fuel or wood is used for cooking. Besides environmental issues, fossil fuel and wood from trees are being depleted at a fast rate. Solar power is available everywhere during day time in all countries. This solar induction cooker uses a solar panel, which gives a variable dc, to charge a battery. The dc from the battery is converted to a high frequency ac voltage by an inverter circuit. This inverter circuit supplies alternating current to a coil on a magnetic core where alternating flux is produced. This alternating flux produces in the magnetic core Eddy current and Hysteresis ‘losses’ inside the magnetic core. In this application, these losses will produce useful heat. A cooking pot placed on the magnetic core will be used for cooking.

Applying Remote Sensing, Sensors, and Computational Techniques to Sustainable Agriculture: From Grain Production to Post-Harvest

In recent years, agricultural remote sensing technology has made great progress. The availability of sensors capable of detecting electromagnetic energy and/or heat emitted by targets improves the pre-harvest process and therefore becomes an indispensable tool in the post-harvest phase. Therefore, we outline how remote sensing tools can support a range of agricultural processes from field to storage through crop yield estimation, grain quality monitoring, storage unit identification and characterization, and production process planning. The use of sensors in the field and post-harvest processes allows for accurate real-time monitoring of operations and grain quality, enabling decision-making supported by computer tools such as the Internet of Things (IoT) and artificial intelligence algorithms. This way, grain producers can get ahead, track and reduce losses, and maintain grain quality from field to consumer.

Defect-steering the prominent thermal conduction, microwave absorption, and electrical insulation of porous g-C3N4 nanofibers

The escalating levels of electromagnetic (EM) pollution and heat accumulation in electronics accentuate the pressing need for developing materials with prominent heat-conducting, microwave-absorbing, and electrical insulating properties. Herein, we pioneered the utilization of porous g-C3N4 nanofibers as a multifunctional filler, which were synthesized by a nitric acid precipitation-annealing route. The annealing temperatures (Ta) was controlled to tune the defect-dependent performance of porous g-C3N4 nanofibers. With Ta elevating from 450 °C to 600 °C, the conductivity (σ) and thermal conductivity (TC) steadily increase and peak at 600 °C (TC = 2.149 W/(m⋅K); σ = 0.00475 S/m). These variations could result from reduced defects, which favor not only the generation and migration of electrons but also the mitigation of phonon-defect scattering. Meanwhile, the low defects can improve their permittivity and attenuation capabilities, attaining optimal microwave absorption properties with a larger absorptive bandwidth (6.4 GHz), higher absorption (−27.56 dB), and a thinner film (2.3 mm). Furthermore, the 1D structure of the porous g-C3N4 nanofibers offers a 3D interconnected continuous path for electron/phonon transfer. These properties distinguish the porous g-C3N4 nanofibers from the majority of other previously reported materials. This study also brings out a straightforward and efficient method for fabricating advanced multifunctional fillers in electronic packaging materials.

Fast-ion orbit origin of neutron emission spectroscopy measurements in the JET DT campaign

In the JET DTE2 deuterium-tritium campaign, neutron diagnostics were employed to measure 14 MeV neutrons originating from D(T,n)4He reactions. In discharge 99965, a diamond matrix detector (KM14) and a magnetic proton recoil (MPRu) detector with a vertical and an oblique line-of-sight were used, respectively. At the timepoints of interest, a significant decrease in the expected diagnostic signals can be observed as electromagnetic wave heating in the ion cyclotron range of frequencies (ICRF) is switched off. Utilizing only TRANSP simulation data, the fast-ion distribution is found to have been likely composed mostly of trapped orbits. In contrast, analysis performed using orbit weight functions revealed that the majority of neutrons in the KM14 Ed=9.3 MeV and MPRu Xcm=33 cm measurement bins are to have originated from fast deuterium ions on co-passing orbits. This work explains the perhaps surprising results and shows that the relative signal decrease as ICRF heating is switched off is largest for counter-passing orbits. Finally, for the magnetic equilibria of interest, it is shown how stagnation orbits, corresponding to ∼1 % of the fast-ion distribution, were completely unobservable by the KM14 diagnostic.

Multi-physical Field Numerical Simulation of Electromagnetic Heating in Heavy Oil Reservoirs with Different Well Configurations

Abstract Electromagnetic (EM) heating effectively reduces oil viscosity and improves oil recovery rate by heating oil layers with EM radiation. However, the selection of well configurations for EM heating oil recovery has yet to be thoroughly studied. This article uses numerical simulation methods to study the effect of different well configurations on the oil recovery efficiency of EM heating heavy oil reservoirs. A complex EM heating model coupled with an EM temperature seepage field was established to simulate two different well configurations: vertical and horizontal wells. The results indicate that the horizontal well configuration is more efficient in heating heavy oil reservoirs in the same area than the vertical well configuration. Vertical heating wells facilitate the swift creation of a flow channel around the wellbore due to the direction of heavy oil flow coinciding with that of the well. However, the horizontal configuration takes longer for a flow channel to form. Despite this, the temperature distribution in the reservoir under the horizontal configuration is more uniform, and high temperatures do not accumulate around the heating wells. On the other hand, with a vertical configuration, the heat accumulates at the bottom of the well along with the flow of heavy oil. Increasing EM power and frequency can lead to a rise in reservoir temperature and facilitate the flow of heavy oil. However, it is important to note that beyond a certain point, the benefits of increased power and frequency become limited and may result in an excessively high temperature of heavy oil.

Investigation of electromagnetic noise in an induction cooktop by examining circular membrane vibration modes in terms of their harmonics

In this study, the mechanism of vibration and noise is analytically investigated in an induction cooktop (IC). By employing the method of an electric motor in estimating its vibration performance, it is found that air-gap force normal to the glass surface is a main source in an IC. Three different types of a cookware in terms of its material are compared as a part of load, and the pattern of their vibration is scrutinized by means of a membrane. It is noted that the mode of vibration in an IC is the circular shape of a membrane. Spatial and temporal harmonics in normal force are obtained through a three-dimensional Fast Fourier transform. This study is focused on spatial harmonic orders in a cylindrical coordinate to determine the dominant mode of vibration, and experimental verification has been performed to prove the feasibility of this proposal.

Perceived Usefulness, Perceived Risk, and Trust towards Intention to Use Induction Stove: A Case Study on Pilot Project of Induction Stove Conversion Program in Surakarta

Perceived Usefulness, Perceived Risk, and Trust towards Intention to Use Induction Stove: A Case Study on Pilot Project of Induction Stove Conversion Program in Surakarta

Radiofrequency absorption of coated ellipsoidal gold nanoparticles in human tissue.

Electromagnetic radiofrequency heating of gold nanoparticles for use in remote hyperthermia cancer treatment has seen rapidly growing interest in the last decade. While most of the focus has been on studying spherical nanoparticles, recent research suggests that using ellipsoidal particles can significantly increase the Joule heating. However, it is still unclear how the presence of ligands affects the electromagnetic absorption in this context. In the present paper, we study the effects of adding a surface coating to ellipsoidal gold nanoparticles, and investigate the change in absorption with respect to coating properties, particle aspect-ratio, and frequency. Both the case of a single nanoparticle and the case of a suspension of nanoparticles are studied. The introduction of a dielectric coating increases the absorption rate for particles with lower aspect ratios and at lower frequencies, potentially improving the flexibility of parameter configurations that can be used in treatment. A thermal analysis reveals that the absorption in the parameter space of lower aspect ratios translate to negligible differential temperature increase, even with the addition of coating. Furthermore, nanoparticles with very large aspect ratios (nanowires) generate less heat with coating compared to no coating. Thus, it is shown that the presence of coating and choice of aspect ratio, have significant impact on the absorption response and must be accounted for in the analysis of ligand-capped nanoparticles. The findings in the present paper provide a valuable tool to optimize the coated gold nanoparticle design parameters, in order to secure clinically useful differential heating.

Electromagnetic Heating for the Separation of Water-Oil Emulsion

Electromagnetic Heating for the Separation of Water-Oil Emulsion

Factors Determining the Adoption of Induction Stove for Household Cooking in Bhaktapur

The current global warming trend is unequivocally the result of human activities and is proceeding at an unprecedented rate over the millennia. About 6.7 percent of global greenhouse gas emissions are caused by household cooking. It is essential to expand the use of clean fuels and technologies to reduce household emissions. Most households in urban areas use LPG for cooking purposes along with a gradual introduction of electric induction stoves. The main objective of this paper is to identify the factors determining the choice of induction stoves for household cooking. Primary data were collected from 300 households of Bhaktapur and Madhyapur Thimi Municipalities in March, 2021. Binomial Logit regression was performed to examine the determinant of induction stove adoption by household. LPG is the primary source of cooking for household. Sixty seven percent of households use electricity partially for cooking purposes. Forty five percent of total households use an electric rice cooker and 27 percent use an induction stove. Twenty six percent of households do not know about induction stoves. The family's education level, particularly the cooking member, is the primary determinant of adopting an induction stove. The probability of adoption of induction stoves increases with an increase in income. Families living in their own houses are more likely to use induction stoves than those living in rented houses.

Monolithic Catalyst of Ni Foam-Supported MnOx for Boosting Magnetocaloric Oxidation of Toluene.

Catalytic oxidation has been considered an effective technique for volatile organic compound degradation. Development of metal foam-based monolithic catalysts coupling electromagnetic induction heating (EMIH) with efficiency and low energy is critical yet challenging in industrial applications. Herein, a Mn18.2-NF monolithic catalyst prepared by electrodeposition exhibited superior toluene catalytic activity under EMIH conditions, and the temperature of 90% toluene conversion decreased by 89 °C compared to that in resistance furnace heating. Relevant characterizations proved that the skin effect induced by EMIH encouraged activation of gaseous oxygen, leading to superior low-temperature redox properties of Mn18.2-NF under the EMIH condition. In situ Fourier transform infrared spectroscopy results showed that skin effect-induced activation of oxidizing species further accelerated the conversion of intermediates. As a result, the Mn18.2-NF monolithic catalyst under EMIH demonstrated remarkable performance for the toluene oxidation, surpassing the conventional nonprecious metal catalyst and other reported monolithic catalysts.

Removal of metal impurities from diamond wire saw silicon powder by vacuum electromagnetic directional solidification

The utilization of high-purity silicon (∼99.9999 %) is prevalent in the solar photovoltaic sector, and achieving a reduction in its cost has emerged as a pivotal engineering objective within the silicon solar industry. Recycling silicon from diamond wire saw silicon powder (DWSSP) is a promising solution to fulfill the continuously expanding of high purity silicon demand. Vacuum directional solidification technology using high-frequency electromagnetic induction heating was proposed to purify DWSSP for the first time efficiently. The silicon melt and gas interface reaction, as well as metal impurities’ microsegregation in silicon ingot were observed. The effects of vacuum level and electromagnetic force on the separation of silicon and metal impurities were investigated using thermodynamics and electromagnetic mechanics. Results indicate that the content of oxygen in the silicon reduced from 30.91 wt% to 5.08 wt%, and the actual sample composition including for uptake of residual gas contamination steadily declined as the vacuum level increased from 600 Pa to 10 Pa. Vacuum electromagnetic directional solidification reduced the content of metal impurities from 641 ppmw to 29.80 ppmw, increases the proportion of crystalline silicon area, and makes the silicon lattice arrangement more regular.

The Law and Mechanism of the Effect of Surface Roughness on Microwave-Assisted Rock Breaking

In physical engineering, a rock surface, whether naturally or artificially formed, is rough. When irradiating rocks, microwaves produce reflections and diffractions on the surface of rough rocks, which significantly affect the absorption of microwave energy by rocks, thus influencing the result of microwave irradiation. In order to explore the influence of rough rock surfaces on the effect of microwave-assisted rock breaking, microwave irradiation tests were carried out on basalt samples with different values of roughness to test the temperature and P-wave velocity of the samples before and after microwave irradiation. Numerical test methods were used to systematically study the influence of rough rock surfaces on microwave irradiation. The results show that, under the same microwave irradiation conditions, the effect of microwave irradiation on rough surface basalt is more significant than that of flat surface basalt. The surface temperature distribution range of flat surface specimens is narrow, the surface temperature range of rough surface specimens is wider and more inhomogeneous, and the maximum surface temperatures of rough surface specimens are much higher than those of flat surface specimens. After irradiation, new macroscopic cracks were generated on the surface of the samples, and the crack propagation of the rough surface samples was more obvious. The decrease in P-wave velocity before and after the irradiation of flat surface samples is small, and that of rough surface samples is larger. The main factors affecting the effect of microwave irradiation on the rough surface are the refraction and reflection of electromagnetic waves, heat conduction, and stress concentration on the surface.

Study on temperature field distribution state of carbon fiber reinforced polymer wound circular tube via electromagnetic induction heating

The variation of temperature fields during the winding process of CFRP (Carbon Fiber Reinforced Polymer) due to fiber winding is a key factor influencing its curing and shaping. Traditional heating methods result in energy wastage and environmental pollution during the heating process. Electromagnetic induction technology, as a non-contact, pollution-free, and efficient heating method, is playing an increasingly significant role in the process of heating and curing CFRP. This study focuses on two heating methods, internal and external, for CFRP wound circular tubes. It establishes finite element analysis models for induction heating with different coil structures. The heating mechanisms of different coil-induced CFRP wound circular tube models are explained, and the effects of external arc-shaped coils and external/internal annular coils on the temperature field distribution of CFRP wound circular tubes are investigated. By comparing simulations with experiments, the correctness of the numerical analysis model in this study is demonstrated. It offers viable heating methods for different conditions in industrial production, providing theoretical support and empirical data for the induction heating of CFRP wound circular tubes.

Effect of Mn2+ substitution on catalytic properties of Fe3-xMnxO4 nanoparticles synthesized via co-precipitation method

Mn-substituted magnetite samples Fe3-xMnxO4 (x = 0.0; 0.02; 0.05; 0.1; 0.15; 0.2; 0.25) were synthesized using the co-precipitation method. X-ray diffraction patterns confirmed the formation of pure, well-crystallized manganese ferrite with a cubic spinel structure. The crystallites size increases sharply for the minimum degrees of substitution, with a subsequent tendency to decrease with the growth of manganese ions content. The catalytic properties of Fe3-xMnxO4 were investigated for the degradation of oxytetracycline (ОТС) and inactivate E. coli. There is a correlation between particle size and catalytic activity. The Fe2.95Mn0.05O4 sample exhibited the highest catalytic activity in the destruction of OTC. The effect of electromagnetic heating (EMH) on the catalytic properties of iron oxides were investigated. The Fe2.9Mn0.1O4 sample with electromagnetic heating achieved 100 % efficiency in decomposing 5 mg/L of OTC. Fe3-xMnxO4 samples reduce the number of Gram-negative bacteria E. coli at concentrations of 104 and 106 CFU/mL. Electromagnetic heating experiments demonstrated high performance, achieving inactivation of 6 logs of E. coli in the presence of Fe2.98Mn0.02O4 and Fe2.95Mn0.05O4 catalysts within 135 minutes. Studies on ecotoxicity have shown that Daphnia magna is a sensitive bioindicator of residual H2O2 concentration. An increase in the Mn2+ content in the synthesized catalysts resulted in a decrease in the toxicity of purified water. The study suggests that Mn-substituted magnetite catalysts are effective materials for catalytic decomposition of OTC and inactivation of E. coli bacteria.

Modeling and Analysis of Cancer Electrothermic Therapy Technique Based on a Digital Arm

Background: Intramuscular hemangioma (IMH) is a diffuse growth hemangioma located in the striated muscle, which is often overlooked due to its rarity. background: Intramuscular hemangioma (IMH) is a diffuse growth hemangioma located in the striated muscle, which is often overlooked due to its rarity. Objective: This patent pertains to the integration of electroacupuncture with electrothermotherapy. By introducing electrical signals into the electroacupuncture system, electromagnetic heat is produced. This heat leads to the electrolysis and thermal destruction of tumor cells, enabling targeted and precise cancer treatment. Furthermore, the patent offers a theoretical foundation for exploring the distribution of electrical signals and the associated heat in arm muscles, ensuring accurate treatment. Material and Method: To enable subsequent experimental validation, this patent integrates human anatomy and histological structure theory. The arm's geometric structure was derived from segmentation, reconstruction, and substantiation based on a digital human image dataset. Using the COMSOL Multiphysics 5.5 software, a semi-detailed finite element model was developed for the numerical simulation of electrothermotherapy. Within a time domain setting, a carrier signal of 1 MHz and 22 V was introduced to assess the distribution of electrical signals and the associated heat in the arm muscle. Results: Electrical signals, electromagnetic heat, and tissue necrosis primarily concentrate in a spherical region within 10 mm of the exposed electroacupuncture tip, with the maximum coupling temperature reaching 250 °C at the tip. Time domain analysis revealed that the coupling temperature can rise within 1 min, sufficiently to cause complete tissue damage, with the tissue necrosis ratio reaching 100% in the same timeframe. While the coupling temperature continues to rise over time, the increment is modest. After 5 min, there is negligible temperature change, and once the tissue necrosis ratio reaches 100%, it remains consistent. Conclusion: In the precision tumor treatment system utilizing electrothermotherapy, factors, such as the magnitude of the injected electrical signal, placement of the electroacupuncture tip, and treatment duration play a crucial role in the treatment's accuracy. This model delves into the treatment of intramuscular hemangiomas using electroacupuncture electrothermotherapy from two perspectives: spatial and temporal domains. It provides a theoretical foundation for precise electrothermotherapy in cancer treatment. conclusion: In the precise tumor treatment system with electrothermotherapy, the size of the injected electrical signal, the position of the electroacupuncture tip and the treatment duration all have a significant impact on the precise treatment. This model is used to analyzes the treatment of intramuscular hemangiomas with electroacupuncture electrothermotherapy from two aspects: spatial and temporal domains, providing a theoretical basis for the precise electrothermotherapy for cancer. other: null

Factors Affecting Technological Readiness and Acceptance of Induction Stoves: A Pilot Project

In 2022, through the state electricity company, the Indonesian government launched a pilot experiment to cut imports of liquefied petroleum gas by giving program packages to 1,000 families in five districts in Surakarta. Objectives: Using the technology readiness and acceptance model (TRAM), this study examined the elements influencing the readiness and acceptability of the induction stove program in Surakarta. Method/Analysis: The empirical findings from a 389-respondent survey showed that the program’s public acceptance was supported by favorable technological preparedness, including elements like innovation and optimism. Findings: Perceived use, enjoyment, usefulness, cost level, and confirmation were all factors that affected participants' happiness and willingness to continue using induction stoves and participating in the program. Interestingly, acceptability, general contentment, and the willingness to use induction stoves were not always affected by issues like discomfort and insecurity. Additionally, this research emphasized how crucial the social context is for successfully implementing a program and embracing new technologies. Novelty:This is the first study that concurrently identifies, assesses, and analyzes the integration of factors impacting technology readiness and acceptance (TRAM) into the community's intention to continue participating in the induction stove conversion program. These empirical results offer practical guidance for stakeholders in induction stove conversion projects, particularly in developing nations, and also add to a theoretical understanding of TRAM factors. Doi: 10.28991/ESJ-2023-07-06-04 Full Text: PDF

Computation of non-Newtonian quadratic convection in electro-magneto-hydrodynamic (EMHD) duct flow with temperature-dependent viscosity

Motivated by novel developments in smart non-Newtonian thermal duct systems, a theoretical study has been presented in this article for electro-magneto-hydrodynamic (EMHD) buoyancy-driven flow of a fourth-grade viscoelastic fluid in a vertical duct with quadratic convection. The viscosity of the fourth-grade fluid model is assumed to be temperature-dependent, and the Reynolds exponential model is deployed. Viscous heating and Joule dissipation effects are included. The duct comprises a pair of parallel electrically insulated vertical flat plates located a finite distance apart. Via suitable scaling transformations, a nonlinear boundary value problem is derived for the momentum and heat transport. A homotopy perturbation method (HPM) solution is obtained coded in Mathematica symbolic software. There is a considerable enhancement in wall skin friction with an increment in fourth-grade fluid parameter, Brinkman number, electrical field parameter, thermal buoyancy parameter, and quadratic thermal convection parameter. However, skin friction is strongly reduced with a rise in variable viscosity parameter, Hartmann (magnetic) number, and electromagnetic heat generation to conduction ratio. Nusselt number magnitudes are elevated with increase in variable viscosity parameter, thermal buoyancy parameter, and quadratic thermal convection parameter, whereas they are significantly suppressed with increment in fourth-grade fluid parameter, Brinkman number, and Hartmann magnetic number.