Magnetic Induction Research Articles

Microstructure induction of quaternary ammonium chitosan microcapsules based on magnetic field and study of their aroma release

Traditional pressure-sensitive microcapsules used in textiles face challenges of insufficient environmental friendliness in the production process and uncontrollable fragrance release. To address this issue, this study utilized quaternary ammonium chitosan and silica as wall materials to develop a magnetic aromatic microcapsule. The microstructure of the microcapsules was controlled by magnetic field induction, and its evolution pattern was investigated. After magnetic field induction, the microcapsules exhibited a trend of evolving from spherical to asymmetrical shapes, accompanied by significant changes in mechanical properties. Asymmetrical microcapsules showed higher adhesion and lower stiffness. When applied to cotton textiles, the cotton textiles treated with asymmetrical microcapsules released 63.40 % of lavender essential oil after 200 friction cycles, representing an 11.3 % improvement in release efficiency compared to regular microcapsules, indicating better mechanical stimulus responsiveness. Additionally, in antibacterial tests, aromatic cotton exhibited a 96.52 % inhibition ratio against Escherichia coli. In summary, this study explores methods to adjust the mechanical properties of microcapsules and the relationship between mechanical properties and microstructure, providing a new approach for functional textiles.

Polarization of radio-frequency magnetic fields in magnetic induction measurements with an atomic magnetometer

Polarization of radio-frequency magnetic fields in magnetic induction measurements with an atomic magnetometer

Multi-frequency Magnetic Induction Tomography based on Identification Method and SAE Network

Multi-frequency Magnetic Induction Tomography based on Identification Method and SAE Network

Posture detection of athletes in sports based on posture solving algorithms

With the rapid development of science and technology, the field of sports is constantly exploring and applying new technical means to improve the training effect and competitive level of athletes. Among them, the athletes' posture detection technology based on the attitude solving algorithm has been widely concerned in recent years. However, the current attitude solving algorithm has the limitation of low precision and low efficiency. Aiming at this, a new attitude solving algorithm is proposed. Firstly, the coordinate system is determined according to the theory of inertial navigation, and the attitude Angle is obtained by calculating the acceleration and magnetic induction intensity. Then the current attitude matrix is calculated according to the obtained attitude Angle. The initializing quaternion based on the attitude matrix is studied. Then, according to the advantages and defects of the three sensors, a complementary filtering algorithm is proposed for data fusion, so as to reduce the error of the final attitude solution. In order to further improve the accuracy of attitude detection, the complementary filter algorithm and double-layer Kalman filter algorithm are combined to process the data, and finally the quaternion is updated. It can be seen that the detection error of the research constructed model is only 9.94%, and its three attitude angle errors are mainly concentrated between -0.5° and 0.5° The model constructed by the research can realize high-precision posture detection, which can provide more scientific and reliable training aids for gymnastics, which has very strict requirements for movements in sports. It has positive significance for the development of sports.

Extreme multi-stability and microchaos of fractional-order memristive Rulkov neuron model considering magnetic induction and its digital watermarking application

Extreme multi-stability and microchaos of fractional-order memristive Rulkov neuron model considering magnetic induction and its digital watermarking application

Characteristics of electromagnetic radiation of the veterinary physiotherapy device UMI-05-V

We studied some physical characteristics of the veterinary physiotherapeutic device UMI-V-05. The magnetic induction at different power levels was determined using TPU 02 militeslameter. The magnetic induction was measured for each power value. The probe of the milliteslameter was placed directly on the working surface, in the center of the inductor. It was found that the minimum magnetic induction of the device is 350±6.0 mTl, and the maximum is 1058±10.0 mTl. During the device operation, the heating of the inductor was determined using a thermal imager and a stopwatch. During the recommended time range (10 minutes), the inductor temperature did not exceed 46 °C. Determination of the pulse radiation frequency depending on the magnetic induction value was carried out using a stopwatch. At each working power the number of pulses per minute was counted and the number of pulses per second was calculated (frequency determination). It was revealed that UMI-V-05 is a low-frequency source of pulsed magnetic radiation with the maximum frequency of 1.3 Hz at the minimum magnetic induction of 350±6.0 mTl and the minimum frequency of 0.1 Hz at the maximum magnetic induction of 1058±10.0 mTl. Using a ruler and a TPU 02 milliteslameter, the degree of magnetic pulse attenuation depending on the distance to the working surface of UMI-V-05 was determined, it was fixed that the value of magnetic induction varies inversely proportional to the distance from the inductor. The penetration ability of the electromagnetic pulse through different media: biological and non-biological using TPU 02 militeslameter was studied. Biological tissues (muscle, bone) and some nonbiological media (paper, glass, wood, polyethylene, water) do not affect the passage of the electromagnetic pulse, while steel significantly reduces the passage of the pulse.

Effect of electroinductive conditions on biofilm production capacity of some industrially important bacteria

Biofilms are intricate microbial deposits on biotic and abiotic surfaces, with significant medical and biotechnological implications. This study explored biofilm formation by Acetobacter aceti ATCC15973, Pseudomonas aeruginosa ATCC9027, Serratia marcescens ATCC14756, Gluconobacter oxydans ATCC19357, Rhodobacter sphaeroides ATCC17023, and Bacillus subtilis ATCC6633 on wood, glass, steel, PVC, and PET surfaces using qualitative methods. Effects of electrical stimulation (6V, 4.5A), magnetic fields (1000 G), and electromagnetic flux (5 mT) on biofilm formation were assessed via Crystal Violet Binding Assay. G. oxydans ATCC19357 exhibited highest adherence on PVC and wood (2.0145 and 2.402 log cfu/ml, respectively) under electrical stimulation. A. aceti ATCC15973 showed highest adherence on steel, PET, and glass (1.944, 0.9005, and 0.876 log cfu/ml). R. sphaeroides ATCC17023 demonstrated highest adherence on PVC, steel, PET, and glass (1.0895 to 1.7495 log cfu/ml) under magnetic induction; B. subtilis ATCC6633 had highest wood adherence (1.491 log cfu/ml). G. oxydans ATCC19357 showed highest overall adhesion with electromagnetic induction. PVC supported highest biofilm growth (39 %). Biophysical factors varied in enhancing biofilm formation, suggesting potential for bacterial immobilization technologies in bioremediation and industrial fermentation

Impact of Iron Oxide Phases on the Magnetic Induction Heating Capacity of Mesoporous 45SiO2-16.5CaO-24.5Na2O-6P2O5-8Fe3O4 Glass-Ceramics.

Sol-gel-based mesoporous 45SiO2-16.5CaO-24.5Na2O-6P2O5-8Fe3O4 bioglass-ceramics were obtained by substituting magnetite nanoparticles for CaO in a 45SiO2-24.5CaO-24.5Na2O-6P2O5 bioglass composition. To enhance the dissolution of the precursors and to vary the crystalline phases, the as-synthesized ceramic powders were processed for 1 h each at temperatures (TA) between 550 and 700 °C. A gradual decline in the saturation magnetization with an increase in TA was observed, which is linked to the gradual conversion of magnetite into hematite at different TA > 550 °C. All of the processed samples indicated a hydroxyapatite surface layer formation in in vitro tests. Aqueous solutions of the ceramic processed at 600 °C exhibited superior magnetic induction capacity. Thus, the substitution of magnetite nanoparticles for CaO in the base composition, coupled with appropriate heat treatment, results in a promising bioactive glass-ceramic for magnetic hyperthermia treatment of deep-rooted cancer cells.

Enhancing unilateral EMAT performance through topological optimization of Halbach permanent Magnet arrays

A novel unilaterally excited electromagnetic acoustic transducer (EMAT) is proposed as a solution to address the challenge of weak electromagnetic ultrasonic detection signals being susceptible to interference from clutter noise signals. EMAT employs Halbach permanent magnet array (HPMA) structure and a coil designed based on Huygens superposition principle. This design enables the generation and reception of highly directive Rayleigh surface waves in aluminum plates. To enhance the operational efficiency of EMAT while maintaining a high level of directivity for surface waves, a penalty function is implemented in COMSOL Multiphysics for the topological optimization of EMAT. The objective function in this optimization process is based on covariance (COV) of the magnetic induction intensity. The research results suggest that the homogeneity of the magnetic induction intensity within the coil region is enhanced by 50 % following topological optimization compared to the original design. The energy conversion efficiency of EMAT is enhanced by 5 times compared to traditional designs. The surface wave speed was determined to be 2631 m/s when measured at a frequency of 400 kHz. The value indicates a relative error of 6.37 % in comparison to the theoretical speed. The results indicate that EMAT has the capability to generate high-directional and pure Rayleigh waves.

Parameters and Effects of Magnetic Field and Potassium Carbonate in Water. Applications

The polar water molecule has an angle between the two-hydroxyl O–H bonds of 104.5∘. The unequal sharing of electrons gives a slight negative charge near the oxygen atom and a slight positive charge near the hydrogen atoms of the water molecule. Water is a polar solvent. Hydrogen electromagnetic bonds are formed between water molecules. They involve hydrogen atoms from one water molecule and oxygen from another one. A permanent magnetic field influences the formation of hydrogen bonds between water molecules. Current research by Wu and Brant, 2020 illustrates that the water conductivity at the magnetic induction B = 13500 or 1.35 T increases from 100 to 250 μS · cm−1. The amount of protons in water (H+) decreases with the water alkalization and increasing pH. The work by Yap and co-authors’ indicates that stronger effects on pH, oxidation-reduction potential (ORP), and dissolved oxygen (DO) are observed in the non-reversed polarity of the magnets. Our study uses a constant magnet with the magnetic induction B = 3000 G or 0.3 T; eight permanent magnets are applied to 1000 L of water. Potassium carbonate (K2CO3) is also added, by increasing the alkalinity of water. The application is in livestock as drinking water for sheep and goats.

Effect of initial grain size on microstructure, texture and magnetic properties of non-oriented electrical steel

The effect of initial grain size prior to cold rolling on the microstructure, texture evolution, and magnetic properties of Fe-3.5 wt% Si non-oriented electrical steel (NOES) was investigated through the introduction of normalization. There were massive intragranular shear bands in {111}<110> and {111}<112> deformed grains in the cold-rolled sheet with large initial grain size, providing nucleation sites for new recrystallized grains with Goss ({110}<001>), λ-fiber, γ-fiber, and {113}<631> components. Subsequent annealing resulted in weaker γ-fiber ({111}<110>−{111}<112>), stronger α*-fiber concentrated at {113}<631>, along with Goss and λ-fiber ({100}<001>−{100}<012>) textures. In addition, appropriate final annealing temperature effectively reduced iron loss. The simultaneous optimization of texture and grain size by normalization and annealing treatments led to improved magnetic properties, with the superior magnetic induction (B50 = 1.719) T, and the lowest core loss (P15/50 = 2.69 W/kg, P10/400 = 16.337 W/kg).

Electromagnetic estimation of mechanical stress in steel elements by using magnetic induction

We present here experimental verification of a theoretical model previously developed to estimate internal mechanical stress in steel-based elements by means of non-contact electromagnetic induction measurements. Results confirm the validity of the proposed model and demonstrate that stress below 50% of the elastic limit can be detected with standard electronics.

Technologies of physical and chemical impact on potato planting material

The paper highlights that it is planned to increase the cultivation area of open ground vegetables and potatoes for ensuring the food security. (Research purpose) This study aims to explore methods and technologies for pre-planting treatment of potatoes. (Materials and methods) The research was conducted in the Tula region where Rannee Utro (Early Morning) and Rokko potato varieties were studied under natural infectious conditions. Various fungicides and biological products containing different active ingredients were applied to protect potatoes. Additionally, the study investigated the eff ects oflow-pressure mercury ultraviolet discharge lamps and magnetic field treatments on the biopotential and pH levels of potatoes. (Results and discussion) The study focuses on enhancing potato yields by applying direct magnetic field exposure before planting and investigates the impact of ultraviolet irradiation on tuber growth and productivity. Signifi cant emphasis was placed on the efficacy of chemical and biological agents in preventing potato scab. The findings show that optimal biometric indicators and potato yields were achieved with a magnetic induction of 30 millitesla. Any deviation from this treatment dose results in reduced biometric indicators and yields, which, however, remain hirer than those of the untreated controls. (Conclusions) The application of fungicidal disinfectants effectively curtails the development of common scab, with the highest efficacy achieved using Rovral Aquafl o 500. Post-treatment with ultraviolet radiation at a dose of 120-240 joules per square meter enhances vegetative growth, productivity, and tuber reproduction rates. The most favorable biometric indicators and yields were observed when a magnetic induction treatment dose of 0.23 joule-seconds per kilogram was applied.

Indicator of abnormal cathode electron emission state with gas flow in Hall thrusters

The accurate diagnosis of abnormal electron emission state in hollow cathodes is crucial for the stable operation of Hall electric propulsion systems. In this study, a method of reducing the cathode working gas flow rate was used to simulate abnormal working conditions in which the cathode electron emission state (CEES) was deteriorating. By analyzing and comparing the oscillation signals under abnormal and steady-state working conditions, it was found that as the CEES deteriorated, the power content of the breathing oscillation decreased in the 1–40 kHz frequency band, and the main frequency decreased; in contrast, the power content of the transit-time oscillation increased in the 100–500 kHz range, and the main frequency was on the rise. Combined with the current growth rate analysis of breathing and transit-time oscillations, when the cathode gas flow rate decreases, the CEES deteriorates, the coupling voltage drop increases, and the potential drop in the channel decreases. The electron temperature and nonlinear power absorption of the electrons decrease, leading to a decrease in the growth rate of breathing oscillations and the breathing oscillation weakens; however, the time-averaged ion velocity and ion sound velocity in the channel decrease simultaneously, but the ion velocity decreases significantly faster than the ion sound velocity, leading to an increase in the growth rate of the transit-time oscillation, and the transit-time oscillation strengthen. Through comparison of the oscillation signals under different working conditions, such as varied anode flow rate, anode voltage, magnetic induction, it was proven to be a unique feature of CEES deteriorates, and can be used as an indicator of CEES deteriorates during the on-orbit operation of the Hall-effect thrusters.

Electrical Conductivity of Subsurface Ocean Analogue Solutions from Molecular Dynamics Simulations.

Investigating the habitability of ocean worlds is a priority of current and future NASA missions. The Europa Clipper mission will conduct approximately 50 flybys of Jupiter's moon Europa, returning a detailed portrait of its interior from the synthesis of data from its instrument suite. The magnetometer on board has the capability of decoupling Europa's induced magnetic field to high precision, and when these data are inverted, the electrical conductivity profile from the electrically conducting subsurface salty ocean may be constrained. To optimize the interpretation of magnetic induction data near ocean worlds and constrain salinity from electrical conductivity, accurate laboratory electrical conductivity data are needed under the conditions expected in their subsurface oceans. At the high-pressure, low-temperature (HPLT) conditions of icy worlds, comprehensive conductivity data sets are sparse or absent from either laboratory data or simulations. We conducted molecular dynamics simulations of candidate ocean compositions of aqueous NaCl under HPLT conditions at multiple concentrations. Our results predict electrical conductivity as a function of temperature, pressure, and composition, showing a decrease in conductivity as the pressure increases deeper into the interior of an icy moon. These data can guide laboratory experiments at conditions relevant to icy moons and can be used in tandem to forward-model the magnetic induction signals at ocean worlds and compare with future spacecraft data. We discuss implications for the Europa Clipper mission.

Performance analysis of a novel single-flywheel resettable-inertia damper with eddy-current damping

The clutching inertia model presents an ideal Bang-Bang control approach, but it is challenging to realize practically through passive means. In this paper, a single-flywheel resettable-inertia damper (SRID) is proposed on the basis of the clutching inertia model. This device is implemented with a rack-and-pinion system, a right-angle gearbox system, and a flywheel-mounted eddy-current damping system. Initially, a mechanical analysis model of this device is established according to its working mechanism. Subsequently, comparative analyses are performed on the performance of SRID in a single degree-of-freedom (SDOF) structure compared to viscous dampers (VDs) subjected to harmonic and seismic excitations. The results show that the SRID can achieve a comparable control effect as VDs with a much smaller need for the damping coefficient, reflecting a damping amplification effect over 100 times. The SRID is effective in controlling peak displacement and absolute acceleration responses, especially for long-period structures. Moreover, the control performance is significantly improved with increasing magnetic induction intensity.

Effects of Cu Content on Mechanical and Magnetic Properties of High‐Strength Nonoriented Silicon Steel

Drive motors for new energy vehicles require nonoriented silicon steel with high strength and excellent magnetic properties, which are always difficult to balance. In this study, the effects of Cu content on the precipitates, microstructure, and properties of nonoriented silicon steel are investigated. The results show that a dispersed and coherent nanoscale B2 Cu‐rich precipitates are formed when Cu addition is 0.91 wt%, while ε‐Cu precipitates with large size and low number density are formed with higher Cu addition. The nanoscale B2 Cu‐rich precipitates afford a higher precipitation strengthening contribution than the larger ε‐Cu precipitates via cutting mechanism. Concurrently, the nanoscale B2 Cu‐rich precipitates nominally affect the iron loss deterioration. With increasing Cu content, the average grain size decreased, while the favorable λ texture diminished, and the unfavorable γ texture increased. With the combined effect of the grain size, texture, and precipitates, the iron loss increased first slightly and then significantly with further Cu addition, whereas the magnetic induction gradually decreased. The comprehensive properties of the steel are optimal when Cu addition was 0.91 wt%, which yielded a yield strength of 571.2 MPa, an iron loss P1.0/400 of 20.05 W kg−1, and a magnetic induction B5000 of 1.621 T.

EFFECT OF VARIATION OF MAGNETIC INDUCTION SOLENOID VALUES ON TENSILE AND IMPACT STRENGTH FOR WELDING BETWEEN LOW CARBON STEEL AND MEDIUM CARBON STEEL

The use of solenoid magnets in welding processes has attracted attention due to their potential to influence the properties of welded joints. This research investigates the effect of the size of the magnetic induction solenoid on the tensile strength and impact toughness of welds between mild steel and medium carbon steel. Welding experiments were carried out using various sizes of solenoid magnets (0; 1.71mT; 2.11mT; 2.31mT; 2.60mT), and the welding results were tested for tensile strength and impact toughness. The findings show that the size of the magnetic induction solenoid has a significant effect on the mechanical properties of the weld. The larger induction size in this study increased the tensile strength of the welded joint, namely 431.576 N/mm2 without induction and 533.33 N/mm2 with induction. Meanwhile, the impact toughness of welded joints also increases, namely 95.92N.m without treatment and 217.35N.m with induction.

STATISTICAL CHARACTERISTICS OF THE GEOPHYSICAL FIELDS DISTURBED BY WEATHER FRONTS

The Earth (internal spheres) — atmosphere — ionosphere — magnetosphere (EAIM) formation is a single integrated system with direct and reverse, positive and negative coupling, as well as with their combination. The high-energy sources of natural and anthropogenic origins activate coupling between the components of the EAIM. The effects that the sources of various physi- cal nature have on the EAIM system have been studied quite well, while the influence of the weather fronts and other powerful atmospheric sources on the EAIM system and its components has been studied only partly. The scientific objective of this study is to conduct a statistical analysis of variations in the basic parameters of the geophysical fields that accompany the movement of atmospheric fronts. The histograms have been constructed that show the atmospheric pressure difference, atmospheric tem- perature difference, duration of the action of the atmospheric front, and the rate of change in the pressure and temperature, as well as the histograms showing the distribution of variations in the atmospheric electric field, the atmospheric current density, and in the magnetic field. The analysis undertaken has shown that these parameters exhibit variations within a broad range of values. The mean values of these parameters are estimated to be 145 Pa, 6 °C, 70 min, 2.4 Pa/min, 0.23 °C/min, 3.2 kV/m, 63 nA/m2, and 20 nT, respectively. The analysis of the scatter diagrams shows that the correlation between the variation in physi- cal parameters is almost always absent. This means that a single governing parameter along the path of the atmospheric front does not exi st. A simplified analytical relation has been derived to estimate the perturbation in the electric field strength caused by the atmospheric front, which yields ~6–60 kV/m values that increase by an order of magnitude during thunderstorms. Under disturbed conditions, the atmospheric current density is shown to increase from 10 –12 A/m2 to 10–11—10–10 A/m 2. The fol- lowing three mechanisms of an increase in the magnetic induction under the influence of the atmospheric front are considered: the disturbances of the external current density, electromagnetic induction, and the magnetic effect of turbulence. All these mechanisms yield the value of the effect less than ~1 nT. Only the magnetic effect of the ionosphere can explain an increase of 10—70 nT in the magnetic field variations. The energetics of the pressure, temperature, electric, and magnetic fields has been estimated to be (~10 16—10 17 J, ~1013—1014 W), (~1018—1019 J, 1015—1016 W), (~109—1011 J, ~106—108 W), (~1010 — 10 11 J, 107—108 W), respectively. The following channels have been validated through which the components of the EAIM sys- tem couple under the action of atmospheric fronts: atmospheric pressure differences, ionospheric electron density differences, the generation of infrasound and gravity waves, the generation of electromagnetic waves by lightning flashes, and the perturba- tions in the global electric circuit.

On Constructing Magnetic and Gravity Images of Mercury from Satellite Data

A new technique for simultaneous reconstruction of “gravity” and “magnetic” images of Mercury from satellite data based on the regional version of S-approximations is proposed. The mathematical statement of the inverse problem on finding the images of a planet from the data on the potential fields recorded at different times with different accuracy is reduced to solving ill-conditioned systems of linear algebraic equations (LAES) with approximate right-hand sides. Based on the analytical approximations of the Mercury’s magnetic and gravity fields determined from the solution of the ill-conditioned SLAE, the distributions of the equivalen sources on the spheres are determined. The results of the mathematical experiment on constructing the magnetic image of Mercury from the radial component of the magnetic induction vector analytically continued towards the field sources are presented.