High-intensity Magnetic Field Research Articles

Magnetic-Manipulation of tribofilm for Si3N4/1045 steel contact toward sustainable reduction in friction and wear

Conventional anti-wear approaches lead to energy inefficiency and excessive waste, posing significant challenges to sustainability and cleaner production. Herein, we investigate the influence of eco-friendly magnetic fields on the tribological behavior of interfaces, with an emphasis on the formation and characteristics of the protective tribofilm. The experimental design combined finite element analysis and friction tests to systematically reveal the relationship between magnetic field strength, oxidation of wear debris, and tribological properties. The results demonstrated that the introduction of a magnetic field led to a 22% reduction in the friction coefficient and a 28% decrease in wear volume. High-intensity magnetic fields refined the wear debris by up to 42.6% and also promoted the oxidation of wear debris, leading to a predominance of Fe3O4 in the tribofilm. The structured arrangement and reorganization of Fe3O4 particles within the tribofilm enhance its density and thickness (from 2 μm to 3 μm). Simultaneously, the rotational motion of Fe2O3 particles at the interface modifies the friction contact state, thereby refining friction performance. The findings underscore the significance of considering magnetic fields in the design of tribological systems for enhanced performance and sustainability.

Preparation of Cu nanolayers by magnetic field-assisted electrodeposition and research on the nucleation and growth mechanism

Electrodeposition technology is widely used in the surface treatment of copper foil, and the core of this technology is roughening and curing treatment. During the electrodeposition process, the deposited layers often exhibits some problems, such as coarse grain size, uneven thickness and difficult control of crystal morphology. The magnetohydrodynamic (MHD) effect of magnetic field can obviously control the electrodeposition of Cu and improve the micro-morphology and performance of deposited layers. In this paper, Linear Sweep Voltammetry (LSV), Cyclic Voltammetry (CV) and Chronocoulometry (CC) curves were adopted to investigate the electrochemical behavior of deposited Cu in ultra-high acidity sulfate systems under different magnetic field conditions. The nucleation and growth mechanism were discussed, and the micro-morphology of deposited layers was analyzed. The results show that the electrodeposition of Cu follows the three-dimensional (3D) growth mechanism of progressive nucleation and diffusion control under the static condition, and the deposits appear cylindrical shape formed by spherical agglomerated. The magnetic field significantly improves the mass transfer rate, and the deposited layers will be more uniform and dense, following 3D growth mechanism under the electrochemical control. With the increasing of magnetic field intensity, the nucleation mechanism gradually shifts from progressive to transient nucleation. At the early stage of nucleation, the high-intensity magnetic field can significantly increase the number of grains and refine them, obtaining uniform and dense deposited nanolayers.

Prototype Cherenkov detector characterization for muon tomography applications

Muography is an innovative imaging technique using naturally produced elementary particles – atmospheric muons – used to determine the distribution of density inside massive objects. The modification of the particles flux – by scattering or absorption – reflects the contrasts in density within the medium and therefore offers the possibility for an image of the crossed volumes. In most muography setups the imaging process is based on the tracking of the particles which accounts for the absorption or the scattering of the muons trajectories. Neither the energy nor the identity of the particles (the so-called PID) is exploited since this information traditionally relies on the use of calorimeters and/or high intensity magnetic fields. Both these techniques hinder detector portability which in the case of muography is important and this renders them impractical for its purpose. In this paper we characterize the performance of a simple and small water Cherenkov detector capable of providing some insights on the energy of muons and the PID for the crossing particles that could potentially improve the background rejection for a muography survey when operating in conjunction with a muon telescope. We tested a prototype of such water Cherenkov detector in combination with two small muon hodoscopes. Both systems are using the same opto-electronics chain – optical fibers and pixellized photosensors – and the same data acquisition (DAQ) readout system which ensures an easy integration and implementation within presently running systems. This article presents the test setup, the detector response to cosmic muons and its performance evaluation against a basic simulation of its geometry and detection principle.

Development of fast 2.5MeV neutron detectors for high-intensity stray magnetic field environments.

Several small to medium-scale magnetic confinement fusion devices operate using deuterium as fuel. These low neutron rate (108-1010 n/s) devices rely on 2.45MeV neutron measurements to validate physical models and to assess their performance. Given the modest rate, neutron monitors have to be placed as close as possible to the machine to maximize data gathering. In these regions, intense stray magnetic fields could affect the detector's performance. In this work, the development of a neutron detector based on an EJ-276D scintillator crystal coupled with a SiPM and a custom-made readout system is presented. The detector has particle discrimination capability and is insensitive to magnetic fields.

Structural, optical and heat transfer characteristics of rotating [MgO+ ZrO2/PEG-H2O]h Hybrid nanofluid flow over an expanding surfaces with activation energy

SignificanceHybrid nanofluids have garnered significant interest due to their potential for enhanced thermal and optical properties compared to their individual counterparts. AimThe aim of this research is to examine the structural, optical, and heat transfer properties of a hybrid nanofluid [MgO+ZrO2/PEG-H2O]h within a rotating system. This research integrated variable viscosity, MHD, convection, and activation energy terms into the momentum, energy, and concentration equations. A comprehensive experimental analysis, including Fourier-transform infrared and ultraviolet visible spectroscopy, elucidates the structural arrangement, optical behavior, and thermal transport properties of the nanofluids. MethodologyThe partial differential equations that govern the system are converted into nonlinear ordinary differential equations through similarity transformations. Then, these ODEs are numerically solved by employing the Runge-Kutta-Fehlberg method in combination with a shooting procedure. FindingsThe research findings demonstrate that the rotational factor impacts skin friction differently by 2 % on x and y axes, while skin friction surges by 3.63 % in [MgO+ZrO2/PEG-H2O]h hybrid nanofluid with higher magnetic field intensity. The heat transmission rates of the [MgO+ZrO2/PEG-H2O]h hybrid nanofluid are significantly higher by 4.58 % compared to the [ZrO2/PEG-H2O]n nanofluid. The mass transfer rate of [ZrO2/PEG-H2O]n declines by 3.57 % with the rise of the activation energy factor. Utilizing spin coating, thin films of nanostructures [ZrO2/PEG-H2O]n, [MgO/PEG-H2O]n and [MgO+ZrO2/PEG-H2O]h are fabricated, resulting in films with a consistent thickness of ∼200 nm at a temperature of 25 °C. A reduction in the difference in energy bandgap values from 4.5 eV for [ZrO2/PEG-H2O]s to 5.3 eV for [MgO/PEG-H2O]n and 4.8 eV for [MgO+ZrO2/PEG-H2O]h is observed. This indicates that the [MgO+ZrO2/PEG-H2O]h hybrid nanofluid yields an appropriate bandgap compared to individual nanofluids because hybrid nanofluids can lead to synergistic mechanisms that elevate their electronic attributes.

The conformational modification of myofibrillar protein by magnetic field improves its emulsification properties

This study investigated the effect of different magnetic field treatments (0, 3, 6, 9, 12 mT) on the structure and emulsification properties of myofibrillar protein (MP). The results showed that the emulsion stabilized by MP with 3, 6, 9 mT magnetic field treatments possessed higher emulsifying ability, storage stability and apparent viscosity, since magnetic field induced the structural unfolding of MP and exposed the hydrophobic groups (the surface hydrophobic increased from 30.10 to 43.73 μg). Meanwhile, the magnetic field treatments decreased the MP particle size from 1752.00 to 1278.67 nm, which was favorable for the diffusion and adsorption of proteins at the oil-water interface, thus improving the MP emulsification ability and stability. Furthermore, the 9 mT magnetic field-treated MP had the best ability to emulsify oil droplets with a more uniform and smaller emulsion size from 28.593 to 23.443 μm. However, high-intensity magnetic field treatment (12 mT) caused MP particles to aggregate and the hydrophobic binding sites to be buried, which was not conducive to encapsulating oil droplets.

High-sensitivity vector magnetic field sensor based on a V-shaped multimode-no-core-multimode fiber structure.

This work proposes and investigates a bent multimode-no-core-multimode optical fiber structure for vector magnetic field sensing applications. The bent no-core fiber (NCF) serves as the sensing area, and the gold film is deposited on its surface to excite the surface plasmon resonance effect. Due to the strong evanescent field of the unclad and bent NCF, the as-fabricated sensor exhibits a high sensitivity of 5630 nm/RIU in the refractive index range of 1.36-1.39. Magnetic fluid is employed as the magneto-sensitive material for magnetic field sensing, exhibiting a high magnetic field intensity sensitivity of 5.74 nm/mT and a high magnetic field direction sensitivity of 0.22 nm/°. The proposed sensor features a simple structure, low cost, point sensing, and excellent mechanical performance.

The significant role of Darcy–Forchhiemer with integrated hybrid nanoparticles (Graphene and TiO 2) on dusty nanofluid flow subjected to heat conduction

The thermal analysis of two-phase models that deal with the fluid and dusty phases has been considered. This study instigates the flow of a non-miscible, dusty hybrid nanofluid over a stretching cylinder with Darcy–Forchheimer permeability in the presence of thermal radiation. The mathematical model is based on the single-phase nanofluid model, which features modified thermophysical characteristics. This innovative flow model explores how important it is to enhance the concentration of dust particles in fluid dynamics. Hybrid nanoparticles are substituted for nanoparticles in a conventional case to accelerate the heat transfer rate of the fluid. Therefore, in this study, the magnetohydrodynamic flow of hybrid nanofluids and heat transfer of non-Newtonian dusty fluids with suspensions of hybrid nanoparticles have been examined. The appropriate dimensionless variables are used to convert the governing periodic model into a non-dimensional form. The finite-difference-based bvp5c algorithm is used through Matlab for numerical analysis of the set of obtained ordinary differential equations. The graphs explored the influences of relatable factors over the profiles of mass, heat, and velocity transfers. It is observed that with intensifying values of Eckert number (Ec) and Biot number (Bi), the temperature of both phases increased at a significant level, and the velocity decreased with increasing intensity of the magnetic field. The computational results of velocity, core temperature, and intensity dispersion are significant for both aspects. Furthermore, it is observed that both the fluid and dust phases exhibit declining behavior as a result of the impact of porosity, mass concentration, and magnetism on the flow stream. Moreover, it is noticed that both the dust phase temperature θ p ( η ) and fluid phase temperature θ ( η ) intensified with the high intensity of magnetic field and thermal radiation. The missile nozzles, nuclear power plants for aerospace and gaseous-core nuclear rocket systems, and the radiation are considered for evaluating heating significance.

Influence of SPION Surface Coating on Magnetic Properties and Theranostic Profile.

This study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (MR/P) and co-precipitation at controlled pH (MpH), were explored, including the assessment of the coating's influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI). Parameters such as size, stability, morphology, and magnetic behavior were evaluated by a detailed characterization analysis. To assess their efficacy in imaging and therapy, relaxivity and hyperthermia experiments were performed, respectively. The results revealed that both synthetic methods lead to SPIONs with similar average size, 9 nm. Mössbauer spectroscopy indicated that samples obtained from MR/P consist of approximately 11-13% of Fe present in magnetite, while samples obtained from MpH have higher contents of 33-45%. Despite coating and functionalization, all samples exhibited superparamagnetic behavior at room temperature. Hyperthermia experiments showed increased SAR values with higher magnetic field intensity and frequency. Moreover, the relaxivity studies suggested potential dual T1/T2 contrast agent capabilities for the coated SPpH-Dx-Au-Gd sample, thus demonstrating its potential in cancer diagnosis.

The search for new pathogenesis of cardiorenal syndrome: the effect of local Schumann resonance on the occurrence of episodes of kidney disease and myocardial infarction

Background. The pandemic of noncommunicable chronic diseases and the high prevalence of combined damage to the cardiovascular system and kidneys determine the relevance of continuing scientific research to solve these medical problems. Therefore, the aim of this study was to compare the influence of the Earth’s electromagnetic field on the occurrence of episodes of kidney disease and myocardial infarction in order to search for new pathogenetic components of cardiorenal syndrome and deepen fundamental knowledge. According to the Lithuanian magnetometer GCI003, a number of stu­dies in 2014–2018 found that changes in the Earth’s electromagnetic field may play an important role in the pathogenesis of cardiovascular diseases as well as their incidence. Since the functioning of the cardiovascular system and kidneys are closely connected through the metabolic processes of the cardiorenal metabolic axis, this study tested the hypothesis that changes in the Earth’s electromagnetic field may also affect the pathogenesis of kidney disease as the changes of local magnetic field have been shown to influence the functioning of the cardiovascular system. Materials and methods. This was a search retrospective study on the relationship between the influence of local Schumann resonances and the occurrence of hospitalizations in 1340 patients with kidney disease. It also examined the relationship between local Schumann resonances and heart attacks in patients admitted to the University Hospital of the Lithuanian University of Health Sciences (703 patients). Mean power of local magnetic field fluctuations in Lithuania was measured in pT2 s2 in five different frequency ranges, which overlaps the Schumann resonance and electroencephalogram’s frequency ranges: SDelta (0–3.5 Hz), STheta (3.5–7 Hz), SAlpha (7–15 Hz), SBeta (15–32 Hz), SGamma (32–66 Hz). The data of hospitalizations to the Nephrology Department of University Hospital and the dynamics of Schumann resonances were analyzed from January 1, 2021 to December 31, 2021. The data of hospitalizations for myocardial infarction to the Cardiology Department of University Hospital and the dynamics of Schumann resonances were studied from January 1, 2016 to December 31, 2016. Results. It was found that changes in the strength of the Earth’s local magnetic field in 2016 and 2021 were comparable and corresponded to the characteristic annual dynamics of the Earth’s local electromagnetic fields. This made it possible to conduct a comparative analysis of annual correlation graphs and establish general trends in the dynamics of indicators and graphical similarities. It confirmed the pre­sence of a general dependence of reactions to the external electromagnetic field of the Earth in female and male patients both with nephrological pathology and myocardial infarction. In nephrological patients of both sexes, all correlation coefficients in all ranges of Schumann resonances were positive. The only negative correlation coefficient P5 (SGamma) [32; 65] Hz (r = –0.069; p = 0.313) was in the female group. This fact as well as the presence of a significant dynamics of the correlation coefficient P5 (SGamma) [32; 65] Hz (r = 0.009; p = 0.475) in the male group indicate that higher magnetic field strength in this frequency range may be associated with a reduced incidence of kidney disease. We obtained data that a higher magnetic field intensity in the gamma range from 32 to 65 Hz as a pathogenetic component can contribute to the destabilization of the cardiovascular system, but at the same time it is associated with a positive effect on the state of nephrological pathology. Based on this, we can tentatively assume the opposite direction of the Earth’s electromagnetic field influence on the pathogenetic mechanisms of renal and cardiovascular diseases. This is clearly demonstrated by comparing the correlation coefficients between the incidence of kidney disease and the occurrence of myocardial infarction in men and women. The Earth’s stronger magnetic field in the gamma range contributes to an increase in the incidence of myocardial infarction, which is confirmed by the large number of patients during this period. Under these same conditions, a decrease in the incidence of kidney disease has been detected. This opposite direction is observed in both sexes. But in women the reaction is stronger, which is confirmed by a larger difference in correlation coefficients. Conclusions. 1. Changes in the Earth’s electromagnetic field are related to the functional state of the cardiovascular system and the condition of the kidneys. 2. It can be assumed that the effect of the Earth’s electromagnetic field on the pathogenetic mechanisms of kidney disease is in the opposite direction of that on the cardiovascular one. 3. Reliable gender differences in correlations between the influence of changes in the local Schumann resonance on the functional state of the cardiovascular system and kidneys were not found. 4. The connection of the Earth’s local geomagnetic field with kidney function may be another new unexplored pathogenetic mechanism in cardiorenal syndrome and noncommunicable chronic diseases.

Effectiveness of Sanatorium Treatment Programs for Women with Chronic Endometritis: a Prospective Randomized Study

INTRODUCTION. The problem of recurrent antibiotic-resistant urogenital infections is increasing, and standard therapy is becoming ineffective. Sanatorium-resort treatment of chronic inflammatory diseases of the pelvic organs in women allows us to solve these problems with the help of natural and preformed physical factors.
 AIM. To study the clinical effectiveness of comprehensive sanatorium treatment programs in patients with chronic endometritis.
 MATERIALS AND METHODS. A prospective randomized trial included 73 patients, aged 35 ± 10 years, diagnosed with chronic endometritis. The control group (n = 25) received «basic» therapy with amplipulstherapy, sodium chloride baths. The comparison group (n = 24) received «basic» therapy and manual therapy. The main group (n = 24) received «basic» therapy, high-intensity pulsed magnetic field and manual therapy. Diagnostic criteria: immunohistochemical examination of the endometrium, echographic examination, dopplerometry of pelvic vessels, laser Doppler flowmetry.
 RESULTS AND DISCUSSION. After treatment, an increase in the uterine arterial perfusion index was noted in all groups compared with baseline values. The median indicator increased in the study groups by 2.36 times, 2.4 times, and 2.6 times, respectively (p 0.05). The decrease in the maximum peak speed in the comparison group and the main group exceeded the indicators of the control group (p 0.001). The systolic-diastolic ratio decreased in the comparison group and the main group (p 0.05). A decrease in stagnation in the venular microcirculation, a normotonic type of microcirculation, improvement in endothelial function (p 0.01) were revealed in the main group.
 CONCLUSION. An algorithm has been developed. In case of endometrial hypoplasia, decreased uterine perfusion, increased uterine artery resistance index, «basic» therapy is recommended, including sodium chloride baths and amplipulstherapy. With an increase in the maximum peak blood flow rate, an increase in the systolic-diastolic ratio, it is necessary to add a course of manual therapy to the «basic» therapy. When detecting violations of venous outflow, it is recommended to include high-intensity pulsed magnetic therapy.

A multi-region and a multiphase MHD OpenFOAM solver for fusion reactor analysis

Several systems in nuclear fusion reactors utilize liquid metals as working fluids and the design of these systems cannot overlook the magnetohydrodynamics effects arising from the interaction between the electrically conductive fluid and the magnetic fields used to confine the plasma, since these effects significantly influence the flow features. In this context, rigorous studies and research activities are imperative to provide high–quality numerical data and develop precise predictive numerical tools. This work introduces two OpenFOAM magnetohydrodynamics solvers and outlines their respective validation processes. The mMRF solver can simulate single–phase, incompressible MHD flow for multiple electro–coupled domains. Meanwhile, the mIF solver is capable of simulating two–phase MHD flow involving incompressible and immiscible fluids. The mMRF solver has demonstrated outstanding results in simulating classical 2D benchmarks up to high magnetic field intensities, while the mIF solver proved its ability by estimating, with a discrepancy of less than 10%, the velocity of a bubble rising within a liquid metal under an imposed magnetic field.

Quantum correlations and coherence in a mixed spin- (12,1) Heisenberg dimer under intrinsic decoherence

This research delves into the dynamical behavior of quantum correlations and coherence within a mixed Heisenberg dimer system under the intrinsic decoherence. Our approach involves the application of logarithmic negativity, local quantum uncertainty, and the ℓ 1 norm-based coherence as quantifiers for entanglement, skew information correlations, and quantum coherence in this qubit-qutrit model. Our primary objective is to explore the impact of various factors on the dynamics of quantum correlations and quantum coherence. These factors encompass the initial density matrix and its mixing parameter, the intrinsic decoherence rate (γ), the external magnetic field, as well as intrinsic system parameters, notably the XXZ and uniaxial single-ion anisotropies. Our results demonstrate that the introduction of intrinsic decoherence (ID) significantly erodes quantum resources. Particularly, for high values of the ID rate (γ), excessive damping occurs, leading to the absence of oscillations or a rapid decay of quantum resources, ultimately stabilizing in steady states. Furthermore, the presence of an external homogeneous magnetic field further diminishes quantum resources within the system. However, despite the degradation induced by the combined influence of intrinsic decoherence and high external magnetic field intensities, the judicious selection of the initial density matrix and precise adjustment of the uniaxial single-ion anisotropy enable the preservation of quantum resources within the mixed spin-(1/2, 1) Heisenberg dimer.

Vibration Analysis of PMLSM Considering Magnetostriction under High-intensity Magnetic Fields

Vibration Analysis of PMLSM Considering Magnetostriction under High-intensity Magnetic Fields

High magnetization composite magnetic fluid: structure, magnetorheology and new sealing mechanism in rotating seals.

The sealing capacity of magnetofluidic (MF) rotating seals is limited by the highest magnetization of the sealing ferrofluids (FFs) of about 1000 G (80 kA m-1). A sharp, almost an order of magnitude, increase in the supported pressure drop is possible by using a magnetorheological (MR) suspension as sealing fluid, owing to the much higher saturation magnetization of MR fluids compared to FFs. However, rotating seals with MR fluids have several shortcomings, such as a significant increase of the friction torque due to the growth of shear stress in the strong magnetic field specific to MF seals and leakage of the non-magnetic carrier liquid. At least partly, these issues can be avoided by using ferrofluid based extremely bidisperse MR suspensions of micrometer-sized iron (Fe) particles dispersed in a ferrofluid, as sealing fluid. The composite Fe3O4-Fe magnetic fluid used in this study consisted of hundreds of nanometers up to few microns size structures of interconnected (welded) Fe nanoparticles (FeMNPs) dispersed in a high colloidal stability ferrofluid with 500 G (40 kA m-1) saturation magnetization. The volume fraction of iron NPs varies from 0.5 to 15% in the ferrofluid carrier which significantly increases the magnetization and simultaneously produces important changes of flow properties in magnetic field of the resulting composite fluid, from Newtonian to strongly non-Newtonian behavior. The evaluation of the magnetic and magnetorheological behavior includes the dependence of magnetization, effective viscosity, magnetoviscous effect and dynamic yield stress on the volume fraction of Fe nanoparticles dispersed in the ferrofluid carrier. The seal gap filled with interconnected Fe nanospheres consists in randomly distributed microregions with a high intensity and high gradient magnetic field that captures the ferrofluid and provides a new sealing mechanism. Already a small amount of interconnected Fe nanospheres additive (2.5-5.0% volume fraction) produces four times increase of the rotating seal burst pressure, a much higher increase than what can be obtained from using a conventional magnetic fluid with the same magnetization. The nano-composite sealing magnetic fluid proved to be a cost-effective solution to significantly increase the performance of multi-stage rotating MF seals.

Influence of uniaxial tensile strain on magnetization behavior of Fe-9wt%Ni steel

This study investigated the effects of uniaxial tensile strain on the magnetization process of an Fe-9wt%Ni (9Ni) alloy to increase understanding of its magnetic behavior. As the applied strain was increased from 0 to 14 %, the magnetization curve changed remarkably, particularly under a high-intensity magnetic field, and magnetic flux density, relative permeability, remanence, and coercive force degraded significantly, especially at strains greater than the upper yield point. Increase in tensile strain caused increase in hysteresis losses, primarily because strain induced crystal defects, which affected the rearrangement of magnetic domains. Increased dislocation density was the primary contributor to the observed deterioration in magnetic properties; changes in texture and phase had little influence. This finding indicates that strain-induced deformation strongly affects the magnetic behavior of 9Ni alloys; this insight will be useful in research aimed at mitigating welding defects such as arc blow, that are attributed to the magnetization of Ni steel.

Evaluation of the effectiveness of complex physical therapy and SIS-therapy in the treatment of cervical disc herniation in the cervical spine

This article provides a review of the literature evaluating treatments for cervical disc herniation.
 As the most common cause of neck pain and even disability, cervical disc herniation often requires a multifaceted approach to treatment. The author examines the effectiveness of complex exercise therapy, including a number of therapeutic exercises and methods of manual therapy and SIS-therapy, using a high-intensity magnetic field. The review contains a description of various clinical trials, and also presents comparative functional characteristics of these methods to assess the effectiveness, safety and effectiveness of treatment. The author conducted a comparative analysis of the SIS-therapy method with the exercise therapy method in the treatment of herniated discs of the cervical spine based on consideration of such aspects of their impact as the mechanism of action, effectiveness, safety, accessibility and convenience, time and cost, and overall impact on health. The results show that complex exercise therapy and SIS-therapy are the most promising non-invasive treatment methods that can significantly improve the degree of pain relief, mobility and overall quality of life of patients with cervical disc herniation. The article provides recommendations for the implementation of these treatment methods in clinical practice and suggestions for further directions of research.

Modeling methodology for the transformer-rectifier flux pump considering electromagnetic and thermal coupling

High-temperature superconducting (HTS) magnets are promising in the application of high-intensity magnetic field. HTS flux pumps are devices that can charge closed HTS magnets without direct electrical contact. Simulation is an effective way to clarify the physical mechanism and provide further insight into the design of the device. In this work, we propose an accurate and efficient modeling methodology to simulate the transformer-rectifier HTS flux pump, which has considered electromagnetic and thermal coupling. The validity of the model has been verified by experimental results and theoretical calculations. The working characteristics of the HTS flux pump are investigated based on the proposed model, including DC bias component in the charging loop, the voltage recovery delay of the dynamic bridge and the temperature distribution in the dynamic bridge. The simulation results clearly depict working details of the device, in terms of electricity, magnetism and heat. The proposed model can serve as a powerful tool to design the HTS flux pump in practical applications.

A lightweight super-resolution network with skip-connections.

In some hospitals in remote areas, due to the lack of MRI scanners with high magnetic field intensity, only low-resolution MRI images can be obtained, hindering doctors from making correct diagnoses. In our study, higher-resolution images were obtained through low-resolution MRI images. Moreover, as our algorithm is a lightweight algorithm with a small number of parameters, it can be carried out in remote areas under the condition of the lack of computing resources. Moreover, our algorithm is of great clinical significance in providing references for doctors' diagnoses and treatment in remote areas. We compared different super-resolution algorithms to obtain high-resolution MRI images, including SRGAN, SPSR, and LESRCNN. A global skip connection was applied to the original network of LESRCNN to use global semantic information to get better performance. Experiments reported that our network improved SSMI by 0.8% and also achieved an obvious increase in PSNR, PI, and LPIPS compared to LESRCNN in our dataset. Similar to LESRCNN, our network has a very short running time, a small number of parameters, low time complexity, and low space complexity while ensuring high performance compared to SRGAN and SPSR. Five MRI doctors were invited for a subjective evaluation of our algorithm. All agreed on significant improvements and that our algorithm could be used clinically in remote areas and has great value. The experimental results demonstrated the performance of our algorithm in super-resolution MRI image reconstruction. It allows us to obtain high-resolution images in the absence of high-field intensity MRI scanners, which have great clinical significance. The short running time, a small number of parameters, low time complexity, and low space complexity ensure that our network can be used in grassroots hospitals in remote areas that lack computing resources. We can reconstruct high-resolution MRI images in a short time, thus saving time for patients. Our algorithm can be biased towards practical applications; however, doctors have affirmed the clinical value of our algorithm.

Investigation of the beneficiation of refractory ferromanganese ores “Zhomart” deposits

In order to provide ferroalloy production with high-quality raw materials, the need to develop technologies for processing of low-grade manganese and ferromanganese ores is becoming increasingly important. In view of the change in the quality characteristics of ores, the decrease in manganese content and the ability to beneficiation by traditional methods, it is necessary to consider new approaches and technological solutions. The article presents data from a study on the beneficiation of refractory iron-manganese ore from the Zhomart deposit. The mineralogy, physical and mechanical properties, and granulometric composition of the ore were determined. The results of a study on gravitational beneficiation using a laboratory pulsator with a pneumatic drive and a laboratory 2-chamber diaphragm jigging machine and magnetic beneficiation of ore with a high-intensity magnetic field are presented. Iron-containing concentrate (Fe-45% and Mn-6.5% is mainly represented by hematite mixed with non-metallic minerals quartz and calcite) and iron-manganese concentrate (Mn-21.7% and Fe-21.1% in the form of hematite, Brownite and pyrolusite, also mixed with quartz and calcite). The concentrates are not suitable for smelting manganese-containing ferroalloys but can be used in the process of electrothermal beneficiation with selective carbothermal reduction of iron in an ore-thermal furnace. The smelting products can be manganese cast iron and iron-free, low-phosphorus limiting manganese slag with a high ratio of manganese to iron.