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The adverse effects of temperature on the lubricating properties of nano magnetorheological grease are reduced by applying of a magnetic field.

Nano magnetorheological grease was prepared via a thermal water bath with stirring. The lubricating properties of the grease were investigated at different temperatures. Then the lubricity of the prepared nano magnetorheological grease was investigated under the effect of thermomagnetic coupling.

As the temperature rises, the coefficient of friction of grease lubrication gradually increases, surface wear gradually increases and lubrication performance gradually decreases. Compared with grease, magnetorheological grease has a decreased coefficient of friction and enhanced lubrication effect under the action of a magnetic field at different temperatures.

A lubrication method using a magnetic field to reduce the effect of temperature is established, thereby providing new ideas for lubrication design under a wide range of temperature conditions.

Several graphs, streamlines, isotherms and 3D plots are illustrated to enlighten the noteworthy fallouts of the investigation. Embedding flow factors for velocity, induced magnetic field and temperature have been determined using parametric analysis.

Ternary hybrid nanofluids has outstanding hydrothermal performance compared to classical mono nanofluids and hybrid nanofluids owing to the presence of triple tiny metallic particles. Ternary hybrid nanofluids are considered as most promising candidates in solar energy, heat exchangers, electronics cooling, automotive cooling, nuclear reactors, automobile, aerospace, biomedical devices, food processing etc. In this work, a ternary hybrid nanofluid flow that contains metallic nanoparticles over a wedge under the prevalence of solar radiating heat, induced magnetic field and the shape factor of nanoparticles is considered. A ternary hybrid nanofluid is synthesized by dispersing iron oxide (Fe3O4), silver (Ag) and magnesium oxide (MgO) nanoparticles in a water (H₂O) base fluid. By employing similarity transformations, we can convert the governing equations into ordinary differential equations and then solve numerically by using the Runge–Kutta–Fehlberg approach.

There is no fund for the research work.

This kind of study may be used to improve the performance of solar collectors, solar energy and solar cells.

This investigation unfolds the hydrothermal changes of radiative water-based Fe₃O₄-Ag-MgO-H₂O ternary hybrid nanofluidic transport past a static and moving wedge in the presence of solar radiating heating and induced magnetic fields. The shape factor of nanoparticles has been considered in this study.

This study aims to deal with entropy generation and thermal analysis of magnetic hybrid nanofluid containing silver and gold as nanoparticles (Au-Ag/NPs) in the Eyring–Powell fluid.

The blood is used as a base fluid to study the rheological effects in a wavy asymmetric channel. The effect of viscous dissipation is also taken into account. The mathematical model is developed using the lubrication technique. The perturbation method is used to solve the nondimensional nonlinear differential equations, whereas the pumping properties have been analyzed using numerical integration.

The impact of entropy generation, Brinkman number, Hartmann number, nanoparticles volume fraction, thermal Grashof number, Brinkman number and Eyring–Powell fluid parameter is examined on the velocity profile, temperature profile and pumping characteristics. It is observed that the introduction of gold and silver nanoparticles boosts the velocity field in a smaller segment of the channel. The temperature profile rises for the increasing values of Hartmann number, Brinkman number and nanoparticle volume fractions while the temperature profile is restrained by the Eyring–Powell fluid parameter. The pumping rate rises in all sections as the thermal Grashof number and Hartmann number increase; however, the Eyring–Powell fluid parameter has the reverse effect. The volume of the trapping boluses is significantly affected by the Eyring–Powell fluid parameter, thermal Grashof number and fluid parameter.

The results are original and contribute to discover the role of hybrid nanoparticles under the influence of entropy generation viscous dissipation and magnetic fields. Pharmaceutical technology may use this research for things like better mucoadhesive drug delivery systems and more productive peristaltic micropumps.

Microribbon with meander type based on giant magnetoimpedance (GMI) effect has become a research hot spot due to their higher sensitivity and spatial resolution. The purpose of this paper is to further optimize the line spacing to improve the performance of meanders for sensor application.

The model of GMI effect of microribbon with meander type is established. The effect of line spacing (Ls) on GMI behavior in meanders is analyzed systematically.

Comparison of theory and experiment indicates that decreasing the line spacing increases the negative mutual inductance and a consequent increase in the GMI effect. The maximum value of the GMI ratio increases from 69% to 91.8% (simulation results) and 16.9% to 51.4% (experimental results) when the line spacing is reduced from 400 to 50 µm. The contribution of line spacing versus line width to the GMI ratio of microribbon with meander type was contrasted. This behavior of the GMI ratio is dominated by the overall negative contribution of the mutual inductance.

This paper explores the effect of line spacing on the GMI ratio of meander type by comparing the simulation results with the experimental results. The superior line spacing is found in the identical sensing area. The findings will contribute to the design of high-performance micropatterned ribbon with meander-type GMI sensors and the establishment of a ribbon-based magnetic-sensitive biosensing system.

The goal of this research is to investigate the convergence behavior of the Newton iteration, when solving the nonlinear problem with consideration of hysteresis effects. Incorporating the vector hysteresis model in the magnetic vector potential formulation has encountered difficulties. One of the reasons is that the Newton method is very sensitive regarding the starting point and states distinct requirements for the nonlinear function in terms of monotony and smoothness. The other reason is that the differential reluctivity tensor of the material model is discontinuous due to the properties of the stop operators. In this work, line search methods to overcome these difficulties are discussed.

To stabilize the Newton iteration, line search methods are studied. The first method computes an error-oriented search direction. The second method is based on the Wolfe-Powell rule using the Armijo condition and curvature condition.

In this paper, the differentiation of the vector stop model, used to evaluate the Jacobian matrix, is studied. Different methods are applied for this nonlinear problem to ensure reliable and stable finite element simulations with consideration of vector hysteresis effects.

In this paper, two different line search Newton methods are applied to solve the magnetic field problems with consideration of vector hysteresis effects and ensure a stable convergence successfully. A comparison of these two methods in terms of robustness and efficiency is presented.

The numerical analysis is to scrutinize the collective effect of convective current along with the thermal energy transport in an inclined lid-driven square chamber with sine curve based temperature at the lower wall in the existence of unchanging external magnetic field. Insulation has been placed on the left and right of the box to increase the effective space volume of the shell. The thermal condition at ceiling wall is kept lower than the one on the floor.

The finite volume method employs to discretize (non-dimensional) system of equations govern the model. The heat transfer rate is measured by adjusting various variables, such as the Richardson number Hartmann number, inclination of an enclosure.

The flow behavior of enclosure convection is more highly influenced within the natural convection when enclosure inclination varies as well as magnetic field strength. The overall heat transfer rate decreases due to increase in both the Hartmann number as well as Richardson number.

The results of the present study are very useful to the cooling of electronic equipments.

The study model is useful to the thermal science community and modelling field.

This research is a novel work on mixed convection flow in an inclined chamber with sinusoidal heat source.

The purpose of this research is to assess the removal of oil spills from the seawater surface as well as the antibacterial activity of ZnFe₂O₄-cetyltrimethylammonium bromide (CTAB, cationic surfactant) magnetic nanoparticles (ZFO-CTAB MNPs).

A CTAB-assisted sol–gel method was used to synthesize ZFO-CTAB MNPs. X-ray powder diffraction and Fourier transform infrared spectroscopy were used for ZFO-CTAB MNPs characterization. Also, the magnetic force and apparent density of ZFO-CTAB MNPs were determined. The oil spill cleanup was investigated by using the gravimetric oil removal (GOR) technique, which used ZFO-CTAB MNPs as oil absorbent material and four oil samples (crude, diesel, gasoline and used oil) as oil spill models. The antibacterial activity of ZFO-CTAB MNPs against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi) was investigated by using the optical density method.

The results revealed that, when the amount of ZFO-CTAB was 0.01 g, gasoline oil had the highest GOR (51.80 ± 0.88 g/g) and crude oil had the lowest (11.29 ± 0.82 g/g). Furthermore, for Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa, ZFO-CTAB MNPs inhibited bacterial growth with a higher percentage (94.24%–95.63%).

The applications of ZFO-CTAB MNPs in the cleanup of oil spills from aqueous solutions, as well as their antibacterial activity. The results showed that ZFO-CTAB MNPs are a promising material for removing oil spills from bodies of water as well as an antibacterial agent against Gram-negative bacterial strains.

The purpose of this study is to investigate the manufacturability of Fe-3Si lattice structures and the resulting mechanical properties. This study could lead to the successful processing of squirrel cage conductors (a lattice structure by design) of an induction motor by additive manufacturing in the future.

The compression behaviour of two lattice structures where struts are arranged in a face-centred cubic position and vertical edges (FCCZ), and struts are placed at body-centred cubic (BCC) positions, prepared by laser powder bed fusion (LPBF), is explored. The experimental investigations are supported by finite element method (FEM) simulations.

The FCCZ lattice structure presents a peak in the stress-strain curve, whereas the BCC lattice structure manifests a plateau. The vertical struts aligned along the compression direction lead to a significant increase in the load-carrying ability of FCCZ lattice structures compared to BCC lattice structures. This results in a peak in the stress-strain curve. However, the BCC lattice structure presents the bending of struts with diagonal struts carrying the major loads with struts near the faceplate receiving the least load. A high concentration of geometrically necessary dislocations (GNDs) near the grain boundaries along cell formation is observed in the microstructure.

To the best of the authors’ knowledge, this is the first study on additive manufacturing of Fe-3Si lattice structures. Currently, there are no investigations in the literature on the manufacturability and mechanical properties of Fe-3Si lattice structures.

The horizontal rotational single-sheet tester (RSST) suffers from weaknesses such as the reduced size of test samples, measurement disturbances due to magnetic flux leakage and nonhomogeneity of field in the measurement area. Although the vertical RSST allows to overcome the first two aforementioned drawbacks, the heterogeneity of the field in the test sample remains an issue. In addition, there is still a lack of device standardization to ensure test repeatability, as already is well established with the Epstein frame. This paper aims to investigate the influence of several parameters on the field homogeneity in the test sample.

A fully 3D finite element model of a vertical RSST is developed and used to perform a sensibility study on several geometrical parameters.

The influence of several parameters on the field homogeneity in the test sample, such as the geometrical dimensions of the yokes, the presence or not of holes drilled inside the test sample for B-coil placement as well as the size of the H-coils and B-coils, is addressed.

It is expected that this study will contribute to the optimization and standardization vertical RSSTs.

Because the nanocrystalline core is widely used in power electronic equipment, and the excitation waveform of its working mode is complex, the vibration at medium and high frequencies cannot be ignored. Therefore, this study aims to study the vibration mechanism of nanocrystalline strip and the vibration characteristics of nanocrystalline magnetic ring under different excitation waveforms.

First, the electromagnetic vibration mechanism between nanocrystalline strips is analyzed by finite element analysis, and the force of the magnetic ring with and without air gap is compared and analyzed. Then, the vibration of nanocrystalline magnetic ring under different excitation waveforms such as sine wave, triangular wave, symmetric rectangular wave and asymmetric rectangular wave is analyzed by experimental method. The acceleration time domain waveform measured by the experiment is analyzed by fast Fourier transform, and the vibration is analyzed according to the spectrum.

Because of the increase of magnetic flux leakage, the volume force density and the Maxwell force on the surface of the nanocrystalline magnetic ring will increase after the air gap is opened, resulting in the intensification of vibration. Under symmetric/asymmetric rectangular wave excitation, the vibration acceleration varies with the duty cycle. Due to the influence of harmonic excitation, the relationship between the main frequency of vibration and the excitation frequency is not two times, and its multiple decreases with the increase of excitation frequency.

The research and analysis of this paper can promote the application of new magnetic materials in electrical equipment in small and medium-sized and medium- to high-frequency fields.