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This paper aims to present an accurate magnetic equivalent circuit for modeling the cylindrical electromagnet so that by analyzing it, the magnetic flux density in different parts of the electromagnet, as well as its lifting force, can be calculated.

The structure of the electromagnet is divided into parts that can be modeled by lumped element parameters. Mathematical equations for calculating these elements are presented and proved. The axial symmetry of the cylindrical electromagnet made it possible to use planar circuits for its modeling. To increase the accuracy of the proposed equivalent circuit, attention has been paid to the leakage flux as well as the nonlinear behavior of the ferromagnetic core. Also, the curvature of the magnetic flux path is considered in the calculation of the corner permeances of the core.

The magnetic flux density in different parts of the electromagnet was calculated using nodal analysis of the circuit and compared to the results of the finite element method. Also, a test bed was established to measure the lifting force of the electromagnet. Comparing the results shows a difference of less than 3% which indicate the good accuracy of the proposed circuit. In addition, due to the curvature of the flux path, there is a no-flux region in the center of the disk, the extent of which depends on the thickness of the disk and the diameter of the middle leg.

Magnetic equivalent circuit is a new contribution to analyze the cylindrical electromagnet and calculate its lifting force with good accuracy. The circuit lumped elements can be quickly calculated using mathematical equations and software such as MATLAB according to the actual path of the magnetic flux. Compared to other methods, the proposed circuit analyzes the electromagnet in a shorter period of time. This is the most important advantage of the proposed circuit model.

This paper deals with the field and force calculation in a model electromagnet which is the power drive of the shuttle loom. Hermitian hierarchical finite elements have been successfully applied to the field and force computation of the electromagnet. The computational results have been reported.

This paper aims to analyze the accuracy of the single and two-phase numerical methods for calculation of ferrofluid convective heat transfer in the presence of a magnetic field. The findings of current study are compared with previous single-phase numerical results and experimental data. Accordingly, the effect of various parameters including nanoparticles concentration, Reynolds number and magnetic field strength on the performance of the single and two-phase models are evaluated.

A two-phase mixture numerical study is carried out to investigate the influence of four U-shaped electromagnets on the hydrodynamic and thermal characteristics of Fe₃O₄/Water ferrofluid flowing inside a heated channel.

It is observed that the applied external magnetic field signifies the convective heat transfer from the channel surface, despite local reduction at a few locations. The maximum heat transfer enhancement is predicted as 23% and 25% using single and two-phase models, respectively. The difference between the results of the two models is mainly attributed to the slip velocity effect which is accounted for in the two-phase model. The magnetic field gradient leads to a significant increase in the slip velocity which in turn causes a slight difference in velocity and temperature profiles obtained by the single and two-phase models in the magnetic field region. According to percentage error calculation, the two-phase method is generally more accurate than the single-phase method. However, the percentage error of both models improves by decreasing either magnetic field intensity or Reynolds number.

For the first time in the literature, to the best of the authors’ knowledge, the current work analyzes the accuracy of the single and two phase numerical methods for calculation of ferrofluid convective heat transfer in the presence of a magnetic field.

An excessive increase in temperature will reduce the lifespan and even burn the coil. The variety of materials in the structure of the electromagnet along with its multi-layer winding creates a complex and heterogeneous thermal structure. There are very few researches that are completely focused on the thermal analysis of electromagnets. The purpose of this paper is to provide an accurate, yet fast and simple method for the thermal analysis of cylindrical electromagnets in both transient and steady-state modes. For this purpose, a thermal equivalent circuit (TEC) is presented based on the nodding approach.

The results of TEC analysis of cylindrical electromagnet, for two orthogonal and orthocyclic winding coil technologies, were compared with the results of the thermal simulation in COMSOL. The authors also built a laboratory model of the cylindrical electromagnet, similar to those analyzed and simulated, and measured the temperature in different parts of it.

The comparison of the results obtained from different methods for the thermal analysis of the cylindrical electromagnet indicates that the proposed TEC has an error of less than 2%. The simplicity and high accuracy of the results are the most important advantages of the proposed TEC.

Comparing the information and results related to winding schemes, indicates that the orthogonal winding has less cost and weight due to the shorter length of the wire used. On the other hand, orthocyclic winding generates lower temperature and has more lifting force, and is simpler to implement. Therefore, in practice, orthocyclic winding technology is usually used.

To provide information on magnetic lens design principles for neutron beam focussing and to characterize the efficiency of these devices.

Magnetostatic and neutron optical computations are presented for permanent magnet and electromagnetic hexapole lenses for neutron beam focusing. The numerical results are verified by magnetic and neutron beam measurements.

Neutron lenses built from brick‐shaped permanent magnets approximating the six‐pole Halbach structure yield relatively high field constant for a relatively small useful diameter. Electromagnets are weaker, but allow field constant adjustment.

The main limitation of both presented solutions resides in the difficulty of obtaining high magnetic flux densities. Superconducting coils in hexapole configuration can overcome this limitation.

The magnetic lenses can be used for beam focusing in scattering neutron instruments. The focused beam is also polarized.

Analytical formulae are supplied for the neutron path calculation in a six‐pole magnetic field. An electromagnet design with permanent magnet flux enforcement is provided.

Deposition of ink containing metal particles is possible using inkjet technologies. The purpose of this paper is to show a novel method for deposition of iron microparticles, with an average diameter of 1.24 μm, on a glass substrate that can potentially achieve concentrations of 0.21 per cent or higher.

The method combines drop‐on‐demand (DOD) technology with a creative way of positioning iron microparticles near to the nozzle's print head. The use of ferromagnetic particles allows the control of particle dispersion on the target sample surface. The particles are positioned close to the nozzle using a sharpened steel rod as holder and their alignment is controlled by generating an external magnetic field along the sharpened steel rod.

Successful deposition of iron microparticles with a potential concentration of 0.21 per cent or higher is reported.

The implemented method is restricted to ferromagnetic particles or alloys of ferromagnetic and non‐ferromagnetic materials.

The method described could be integrated to control the deposition of iron microparticles in the production of optoelectronic devices and biosensors. This method speeds up the deposition process due to the higher metal microparticle concentrations achieved.

The deposition method introduced in the paper reached concentrations of 0.084 per cent, similar to the highest concentrations (0.1 per cent) reported with conventional methods (inkjet inks containing metal nanoparticles). It also prevents the blocking of the print head nozzles, thus improving the efficiency of Fe particle deposition.

The purpose of this paper is to carry out research on friction and wear behavior of pin-bushing with magnetorheological fluids (MRFs).

The oscillation friction characteristics of MRFs with a magnetic field are evaluated by a pin-bushing friction wear tester. The housing is adjusted to apply the magnetic field to MRFs. Experiments are carried out with and without a magnetic field, and the coefficient of friction and temperature on the contact interface are measured. The surfaces of the pin and bushing are also examined by a surface profilometer and an optical microscope before and after tests. The experiment results show a lower coefficient of friction is observed when a magnetic field is applied.

The temperature is lowest when grease is used. The case when a magnetic field is present shows the higher temperature. The coefficient of friction is higher than grease lubrication when an MRF is applied. The coefficient of friction of the pin-bushing is lowest with grease and highest when a magnetic field is present. The friction coefficient of grease and MRFs decreases as the load increases and remains stable after 3 kN is added. The roughness, surface profile and morphology of the pin show the best results when grease is used as compared with MRFs.

The tribology characteristic of pin-bushing with MRFs shows more deficiency than that with grease. Nevertheless, it is necessary to carry out the research on the friction and wear characteristics of a pin-bushing with MRFs, as it is expected to increase the load-carrying capacity when an MRF is applied to the pin-bush system. Better friction and wear characteristics could be achieved by enhancing the property of MRFs.

This paper aims to prove the expediency and effectiveness of magnetic textiles use obtained by adding nanopowder synthesized on the basis of oxides of divalent and trivalent iron oxides, taking into account bacteriostatic, magnetotherapeutic and compressive properties.

The research includes methods of synthesis of nanoelements of bivalent and trivalent iron, methods of the theory of elasticity for determining the pressure between compression clothing and a limb, methods of creating an annular magnetic field with determination of its voltage, methods of determining the growth dynamics of mold bacteria and methods of approximation of experimental data.

On the base of the determination of the forces arising from the interaction of magnetic nanotextiles with a magnetic field, the expediency of using these materials in the creation of compression clothing has been proven. An additional medical value of magnetic textiles is the bacteriostatic effect. The content of magnetic nanoelements in the textile composition of 0.2% almost completely suppresses mold infections

Cotton samples with the addition of nanocomponents based on ferric and ferric oxides were studied.

Magnetotextile materials can be used in magnetotherapy, compression clothing, in textile products that provide bacteriostatic properties.

The use of magnetic textile materials is a perspective direction for the creation of medical textile products with complex properties.

A magnetorheological knee prosthesis is presented that automatically adapts knee damping to the gait of the amputee using only local sensing of knee force, torque, and position. To assess the clinical effects of the user‐adaptive knee prosthesis, kinematic gait data were collected on four unilateral trans‐femoral amputees. Using the user‐adaptive knee and a conventional, non‐adaptive knee, gait kinematics were evaluated on both affected and unaffected sides. Results were compared to the kinematics of 12 age, weight and height matched normals. We find that the user‐adaptive knee successfully controls early stance damping, enabling amputee to undergo biologically‐realistic, early stance knee flexion. These results indicate that a user‐adaptive control scheme and local mechanical sensing are all that is required for amputees to walk with an increased level of biological realism compared to mechanically passive prosthetic systems.

To review and discuss recently proposed homogenization methods for laminated magnetic cores and multi‐turn windings in FE models of electromagnetic devices.

The frequency‐domain homogenization is based on the adoption of complex and frequency‐dependent material characteristics (e.g. reluctivity) in the homogenized domain. The value of the complex quantity is obtained analytically or by means of a simple 2D FE model. The time‐domain counterpart requires the introduction of additional unknowns and equation.

The homogenization methods allow to take into account the global eddy current effect in the individual laminations and wires, with a reasonable precision and computational cost.

The homogenization methods have been validated numerically, i.e. by comparison with brute‐force FE computations where the eddy current effects are directly and accurately taken into account. Experimental validation should follow.

The analogy between the homogenization of laminated cores and windings has been evidenced.