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In this article, a novel fault-tolerant design process of the spoke-type interior permanent magnet (IPM) motor is proposed to prevent the increase of cogging torque and torque ripple due to partial demagnetization fault and to minimize the motor size. First, unlike other research papers on the irreversible partial irreversible demagnetization of permanent magnet (PM), in this article, the effect of partial irreversible demagnetization faults on the cogging torque and torque ripple for the fault cases is investigated. Then, a novel fault-tolerant design process is proposed to solve the problem of partial demagnetization faults that increase the cogging torque and torque ripple. In the novel fault-tolerant design process, first, to solve the problem of increasing cogging torque and torque ripple due to the partial demagnetization fault, a process for implementing a uniform irreversible PM demagnetization is proposed. Second, to compensate for the motor torque constant decreased by degraded PM, which is caused by irreversible demagnetization of PM, a torque compensation coefficient is also proposed. The proposed fault-tolerant design process is applied to the motor design for the integrated electric brake (IEB) system that requires high torque density. In the optimal design process, Latin hypercube sampling (LHS), a kriging method, and a genetic algorithm are utilized. To verify the effectiveness of the proposed fault-tolerant design process, it is compared with the conventional optimized design results in which irreversible demagnetization of PM is not allowed at all to prevent the partial demagnetization faults. As a result of comparing the optimal design results, the proposed optimization model utilizing the fault-tolerant design process can significantly reduce the motor volume by 12.9%, compared to the conventional optimization model. [ABSTRACT FROM AUTHOR]

Magnetic nanowires (MNWs) can have their moments reversed via several mechanisms that are controlled using the composition, length, diameter, and density of nanowires in arrays as-synthesized or as individual nanoparticles in assays or gels. This tailoring of magnetic reversal leads to unique properties that can be used as a signature for reading out the type of MNW for applications as nano-barcodes. When synthesized inside track-etched polycarbonate membranes, the resulting MNW-embedded membranes can be used as biocompatible bandaids for detection without contact or optical sighting. When etched out of the growth template, free-floating MNWs are internalized by cells at 37 °C such that cells and/or exosomes can be collected and detected. In applications of cryopreservation, MNWs can be suspended in cryopreservation agents (CPAs) for injection into the blood vessels of tissues and organs as they are vitrified to −200 °C. Using an alternating magnetic field, the MNWs can then be nanowarmed rapidly to prevent crystallization and uniformly to prevent cracking of specimens, for example, as grafts or transplants. This invited paper is a review of recent progress in the specific bioapplications of MNWs to barcodes, biocomposites, and nanowarmers. [ABSTRACT FROM AUTHOR]

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Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication. [ABSTRACT FROM AUTHOR]

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication. [ABSTRACT FROM AUTHOR]

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication. [ABSTRACT FROM AUTHOR]

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication. [ABSTRACT FROM AUTHOR]

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It is important to explore better alternatives to CMOS to sustain Moore’s law far in the future. One option is to integrate non-volatile spin devices, such as magnetic tunnel junction (MTJ), with the existing CMOS technology to augment its capability. This article presents five approximate 1 bit full adders for applications where accuracy can be traded for energy, speed, and area. The application of an approximate adder is demonstrated in image processing for smoothening an image. Three of these adders are fully non-volatile, one is partially volatile, and one is fully volatile. All the adders use SRAM-based sense amplifier (SA) to reduce sensing energy and hardware count. To reduce the delay, some of the adders utilize the parallel connection of logic devices (MTJ or MOSFET) in the logic tree. All the adders are simulated using 45 nm CMOS predictive technology model (PTM) and perpendicular magnetic anisotropy (PMA) CoFeB/MgO/CoFeB MTJ model with HSPICE simulator. After performing simulations, results show that the proposed fully non-volatile approximate adder (AXFA4) performs exceptionally well against its existing counterpart AX_MFA2 in terms of the energy-delay product (EDP) and the area-delay product (ADP) with a decrement of 84% and 80%, respectively. All the adder designs compute sum at 75% and carry at 100% accuracy, respectively. [ABSTRACT FROM AUTHOR]

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In this article, to accurately analyze the magnetic properties of high-temperature superconductor (HTS), a superconductor hysteresis model is proposed. Based on the physical mechanism, the hysteresis loop of HTS can be decomposed into an antimagnetic curve and a paramagnetic loop. The calculated and measured results of silver-sheathed Bi2223 superconducting tape samples under an external magnetic field are compared to show the effectiveness and accuracy of the presented method. [ABSTRACT FROM AUTHOR]

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In this article, boundary conditions for Landau–Lifshitz equations at the interface between two ferromagnets with different interfacial Dzyaloshinskii–Moriya interactions (iDMIs) are derived. We calculated and verified the analytical expression for the energy flux density continuity for the spin-wave (SW) propagation through the ferromagnet with stepwise iDMI considering the boundary conditions mentioned. Analytical expressions for reflection, transmission coefficients, and the nonreciprocity factor are calculated in the case of SW propagation through a ferromagnet with the stepwise iDMI. Two different types of nonreciprocity effects for SW propagation through a ferromagnet with the stepwise interface Dzyaloshinskii–Moriya interaction are revealed for opposite orientations of Dzyaloshinskii–Moriya vector. The material parameters of a ferromagnet and the stepwise iDMIs are found for which the extremely high nonreciprocity factor (>10) is expected according to the results of calculations. The results of this article deepen the knowledge about the SW propagation control in magnonic devices. [ABSTRACT FROM AUTHOR]

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Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers. [ABSTRACT FROM AUTHOR]

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In this work, a simple method is proposed to simultaneously reduce the size and cross-polarization level (XPL) of quarter-wave microstrip antennas by reconstructing the magnetic currents along the radiation edges. A design example of five shorted elements is given with a comparison of the quarter-wave microstrip antennas at 1.88 GHz. Measured results show an over 64% size reduction and 17-dB cross-polarization suppression enhancement for the proposed scheme as compared with the conventional one. Moreover, the proposed scheme exhibits good broadside radiation patterns with a gain of 5.4 dBi and the half-power beamwidths of about 104° in the E-plane and 84° in the H-plane. [ABSTRACT FROM AUTHOR]

The laser beam melting (LBM) additive manufacturing (AM) technology is used for processing a high silicon steel (Fe 6.5%wtSi). The effects of LBM machine parameters over microstructure and magnetic properties are studied. Particular attention is dedicated to determining the influence of a normalized energy density over the material density, the grain size, and the crystallographic texture and their impact on the magnetic properties: magnetic flux density and coercivity. [ABSTRACT FROM AUTHOR]

This article serves as an overview of existing models of permanent magnets (PMs) for electrical machines. The review study starts with the linear recoil model, which is commonly used to describe the reversible part of the demagnetizing curve. It is a simple model, especially useful for representing materials with high anisotropy, such as ferrite, NdFeB, and SmCo. The model is harder to apply for nonlinear materials, such as Alnico, but still possible since their recoil curves are linear. The study shows how the linear recoil model could be extended to include irreversible demagnetization, temperature dependence, and angular dependence. All such models have their advantages and disadvantages, which will be discussed further. Both the magnetization and the risk of demagnetization are temperature-dependent. It could be noted that NdFeB has an increased risk of demagnetization at high temperatures, while ferrite has it at very low temperatures. The temperature dependence is described and compared for several materials, also including simplifying models. There are different methods to include the inclination angle of an applied magnetic field when studying the demagnetization of PMs. Several models describe different phenomena associated with the underlying dynamics of magnetism. Such models could then consider coercivity mechanisms and coherent rotation of magnetization, both with the Stoner–Wohlfarth model and models of domain wall motions. [ABSTRACT FROM AUTHOR]

Based on thermoelectric analogy method, a thermal network model coupled with electromagnetic loss is presented. According to the actual structure of dry-type transformer windings, an accurate thermal network is established. Considering the distribution characteristics of heat source along the cooling ducts inside the dry-type transformer, the thermal parameters such as heat flux and convective heat transfer coefficients are calculated by finite element method (FEM) analysis and computational fluid dynamics (CFD). Based on the temperature rise experiment, the hottest spot located at the top of the outmost high-voltage (HV) winding is 151.8 °C, which verified the correctness of thermal network model. [ABSTRACT FROM AUTHOR]

This article presents the electromagnetic and mechanical design and analyses of a 7.67:1 gear ratio magnetic gear (MG) for a wave energy converter demonstrator. A 2-D and 3-D magnetostatic finite-element analysis (FEA) was conducted to maximize the mass torque density. To increase torque without increasing the diameter, a unique dual-stack rotor topology was used along with a 12-segment per pole-pair inner rotor Halbach array and a four-segment per pole-pair outer rotor Halbach topology. The eddy current loss within the MG was mitigated by using laminated magnets and low-loss electrical steel. The experimentally tested MG had a peak torque of 1796.8 $\text{N}\cdot \text{m}$ , which corresponds to an active region volumetric and mass torque density of 221.1 $\text{N}\cdot \text{m}$ /L and 105.74 $\text{N}\cdot \text{m}$ /kg, respectively. The efficiency at rated speed and maximum torque was measured to be 95%. A new in-plane eddy current loss mechanism was identified as being a primary reason for the measured electrical losses being higher than the initially calculated one. [ABSTRACT FROM AUTHOR]

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With the emergence of electric vehicles and electric aircraft technologies, lightweight motors have become a requirement. Conventional motors are generally made up of coils, permanent magnets, heavy iron stators, and rotor cores. This article presents complete analytical modeling and design of a novel coreless multi-phase magnetic resonant motor (MMRM), conceptualized through the approach of magnetic resonance coupling. The removal of magnetic iron cores drastically reduces the weight of the resulting motor. The stator and rotor cores of the motor are made of reinforced plastic fibers and can be 3-D printed. Unrelated to the general operating principle of the existing conventional electric motors, resonant wireless power transfer (WPT) is the key feature of these motors. All the essential machine characteristics, such as self-inductance, mutual inductance, torque, and frequency domains, are fully developed. The mathematical modeling of the machine’s physical phenomena is linked to its operation by simulation. This article shows the design concept and discusses the simulation procedure used to verify the developed analytical model through a finite-element analysis (FEA) from the established modeling topology equivalent to the proposed configuration motor model. Although the design is straightforward, an accurate analytical modeling and analysis are significant challenges to consider. [ABSTRACT FROM AUTHOR]

This article presents an accurate analytical model (AM) for synchronous reluctance machine (SynRM) that incorporates the effect of stator slots on the air gap flux density and torque waveforms. From the formulation of magnetic potential in the air gap for both the stator and rotor, the flux density is obtained, considering the first harmonic of the flux density and the electric loading, the average torque is calculated using the Lorentz’s force. The ripple torque is obtained from the energy stored in magnetic circuit. The method is developed for a rotor with one flux barrier per pole and then extended to a larger number of barriers. To validate the results obtained by the AM proposed finite element analysis have been carried out. Several comparisons have been derived considering different rotor positions as well as different harmonic orders, and the pros and cons of the method are highlighted. The model performs fast and can predict results with high accuracy, and can be adopted to speed up the preliminary design and optimizations of this type of motors, with respect to finite element. In addition, from the analytical expressions it is possible to obtain all the correlations between electrical, magnetic, and geometrical characteristics of the machine, with the advantage of enabling a faster machine design. [ABSTRACT FROM AUTHOR]