The objective of present study is to examine the effects of nanoparticles shapes on magnetohydrodynamic (MHD) boundary layer flow and heat transfer of nanofluid over a flat plate in the presences of thermal radiation. Three categories of fluids such as pure water, ethylene glycol and engine oil with Prandtl number (Pr) = 7.8 containing three different shapes of Gold (Au) nanoparticles i.e. sphere, platelet and lamina have used in this study. By using unique similarity transformation, the governing partial differential equations (PDEs) are converted into a system of non-linear ordinary differential equations (ODEs) which have tackled numerically by bvp4c program. The behaviours of several pertinent parameters i.e. solid volume fraction (φ), magnetic field (M) and thermal radiation (R_d) for different shapes of nanoparticles also elucidated in detail. The results indicated that all selected parameters have a significant impact on the thermal boundary layer. The Nusselt number is presented in graphically form. The nanoparticles of sphere shape in Au-Ethylene glycol are more significant for temperature disturbance. The heat transfer rate has found greater for lamina shapes in Au-Engine oil.

Pure and Mn (2.5 %, 5 % and 10 %) doped CuO nanoparticles were synthesized via chemical process of ultrasonic spray pyrolysis method. The crystal structure and grain size of the particles were determined using XRD. The optical properties of the samples were investigated using UV-Visible spectroscopy. The SEM micrographs revealed the surface morphology of sphere-shaped particles in all samples. The ZFC magnetization exhibits a sharp peak at 32 K and the FC magnetization saturated below this peak temperature. This is a characteristic feature of typical spin-glass behavior. In addition, the AC conductivity curves show an increasing conductivity value with increasing Mn content. The enhanced conductivity is due to the Mn doping in CuO induce defects in grain boundary.

In the paper, the core loss of SPWM inverter drive IPMSM is analyzed considering high frequency harmonics caused by SPWM and field weakening control. The output current of SPWM inverter has many high frequency harmonics at the field weakening region. The high frequency harmonics would affect the core loss on each part such as the yoke, teeth, shoe, and rotor. Therefore, IPMSM core of double layer type is divided into 6 parts to analyze the core loss in each part. In order to calculate the core loss considering the harmonics, the SPWM current is required. This is extracted by linking the SPWM inverter drive IPMSM. FEM analysis is used to compare the core loss when sinusoidal current and SPWM current are applied. The result that which part of the core is most affected is analyzed by FFT analysis applying the P.U. system.

This paper proposes a dual layer (delta-shaped) interior permanent magnet rotor with concentrated winding stator for the air conditioner refrigeration compressor of hybrid and pure electric vehicles. The proposed concentrated winding stator design is better than the existing distributed winding stator in terms of the refrigeration vehicle compressor internal flow, light weight structure, and compact design with small end-turn height (thin). However, concentrated winding also has some disadvantages including additional harmonics and torque ripple due to partial saturation. Therefore, this study proposes a design process for a dual layer interior permanent magnet rotor in order to minimize the torque ripple and magnet volume using the finite element method (FEM). The FEM result is determined at the weighted optimum operating point of the electric compressor, and is compared with that of the existing distributed winding model.

This work deals with the torque ripple minimization techniques of Segmented Rotor Switched Reluctance Motor (SSRM) for cooling fan application. Torque ripple, acoustic noise and vibration are factors resisting the segmented rotor SRM. To overcome this, stator and rotor pole modifications along with the effects of laminating steel material have been analyzed for the performance improvement of the machine. The performance of the machine with different laminating steel materials such as M19, M850-65A, M890-50d and M43 are compared with the conventional CR-10 steel material. With respect to pole shape modifications the analysis has been performed by considering stator pole taper, stator pole arc, rotor segement structure and rotor pole depth. The results highlight the influence of structural modifications and material properties on the performance of the motor. The results of electromagnetic analysis disclose that the segmented rotor configuration with M890-50d material exhibits superior electromagnetic characteristics.

This paper describes design modifications and optimization of a brush permanent magnet DC motor. The test model was optimized using the analytical method via an equivalent circuit, and the final model simulation was performed using the finite element method (FEM). For the optimization method, a central composite design of the response surface analysis was used, and torque and current ripples were analyzed using 2-D FEM. The back-to-back test method was used to evaluate the developed model to minimize the burden on the construction of the test equipment. The test results were validated through a comparison of the analysis results.

This study intended to evaluate the effect of the material of phantom-container on the MRS signal in 3T MRI. Three phantom-container consisting of clear laboratory-glass, PET-bottle, and falcon-tube was used. The metabolites contained 6 mM Cr and 3 mM Cho. FWHM and SNR of Cho and both peaks of Cr were calculated. FWHM of all the peaks of glass-phantom was 50.08 and 19.48 % fewer than those provided by PET and falcon-tube; also, the SNR of the all the peaks of the PET and falcon-tube were by average 77.99 and 91.18 % fewer than the peaks provided by glass-phantom. The laboratory-glass is a good material for building MRS phantoms since it does not affect the baseline-noise, FWHM, and SNR of the spectra. It was also revealed that the size of the phantom and the distance between the spectroscopy volume and phantom walls were important and can affect the baseline-noise.

In this paper, numerical simulation is used to simulate the sedimentation process of magnetorheological fluid (MRF), and the sedimentation time of MR fluid is predicted by this method. Firstly, based on the existing literature simulation method and its improvement, a numerical simulation method is proposed to simulate the MR fluid sedimentation process. Finally, a variety of MR fluid samples are prepared to detect the accuracy of the simulation results of the constructed numerical simulation method. It can be proved by comparing the measured sedimentation time with the simulated sedimentation time, and the method constructed in this paper can predict the sedimentation time of the more complicated MR fluid well, which has good practicability.

A reciprocating magnetic field was applied to prepare functionally graded materials (FGM) comprised of magnetic Ni and nonmagnetic epoxy resin. The reciprocating field was achieved by shifting a cylindrical permanent magnet along the axis towards or away from the sample in cycle. Ni decreases gradually with the distance from surface to bottom, which attributes to the continuously changing driving force on magnetic Ni particles by the reciprocating field. The gradient of Ni increases with cycle times, while decreases with the increase of the velocity of the reciprocating magnet. The results reveal that it is a more effective way to prepare FGMs by using reciprocating magnetic field compared with normal static magnetic field.

This paper presents a new framework for integrating a planar three-dimensional (3D) magnetometer, featuring high accuracy and reduced size. Sensing elements in this design are magnetoresistance (GMR) sensors, which generally exhibit good in-plane sensitivity but limiting performance when working out-of-plane. Therefore, to improve the out-of-plane sensing ability of the GMR sensors, we design a flux guide (FG) to redirect the out-of-plane magnetic field component to the sensitive plane of the sensors. In doing so, a Ni-Zn cubic FG, combined with a full-bridge of GMR, is exploited for z-sensing axis detection. The cross-detection minimization of in-plane magnetic fields is optimized by an FG rotated by 45° in the x-y axes. Moreover, for boosting the planar sensitivity, two half-bridge GMRs are incorporated into a cross-shaped flux concentrator, working as a fullbridge sensor. The performance of the proposed design is simulated, as well as estimated the sensing features.

This study examined the effects of transcranial direct current stimulation (tDCS) on different electrode sites on the activity of the upper extremity in chronic stroke patients. Forty-five subjects were randomly assigned to unilateral tDCS, dual tDCS, and control groups, and tDCS was applied to the unilateral tDCS and dual tDCS groups for 20 minutes per day, 5 times a week for a total of 4 weeks. The activity of the subject’s upper extremity was evaluated by a hand grip strength test, an elbow flexor and wrist flexor muscle tone test, and a Jebsen Taylor hand function test. In the unilateral tDCS group, dual tDCS group, and control group, significant improvement was observed in the hand grip strength test and the Jebsen Taylor hand function test after intervention (p<.05), and there was significant improvement in the hand grip strength test and the Jebsen Taylor hand function test compared to the control group (p<.05). The results of this study suggest that tDCS applied to the primary motor cortex (M1) positively affects the activity of the upper extremity in stroke patients.

This study was conducted to investigate the effects of high frequency repetitive transcranial magnetic stimulation (rTMS) combined with treadmill training on recovery of lower limb function in chronic stroke patients. 13 subjects were randomly assigned to 7 in the experimental group and 6 in the control group. The experimental group was applied 5 Hz high frequency rTMS of 15 minutes and treadmill training of 20 minutes, and the control group was applied sham rTMS of 15 minutes and treadmill training of 20 minutes per day, 5 times a week for a total of 4 weeks. The subjects were assessed for gait speed by 10-meter walk test (10MWT), gait endurance by 6-minute walk test (6MWT) and ability of dynamic stability by Timed up and go test (TUG). A significant improvement in 10MWT, 6MWT and TUG was observed after intervention in the experimental group (p < 0.05), and there was a significant improvement in all evaluation items compared to the control group (p < 0.05). The results of this study suggest that high frequency rTMS applied to primary motor cortex (M1) combined with treadmill training has a positive effect on the recovery of lower limb function in chronic stroke patients.

The purpose of this study is to investigate the effects of the dose distributions caused by a low-strength magnetic field transverse to the incident photon beams in inhomogeneous medium of the body such as the lung. A simple water-air-water phantom was used to evaluate the magnetic field induced dose effect by the field size of the beam and the beam energy. The Gafchromic BET3 self-developing dosimetry film was utilized for all measurements. Our results indicated that a localized magnetic field within the air region offers the capability of producing dose enhancement and dose reduction regions between the proximal and distal interfaces. It was demonstrated that the magnitude of the dose perturbation depends not only on the beam energy, but also on the field size of the beam. It is expected that this magnet technology could be further developed to provide higher dose to the tumor and lower dose to the normal tissue in radiation therapy for lung cancer.

Electromagnetic radiation camera (ERC) provides functional information about the left ventricle. We need new methods of quantitative analysis, such as the segmentation myocardial images for maximum utilization of ERC. The level set method(semi-automatic) based approach method that has excellent potential with regarding mapping topological change in 2D images but the crucial point is when stopping iteration to obtain the optimal segmentation result. This study suggests the Courant–Friedrichs–Lewy (CFL) condition, feature measurement index (FMI), and modified Thompson Tau technique (MTTT) to investigate the optimal convergence problem. The CFL condition contributes to the stable numerical iteration of the level set, whereas the FMI and MTTT are used for exact iteration stopping. This study compared the auto segmentation method and the manual segmentation method through assessments. The results were so matched (82.39±13.92 %) so we can develop a 3D model that could be used to diagnose ischemic heart disease and infarction. The proposed segmentation method can help to diagnose the disease conveniently and accurately in the clinic.

Recently, many design problems in the field of electrical engineering tend to be more complex, which are characterized by large scale in size, strong nonlinearity for performance analysis, and multi-dimensional design parameters. Therefore, it is not easy to seek for optimum effectively by traditional optimization algorithms. In order to solve optimal design of complex practical problems, in this paper, a novel hybrid optimization algorithm based on the differential evolution algorithm and the black hole theory is proposed and investigated. The differential evolution (DE) algorithm owns good diversity and flexibility, while the black-hole based optimization algorithm (BHBO) possesses faster convergence. In addition, these two algorithms have simple structures. The proposed algorithm with better merits combination may guarantee better convergence and stronger robustness than its independent counterparts of DE and BHBO. The searching performance is deeply investigated through numerical experiments on benchmark functions and practical electromagnetic applications.

Pulsed eddy current (PEC) testing is an electromagnetic nondestructive evaluation (NDE) technique which is used for detection and classification of flaws. This paper presents an approach for the extraction of novel timedomain flaw parameters viz. amplitude ratio (V₁/V₀) and time constant (τ) for detection and classification of different flaws. Experiments are carried out on stainless steel (SS-316) plate with artificial EDM notches whose width (1.0 mm & 3.0 mm) and depth (1.0 mm to 6.0 mm) varied. The proposed approach can classify both surface and sub-surface flaws in an 8.0 mm thick SS plate. The advantage of the proposed approach is that it doesn’t require a reference signal subtraction or signal processing methodologies for the detection and classification of flaws.