The patterned substrates have been widely developed for various applications in the nanotechnology. In particular, the magnetic ring arrays could be utilized to not only the magnetic devices, such as memories and logics, but also magnetic stealth films using spin wave excitations. In this works, the magnetic switching behaviors and the thermally excited spin wave properties of the NiFe (permalloy) ring arrays on the anodic aluminum oxide template with carbon nanotubes were investigated. With increasing the diameter of the rings, the larger dipole interactions induced the larger coercive field of the array films in the plane directions. At the magnetically saturation conditions, the smaller diameter of the rings produced the single and broad spin wave absorptions due to the isotropic magnetic domains in both the horizontal and the vertical directions. When the size of the ring increased, each component felt different magnetic anisotropy field so that the two spin wave excitation peaks revealed. In terms of the mass production of the magnetic nano-ring arrays on the anodic aluminum oxide template, the various size and the shapes of the magnetic ring patterns could be good candidates for the rf stealth films of the defense industries.

The 1D chain-like α-Fe₂O₃ nanostructures were synthesized using a facile solvothermal method followed by subsequent annealing in air at 450 ℃ for two hours. We have investigated the microstructure and magnetic properties of the samples in detail. Field emission scanning electron microscopy revealed the formation of 1D chain-like morphology of α-Fe₂O₃ nanostructures. The presence of the pure hematite phase in all samples was confirmed by X-ray diffraction (XRD). Further, results obtained from Raman and FT-IR spectra are consistent with XRD outcomes. The magnetic studies (M-H curves) of samples exhibited a wide range of properties. The S₁ and S₅ samples exhibit large coercivity (H_C) values of 878 Oe and 1092 Oe, respectively. Interestingly, large magnetization 15 emu/g and lowest H_C (= 56 Oe) were observed for sample S₂ compared to all other samples. The unusual magnetic properties of the samples are due to morphology (shape, size, and self-assembled 1D orientation of particles), surface spin disorder, and (surface/interface) anisotropy of the nanoparticles.

In this study, the mathematical expression of temperature dependence upper critical magnetic field (H_c2), angle dependence of upper critical magnetic field (H_c2), and temperature dependence of Ginzburg-Landau (GL) characteristics were investigated. The parameters were computed by using two band Ginzburg-Landau (GL) phenomenological model for Ba(Fe_1-xNi_x)₂As₂ iron based superconductor. Application of very small external magnetic field at low temperature to nickel doped BaFe2As2 changes to Ba(Fe_1-xNi_x)₂As₂ iron based superconductor at a critical temperature of 19.5 K. The phase diagrams of the two upper-critical field and GL characteristics length were plotted as a function of angle and temperature for Ba(Fe_1-xNi_x)₂As₂ iron based superconductor using the experimental values. The phase diagram shows the linear dependence of upper critical magnetic field parallel and perpendicular with temperature (T). Correspondingly, the phase diagrams of the upper critical field (H_c2(θ)) versus the angle (θ) were plotted. The parallel and perpendicular to the symmetry axis of coherence length (ξ_GL(T)) and penetration depth (λ_GL(T)) versus temperature were plotted. In these plots both parameters are increased with increasing temperature and diverges at the critical temperature for the superconductor Ba(Fe_1-xNi_x)₂As₂. This theoretical investigation was found to be in agreement with the obtained experimental results.

The nanocrystalline powders of Cr-doped SnO₂ with Cr-dopant concentrations of 2, 4 and 6 wt%, were synthesized by a simple hydrothermal method. XRD results, along with the FT-IR and SAED patterns, confirmed the formation of the SnO₂’s tetragonal phase without other impurity phases. Optical analysis revealed a significant decrease in the energy gap of the doped samples from 3.69 to 3.40 eV. X-ray absorption spectroscopy, including x-ray absorption near-edge spectroscopy, was used to qualitatively investigate the valence states of doped Cr.

Using first principles calculation, we investigated the magnetic anisotropy of Pd/Co/Pd ultrathin film. Here, we explored the magnetic anisotropy of pristine Pd/Co/Pd ultrathin film and also interface vacancy defect (Pd or Co) and the oxygen diffusion as well. No substantial change in the magnetic moment is found in the vacancy defect and also in the O diffusion structure relative to the pristine system. We found that the pristine Pd/Co/Pd system has a perpendicular magnetic anisotropy of 1.37 meV/cell. This perpendicular magnetic anisotropy decreased to 0.46 meV/cell in Pd vacancy defect and it became 0.56 meV/cell in Co vacancy defect. We also obtained similar magnetic anisotropy energy of 0.52 meV/cell in the O impurity system. Although the vacancy defect and O impurity system exhibited a similar magnetic anisotropy, we found that this feature originated from different spin-orbit coupling effect which is sensitive to the sample preparation condition.

Owing to thermal requirements of many industrial and engineering processes, this research presents the improved feature of hybrid nanofluid with applications heat source and sinks features. The most fascinating Zinc ferrite and Nickle Zinc ferrite nanoparticles are used to predict the thermal enhancement in engine oil and Kerosene oil base materials. The radiative phenomenon with nonlinear relations is encountered to enhance the heat transportation pattern. Moreover, the entropy generation assessment is also observed with significances of optimized analysis. The consideration of porous space is inspected by using the Darcy-Forchheimer theory. A comprehensive comparative analysis for enchantment of heat transfer rate is examined between both types of nanoparticles. The physical influence of parameters for velocity, thermal gradient and entropy generation phenomenon is visualized. It is observed that thermal efficiency of ferrite nanoparticles (MnZnFe₂O₄) with suspension of engine oil (C₈H₁₈) base liquid is more progressive as compared to the suspensions of ferrite nanoparticles and kerosene oil (C₁₀H₂₂) hybrid material.

This study incorporates the numerical behavior of radiative flow of electrically conductive viscous fluid though porous medium with slip effects. The boundary is supposed to be convective during the flow. The governing nonlinear partial differential equations are transformed into its corresponding ode’s with the help of suitable similarity transformations.

The theme of this article is to investigate hydrodynamic flow of an incompressible second grade nanoliquid by a curved stretched sheet. Energy expression is developed through dissipation and Joule heating. Brownian and thermophoresis diffusion are also scrutinized. Physical feature of entropy generation is discussed. Isothermal cubic autocatalytic chemical reactions are discussed. Suitable transformations are used to develop the ordinary differential system. To develop a convergent series solution we employed the Optimal Homotopy Analysis Technique (OHAM). Graphical description of velocity, entropy generation, temperature distribution and concentration versus sundry parameters are discussed. An opposite behavior in velocity field is noted for magnetic and curvature parameters. Temperature distribution and velocity field have reverse trends for melting parameter. An augmentation in temperature is observed for radiation parameter. Larger magnetic variable lead to improve the entropy generation. Entropy optimization is boosted versus higher magnetic parameter.

The purpose of this study was to compare the effect of 8-channel and 32-channel head coils for 3 Tesla brain single shot spin echo diffusion-weighted imaging (DWI) with different b-values. All experiments were performed on a 3 Tesla magnetic resonance scanner using an 8-channel and a 32-channel head coils. The signal-to-noise ratio (SNR), apparent diffusion coefficient (ADC) values, and image distortions were measured with an American College of Radiology (ACR) head phantom. The SNR and ADC values decreased with increasing bvalue, and the distortion and image noise increased. In particular, DWI with a b-value ≥ 2000 showed significant noise and distortion for both coils. In conclusion, the use of 32-channel head coils has advantage for brain DWI compared with 8-channel head coils. However, brain DWI with a b-value ≥ 2000 did not statistically improve SNR on 32-channel coils compared with 8-channel coils, and showed a significant noise and distortion for both coils

Integrated positron emission tomography (PET)/magnetic resonance (MR) imaging is gradually being used to improve the rate of cancer lesion detection in the medical field. To enhance the quality of PET/MR images, attenuation correction (AC) techniques are used by applying MR pulse sequences of the controlled aliasing in parallel imaging results in higher acceleration (CAIPI; MR AC_Dixon-Caipi) and the generation autocalibrating partially parallel acquisition (GRAPPA; MR AC_Dixon-Grappa), based on the T1-weighted two-point Dixon pulse sequence. In addition, quality control using a Jaszczak phantom filled with water and radioisotopes is frequently performed when scanning the patient. When acquiring MR-based AC PET images in the phantom study, artifacts are caused by high permittivity in water, and there is a limitation in the acquisition of uniform image quality. Therefore, the purpose of this study was to compare the image quality using phantom fluids with lower permittivity than water (sodium chloride (NaCl) NaCl+nickel sulfate (NiSO₄)) according to MR AC_Dixon-Caipi and MR AC_Dixon-Grappa pulse sequences using various quantitative analysis parameters: percent of non-uniformity (PNU), percent contrast recovery (PCR), signal to noise ratio (SNR), and coefficient of variation (COV). The results indicated that the image quality with NaCl+NiSO₄ fluid based on the results was 1.2-, 1.6-, 1.4-, and 1.1 times superior to that of NaCl fluid, respectively. In conclusion, NaCl+NiSO₄ fluid is suitable as a phantom fluid material in PET/MR images.

In this study, we investigated the synthesis of Na-La system M-type ferrite with different mole ratios. Some part of Fe in the M-type ferrite was substituted by Co, and variation of fraction of the M-type ferrite as function of mole ratio was investigated. Sample with/without Co-substitution composed of multiphases of M-type ferrite and other phases. Fraction of M-type ferrite in the samples was depending on mole ratio in the raw material. Curie temperatures of Co-free and Co-substituted M-type ferrite were approximately 432℃ and 428 ℃, respectively. Saturation magnetisation of the Co-free Na_0.5La_0.5 system M-type ferrite was approximately 72.5 emu/g.

Motors used as power source for electrified vehicles require secure of rotors rigidity leading by high-voltage and high-speed technology for miniaturization, large output, and high efficiency. Therefore, most of automobile manufacturers adopt Interior Permanent Magnet Synchronous Motor (IPMSM). Temperature change in Permanent Magnet Synchronous Motor leads to temperature change in permanent magnet which is inserted inside of rotor, and the change occurs into magnetic flux density change depending on the nature of material. Therefore, heat control technique and compensation for reduce power is necessary since the efficiency drop leaded by temperature change in motor of electrified vehicles directly affects power performance and mileage. This paper suggests the way to react to temperature change compensating real-time flux and torque according to motor temperature change using single Look-Up Table (LUT) which is measured at intermediate temperature. Matlab Simulink is used to verify, and Motor Dynamo is used to compare with existing method, and eventually to demonstrate feasibility.

Fe–Ni alloys have attracted interest as important magnetic alloys without rare-earth (RE) elements, which exhibit a wide variety of magnetic properties depending on the atomic ratios of Fe and Ni. Here, we attempted to synthesize Fe-Ni magnetic materials using a Fe based amorphous alloy precursor that is thermodynamically metastable and has more open atomic packing structure than crystalline alloys. High energy ball milling was applied to promote the formation of various Fe-Ni phases using mixtures of the amorphous precursor powder and 10-50% crystalline Ni powder. The as-milled composite powders as well as the composite powders annealed at 673 K were analyzed by X-ray diffractometer, differential scanning calorimeter, scanning electron microscope, and vibrating sample magnetometer to investigate their magnetic properties in terms of phase transformation behavior of the composite powders.

In this study, Cu-doped intermetallic compounds with the chemical composition of Pr₂Fe_17-xCu_x (x = 0, 0.1, 0.2) were prepared by the arc-melting process. SEM analysis revealed that the samples consist of irregularly shaped and strongly connected micron-scale particles range from 0.5 μm to 4 μm. EDX analysis showed that all the samples consist of a single phase.

This study examined the effects of repetitive peripheral magnetic stimulation and exercises on pain, leg muscle strength, and WOMAC index in knee osteoarthritis patients. Twenty subjects were randomly assigned to experimental and control groups. rPMS and exercises were applied to the experimental group for 20 minutes per day, 5 times a week for a total of 4 weeks. The subjects were evaluated by a VAS test, FTSST test, and WOMAC test. In the experimental group, significant decrease was observed in the VAS test after treatment (p<.05), and there was significant difference in the VAS test compared to the control group (p<.05). In both the experimental group and control groups, significant decrease was observed in the FTSST test and WOMAC test after treatment (p<.05), and there was no significant difference in the FTSST test and WOMAC test compared to the control group (p>.05). The results of this study suggest that rPMS and exercises applied effects the pain relief and improve knee joint function in knee osteoarthritis patients.

This communication based on nanofluid theory is exhibited to study the squeezing mechanism. Hydro-magnetic phenomenon is incorporated in the analysis of nanofluid flow. The flow of heat and mass transport is interpreted by the constitutive relationship of modified diffusion model which overcomes the deficiencies in Fourier’s and Fick’s classical theories. The nano-fluid theory also incorporates the features of two important slip mechanisms namely Brownian diffusion and thermophoresis. Resulting heat and mass transport problems are figure out to develop the series solutions. Interval of convergence is established for computed series solutions. Behavior of emerging parameters in flow distributions are graphed and discussed. The major founds in this attempt is that higher Brownian diffusion strengthens the both heat and mass fluxes, while larger thermophoresis parameter enhances the heat flux but it weakens the mass flux. Moreover, both heat and mass flow field decays for enlarge estimation of thermal and solutal time relaxation parameters, respectively. Velocity field shows dual behavior for dominant magnetic parameter.

These authors contributed equally to this work