Recent advances in the research area of 2D magnetic topological solitons (vortices and skyrmions) in restricted geometries are reviewed. The description of the solitons is based on macroscopic micromagnetic approach and the Landau-Lifshitz equation of the magnetization motion. The vortex/skyrmion stability, energy barriers, gyrotropic and spin wave excitation modes in thin ferromagnetic films and dots are considered.

Solid rotor induction motor (SRIM) is widely used in many fields due to its sturdy construction, low maintenance costs, and soft mechanical characteristic. A novel SRIM with toroidal winding (N-TWSRIM) is proposed and its equivalent circuit model (ECM) is established herein. The structure of N-TWSRIM is introduced and its operating principle is analyzed according to the movement of armature magnetic field at different times. The main structural parameters of N-TWSRIM are given, an equivalent circuit model is established to analyze performance of motor, and the results of ECM and two-dimension finite element model (FEM) are compared. Finally, to validate the correctness of operating principle and equivalent circuit model, a prototype of N-TWSRIM has been built and experimented. It shows that the experimental results are consistent with the finite element and analytical results.

The interior permanent magnet synchronous motor (IPMSM) has many advantages like high torque density, high efficiency, and a wide range of operation area since the reluctance torque and magnetic torque can be applied simultaneously. However, cogging torque that is generated by difference in magnetic resistance due to salient rotor topology and its position is one of the most important factors to be considered while designing an IPMSM as it causes vibration and noise. This paper presents a method for reduction of cogging torque in IPMSM by using random optimization. Random optimization is a constrained stochastic approximation procedure that uses random-direction finite difference gradient estimates. Random optimization is advantageous in cases where the objective function is unclear or cannot be differentiated. In this paper, the use of improved random optimization technique than the existing one for optimal design of IPMSM with minimized cogging torque is proposed.

In order to study the temperature characteristics of magnetorheological fluid dynamometer, the torque model and working principle of magnetorheological fluid dynamometer were analyzed, the temperature experiment of magnetorheological fluid dynamometer was conducted, and the experimental data were analyzed and processed in this paper. The fitting curves between the speed of magnetorheological fluid dynamometer and the experimental temperature, the speed and the torque, the current and the torque as well as the current and the temperature were obtained. Then, the temperature field of magnetorheological fluid was simulated by FLUENT based on the experimental data. The temperature field nephograms and temperature values of test points under different working conditions were obtained. Comparing the experimental values with the simulation values, the relative error was less than 7.8 %, which was within a reasonable range. Finally, from the aspect of temperature reduction, the simulation model was optimized. Based on the principle of heat convection, the simulation model was reconstructed. The maximum temperature drop was 10 ℃.

This paper first proposes an electromagnetic actuator design and dynamic optimization method for selective miniature circuit breaker (SMCB), and realizes good coordination of electromagnetic actuator force and energy characteristics. Based on short delay tripping mechanism force and magnetic field model, it builds Matlab and Adams co-simulation platform, simulates and analyzes the magnetic field distribution and force energy property under different electromagnetic topological structure, and establishes the permanent magnet electromagnetic structure model. Then, it builds multi-field coupled mathematical model, and studies multi-objective dynamic optimization design for electromagnetic actuator based on quantum particle swarm algorithm. Finally, it develops the 100A miniature circuit breaker. The experimental results show that the optimized electromagnetic actuator design can effectively control the miniature circuit breaker tripping action threshold and mechanical characteristics.

This paper proposes a design method of the surface-mounted permanent magnet synchronous motor using electromagnetic and thermal analysis. Since the electromagnetic and thermal fields are related, the permanent magnet synchronous motor should be considered not only in terms of the power density but also the thermal characteristics. The analytic method was used to investigate the power density of the concentrated winding model using the same number of poles. In the thermal design process, the analytic prediction was carried out by using the electromagnetic and thermal analysis called the lumped parameter thermal network (LPTN). The optimized geometry and losses which were calculated by the electromagnetic finite-element analysis were considered in the LPTN. As a result, an improved model was designed with superior power density and thermal characteristics to the prototype. Finally, the experiments were conducted to verify the validity of the design process and results.

Ce-containing (Nd,Ce)-Fe-B-type hybrid magnet was fabricated by die-upset technique using two different types of materials: Ce-substituted (Nd_0.55Ce_0.45) ₁₅Fe_72.2Co_6.6Ga_0.6B_5.6 HDDR powder and melt-spun Nd_13.6Fe_73.6Co_6.6Ga_0.6B_6B5.6 flakes. Magnetic performance of the hybrid magnet was superior to that of the single alloy magnet when they had identical overall composition: _iH_c = 6.8 kOe, M_r = 10.6 kG, and (BH)_max = 19.8 MGOe for the Ce-containing hybrid magnet and _iH_c = 3.9 kOe, M_r = 9.8 kG, and (BH)_max = 11.6 MGOe for the magnet from the single alloy HDDR powder. Die-upset hybrid magnet consisting of two constituent materials showed smooth and single-material-like demagnetization behavior, and this was attributed to the exchange interaction between neighbouring grains in the magnet.

Texture development in the Ce-substituted Nd-Fe-B-type die-upset hybrid magnet, which was fabricated using starting materials of Ce-substituted (Nd_0.55Ce_0.45)₁₅Fe_72.2Co_6.6Ga_0.6B_5.6 HDDR-treated alloy powder and meltspun Nd_13.6Fe_73.6Co_6.6Ga_0.6B_5.6 flakes (MQU-F) without Ce, was investigated. Noticeably better texture developed in die-upset magnet from the MQU-F flakes alone with respect to magnet from the HDDR-treated powder alone. Better texture developed also in the MQU-F flake regions in the die-upset hybrid magnet with respect to the HDDR particle regions, and overall texture in the hybrid magnet was dominantly controlled by the texture in the MQU-F flake regions. Overall texture in the hybrid magnet was not as good as the weighted average of texture expected from texture of the single alloy magnets from the HDDR powder alone and the MQU-F flakes alone.

With the development of switching power supplies, miniaturization and high efficiency become hot research issues, and decreasing high-frequency losses is an effective method to achieve it. In this article, the effect of different calcination temperature on the power losses of MnZn ferrites at high frequency (500 kHz) over a broad temperature range is reported. The MnZn ferrites samples were prepared by ceramic process and the effect of calcination temperature was analyzed. The raw materials were calcined at 775 ℃, 800 ℃, 825 ℃, 850 ℃, 875 ℃, 900 ℃, 925 ℃ and 950 ℃, and the regular fluctuations of particle size (as-calcined), density (as-sintered) and magnetic properties are presented in this work. It is shown that the samples calcined at 850 ℃ exhibit optimal microstructure and magnetic properties. The newly developed MnZn ferrites are characterized by sintered density of 4.61 g/cm³, initial permeability of 1223 (10 kHz/0.1 mT/25 ℃), saturation magnetic flux density of 488 mT (10 kHz/1200 A/m/25 ℃) and power losses of 68 mW/cm³ (500 kHz/50 mT/100 ℃).

We report the preparation of a magnetorheological fluid with a high working temperature by using fluorocarbon surfactant and titanate coupling agent as additives at appropriate contents determined by a series of experiments. The sedimentation ratio, apparent viscosity, and yield stress are measured to evaluate the performance of the prepared magnetorheological fluid. Results indicate that AES dispersants, titanate coupling agents, and fluorocarbon surfactants all have improved dispersion properties, and that the compounding fluorocarbon surfactants and titanate coupling agent can further improve the settlement stability of magnetorheological fluid, with < 7 % one-week settlement rate. Diatomite has a good thixotropic effect, and the antisettling effect enhanced with increased content. The types of carrier fluid have no significant effect on the performance of MR fluids. The prepared MR fluid can also work at 180 °C, which is higher than most commercial fluids, and the shear yield stress can reach 50 kPa.

This paper examines the differences between the magnetic and mechanical characteristics of the motor core depending on the lamination method (weld and bond lamination) and analyzes the effects of these differences on the motor performance and vibration using analytical methods and tests. First, to analyze the magnetic and mechanical properties of iron cores according to lamination method, the initial magnetization curve and iron loss were measured, and the natural frequencies and damping ratios were identified through a modal test. Next, no-load and blocked-rotor tests of an induction motor were performed to determine the difference in the performance of the motor according to the lamination method. At this time, the loss occurring in the motor was divided into the primary copper loss, secondary copper loss, iron loss, and mechanical loss. Finally, the output, efficiency, and vibration of the motor were measured to analyze the effects of the magnetic and mechanical characteristics on the motor performance.

We report the phase stability, microstructure and magnetic properties of MgFe₂O₄ nanoparticles under different annealing conditions. Magnetic properties of MgFe₂O₄ are strongly influenced by the crystal structure and morphology, which in turn, depend on annealing conditions. The as-prepared and samples annealed at 1200 ℃ show a pure spinel phase. Whereas the samples annealed and quenched at 600 °C-1000 °C exhibit the spinel phase along with a small fraction of the secondary phase of α-Fe₂O₃, which causes deterioration of magnetic properties. On the other hand, samples annealed at 600 ℃-1000 ℃ under Argon atmosphere display superior magnetic properties (M = 44-56 emu/g at room temperature) due to the presence of pure spinel phase. Interestingly, the sample quenched at 1200 ℃ exhibits large saturation magnetization, M_S = 63 emu/g at 5 K which is arising from the optimum cationic distribution (δ = 0.77) grown at elevated temperature is retained in the rapid cooling process.

This paper presents a new stator topology of fractional-slot concentrated-windings permanent-magnet (FSCW-PM) machine in order to reduce the electromagnetic vibration. First of all, the space orders and corresponding frequencies of the lowest order radial force of FSCW-PM machines is studied. A 12-slot/10-pole FSCW-PM machine is used as an example, and its lowest order radial force harmonics are calculated by analytical method and finite element method, respectively. Then, in order to minimize the amplitude of the vibration acceleration, a new stator structure of 12-slot/10-pole machine is designed, by which the amplitude of the lowest order radial force is greatly reduced. Afterwards, the modal and vibration experiments are performed. The result shows that the 2^nd order radial force with 2f₀ frequency contributes most to overall vibration. Finally, vibration simulation models of both machines are established, the results show that the machine with unequal teeth design effectively reduce the electromagnetic vibration.

The use of Static Magnetic Field (SMF) in medicine is currently under consideration. In this experimental study, the aim is to investigate the possible effects of SMF on nerve excitation and conduction characteristics. Our objectives are to take Compound Action Potential (CAP) measurements from an isolated frog sciatic nerve under SMF, and to calculate the amplitude and latency parameters of the CAP in order to assess possible effects. The experimental study was carried on twelve Rana Ridibundas. The sciatic nerve of the frogs were isolated from their locations and transferred to the nerve chamber. The nerve was stimulated with an electrical impulse of 0.2 ms duration and 1.4 V amplitude at the proximal end and its response was recorded at the distal end. The possible effects of SMF on the frog sciatic nerve were examined. A sequence of CAP measurements were taken with and without SMF exposure. Changes in four variables were observed. Two of the measurement variables were peak-to-peak amplitudes. The other two variables were the durations of stimulus artifact from the onset to the appearance of the first negative and first positive peaks respectively. After the first, second and third SMF exposure periods, there was a significant increase in the height of PP-1 and PP-2 which are peak-to-peak variables of CAP in both during and after exposure. Similarly, after the first, second and third SMF exposure periods, there was a significant increase in the length of Latency-1 and Latency-2 which are linked with the duration of CAP. In this study, it was observed that SMF exposure increases both the amplitude and duration of nerve CAP. Our study gave a different perspective on the effects of SMF on neuronal excitation mechanism of sciatic nerves. Besides, it provided a better understanding of the pain perception phenomenon based on transmembrane Na⁺ channel dynamics and nerve conduction velocity.

In general, when a brain neural stimulation device is used in brain disease or dementia, it does not reflect the pathophysiology, because regardless of the brain disease state, it stimulates only the motor cortex. In particular, it is necessary to be more cautious about the reactivity, plasticity, and connectivity of brain diseases and the dementia-related cortex. The brain neural stimulation device affects the distance and intensity of the stimulus coil from the initial brain axis of Alzheimer’s Disease (AD). The volume of cerebrospinal fluid increased by cortical hyperactivity and cerebral atrophy changes the characteristics of the brain tissue, and the current induced in the magnetic stimulation device has a negative effect. The stimulation site is biochemically and metabolically invaded by areas other than the motor cortex. Changes in the motor cortex cause problems later on. The present research confirms the cerebral state in real time by the EEG sensor that grasps the cerebral state, and the EMG sensor that can grasp the nerve conduction state, for the treatment suitable for the modified cortical form of the brain disease patient. The optimal stimulation therapy pulse and optimal pulse-forming device suitable for lesion-modified cerebral morphology were used. EEG and EMG are monitored in real time by cell phones, computers, and the web to implement the neural stimulation device of therapy pulse suitable for the modified cerebral cortex. In addition, stimulation coils can be replaced or added depending on the performance and capacity of the power source device, and control of the pulse shaping device, in order to implement a therapy pulse corresponding to the modified cortical morphology of the brain disease patient.

Analysis regarding convective surface phenomenon has emerged to be effective approach to depict refinements in thermal features, since most of the heat/mass transfer surfaces are disclosed to a convective environment at specified parameters which cannot be achieved through energy analysis. The development in the dynamics of convective heat and mass transport is significant in understanding diverse engineering and industrial phenomena such as in thermal energy storage material drying process, transpiration cooling process, and many others. Keeping aforementioned usefulness in mind, the current analysis is aimed to demonstrate the convective features in squeezed Sutterby fluid flow through parallel surfaces. Magneto-hydrodynamic (MHD) theory is incorporated to describe the squeezing flow phenomenon. The Sutterby fluid model is accounted in order to specify the flow nature in squeezed channel. The top plate is assumed to be squeezed whereas the lower plate is at rest. The convective heating is incorporated at both lower and upper plates. Inspection of mass transfer has been accomplished in the occupancy of solutal convective conditions at the both surfaces. The equations governing the flow, heat and mass transport are first derived under the assumptions of low magnetic Reynolds number and negligible viscous dissipation, and then made non-dimensional by defining the similarity variables. Series solutions representing the flow velocity, temperature and concentration distributions are computed for definite values of power law index by utilizing convergent approach. Results are graphed and physical elucidated is seen for involved flow parameters. Variations in co-efficient of skin friction, Nusselt and Sherwood numbers are reported graphically. Significant findings in this attempt is that higher lower plate thermal and solutal Biot numbers strengthen the both heat and mass fluxes, while larger upper plate thermal and solutal Biot numbers weaken the heat and mass fluxes.

The incidence of prostate cancer has gradually increased with obesity in Korean males. We aimed to quantify visceral fat content measured by magnetic resonance imaging (MRI) as a risk factor of prostate cancer. This case-control study that included 100 patients (mean age, 66.1 ± 7.1 years) newly diagnosed with prostate cancer and 100 healthy males (mean age, 63.4 ± 4.6 years) without cancer. All subjects underwent 3.0 Tesla MRI. Prostate cancer patients had a significantly higher abdominal fat ratio (p < 0.04) and regression for prevalence (β = 0.52, p < 0.01), other than obesity factors (waist circumference and body mass index), than the controls. In prostate cancer patients, a higher abdominal fat ratio was associated with a higher Gleason score level using odds ratios but excluding other obesity factors. Abdominal fat ratio is a risk factor of prostate cancer and clinical stage.

The relationship between transverse relaxation time (T₂) and pore size distribution is the basis of NMR applications for rocks. However, the equations for T₂ are not accurate enough in rocks with complicated pore structures. Taking pebbly sandstone from the northwestern Junggar Basin in China as an example, the aim of this study is to discover the spatial distribution of pores and its influence on T₂. Porosity, permeability, micro-images and T₂ distributions were acquired from rock samples, and pore structure parameters were obtained from binarized thin section images. The results show that as the grain size increases, the proportion of dissolution pores increases and the spatial distribution of pores changes from a random to a clustered pattern. The relaxation of a hydrogen atom takes longer and T₂ is higher in dissolution pores compared with those in intergranular pores. New equations for T₂ that consider the spatial distribution of pores are proposed.

This study evaluated the effects of applying the compress-sensing technique and the increase of the CS factor on the quality of the image in the test using the time-of-flight sequence. A 3D TOF MRA test was performed while maintaining a constant flow rate (2.0 ml/sec) by connecting an auto-injector to a self-fabricated flow phantom. Images were obtained by applying the 3D TOF sequence without CS and with CS to evaluate the difference in image quality with or without application of the CS technique. Moreover, in order to analyze the quality of images according to the CS factor, images were obtained while increasing the CS factor from 1.2 to 1.8 by 0.2. The examination time was 44 seconds when the CS technique was not used. When the CS technique was applied, the examination time decreased to 30, 27, 25, and 23 with the CS factor of 1.2, 1.4, 1.6, and 1.8, respectively. On the other hand, the application of the CS technique did not change the SNR or the CNR of the image significantly (p > 0.05). Moreover, the SNR and the CNR of the image were not significantly affected by the changes in the CS factor (p > 0.05). However, as the CS factor increased, the similarity and precision decreased more than in the images where the CS technique was not used. The application of the CS technique to the TOF MRA test can reduce the examination time drastically without changing SNR and CNR. However, we found that, as the CS factor increased, the similarity and precision decreased more than in the test without the CS technique. Therefore, it is necessary to continuously verify the effectiveness of the CS technique and study it more.

In this study, we designed a depth of interaction (DOI) detector module for use in a magnetic resonance imaging (MRI) system. The detector uses a semiconductor photosensor that is unaffected by a magnetic field. The detector module consists of two layers of a crystal array that have different l ight sharing characteristics. To verify the performance of the detector module, simulations of the optical photon transport in the crystal array were performed with a DETECT2000 tool. Various combinations of the parameters, such as the reflector used and the treatment of crystal surfaces, were simulated and the characteristics were evaluated through a reconstructed flood image. In certain combinations of the simulation conditions, all of the crystal pixels could be identified along all directions. Thus, the proposed DOI detector module could extract the three-dimensional gamma ray interaction position from the two-dimensional flood image.

X-ray mammography can be used to acquire images useful for early breast cancer detection in medical applications. There have been a number of approaches to diagnostic low-dose mammography. The purpose of this study was to design a concept for use of monochromatic X-ray beams by using K-edge filters for low dose mammography. The SRS-78 X-ray simulation code and Monte Carlo simulation GATE code were used to model the X-ray tube, target material, filter material, breast phantom, and detector. To achieve a monochromatic X-ray beam, molybdenum (Mo) and rhodium (Rh) were used as filter materials in various thicknesses. The direct conversion detector (FDXD 1417, Drtech, Seongnam, Korea) composed of thin-film transistor (TFT)-amorphous selenium (a-Se) was modelled through Monte Carlo simulation. According to the CVR and EER results, the filter thickness for optimal mammographic imaging is set to 6 and 3 HVL for Mo and Rh, respectively. SNR values with the Rh filter improved by 1.01, 6.28, 5.60, 5.60, 5.60, 5.60 % over the range from 0.1 to 0.6 μGy compared to analogous SNR values without filter. The present work demonstrates that monochromatic X-ray beams can be generated for low dose mammography. According to the results, Rh filter could be useful for enhancing calcification while absorbed dose is reduced.

This study measures retentive force as function of the diameter, the cross-head speed, and the number of detachments of dental magnetic attachments in a clinical environment, and analyzes the validity of the international standard method for testing them. In this study, tests 1, 2, and 3 were used to measure the retentive force as a function of the contact area of the magnetic attachment, and tests 2 and 4 as a function of the cross-head speed. Test 2 and 5 compared function of the retentive force as a function of repeated detachments Results showed that the retentive force increases as the sample surface increases, and decreases as the cross head speed increases. Additionally, after 1500 detachment cycles, the retentive force increased. Finally, the international standard test method was validated, because an objective method for testing magnetic attachments in clinical environment could not be found.

A GAGG-GAPD detector module was proposed and developed for DEXA application and was characterized under various conditions. The proposed detector consists of GAGG and GAPD. The effect of kVp on energy spectra was assessed for different tube voltages in air condition. Also, the effect of the filter on dual energy X-ray spectra was examined by using K-edge filter with different thickness. The mean photon energy and beam peak energy are increase linearly from 40 kVp to 80 kVp. The dual energy peaks were located around 32 keV and 65 keV and were considerably isolated. The DEXA phantom image for each steps were clearly resolved. These results demonstrate the feasibility of GAGG-GAPD detector allowing more potential merits than conventional CZT detector for DEXA application.

The purpose of study is to investigate optimal exposure parameters for full-field digital electromagnetic radiation mammography (FFDM) and to reduce the average glandular dose (AGD) by applying a noise reduction algorithm. To find an optimal exposure parameter, filtration-target material combinations (Mo/Rh, Mo/Mo, W/Rh) were applied by each tube voltages (23-35 kVp). AGD, Noise, Figure-of-merit (FOM) were measured. The experimental results, using 29 kVp of W/Rh was found to be best in all cases before and after applying the denoising filter. With a denoising filter, noise decreased 76.44 % and SNR increased 76.18 %, which improved image quality. If a denoising method is suggested for images of 35 kVp of W/Rh (SNR: 3.58, AGD: 0.67 mGy) using the smallest AGD when using FFDM, better picture quality (SNR 9.73, ADG: 0.67 mGy) could be gotten than 23 kVp of Mo/Mo combination. From this study, it is possible to obtain good quality images with a lower dose than FFDM used in the clinic.

In modern society, drinking is becoming a culture while alcohol consumption continues to increase. Studies show that alcohol consumption in the oral cavity averages 2 hours, and alcohol consumption seems to have a high effect on tooth damage. Therefore, this study was conducted to evaluate the possibility of dental erosion due to intake of some alcoholic beverages in the market. Six types of alcoholic beverages were immersed in 1 ml of each alcohol for 10 min, 60 min, and 120 min to obtain only enamel of the tooth and observe changes over time. The crystal structure of the enamel surface was observed by scanning electron microscopy (SEM), and the changes in calcium and phosphorus, the major constituents of teeth, were analyzed by energy dispersive electromagnetic wave (X-ray) spectroscopy (EDS). Based on the results, the tooth showed a destructive pattern while and loss of calcium (Ca) and phosphorous (P) increased significantly as exposure time to the low pH alcoholic drinks increased. Since this causes the demineralization of inorganic components and greatly affects the risk of tooth erosion, long contact with alcohol should be avoided.

The purpose of this study was to evaluate the effect of 1 Hz low frequency repetitive transcranial magnetic stimulation (rTMS) on cerebral cortex activity and recovery of hand function in chronic stroke patients. It was evaluated by motor evoked potentials (MEPs) amplitude, latency, and MFT. In Results, rTMS group and neurorehabilitation training (NRT) group showed differences in MEPs amplitude, latency, and MFT before and after intervention (p < 0.05). and rTMS group showed significant differences in MEPs amplitude and MEPs latency compared to NRT group (p < 0.05), but both groups did not show significant differences (p < 0.05). These results suggest that rTMS and NRT in chronic stroke patients have positive changes in cerebral cortex activity, but 1 Hz rTMS is more effective in cerebral cortex activity than in NRT. However, for recovery of hand function in chronic stroke patients,

The purpose of this study was to investigate the effect of motor imagery combined with neuromuscular electrical stimulation (MI-NMES) on cerebral cortex excitability in stroke patients. We examined the effect of MI-NMES on cerebral cortex excitability using transcranial magnetic stimulation (TMS) of motor evoked potential (MEP) amplitude and latency, quantitative electroencephalography (QEEG) of δα ratio (DAR) and power ratio index (PRI) assessments. This study was to evaluate 30 stroke patients who were satisfied the selection criteria of the study. Experiments were divided into MI-NMES group, motor imagery (MI) group. This study showed that there was a significant difference for all evaluations within the MI-NMES group, with significant differences in MEP amplitude and latency, QEEG DAR, and PRI index values in the comparison that those of the MI group. MI-NMES is suggested to be an effective approach for cerebral cortex excitability in stroke patients.

The aim of this study was to investigate the effects of action observation training with low frequency repeated transcranial magnetic stimulation (rTMS) on cerebral cortex activity and hand function in patients with ideomotor apraxia after Stroke. Fourteen patients were randomly divided into two groups which in action observation training (AOT) with 1 Hz low-frequency rTMS and AOT without rTMS. Motor evoked potential (MEP) amplitude and latency were examined by TMS for cerebral cortex activity and hand function was evaluated by manual function test (MFT). As a result, there was a significant difference in MEP amplitude in group, but only AOT with rTMS group was a significant difference in MEP latency and MFT. In addition, there was a significant difference of MEP amplitude, latency and MFT between groups. These results suggest that application of AOT and rTMS can have a positive effect on the recovery of hand function in ideomotor apraxia after patients.

Fluoride toothpaste is not only sold globally but also has a global trend in domestic toothpaste products. This study is to compare whether the total fluoride (TF) of adult fluoride toothpaste in Korea is compatible with the standard indicated by the manufacturer. Therefore, this study was performed by Fluorine (¹⁹F) nuclear magnetic resonance (NMR) spectroscopy to quantify the fluoride contained in seven fluoride toothpastes. The results were 1128 ppm (2080 pure), 929 ppm (anti-plaque), 1091 ppm (bamboo). 1033 ppm (double action), 597 ppm (perioe), 198 ppm (pleasia), and 1131ppm (smaland). In conclusion, quantitative evaluation of TF in toothpaste may lead to oral health improvement through safe toothpaste selection.

The diagnostic reference levels (DRLs) for a 10-year-old patient were established for the most common types of general radiography in this study, using a glass dosimeter and a phantom corresponding to the international standards. The DRLs are set by measuring the entrance surface doses (ESD) at 211 medical institutions. The ESD of the skull posterior-anterior (PA) projection is between 0.11 and 5.59 mGy, with the average dose at 1.03 mGy, and the third quartile value at 1.17 mGy. The ESD of the skull lateral (LAT) projection is between 0.08 and 5.20 mGy, with the average dose at 0.78 mGy, and the third quartile value at 0.96 mGy. The ESD of the chest PA projection is between 0.01 and 1.38 mGy, with the average dose at 0.18 mGy, and the third quartile value at 0.20 mGy. The ESD of the chest LAT projection is between 0.04 and 3.36 mGy, with the average dose at 0.42 mGy, and the third quartile value at 0.46 mGy. The ESD of the abdomen AP projection is between 0.09 and 4.64 mGy, with the average dose at 0.85 mGy, and the third quartile value at 1.13 mGy. The ESD of the pelvis AP projection is between 0.1 and 5.26 mGy, with the average dose at 0.85 mGy, and the third quartile value at 1.06 mGy. Based on third quartile values and through clinical expert consultation, the DRLs for 10-year-olds in Korea were established at 1.1 mGy for skull PA, 0.9 mGy for skull LAT, 0.2 mGy for chest PA, 0.4 mGy for chest LAT, 1.1 mGy for abdomen AP, and 1.0 mGy for pelvis AP.

At present, almost all hybrid excitation machines (HEMs) apply DC field current to control the air-gap flux. However, the DC field control mode results in a problem that the capability of field-weakening is not equal to that of field-strengthening. This paper briefly explains the mechanism of asymmetric bidirectional field control capability in present HEMs, proposes a consequent pole hybrid excitation synchronous (CPHES) machine with AC field control mode to solve the asymmetric problem. The structure and principles of CPHES machine are presented. Additionally, the equivalent magnetic circuit model of CPHES machine is derived to reduce the computational complexity of analyzing CPHES structure by using three-dimensional finite element analysis (3D-FEA). The proposed equivalent model and 3D-FEA are compared, the results verify the proposed model is basically consistent with the 3D-FEA, and the proposed model is able to reduce the computational complexity greatly.