Instead of modeling the magnetic properties of both the geometry and internal ferromagnetic structure of the ship, this study proposes a modeling method that simplifies the ship into zones and analyzes the magnetic signal using zone-specific spatial permeability. The interior of the ship is divided into ten zones, each assigned a spatial permeability for magnetic field analysis. This approach simplifies the analysis model and significantly reduces both the modeling and computation times. The validity of the modeling method was confirmed by comparing the analytical results with measurements from an actual ship, resulting in an error of approximately 2%. The proposed method is expected to be highly useful for practical ship design because it reduces the computation time required for repeated magnetic field analyses during the design phase.

To enhance the quality of power generation, a magnetorheological transmission device (MRTD) has been developed for traveling power generation. This design facilitates precise speed regulation and ensures consistent output. A simulation model, along with a corresponding experimental system, has been established to evaluate the performance of the MRTD. The simulation results indicate that, with a cooling water temperature of 25 °C, a cooling water gap of 1 mm, and a slip power of 5 kW, the temperature within the transmission space remains within the normal operating range for magnetorheological fluids after achieving a steady state. Notably, there is no observed expansion or deformation of the core transmission components under high-temperature conditions. Moreover, results from the experimental system demonstrate that, under operational conditions of 5 kW and a flow rate of 0.72 m³/s, the maximum temperature at the measurement point increased by 83 °C over a period of 1250 seconds, ultimately reaching a peak temperature of only 95.2 °C. The temperature rise curve exhibits a tendency to stabilize, suggesting that the designed transmission device can operate reliably at a slip power of 5 kW and is suitable for providing constant-speed power output during vehicle operation.

This study proposes a scalable winner-takes-all (WTA) circuit for thallium-doped cesium iodide CsI(Tl) Geiger-mode avalanche photodiode (GAPD) radiation detectors. The proposed circuit was implemented and evaluated in a proof-of-concept 4×4 CsI(Tl)-GAPD radiation detector. The uniformity of the photopeak position was assessed before and after gain correction. The performance of the radiation detector was also measured at various GAPDs bias voltages. With a trigger activation duration of 500 ns, the analog signal reset mechanism functioned effectively without significantly affecting the analog output signal. Gain correction in the gain-level adjustment block significantly improved the uniformity of the photopeak positions in the energy spectra, reducing the ratio of the highest to lowest photopeak positions from 1.3 to 1.0. As the bias voltage increased, the photopeak position linearly increased from 507.4 to 1444.7 due to the increasing gain of the GAPDs. The best energy resolution was obtained at a bias voltage of 27.8 V, which was 3.1 V above the breakdown voltage in our experimental setup. This study demonstrated the feasibility of the WTA circuit for the CsI(Tl)-GAPD radiation detector and highlighted the potential advantages of the scalable WTA circuit for developing MR-compatible radiation detectors with multiple input channels.

This study proposed a three-layer depth of interaction (DOI) detector utilizing a quasi-monolithic crystal to address spatial resolution degradation caused by parallax errors in positron emission tomography (PET) detectors. Monte Carlo simulations were performed to analyze optical signals, and the modified resistive charge division method, combined with the maximum likelihood position estimation (MLPE) algorithm, was used for analysis and evaluation. The 2D flood histogram results indicated that light spread in the quasi-monolithic layer with layer thickness, complicating DOI identification. The MLPE results demonstrated that as the thickness of the quasi-monolithic layer increases, DOI identification accuracy exceeding 70% was achieved, with the highest accuracy of 84.2% observed at a total thickness of 7 mm. These findings show that the three-layer DOI-PET detector using a quasi-monolithic crystal is capable of accurate three-layer DOI identification.

While previous studies have proposed using circular arrangements of permanent magnets to capture magnetic micro robots, this research focuses on a novel approach: arranging permanent magnets in a linear configuration within an open rectangular shape to efficiently trap the magnetic robot in space. Additionally, a driving system comprising a robotic arm and robot tracking system is developed to manipulate the array. The design process involves a parameter-based optimization of the permanent magnet array to maximize capturing force on the magnetic robot while minimizing undesired forces. A driving system is devised to translocate the magnet array, effectively relocating the magnetic robot remotely. Experimental validation of the magnet array driving system demonstrates a reasonable 5 % error in position accuracy. This study not only establishes a foundation for further exploration into open-shaped permanent magnet arrays but also suggests improvements in manipulation systems for micro robot control.

For nano-magnetic fluid(NMF), the magnetic nano-particle(MNP) kinematic behavior in a magnetic field and the chain-like microstructure evolution are important to study the NMF properties at the microscopic level. However, the chain structure formation mechanism and the effects of multiple environmental factors on microstructural morphology remain unclear. In this paper, the interaction of a two-particle system, chain structure formation process, microstructure evolution and response time simulation of NMF is investigated by the discrete element simulation method. The results show that the magnetic dipole and repulsive forces dominate the chain structure formation and evolution under a uniform magnetic field. MNPs assemble into chain-like structures and various complex structures along the magnetic f ield direction. The volume fraction, magnetization intensity and particle size significantly affect the microstructure and the response time. The above study can obtain the specific morphology of the microstructure at different working conditions and broaden the application of NMF in practical engineering.

This paper presents a harmonic analytical method for modular permanent-magnet (PM) machines. By using the complex Fourier separation method, the magnetic field in all parts of machine regions is solved from system equations through the application of boundary conditions with take into account the permeability of iron parts. Three types of concentrated winding have been used, namely, single layer, double layer same phase and double layer between phase. Additionally, the performance results of these configurations are also compared. Finally, to validate the proposed analytical method, the results are verified with the finite-element method (FEM). Thus, the validation shows good results for the proposed model.

This study sought to examine tooth surface changes and remineralization after treatment with 38 % waterbased silver fluoride (AgF) solution and potassium iodide (KI), which are known to have teeth-remineralization effects. Tooth samples were prepared by exposing enamel and dentin. Riva Star Aqua (SDI, Bayswater, Australia), consist of AgF and KI ,was applied to tooth surfaces, after treatment, stored in artificial saliva for 7 or 14 days. Using scanning electron microscopy, changes in tooth surface shape and remineralization were assessed. Our analysis revealed that upon treatment with AgF for 7 or 14 days, the dentin surface appeared very smooth, indicating remineralization. Analysis of the levels of calcium (Ca), phosphorous (P), and argentum (Ag) using electromagnetic radiation spectroscopy revealed changes in the levels of Ca and P in the enamel and that after 14 days, there were significant changes in the levels of Ag in dentin. These findings indicate that the agent applied using AgF and KI led to teeth remineralization, highlighting them as effective remineralization materials.

A new gamma camera was designed to reduce edge effect that can occur in conventional gamma cameras and increase the useful field of view (UFOV). In order to reduce edge effect and increase UFOV, a new gamma camera was designed to collect light incident on the side of the scintillator by plaing an additional photosensor used in the conventional gamma camera to prevent the occurrence of edge effect. DETECT2000 was used to evaluate the useful field of view of the desinged gamma camera and the conventional gamma camera. As a result, the UFOV of the new gamma camera was improved by about 95.8 % compared to the UFOV of the conventional gamma camera. If the results of this study are used when designing a gamma camera, it is considered that edge effects can be prevented and an expanded UFOV can be achieved.

Thin magnetic films displaying perpendicular magnetic anisotropy, with an out-of-plane easy axis, often show the presence of stripe domains that can break into cylindrical domains, producing in the end the formation of bubbles or skyrmions. Perpendicular magnetic anisotropy is considered to provide spin texture stabilization in topological materials. This paper reports a theoretical study of the stability of cylindrical domains and the interaction of cylindrical domains with each other and with the magnetic host material. In particular, the case of cylindrical domains of circular cross section has been deepened and a method for experimental determination of the saturation magnetization in a thin ferromagnetic film has been proposed.