No abstract

-This paper deals with torque analysis of magnetic spur gear with radial magnetized permanent magnets based on analytical method. The analysis is implemented in three parts: First, on the basis of magnetic vector potential and a two-dimensional (2D) polar-coordinate system, the magnetic field solution due to permanent magnet of source gear are obtained. And by using derived magnetic field solutions, the analytical solutions for external magnetic field distribution which affects load gear are obtained. Second, by using coordinate conversion, external magnetic field which is on the primary coordinate system is converted to the secondary coordinate system. Finally, the load gear is reduced to equivalent current densities, and the torque is computed on these currents in the external field of the source magnet. These analytical results are validated by comparing with the 2-D finite element analysis (FEA).

-This paper deals with eddy current loss of magnetic coupling with radial permanent magnet (PM) using analytical method such as a space harmonic method. Superposition of two kinds analysis model is used to analyze eddy current loss induced in inner PM and outer PM of magnetic coupling. When the eddy current is induced, the environmental temperature increases, and the permanent magnet(PM) characteristics are degraded because the performance of PM is greatly influenced by temperature rise. Hence, the calculation of eddy current loss becomes an important factor in the magnetic coupling. In order to analyze eddy current loss, first, on the basis of the magnetic vector potential and two-dimensional(2-D) polar-coordinate system, the magnetic field solutions of the radial magnetized PM are obtained. And we obtain the analytical solutions for the eddy current density produced by permanent magnet. Lastly, analytical solutions for eddy current loss are derived by using equivalent, electrical resistance calculated from magnet volume and analytical solution for eddy current density. This analytical results are validated by comparing with the 2-D finite element analysis (FEA).

We recovered Si from the waste Si solar cell through a three-stage chemical process at room temperature and recycled the recovered Si to investigate the manufacture of SiC particles. Metal electrodes made of Ag and Al were removed using either nitric acid solution or hydrochloric acid solution. After etching the metal electrodes, the anti-reflection coatings containing SiNx and SiOx were removed by employing a mixed solution of NH 4 HF 2 , H 2 O 2 , and H 2 SO 4 . Small quantities of impurities remaining in the Si solar cells were subsequently removed through the application of potassium hydroxide to recover Si. Based on the measurements conducted through inductively coupled plasma atomic emission spectroscopy, the purity of the recovered Si was found to be 99.99% (4N), and no high energy-consuming steps were involved in the proposed chemical process. Furthermore, by incorporating the 4N purity-grade Si, we successfully obtained SiC particles for usage in structural ceramic materials. This suggests that the proposed chemical process can aid in recycling recovered Si.

No abstract