In this study, a new type of composite material combined with carbonyl iron, a relatively strong ferromagnetic material, was prepared to overcome the current application limitations of Prussian blue, which is effective in removing radioactive cesium. The surface of the prepared composite was analyzed using SEM and XRD, and it was confirmed that nano-sized Prussian Blue was synthesized on the particle surface. In order to evaluate the cesium removal ability, 0.2 g of the composite prepared for raw cesium aquatic solution at a concentration of 5 μg was added and reacted, resulting in a cesium removal rate of 99.5 %. The complex follows Langmuir’s adsorption model and has a maximum adsorption amount (qe) of 79.3 mg/g. The Central Composite Design (CCD) of the Response Surface Method (RSM) was used to derive the optimal application conditions of the prepared composite. The optimal application conditions achieved using Response optimization appeared at a stirring speed of pH 7, 17.6 RPM. The composite manufactured through this research is a material that overcomes the Prussian Blue limit in powder form and is considered to be excellent economically and environmentally when applied to a cesium removal site.

Most structures require high reliability to ensure safety and soundness. The materials used for these structures are not only defective in the manufacturing process and construction process, but also cause generation and progress of defects due to operation of various complex use environments. In order to improve the reliability of the structure, it is very important to detect and estimate the defect size. The method of evaluating these defects without damaging the structure is a non-destructive method. In this paper, an aluminum probe of AC potential drop(ACPD) method is applied to the evaluation of two-dimensional artificial defects in ferromagnetic materials. Since the potential drop of the defect end is larger than that of the sound area, the defect can be detected and its position can be clearly confirmed, and the potential drops are changed according to the depth of the defect. The potential drop ratio (Vjmax/Vs) of the defective area has a large value for the defect. The relationship between the potential drop ratio (Vjmax/Vs) of 10 kHz and the defect depth can reduce the error in predicting the depth.

This paper studies the repulsion occurring between the permanent magnet by the simulation analysis. Nowadays, there are many cases such as magnetic levitation, safety bumper device and so on using the properties of the permanent magnet. As the neodymium magnet of the powerful ferromagnetic material is less expensive by comparing with the strong magnetic force for industrial, medical areas and etc., it can be used at the various applications. The prediction of the magnetic force is becoming increasingly important in order to be used effectively permanent magnet in various fields. Therefore, the results of the magnetostatics by Ansys and the MAXWELL of commercial electromagnetic analysis software are analyzed and compared. Magnetic force is inversely proportional to the distance and power. In this paper, the permanent magnet was simulated and compared by the two permanent magnets of the small sizes with the diameter of 4mm and the length of 8mm. In addition, the forces between the ferromagnetic iron and permanent magnets are simulated.