In this paper, we investigated a thermal fluid simulation model to predict the fillet shape formed by the melting of brazing filler metal. Because it is difficult to measure changes in physical properties during the melting process of brazing filler metal, previous research has predicted the fillet shape by steady-state analysis using the physical properties of the molten metal. However, dynamic analysis is necessary in predicting fillet shapes that change depending on heating conditions. Therefore, we created a dynamic analysis model that incorporates the correlation between temperature and effective viscosity obtained from a comparison of experimental data and analytical results. Furthermore, it was confirmed that changes in fillet shape during heating were accurately reproduced using the same temperature profile as in the actual evaluation.

If a current overloads a PCB pattern capability, the PCB pattern is heated by the current. The method of stopping abnormal current is pattern fusing. It is important to clarify the pattern fusing characteristics because pattern fusing carries the risk of insulation deterioration due to long-term heating.

The risk of a fire hazard can be reduced by taking advantage of the fusing characteristics of PCB patterns. A simple method is proposed based on static approximation without iterative calculations. Model parameters are determined experimentally and can then be used to design safe equipment.

This study developed a wearable salt concentration sensor for real-time monitoring of sweat salt concentration. Combined with a perspiration measurement device, it estimates total-body salt loss. Using the whole-body sweat collection and replacement method, a high correlation (r = 0.96) was shown between the sensor and an ion chromatography analysis. Additionally, a correlation (r = 0.88) was found between the estimated total salt loss measured by the sensor and perspiration measurement device, and that calculated from ion chromatography and weight loss. These devices enable accurate real-time estimation of total-body salt loss through sweat concentration and sweat rate.