In this study, a new technique was developed to measure time-series temperature during the combustion of volatile matter and coal char using magnified two-color pyrometry with high-speed blue backlit imaging. A steep temperature gradient was reproduced by supplying pulverized coal particles to a high-temperature region formed by a counterflow hydrogen/air diffusion flame. The time-series temperature measurement of the volatile matter combustion and surface combustion of a single pulverized coal particle was successfully performed with high-speed magnified imaging and two-color pyrometry. The results indicate that the particle size affects the volatile matter and char combustion. The estimation of the duration of the combustion of volatile matter from the existence of soot particles resulted in an average combustion duration of 3 ms and an average flame temperature of 2000 K under the 21% oxygen condition. The volatile matter combustion duration and flame size increased as the particle size of the coal increased due to an increase in the amount of volatile matter. The combustion temperature of the coal char decreased because the heat capacity of coal particles increased with an increase in the coal particle size.

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Al-Zn-Mg alloys with different precipitate sizes were investigated to determine the influence of the precipitate size on the flow stress and dislocation density change during tensile deformation. The dislocation density was measured using in-situ X-ray diffraction at the SPring-8 synchrotron radiation facility with a time resolution of about 2 s. In region II with rapid dislocation multiplication, from under-aging to peak aging, the dislocation density increased with increasing aging time. Under over-aging conditions, the amount of dislocation multiplication in region II decreased with increasing aging time. Even in region III, the increase in dislocation density with plastic deformation was the largest for the peak aging conditions. However, the amount of work hardening was small and the contribution of dislocation hardening to the strength of the material was minimal. For over-aging conditions, the increase in dislocation density in region III was smaller than for the other regions, but the amount of work hardening was relatively large. It is considered that the influence of the dislocation density on work hardening is determined by the effectiveness of precipitates as obstacles to dislocation motion.