Hiromichi Murai

A high output power density 400/400V isolated DC/DC converter with hybrid pair of SJ-MOSFET and SiC-SBD for power supply of data center

In this paper, a design of high output power density 400/400V isolated dc/dc converter for power supply in data center is discussed. The isolated DC/DC converter uses the hybrid pair of SJ-MOSFET and SiC-SBD power devices. A high accuracy of DC/DC converter analysis is carried out by considering the intrinsic and extrinsic loss parameter of power devices and circuit board. Based on this analysis, the efficiency and power density of isolated DC/DC converter are estimated for various high switching frequencies (100 kHz, 200 kHz and 300 kHz) and various junction temperatures of power switching devices (125°C and 150°C). The analysis estimates that the isolated DC/DC converter with efficiency around 97% and power density equal to or larger than 10 W/cm3 is possible to be realized. To verify the estimation results, 10-W/cm3 class power density of 5kW isolated DC/DC converter is fabricated and current results are shown in this paper.

Improvement of Skin Moisture Capacity through Dietary Beauty Supplement Containing Ceramides Derived from Rice

A placebo-controlled double-blind ingestion study of a beauty supplement containing rice-derived ceramide was performed. Thirty three subjects who always tended to have rough skin due to dryness participated in the study. Dermatological diagnosis by physicians showed that the supplement significantly improved dryness and itching of the skin. On measurement of water content in the skin, the supplement was shown to significantly increase water content in the skin. On microscopic three-dimensional analysis of the epidermis, the supplement was shown to improve smoothness, exfoliation, and short-term ingestion of the supplement containing rice derived ceramide, which is very effective as skin beautifying food.