日本一家集发电、输电和配电于一体的大型电力企业。其电网主要覆盖东京都及周边8个县，承担了日本近1/6的电力供应份额。它是日本收入最高的电力公司，也是全球最大的民营核电商。截止到2010年3月底，公司销售总额为5万亿日元（约4000亿元人民币），工作人员有5.2万人。
Climate change and urban heat islands intensify heat waves, raising health risks. In 2003, France saw 14,800 heat-related deaths, while Japan’s 2024 heatstroke cases hit a record high since 2008. The Ministry of Environment issues WBGT-based heat alerts, but these have limitations. Heatstroke risks differ between indoor and outdoor environments due to varying thermal conditions and countermeasures, making it essential to assess outdoor risks separately. Indoors people can cope with extreme heat, but outdoors they are directly harmed. Predicting outdoor heatstroke remains difficult because thermal environments vary by location. In this study, we simulated the outdoor thermal environment for 1-km² city blocks daily during summer over nine years using a meteorological model. Morbidity was calculated as heatstroke-related emergency transports divided by the estimated outdoor population for the same area and period. These values were aggregated into a single dataset for the 23 wards using a population-weighted average to construct an outdoor heatstroke risk model. The model showed high accuracy, with a root mean squared error (RMSE) of 1.77 × 10⁻⁶, corresponding to 0.18 per 100,000 people, indicating performance comparable to previous studies.
In this chapter, the heat transfer characteristics in the steam injector that has been proposed to introduce into boiling water reactors as a feed water heat exchanger and a safety injection pump are examined. The temperature and the velocity distribution in the injector were measured. The heat transfer rate from the steam flow around the water jet to the water jet was greatly larger than that of the usual turbulent flow in a pipe. High-speed camera pictures revealed the surface of the water jet was very wavy. It was supposed that the wavy motion on the water jet surface created the effective large-internal circulation flow in the water jet, which resulted in the tremendously effective heat transport from the surface into the center portion of the water jet. From the high-speed camera pictures, the characteristics of waves on the surface; the wave height, the wave velocity, and the wave length were obtained. In addition, the dimensionless numbers were found from the parameters that related to the phenomena in the steam injector. By using these dimensionless numbers, a correlation for the heat transfer from steam flow to the water jet in the steam injector was proposed.
