Japan encounters an urgent issue of “Carbon Neutrality” as a member of the international world and is required to make the action plans to accomplish this issue, i.e., the zero emission of CO2 by 2050. Our world must change the industries to adapt to the electrification based on the renewable powers. Microwave chemistry is a candidate of electrification of industries for the carbon neutrality on the conditions of usage of renewable energy power generation. This invited paper shows an example of “Microwave Pidgeon process” for smelting magnesium in which heating with burning fossil coals can be replaced with microwave energy for discussing how microwave technology should be developed for that purpose from both the academic and industrial sides.

Hyperthermia is one of the modalities for cancer treatment, utilizing the difference of thermal sensitivity between tumor and normal tissue. Interstitial microwave hyperthermia is one of the heating schemes and it is applied to a localized tumor. In the treatments, heating pattern control around antennas are important, especially for the treatment in and around critical organs. This paper introduces a coaxial-dipole antenna, which is one of the thin microwave antennas and can generate a controllable heating pattern. Moreover, generations of an arbitrary shape heating patterns by an array applicator composed of four coaxial-dipole antennas are described.

Materials for a new reinforcement method using an internal heating technique have been developed experimentally for fusion splices. The method employs a protective package of a carbon-fiber composite and a hot-melt adhesive in a heat-shrinkable tube. The most appropriate heating current and heating time were determined from a consideration of the decomposition temperature of the adhesive (300) and the complete shrinking temperature (115) and the minimum welding temperature of Nylon 12 (about 180). The protective package can be installed in less than 30 seconds at a power of 10 W. Air bubbles which might cause microbending were completely eliminated by using Nylon 12 as the hot-melt adhesive, irradiated polyethylene as the heat-shrinkable tube and a carbon-fiber-composite electrical heating rod which also acted a tension member. The key for preparing the carbon-fiber composite was to remove its impurities. Under the condition of temperature difference larger than 40 deg. between the shrinking temperature of the heat-shrinkable tube and the melting temperature of the hot-melt adhesive. Nylon 12 and irradiated polyethylene were needed for the complete elimination of residual bubbles. By using Nylon 12 as the hot-melt adhesive, a reliable protective package could be achieved for a fusion spliced optical fiber with a low excess loss of less than 0.06 dB/splice between -60 and +70 and a high tensile strength of 3.9 kg.