Papers by Author: Masayuki Niino

Abstract: Objective of study was the development of core-shell type ZnS-CdS photocatalyst with the stratified morphology. To form the stratified morphology, condition of the precursor is extremely important. For this purpose, three types of precursors, thus core-shell type, egg-shell type and uniform type, was tried to synthesize by utilizing the results of the calculation. The size of the synthesized precursor particles was about 40-100 nm. Main phase of the particle was gradually changed from ZnO (pH8.0) to Cd(OH)2 (pH9.5). Detailed analysis of the synthesized precursor was clearly demonstrated that these have the crystalline structure and each metal element was co-existed in one particle. Therefore, it could be concluded that core-shell type or uniform type precursor was successfully synthesized. Core-shell type ZnS-CdS stratified photocatalyst could be successfully synthesized by sulfurization for 1h, and it shows the high photocatalytic activity under visible light irradiation.

Abstract: Functionally Graded Materials Database (hereinafter referred to as FGMs Database) has been run by Japan Aerospace Exploration Agency (JAXA) since October, 2002. So far, the database contains 1,815 research paper information including 12,790 figures and tables, 2,632 author information, 904 PDFs, and 563 university, research institution and company information. The database had been used by 34,968 users from 113 countries in FY2007, where the effective total visits counted to 73,072. Approx. 20% of users had repeatedly visited the website. In FY 2007 users from Japan were significantly increased. Additionally, the interest of Europe and Middle east/Africa region was remarkable.

Abstract: Japan Aerospace Exploration Agency (JAXA) has studied Space Solar Power Systems (SSPS) using laser and microwave beams for years since 1998. Current SSPS study undertaken by JAXA consists of three main subjects, SSPS concepts and architectures study, technology demonstration and elemental technology development. In current research of Laser based SSPS (L-SSPS), we have studied some elemental technologies such as ultralight film mirror, wavelength selective mirror, laser generator based on direct solar pumping solid-state laser diode, laser transmission property in atmosphere, photovoltaic generation converting laser energy to electricity and photocatalytic hydrogen generation. This paper presents the introduction of SSPS concepts and architectures study and elemental technology development of L-SSPS.

Abstract: In this paper, we introduced research and development of technology of low cost production of FGMs. This research is designated for development of mass production technology for production of ceramic wares with induction heating (IH) function. Slurry lamination method has advantage in forming graded layers due to its simplicity and easiness. However, this method has a disadvantage to generate cracks during drying process. Therefore, freeze-dry in vacuum was introduced in drying process of slurry lamination. By doing so, mass production could be achieved. In this trial production, we adopted SPS sintering method to production technique. In the future, we will further develop other applications of FGMs into industrial products.

Abstract: In this paper, we introduce research and development in SSPS (aimed at global energy supply) in Japan. To build SSPS, we must develop ultra lightweight materials and high efficiency energy conversion materials. Feasibility of adapting FGM concept for those new demands and advanced research theme for future FGM research are also introduced in this paper.

Abstract: In 2003, a joint research project entitled “Nano and graded thermoelectric materials/Photovoltaic-thermoelectric-wind power generation” is established in cooperation among research institutes from Japan and China. The major research institutes include State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (Wuhan University of Technology, China), Shanghai Institute of Ceramics (Chinese Academy of Sciences, China), State Key Laboratory of New Ceramics and Fine Processing (Tsinghua University, China), Japan Aerospace Exploration Agency (JAXA, Japan) and Foundation for Promotion of Japanese Aerospace Technology (JAST, Japan). The main aim of this project is to develop a photovoltaic-thermoelectric-wind power generation system with high efficiency solar energy conversion. The key works of the project include: (1) fabrication of high efficiency nano thermoelectric materials with a maximum figure of merit Z≥1.3; (2) design and fabrication of nano graded thermoelectric material/component with efficiency conversion larger than 12% for wide temperature range and (3) design and construction of photovoltaic- thermoelectric coupled power generation system. The recent progress about the joint research project is reported in this paper. Emphasis is put on the mechanism, design and fabrication of high efficiency nano graded thermoelectric materials. The future research plan is also mentioned in brief.