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Diesel engines have high potential for better fuel economy due to a high thermal efficiency and fuel diversity. They are largely expected to contribute to a low carbon society in the future. This paper describes how the increase of the Biodiesel Fuel (BDF) mixing ratio reduces CO, HC, smoke and engine-out particle number (PN) concentration. Most notably, the PN concentration by using BDF100 can be reduced to approximately a half of diesel fuels. Additionally, this paper shows that the PN concentration from the tail pipe is reduced by over 99.95% with a DPF. Further, this paper also introduces the relationship between fuel consumption (FC), PN concentration and engine oil.

A fundamental study was performed to develop a high efficiency solar heat receiver for a solar energy experiment mission on the Japan experiment module - exposed facility of the international space station. It is composed of a solar heat absorber, thermal energy storage and heat pipes. This system is aimed to transport solar thermal energy to a bottoming system with an efficiency of 80 %. Thermal analysis of each component was performed to assess its design approach. One ground testing model of the solar receiver was designed and fabricated in 1998, and then would be experimentally evaluated in 1999 at a test vacuum chamber of National Aerospace Laboratory.

A semi free-piston Stirling engine alternator, called NALSEM500, has been experimentally studied since April 1994, as part of a space solar power technology program in NAL (National Aerospace Laboratory). The Stirling alternator is one of candidates for future space power applications, and will be integrated with the solar cavity receiver subsystem, having both Na heat pipes and thermal energy storage. Through a series of preliminary bench tests, it was found that the efficiency of the linear alternator was significantly low as compared to our initial design. To improve the alternator performance, some design modifications of the magnet assembly and stator core have been made. As a result, the thermodynamic efficiency of 33% and system efficiency of 20% was obtained.