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For a high speed Diesel engine , gas oil and lighter heavy oil are used in general, but, in order to reduce NOx (Nitorogine Oxide) in exhaust gas and also to prepare for the future world wide oil shortages, blends of alternative fuels, such as alcohols are of interest. These additive to Diesel engines have been studied for a long time in this institute, as well as in many other institutes in JAPAN. Here, the ignition temperature of blended gas oil and others, mixed with various alcohols (mainly ethanol) and Decanol or Isoamyl Ether, are measured independently to analyse the effect of this blending on the improvement of emission quality. Ethanol is of paticular interest because it is a fuel produced from all biomass including cereals, rice, corn, potatoes etc, crops widely produced in many places in the world, as seen in Figure 1.

The performance of Stirling engines depends on the performance of regenerators. Regenerators are primarily expected to have good temperature efficiency. In addition, the flow losses and dead space must be minimized. These factors, however, are in opposition to each other. Although a considerable amount of research has focused on these three factors, few studies have analyzed them in actual reciprocating flows. Moreover, it has not been possible to measure the temperature efficiency by using a working gas due to the rapid change of the gas temperature. Therefore, in this study, we measured the transition of the temperature in the reciprocating flows in a regenerator by using water instead of a gas and then examined the characteristics of the regenerator. Here, we report the observed transition of temperature, which almost coincided with results previously obtained by computer simulation.

To get a simple and low cost Stirling engine that would be manufactured and used in any district of the world, a unique atmospheric Stirling engine named NAS-1 is under study at NIHON University. NAS-1 was originally planned to be used for the solar field, so the cylinder head was designed to have a glass head at its top with the concentrated solar beam penetrating the glass. NAS-1 uses a rubber diaphragm for the power piston, and it has proved to be very reliable and successful. It has James Watt's approximate linear motion link mechanisms (Watt link) for the main crank shaft, instead of the usual crossed head to eliminate liquid oil lubrication. This kind of engine has been thought to furnish very simple, low cost and efficient power for future clean energy fields. This engine design is simple, low in cost, and doses not involve problems of high pressure, and does not produce any pollutants whatsoever such as carbonic acid gas, NOx and others' pollution.