Metallic compound of ternary Al-B-C system was prepared by mechanical alloying (MA) using Al, boron and graphite powders as starting materials. MA was carried out using Spex 8000 mixer/mill for 50 hours in an argon atmosphere without process control reagent such as methyl alcohol. The MA powders obtained were heat-treated in vacuum at the temperature of 873 and 1273 K for 5 hour. Pure ternary Al-B-C compound was obtained in the chemical content of Al:B:C=55:27:18. The ternary compound obtained in this study has a new phase whose crystal structure is not identified yet.
The oil-impregnated sintered bearings are used for various aplecations and, wide usages without refueling. The oil circulating mechanism operates smoothly the behavior of oil If doing at the time of passing and becoming a stationary state, and there is little thing where trouble is caused. On the other hand, the trouble of such as starting noise might be caused in the unstationary state that repeats operation for a short time. To study the behavior of oil of each parameter, we execute the numerical simulation and various verification experiments. As a result, we developed that the bearings were able to be used enough for various brief operating time in the unstationary state. Finally we have expanded the usage of the oil-impregnated sintered bearings by adding the consideration of the behavior of oil.
In late years, from a trend for ecology of auto motive engine, low emission and low fuel consumption of engine become a social assignment. At the same time, the high output (high efficiency) is required, too. In order to meet those requirements, in comparison with conventional engines, lean A/F (Air fuel ratio) setting is becoming popular for the high performance engines of late years. Exhaust valve seat (sintered material) used in these engines has a problem in wear resistance, because it is exposed to the surroundings that is clean and a high temperature in comparison with the conventional engines. Therefore, wear mechanism with lean A/F of engine was analyzed.The exhaust valve seat (sintered material), that was superior in wear resistance, was developed.
In this paper, offshore wind resources within the Japan’s EEZ (Exclusive Economic Zone) are assessed using wind speed data from the microwave scatterometer SeaWinds onboard QuikSCAT. At first, from the 10m-height wind speed from QuikSCAT, 60 m-height wind speed is estimated by using an empirical equation for height correction. Based on the 60m-height wind speeds, annual energy production is calculated under an assumption of installing 2 MW wind turbines every 0.64 km2. The annual energy production is then accumulated for the entire Japan’s territorial waters and EEZ (4.47×106 km2). As a result, it is shown that the total energy production is estimated to be 4.86×104 TWh/yr. This offshore wind energy potential within the EEZ is approximately 50 times higher than the actual annual electricity production in Japan.