We must overcome the global warming problem caused by increase of atmospheric CO_2 concentration to keep our sustainable growth. GLAD (Gas Lift Advanced Dissolution) System has been investigated to mitigate the estimated peak of atmospheric CO_2 concentration over the next few hundreds years. The system dissolves gaseous CO_2 at a shallow portion and transports CO_2 solution to a great depth via gas-lift pump. In the present paper, first, we investigate a structure of bubbly flows in a large-diameter pipe. Second, on the basis of the experimental results, numerical model of the flows are discussed. Third, we carry out numerical simulation of the GLAD System to obtain pH level of CO_2 solutions discharged from the system. Environmental acceptability of the GLAD System will be discussed on the basis of these results.

抄録全体を表示

This study deals with theoretical analysis of the frequency response of thermistors and a compensation technique for the delay of the response. A "two-thermocouple probe technique" developed previously (Tagawa & Ohta, 1997) was applied to the identification of the time-constants of thermistors whose frequency response approximate a first-order system. Two different thermistors were combined into a probe, and the schemes for the time-constant identification and for the response compensation were tested in two working fluids of water ans air. The results show the compensation technique to be successful.

抄録全体を表示

High performance fuel consumption engine on economy car has simple carburetor with variable venturi. But it is very difficult to keep steady air-fuel ratio by the carburetor as engine runs from low to high speed. As the air-fuel ratio is got by the venturi pressure, it is necessary to know the venturi pressure caused by engine rotating. As a simple method to measure the pressure, motoring metod was employed.

抄録全体を表示