| Project/Area Number |
05454104
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
生物環境
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TAKAKURA Tadashi The University of Tokyo, Faculty of Agriculture, Professor, 農学部, 教授 (50011929)
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| Co-Investigator(Kenkyū-buntansha) |
IBARAKI Yasuomi The University of Tokyo, Faculty of Agriculture, Professor, 農学部, 助手 (50242160)
GOTO Eiji The University of Tokyo, Faculty of Agriculture, Professor, 農学部, 助手 (00186884)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1994: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1993: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Closed ecosystems / Gas circulation / Variation of oxygen concentration / 酸素濃度 |
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| Research Abstract |
Through the study of the nature of closed ecosystems, the final goal of the present study is to investigate the ecological balance of the living earth where we live. The earth itself is alive because of having many living creatures on it. It is believed that the present situation of the earth is maintained because many living creatures in its biosphere control the earth environment.
The closed ecosystems in the present research are the systems which are isolated regarding gas and water exchange but are not energetically. Solar radiation is the energy source to the system. The purpose of the present study is to investigate the balance of the system under the change of outside environment or the change of inside ecosystems.
The desiccator made of polycarbonate whose volume is 20L was used for an encapsulated ecosystem vessel and it consisted of soil, pebble, three kinds of aquatic plants, and three shrimps of 10 to 20mm long. The initial oxygen concentration levels were 10.1,20.2 and 30.3% for 10,20, and 30% sections, respectively. Measurement of oxygen concentration was made by an oxygen meter and carbon dioxide concentration was checked by a gas-chromatograph. The total observation was carried out for 84 days. Up to 54th day from the starting day, it was verified that shrimps were alive. An aquatic plant has changed its color gradually and after 40th day there was no green in the vessel. Another kind of aquatic plant grew considerably. The oxygen concentrations in the vessels of 10 and 20% increased, on the other hand, it decreased in the vessel of 30%.
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