1990 Fiscal Year Final Research Report Summary
Development of a New Method for Monitoring Time-Integrated Water Fugacity by the Use of Elastic Recoil Detection Analysis
| Project/Area Number |
63470033
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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 |
分析・地球化学
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| Research Institution | Kitasato University |
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Principal Investigator |
NOZAKI Tadashi Kitasato University, School of Hygienic Sciences Professor, 衛生学部, 教授 (00087488)
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| Co-Investigator(Kenkyū-buntansha) |
ARATANI Michi Inst. Phys. Chem. Res., Radiochemistry lab. Researcher, 核化学研究室, 研究員 (40087490)
AONO Keiko Kitasato, University, Common Faculty of Culture Lecturer, 教養部, 講師 (10050444)
NIISAWA Kazuhiro Kitasato University, School of Hygienic Sciences Assistant, 衛生学部, 助手 (90050616)
IWAHASHI Makio Kitasato University, School of Hygienic Sciences Lecturer, 衛生学部, 講師 (70087120)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Elastic Recoil Detection Analysis (ERDA) / Rutherford Back-scattering Analysis (RBS) / Glass Surface / H-D exchange / Time-integrated Water-fugacity / Cations in Soil Solutions |
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| Research Abstract |
Cations in surfaces of various glasses were leached in H O or D O, and H-D exchange and H (D) -by-cation replacement in the hydrated layer were investigated mainly by elastic recoil detection analysis and Rutherford back-scattering, in search of possibilities for the use of the glasses in the monitoring of moisture and dissolved cations in the soil. Similarly with the hydration rate, the rates of the exchange and replacement were found to depend markedly on the composition of glass, especially on alumina content. For some soda-lime glasses of low alumina contents, the two reactions were shown to proceed by at least two stages and mechanisms of different temperature dependences. These results suggest the following potentialities in the utilization of glass for the monitoring : (1) the hydration rate of a sodium silicate glass for water fugacity in the soil, (2) the H-D exchange rate in low alumina-content glasses for water vapor in special, dry and hot area, though the exchange capacity is deficient for usual environments, and (3) rate and resultant depth profile of the H-by-cation replacement for cations in the soil. Our first plan for practical use of the glass monitors has delayed, but we are ready for field experiments by (1) and intend to begin soon other monitorings in collaboration with the institute of Academia Sinica in Ulumuqi, China. We can now obtain various glasses of desired compositions, and can use particle accelerators for the ERDA and RBS measurements. We have, however, still a lot of studies to carry out, preparing a variety of samples under well-defined conditions to obtain more reproducible data, before fully effectuating the practical monitoring.
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