| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Research Abstract |
Nowadays, the subsurface contaminant problem is a very important subject in all over the world. The study on this subject may often face with the difficulty in evaluating qualitatively the constituents of contaminated subsurface, like soil, pore air and pore water, because there is not yet a well-established and applicable sensor for such purpose.
For evaluating subsurface contamination at present time, the undisturbed sample is commonly taken out by sampling (boring) method, and then the contamination is extracted offsite. This method will not favor a good possible to obtain an accurate data on the contamination rate and concentration, which are very important input data for modeling the evolution of solute concentration in the contaminated subsurface.
Accordingly, as the purpose of this study is to develop the measuring system for subsurface contamination, what so-called FDR-V system (Frequency Domain Reflectometry with Vector network analyzer) was applied to measure the concentration of contaminant. The FDR-V method used in this study is the coaxial probe method (one port reflective method and S parameter) which allows the measurement of the complex dielectric constant from 1GHz to 18GHz. For the purpose of measuring the concentration of a contaminant, the FDR-V system separates two reflectives, which consist of a real part and an imaginary part of complex dielectric constant in the frequency domain. In this experiment, oil was used as a contaminant ; and then the spectrum difference were analyzed based on different dielectric constant of oil and water. Thus, this experiment indicates that it is possible to measure the concentration of contaminant both in saturated and unsaturated condition.
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