Kenichi Ando

Hydraulic Tomography for Detecting Fracture Zone Connectivity

Fracture zones and their connectivity in geologic media are of great importance to ground water resources management as well as ground water contamination prevention and remediation. In this paper, we applied a recently developed hydraulic tomography (HT) technique and an analysis algorithm (sequential successive linear estimator) to synthetic fractured media. The application aims to explore the potential utility of the technique and the algorithm for characterizing fracture zone distribution and their connectivity. Results of this investigation showed that using HT with a limited number of wells, the fracture zone distribution and its connectivity (general pattern) can be mapped satisfactorily although estimated hydraulic property fields are smooth. As the number of wells and monitoring ports increases, the fracture zone distribution and connectivity become vivid and the estimated hydraulic properties approach true values. We hope that the success of this application may promote the development and application of the new generations of technology (i.e., hydraulic, tracer, pneumatic tomographic surveys) for mapping fractures and other features in geologic media.

Basic experimental study on effect of bentonite to efficiency of wireless power transfer using magnetic resonance coupling method

Nuclear power has become one of the significant sources for electricity generation and one crucial issue in operating nuclear power plant is radioactive waste management. Multi Barrier System has been utilized to handle high-level nuclear waste. Several sensors are equipped to ensure the safety condition inside the repository, but with current method, signal cables and power cords have to be drawn to the outside through small hole. To construct Multi Barrier System, the option of completely sealing the repository and transmitting data and power wirelessly has been proposed. Wireless power transfer via magnetic coupling is an attractive method for such application due to its advantage of being able to transfer power across longer distance with high efficiency while being robust to positional shift of antennas and that using repeater antenna can also enable power transmission across even further distance. However, obstacle between antenna, although will not completely disrupt the power transmission, is most likely to have influence on power transfer efficiency. Therefore, in this paper, the efficiency of wireless power transfer with bentonite, which is common component of Multi Barrier System, as transmission obstacle, with and without repeater antenna, is investigated and compared to the efficiency of wireless power transfer with no barrier material.