A new cogeneration system using a diesel engine was proposed to achieve power generation and carbon nanotube (CNT) synthesis simultaneously. Multi-walled carbon nanotube (MWNT) was synthesized during combustion in a diesel engine, in which gas oil/ethanol mixing fuel was employed as a carbon and heat source. Ferrocene was used as a floating catalyst for MWNT formation and additive such as sulfur was employed as a promoter of MWNT formation. When catalysts were included in fuel, MWNTs were successfully synthesized. The influence of sulfur amount in fuel on MWNT growth and fuel consumption was investigated. It was revealed that sulfur had a crucial role for MWNT growth and an engine performance was improved by adding sulfur into gas oil/ethanol mixing fuel. The results of this study suggest that a diesel engine is a potential candidate to produce CNT as a combustion reactor in addition to simultaneous power generation.

Damage mechanism of hydrogen induced cracking (HIC) under wet environment can be regarded as behavior of hydrogen embrittlement. Linear ultrasonic inspection method as a measurement method of non-destructive inspection of HIC is effective for straight cracks, and stepwise crackings in which differences exist in acoustic impedance of ultrasonic waves incident on device materials. However, detection of distortion of HIC tip reason, microcrackings, grain boundary voids, etc. due to aged deterioration is difficult. Therefore, research results in which behavior of precursory driving force of minute defects in the HIC tip region can be caught by analyzing backscatter waves of nonlinear ultrasound (noise component) will be described in detail