Showing papers by "Satoshi Nagai published in 2000"
TL;DR: In this paper, an under-sodium ultrasonic visual inspection technique was developed in order to observe in-vessel structures in a Fast Breeder Reactor (FBR) whose reactor vessel is filled with opaque liquid sodium.
Abstract: We have developed an advanced under-sodium ultrasonic visual inspection technique in order to observe in-vessel structures in a Fast Breeder Reactor (FBR) whose reactor vessel is filled with opaque liquid sodium. The final goal of this work is achievement of resolution equivalent to that of an image obtained by optical fiber scope. The under-sodium ultrasonic visualizing system consists of a matrix-arrayed transducer and a signal- processing device. The matrix-arrayed transducer, in which 36x36 piezoelectric elements are arranged with 5 mm interval and sealed by a thin metal diaphragm, can realize a 3-dimensional image with high resolution. Regarding signal processing, the 3-dimensional image synthetic processing and the cross correlation processing for the purpose of improving S/N ratio of ultrasonic echoes are implemented on a high-speed parallel processor. Under-sodium imaging test was carried out, and it was confirmed that a 3-dimensional image of the blind target, which was prepared without informati...
58 citations
Patent•
31 Jan 2000
TL;DR: In this article, an ultrasonic wave was emitted toward a coating layer to detect energy change based on a received wave from the coating layer, so as to exactly determine a degree of deterioration of a coating material based on the energy change.
Abstract: PROBLEM TO BE SOLVED: To emit an ultrasonic wave toward a coating layer to detect energy change based on a received wave from the coating layer, so as to exactly determine a degree of deterioration of a coating material based on the energy change. SOLUTION: In this invention, a part for evaluating the degree of deterioration in the coating material is selected (step 1), the energy change by the ultrasonic wave in the selected part is found (step 2), a layer thickness of the coating layer is found (step 3), the energy changes are classified in the every found layer thickness (step 4), an image is formed in the every found layer thickness based on the energy change (step 5), the imaged energy change is collated with a master curve prepared preliminarily to determine the necessity for repairing (step 7), and information therein is displayed (step 8).
1 citations