We performed size-dependent nickel plating of a tapered fiber under 1MHz ultrasonic irradiation using two plating units with different water depths of 8 cm and 23 cm. The two obtained probes have nickel thickness profiles which gradually decrease from the foot of the tapered core toward the tip. However, we could not uniformly plated the whole flat end of the clad with nickel by the unit with a smaller water depth of 8 cm.

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The purpose of this paper is to bond electrodes between the rigid printed circuit board (RPCB) and flexible PCB (FPCB) using ultrasonic vibration. The electrodes of FPCB and RPCB were electroless-plated with Sn and electroless Ni/immersion Au (ENIG), respectively. The peel strengths of the joints were investigated with various parameters, such as bonding pressure, time and temperature. This study showed that the electrodes between the RPCB and FPCB were successfully bonded without any adhesive at a low temperature for a short low time, compared to other bonding methods: adhesive bonding and thermo-compression bonding.

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The purpose of this experiment was to diffuse a microorganism in air. A nebulizer is one of the methods to diffuse them, however the particles were moisturized. It is important to obtain dried airborne microorganism alive to evaluate air cleaners. In this experiment, an airborne ultrasound at 27kHz was used to diffuse the microorganism, a stepped circular vibrating plate was set in a chamber and sound pressure level up to 155dB was generated. It was found that the microorganism was diffused alive with homogeneous dispersion by ultrasound.

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To achieve a high speed acoustic data transmission, it is being considered to use the frequency band of 80 kHz ± 20 kHz. However, the absorption attenuation coefficient in these frequencies only has empirical formula. Therefore, the absorption attenuation was measured by the frequency of 60 kHz to 100 kHz within the range of propagation distance of 250 to 510 m at 1,000m depth area. As a result, a corresponding comparatively good for the empirical formula of Schulkin & Marsh result was obtained.

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In the acoustic field of a phase conjugated wave, the sound wave emitted from TRA is converged on the sound source position. Receiving point is put on space between the sound source position and TRA, and the sound wave and the time reversal wave which enter into the point are compared. As a result, the sound wave and the time reversal wave to pass receiving point checked that correlation could be taken. Using these characteristics, a new vertical array is arranged and performs time reversal processing between TRA and a new array. In this manner, it turned out that it is possible to move a focus to the arbitrary positions of the direction of distance.

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Dispersion curves and wave structures are indispensable to guided wave non-destructive testing, but they cannot be easily derived especially for a bar with an arbitrary cross-section like a railway rail. Authors have developed a calculation technique and software for deriving them with the semi-analytical finite element method. This paper describes the calculation technique and its application to guided wave NDT. As an example of guided wave NDT using the dispersion curve software, inspection for bottom edges of rails was introduced. Among thousands of possible guided wave modes for a rail, suitable modes were selected considering characteristics of defect detection, long-range propagation and attenuation at fastenings. Inspection equipments designed for generating and receiving the most suitable modes for bottom-edge inspection enabled us to find defects at bottom edges of a rail with high accuracy.

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The purpose of Rheology is to show relations between strain and stress as a function of the time. Rheology is the learning of a sense. Therefore, it is expressed with a logarithm. The directions which give material strain or stress are shear and extension. The methods which give material strain or stress are static measurement and dynamic measurement. Dynamic measurement is method which gives it Sine oscillation. Ultrasonic oscillation is very high frequency. Therefore, it is suitable for the phenomenon that a change is fast.

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