Propagation characteristics of leaves using ultrasonic transmission waves

Five kinds of leaves and agar sheets (as an imitation of leaves) suspended in water were characterized nondestructively using ultrasonic transmission analysis of longitudinal ultrasonic waves. The wave patterns of morning glory, persimmon, hydrangea, fragrant olive and tea were found to be simple compared with those of artificial solids. As the thickness of tea leaves increases, the phase velocity increases and attenuation coefficient, frequency and phase decrease. In contrast, the phase velocity of agar sheets decreases with increasing thickness and content of agar. This shows that acoustic properties of leaves cannot be interpreted by their agar component alone.