The effect of ultrasound on total mass, dewaterability, turbidity, and coliform counts of livestock waste sludge was investigated. The study involved laboratory tests and pilot plant experiment under various test conditions including sonication time, ultrasonic energy level, and sludge volume. Laboratory test results showed that sonication caused a decrease in sludge particle size, capillary suction time, and coliform counts. Pilot plant experiment results showed that ultrasonic treatment significantly improved dewaterability, and reduce the volume, mass, and water content of sludge.

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We studied changes in average particle size and particle size distribution of nanometer-sized diamond particles caused by variations in ultrasound exposure time. The diamond particles had a primary particle size of about 5 nm, but aggregated to about 5 μm immediately after manufacture. Particles of this type were exposed to ultrasound at 150 kHz in water tank, and ultrasound exposure time was varied over a range of 20 s to 1200 s. Our results show that average particle size and particle size distribution of the diamond particles changed with increasing ultrasound exposure time. At exposure times of 300 s and 1200 s, the diamond particles had an average particle size less than about 100 nm. Furthermore, at 300 s and 1200 s, the diamond particles had a narrow particle size distribution in the nanometer range. In our future work, changes to the zeta potential of nanometer-sized diamond particles by increased ultrasound exposure time will be measured as well, because zeta potential affects the dispersion stability of diamond particles. The dispersion mechanism of the diamond particles by ultrasound exposure will also be considered.

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Maximum speed of 1.5m/s and 1nm positioning accuracy ultrasonic motors have been minimized and developed. By using a V-shape transducer ultrasonic motor, a 10kg weight massive stage was driven. The stage speed reached at 0.2m/s with controlled maximum acceleration of 3m/s^2 for thrust of 30N. For the high speed and precise positioning, the driving mode of the transducers changed from a resonance frequency drive, an impact inertial drive and a DC drive depending on the required speed, acceleration, positioning stroke and resolution. The stage was driven 20mm distance from an initial position in static condition with 1 nm resolution within 350ms.

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The structure of ultrasonic waves that had passed through bovine cortical or cancellous bones has been observed by using the shilieren visualization technique. Wave front deformation in the results for cortical bones can be attributed to the refraction at the curved interface between the bone and water. On the other hand, results for the cancellous bones, which showed small deformation, need further investigation to be fully accounted for. At present, we consider that the trabecular structure of the cancellous bone did generate a large amount of scattered waves, but they were hardly observable by the schlieren system because they diverged from various points in the bone, and, resultantly, the remaining portion of the ultrasound was effectively visualized.

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Sound speed reconstructive imaging for the human abdomen using transmission type computed tomography was studied, aiming at the measurement of the visceral fat area for the metabolic syndrome diagnosis. In this paper, examinations were made to verify the validity and precision of the visceral fat area measurement based on experiment using a phantom specimen of human abdomen. As a result, it was demonstrated that the reproducibility of the image and precision of the visceral fat measurement was almost satisfactory, which can serve as the metabolic syndrome diagnosis.

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Ultrasound inverse scattering imaging technique from the quadrangular observation data configured with four linear array probes was proposed, aiming at a practical and versatile inverse scattering imaging system featuring lower cost and higher-speed data acquisition. In the present method, backward and sideward scattering wave data as well as the conventional forward scattering data were incorporated in the reconstruction calculations based on the Fourier slice theorem. From the simulation examinations, validity of the method was demonstrated, despite the difficulty of the inverse problem due to the limited quadrangular observation view as well as the finite aperture of the linear arrays.

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