PURPOSE Palpation is used most commonly to assess tissue stiffness despite its well-known deficiencies. As an improvement, a mechanical technique known as ultrasonic indentation has been proposed. The purpose of this study was to compare the accuracy of 3 ultrasonic indentation techniques in quantifying bone displacement in a specially constructed tissue simulator. METHODS Three ultrasonic in...

Friction stir welding (FSW) is an innovative process that has been successfully used in joining aluminum alloys, normally difficult to weld. Important advantages over fusion welding are better retention of baseline material properties, lower residual stresses and excellent mechanical properties. Defects that occur in FSW joints are due to improper tooling or setup. Non-destructive techniques us...

The pulse compression technique is successfully and widely used in many fields for improving the signal to noise ratio (SNR); which is especially useful when the environment is noisy and the SNR is poor. Since high frequency ultrasound is strongly attenuated in concrete, only low frequency ultrasound can be used in ultrasonic nondestructive testing (NDT) of concrete. In this study the pulse com...

The velocity #uctuations and local strain rate in a #uidized suspension of particles are investigated using the new ultrasonic technique of di!using acoustic wave spectroscopy. DAWS probes the relative motion of the particles at very short length scales down to the inter-particle separation, and allows the spatial correlations of the velocity #uctuations to be probed by varying the transport me...

We present here a new ultrasonic diagnosis technique in natural, porous rocks. This method, based on the ultrasonic velocity changes, allows us to measure the transient spacial distribution of two liquids (water and oil) in a sandstone.

Thin walled large structures are widely used for pipes, bridges, wings and body of aircrafts, and automobile bodies. To maintain such large structures, in addition to visual inspection, non-destructive testing with X-ray and ultrasonic is periodically implemented for essential parts. In ultrasonic non-destructive testing, ultrasonic pulse echo technique is generally used, in which plate thickne...