Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave ...

The nondestructive evaluation (NDE) of adhesively bonded structures is a complex process. Earlier work has confirmed that ultrasonic waves are influenced by the properties of the material in which they travel. Acousto-ultrasonic methods have been widely used by previous researchers to generate ultrasonic waves in plates and bonded structures for flaw detection, visualization, and measurements o...

Particles accumulated in a coupled acoustic-gravity field, in which the base-material of a particle determines the equilibrium aggregation positions, are eluted from a separation channel by an orthogonal laminar flow. Elution times are controllable by changing the intensity and frequency of the ultrasonic waves.

medical plants are adapted to different kinds of dormancy to survive in the worst situations. regarding to ecological viewpoint, this kind of adaptation is very important in respect to restriction of genetic draft and decrease of genetic resource of medicinal plants. this leads to plant survival even after prolonged drought. since some of them are endangered species and in the other hand increa...

In the fields such as evacuation guidance and entertainment, it is important for each listener to provide different sound information by using some loudspeakers in a same room. However, listeners have difficulty obtaining target sound information because various sound signals are mixed by using a general loudspeaker which has a wide directivity. To solve this problem, a parametric loudspeaker w...

In part one of this series of articles, level measurement using a floating system was discusses and the instruments were recommended for each application. In the second part of these articles, level measurement with the aid of pressure instruments was discussed. In the third part of this series of articles, radar level measurement basics and parameters affecting its efficiency were explained an...

Similar to pulse-echo ultrasound, optoacoustic imaging encodes the location of optical absorbers by the time-of-flight of ultrasound waves. Yet, signal generation mechanisms are fundamentally different for the two modalities, leading to significant distinction between the optimum image formation strategies. While interference of back-scattered ultrasound waves with random phases causes speckle ...