development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

Low seismic velocity regions in the mantle and crust are commonly attributed to the presence of silicate melts. Determining melt volume and geometric distribution is fundamental to understanding planetary dynamics. We present a new model for seismic velocity reductions that accounts for the anomalous compressibility of silicate melt, rendering compressional wave velocities more sensitive to mel...

There is a general consensus that 3D reference models can be used to isolate effects of wave propagation and thus help in improving characterization of seismic sources. Advances in computation and numerical method have made it possible to capture increasingly broadband, full wave generation and propagation in 3D earth models. The main objectives of this project are to construct hierarchical, mu...

Shear-wave velocity is an indication of the shear strength of the ground since the velocity is related to the shear modulus. Therefore, monitoring the velocities is useful for site characterization and disaster prevention. We estimate the time-lapse change in shear-wave velocity as well as shear-wave splitting in the shallow subsurface throughout Japan by applying seismic interferometry to the ...

We have conducted a series of experiments designed to investigate elastic and electromagnetic (EM) velocity anisotropy associated with a preferentially aligned fracture system on a temperate valley glacier in south-central Alaska, USA. Measurements include a three-dimensional compressional wave (P-wave) seismic reflection survey conducted over a 300m 300m survey patch, with uniform source grid ...

The disadvantages of conventional seismic tomographic ray tracing and inversion by calculus-based techniques include the assumption of a single ray path for each source– receiver pair, the non-inclusion of head waves, long computation times, and the difficulty in finding ray paths in a complicated velocity distribution. A ray-tracing algorithm is therefore developed using the reciprocity princi...

We used continuous recordings in Sichuan, China to track the temporal change in elastic properties of the medium, namely the seismic speed, at a regional scale in a 2 year period which includes the great Wenchuan Mw 7.9 earthquake. The data are recorded by a temporary network of 156 broad-band seismographs, in a 200km × 200km region that covers the southern 2/3 of the fault system activated dur...

In this paper, a six-stage interactive model is presented for the perforation of metallic plates using blunt deformable projectiles when plastic wave propagation in both target and projectile is considered. In this analytical model, it is assumed that the projectile and target materials are rigid – plastic linear work hardened. The penetration of the projectile into the target is divided into s...