earthquakes travel times inversion for determination of velocity structure of crust is one of the most important objectives in seismology. in the simultaneous inversion method, the parameters of earthquakes and velocity model are determined initially and are improved during inversion steps. in this study, we have used more than 22000 calculated travel times for first arrivals of 6000 earthquake...

by growing the population and need for settlement, many cities have been built on soft sediments and seismic areas. it emphasizes the need for a careful and reliable assessment of site effect phenomena. beyond the methods of studying site effects, microtremor recordings has become popular over the last decades as it offers a convenient, practical and low cost tool to be used in urbanized areas....

In this paper we present the first detailed study of the excitation of high phase velocity plasma waves by colinear optical mixing. The plasma wave frequency and wavenumber, hence the phase velocity, are directly measured using Thomson scattering. The amplitude of the plasma wave and therefore the longitudinal electric field is inferred from the magnitude of the Thomson scattered light. For a m...

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...

Introduction:In this study, a non-invasive method based on consecutive ultrasonic image processing is introduced to assess time rate changes of the carotid artery wall displacement, velocity and acceleration in the longitudinal direction. The application of these parameters to discriminate healthy and atherosclerotic arteries was evaluated. Methods:Longitudinal displacement rate of common ...

shear and compressional wave velocities along with other petrophysical logs, are considered as upmost important data for hydrocarbon reservoirs characterization. shear wave velocity (vs) in well logging is commonly measured by some sort of dipole logging tools, which are able to acquire shear waves as well as compressional waves such as sonic scanner, dsi (dipole shear sonic imager) by schlumbe...