The propagation of shear waves in an anisotropic fluid saturated porous layer over a prestressed semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary has been studied. The rectangular irregularity has been taken in the half-space. The dispersion equation for shear waves is derived by using the pertur...

seismic refraction and downhole survey were employed to study dynamic characteristics of subsurface materials in bam city, southeast of iran. the data acquisition was performed at 160 p and s-wave refraction stations and 15 boreholes in the city. to derive velocity depth sections along these profiles as well as to perform downhole diagrams, seisimager software was used. based on the obtained va...

The computer simulation of helix travelling-wave tubes requires accurate information about the phase velocity, interaction impedance and attenuation of the helix slow wave structure at each frequency. This has received considerable attention, from the pioneering work of Pierce onwards, and it is possible to compute or measure the phase velocity with sufficient accuracy. The methods available fo...

This paper examines the generation and propagation of a Third order solitary water wave along the channel. First the Incompressible Smoothed Particle Hydrodynamics (ISPH) numerical method is described and the boundary condition handling method is presented. The numerical model is then used to simulate solitary wave propagation along the fixed depth channel. The numerical results are compared wi...

Wave, antenna impedance, plasma density, and temperature anisotropy measurements are carried out for a helicon plasma source in nonuniform and uniform static magnetic fields. Strong axial density gradients associated with the nonuniform magnetic fields are observed to affect wave fields, absorption, and source efficiency. The wave field and antenna input impedance measurements are compared with...

A GaAs/A1GaAs traveling wave Mach-Zehnder electro-optic modulator with novel slow wave electrodes was fabricated on undoped epitaxial layers. Using appropriate electrode engineering velocity matching with matched impedance and low microwave loss was achieved. Device had a measured electrical bandwidth greater than 40 GHz at 1.55 j.un. The measured bandwidth at 1.3 j.m was 37 GHz. The mechanism ...

The method of simultaneous PP-PS inversion has recently been developed and tested on the 3-D Blackfoot seismic data set. This paper shows the application of this method on 3C-2D seismic data from Pikes Peak oilfield. The inversion was accomplished with a newly installed inversion module in ProMAX. After careful prestack processing, five limitedoffset stacked sections for each of the vertical an...

the goal of this laboratory study is to investigate the effect of pore shapes on seismic wave velocities in carbonate rocks under reservoir conditions. in this research, 41 core plugs of carbonate rocks from oil fields of the southwest of iran were prepared. the compressional and shear wave velocities were measured in both dry and brine saturated samples under several pressures especially reser...