Ultrasonic shear-wave propagation studies have been carried out for the measurements of velocity and attenuation in some rocks, concrete and synthetic materials at room conditions. It has been found that ‘pulse broadening’, which occurs due to attenuation, can be measured quite accurately while carrying out shearwave velocity measurements in them. The pulse broadening data could be used to dete...

this paper describes the effects of induced magnetic field and partial slip on the peristaltic flow of a couple stress fluids in an asymmetric channel. the two dimensional equation of couple stress fluid are simplified by making the assumptions of long wave length and low reynolds number. the exact solutions of reduced momentum equation and magnetic force function have been computed in wave fra...

1. A family of structurally related but genetically distinct natriuretic peptides exist which include atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) of myocardial cell origin and C-type natriuretic peptide (CNP) of endothelial and renal epithelial cell origin. All three exert actions via cGMP, with ANP and BNP functioning via the natriuretic peptide A receptor and CNP via ...

A sparse array guided wave tomography system is investigated for monitoring plate wall thinning status caused by corrosion/erosion. Because of their group velocity dependence on the structure wall thickness of some special modes, ultrasonic guided waves are sensitive to structure wall thinning status. As a low resolution imaging technique, a sparse array system provides many advantages. First, ...

A new technique utilizing theoretical wave forms has been developed to determine precise shear wave travel times. This technique was applied to long-period World-Wide Standard Seismograph Network and Canadian network seismograms of five large nuclear explosions to obtain a surface focus shear wave data set containing about 100 travel times for distances greater than 30 ø. Very little scatter is...

an active antenna for transmitter application in s frequency band is designed and analyzed using harmonic balance technique which is based on the nonlinear model of active devices. in this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. this patch antenna is analyzed employing full-wave momentum method. by applying nonlinear model of transisto...

seismic piezocone device (scptu) together with resonant column and cyclic triaxial test apparatus are employed to measure small strain shear modulus (g0) of carbonate sandy and clayey soils of southern coasts of iran. a large area of southern regions of iran is formed from clay, silt and sand. in this study, maximum shear modulus that is derived from both field (by seismic piezocone) and labora...

Seismic amplitudes contain important information which can be related to fluid saturation. The amplitude-versus-offset (AVO) analysis of seismic data based on Gassmann’s theory and approximation of the Zoeppritz equations, has played an central role in reservoir characterization. However, this standard technique faces a long standing problem, its inability to distinguish between partial gas and...