The frequency dependence of the ultrasound signal backscattered by blood in shear flow was studied using a simulation model. The ultrasound backscattered signal was computed with a linear model that considers the characteristics of the ultrasound system and tissue acoustic properties. The tissue scattering properties were related to the position and shape of the red blood cells (RBCs). A 2D mic...

– From both NMR and conventional rheometrical data we show that a foam cannot flow steadily below a critical, apparent shear rate and a critical shear stress. At low velocities the shear localizes in a layer of thickness decreasing with the apparent shear rate. When this thickness becomes smaller than a critical value hc (about 25 bubble diameters) the continuum assumption is no longer valid an...

Two of the factors, shear erosion and diffusive mass transfer, which limit the growth of heterogeneous biofilms are considered. For permeable beds of particulates, with a regulated throughflow, equating shear induced erosion and biofilm growth, leads to estimates of biofilm thickness and activity which conform with experimental measurements. In the more open environments of pipes and channels, ...

contrary to the long period ground motions that can be predicted and estimated, high frequency ground motions have random character and behave stochastically. stochastic modeling methods are usually used for the modeling of high frequency ground motions where there are not strong ground motion records. stochastic methods are of two kinds: in the first one, the seismic source is considered as a ...

Abstract   In this paper elastoplastic buckling of rectangular plates with different boundary conditions are investigated. Differential governing equations of plate are obtained on the basis of general loading and according to deformation theory (DT) of plasticity. Various loading conditions contain uniaxial, biaxial and shear are studied. The employed material is AL7075T6 which is usually used...

In this paper, dynamic modeling of a double layer cylindrical functionally graded (FG) microshell is considered. Modeling is based on the first-order shear deformation theory (FSDT), and the equations of motion are derived using the Hamilton's principle. It assumes that functionally graded length scale parameter changes along the thickness. Generalized differential quadrature method (GDQM) is u...

The fluctuating wall shear stress, wall pressure, and streamwise velocity were measured simultaneously in a cylindrical boundary layer at a momentum thickness Reynolds number of Reu52160 and a boundary layer thickness to cylinder radius ratio of d/a55 using a hot wire wall shear stress probe mounted just upstream of a hearing aid microphone and a hot wire velocity probe. Variable Interval Time ...

Tissue viscosity is correlated with tissue pathological changes and provides information for tissue characterization. In this study, we report an optical method to track continuous shear-wave propagation at centimeter depths in an optically turbid medium. Shear-wave attenuation coefficients were measured at multiple frequencies using shear-wave laser speckle contrast analysis (SW-LASCA) to quan...

In this paper, an attempt is made for solution of free vibration analysis of annular plate reinforced with carbon nanotubes for Uniformly Distribution (UD), resting on an elastic foundation using a refined theory presented. In this theory, a parabolic distribution of shear stress and strain in the thickness direction and satisfies the boundary conditions of zero shear stress on the upper and lo...

The aim of this study was to understand the microscopic characteristics of the bamboo bonding interface with phenol formaldehyde resin modified with larch thanaka and urea (PTUF) and its effect on the shear strength of two-ply bamboo laminated lumber. Bleached and carbonized bamboo strips were used, and two assembly patterns (outer-to-outer and inner-to-inner) were adopted to make two-ply bambo...