AS BLOOD FLOWS THROUGH the vascular network, it creates fluid mechanical forces that can be predicted based on established physical principles of fluid dynamics. The major components of flow-generated force in the vasculature include pressure and shear stress, both of which are imparted directly onto the vessel wall. The realization that different patterns (laminar vs. oscillatory), magnitudes ...

Dual systems of steel moment frame and reinforced concrete shear wall have combined the advantages of steel frames and reinforced concrete shear wall. These walls have increased the lateral stiffness of steel frames and have reduced seismic demands on steel frames thus providing opportunities to use such system. In this research intermediate dual system of steel moment frame was chosen with int...

Recent investigations indicate that the initial event in the pathogenesis of atherosclerosis involves an (auto)immunologic injury to the vessel wall. Heat shock proteins (hsps), which are expressed on the endothelial cell surface, constitute possible autoantigens. After being exposed to shear stress of 30 dyne/cm in vitro by means of a rotational viscometer, human umbilical vein endothelial cel...

We consider here pulsatile flow in circular tubes of varying cross-section with permeable walls. The fluid exchange across the wall is accounted for by prescribing the normal velocity of the fluid at the wall. A perturbation analysis has been carried out for low Reynolds number flows and for small amplitudes of oscillation. It has been observed that the magnitude of the wall shear stress and th...

Attractive colloidal particles are trapped in metastable states such as colloidal gels at high attraction strengths and attractive glasses and high volume fractions. Under shear such states flow via a two step yielding process that relates to bond and cluster or cage breaking. We discuss the way the structural properties and related stress response are affected by the shear rate. At low rates c...

We generate and study electroosmotic shear flow in microchannels. By chemically or electrically modifying the surface potential of the channel walls a shear flow component with controllable velocity gradient can be added to the electroosmotic flow caused by double layer effects at the channel walls. Chemical modification is obtained by treating the channel wall with a cationic polymer. In case ...

Leukocytes roll on selectins at nearly constant velocities over a wide range of wall shear stresses. Ligand-coupled microspheres roll faster on selectins and detach quickly as wall shear stress is increased. To examine whether the superior performance of leukocytes reflects molecular features of native ligands or cellular properties that favor selectin-mediated rolling, we coupled structurally ...

Abdominal aortic aneurysm (AAA) is a localized dilatation of the abdominal aorta .It occurs when there is a increase in the normal diameter of the blood vessels by more than 50 percent. Approximately 90 percent of abdominal aortic aneurysms occur infrarenally , but they can also occur pararenally or suprarenally. This is because of some catastrophic outcome. Due to this, the blood flow is exagg...

Wall-bounded flows at high Reynolds number are characterized by high rates of shear at the walls. Resolving the flow near the wall, is critical to correctly reproducing the turbulence. In the present paper, we show that the accurate prediction of spatially varying wall shear stress requires additional near-wall resolution for large eddy simulation. We also demonstrate the advantage of the use o...

BACKGROUND AND PURPOSE Attempts have been made to associate intracranial aneurysmal hemodynamics with aneurysm growth and rupture status. Hemodynamics in aneurysms is traditionally determined with computational fluid dynamics by using generalized inflow boundary conditions in a parent artery. Recently, patient-specific inflow boundary conditions are being implemented more frequently. Our purpos...