In this paper, the Al2O3-water nanofluid flow in laminar and turbulent flows inside tubes fitted with diamond-shaped turbulators is numerically modeled. The nanofluid flow is modeled by employing a two-phase mixture method and applying the constant heat flux boundary condition at tube walls. In the results, the effects of different parameters such as the geometry of turbulators, volume fraction...

OBJECTIVE The cysteine proteases, cathepsins, have been implicated in vascular remodeling and atherosclerosis, processes known to be regulated by shear stress. It is not known, however, whether shear regulates cathepsins. We examined the hypothesis that shear stress regulates cathepsin activity in endothelial cells. METHODS AND RESULTS Mouse aortic endothelial cells (MAECs) exposed to atherop...

An investigation has been made to analyze the effects of viscous dissipation on the heat transfer characteristics for both hydro-dynamically and thermally fully developed, laminar shear driven flow between two infinitely long parallel plates, where the upper plate is moving in an axial direction at a constant speed. On the basis of some routine assumptions made in the literature, a close form a...

We investigate the mechanical responses of dense granular materials, using a direct shear box combined with simultaneous acoustic measurements. Measured shear wave speeds evidence the structural change of the material under shear, from the jammed state to the flowing state. There is a clear acoustic signature when the shear band is formed. Subjected to cyclic shear, both shear stress and wave s...

BACKGROUND The complement system is implicated in the pathogenesis of atherosclerosis. Complement has been shown to activate endothelial cells (ECs) by inducing a proinflammatory response. Physiological levels of shear stress exert potent antiatherosclerotic effects. Therefore, we investigated whether shear stress antagonizes the effects of complement on ECs. METHODS AND RESULTS Incubation of...

Caveolae are plasmalemmal domains enriched with cholesterol, caveolins, and signaling molecules. Endothelial cells in vivo are continuously exposed to shear conditions, and their caveolae density and location may be different from that of static cultured cells. Here, we show that chronic shear exposure regulates formation and localization of caveolae and caveolin-1 in bovine aortic endothelial ...

Laminar shear stress exerts important effects on endothelial cell (EC) function and inhibits apoptosis of ECs induced by various stimuli. The mechanism by which hemodynamic forces, such as shear stress, are transduced into cellular signaling is still not known. Located at the cell surface, integrins, which are required for cell adhesion and cell survival, are potential mechanotransducers. There...

OBJECTIVE We attempted to determine the molecular mechanism of fluid shear stress-induced lipocalin-type prostaglandin D synthase (l-PGDS) expression in vascular endothelial cells. METHODS AND RESULTS We examined the promoter region of the l-PGDS gene by loading laminar shear stress (20 dyne/cm2), using a parallel-plate flow chamber, on endothelial cells transfected with luciferase reporter v...

Nanosilica dispersion was added to waterborne polyurethane by using three different physical mixing procedures differing in the flow regime (tangential, laminar, radial) and stirring rate (300–2400 rpm). The influence of procedure on structural, thermal, rheological, mechanical, surface adhesion properties polyurethanes (PUs) containing 1 wt% nanosilica evaluated. functionalized with acrylic mo...

In this paper, we show that all the coordinate functions of the Advanced Encryption Standard (AES) round function are equivalent under an aane transformation of the input to the round function. In other words, let fi and fj be any two distinct output coordinates of the AES round function, then there exists a nonsingular matrix Aji over GF(2) such that fj(Ajix) + bji = fi(x); bji 2 GF(2). We als...