INTRODUCTION Enlargement of a pre-existing intracranial aneurysm is a well-established risk factor of rupture. Excessive low wall shear stress concomitant with turbulent flow in the dome of an aneurysm may contribute to progression and rupture. However, how stress conditions regulate enlargement of a pre-existing aneurysm remains to be elucidated. RESULTS Wall shear stress was calculated with...

In this study the performance of three macro-models in predicting the nonlinear response of different walls is investigated. The macro-models used are: Equivalent Beam Model, Multiple Vertical Line Element Model and a shear panel model developed by Massone et al. (2006). The walls are classified as slender, intermediate, and squat walls according to their shear-span ratio. First, three single w...

The finite element method (FEM) can be applied to practically analyze the tall buildings in which the shear walls are used to resist the lateral loads. Accordingly, a variety of displacement and strain-based as well as frame macro elements have been proposed for analysis of the tall buildings. With respect to application of the lower order plane stress elements, analytical problems may arise wi...

We theoretically investigate general properties of driven (sheared) colloidal suspensions in confinement, based on methods of classical density functional theory. In the absence of an exact closed (Smoluchowski-) equation for the one-particle density under shear, we formulate a set of general conditions for approximations, and show that a simple closure fulfills them. The exact microscopic stre...

Experimental results for quasi-static cyclic tests on reinforced concrete (RC) walls have shown that shear deformations can constitute a significant ratio of the total deformations when the wall is loaded beyond the elastic regime. For walls, which form a stable flexural hinge at their base, the ratio of shear to flexural deformations remains approximately constant over the entire range of impo...

BACKGROUND Unlike arteries, in which regionally distinct hemodynamics are associated with phenotypic heterogeneity, the relationships between endocardial endothelial cell phenotype and intraventricular flow remain largely unexplored. We investigated regional differences in left ventricular wall shear stress and their association with endocardial endothelial cell gene expression. METHODS AND R...

Pulsatile motion of blood in a circular tube of varying cross-section has been developed by considering slip flow at the tube wall and the blood to be a non- Newtonian biviscous incompressible fluid. The tube wall is supposed to be permeable and the fluid exchange across the wall is accounted for by prescribing the normal velocity of the fluid at the tube wall. The tangential velocity of the fl...

Coronary artery bypass graft (CABG) operation for coronary artery disease with different types of grafts has a large clinical application world wide. Immediately after this operation patients are usually relieved of their chest pain and have improved cardiac function. However, after a while, these bypass grafts may fail due to for example, neointimal hyperplasia or thrombosis. One of the causes...

We experimentally investigate the mechanical behaviour in cyclic shear of a granular material near a solid wall in a pressure controlled annular shear cell. The use of a model system (glass beads and sawtooth shaped solid surface) enables the study of the influence of the wall roughness. After an initial shakedown procedure ensuring reproducible results in subsequent tests, wall shear stress S,...

Cross correlations of the fluctuating wall-shear stress and the streamwise velocity in the logarithmic region of turbulent boundary layers are reported over 3 orders of magnitude change in Reynolds number. These results are obtained using hot-film and hot-wire anemometry in a wind tunnel facility, and sonic anemometers and a purpose-built wall-shear stress sensor in the near-neutral atmospheric...