Flow past a disk was investigated experimentally in a low-velocity water channel in the range of intermediate Reynolds numbers. Systematic experiments with flow visualization and particle image velocimetry measurements are presented. Different disks with the aspect ratio χ = d/h varying from 1 to 24 were investigated. The measurements were made in the range of Reynolds numbers from 0 to 500, wh...

We present experimental results for early transients near the onset of convection of an ethanol-water mixture in cylindrical containers heated from below. The separation ratio of the mixture was c'20.08, and the aspect ratios G[r/d (r is the radius and d the height of the sample cell! of two different containers were 10.91 and 11.53. For this system the onset of convection occurs via a subcriti...

Computational investigations have been performed into the behavior of an incompressible fluid flow in the vicinity of a plane symmetric channel contraction. Our aim is to determine the critical Reynolds number, above which the flow becomes asymmetric with respect to the channel geometry using the bifurcation diagram. Three channels, which are characterized by the contraction ratio, are studied ...

INTRODUCTION Stent-coiling of bifurcation aneurysms has significantly expanded the spectrum of aneurysms amenable to endovascular therapy. A variety of techniques have evolved to deal with wide-necked bifurcation aneurysms such as Y-stenting and WEB embolization device. In our 2 institutions, we have primarily used a single stent coiling to treat most bifurcation aneurysms. We present a large s...

OBJECTIVE Kissing stents (KS) are commonly used to treat aortoiliac occlusive disease, but patency results are often lower than those of isolated stents. The Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) technique was recently introduced to reconstruct the aortic bifurcation in a more anatomical and physiological fashion. The aim of this study is to compare the geometric...

this paper is devoted to study of a partial differential equation governing panel motion in supersonic flow. this pde can be transformed to an ode by means of a galerkin method. here by using a criterion which is closely related to the routh-hurwitz criterion, we investigate the mentioned transformed ode from hopf bifurcation point of view. in fact we obtain a region for existence of simple hop...

Chaotic motions of a two dimensional airfoil with coupled structural nonlinearities, both in pitch as well as plunge degrees of freedom, are investigated via a numerical integration method. The original system of coupled integro-differential equations governing the motion of the present aeroelastic model is transformed into a simple system of six ODEs. Complex dynamical behaviors are revealed a...

BACKGROUND AND PURPOSE Retrospective analysis of clinical data has demonstrated major variations in carotid bifurcation geometry, in support of the notion that an individual's vascular anatomy or local hemodynamics may influence the development of atherosclerosis. On the other hand, anecdotal evidence suggests that vessel geometry is more homogenous in youth, which would tend to undermine this ...

Quantitative information about the geometry of the carotid artery bifurcation is relevant for investigating the onset and progression of atherosclerotic disease. This paper proposes an automatic approach for quantifying the carotid bifurcation angle, carotid area ratio, carotid bulb size and the vessel tortuosity from multispectral MRI. First, the internal and external carotid centerlines are d...

       In this paper an SIS epidemic model with saturated incidence rate and treatment func- tion is proposed and studied. The existence of all feasible equilibrium points is discussed. The local stability conditions of the disease free equilibrium point and endemic equilibrium point are established with the help of basic reproduction number.However the global stabili- ty conditions of these eq...