Low-frequency noise pollution in substations has a significant impact on the physical and mental health of workers. Reduction low-frequency is an urgent problem to solve for researchers. In this paper, different structures Al 2 O 3 -polyurethane composites micro-perforated plate were constructed, effects cavity depth, perforated plate, foam position sound absorption properties comprehensively i...

BACKGROUND AND PURPOSE A recent randomized clinical trial on intracranial atherosclerosis was discontinued because of the higher frequency of stroke and death in the angioplasty and stent placement group than in the medical treatment group. An in-depth understanding of the relationship between biologic responses and flow dynamics is still required to identify the current limitations of intracra...

In continuing the investigation of AAA hemodynamics, unsteady flow-induced stresses are presented for pulsatile blood flow through the double-aneurysm model described in Part I. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-average Reynolds numbers 50< or =Re(m) < or =300. Hemodynamic disturbance is evaluated for a modified set of indi...

BACKGROUND AND PURPOSE Mechanical stresses on the arterial wall participate in the pathogenesis of atherosclerosis as local factors. The relationships between local mechanical forces and risk factors for atherosclerosis were investigated. METHODS Mechanical forces on the arterial wall were evaluated in the carotid artery in 117 patients with risk factors for atherosclerosis including hyperten...

Flow stasis in an artificial heart may provide a situation where thrombus develops. Should part, or all, of the clot dislodge, a thromboembolism may lead to stroke(s), neurologic deficits, or even death. In an effort to determine if the regime of low shear or stasis exists, a two-dimensional particle image velocimetry (PIV) system was implemented to measure the velocity field within the 50 cc P...

INTRODUCTION Among cardiovascular diseases, arterials stenosis is recognized more commonly than the others. Hemodynamic characteristics of blood play a key role in the incidence of stenosis. This paper numerically investigates the pulsatile blood flow in a coronary bifurcation with a non-planar branch. To create a more realistic analysis, the wall is assumed to be compliant. Furthermore, the fl...

We investigated the effects of sequential and prolonged exposure to high and low wall shear stress on arterial remodeling using a rabbit arteriovenous fistula (AVF) model. Blood flow was increased by approximately 17-fold to 20-fold when the AVF was open, and returned to normal when the AVF was occluded. Repeated opening and closing of the AVF resulted in sequential exposure of the artery to hi...

We have recently described patterns of adhesion of different types of leukocytes downstream of a backward facing step. Here the predicted fluid dynamics in channels incorporating backward facing steps are described, and related to the measured velocities of flowing cells, patterns of attachment and characteristics of rolling adhesion for neutrophils perfused over P-selectin. Deeper (upstream de...

Molecular dynamics (MD) simulation is used to study slip at the fluid-solid boundary in an unsteady flow based on the Stokes’ second problem. An increase in slip is observed in comparison to the steady flow for shear rates below the critical shear rate of the corresponding steady flow. This increased slip is attributed to fluid inertial forces not represented in a steady flow. An unsteady mathe...

the effect of welding residual stresses that was created in thin infill plate of steel plate shear wall system during constructional processes was studied in this research. residual stresses in a welded structure is the result of the non-uniform expansion and contraction and plastic deformation of the weld and surrounding base metal due to heating and cooling cycle, during welding process, this...