the unsteady free convection flow between two long vertical parallel plates withvariable temperature and mass diffusion in the presence of the thermal radiation hasbeen presented. the governing dimensionless coupled linear partial differentialequations on the flow are solved by using the laplace transform technique. theexact solutions have been obtained for the fluid velocity, temperature and t...

in this article, stress analysis and energy estimation during cold-roll forming of symmetrical channel sections have been discussed. geometry of sheet strip is pre-estimated by a shape function. then longitudinal, transversal and shear strains have been calculated. using both the levy-mises and the prandtl reuss equations, and also considering the bauschinger effect, stress distributions have b...

the aim of this research is to investigate the effect of carbon fiber reinforced polymer (cfrp) composite fabric on monotonic and fatigue behaviors of reinforced concrete beams. to control the failure occurrence, a small notch was induced at the middle span in bottom surface for all of the studied rc specimens. totally 12 beams were tested from which 6 beams tested under monotonic and 6 other t...

The present study aimed to identify threshold shear stresses to cause benthic invertebrates to drift in boundary shear layers. Laboratory experiments were carried out in a small tilting flume, 10 cm wide and 3 m long with a closed recirculation system and a fixed sand bottom of uniform grain size. Benthic invertebrates from different orders (Achaeta, Gastropoda, Crustacea, Ephemeroptera, Odonat...

Pathological arterial blood flow generates fluid shear stresses that directly cause platelet aggregation. The mechanism of shear-induced platelet aggregation is incompletely understood, but involves von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib and GP IIb-IIIa, leading to the transmembrane influx of Ca2+ and the activation of protein kinase C. To investigate this further,...

Circulating tumor cells (CTCs) are the primary targets of cancer treatment as they cause distal metastasis. However, how CTCs response to exercise-induced high shear stress is largely unknown. To study the effects of hemodynamic microenvironment on CTCs, we designed a microfluidic circulatory system that produces exercise relevant shear stresses. We explore the effects of shear stresses on brea...

Virchow rightly recognised that blood flow plays an important role in thrombosis. The roles of blood flow in haemostasis, and in arterial, intra-cardiac, and venous thrombosis are reviewed. In streamline (laminar) flow, shear stresses are maximal at the vessel wall, and affect endothelial cell morphology and function (e.g. secretion of NO, prostacyclin,t-PA and vWF). Platelets are also concentr...

BACKGROUND Pelvic incidence, sacral slope and slip percentage have been shown to be important predicting factors for assessing the risk of progression of low- and high-grade spondylolisthesis. Biomechanical factors, which affect the stress distribution and the mechanisms involved in the vertebral slippage, may also influence the risk of progression, but they are still not well known. The object...

BACKGROUND Reports including our own describe that intravascular hemolysis increases the risk of thrombosis in hemolytic disorders. Our recent study shows that plasma Hb concentrations correlate directly with platelet activation in patients with paroxysmal nocturnal hemoglobinuria (PNH). The binding of Hb to glycoprotein1bα (GP1bα) increases platelet activation. A peptide AA1-50, designed from ...

BACKGROUND AND PURPOSE Vascular shear stress is essential for maintaining the morphology and function of endothelial cells. We hypothesized that shear stress in the internal carotid artery (ICA) may differ between patients with ischemic stroke and healthy control subjects. METHODS ICA shear stress was calculated in 143 controls and 122 patients with ischemic stroke who had a normal ICA or an ...