In this paper, the effect of autofrettage process parameters on the ultimate pressure that functionally graded spherical vessel can tolerate are investigated. FGM properties and autofrettage pressure are considered as important parameters. Assumptions are variation of properties of FGM in radial direction, the residual stress in the absence of Bauschinger effect with the operation of variable m...

Coronary stents are the most important supports in present day cardiology. Flexibility and trackability are two basic features of stents. In this paper, four different balloon-expandable coronary stent systems were investigated mechanically in order to compare their suitability. The coronary stent systems were assessed by measurements of stent flexibility as well as by comparison of forces duri...

This paper presents an ultrasound simulation model for pulsatile blood flow, modulated by the motion of a stenosed vessel wall. It aims at generating more realistic ultrasonic signals to provide an environment for evaluating ultrasound signal processing and imaging and a framework for investigating the behaviors of blood flow field modulated by wall motion. This model takes into account fluid-s...

An analytical method for predicting elastic–plastic stress distribution in a cylindrical pressure vessel has been presented. The vessel material was a ceramic/metal functionally graded material, i.e. a particle–reinforcement composite. It was assumed that the material’s plastic deformation follows an isotropic strain-hardening rule based on the von-Mises yield criterion, and that the vessel was...

Purpose: Doing plyometric training with and without the vessel occlusion is an effective practice for rapid increase of muscles strength their hypertrophy. We evaluated the effects of plyometric training with and without the vessel occlusion on electromyographic parameters. Methods: In this quasi-experimental study, 22 females were selected through convenience sampling method. They were random...

Bulk carriers have an important role in international maritime transport. In this paper, we carried out a numerical study on a model of bulk carrier vessel and calculated total resistance of the model. A model of a bulk carrier vessel with length of 2.76 m, breadth of 0.403 m and draught of 0.173 m was selected for numerical modeling. Numerical work was done by commercial CFD software ANSY...

PURPOSE To compare vascular displacement in the macula after surgical closure of idiopathic macular hole (MH) after single-layered inverted internal limiting membrane (ILM) flap technique and conventional ILM removal. METHODS This retrospective study included patients who underwent either vitrectomy and ILM removal only or vitrectomy with single-layered inverted ILM flap for idiopathic MH lar...

background haemorrhoids are cushions of submucosal vascular tissue located in the anal canal starting just distal to the dentate line. haemorrhoidal disease is a common anorectal disorder which has symptoms of bleeding, prolapse, pain, thrombosis, mucus discharge, and pruritus. haemorrhoidectomy is one of most frequently performed anorectal operation worldwide. objectives the aim of this study ...

Core-annular flow is common in nature, representing, for example, how streams of oil, surrounded by water, move in petroleum reservoirs. Oil, typically a nonwetting fluid, tends to occupy the middle (core) part of a channel, while water forms a surrounding wall-wetting film. What is the thickness of the wetting film? A classic theory has been in existence for nearly 50 years offering a solution...

We study experimentally how wettability impacts fluid–fluid displacement patterns in granular media. We inject a low-viscosity fluid (air) into a thin bed of glass beads initially saturated with a more-viscous fluid (a water/glycerol mixture). Chemical treatment of glass surfaces allows us to control the wetting properties of the medium and modify the contact angle θ from 5 deg (drainage) to 12...