Transition of additive and non-additive pulsatile flows through a simple 3D model of arterial stenosis is investigated by using a large eddy simulation (LES) technique. We find in both the pulsatile cases that the interaction of the two shear layers, one of which separates from the nose of the stenosis and the another one from its opposite wall, causes recirculation in the flow downstream of th...

OBJECTIVES The atherosclerotic process in arteries is correlated with the local wall shear stress (WSS). Plaque development particularly occurs in regions with recirculation (ie, where the WSS oscillates). We investigated the effects of non-Newtonian blood viscosity, variations in flow rate, and vessel diameter on wall phenomena in a carotid bifurcation model. MATERIALS AND METHODS The flow t...

The flow field characteristics downstream of the evaporative flameholder in subsonic–supersonic mixing were experimentally investigated. study focused on examining effects different inlet static pressure ratios characterized by supersonic and subsonic parameters. results indicated that increase ratio enhanced fragmentation multiple vortices located mainstream. It also exacerbated asymmetry reci...

a mixed solar dryer with a specific mechanism to vary the tilted angle of collector, is utilized to fulfill all tests. the efficiency of the dryers is low because of various reasons such as heat loss of air in an open flow circuit. getting air back toward the air inlet of dryer can increase the efficiency of dryer and decrease drying process period. a new mechanism considered for dryer which co...

We investigated the effects of intravenous application of nimodipine on the neurophysiologic, biochemical, and morphologic consequences of 15 minutes of global cerebral ischemia in seven rabbits. In vivo dialysis of the hippocampus was used to determine changes in extracellular concentrations of extracellular calcium and amino acids and blood-brain barrier permeability. Ischemia without treatme...

A fuzzy linguistic model was developed to simulate the effect of leachate recirculation and sludge addition on the biogas generation in anaerobic bioreactor landfills. The model was designed using a fuzzy logic system which incorporated 3 input variables (time, leachate recirculation, and sludge addition) and a single manipulated output (biogas generation rate). The experimental work involved t...

Vascular accesses consist of permanent arteriovenous (AV) accesses (autogenous fistulas and synthetic grafts) and venous accesses (central venous catheters [CVCs]). AV accesses have fewer complications than venous accesses, and are therefore the preferred hemodialysis access. An important additional issue is whether the type of access influences adequacy of dialysis (i.e. Kt/V). Key limiting fa...

This work considers the momentum transport and mass transfer of O2 in a novel aerial rotating disk bioreactor (RDB) for animal cell or tissue culture. Specifically, this design uses a rotating lid placed above the surface of the culture medium to provide a stirring mechanism, which has potential benefits of enhanced gas transfer, reducing possible contamination, and better access to the culture...

Simulations of turbulent convection flow adjacent to a two-dimensional backward-facing step are presented to explore the effects of step height on turbulent separated flow and heat transfer. Reynolds number and duct’s height downstream from the step are kept constant at Re0 = 28,000 and H = 0.19 m, respectively. Uniform and constant heat flux of qw = 270 W/m 2 is specified at the stepped wall d...

Article history: Received on: 05/01/2015 Revised on: 22/01/2015 Accepted on: 07/02/2015 Available online: 27/02/2015 The purpose of current study was to compare the influence on sanitary hygienic parameters of water in recirculation aquaculture systems (RAS) using natural zeolite and macrophytes Lemna minor and Elodea canadensis like a part of its filtration system with the microbiological indi...