the thermo-hydraulic behavior of the air flow over a two dimensional ribbed channel wasnumerically investigated in various rib-width ratio configurations (b/h=0.5-1.75) atdifferent reynolds numbers, ranging from 6000 to 18000. the capability of differentturbulence models, including standard k-ε, rng k-ε, standard k-ω, and sst k-ω, inpredicting the heat transfer rate was compared with the experi...

here, we propose an add-drop and a channel drop filter based on two-dimensional photonic crystal all circular ring resonators. these structures are made of a square lattice of silicon rods with the refractive index n1=3.464 surrounded by air (with refractive index n2=1). the broadest photonic band gap occurs at the filling ratio of r/a = 0.17. two linear defect w1 waveguides couple to the ring....

open-channel junctions have a broad application in civil and environmental engineering. formation of a low-pressure zone with recirculating flow (high sedimentation) accompanied by a high-velocity zone (high erosion) is the most characteristic feature of flow in junctions. a large number of researches have been performed to study the complexity of the flow in junctions in open-channel flows. in...

a three dimensional, compressible, steady, one phase flow of reactant-product mixture in the air side electrode of proton exchange membrane fuel cell (pemfc) is numerically studied in this paper. the mixture is composed of three species: oxygen, nitrogen and water vapor. the performance of the cell is enhanced by partial blockage of the flow field channels. various types of these blocks also ca...

modeling the hydraulic geometry of gravel rivers is of intrest to hydraulic engineers, hydrologists and enviromental scientists who are engaged in predicting the adjustments of an alluvial channel to an altered upstream runoff or sediment supply. the widely used qualitative and regime models, while indicating the general direction of river adjustment, are not able to deal with river response at...

1. introduction floods are among earth's most common and most destructive natural hazards. floods create geomorphic hazards via changes in sediment transport and channel configuration (e.g. channel width, lateral migration, planform changes, etc). in this context, floodplain zoning and its application in spatial planning is important in non- structural measures in order to reducing flood damage...

The numerical simulation of a Poiseuille flow in a narrow channel using the molecular dynamics simulation (MDS) is performed. Poiseuille flow of liquid Argon in a nanochannel is simulated by embedding the fluid particles in a uniform force field. Density, velocity and Temperature profiles across the channel are investigated. When particles will be inserted into the flow, it is expected that the...

A B S T R A C T Introduction: Even today there is no effective drug therapy to prevent neuronal loss after brain stroke. In the present study we studied the effect of mitochondrial KATP channel regulators on neuronal ultrastructure after ischemia reperfusion in the rat. Materials & Methods: Rats temporarily subjected to four vessels occlusion for 15 minutes followed by 24 hours reperfusion with...

Introduction: Loss of inhibitory output from Purkinje cells leads to hyperexcitability of the Deep Cerebellar Nuclei (DCN), which results in cerebellar ataxia. Also, inhibition of small-conductancecalcium-activated potassium (SK) channel increases firing rate  f DCN, which could cause cerebellar ataxia. Therefore, SK channel activators can be effective in reducing the symptoms of this disease, ...

secondary flow investigation could be regarded as an important issue in open channel flow, in spite of its lower quantity compared to the base flow in the water course. it should be given special consideration because of the influence on some hydraulic factors in open channel, specifically in compound channels. in compound channels' due to the difference in the flow velocity of the main ch...