for non-darcy flow in submerged porous media a one- dimensional mathematical model has been developed. rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. in this research the focus was on the rockfill detention dams in submerged condition. the existence of overtopping rock...

in this work, a thermoplastic polyurethane elastomer (tpue) model based on polytetramethylene glycol, toluene diisocyanate and 1,4-butanediol was selected and synthesized. according to this model two types of polyurethane nanocomposites were prepared by in situ polymerization and melt intercalation procedures. the organo-modified nanoclay was used in nanocomposites samples in 0.4 weight percent...

The performance of asphalt binders at high and low temperatures has an important role on the rutting and crackingresistance of asphalt pavements. Crumb Rubber Modified (CRM) is one of the asphalt modifiers that improves asphaltphysical and mechanical properties and helps reducing environmental pollution. In this research, three unmodifiedand six CRM modified binders were teste...

one of the most important factors that affect tire friction is surface roughness, which determines the size of the real contact area, real pressure distribution on the contact interface, and scales of mechanical engagement between viscoelastic rubber and a rough substrate. the need to predict coefficient of friction (cof) for rubber on rough surfaces for applications such as traction of tires o...

the aim of the study was to develop a non-exercise vo2max predictive model using a physical activity (pa) variable determined by pedometer-determined step counts (sc: steps/day) in active lifestyle men aged between 40 and 65. for this purpose, 69 subjects were used to develop and validate the new model. vo2max was measured using rockport fitness walking test. anthropometric variables were measu...

Antibubbles are ephemeral objects. Their lifetime is driven by the slow drainage of the air shell from the bottom to the top of the antibubble under the action of hydrostatic pressure. We show in this paper that this argument is only valid if the water used to make the surfactant mixture is saturated in air. Otherwise, two paths are used by the air, which conduct to the thinning and the eventua...

In this paper, we design a new model of preconditioner for systems of linear equations. The convergence properties of the proposed methods have been analyzed and compared with the classical methods. Numerical experiments of convection-diffusion equations show a good im- provement on the convergence, and show that the convergence rates of proposed methods are superior to the other modified itera...