nowadays acoustic emission (ae) testing based on the kaiser effect (ke) is increasingly used to estimate the in-situ stress in laboratories. in this work, this effect is assessed on cylindrical specimens in numerical simulations of the cyclic loadings including loading, unloading, and re-loading cycles using a 3d code called the particle flow code (pfc) based upon the distinct element method. t...

Degradation of cleavage fracture toughness for low carbon steels due to pre-straining and irradiation was investigated on the basis of the local fracture criterion approach. Formulation of cleavage fracture toughness through the statistical modelling proposed by BEREMIN has been simplified by the present authors to the expression involving yield stress and cleavage fracture stress of materials....

This study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully Eulerian two-fluid model. The closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. Gas phaseturbulence is modeled by one-equation model and solid phase turbulence by MLH theory. Resultsof one-way and...

In order to determine hydrological behavior and water management of Sepidroud River (North of Iran-Guilan) the present study has focused on stream flow prediction by using artificial neural network. Ten years observed inflow data (2000-2009) of Sepidroud River were selected; then these data have been forecasted by using neural network. Finally, predicted results are compared to the observed dat...

The spatial distribution of petrophysical properties within the reservoirs is one of the most important factors in reservoir characterization. Flow units are the continuous body over a specific reservoir volume within which the geological and petrophysical properties are the same. Accordingly, an accurate prediction of flow units is a major task to achieve a reliable petrophysical description o...

percutaneous coronary angioplasty (ptca) of a coronary stenosis without documented ischemia at noninvasive stress testing is often performed, but its benefit is unproven. coronary pressure– derived fractional flow reserve (ffr) is an invasive index of stenosis severity defined as the ratio of maximal blood pressure in a stenotic vessel to the normal maximal pressure in the same vessel. ffr is a...

pavement permanent deformations due to lack of shear strength in mixture are a major reason of rutting. any simple test to determine mixtures resistance to permanent deformation isn’t distinguished in the 1st level of superpave mix design method and prevalent methods for evaluating mixture rut resistance are expensive and time-consuming. two aggregate types, gradations, asphalt cements and fill...

The aim of this paper is to study the effect of slip velocity and shape of stenosis on non-Newtonian flow of blood through a stenosed arterial segment. Blood is modeled as Bingham-Plastic fluid in a uniform circular tube with a radially non-symmetric stenosis. The problem is investigated by a joint effort of analytical and numerical techniques. The influence of stenosis shape parameter, slip ve...

The analysis of impeller shape performance was carried out with the SST (Shear-Stress Transport) model coupled with the streamline curvature turbulence model. This model combines the advantages from the κ−ε and κ−ω models, ensuring proper relation between turbulent stress and turbulent kinetic energy and allowing accurate and robust prediction of the impeller blade flow separation. The Multiple...