background and aims. because of compromised angulations of implants, the abutments are sometimes prepared. the purpose of this study was to investigate the effect of removing one wall of the implant abutment on the retention of cement-retained crowns. materials and methods. four prefabricated abutments were attached to analogues and embedded in acrylic resin blocks. the first abutment was left ...

this paper presents the results of a numerical study on the removal process of fluid particles under the influence of mixed convection in a horizontal channel with an open cavity. the bottom wall of the cavity is heated at a constant temperature (th), while the top wall is maintained at a relatively low temperature (tc). fluid with a uniform velocity (uo) and temperature (tc) is introduced into...

a numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. the continuity and momentum equations were solved first, assuming the wall reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. the results show that at constant inlet and...

the present paper investigates turbulent mixed convection - radiation flow between two vertical parallel plates kept at different temperatures with variable thermophysical properties. the reynolds number, based on channel half-width and friction velocity and the grashof number, based on channel width and wall temperature difference, were assumed to be 150 and 1.6×106, respectively. numerical si...

in this study, flow field and heat transfer of al2o3-cu/water micropolar hybrid nanofluid is investigated in a permeable channel using the least square method. the channel is encountered to chemical reaction, and a constant magnetic field is also applied. the bottom wall is hot and coolant fluid is injected into the channel from the top wall. the effects of different parameters such as the reyn...

River bed sand and gravel are utilized more than mountain materials due to their availability and closeness to the transit roads and sites of usage. Excessive and non-technical extraction of gravel and sand bring a kind of interference in them, leading to many negative consequences. Therefore, presenting solutions to reduce these impacts and infilling mining pits are essential. In this researc...

This study makes use of the Tsallis entropy to predict the shear stress distribution. Given a definition of the Tsallis entropy, it is maximized by using the probability density function, which then is used to attain a novel shear stress equation. This is then employed for calculating the shear stress distribution in rectangular channels in different aspect ratios and finally, for viability, th...

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...