objectives: periodontal pathogens need acidic environments to proliferate in periodontium, and their growth is affected by the salivary flow rate and ph of the mouth. alterations in flow and acidity of saliva have an important effect on oral diseases such as periodontitis. this study was designed to compare salivary ph and flow rate before and after using green tea, black tea and coffee in pati...

introduction : cerebral autoregulation (ca) and mean cerebral blood flow velocity in males and females are still under controversy. the present study was scheduled to address the effect of sex on these parameters. materials and methods : the present study was interventional and performed on 30 healthy volunteers (15 males aging from 20-30 yrs and mean age of 23.9±3 years old and 15 females agin...

regional analysis is one of the important methods for estimating the low flow in ungagged regions. investigation of the relations between effective factors of hydrological drought is the most important strategy to contrast and reduction of drought losses. in this study to analyze of low flow, the daily discharge data from 20 gauging stations with 25 years period (1988-2012) in the kashafroud ba...

existence of capacity drop phenomenon, as the difference between pre-queue and queue discharge flow rates, has been one of the controversial concepts of traffic engineering. several researches have focused on capacity drop existence and also its estimation issues. this paper aims to estimate capacity drop based not only on a comparison between breakdown and queue discharge flow rates, but also ...

the monolithic catalytic converter is still the main pollution control device for modern vehicles in order to reach the ever-increasing legislative demands for low emission standards. the catalytic converters require a large expansion from the exhaust pipe to the front face of the monolith. unfortunately, packaging constraints often do not permit the use of long diffusers. hence, flow separatio...

in the present study, the nonlinear model of non-newtonian blood flow in cosine-shape stenosed elastic artery is numerically examined. the model is carried out for axisymmetric, two-dimensional and fully developed blood flow. the vessel wall is assumed to be have time-dependent radius that is important factor for study of blood flow. the cosine-shape stenosis convert to rigid artery by using a ...

in this study, using sound created by wheat grain passing through a pipe, wheat flow rate was measured. the developed device consists of a hopper, metering device, sound sensor, delivery tube, dc motor and power supply. several wheat mass flow rates were tested and the sound signal created by the passage of the grain through the discharge tube was measured and transferred to a computer using da...

In the present study, commonly used weakly compressible lattice Boltzmann method and Guo incompressible lattice Boltzmann method have been used to simulate fluid flow in a stirred tank. For this purpose a 3D Parallel code has been developed in the framework of the lattice Boltzmann method. This program has been used for simulation of flow at different geometries such as 2D channel fluid flow an...