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...

Use of nanotechnology has proven to be a promising approach toward remediation of all phases of environment. The aim of this work is to investigate the effects of different parameters on using iron III oxide nanoparticles in a continuous flow configuration for the removal of Cd2+ ionsfrom contaminated soils. Also selective sequential extraction tests are carried out to evaluate the nanoparticle...

background: measuring peak expiratory flow rate has been suggested as an important tool in asthma management by all international guidelines.   objective: studies on various populations have shown considerable variations in normal values of peak expiratory flow rate. since reference standards for iranian children are not available, the present study was performed to establish these standards.  ...

tip leakage loss introduces major part of losses of the rotor in axial gas turbines. therefore, the rotor blade tip has a considerable effect on rotor efficiency. to understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). various blade tip configurations such ...

The soil is a heterogeneous and anisotropic medium. Hydraulic conductivity, an intrinsic property of natural alluvial deposits varies both deterministically and randomly in space and has different values in various directions. In the present study, the permeability of natural deposits and its influence on the seepage flow through a natural alluvial deposit is studied. The 2D Finite Difference c...

In this paper, a mathematical model is developed to calculate the conversion and the residence time reaction for plug flow and mixed flow in the reactors filled with cylin-drical particles using the shrinking core model. In this modeling, the size of the particles is un-chamged during the reaction. Also, the reaction rate is controlled by the gas layer resistance, the ash layer resistance, and ...

low level of efficiency is a main problem of surface irrigation systems that is due to their poordesign and management. furrow inflow rate and cut off time are the most important design parametersthat affect the efficiency of furrow irrigation. in this study, furrow irrigation condition of amir kabiragro-industry sugarcane fields was simulated with winsrfr3.1 model. then, irrigation performance...

There have been important changes in the United Kingdom’s (UK) fertility and immigration in the past decade, with a large share contributed by migrants from Poland. A detailed understanding of Polish migrant fertility is lacking, however, because the relevant data are not routinely collected. This paper provides new insights into the fertility patterns of Polish migrants in the UK, and compares...