INTRODUCTION Although water pipe tobacco smoking is common in Lebanon and Syria, prevalence in neighboring Jordan is uncertain. The purposes of this study were (a) to assess the prevalence of water pipe tobacco smoking among university students in Jordan and (b) to determine associations between sociodemographic variables and water pipe tobacco smoking in this population. METHODS A trained in...

BACKGROUND The objective of this study was to examine the association between tobacco smoking, in particular water pipe smoking, and periodontal health. METHODS A total of 262 citizens of Jeddah, Saudi Arabia in the age range from 17 to 60 years volunteered to participate in the study. The clinical examinations were carried out at King Faisal Specialty Hospital and Research Center in Jeddah a...

To compare the effect of various pipe materials on biofilm formation, surface water was used as the test water source; plastic-based pipe materials (polyvinyl chloride-PVC, unplasticised polyvinyl chloride-UPVC, medium density polyethylene-MDPE) and cement-based pipe materials (cement and asbestos cement) are commonly used in drinking water distribution systems in South Africa as test pipe mate...

A significantdbut underutilizeddwater resource is reclaimed water, i.e., treated wastewater that is reintroduced for various purposes. Especially in water scarce regions, reclaimed water is often the only remaining source of water to meet increasing population and water demands. In this paper, we develop a newmodel formulation for the cost-effective branched reclaimed water network design and s...

In the present study, non-Newtonian flow in annular pipe is considered. The analytical solution for velocity and temperature fields is presented while entropy generation due to fluid friction and heat transfer is formulated. The third grade fluid with constant properties is accommodated in the analysis. It is found that reducing non-Newtonian parameter increases maximum velocity magnitude and m...

This chapter deals with the optimal design of the most expensive part of a pressurised irrigation system, i.e., its pipe network. The problem of calculating the optimal pipe size diameters of an irrigation network has attracted the attention of many researchers and designers. During the process of designing an irrigation pipe network, the hydraulic engineer will face the problem of determining ...

1.1. Flows driven by a constant pressure gradient through a pipe of circular cross section When the flow of a Newtonian fluid in a pipe of circular cross section is driven solely by a constant pressure gradient, the resulting velocity distribution is a quadratic function of the radial distance from the axis of the pipe. The velocity profile of such a flow has, therefore, a parabolic distributio...

An expression for the transmitted fraction of the uniform and parallel radiation incident upon the coupler between two rectangular light pipes of different physical dimensions is derived. It is a function of the pipe dimension ratio and the angle of the incident radiation. It is shown that for radiation nearly parallel to the pipe axis, it is possible to design a coupler for any pipe dimension ...

Waves and vortex shedding in corrugated pipes during gas injection can produce distinct tonal noise and structural vibration. In this study, we propose a model which couples an acoustic pipe and self-excited oscillation with vortex shedding over the cavity. In the model, the acoustic response of the corrugated pipe is simulated by connecting the lossless medium moving with a constant velocity w...