The anechoic assumption has long been used for the modeling of long exit pipes or ducts of acoustic elements [1, 2, 3, 4, 5, 6, 7]. Especially in compressor discharge line modeling, the exhaust pipe from the compressor manifold leading all the way to the condenser is usually assumed to be anechoic since it is very long. Also, experimental efforts have been made by investigators using different ...

Background In contrast to cigarette smoking, the association between water pipe smoking and airway hyperresponsiveness remains widely unexplored. Methods A bronchoprovocation challenge with mannitol was performed in young adults recruited at the University of Basel, Switzerland. Subjects were categorized as acute water pipe smokers (single episode of water pipe smoking, no or <0.5 pack-years ...

In the present contribution optimization and simulation methods are investigated in order to attain optimal scaling of labial organ pipes. The goal is to determine the optimal dimensions of the pipe, by which a desired steady state sound spectrum can be achieved. By modifying the geometry of the pipe body, the eigenfrequencies of the acoustic resonator can be tuned in order to amplify or repres...

BACKGROUND The Federal excise tax was increased for tobacco products on April 1, 2009. While excise tax rates prior to the increase were the same for roll-your-own (RYO) and pipe tobacco, the tax on pipe tobacco was $21.95 per pound less than the tax on RYO tobacco after the increase. Subsequently, tobacco manufacturers began labeling loose tobacco as pipe tobacco and marketing these products t...

In the present study, an unlooped pulating heat pipe has been considered with two liquid slugs and three neighboirng vapor plugs.The governing equations such as momentum, energy and mass equations are solved explicitly except the energy equation of liquid slugs.The aim of the present study is to calculate the entropy generation through the performance of a pulsating heat pipe. Additionally, the...

This paper presents a numerical investigation of two horizontally mounted four-lobed swirl pipes in terms of swirl induction effectiveness into flows passing through them. The swirl flows induced by the two swirl pipes have the potential to improve the efficiency of Clean-In-Place procedures in a closed processing system by local intensification of hydrodynamic impact on the internal pipe surfa...

We study the Riemann problem for isothermal ow of a gas in a thin pipe with a kink in it. This is modeled by a 22 system of conservation laws with Dirac measure sink term concentrated at the location of the bends in the pipe. We show that the Riemann problem for this system of equations always has a unique solution, given an extra condition relating the speeds on both sides of the kink. Further...

What trajectory in the laboratory frame does a marble follow if it is held inside a freely rotating pipe and then suddenly released so that it can slide frictionlessly outward along the pipe? A previously published solution is only valid for a pipe of small moment of inertia (so that it is either low in mass or short in length). IOP

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...