Just as the double-pipe heat exchanger is being utilized in an increasing number of applications, its research content also deepening. For this paper, based on air-conditioning cold and source project a building Handan, Hebei Province, 300-meter medium-shallow well was used for heating cooling, corresponding transfer model established. The changes parameters such inlet outlet temperature, excha...

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...