This paper presents a two-dimensional analytical model for low-temperature cylindrical heat pipes. A closed-form solution which incorporates liquid±vapor interfacial hydrodynamic coupling and non-Darcian transport through the porous wick for the ®rst time, is obtained for predicting the vapor and liquid velocity and pressure distributions. In addition, the steady-state vapor and wall temperatur...

The structural response and failure mechanisms of 35 used concrete sewer pipes are investigated by means a combined experimental–numerical approach, whereby specific attention focuses on determining the effect biochemical attack. Accordingly, degree degradation inner outer surfaces is carefully analysed visual inspection, subsequently categorized in 6 different surface condition classes. type a...

Abstract: In this paper we extend the theory of Radio Frequency (RF) propagation as it relates to propagation within metal circular pipes. This work is motivated by a need to understand the operation of UHF Radio Frequency IDentification (RFID) systems when the tags are placed within the pipes. These circular pipes are shown to be similar to metal tube waveguides which are hollow. We derive the...

Characterization and design of fluid-thermal transport through random porous sintered beds is critical for improving the performance of two-phase heat transport devices such as heat pipes. Two-dimensional imaging techniques are quite well developed and commonly employed for microstructure and material characterization. In this study, we employ 2D image data (thin sections) for measuring critica...

Reprocessing cells of nuclear plants are constituted by a great number of specular metallic pipes. When they are illuminated, this kind of pipes generates areas of high light intensity, called highlights. The latter can produce erroneous results, especially in edge detection. The matter of this paper is to suppress and further to exploit the highlight effects. With this aim in view, we propose ...

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Pollutants discharged from stormwater pipes can cause water quality and ecosystem problems in coastal bayous. A study was conducted to characterize sediment and nutrients discharged by small and large (< 20 cm and >20 cm in internal diameters, respectively) pipes under different rainfall intensities (< 2.54 cm and > 2.54 cm, respectively). Results showed that large pipes had greater discharge t...

Water distribution networks comprised of underground reinforced concrete pipes deteriorate with time due to environmental conditions, such as chloride-induced corrosion and differential soil movements [1]. If the pipes in these networks are not periodically replaced, they will eventually fail. Strategies for replacement for these pipes depend on 1) the risks associated with failure of a water d...

Recently many plants' pipes and drains became old and many robots to inspect these pipes were developed in the past. Wired robots were put to practical use, but they had a heavy power supply and a signal wire. Therefore, new inspection robots using wireless radio communication system are considered useful for long complex pipes and long distance pipes including straight, vertical and bend line....