Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical mode...

Power plant boiler had no arrangement of measure the coal pipe temperature in a continuous basis, though it is an important parameter for any coal fired large boiler. As pulverized coal flows through the long coal-pipe by the help of flow of hot air as a carrier, coal pipe temperature is only the measurement of the coal flow through the pipe to boiler. Low temperature indicates improper flow of...

Prediction of service life of ductile iron pipe is carried out using the information on pipe condition, backfill/soil properties, and corrosion rates, as well as historical failure records. Among the factors that affect pipe condition, external pitting corrosion is a prominent variable contributing to the disintegrity of the pipe. A pipe scanner equipped with a laser displacement sensor was use...

Results are presented from a numerical study of transient growth experienced by infinitesimal perturbations to flow in an axisymmetric pipe with a sudden 1–2 diametral expansion. First, the downstream reattachment point of the steady laminar flow is accurately determined as a function of Reynolds number and it is established that the flow is linearly stable at least up to Re=1400. A direct meth...

OBJECTIVES The objectives of this analysis were to identify the sociodemographic characteristics of water-pipe users in a North American context and to describe concurrent psychoactive substance use. METHODS Data on sociodemographic characteristics, water-pipe smoking, and use of other psychoactive substances were collected in 2007 through mailed self-report questionnaires completed by 871 yo...

in this paper, nonlinear vibration and instability response of an embedded pipe conveying viscose fluid is investigated. the pipe is considered as a timoshenko beam embedded on an elastic foundation which is simulated by spring constant of the winkler-model and the shear constant of the pasternak-model. the external flow force, acting on the beam in the direction of the flexural displacement is...

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...