The analyzed electrohydraulic servo valve is jet pipe type, is one of the mechatronics component used for precision flow control application. The jet pipe servo valves have one movable nozzle and two collector ports, from where fluid is ducted to the main valve spool. The servovalve analyzed here is basically used in fuel control application in Variable Geometry Actuation System (VGAS) of a gas...

The safety of lifelines, as the most important urban facilities, under different conditions highly depends on the safe design and performance of these buried structures. This cannot be achieved unless their actual behaviors are well understood and considered at the designing stage. A new physical model was developed in Amirkabir University of Technology to study the behavior of buried pipes und...

Over the past several years, the presence of fibrous asbestos particulates has been observed in a number of municipal water supplies throughout the USA, Canada, and several other regions all over the world. The possible health hazards which these fibers present have spurred a great deal of interest in the problems of detection and removal of the submicroscopic particulates in water. Asbestos is...

To meet the great needs for MFL (magnetic flux leakage) inspection of drill pipes at wellheads, a lift-off-tolerant MFL testing method is proposed and investigated in this paper. Firstly, a Helmholtz coil magnetization method and the whole MFL testing scheme are proposed. Then, based on the magnetic field focusing effect of ferrite cores, a lift-off-tolerant MFL sensor is developed and tested. ...

Pipe inspection is one of the areas that have attracted high research interest for robot applications especially in oil and chemical industry and civil engineering. Robot body rolling while it travels within a pipe has been a problem for accurately collecting inspection data. Under certain circumstances where vision systems have to be employed, robot body rolling may cause vision inspection dat...

An experiment featuring waterhammer in viscoelastic pipes is presented in which the effects of pipe-wall viscoelasticity on waterhammer pressures are investigated. A large-scale pipeline apparatus made of polyvinyl chloride (PVC) at Deltares, Delft, The Netherlands, has been used to carry out waterhammer experiments. Tests have been conducted in a reservoir-pipeline-valve system consisting of a...

We developed a novel fiber-optic acoustic emission (AE) monitoring system and applied this to gas-leak detection. The system is a Mach-Zehnder, homodyne-type optical fiber laser interferometer with a phase compensation feedback circuit. The phase compensation was given by a piezo-actuator, which can maintain the system at being quadurature condition. The system was demonstrated to measure the i...

Information personalization refers to the automatic adjustment of information content, structure, and presentation tailored to an individual user. By reducing information overload and customizing information access, personalization systems have emerged as an important segment of the Internet economy. This paper presents a systematic modeling methodology — PIPE (‘Personalization is Partial Evalu...