The authors have been developing a pipe bender which fabricates pipes of three-dimensional complex shapes from straight pipes based on the penetration bending method. This bender is composed of a movable die supported by a drive mechanism, a fixed die and a pipe feeder. A 3-RPSR parallel mechanism was employed as the movable-die drive mechanism, and its kinematic design was figured out under th...

The importance of lateral pipe flow on runoff generation in wet steep hillslopes has been described in many case studies from around the world. However, most hillslope studies are done in isolation and usually focus on the idiosyncrasies of individual hillslope characteristics and pipe flow response at a single site. Consequently, the first order controls on pipe flow responses remain poorly un...

The paper describes the work aimed at controllable loop heat pipe (CLHP) operation study when noncondensable gases (NCGs) are injected. In this work, the effect of NCG on the operating performance of an ammonia– stainless steel CLHP was experimentally investigated. Nitrogen was selected as NCG, and the steady-state operating characteristics of the CLHP with NCG was systematically studied for di...

efflux time measurements are carried out for gravity draining of a liquid from a large cylindrical tank (where the flow is essentially laminar) through single exit pipe in the absence and presence of cetyl pyridinium chloride (cpc) surfactant solutions. the variables considered are initial height of liquid in the tank, dia. of tank, length of the exit pipe and concentration of surfactant. the d...

BACKGROUND Smoking tobacco preparations in a water pipe (hookah) is widespread in many places of the world, including the United States, where it is especially popular among young people. Many perceive water pipe smoking to be less hazardous than cigarette smoking. We studied systemic absorption of nicotine, carbon monoxide, and carcinogens from one water pipe smoking session. METHODS Sixteen...

Petri nets are a formal, graphical and executable modeling technique for the specification and analysis of concurrent systems and have been widely applied in computer science and many other engineering disciplines. Low level Petri nets are simple and useful for modeling control flows; however, they are not powerful to define data and system functionality. High level Petri nets were developed to...

Large-scale motions (LSMs; having wavelengths up to 2-3 pipe radii) and very-LSMs (having wavelengths more than 3 pipe radii) have been shown to carry more than half of the kinetic energy and Reynolds shear stress in a fully developed pipe flow. Studies using essentially the same methods of measurement and analysis have been extended to channel and zero-pressure-gradient boundary-layer flows to...

This work presents an experimental investigation of the thermal performance of a flatplate heat pipe during startup and shutdown operations. Using the analytical model developed in a previously study, analytical and experimental results on the effect of input power and cooling heat transfer coefficient on the thermal performance of the heat pipe are presented and discussed. The results indicate...

DESCRIPTION As the infrastructure in the United States ages, increasing importance is being placed on rehabilitating the nation's wastewater treatment collection systems. Cracks, settling, tree root intrusion, and other disturbances that develop over time deteriorate pipe lines and other conveyance structures that comprise wastewater collection systems. These deteriorating conditions can increa...

Bayesian Belief Networks for Predicting Drinking Water Distribution System Pipe 1 Breaks 2 Royce A. Francis ([email protected]), Seth D. Guikema ([email protected]), Lucas Henneman 3 ([email protected]) 4 a Department of Engineering Management and Systems Engineering, 1776 G St., NW #159, The George Washington 5 University, Washington, DC, USA 20006 6 b Department of Geography and Environmental Eng...