UNLABELLED Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour urinary cotinine level equivalent to smoking 10 cigarettes per day. AIM We aimed to ...

The characterization of navigational maps for Web applications helps its developers in the process of construction of these applications and it also helps users while performing their browsing. This paper presents the Pipe approach for characterizing navigational maps for Web applications at their conceptualization stage. Although Pipe was originally intended as a hypermedia-oriented notation i...

This paper describes the analysis of a long length reinforced thermoplastic pipe. For this new class of pipe, which is constructed of a polyethylene liner pipe over wrapped with two layers of non-impregnated twisted aramid cords, peculiar deformation behaviour was observed when a pipe was pressurised. This behaviour was found to be a result of a difference in cord-slack between the two reinforc...

The field of in-pipe robotics covers a vast and varied number of approaches to the inspection of pipelines with robots specialising in pipes ranging anywhere from 10 mm to 1200 mm in diameter. Many of these developed systems focus on overcoming in-pipe obstacles such as T-sections and elbows, as a result important aspects of exploration are treated as sub-systems, namely shape adaptability. One...

This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined by using a pulsed ultrasonic Doppler velocimeter. This approach is ideal for ma...

This paper addresses the problem of navigation of an autonomous robot when it moves in a modern concrete sewer. The robot must keep its orientation within mostly cylindrical sewer pipes. This implies a geometrical constraint on the environment in which the robot operates. We present a hybrid vision system that consists of (a) an optical camera and (b) a laser crosshair projector generating a cr...

Executive Summary This report presents detailed information on the effort to develop acoustic sensing technologies for natural gas pipe line monitoring. It starts with a historical evolution of the project and ends with the current status. The various technical accomplishments during this effort are pointed out. The latest technique involves the use of Lamb wave propagation in the wall of a pip...

To evaluate the seismic performance of pre-cast concrete shear wall with vertical reinforcements spliced by two different grout ways, quasi-static tests of two concrete shear walls holed by prefabricated corrugated pipe and one concrete shear wall holed by drawing out the pipe were tested. The test results showed that the wall holed by prefabricated corrugated pipe was basically the same as the...

1. ABSTRACT It has been about fifty years ago since the first unplasticized poly(vinyl chloride) (uPVC) pipes were installed for use in gas distribution purposes. Currently, about 22,500 km of uPVC is still in use in the Dutch gas distribution network. The pipes were originally designed for a lifetime of 50 years, but due to positive experiences the question arises if (and how long) the lifetim...