Artificial Pipes Research Articles

Research results on underground cotton irrigation through artificial pipes

The article presents the results of laboratory-field tests of a working body that creates an artificial pipe for irrigation of cotton with a row spacing of 60 cm from under the soil. As evaluation criteria, water flow distance and moisture dispersion were taken from inside the formed pipe without spilling onto the field surface. When using this working body, it was found that a pipe with dense walls was formed under the soil with low energy consumption, and water flow was observed for a long distance. Generated to the proximity of the constructed artificial pipes to the cotton roots, the water demand is met quickly and the irrigation time and water consumption are reduced.

Estimation of Pipe Wall Thinning Using a Convolutional Neural Network for Regression

A pipe wall thinning diagnosis method based on vibration characteristics is proposed. Elbow specimens with artificial pipe wall thinning were fabricated and combined in a loop. By running a pump in the loop, vibration was induced by flow, and the vibrational signals were measured with accelerometers. The effect of pipe wall thinning on the vibrational signals was investigated by analyzing the spectral data of the acceleration signals. The analyzed vibration characteristics were difficult to observe because the change in characteristics was small. A convolutional neural network (CNN) specialized for data recognition was applied to recognize the small change in vibrational signal resulting from the pipe wall thinning. A regression model based on CNN was chosen to learn the tendency of change in the vibrational signals with varying thinning. The data types advantageous for training the regression model were identified. An early stopping technique using the validation data set was adopted to regularize the regression model. The trained regression model was able to predict pipe thinning.

Stress distribution analysis of composite repair with Carbon Nanotubes reinforced putty for damaged steel pipeline

Composite pipeline repair systems involving infill material and composite wrapper are a common method of enhancing the integrity of damaged oil and gas pipelines. Composite wrappers can be theoretically optimised by minimising the layers of wrapper whilst reinforcing the infill material; i.e., putty. Integrating nanomaterial into putty to enhance its strength is a novel approach to provide secondary layer protection of damaged pipelines. A finite element model simulating a composite repaired pipe was developed to investigate the influence of reinforced Carbon Nanotubes putty on the system's overall repair performance and behaviour. The result was verified with a previous experimental hydrostatic burst pressure test and industrial standard resulting in less than a 15% error margin. The result shows the damaged artificial pipe segment filled with two different putties, namely Grout A and Grout B, ruptured at 32.22 MPa and 32.93 MPa, respectively. The reinforced putty improved the load-bearing capacity of the repaired pipe by a marginal increment of 2.2%. It demonstrated a better load-transfer and load-sharing mechanism than the common composite repair system. The recorded burst failure of the repaired pipe was less abrupt, thus minimising the sudden rupture of the pipeline by acting as a secondary layer of protection in the event of a composite wrapper failure.

Simulating flow through scour valve in the water distribution networks

ABSTRACT In water distribution networks, the scour valves are used to flush out the sediments and contaminants accumulated over a period of time. Frequent operation of the scouring valves is needed for the effective maintenance of the system and efficient operation of the network. Sometimes, the draining of water is also necessary to repair broken components such as pipes and appurtenances or to perform regular maintenance. The sizing of the scour valve, its placement, and the actual number are a judgment decision by the design engineer. Generally, scour valves are located at the lowest elevated point to drain off the water by gravity. The scour valve will have a connection with a pipe on one side and on the other side it faces the atmosphere in order to drain off the water to an open drain. In the present available hydraulic simulation software, no provision is made to study the flow behavior of scour valve though there are options available for other types of valves such as flow control valve (FCV), pressure reducing valve (PRV), pressure sustaining valve (PSV), pressure breaker valve (PBV), throttle control valve (TCV) and general-purpose valve (GPV). This paper proposes a simple approach to study the flow through scour valve in the water distribution network by connecting the scour locations with an artificial reservoir using an artificial pipe consisting of a check valve. The proposed arrangement shows the rate of flow through scour valve and also it is able to assess the velocity of flow in the pipelines and to calculate the time of emptying the water during scouring. The simulation analysis of the proposed sequence of the artificial elements in the network is illustrated using three water distribution networks.

Improvement of cotton nutrition procedure and irrigation technologies

This article presents the results of research-fertilization by laying a black polyethylene film between the rows of cottonand field experiments on irrigation technologies conducted in the conditions of typical gray soils of Tashkent region. In order to save water in the irrigation of cotton and other crops, mulching between rows with black polyethylene film and straw and the introduction of irrigation technology using flexible artificial pipes is highly effective. The plant thrives only when the soil moisture is moderate. This can be achieved by improving irrigation techniques and technologies. In field experiments, the timing and rate of cotton irrigation were determined by soil moisture. It was found that the seasonal water norm saved an average of 1,095 m3 or 27.3% of irrigation water per hectare in the variants irrigated between rows with black polyethylene film compared to the options irrigated by conventional irrigation.

Development and application of trenchless magnetic detector for oil and gas pipeline defect

Trenchless detection technology for oil and gas pipeline defect is of great significance to remedy the shortcomings of in-pipeline detection and pipeline direct assessment technology. Pipeline defect detection technology can be expanded and the long-term service of the pipeline can be achieved due to the trenchless detection technology. According to the fluctuation range of ground magnetic field caused by typical pipeline defect, fluxgate sensor was selected as the sensitive element to detect the magnetic fluctuation of the pipeline in this paper. Excitation circuit, detection circuit and data processing circuit of fluxgate sensor were designed. Long-distance pipeline defect detection experiments under indoor and field conditions were carried out by using a self-made fluxgate detector. The indoor experimental results showed that the sensitivity of the magnetic detector is higher than that of the international advanced magnetic detector, and it can detect artificial pipe defects with a depth greater than 20% of the wall thickness at a distance of 1.6 ∼ 2.2 m (7 ∼ 10 times the pipe diameter). The field experimental results showed that the magnetic detector could detect corrosion thinning of pipeline with buried depth of 2.5 m (3.5 times diameter) effectively.

Pipe network modeling for analysis of flow in porous media

In this paper, a new matrix framework has been developed for the simulation of flow and pressure in porous media. In this framework, the pressure gradient formulation in Darcy’s law is considered as the head-loss equation in pipe network modeling. Then, an artificial pipe network has been constructed to find the pressure head profile in porous media. Two explicit and implicit formulations have been advanced for linear and nonlinear analysis, which the latter is an implementation of the Newton–Raphson algorithm. Both formulations iteratively solve a linear system of equations for calculating the nodal heads and apply a matrix multiplication for updating the flow vector. While the explicit method needs few iterations, the implicit method requires at least 20 iterations to converge with acceptable accuracy. For testing these formulations, four different types of network configurations were tested. The analysis of three laboratory tests showed that the application of the implicit method provides reliable and accurate results.

Bench-Scale Experiments on Effects of Pipe Flow and Entrapped Air in Soil Layer on Hillslope Landslides

Soil pipes are commonly found in landslide scarps, and it has been suggested that build-up of pore water pressure due to clogged soil pipes influences landslide initiation. Several researchers have also suggested that entrapped air in the soil layer increases the pore water pressure. We carried out bench-scale model experiments to investigate the influence of soil pipes and entrapped air on the build-up of pore water pressure. We installed a water supply system consisting of an artificial rainfall simulator, and used a water supply tank to supply water to the model slope and artificial pipe. We used two types of artificial pipe: A straight pipe, and a confluence of three pipes. Furthermore, we placed a layer of silica sand on top of the model slope to investigate the effect of entrapped air in the soil layer on the build-up of pore water pressure. Silica sand is finer than the sand that we used for the bulk of the model slope. Our results indicate that, although artificial pipes decrease the pore water pressure when the amount of water supplied was smaller than the pipe drainage capacity, the pore water pressure increased when the water supply was too large for the artificial pipe to drain. In particular, the confluence of pipes increased the pore water pressure because the water supply exceeded the drainage capacity. The results also indicate that entrapped air increases the pore water pressure in the area with relatively low drainage capacity, too. Based on these results, we found that although soil pipes can drain a certain amount of water from a soil layer, they can also increase the pore water pressure, and destabilize slopes. Furthermore, entrapped air enhances the trend that the pore water pressure can increase in the area with relatively low drainage capacity, as pore water pressure increases when too much water is supplied, and the artificial pipe cannot drain all of it.

An Experimental Investigation of Piping Effects on the Mechanical Properties of Toyoura Sand

Piping is a complicated natural phenomenon of internal erosion, which threatens the safety of hydraulic earth structures. Despite of the comprehensive research aiming to figure out the onset condition and development of piping, there is little element experiment in laboratory regarding the mechanical properties of disturbed soil. In this paper, as an attempt to create piping erosion under controlled conditions, glucose with certain shape and volume was placed in sand samples. With the dissolution of glucose pipes, artificial piping erosion was reproduced. Based on this approach, a series of experiments were performed in a hollow cylindrical torsional shear apparatus under different confining pressures for both intact specimens and eroded ones. Strains during piping propagation were measured by local sensors. Shear modulus was obtained by conducting torsional cyclic loadings with peak to peak stress magnitude of 4 kPa under various directions of principal stress axes. Furthermore, shear strength and the development of shear band were studied. The results clearly indicate the weakened mechanical behavior of sand subjected to piping erosion. Influence of piping-induced anisotropic fabric on shear strength and shear band was also confirmed.

Modeling of Flow Control Valves with a Nonzero Loss Coefficient

AbstractAs shown by the examples given in this paper, a commonly used, commercially available water distribution network modeling software may produce unrealistic results for flow control valves (FCVs) with a nonzero loss coefficient. This paper presents and discusses a simple technique to remedy this problem. According to this technique, an FCV with a nonzero loss coefficient K is modeled as a composite link that consists of an FCV of the same setting with a zero loss coefficient and an artificial pipe of negligibly small major loss with a diameter equal to the FCV diameter and a minor loss coefficient equal to K. The proposed technique can be implemented using the discussed software without any modification of its hydraulic solver.

Noniterative Implementation of Pressure-Dependent Demands Using the Hydraulic Analysis Engine of EPANET 2

To analyze water distribution networks under pressure-deficient conditions, most of the available hydraulic simulators, including EPANET 2, must be either modified by embedding pressure-dependent demands in the governing network equations or run repeatedly with successive adjustments made to specific parameters until a sufficient hydraulic consistency is obtained. This paper presents and discusses a simple technique that implements the square root relationship between the nodal demand and the nodal pressure using EPANET 2 tools and allows a water distribution network with pressure-dependent demands to be solved in a single run of the unmodified snapshot hydraulic analysis engine of EPANET 2. In this technique, artificial strings made up of a flow control valve, a pipe with a check valve, and a reservoir are connected to the demand nodes before running the engine, and the pressure-dependent demands are determined as the flows in the strings. The resistance of the artificial pipes is chosen such that the demands are satisfied in full at a desired nodal pressure. The proposed technique shows reasonable convergence as evidenced by its testing on example networks.

Inflow boundary profile prescription for numerical simulation of nasal airflow

Knowledge of how air flows through the nasal passages relies heavily on model studies, as the complexity and relative inaccessibility of the anatomy prevents detailed in vivo measurement. Almost all models to date fail to incorporate the geometry of the external nose, instead employing a truncated inflow. Typically, flow is specified to enter the model domain either directly at the nares (nostrils), or via an artificial pipe inflow tract attached to the nares. This study investigates the effect of the inflow geometry on flow predictions during steady nasal inspiration. Models that fully replicate the internal and external nasal airways of two anatomically distinct subjects are used as a reference to compare the effects of common inflow treatments on physiologically relevant quantities including regional wall shear stress and particle residence time distributions. Inflow geometry truncation is found to affect flow predictions significantly, though slightly less so for the subject displaying more pronounced passage area contraction up to the internal nasal valve. For both subject geometries, a tapered pipe inflow provides a better approximation to the natural inflow than a blunt velocity profile applied to the nares. Computational modelling issues are also briefly outlined, by comparing quantities predicted using different surface tessellations, and by evaluation of domain-splitting techniques.

Effect of Cooling by Water Flowing in Nonmetal Pipes Embedded in Mass Concrete

Although roller compacted concrete was developed in recent years, artificial pipe cooling still is used widely to control the temperature of mass concrete in dam construction. There is a tendency to replace the metal pipes with nonmetal pipes, but there is not an appropriate method to compute the effect of cooling by nonmetal pipes. This problem is studied in this paper. Four methods are given to compute the effect of cooling, one formula is given to compute the radius of pipe, one formula is given to compute the horizontal spacing between pipes, and one formula is given to compute the time required for two different kinds of pipes to get the same cooling effect. All these methods and formulas are very convenient to use. The radius, the spacing, the time required to get a predetermined temperature in mass concrete and the economy of the artificial cooling by nonmetal pipes relative to the metal pipes may be determined by these formulas.

Survival Rates of Artificial Piping Plover Nests in American Avocet Colonies

Journal Article Survival Rates of Artificial Piping Plover Nests in American Avocet Colonies Get access Paul M. Mayer, Paul M. Mayer The School of Natural Resources, University of Missouri, Columbia, MO 65211 Search for other works by this author on: Oxford Academic Google Scholar Mark R. Ryan Mark R. Ryan The School of Natural Resources, University of Missouri, Columbia, MO 65211 Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 93, Issue 3, 1 August 1991, Pages 753–755, https://doi.org/10.2307/1368208 Published: 01 August 1991 Article history Received: 02 July 1990 Accepted: 06 February 1991 Published: 01 August 1991

Effects of Research Activity on Piping Plover Nest Predation

We examined whether nest monitoring and other research activities influenced rates of red fox (Vulpes vulpes) predation on both natural and artificial piping plover (Charadrius melodus) nests in Massachusetts. The percentage of nests depredated did not differ significantly (P > 0.05) between nests where we trapped and banded incubating adults and nests where we did not trap. Nest predation was significantly lower (P 0.05) predation rates compared to artificial nests monitored from a distance. Daily monitoring of piping plover nests is not likely to result in increased fox predation, and it seems to be an acceptable practice; but, nest visits should be conducted in a manner that minimizes disturbance to nesting plovers. Further research should test whether human scent at piping plover nests is a deterrent to red foxes. J. WILDL. MANAGE. 54(3):443-447 For scientific and ethical reasons, researchers must be concerned about the influence their activities may have on nesting success of groundnesting birds and on the behavior of nest predators (Livezey 1980, Nol and Brooks 1982, Galbraith 1987). This concern extends to piping plovers that nest on beaches, dunes, and sand spits along the Atlantic Coast of North America. Because of its threatened status (Dyer et al. 1988), the piping plover is the focus of intensive conservation efforts, including protection of nests from human disturbance, censuses of breeding pairs, monitoring of nest success and productivity, and trapping and banding of incubating adults to determine movement patterns and survival rates. During studies of the population ecology of piping plovers on outer Cape Cod, Massachusett , between 1985 and 1987, predators destroyed 52-81% of all active plover nests at one of our principal study sites. Red foxes were responsible for 71-100% of the nests that were lost to predators at that site each year. These results led us to examine whether our activities attracted predators, particularly red foxes, to plover nests and thus reduced nest success. Our objectives were (1) to examine effects of research activities on fates of both natural and artificial plover nests and (2) to determine if foxes located plover nests by following researcher tracks and scent trails. Financial and logistical support for our study we e provided by the National Park Service, Massachusetts Division of Fisheries and Wildli e, U.S. Fish and Wildlife Service, Cape Cod M seum of Natural History, and several private contributors. J. F. Milton monitored artificial nests at Parker River National Wildlife Refuge (NWR), and M. J. Croonquist monitored red fox movements at Coast Guard Beach. Conversa'Present address: Maine Department of Inland Fisheries and Wildlife, P.O. Box 1298, Bangor, ME 04401. This content downloaded from 207.46.13.25 on Mon, 12 Sep 2016 04:05:07 UTC All use subject to http://about.jstor.org/terms 444 PLOVER NEST PREDATION * Maclvor et al. J. Wildl. Manage. 54(3):1990 tions with J. J. Hatch stimulated the artificial nest portion of the study. We gratefully acknowledge the assistance of V. A. Rosenberg, E. M. Hoopes, R. C. Humphrey, B. A. Samora, and K. Carlson. We thank R. M. Erwin, A. Hecht, and an anonymous reviewer for their comments on an earlier draft of this manuscript.

Leak rate experiments for through-wall artificial cracks

An experimental program of leak rate testing has been carried out for different geometries of artificial cracks in piping under various thermo-hydraulic conditions. The objective of these tests was to obtain a database of measured leak rates from artificial piping cracks and to compare test results with leak rate predictions obtained from the EPRI developed analytical model called PICEP. Experimental results for leak rates associated with rectangular and flare crack geometries are presented. Initial results of comparing analytical leak rate predictions with the experimental data is also presented.

Communication with Queen Honey Bees by Substrate Sound

A caged queen honey bee, installed in an observation hive which already contained a virgin queen, piped in response to artificial piping which was played to it through the substrate. The experiments which followed this observation provide the first direct quantitative evidence that sound, at least in the range of 600 to 2000 cycles per second, is perceived by honey bees and that information is transmitted through sound from one bee to another.