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1
FLORESTA, F. M., C. S. VIEIRA, L. A. MENDES, and D. L. N. F. AMORIM. "Statistical analysis of the design procedure used in reinforced concrete pipes." Revista IBRACON de Estruturas e Materiais 13, no. 1 (February 2020): 69–86. http://dx.doi.org/10.1590/s1983-41952020000100006.
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Abstract Structural design procedures are based on simplified hypotheses that attempt to approximate the actual behaviour. Depending on the adopted hypothesis, the design procedure may not satisfactorily describe the structural actual behaviour. Such condition occurs in the design of reinforced concrete pipes, where there are uncertainties related especially on the internal forces and the installation type of the pipe. Moreover, the main design hypothesis is that the cross section is plane and perpendicular to the deformed axis. Based on materials resistance principles it is known that this hypothesis is unsatisfactory to pipes with aspect ratio lower than ten. Note that the commercial reinforced concrete pipes usually present aspect ratio well below ten. In the light of the foregoing, the main objective of this paper is to analyse the accuracy of the design procedure for reinforced concrete pipes. Therefore, statistical processes were used to compare design values with experimental results. The comparisons in this paper showed that the design procedure results in oversized pipes.
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Jones, N., and R. S. Birch. "Influence of Internal Pressure on the Impact Behavior of Steel Pipelines." Journal of Pressure Vessel Technology 118, no. 4 (November 1, 1996): 464–71. http://dx.doi.org/10.1115/1.2842215.
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This article presents some experimental data recorded from 54 impact tests on pressurized mild steel pipes. The pipes were fully clamped across a span which was ten times the outside pipe diameter of 60 mm. The pipes had a wall thickness of 1.70 mm and were impacted laterally by a rigid wedge indenter at the mid-span and one-quarter-span positions. The impact velocities ranged up to 13.6 m/s and caused large inelastic indentations for the lower values and at higher values a loss of integrity which could occur underneath the indenter and/or at an end support. The critical values for the two failure energies were obtained for a range of internal gas pressures.
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Qin, Ming, Hai Tao Dai, and Ming Wei Ge. "Evaluation of Water Cooling System of 1.5MW Rotor Based on CFD." Advanced Materials Research 472-475 (February 2012): 386–90. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.386.
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The water cooling system of 1.5MW rotor is evaluated using Computational Fluid Dynamics (CFD). 48 cooling holes are opened on the rotor stator to arrange the water cooling pipes, the temperature of inlet of the cooling water is 50 C with the velocity 1.2m/s. It is found that the air gap between the cooling pipes and holes on the stator hinders the heat exchange extensively. For this reason, the cooling system can't meet the design requirement. In order to solve this problem, the pourable silicone is filled in the gap between the cooling pipes and holes to enhance thermal conductivity. Based on this idea, ten kinds of piping arrangements are proposed, among which, nine kinds can achieve the cooling requirement.
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Jones, N., S. E. Birch, R. S. Birch, L. Zhu, and M. Brown. "An Experimental Study on the Lateral Impact of Fully Clamped Mild Steel Pipes." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 206, no. 2 (August 1992): 111–27. http://dx.doi.org/10.1243/pime_proc_1992_206_207_02.
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This report presents some experimental data that were recorded from 130 impact tests on mild steel pipes in two drop hammer rigs. The pipes were fully clamped across a span which was ten times the corresponding outside pipe diameters which lie between 22 and 324 mm. All of the pipes except five had wall thicknesses of 2 mm approximately and were impacted laterally by a rigid wedge indenter at the mid span, one-quarter span or near to a support. The impact velocities ranged up to 14 m/s and caused various failure modes. Some comparisons between two sets of experimental results indicate that the laws of geometrically similar scaling are almost satisfied over a scale range of approximately five.
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Dohi, Masahiro, Hirotaka Kamiyama, Shin-Ichi Nishida, Yuji Kotani, and Hisaki Watari. "Manufacturing Method of Increasing Hollow Steel Shaft Thickness Using Uniaxial Pressing." Applied Mechanics and Materials 705 (December 2014): 44–50. http://dx.doi.org/10.4028/www.scientific.net/amm.705.44.
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In manufacturing car components, the hollow parts manufacturing method is useful for reducing the product weight, especially in drivetrain parts such as long shafts. Long, hollow shafts should have middle portions with large diameters and thin walls and end portions with small diameters and thick walls in order to reduce weight while maintaining pipe strength.Generally, such long shaft parts are manufactured by reducing the end portion of the pipes with the equivalent diameter and desired hollow part thickness for the middle portion of the parts. It is difficult for manufacturers to successfully thicken the pipe wall locally by press forming because pipes buckle easily during the process. Using thick pipe is one way to prevent buckling, but when using thick pipes, we could not reduce weight much. Automotive industries have desired a manufacturing process that can reduce pipes (relatively thin pipes) without buckling.This paper clarifies the relationships among the forming conditions and the thickening ratio (thickness after forming / thickness before forming) in uniaxial press forming by experiments and finite-element simulation. Steel pipes with 39.0mm outer diameter and 7.6mm thickness were used in the experiment. The relationship between the thickening ratio and the forming load that depends on the die shape, lubrication, and slide motion of the press machine was investigated. An appropriate manufacturing condition that could reduce pipes without buckling was obtained. We clarified that the pipe wall thickness could be increased ten percent. The details of material flows in reducing pipes without buckling were discussed using finite-element simulation.
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Mahdi Saad, Elsadig, Samer Gowid, and John John Cabibihan. "Rupture of an Industrial GFRP Composite Mitered Elbow Pipe." Polymers 13, no. 9 (May 3, 2021): 1478. http://dx.doi.org/10.3390/polym13091478.
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This paper examines the immature rupture of glass fiber reinforced plastic composite (GFRP) mitered elbow pipes. The GFRP composite mitered elbow pipe’s lifespan was twenty-five years; however, the pipes in question experienced immature failures, resulting in the reduction of their lifetimes to seven, nine, and ten years, respectively. The GFRP cooling water mitered elbow pipe’s service conditions operate at a pressure of up to 7 bar and temperatures between 15–36 °C. The root cause of failure was determined using visual inspection, analytical, microstructural, mechanical characterizations, and chemical analysis. The initial visualization inspection revealed an improper joint between the composite overwrapped and the straight pipe sections. Mechanical properties along the axial, hoop and 45° from the axial direction were obtained. The results from the analytical analysis indicated that the elbow might withstand the operating pressure depending on the quality factor, which was confirmed to be low due to the elbow joint’s improper fabrication process. As evidence of this, the numerical analyses’ results indicated that the safety factor in withstanding the operating pressure of 5 bar is dropped down in the radial region where the thickness is reduced to simulate the failure zone. This study’s findings recommend that thickness of less than 15 mm be reinforced using overwrapped composites. It is recommended for future installations that the fabrication process be appropriately monitored and controlled and avoids using 45°/−45° fiber orientation and multiple layers of chopped strand mat glass fiber.
7
Latvala, A. "Advanced Chemical Treatment with Flocculation in Pipes." Water Science and Technology 22, no. 3-4 (March 1, 1990): 195–202. http://dx.doi.org/10.2166/wst.1990.0201.
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At the beginning of 1988 there were in Finland about ten small chemical wastewater treatment plants that were using flocculation in pipes instead of flocculation basins. This method consists of Me+++-chemical feeding, mixing, flocculation and sedimentation. Chemicals were fed into the suction openings of the wastewater pump, which is used for rapid mixing and also for pumping wastewater flow to the sedimentation basin. In the sedimentation sludge blanket sedimentation in deep vertical sedimentation basins was used. The sedimentation basin can also be used as sludge storage, if it is made sufficiently large. This method has been found especially suitable for small wastewater treatment plants, because it needs little labour and is cheap to build and to use and it is not affected negatively by fluctuations in the flow. The construction costs of this system in Finland have been about 50 % of those involved in traditional chemical package plants. The limitations of this method are its weakness in removing soluble organic load and its inability to oxygenate or remove nitrogen. However, a biological unit designed to cope with these limitations is under development.
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Horká, Lucie, and Jiri Hirs. "Simulation Study of Dry Floor Heating Systems." Applied Mechanics and Materials 887 (January 2019): 196–203. http://dx.doi.org/10.4028/www.scientific.net/amm.887.196.
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This case study is aimed at simulation of dry floor heating system. Heating pipes are inserted in system boards made of thermal insulation. These boards should be supplemented with spreader plates which are installed under the heating pipes. Impact of different thermal conductivity of spreader plates on useful heat flux and uniformity of temperature field is examined. Heat losses are also investigated. These simulations are performed using software CalA with time steady-state boundary conditions. The results show that the dry floor heating system without spreader plates has very low useful heat flux caused by positioning of heating pipes in the insulation material. On the other hand, use of spreader plates causes significant increase of useful heat flux of this system. The higher heat conductivity of spreader plates is, the higher useful heat flux is. The floor surface temperature is also more uniform and the thermal comfort is better. The minimal thickness of additional heat insulation is determined in order that heat losses are lower than ten percent of total heat flux.
9
Hull, J. R. "Analysis of Heat Transfer Factors for a Heat Pipe Absorber Array Connected to a Common Manifold." Journal of Solar Energy Engineering 108, no. 1 (February 1, 1986): 11–16. http://dx.doi.org/10.1115/1.3268037.
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Heat transfer factors and thermal efficiency are calculated for a heat pipe absorber array connected to a common manifold. Arrays with less than ten heat pipes are shown to have significantly less efficiency than a conventional flow-through collector. Efficiency is also sensitive to the heat transfer rate per unit temperature difference from the heat pipe fluid to the manifold fluid divided by that from the heat pipe surface to the ambient, with maximum efficiency occurring for ratios greater than 100.
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Mangs, Sara, Olle Ramnäs, and Ulf Jarfelt. "Mass Transport of Cell Gases in Carbon Dioxide Blown PET (Polyethylene Terephthalate) Foam Insulation." Cellular Polymers 24, no. 3 (May 2005): 115–26. http://dx.doi.org/10.1177/026248930502400301.
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Polyethylene terephthalate (PET) foam is a possible replacement option for polyurethane (PUR) foam as insulation material in district heating pipes. In this study, the diffusion coefficients and activation energies of cell gases in carbon dioxide blown PET foam (densities 148–157 kg·m−3) were determined at temperatures between 23 °C and 90 °C. The foam thermal ageing due to the mass transport of air into and carbon dioxide out of the foam was about ten times slower in PET foam than in PUR foam. The thermal conductivities of the PET foam boards were determined in a heat flow meter apparatus. The contribution to the foam thermal conductivity due to conduction in the solid polymer and radiation within the cell voids was determined to 17 mW·m−1·K−1 at 20 °C. This is higher than the value estimated for PUR foam in district heating pipes, 12 mW·m−1·K−1. This contribution can probably be reduced by developing low density PET foam and reducing the cell size.
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van den Boomen, M., A. van Mazijk, and R. H. S. Beuken. "First evaluation of new design concepts for self-cleaning distribution networks." Journal of Water Supply: Research and Technology-Aqua 53, no. 1 (February 1, 2004): 43–50. http://dx.doi.org/10.2166/aqua.2004.0005.
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Ten years of joint research on the nature and causes of discoloured water has resulted in guidelines for the implementation of self-cleaning distribution networks. These were first introduced in the Netherlands in 1999. The self-cleaning concept has been monitored right from its beginnings. Based on this evaluation, significant observations were found on the contribution of changes in flow velocity to the self-cleaning characteristics of pipes. These observations will be further investigated and will form the basis for the concept of dynamic sediment transportation modelling.
12
Ma, H. B., and G. P. Peterson. "Experimental Investigation of the Maximum Heat Transport in Triangular Grooves." Journal of Heat Transfer 118, no. 3 (August 1, 1996): 740–46. http://dx.doi.org/10.1115/1.2822694.
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An experimental investigation was conducted and a test facility constructed to measure the capillary heat transport limit in small triangular grooves, similar to those used in micro heat pipes. Using methanol as the working fluid, the maximum heat transport and unit effective area heat transport were experimentally determined for ten grooved plates with varying groove widths, but identical apex angles. The experimental results indicate that there exists an optimum groove configuration, which maximizes the capillary pumping capacity while minimizing the combined effects of the capillary pumping pressure and the liquid viscous pressure losses. When compared with a previously developed analytical model, the experimental results indicate that the model can be used accurately to predict the heat transport capacity and maximum unit area heat transport when given the physical characteristics of the working fluid and the groove geometry, provided the proper heat flux distribution is known. The results of this investigation will assist in the development of micro heat pipes capable of operating at increased power levels with greater reliability.
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Howard, A. H., and G. P. Peterson. "Investigation of a Heat Pipe Array for Convective Cooling." Journal of Electronic Packaging 117, no. 3 (September 1, 1995): 208–14. http://dx.doi.org/10.1115/1.2792093.
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A combined experimental and analytical investigation was conducted to evaluate a heat pipe convective cooling device consisting of sixteen small copper/water heat pipes mounted vertically in a 4 × 4 array which was 25.4 mm square. The analytical portion of the investigation focused on determination of the maximum heat transport capacity and the resistance of the individual heat pipes. The resistance of each heat pipe was found to be 2.51 K/Watt, or more than 3 times smaller than the resistance produced by a solid copper rod with the same dimensions. The maximum predicted heat rejection for the module was over 50 Watts, or a power density in excess of 7.75 Watts/cm2. In the experimental portion of the investigation, two different modules were tested. The first module utilized ten circular aluminum fins mounted on the condenser end of each heat pipe to enhance heat rejection, while the second contained only the sixteen copper/water heat pipes. The effects of flow velocity, input power, and base plate temperature on the overall thermal resistance and the heat rejection capacity were determined, as well as the pressure drop resulting from each module. The finned heat pipe array was found to have a lower overall thermal resistance and thus, a higher heat rejection capacity, but also resulted in a significantly larger pressure drop than the array without fins. The results of the heat pipe array experiments were also compared with experimental and empirical results obtained from flow over a flat plate 25.4 mm square.
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Rakshit Tyagi and Prof. Shreya Kapoor. "Comparing 2D game in Lua with game engine of love and in python with pygame." International Journal for Modern Trends in Science and Technology 6, no. 12 (December 18, 2020): 370–72. http://dx.doi.org/10.46501/ijmtst061269.
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The game flappy bird is used in the process of research .The game is used in both LUA and python programming language and the main aim of the user in game is to move forward by avoiding any contact with tunnel sprite .Also ,Flappy has to stay in air all the time without touching with ground and collects coins in between to increase the score. The game is 2D. [1]Flappy Bird is an arcade-style game in which the player controls the bird Flappy, which moves persistently to the right. The player is tasked with navigating Flappy through pairs of pipes that have equally sized gaps placed at random heights. Flappy automatically descends and only ascends when the player taps control . [2]Each successful pass through a pair of pipes awards the player one point. Colliding with a pipe or the ground ends the gameplay. During the game over screen, the player is awarded a bronze medal if they reached ten or more points, a silver medal from twenty points, a gold medal from thirty points, and a platinum medal from forty points.
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Pai¨doussis, M. P. "1992 CALVIN RICE LECTURE: Some Curiosity-Driven Research in Fluid Structure Interactions and Its Current Applications." Journal of Pressure Vessel Technology 115, no. 1 (February 1, 1993): 2–14. http://dx.doi.org/10.1115/1.2929491.
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This lecture has a dual purpose: (i) to present, in outline, the research on a couple of interesting topics in fluid-structure interaction; and (ii) to show that, although this research was undertaken with little or no practical application in mind, unexpected uses and applications materialized ten or twenty years subsequently. The two topics of research chosen are (a) stability of pipes conveying fluid, and (b) stability of cylinders in axial flow. The applications and uses range from a marine propulsion system, to research on emphysema, to understanding and modeling of flow-induced vibration and leakage-flow-induced instabilities in power-generating equipment, and to the dynamics of deep-water risers.
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Hafizi, Z. M., Che Ku Eddy Nizwan, M. F. A. Reza, and M. A. A. Johari. "High Frequency Acoustic Signal Analysis for Internal Surface Pipe Roughness Classification." Applied Mechanics and Materials 83 (July 2011): 249–54. http://dx.doi.org/10.4028/www.scientific.net/amm.83.249.
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This research highlights a method of acoustic emission analysis to distinguish the internal surface roughness of pipe. Internal roughness of pipe indicates the level of corrosion occurring, where normally it is difficult to be monitored online. Acoustic Emission (AE) technique can be used as an alternative solution for corrosion monitoring in pipes, especially for complex pipelines that are difficult to achieve by other monitoring devices. This study used a hydraulic bench to provide fluid flow at two different pressures in pipes with different internal surface roughness (rough and smooth). The main source of acoustic emission was from activity in the control valve, coupled with high pressure water flow friction on the surface of the pipe. The signal from these sources was detected by using the AED-2000V instrument and assisted by the Acoustic Emission Detector (AED) software. The time domain parameter; root mean square, RMS amplitude were processed and compared at different pressures for each type of internal pipe roughness at ten different locations. It was observed that a unitless Bangi number, AB, derived from RMS values, can be used for discriminating different level of internal surface roughness. Internal surface pipe can still be considered as smooth if AB value is above 1.0.
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Smith, Richard S., A. Peter Annan, Jean Lemieux, and Rolf N. Pedersen. "Application of a modified GEOTEM® system to reconnaissance exploration for kimberlites in the Point Lake area, NWT, Canada." GEOPHYSICS 61, no. 1 (January 1996): 82–92. http://dx.doi.org/10.1190/1.1443959.
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Airborne geophysical surveying with electromagnetic (EM) and magnetic methods is an effective reconnaissance exploration tool for kimberlite pipes because the target can have an associated EM and magnetic anomaly. The EM response of kimberlite pipes is most often attributed to weathering alteration in a near‐surface layer, whereas the magnetic response is attributed to magnetite and ilmenite within the deeper unweathered kimberlite pipe. The discrete shape of kimberlite diatremes results in an easily identifiable anomaly pattern. Diamondiferous kimberlites have recently been found in the Northwest Territories (NWT) of Canada, an area glaciated in the Pleistocene and therefore devoid of a strongly weathered zone. By configuring the GEOTEM® airborne EM system to operate at high frequencies (270 Hz) and to take measurements while the transmitter is switched on, weakly conductive bodies may be detected because there is an adequate contrast with the surrounding highly resistive country rock. System modifications also allow the magnetic field to be sampled at an altitude of only 73 m instead of 120 m and ten times per second instead of once a second. This allows much better definition of weak, small magnetic anomalies. Data sets from two test areas (Point Lake and Willy Nilly, near Lac de Gras, NWT) demonstrate the effectiveness of the airborne system for reconnaissance surveying.
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Jiang, Changliang, Pengchao Chen, Rui Li, and Xiaoben Liu. "A Multisource Monitoring Data Coupling Analysis Method for Stress States of Oil Pipelines under Permafrost Thawing Settlement Load." Mathematical Problems in Engineering 2020 (November 24, 2020): 1–15. http://dx.doi.org/10.1155/2020/6696680.
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Thaw settlement is one of the common geohazard threats for safe operation of buried pipelines crossing permafrost regions, as pipes need to bear additional bending stress induced by settlement load. In the presented study, a novel coupled data analysis method was proposed for stress state estimation of buried steel pipeline under thawing settlement load. Multisource data including pipe bending strain derived by inertial measurement unit, pipe longitudinal strain derived by strain gauges, and thawing displacement loads derived by soil temperature monitoring were used to estimate the pipe’s mechanical states. Based on the derived data, finite element method-based pipe soil interaction model was established to predict pipe’s actual stress distribution. A monitored pipe segment of one crude oil pipeline in northeast China operated since 2010 was adopted as a prototype for the investigation, monitoring data derived in the last ten years was employed to predict the settlement loading, and relative accurate stress results was obtained via the established pipe soil interaction model. The mean absolute error (MAE) of the predicted pipe stresses compared with the monitoring results in 2014, 2017, and 2018 are 5.77%, 12.13%, and 13.55%, respectively. Based on the analyzed stress results, it can be found that the investigated pipe was subjected to an increasing settlement load from 2010–2016, made the bending stress increased up to 149.5 MPa. While after 2016, due to the depth of frost soil in this area is no more than 3.5 m, the thawing settlement load almost remained constant after 2016. As the investigated pipe is made by X65 line pipe steel, the von-Mises stress in pipe is much smaller than the allowable one indicating pipe’s structural safety status so far. The proposed method can also be referenced in the status monitoring of buried pipeline crossing other geological hazard regions.
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Zhang, Xi Ming, and Xue Li. "Gravimetric Method for Calibrating Flow Meter." Applied Mechanics and Materials 501-504 (January 2014): 2335–37. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.2335.
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What the earth obtain the energy annually is ten thousand times of the earth energy consumption at present,but the solar energy has a lower energy density on the earth’s surface .solar energy is the main source of all energy The experimental research was conducted for the heating performance utilizing the solar-assisted heat pump experimental platform. Experimental errors will be caused to flow meter by different measured media and long time usage In order to improve measurement precision and reduce the experimental errors, this test use gravimetric method to calibrate the LZB glass rotor meter and MCE08-787 cumulative flow meter of indoors and outdoors pipes. The paper also presents flow correction coefficient to guarantee both the accuracy and reliability of the experimental results.
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Marfo, S. A., P. Opoku Appau, J. Acquah, and E. M. Amarfio. "Flow Assurance in Subsea Pipeline Design - A Case Study of Ghana’s Jubilee and TEN Fields." Ghana Mining Journal 19, no. 1 (June 30, 2019): 72–85. http://dx.doi.org/10.4314/gm.v19i1.9.
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The increasing exploration and production activities in the offshore Cape Three Point Blocks of Ghana have led to the discovery and development of gas condensate fields in addition to the oil fields which produce significant amount of condensate gas. These discoveries require pipelines to transport the fluids avoiding hydrates and wax formation. This paper focuses on subsea pipeline design using Pipesim software that addresses flow assurance problems associated with transporting condensate gas from the Jubilee and TEN Fields to the Atuabo Gas Processing Plant. It also considered an alternate design that eliminates the need for capacity increase of flowlines for the futuristic highest projected flow rates in 2030. The design comprises of two risers and two flowlines. Hydrate formation temperature was determined to be 72.5 ˚F at a pressure of 3 000 psig. The insulation thickness for flowlines 1 and 2 were determined to be 1.5 in. and 2 in. respectively. The pipe size for flowlines 1 and 2 were determined to be 12 in. and 14 in. respectively. The maximum designed flow rate was determined to be 150 MMSCFD. To meet the highest projected flow rate of 700 MMSCFD in the year 2030 at the processing plant, a 16 in. ID pipeline of 44 km length was placed parallel to the 12 in. ID flowline 1. This parallel pipeline increased the designed flow rate by approximately 4.7 times (705 MMSCFD). The alternate design employs 18 in. and 20 in. ID pipes for flowlines 1 and 2 respectively. Keywords: Condensate Gas; Flowline; Flow Assurance; Hydrate; Pipesim
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Hassan, Abdulsalam D. M., and Rwaa Alaa Hussein. "The Variation Effect of Collector Tilt Angle on the Heat Pipe Solar Collector Performance." Wasit Journal of Engineering Sciences 6, no. 2 (August 30, 2018): 21–27. http://dx.doi.org/10.31185/ejuow.vol6.iss2.88.
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The thermal performance of FPHPSC has been studied experimentally and theoretically. The collector consists of copper absorber plate, single glass cover, glass wool insulation and aluminum case, ten wickless heat pipes of 12.7 mm inner diameter. The experimental studies of collector performance have been performed on four different CTA (22°, 32°, 45° and 60°). The relation between the solar intensity and the collector energy losses are also discussed. The collector are tested under the climate condition of Kut city (32.602 latitude and 45.752 longitude). It is investigated that the increasing of CTA increase the efficiency of collector up to certain limit after that the efficiency decreases with the increasing of tilt angle of collector. A computer program which is based on VISUAL BASICE language (version 6) is made for the theoretical analysis. The experimental results agree reasonably with the theoretical predictions.
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Jeong, GyeSoon, and John M. Brown. "DISPERSAL OF TRICHODERMA VIA IRRIGATION WATER." HortScience 27, no. 6 (June 1992): 631g—631. http://dx.doi.org/10.21273/hortsci.27.6.631g.
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Trichoderma has been known to control soil-borne pathogens and to enhance plant growth and development. The objective of the study was to evaluate dispersal of Trichoderma via irrigation water in container production. 3.81 × 30 cm PVC pipes were filled with Sunshine Mix #5 up to 25 cm. Ten tomato seeds, boiled and coated with T. harzianum, were placed at 0.5 cm depth in each pipe. All treatments were irrigated carefully with 100 ml of DD water from top every 2 days. Before and one hour after irrigation the potting mix was sampled from 5 depths at 5.5 cm intervals every 2 days for 8 days to determine Trichoderma density. Trichoderma density was significantly higher in after irrigation. Trichoderma dispersed up to 25 cm deep in container potting mix after 4 days via irrigation water. This study successfully demonstrates that Trichoderma can be rapidly dispersed via irrigation water.
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Okotto-Okotto, Joseph, Weiyu Yu, Emmah Kwoba, Samuel M. Thumbi, Lorna Grace Okotto, Peggy Wanza, Diogo Trajano Gomes da Silva, and Jim Wright. "A mixed methods study to evaluate participatory mapping for rural water safety planning in western Kenya." PLOS ONE 16, no. 7 (July 28, 2021): e0255286. http://dx.doi.org/10.1371/journal.pone.0255286.
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Water safety planning is an approach to ensure safe drinking-water access through comprehensive risk assessment and water supply management from catchment to consumer. However, its uptake remains low in rural areas. Participatory mapping, the process of map creation for resource management by local communities, has yet to be used for rural water safety planning. In this mixed methods study, to evaluate the validity of participatory mapping outputs for rural water safety planning and assess community understanding of water safety, 140 community members in Siaya County, Kenya, attended ten village-level participatory mapping sessions. They mapped drinking-water sources, ranked their safety and mapped potential contamination hazards. Findings were triangulated against a questionnaire survey of 234 households, conducted in parallel. In contrast to source type ranking for international monitoring, workshop participants ranked rainwater’s safety above piped water and identified source types such as broken pipes not explicitly recorded in water source typologies often used for formal monitoring. Participatory mapping also highlighted the overlap between livestock grazing areas and household water sources. These findings were corroborated by the household survey and subsequent participatory meetings. However, comparison with household survey data suggested participatory mapping outputs omitted some water sources and landscape-scale contamination hazards, such as open defecation areas or flood-prone areas. In follow-up visits, participant groups ranked remediation of rainwater harvesting systems as the most acceptable intervention to address hazards. We conclude that participatory mapping can complement other established approaches to rural water safety planning by capturing informally managed source use and facilitating community engagement.
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Lindblad-Påsse, Annika. "Clogging Problems in Groundwater Heat Pump Systems in Sweden." Water Science and Technology 20, no. 3 (March 1, 1988): 133–40. http://dx.doi.org/10.2166/wst.1988.0091.
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A number of groundwater heat pump systems have been investigated to determine the extent of problems caused by the chemistry of the groundwater used. The main purpose was to investigate sites using iron rich groundwater. Fifteen facilities were studied regularly for three years. Ten of these facilities had some kind of problem caused by iron precipitation. Four of the sites were rebuilt because of severe plugging due to iron sludge in wells, pumps and pipes. In all facilities with severe problems, iron bacteria were found. Low redox potential, indicated by hydrogen sulphide in the groundwater, seems to protect from iron bacteria. In some of the systems using groundwater with H2S the problems were corrosion and sludge formation caused by sulphur oxidizing bacteria. Rapid clogging was caused by aeration of the groundwater due to improper design of the system. Knowledge of the water composition, design of the systems to minimize aeration, and control of clogging turned out to be important factors to maintain operation safety.
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Rigal, S., and J. Danjou. "Tastes and Odors in Drinking Water Distribution Systems Related to the Use of Synthetic Materials." Water Science and Technology 40, no. 6 (September 1, 1999): 203–8. http://dx.doi.org/10.2166/wst.1999.0299.
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Plastic pipes, organic coatings and membranes, and epoxy relining products are progressively replacing existing traditional metallic or cementitious materials. Despite existing controls, and for different reasons, additives, solvents, or monomers can be leached into the drinking water. Until ten years ago, such problems frequently occurred. French regulations now oblige the manufacturers to obtain approvals for their products for contact with drinking water, and such problems now occur less and less. The objectives of this research were to investigate the causes of odor and flavor problems generated in distribution systems, water towers, and lined systems. Four case studies and an experimental study of taste and odor deterioration of water quality are presented to identify the responsible substances related to materials. In each case study, organic components which characterized the cause of the problems were measured experimentally. Components (e.g., styrene and chlorinated by-products) resulting in a high TON/TFN were identified as the chemicals responsible for the cause of odor and flavor problems.
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Pan, Gang, Bao Wang, Shuai Guo, Wenming Zhang, and Stephen Edwini-Bonsu. "Statistical analysis of sewer odour based on 10-year complaint data." Water Science and Technology 81, no. 6 (March 15, 2020): 1221–30. http://dx.doi.org/10.2166/wst.2020.217.
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Abstract The City of Edmonton has been suffering from sewer odour problem for many years. Ten years of odour complaints data from 2008 to 2017 were statistically analyzed to identify major factors that relate to the odour problem. Spatial and temporal distributions of odour complaints in the city were first presented. Then relationships between the complaints and physical attributes of the sewer systems were analyzed by introducing a parameter of risk index. It was found that the snowmelt and storm events could possibly reduce odour complaints. Old sewer pipes and large drop structures are statistically more linked and thus significantly contribute to the complaints. The risk index relationship for three pipe materials is clay pipe > concrete pipe > PVC pipe. Combined sewers are more problematic in terms of odour complaints than sanitary sewers. And no clear correlation has been found between the changes of sewer pipe slope or angle and the complaints.
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Hassan, Abdulsalam D. M., and Rwaa Alaa Hussein. "The Effect of Cooling Water Mass Flow Rate Variations on the Heat Pipe Solar Collector Performance." Wasit Journal of Engineering Sciences 5, no. 2 (May 9, 2017): 31–41. http://dx.doi.org/10.31185/ejuow.vol5.iss2.56.
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The thermal performance of FPHPSC has been studied experimentally and theoretically. The collector consists of copper absorber plate, single glass cover, glass wool insulation and aluminum case. Ten wickless heat pipes of 12.7 mm inner diameter. The experimental studies of collector performance have been performed on four different CWMFR (0.03, 0.04, 0.05 and 0.06) kg/s. The relation between the amount of useful heat, instantaneous collector efficiency and solar intensity is discussed. The collector are tested under the climate condition of Kut city (32.6 latitude and 45.7 longitude). It is investigated that the increasing of CWMFR increase the efficiency of the collector. The percentage increase in the efficiency of the solar collector is in order of (13%), when the cooling water mas flow rate changes from 0.03 kg/sec to 0.06 kg/sec at (45o) collector tilt angle. A computer program based on VISUAL BASIC language (version 6) used for the theoretical analysis. The experimental results are in agreement reasonably with the theoretical predictions.
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Verstraete, Matthias, Stijn Hertelé, Wim De Waele, and Rudi Denys. "Influence and evaluation of constraint on fracture toughness in pipeline research." International Journal Sustainable Construction & Design 3, no. 1 (November 6, 2012): 25–35. http://dx.doi.org/10.21825/scad.v3i1.20553.
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Accessing nowadays fossil fuel reserves requires a strain-based design approach. Within suchdesign, the ductile tearing resistance is a key parameter in assessing the defect tolerance. To determinethis tearing resistance, full scale (pressurized) tests can be performed. However, such approach would becostly and time consuming. Consequently, effort is made to select appropriate small scale test specimens.Most research has focused so far on the single edge notch bend (SENB) and tensile (SENT) specimen. Toevaluate the suitability of these test specimens, the crack tip stress fields can be examined or theresistance curves compared with full scale structures. This paper aims at comparing the trends observedusing these techniques. Furthermore, the suitability of the small scale test specimens is evaluated. It isconcluded that sufficiently long (length-to-width ratio equal to ten) clamped SENT specimens have thepotential to predict the tearing resistance of full scale pipes. In addition, the internal pressure does notsignificantly affect the fracture toughness. These conclusions are stated by both experimental results andfinite element simulations.
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Yuki, Yosuke, Enao Takayanagi, and Takashi Abe. "Design of Multi-Story Sewage Treatment Facilities." Water Science and Technology 23, no. 10-12 (May 1, 1991): 1733–42. http://dx.doi.org/10.2166/wst.1991.0628.
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In Osaka City, due to rises in land prices and the rapid advances of urbanization, it is difficult to enlarge sites for sewage treatment facilities. To enhance efficient land utilization, construction of multi-story facilities has been promoted. This effort commenced with the building of a two-story primary settling tank, followed by two-story final settling tanks, aeration tanks vertically combined with final settling tanks and three-story final settling tanks. Together with the introduction of these multi-story facilities, efforts have also been made to further deepen the aeration tanks. One of the features of the city's multi-story sewage treatment facilities is the use of outlet pipes for purified wastewater in the final settling tanks. This has helped promote introduction of multi-story facilities. These multi-story facilities in Osaka City have already been in operation for ten to twenty years under satisfactory treatment conditions. The area occupied by a multi-story structure is only 46% that of conventional single-story structures. Construction cost for single- and multi-story structures is almost equal.
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Moosavian, Naser, and Barbara Lence. "Testing evolutionary algorithms for optimization of water distribution networks." Canadian Journal of Civil Engineering 46, no. 5 (May 2019): 391–402. http://dx.doi.org/10.1139/cjce-2018-0137.
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Water distribution networks (WDNs) are one of the most important elements of urban infrastructure and require large investment for construction. Design of WDNs is classified as a large combinatorial discrete nonlinear optimization problem. The main concerns associated with the optimization of such networks are the nonlinearity of the discharge-head loss relationships for pipes and the discrete nature of pipe sizes. Due to these issues, this problem is widely considered to be a benchmark problem for testing and evaluating the performance of nonlinear and heuristic optimization algorithms. This paper compares different techniques, all based on evolutionary algorithms (EAs), which yield optimal solutions for least-cost design of WDNs. All of these algorithms search for the global optimum starting from populations of solutions, rather than from a single solution, as in Newton-based search methods. They use different operators to improve the performance of many solutions over repeated iterations. Ten EAs, four of them for the first time, are applied to the design of three networks and their performance in terms of the least cost, under different stopping criteria, are evaluated. Statistical information for 20 executions of the ten algorithms is summarized, and Friedman tests are conducted. Results show that, for the two-loop benchmark network, the particle swarm optimization gravitational search and biology and bioinformatics global optimization algorithms efficiently converge to the global optimum, but perform poorly for large networks. In contrast, given a sufficient number of function evaluations, the covariance matrix adaptation evolution strategy and soccer league competition algorithm consistently converge to the global optimum, for large networks.
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Mutizhongo, Fanos, Lukas Willem Snyman, and Kevin Jalet. "Development of low-cost reflective plate thermal energy absorber systems for application in South Africa." Journal of Energy in Southern Africa 32, no. 3 (September 19, 2021): 51–66. http://dx.doi.org/10.17159/2413-3051/2021/v32i3a8044.
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An innovative solar heat collector system was developed from low-cost materials by applying innovative design technology and using adaptive technologies. The system design entails placing long black polymer pipes connected in series circulation, mounted and positioned in grooves of inverted box rib galvanised steel plating. The grooves reflect and focus the incident rays on the centre piping, concentrating incident sun rays on the black piping and increasing the absorption of thermal energy in the piping filled with circulating water. The circulation of the water is facilitated by a direct-current solar-driven pump powered by a small photovoltaic panel. The thermal energy as collected is stored in a standard household geyser tank. A 3 × 4 m heat absorber of this type collects approximately 10 kWh of energy per day. The estimated cost of the system, considering the capital outlay over an expected ten-year life cycle for the product was estimated at R0.25 per kWh. This pricing competes extremely favourably with the general cost of grid electricity in South Africa for medium-sized households, which is of the order of R2 per kWh up to 1000 kWh per month, including taxes. With an estimated electricity cost escalation of above 5% every year, the ten-year saving for a household using this prototype can be approximately R200 000. The technology and designs developed through the study can create many new business opportunities in South Africa in both urban and rural environments, through manufacturing, installing, repairing, and maintaining the systems.
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Yan–hua, Li, Feng Hui, Chi Qiang, Fei Fan, Gao Xiong-xiong, Li Wei-wei, Xu Xiao-feng, Chen Hong-yuan, and Zhang Hua. "Experimental Research on Fatigue Properties of X80 Pipeline Steel for Synthetic Natural Gas Transmission." Mathematical Problems in Engineering 2021 (January 27, 2021): 1–9. http://dx.doi.org/10.1155/2021/6631031.
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In recent years, many synthetic natural gas demonstration projects have been put into operation all over the world, and hydrogen is usually contained in synthetic natural gas. X80 is the most commonly used high-grade pipeline steel in the construction of natural gas pipelines. The compatibility between high-grade pipeline steel and hydrogen directly affects safety and reliability of long-distance pipelines. Therefore, in order to study the effect of hydrogen content on fatigue properties of high-grade pipeline steel, fatigue specimens were taken from base metal, spiral welds, and girth weld of submerged arc spiral welded pipes, respectively. Specifically, the total pressure was 12 MPa and hydrogen content was from 0 to 5vol%. Experimental results indicate that the hydrogen significantly increases the fatigue crack growth rate for both base metal, spiral weld, and heat-affected zone of X80 pipeline steel for about ten times compared with reference environment nitrogen, hydrogen would greatly reduce the fatigue life of the X80 pipeline steel, and the fatigue lifetime would decrease with the increase in hydrogen volume fraction. In order to ensure the safe operation of SNG pipeline, the hydrogen content should be controlled as low as possible.
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Ortenzi, Altibano, Andrea Corvi, and Antonio Virga. "Preliminary Study on the Acoustic Emission Wave Velocity on Filament Wound Glass Fiber Reinforced Polymer Pipes and its Correspondence with the Winding Angle." Advanced Materials Research 891-892 (March 2014): 1243–48. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1243.
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In this study, three types of filament wound glass fiber reinforced epoxy composite specimens were tested according to the ASTM standards to evaluate preliminary, the acoustic emission wave velocity. The pipe specimens had 300.0 mm of length, 50.5 mm of diameter and 3.5 mm of wall thickness. Ten points were marked over the imaginary central circle on the pipe middle, from zero degree up to 90º with nine divisions of 10º each one and an additional point representing the crossing of plies. Next, there are positioned two collinear acoustic emission (AE) sensors along the length, positioned at 35 mm from middle, axially. After the specimen preparation, took place theHSU-NIELSENor pencil lead break (PLB) tests to analyze the signal wave time for both sensors, by means of the 0.3mm – 2H graphite lead brake. The results were compared to considering the angular variation and the velocity for each winding angle. It was evident that the procedure above can determine with good precision the variations occurred on the acoustic emission velocity on filament wound composite pipes, regarding the three angular variations compared. This study was the parameter of control to proceed with the acousticemission evaluation over tensile tests in further studies to predict the fatigue and the damage propagation on this typology of laminates.
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Surya Irawan, Diki, Deffi Ayu Puspito Sari, and Anggita Ariesta. "Domestic Wastewater Piping Network Planning and Technology Recommendations for Wastewater Treatment Case Study: The Ambarita Area, Samosir Regency, North Sumatra." Cerdika: Jurnal Ilmiah Indonesia 1, no. 3 (March 25, 2021): 189–208. http://dx.doi.org/10.36418/cerdika.v1i3.42.
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Lake Toba is one of ten programs the Ministry of Tourism in the Republic Indonesia, as a priority tourism area because of its unique potential. The Ambarita is one of 16 villages that are priority areas in Simanindo Subdistrict, Samosir Regency. At present, the quality of Lake Toba's waters has been polluted, the pollution is caused by domestic waste water which is discharged directly without prior treatment. The purpose of this study is to plan a domestic wastewater pipeline network and recommendations for wastewater treatment plants with a centralized system in the Ambarita. This study uses a data analysis method by using a population projection approach with maximum capacity to be planned in the draft MasterPlan of Ambarita and literature study for WWTP technology recommendations. The results showed that the total discharge of wastewater in the Ambarita was 0,06495 m3/second and the results of laboratory tests showed the parameters that exceeded quality standard were free chlorine and fecal coli. Piping network planning in the Ambarita uses concrete type pipes with diameters of 100 mm, 125 mm, 150 mm, 200 mm and 250 mm. The selected Waste Water Treatment Technology recommended is anaerobic-aerobic biofilter technology with removal efficiency for fecal coli and free chlorine are 99.9% and 65%.
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Sweelssen, Jörgen, Huib Blokland, Timo Rajamäki, Risto Sarjonen, and Arjen Boersma. "A Versatile Capacitive Sensing Platform for the Assessment of the Composition in Gas Mixtures." Micromachines 11, no. 2 (January 21, 2020): 116. http://dx.doi.org/10.3390/mi11020116.
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The energy market is facing a major transition, in which natural gas and renewable gasses will play an important role. However, changing gas sources and compositions will force the gas transporters, gas engine manufacturers, and gas grid operators to monitor the gas quality in a more intensive way. This leads to the need for lower cost, smaller, and easy to install gas quality sensors. A new approach is proposed in this study that is based on the chemical interactions of the various gas components and responsive layers applied to an array of capacitive interdigitated electrodes. For Liquid Natural Gas (LNG), containing a relative high concentration of higher hydrocarbons, an array of ten capacitive chips is proposed, that is sufficient to calculate the full composition, and can be used to calculate energy parameters, such as Wobbe Index, Calorific Value, and Methane Number. A first prototype was realized that was small enough to be inserted in low and medium pressure gas pipes and LNG engine fuel lines. Adding the pressure and temperature data to the chip readings enables the determination of the concentrations of the various alkanes, hydrogen, nitrogen, and carbon dioxide, including small fluctuations in water vapor pressure. The sensitivity and selectivity of the new sensor is compared to a compact analyzer employing tunable filter infrared spectrometry.
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Чижиков, Mikhail Chizhikov, Жуков, and Nikolay Zhukov. "Automated Scanner for External Pipe Non-Desructive Testing." NDT World 19, no. 4 (December 15, 2015): 48–52. http://dx.doi.org/10.12737/23504.
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For more than ten years the Diagnostic Scientific and Technical Center (DSTC) "Defectoskopiya" is engaged in the development of flaw detectors using magnetic inspection method. The main object of testing were the pipes with their diameters ranging from 1020 mm to 1420 mm and wall thickness up to 28mm.
The “Orbita” Magnetic Diagnostic Complex (MDC) is the newest detector developed. It is designed for automated pipe body testing using magnetic method. MDC “Orbita” allows searching and identification of such common defects as pitting corrosion, stress corrosion, cracking, pipe wall separation, as well as changes in the pipe geometric parameters such as jam, flutes, nicks.
MDC “Orbita” performance features are the low weight, easy transportability and maintenance, indiscriminateness to the operating personnel qualifications.
The efficiency and reliability of the MDC “Orbita” components and assemblies were tested on a real pipe in field conditions (in the column for the removal of the insulating coating during the works of re-isolation section of the main ø1420 mm gas pipeline "Urengoy-Novopskov" 3007-3030 km), as well as in the pits (the main gas pipeline "Petrovsk-Novopskov" Bubnovsky LPU MG OOO "Gazprom transgaz Volgograd" on 325 and 326 kilometres MG "Petrovsk-Novopskov") during the period of April 21-23, 2015.
MDC “Orbita” is designed for external inspection of pipes coated with insulating material, or after purification, in the pits, on the inventory of resting after pruning, as well as in the column with a cleaning machine.
Operation with the scanner can take place at any time of the day, in the ambient temperature range from -200C to +400C in any weather conditions.
The operating personnel amounts to not more than two persons, the deployment time (loading from a fully disassembled state until you are ready to work including erection onto the pipe) takes not more than 15 minutes.
Mounting on a pipe in the assembled state takes not more than 1 minute.
Scanner weight does not exceed 25 kg, and when assembled it can be transported by any means of transport. Automated scanner flaw-detector tests showed the claimed technical characteristics, high reliability, the reliability of the scan results, and its handiness.
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Kim, Hyun Il, Jae Young Lee, Kun Yeun Han, and Jae Woong Cho. "Applying Observed Rainfall and Deep Neural Network for Urban Flood Analysis." Journal of the Korean Society of Hazard Mitigation 20, no. 1 (February 29, 2020): 339–50. http://dx.doi.org/10.9798/kosham.2020.20.1.339.
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Urban flooding primarily occurs due to flash floods in low-lying regions or insufficient capacity of drainage systems. Urban inundation has become more dangerous to residents because of an increase in impermeable areas, uncertainties in urban sewage planning, and the accumulation of sedimentation in drainage pipes. As an urban watershed with a drainage system and an urbanized river is complicated, a specific time interval is required for the preparation and processing of urban runoff analysis. To allow for rapid simulations of urban runoff estimation during heavy rainfall, a deep neural network model that imitates the conditions of a 6-h duration rainfall was developed in this study. Ten different statistical aspects for each rainfall event were considered as input data, and the total accumulated overflow from a manhole was calculated at intervals of 10 min using storm water management model (SWMM). To verify the accuracy of the results from SWMM, the results obtained from a two-dimensional hydraulic model and an inundation trace map were compared. The computational times for the deep neural network and rainfall data-based models proposed in this study were estimated to be within 1 s, whereas the simulation using SWMM required 14 min. The proposed deep learning model was tested using the total accumulated overflow for the rainfall event observed at Gangnam (400) automatic weather station on July 27, 2011. The simulated results agreed with the observed results in terms of the total accumulated discharge.
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Zoladz, Glen V., Timothy J. McGrath, and Ernest T. Selig. "Laboratory Tests of Buried Pipe Installation Procedures." Transportation Research Record: Journal of the Transportation Research Board 1541, no. 1 (January 1996): 86–96. http://dx.doi.org/10.1177/0361198196154100111.
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Laboratory testing of buried pipe was conducted to evaluate the pipe-soil interactions that take place as pipes are backfilled. The program consisted of 25 tests with metal, plastic, or concrete pipe. In addition to pipe type, test variables included trench conditions, backfill material, compaction method, haunching effort, and bedding condition. The tests were conducted in an indoor test facility designed to allow for the installation of pipe in a realistic manner. Pipe and soil behavior were monitored during installation, and measurements included pipe deflections, pipe strain, pipe-soil interface pressures, soil density, soil strength, and horizontal soil stresses. Backfill was placed to at least 150 mm above the spring line to observe the effects in the important haunch zone. Ten of the tests were continued until the backfill was at least 300 mm over the pipe. The results indicated significant variations in pipe behavior because of installation practices. The wider trench produced greater upward deflections during sidefill compaction. The rammer compactor was the most effective means of achieving high backfill density and stiffness, forcing backfill into the haunch zone, and developing beneficial lateral soil stresses at the sides of the pipe. Installation in trenches with walls of soft materials results in lower lateral pressures and higher invert pressures on the pipe. The coarser-grained backfill material achieved suitable soil unit weight and stiffness with less compactive energy than the finer-grained material. The haunching effort provided improved pipe support in the lower haunch zone.
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El Ame, F., J. N. Mwero, and C. K. Kabubo. "Openings Effect on the Performance of Reinforced Concrete Beams Loaded in Bending and Shear." Engineering, Technology & Applied Science Research 10, no. 2 (April 4, 2020): 5352–60. http://dx.doi.org/10.48084/etasr.3317.
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Transverse openings are often provided to reinforced concrete beams to accommodate utility ducts and pipes. This technique is usually adopted to avoid the creation of dead space in structures caused by extended dropped ceilings and leads to significant cost saving. On the other hand, the provision of openings through a beam creates a reduction in its strength and affects serviceability. In this study, ten reinforced concrete beams were cast using C30 concrete. Material characterization and engineering properties tests were carried out to ensure compliance with the requirements provided by the codes of practice. The effect of vertical positioning and size of openings was investigated through subjecting the beams to a four-point bending test after 28 days of curing. Maximum load capacity, first cracking load, and deflections at mid-span were recorded and crack pattern and failure mode were evaluated. Test data showed that openings of depth greater than 0.4d significantly affect the beams’ strength and lead to earlier cracking, while the failure mode remains essentially the same, a diagonal tension crack through the opening except for opening of 0.5d size where the failure occurred by a sudden formation of two independent shear cracks above and below the opening. When holes were located above the centroid of the section, the beams exhibited a lesser deflection characterized by the absence of plastic deformation. Furthermore, a significant reduction in strength was recorded compared to cases where the positioning of openings was in tension chords. This was validated using equations from the ACI code of reinforced concrete design.
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Luo, Jiang, and Eli H. Razinsky. "Conjugate Heat Transfer Analysis of a Cooled Turbine Vane Using the V2F Turbulence Model." Journal of Turbomachinery 129, no. 4 (July 24, 2006): 773–81. http://dx.doi.org/10.1115/1.2720483.
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The conjugate heat transfer methodology has been employed to predict the flow and thermal properties including the metal temperature of a NASA turbine vane at three operating conditions. The turbine vane was cooled internally by air flowing through ten round pipes. The conjugate heat transfer methodology allows a simultaneous solution of aerodynamics and heat transfer in the external hot gas and the internal cooling passages and conduction within the solid metal, eliminating the need for multiple/decoupled solutions in a typical industry design process. The model of about 3 million computational meshes includes the gas path and the internal cooling channels, comprising hexa cells, and the solid metal comprising hexa and prism cells. The predicted aerodynamic loadings were found to be in close agreement with the data for all the cases. The predicted metal temperature, external, and internal heat transfer distributions at the midspan compared well with the measurement. The differences in the heat transfer rates and metal temperature under different running conditions were also captured well. The V2F turbulence model has been compared with a low-Reynolds-number k-ε model and a nonlinear quadratic k-ε model. The V2F model is found to provide the closest agreement with the data, though it still has room for improvement in predicting the boundary layer transition and turbulent heat transfer, especially on the suction side. The overall results are quite encouraging and indicate that conjugate heat transfer simulation with proper turbulence closure has the potential to become a viable tool in turbine heat transfer analysis and cooling design.
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Jasim, Waleed A., Abbas Abdulmajeed Allawi, and Nazar K. Oukaili. "Strength and Serviceability of Reinforced Concrete Deep Beams with Large Web Openings Created in Shear Spans." Civil Engineering Journal 4, no. 11 (November 29, 2018): 2560. http://dx.doi.org/10.28991/cej-03091181.
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Deep beams are used in wide construction fields such as water tanks, foundations, and girders in multi-story buildings to provide certain areas free of columns. In practice it is quite often occurring to create web opening in deep beams to supply convenient passage of ventilation ducts, cable channels, gas and water pipes. Experimental studies of ten 10 deep beams were carried out, where two of them are control specimens without openings and eight with large web openings in the shear spans. The variables that have been adopted are the ratio of the shear span to the overall depth of the member cross-section, location and dimensions of the opening. Test results showed that there was a decrease in the load carrying capacity of deep beams with openings compared to the control deep beams. This reduction may reach 66% in particular cases. It is clear that, the position of opening in shear span has less effect on the performance of structural concrete deep beams at different serviceability stages. Only 11% increase in load capacity at failure was observed in specimens with openings adjacent to the interior edges of shear spans in comparison with specimens with openings at the center of shear span because the discontinuity of the load path is less. Also the midspan deflection at service load level of the reference beam in specimens with openings adjacent to interior edge of shear spans was less than the midspan deflection of reference specimens by 10% - 33%. Evaluating all these advantages facilitates to recommend, if it is very required, the creation of openings at the interior edges of shear spans of the structural concrete deep beams.
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Bauné, Emmanuel, E. Galand, B. Leduey, G. Liberati, G. Cumino, S. Caminada, A. Di Gianfrancesco, and L. Cipolla. "Grades 92 and 23: Weldability Assessment and Long-Term Performances for Power Generation Applications." Materials Science Forum 580-582 (June 2008): 383–88. http://dx.doi.org/10.4028/www.scientific.net/msf.580-582.383.
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Increased efficiency and emission reduction in modern power plants lead to the use of new advanced materials with enhanced creep strength, with the objective to increase the steam parameters of power plants. With over ten years on market and wide experience related to its use, ASTM Grade 92 is becoming one of the most required materials when high service temperatures are reached (max. 610°C). Its composition, with 9%Cr and 1.5%W, gives rise to martensitic microstructures which offer very high creep strength and long term stability. The improved weldability and creep-strength between 500 and 580°C of the low alloy ASTM Grade 23, as well as a cost advantage over higher Cr materials in this temperature range, make it one of the possible candidates to meet the stringent requirements of modern power plants. Air Liquide Welding (ALW) has optimized and distributes a complete product family for the welding of Grades 23 and 92. TenarisDalmine (TD) focused on the development of Grade 23 tubes and pipes and is working on the development of Grade 92. A deep characterization work of the microstructural evolution and long term creep performances of these high temperature resistant materials was thus undertaken by ALW and TD, in collaboration with the Centro Sviluppo Materiali (CSM). The joint characterization program consisted in the assessment of welded joints creep properties. Welded joints were produced using the gas tungsten (GTAW), shielded metal (SMAW) and submerged arc welding (SAW) processes. Mechanical and creep properties of weldments were measured both in the as welded and post weld heat treated conditions and proper WPS’s were designed in a manner such that industrial production needs were satisfied. Short term creep resistance of cross weld specimens was measured to be within the base material acceptance criteria. Long term base material and cross weld creep performance evaluation are now in progress.
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Mambetov, Rinat F., Vladimir M. Kushnarenko, Fanil S. Khafizov, and Ildar F. Khafizov. "Causes of through damage to the pipeline weld." SCIENCE & TECHNOLOGIES OIL AND OIL PRODUCTS PIPELINE TRANSPORTATION 10, no. 1 (February 29, 2020): 42–51. http://dx.doi.org/10.28999/2541-9595-2020-10-1-42-51.
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The article presents the study results of the flowline pipeline to determine the causes of the through hole (weld hole) in the butting side weld of pipelines. It was made assessment by the Bauman method of sulfur imprints for the presence of deposits of iron sulfides on the inner surface of the pipes. The phase composition of corrosion products was determined by X-ray diffraction analysis. It was revealed that the chemical composition and mechanical properties of the metal of the studied fragment of the pipeline comply with regulatory requirements. The hardness values, including those in the weld zones, obtained from the test results, indicate that the metal is resistant to corrosion cracking. According to the results of metallographic studies on longitudinal full-thickness thin sections, it was established that in the through hole area at the bottom of the corrosion spot, there are remains of the facing seam layer, where there are multiple pores with a diameter of up to 3 mm. The surface of the spot is covered with a layer of iron sulfide with a thickness of 1–3 mm. The thickness of the sulfide layer in the spot is ten or more times greater than on the rest of the pipe surface – this shows that the corrosion processes developed here faster. The cause of the damage to the welded connection of drill line is pit corrosion, which occurred under the influence of H2S on the lower part of welded lock, where was observed concavity of the joint root. Probably, in the area of the corrosion pit, there was a defect in the first layer of the weld (suck-up, faulty penetration, pore or others, etc.), and accelerated corrosion was the result of the accumulation of H2S fluid here.
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Sukini, Tuti, Arfiana, Bekti Yuniyanti, Munayarokh, and Nuril Nikmawati. "Red Betel Leaf (Piper crocatum) Tea Efication in Overcoming Leucorhea." International Journal of Psychosocial Rehabilitation 24, no. 02 (February 12, 2020): 1395–402. http://dx.doi.org/10.37200/ijpr/v24i2/pr200439.
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Balakrishnan, Arun Seeralan, Farrukh Nagi, Khairul Salleh, and Prem A/L Gunnasegaran. "Harvesting Waste Heat Energy from Automobile Engine Exhaust Using Teg with Heat Pipes." International Journal of Engineering & Technology 7, no. 4.35 (November 30, 2018): 85. http://dx.doi.org/10.14419/ijet.v7i4.35.22332.
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This research investigates how the heat from car exhaust pipe line can be recovered as power using passive Thermo electric generator (TEG) using heat pipes. In this research the heat pipes are place on the cold side of TEG to remove the rising temperature and hot side of TEG is placed on the circumference of exhaust pipe line of car engine. The heat pipes with and without nano-fluids were placed on cold side of TEGs to investigate heat removal from increasing temperature and too maintain constant temperature on cold side. On the basis of results from 3D finite element simulations and experiments in the setup, the heat flow, voltage, and current were measured. The method presented in this paper gives detailed insight into how TEG modules perform in general, and also enables prediction of potential improvement in module performance by using different nano-fluids as coolants and Preliminary results were obtained. The results of Finite Element Analysis are analogous with the experimental results of TEG with water filled heat pipes with minimal possible errors. Therefore, the performance of nano-fluids in heat pipes are numerically evaluated and proposal are made for the enhancement of Module power outputs in Harnessing exhaust heat energy.
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Cai, Cheng-Cheng, Ma-Cheng Yan, Hui Xie, and Sheng-Li Pan. "Simultaneous Determination of Ten Active Components in 12 Chinese Piper Species by HPLC." American Journal of Chinese Medicine 39, no. 05 (January 2011): 1043–60. http://dx.doi.org/10.1142/s0192415x11009391.
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Piper is a genus that is recently valued for the treatment of central nervous system diseases. The major constituents, amides and lignans, are responsible for the antinociceptive and antidepressant activities. This study developed a RP-HPLC-UV method for the simultaneous determination of eight amides and two lignans in twelve different species of Piper. HPLC separation was accomplished on a C18 analytical column (5 μm, 250 mm × 4.6 mm, i.d.) with a gradient mobile phase consisting of acetonitrile and water at a flow rate of 1.0 ml/min. All the calibration curves showed good linear correlation coefficients (r > 0.9997) over the test ranges. The relative standard deviation of the current method was less than 2.90% for intra- and inter-day assays and the average recoveries were between 98.25% and 103.08%. The HPLC method established is appropriate for quality control purposes and allows for the differentiation of Piper species.
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Takahashi, Koji, Kotoji Ando, Akihiko Kato, Yusuke Kimura, Masakazu Hisatsune, and Kunio Hasegawa. "OS12W0350 Fracture strength of tee pipe with local wall thinning." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS12W0350. http://dx.doi.org/10.1299/jsmeatem.2003.2._os12w0350.
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Greenslade, Thomas B. "Whistling Tea Kettles, Train Whistles, and Organ Pipes." Physics Teacher 54, no. 9 (December 2016): 518–19. http://dx.doi.org/10.1119/1.4967886.
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Cain, M. D. "Ten-Year Results From Precommercial Strip-Thinning: Paradigm Lost or Reinforced?" Southern Journal of Applied Forestry 17, no. 1 (February 1, 1993): 16–21. http://dx.doi.org/10.1093/sjaf/17.1.16.
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Abstract Pine growth was monitored for 10 yr after mechanically strip-thinning a dense, naturally regenerated, even-aged stand of 6-yr-old loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) in southern Arkansas. From age 12 to 16 yr, annual growth in height and dbh for 200 croptrees/ac was significantly better on precommercially thinned plots compared to unthinned plots. Commercial thinning was done during the 17th growing season, with volumes removed from unthinned plots averaging 8 cords/ac more than volumes removed from precommercially thinned plots. Pine volumeproduction on precommercially thinned plots may have been reduced by crown scorch from two of three prescribed winter burns and by the disproportionate number of shortleaf pines on those plots as compared to unthinned plots. South. J. Appl. For. 17(1):16-21
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Chang, Cheng, Zhenyu Han, Xinyu Li, Shouzheng Sun, Jihao Qin, and Hongya Fu. "A Non-Geodesic Trajectory Design Method and Its Post-Processing for Robotic Filament Winding of Composite Tee Pipes." Materials 14, no. 4 (February 10, 2021): 847. http://dx.doi.org/10.3390/ma14040847.
Full textAbstract:
With the advantages of high specific strength and well corrosion resistance, polymer-matrix composite tee pipes are widely used in aerospace and civilian fields. The robotic filament winding technology is suitable for forming complex shape parts. This paper aims to provide a novel non-geodesic trajectory design method to get a continuous trajectory for tee pipe winding. Furthermore, post-processing methods are proposed for realizing the full coverage of tee pipes by robotic filament winding. The CAD/CAM software is then designed to simulate the winding process and realize the cover of the whole tee pipe. Finally, experiments of winding a tee pipe with a desktop winding machine and a six-axis winding robot are carried out. The results show that the tee pipe is fully covered, verifying the accuracy of the design method and post-processing methods.