Journal articles on the topic 'Piping'
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1
Zheng, San Long, Zeng Liang Gao, Nian Jin Chen, Li Jian Zhuang, Yu Feng Ye, and Xue Feng Yu. "Safety Evaluation of Pressure Piping with Weld Flaw after Long Time Service in a Water Power Plant." Key Engineering Materials 353-358 (September 2007): 2601–5. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.2601.
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Pressure steel pipings in a water power plant have been in service for over fifty years. In order to assess the safety of the piping, whole check and tests for the piping were carried out. The material for some piping is ST3 from former USSR, the other is A3 made in China. The mechanical properties were investigated by tests and were compared with the original material properties. The result shows the yield strength and tensile strength of serviced steels are less than those of original materials. The surfaces of the piping were checked to investigate the corrosion, surface defects. The flaws in the welds and near the welds of the pipings were detected by UT and MT, and several weld flaws were found. Based on the test and NDT investigation results, the strength, fracture and fatigue life of the pipings are assessed according to Chinese standard GB/T19624-2004 and British standard BS7910-2000. The assessment results show that the strength of the piping is enough, and the pipings with these flaws does not fracture. The piping can be safe in service under the normal operating condition for 104 to 106 cycles.
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Choi, Sun Yeong, and Young Hwan Choi. "Evaluation of Nuclear Piping Failure Frequency in Korean Pressurized Water Reactors." Key Engineering Materials 297-300 (November 2005): 1645–51. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.1645.
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The purpose of this paper is to evaluate the piping failure frequency based on the piping failure events in Korean pressurized water reactors (PWRs) until the end of 2003. Two types of the piping failure frequencies including the piping damage frequency and the piping rupture frequency are considered in this study. The piping damage frequency for the failed piping system was estimated by using the piping population data such as the weld count or the base metal count. The piping rupture frequency related to the initiating event in a probabilistic safety assessment (PSA) was evaluated by using both the Bayesian approach (Method 1) and the conditional rupture probability approach (Method 2). In the Bayesian approach, two methods using Jeffreys noninformative prior (Method 1-1) and prior distributions based on the results in NUREG/CR-5750 (Method 1-2) were considered. Thirty piping failure events in ASME safety class pipings of Korean PWRs were identified and analyzed in this study. The results showed that the piping damage frequency for the events ranged from 5.42E-3/cr.yr to 2.77E-5/cr.yr. Three kinds of initiating events including the very small LOCA, the feedwater line break, and the flood are evaluated for Korean PWRs. The results for the piping rupture frequency in Korean PWRs were as follows: 1) The mean piping rupture frequency of the very small LOCA event ranged from 3.6E-3/cr.yr to 1.2E-2/cr.yr, the feedwater line break event from 3.6E-3/cr.yr to 2.5E-2/cr.yr, and the flood event from 7.8E-4/cr.yr to 3.6E-3/cr.yr. The mean piping rupture frequencies of the very small LOCA and feedwater line break events were higher than that of the flood event by one order of a magnitude. 2) Method 2 gave conservative results in the very small LOCA and feedwater line break events compared to Method 1-1 or Method 1-2, while Method 1-1 gave conservative results in the flood event. 3) The order of magnitudes in the mean piping rupture frequencies of the very small LOCA, the feedwater line break, and the flood in Korean PWRs were similar to those in the U.S. PWRs.
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Hasanah HM, Fitri Hardiyanti, and Lutfiyah Hidayati. "Penerapan Hiasan Bias Piping pada Busana Pesta Malam dengan Tema Lawang Sewu." BAJU: Journal of Fashion & Textile Design Unesa 1, no. 2 (December 24, 2020): 91–98. http://dx.doi.org/10.26740/baju.v1n2.p91-98.
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Lawang sewu merupakan sebuah bangunan tua yang menyimpan sisi keindahan, sehingga menginspirasi untuk menjadikannya sumber ide rancangan busana pesta malam. Tujuan penelitian ini adalah: 1) mendeskripsikan proses penerapan hiasan bias piping pada busana pesta malam bertema lawang sewu. 2) mendeskripsikan hasil busana pesta malam bertema lawang sewu dengan penerapan hiasan bias piping. Metode penelitian ini menggunakan penciptaan karya, yang terdiri atas empat tahap, yaitu pra-perancangan, perancangan, perwujudan, dan penyajian. Hasil penelitian menyatakan bahwa: 1) proses penerapan hiasan bias piping pada busana pesta malam bertema lawang sewu meliputi pada a) bagian bawah atau rok, terdapat hiasan bias piping berupa garis yang membentuk menyerupai lawang sewu. b) bagian atas atau bustier, terdapat hiasan bias piping berupa garis garis siku atau sudut dari bagian lawang sewu. 2) hasil busana pesta malam bertema lawang sewu dengan penerapan hiasan bias piping jika dijelaskan secara keseluruhan terlihat menonjol pada bagian bawah atau rok. Sedangkan pada bagian atas atau bustier digunakan sebagai pelengkap dengan pengaplikasian hiasan bias piping berupa garis garis siku atau sudut dari bagian lawang sewu.
Lawang sewu is a historic old building that holds a side of beauty, thus inspiring it to be a source of ideas for evening party fashion designs. The purpose of this study are: 1) describe the process of applying bias piping decorations on the lawang sewu evening party outfits. 2) describe the results of the lawang sewu night party dressings with the application of bias piping decorations. This research is a work creation study, which consists of four stages, namely pre-design, design, embodiment, and presentation. The results of the study stated that: 1) the process of applying the bias pipng decoration on the lawang sewu evening party dress includes on a) the bottom or skirt, there is a bias piping decoration in the form of a line forming like a lawang sewu gutter. b) the top or bustier, there is a refractive decoration bias piping in the form of elbow lines or angles of the gutter sewu. 2) the results of the lawang sewu evening party clothing with the application of bias piping decoration if explained as a whole stand out on the bottom or skirt. While at the top or bustier is used as a complement to the application of bias decoration bias piping in the form of elbow lines or angles of the gutter sewer. evening party fashion design has a design that consists of many pieces and there are variations in the shape of a rectangular, so it requires the application of bias piping decoration. The purpose of writing this article is to discuss the process of applying bias piping decorations, along with the finished clothing.
4
Chiba, T., and H. Kobayashi. "Response Characteristics of Piping System Supported by Visco-Elastic and Elasto-Plastic Dampers." Journal of Pressure Vessel Technology 112, no. 1 (February 1, 1990): 34–38. http://dx.doi.org/10.1115/1.2928583.
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Improving the reliability of the piping systems can be achieved by eliminating the mechanical snubber and by reducing the response of the piping. In the seismic design of piping system, damping is one of the important parameters to reduce the seismic response. It is reported that the energy dissipation at piping supports contributes to increasing the damping ratio of piping system. Visco-elastic damper (VED) and elasto-plastic damper (EPD) were developed as more reliable, high-damping piping supports. The dynamic characteristics of these dampers were studied by the component test and the full-scale piping model test. Damping effect of VED is independent of the piping response and VED can be modeled as a complex spring in the dynamic analysis. On the other hand, damping ratio of piping system supported by EPD increases with the piping response level. So, these dampers are helpful to increase the damping ratio and to reduce the dynamic response of piping system.
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Kotek, Hadas, and Michael Yoshitaka Erlewine. "Covert Pied-Piping in English Multiple Wh-Questions." Linguistic Inquiry 47, no. 4 (October 2016): 669–93. http://dx.doi.org/10.1162/ling_a_00226.
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In this article, we argue for the existence of covert pied-piping in wh-questions through a previously unnoticed pattern of intervention effects in Superiority-obeying English multiple wh-questions. We show that the preference of covert pied-piping, unlike that of overt pied-piping, is for movement of larger constituents. We argue that this discrepancy stems from conflicting requirements of PF and LF: overt pied-piping feeds both LF and PF, but covert pied-piping feeds LF only. The study of covert pied-piping thus reveals the true preference of LF and narrow syntax with regard to pied-piping: larger pied-piping constituents are preferred over smaller ones. This preference can be overridden by certain PF constraints that apply to overt pied-piping.
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Lewis, G. D., and Y. J. Chao. "Flexibility of Trunnion Piping Elbows." Journal of Pressure Vessel Technology 112, no. 2 (May 1, 1990): 184–87. http://dx.doi.org/10.1115/1.2928607.
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Trunnion piping elbows are commonly used in piping systems in power and chemical plants. The flexibility of the trunnion piping elbows is normally less than that of the plain piping elbows. In this paper, the finite element method is used to derive the in-plane and out-of-plane flexibility factors of trunnion piping elbows. The results can be easily adopted into the piping flexibility analysis.
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Chiba, T., and R. Koyanagi. "Dynamic Response Studies of Piping-Support Systems." Journal of Pressure Vessel Technology 112, no. 1 (February 1, 1990): 39–45. http://dx.doi.org/10.1115/1.2928584.
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Considering the effect of the interaction between piping and support systems in the piping design is a more integrated approach to improve the reliability of piping systems. So, it is important to clarify the dynamic characteristics of the piping and the restraint structure during the seismic events. It may be desirable to investigate the effect of the gap on the response and the local stress of the piping systems. The dynamic characteristics of a simplified piping model with gaps was investigated by the tests and the analysis. Three-dimensional piping model test was performed to estimate the effect of the gap on the response of the piping system. It can be found that the local stress and the stiffness of the piping and the restraint structure under the seismic loadings should be considered in the seismic design. The gap size was not so effective on the response of the 3-dimensional piping system in the high-level response.
8
Milner, Christopher W., and Jack W. Davidson. "Quick piping." ACM SIGPLAN Notices 37, no. 7 (July 17, 2002): 175–84. http://dx.doi.org/10.1145/566225.513859.
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Williams, Nigel. "Piping hot." Current Biology 16, no. 18 (September 2006): R779—R780. http://dx.doi.org/10.1016/j.cub.2006.08.061.
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ABDUL AZIZ, HANIDA, Lee Jia Chien, Hairunnisa Osman, Tan Lian See, and Norhuda Abdul Manaf. "In-service Piping Inspection Work-aid Tool for Oil & Gas Industries." Current Science and Technology 1, no. 1 (May 12, 2021): 32–43. http://dx.doi.org/10.15282/cst.v1i1.6441.
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Piping systems are important in the oil and gas plant’s operation, but continuous damage is harming the piping system due to extensive usage resulting in the increase of accident cases. API 570 Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems has proposed an in-service piping inspection practice to ensure the in-service piping is functionable by identifying the remaining life of the piping system. However, the in-service piping inspection process is numerous and complicated where certain steps may be skipped, and data collected may lost along the process. The in-service piping inspection framework followed by a work-aid tool is developed in this study based on API 570 to guide the user the piping inspection process along with providing a depository database for document storage. Validation test is conducted by collecting feedback from professional piping engineer using System Usability Scale followed by conducting a case study using secondary data and sample attachment to test the functionality of the work-aid tool. The work-aid tool can guide the piping inspection process and provide a systematic documentation method for corresponding inspection documents. Case study in the industry is recommended to test the usability of the tool in the industry.
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Qu, Bo. "Design of Piping Functionality for Multi-Process Micro-Kernel Embedded OS on ARM." Applied Mechanics and Materials 427-429 (September 2013): 937–40. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.937.
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This paper describes the design and implementation of piping functionality for multi-process micro-kernel embedded operating system on ARM, including overview of message passing and piping, pipe creation, pipe accessing via message passing, and pipe termination. The ways to implement piping for micro-kernel or mono-kernel are markedly different and this paper focuses on the piping implementation for multi-process micro-kernel. At the final, the paper provides a demo example to show the effect of piping. Based on the piping functionality described in this paper, more powerful shell interpreter with piping function can be designed.
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Menier, K., G. Brown, and J. E. Cooper. "Megninia ginglymura feather mites from a captive piping-guan (Pipile pipile)." Veterinary Record 160, no. 26 (June 30, 2007): 909–10. http://dx.doi.org/10.1136/vr.160.26.909.
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Short II, W. E. "Coverage of Non-Metals in the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 206, no. 1 (February 1992): 67–72. http://dx.doi.org/10.1243/pime_proc_1992_206_199_02.
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The chemical and petrochemical industries have decades of experience in specifying metallic piping lined with non-metals as a cost effective alternative to high-priced alloy materials of construction for piping in corrosive service. Early on, application of plastic piping was essentially limited to atmospheric chemical sewage service and to above-ground vents and drains. However, applications and usage of plastic piping continue to increase as engineers become more confident in specifying plastic materials and mechanical contractors gain experience with their installation. Non-metallic materials are being developed that are not only corrosion resistant but also have increasingly higher pressure and temperature capabilities. Plastic double-containment piping has experienced tremendous growth for handling hazards and toxic fluids. In the United States, recent dramatic growth of plastic double-containment piping applications has been, to a large extent, for compliance with the Environmental Protection Agency (EPA) regulations of the 1976 Resource Conservation and Recovery Act (RCRA). Related EPA regulatory efforts were accelerated in 1988 by more stringent amendments to this legislation. Industry in the United States must comply with these EPA regulations by December 1998. Plastic piping and metallic piping lined with non-metals have been covered to some extent by the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code for several years. The distinctive requirements of non-metallic piping and piping lined with non-metals were incorporated into the 1980 edition as a separate Chapter VII, which is dedicated to this growing area of interest in piping. This paper provides an overview of the present coverage of non-metallic piping lined with non-metals in the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code (1). Some topics that warrant further investigation are presented as well.
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Li, Renzhi, Zhonggen Wang, Hongquan Sun, Shugui Zhou, Yong Liu, and Jinping Liu. "Automatic Identification of Earth Rock Embankment Piping Hazards in Small and Medium Rivers Based on UAV Thermal Infrared and Visible Images." Remote Sensing 15, no. 18 (September 12, 2023): 4492. http://dx.doi.org/10.3390/rs15184492.
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Piping is a major factor contributing to river embankment breaches, particularly during flood season in small and medium rivers. To reduce the costs of earth rock embankment inspections, avoid the need for human inspectors and enable the quick and widespread detection of piping hazards, a UAV image-acquisition function was introduced in this study. Through the collection and analysis of thermal infrared and visible (TIR & V) images from several piping field simulation experiments, temperature increases, and diffusion centered on the piping point were discovered, so an automatic algorithm for piping identification was developed to capture this phenomenon. To verify the identification capabilities, the automatic identification algorithm was applied to detect potential piping hazards during the 2022 flooding of the Dingjialiu River, Liaoning, China. The algorithm successfully identified all five piping hazard locations, demonstrating its potential for detecting embankment piping.
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Schott, G. A., G. M. Hulbert, and C. F. Heberling. "Results From Dynamic Tests and Analyses of a Medium Diameter LMFBR Piping System." Journal of Pressure Vessel Technology 108, no. 3 (August 1, 1986): 330–33. http://dx.doi.org/10.1115/1.3264793.
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This paper presents results and observations from dynamic tests and analyses performed on an 8-in. (0.20-m) diameter, thin-walled piping system. The piping system is a scaled representation of a Liquid Metal Fast Breeder Reactor (LMFBR) large diameter piping loop. Prototypic piping restraints were employed, including mechanical snubbers, rigid struts, pipe hangers and nonintegral pipe clamps. Snap-back, sine-sweep and seismic tests were performed for various restraint configurations and piping conditions. The test results are compared to analytical predictions for verification of the methods and models used in the seismic design of LMFBR piping systems. Test program conclusions and general recommendations for piping seismic analyses are presented along with a discussion of test and analysis results.
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Ghazali, M. Haryzul, Lim Meng Hee, and M. Salman Leong. "Piping Vibration due to Pressure Pulsations: Review." Advanced Materials Research 845 (December 2013): 350–54. http://dx.doi.org/10.4028/www.scientific.net/amr.845.350.
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Excessive piping vibrations are a major cause of machinery downtime, leaks, fatigue failure, high noise, fires and explosions in refineries and petrochemical plants. In piping system, vibration excitation sources may come from mechanical sources, hydraulics sources or can be the combination of both. Low level vibration amplitude can be amplified when acoustic natural frequency of piping system coincide with the mechanical natural frequency of the piping system of which could lead to piping failure. To address these issues, several condition monitoring techniques to assess and detect excessive piping vibration is discussed in this paper.
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Nakamura, Izumi, Akihito Otani, and Masaki Shiratori. "Failure Behavior of Piping Systems With Wall Thinning Under Seismic Loading." Journal of Pressure Vessel Technology 126, no. 1 (February 1, 2004): 85–90. http://dx.doi.org/10.1115/1.1638787.
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Shaking table tests of three-dimensional piping models with degradation were conducted in order to investigate the influence of degradation on dynamic behavior and failure modes of piping systems. The degradation condition induced in the piping models was about 50 percent full circumferential wall thinning at elbows. Four types of models were made for the shaking table tests by varying the location of wall thinning in the piping models. These models were excited under the same input acceleration until the models failed and a leak of pressurized internal water occurred. Through these tests, the change of the vibration characteristics and processes to failure of degraded piping models were obtained. The deformation of the piping models tended to concentrate on the degraded elbows, and the damage was concentrated on the weakest elbow in the piping models. The failure mode of the piping models was a low-cycle fatigue failure at the weakest elbow.
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Hatfield, F. J., and D. C. Wiggert. "Seismic Pressure Surges in Liquid-Filled Pipelines." Journal of Pressure Vessel Technology 112, no. 3 (August 1, 1990): 279–83. http://dx.doi.org/10.1115/1.2928626.
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Observed damage and analytic studies indicate that earthquakes may cause destructive pressure surges in liquid-filled piping. Most studies have concerned buried piping that could be assumed to move with the ground. However, pressure surges also would be expected in above-ground piping, where they would affect the displacement response and, hence, the amplitude of flexural stress in the piping. Current aseismic design practice is to simplify this effect by treating the contained liquid as incompressible mass. This paper describes a technique for computing pressure and relative displacement that incorporates elasticity of both the piping and the liquid. Seismic responses of an example pipeline are predicted. It was found that assuming the piping to be rigid produced an upper-bound estimate of pressure, but assuming the liquid to be incompressible resulted in underestimating displacement of the piping.
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Liu, Rulin, Hui Shi, Qiyong Zhou, Weitong Ma, Tengfei Wang, and Song Lu. "Simulation of Fire Extinguishing Agent Transport and Dispersion in Aircraft Engine Nacelle." Fire 5, no. 4 (July 11, 2022): 97. http://dx.doi.org/10.3390/fire5040097.
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The flow and dispersion characteristics of the fire extinguishing agent in the pipings and the concentration distribution in the nacelle are essential for optimizing the aircraft fire extinguishing system. In the present work, we developed a three-dimensional CFD model to simulate the transport and dispersion of the agent in piping and nacelle. The results show that the length and structure of the pipings near the nozzles affect the concentration, pressure, flow rate, and flow distribution of the extinguishing agent. The smaller the bend of the pipings near the nozzles and the angle of connection with the main piping, the less time it takes for the agent to reach the nozzles and the more mass flow rate of the agent is injected, which is more conducive to extinguishing fire rapidly. External ventilation and the blockage of the nacelle’s ribs and other components impact the concentration distribution of the fire extinguishing agent in the nacelle. The agent is mainly concentrated in the middle and rear areas of the engine nacelle. Agent concentration tests were carried out in the simulated engine nacelle. The experimental result is similar to the simulation result, which verifies the feasibility of the simulation method. The simulation method can be used to increase the concentration of fire extinguishing agent to meet the safety requirements by changing the outside ventilation and increasing the filling amount of fire extinguishing agent, so as to achieve the optimization of the fire extinguishing system.
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Choi, Ho-Sung, Jung-Hwan Moon, and Jae-Ou Lee. "Fluid Behavior Modeling Optimal Design Using Network Piping Analysis Method." Fire Science and Engineering 35, no. 1 (February 28, 2021): 93–99. http://dx.doi.org/10.7731/kifse.6af732a2.
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The piping design should be considered by way of the network system in order to supply water for reliable fire extinguishing. However, the pipe scheduling method in line by the National Fire Safety Code is typically applied. When the modeling analysis method of fluid behavior is utilized based on the piping network theory, the fire-extinguishing water can be supplied more stably in a large-scale plant. Because a piping network consists of a large number of node points as well as consumes a lot of time and effort, it is recommended to use the commercial analysis program according to international standards. In this study, we used a piping network analysis program, sisHYD, which can model the actual piping according to the coordinates and analyze the fluid behavior inside the piping. As a result of the piping network analysis, it was possible to reduce the diameter of piping while ensuring the supply stability of firefighting water compared to the pipe scheduling method. Consequently, the value engineering effect of a construction project can be enhanced by reducing the wasted budget and inefficient factors.
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Foster, Mark, Robin Fell, and Matt Spannagle. "A method for assessing the relative likelihood of failure of embankment dams by piping." Canadian Geotechnical Journal 37, no. 5 (October 1, 2000): 1025–61. http://dx.doi.org/10.1139/t00-029.
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A method for estimating the relative likelihood of failure of embankment dams by piping, the University of New South Wales (UNSW) method, is based on an analysis of historic failures and accidents in embankment dams. The likelihood of failure of a dam by piping is estimated by adjusting the historical frequency of piping failure by weighting factors which take into account the dam zoning, filters, age of the dam, core soil types, compaction, foundation geology, dam performance, and monitoring and surveillance. The method is intended only for preliminary assessments, as a ranking method for portfolio risk assessments, to identify dams to prioritise for more detailed studies, and as a check on event-tree methods. Information about the time interval in which piping failure developed and the warning signs which were observed suggest that the piping process often develops rapidly, giving little time for remedial action. In the piping accidents, the piping process reached some limiting condition allowing sufficient time to draw down the reservoir or carry out remedial works to prevent breaching.Key words: dams, failures, risk, probability, piping.
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Amy, Daniel G. "Re-constraining massive pied-piping: An argument for non-interrogative CPs." Proceedings of the Linguistic Society of America 5, no. 1 (March 23, 2020): 573. http://dx.doi.org/10.3765/plsa.v5i1.4734.
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Unlike traditional wh-movement and obligatory pied-piping, massive pied-piping is restricted in the types of clauses in which it may occur. Heck (2004, 2008) argues that massive pied-piping constructions are restricted to non-subordinate clauses in English. This paper (i) investigates the availability of massive pied-piping of DPs in complements of know and surprise-type predicates; (ii) proposes a revised generalization on massive pied-piping that restricts the construction to non-interrogative clauses; and (iii) proposes a hybrid analysis that combines Cable's (2010) Q-movement analysis with Den Dikken's (2003) two-stage wh-movement operation, thus accounting for the wider set of environments covered by the revised generalization on massive pied-piping in English.
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Gao, Jun, Jiaote Dang, Xiaoke Han, Jianyin Fang, Jie Ren, and Wei Tian. "A Study on the Generation Mechanism and Development Process of Piping Based on the Theory of Muddy Water Seepage." Geofluids 2022 (July 30, 2022): 1–9. http://dx.doi.org/10.1155/2022/6987524.
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In the process of piping development, the sediment carried by seepage causes the change of porosity and then causes the change of permeability coefficient. Therefore, piping belongs to muddy water seepage (i.e., unstable seepage). Based on the theory of muddy water seepage, the new control equation of piping model is established. The generation mechanism and development process of piping for white fine sand and sand gravel are explored. The advantages for the new control equation of piping model are discussed. The results show that the new control equation of piping model is not only simpler in form but also easier to solve and can better describe the characteristics of piping generation, development, and stability. Compared with white fine sand (the initial relative density and porosity are smaller, and the initial permeability coefficient and critical gradient are larger), the porosity, permeability coefficient, seepage flow, and sediment volume of sandy gravel increase faster with time. When the porosity is the same, the permeability coefficient, seepage flow, and sediment volume of sand gravel are larger. The smaller the area affected by piping, the faster the increase of porosity, permeability coefficient, seepage flow, and sediment volume. When the porosity and permeability coefficient are the same, the seepage flow and sediment volume are smaller. The smaller the initial porosity and permeability coefficient, the later the generation, and development of piping. It can provide a reference for piping danger forecast and emergency response.
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Kusumastuti, Dyah Pratiwi, and Husna Alghoida. "Angka Keamanan Piping di Bawah Tubuh Bendungan dengan Metode Harza." FORUM MEKANIKA 10, no. 1 (May 3, 2021): 1–8. http://dx.doi.org/10.33322/forummekanika.v10i1.1266.
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Abstract
Dams have many benefits such as irrigation, flood prevention, power generation and even tourism, especially in areas where the dam is located. So that the benefits received can last a long time, in the planning, it must be analyzed for stability, seepage discharge that occurs and the safety of the piping. The piping hazard safety figures in this study were calculated using the Harza method for maximum water level conditions, normal water levels, fast receding and empty dams at sta 0 + 150, sta 0 + 200, sta 0 + 250 and sta 0 + 300. Based on the calculation results, it is found that the safety of piping hazards without filters with the grouting method do not meet the requirements safety factor, especially in conditions of maximum water level, normal water level and fast receding. In order for the safety of piping hazard in order to meet the requirements, a filter is applied under the dams. The filter is applied so that the piping hazard safety figure meets the requirements of all water level conditions and all station is 80 cm deep.
Keywords: safety factor, piping, Harza method, filter
ABSTRAK
Bendungan memiliki banyak manfaat seperti irigasi, pencegah banjir, pembangkit listrik bahkan pariwisata khususnya pada wilayah dimana bendungan tersebut berada. Agar manfaat yang diterima dapat berlangsung lama maka dalam perencanaannya wajib dianalisis terhadap stabilitas, debit rembesan yang terjadi maupun keamanan dari piping. Angka keamanan bahaya piping pada penelitian ini dihitung dengan menggunakan metode Harza untuk kondisi muka air maksimum, muka air normal, surut cepat dan bendungan kosong di sta 0+150, sta 0+200, sta 0+250 serta sta 0+300. Berdasarkan hasil perhitungan didapatkan bahwa angka keamanan bahaya piping tanpa penggunaan filter dengan metode grouting tidak memenuhi persyaratan angka keamanan khususnya pada kondisi muka air maksimum, muka air normal dan surut cepat. Agar angka keamanan bahaya piping memenuhi persyaratan maka diaplikasikan filter dibawah tubuh bendungan. Filter yang diaplikasikan agar angka keamanan bahaya piping memenuhi persyaratan diseluruh kondisi muka air dan seluruh sta adalah dengan kedalaman 80 cm.
Kata kunci: angka keamanan, piping, metode Harza, filter
Abstract
Dams have many benefits such as irrigation, flood prevention, power generation and even tourism, especially in areas where the dam is located. So that the benefits received can last a long time, in the planning, it must be analyzed for stability, seepage discharge that occurs and the safety of the piping. The piping hazard safety figures in this study were calculated using the Harza method for maximum water level conditions, normal water levels, fast receding and empty dams at sta 0 + 150, sta 0 + 200, sta 0 + 250 and sta 0 + 300. Based on the calculation results, it is found that the safety of piping hazards without filters with the grouting method do not meet the requirements safety factor, especially in conditions of maximum water level, normal water level and fast receding. In order for the safety of piping hazard in order to meet the requirements, a filter is applied under the dams. The filter is applied so that the piping hazard safety figure meets the requirements of all water level conditions and all station is 80 cm deep.
Keywords: safety factor, piping, Harza method, filter
ABSTRAK
Bendungan memiliki banyak manfaat seperti irigasi, pencegah banjir, pembangkit listrik bahkan pariwisata khususnya pada wilayah dimana bendungan tersebut berada. Agar manfaat yang diterima dapat berlangsung lama maka dalam perencanaannya wajib dianalisis terhadap stabilitas, debit rembesan yang terjadi maupun keamanan dari piping. Angka keamanan bahaya piping pada penelitian ini dihitung dengan menggunakan metode Harza untuk kondisi muka air maksimum, muka air normal, surut cepat dan bendungan kosong di sta 0+150, sta 0+200, sta 0+250 serta sta 0+300. Berdasarkan hasil perhitungan didapatkan bahwa angka keamanan bahaya piping tanpa penggunaan filter dengan metode grouting tidak memenuhi persyaratan angka keamanan khususnya pada kondisi muka air maksimum, muka air normal dan surut cepat. Agar angka keamanan bahaya piping memenuhi persyaratan maka diaplikasikan filter dibawah tubuh bendungan. Filter yang diaplikasikan agar angka keamanan bahaya piping memenuhi persyaratan diseluruh kondisi muka air dan seluruh sta adalah dengan kedalaman 80 cm.
Kata kunci: angka keamanan, piping, metode Harza, filter
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Qu, Bo. "Design of Piping Functionality for ARM Based Multi-Process Mono-Kernel Embedded OS." Applied Mechanics and Materials 373-375 (August 2013): 1634–37. http://dx.doi.org/10.4028/www.scientific.net/amm.373-375.1634.
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This paper describes the design and implementation of piping functionality for ARM based multi-process mono-kernel embedded operating system, including overview of inter-process communication, key techniques of designing piping routines such as getting i-node for piping, creating pipe, reading and writing pipe, and terminating pipe, etc. At the final, the paper provides a demo example to show the effect. Based on the piping routines described in this paper, more powerful shell interpreter with redirecting and piping functionalities as well as other shell commands analogous to that of embedded Linux can be implemented.
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Parulekar, Y. M., G. R. Reddy, K. K. Vaze, and K. Muthumani. "Passive Control of Seismic Response of Piping Systems." Journal of Pressure Vessel Technology 128, no. 3 (August 30, 2005): 364–69. http://dx.doi.org/10.1115/1.2217969.
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Passive energy dissipating devices, such as elastoplastic dampers (EPDs) can be used for eliminating snubbers and reducing the response of piping systems subjected to seismic loads. Cantilever and three-dimensional piping systems were tested with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping systems supported on elastoplastic damper. An iterative response spectrum method is used for evaluating response of the piping system using this equivalent damping. The analytical maximum response displacement obtained at the elastoplastic damper support for the two piping systems is compared with experimental values and time history analysis values. It has been concluded that the iterative response spectrum technique using Caughey equivalent damping is simple and results in reasonably acceptable response of the piping systems supported on EPD.
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Chiba, T., R. Koyanagi, N. Ogawa, and C. Minowa. "A Test and Analysis of the Multiple Support Piping Systems." Journal of Pressure Vessel Technology 111, no. 3 (August 1, 1989): 291–99. http://dx.doi.org/10.1115/1.3265677.
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One of the current topics in the seismic design of piping systems is the overall reliability of them in earthquake events. Actual piping systems are generally supported by independent structures such as vessels and steel structures. So, it is very important to clarify the behavior of actual piping systems during the seismic events. For this purpose, the analytical method of multiple excitation problems is a preferable approach to not only evaluate the actual behavior of the piping systems, but also improve the reliability of piping systems. To clarify the dynamic characteristics of the piping systems and to assess the computational methods in the linear system subjected to multiple support excitations, an experimental study using a realistic large-scale piping model has been conducted. The equations for the multiple excitation problem have been validated and the adequacy of the multiple response spectra method has been confirmed by the comparison of the test results with the analytical one. This paper reports the results focusing on the analytical methods of the multiple support piping system. It is noted that the multiple response spectrum method is efficient for the multiple excitation problems.
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Wang, T. "Dynamic Forcing Function for Flow-Acoustic-Induced Vibration." Journal of Pressure Vessel Technology 111, no. 4 (November 1, 1989): 361–70. http://dx.doi.org/10.1115/1.3265692.
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Vibration problems in piping systems can manifest themselves in two forms: excessive noise generated from wall flexural vibrations, that in combination with jet noise itself may exceed OSHA limits, and piping system vibration, which could lead to fatigue failure at stress risers. Thus, a comprehensive dynamic forcing function for flow-acoustic-induced vibration on piping system needs to consider both the flexural and system excitation sources. Jet column instabilities and acoustic standing waves are utilized to identify the vibration sources in a large-capacity steam piping system. Initial noise generation originates from approximately six jet diameters downstream of a control valve. It consists of two sharply defined high-frequency sources, the shock cells and the large-scale axisymmetric coherent turbulent structure generated from the nonlinear shear layer instability. These sources effectively excite wall flexural vibrations because of their nonzero net dynamic forcing on pipe “shells.” The compact shock and instability wave noise sources further excite the low-frequency acoustic standing wave in the acoustic duct formed by the discharge piping. The low-frequency acoustic standing wave excites the piping system vibration axially. The piping system was also excited transversely by a more potent vibration source incurred by the spiral mode provoked by a piping elbow. Field observation and measurement of the vibration problem of a large-diameter piping system confirm the prediction.
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Chang, Seongkyu, Weipeng Sun, Sung Gook Cho, and Dookie Kim. "Vibration Control of Nuclear Power Plant Piping System Using Stockbridge Damper under Earthquakes." Science and Technology of Nuclear Installations 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/5014093.
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Generally the piping system of a nuclear power plant (NPP) has to be designed for normal loads such as dead weight, internal pressure, temperature, and accidental loads such as earthquake. In the proposed paper, effect of Stockbridge damper to mitigate the response of piping system of NPP subjected to earthquake is studied. Finite element analysis of piping system with and without Stockbridge damper using commercial software SAP2000 is performed. Vertical and horizontal components of earthquakes such as El Centro, California, and Northridge are used in the piping analysis. A sine sweep wave is also used to investigate the control effects on the piping system under wide frequency range. It is found that the proposed Stockbridge damper can reduce the seismic response of piping system subjected to earthquake loading.
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Yee, Raymond K., and Marvin J. Cohn. "Creep Relaxation Behavior of High-Energy Piping." Journal of Pressure Vessel Technology 122, no. 4 (July 24, 2000): 488–93. http://dx.doi.org/10.1115/1.1311958.
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The analysis of the elastic stresses in high-energy piping systems is a routine calculation in the power and petrochemical industries. The American Society of Mechanical Engineers (ASME) B31.1 Power Piping Code was developed for safe design and construction of pressure piping. Postconstruction issues, such as stress relaxation effects and selection of maximum expected creep damage locations, are not addressed in the Code. It has been expensive and time consuming to evaluate creep relaxation stresses in high energy piping systems, such as main steam and hot reheat piping. After prolonged operation of high-energy piping systems at elevated temperatures, it is very difficult to evaluate the redistribution of stresses due to dead weight, pressure, external loading, and thermal loading. The evaluation of stress relaxation and redistribution is especially important when nonideal conditions, such as bottomed-out or topped-out hangers, exist in piping systems. This paper uses three-dimensional four-node quadrilateral shell elements in the ABAQUS finite element code to evaluate the time for relaxation and the nominal relaxation stress values for a portion of a typical high-energy piping system subject to an ideally loaded hanger or to an overloaded hanger. The stress relaxation results are evaluated to suggest an approximation using elastic stress analysis results. [S0094-9930(00)01304-4]
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Najib, Agus Setyawan, Indriyani Ardyarini, and Dwiyanto Joko Suprapto. "Analysis of Piping at Kedung Uling Earthfill Dam, Wonogiri Regency, Central Java Province, Indonesia." MATEC Web of Conferences 159 (2018): 01039. http://dx.doi.org/10.1051/matecconf/201815901039.
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Kedung Uling earthfill dam is located between Eromoko and Wuryantoro district, Wonogiri Regency, Central Java, Indonesia. Water leaked from the dam was found and could decrease volume of dam. The objectives of this study are to identify piping and to recommend for solving piping problem. In order to determine the piping direction and litological pattern, investigation of 10 boreholes with various depth has been carried out. This investigation aim to determine characteristics of soil and rock by analyzing 45 cm of thickness of undisturbed samples and to perform permeability test. Permeability test have been conducted by falling head method with 3 different depths. Leaking at the dam was analyzed by Slide 6.0 software. The results indicated that litology of dam have been identified as claystone, sand and tuff. The piping passed under the eastern abutment of the dam is the accumulation of groundwater in the aquifers formed by 8-10 meters thick layer of sand. The total debit of piping is 17,774 cm3/sec. The Factor of safety of piping is under the minimum of standard namely 3,6. Grouting is one of alternative method to minimize the piping. Grouting was simulated to reduce permeability value and increase soil strength. By grouting, the total debit of piping was reduced to 3.314 cm3/sec.
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Ratnasari, Putri, Judi Alhilman, and Aji Pamoso. "Penilaian Risiko, Estimasi Interval Inspeksi, dan Metode Inspeksi pada Hydrocarbon Piping Menggunakan Metode Risk Based Inspection (RBI)." Jurnal INTECH Teknik Industri Universitas Serang Raya 5, no. 2 (December 27, 2019): 67–74. http://dx.doi.org/10.30656/intech.v5i2.1575.
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Piping adalah sistem perpipaan yang digunakan untuk mengalirkan fluida dari satu proses ke proses lainnya. Jenis piping yang diteliti adalah Hydrocarbon Piping yaitu sebagai penyalur fluida antara reaktor, regenerator, dan main column pada proses catalytic cracking. Fluida yang mengalir pada Hydrocarbon Piping dapat menyebabkan korosi dan mengakibatkan terjadinya penipisan bahkan kebocoran pipa sehingga menimbulkan dampak yang buruk, baik pada lingkungan, keamanan, keselamatan, dan kerugian biaya. Peralatan bertekanan seperti piping memerlukan program inspeksi agar dapat bekerja dengan baik. Risk Based Inspection (RBI) adalah suatu metode untuk menentukan rencana program inspeksi berdasarkan risiko kegagalan peralatan. Metode RBI yang digunakan adalah RBI Semi-Kuantitatif dengan standar API 581. Tujuan penelitian ini adalah untuk mengetahui tingkatan risiko, estimasi interval inspeksi, dan penentuan metode inspeksi pada piping. Dari hasil penelitian menunjukkan bahwa Hydrocarbon Piping terdiri dari 16% pipa dengan tingkat risiko low dan 84% pipa dengan tingkat risiko medium. Estimasi interval inspeksi dianjurkan tidak melebihi setengah remaining life pipa. Dengan mekanisme kerusakan thinning, metode inspeksi yang dianjurkan ialah profile radiography, UT scans, dan visual examination.
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Zhang, Xiao Yue, and Jun Yan. "Dynamic Simulation of Sluice Foundation Piping Using Variable Grid Method." Advanced Materials Research 446-449 (January 2012): 900–905. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.900.
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The occurrence of underground piping is a pluralistic and complex problem. Due to the great difficulty of the 3D dynamic simulation of piping both by theoretical and numerical analysis, currently there is no satisfactory mathematical model and numerical analysis software for it. In order to simulate the piping development process of sluice or dike foundation, in this paper, the 3D steady-unsteady saturated-unsaturated FEM seepage simulation method is used, and the concepts of destroyed element and variable grid method are introduced. The destroyed elements are removed from the original grid during the iterative calculation process, and the corresponding procedure for the 3D steady-unsteady piping process of sluice foundation is designed. Using appropriate post-processing program, the whole piping development of a sluice foundation can be displayed. A piping test of a sluice foundation model is simulated by the method provided in this paper. For the comparison of the experimental result and the simulation result, they showed very good agreement, which can verify the correctness of the piping simulation and programming methods given in this paper.
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Ryu, Yonghee, Shinyoung Kwag, and Bu‐Seog Ju. "Fragility Assessments of Multi-Story Piping Systems within a Seismically Isolated Low-Rise Building." Sustainability 10, no. 10 (October 19, 2018): 3775. http://dx.doi.org/10.3390/su10103775.
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A successful, advanced safety design method for building and piping structures is related to its functionality and sustainability in beyond-design-basis events such as extremely strong ground motions. This study develops analytical models of seismically isolated building-piping systems in which multi-story piping systems are installed in non-isolated and base-isolated, low-rise buildings. To achieve the sustainable design of a multi-story piping system subjected to strong ground motions, Triple Friction Pendulum (TFP) elements, specifically TFP bearings, were incorporated into the latter building structure. Then, a seismic fragility analysis was performed in consideration of the uncertainty of the seismic ground motions, and the piping fragilities for the seismically non-isolated and the base-isolated building models were quantified. Here, the failure probability of the piping system in the non-isolated building was greater than that in the seismically isolated building. The seismic isolation design of the building improved the sustainability and functionality of the piping system by significantly reducing the seismic energy of extreme ground motions which was input to the building structure itself.
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Hara, F. "Seismic Vibration Analysis of Fluid-Structure Interaction in LMFBR Piping Systems." Journal of Pressure Vessel Technology 110, no. 2 (May 1, 1988): 177–81. http://dx.doi.org/10.1115/1.3265583.
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This paper is a basic study on the vibrational characteristics of an LMFBR piping system containing liquid sodium under one-dimensional seismic excitation. Using Z-shaped piping, we formulate coupled equations for the pipe’s bending vibration and pressure wave, and transform them into two-degree-of-freedom vibration equations for the first modes of the piping vibration and pressure wave. A numerical study using the vibration model shows that: 1) the coupling effect appears between piping acceleration and liquid pressure for a piping configuration having a natural frequency ratio ν = about 0.5 to 2.0; 2) the magnitude of seismically induced pressure reaches 0.7 kPa to 1 kPa per gal; and 3) the dead-mass model of liquid gives a nonconservative response depending on the pipe’s geometrical configuration, compared to that from the pressure-wave-piping-interaction model.
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Li, Yong Dong, Sheng Liang Han, Jie Liu, Ji Yong Liu, and He Du. "Vibration Analysis and Control for Reciprocating Compressor Piping System." Applied Mechanics and Materials 157-158 (February 2012): 930–34. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.930.
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Following the adequate model of the reciprocating compressor piping system and the compressor design parameters, operating conditions and gas parameters, the mechanical system of compressor piping, gas-column system, pressure pulsations and of vibration response are numerically simulated. And the main factor bringing to the compressor piping system vibration is identified. A reasonable way to controlling piping vibration is developed to achieve a better efficiency. Keywords: Compressor; Pipe vibration; Vibration Analysis; numerical simulation.
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Branan, Kenyon, and Michael Yoshitaka Erlewine. "Anti-Pied-Piping." Language 99, no. 3 (September 2023): 603–53. http://dx.doi.org/10.1353/lan.2023.a907013.
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Abstract: Anti-pied-piping is a widespread but understudied phenomenon where a language targets a proper subpart of the logical focus for focus morphosyntax: for example, focus particle placement or focus movement. We show that anti-pied-piping is attested in over sixty languages from over forty distinct language groups. We present a theory of focus particle syntax/semantics that involves severing the pronounced position of a focus particle and the logical position of its corresponding semantic contribution, which successfully accounts for both anti-pied-piping and pied-piping behavior. Constraints on attested anti-pied-piping behavior and its interaction with movement show that particle placement takes place at particular, punctuated points in the derivation, in a cyclic model of syntactic structure building. We also discuss the relation of particle placement to other processes such as linearization and stress assignment.
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Sharma, Abhishek, and Ankush Thakur. "Basics of Piping." International Journal of Scientific Engineering and Technology 7, no. 2 (2018): 13. http://dx.doi.org/10.5958/2277-1581.2018.00005.0.
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Choi, Young-Sik. "Against Pied-Piping." Language and Information 6, no. 2 (December 31, 2002): 171–85. http://dx.doi.org/10.29403/li.6.2.9.
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Marshalek, Sonja. "Paths and Piping." OCLC Micro 3, no. 5 (May 1987): 21–26. http://dx.doi.org/10.1108/eb055865.
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Ray, L. B. "Piping Calcium Around." Science 341, no. 6144 (July 25, 2013): 321. http://dx.doi.org/10.1126/science.341.6144.321-b.
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DeAngelis, Matthew M. "Active acoustic piping." Journal of the Acoustical Society of America 115, no. 5 (2004): 1864. http://dx.doi.org/10.1121/1.1757123.
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Guzy, D. "Piping research overview." Nuclear Engineering and Design 98, no. 2 (January 1987): 103–7. http://dx.doi.org/10.1016/0029-5493(87)90158-0.
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Tuthill, Arthur H. "Stainless-steel piping." Journal - American Water Works Association 86, no. 7 (July 1994): 67–73. http://dx.doi.org/10.1002/j.1551-8833.1994.tb06225.x.
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Kang, Dong-Han, So-Won Choi, Eul-Bum Lee, and Sung-O. Kang. "Auto-Routing Systems (ARSs) with 3D Piping for Sustainable Plant Projects Based on Artificial Intelligence (AI) and Digitalization of 2D Drawings and Specifications." Sustainability 16, no. 7 (March 27, 2024): 2770. http://dx.doi.org/10.3390/su16072770.
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The engineering sector is undergoing digital transformation (DT) alongside shifts in labor patterns. This study concentrates on piping design within plant engineering, aiming to develop a system for optimal piping route design using artificial intelligence (AI) technology. The objective is to overcome limitations related to time and costs in traditional manual piping design processes. The ultimate aim is to contribute to the digitalization of engineering processes and improve project performance. Initially, digital image processing was utilized to digitize piping and instrument diagram (P&ID) data and establish a line topology set (LTS). Subsequently, three-dimensional (3D) modeling digital tools were employed to create a user-friendly system environment that visually represents piping information. Dijkstra’s algorithm was implemented to determine the optimal piping route, considering various priorities during the design process. Finally, an interference avoidance algorithm was used to prevent clashes among piping, equipment, and structures. Hence, an auto-routing system (ARS), equipped with a logical algorithm and 3D environment for optimal piping design, was developed. To evaluate the effectiveness of the proposed model, a comparison was made between the bill of materials (BoM) from Company D’s chemical plant project and the BoM extracted from the ARS. The performance evaluation revealed that the accuracy in matching pipe weight and length was 105.7% and 84.9%, respectively. Additionally, the accuracy in matching the weight and quantity of fittings was found to be 99.7% and 83.9%, respectively. These findings indicate that current digitalized design technology does not ensure 100% accurate designs. Nevertheless, the results can still serve as a valuable reference for attaining optimal piping design. This study’s outcomes are anticipated to enhance work efficiency through DT in the engineering piping design sector and contribute to the sustainable growth of companies.
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Kawashima, K., S. Yamanishi, S. Kanai, and H. Date. "Finding the next-best scanner position for as-built modeling of piping systems." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-5 (June 6, 2014): 313–20. http://dx.doi.org/10.5194/isprsarchives-xl-5-313-2014.
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Renovation of plant equipment of petroleum refineries or chemical factories have recently been frequent, and the demand for 3D asbuilt modelling of piping systems is increasing rapidly. Terrestrial laser scanners are used very often in the measurement for as-built modelling. However, the tangled structures of the piping systems results in complex occluded areas, and these areas must be captured from different scanner positions. For efficient and exhaustive measurement of the piping system, the scanner should be placed at optimum positions where the occluded parts of the piping system are captured as much as possible in less scans. However, this "nextbest" scanner positions are usually determined by experienced operators, and there is no guarantee that these positions fulfil the optimum condition. Therefore, this paper proposes a computer-aided method of the optimal sequential view planning for object recognition in plant piping systems using a terrestrial laser scanner. In the method, a sequence of next-best positions of a terrestrial laser scanner specialized for as-built modelling of piping systems can be found without any a priori information of piping objects. Different from the conventional approaches for the next-best-view (NBV) problem, in the proposed method, piping objects in the measured point clouds are recognized right after an every scan, local occluded spaces occupied by the unseen piping systems are then estimated, and the best scanner position can be found so as to minimize these local occluded spaces. The simulation results show that our proposed method outperforms a conventional approach in recognition accuracy, efficiency and computational time.
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Tan, Jie, Peng Zhang, Qian Feng, and Gangbing Song. "Passive Seismic Protection of Building Piping Systems — A Review." International Journal of Structural Stability and Dynamics 20, no. 03 (February 27, 2020): 2030001. http://dx.doi.org/10.1142/s0219455420300013.
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Piping systems are typical nonstructural components of a building. Previous investigations have reported many cases that earthquake causes damages or failures of piping system, resulting in secondary disasters. Therefore, this paper conducts a survey of the seismic damage of the piping systems of buildings and then reviews the state-of-the-art of the passive seismic protection methods. This paper proposes to classify the building piping system into rigid connected pipes, flexible connected pipes and semi-rigid connected pipes. Typical seismic damages of building pipes are presented following this classification. Then, several current seismic protection methods (including constructional measures, seismic braces, damping techniques and base isolation methods) are discussed regarding the theoretical mechanism and feasibility. Furthermore, the state-of-the-art of the building piping system and the passive protection methods with application prospects are evaluated. Based on the review, the flexible piping systems are most commonly used in existing old buildings and are more vulnerable in earthquakes due to their high flexibility. New buildings prefer the rigid connections which tend to restrain the motion of the pipe. However, the excessive stiffness of the rigid connection may cause overlarge internal stresses in both the connection and the pipe. Semi-rigid piping systems have sufficient overall stiffness and a degree of local deform ability and thus have the best seismic performance. In future studies, more research should be devoted to propose and develop new dampers suitable for piping systems, which will improve the seismic safety of building piping systems.
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Ahmad Radzi, M. F., F. A. Abd Dzubir, N. A. Abdul Jalil, Z. A. Zulkefli, and A. Putra. "Evaluation of viscous damper on the vibration transmission to the piping system and the support structure exposed to sinusoidal vibration in vertical, horizontal, and lateral directions." Journal of Physics: Conference Series 2721, no. 1 (March 1, 2024): 012017. http://dx.doi.org/10.1088/1742-6596/2721/1/012017.
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Abstract Viscous dampers have been shown to be a potential solution to addressing piping vibration problems. The primary objective of this study is to confirm the ability of viscous dampers in addressing piping vibration problem in a piping system at different supporting structural stiffness. The piping systems were fabricated and arranged horizontally, vertically, and axially with respect to the direction of the input vibration force. Input force was applied to the piping system using an electromagnetic shaker. A sinusoidal vertical vibration at a 5 Hz frequency (21 mm/s RMS) was applied at one end of the piping system. The use of viscous damper was varied from no viscous damper to one, two and three dampers. Results showed that having three viscous dampers installed caused the piping vibration at point P2 showed the maximum reduction in vibration of up to 80% for three axes, respectively. For the case of structural vibration, the measurement results showed that point S1 experienced the highest vibration exposure before the installation of the viscous dampers, in all axes. With the three viscous dampers installed, the maximum vibration reduction for the sinusoidal vibration test case at point S1 were 86% and 91% for the x- and z-axes, respectively. In conclusion, viscous dampers able to reduce both the piping and structural vibration in multiple axes. This study also highlights the importance of positioning dampers in reducing piping vibration and vibration transmitted to the structure, with reduction up to 90% amplitude for sinusoidal input and 80% for random input.
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Choi, Sun Yeong, and Young Hwan Choi. "A New Strategy for In-Service Inspection of Nuclear Piping Considering Piping Failure Frequency." Key Engineering Materials 353-358 (September 2007): 2088–91. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.2088.
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The current in-service inspection (ISI) strategy for the nuclear piping in many countries consists of both the code requirements such as ASME B & PV Code Sec. XI and the country-specific regulatory requirements, so called as the enhanced ISI. The enhanced ISI reflects the operating experience of piping failure, while the ASME Code Sec. XI requirement is based on random sampling for the inspection points. In this study, a new strategy for ISI of nuclear piping was proposed based on piping failure frequency. This strategy basically reflects the operating experience because the piping failure frequency is based on the piping failure database. The new concept of minimum inspection rate was also introduced in this new ISI strategy. As pilot study, the new ISI strategy was applied to the Class 1 piping system such as reactor coolant system and safety injection system of Ulchin Unit 5 which is the 1,000 MWe Korean Standard PWR. The results from the proposed new strategy were compared to those from the ASME Code Sec. XI. The results show that the new ISI strategy reasonably reflects the operating experience. The results also show that the concept of the minimum inspection rate can compensate the unbalance in the number of inspection points between the very large differences in the piping failure frequency.
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Band, Shahab S., Saeid Janizadeh, Sunil Saha, Kaustuv Mukherjee, Saeid Khosrobeigi Bozchaloei, Artemi Cerdà, Manouchehr Shokri, and Amirhosein Mosavi. "Evaluating the Efficiency of Different Regression, Decision Tree, and Bayesian Machine Learning Algorithms in Spatial Piping Erosion Susceptibility Using ALOS/PALSAR Data." Land 9, no. 10 (September 23, 2020): 346. http://dx.doi.org/10.3390/land9100346.
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Piping erosion is one form of water erosion that leads to significant changes in the landscape and environmental degradation. In the present study, we evaluated piping erosion modeling in the Zarandieh watershed of Markazi province in Iran based on random forest (RF), support vector machine (SVM), and Bayesian generalized linear models (Bayesian GLM) machine learning algorithms. For this goal, due to the importance of various geo-environmental and soil properties in the evolution and creation of piping erosion, 18 variables were considered for modeling the piping erosion susceptibility in the Zarandieh watershed. A total of 152 points of piping erosion were recognized in the study area that were divided into training (70%) and validation (30%) for modeling. The area under curve (AUC) was used to assess the effeciency of the RF, SVM, and Bayesian GLM. Piping erosion susceptibility results indicated that all three RF, SVM, and Bayesian GLM models had high efficiency in the testing step, such as the AUC shown with values of 0.9 for RF, 0.88 for SVM, and 0.87 for Bayesian GLM. Altitude, pH, and bulk density were the variables that had the greatest influence on the piping erosion susceptibility in the Zarandieh watershed. This result indicates that geo-environmental and soil chemical variables are accountable for the expansion of piping erosion in the Zarandieh watershed.