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Basics of the Unix System
Published in Paul W. Ross, The Handbook of Software for Engineers and Scientists, 2018
F. Sanders Alton, Pickering Robert
We can go further. If we wished to concatenate the three files “start,” “middle,” and “finish” into a single new file and then view the results, we could use the “cat” command and then the “more” command as we did above or we could employ the “tee” command. The “tee” command is used in pipe sequences to save intermediate results into a file. Thus another way to do what we did above would be cat start middle finish | tee gettysburg.address | more which would save the concatenated file as well as display the results one page at a time.
Dynamic reliability analysis for residual life assessment of corroded subsea pipelines
Published in Ships and Offshore Structures, 2021
Reza Aulia, Henry Tan, Srinivas Sriramula
The above studies offer relevant options for predicting the pipeline performance and life extension requirements. However, they still contain some unknown variables and require expert judgement due to a lack of quantitative data and/or information. All of this may lead to making several assumptions in the model and analyses, increasing the uncertainty in the results. Given a large number of uncertainties that most likely will be involved in analyses for life extension assessments, Pesinis and Tee (2018) stated that Bayesian networks are a possible approach for modelling and predicting the pipeline performance. It is a powerful tool for reasoning under uncertainty, using well-established theoretical foundations of probability as the base for performing inference and handling uncertainty. Bayesian networks can be extended to consider the dynamic behaviour of a system by introducing temporal dependencies in the network. Several static and dynamic Bayesian network models are developed for assessing reliability and maintenance performance of technical systems (Shabarchin and Tesfamariam 2016; Zarei et al. 2017). They have also been applied to assess and predict the performance of degrading repairable systems.
Allowable Rates of Fluid Temperature Variations and Thermal Stress Monitoring in Pressure Elements of Supercritical Boilers
Published in Heat Transfer Engineering, 2019
Jan Taler, Dawid Taler, Karol Kaczmarski, Piotr Dzierwa, Marcin Trojan, Magdalena Jaremkiewicz
During the starts, shutdowns and load changes of supercritical boilers, thick-walled pressure components of complex shape are subjected to rapid temperature variations and high thermal stresses. The critical pressure components such as the steam-water separator, inlet and outlet headers of the superheater stages, coolers, tees, and valves, limit the rates of fluid temperature changes. The lifetime of pressure elements and damage-free operation of the boiler can be reduced by high-rate heating or cooling of the boiler during its start-up or shutdown. Permissible variations in fluid temperature were determined for the boiler start-up from the cold, warm, and hot state. Also, allowable temperature-decreasing rates during the scheduled shutdown of the boiler, and the variations of temperature and stresses in the critical parts of the boiler during an emergency shutdown were determined. The detailed structural analysis using the ANSYS software was performed for the outlet header of the final superheater stage and tee in the pipeline connecting the feed water heater of the boiler with spiral water-walls of the combustion chamber. The coefficients of thermal stress concentration at the edge of the hole in the header and tee were determined as a function of the heat transfer coefficient.
Comparison of the Axial Dispersion Performance of Pulsed Solvent Extraction Columns with Tenova Pulsed Column–Kinetics Internals and Standard Disc and Doughnut Internals
Published in Solvent Extraction and Ion Exchange, 2018
Wen Li, Yong Wang, Kathryn A. Mumford, Kathryn H. Smith, Geoff W. Stevens
The 2-m high pilot-scale, pulsed solvent extraction column used in this study was designed and constructed in the solvent extraction pilot plant in the Department of Chemical and Bio-molecular Engineering at The University of Melbourne. The column comprised four QVF® precision pipeline components – an unequal tee piece, two 1-m high precision boreglass tubes, and a concentric reducer – and connected with couplings and sealings. A pulsation unit was assembled with a three-phase induction motor and a zero-max gearbox connected to the bottom of the column with pulsation rates ranging from 15 rpm to 180 rpm and a maximum pulsing amplitude of 15 cm. Four Stainless Steel (SS) tanks were set up for storage of organic phase, aqueous feed phase solution, loaded organic, and raffinate, and were connected to the corresponding inlets and outlets of the aqueous and organic phase. Pumps and flowmeters were inserted in the tubing for each phase (Refer to Fig. 1). More detailed information of column setup can be found in the previous hydrodynamic study.[12]