scholarly journals Failure analysis of an economizer tube sheet & its cover due to corrosionand imperfection

2021 ◽  
Vol 2080 (1) ◽  
pp. 012023
Author(s):  
Shaiful Rizam Shamsudin ◽  
Rajaselan Wardan ◽  
Faizal Ibrahim ◽  
Muhammad Lutfi Ibrahim
Keyword(s):  
Flue Gas ◽  
Visual Inspection ◽  
Composition Analysis ◽  
Tube Sheet ◽  
Residual Welding Stress ◽  
Welding Stress ◽  
Economizer Tube ◽  
Outer Cover ◽  
Selection For ◽  
The Right

Abstract The boiler's economizer was found to be inefficient. Corrosion is suspected to be the source of the economizer's pressure reduction. The examinations included visual inspection, stereomicroscope, metallography, elemental microanalysis by EDS, and chemical composition analysis. The economizer failed due to a weld crater caused by improper welding, which induced residual welding stress. The slight sulfur content of the condensed or flue gas that causes rusting on the economizer's outer cover is not considered a severe failure issue. Material SUS304 stainless steel is the right selection for economizer materials.

Control of Cold Welding Cracks in 30CrMnSi Steel by Welding with Trailing Impacting and Rolling

2011 ◽  
Vol 295-297 ◽  
pp. 1251-1258 ◽  
Author(s):  
Jian Guo Yang ◽  
Lu Yong Huang ◽  
Hai Bo Pan ◽  
Xue Song Liu ◽  
Hong Yuan Fang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Welded Joints ◽  
High Strength ◽  
Cold Welding ◽  
Low Alloy Steel ◽  
Residual Welding Stress ◽  
Welding Stress ◽  
Scanning Electron ◽  
Main Factor

As a kind of the high strength low alloy steel (HSLA), 30CrMoSi has been used widely in some industrial fields. However, just like some HSLA, this steel also faces some problems when it is welded, especially such problem as cold cracking in the welded joints. In this paper, the cold welding cracks and microstructure of the joints of 30CrMoSi steel were studied by scanning electron microscopy (SEM) and optical microscopy (OM), and a method called welding with trailing impacting and rolling (WTIR) was utilized to solve the problem mentioned above by decreasing the residual welding stress which is one main factor to lead to cold welding crack in the joint of HSLA. The crack-free joints of 30CrMoSi steel were obtained by using proper parameters.

scholarly journals Serangan Korosi Sumuran pada Tube Heat Exchanger di Kilang Pengolahan Minyak

2019 ◽  
Vol 8 (3) ◽  
pp. 107-114
Author(s):  
Hadi Sunandrio ◽  
Sutarjo
Keyword(s):  
Heat Exchanger ◽  
Pitting Corrosion ◽  
Visual Inspection ◽  
Outer Tube ◽  
Oil Refinery ◽  
Composition Analysis ◽  
Heat Exchanger Tube ◽  
Corrosion Attack ◽  
Tube Heat Exchanger ◽  
Exchanger Tube

Alat penukar panas (Heat Exchanger) adalah suatu alat yang berfungsi untuk menaikkan temperatur. Apabila salah satu komponen dari Heat Exchangertersebut mengalami kerusakan, maka temperatur yang diinginkan tidak akan tercapai. Salah satu dari tube heat exchanger yang ada di Kilang Pengolahan Minyak mengalami kerusakan berupa putus akibat terkorosi. Setelah dilakukan pemeriksaan dan pengujian yang meliputi : pemeriksaan visual, metalografi, uji kekerasan, analisa komposisi kimia, dan analisa EDAX. Maka diketahui bahwatube Heat Exchanger telah mengalami serangan korosi sumuran (pitting corrosion) pada permukaan dalam dan luar tube. Terjadinya serangan korosi sumuran, karena pada permukaan dalam dan luar tube terlapisi oleh deposit yang cukup tebal dan mengandung unsur-unsur Sulphur (S) dan Chlor (Cl) yang dapat memicu timbulnya serangan korosi sumuran (pitting corrosion), hingga tube mengalami penipisan di mana-mana dan putus.Kata kunci : Alat penukar panas, Tube, Endapan, Korosi sumuran, putus.AbstractHeat exchangers is a tool that serves to raise the temperature. If one component of the Heat Exchanger is damaged, then the desired temperature will not be reached. One of the tube heat exchanger that is in Oil Refinery suffered damage in the form of broken due to corroded. After examination and testing that includes visual inspection, metallography, hardness testing, chemical composition analysis, and analysis of EDAX. It is known that the tube Heat Exchanger has suffered attacks pitting corrosion on the surface of the inner and outer tube. Pitting corrosion attack, because the surface of inner and outer tube coated by a deposit that is thick and contains elements of Sulphur (S) and Chlor (Cl) which can lead to pitting corrosion attack, to experience thinning tube where everywhere and brokenKeyword : Heat exchanger, Tube, Deposit, Pitting corrosion, Broken.

Analysis of the results of competitions held in 2020 for the right to receive grants from the President of the Russian Federation for state support of young Russian scientists and competitive selection for personal scholarships named after ZH.I. Alferov for young scientists in the field of physics and nanotechnology

2021 ◽  
pp. 44-51
Author(s):  
B.V. Ivanov ◽  
S.V. Kristalinskaya ◽  
E.A. Gladysheva ◽  
D.A. Dobrynin
Keyword(s):  
Russian Federation ◽  
State Support ◽  
Competitive Selection ◽  
Research Areas ◽  
Federal Districts ◽  
The Russian Federation ◽  
Selection For ◽  
Number Of Publications ◽  
The Right ◽  
To Receive

The article presents the results of the analysis of the indicators of the competitions of grants of the President of the Russian Federation held in 2020 for state support of young Russian scientists and competitive selection for receiving personal scholarships named after J.I. Alferov for young scientists in the field of physics and nanotechnology: generalized data on the number of publications of winners, distribution of participants and winners by research areas, federal districts, regions, departments and organizations.

scholarly journals Lateralization correlates with individual differences in inhibitory control in zebrafish

2020 ◽  
Vol 16 (8) ◽  
pp. 20200296
Author(s):  
Tyrone Lucon-Xiccato ◽  
Giulia Montalbano ◽  
Marco Dadda ◽  
Cristiano Bertolucci
Keyword(s):  
Inhibitory Control ◽  
Cognitive Differences ◽  
Cerebral Lateralization ◽  
Brain Hemisphere ◽  
Selective Pressures ◽  
Individual Fitness ◽  
Left Brain ◽  
Selection For ◽  
The Right ◽  
Selection Mechanisms

Individual fitness often depends on the ability to inhibit behaviours not adapted to a given situation. However, inhibitory control can vary greatly between individuals of the same species. We investigated a mechanism that might maintain this variability in zebrafish ( Danio rerio ). We demonstrate that inhibitory control correlates with cerebral lateralization, the tendency to process information with one brain hemisphere or the other. Individuals that preferentially observed a social stimulus with the right eye and thus processed social information with the left brain hemisphere, inhibited foraging behaviour more efficiently. Therefore, selective pressures that maintain lateralization variability in populations might provide indirect selection for variability in inhibitory control. Our study suggests that individual cognitive differences may result from complex multi-trait selection mechanisms.

Operational Forces Identification From Helicopter Model In-Flight Data With Use of Inverted Regressive Parametric Models

2008 ◽  
Author(s):  
Krzysztof Mendrok ◽  
Piotr Kurowski ◽  
Tadeusz Uhl
Keyword(s):  
Control System ◽  
Visual Inspection ◽  
Control Unit ◽  
Parametric Models ◽  
Identification Procedure ◽  
Force Identification ◽  
Flight Data ◽  
Inspection Robot ◽  
Selection For

The paper presents an attempt to identify forces acting on the control unit of a helicopter model during flight. The helicopter model will, according to the project assumptions, operate as an inspection robot i.e. it will autonomously fly in selected regions and monitor them with an embedded camera. It could be used for visual inspection of high masts or chimneys. Autonomous flying requires a sophisticated control system. The control unit is placed in an additional box hung under the fuselage. One of the stages of the unit development was examination of in-flight forces acting on the box and if it was necessary, a vibroinsulation selection. For this reason, an experiment was conducted. During the test, forces in the box suspension and accelerations in selected locations of the object were recorded. Having both, forces and responses in the form of vibrations accelerations, enabled to verify a force identification procedure. It is a procedure based on regressive parametric models inversion. The paper presents this method’s description and an attempt to apply it to the described forces identification.

scholarly journals A Case of Hydrocele Stone with Its Composition Analysis

2010 ◽  
Vol 2010 ◽  
pp. 1-2
Author(s):  
Masayoshi Zaitsu ◽  
Koji Mikami ◽  
Yuta Takeshima ◽  
Takumi Takeuchi
Keyword(s):  
Prostate Cancer ◽  
Calcium Carbonate ◽  
Calcium Phosphate ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Endocrine Treatment ◽  
Composition Analysis ◽  
Tunica Vaginalis ◽  
Infrared Spectrophotometer ◽  
The Right

Hydrocele stones are freely mobile calcified bodies lying between the tunica vaginalis layers, and they are relatively rare. We present here another case of hydrocele stone incidentally discovered when castration was being undergone for the endocrine treatment of prostate cancer. A 71-year-old man was diagnosed as stage D2 prostate cancer with his prostate-specific antigen 387 ng/ml. A white smooth stone of 11 mm in diameter was incidentally found moving freely in the right hydrocele space during castration. The hydrocele stone was of yellow hard center with white materials around it. Crystallographical analysis of the hydrocele stone by a infrared spectrophotometer showed that the center was composed of 64% calcium carbonate and 36% calcium phosphate, while the outer portion was protein. Our case is the fourth where crystallographical analysis was reported for hydrocele stones.

scholarly journals Smart Content Selection for Public Displays in Ambient Intelligence Environments

2013 ◽  
Vol 5 (2) ◽  
pp. 35-55 ◽  
Author(s):  
Fernando Reinaldo Ribeiro ◽  
Rui José
Keyword(s):  
Social Context ◽  
Ambient Intelligence ◽  
Content Adaptation ◽  
Public Display ◽  
Public Displays ◽  
Content Selection ◽  
Tag Cloud ◽  
Selection For ◽  
The Right

A public display that is able to present the right information at the right time is a very compelling concept. However, realising or even approaching this ability to autonomously select appropriate content based on some interpretation of the surrounding social context represents a major challenge. This article provides an overview of the key challenges involved and an exploration of some of the main alternatives available. It also describes a novel place-based content adaptation system that autonomously selects from web sources the content deemed more relevant according to a dynamic place model. This model is based on a tag cloud that combines content suggestions expressed by multiple place visitors with those expressed by the place owner. Evaluation results have shown that a place tag cloud can provide a valuable approach to this issue and that people recognize and understand the sensitivity of the system to their demands.

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