• 제목/요약/키워드: mild solution

검색결과 257건 처리시간 0.023초

Thiadiazolopyrimidines as Acid Corrosion Inhibitors for Mild Steel

  • Chitra, S.;Parameswari, K.;Vidhya, M.;Kalishwari, M.;Selvaraj, A.
    • Corrosion Science and Technology
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    • 제10권1호
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    • pp.13-23
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    • 2011
  • The inhibitive action of thiadiazolopyrimidines on mild steel in 1 M $H_{2}SO_{4}$ has been studied using weight loss, gasometric studies and electrochemical polarization and AC impedance measurements. The effect of temperature on the corrosion behaviour of mild steel in 1 M $H_{2}SO_{4}$ with optimum concentration of inhibitors was studied in the temperature ranging from 313-333K The adsorption of the inhibitor on the surface of mild steel was found to be exothermic, spontaneous and followed the mechanism of physisorption. The adsorption of these compounds on mild steel surface was found to obey Langmuir adsorption isotherm. The protective film formed on the surface of mild steel by the adsorption of inhibitor in 1 M $H_{2}SO_{4}$ solution was confirmed by optical microscopic technique. Synergistic effect of halide ions on mild steel in 1 M $H_{2}SO_{4}$ was studied by weight loss technique.

The Inhibitor Effect of (E)-5-[(4-(benzyl(methyl)amino)phenyl)diazenyl]-1,4-dimethyl-1H-1,2,4-triazol-4-ium zinc(II) Chloride, an Industrial Cationic Azo Dye, onto Reducing Acidic Corrosion Rate of Mild Steel

  • Ozkir, Demet;Kayakirilmaz, Kadriye
    • Journal of Electrochemical Science and Technology
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    • 제11권3호
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    • pp.257-272
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    • 2020
  • This study covers the stages of testing whether the azo dye with chemical name (E)-5-[(4-(benzyl(methyl)amino)phenyl)diazenyl]-1,4-dimethyl-1H-1,2,4-triazol-4-ium zinc (II) chloride (DMT), known as Maxilon Red GRL in the dye industry, can be used as an anticorrosive feasible inhibitory agent, especially in industrial areas other than carpet, yarn and fibre dyeing. These test stages consist of the electrochemical measurement techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) for diverse concentrations and durations. The adsorption of the viewed DMT molecule on the mild steel surface obeyed the Langmuir isotherm. The zero charge potential (PZC) of mild steel was also found to assess the inhibition mechanism in containing DMT solution. The inhibition performance of DMT on the mild steel in a 1.0 M HCl solution was also investigated using methods such as metal microscope, atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM).

Electrochemical Studies on Corrosion Inhibition Behaviour of Synthesised 2-acetylpyridine 4-ethyl-3-thiosemicarbazone and Its Tin(IV) Complex for Mild Steel in 1 M HCl Solution

  • Hazani, Nur Nadira;Mohd, Yusairie;Ghazali, Sheikh Ahmad Izaddin Sheikh Mohd;Farina, Yang;Dzulkifli, Nur Nadia
    • Journal of Electrochemical Science and Technology
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    • 제10권1호
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    • pp.29-36
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    • 2019
  • Corrosion inhibition by synthesised ligand, 2-acetylpyridine 4-ethyl-3-thiosemicarbazone (HAcETSc) and its tin(IV) complex, dichlorobutyltin(IV) 2-acetylpyridine 4-ethyl-3-thiosemicarbazone ($Sn(HAcETSc)BuCl_2$) on mild steel in 1 M hydrochloric acid (HCl) was studied using weight loss measurement, potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The inhibition efficiency increases by increasing the inhibitor concentrations. The polarisation study showed that both synthesised compounds were mixed type inhibitors. The electrochemical impedance study showed that the presence of inhibitors caused the charge transfer resistance to increase as the concentration of inhibitors increased. The adsorption of these compounds on mild steel surface was found to obey Langmuir's adsorption isotherm with the free energy of adsorption ${\Delta}G{^o}_{ads}$ of -3.7 kJ/mol and -7.7 kJ/mol for ligand and complex respectively, indicating physisorption interaction between the inhibitors and 1 M HCl solution.

The Synergistic Effect of 2-Chloromethylbenzimidazole and Potassium Iodide on the Corrosion behavior of Mild Steel in Hydrochloric Acid Solution

  • Zhou, Liben;Cheng, Weizhong;Wang, Deng;Li, Zhaolei;Zhou, Haijun;Guo, Weijie
    • Journal of Electrochemical Science and Technology
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    • 제13권1호
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    • pp.138-147
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    • 2022
  • The synergistic effect of 2-chloromethylbenzimidazole (2-CBI) and potassium iodide (KI) for mild steel in 1 M hydrochloric acid solution was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that, with the addition of 100 ppm potassium iodide, the inhibition efficiecy (IE) of 100 ppm 2-CBI in 1 M hydrochloric acid had been improved from 91.14% to 96.15%. And synergistic parameter of 100 ppm 2-CBI with different amounts of potassium iodide is always greater than 1. The adsorption of potassium iodide combining with 100 ppm 2-CBI obeys to the Langmuir adsorption isotherm. Thermodynamic adsorption parameters, including ∆G0ads, ∆Ha and ∆Sa of the adsorption of the combinned inhibitor, as well as the Ea of the mild steel corrosion in 1 M HCl with the combinned inhibitor, were calculated.

분심기음의 우울증 모델 흰쥐에 대한 실험적 연구 (The Effects of Punsimgi-eum(fenxinqi-yin) in the Chronic Mild Stress Model of Depression in Rats)

  • 이승기;김종우;황의완;김현택;곽소영;박은혜
    • 대한한의학회지
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    • 제22권3호
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    • pp.129-140
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    • 2001
  • Objectives : The aim of this study was to evaluate the effects of Punsimgi-eum(fenxingi-yin) in rat model of depression induced by chronic mild stress (CMS). Methods : The change of the consumption of sucrose solution was measured, and the open field test and passive avoidance conditioning test were performed to investigate the anti-depressive effect of Punsimgi-eum(fenxingi-yin). Results : The results were as follows; I. The consumption of sucrose solution was significantly reversed in the test group at 5, 7 and 8 weeks, but there was no significant change in the control group. 2. There was no significant change of body weight after 8 weeks in each group 3. In the open field test, there was significant increase of exploratory activity in the test group. 4. In the passive avoidance test, the test group showed differences in the maintenance of retention from the control group at the 2-week training-testing interval. Conclusions : The present results suggest that Punsimgi-eum(fenxingi-yin) has an anti-depressive effect.

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Comparative study on Corrosion Inhibition of Vietnam Orange Peel Essential Oil with Urotropine and Insight of Corrosion Inhibition Mechanism for Mild Steel in Hydrochloric Solution

  • Bui, Huyen T.T.;Dang, Trung-Dung;Le, Hang T.T.;Hoang, Thuy T.B.
    • Journal of Electrochemical Science and Technology
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    • 제10권1호
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    • pp.69-81
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    • 2019
  • The corrosion inhibiting mechanism of Vietnam orange peel essential oil (OPEO) for mild steel in 1 N HCl solution was investigated elaborately. Corrosion inhibition ability of OPEO was characterized by electrochemical polarization, electrochemical impedance spectroscopy (EIS), and weight loss method. In the corrosive solution, OPEO worked as a mixed inhibitor and the inhibition efficiency of OPEO increased with the increase of its concentration. High inhibition efficiencies over 90% were achieved for the concentration of 3 - 4 g/L OPEO, comparable to that of 3.5 g/L urotropine (URO), a commercial corrosion inhibitor for acid media used in industry. By using adsorption isotherm models (Langmuir, Temkin and Frumkin), thermodynamic parameters of adsorption were calculated. The obtained results indicated physical adsorption mechanism of OPEO on the steel surface. The components responsible for the corrosion inhibition activity of OPEO were not only D-limonene, but also other compounds, which contain C=O, C=C, O-H, C-O-C, -C=CH and C-H bonding groups in the molecules.

Corrosion Inhibition of Mild Steel in Acidic Medium by Jathropha Curcas Leaves Extract

  • Odusote, Jamiu K.;Ajayi, Olorunfemi M.
    • Journal of Electrochemical Science and Technology
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    • 제4권2호
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    • pp.81-87
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    • 2013
  • Inhibition of corrosion of mild steel in sulphuric acid by acidic extract of Jatropha Curcas leaves has been studied using weight loss and thermometric measurements. It was found that the leaves extract act as a good corrosion inhibitor for mild steel in all concentrations of the extract. The inhibition action depends on the concentration of the Jatropha Curcas leaves extract in the acid solution. Results for weight loss and thermometric measurements indicate that inhibition efficiency increase with increasing inhibitor concentration. The adsorption of Jatropha curcas leaves extract on the surface of the mild steel specimens obeys Langmuir adsorption isotherm. Based on the results, Jatropha curcas leaves extract is recommended for use in industries as a replacement for toxic chemical inhibitors.

유체환경 중에서 연강재의 간극부식에 관한 연구 (Study on the Crevice Corrosion of Mild Steel in Fluid Environment)

  • 임우조;윤병두
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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    • pp.373-378
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    • 2000
  • The crevice corrosion of local corrosion occur when the gap exist on metal surface. This crevice corrosion happen to region such as flange of pipe, contact part of casing, under gasket and packing, between valve disk and seat of pump etc. Especially The crevice corrosion of mild steel(SS 400) get serious. This paper was studied on the crevice corrosion of SS 400 in fluid environment. In $0\%,\;2\%,\;3.5\%,\;5\% NaCl$ solution, the aspect of the crevice corrosion and polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 with crevice and non-crevice was measured according to the NaCl concentration. The main results obtained are as follows : 1) Under crevice corrosion, the corrosion potential become less noble as the concentration of NaCl solution increased. 2) The current density under open circuit potential was high drained as concentration of NaCl solution increased by $3.5\%$ but the concentration increased over $3.5\%$, the current density was low drained. 3) The weight loss rate of SS 400 was increased as concentration of NaCl solution Increased by $3.5\%$, but the concentration increased over $3.5\%$, that of SS 400 was decreased. 4) Effect of oxygen for crevice corrosion in the concentration of $3.5\%$ NaCl solution become sensitive than that $0\%$ NaCl solution.

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트렌치 위를 통과하는 장파의 변형 (Transformation of Long Waves Propagating over Trench)

  • 정태화;서경덕;조용식;박승현
    • 한국해안해양공학회지
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    • 제19권3호
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    • pp.228-236
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    • 2007
  • 비대칭 트렌치 지형 위를 통과하는 장파의 해석 해를 유도하였다. 트렌치 내부의 수심은 트렌치 중심으로부터 거리의 멱에 비례하여 감소한다. 장파의 가정을 사용하여 지배 방정식인 완경사 방정식을 변수 계수를 갖는 이차 상미분 방정식으로 변환하였으며 멱급수를 이용하여 해석 해를 구하였다. 수치 모델과의 비교를 통하여 해석 해의 타당성을 확인하였다. 다양한 조건에서 해석 해를 계산하여 그 결과를 분석하였다.