• Title/Summary/Keyword: 3% NaCl solution

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The Study on the Influence of the Concentration NaCl Solution on Corrosion Fatigue Behavior of T.M.C.P. Steel (T.M.C.P. 강의 부식피로거동에 미치는 염분의 영향에 관한 연구)

  • 이상호;한정섭
    • Journal of Ocean Engineering and Technology
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    • v.7 no.2
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    • pp.131-140
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    • 1993
  • To study the corrosion fatigue begavior of T.M.C.P. steel, the rotary bending fatigue test with the change of concentration of NaCl solution was carried out. Fatigue life in the corrosion environment is decreased markedly in comparision with that in the air. Fatigue limit in the air was about 225 MPa. In case of 3.5% NaCl solution fatigue life could be expressed as .sigma./sub f/=10,392 * (N/sub f/)/sup -o.2923 . According to the paris's rule, crack growth rates could be expressed as da/dN=2.62.*10/sup -7/ .DELTA. K/sup 1.09/(3.5% NaCl solution), da/dN=1.95 *10/sup -7 .DELTA. K/sup 1.05/(1% NaCl solution), da/dN=2.62 * 10/sup -7/.DELTA./sup 0.72/(0.01% NaCl solution) with da/dN expressed in mm/cycle and .DELTA.K in MPa.GAMMA.m. The crack growth rate in the corrosion environment was highest under 3.5% NaCl solution.

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Corrosion of Dental Au-Ag-Cu-Pd Alloys in 0.9 % Sodium Chloride Solution

  • Chiba, Atsushi;Kusayanagi, Yukiharu
    • Corrosion Science and Technology
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    • v.4 no.1
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    • pp.19-22
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    • 2005
  • Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_2S$. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_{2}S$. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing $Na_{2}S$.

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

  • Lim, Uh Job;Yun, Byoung Du
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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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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Physiological Response of Barley Seedlings to Salt Stress (염농도에 따른 보리 유묘의 생리반응)

  • 이석영;김충수;조진웅;강윤규
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.6
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    • pp.665-671
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    • 1996
  • The salt stress at seedling stage of barley was examined in different concentrations of NaCl containing 1/2 Hoagland solution. Among the physiological factors electric conductivity and sodium content of cell sap outflow solution were increased according to the in-crease of NaCl concentration in 1/2 Hoagland solution but the total protein content of root cell sap outflow solution was decreased. Changing pattern of amino acids content in plant was divided into 3 groups which were increased, decreased or unchanged by NaCl concentration in solution. In normal condition, sugar content in plant was higher than potassium or sodium but if NaCl was added more than 25mM in 1/2 Hoagland solution, sodium was the highest. Potassium content in shoot was decreased as 67% of control at 100mM of NaCl containing solution and in root it was decreased as 8%. Sum of the potassium and sodium content in shoot was seriously increased in accordant with NaCl concentration in culture solution, but in root it was gradually decreased. Chlorophyll content per g fresh weight and photosynthetic ability per $\textrm{cm}^2$ in first leaf were not affected by NaCl concentration of 1/2 Hoagland solution but root activity was slightly decreased compared to control.

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Study on the Characteristics of Crevice Corrosion Prevention of SS 400 in Marine Environment (해양환경 중에서 SS400강재의 간극부식방지 특성에 관한 연구)

  • 임우조;정기철;구영필;윤병두
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2001.05a
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    • pp.152-157
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    • 2001
  • This paper was studied on the characteristics of crevice corrosion prevention of SS 400 in marine environment. In NaCl solution, polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 applied cathodic protection and non cathodic protection was measured according to the NaCl concentration. The main results obtained are as follows : The weight loss rate of Al-alloy galvanic anode was increased as the concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of Al-alloy galvanic anode become decreased. The protective potential of SS 400 used Al-alloy galvanic anode becomes more cathodic polarization with increasing concentration of NaCl solution. Effects of oxygen on the weight loss rate of Al-alloy sacrificial anode for cathodic protection as the concentration of 3.5% NaCl solution become sensitive than that of 0% NaCl solution.

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Cellular Structural Change of Barley Seedling on Different Salt Concentration under Hydroponic Culture (보리 유묘의 염농도에 따른 세포의 형태반응)

  • 이석영;김충수
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.4
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    • pp.481-486
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    • 1995
  • The salt stress at seedling stage of winter barley was examined in different concentrations of NaCl containing 1/2 Hoagland solution. Fresh weight of seedling at 30 days after seeding was highest at 25mM of NaCl concentration containing 1/2 Hoagland solution but if the NaCl concentration was more than 50mM it began to decrease seriously. Water content in plant was decreased according to increase of NaCl concentration in 1/2 Hoagland solution, so physiological mechanism of NaCl in barley was different from saline plant. Stoma number per cm$^2$ of first leaf was higher than that of control in case of stressed by NaCl but in that case the leaf length was decreased so the number of stoma per first leaf was slightly decreased. Chloroplast shape was not changed by 75mM of high NaCl contained 1/2 Hoagland solution but cell division at root growing point was inhibited by 75mM of NaCl. As the result of salt stress mitochondria was ruined in structure and irregular solid was found to be transfered from the cytoplasm to the cell wall in root growing point.

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Optimization of Gold Leaching from the Refractory Sulfide Concentrate by HCl-NaClO-FeCl3 Solution (HCl-NaClO-FeCl3 용액을 이용한 저항성 황화광물 정광으로부터 금 용출 최적화)

  • Kim, Bong-Ju;Cho, Kang-Hee;Lee, Jong-Ju;Choi, Nag-Choul;Park, Cheon-Young
    • Economic and Environmental Geology
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    • v.46 no.1
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    • pp.21-28
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    • 2013
  • In order to optimize gold leaching from refractory sulfide concentrate, a HCl-NaClO-$FeCl_3$ solution with varying attributes was applied to the roasted concentrate from Uil mine. The gold from Uil mine occurs in the form of invisible gold that is difficult to leach. The results of the gold leaching experiments showed that the best gold leaching parameters were $550^{\circ}C$ of roasting temperature, 2.0 M of concentration, 1.0% of pulp density, and $70^{\circ}C$ of leaching temperature. It is confirmed that the HCl-NaClO-$FeCl_3$ solution was an environmentally friendly method to leach gold and silver from the refractory sulfide concentrate as an alternative lixiviant to cyanide.

Study on the Crevice Corrosion Behavior of SS 400 in Marine Environment (해양환경중에서 SS400강재의 간극부식거동에 관한 연구)

  • 임우조;정기철;안석환;윤병두
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.11a
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    • pp.1-6
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    • 2000
  • This paper was studied on the crevice corrosion behavior of SS 400 in marine 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 SS400 was increased as concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of SS400 was decreased.

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Corrosion Behavior of the parts of Carbon Steel Bolted GECM(Graphite Epoxy Composite Material)/Al plates (탄소강 볼트 체결된 GECM(Graphite Epoxy Composite Material)/Al 판재의 구성 부재의 부식 거동)

  • Kim, Youngsik;Park, Sujin;Yoo, Youngran
    • Corrosion Science and Technology
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    • v.11 no.6
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    • pp.232-241
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    • 2012
  • This work focused on corrosion of carbon steel bolted GECM/Al parts in tap water and NaCl solutions. In tap water and NaCl solutions, open circuit potential of GECM and its potentials in a series of carbon steel bolt>Ti>Al became active. Regardless of test materials, open circuit potentials in tap water were noble, and increasing NaCl concentration, its potentials became active. Immersion test of single specimen showed that no corrosion occur in Ti and GECM. In tap water, carbon steel bolt didn't show red corrosion product and in chloride solutions, corrosion rate in 1% NaCl solution was greater than its rate in 3.5% NaCl solution and red corrosion product in 1% NaCl solution was earlier observed than that in 3.5% NaCl solution. It seems that this behavior would be related to zinc-coatings on the surface of carbon stee l bolt. On the other hand, aluminium was corroded in tap water and chloride solutions. Corrosion of aluminium in tap water was due to the presence of chloride ion in tap water by sterilizing process.

Effect of Diluents on the Cold Storage of Sperm in Scapharca broughtonii (Schrenck) (피조개, Scapharca broughtonii (Schrenck) 정자의 냉장보존에 미치는 희석액의 효과)

  • Rha, Sung-Ju;Lee, Sung-Hun;Kho, Kang-Hee
    • The Korean Journal of Malacology
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    • v.26 no.2
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    • pp.145-149
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    • 2010
  • The effects of diluents composition on cold storage for Scapharca broughtonii (Schrenck) sperm were examined in the percentage of sperm activity and survival rate. Various diluents of glucose solutions (10 mM Hepes-pH 7.8), 600 mM NaCl, stein solution, Ringer's solution (230 mM NaCl, 8 mM KCl, 2 mM $CaCl_2$, 3.7 mM $MgCl_2$, 0.2 mM $NaHCO_3$, 10 mM Hepes-pH 7.8), 20%, 25% ASW (NaCl 2.7 g + KCl 0.07 g + $CaCl_2$ 0.12 g + $MgCl_2$ 0.46 g + $NaHCO_3$ 0.05 g + distilled water 100 ml) were used to store th sperm at $4^{\circ}C$. The storage effect was evaluated using sperm activity and survival rate. Ringer's solution was found to be better diluents which maintained high activity and survival rate of sperm for a storage period of 7 days. Optimal pH of diluents to store the sperm at $4^{\circ}C$ is 7.5.