• Journal of the Korean institute of surface engineering
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• v.27 no.3
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• pp.158-165
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• 1994

Cu-Cr alloy thin film requires good quality of etching be used for TAB technology. The etched cross sec-tion was clean enough when the etching was performed in 0.1M $FeCl_3$ solution at $50^{\circ}C$. The etching rate was increased with the amount of $KMnO_4$. For enhanced profile of cross section and rate, the spray etchning was found to be superior compared to the immersion etching. A series of experiments were performed to improve the uniformity of the current distribution in electrodeposition onto the substrate with lithographic patterns. Copper was electrodeposited from quiescent-solution, paddle-agitated-solution, and air-bubbled-solution to in-vestigate the effect of the fluid flow. The thickness profile of the specimen measured by profilmetry has the non uniformity at feature scale in quiescent-solution, because of the longitudinal vortex roll caused by the natural convection. However, uniform thickness profile was achieved in paddle-agitated or air bubbled solu-tion.

• Corrosion Science and Technology
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• v.23 no.2
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• pp.166-178
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• 2024

The localized corrosion resistance of UNS N07718 alloy was investigated after solution heat treatment. When the alloy was heat-treated at 1050 ℃ for 2.5 hours, it experienced an increase in average grain diameter, a reduction in grain boundary area, and the dissolution of delta phases along grain boundaries. Additionally, primary metallic nitrides (MN) and metallic carbides (MC), enriched with either Ti or Nb, were identified and exhibited a random distribution within the microstructures. Despite the solution heat treatment, the composition, diameter, and abundance of MNs and MCs remained relatively consistent. The critical pitting temperature (CPT), as determined by the ASTM G48-C immersion test, revealed similar values of 45 ℃ for both treated and untreated alloys. However, a decrease in maximum pit depth and corrosion rate was observed after the solution heat treatment. The microstructural changes that occurred during the heat treatment and their potential implications were discussed to understand the influence of the solution heat treatment.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.60-71
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• 2014

This study was conducted to identify the potential of rape stalk as a raw material for biorefinery process of rape flower. At first, rape stalk (RS) was immersed in distilled water (DW), acetic acid (AA), oxalic acid (OA), sulfuric acid (SA) and sodium hydroxide (SH) solutions, and the content of reducing sugars liberated from immersed RS was analyzed. Glucose, xylose, arabinose and sucrose were detected varying with the immersion type. In particular, 1% AA-immersion of RS for 72 hr was the most effective conditions to liberate glucose from RS. Secondly, the RS residues were used for elementary analysis and fabrication of fuel pellets. In addition to the solution type, concentration of immersion solutions (0%, 1%, 2%) and immersion time (24, 72, 120 hr) were used as experimental factors. The contents of nitrogen, sulfur and chlorine reduced effectively through the immersion of RS in DW, AA and OA solutions. For properties of RS-based pellets, bulk density and higher heating value of RS-based pellets greatly increased with the immersion of RS, and the qualities were much higher than those of the A-grade pellet of the EN standards. Ash content decreased remarkably through the immersion of RS, and was satisfied with the A-grade pellet standard. Durability was negatively affected by the immersion of RS, and did not reached to B-grade of the EN standard. In conclusion, acid immersion of RS can be a pretreatment method for the production of fuel pellet and bioethanol, but use of the immersed RS for the production of high-quality pellets might be restricted due to low durability of immersed-RS pellets. Therefore, further studies, such as investigation of detailed immersion conditions, fabrication of mixed pellets with wooden materials and addition of binders, are needed to resolve the problems.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.107-108
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• 2002

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.81-82
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• 1997

1. Introduction : The growth of membrane science was initiated by the invention of asymmetric membrane which can be formed by the technique known as phase inversion. The basic procedure of phase inversion involves casting a thin film of polymer solution onto a suitable substrate followed by immersion in a coagulation bath (quench step). Therefore, events occurring during the quench period, at which time solvent-nonsolvent exchange and eventual polymer precipitation take place, can play a controlling role in the determination of ultimate membrane structure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.520-523
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• 2000

Anti-ulcer effects of depolymerized alginate (HAG-10, average molecular weight 10,000; HAG-50, average molecular weight 50,000; HAG-100, average molecular weight 100,000) obtained by hydrolysis of alginate by heating at $121^{\circ}C$, against $HCl{\cdot}ethanol$ and water-immersion stress in rats were investigated. The acute gastritis, induced by $HCl{\cdot}ethanol$, and the gastric ulcer, induced by water-immersion stress, were inhibited dose-dependently by administration of HAG-50, HAG-100 and alginate. Histopathological lesions of the gastritis and gastric ulcer in rats treated with HAG-50, HAG-100 and alginate were significantly lower than those in rats fed with HAG-10. The inhibition rates (${\%}$) on acute gastritis induced by $HCl{\cdot}ethanol$ and gastritis ulcer induced by water-immersion stress in rats, were $13.00{\%}\;and\;15.74{\%}$of HAG-10, $41.15{\%}\;and\;35.72{\%}$ of HAG-50, $41.58{\%}\;and\;35.37{\%}$ of HAG-100, and $45.17{\%}\;and\;41.11{\%}$ of alginate, respectively. These results suggested that HAG-50, HAG-100 and slginate had a protective effect against the gastritis and gastric ulcer. The effect was not as visible when using HAG-10 in rats. From the present results, it was suggested that HAG-50 was an effective anti-ulcer agent against $HCl{\cdot}ethanol$and water-immersion stress in rats.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.217-221
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• 2003

Effect of direct addition of $CaCl_2$ into sodium alginate film-making solution and immersion of alginate films into $CaCl_2$ solutions on tensile strength (TS), percentage elongation at break (E), water vapor permeability (WVP), and water solubility (WS) of the films were investigated. TS of alginate films prepared by both methods increased. E of $CaCl_2-added$ films did not change significantly (P>0.05), whereas that of $CaCl_2-immersion$ films decreased significantly (p<0.05). WVP of films prepared by both methods decreased significantly, but the effect was more significant in the $CaCl_2-immersion$ films. Water resistance was not changed in the $CaCl_2-added$ films, whreras increased significantly in $CaCl_2-immersion$ films (p<0.05). Properties of alginate films depend on the concentration of $CaCl_2$ treatments in both methods, and they also depend on treatment time in the immersion method.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.292-296
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• 2018

Softening effects of enzyme following pre-treatments were examined. Four pre-treatments: raw (R), heat (H), heat and freeze-thawing (HFT), heat and freeze-drying (HFD) were applied to carrot. Subsequently, each treated sample was immersed in 10% celluclast enzyme solution for up to 6 h and then their properties were compared. The minimum and the maximum color change was observed in HFD and H, respectively. R showed no change in hardness after 6 h immersion, indicating that the enzyme did not penetrate the carrot. The number and size of pores were greater in samples undergone HFT or HFD as observed by microstructure analysis using SEM, and HFD caused 99.5% reduction in hardness after 6 h immersion. After 6 h immersion post-HFT or 3 h immersion post-HFD, the hardness was less than $20,000N/m^2$, indicating tongue ingestion was possible, and the samples retained their original shape and easily collapsed by spoon pressing.

• Korean Journal of Metals and Materials
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• v.48 no.6
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• pp.523-532
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• 2010

Co-application of organic coating and cathodic protection has not provided enough durability to low-alloyed steels inseawater ballast tank (SBT) environments. An attempt has made to study the effect of alloy elements (Al, Cr, Cu, Mo, Ni, Si, W) on general and localized corrosion resistance of steels as basic research to develop new low-allowed steels resistive to corrosion in SBT environments. For this study, we measured the corrosion rate by the weigh loss method after periodic immersion in synthetic seawater at $60^{\circ}C$, evaluated the localized corrosion resistance by an immersion test in concentrated chloride solution with the critical pH depending on the alloy element (Fe, Cr, Al, Ni), determined the permeability of chloride ion across the rust layer by measuring the membrane potential, and finally, we analyzed the rust layer by EPMA mapping and compared the result with the E-pH diagram calculated in the study. The immersion test of up to 55 days in the synthetic seawater showed that chromium, aluminium, and nickel are beneficial but the other elements are detrimental to corrosion resistance. Among the beneficial elements, chromium and aluminium effectively decreased the corrosion rate of the steels during the initial immersion, while nickel effectively decreased the corrosion rate in a longer than 30-day immersion. The low corrosion rate of Cr- or Al-alloyed steel in the initial period was due to the formation of $Cr_2FeO_4$ or $Al_2FeO_4$, respectively -the predicted oxide in the E-pH diagram- which is known as a more protective oxide than $Fe_3O_4$. The increased corrosion rate of Cr-alloyed steels with alonger than 30-day exposure was due to low localized corrosion resistance, which is explained bythe effect of the alloying element on a critical pH. In the meantime, the low corrosion rate of Ni-alloyed steel with a longer than 30-day exposure wasdue to an Ni enriched layer containing $Fe_2NiO_4$, the predicted oxide in the E-pH diagram. Finally, the measurement of the membrane potential depending on the alloying element showed that a lower permeability of chloride ion does not always result in higher corrosion resistance in seawater.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.185-189
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• 2012

A.c. impedances of mechanically polished CP-Ti specimens were measured at open-circuit potential (OCP) with immersion time and under applied anodic potentials between -0.2 and 1 $V_{Ag/AgCl}$ in 0.1 M NaOH solution. Capacitances of native oxide films ($C_{ox,na}$) grown naturally and capacitances of anodic oxide films ($C_{ox,an}$) formed under applied anodic potentials were obtained to examine the growth of native and anodic oxide films in 0.1 M NaOH solution and how to use $C_{ox,na}$ for the surface area measurement of Ti specimen. $1/C_{ox,na}$ and $1/C_{ox,an}$ appeared to be linearly proportional to OCP and applied potential ($E_{app}$), with proportional constants of 0.086 and 0.051 $uF^{-1}\;V^{-1}$, respectively. The $C_{ox,na}$ also appeared to be linearly proportional to geometric surface area of the mechanically polished CP-Ti fixture specimen, with proportional constants of 11.3 and $8.5{\mu}F\;cm^{-2}$ at -0.45 $V_{Ag/AgCl}$ and -0.25 $V_{Ag/AgCl}$ of OCPs, respectively, in 0.1 M NaOH solution. This linear relationship between $C_{ox,na}$ and surface area is suggested to be applicable for the measurement of real surface area of Ti specimen.