• Computers and Concrete
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• v.3 no.6
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• pp.401-422
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• 2006

A multi-species model based on the Nernst-Planck equation has been developed by using a finite volume method. The model makes it possible to simulate transport due to an electrical field or by diffusion and to predict chloride penetration through water saturated concrete. The model is used in this paper to assess and analyse chloride diffusion coefficients and chloride binding isotherms. The experimental assessment of the effective chloride diffusion coefficient consists in measuring the chloride penetration depth by using a colorimetric method. The effective diffusion coefficient determined numerically allows to correctly reproduce the chloride penetration depth measured experimentally. Then, a new approach for the determination of chloride binding, based on non-steady state diffusion tests, is proposed. The binding isotherm is identified by a numerical inverse method from a single experimental total chloride concentration profile obtained at a given exposure time and from Freundlich's formula. In order to determine the initial pore solution composition (required as initial conditions for the model), the method of Taylor that describes the release of alkalis from cement and alkali sorption by the hydration products is used here. Finally, with these input data, prediction of total and water-soluble chloride concentration profiles has been performed. The method is validated by comparing the results of numerical simulations to experimental results obtained on various types of concretes and under different exposure conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.25-26
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• 2018

In this study, the device was developed for evaluating the effect of pressure on chloride ion penetration of concrete. And chloride-ion penetration depth and water soluble chloride contents was evaluated concrete using ordinary portland cement and blast-furnace slag cement using developed device. As a result, chloride ion penetration of concrete was promoted according to the action of pressure and the exposure period. and the incorporation of blast-furnace slag was effective for chloride attack resistibility under pressure.

• Magazine of the Korea Concrete Institute
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• v.6 no.2
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• pp.129-137
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• 1994

This study was performed for the purpose of obtaining the fundamental data to establish the criterion of concrete deterioration and presuming steel corrosion of concrete structures under the environment of seawater. Steel embedded concrete specimens were exposed in seawater for 1year. The soluble chloride content in concrete, corrosion potential and steel corrosion were considered. The results show that soluble chloride content in concrete was decreased with lower water-cement ratio and with mineral admixtures. Half-cell potential is reduced with steel corrosion. Corrosion area ratio is correlative with half-cell potential.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.23-25
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• 1957

The herb of Geranium sibirium L, a drug knwon as "Chui Sonni Poul" distributed widely, has been used as a folk-medicine for the treatment of diarrhea. The dried entire herb is boiled with methanol and methanol is distilled of from the filtered methanol extract under reduced pressure. Then the extract is boiled with water and filtered off. From the filtrate, the following substances are isolated and identified by treating with organic solvents as ether, ethyl acetate, and etc.: 1. Gallic acid: a colorless needle crystal which is soluble in alcohol and water. mp.235.deg. C, positive (dark blue) against the ferric chloride reagent. 0.76 percent of gallic acid is yielded from the herb. 2. Quercetin: a light yellow crystal. mp.194.deg. C. negative against the ferric chloride reagent. 3. Ellagic acid: a light yellow crystal which is insoluble in ehter and acetone and slightly soluble in alcohol. Positive (blue) against the ferric chloride reagent. The crystal obtained by recrystalisation from pyridine, does not melt by 360.deg. C. Represent a yield of 0.03 percent from the herb. 4. Crude tannin: a approximately 7.6 percent of crude tannin is yielded by treating with ethyl acetate. gallic acid and querceetin are yielded by hydrosis with dliute sulfuric acid. Based on the above results, the following suggestion could be recommendable; Geraed in the Japanese Pharmacoeia VI.acoeia VI.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.51-52
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• 2016

This paper researches the Chloride Binding of Cement Paste according to the Ca/Si and Ca/Al Ratio. The mechanisms of chloride ion binding are not completely known, although it is believed that Alumina contents in cementitious system have an important role. For changing cement paste composition, Ordinary Portland Cement(OPC) paste is substituted by Granulated Ground Blast Slag(GGBS). With increasing the ratio of GGBS substitution(Thus alumina contents is increasing), The chloride binding capacity has a tendency to increase of binding chloride ion capacity.

• Journal of Ginseng Research
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• v.16 no.2
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• pp.99-104
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• 1992

Korean red ginseng and water extract residue of red ginseng roots were treated with dry heat and incorporated in PDA medium to examine the effect of the materials on induced tolerance against mercury chloride and mycelial growth of Fusarium oxysporum. Ginseng residue was not effective in the inducement of tolerance to mercury chloride regardless of dry heat treatment. However, the heat treatment of ginseng and ginseng residues stimulated the mycelial growth of the fungus. The materials responsible for the detoxification appeared to be water-soluble. The stimulation of the fungal mycelial growth on the media by the heat treatment was highest in the water extract of ginseng. Due to the heat treatment, the mycelial growth was also slightly increased in n-hexane and methanol extracts of ginseng, compared with the ginseng fractions without dry heat treatment.

• Nuclear Engineering and Technology
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• v.43 no.3
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• pp.195-204
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• 2011

The effects on pool boiling heat transfer of aqueous solutions of boric acid ($H_3BO_3$) and sodium chloride (NaCl) as working fluids have been studied. Borated and NaCl water were prepared by dissolving 0.5~5% volume concentration of boric acid and NaCl in distilled-deionized water. The pool boiling tests were conducted using $1{\times}1\;cm^2$ flat heaters at 1 atm. The critical heat flux (CHF) dramatically increased compared to boiling pure water. At the end of boiling tests it was observed that particles of boric acid and NaCl had deposited and formed a coating on the heater surface. The CHF enhancement and surface modification during boiling tests were very similar to those obtained from boiling with nanofluids. Additional experiments were carried out to investigate the reliability of the additives deposition in pure water. The boric acid and NaCl coatings disappeared after repeated boiling tests on the same surface due to the soluble nature of the coatings, thus CHF enhancement no longer existed. These results demonstrate that not only insoluble nanoparticles but also soluble salts can be deposited during boiling process and the deposited layer is solely responsible for significant CHF enhancement.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.463-474
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• 2010

In this study, chemical coagulation conditions for treating combined sewer overflow(CSO) occurred during rainy season were evaluated by jar tests with aluminum sulfate[$Al_2(SO_4)_3{\cdot}17H_2O$] and ferric chloride[$FeCl_3{\cdot}6H_2O$]. The raw domestic sewage sampled from the primary sedimentation tank at a local sewage treatment plant was filtered through $150{\mu}m$ sieve before using. Point of zero charge(PZC) for various dose of aluminum sulfate occurred at pH 5.8-6.5, while for ferric chloride occurred at pH 5.3-6.0 in term of streaming current(SC) values. Charge neutralization ability of aluminum sulfate was bigger than that of ferric chloride. Optimum pH and dose of aluminum sulfate and ferric chloride were 6.2, 0.438mM and 5.8, 0.925mM, respectively. Removal efficiencies of TCOD, turbidity, SS and TP were 75, 97, 95, 96% with aluminum sulfate and 74, 96, 98, 99% with ferric chloride at their optimum coagulation conditions. More efficient removal of SS, TP and small particles was possible with ferric chloride at optimum coagulation conditions. Both SC values and COD removal started to increase where soluble phosphorus was completely removed.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.57-63
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• 1971

1) Among five lactic acid bacteria examined, Str. thermophilus and Str. diacetilactis produced remarkably greater amount of acids in soybean milk than Str. lactis, Str. cremoris and L. bulgaricus. 2) Soybean milk and skimmed dry milk were combined in the ratio of 7 : 3 and were carried out in lactic acid fermentation for 24 hours at optimum temperature. The result indicated that the yield of precipitation and protein content of it were the most, the moisture content was the least and curd structure formed was considered too hard. 3) Based on these and other results, following procedure was used for manufacturing: soybean milk and skimmed dry milk were combined in the ratio of 7 : 3, heated at $121^{\circ}C$ for 20 min., cooled, added Str. thermophilus as lactic acid starter and incubated for 24 hours and $37{\pm}1^{\circ}C$. The curd was cooked, hooped, and pressed for 24 hours, to the surface of which, Penicillium caseicolum and sodium chloride were spread. During ripening of the curd at $15^{\circ}C$ and $85{\sim}90%$ RH for 21 days, Pen. caseicolum was highly developed after 7 days, pH was increased and proteolytie activity has reached to the peak point after 14 days. After 7 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino acids nitrogen were begun to increase. After 21 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino-N reached to 52%, 32% and 14% of total nitogen. In the soybean cheese, after 21 days of ripening, 17 or more kinds of amino acids were detected by two-dimentional paper chromatography. The product contained 63.2% of moisture, 17.5% of crude protein, 13.2% of crude fat, 2.8% of crude ash and 2.5% of sodium chloride.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.52-53
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• 2018

As a result of exposing the concrete at 1 and 6 atm in order to evaluate the salt resistance of the pressurized marine concrete, the pressure resulted in promoting the chloride ion penetration of the concrete. Particularly, the amount of water soluble chloride in the surface area tends to increase rapidly, and this cause is considered to be highly correlated with the size of the capillary pores of the concrete. On the other hand, the blending of blast furnace slag was effective to increse chloride attack resistibility even under the pressure.