• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.427-430
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• 1995

• 보존과학연구
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• s.33
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• pp.57-67
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• 2012

The Uiseong Tapriri Five-Storied stone pagoda has occurred exfoliation, granular disintegration and discoloration by physical and chemical weathering factors with the major deterioration occurring due to efflorescence by salt. According to the results of SEM-EDS and X-ray diffraction analysis, salts consists of gypsum, taranakite. Artificial salt weathering tests were carried out using the same type of rocks as those in the stone pagoda. The test results showed that efflorescence occurred on the surface of the rock, and that exfoliation and granular disintegration occurred inside the rock due to salt crystallization.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.173-176
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• 1994

Stem and petiol explants of peony culture turned to brownish black soon after placing onto medium and degenerated to death. Disroloration was caused mainly by ferrous and calcium cloride. Nitrate was a main factor for the death of culture. The culture damage was increased with the increment of the medium salt strength. A few latent axillary buds were elongated to shoots without forming callus.

• Korean Journal of Environmental Agriculture
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• v.15 no.1
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• pp.77-85
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• 1996

Chestnut(Castanea crenata) were trunk-injected by two methods to check the changes around the injection wound. In September 1993, high concentration of oxytetracycline(OTC) was injected through the injection wound of 1cm diameter and low concentration of OTC through 0.5cm diameter. Trunk diameter of injected trees ranged from 10cm to 20cm. All trees were in their vigorous conditions. Tree reaction was examined in June, 1994. None of them showed any sign of decay by the time. However, under the bark, sapwood was remarkably discolored. But, more severe discoloration was found in 1cm-injection wound than in 0.5cm one. Sapwood of some trees split from the injection wound, and the split was longer in 1cm-injection wounded trees than in 0.5cm trees. From the split, callus grew out and the split was closing. In this kind of trunk injection, the damage was more severe in 1cm-injection wound than in 0.5cm-injection wound.

• Journal of Conservation Science
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• v.30 no.2
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• pp.157-168
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• 2014

This study, by selecting 3 kinds(Polish T, H, C) of metal polish being frequently used for silver archival objects treatment at present, a polish having excellent conservative property that minimizes damage of silver surface while effectively removing its yellow discolored layer by each using tool was intended to be discovered by comparing performance of tarnish inhibitor, corrosion inhibitor contained in each polish. As a result of analysis, it was confirmed that specimen that was cleaned with cotton swab and lint-free wipe by using Polish C provides not only uniformed surface expression and minimum damage but also removal function of corrosion layer. In addition, even though tarnish inhibition film should be formed after polish treatment, discolored phenomenon is unable to be prevented but among those polishes, Polish C was represented to be most stable against UV and yellowing and it showed relatively better features than that of Polish H and T in terms of hydrophobic, dispersive property. Through this, it is confirmed that Polish C would show the most excellent performance among polishes being used for conserving silver archival objects.

• Journal of Conservation Science
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• v.26 no.4
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• pp.385-395
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• 2010

This study aimed to identify weathering factors and to assess the conservation environment through microclimatic analysis of Hyeonpung Seokbinggo (ice-storing stone warehouse). The stone blocks inside Seokbinggo suffered crack, displacement, break-out, exfoliation, efflorescence, brown and black discoloration, and biological colonization. Biological colonization represented the maximum deterioration rate(24%) among those weathering forms. The indoor microclimate showed parallel patterns with outdoor one, but the indoor temperature and relative humidity ranged far narrower than outdoor and remained steady. The environmental characteristics resulted from blocking-out of outdoor heat by the closed entrance and surrounding microtopography. This prevented water condensation and freezing effects, so that it reduced physical deterioration of rock, and maximized ice-storing effect for long time. However, contrary to positive effect, extremely high relative humidity over 99% accelerated biological colonization inside the Seokbinggo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.211-214
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• 1988

The thermal drying of chestnut powder showed a distinct discoloration from yellow to reddish brown color and resulted in a decrease in lysine content of chestnut protein. Chanted powders were blanched in hot solutions of 0.1% sodium bisulfate, 0.2% alum, 0.05% vitamin C and 0.1% citric acid and dried for 7 days in $50^{\cire}C$ of heatine drier. The color difference values in contrast with the original chestnut powder were 1.05, 1.24, 3.47 and 3.34, respectively. In particular, the effect of 0.1% potassium metabisulfide was distinguished. Under the blanching conditions used, a blanching period of 3 min resulted in the most favorable color of chestnut powder.

• Journal of Conservation Science
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• v.34 no.2
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• pp.69-76
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• 2018

Lead-based pigments (Lead White, Massicot, and Red Lead) are known to cause discoloration easily in indoor air environments. This study was conducted to investigate the effect of representative indoor air environment factors ($O_2$, $CO_2$) on lead-based pigments. As a result of the experiment, almost all of the specimens showed changes of more than ${\Delta}E=5.0$ in their values of chromaticity under $O_2$ (99%, RH 99%) and $CO_2$ (36,000 ppm, RH 99%) environments. Scanning electron microscopy also showed that the pigment particles lose sharpness of the edge. Furthermore, under the degradation, the intensities of the characteristic peaks in the X-ray diffraction patterns were decreased, and Lead White, Massicot, and Red Lead exposed to $CO_2$ (36,000 ppm, RH 99%) were shown to include the new material cerussite ($PbCO_3$). In particular, Plattnerite ($PbO_2$) was identified on Massicot, and for white lead, the characteristic peaks disappeared and those of Cerussite were identified. It was confirmed that chemical change with discoloration can occur when these lead-based pigments are exposed to a high-humidity $CO_2$ environment.

• The Journal of the Petrological Society of Korea
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• v.17 no.2
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• pp.95-107
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• 2008

The Carved Buddhist Triad on Rock-cliff in Sinarnri (Treasure No. 680) consists of biotite granodiorite, which were positively carved on fore and west planes of four subvertical cliffs by two joint sets of NE-SW and NNW-SSE directions. The cliffs are $N50^{\circ}E\;85^{\circ}SE$ in fore plane, $N25^{\circ}W\;90^{\circ}$ in west plane, $N40{\sim}50^{\circ}E\; 82{\sim}85^{\circ}NW$, back plane, $N20^{\circ}W\;75^{\circ}SW$ in east plane, which are parallel to two joint sets of NE-SW and NNW-SSE directions in geology around it. The chemical index of alteration ranges 60.3 to 62.0 from the major elements in the rock that was weathered into producing kaolin minerals from alteration of feldspars and biotite. The Buddhist image has been deteriorated into joints, brown rusts, discolorations and granular disintegrations by such deterioration causes as deformation, moisture, temperature variation and microorganic living. The moisture, which leaks from groundwater in the rock, dissolve to decompose minerals.

• Food Science and Preservation
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• v.12 no.2
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• pp.151-155
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• 2005

General problems on the quality in circulation process of Kochujang are fluidity, separated water at upper layer, and color change to dark-brown. Rice powders, glutinous rice powder and gelatinized rice powder, gelatinized glutinous rice powder were applied for solving such problems to Kochujang. Relationship between blending ratio of com syrup and fluidity had a linear correlation. Water separation in Kochujang was prevented by addition of gelatinized cereal powders, and gelatinized glufinous rice powder was most effective. Optimal amount of gelatinized glutinous rice powder was $0.5\~1.0\%$ (w/w).