• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.5
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• pp.174-180
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• 2023

Porcelain (white ware, celadon ware) coated with a ferrous sulfate and ferrous/cobalt sulfate was sintered at 1250℃. The specimens were investigated by HR-XRD, FE-SEM, HR-EDS, and UV-vis spectrophotometer. Through X-ray rietveld quantitative analysis, quartz and mullite were found to be the main phases for white ware, and mullite and plagioclase were found to be the main phases for celadon ware. When the pigment of ferrous/cobalt sulfate was applied, were identified as an andradite phase for celadon ware and a spinel phase for the white ware, and the amorphous phase, respectively. The L^* value, which was the brightness of the specimen, was 72.01, 60.92 for white ware and celadon ware, respectively. The ferrous and ferrous/cobalt pigment coated porcelain had L^* values of 44.89, 52.27 for white ware and celadon ware, respectively; with a^* values of 2.12, 1.40, an d at b^* values of 1.45 and 13.79. As for the color of the specimens, it was found that the L^* value was greatly affected by the white ware, and the b^* value differed greatly depending on the clay. It was thought to be closely related to the production of the secondary phase such as Fe₂O₃ and andradite phase produced in the surface layer.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.247-254
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• 2005

General composition, total anthocyan content, and antioxidative and antimicrobial activities of Korean purple. fleshed potatoes (varieties A-D based on coloring degree of cross sections) were investigated. Slight differences in composition content were observed among varieties. Color intensity analyzed by sensory evaluation test decreased in order of PL-14, 31, 28, 3, 17, and 6, Total anthocyanin contents differed significantly among varieties from 3 to 29 mg Per 100 g, and decreased in order of PL-28, 31, 14, 12, 5, and 3. PL-28, 31, and Jasim potatoes showed slightly higher antioxidant activities than ${\alpha}$-tocopherol. PL-28, 31, 6, and Jasim showed antimicrobial activities against three species each of Gram-positive and-negative bacteria, with highest activities observed against Bacillus subtilis and relatively high activities against E. coli.

• Food Engineering Progress
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• v.13 no.2
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• pp.138-146
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• 2009

The crude polysaccharide fraction from fruit body of Auricularia auricula were obtained by using hot water extraction and ethanol precipitation. As the crude polysaccharide fraction contained the brownish dark colored compounds, the adsorption study of pigments from the crude polysaccharide using activated carbon was carried out. The pigment compounds showed an absorption characteristic with $\lambda_{max}$ of 230 nm and the absorbance at 230 nm was taken as color intensity. Adsorption capacity of pigment depended on increase of the activated carbon to sample loading ratio. The adsorption capacity increased with increase of pH and temperature in the pH range of 3.0-7.0 and temperature range of 25-40$^{\circ}C$, but decreased in the temperature range of 40-70$^{\circ}C$. The optimum capacity was obtained at addition of 16.7 mg activated carbon per mL sample solution (concentration = 3 mg/mL) at pH of 7.0 and temperature of 40$^{\circ}C$. Treatment for 10 min was sufficient to achieve the 80% decolorization and 1.25 fold purification of polysaccharide. Langmuir isotherm and pseudo second-order kinetic model provided the best fitting for adsorption of the brownish dark colored compounds onto powdered active carbon. The activation energies of adsorption from the Langmuir isotherm parameter in the ranges of 25-40$^{\circ}C$ and 40-70$^{\circ}C$ was -2.54 and 4.38 kcal/g, respectively. The results of low activation energy also indicated that the adsorption process was a physical adsorption which was controlled by diffnsion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.66-72
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• 1983

In order to improve the quality of salted sea mustard, the conditions of blanching, salting, and storage were examined. The process in which sea mustard was blanched for 20 seconds in boiling seawater, soaked in saturated brine solution for 20 hours and then salted for 10 hours by the spreading 10~20% (w/w) of granulated dry salt to obtain the moisture content of about 60% or below, resulted a good color retention of chlorophyll and carotenoid pigments, and organoleptic quality. The shelf-life of the product estimated by 30-40% pigment retention was 50-60days when stored at $4^{\circ}C$ or below.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.123-135
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• 2018

This study tried to find the clue to Seokrok province by comparing Seokrok used in painting culture properties with Seokrok ore from domestic occurrence and imported Seokrok ore. To this end, chemical and mineralogical characteristics of painting cultural properties were identified with portable X-ray Florescence (p-XRF), micro X-ray diffraction (micro XRD) and SEM/EDS Analysis. To obtain Pb isotopic ratio, the Pb contained in Seokrok has been analyzed with Thermal Ionization Mass Spectrometer. Atacamite (or botallackite) and small quantity of brochantite were identified from Seokrok in Dancheong, and malachite was also identified from Buddhist painting besides those two ingredients. Without distinction of type, most Seokrok used in painting cultural properties is atacamite composed of Cu and Cl. From Pb isotope analysis, it was found that Seokrok in painting cultural properties was closer to that of north Korea, north China and Japan than south Korea as in regional division for East North Asia suggested by Mabuchi. The Pb isotopic ratio of domestic green mineral belongs to the distribution of Seokrok inside the painting cultural properties but imported malachite showed considerably difference. Considering the fact that atacamite, the main mineral of Seokrok in painting cultural properties is rarely produced from southern mine of the Korean Peninsula and the result of Pb isotope analysis.

• Journal of Conservation Science
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• v.34 no.5
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• pp.397-405
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• 2018

Currently, there are very few studies on Korean wall paintings. Therefore, this study discusses the current conditions of wooden paintings and the characteristics of the adhesive agent in the painting layer separation. Korean land pine was chosen as the support, while white oysters shells, orpiment, red ocher, Noerok, and azurite were used as pigments. With four adhesive agents, including animal glue, Gelidium, methyl cellulose, and PVAc (caparol binder), a comparative experiment was conducted, by dividing them into two concentrations, of 0.5% and 1.5%. The temperature, humidity, and ultraviolet rays, which are contributing environmental factors in cultural assets after fixing, were artificially investigated. After deterioration, observed color difference, fixing, and the surface. Results showed that the animal glue strongly fixing all the colored layers compared to the other adhesives; however, azurite had a partial change when used outdoors. With Gelidium, which functioned similar to animal glue, the azurite was affected by the ultraviolet rays; nevertheless, despite the variations in temperature and humidity, it had the best gripping force compared to the other adhesive agents. Methyl cellulose was glossy at a high concentration, and was relatively strong against rapid changes in temperature and humidity. PVAc significantly reduced the binding force, compared to other adhesive agents.

• Journal of Life Science
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• v.32 no.5
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• pp.411-419
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• 2022

Carotenoids are red, orange, and yellow fat-soluble pigments that exist in nature, and are known as physiologically active substances with various functions, such as provitamin A, antioxidant, anti-inflammatory, and anticancer. Because of their physiological activity and color availability, carotenoids are widely used in the food, cosmetics, and aquaculture industries. Currently, most carotenoids used industrially use chemical synthesis because of their low production cost, but natural carotenoids are in the spotlight because of their safety and physiologically active effects. However, the production of carotenoids in plants and animals is limited for economic reasons. Carotenoids produced by bacteria have a good advantage in replacing carotenoids produced by chemical synthesis. Since carotenoids produced from bacteria have limited industrial applications due to low productivity, studies are continuously being conducted to increase the production of carotenoids by bacteria. Studies conducted to increase carotenoid production from bacteria include the activity of enzymes in the bacterial carotenoid biosynthesis pathway, the development of mutant strains using physical and chemical mutagens, increasing carotenoid productivity in strain construction through genetic engineering, carotenoid accumulation through stress induction, fermentation medium composition, culture conditions, co-culture with other strains, etc. The aim of this article was to review studies conducted to increase the productivity of carotenoids from bacteria.

• Journal of Life Science
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• v.32 no.5
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• pp.355-361
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• 2022

Melanin pigments are the main cause of skin color. They are produced in melanocytes and then transferred to keratinocytes, which eventually gives the skin surface a variety of colors. Although many skin-lightening or depigmenting agents have been developed, the demand for materials to reduce pig- mentation is still increasing. Here, we tried to find materials for skin-lightening or depigmentation using natural compounds and found that mistletoe (Viscum album var. coloratum) extracts (ME) had an inhibitory effect on tyrosinase activity. As a result, ME significantly reduced pigmentation in human primary melanocytes. In addition, a promoter reporter assay revealed that ME inhibited the transcription of microphthalmia-associated transcription factor (MITF), melanophilin (MLPH), tyrosinase-related protein-2 (TRP-2), and tyrosinase (TYR) genes in HM3KO melanoma cells. In addition, ME decreased the protein level for pigmentation-related molecules, such as TYR and TRP-1. Furthermore, it markedly inhibited the melanogenesis of zebrafish embryos, an in vivo evaluation model for pigmentation. To elucidate the action mechanism of ME, we investigated its effects on intracellular signaling. Eventually, the ME dramatically decreased the phosphorylation of the cAMP responsive element binding protein (CREB), AKT, and ERK. The data suggest that ME may inhibit the melanogenesis pathway by regulating the signaling pathway related to pigmentation. Taken together, these data propose that ME can be developed as a depigmenting or skin-lightening agent.

• Mycobiology
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• v.32 no.1
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• pp.1-5
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• 2004

The present study was carried out to investigate morphological characteristics of pseudosclerotia of Grifola umbellata formed by artificial cultures. Isolate G. umbellata DUM GUS-01 was obtained from sclerotium cultivated in field. The fungal isolate was cultured on PDYM broth, PDYMA(potato dextrose yeast malt agar) and oak sawdust media at $20^{\circ}C$ under the dark condition. G. umbellata DUM GUS-01 showed a volumetric increment of fungal lumps rather than mycelial growth. Particularly, G. umbellata DUM GUS-01 produced a large amount of melanin pigments in all culture treatments. The color of the fungal mass has been changed into grey gradually, and then formed melanized rind-like structure on its superficial part. The fungal structures which were covered with melanized rind-like layer were named as pseudosclerotia of G. umbellata. The pseudosclerotia of G. umbellata DUM GUS-01 formed a new white mycelial mass, which was swollen out of the melanized rind structure for its volumetric increment. When the pseudosclerotia were sectioned, their structure was discriminated from two structures such as a melanized rind-like structure layer formed by aggregation of aged mycelia and a white mycelial mass with high density. As results of scanning electron microscopic examination, the pseudosclerotia of G. umbellata DUM GUS-01 which were formed in in vitro conditions were similar to the sclerotia of G. umbellata cultivated in natural conditions except for the crystals formed in medula layer of natural sclerotia. Although size, solidity of rind structure and mycelial compactness of pseudosclerotia were more poor than those of natural sclerotia, the morphological structure and growth pattern of pseudosclerotia were very similar to those of natural sclerotia. Therefore, it is probable to induce pseudosclerotia to sclerotia of G. umbellata in in vitro conditions. Consequently, it seems that the induced pseudosclerotia can be used as inoculum sources to substitute natural sclerotia in field cultivation.

• Journal of Conservation Science
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• v.30 no.2
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• pp.123-136
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• 2014

Considering that decision in conservation treatment for damaged objects should consider not only various options of methodology of intervention but also possible consequences of different types of intervention, it is a difficult task to decide and propose clear and safest solution of preserving an object. In addition, it should be constantly challenged by conservators even if it is proved technique or methodology in a past treatment. Therefore, there is no absolute solution which can be applied to all practice but each decision can be different case by case. It is not possible to estimate the way how the present condition of material and environmental aspects would affect to the condition of an object in future. However if conservators keep trying to set out various ways of analysing pro and against effect of past treatments, it would be able to provide useful logics of proving efficiency and appropriateness of a certain treatment. Understanding that the advantage of laser technique is to adopt a way of cleaning an object without making a direct contact, which is different from other techniques, this paper aims at securing stability of laser techniques, although it remains a limitation in the compatibility to all other materials. This study has examined reacting process on the painted pigments against laser beam by using CLSM in order for it to display both the problems from such reacting process and the efficiency of it as a cleaning methodology. It has intended to estimate the result of laser techniques and propose the range of applicability.