• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1289-1295
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• 2004

In this paper, degradation in field-aged PV modules including degradation of interconnect, discoloration of encapsulant and hot spot have been observed and analyzed. From the results, photovoltaic module installed for 6 years shows around 16 % drop of electrical properties due to the interconnect degradation and PV module passed 18 years has been found to drop of around 20 % mainly by the encapsulant discoloration. Furthermore the difference between low and high temperature of PV array at hot spot goes up to 3$0^{\circ}C$ and it leads to interconnect degradation. On the other hands, the temperature difference was observed to be around 15$^{\circ}C$ at the encapsulant discoloration spot of PV array.

• Korean Journal of Rural Living Science
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• v.10 no.1
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• pp.1-6
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• 1999

Dyeing and discoloration effects on the fabrics of cotton, silk and rayon with unriped persimmon juice were investigated. Color of dyed fabrics treated with persimmon juice only, added 3% tartaric acid or 3% aluminium sulfate was not different each other. Dyeing assistants such as tartaric acid or aluminium sulfate were effective on the prevention from discoloration of dyed fabrics and ultraviolet rays. Discoloration were supposed to derive from tannin in unriped persimmon, ultraviolet rays, oxygen, enzyme and so on, ultraviolet rays at wavelength of 253.7nm was the most active the chromatophores and discoloration. The fabrics could be dyed, when unriped persimmon juice was store at low temperature or freezing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.28-32
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• 2004

In this paper, degradation in field-aged PV modules including degradation of interconnect, discoloration of encapsulant and hot spot have been observed and analyzed. From the results, photovoltaic module installed for 6 years shows around 16% drop of electrical properties due to the interconnect degradation and PV module passed 18 years has been found to drop of around 20% mainly by the encapsulant discoloration. Furthermore the difference between low and high temperature of PV array at hot spot goes up to $30^{\circ}C$ and it leads to interconnect degradation. On the other hands, the temperature difference was observed to be around $15^{\circ}C$ at the encapsulant discoloration spot of PV array.

• Restorative Dentistry and Endodontics
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• v.37 no.2
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• pp.119-122
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• 2012

Regenerative endodontics has a potential to heal a partially necrotic pulp, which can be beneficial for the continued root development and strengthening of immature teeth. For this purpose, triple antibiotic mixture of ciprofloxacin, metronidazole, and minocycline was recommended as intracanal medicament in an attempt to disinfect the root canal system for revascularization of a tooth with a necrotic pulp. However, discoloration of the tooth was reported after applying this. This case shows the idea for preventing the tooth discoloration using a delivery syringe to avoid the contact between the clinical crown and the antibiotics.

• Journal of Technologic Dentistry
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• v.1 no.1
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• pp.11-13
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• 1979

이런 기법을 통해 porcelain의 변색이 합금에 포함된 silver의 탓이라고 충분히 이해할 수는 없을 것이며 변색을 완전히 제거할 수 있는 기술적인 방법도 없다. 단지 그것을 조절할 수는 있다는 것이다.

• The korean journal of orthodontics
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• v.23 no.3 s.42
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• pp.327-340
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• 1993

The purpose of this study was to estimate the possibility of practical application of TiN ion-plating method on orthodontic appliances. TiN was coated on the surface of orthodontic stainless steel roll band by means of ion-plating method, and colorimetric properties of its obtained TiN film were investigated by using color analyzer. Also its corrosion and discoloration properties were compared with those of non ion-plated stainless steel roll band by using immersion test, which was done in 1N HCl solution for 10 days. Both weight changes and surface corrosion appearances of specimens for each day were respectively investigated by using electronic weighing machine and SEM(Scanning Electron Microscope). The discoloration degress of TiN-coated specimens immersed in 1N HCl solution were investigated by using color analyzer and then judged by N.B.S.(National Bureau of Standard) Unit. The results of this study were summarized as follows. o TiN ion-plated films showed the hue of 5Y, the value of 7, and the chroma of 3 by Munsell notations. o The weight losses and surface changes of TiN ion-plated specimens immersed in 1N HCl solution were less than those of non ion-plated specimens. It was shown, therefore, that the corrosion resistance was significantly improved by TiN ion-plating. o The discoloration degrees of non ion-plated specimens were too significant to be examined by color analyzer, while those of TiN ion-plated specimens were slight when judged by N.B.S. Unit. It was also apparent, therefore, that the anti-discoloration property was significantly improved by TiN ion-plating.

• Journal of Conservation Science
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• v.34 no.2
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• pp.77-85
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• 2018

In order to understand the influence of light artifact discoloration, priority must be given to the reaction characteristics of the light the materials constituting the product. In this study, we focus on two representative medium, animal glue and linseed oil which constitute the colored layer of the painting relics. This study is based on an accelerated degradation test using two types of light emitting diods (LEDs) with different wavelength characteristics. In the experiments, discoloration appeared markedly in the animal glue and linseed oil under accelerated aging test conditions using Blue LED. Among the two types of LEDs, the degree of discoloration of the material was much higher with the Blue LED having the total radiation flux (mW). This indicates that the discoloration of painting artifacts such as animal glue and linseed oil is more significantly influenced by the total radiation flux (mW) of the light source than the total luminous flux (lm).

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.76-84
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• 2008

This study was conducted to find out the cause of discoloration after pressing yellow-colored flowers. Plant materials used were Lilium Asiatic Hybrids, Oncidium spp., Rosa hybrida, $Tulipa{\times}gesneriana$, Antirrhinum majus, Dianthus caryophyllus, Freesia hybrida, Zantedeschia elliottiana, Gerbera jamesonii, Helianthus annuus, and Ranunculus asiaticus. Thickness, ratio of length to width, and water content of petals did not considerably affect discoloration of pressed flowers. Expression of yellow color in petals was caused by carotenoids in Lilium Asiatic Hybrids, Oncidium spp., Rosa hybrida and $Tulipa{\times}gesneriana$, by flavonoids in Antirrhinum majus, Dianthus caryophyllus, Freesia hybrida and Zantedeschia elliottiana, and by coexistence of carotenoids and flavonoids in Gerbera jamesonii, Helianthus annuus and Ranunculus asiaticus. Carotenoids that expressed yellow color in petals affected significantly on discoloration in pressed flowers containing carotenoids alone or both carotenoids and flavonoids. However, discoloration was hardly ever found in yellow-colored species as affected by flavonoids. Dark treatment was effective for almost perfect preservation in color of pressed flowers, while light treatment resulted in severe discoloration.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.43-50
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• 2012

The concept of revascularization of necrotic pulps regained interest and became an alternative conservative treatment option for young permanent teeth with immature roots. Revascularization of immature teeth with apical periodontitis depends mainly on disinfection of the canal. Since the infection of the root canal system is considered to be polymicrobial, a combination of drugs would be needed to treat the diverse flora. A triple antibiotic mixture of metronidazole, ciprofloxacin, and minocycline was used as an intracanal medicament. However, discoloration was developed after applying the triple antibiotic mixture. It is believed that the marked discoloration is related to the use of minocycline. The aim of this article was to present cases of coronal discoloration after triple antibiotic therapy in immature tooth and was treated with bleaching technique to control coronal discoloration. In conclusion, revascularization by using triple antibiotics promotes a paradigm shift in treating endodontically involved permanent teeth. However, we should understand that triple antibiotics containing minocycline induces tooth discoloration. Further research to prevent coronal discoloration should be investigated and suggested for the safe use of triple antibiotics.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.378-383
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• 2017

There are many reasons for tooth discoloration. An increase in the bilirubin level may cause tooth discolorations. Such cases are rare, but most involve tooth discoloration with a greenish hue. The purpose of this case report is to describe green discoloration of the primary dentition in the presence of neonatal hyperbilirubinemia. 2 boys aged 16 and 22-months presented with chief complaints of erupting teeth of abnormal color. Their primary teeth exhibited a greenish discoloration along enamel hypoplasia. Both patients were born prematurely with a low birth weight and had been diagnosed with neonatal hyperbilirubinemia. Systematic diseases can affect the hard tissue of teeth during their formation and result in changes in tooth color. Periodic follow-ups are required for establishing a normal dental condition and meeting the esthetic needs of patients. A pediatric dentist may be the first person to observe patients with discoloration in their primary dentition. In such cases the dentist can deduce the systematic disease responsible for this discoloration.