• Journal of Conservation Science
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• v.29 no.1
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• pp.1-14
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• 2013

The Hongjimun Ogansumun (Five-arched floodgates) is composed mainly of biotite granite, pink feldspar granite and granodiorite that are very similar with granitic rocks around the Seoul. Main damage in the floodgates was gray, yellow and predominantly white discoloration on the surface of stone blocks. All floodgates showed more discoloration in the wall than ceiling, and there were growing stalactite on the ceiling. Scientific analyses determined that the white discoloring substrates were mainly calcite. Therefore, conservation treatment was carried out to remove the substrates by using dry cleaning, high pressure cleaning and chemicals. The floodgates have been restored to good state, but it is still significantly necessary to install drainage on the top of the gates.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.102-103
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• 2002

금속 입자들이 채워진 유리는 광 호변성 물질로써 광 저장 디스크, 광 도파로 그리고 도파로 레이저, 광 스위치 등의 다양한 응용분야에 이용될 수 있음이 여러 연구진들에 의해서 밝혀져 왔다. [1] 광 호변성이란 외부에서 입사되는 광에 의해서 유리의 색이 변색되는 현상인데 이는 유리에 함유된 물질들이 광이나 열에 의해서 변화하기 때문이다. Wood 등은 열처리와 불꽃에 의한 가열 등을 이용하여 은 입자를 작은 입자로 쪼개고. 이를 엑시머 레이저로 열처리시키면 은 입자가 분해된다는 것을 보였다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.107-109
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• 2000

식품을 가공ㆍ저장하는 동안에 발생하는 효소적 갈변현상은 외관의 변색에 의한 소비자의 기호성을 저하시킬 뿐만 아니라 상품의 가치를 하락시켜 경제적인 손실을 초래 할 수 있으므로 식품 가공에 있어서 중요한 분야이다. 우렁쉥이는 양식 기술의 향상에 힘입어 한시적으로 대량 생산되는 물량에 비해 그 이용은 대부분 생식에 의존하므로 대량소비의 가공품 개발이 요청된다.(중략)

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.364-367
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• 2001

lithography를 사용하여 패턴 형성에 이용되는 감광성 고분자 바인더 수지로는 통상 아크릴수지 또는 폴리이미드 수지가 사용된다. 폴리이미드 수지는 양호한 성능을 나타내지만 패턴 형성에 난점이 있다. 반면 아크릴수지는 패턴현상성은 우수하지만, 내열성능이 폴리이미드 수지보다는 낮기 때문에 고온 고습하에 기판을 장시간 방치한 경우, 화소내 도막의 변색이나 중량감소 등 여러 문제가 생길 수 있다. (중략)

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.22-30
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• 1995

Responses of Pospam-injected chestnut and pine trees to drill wound were examined. Pospam was injected into the stem by just filling up the drill wound in September 10, 1993. The diameter of the injection wound were 0.5 and 1cm. DBH of chestnut trees and pine trees injected were 10, 15, 20 and 10, 20, 30cm, respectively. The results of tree response were examined in June, 1994. None of them showed any symptom of decay by the time. However, sapwood under the bark was remarkably discolored. The discoloration was more severe in 1cm-injection wound than in 0.5cm one. The severity of discoloration was not differed between species and among DBH applied. The sapwood split was longer in 1cm-injection wounded trees than in 0.5cm trees and longer in chestnut trees than in pine trees. From the split, callus grew out and almost closed the splits. In the trunk injection tested, the damage was mare severe in 1cm injection wound of chestnut trees than in any other combination.

• Journal of Conservation Science
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• v.26 no.4
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• pp.349-360
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• 2010

The Yeongsheon Sinwoldong three-storied stone pagoda (Treasure No. 465) composed mainly of drusy alkali-granite. The major rock-forming minerals are biotite, quartz, amphiboles, orthoclase and plagioclase. Yellowish brown and black discoloration are formed at the eight sculpture Buddha of the stylobate. A broken rock fragments in the roof material were repaired using epoxy resin and cement mortar in the past. As a result of the infrared thermography analysis from the pagoda, cracks and exfoliation were not serious. Also, P-XRF analysis showed that concentration of Fe (mean 5,599ppm) and S (mean 3,270ppm) were so high in yellowish discoloration parts. Black discoloration area was detected highly Mn (mean 2,155ppm) concentration around the eight sculpture Buddha of the stylobate. The main reason for these are inorganic contaminants from disengaged rock ingredient and organic contaminants from withered plant body. Degree of physical weathering is relatively high in the southern and northern side. The eastern and western side had similar with weathering condition. The northern and eastern side were serious discoloration and biological weathering relatively. Therefore, we suggest that the pagoda need to do cleaning of biological contaminant and conservation treatment to weakened materials of rock and long term monitoring.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.654-660
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• 2001

Dentinogenesis imperfecta is an example of an inheritable dentinal defect originating during the histodifferentiation stage of tooth development, with involvement of the primary and permanent teeth. Shields, Bixler and El-Kafrawy proposed three types of Dentinogenesis imperfecta : Type I, II, III. Witkop reported a prevalence of 1 in 8000 with the trait, and no significant difference between male and female. Affected teeth have red-brown discoloration often with distinctive wearness of occlusal surface of posterior teeth and incisal surface of anterior teeth. Once enamel seperated from underlying defective dentin, the dentin demonstrates significantly acclerated attrision. Radiographically, the teeth have thin roots, bulbous crown, cervical constriction, and obliteration of the root canals and pulp chambers. In primary dentition periapical lesions or multiple root fractures are often observed. In successive generations the phenotypes of discoloration and wearness of teeth occurred, and one of the patient's subships, 10 year-old sister, showed general discoloration of her teeth and mild wearness. In this case, a 4 year-old male reported to the Yonsei University Pedodontics clinic, with a chief complaint of discolored teeth. The teeth showed generally yellowish-brown discoloration and moderate wearness. In radiographic features, obliteration of pulp, bulbous crown, and short roots were observed. It was diagnosed as Dentinogenesis imperfecta. The posterior teeth were restored with Stainless Steel Crown, and defective incisors including left upper primary central incisor which was extracted due to a root fracture with Open-faced Stainless Steel crown.

• Journal of Conservation Science
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• v.28 no.4
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• pp.329-341
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• 2012

Magai Wareiishi Jizo (Buddhist statue carved on rock surface) is close to shoreline and a part of rock block is periodically immersed by seawater. Rock material of the Wareiishi-jizo statue is composed mainly of medium or coarse-grained biotite granite and very durable. However, physical properties of the rock have been changed according to the complex interactions of the salt solution and surrounding environment. Exfoliation of the rock surface is a serious condition by salt crystallization. Exfoliation (14.6%) is concentrated on the upper part of the rock block with mainly boundary of seawater as the center. On the other hand, lower part of the rock block show black layers by contaminants deposition. In addition, brown discoloration and biological contaminants is overlapped. Rock surface show high discoloration rate of 50.5% (black discoloration, 29.2% > yellow discoloration, 14.1% > brown discoloration, 4.4% > green discoloration, 2.9%). Upper part of the rock block had a lot of change in the physical properties than lower part that is immersed by seawater. In particular, surface properties of the rock block was very weak state at the boundary surface of seawater permeation.

• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.46-51
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• 2004

The objective of this study was to evaluate the applicability of high temperature drying to pitch pine (Pinus rigida) lumber, especially intended for use as lamina of structural glued laminated timber (glulam), to enhance the efficient utilization and provide added-value to that species. The high temperature schedule and drying procedures utilized were shown to be reasonable for drying glulam lamina due to the occurrence of small moisture gradients, minimal residual drying stress, and low warpage. Through preliminary tests, it was confirmed that residual resin at lamina surfaces did not adversely affect the gluing process. However, quantitative analysis of resin is required for developing a method to constrain the occurrence of pitch trouble with respect to decreasing long-term adhesive and finish durability of glulam in use after manufacturing. The final moisture content of high temperature dried lamina was much lower than target moisture content and discoloration was more severe than anticipated. In a further study, it will be necessary to determine the optimal drying conditions, such as temperature, humidity, drying time, and top load restraint level, which could best control discoloration, warpage, and moisture content of the lamina, while minimizing fuel expense.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.86-92
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• 2003

It is already known that the color of wool fabric dyed with disazo acid dyes could be changed in dyeing process and this is accelerated under alkaline condition. Focus was given to figuring out the mechanism of this color change, through the LC-MS analysis. In this study, no color change was seen in wool fabrics dyed with C. I. Acid Blue 113 under weak acidic, neutral and weak alkaline conditions for 1hour. However, the wool fabrics dyed under weak alkaline condition for a long time over 3 hours fumed reddish orange. When the wool fabrics dyed under weak acidic, neutral and weak alkaline conditions were treated with $0.5g/L\;Na_2C0_3$ solution, all of them turned reddish orange. On the other hand, the color of silk fabrics dyed with C. I. Acid Blue 113 were not changed after the same alkaline treatment. Wool contains cystine and cysteine, whereas silk does not. Due to the reversible reduction/oxidation process of cystine and cysteine in wool dyeing, the C. I. Acid Blue 113 of the dis-azo type is decomposed by reduction and consequently turned them into the reddish orange mono-azo types dye.