• The Korean Journal of Ecology
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• v.4 no.1_2
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• pp.25-32
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• 1981

During the period of 1975∼77, a survey and an investigation were carried out to estimate the frequency of lime-chlorosis in the natural vegetation in Korea and the relationships between plants and calcareous soils. The symptoms of lime-chlorosis were observed in flowering plants in the calcareous areas of Weonju (I, II), Yeongweol(I, II), Jecheon, Danyang and Samcheok. Although the species found to be lime-chlorotic on at least one occasion numbered 60, the total quantity of lime-chlorotic foliage observed was small. Severe lime-chlorosis of Capsicuym annuum in agricultural fields was found out at Danyang. However, some of the species which were of widespread occurrence in affected areas showed no lime-chlorosis. The comparison of the inorganic components in calcareous soils in lime-chlorotic and normal leaves showed that the essential mineral nutrients substantially less soluble in water in alkaline than in acid conditions and calcifuges planted on calcareous soils often show visual signs resembling those of P or Fe deficiency.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.197-198
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• 2001

일반적으로 해조류가 번무하고 있던 암초지대에서 무엇인가의 원인으로 해조류가 고사ㆍ소멸하고, 그 공간을 석회조류로 불리는 여러 종류의 산호말류 (coralline algae)이 점유하여 암반이 백색 또는 황색, 분홍색을 나타내는 현상을 ‘백화현상’ 이 라고 한다. 현재 추측되는 백화현상의 원인으로는 해양생태계 내에서의 환경변화 - 대기중 이산화탄소의 증가, 지구 온난화에 의한 수온상승, 그리고 연안역의 오염 -와 군집의 동태와 생물학적 작용-엽상형 해조류와 무절석회조류간의 경쟁과 성게를 포함한 초식동물의 초식작용, 질소, 인등의 결핍이 불러오는 빈(貧)영양화 - 에 의해 일어난다고 추측된다 (analysis.cheju.ac.kr.). (중략)

• Journal of architectural history
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• v.22 no.6
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• pp.59-66
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• 2013

This study progressed an investigation on the cause of the efflorescence phenomenon of bricks in Suwon Hwaseong Fortress, which is designated as a UNESCO World Heritage by using diverse scientific analyses. The samples were taken in Hwaseong and analyzed using XRD and SEM-EDS for the material identification of efflorescence. We observed under a polarizing microscope and measured absorption factors for the basic investigation for traditional bricks. As a result of material identification, soluble salt($Na_2SO_4$, $KNO_3$) and insoluble salt($CaCO_3$) were detected. There was no big difference between original bricks and repaired bricks under the polarizing microscope. However, in terms of the water absorption rate, bricks which were used for repair nowadays showed low water absorption rate(1%). In conclusion, soluble salt and insoluble salt appeared due to an effect of an air pollution and joint mortar. Soluble salt was removed in the rainy season, but insoluble salt was not removed. As a result of the efficiency and safety tests for chemicals removing efflorescence, chemical E is likely to be the suitable chemicals for the efflorescence phenomenon of traditional bricks in Suwon Hwaseong Fortress. In the future, consideration whether the use of lime is available or not should be studied through comprehensive researches including repair work, construction work and the environment factor with lime. Also, physical, chemical identifications of repairing bricks will be required.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.374-379
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• 2014

After completing deacidification process and evacuating rest of solvent, white fine particles of MgO are found on the surface of archival materials, such as books and documents. When MgO particles remain on the surface of archives, instead of being well dispersed and absorbed into cellulose fiber of archives, such white fine particles are found. These particles have raised concerns for employees' deacidification environment and their health; however, the concerns have not been addressed. To find the cause of white fine particles on the surface of archives after deacidification process and to propose the its solution, an acidic paper and wood free paper were applied with deacidifying chemicals. We analyzed the domestic and abroad deacidifying chemicals' physical properties and conducted deacidifcation processes to find effects of different contents and sizes of MgO on white fine particles. When the size of MgO particle was 847 nm, there was significantly less amount of white fine particles on the surface of archival materials. This means that the size of MgO particle plays a significant role in producing white fine particles on the surface of archives.

• Elastomers and Composites
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• v.47 no.3
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• pp.210-215
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• 2012

Whitening phenomena of the EPDM composites with different inorganic filler compositions which were aged at $90^{\circ}C$ for 7 days in air and tap water atmospheres, respectively, were investigated. The aged samples in tap water containing stearic acid exhibited severe whitening phenomena, while all the samples aged in air did not show any whitening. Depending on the filler compositions, there was no big difference in the whitening phenomena. The whitening materials were analyzed using gas chromatography/mass spectrometry (GC/MS), image analysis, energy-dispersive X-ray spectroscopy (EDX), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The whitening materials were identified to be salts of stearic acid. The salts of stearic acid were formed by reaction of metal cation in tap water and stearic acid in the sample.

• 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 Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.408-411
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• 2011

본 연구는 목조 문화재나 전통사찰 등에서 많이 적용되고 있는 단청처리된 목재에 대해 방염액을 사용하여 방염처리를 진행하였을 때 발생될 수 있는 백화현상를 단청목제가 적용 될 수 있는 외부환경과 일반적인 내부환경에 위치시켜 발생여부를 확인하여 보았다. 일반적으로 사용되어지는 6가지 종류의 단청색상에서 햇빛이나 눈비 등에 의한 영향, 습도 등에 따른 영향은 크지 않은 것으로 나타났으나 일부 단청 색상에서는 다소 습도가 높았던 실내 환경에서는 방염액이 많이 도포되어진 부분에서 백화현상이 일부 나타나는 것을 확인할 수 있었으며 단청의 색상을 구성하는 성분 차이에 의해 백화현상이 발생될 수 있음을 확인할 수 있었다.

• 레미콘
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• no.1 s.58
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• pp.16-25
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• 1999

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.127-131
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• 2006

The efflorescence mechanism of ceramic bodies with different sintering temperature was studied by quantitative analysis for the effect of various metal ions and anions. SEM and EDS characterization for efflorescence formed on the surface of the ceramic body showed that the main components of the efflorescence were Ca and S atoms. Leaching concentrations of various metal ions and anions for the ceramic bodies prepared by wet mixing with pH 7 and pH 10 were evaluated by ICP and IC analysis. The results of leaching test showed that the concentration of Ca ion at pH 7 body was eight times more than that of pH 10 body. Ca-rich efflorescence was not formed on the surface of ceramic body which prepared at pH 10 and sintered over $1100^{\circ}C$.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.56-69
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• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.