• Journal of Conservation Science
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• v.37 no.4
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• pp.340-356
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• 2021

We have tried the experimental research of lost-wax casting to reconstruct Gilt-Bronze Pensive Bodhisattva; preliminary and reconstruction experiment based on ancient texts. Main object to reconstruct is Korean National Treasure No.83, Gilt-Bronze Pensive Bodhisattva (Maitreya), then we measure alloy ratio and casting method based on the scientific analysis. Other impurities were removed from the base metal components(copper : tin : lead) and their ratio was set to 95.5 : 6.5 : 3 where the ratios for tin and lead were increased by 2.5% each. The piece-mold casting method was used, and piece-mold casting experiments were carried out twice in this study but supplementary research on piece-mold casting was necessary. The microstructure was confirmed to be typical cast microstructure and the component analysis result was similar to that of the prior study. Analysis of the chemical composition is confirmed to copper, tin, lead, and zinc, and the chemical composition of the matrix was 87.8%Cu-7.5%Sn-2.7%Pb-2.1%Zn, and similar to previous experimental research. Also resulted in the detection of small impurity in Zn. Analysis of the mould revealed that the mould was fabricated by adding quartz and organic matter for structural stability, fire resistance, and air permeability. We expect that our research will contribute to provide base data for advanced researches in future.

• Journal of Conservation Science
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• v.38 no.3
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• pp.180-191
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• 2022

Wooden cultural heritage are exposed to the external environment as they and there are many difficulties in conservation due to their location and size. Among them, biological damage caused by termites or mold consumes a lot of money and time. Select and use wood preservatives to prevent biological damage: Wood preservatives were selected and the worst environmental conditions, temperature 60±3℃, humidity 55±5%, and light intensity of 0.35 W/m², were subjected to aging treatment to analyze chemical changes. Through the deterioration process, it was confirmed that the change in color difference decreased in the wood preservative treatment compared to the Control group. As a result of measuring the content of the active ingredient contained in the deterioration process of the wood preservative, it was confirmed that the active ingredient content of Gori22 and Bondex Preserve III was higher than that of the comparative Wood Keeper A. Through experiments, the shelf life and treatment period can be predicted by measuring the extent to which wood preservatives affect the change of wood specimens during the deterioration process and the content of active ingredients. In conclusion, various wood preservatives were prepared, and the possibility of selectively selecting wood preservatives according to the environment, topography and period was presented as a major evaluation factor.

• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.153-162
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• 2016

Chilli is a widely consumed crop throughout the world. However, chilli anthracnose is a major constraint in chilli production leading to huge economic losses worldwide. Colletotrichum is a large genus of Ascomycete fungi, containing species that cause anthracnose diseases on a wide range of crops of economic value. This review is aimed at critically and accurately examining the taxonomic identification of Colletotrichum species by morphological and molecular approaches as well as assessing their management options. The use of appropriate integrated management practices, such as cultural, mechanical, chemical, and biological control, are important in chilli anthracnose disease prevention and control. Emphasis is laid on the use of biological control because it is cost effective and eco-friendly, and is an appropriate approach for disease management. The use of resistant cultivars is the cheapest, easiest, safest, and most effective means of controlling crop diseases. But, since no resistant cultivars of chilli have been developed and commercialized, it is very important to develop biological management strategies. Further studies leading to integrated disease management strategies need to be carried out.

• Journal of Conservation Science
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• v.32 no.2
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• pp.249-259
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• 2016

Effect of the flame retardants on Dancheong is studied in the present work. Two kinds of flame retardants were applied on Dancheong specimens and compared with control groups on which distilled water was applied instead of the flame retardants. The flame retardants enhanced the hygroscopic property of the surface of Dancheong. Furthermore, the added flame retardants reacted with oyster shell white($CaCO_3$) and lead red($Pb_3O_4$), producing new chemical compounds like Calcium phosphate tribasic and Lead Phosphates which make the painted layer of Dancheong dissolving and whitening over certain period of time. When applied in excessive amount and exposed in repetitive wet and dry condition, especially, they aggravate the surface problems significantly. These results will provide a good reference on the study of the discoloring/whitening effect of Dancheong layers at many traditional wooden building in Korea.

• Journal of Conservation Science
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• v.34 no.6
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• pp.443-458
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• 2018

An archive is a collection of documents or records. Currently, most archived documents are made of paper. Paper is susceptible to biological damage and deterioration due to its material properties. To control the biological damage, treatment with chemical disinfectants and control of the storage environment are often used. In government-controlled bulk public archives, all documents are chemically sterilized before storage. However, an extremely large quantity of public records have been produced, and storage space and conservation management are gradually reaching their limits. In this study, 60 species of microbes were identified using a genetic method. We successfully applied the adenosine triphosphate (ATP) bioluminescence method to detect microbial contamination on paper documents. A calibration curve of the ATP bioluminescence as a function of the microbe quantity was obtained, and the microbial activity on non-sterilized paper archives from 1951 was analyzed using an ATP luminometer. It was found that the microbial activity was suppressed or reduced in climate-controlled storage environments at $22^{\circ}C$ and 55% relative humidity. We anticipate that these results will be used to establish selective sterilization systems for government-controlled bulk public archives.

• Journal of Conservation Science
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• v.38 no.2
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• pp.80-86
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• 2022

Termites cause massive damage to wooden architectural heritage structures. Chemical treatments have been commonly used to control them. In foreign countries, physical barriers made of sheet and particles impenetrable to termite are being used as an alternative to the chemical method. To study the efficacy of physical barriers, we investigated the appropriate sand particle size that can prevent the penetration of R. speratus kyushuensis. Upon evaluating the barrier properties of sand with particle sizes ranging from 0.85 to 4.00 mm, the penetration of termites was found to be effectively blocked at a particle size range of 1.00 to 2.80 mm. At smaller particle sizes, termites managed to move the sand particles and build an almost linear mud tube to penetrate the sand layer. At larger particle sizes, the termites could penetrate the sand layer by passing through the sand gaps.

• 보존과학연구
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• s.32
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• pp.123-136
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• 2011

There are more than 2,800 different species of termites in the world, but just there is one species (Reticulitermes speratus kyushuensis Morimoto) in Korea. Once wooden structures are damaged by termites, we are applying chemical control methods such as fumigation, treatment of insecticidal and antiseptic chemicals, soil termiticide treatment, and termite colony elimination system to pest control. But in Korea, the termite infestation is gradually increasing, so it is essential to study on the present situation of termite control in US or Japan. Accordingly, in this part we have studied focusing on the case of US. In the US, there are three groups of termites : Subterranean, Drywood, Dampwood termites, and they caused more severe infestation compared with Korea. When a structure has become infested with termites, it is important that appropriate action must be taken: the chemical pest control (soil treatment, termite baiting, termite colony elimination), the modification and maintenance of buildings and the regular inspection for follow-up. And with consideration for different characteristics of termites, the process of pest control is made according to each species of termites. Most of the subterranean termite control is done by applying either termiticide to the soil or termite monitoring and baiting system around the structure. On the other hand, drywood termite control methods can be categorized as either the treatment for the whole structure or the treatment for localized area. Applications to the whole structure are done by fumigants or heat and the localized treatments are carried out with chemicals as well as heat, freezing, microwave and electricity.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.896-906
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• 2020

Wood deterioration experiments were carried out for 6 months in an intertidal zone of South Korea to monitor the changes in the chemical properties of two types of species, Korean red pine and sawtooth oak. The results of FT-IR spectra and XRD patterns have shown that the chemical properties of the wood did not change significantly during the 6-month burial period. However, the brightness of the surface decreased after burial; the value of the sawtooth oak sample was lower than that of the Korean red pine sample owing to an accumulation of inorganic compounds in cell lumen as observed by ICP analysis. Among the inorganic compounds, sodium and sulfur concentrations increased significantly over the burial period compared with the control. Further, the maximum moisture content decreased from 199% to 136% in the Korean red pine and 62% to 60% for the sawtooth oak. Nevertheless, the major chemical composition of both the wood species did not change significantly during the 6-month burial period, whereas, the crystallinity decreased with an increasing burial period owing to an accumulation of inorganic compounds in the lumen.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.643-648
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• 2005

The objective of this paper is to analyze the environmental effects by the fertilizer change with wastewater reuse for agriculture. For this research, Lysimeter tests are being implemented to cultivate rice with different levels of fertilizer applications with wastewater irrigation., and to analyze the nutrient loading by wastwater reuse in paddy fields was examined the CREAMS-PADDY model. CREAMS-PADDY model is modified from CREAMS model for considering the hydrologic cycles in paddy field. As a result, in the lysimeter treated by irrigation with wastewater and chemical fertilizer with half of the conventional amount showed generally similar tendency to the control plot. This may require the modifications of standard cultural practices for rice in terms of fertilizer and pesticide applications. However, high concentration of sodium in wastewater might cause damage to physico-chemical properties of paddy soil. And the wastewater reuse effects on nutrient loads were quantitatively analyzed and this results provide the reasonable management for agricultural reuse.

• Mycobiology
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• v.36 no.4
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• pp.222-227
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• 2008

Upon studying the diversity of fungal endophytes associated with pine trees in Korea, many species of Penicillium were encountered. In this study, we report two species of Penicillium isolated from the needles of Pinus rigida. Based on ID region analysis, cultural and morphological characteristics, the two species were identified as Penicillium fellutanum and P. toxicarium, both of which are new to Korea.