• Title/Summary/Keyword: Conservation Mechanism

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Evaluation of Characteristics of Wax-treated Paper Depending on Coating Methods (도포방식에 따른 밀랍지 시제품의 특성 분석)

  • Seo, Jin-Ho;Choi, Kyoung-Hwa;Park, Ji-Hee;Kang, Yeong-Seok;Yoon, Kyoung-Dong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.2
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    • pp.64-69
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    • 2009
  • Cultural heritages represent the histories and intellectual level of a country. The Annals of Joseon Dynasty are regarded as the most valuable resources containing the record of Korean history. In some periods, wax-treated paper was used as the material of the Annals of Joseon Dynasty. Many previous studies have focused on the development of paper used as the material of the Annals of Joseon Dynasty, but the manufacture method of wax-treated volumes and the degradation mechanism of wax have been not fully understood yet. The purposes of the present study are to produce various kinds of wax-treated paper using by different coating methods and to analyse the morphological properties of wax-treated paper. The analysis of SEM demonstrates that beeswax treated paper made by brushing method produces flatter surface and more excellent penetration. Wax layer is produced on the cross section of beeswax treated paper as the increase of coating amount.

Deterioration Mechanism Interpretation and Surface Contaminant Analysis of the Five-Storied Stone Pagoda in Tapriri, Uiseong (의성 탑리리 오층석탑의 표면오염물 분석 및 손상메커니즘 해석)

  • Lee, Mi Hye;Chun, Yu Gun;Lee, Myeong Seong
    • Economic and Environmental Geology
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    • v.46 no.5
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    • pp.445-453
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    • 2013
  • The Uiseong Tapriri Five-Storied Stone Pagoda (National Treasure No. 77) is typical stone cultural heritage in Unified Silla Dynasty, Korea. The pagoda has been occurred black, brown discoloration and microcrack, exfoliation, granularity decomposition with white discoloration because of continuous weathering. As the results of analysis for the contaminants, chemical weatherings are generated that black contaminant by manganese oxide, brown contaminant by iron oxide, white contaminants by gypsum and taranakite. And physical weatherings, such as microcrack, exfoliation, are occurred by salt(gypsum) crystallization. Therefore, these need to remove the contaminants according to the conservation treatment manual, and regular monitoring using P-XRF to preserve long-term the Five-Storied Stone Pagoda at Tapri-ri, Uiseong.

A Study on the Change of Conservation Materials Properties Using Artificial Weathering Test (인공풍화 실험을 이용한 보존처리제의 물성 변화 연구)

  • Do, Min-Hwan;Han, Min-Su;Lee, Jang-Jon;Jun, Byung-Kyu;Song, Chi-Young
    • 보존과학연구
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    • s.29
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    • pp.149-162
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    • 2008
  • Because stone cultural heritages in Korea are mostly situated outdoors without any notable protection, there are severe damages from physical, chemical and biological weathering. And this in turn causes deformation and structural damage. To counteract this problem and increase durability, various kinds of conservation materials are used in the conservation and restoration treatment. However, there are not many practical and technological experiments on this subject. Accordingly this research is for analysis of effect for treatment to make use a resin of the ethyl silicate for the granite in Mt. Nam of Gyeongju. It takes a long time to confirm the test result regarding durability and side effects of the conservatives after treatment. So we built up an artificial environment through freezing and melting test, and evaluated the conservation materials. As a result of this experiment, porosity and absorptivity was increased in accordance with processing of freezing and melting test. But other things such as elastic wave speed, elastic modulus, uniaxial compressive strength and tensile strength was decreased. It will make a plan to form a method of research systematically for mechanism and element of weathering and to elicit a correlation among experiment of artificial weathering and practical natural weathering from next research.

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Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

  • Li, Yan;Chang, Jie;Ouyang, Yong;Zheng, Xianwei
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1654-1658
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    • 2014
  • High value-added aromatic aldehydes (e.g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide ($H_2O_2$) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin ($Co(TPPS_4)$) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without $Co(TPPS_4)$. Moreover, a possible mechanism of HFBO oxidation using $Co(TPPS_4)/H_2O_2$ was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under $Co(TPPS_4)/H_2O_2$ system.

Salt Weathering Characteristics and Mechanism Interpretation of the Five-Storied Stone Pagoda in Tapri-ri, Uiseong (의성 탑리리 오층석탑의 염풍화 특성과 메커니즘 해석)

  • Lee, Mi Hey;Lee, Myeong Seong;Lee, Jae Man;Chun, Yu Gun
    • 보존과학연구
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    • s.33
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    • pp.57-67
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    • 2012
  • The Uiseong Tapriri Five-Storied stone pagoda has occurred exfoliation, granular disintegration and discoloration by physical and chemical weathering factors with the major deterioration occurring due to efflorescence by salt. According to the results of SEM-EDS and X-ray diffraction analysis, salts consists of gypsum, taranakite. Artificial salt weathering tests were carried out using the same type of rocks as those in the stone pagoda. The test results showed that efflorescence occurred on the surface of the rock, and that exfoliation and granular disintegration occurred inside the rock due to salt crystallization.

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Optimization of the Spring Design Parameters of a Circuit Breaker for Satisfying Specified Dynamic Characteristics (규정된 동적특성을 위한 회로차단기의 스프링 설계변수의 최적화)

  • 안길영;정광영
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.3
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    • pp.132-138
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    • 2004
  • In a vacuum circuit breaker mechanism, a spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of electric contacts. If the type and structure of the linkage system required to the circuit breaker is predetermined, the stiffness, free length and attachment points of a spring become the important design parameters. In this paper, based on the energy conservation that the total system energy is constant throughout the operating range of the mechanism, a systematic procedure for optimizing the spring design parameters is developed and applied to the simplified mechanism of a circuit breaker. Then, in order to consider the complex dynamics of the circuit breaker mechanism rather well, the developed procedure is converted to the environment of a multi-body dynamics program ADAMS.

A Numerical Study on the Formation Mechanism of a Mesoscale Low during East-Asia Winter Monsoon

  • Koo, Hyun-Suk;Kim, Hae-Dong;Kang, Sung-Dae;Shin, Dong-Wook
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.613-619
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    • 2007
  • Mesoscale low is often observed over the downstream region of the East Sea (or, northwest coast off the Japan Islands) during East-Asia winter monsoon. The low system causes a heavy snowfall at the region. A series of numerical experiments were conducted with the aid of a regional model (MM5 ver. 3.5) to examine the formation mechanism of the mesoscale low. The following results were obtained: 1) A well-developed mesoscale low was simulated by the regional model under real topography, NCEP reanalysis, and OISST; 2) The mesoscale low was simulated under a zonally averaged SST without topography. This implies that the meridional gradient of SST is the main factor in the formation of a mesoscale low; 3) A thermal contrast ($>10^{\circ}C$) of land-sea and topography-induced disturbance served as the second important factor for the formation; 4) Paektu Mountain caused the surface wind to decelerate downstream, which created a more favorable environment for thermodynamic modification than that was found in a flat topography; and 5) The types of cumulus parameterizations did not affect the development of the mesoscale low.

Gain of New Exons and Promoters by Lineage-Specific Transposable Elements-Integration and Conservation Event on CHRM3 Gene

  • Huh, Jae-Won;Kim, Young-Hyun;Lee, Sang-Rae;Kim, Hyoungwoo;Kim, Dae-Soo;Kim, Heui-Soo;Kang, Han-Seok;Chang, Kyu-Tae
    • Molecules and Cells
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    • v.28 no.2
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    • pp.111-117
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    • 2009
  • The CHRM3 gene is a member of the muscarinic acetylcholine receptor family that plays important roles in the regulation of fundamental physiological functions. The evolutionary mechanism of exon-acquisition and alternative splicing of the CHRM3 gene in relation to transposable elements (TEs) were analyzed using experimental approaches and in silico analysis. Five different transcript variants (T1, T2, T3, T3-1, and T4) derived from three distinct promoter regions (T1: L1HS, T2, T4: original, T3, T3-1: THE1C) were identified. A placenta (T1) and testis (T3 and T3-1)-dominated expression pattern appeared to be controlled by different TEs (L1HS and THE1C) that were integrated into the common ancestor genome during primate evolution. Remarkably, the T1 transcript was formed by the integration event of the human specific L1HS element. Among the 12 different brain regions, the brain stem, olfactory region, and cerebellum showed decreased expression patterns. Evolutionary analysis of splicing sites and alternative splicing suggested that the exon-acquisition event was determined by a selection and conservation mechanism. Furthermore, continuous integration events of transposable elements could produce lineage specific alternative transcripts by providing novel promoters and splicing sites. Taken together, exon-acquisition and alternative splicing events of CHRM3 genes were shown to have occurred through the continuous integration of transposable elements following conservation.

A Study on Auction Mechanism for DMZ Conservation using the South-North Korean Economic Development Projects (남북경제협력에 따른 개발이익 경매와 DMZ 보전기금 확보)

  • Park, Hojeong;Kim, Joonsoon;Kim, Hyunhee
    • Environmental and Resource Economics Review
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    • v.28 no.1
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    • pp.39-59
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    • 2019
  • The Korean Demilitarized Zone (DMZ) has the great ecosystem as all the artificial activities in DMZ have been prohibited over half a century. The ecosystem should be conserved even after the reunification of Korea and hence the conservation plan should be established not after the reunification but before it. It requires a considerable budget to conserve DMZ, considering management of ecology resource, recovery, and research. The objective of this paper is to analyze a fund-raising measure for DMZ conservation, using economic incentives mechanism when multiple developers participate in the auction to get the right to develop North Korean regions, have private information about their sunk costs and pay a part of their profits for the fund. First, we analyze the real option model to decide the optimal investment time. Second, we construct the auction for bidders not to misrepresent their private information, based on Bayesian Nash equilibrium.