• Title/Summary/Keyword: 백토(白土)

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Reason and Prevention of Color Reversion of Corn Oil in Summer (옥수수기름의 하절기 변색현상 원인규명 및 방지대책)

  • Koo Bon-Soon
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.485-490
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    • 2004
  • Crude corn oil (CCO) was obtained through the expression-extraction process from corn germ. The CCOs of final process at $90^{\circ}C,\;70^{\circ}C\;and\;50^{\circ}C$ were stored in outdoor storage tanks. From the samples, refined CCO (RCCO) were prepared with $0\%,\;10\%\;and\;20\%$ excessive of phosphoric acid, caustic solution and acidic clay were used in degumming-alkali refining-bleaching process. RCCOs were stored at room temperature in dark places. The color change was not effected by the amount of phosphoric acid, caustic solution and acidic clay, but temperature of process affects the color change. Finally, the prevention for color reversion of RCCO could be obtained by lowering the temperature of final process and optimal temperature of RCCO in summer was found about less than $50^{\circ}C$.

Microstructural Study and Firing Temperature Presume from Mt. Gyeryong Hakbong-ri Kiln (계룡산 학봉리 출토 도편의 미세조직 관찰과 번조온도 추정에 관한 연구)

  • Hwang, Hyun-Sung;Kwak, Eung-Yung;Lee, Da-Hae
    • Journal of Conservation Science
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    • v.27 no.1
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    • pp.13-30
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    • 2011
  • This study compared Pottery, Hwaecheongware, Buncheongware and Whiteware pieces excavated in Hakbong-ri of Chungnam analytically by observing their refined structures and estimating their firing temperature. As a result, base soil components of the specimens were mostly similar to those of typical Buncheongware, but the content of the fluxing agent was rather high, and it seemed that the Whiteware had been made with fairly different components from those of other sherds. Although the glaze showed less difference than base soil in general, the content of the glaze changed according to the decorating methods of Buncheongware. Based on the SEM-EDS analysis, it was found that the base soil components of the ceramics seemingly rather different were actually different and the analysis on the fine crystals of the base soil, the anorthite in the glaze and crystals in the ironing part, and the components and contents of white earth showed there were some noticeable points in the process of making each of the sherds. In the refiring experiment to estimate the firing temperature, mostly similar results were gained as $1150^{\circ}C$ to $1200^{\circ}C$ for pottery, $1100^{\circ}C$ to $1150^{\circ}C$ for Hwaecheongware, and $1100^{\circ}C$ to $1200^{\circ}C$ for iron-brown Buncheongware however, the results imply good quality Whiteware was burnt at above $1300^{\circ}C$ while bad quality Whiteware was burnt at a temperature far lower than that. Thus, there was clear difference between Whiteware sherds and other kinds of sherds.

Mineralogical Properties and Paragenesis of H-smectite (H-스멕타이트의 광물학적 특성과 생성관계)

  • Noh, Jin-Hwan;Hong, Jin-Sung
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.4
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    • pp.377-393
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    • 2010
  • Pumiceous tuffs occurring in the Beomgockri Group are examined applied-mineralogical characteristics and their controling factors to evaluate their potentials as the adsorption-functional mineral resources. The pumiceous tuffs are diagenetically altered to low-grade zeolitcs and bentonites in the Janggi area. Compositional specialty due to the presence of pumice fragments induces the altered tuffs to exhibit the characteristic adsorption property combined with cation exchange capacity, specific surface area, and acidic pH. Unusual lower pH in the adsorption-functional mineral substances is turned out to be originated from the presence of H-smectite having $H^+$ in the interlayer site of the sheet structure. On account of disordered crystallinity resulting from the exchanged $H^+$ in the interlayer site, the smectite commonly forms crenulated edges in the planar crystal form and exhibits characteristic X-ray diffraction patterns showing comparatively lower intensities of basal spacings including (001) peak than conventional Ca-smectite. Based on the interpretation of paragenetic relations and precursor of the H-smectite, a genetic model of the peculiar clay mineral was proposed. The smectite formation may be facilitated resulting from the precipitation of opal-CT at decreasing pH condition caused by the release of H+ during diagenetic alteration of pumice fragments. Because of the acidic smectite, the low-grade mineral resources from the Beomgockri Group may be applicable to the adsorption industry as the raw materials of acid clays and bed-soil.

Study on Manufacturing Techniques of Bracket Mural Paintings of Daeungbojeon Hall in Naesosa Temple (내소사 대웅보전 포벽화 제작기법 연구)

  • Lee, Hwa Soo;Lee, Na Ra;Han, Gyu-Seong
    • Journal of Conservation Science
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    • v.34 no.6
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    • pp.557-568
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    • 2018
  • The manufacturing techniques were studied by investigating a precise analysis on wall structure, features of materials and the painting layer of the bracket mural paintings at Daeungbojeon Hall in Naesosa temple. The wall frame is a single-branch structure, and The mural paintings are composed of 3 layers which are a support layer, a finishing layer and a painting layer. The support layer and the finishing layer are an earth wall that sand and clay such as Quartz, Feldspar, and etc. are mixed. The support and the finishing layers have a combination of medium particle sand and smaller than fine particle sand in the approximate ratios of 0.8:9.2 and 6:4, respectively. Therefore, the aforementioned ratio of sand with medium or large particles is relatively higher in the finishing layer than the support layer. As a result of a precise analysis on the painting layer, it has a relatively thick ground layer for painting which is maximum $456.15{\mu}m$ by using Celadonite or Glauconite and the paintings were colored by using pigments such as Atacamite, Kaolinite or Halloysite, Oxidized steel, and etc. on it. The manufacturing style and the painting techniques of an earth wall are included in the category of the Joseon Dynasty style that have been studied up to now, but the facts that the finishing layer has a high content of sand and a middle layer and chopped straw have not been identified. These are remarkable points in terms of structure and materials, and can be crucial in the evaluation of the state of conservation of mural paintings or preparation of a conservation plan.

The Installation of Royal Kilns in Joseon Dynasty and Its Impact on Local Kilns (음각운문청자의 제작현황으로 본 조선시대 관요의 설치와 지방 가마)

  • Oh, Young-In
    • Korean Journal of Heritage: History & Science
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    • v.50 no.4
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    • pp.38-63
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    • 2017
  • This study sets out to investigate the installation of royal kilns and its impact on local kilns, taking note of celadon vase with inlaid cloud pattern in Joseon Dynasty. For that purpose, it determined the kilns and period to produce celadon vases with inlaid cloud pattern, and compared them with the pattern, design, and deformity of the celadon vases produced in the royal kilns in the 15th centuries. The celadon vase with inlaid cloud pattern was superior in quality than the porcelain for tribute ware manufactured together in Jeolla Province before the installation of royal kilns. And then a majority of sagijangs at local kiln had difficult time securing enough supply of manpower and resources, and discontinued manufacturing the celadon vase with inlaid cloud pattern. En revanche, celadon vases with inlaid cloud pattern produced from specially fixed royal kilns reflected the local sagijang's skill. Local kilns were strongly influenced by the installation of royal kilns. Those could not freely use high-quality white clay, limited to the market. Besides, most of the skillful sagijangs were assigned to royal kilns. Celadon vases with inlaid cloud pattern can be used as evidence to show that the manufacturing technique was transferred from local kilns to the royal kilns as well as to show that their production in royal kilns soon became stabilized.

A Scientific Analysis of Dancheong Pigments at Yaksajeon Hall in Gwallyoungsa Temple (창녕 관룡사 약사전 단청안료의 과학적 분석)

  • Han, Min-su;Kim, Jin-hyoung;Lee, Jang-jon
    • Korean Journal of Heritage: History & Science
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    • v.47 no.1
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    • pp.18-31
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    • 2014
  • This study aims at identifying of characteristics and types of the pigments used for Dancheong(surface decorative and protective pigments) of Yaksajeon Hall in Gwallyoungsa Temple using a Micro-XRF, XRD, SEM-EDS and thereafter, comparing it with the pigments of the wall painting in the same building and with Dancheong pigments of Daeungjeon Hall. The results can be briefly summarized as two points. First, different types of pigments for red, green and white colours had been applied based on different parts of the building and more than two different pigments had been mixed to produce various colours in so me parts. Second, scientific analysis has confirmed that raw minerals for each colour groups are: Cinnabar, minium and Hematite for red; white clay and oyster shell white($Al_2O_3{\cdot}SiO_2{\cdot}4H_2O$) for white; Atacamite and Celadonite for green; carbon(C) for black; Yellow Ocher for yellow; and Lazulite for blue. Comparative analysis of such result with that of the wall paintings and of Dancheong of Daeungjeon Hall has revealed that similar minerals had been used in overall except that several different pigments had been added or removed for making green, white and yellow colour groups in some parts. In conclusion, the result has displayed that painters had used different ways of producing pigments by a type of painting or a building within the same period or for the buildings in the same buddhist temple compound.

Effects of different sizes of Hydroxyapatite/$\beta$-Tricalcium phosphate particles on vertical bone augmentation (수직골 증대술에서 $\beta$-Tricalciumphosphate/Hydroxyapatite 골 이식재 입자 크기의 영향)

  • Huh, Jung-Bo;Jung, Dong-Hee;Kim, Ji-Sun;Shin, Sang-Wan
    • The Journal of Korean Academy of Prosthodontics
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    • v.48 no.4
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    • pp.259-265
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    • 2010
  • Purpose: This study was aimed to evaluate the effect of different sizes of $\beta$-TCP/ HA particles on vertical bone augmentation using titanium mesh in the cranium of rabbits. Materials and methods: Six white rabbits weighing 5kg were used. Four circular grooves of 6mm diameter were made by trephine, and five small holes were drilled in the inner surface of each circular gooves. Different sizes of grafts (small 0.3 - 0.5 mm, medium 0.5 - 1.0, large 1.0 - 2.0 mm) were placed respectively in the experimental groups. Titanium mesh (height 3 mm, width 6 mm) was placed. After 8weeks healing period, the rabbits were euthanized, and the specimens were prepared for histological findings. New bone formation and remaining graft area were measured to calculate the ratio of areas occupying the inner space of titanium mesh. Mann-Whitney U-test and Wilcoxon signed rank-test were used for statistical analysis ($\alpha$ = .05). Results: The experimental groups with $\beta$-TCP/HA graft showed a significantly higher new bone formation (P = .003). Comparing different sizes of $\beta$-TCP/HA, there was no statistical difference in terms of new bone formation. The vertical bone formation (i.e. new bone and graft area) was significantly greater in $\beta$-TCP/HA groups (P = .001). In comparison between different sizes of $\beta$-TCP/HA, medium size group had significantly greater area than large particle size group (P = .039). Conclusion: The use of $\beta$-TCP/HA with titanium mesh showed a higher vertical bone formation, particularly the medium sized $\beta$-TCP/HA particles (0.5 - 1.0 mm) produced better results in vertical bone augmentation.

Applied-Mineralogical Characterization and Assessment of Some Domestic Bentonites (I): Mineral Composition and Characteristics, Cation Exchange Properties, and Their Relationships (국내산 벤토나이트에 대한 응용광물학적 특성 평가 (I): 광물 조성 및 특징과 양이온 교환특성과의 연계성)

  • 노진환
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.4
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    • pp.329-344
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    • 2002
  • Mineralogical and chemical characterization of some domestic bentonites, such as quantitative XRD analysis, chemical leaching experiments, pH and CEC determinations, were done without any separation procedures to understand their relationships among mineral composition, characteristics, and cation exchange properties. XRD quantification results based on Rietveld method reveal that the bentonites contain totally more than 25 wt% of impurities, such as zeolites, opal-CT, and feldspars, in addition to montmorillonite ranging 30~75 wt%. Cation exchange properties of the zeolitic bentonites are deeply affected by the content of zeolites identified as clinoptilolite-heulandite series. Clinoptilolite is common in the silicic bentonites with lighter color. and occurs closely in association with opal-CT. Ca is mostly the dominant exchangeable cation, but some zeolitic bentonites have K as a major exchangeable cation, The values of cation exchange capacity (CEC) determined by Methylene Blue method are comparatively low and have roughly a linear relationship with the montmorillonite content of the bentonite, though the correlated data tend to be rather dispersed. Compared to this, the CEC determined by Ammonium Acetate method, i.e.‘Total CEC’, has much higher values (50~115 meq/100 g). The differences between those CEC values are much greater in zeolitic bentonites, which obviously indicates the CEC increase affected by zeolite. Other impurities such as opal-CT and feldspars seem to affect insignificantly on the CEC of bentonites. When dispersed in distilled water, the pH of bentonites roughly tends to increase up to 9.3 with increasing the alkali abundance, especially Na, in exchangeable cation composition. However, some bentonites exhibit lower pH (5~6) so as to regard as ‘acid clay’. This may be due to the presence of $H^{+}$ in part as an exchangeable cation in the layer site of montmorillonite. All the works of this study ultimately suggest that an assesment of domestic bentonites in grade and quality should be accomplished through the quantitative XRD analysis and the ‘Total CEC’measurement.

The Effects of Anoxic Treatments on Color and Mechanical Property in Fabrics, Natural Dyed Fabrics, Papers, Natural Dyed Papers and Paints (저산소 농도 살충처리가 직물, 염색 직물, 종이, 염색지 및 채색편의 색상 및 기계적 성질에 미치는 영향)

  • Oh, Joon Suk;Choi, Jung Eun;Noh, Soo Jung;Eum, Sang Wook
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.219-234
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    • 2014
  • Fabrics, natural dyed fabrics, papers, natural dyed papers and paints were examined effects of colors and mechanical properties for materials of museum collections under anoxic treatment. Anoxic conditions using nitrogen and argon were oxygen concentration 0.01%, temperature($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$), 50% RH and exposure time 30 days. Examined fabrics were raw silk fabric, UV irradiated raw silk fabric, degummed silk fabric, UV irradiated degummed silk fabric, cotton fabric, and UV irradiated cotton fabric. Natural dyed silk and cotton fabrics were dyed with fresh indigo, indigo, safflower, gromwell, madder sappanwood, amur cork tree, turmeric, gardenia, barberry root, pagoda tree flower, cochineal, lac, alnus japonica, gallnut, chestnut shell, and combination(indigo and safflower, indigo and amur cork tree, indigo and pagoda tree flower, indigo and sappanwood). Papers were Korean papers(mulberry paper, mulberry(70%) and rice straw(30%) mixed paper), Japanese paper(gampi paper), cotton paper, refined linen paper, cotton, linen & manila mixed fibre furnish, copy paper, news print, and alum sized mulberry paper. Natural dyed papers were dyed with indigo, sappanwood, madder, safflower, gardenia, amur cork tree, and pagoda tree flower. Paints were painted on alum-sized papers and silk fabrics using glue and pigments(azurite, malachite, cinnabar, vermilion, orpiment, gamboge, red lead, haematite, iron oxide red, indigo(lake), lac, cochineal, safflower, madder root lake, celadonite, smalt, ultramarine blue, lapis lazuli, prussian blue, kaolin, lead white, oyster-shell white, and clam-shell white). The color differences(${\Delta}E^*$) of all examined materials were below 1.5 or lowered than control samples after anoxic treatment. The variations of tenacity of yarns of fabrics and natural dyed fabrics after anoxic treatment were within that of standard silk and cotton fabrics. Gases(nitrogen and argon) and temperatures of anoxic treatment did not also affected color differences and variations of tenacity of materials.

A Scientific Analysis of Ancient Pigments on Wall Paintings at Yeongsanjeon in Tongdo Temple Using a Field-XRF (휴대용X선형광분석기를 이용한 통도사 영산전 벽화 안료의 과학적 성분분석)

  • Han, Min Su;Lee, Han Hyoung;Kim, Jae Hwan
    • Korean Journal of Heritage: History & Science
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    • v.44 no.3
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    • pp.132-149
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    • 2011
  • In ancient period, a variety of inorganic or organic pigments had been used as colorants in various kinds of religious and secular paintings such as tomb paintings and wall and scroll paintings in buddhist temples, and danchung(cosmic patterns) for the surface of wooden buildings. This study discusses the results obtained from an analysis of the pigments on the wall paintings of Yeongsanjeon(Hall of Vulture Peak) in Tongdo temple by a qualitative analysis using a field-XRF. The results can be briefly summarized as follows. Firstly, assuming from the major components examined from F-XRF analysis, raw materials of pigment of each color are: red to be Cinnabar(HgS) or Hematite($Fe_2O_3$); white to be White Lead[$2PbCO_3{\cdot}Pb(OH)_2$] in most cases and Calcite($CaCO_3$) or Chalk($CaCO_3$), Kaolin($Al2O_3{\cdot}SiO_2{\cdot}4H_2O$) in some cases; yellow to be Yellow Ocher[$FeO(OH){\cdot}nH_2O$]; black to be carbon(C); green on the painted surface to be Celadonite[$K(Mg,Fe^{2+})(Fe^{3+},Al)(Si_4O_{10})(OH)_2$] in most cases; dark green on the halo of figures to be Malachite[$CuCO_3{\cdot}Cu(OH)_2$], Copper Green[$2CuO{\cdot}CO_2{\cdot}H_2O$] or Atacamite[$Cu_2Cl(OH)_3$]. Secondly, incarnadine and pink were made by mixing with more than two pigments such as red and white for making various tone of colors. The qualitative analysis of pigments on the wall paintings of Yeongsanjeon, in conclusion, displays that the all pigments for ancient periods are inorganis pigments. However, it has the limitation to identify a definite kinds of mineral for each pigment because it was not possible to collect samples from cultural heritage for conducting a crystalline analysis of XRD.