• Title/Summary/Keyword: SEM and EDS

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A Scientific Analysis on the Glass Beads Excavated from the Daho-ri site NO. 6, Changwoen (창원 다호리 유적 6호분 출토 유리구슬의 과학적 분석)

  • Yun, Eunyoung;Kang, Hyungtae
    • Conservation Science in Museum
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    • v.13
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    • pp.45-49
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    • 2012
  • A scientific analysis was carried out on the 14 pieces of glass beads excavated from the Daho-ri site NO. 6, Changweon. Most of the glass pieces were made of light blue transparent glass with round bubbles aligned in a regular direction. As a result of the SEM-EDS analysis, all the glass pieces turned out to be within the potash glass group (K2O-SiO2) and were identified to be the LCA (Low CaO, Low Al2O3) series glass, of which the concentration is 5% or below for CaO and Al2O3 respectively. In addition, it is presumed that plant materials were refined or a mineral (saltpetre, KNO3) was used as the raw materials for making potash and also that the ingredient acting as a colorants for light blue color was affected deeply by CuO.

Heavy Metal Retention by Secondary Minerals in Mine Waste Rocks at the Abandoned Seobo Mine (서보광산 폐광석 내 2차 광물에 의한 중금속 고정화)

  • 이평구;강민주;최상훈;신성천
    • Economic and Environmental Geology
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    • v.36 no.3
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    • pp.177-189
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    • 2003
  • The main purposes of this study are to utilize mineralogical studies such as optical microscope, XRD and SEM/EDS analyses to characterize the oxidation of sulfide minerals and the mechanisms controlling the movement of dissolved metals from waste rocks at the abandoned Seobo mine. Mineralogical research of the waste rocks confirms the presence of anglesite, covellite, goethite, native sulfur and nsutite as secondary minerals, suggesting that these phases control the dissolved concentrations of As, Cu, Fe, Mn, Pb and Zn. The dissolved metals are precipitated, adsorbed and/or coprecipitated with(or within) Fe(Mn)-hydroxides and Mn(Fe)-hydroxides. The main phases of secondary mineral, Fe-hydroxide, can be classified as amorphous or poorly crystalline and more crystallized phases(e.g. goethite) by crystallinity. Amorphous or poorly crystalline Fe-hydroxide has relatively high As contents(9-24 wt.%). This poorly crystalline Fe-hydroxide changes toward more crystallized phase(e.g. goethite) which contains relatively low As(0.6-7.7 wt.%). These results are mainly due to the progressive release of As with the crystallization evolution of the As-trapping poorly crystalline Fe-hydroxides. It is also attributed to the differences of specific surface areas between the poorly crystalline Fe-hydroxides and well crystallized phases. The dissolved metals from waste rocks at Seobo mine area are naturally attenuated by a series of precipitation(as Fe, Mn, Cu, Pb), coprecipitation(Fe, Mn) and adsorption(As, Cu, Pb, An) reactions. The results of mineralogical researches permit to assess the environmental impacts of mine waste rocks in the areas, and can be used as a useful data to lay available mine restoration plan.

A Study on Gilded Ornamental Shoes Excavated from Beopcheon-ri, Wonju (원주(原州) 법천리출토(法泉里出土) 금동식리(金銅飾履)에 대한 연구(硏究))

  • Kwon, Hyuk-nam;Yu, Hei-sun
    • Conservation Science in Museum
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    • v.3
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    • pp.65-69
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    • 2001
  • Scientific analysis are carried on gilded ornamental shoes, which have been excavated from tomb No 1. and No 4. in Beopcheon-ri, Wonju dated from Baekje Period. This object is a very important because it provides valuable information on the development of metal-making techniques of that period. Thus, this article illustrates the investigation conducted to reveal how the object was created using what materials and techniques. Instead of the spikes-attached to the bottom plate of the object-that couldn't be sampled, a sample of a decorative rivet showing a similar structure to the spikes-attached to the other parts of the shoes-was prepared for a cross-section examination. Using radiography and microscopes, it was found that the head of a spike was placed and then punched to the gilded plate, so it can be held to the shoes. Under the SEM-EDS, the cross-section of the rivet shows that the gilding layer was applied before the attachment of the rivets. It also shows that the gilding layer is distributed unevenly and there are empty spaces indicating amalgam gilding was employed. This was confirmed as Mercury was detected on the SEM-EDS analysis of the object. The examination of the microstructure of the plate using the SEM-EDS revealed that the object is made of a single copper alloy plate with recrystallized twining and non-metallic white inclusions, which found to be lead in this case.

A Study of Conservation and Desalination Methods for an Iron Stele of the Joseon Dynasty (조선시대 철비(鐵碑)의 보존처리와 탈염방법 비교 연구)

  • Lee, Hye-Youn;Cho, Nam-Chul
    • Journal of Conservation Science
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    • v.25 no.4
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    • pp.399-409
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    • 2009
  • Outdoor iron artefacts are easily corroded by affection of environmental pollutants directly. Especially they need to be removed $Cl^-$ ions, but outdoor iron artefacts are excluded for desalination owing to their special features. Therefore this study contains the conservation processes of an iron stele of the Joseon Dynasty as the sample as well as desalination experiments that were carried out the desalting method using spill pads and the immersion desalting method together in order to compare. Desalting methods were compared by analyses such as an optical and metallurgical microscope, SEM-EDS, pH meter, Ion Chromatography and X-ray diffraction. As a result of the analysis, the optical and metallurgical microscopy show that the corrosion products are constituted by the layers and the metallurgical microstructure is a white cast iron. The SEM-EDS results of corrosion products detected mainly Fe, O, and especially Cl upto 2.48wt%. The results of pH and anion analysis for the washing solution, the desalting method using spill pads shows the similar effect to the immersion desalting method. As a result of XRD analysis before and after desalting corrosion products, goethite, magnetite, lepidocrocite and akaganeite are detected before desalting, but akaganeite is not detected after desalting at the desalting methode using spill pads, which indicates to have an effect on desalination. Therefore the results show that the desalting method using spill pads has an effect on desalination similar to the immersing desalting method.

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Production Techniques for Goryeo Wooden Lacquerware (고려시대 목심칠기 木芯漆器의 제작기법 연구)

  • Yi, Yonghee;Park, Suzin;Yun, Eunyoung;Jung, Hyejin
    • Conservation Science in Museum
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    • v.15
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    • pp.78-95
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    • 2014
  • To examine the materials, production techniques, and key features of Goryeo wooden lacquerwares, scientific analysis was conducted on six relevant lacquerware items. All of the items, except for a lacquered bowl duksu 4123, were found to have been made by first covering the surface of the wood with cloth and then varnishing with lacquer. The wooden frames of flower-shaped lacquered case and pine leaves shape lacquered case were made by wrapping thin wood around either the lid or bottom panel. In most cases, microscopic analysis revealed a lower layer of lacquer mixed with bone ash and bone dust, followed by an upper varnish layer of lacquer. SEM-EDS analysis and μ-XRF Micro-X-ray Fluorescence analysis showed that vermilion lacquer mixed with cinnabar was used on the surface. A lid decorated with a dot pattern was made by first varnishing the surface with yellow lacquer mixed with orpiment, and then irregular dot pattern with a mixture of black lacquer and soot. The vermilion lacquer used to varnish the side of the lacquered bowls was composed of lacquer mixed with cinnabar and minium Red Lead.

Bioaccumulation of Heavy Metals in Intestine of Nacella concinna (남극삿갓조개 (Nacella concinna) 장의 중금속 축적에 관한 연구)

  • Lee, Yong-Seok;Jo, Yong-Hun;Han, Yeon-Soo;Kho, Weon-Gyu;Ahn, In-Young;Jeong, Kye-Heon
    • The Korean Journal of Malacology
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    • v.22 no.1 s.35
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    • pp.87-95
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    • 2006
  • Immunohistochemical and ultrastuructural experiments were conducted to find out heavy metal accumulation in the intestine of an Antarctic gastropod Nacella concinna. According to the immune-histochemical experiment the apical cytoplasm of the intestinal epithelium showed positive reactions to anti-MT (rnotallothionein), indicating the presence of MT, a metal-binding protein involved in metal detoxifying process. In the transmission electron microscopic observations, the epithelial cells of the intestine exposed to Cd for over three hours showed irregular nuclear membranes, secretory granules, and probable metal granules. According to the SEM-EDS experiments on the intestine, concentration of Pb in the apical epithelium was in inverse proportion to that in the intestinal lumen. After exposing to Cd for over three days, S was rapidly reduced. Ca and Zn were rapidly increased after exposure to Cd. These elements are supposed to be concerned with the MT-reaction in the intestine. laken together, these data suggest that N. concinna could be used as a potential biomarker species.

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Synthesis and Characteristic Evaluation of Downward Conversion Phosphor for Improving Solar Cell Performance (태양전지 성능향상을 위한 하향변환 형광체의 합성 및 특성평가)

  • Jae-Ho Kim;Ga-Ram Kim;Jin-To Choi;Soo-Jong Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.5
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    • pp.523-528
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    • 2023
  • The applicability as a material to improve solar cell performance was reviewed by synthesizing a phosphor that emits red wavelengths by a liquid synthesis method using a metal salt aqueous solution and a polymer medium as a starting material. An aqueous solution was prepared using nitrate of metals such as Ca, Zn, Al, and Eu, and a precursor impregnated with starch, a natural polymer, was sintered to synthesize CaZnAlO:Eu phosphor powder. The surface structure and composition analysis of the synthesized CaZnAlO:Eu phosphor powder were analyzed by scanning electron microscope(SEM) and energy-dispersed X-ray spectroscopy(EDS). The crystal structure of CaZnAlO:Eu phosphor particles was analyzed by an X-ray diffraction analyzer (XRD). As a result of measuring the photoluminescence(PL) characteristics of the phosphor, it was confirmed that a red phosphor with a light emitting wavelength of 650-780nm was successfully synthesized. According to SEM and EDS analysis, the synthesized Ca14Zn6Al9.93O35:Eu3+0.07 phosphor powder has a uniform particle size, and Eu ions used as an activator are present. The synthesized CZA:Eu3+ phosphor can be used as a material that can increase the light absorption efficiency of the solar cell by converting ultraviolet or visible light down conversion into a wavelength in the near-infrared region.

Identification of the Materials of the Decorative Pieces Excavated from Geumnyeongchong Tomb (금령총 출토 장식편 재질 규명)

  • Lee Gyuhye;Shin Seungchul;Gwak Hongin;Yang Seokjin
    • Conservation Science in Museum
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    • v.30
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    • pp.89-100
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    • 2023
  • Museum collections are comprised of a variety of materials, and different scientific examinations are being conducted according to the types and production properties of the materials, but insufficient research has been carried out on ultra-small artifacts. To identify the material characteristics of the white ultra-small materials excavated from Geumnyeongchong tomb, this study carried out a wide range of non-destructive analyses (specific gravity, microscopy, nano-computed tomography (Nano-CT), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Raman spectroscopy) and compared the said artifacts with the Goryeo-era burial accessories examined in prior research. Non-destructive analysis confirmed the presence of aragonite, which mainly consists of calcium carbonate (CaCO3) as the constituent mineral, and identified the material used for the ornaments as the gemstone pearl based on its growth lines. This study concludes that pearls began to be used in the ancient Korean Peninsula in the 6th century. It is expected that scientific examinations of the white ultra-small artifacts will yield information about the social culture of the time.

Application Study of Raman Micro-Spectroscopy for Analysis on Corrosion Compound of Iron Artifacts (철제유물 부식화합물 분석의 표준데이터 확보를 위한 라만 분광법 적용성 연구)

  • Park, Hyung Ho;Lee, Jae Sung;Yu, Jae Eun
    • 보존과학연구
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    • s.32
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    • pp.89-98
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    • 2011
  • It is quite difficult to identify its corrosion compound because they have a wide variety of crystal structures and they are mixed with two component. This study was conducted with the standard iron corrosion compounds through the analysis by Raman Micro-Spectroscopy, which aims to obtain standard Raman Data. To assess the reliability of standard iron corrosion compounds, SEM-EDS analysis and XRD analysis were conducted. Through SEM-EDS analysis, the elements of corrosion compound matched with those of standards iron corrosion compounds except Goethite. XRD analysis showed that the structures of corrosion compounds were identical to those of standard iron corrosion compounds, however, it was identified that Iron sulfate ($FeSO_4{\cdot}6H_2O$) is the Rozenite ($FeSO_4{\cdot}4H_2O$). Through Raman Micro-Spectroscopy analysis, the new peak was detected from the wavenumbers of hydroxide and iron oxide. It is considered that it is due to changes in the wavelength of the laser. As the wavenumbers of iron chloride and iron sulfate have been identified, eight kinds of Raman Data were obtained. It can be considered to contribute to cultral heritage for iron objects that Raman Micro-Spectroscopy analysis which is relatively easy to compare material properties and structures can be highly applicable to the research on cultural heritage with the limited amount of samples.

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Analysis of Ceramics Using Scanning Electron Microscopy (주사전자현미경을 활용한 세라믹의 분석)

  • Lee, Sujeong
    • Ceramist
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    • v.22 no.4
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    • pp.368-380
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    • 2019
  • A ceramic is used as a key material in various fields. Accordingly, the use of scanning electron microscopy is increased for the purpose of evaluating the reliability and defects of advanced ceramic materials. The scanning electron microscope is developed to overcome the limitations of optical microscopy and uses accelerated electrons for imaging. Various signals such as SE, BSE and characteristic X-rays provide useful information about the surface microstructure of specimens and, the content and distribution of chemical components. The development of electron guns, such as FEG, and the improved lens system combined with the advanced in-lens detectors and STEM-in-SEM system have expanded the applications of SEM. Automated SEM-EDS analysis also greatly increases the amount of data, enabling more statistically reliable results. In addition, X-ray CT, XRF, and WDS, which are installed in scanning electron microscope, have transformed SEM a more versatile analytical equipment. The performance and specifications of the scanning electron microscope to evaluate ceramics were reviewed and the selection criteria for SEM analysis were described.