• Journal of dental hygiene science
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• v.9 no.2
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• pp.153-160
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• 2009

The purposed of this study was to investigate the effect of Gold bonding agent as intermediate layer between metal substrate and ceramic coating. Gold bonding agent used to seal off any surface porosity, to mask the greyish color of the metal, and to provide an underlying bright golden hue to the ceramic coverage. The adhesion between metal substrate and ceramic is related to diffusion of oxygen during ceramic firing. The oxide layer produced on non-precious alloy anti titanium was considered to have a potentially adverse effect on metal-ceramic bonding. The oxidation characteristics of titanium and non-precious alloys are the main problem. Every group were divided into test and control groups. Control groups are carried out process of degassing for product oxide layer. Au coating was applied on each Ni-Cr, Co-Cr alloys and cp-Ti specimens with difference surface condition or degassing. Specimens surfaces and cutting plane was characterized by SEM/EDS. Results suggested that Au coating is effective barriers to protect metal oxidation during ceramic firing.

• Journal of Conservation Science
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• v.35 no.2
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• pp.145-152
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• 2019

The metal-manufacturing method and smelting temperature of ancient metal-production processes have been studied by analyzing the principal elements and microstructures of slag. However, the microstructure of slag varies according to the solidification cooling rate and types and relative amounts of various oxides contained within the smelting materials. Hence, there is a need for accurate analysis methods that allow slag to be distinguished by more than its composition or microstructure. In this study, the microstructures of slag discharged as a result of smelting iron sands collected from Pohang and Gyeongju, as well as the slag excavated from the Ungyo site in Wanju, were analyzed by using metalloscopy, scanning election microscopy-energy dispersine X-ray spectroscopy(SEM-EDS) and wavelength dispersive X-ray fluorenscence(WD-XRF). Furthermore, the microcrystals were accurately characterized by performing Raman micro-spectroscopy, which is a technique that can be used to identify the microcrystals of slags. SEM-EDS analysis of Pohang slag indicated that its white polygonal crystals could be Magnetite; however, Raman micro-spectroscopy revealed that these crystals were actually $ulv{\ddot{o}}spinel$. Raman micro-spectroscopy and SEM-EDS were also used to verify that the coarse white dendritic structures observed in the Gyeongju-slag were $W{\ddot{u}}stites$. Additionally, the Wanju slag was observed to have a glassy matrix, which was confirmed by Raman micro-spectroscopy to be Augite. Thus, we have demonstrated that Raman micro-spectroscopy can accurately identify slag microcrystals, which are otherwise difficult to distinguish as solely based on their chemical composition and crystal morphology. Therefore, we conclude that it has excellent potential as a slag analysis technique.

• Restorative Dentistry and Endodontics
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• v.49 no.1
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• pp.6.1-6.16
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• 2024

Objectives: This study aimed to investigate the elemental analysis and microhardness of a bioactive material (Activa) and marginal tooth structure after storage in different media. Materials and Methods: Fifteen teeth received cervical restorations with occlusal enamel and gingival dentin margins using the tested material bonded with a universal adhesive, 5 of them on the 4 axial surfaces and the other 10 on only the 2 proximal surfaces. The first 5 teeth were sectioned into 4 restorations each, then stored in 4 different media; deionized water, Dulbecco's phosphate buffered saline (DPBS), Tris buffer, and saliva. The storage period for deionized water was 24 hours while it was 3 months for the other media. Each part was analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis for different substrates/distances and the wt% of calcium, phosphorus, silica, and fluoride were calculated. The other 10 teeth were sectioned across the restoration, stored in either Tris buffer or saliva for 24 hours or 3 months, and were evaluated for microhardness of different substrates/areas. Data were analyzed using analysis of variance and Tukey's post hoc test. Results: Enamel and dentin interfaces in the DPBS group exhibited a significant increase in calcium and phosphorus wt%. Both silica and fluoride significantly increased in tooth structure up to a distance of 75 ㎛ in the 3-month-media groups than the immediate group. Storage media did not affect the microhardness values. Conclusions: SEM-EDS analysis suggests an ion movement between Activa and tooth structure through a universal adhesive while stored in DPBS.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.109-114
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• 2004

The purpose of this study lies in analyzing the characteristics of the carbonized textile fabrics and to know the carbonizing mechanism. Samples were Jiyo excavated from the grave of Mrs. Hansan Lee as the wife of Jinju Kang at Daeduk-gu, Daejon, and black fragements assumed as of the outside material of cotton skirt and black dusts collected out of Jikryung for official dress. The composition and status of the fiber were clarified by means of Microscopic FT-IR and both cross sectioanl and side parts of the fiber were observed using the technique of scanning electron microscopy(SEM). Finally EDS analysis was carried out to qualitatively analyze inorganic ingredients contained in the carbonized fiber. As a result of FT-IR measurement, characteristic peak was very strong around $1625cm^{-1}$ and could be found even between 2500 and $2300cm^{-1}$ because of a high-molecule pigmental substance, melanine. When SEM photography was applied to the fractions, the tissues were identified as silk fiborine through the observation of their side and cross sectional parts. SEM-EDS measurement indicated that both the cotton skirt and Jikryung for official dress contained a high proportion of inorganic substances such as Si, Ca suggesting the existence of silicide and calcium carbonate.

• 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.

• 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}.

• 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.

• 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.

• 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.

• 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.