• Journal of Conservation Science
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• v.35 no.5
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• pp.385-391
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• 2019

In order to examine the material characteristics of a black and white photograph of the Borobudur temple, in Indonesia, several analyses were conducted. A sample was taken from a black and white photograph; microscopy, Fourier transform-infrared spectroscopy, scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and X-ray fluorescence analyses showed that the black and white photograph was composed of four layers including a paper substrate, baryta, binder and surface layers. It was confirmed that the substrate was paper made of cellulose fiber from Cannabis sativa, the baryta layer was made of barium sulfate(BaSO₄) in powder form, the binder was an emulsion containing silver halide, and the surface protective layer was made of gelatin. Since photographs have different characteristics and require different preservation environments depending on the material of construction, it is necessary to study various black and white photographic material characteristics corresponding to each time period.

• Journal of the Korean Ceramic Society
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• v.30 no.6
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• pp.433-440
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• 1993

The bioactivity of glasses in the CaO-SiO2 system and CaO-P2O5-SiO2 system with less than 10mol% of P2O5 was investigated by in vitro test in simulated body flood(SBF). The formation of Ca.P film and hydroxyapatite on the surface of glasses after in vitro test was analysed by X-ray photoelectron spectoscopy (XPS), fourier transform infrared reflection spectroscopy (FT-IRRS), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) observation. In the early stage of Ca.P film formation after in vitro test for CaO-SiO2 and CaO-P2O5-SiO2 glasses, the rate of Ca.P film formation on the surface of the glasses was dependent of structural parameter (Y) evaluated from the glass composition. First, in the case of the glasses having Y value below 2, Ca.P film and SiO2-rich layer were formed simultaneously, and there were no differences of the rate of Ca.P film formation in terms of the Y values. Second, in the case of the glasses having Y value above 2, the SiO2-rich layer was formed, and then Ca.P.Si mixed layer was formed in the silica gel structure of the SiO2-rich layer, and finally the Ca.P film on the surface of SiO2-rich layer. The rate of Ca.P film formation delayed as the Y values increased. The rate of hydroxyapatite formation of glasses (the rate of transformation from Ca.P film to hydroxyapatite) seems to be propotional to the rate of Ca.P film formation and Y value. The rate of hydroxyapatite formation of glasses belonging to the second group was delayed as structural parameter increased, and the hydroxyapatite crystal showed spherical growth in the early reaction stage, and then showed silkworm-like linear growth as the reaction time increased.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.610-615
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• 2001

Over 800 thousand tons per year (TPY) agricultural biowastes, such as sugar cane bagasse, sugarcane leaf, rice straw, rice husk and corn leaf, are produced in Taiwan. These biomasses are the major types of agricultural wastes and are abundantly available. However, these biowastes cause disposal and landfill problems. Ossification ashes of the agricultural biowastes containing 70-95 % amorphous silica would make the utilization system of agricultural biowaste ashes become highly economically and environmentally attractive. Experimentally, high crystallinity (99%$^{+}$) zeolites ZSM-5 and ZSM-48 synthesized from the reaction mixtures containing a silica source from ashes of these biowastes gasification were investigated. Tetrapropylammonium bromide (TPABr) and 1,6-diamino-hexane (C$_{6}$ DN) were used as structure-directing agents in syntheses of ZSM-5 and ZSM-48, respectively. X-ray powder diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDX) data indicated that ZSM-5 or ZSM-48 with a high crystallinity can be obtained within 48 hours of crystallization in the high pressure (15-20 atm) autoclave at 393-473 K. The Si/Al ratios of synthetic zeolite products were determined by X-ray fluorescence (XRF) and induced couple plasma/mass spectroscopy (ICP/MS). It was observed that the ZSM-5 crystals a.e composed of hexagonal rod-shaped crystals with typically 8-13 пm in size by SEM. In addition, ZSM-48 crystalline materials are composed of spherical aggregates of needle-shaped or rod-like crystals with typically 2-3 пm in diameter and 6-8 пm in length.h.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.126-132
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• 2018

SnS thin films with different substrate temperatures ($150 {\sim}300^{\circ}C$) as process parameters were grown on soda-lime glass substrates by RF magnetron sputtering. The effects of substrate temperature on the structural and optical properties of SnS thin films were investigated by X-ray diffraction (XRD), Raman spectroscopy (Raman), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and Ultraviolet-visible-near infrared spectrophotometer (UV-Vis-NIR). All of the SnS thin films prepared at various substrate temperatures were polycrystalline orthorhombic structures with (111) planes preferentially oriented. The diffraction intensity of the (111) plane and the crystallite size were improved with increasing substrate temperature. The three major peaks (189, 222, $289cm^{-1}$) identified in Raman were exactly the same as the Raman spectra of monocrystalline SnS. From the XRD and Raman results, it was confirmed that all of the SnS thin films were formed into a single SnS phase without impurity phases such as $SnS_2$ and $Sn_2S_3$. In the optical transmittance spectrum, the critical wavelength of the absorption edge shifted to the long wavelength region as the substrate temperature increased. The optical bandgap was 1.67 eV at the substrate temperature of $150^{\circ}C$, 1.57 eV at $200^{\circ}C$, 1.50 eV at $250^{\circ}C$, and 1.44 eV at $300^{\circ}C$.

• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.235-243
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• 2014

Purpose: The aim of this study was to prepare and evaluate a natural material extracted from germinated brown rice (GBR). Herein, we evaluated whether the natural material could positively activate the biological effects seen during bone formation, including enhancement of metabolic activity, osteogenesis, and the expression of vascular endothelial growth factor (VEGF), one of the growth factors in human osteoblast-like cells. Methods: The natural material was created by a hot water extraction process after being soaked for 2~3 days in tap water and dried at $50^{\circ}C$. The material was characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) spectroscopy. The biological behaviors of the material were also investigated; we performed tests to assess cell cytotoxicity, metabolic activity, osteogenic markers related to bone formation, and VEGF. Results: The EDX, XRD, and FTIR results for the natural material indicated the presence of organic compounds. The natural material caused positive increases in cell metabolic activity and mineralized bone formation without cytotoxicity. The protein levels in the extract for the $6.25{\mu}g/mL$, $12.25{\mu}g/mL$, $25{\mu}g/mL$, $50{\mu}g/mL$, and $100{\mu}g/mL$ groups were significantly different from that for the control. Conclusions: The GBR-based natural material was easy to prepare and had characteristics of a potential biomaterial. The biocompatibility of this natural material was evaluated using in vitro techniques; our findings indicate that this novel material is promising for agricultural and biological applications.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.101-101
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• 2018

Quantitative measurement of chloride ion concentration has an important role in various fields of electrochemistry, medical science, biology, metallurgy, architecture, etc. Among them, its importance of architecture is ever-growing due to unexpected degradations of building structure. These situations are caused by corrosion of reinforced concrete (RC) structure of buildings. And chloride ions are the most powerful factors of RC structure corrosion. Therefore, precise inspection of chloride ion concentration must be required to increase the accuracy of durability monitoring. Multi-walled Carbon nanotubes (MWCNTs) have high chemical resistivity, large surface area and superior electrical property. Thus, it is suitable for the channels of electrical signals made by the sensor. Silver nanoparticles were added to giving the sensing property. CuBTC, one of the metal organic frameworks (MOFs), was employed as a material to improve the sensing property because of its hydrophilicity and high surface area to volume ratio. In this study, sensing element was synthesized by various chemical reaction procedures. At first, MWCNTs were functionalized with a mixture of sulfuric acid and nitric acid because of enhancement of solubility in solution and surface activation. And functionalized MWCNTs, silver nanoparticles, and CuBTC were synthesized on PTFE membrane, one by one. Electroless deposition process was performed to deposit the silver nanoparticles. CuBTC was produced by room temperature synthesis. Surface morphology and composition analysis were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), respectively. X-ray photoelectron spectroscopy (XPS) was also performed to confirm the existence of sensing materials. The electrical properties of sensor were measured by semiconductor analyzer. The chloride ion sensing characteristics were confirmed with the variation of the resistance at 1 V.

• Korean Journal of Materials Research
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• v.26 no.7
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• pp.393-399
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• 2016

Flower-like nickel oxide (NiO) catalysts were coated on NiCrAl alloy foam using a hydrothermal method. The structural, morphological, and chemical bonding properties of the NiO catalysts coated on the NiCrAl alloy foam were investigated by field-emission scanning electron microscopy, scanning electron microscopy-energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, respectively. To obtain flower-like morphology of NiO catalysts on the NiCrAl alloy foam, we prepared three different levels of pH of the hydrothermal solution: pH-7.0, pH-10.0, and pH-11.5. The NiO morphology of the pH-7.0 and pH-10.0 samples exhibited a large size plate owing to the slow reaction of the hydroxide ($OH^-$) and nickel ions ($Ni^+$) in lower pH than pH-11.5. Flower-like NiO catalysts (${\sim}4.7{\mu}m-6.6{\mu}m$) were formed owing to the fast reaction of $OH^-$ and $Ni^{2+}$ by increased $OH^-$ concentration at high pH. Thus, the flower-like morphology of NiO catalysts on NiCrAl alloy foam depends strongly on the pH of the hydrothermal solution.

• Korean Journal of Materials Research
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• v.24 no.8
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• pp.393-400
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• 2014

NiO catalysts were successfully coated onto FeCrAl metal alloy foam as a catalyst support via a dip-coating method. To demonstrate the optimum amount of NiO catalyst on the FeCrAl metal alloy foam, the molar concentration of the Ni precursor in a coating solution was controlled, with five different amounts of 0.4 M, 0.6 M, 0.8 M, 1.0 M, and 1.2 M for a dip-coating process. The structural, morphological, and chemical bonding properties of the NiO-catalyst-coated FeCrAl metal alloy foam samples were assessed by means of field-emission scanning electron microscopy(FESEM), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), X-ray diffraction(XRD), and X-ray photoelectron spectroscopy(XPS). In particular, when the FeCrAl metal alloy foam samples were coated using a coating solution with a 0.8 M Ni precursor, well-dispersed NiO catalysts on the FeCrAl metal alloy foam compared to the other samples were confirmed. Also, the XPS results exhibited the chemical bonding states of the NiO phases and the FeCrAl metal alloy foam. The results showed that a dip-coating method is one of best ways to coat well-dispersed NiO catalysts onto FeCrAl metal alloy foam.

• Journal of Electrochemical Science and Technology
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• v.2 no.1
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• pp.1-7
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• 2011

Nanocomposites of reduced graphene oxide and manganese (II,III) oxide can be synthesized by the freeze-drying process of the mixed colloidal suspension of graphene oxide and manganese oxide, and the subsequent heat-treatment. The calcined reduced graphene oxide-manganese (II,III) oxide nanocomposites are X-ray amorphous, suggesting the formation of homogeneous and disordered mixture without any phase separation. The reduction of graphene oxide to reduced graphene oxide upon the heat-treatment is evidenced by Fourier-transformed infrared spectroscopy. Field emission-scanning electronic microscopy and energy dispersive spectrometry clearly demonstrate the formation of porous structure by the house-of-cards type stacking of reduced graphene oxide nanosheets and the homogeneous distribution of manganese ions in the nanocomposites. According to Mn K-edge X-ray absorption spectroscopy, manganese ions in the calcined nanocomposites are stabilized in octahedral symmetry with mixed Mn oxidation state of Mn(II)/Mn(III). The present reduced graphene oxide-manganese oxide nanocomposites show characteristic pseudocapacitance behavior superior to the pristine manganese oxide, suggesting their applicability as electrode material for supercapacitors.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.611-620
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• 2018

In this study, a metal-organic framework (MOF) material $NH_2$-MIL-101(Fe) was synthesized using the solvothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectrophotometry, field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and surface area measurements. The XRD pattern of the synthesized $NH_2$-MIL-101(Fe) was similar to the previously reported patterns of MIL-101 type materials, which indicated the successful synthesis of $NH_2$-MIL-101(Fe). The FT-IR spectrum showed the molecular structure and functional groups of the synthesized $NH_2$-MIL-101(Fe). The UV-visible absorbance spectrum indicated that the synthesized material could be activated as a photocatalyst under visible light irradiation. FE-SEM and TEM images showed the formation of hexagonal microspindle structures in the synthesized $NH_2$-MIL-101(Fe). Furthermore, the EDS spectrum indicated that the synthesized material consisted of Fe, N, O, and C elements. The synthesized $NH_2$-MIL-101(Fe) was then employed as an adsorbent and photocatalyst for the removal of Indigo carmine and Rhodamine B from aqueous solutions. The initial 30 min of adsorption for Indigo carmine and Rhodamine B without light irradiation achieved removal efficiencies of 83.6% and 70.7%, respectively. The removal efficiencies thereafter gradually increased with visible light irradiation for 180 min, and the overall removal efficiencies for Indigo carmine and Rhodamine B were 94.2% and 83.5%, respectively. These results indicate that the synthesized MOF material can be effectively applied as an adsorbent and photocatalyst for the removal of dyes.