• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.109-115
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• 2005

Beidellite, a member of the smectite group, was synthesized hydrothermally from dickite. Physical and chemical properties of the synthetic Na-beidellite were characterized by the analytical methods of XRD, IR, TG, DTA, EDS, XRF and ICP. The result of Greene-Kelly test indicates that the synthesized smectite is Na-beidellite. IR spectrum of synthesized beidellite exhibited Al-O-H bending vibration at $818\;cm^{-1}\;and\;770\;cm^{-1}$ which was observed particularly in pure beidellite. TGA analysis revealed that the synthesized Na-beidellite comprises $16\;wt\%$ of water. DTA curve showed an endothermic peak at $117^{\circ}C$ due to dehydration reaction and peaks at $482^{\circ}C$ and $685^{\circ}C$ due to dehydroxylation reaction. The clay mineral was transformed to mullite and cristobalite at the temperature of $1028^{\circ}C$. The CEC value, Methylene Blue test and swelling capacity was determined to be $116\~118\;cmol/kg,\;84\~91\%,\;29\~32\;mL/2g$, respectively. The chemical composition of the synthesized phase was identified as $Na_{0.5}Al_{2.5}Si_{3.5}O_{10}(OH)_2$ from EDS and XRF analyses.

• Particle and aerosol research
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• v.7 no.4
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• pp.139-149
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• 2011

It is very important to measure atmospheric particles and evaluate the characteristics of them since aerosol can influence atmospheric environment, climate, and health. Satellite, aircraft, radio sonde are usually used to measure the vertical distribution of particle properties, temperature, humidity, and pressure. Although the method of using an aircraft is favorable to collect the horizontal distribution of the particles, but unadaptable to measure the vertical distribution of the particles. However, all-in-one balloon particle sampler system can collect particles depending on each altitude controling the balloon by winch. In this research, we performed the air sampling on the TEM grids using house made light weight impactor at the altitude of 300m and 900m. The collected particles were analyzed using TEM/EDS.

• Textile Coloration and Finishing
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• v.28 no.4
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• pp.271-279
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• 2016

This study deals with antibacterial properties of nylon fiber treated with glycidyltrimethylammonium chloride(GTAC) and silver nanoparticles(AgNPs). Nylon fibers were soaked into GTAC(2-30%, v:v) solution for 20 min. After sample was pre-drying at $80^{\circ}C$ for 10min and cured at $180^{\circ}C$ for 5min. The AgNPs coating was accomplished by soaking in silver colloid solution at $45^{\circ}C$ for 90min. The coated nylon fibers were characterized by scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS). EDS analysis indicated that AgNPs and GTAC was attached on nylon fibers. The treated nylon fibers showed antimicrobial properties against Escherichia coli(ATCC 43895), Pseudomonas aeruginosa(ATCC 13388) and Staphylococcus aureus(ATCCBAA-1707).

• Advances in nano research
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• v.5 no.3
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• pp.203-214
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• 2017

In this study we present the reaction mechanism of $Cu_2ZnSnSe_4$ (CZTSe) nanoparticles synthesized by microwave-assisted chemical synthesis. We performed reactions every 10 minutes in order to identify different phases during quaternary CZTSe formation. The powder samples were analyzed by x-ray diffraction (XRD), Raman spectroscopy, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that in the first minutes copper phases are predominant, then copper and tin secondary phases react to form ternary phase. The quaternary phase is formed at 50 minutes while ternary and secondary phases are consumed. At 60 minutes pure quaternary CZTSe phase is present. After 60 minutes the quaternary phase decomposes in the previous ternary and secondary phases, which indicates that 60 minutes is ideal reaction time. The EDS analysis of pure quaternary nanocrystals (CZTSe) showed stoichiometric relations similar to the reported research in the literature, which falls in the range of Cu/(Zn+Sn): 0.8-1.0, Zn/Sn: 1.0-1.20. In conclusion, the evolution pathway of CZTSe synthesized by this novel method is similar to other synthesis methods reported before. Nanoparticles synthesized in this study present desirable properties in order to use them in solar cell and photoelectrochemical cell applications.

• Journal of Korean Society of Water and Wastewater
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• v.9 no.3
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• pp.108-115
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• 1995

The feasibility study of using converter slag as a solidifying agent of digested sewage sludge cake has been performed. The availability of converter slag as solidifying agent has been investigated by several trial tests. Based on the trial test results, the optimum mixing ratios of sludge cake and solidification additive are estabilished. Finally the solidification characters of sludge cake are elucidated by SEM and EDS. It is ascertained that converter slag with a small amount of quicklime enhences the solidification. From the result of pH test, overall pH of specimens tends to decrease slowly with curing time. After solidifying specimens had been cured for 7 days, these are water-cured for 24 hours. The weight and strength of all the specimens are nearly the same regardless of the mixed ratios of solidifying agent. The result of leaching tests for four heavy metal ions, Cd, $Cr^{6+}$, Pb and Cu show that the leaching strength becomes below the decision criteria of the specific wastes, respectively. The SEM observation of the delicate structure shows that needlelike crystals appear after solidification which are not observed before. From the EDS analysis, it is found that the main ingredients of needlelike crystals are Ca, Si, Al and O.

• Corrosion Science and Technology
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• v.16 no.5
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• pp.247-256
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• 2017

The feasibility of using hydrazine for inhibiting pitting corrosion in copper sprinkler tubes was investigated by examining microscopical and structural evolution of corrosion by-products with SEM, EDS, and XRD. Hydrazine removed dissolved oxygen and reduced CuO and $Cu_2O$ as well. The stable phase was changed from CuO to $Cu_2O$ or Cu depending on hydrazine concentration. Hydrazine concentration of 500 ppm could convert all CuO corrosion by-products to $Cu_2O$. In a tightly sealed acryl tube filled with aqueous solution of 500 ppm hydrazine, octahedral $Cu_2O$ particles were formed while plate-like structures with high concentration of Cu, O, N and C were formed near a corrosion pit. The inside structure of a corrosion pit was not altered by hydrazine aqueous solution. Uniform corrosion of copper was almost completely stopped in aqueous solution of 500 ppm hydrazine. Corrosion potential of a copper plate was linearly dependent on log (hydrazine concentration). The concept of stopping pitting corrosion reaction by suppressing oxygen reduction reaction could be verified by applying this method to a reasonable number of real sprinkler systems before full-scale application.

• Journal of Technologic Dentistry
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• v.34 no.2
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• pp.145-153
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• 2012

Purpose: The purpose of this study was to investigate to effect of the electro-polishing condition according to electrolyte temperature and current and polishing time on surface morphology and composition by scanning electron microscopy(SEM) and energy dispersive X-ray spectrometer(EDS) in dental casting Co-Cr-Mo alloys. Methods: 16 specimens were divided into 4 groups which have each 4 specimens. The size of specimens were 10mm wide and 5mm height. the electro-polishing of specimens are by polishing solution temperature and times in Co-Cr-Mo alloy by SEM and EDS analysis. Results: The results shows that most smooth surface is obtained when electro-polishing is performed at $49^{\circ}C$ for 30-40sec with electro gap of 10mm and 8 voltage. Conclusion: The morphologies of specimens after electro-polishing were scratch absent and significant between at $40^{\circ}C$ for 45sec and at $49^{\circ}C$ for 45sec.

• Applied Science and Convergence Technology
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• v.26 no.5
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• pp.143-147
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• 2017

Structural studies on the addition characteristics of Nb ions to $BaTiO_3$ solid solutions were performed by XRD and SEM/EDS technique. The X-ray diffraction peaks of the (111), (200) and (002) planes of Nb-doped $BaTiO_3$ solid solutions with different mole% of Nb were analyzed. We also investigated the relationship between the dielectric and structural properties of Nb-doped $BaTiO_3$. The transition temperatures of $BaTiO_3$ solid solution doped with 0.5mole%Nb and 1.0 mole%Nb were ${\sim}116^{\circ}C$ and ${\sim}87^{\circ}C$, respectively, which were found to be shifted to very low temperature from the transition temperature of pure $BaTiO_3$ (about $125^{\circ}C$). As a result of analysis of 1/K versus T and ln[$(1/K)-(1/K_m)$ versus ($T-T_m$)] of the two compositions used in this experiment, the diffusivity slightly differs from that of pure $BaTiO_3$ at temperatures above Curie temperature. And this characteristic was analyzed by applying the modified Curie-Weiss law.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.3
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• pp.138-145
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• 2012

An ${\alpha}$-Ferrite (Fe) powder dispersed with 4 vol.% of $Al_2O_3$ was successfully produced by a simple miling at 210 K with a mixture of $Fe_2O_3$, Fe and Al ingredient powders, followed by 2 step high temperature consolidation: Hot Pressing (HP) at 1323 K and then Hot Isostatic Pressing at 1423 K. The microstructure of the consolidated material was characterized by standard metallographic techniques such as XRD (X-ray Diffraction), TEM and STEM-EDS. The results of STEM-EDS analysis showed that the HIPed materials comprised a mixture of pure Fe matrix with a grain size of ~20 nm and $Al_2O_3$ with a bimodal size distribution of extremely fine (~5 nm) and medium size dispersoids (~20 nm). The mechanical properties of the consolidated materials were characterized by compressive test and micro Vickers hardness test at room temperature. The results showed that the yield strength of the ODS (Oxide Dispersion Strengthened) Fe alloy are as much as $674{\pm}39$ MPa and the improvement of the yield strength is attributed to the presence of the fine $Al_2O_3$ dispersoid.

• 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.