• The Korean Journal of Malacology
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• v.28 no.2
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• pp.157-164
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• 2012

The patterns in X-ray diffraction (XRD) spectroscopy provide useful clue at $29.4^{\circ}$ to discriminate two types of Akoya cultured pearl which occurs difference of surface luster. Using the optical microscope, we could be confirmed that the nareous layer of each sample consist of different crystal form. In Fourier Transform Infrared (FT-IR) Spectroscopy analysis, the nareous layer of Akoya cultured pearls with poor luster shows some peaks at 712, 699, 1435, $1444cm^{-1}$ region and these peaks depend on the Calcite. But the nareous layer of pearls with excellent luster could not observed those peaks related with Calcite, we could observed Aragonite band at 699, $1085cm^{-1}$ region. Though this result, we know that the nareous layer of Akoya cultured pearls with excellent luster is mainly composed by Aragonite. Raman bands are also clearly demonstrated to occur difference of band intensity by difference of Aragonite content. In the Scanning Electron Microscope (SEM) analysis, we found that the Akoya cultured pearl luster and surface condition is associated with internal structure.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.92-100
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• 2014

Hydrophobic magnesium hydroxide [$Mg(OH)_2$] was modified by hydrothermal method using non-ionic sorbitol surfactant with Span series. Mganesium chloride [$MgCl_2$] and sodium hydroxide [NaOH] were used for synthesis of $Mg(OH)_2$. Also non-ionic surfactant were added as a stabilizer, dispersant and surface modifier. Addition of non-ionic surfactant was favourable to obtain small sized $Mg(OH)_2$ particles with better dispersibility and hydrophobic property of $Mg(OH)_2$ particles. The obtained product were characterized by particle size analysis(PSA), scanning electron microscope(SEM), energy dispersive spectroscopy(EDS), x-ray diffraction(XRD) and fourier transform infrared spectroscopy(FT-IR). The results show that the product are prepared with this method has a well hydrophobic properties and dispersity compared with unmodified $Mg(OH)_2$ particles. The improve properties of surface modified $Mg(OH)_2$ particles were also verified by similarity synthesizing under slightly different conditions.

• 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.

• Journal of Conservation Science
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• v.34 no.1
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• pp.51-57
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• 2018

Herein, we present the results of the analysis of a lacquer coating fragment excavated from 'Daesungdong No.88 tomb of Gimhae'. We observed the fragment with an optical microscope and used scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) as well as Fourier-transform infrared spectroscopy analysis to determine the structure of the lacquer coating and the technique used for coating. The sample was identified as a Moksim Jophy Lacquer. It is made from wood, painted with textile fabric and coated with soil clay. The SEM-EDS analysis revealed residues of bone meal at the bottom part of the sheath layer. The incorporation of bone meal in a lacquer coating layer is one of the characteristics of the Han Dynasty, and was also found in the Nangnang Region and the United Silla Dynasty. Inside the sword sheath is a specific adherent structure of silk fabric, the same type of leguminous plant found in another sword sheath excavated from the Eastern Han-tomb of Xi'an. Results constitute the latest information about lacquer ware found in the southern district of the Korean peninsula. Moreover, the findings shed light on an international relationship with Kumkwan-Kaya where the sword sheath was produced.

• Resources Recycling
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• v.29 no.6
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• pp.98-103
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• 2020

In this study, the depression behavior of zinc sulfate on the sphalerite with the addition of potassium butyl xanthate was investigated to clear the relationship between zinc sulfate and xanthate in depression of sphalerite. As a result of the experiment, it was confirmed that the depress effect of zinc sulfate on the sphalerite declined with the increase of its addition amount. From the results of SEM-EDS and FT-IR analysis, it was found out that the amorphous precipitate of metal xanthate (Zn-BX) was formed in sphalerite concentrate, when the solubility product of [Zn+]·[BX] in the pulp solution exceeded 3.71×10-11, which is the solubility of Zn-butyl xanthate. It is considered that the Zn-butyl xanthate had a negative effect on the depression of sphalerite.

• Journal of Magnetics
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• v.20 no.3
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• pp.229-240
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• 2015

In this study, nanocrystalline ferrite powders with the composition $Ni_{0.5}Zn_{0.5}Fe_2O_4$ were prepared by the autocombustion method. The obtained powders were sintered at $800^{\circ}C$, $900^{\circ}C$ and $1,000^{\circ}C$ for 4 h in air atmosphere. The as-prepared and the sintered powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and magnetization studies. An increase in the crystallite size and a slight decrease in the lattice constant with sintering temperature were observed, whereas microstrain was observed to be negative for all the samples. Two significant absorption bands in the wave number range of the $400cm^{-1}$ to $600cm^{-1}$ have been observed in the FT-IR spectra for all samples which is the distinctive feature of the spinel ferrites. The force constants were found to vary with sintering temperature, suggesting a cation redistribution and modification in the unit cell of the spinel. The M-H loops indicate smaller coercivity, which is the typical nature of the soft ferrites. The observed variation in the saturation magnetization and coercivity with sintering temperature has been attributed to the role of surface, inhomogeneous cation distribution, and increase in the crystallite size.

• Transactions on Electrical and Electronic Materials
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• v.10 no.6
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• pp.217-221
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• 2009

The use of the carbon nanotube (CNT) is superior to the general powder state materials in their thermal and chemical properties. Because its ratio of diameter to length (aspect ratio) is very large, it is known to be a type of ideal nano-reinforcement material. Based on this advantage, the existing carbon black of the semiconductive shield materials used in power cables can acquire excellent properties by the use of a small amount of CNTs. Therefore, we fabricated specimens using a solution mixing method. We investigated the thermal properties of the CNT, such as its storage modulus, loss modulus, and its tan delta using a dynamic mechanical analysis 2980. We found that a high thermal resistance level is demonstrated by using a small amount of CNTs. We also investigated the chemical properties of the CNT, such as the oxidation reaction by using Fourier transform infrared spectroscopy (FT-IR) made by Travel IR. In the case of the FT-IR tests, we searched for some degree of oxidation by detecting the carboxyl group (C=O). The results confirm a tendency for a high cross-linking density in a new network in which the CNTs situated between the carbon black constituent molecules show a bond using similar constructive properties.

• Korean Journal of Materials Research
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• v.19 no.4
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• pp.179-185
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• 2009

We fabricated thermally evaporated 30 nm-Ni/(20 nm or 60 nm)a-Si:H/Si films to investigate the energy-saving property of silicides formed by rapid thermal annealing (RTA) at temperatures of $350^{\circ}C$, $450^{\circ}C$, $550^{\circ}C$, and $600^{\circ}C$ for 40 seconds. A transmission electron microscope (TEM) and a high resolution X-ray diffractometer (HRXRD) were used to determine the cross-sectional microstructure and phase changes. A UVVIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were employed for near-IR and middle-IR absorbance. Through TEM and HRXRD analysis, for the nickel silicide formed at low temperatures below $450^{\circ}C$, we confirmed columnar-shaped structures with thicknesses of $20{\sim}30\;nm$ that had ${\delta}-Ni^2Si$ phases. Regarding the nickel silicide formed at high temperatures above $550^{\circ}C$, we confirmed that the nickel silicide had more than 50 nm-thick columnar-shaped structures with a $Ni_{31}Si_{12}$ phase. Through UV-VIS-NIR analysis, nickel silicide showed almost the same absorbance in the near IR region as well as ITO. However, in the middle IR region, the nickel silicides with low temperature showed similar absorbance to those from high temperature silicidation.

• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.39-45
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• 2013

The gas generated from the fire which is continuous until material is completely burned. We can analyze usual gas using chromatography analysis but it can not be applicated to analyze for the gas from the fire because which gas is enormously generated. Besides, chromatography analysis has the disadvantage that it can not continuously analyze the sample's representativness, gas from the fire, Fourier transform infrared spectroscopy, FT-IR, has been utilized for effective combustion gas analysis method in small-scale combustion and on-line analysis has been attempted continuously. However, continuous sampling of 3.5l/min can not be representativness of sample if the gas caused by a massive fire and space. And the gas sampling is practically impossible in such a case. In this study, we attempted remote analysis while overcoming the disadvantages of the current gas analysis by using an Open-Path Infrared Analyzer without pre-treatment of the sampling. For the remote analysis, quantitative analysis method was established regarding each combustion toxic gases. And we measured the gases from the fire that occurs in the real case.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.442-450
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• 2014

Concern has grown over a presence of micropollutants in natural water since sulfonamide antibiotic substances such as sulfamethazine, sulfamethoxazole, sulfathiazole have been frequently detected in Nakdong River, Korea. The current work investigates the degradation of the three sulfonamide substances by using quantum chemistry calculations of density functional theory (DFT) and experimental measurement techniques of Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometer (UV-VIS). DFT calculations demonstrate that the lowest energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbitals (LUMO) lies in sulfanilamide functional group of sulfonamide, implying that the sulfanilamide functional group would be the most active site for ozone oxidation. Also, UV-VIS spectra and FT-IR analysis reveal that 260 nm band originated from sulfanilamide group was absent after ozone oxidation, indicating that a functional group of amine (N-H) was removed from sulfanilamide. Both theoretical and experimental observations agree well with each other, demonstrating the DFT calculation tool can be an alternative tool for the prediction of chemical reactions in purification treatment processes.