• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.773-780
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• 2003

The characteristics of soft clays is very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the disturbed clay samples obtained from Sihwa area. This study included X-Ray Diffraction Analysis, X-Ray Fluorescence Spectrometer Analysis, Scanning Electron Microscopy Analysis and Energy Dispersive X-Ray Spectrometer Analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.155-166
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• 2004

The characteristics of soft clays are very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the undisturbed clay samples obtained from Sihwa area. This study included X-Ray diffraction analysis, X-Ray fluorescence spectrometer analysis, scanning electron microscopy analysis and energy dispersive X-Ray spectrometer analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated. The characteristics of soft clay in Sihwa area were compared with those in Yangsan and Kunsan area.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.10
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• pp.1770-1778
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• 2001

황토는 대표적인 천연 무기염재의 일종으로서 바람에 의해 운반되어 퇴적된 담황색 내지는 황회색을 띠는 실트질의 퇴적물을 일컫는다. 황토의 구성물질은 주로 석영, 장석, 산화철광물, 깁사이트 등의 여러 가지 점토광물을 포함하는데, 주로 적색을 띠는 것은 소량의 산화철 광물에 기인되는 경우가 많으며 황토를 구성하는 점토광물로는 버미큘라이트, 카오린 광물인 캐올리나이트와 할로이사이트, 일라이트 등이 있다. 본 연구에서는 면직물에 천연 무기염재인 황토를 사용한 염색시에 황토 단독염색과 콩즙 전처리 후 황토염색으로 나누어 염색을 실시하고, 원료 황토와 황토염색 후 면직물에 부착된 성분 간에 차이가 있는지를 확인하기 위해 X선 형광분석(X-ray fluorescence analysis, XRF)을 이용하여 염색 전.후 황토의 성분을 분석하였고, X선 회절분석(X-ray diffraction analysis, XRD)을 이용하여 황토 및 염색 전 후 면직물에 부착된 광물질의 주성분을 분석하였으며, energy dispersive spectrometer (EDS)가 장착된 주사전자현미경을 이용하여 면직물에 부착된 광물의 성분을 조사하였다. 그 결과, 황토로 면직물을 염색하는 경우 면직물에 부착되는 황토의 양과 K/S 값은 거 의 비례하여 증가하는 것으로 나타났다. 황토 염색 후 면직물에 부탁되는 주성분은 주로 SiO$_2$, A1$_2$O$_3$, Fe$_2$O$_3$등인 것으로 나타났으며, X선 회절분석과 EDS분석에 의해 캐올리나이트, 일라이트 등의 점토광물의 형태로 존재하는 것이 확인되었다.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.484-487
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• 2012

A discrimination technique for domestic and imported Scutellaria baicalensis was developed using an energy dispersive X-ray fluorescence spectrometer (ED-XRF). Mineral content ratios, of a total of 43 species, including P, S, Cl, K, Ca, Mn, Fe, Cu, and Zn, were measured among 204 samples. Macro element content ratios and trace element content ratios were determined using the standardless fundamental parameters (SLFP) analysis. Inorganic element ratios of P, S, K, Ca, Cl, Mn, and Fe were significantly different between domestic and imported samples. The result from the canonical discriminant analysis showed that the accuracy of geographical origin discrimination was 95.15%; the correlation coefficient was 0.888. It was concluded that this technique could be used as a useful method in discriminating the geographical origins between domestic and imported Scutellaria baicalensis.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.125-129
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• 2020

In this study we developed a method for determining the geographic origin of soybeans by combining energy dispersive X-ray fluorescence spectrometry with statistical analysis. In 2018, 197 soybean samples (100 Korean domestic samples and 97 foreign samples) were collected for the construction of a geographic origin model. The mineral concentrations of 26 elements were measured and determined via the fundamental parameters approach. One-way analysis of variance, t-test, and canonical discriminant analysis were employed to reveal five elements (P, Ni, Br, Zn, and Mn) that could be used for the determination of geographic origins. The sensitivity, specificity, and efficiency for the above method were 91.0, 95.9, and 93.4%, respectively. Validation results from 60 samples collected in 2019 showed a predictive rate of 93.3% for Korean domestic soybeans and 100.0% for foreign soybeans. In conclusion, the combination of energy dispersive X-ray fluorescence spectrometry and chemometrics could be used to effectively determine the geographic origin of soybeans.

• Journal of the Korean institute of surface engineering
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• v.50 no.6
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• pp.531-535
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• 2017

Enormous amount of waste oyster-shell (OS) has a major disposal problem in coastal regions. OSs have attracted much attention for recycling, because these are mainly composed of calcium carbonate with rare impurities. In this study, we demonstrate the calcareous deposit films on steel plate by using OSs on the basic of cathodic protection technique. The composition of the OSs was analyzed by wavelength dispersive X-ray fluorescence spectrometer. Carbon dioxide gas was pumped into distilled water to make carbonic acid solution for dissolution of OS. The calcareous deposit was characterized by second electron microscope (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction. Corrosion rates were estimated by measurements of anodic polarization and immersion test. It is confirmed that calcareous deposits on steel plate are formed under all condition of cathodic protection by using waste OS from the SEM and EDX results. Calcareous deposits on steel by OS provide good corrosion resistance by acting as a barrier to oxygen supply to the steel surface.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.618-622
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• 2014

Oxide phosphorescent phosphor has an wide application in ceramic art and decoration due to its chemical and mechanical properties. Here, phosphorescent properties of strontium aluminate phosphor ($SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$) emitting yellowish-green light was investigated with thermal treatment at $1250^{\circ}C$ under air and reducing atmosphere. The characterizations of thermally treated samples were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fluorescence spectrometer. $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ still showed a good phosphorescent properties after annealing process in reducing atmosphere, while phosphorescence of $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ annealed in air seriously degraded, due to oxidation of $Eu^{2+}$ to $Eu^{3+}$ ions. It was also observed that $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ annealed in reducing atmosphere emitted yellowish-green light during 3 h after being exposed to sunlight.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1230-1236
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• 2016

This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.513-517
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• 2013

This study focused on the synthesis of $Nb_xSrTi_{1-x}O_3$ photocatalysts which partially inserted Nb ions with excellent ability of fluorescence into the perovskite structured $SrTiO_3$ frameworks and their photocatalytic hydrogen productions from methanol/water splitting corresponding to the molar ratios of Ti and Nb. The characteristics of the synthesized $SrTiO_3$ and $Nb_xSrTi_{1-x}O_3$ powders were analyzed by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), and UV-Visible spectrometer. The hydrogen evolution from methanol/water photo-splitting was enhanced over $Nb_{0.05}SrTi_{0.95}O_3$ compared to those over $SrTiO_3$ and another $Nb_xSrTi_{1-x}O_3$; 4.9 mL of hydrogen gases was collected after 8 h when 0.5g of $Nb_{0.05}SrTi_{0.95}O_3$ catalyst was used in pH 10.

• Analytical Science and Technology
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• v.11 no.2
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• pp.112-119
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• 1998

A Siemens SemiQuant (SSQ) 3000 program, a precalibrated 'standardless' analytical program handling up to 90 elements, was evaluated for the fast analysis of various types of reference materials using a wavelength dispersive X-ray spectrometer. Various types of standard reference materials such as metal discs, metal chips, and geological materials in powder form were analysed and it took 23 minutes of measuring time for 75 elements. Measurements of geological reference materials using different sampling methods were carried out and their data were interactively evaluated. The analysis of materials of a known matrix concentration such as stainless steels provided higher precision value compared to totally unknown samples. The analyses of materials prepared as pressed pellets or fused glass beads provided higher precision values compared to the measurement of loose powders with a foil on the sample surface and helium operation, though their sampling procedures were more complicate and took more time. Since very light elements such as boron, carbon, and oxygen have a strong influence on the matrix effects and also on the calculation of effective matrix corrections, the rhodium Compton check was applied to verify the reliability of the defined light element concentrations of light matrix materials and the defined major sample compounds. Failure of defining correct matrix resulted in an unoptimized matrix correction and therefore in the wrong calculation of the element concentration.