• Journal of Conservation Science
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• v.31 no.3
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• pp.181-192
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• 2015

This study aims to examine production technique of twelve white wares from the Gangneung Namyang-ri and Donghae Balhan-dong2(Samun-dong) kiln sites, Kangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$. Analyzing the excavated white wares using the Seger formula, compositional properties of white wares in Gangneung Namyang-ri kiln showed diffrently from the Donghae Balhan-dong2(Samun-dong) kiln. The body of white wares from Gangneung Namyang-ri kiln have higher raito of $RO_2$ and $RO+R_2O$ than of white wares from Donghae Balhan-dong2(Samun-dong) kiln site. The white wares from Gangneung Namyang-ri kiln and Donghae Balhan-dong2(Samun-dong) kiln were made of host rocks of the different geological origin, according to the result of rare earth elements analysis.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.233-239
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• 2014

The slagging which generated from ash deposition on furnace wall and tube in boiler reduces the heat transfer efficiency and damages to safety of boiler. The slag flow behavior in boiler is affected by melting temperature which is related to ash compositions. In this study, the behavior of slag is researched by using ash fusibility test, called TMA (Thermo-Mechanical Analysis). The technique measures the percentage shrinkage as the function of temperature, T25%, T50%, T75%, T90%. These temperatures indicate different stages of melting. Then, the effect of ash chemical compositions measured from XRF (X-ray Fluorescence Spectrometer) to ash fusion temperatures is discussed. Among the chemical compositions, refractory and fluxing influence on ash fusibility is described. High levels of refractory component and limited amount of fluxing components ($Fe_2O_3$, $K_2O$, CaO) increase overall melting temperatures. High $SiO_2/Al_2O_3$ ratio decrease high melting temperatures (T75%, T90%). Meanwhile, the presence of reasonable levels of fluxing components reduces overall melting temperature. A presence of fluxing component such as $K_2O$ and CaO is found to decrease the T25% values significantly. From this research, it is possible to make a reasonable explanation and prediction of ash fusion characteristic from analysis of TMA results and ash chemical compositions.

• Journal of Conservation Science
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• v.30 no.3
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• pp.249-261
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• 2014

This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.179-186
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• 2017

This study investigated the mineralogical characteristics of lime mortars used in pointing of Namhansanseon Yeojang from Joseon dynasty. Polarization microscopy revealed quartz, feldspar, mica, pyroxene and opaque minerals in the lime mortars. XRD analysis also confirmed clay minerals chlorite and kaolin. As a result of particle size analysis of lime mortars, the particle size distribution was wide and size was not uniform. 60% of samples were corresponded to the sand area. The chemical components detected from XRF analysis, 8.71-11.18 % of Ca as the main component of lime and $SiO_2$, $Al_2O_3$, and $Fe_2O_3$ in soil minerals were main components. The lime mortars showed an endothermic peak due to decarbonization reaction of $CaCO_3$ at $750^{\circ}C$ and weight reduction rate of 10%. The microstructures were agglomerated amorphous and observed rhombohedral calcite crystals by scanning electron microscope. It is considered that the pointing of Yeojang is a mortar mixed with lime and soil. In addition the Hanbongseong Yeojang was constructed using the same materials and construction technique because the minerals composition is not different according to the Yeojang location and use.

• Journal of Conservation Science
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• v.35 no.3
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• pp.253-258
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• 2019

The gilt bronze statue, Seated Avalokiteshvara with a Thousand Hands, of the Goryeo dynasty, is the only one in Korea of its kind that has undergone a conservation process for the special exhibition entitled GORYEO: The Glory of Korea. For the conservation treatment, first, a component analysis (XRF) was conducted, and a manufacturing technique (CT) was analyzed. The results of the investigation revealed that the statue was alloyed with Cu, Sn, and Pb ternary bronze. Its surface, except for the detached plating layers, was originally plated using the mercury amalgam method. This statue was assembled after separately casting each part of the body, such as the left and right arms and the wrists, including the hands, with objects. In particular, each wrist was cast and fitted with a metal nail to express each object in the hands more precisely. Inside the statue, there were five iron cores: two for the head, one for the left elbow, one for the right flank, and one for the right waist. For the preservative treatment, natural adhesive agents, including vegetable gelatin and glue (20%), were mixed with alcohol to protect the base metal and adhere to the plating layers. Using synthetic resin (CDK 520+SN-sheet) for the damaged parts, the restored parts could be attached and detached to/from the statue. Eventually, the compositional analysis and conservation treatment left the statue in a stable condition and ready for exhibitions and future studies.

• Journal of Conservation Science
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• v.32 no.1
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• pp.89-100
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• 2016

We estimated pigments and painting techniques with nondestructive analysis for Yu Eonho's portrait made in the eighteenth century, then compared with 11 portraits and painting characteristics at that time. The pigments used to Yu Eon-ho's portrait include lead white, yellow dye, cinnabar, minium, and pink dye, malachite, azurite, iron oxide red and brown dye, blue and pink dye for purple. In the result compared with painted pigments of 11 portraits, iron oxide red without cinnabar was used on the face part and organic green dye only was used instead of inorganic pigments on the other side of clothing after Yu Eonho's portraits portrait. This study is show the painting techniques on the portraits in the late $18^{th}$ century. We expect to use as useful referencing data for the study on the coloring technique of a portrait in the late Joseon Dynasty.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.282-305
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• 2010

Many earrings were excavated from Bujang-ri site in Seosan with various prestige goods such as the golden crowns, shoes and decorated swords. This proved that Bujang-ri site in Seosan fell within Hanseong Backjae area of influence in the 4~5th centuries. The earpieces of excavated prestige goods had been considred subordinate elements compared with the golden crowns, shoes and decorated swords. Twenty one earpieces were excavated from Bujang-ri site and formative features and material characteristics of them were analyzed by microscope and XRF. The material and manufacturing technique of earpieces were compared with excavated aspects of prestige goods. As a results, the earpieces that made of a small amount gold and by simple technique were the most whereas the earpieces that required advanced skills such as welding, workmanship and high purity of gold were smaller. Also the earpieces that required advanced skills were excavated from the tombs where the prestige goods such as the golden crowns, shoes and decorated swords appeared. Therefore, considering Hanseong Backjae used the gold wares as means in showing power for local influence men, the earpiece from Bujang-ri site in Seosan would be the standard on superiority of tomb's owner as gold purity.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.345-348
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• 2015

Dried Rehmannia Radix Preparat, produced in different geographic origins of Korea and China, were investigated for the trace element contents using X-ray fluorescence spectrometry. When the estimated data for 35 kind of elements including K, P, S, Cl, Si, Al, Fe, Sn, etc on 143 samples were analyzed by canonical discrimination technique, the average classification correct rate was 92.3% and the significance was less than 0.0001. In case of reducing the number of elements for statistic analysis from 35 to 8 and to 3, the correct rates were also reduced to 88.1% and to 84.6%. The correct rate for Chinese samples ranged from 94.6-96.0%, while those for Korean ranged from 72.5-89.9%.

• Asian Journal of Atmospheric Environment
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• v.4 no.2
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• pp.80-88
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• 2010

In order to offer a better understanding of air pollution of China as well as East Asia we attempted to characterize the chemical properties of the raw coal materials mined in China and their combusted bottom ashes generated from coal fired power plant. To this end, we measured the chemical characteristics of individual bottom ashes and feed coal fragments collected at a coal fired power generator which was operated with the raw coal dug at a coal mine in China. The chemical properties of these two sample types were determined by a synchrotron radiation X-ray fluorescence (SR-XRF) microprobe method. Through an application of such technique, it was possible to draw the 2D elemental maps in and/or on raw coal fragments and fired bottom ashes. The pulverized fine pieces of feed coal mainly consisted of mineral components such as Fe, Ca, Ti, Ca, and Si, while Fe was detected as overwhelming majority. The elemental mass of combusted bottom ash shows strong enrichment of many elements that exist naturally in coal. There were significant variations in chemical properties of ash-to-ash and fragment-to-fragment. Although we were not able to clearly distinguish As and Pb peaks because of the folding in their X-ray energies, these two elements can be used as tracers of coal fire origin.

• Current Photovoltaic Research
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• v.3 no.3
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• pp.75-79
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• 2015

Recently, $Cu_2ZnSn(S_xSe_{1-x})_4$ (CZTSSe) has been received a tremendous attraction as light absorber material in thin film solar cells (TFSCs), because of its earth abundance, inexpensive and non-toxic constituents and versatile material characteristics. Kesterite CZTSSe thin films were synthesized by sulfo-selenization of sputtered Cu/Sn/Zn stacked metallic precursors. The sulfo-selenization of Cu/Sn/Zn stacked metallic precursor thin films has been carried out in a graphite box using rapid thermal annealing (RTA) technique. Annealing process was done under sulfur and selenium vapor pressure using Ar gas at $520^{\circ}C$ for 10 min. The effect of tuning Se/(S+Se) precursor composition ratio on the properties of CZTSSe films has been investigated. The XRD, Raman, FE-SEM and XRF results indicate that the properties of sulfo-selenized CZTSSe thin films strongly depends on the Se/(S+Se) composition ratio. In particular, the CZTSSe TFSCs with Se/(S+Se) = 0.37 exhibits the best power conversion efficiency of 4.83% with $V_{oc}$ of 467 mV, $J_{sc}$ of $18.962mA/cm^2$ and FF of 54%. The systematic changes observed with increasing Se/(S+Se) ratio have been discussed in detail.