• 보존과학연구
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• s.22
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• pp.93-114
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• 2001

The composition analysis of Danchung pigments at Geunjeongjeon Hall in Gyeongbokgung Palace were carried out by FXRF and MXRD. The analytical result of the inside pigments at Geunjeongjeon showed that these painted in use the mineral pigments. Gold pigment was pure gold(Au).The main composition identified in green pigments were chalcanthite($CuSO_4$.$5H_2O$) and celadonite($K(Mg, Fe, Al)_2$.$(Si, Al)_4O_10(OH)_2$ ). Red pigments werecinnnabar(HgS).The analytical result of the outside pigments at Geunjeongjeon revealed that these applied to the artificial synthetic pigment. Yellow pigment was chromeyellow($PbCrO_4$). The main composition identified in red pigments were red lead($Pb_3O_4$)and hematite($Fe_2O_3$). Green pigments were emeral green($C_2H_3A_s3Cu_2O_8$) and chromegreen($Cr_2O_3$). Blue pigment was lazurite($Na_6Ca2Al_6Si_6O_24(SO_4)_2$), titanium dioxide($TiO_2$) of white pigment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.376-380
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• 1998

The chemical copositions in rice hulls of twenty six varieties which are one of the largest agricultural by-products in Korea were analyzed. The chemical compositions were 8.56~9.70% moisture, 10.01~17.16% ash, 44.02~55.50% crude fiber, 0.26~2.90% crude protein, 9.20~14.50% starch, and 0.28~0.69% lipid. There were no significantly difference in chemical compositions among twenty six varities. The mineral contents(mg/100g) were 14.3~392.4mg K, 59.4~389.1mg Ca, 31.78~377.8mg Zn, 19.4~104.4mg Na, 12.9~47.6mg Mg, 12.8~37.0mg Si, 8.3~30.5mg Fe, 7.9~26.1mg Al, 7.6~23.5mg Mn, and 6.3~40.3mg P. The contents of IDF (insoluble detergent fiber), SDF(soluble detergent were 70%, 1~2%, 67~73%, 51~60%, 11~17% and 0.3~2%, respectively. The lignin content was higher in Hwa-Young and Mankum than in others. The amounts of ethanol extracts of rice hulls were 1.01~1.52%. In conclusion, the chemical compositions were not significantly difference among twenty six rice hulls varieties.

• Journal of Conservation Science
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• v.27 no.3
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• pp.243-250
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• 2011

Seven glass beads from Bupwha-ri site, Yeongdong dated Joseon dynasty were analyzed with SEM/EDS and X-ray diffraction methods. Six samples were classified to potash glass system($K_2O-CaO-SiO_2$) with HCA(High CaO and $Al_2O_3$) and high concentration of MgO suggested raw materials to plant ashes. Especially one sample from tomb no. 8 was highly different concentration of $K_2O$ and MgO with others. It was shown that they were different sources of raw materials. Mostly coloring agents of potash glasses were owing to Fe and Cu. One sample was found to lead glass system(PbO-$SiO_2$) with 12% PbO. The content of PbO was differentiated with other lead glasses since we analyzed so far. It needs more study for compositions of lead glasses with regions and ages.

• Journal of Conservation Science
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• v.8 no.1 s.11
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• pp.10-15
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• 1999

The chemical compositions and microstructure of the punch'ong excavated from Bokwangri, Kangnung were investigated by the scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDS), X-ray diffractometer (XRD), and dilatometer. The compositions of body were $SiO_2(73-78\%),\;Al_2O_3(13-16\%)$, $RO{\cdot}R_2O(4-5\%,\;R=Ca,\;Mg,\;Na,\;K),\;R_xO_y(3-6\%,\;R=Fe,Ti)$ in weight ratio, which were higher silica and flux $(RO{\cdot}R_2O)$ but lower alumina. Owing to the high content$(21-30\%)$ of calcium oxide the glaze is considered lime type. Firing temperature range for the ceramic was presumed to about $1150^{\circ}C$.

• Resources Recycling
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• v.6 no.3
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• pp.3-8
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• 1997

The EA.F. sleelmaking slag (slag that follow) of a cnmvany 1 Co.. containzd a simple substance of a metal, wustlte (FeO), magnetite (Fe,O,), gehlenite (CaAl,SiO,), monlicellite (CaMgSiO,), dc. To recovere a metal (Fe grade . t95%) in the slag, it is desirable that the particles of a metal are isolated from thc slag and madc for a liberated subslance. Then, the liberaled melal is easlly recoveled by a magnetic separation. If thc rcclarnalcd slag, the sizc of which ranges under 40 nun, have a mulli-stage crushing, the most of a metal in thc slag is simply isolaled as a liberated subslance. If the mad, lhat is a liberated subslance and a sphere, is recovered by a magnetic field intensity. the minimum intensity, at which a metal is attracted, is approximately IOOG and did no1 dcpcnd on the particle size of a metad in the same particles. TIe recovered material. that contdined a iron (Fe) over 95% is a metal which is crushed slag by l00G in the multi-stage. If the magnetic field intcns~ty increase, the recovery mcrcasc, but the concentration grade decrease Bewusc thc concentration eams more and more impurities, iron oxide and the coml~ound of alkali earth element. 'll~ercforc If the rccla~nated slag have the multi-stage crushing, the metal is almostly recovered in the crushed slag by lO0G on each particles. If the slag, used as a rcclamatian lhat is a amount of 350,000 tan from I Co., was undcr the multistage crushing and then separaled by 100gauss, it is possible to recova a metal approximately 2.500 Ion, lhat is 0.73% of n ~eclamated slag. in 304.7 mm particles and to recover 4.200 tan in 0.3-1.7 mm particles , that is 1.2% nf a rcclamated slag, in a year. Therefore, ihe told recoverable meld is 6,700 ton, that is 19% of a reclmated slag, in a year, too.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1662-1672
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• 2016

To address physicochemical factors of yellow clay for removing Cochlodinium polykrikoides blooms, the correlation of removal efficiency with mineralogical characteristics of yellow clay collected from various areas was surveyed. Yellow clay from different localities showed the wide range of chemical compositions $SiO_2$ : 43~71%, $Al_2O_3$ : 13~26%, $Fe_2O_3$ : 5~14%, MgO : 0.4~1.8%, $K_2O$ : 0.6~3.3%, L.O.I.(Loss of Ignition) : 4.5~15%. The mineral compositions of yellow clay were mainly consisted of quartz and feldspar including small amounts of kaolinite, chlorite, and Fe-oxides. The result of size analysis showed that $6{\Phi}(31{\sim}16{\mu}m)$ and $7{\Phi}(16{\sim}8{\mu}m)$ were dominated sizes. The zeta-potential were in the range of -4.1~-20.7mV(average -13.7). As increasing removal efficiency of C. polykrikoides, contents of $Al_2O_3$, $Fe_2O_3$ and L.O.I. in yellow clay increased, whereas $SiO_2$ content decreased. Furthermore, the amounts of silt mineral and small particle were high when the removal efficiency was high. According to factor analysis using principle component analysis, two components of factor 1 and factor 2 showed 79% of the total variance, which is related to cohesion and adsorption. Inducing cell lysis of C. polykrikoides by cohension and adsorption between C. polykrikoides and yellow clay.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.157-162
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• 2017

Inorganic stiffening agents were prepared by mixing paper sludge incineration ash, blast furnace slag fine powder quicklime, anhydrous gypsum and fly ash. The main components of the solidifying agent developed for sludge treatment were SiO, $Al_2O_3$, $TiO_2$, $Fe_2O_3$, $Mn_2O_3$, CaO, MgO, $Na_2O$, $K_2O$, $P_2O$, and $SO_3$. Unlike cement, the developed solidifying agent did not contain $Cr^{6+}$, which is known as a carcinogen. Heavy metals and oil contaminated soil were mixed with solidifying agent and cured for 7 days and the heavy metal content was below the environmental standard. Sewage sludge cake, food waste and solidifying agent were mixed with each other, and after 7 days curing, soil component test showed that the heavy metal content was below the environmental standard. After mixing the sludge, solidifying agent and additive mixture into the beaker, the ammonia concentration was measured to be 0 after 3 days.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.643-659
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• 2012

The Chungju Fe-REE deposit is located in the Kyemyeongsan Formation of the Ogcheon Group. The Kyemyeongsan Formation includes meta-volcanic rocks and pegmatite hosted REE deposit which show different kind of REE-containing minerals. The meta-volcanic rocks hosted REE deposits' main REE minerals are allanite, zircon, apatite, and sphene, whereas the pegmatite hosted REE deposits is mainly composed of fergusonite, and karnasurtite, zircon, thorite. The meta-volcanic rock hosted major REE mineral is allanite as the form of aggregation and contains 23.89-29.19 wt% TREO (Total Rare Earth Oxide), 4.71-9.92 wt% $La_2O_3$, 11.30-14.33 wt% $Ce_2O_3$, 0.11-0.29 wt% $Y_2O_3$, 0.15-0.94 wt% $ThO_2$, as a formula of (Ca, Y, REE, Th)$_{2.095}$(Mg, Al, Ti, Mn, $Fe^{3+})_{2.770}(SiO_4)_{2.975}(OH)$. Accompanying REE in a coupled substitution for $Ca^{2+}$ (M1 site) and $Al^{3+}-Fe^{2+}$ (M2 site) leads to a large chemical variety. Due to the allanite's high contents of Fe, it belongs to Ferrialanite. The pegmatite hosted deposit's domi-nant REE mineral is fergusonite as prismatic or subhedral grains associated with zircon, fluorite and karnasurtite. Geochemical composition of the fergusonite($YNbO_4$) suggests substitution of Y-REE and Y-Th in A-site, and Nb-Ta-Ti in B-site, furthermore the proportion of $Y_2O_3$ and $Nb_2O_5$ is oddly 1:1.5 comparing to the ideal ratio 1:1 and Nb is higher than Y, also A-site Y actively substitutes with REE. Karnasurtite in pegmatite variously ranges 9.16-22.88 wt% $Ce_2O_3$, 2.15-9.16 wt% and $La_2O_3$, 0.44-10.8 wt% $ThO_2$, as a calculated formula (Y, REE, Th, K, Na, Ca)$_{1.478}(Ti, Nb)_{1.304}$(Mg, Al, Mn, $Fe^{3+})_{0.988}$(Si, P)$_{1.431}O_7(OH)_4{\cdot}3H_2O$. Firstly the 870-860 Ma is the initial age of the supercontinent Rhodinia dispersal and subsequent A-1 type volcanism, which contains Fe, REE, and HFS(High Field Strength elements; Nb, Zr, Y etc.) elements in Fe-rich meta-volcanic rocks dominant Kyemyeongsan Formation, might mineralized allanite. Another synthesis is that regional metamorphism at late Paleozoic 300-280 Ma(Cho et al., 2002) might cause allanite mineralization. Also pegmatite REE mineralization highly related to the granite intrusion over the Chungju area in Jurassic(190 Ma; Koh et al., 2012). Otherwise above all, A-1 type volcanism at the same time of the Kyemyeongsan Formation development, regional metamorphism and pegmatite, might have caused REE mineralization. Although REE ore bodies display a close spatial association, each ore bodies display temporal distinction, different mineral assemblage and environment of ore formation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.74-74
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• 2018

Ti-6Al-4V alloys have been widely used as orthopedic materials because of their excellent corrosion resistance and mechanical properties. However, it does not bind directly to the bone, so it requires a surface modification. This problem can be solved by nanotube and micropore formation. Plasma electrolytic oxidation (PEO) treatment for micropore, which combines high-voltage spark and electrochemical oxidation, is a new way of forming a ceramic coating on light metals such as titanium and its alloys. This method has excellent reproducibility and can easily control the shape and size of the Ti alloy. In this study, formation of bioactive surface by PEO-treatment after $2^{nd}$ ATO technique of Ti-6Al-4V alloy was invesgated by various instrument. Nanotube oxide surface structure was formed on the surface by anodic oxidation treatment in 0.8 wt.% NaF and 1M $H_3PO_4$ electrolytes. After nanotube formation, nanotube layer was removed by ultrasonic cleaning. PEO-treatment was carried out at 280V for 3 minutes in the electrolytic solution containing the bioactive substance (Mg, Zn, Mn, Sr, and Si). The surface of Ti-6Al-4V alloy was observed by field emission scanning electron microscopy (FE-SEM, S-4800 Hitachi, Japan). An energy dispersive X-ray spectrometer (EDS, Inca program, Oxford, UK) was used to analyze the spectra of physiologically active Si, Mn, Mg, Zn, and Sr ions. The PEO film formed on the Ti-6Al-4V alloy surface was characterized using an X-ray diffractometer (TF-XRD, X'pert Philips, Netherlands). It is confirmed that bioactive ions play an essential role in the normal bone growth and metabolism of the human skeletal tissues.

• Journal of Korea Foundry Society
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• v.3 no.4
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• pp.239-247
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• 1983

CV graphite cast iron has been studied and generally known to have properties close to the average values of those between flake and spheroidal graphite cast iron. However, the thermal diffusivity of CV graphite cast iron is much larger than that of the average value of those between flake and spheroidal graphite cast iron. In this study, an easy production method of CV graphite cast iron with small additions of a Al-Cu which is known as the element of the graphitization was investigated. The effects of hold time and of Al-Cu additions after the treatments with spheroidizer (Fe-Si-Mg alloy) were also investigated. Increasing the additions of a Al-Cu alloy, the holding time to form a CV graphite cast iron was decreasing. Tensile strength and thermal diffusivity (flash method) were measured in order to find the changes of the mechanical properties and the physical properties. Spheroidal, CV, and flake graphite cast iron have tensile strengths 46.44, 38.29, and $27.29\;kg/mm^2$ and thermal diffusivities $3.95{\times}10^{-6,}$ $8.41{\times}10^{-6}$, $8.81{\times}10^{-6}m^2/sec$, respectively at room temperature.