• Analytical Science and Technology
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• v.21 no.6
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• pp.553-561
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• 2008

$CNT/TiO_2$ composites were prepared by using multiwall carbon nanotubes (MWCNT) and various titanium alkoxide precursors. The composites were comprehensively characterized by scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation, was tested using the conversion of MB from model aqueous solution. Finally, according to the results of methylene blue (MB) removal experiment, we could see that sample CTOS have better MB removal effect than samples CTIP and CTPP.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.15-19
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• 1973

A method was developed for the separation of titanium, niobium and zirconium together in a group from the coexisting ions of various metals such as iron, cobalt, nickel, yttrium and rare earths by means of the cation exchange column using ${\alpha}$-hydroxyisobutyric acid as the eluent. In the course of the present investigation, it was found that the tailing phenomena of zirconium were attributable to the hydroxide precipitation which was made prior to the elution. For example, if zirconium was precipitated by sodium hydroxide, the tailing of zirconium became very serious in contrast to the results reported by others. This paper describes how these tailing phenomena of zirconium were prevented and how a practical procedure for the separation of these ions was, achieved using ion-exchange method. Using the present method the nuclides of $^{90m}Y$ and $^{90}Y$ were separated with radiochemical purity from the irradiated zirconium.

• Analytical Science and Technology
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• v.12 no.5
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• pp.382-386
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• 1999

Spherical particles of barium titanyl oxalate(BTO) were homogeneously precipitated by thermal decomposition of dimethyl oxalate in hydrochloric mixture solutions of water and ethanol. The experimental parameters such as composition of the mixture solvents. the eoncentration of hydrochloric acid and reaction temperature had the paramount effect on the size of panicles collected from the bottom of the reaction vessel at the aging time of 120 min and the composition of BTO. Stoichiometric BTO powders were obtained under certain conditions as relatively low alcohol content in the mixtures, high chloride concentration and high temperature, Monosized, submicrometer, but titanium excess particles were obtained under certain reverse conditions.

• Journal of the Korean Electrochemical Society
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• v.6 no.2
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• pp.130-133
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• 2003

3,4-dihydroxybenzoic acid(3,4-DHBA) was electropolymerized on glassy carbon electrode to give the GC/p-3,4-DHBA type electrode which was modified with dopamine by the help of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride(EDC) acting as a coupling agent. The carboxylic sites on the polymeric surface of p-3,4-DHBA and mine group at the dopamine gave a QCA(Au)/p-3,4-DHBA-dopamine type of modified electrodes. The o-quinone moieties at the electrode surface exhibited high selectivity to titanium ions in solution. The redox process of the electrode is hydroquinone : quinone +$2H^+2e^-$, which had two strong and two weak pairs of peaks at CV. The modified electrode can deposit Ti(IV) ions as much as $4.13\times10^{-5}gcm^{-2}$. The calibration curve of the electrodes, log of the surface coverage-normalized redox response vs log[Ti], exhibited an excellent correlation$(r{\geq}0.997)$ for titanium concentrations ranging from $5.25\times10^{-4}\;to\;5.25\tiems10^{-8}M.$.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.1-5
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• 1999

The dispersing performance of oligomer-type anionic surfactants ($C_mD-Na$), cooligomers of diethylester maleate and alkylvinylether of different alkyl chain lengths or polymerization degree were studied on the aqueous suspension of iron dxide or titanium dioxide particles which are hydrophilic pigments. The dispersion behavior of oligomer-type surfactants for these dispersoids, although anion charges on the surface of pigments particles showed different dispersing properties, was dependent upon the side alkyl chain length. Oligomer-type surfactants having more than $C_8$ side alkyl chain exhibited large dispersing action for relatively hydrophobic ${\alpha}-Fe_2O_3$ and Anatase $TiO_2$ in the concentration range of more than 0.1% oligomer-type surfactant solutions.

• Journal of the Mineralogical Society of Korea
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• v.25 no.1
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• pp.41-50
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• 2012

페루 남동부 지역에 위치한 꾸스코 동-금을 포함한 다중금속 광상 지역의 지질은 고생대 페름기-중생대 삼첩기 변성퇴적암인 미투(Mitu)층군과 이를 관입한 동시기 관입암으로 구성되어 있다. 조사지역은 페름기-삼첩기 관입암과 관련된 U-W-Sn-Mo, Au-Cu-Pb-Zn, REE 광화작용과 관련된 금속광화 대로 알려져 있다. 특히 해당 관입암은 대자율 측정 결과 S-type, 티탄철석계열과 관련이 있는 것으로 보인다. 꾸스코 지역은 깔까 북쪽과 시꾸아니 부근에 주요 광화대가 발달하고 있다. 조사대상 광상은 아줄 동, 올미오 동, 빅토리아 금, 빠딴자 동, 나우챠피-초차까나 동, 체카 금광상이다. 아줄 광상의 모암은 안산암질암이며 광석광물로는 반동석 및 황동석이 산출하며, 동은 7.81~15.3%의 범위를 가지고 평균 10.7%이다. 올미오 광상의 모암은 흑색편암이며 엽리를 따라 산화동이 충진되어 있고, 동은 0.61~2.60%의 범위를 가지고 평균 1.74%이다. 빅토리아 광상의 모암은 변성퇴적암이며, 석영맥 충진형 광상으로 금함량은 < 0.1 g/t, 은함량은 < 0.1~< 0.3 g/t이다. 빠딴자 광상에서는 이암 또는 실트암의 층리를 따라 충진하고 있는 산화동이 산출하며, 동은 3.74~9.21%의 범위를 보이며 평균 6.21%이다. 나우챠피-초차까나 광상은 적색사암의 층리를 교대충진하고 있는 산화동 광체이며, 동은 1.62~10.5%의 범위를 가지며 평균 6.39%이다. 체카 광상은 모암인 규암이 각력화작용을 받은 부분에서 금이 산출되고 있는 것으로 보고되어있으나 분석결과 금이 탐지되지는 않았다.

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.34-45
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• 1999

Mafic granulite xenoliths are found in precambrian porphyroblastic gneiss of the Mt. Jiri area, SW Sobaegsan massif, Korea. The xenoliths are rounded to ellipsoidal in shape, 50-100 cm in length and coarse-grained with granoblastic and foliated texture. The xenoliths consist of orthopyroxene, garnet, biotite, plagioclase, quartz, ilmenite and secondary orthoamphibole. Orthopyroxene is mostly resorbed and rimmed by coronitic orthoamphiboles. Garnets occur as porphyblasts and are zoned with higher pyrope content in cores than in rims. Geothermo-barometry results yield conditions of about $800-850^{\circ}C$, 6 kb and $500^{\circ}C$, 4 kb for early and retrograde stages of equilibration, respectively. According to available geochronological data, it is suggested that the granulite facies metamorphism occurred prior to 2.1-1.9Ga and that the area was superimposed by the high-grade (over $600-700^{\circ}C$) metamorphism between 1.9-1.7Ga, followed by cooling during uplift.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.652-656
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• 1998

$(Ba_{0.8-x}Sr_{0.2})Y_xTiO_3\;(BSYT)$ powders were prepared by the calcination of metal-oxalate precipitates, which were obtained by wet chemical method using Ba, Sr, Y and Ti-nitrates and oxalic acid. Yttrium content, sintering temperature and cooling rate were taken as experimental factors. Response surface method was applied to modelling of the room temperature resistivity of BSYT. The results indicated that the Yttrium content had larger effect on the room temperature resistivity and minimum room temperature resistivity was at Yttrium content of 0.24 mol%. The validity of a modelling equation was confirmed by comparing the measured room temperature resistivity with the calculated one.

• Journal of the Korean Chemical Society
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• v.25 no.3
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• pp.183-189
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• 1981

Iron and titanium, the major constituents in iron ores, were X-ray spectrometrically determined by using the dilution parameter method. A standard and samples possessing a similar composition were diluted with the diluent $ZrO_2$ to their proper respective ratios. After measuring the intensity of the fluorescent X-ray, the dilution parameter was calculated from the following equation. $Pa=\frac{\frac{I_{as}}{(I_{as})_d}}{D-1}{^{-1}}$The dilution parameters were used to correct the difference between the matrix effect of the standard and that of the sample. The content of the major constituents was calculated, without using any standard calibration curves, from the following equation;$W_a=W_a^*{\cdot}{\frac{I_as}{I_{as}^*}{\cdot}\frac{P_a^*}{P_a}$where asterisks indicate the standard. The results agreed with those of the wet analysis within 2% of relative error, and the precision of the experiment was also tolerably good.

• Journal of the Korean Chemical Society
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• v.18 no.6
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• pp.408-414
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• 1974

The direct reactions of titanium tetrachloride with piperidine and diphenylamine in dichloromethane have been studied by examining the isolated reaction products. In the reaction with piperidine, titanium tetrachloride undergoes both addition and substitution reactions as in the following: $TiCl_4+C_5H_{10}NH{\to}TiCl_4{\cdot}C_5H_{10}NH$$TiCl_4+C_5H_{10}{\to}TiCl_3{\cdot}NC_5H_{10}+HCl$ The addition reaction is relatively fast and completed in minutes whereas the substitution reaction is very slow. The both reaction products coprecipitated with piperidine hydrochloride formed during the substitution reaction were isolated and characterized. The reaction with diphenylamine resembles to the above reaction but the addition compound could be obtained in pure crystal form.