• Journal of Ecology and Environment
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• 제30권1호
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• pp.81-86
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• 2007

Human activities have enhanced the influx of heavy metals to aquatic ecosystem and hanged the abiotic environment such as the sediments supporting benthic organisms. The levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the benthic gastropod Oxyloma hirasei and the sediments around their habitat were investigated to examine heavy metal levels and the potential of the gastropod as a bioindicator. We detected different levels of heavy metals in the sediments of two wetland areas, Upo and Mokpo, in the relatively well-conserved Upo wetland, Ramsar Convention Area. Oxyloma hirasei had higher concentrations of heavy metals except Cr and Ni in their soft tissues than in their shells (Cd: $2.10{\sim}3.16$, Cu: $19.73{\sim}28.66$, Pb: $0.67{\sim}1.17$, Zn: $216.1{\sim}285.7\;{\mu}g/g$ dry weight in the soft tissues; Cr: $1.19{\sim}2.58$, Ni: $0.47{\sim}1.16\;{\mu}g/g$ dry weight in the shells). Differences in the Cd, Cu, Ni and Pb concentrations in O. hirasei soft tissues reflected differences in heavy metal concentrations in the sediments at the sampling sites. The coefficients of variation for Cd, Cu and Pb were lower than those for other metals in the soft tissues. Levels of Cd in the tissues of O. hirasei were the highest among the metals examined in this study. Therefore, the soft tissue of O. hirasei appears to be a promising bioindicator particularly for Cd.

• 한국염색가공학회지
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• 제12권6호
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• pp.389-395
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• 2000

A natural colorants was extracted from cherry by 10wt% aqueous acetic acid solution as an extractant. Silk and cotton fabrics were dyed with the cherry extract in the temperature range of $40-80^\circ{C}$ and for the time range of 30-60min. by pre- and post-mordanting with various mordants, their dyeability and fastness were investigated. The natural cherry extract prepared in this study has a maximum absorbance at 520nm. It was found that the optimum dyeing temperature and time were $40^\circ{C}$ and 50min, respectively. The pre-mordanting method was more effective than post-mordanting. All mordants except $SnCl_2\cdot{2H}_2O\;and\;FeSO_4\cdot{7H}_2O$ were effective for silk fabrics. However, the dyeability on cotton fabrics increased in the order of $CrK(SO_4)_2\cdot{12H_2O>(CH_3COO)_2Cu\cdot{H}_2O>CuSO_4\cdot{5H}_2O>AlK(SO_4)_2\cdot{12H}_2O>FeSO_4\cdot{7H}_2O>SnCl_2\cdot{2H}_2O$ among the mordants used in this study Fastness(light, water, washing, perpspiration fastness) on the silk and cotton fabrics increased with using mordants. The post-mordanting using mordant$(CH_3COO)_2Cu\cdot{H}_2O$ among the various mordants in this study gave the best fastness.

• Journal of Magnetics
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• 제13권4호
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• pp.163-166
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• 2008

Multiferroic $CoCr_2O_4$ film was deposited on MgO and $MgAl_2O_4$ substrates by the rf-sputtering process. The films were prepared at an RF-magnetron sputtering power of 50 W and a pressure of 10 mtorr (20 sccm in Ar), and at substrate temperatures of $550^{\circ}C$. The crystal structure was determined to be a spinel (Fd-3m) structure by means of X-ray diffraction (XRD) with Cu $K{\yen}{\acute{a}}$ radiation. The thickness and morphology of the films were measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The magnetic properties were measured using a Superconducting Quantum Interference Device (SQIUD) magnetometer. While the ferrimagnetic transitions were observed at about 93 K, which was determined as the Neel temperature, the magnetic properties all show different behaviors. The differences between the magnetic properties can be explained by the stress effects between $CoCr_2O_4$ and the substrates of MgO and $MgAl_2O_4$.

• Progress in Superconductivity
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• 제1권2호
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• pp.146-150
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• 2000

Step edge Josephson junctions in c-axis oriented $YBa_2Cu_3O_7$ films were fabricated on $CeO_2$ buffered sapphire substrates. The step angle was controlled in the wide range of $20^{\circ}\sim75^{\circ}$ by the Ar ion milling technique. I-V curves of junction fabricated on the thickness ratio of $\sim$0.8 and the step angle of $35^{\circ}$ were exhibited RSJ-like behavior with $I_CR_N$ product of $\sim250{\mu}A$ and critical current density of $\sim2\times10^4A/cm^2$ at 77 K. Critical current of step edge junction was increased linearly with decreasing temperature but the normal resistance was almost constant. Total samples of step edge Josephson junction was satisfied a scaling behavior of $I_CR_N{\propto}(J_C)^{0.5}$.

• 자원환경지질
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• 제32권3호
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• pp.247-260
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• 1999

Geochermical characteristics of the fluvial sediments deprnding on particle size distribution size were investigated in the respect of majir, minor and rare eath element chemisitry. Ratios of $Al_{2}O_{3}/Na_{2}O$ and $K_{2}O/Na_{2}O$ of the sediments show the homogeneous valus, and partly positive correlation with $SiO_{2}/Al_{2}O_{3}$, respecively. Characteristics of minor element ratios (V/Ni, Cr/V, Ni/Co and Zr/Hf)are within the lower and narrow range. Thesesuggested that sediment sources may be acidic to intermediate granitic rock, and may be explained by simple weathering and sedimentation. With increasing SiO2 contents, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO and MgO decreased, but those of $K_{2}O$ and $Na_{2}O$ increased, Concentrations of Ba, Be, Cs, Cu, Li, Ni, Sr, V and Zr show comparatively normal negative and some positive trends. Compared with the mean composition of granite, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, MnO, CaO and MgO in the sediments of the study area were highly enriced. Among some minor and rare earth elements, concentrations of As, Cd, Cu, and V were enriched, but those of Be, Ce, Rb, Sc, Sr and Zn were depleted when compared with average composition of granite. By decreasing of particle size fractions, SiO2, Rb and Sr conterts decreased, but concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO, MgO, $TiO_{2}$, MgO, $P_{2}O_{5}$, Be, Cu, Hf, Pb, V and Zr increased. From the correlations between particle size fractions and element concenreations, some elements of $Fe_{2}O_{3}$, CaO, MgO, $P_{2}O_{5}$, Cu, Ni, Zn and Zr showed typical trends in the secondary contramination sediments. These trends are typically shown under 100 mesh fractions. It indicates that the fraction of minus 100 mesh is the optimum size fraction for geochemical and environmental survey.

• 한국광물학회지
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• 제21권1호
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• pp.37-44
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• 2008

본 연구는 마포소각장에서 발생된 용융슬래그로부터 Na-A형 제올라이트를 합성하여 환경 저감재로 재활용키 위한 목적에서 수행되었다. 초기물질로 사용된 용융슬래그는 용제(flux)로 사용된 Fe 성분(19.6% of $Fe_2O_3$, and 18.9% of FeO)이 비교적 높기는 하지만, 상대적으로 제올라이트의 주요 성분인 $SiO_2$, $Al_2O_3$ 및 $Na_2O$가 각각 26.6%, 10.9% 및 2.7% 함유되어 제올라이트의 합성에 유리한 조성을 가지고 있다. 제올라이트의 수열합성은 $80^{\circ}C$에서 수행되었으며, $SiO_2/Al_2O_3\;=\;0.80{\sim}1.96$인 넓은 범위의 화학조성에서 Na-A형 제올라이트가 합성되는 것을 확인하였다. 제올라이트의 양이온 교환 능력은 10 h 이상의 합성시간에서 일정하게 거의 220 cmol/kg인 것으로 측정되었다. 합성된 제올라이트의 중금속 (As, Cr, Cd, Cu, Mn 및 Pb)에 대한 흡착능을 측정한 결과, As 및 Cr을 제외한 모든 중금속에서 높은 흡착율을 보였다. As와 Cr은 Eh-pH분석을 통해 각각 $HAsO_4^{2-}$와 $CrO_4^{2-}$인 이온상으로 존재하고 있음을 확인하였다. As와 Cr에 대한 제올라이트의 흡착률이 낮은 것은 이들 이온상들의 크기가 Na-A형 제올라이트의 pore size ($4\;{\AA}$)보다 상대적으로 큰 유효 이온반경($4\;{\AA}$, 직경 $8\;{\AA}$)을 가지고 있기 때문인 것으로 결론지었다.

• 한국지구과학회지
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• 제27권1호
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• pp.49-60
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• 2006

본 연구는 나주지역 하상퇴적물에 대한 지구화학적 특성 연구이다. 이를 위해 1차 수계를 대상으로 139개의 하상퇴적물 시료를 채취하였다. 채취된 시료는 실험실에서 자연 건조시켰으며, XRF, ICP-AES, NAA를 이용하여 화학분석을 실시하였다. 기반암에 따른 지구화학적 특성을 알아보기 위하여, 화강암질편마암 지역, 편암류 지역, 화강암류 지역, 사질암 지역, 응회암 지역, 안산암 지역, 유문암 지역으로 분류하였다. 나주지역 하상퇴적물의 지질집단별 주성분원소 평균함량은 $SiO_2\;58.37{\sim}66.06wt.%,\;Al_2O_3\;13.98{\sim}18.41wt.%,\;Fe_2O_3\;4.09{\sim}6.10wt.%,\;CaO\;0.54{\sim}1.33wt.%,\;MgO\;0.86{\sim}1.34wt.%,\;K_2O\;2.38{\sim}4.01wt.%,\;Na_2O\;0.90{\sim}1.32wt.%,\;TiO_2\;0.82{\sim}1.03wt.%,\;MnO\;0.09{\sim}0.15wt.%,\;P_2O_5\;0.11{\sim}0.18wt.%$이다. 주성분원소의 평균함량 비교에서 $Al_2O_3$와 $K_2O$는 화강암질편마암 지역에서, $Fe_2O_3,\;CaO,\;P_2O_5$는 응회암 지역에서, MgO와 $TiO_2$는 안산암 지역에서, $Na_2O$는 유문암 지역에서 높고, $SiO_2$와 MnO 함량은 사질암 지역에서 약간 높다. 미량성분 및 희토류원소의 지질집단별 평균함량은 $Ba\;1278{\sim}1469ppm,\;Be\;1.1{\sim}1.5ppm,\;Cu\;18{\sim}25ppm,\;Nb\;25{\sim}37ppm,\;Ni\;16{\sim}25ppm,\;Pb\;21{\sim}28ppm,\;Sr\;83{\sim}155ppm,\;V\;64{\sim}98ppm,\;Zr\;83{\sim}146ppm,\;Li\;32{\sim}45ppm,\;Co\;7.2{\sim}12.7ppm,\;Cr\;37{\sim}76ppm,\;Cs\;4.8{\sim}9.1ppm,\;Hf\;7.5{\sim}25ppm,\;Rb\;88{\sim}178ppm,\;Sc\;7.7{\sim}12.6ppm,\;Zn\;83{\sim}143ppm,\;Pa\;11.3{\sim}37ppm,\;Ce\;69{\sim}206ppm,\;Eu\;1.1{\sim}1.5ppm,\;Yb\;1.8{\sim}4.4ppm$이다. Pb, Li, Cs, Hf, Rb, Sb, Pa, Ce, Eu, Yb 평균함량은 화강암질편마암 지역에서, Ba, Co, Cr 평균함량은 편암류 지역에서, Nb, Ni, Zr 평균함량은 사질암 지역에서, Sr 평균함량은 응회암 지역에서 높고, Be, Cu, V, Sc, Zn 평균함량은 안산암 지역에서 다른 지질집단에서 보다 높다.

• 한국표면공학회지
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• 제38권2호
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• pp.49-54
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• 2005

Flexible copper clad laminates (FCCL) fabricated by sputtering has advantages in fine pitch etching and dimensional accuracy than previous casting or laminating type FCCL, But its lower adhesion is inevitable technical challenge to solve for commercializing it. Chromium (Cr) which strongly reacts with O moiety was used as tie-coating layer in order to improve low adhesion between copper (Cu) and polyimide (PI). Sputtering raw polyimide (SRPI) and casting raw polyimide (CRPI) were used as substrates at this research. PI was pretreated by plasma before sputtering, and each sample was varied with RF power and Cr thickness on sputtering. Peel strength of the FCCL on SRPI was higher than that on CRPI. Adhesion had maximum value when 10 nm of Cr was deposited on SRPI by RF power of 50 W. It seems to be by the formation of Cu-Cr-O solid solution at the metal-PI interface.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2012년도 임시총회 및 하계학술연구발표회
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• pp.116-117
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• 2012

• 대한화학회지
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• 제54권1호
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• pp.43-48
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• 2010

p-페닐렌 디아민과 maleic anhydride, 아세틸 아세톤과 커플된 O-아미노 페놀의 아조화합물으로 부터 폴리이미드가 만들어졌다. 합성된 폴리이미드(PA)는 DMF용매 속에 다른 몰비율로 녹아있는 $Co^{+2},\;Cr^{+2},\;Ni^{+2},\;Cu^{+2},\;Zn^{+2},\;Cd^{+2}$ and $Fe^{+3}$ 를 포함하는 전이금속이온들의 금속염들과 함께 환류되었다. 이 complex들은 원소분석과 열분석, IR, $^1H$ NMR으로 구조분석, 특성 연구되었다.