• 제목/요약/키워드: co-anion

검색결과 264건 처리시간 0.024초

초순수의 오염과 반도체 제조에 미치는 영향에 대한 연구 (A Study on the Contamination of D.I. Water and its Effect on Semiconductor Device Manufacturing)

  • 김흥식;유형원;윤철;김태각;최민성
    • 전자공학회논문지A
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    • 제30A권11호
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    • pp.99-104
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    • 1993
  • We analyzed the D.I. water used in wet cleaning process of semiconductor device manufacturing both at the D.I. water plant and at the wafer cleaning bath to detect the impurity source of D.I. water contamination. This shows that the quantity of impurity is related to the resistivity of D.I. water, and we found that the cleanliness of the wafer surface processed in D.I. water bath was affected by the degree of the ionic impurity contamination. So we evaluated the cleaning effect as different method for Fe ion, having the best adsoptivity on wafer surface. Moreover the temperature effect of the D.I. water is investigated in case of anion in order to remove the chemical residue after wet process. In addition to the control of D.I. water resistivity, chemical analysis of impurity control in D.I. water should be included and a suitable cleaning an drinsing method needs to be investigated for a high yielding semiconductor device.

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Synthesis and Characterization of New Intermetallic Compounds $M_3(AsTe_3)_2$ (M=Cr, Fe, Co)

  • 정진승;김현학;강석구;채원식;김돈;이성한
    • Bulletin of the Korean Chemical Society
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    • 제18권10호
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    • pp.1105-1108
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    • 1997
  • The new amorphous intermetallic compounds, M3(AsTe3)2: M=Cr, Co, Fe, were synthesized by the precipitation reaction of the Zintl anion AsTe33- with the divalent transition metal halides in aqueous solution and analyzed by EDS equipped with SEM and PIXE. The empirical formula of the specimens was found to be Fe3.0As1.8Te5.9, Co3.0As2.1Te6.5, and Cr3.0As2.0Te6.9 by the quantitative elemental analysis. The dc specific resistivity of the materials was measured as a function of temperature in the range from 20 to 300 K, in which their resistivity of Cr3(AsTe3)2 was largely dependent on temperature, while those of Co3(AsTe3)2 and Fe3(AsTe3)2 were only slightly dependent on temperature. To characterize the spin glass state of the specimens, the ac and dc magnetic susceptibility were measured and it was found that Co3(AsTe3)2 and Fe3(AsTe3)2 undergo a transition to a spin glass state at 6 K and 38 K, respectively. Magnetization data are reported as both thermal remanent magnetization (TRM) and isothermal remanent magnetization (IRM) as a function of magnetizing field and temperature.

Sorption and Separation of Thiocyanate Gold and Silver Complexes and Determination of Gold by Diffuse Reflectance Spectroscopy

  • Danilenko, N.V.;Kononova, O.N.;Kachin, S.V.;Kholmogorov, A.G.;Dmitrieva, Zh.V.;Plotnikova, E.A.
    • Bulletin of the Korean Chemical Society
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    • 제25권7호
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    • pp.1019-1024
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    • 2004
  • The present paper is focused on simultaneous sorption concentration of gold (III) and silver (I) from thiocyanate solutions using high-selective anion exchanger AN-25 and subsequent separation of these ions at various concentrations of thiocarbamide (eluent). As a result, silver (I) ions are completely eluted from AN-25 and gold (III) ions remain in the resin phase and can be determined directly in the solid phase by diffuse reflection spectroscopy. It is proposed to use the sorption-spectroscopic method for Au(III) determination in aqueous solutions. The calibration curve is linear in the concentration range of 1-19 mg/L (sample volume is 10.0 mL) and the detection limit is 0.05 ${\mu}g/mL$. The presence of Cu(II), Co(II), Fe(II) do not hinder this determination. Au(III) was determined in industrial solutions.

과황산나트륨을 이용한 유기 오염물 산화와 영향인자 평가 (Evaluation of Affecting Factors on the Ferrous Catalyzed Sodium Persulfate Oxidation for the Destruction of Organic Pollutant)

  • 윤여복;박해미;고성환;고석오
    • 한국물환경학회지
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    • 제25권1호
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    • pp.151-158
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    • 2009
  • The objective of this study was to determine on optimum ratio of oxidant and catalyst and to evaluate affecting factors such as anions and cations on persulfate oxidation of organic pollutant. Fe(II) activated the persulfate anion to produce a sulfate free radicals and thus effectively used to degrade the target organic pollutant in aqueous system. The chloride ions reacted with sulfate radical produced the $Cl^{\cdot}$ atom and had positive effects on the oxidation of organic pollutant at the initial stage. However, it was observed that chloride ions had the scavenging effects on the rate of oxidation of organic pollutant. Cations and some heavy metals were partly able to activate the persulfate anion to generate a sulfate free radical. However, high levels of cations inhibited the oxidation of organic pollutant.

UV/TiO2와 유동층 반응기를 이용한 안료의 광촉매 탈색 (Photocatalytic Decolorization of Dye usingUV/TiO2 and Fluidized Bed Reactor)

  • 박영식
    • 한국환경과학회지
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    • 제13권10호
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    • pp.921-928
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    • 2004
  • The photocatalytic decolorization of Rhodamine B (RhB) was studied using immobilized $TiO_2$ and fluidized bed reactor. Immobilized $TiO_2$(length: 1$\~$2 mm, width: 1$\~$3 mm, thickness: 0.5$\~$2 mm) onto silicone sealant was employed as the photocatalyst and a 30 W germicidal lamp was used as the light source and the reactor volume was 4.8 L. The effects of parameters such as the amounts of photocatalyst, initial concentration, initial pH, superficial velocity, $H_2O_2$ and anion additives. ($NO_3^{-},\;SO_4^{2-},\;Cl^{-},\;CO_3^{2-}$) The results showed that the optimum dosage of the immobilized $TiO_2$ were 87.0 g/L. Initial removal rate of RhB of the immobilized $TiO_2$ was 1.5 times higher than that of the powder $TiO_2$ because of the adsorption onto the surface of immobilized $TiO_2$ In the conditions of acidic pH, initial reaction rate was increased slowly and reaction time was shorted. The effect of anion type on the reaction rate was not much.

국내 유통 중인 식용식물 추출물의 항산화효과 (Anti-oxidative Activities of Commercial Edible Plant Extracts Distributed in Korea)

  • 김경범;유기환;박하얀;정종문
    • Applied Biological Chemistry
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    • 제49권4호
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    • pp.328-333
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    • 2006
  • 많은 식물 추출물들은 항산화 효능을 지니고 있으나 대량 생산 공정시 그들의 활성을 잃어버리는 경향이 있다. 따라서 본 본문에서는 대량 생산 공정을 거쳐 국내 유통 중인 43종의 식용식물 추출물을 대상으로 총 페놀 함량, DPPH 라디칼 포착 효능, 그리고 superoxide anion 라디칼 포착 효능을 측정하였다. 그 결과 개똥쑥(Artemisia annua, whole plant), 마태(Ilex paraguariensis leaf), 엉겅퀴(Silybum marianum, fruit 그리고 leaf), 유근피(Ulmus pumila, bark), 운지버섯(Coriolus versicolor, fruit) 그리고 울금(Curcuma longa, root 그리고 stem) 추출물은 70 mg/g 이상의 높은 페놀화합물을 함유하는 것으로 나타났다. DPPH 라디칼의 포착 효능에서 개똥쑥, 마테, 솔잎(Pinus densiflora, leaf), 엉겅퀴, 유근피, 그리고 울금 추출물의 $SC_{50}$ 값 측정 결과 각각 $53.96{\pm}0.81ppm,\;24.61{\pm}2.12ppm,\;35.96{\pm}1.11ppm,\;57.45{\pm}2.13ppm,\;55.25{\pm}1.65ppm$ 그리고 $12.99{\pm}1.67ppm$으로 나타났다(비타민 C의 $SC_{50}$값: $3.86{\pm}0.81ppm$). 또한 superoxide anion 라디칼 포착 효능에서는 개똥쑥, 계피(Cinnamomum zeylunicum, bark), 마테, 복분자(Rubus coreanus, fruit 그리고 leaf), 상엽(Morus alba, leaf), 솔잎, 엉겅퀴, 유근피, 운지버섯, 울금, 자소엽(Perilla frutescens var. acuta, leaf) 그리고 히비스커스(Hibiscus sabdariffa, leaf) 그리고 flower) 추출물의 $SC_{50}$ 값 측정 결과 각각 $53.21{\pm}1.83ppm,\;50.12{\pm}2.12ppm,\;5.59{\pm}0.84ppm,\;41.60{\pm}8.93ppm,\;20.19{\pm}0.97ppm,\;15.19{\pm}1.66ppm,\;21.20{\pm}1.88ppm,\;15.71{\pm}0.91ppm,\;55.48{\pm}2.42ppm,\;52.12{\pm}2.44ppm,\;23.80{\pm}1.98ppm$ 그리고 $11.14{\pm}0.51ppm$인 것으로 나타났다(비타민 C의 $SC_{50}$ 값:$9.61{\pm}0.93ppm$). 특히 마테 추출물과 솔잎 추출물은 총 페놀 함량이 높으면서 DPPH 라디칼과 superoxide anion 라디칼을 동시에 효율적으로 포착하는 효능을 지니고 있는 것으로 나타났다. 결론적으로 마테와 솔잎의 상업적인 추출물은 기능성 항산화제로서 유용한 소재로 사용 가능 할 것으로 사료된다.

Ferrocyanide-음이온 교환수지에 의한 모의 토양제염 폐액 처리 (Treatment of Simulated Soil Decontamination Waste Solution by Ferrocyanide-Anion Exchange Resin Beads)

  • 원휘준;김민길;김계남;정종헌;박진호;오원진
    • 방사성폐기물학회지
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    • 제3권1호
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    • pp.41-47
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    • 2005
  • Cs$^{+}$ 이온에 대해 선택성을 갖는 ferrocyanide-음이온 교환수지를 제조하여 모의 제 염폐액 내에 존재하는 Cs$^{+}$ 이온에 대한 흡착실험을 수행하였다. 제조된 이온교환 수지가 citric acid를 주제염제로 하는 제염폐액 내에 존재하는 Cs+ 이온에 대한 흡착능력은 상용 양이온교환수지에 비해 4배 이상 효과적인 것으로 나타났다. 모의 제염폐액과 선택성 이온교환수지를 접촉시킨 후 360분이 경과하면 금속이온에 대한 흡착반웅이 평형에 도달하였다. 본 연구범위에서 Co$^{2+}$ 이온농도가 필요이상 증가하게 되면 Cs$^{+}$ 이온의 흡착율은 감소하였다. 과산화수소와 히드라진을 사용한 선택성 폐 이온교환수지의 재생실험 결과 전기중성화조건을 만족시키기 위해 Cs$^{+}$ 이온이 수지로부터 용출됨을 확인하였고 열화없이 재 사용가능성을 확인하였다.

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폴리(에테르)사슬이 결합된 Cobalt(II)bipyridine 착물의 합성과 전기화학적 성질 (Electrochemical Properties and Synthesis of Poly(ether)tailed Cobalt(II)bipyridine Complex)

  • 김일광;전일철
    • 분석과학
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    • 제9권3호
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    • pp.292-301
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    • 1996
  • 산화환원반응 탐침제로, poly ether 꼬리가 결합된 Cobalt(II)bipyridine 착물을 합성 하였고, 이들 화합물의 느린 확산계수와 불균일 전자이동을 설명하였다. $Co(bpy(ppgm)_2)_{3^-}(ClO_4)_2$에 전해질 $LiClO_4$가 혼합된 neat 상태의 산화반응에 대한 확산계수는 $1.5{\times}10^{-15}cm^2/s$ 였다. 이 화합물들의 불균일 전자이동 속도상수들은 확산계수와 관련이 있었다. 확산계수의 감소에 따라 속도상수(k)의 감소가 일어났다. 강한 이온쌍을 형성하는 $ClO{_4}^-$의 화합물은 약한 이온 쌍을 형성하는 $CF_3COO^-$ 화합물보다 확산계수가 훨씬 작았다.

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감태 효소 추출물을 이용한 즉석 국수의 항산화성 개선 및 품질 특성 (Improvement on the Antioxidant Activity of Instant Noodles Containing Enzymatic Extracts from Ecklonia cava and Its Quality Characterization)

  • 허민수;윤민석;김형준;박권현;이종현;조미란;이정석;전유진;김진수
    • 한국수산과학회지
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    • 제43권5호
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    • pp.391-399
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    • 2010
  • This study was conducted to improve the antioxidative activity of instant noodles containing enzymatic extracts from Ecklonia cava (EEC). EEC has relatively better antioxidative activity than extracts from other indigenous plants in Jeju Island. The EEC (2.5 mg/mL) had 82.5% for the hydroxy radical, 78.4% for the DPPH radical, and 64.9% for the superoxide anion radical scavenging activities, and 65.2% for the cell viability (100 ${\mu}g/mL$). According to the texture of the dough, the DPPH free radical scavenging of uncooked instant noodles, sensory evaluation of cooked instant noodles, and turbidity of the cooking drip, the optimal EEC concentration was 1.8% for the instant noodles. The major amino acids in the instant noodles with EEC were glutamic acid (24.2%), proline (10.2%), valine (10.0%), and isoleucine (12.3%). The zinc and iron in the instant noodles were enhanced by adding 1.5-1.8% EEC. The antioxidant activity of instant noodles with EEC was 75.4% for the hydroxy radical, 74.1% for the DPPH radical, and 51.2 % for the superoxide anion radical scavenging activities.

Study on Separation of Heavy Metal Ions in A Neutral Macrocycle-Mediated Emulsion Liquid Membrane System

  • Moon-Hwan Cho;Hea-Suk Chun;Jin-Ho Kim;Chang-Hwan Rhee;Si-Joong Kim
    • Bulletin of the Korean Chemical Society
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    • 제12권5호
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    • pp.474-477
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    • 1991
  • The preferential transport phenomena of neutral cation-anion moieties in neutral macrocycle-facilitated emulsion liquid membrane were described in this study. Emulsion membrane systems consisting of (1) aqueous source phase containing 0.001 M M($NO_3$)$_2(M=Mn^{2+},\;Co^{2+},\;Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Sr^{2+},\;Cd^{2+},\;and\;Pb^{2+})$ (2) a toluene membrane containing 0.01 M ligand $(DBN_3O_2$, DA18C6, DT18C6, TT18C6, HT18C6) and the surfactant span 80 (sorbitan monooleate) (3% v/v) and (3) an aqueous receiving phase containing $Na_2S_2O_3$ or $NaNO_3$ were studied with respect to the disappearence of transition metal ions from the source phase as a function of time. Cation transports for various two component or three component equimolar mixture of transition metal and $Cu^{2+}$ in a emulsion membrane system incorporating macrocyclic ligand (HT18C6) as carrier were determinded. $Cu^{2+}$ was transported higher rates than the other $M^{2+}$ in the mixture solution. Equilibrium constants for cation-source phase co-anion, cation macrocycle and cation-receiving phase reagent interaction are examined as parameters for the prediction of cation transport selectivities.