• 한국토양비료학회지
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• 제28권2호
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• pp.114-122
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• 1995

토양유기물(土壤有機物)에 의한 중금속(重金屬)의 흡착(吸着)현상을 구명(究明)하기 위하여 이탄토(泥炭土)에서 humic acid를 분리정제(分離精製)하여, humid acid-metal complex 생성반응(生成反應)에 대한 mechanism을 조사(調査)하였다. 1. Humic acid-metal complex의 흡광도(吸光度)는 장파장영역(長波長領域)에서 단파장영역(短波長領域)으로 갈수록 Zn-HA > Cd-HA > Cu-HA의 순(順)으로 증가(增加)하였다. 2. Humic acid의 carboxyl group과 phenolic OH group들이 중금속(重金屬) ion들과 반응(反應)하여 complex를 생성(生成)하였으며 그 생성량(生成量)은 Cu > Zn ≧ Cd의 순(順)이었다. 3. Humic acid-medal complex의 안정도(安定度) 상수(常數)는 pH가 증가(增加)함에 따라 增加하였으며 1차(次) 안정도(安定度) 상수(常數)는 Zn>Cd>Cu 순(順)이었고, 2차(次) 안정도(安定度) 상수(常數)는 Cu>Zn>Cd의 순(順)이었으며, 總安定도 常數는 Cu>Zn>Cd의 순(順)이었다. 4. Humlc acid와 중금속(重金屬)ion들 상호(相互) 간(間)의 평균결합수(平均結合數)는 pH가 증가(增加)함에 따라 Cu>Zn>Cd의 順으고 增加하였다. 5. Humic acid에 의한 중금속(重金屬) ion들의 complex생성과정(生成課程)에서 barboxyl group만이 관여(關與)하는 것과 car-boxyl gruup 및 phenolic OH group이 동시(同時)에 관여(關與)하는 두가지 흡착(吸着)mechanlsm을 제안할 수 있었다.

• 대한화학회지
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• 제47권2호
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• pp.121-126
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• 2003

Cyclohexanone,과 tris(2-aminoethyl)amine을 이용하여 Schiff 연기 축합반응으로 tren의 유도체인 tris(2-cyclohexylaminoethyl)amine (L)을 합성하였다. 또한 합성한 tren의 유도체인 tris(2-cyclohexylaminoethyl)amine (L)과 Zn(II) 착물의 열역학적 특성과 안정도 상수, Zn(II)와의 착물 조성비 등을 순환전압전류법과 열량계법으로 측정하였다. Zn(II)과 [Zn(II)-L] 순환전압전류 곡선을 0${sim}$-1.5 V vs. Ag/AgCl의 가전압 범위에서 측정하였다. 금속인 경우, -1.02V와 -0.48V vs. Ag/AgCl에서 각각 환원피이크와 산화피이크가 나타났으며, 금속착물인 경우에는 -1.19V와 -0.45V vs. Ag/AgCl에서 각각 환원피이크와 산화피이크가 나타났다. 또한 피이크 전류(IP)는 주사속도의 평방근 $(v^{1/2})$에 비례하였으며 이것은 전류의 유형이 확산 지배적인 전류임을 나타낸다. 그리고 [Zn-L] 착물에 대해서 전압전류법적으로 구한 안정도상수는 logK$_f$ = 5.8, 결합비는 1:1을 나타내었다. 또한 열량계법적으로 [Zn-L] 착물의 열역학적 파라메타를 조사한 결과, 리간드 L과 Zn(II)는 1:1의 4 배위수를 가지는 착물을 이룬다는 것을 알 수 있었고, 이때 25 ${\circ}$C에서 logK=5.4, ${\Delta}H$= -53.0 kJ/mol, ${\Delta}$G의 값은 -31.1 kJ/mol이었으며 T${\Delta}$S는 -21.9 J/K${\cdot}$mole이었다.

• Journal of Magnetics
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• 제1권1호
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• pp.37-41
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• 1996

The frequency dependence of complex permeability for various NiCuZn ferrites was investigated. The variation of complex permeability for NiCuZn ferrites can be presented as a form of a semi-circle, so called the Cole-Cole plot, and the relaxation phenomena were explained with various shapes of the plots. The relaxation time $\Upsilon$ was calculated from $f_rx$, which is a relaxation frequency at ${\mu"}_{max}$. Relations between anisotropy field $H_A$ and relaxation time $\Upsilon$, initial permeability $\mu_i$ and $H_A$ were plotted to identify the frequency dependence of complex permeability.lity.

• 분석과학
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• 제25권6호
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• pp.416-420
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• 2012

재활용 제품의 사용이 증가함에 따라 이에 대한 위해성 평가가 필요한 실정이다. 본 연구에서는 재활용 제품 중 재활용 고무분말을 이용한 놀이터용 바닥재와 해당 고무분말의 중금속 함량을 비교하였다. 또한 각각의 물질이 경피로 전이되는 양을 확인하여 피부에 흡수되는 중금속 노출 특성을 살펴보았다. 아연의 경우 함량이 높은데 반해 전이량이 0.1 $mg/cm^2$으로 매우 낮았는데 이는 아연은 표면 접촉으로는 잘 묻어나지 않는다는 것을 나타낸다. 그러나 철과 알루미늄의 경우, 함량이 바닥재에서 12 배 높게 나타났고, 전이량이 아연보다 약 5 배 높게 나타났다. 이것은 철과 알루미늄이 바닥재에 사용된 안료에서 기인했다는 것을 말한다. 놀이터 6 개소를 대상으로 피부 흡수에 의한 중금속 노출량을 산정한 결과, Ba의 경우 타 중금속에 비하여 비교적 높게 산정되었다. Zn의 함량이 높음에도 불구하고 Ba의 노출량이 더 높은 것은 Ba의 피부흡수율이 Zn에 비해 약 5 배 높기 때문인 것으로 판단된다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.93-96
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• 2000

In this study, we investigated the electromagnetic properties of Mn-Zn ferrite doped with rare earth oxide (Dy$_2$O$_3$, Er$_2$O$_3$). The main composition is 52mo1% $\alpha$-Fe$_2$O$_3$, 25mo1% Mn$_3$O$_4$23mo1% ZnO and doped with them(0.05wt%~0.25wt%, step:0.05wt%). An experimental process has advanced by conventional ferrimagnetism manufacturing that was prepared by standard ceramic techniques. The XRD pattern of all doped sample were observed spinel and secondary phase. The density of sample were measured nearly constant value. As increased the additive, resistivity, initial permeability and real component of the series complex permeability increased with setting limits each other. In case of Mn-Zn ferrite excess doped with them, resistivity, initial permeability and real component of the series complex permeability decreased and magnetic loss increased in proportion to increasing the additive.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.93-96
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• 2000

In this study, we investigated the electromagnetic properties of Mn-Zn ferrite doped with rare earth oxide (Dy$_2$O$_3$, Er$_2$O$_3$). The main composition is 52mo1% ${\alpha}$-Fe$_2$O$_3$, 25mol% Mn$_3$O$_4$ 23mo1% ZnO and doped with them(0.05wt% ∼ 0.25wt%, step:0.05wt%). An experimental process has advanced by conventional ferrimagnetism manufacturing that was prepared by standard ceramic techniques. The XRD pattern of all doped sample were observed spinel and secondary phase. The density of sample were measured nearly constant value. As increased the additive, resistivity, initial permeability and real component of the series complex permeability increased with setting limits each other. In case of Mn-Zn ferrite excess doped with them, resistivity, initial permeability and real component of the series complex permeability decreased and magnetic loss increased in proportion to increasing the additive.

• 한국산학기술학회논문지
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• 제7권4호
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• pp.733-737
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• 2006

본 논문은 수용액에서 Zn 이온이 tetraaza 거대고리 리간드의 일종인 1,4,8,11-tetraazacyclotetradecane(cyclam) 리간드와 결합하여 착물(배위화합물)을 형성할 때, 리간드의 배위상태와 착물의 구조를 Raman 스펙트럼, 전기전도도법을 통하여 알아보았다. Raman 스펙트럼에 의해, Zn이온의 trans 배위자리에 $H_{2}O$ 분자와 $Cl^{-}$이온이 경쟁하고 있음을 알았다. 전기전도도법에 의하면, $ZnCl_{2}$ 수용액에 1,4,8,11-tetraazacyclotetradecane(cyclam) 리간드를 가하면 2:1 전해질에서 1:1 전해질로 바뀐다. 즉, Zn이온의 trans 배위자리에 $H_{2}O$ 분자와 $Cl^{-}$이온이 경쟁하고 있음을 확인하였다. 또한, macrocyclic polyamine의 일종인 1,4,8,11-tetraazacyclotetradecane(cyclam) 리간드의 중금속 친화력 효과를 통해, 유해 중금속을 몸에서 배출시킬 수 있는 chelating agent로 사용될 수 있는 가능성을 보여 주었다.

• Molecular & Cellular Toxicology
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• 제3권2호
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• pp.132-136
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• 2007

Zinc is essential metal and plays a role in a wide variety of physiological and biochemical processes. Prostate gland contains high level of zinc, generally 3-10 folds higher than other organs. Prostatic zinc uptake is resulted from the existence of zinc transporter (ZnT) protein families in membrane. In this study, we investigated the difference of zinc uptake efficiency of zinc-aspartate complex (Zn-Asp) into various organs compared with $ZnSO_4$. We observed that Plasma zinc concentration in both $ZnSO_4$ and Zn-Asp administrated group was increased progressively following administration, and reached a peak level at 2 hr. The increasing pattern of zinc concentration was similar to each groups, however the zinc concentration of Zn-Asp administrated group was higher than that of $ZnSO_4$ administrated group. We found that prostatic zinc level of Zn-Asp administrated group was higher than $ZnSO_4$ administrated group, and was increased approximately $\sim$2.7 fold and $\sim$4.2 fold at 4 and 8 hr after administration. From these observations, we suggest than Zn-Asp has high uptake efficiency of zinc into the prostate gland. Therefore, Zn-Asp is potentially useful treatment of many prostatic diseases.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1477-1483
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• 2004

We present the tandem mass spectrometry applications carried out to elucidate the coordination structure of Zn(II) bound lysine ternary complexes, $(Zn+Lys+Lys-H)^+$, which is a good model system to represent a simple (metallo)enzyme-substrate complex (ES). In particular, experimental efforts were focused on revealing the involvement of a lysine side chain ${\varepsilon}$-amino group in the coordination of $Zn^{2+}$ divalent ions. MS/MS fragmentation pattern showed that all the oxygen species within a complex fell off in the form of $H_2O$ in contrast to those of other ternary complexes containing amino acids with simple side chains (4-coordinate geometries, Figure 1a), suggesting that the lysine complexes have different coordination structures from the others. The participation of a lysine basic side chain in the coordination of Zn(II) was experimentally evidenced in MS/MS for $N{\varepsilon}$-Acetyl-L-Lys Zn(II) complexes with acetyl protection groups as well as in MS/MS for the ternary complexes with one $NH_3$ loss, $(Zn+Lys+Lys-NH_3-H)^+$. Detailed structures were predicted using ab initio calculations on $(Zn+Lys+Lys-H)^+$ isomers with 4-, 5-, and 6-coordinate structures. A zwitterionic 4-coordinate complex (Figure 7d) and a 5-coordinate structure with distorted bipyramidal geometry (Figure 7b) are found to be most plausible in terms of energy stability and compatibility with the experimental observations, respectively.

• 자원환경지질
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• 제33권5호
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• pp.379-389
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• 2000

This study was focused on the investigation for the heavy metal contamination of soils derived from Yoecheon Industrial Complex in Chonnam Province. Total 201 soil samples including farmland, paddy, forest and playground soils were collected, extracted by 0.1N HCl and analyzed for Cd, Cu, Cr, Fe, Mn and Zn using AAS. Most pH values in soils were weak acidic ranges of 4-6, while some of them were over 8.0. Concentrations of Cd, Cu, Fe and Zn in the soils tend to be relatively high around the Au-Ag mine area, railroad stations and oil station, however, those of Cr, Mn and Pb show high at the northside of Pohang Steel Co (POSCO). Cadmium-Zn couples, and Cd-Zn and Zn-Cr couples have relatively good correlations in the farmland soils and paddy soils, respectively. Concentrations of Cd, Fe and Zn with depth tend to be higher in the top soils than in the bottom soils, but those of Cu and Pb do not show regular variations with depth.