• Bulletin of the Korean Chemical Society
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• 제21권7호
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• pp.685-689
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• 2000

The complexation reaction between Pb2+,TI and Cd2+ions and macrocyclic ligands, 18-crown-6 ( 18C6) and dibenzo- 18-crown-6 (DB 18C6), was studied in dimethylsulfoxide (DMSO)-nitromethane (NM) and dimethyl-formamide (DMF)-nitromethane binary system s by square wave polarography (SWP) technique. The stoichiometry and stability of the complexes were determined by monitoring the shifts in half-waves or peak potentials of the polarographic waves of metal ions against the Iigand concentration. In most cases, the stability constants of complexes increase with increasing amounts of the nitromethane in mixed binary solvents used in this study. The complexes formed between 18C6 and DB18C6 and these metal cations in all cases had a stoichiometry of 1 : 1. The results obtained show that there is an inverse relationship between the formation constant of complexes and the donor number of solvents based on a Gatmann donocity scale and the stability constants show a high sensitivity to the composition of the mixed solvent systems. A linear behavior was observed for variation of log Kf of I8C6 complexes vs the composition of the mixed solvent systems in NM/DMSO and NM/DMF,but a non-linear behavior was observed in the case of DB 18C6 complexes in these binary systems. In most of the systems investigated, the Pb2+ cation forms a more stable complex with the 18C6 than other two cations and the order of selectivity of this Iigand for cations is: Pb2+ > TI+,Cd2+.

• Bulletin of the Korean Chemical Society
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• 제17권2호
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• pp.173-179
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• 1996

A series of tetradentate Schiff base ligands; [1,2-bis(naphthylideneimino)ethane, 1,3-bis(naphthylideneimino)propane, 1,4-bis(naphthylideneimino)butane, and 1,5-bis(naphthylideneimino)pentane] and their Ni(Ⅱ) complexes have been synthesized. The properties of these ligands and their Ni(Ⅱ) complexes have been characterized by elemental analysis, IR, NMR, UV-vis spectra, molar conductance, and thermogravimetric analysis. The mole ratio of Schiff base to Ni(Ⅱ) metal was found to be 1:1. The electrochemical redox process of the ligands and their Ni(Ⅱ) complexes in DMF and DMSO solution containing 0.1 M tetraethyl ammonium perchlorate (TEAP) as a supporting electrolyte have been investigated by cyclic voltammetry, chronoamperometry, differential pulse voltammetry, and controlled potential coulometry at glassy carbon electrode. The redox process of the ligands was highly irreversible, whereas redox process of Ni(Ⅱ) complexes were observed as one electron transfer process in quasi-reversible and diffusion-controlled reaction. The electrochemical redox potentials of the Ni(Ⅱ) complexes were affected by the chelate ring size of ligands. The diffusion coefficients of Ni(Ⅱ) complexes containing 0.1 M TEAP in DMSO solution were determined to be 5.7-6.9 × 10-6 cm2/sec. Also the exchange rate constants were determined to be 1.8-9.5 × 10-2 cm2/sec. These values were affected by the chelate ring size of ligands.

• 디지털정책학회지
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• 제1권2호
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• pp.41-45
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• 2022

본 연구에서는 산업단지의 현주소와 지금까지의 산업단지에 대한 정부의 지원정책을 살펴보고 대전환의 시대 산업단지의 문제점과 개선점을 살펴본 후 산업단지를 어떻게 하면 혁신할 수 있는지, 그 방안과 과제를 제시해보고자 한다. 결론을 요약하면, 국가 경제의 주축인 산업단지의 경쟁력과 혁신을 제고 하기 위해 정부, 지역혁신기관, 기업이 협력하는 거버넌스 체계를 구축하여 대전환기에 적합한 산업단지로 변모, 우수 산업단지를 육성해야 하고 정부 각 부처의 정책과 예산 투입을 적극 지원하는 것이 시급하다.

• 분석과학
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• 제37권4호
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• pp.239-250
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• 2024

This study reports the synthesis of a bi-dentate Schiff base ligand (L), 7-(2-((2-formylbenzylidene) amino)-2-phenylacetamido)-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, prepared from phthalaldehyde and cephalexin antibiotic. The synthesized Schiff base ligand (L) and the secondary ligand alizarin (Az) are used to prepare the new complexes [M(Az)₂(L)] and [Cr(Az)₂(L)]Cl, where M = Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). The mode of bonding of the Schiff base has been characterized by UV-Visible, FT-IR, Mass, ¹H-, and ¹³C-NMR spectroscopic techniques, and micro elemental analysis (CHNS). The complexes were characterized using UV-Vis, FT-IR, molar conductance, magnetic moment, and thermal analysis (TG/DTG). The molar conductance data revealed that the complexes are non-electrolytes except for [Cr(L)(Az)₂]Cl, which is an electrolytic type 1:1. The Schiff base and its complexes have been tested for their biological activity against two strains of bacteria and one fungus. When screened against gram-positive and gram-negative pathogens, the Az and L ligands and their complexes showed potential antimicrobial activity.

• 한국대기환경학회지
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• 제34권2호
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• pp.269-280
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• 2018

This paper reports the results of field evaluation to determine the levels of heavy metals in major industrial complexes in Korea over a seven year period (2007~2013). The measurement of heavy metal was conducted using quartz fiber filter sampling and ICP-AES analysis. In order to validate the analytical performance of these methods, studies were also carried out to investigate data quality control(QC) parameters, such as the method detection limit (MDL), repeatability, and recovery efficiencies. The average concentrations of total suspended particulates (TSP) for the nine industrial complexes in Korea were $104{\sim}169{\mu}g/m^3$, which was higher than other industrial complexes and urban areas. The Sihwa and Banwol industrial complexes were shown to be the biggest contributing sources to high TSP emission ($159{\mu}g/m^3$ and $169{\mu}g/m^3$, respectively). The concentrations of heavy metals in TSP were higher in the order of Fe>Cu>Zn, Pb, Mn>Cr, Ni, As and Cd. It was observed that Fe was the highest in the Gwangyang and Pohang steel industrial complexes. The concentrations of Zn and Pb were high in Onsan, Sihwa and Banwol industrial complexes, and this was attributed to the emission from the nonferrous industry. Additionally, Cr and Ni concentrations were high in the Sihwa and Banwol industrial complexes due to plating industry. On the other hand, Ulsan and Onsan industrial complexes showed high Cr and Ni concentrations as a response to the emission of metal industry related to automobile. The correlation analysis revealed the high correlation between Cr and Ni in plating industry from Sihwa and Banwol industrial complexes. Adding to this, components related to coal combustion and road dust showed high correlation in Pohang and Gwangyang industrial complexes. Then Onsan and Ulsan industrial complexes showed high correlation among components related to the nonferrous metals.

• 대한화학회지
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• 제34권1호
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• pp.51-62
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• 1990

다섯 자리 Schiff base cobalt(II) 착물로서 Co(II)(Sal-DET)와 Co(Ⅱ)(Sal-DPT)들을 합성하여 비수용매에서 산소와 반응시켜 산소첨가 착물로서 [Co(III)(Sal-DET)]$_2O_2$ 및 [Co(III)(DPT)]$_2O_2$들을 합성하였다. 이 착물들은 원소분석, IR spectra, TGA, DSC 및 자화율을 측정하여 확인하였으며, 비수용매에서 이들 착물들의 산소와의 몰결합비가 첫단계는 1:1이나 시간이 경과하면 고체상태에서와 같이 1:2로 가는 $\mu$-peroxo형의 6배위 Cobalt(III)착물들이 형성됨을 알았다. Co(II)(Sal-DET)및 Co(II)(Sal-DPT)와 이들 산소첨가 착물들의 0.1M TEAP-DMSO와 0.1M TEAP-pyridine 용액에서 순환전압-전류법 및 DPP법에 의한 환원과정은 두 단계로 일전자의 비가역적인 Co(III)/Co(II)와 Co(II)/Co(I)의 과정이 주어지나 산소첨가 착물에서 산소결합의 환원전위는 $E_{pc}$ = -0.97V∼-0.86V이고 이에 couple인 산화전위는 $E_{pa}$ = -0.87V ∼ 0.64V에서 일전자의 준가역적 산화환원 과정으로 일어남을 알았다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제19권4호
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• pp.349-361
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• 2012

CAT(0) cubical complexes are a key to formulate geodesic spaces with nonpositive curvatures. The paper discusses the median structure of CAT90) cubical complexes. Especially, the underlying graph of a CAT(0) cubical complex is a median graph. Using the idea of median structure, this paper shows that groups acting on median complexes L(${\delta}$) groups and, in addition, work L(0) groups are closed under free product.

• 약학회지
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• 제7권1호
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• pp.13-17
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• 1963

The purpose of this work is to investigate the molar ratio, the precipitation condition and the color of copper sulfa-drugs complexes. The colors of the complexes are observed at every precipitation condition is obtained as pH 7-9. The determination of the molar ratio of complexes is able to be carried out by way of gravimetric method and solvent extraction method. The molar ratios of sulfa-drugs and copper in identified complexes are 2:1 when utilizing both methods.

• 대한수학회논문집
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• 제33권4호
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• pp.1357-1366
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• 2018

It is shown that the Mayer-Vietoris sequence holds for the cohomology of complexes of Lie algebroids which are defined on simplicial complexes and satisfy the compatibility condition concerning restrictions to the faces of each simplex. The Mayer-Vietoris sequence will be obtained as a consequence of the extension lemma for piecewise smooth forms defined on complexes of Lie algebroids.

• 대한화학회지
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• 제13권1호
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• pp.25-28
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• 1969

몇가지 monoazo 一金屬錯鹽들의 UV吸收 spectra를 測定하여 이것을 基礎로 하여 그 金屬錯鹽들의 構造를 論하였다. 옆으로 찌그러진 八面體모양의 幾何學的構造를 提案하였다.