• 대한화학회지
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• 제54권3호
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• pp.329-337
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• 2010

본 연구는 과학 교사들에게 교과서에 실린 문항에 대한 관심을 높일 뿐 아니라 교과서 문항을 효과적으로 사용할 수 있는 기초 자료를 제공하고자 고등학교 화학II 교과서 8종의 단원 평가 문항을 블룸의 개정된 교육목표 분류틀에 따라 분석하였다. 연구 결과 블룸의 인지 영역에 따른 분류에서는 '이해(44.7%)'에 해당하는 문항이 가장 많았고, '적용(29.9%)', '지식(15.6%)', '분석(9.5%)' 순이었으며 이러한 결과는 일반화학 교재의 단원 평가 문항 분석 결과인 '적용', '분석', '이해' 순으로 되어 있는 것과 뚜렷한 차이를 보였다. 특히 '평가'에 해당하는 문항은 전체 화학II 교과서에서 단 한 문제도 발견되지 않았으며 '종합(0.3%)'에 해당하는 문항도 거의 찾아볼 수 없었다. 한편 '적용'에 해당하는 문항의 대부분이 특정한 계산을 요하는 '양적인 수행'이었으며 '이해' 및 '양적인 수행'에 해당하는 문항의 비율은 분석된 총 문항의 70%에 이르렀다.

• 대한화학회지
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• 제65권5호
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• pp.347-357
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• 2021

이 연구는 우리나라와 에스토니아의 과학과 교육과정을 화학 영역을 중심으로 비교 분석하여 차기 교육과정 개정을 위한 시사점을 도출하는데 목적이 있다. 이를 위해 과학 교과를 중심으로 전반적인 교육과정 설계와 두 나라의 공통 교육과정에 해당하는 과목에서 다루어지는 화학 영역의 핵심 개념을 비교하였다. 분석 결과 첫째로, 에스토니아는 총론에서 제시한 핵심역량이 과학 교과에서 어떻게 구체적으로 연결되는지를 구체적으로 제시하고 있었다. 뿐만 아니라, 탐구 기능 및 태도와 가치를 교육과정 문서에 구체적으로 제시한 특징이 있었다. 둘째로, 화학의 핵심 개념 분석 결과 우리나라에서 다루어지는 개념이 대부분 에스토니아에서도 다루어졌다. 다만, 에스토니아는 더 광범위한 개념을 보다 정성적으로 다루는 경향이 컸다. 화학 과목에서 다루어지는 개념은 우리나라의 공통 교육과정 수준을 넘었으나, 이 과목도 정성적인 접근을 시도한다는 특징이 있었다.

• 대한화학회지
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• 제23권5호
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• pp.307-313
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• 1979

N-Aryllsufonylbenzimidoyl chloride를 출발물질로 사용하여 다음과 같은 7가지 새로운 히드라진 유도체들을 합성하였다. ${\beta}-({\alpha}-Benzenesulfonamidobenzal)hydrazine\;(II),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylmethylenehydrazine\;(III),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)phenylhydrazine\;(VII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-4-nitrophenylhydrazine\;(VIII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-2,4-dinitrophenylhydrazine\;(IX),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylhydrazine\;(X),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-p-methylphenylhydrazine\;(XI)$ 이 유도체들의 구조를 원소분석, ir, nmr, mass 스펙트럼 및 기타 화학적인 방법을 통해서 확인하였다. 일반적으로 이 치환반응은 극성인 용매에서, 그리고 친핵체인 페닐히드라진 유도체에 전자를 끄는기가 있을 때 수득율이 높았다.

• Mass Spectrometry Letters
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• 제6권1호
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• pp.7-12
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• 2015

In the present study, we proposed a simple ESI-MS model for determining $Zn^{2+}$ binding (or dissociation) constants for zinc finger peptides (ZFPs) with a unique ${\beta}{\beta}{\alpha}$ fold consensus. The ionization efficiency (response) factors for this model, i.e., ${\alpha}$ and ${\beta}$, could be determined for ZiCo ZFP with a known $Zn^{2+}$ binding constant. We could determine the binding constants for other ZFPs assuming those with a ${\beta}{\beta}{\alpha}$ consensus conformation have the same ${\alpha}/{\beta}$ response ratio. In general, the ZPF dissociation constants exhibited $K_d$ values of $10^{-7}{\sim}10^{-9}M$, while $K_d$ values for a negative control non-specific $Zn^{2+}$ peptides were high, e.g., $5.5{\times}10^{-6}M$ and $4.3{\times}10^{-4}M$ for BBA1 and melittin, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.366-367
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• 2006

In general, HF chemistry lifts off the particles during scrubbing after polishing and effectively removes particles. It is sometimes impossible to apply HF chemistry on W plug due to the degradation of electrical characteristics of a device. In this paper, a post W CMP cleaning process is proposed to remove residue particles without applying HF chemistry. After W CMP, recessed plugs are created, therefore they easily trap slurry particles during CMP process. These particles in recessed plug are not easy to remove by brush scrubbing when $NH_4OH$ chemistry is used for the cleaning because the brush surface can not reach the recessed area of plugs. Buffing with oxide slurry was followed by W CMP due to its high selectivity to W. The buffing polishes only oxide slightly which creates higher plug profiles than surrounding oxide. Higher profiles make the brush contact much more effectively and result in a similar particle removal efficiency even in $NH_4OH$ cleaning to that in HF brush scrubbing.

• Carbon letters
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• 제6권3호
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• pp.166-172
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• 2005

The objective of this study was to investigate the possibility of application for water treatment using the zeocarbon. The zeocarbon was mixture of zeolite and activated carbon. In general, the application of commercial zeocarbon to water treatment is difficult because of weak strength in water and the high pH value of effluents after water treatment. Therefore, we have modified the surface of zeocarbon. For the surface modification, we used the acid treatment to make surface functional group. As a result of modification, was created functional group on zeocarbon surface and was formed mesopore in zeocarbon. The surface modified zeocarbon was applied to removal of nitrogen. In removal experiments of nitrogen, removal efficiency was very high. And, strength of zeocarbon after water treatment and pH of effluents were stabilized. This indicates that the surface modified zeocarbon was easy to recover and reuse. Consequently, our results were shown the possibility of application for water treatment using the surface modified zeocarbon.

• 한국응용과학기술학회지
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• 제12권2호
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• pp.93-98
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• 1995

The rate constant of Nucleophilic addition of sodium thiophenoxide to nitrone were determined by UV Spectrophotometry and a rate equation which can be applied over wide pH range was obtained. Base on the rate equation, general base effect, substituent effect and final product, plausible mechanism of addition reaction have been proposed. Blow pH 3.0, the reaction was initiated of thiophenol, and in the range of pH $3.0{\sim}10.0$, proceeded by the competitive addition of thiophenol and thiophenoxide anion. Above the pH 10.0, the reaction proceeded through the addition of a thiophenoxide anion.

• Applied Biological Chemistry
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• 제12권
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• pp.7-11
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• 1969

Mucor-rennin, the crystalline milk-clotting enzyme, isolated from Mucor pusillus var. Lindt, has an acid protease activity. The optimum pH for the digestion of k-casein is 4.5, while that for hemoglobin digestion is 4.0. The skim milk solution was easily clotted acidic solution than alkalin solution, and the milk clotting activated by Ca ion. The enzyme was heat stable against heat from pH 4.0 to 6.0 but was more stable at pH 5.0. The activity of the enzyme at pH 5.0 did not decrease at 30 C for 15 days and the activity was not effected by sodium propionate and salicilic acid. Therefore, the enzyme of liguid type could store for a long time and could be transported from Erzyme production Co. to Manufacture of cheese Co. by adding the antiesptic and by adjusting pH to 5.0.

• 공업화학
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• 제10권2호
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• pp.287-292
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• 1999

Polycarbonate (PC)를 matrix로 사용하여 전도성 고분자인 polyaniline (PANI)과의 복합체를 블렌딩 방법에 의하여 제조하였다. 용매로는 chloroform을 사용하였으며 PANI는 전하수송을 가능하게 하고 유기용매에 잘 용해될 수 있도록 camphorsulfonic acid (CSA) 혹은 dodecylbenzenesulfonic acid (DBSA)와 같은 알킬 벤젠 술폰산으로 양성화시켰다. 또한, 전도성 복합체의 전기전도성은 압축성형이 아닌 solution casting법에 의하여 향상시켰다. 아울러 양성화제 유무, PANI의 함량 또는 온도에 따라 전기전도도, 몰포로지 및 인장강도 등을 측정 분석하였다. PANI 착체의 함량이 많을수록 전기전도도는 증가하였으며 알킬사슬이 긴 DBSA로 양성화된 25 wt % PANI 착체의 전도성 복합체의 전기전도도는 3.18 S/cm까지 향상되었다.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1305-1310
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• 2007

A conjugated spirocyclic polymer was synthesized via the cyclopolymerization of 1,1-dipropargyl-1- silacyclohexane with various transition metal catalysts. The monomer, 1,1-dipropargyl-1-silacyclohexane was synthesized by Grignard reaction of 1,1-dichloro-1-silacyclohexane with propargyl magnesium bromide. This polymerization proceeded well to give the corresponding poly(1,1-dipropargyl-1-silacyclohexane). The catalytic activity of WCl6 was found to be similar with that of MoCl5. The structure of polymer having the conjugated backbone with silacyclohexane moieties was characterized by such instrumental methods as NMR (1H-, 13C-), IR, and UV-visible spectroscopies. The resulting polymers were mostly yellow or light-brown powders, depending on the catalyst systems used. This polymer was completely soluble in halogenated and aromatic hydrocarbons such as chloroform, 1,2-dichloromethane, benzene, toluene, and chlorobenzene, etc. The thermal and oxidative stabilities of polymer were also studied and discussed.