• 농약과학회지
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• 제6권1호
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• pp.31-35
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• 2002

본 논문의 목적은 benfuracarb 원제(90.2%)에 함유된 불순물의 glutathione-S-transferase와 amidase에 대한 저해 특성과 해당 불순물의 구조를 밝히는데 있다. Benfuracarb 원제, 유효성분 및 불순물은 glutathione-S-transferase(GST)를 효과적으로 저해하였으나, 그 저해력은 GST 효소 저해제인 ethacrynic acid의 저해력보다는 낮았다. 즉, GST에 대한 benfuracarb 원제, 유효성분 및 불순물의 $I_{50}$은 각각 $9.7{\times}10^{-4}M,\;>1.0{\times}10^{-3}M,\;1.8{\times}10^{-4}M$이었으나, ethacrynic acid의 $I_{50}$은 $1.7{\times}10^{-5}M$이었다. Benfuracarb 원제, 유효성분 및 불순물은 amidase를 저해하였는데, 이들의 효소저해력은 iprobenfos의 저해력($I_{50},\;8.2{\times}10^{-7}M$)보다는 낮은 $6.0{\times}10^{-5}M,\;4.3{\times}10^{-4}M,\;7.6{\times}10^{-5}M$이었다. Benfuracarb 원제에는 4종의 불순물(IM $1{\sim}4$)이 검출되었는데, 이들 중 IM 2와 3은 GST와 amidase의 활성을 저해하였던 반면, IM 4는 효소활성을 저해하지 않았다. 이들 불순물 중 효소활성 저해특성을 갖는 IM 2와 3을 IR, $^1H$-NMR, $^{13}C$-NMR, LC-MS를 이용하여 구조를 분석한 결과, IM 2는 ethyl-N-isopropylamino propionate로, 그리고 IM 3은 ethyl-N-isopropyl-N-(chlorosulfenyl) aminopropionate로 확인되었다.

• 분석과학
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• 제30권5호
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• pp.240-251
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• 2017

1,1,1,2-수소불화탄소(HFC-134a)는 에어컨에 주로 사용되는 냉매로, 최근 온실가스로 규제되어 정제를 통한 재사용 방법이 권장되고 있다. 폐냉매의 재사용 기준 평가를 위해서는 폐냉매에 존재하는 미량 성분의 정량분석이 매우 중요하다. 본 연구에서는 표준 물질이 없어서 정량화하기 어려웠던 C, H, Cl, F가 포함된 미량 성분들을 GC/AED (gas chromatograph-atomic emission detector)를 이용하여 정량분석하였다. 이를 위하여 GC/MSD (mass selective detector)를 통한 정성분석을 선행하였다. 또한 성분의 원자 수와 비례하여 반응하는 AED의 특성을 조사하기 위하여, 탄화수소 혼합 표준물질을 이용하여 선형성을 확인하였다. 시료 중 C, H, Cl, F가 포함된 미량 성분의 정성 분석 결과, 주성분인 HFC-134a와 유사 냉매류들을 포함한 총 15 개의 성분이 검출되었다. MSD 결과를 토대로 AED를 이용한 미량 성분들을 정량 분석한 결과, 한 시료는 $CHClF_2$ 성분($45438.38{\mu}mol/mol$), 또 다른 시료는 $C_2H_2ClF_3$ 성분($1311.47{\mu}mol/mol$)이 가장 높은 몰분율을 나타냈다. 본 연구에서는 이 분석법을 기반으로 하여, 표준 물질이 존재하지 않아 정량화하기 어려운 복합 성분들의 정성 및 정량 분석의 확장 적용이 가능할 것으로 보인다.

• 한국재료학회지
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• 제14권1호
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• pp.9-12
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• 2004

Metallic impurities, such as Fe, Cu, and Au, become generation and recombination centers for minority carriers when combined with oxide precipitates or silicon self-interstitial clusters. As these centers may cause leakage and discharge in silicon devices, their prevention through gettering of the metallic impurities is an important issue. In this article, key aspects of intrinsic gettering, such as oxygen control, wafer cleaning, device area denudation, and bulk oxygen precipitation are discussed, and a practical method of implementing intrinsic gettering is outlined.

• E2M - 전기 전자와 첨단 소재
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• 제10권5호
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• pp.447-452
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• 1997

Effects of metal impurities in insulation of distribution cables on electrical conduction of distribution cables was investigated. Samples of Al, Cu, Fe are fabricated as metallic impurities, and measured electrical conductivity in the voltage range of 0~10 KV. Temperature dependent effect of hysteresis curves and the relationship between forward and reverse current due to impurity content are discussed.

• 자원리싸이클링
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• 제11권5호
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• pp.21-23
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• 2002

A new process based on the co-precipitation method was developed fer removing harmful impurities during Mn-Zn ferrite production such as $SiO_2$ and P from waste pickle liquor. By this process a final result of less than 100 ppm of $SiO_2$ and less than 10 ppm of P content in the ferric oxide is easily attained. Though Ca cannot be removed by this process, water rinsing of the ferric oxide is effective fer reducing Ca content to less than 100 pm. For further purification, the origins of each impurity must be investigated and then taken away.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.58-61
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• 1997

Effects of ionic impurities on the dielectric breakdown of the crosslinked polyethylene (XLPE) were studied using aqueous electrolytes. It was found that the AC breakdown strength of XLPE decreases considerably when the ions are present in the electrodes composed of aqueous electrolyte. Details of results were described.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.301-304
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• 1997

Effects of volatile impurities on deterioration characteristics of XLPE were investigated. Block type plate with needle-plane electrode and artificial void filled with $N_2$gas or humidity was subjected under high electric field. The dyed region by oxidation reaction around the artificial void filled with humidity was detected before tee initiation. Electrical tree was started from the tip of void filled with $N_2$gas earlier than humidity.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.239-242
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• 2002

Luminescence efficiency of phosphors, $SrTiO_3;Pr^{3+}$ and $SrIn_2O_4:Pr^{3+}$, is increased remarkably by III-group impurities. This effect is explained by a picture that carriers thermally released from impurity-induced traps supply energy to $Pr^{3+}$ ions. The impurities also improve carrier transport efficiency by reducing lattice defects. This picture indicates a possibility to develop new ternary oxide phosphors.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.69-70
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• 2006

Waste vinyl tretreatment system has been developed by the joint project between KIMM and Woosung Co. General process for removal of impurities from waste vinyl is consisted of feeding, separating, cutting, washing, drying and recovering impurities. However, there are problems such as wastewater when washing of waste vinyl. In order to solve these problems we have developed new dry type cleaning system.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.412-414
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• 2014

In this study, we investigate atomic and electronic structure of graphene with substitutional impurities such as boron or nitrogen atom using density functional theory (DFT) calculations. To investigate the effects of substitutional impurities in graphene, we consider a ($6{\times}6$) supercell of graphene in our calculations. For detailed electronic properties of graphene, we compare the energy band structure of B- or N-doped graphene with that of pristine graphene.