• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.41-47
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• 2017

After $SF_6$, which is being used in power equipment as an insulating material, is classified as one of the 6 major greenhouse gases, the maintenance and the refinement of used $SF_6$ started to get attention. In regard to this, KEPCO Research Institute (KEPRI) is developing $SF_6$ recovery and refinement technology starting with establishing a comprehensive $SF_6$ analysis system. With the analysis system, qualitative and quantitative analyses of the purity and the impurities of $SF_6$ before and after recovery, and before and after refinement have been carried out. The analysis system is comprised of GC-DID (Gas Chromatograph -Discharge Ionization Detector) for trace impurities analysis, GC-TCD (Thermal Conductivity Detector) for analyses of $SF_6$ purity and major impurities concentration from several hundred ppm up to percent range, GC-MSD (Mass Selective Detector) for analyses of impurities not included in standard gas, FT-IR (Fourier Transform-Infrared) Spectrometer for analysis of HF and $SO_2$, and moisture analyzer for analysis of moisture below 100 ppm. With this analysis system, complete analysis method of $SF_6$ has been established. This analysis system is being used in the maintenance of power equipment and the development of $SF_6$ recovery and refinement technologies. In this paper, the analysis results of four samples - gas and liquid phase $SF_6$ samples from a $SF_6$ refinement system before and after refinement are presented.

• 한국토양환경학회지
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• 제3권3호
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• pp.75-86
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• 1998

쓰레기매립장에서 복토층을 통하여 대기중에 유출하는 가스를 현장에서 단시간내에 측정이 가능한 밀폐형 chamber법을 제시하였다. 또한, 최종복토층에서의 유출가스 실측치를 모델해석으로 모사하여 다음의 결과를 얻었다. 1) 시간변화에 따른 chamber내(H=10-30 cm)의 농도 변화는 30분이내로, G.C의 분석시간을 고려하여 5분단위로 분석한다. 2)메탄산화 반응의 영향으로 $CH_4$/$CO_2$비가 복토층 표면근처에서 급격히 변화한다. 3)매립지 표면의 flux가 F =$10^{-5}$mol/($m^2$.s)일 경우에는 메탄산화반응에 의해 가스조성에의 영향이 있으나, F =$10^{-6}$moll($\textrm{m}^2$.s)의 경우에는 복토층내의 메탄가스 농도가 상대적으로 적으므로 메탄산화반응에의 영향이 적다.

• 공업화학
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• 제10권1호
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• pp.30-34
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• 1999

클로로타노닐과 엔도슬판을 UV 조사, pH 3.0에서의 UV조사, 그리고 3.5% 염수에서 UV조사를 하여 광분해 거동을 연구하였다. 농약의 광분해과정은 가스크로마토그래프, 총유기탄소, 그리고 이온크로마토그래프를 사용하였다. Low pressure mercury multilamp($8W{\times}6$)를 반응기에 잠수시켜 실험을 하였으며, 초기농도는 10 ppm으로 하였다. 클로로타노닐은 UV 조사, pH 3.0조건에서 UV조사, 그리고 3.5% 염수조건에서 UV조사 조건에서 반응시간 30분에 거의 광분해되었다. 자외선조사에서 엔도슬판-${\alpha}$는 38%, 엔도슬판-${\beta}$는 25% 분해되었다. 엔도슬판-${\alpha}$(83%)는 자외선조사에서 65%, pH 3.0의 자외선조사에서 70%, 35% 염수의 자외선조사에서는 75% 분해되었다. 엔도슬판(16%)는 자외선조사에서 80%, pH 3.0의 자외선조사에서는 98%, 3.5% 염수의 자외선조사에서는 90% 분해되었다.

• 농업과학연구
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• 제43권4호
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• pp.634-640
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• 2016

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were $39.7ng\;g^{-1}$ and $40.51ng\;g^{-1}$, respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

• 분석과학
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• 제12권2호
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• pp.136-140
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• 1999

Sorbus Cortex를 실리카겔 칼럼크로마토그래피하여 lupane계 triterpenoids인 lupenone과 lupeol을 분리, 분광학적 방법으로 화학적 구조를 확인한 후 그 화합물들을 3종의 Sorbus Cortex에 대한 정량분석 표준품으로 이용하였다. Lupenone과 lupeol은 VA-5MS[(5%-phenyl)methylpolysiloxane, $30m{\times}0.25mm$, $0.25{\mu}m$] 칼럼으로 기체크로마토그래피법으로 분석하였으며 lupenone과 lupeol의 함량은 시료의 종류에 관계없이 각각 0.050~0.056%와 0.772~0.834%로 나타났다.

• 한국식품과학회지
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• 제5권1호
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• pp.65-69
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• 1973

여러가지 선량(線量)의 방사선조사(放射線照射)가 감자 박편(薄片)$(1\;cm{\times}2\;mm)$ 의 치유조직(治癒組織) 형성에 미치는 효과를 무균 상태하에서 조사(調査)하였다. 세포분열은 선량(線量)이 증가함에 따라 점차 억제되었고 16 krad 처리에서는 완전히 억제되었다. Solanine 함량은 선량(線量)에 따라 유의적(有意的)인 차이를 나타내지 않았다. 방사선조사(放射線照射)에 의하여 감자 괴경(塊莖) 내에 유기(誘起)된 carbonyl 화합물로부터 생성된 2,4-dinitrophenylhydrazone 침전물을 gas chromatograph 로 분리한 결과 formaldehyde 및 acetone 은 고선량(高線量)에서만 증가하는 경향을 보였다.

• 한국토양비료학회지
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• 제30권3호
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• pp.295-300
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• 1997

12개 지역의 한국자생차 향기성분을 기체크로마토그래프 및 질량분광계를 이용하여 분석한 결과는 다음과 같다. 다엽중의 향기성분으로 70~80개 성분을 GC를 이용해 분리할수 있었고, 그중 52개 성분은 GC/MSD로 동정하였는데, 이들을 분류하면 alcohol류 19종, aldehyde류 5종, hydrocarbon류 2종, ketone류 6종, ester류 4종, lactone류 3종, acid류 2종, phenol류 3종, pyrazine류 4종, 그리고 질소화합물 4종이였다. 이중 geraniol, linalool oxide, 1-hexanol, ehtanol등이 주요 향기 성분이었다.

• 공업화학
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• 제16권4호
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• pp.513-518
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• 2005

혼합비율 및 반응온도의 변화에 따른 ZnO가 첨가된 PVC와 PS의 혼합 열분해 특성에 관한 연구를 TG와 GC-MS를 이용하여 수행하였다. 본 연구로부터 혼합물에 있어서 PS의 양이 증가할수록 액상 생성물은 증가하였으며 기상 생성물은 감소함을 알 수 있었다. 또한 ZnO의 첨가량이 증가할수록 기상 생성물과 염화수소의 발생량은 감소하였으며 염화수소의 발생 억제 및 액상 생성물의 최대수율을 얻기 위한 최적의 반응온도는 $500^{\circ}C$임을 알 수 있었다.

• 설비공학논문집
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• 제26권6호
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• pp.269-274
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• 2014

The experimental performance evaluation of a cylindrical steam reformer with various thermal conditions has been conducted. The bottom space of the cylindrical reactor was packed with Ruthenium (Ru) catalyst. A three-segment furnace was installed to create the axially variable boundary temperature distribution. Six K-type thermocouples were inserted into the catalyst layer, and three exhaust ports were fabricated on the side wall along the flow direction. The exhausted gases at each port were analyzed by using gas chromatograph (GC) system. The experimental results showed that the reforming reaction occurs intensively in the upstream region and more hydrogen is obtained when the intake gas is sufficiently heated up through the enhanced steam reforming (SR) reaction. The axially increasing boundary temperature setup provided the maximally accumulated reforming efficiency of 74.8%, when the reactor was placed at the 3rd section of the furnace.

• KSBB Journal
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• 제5권1호
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• pp.25-35
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• 1990

In the Xanthan gum fermentation by Xanthomonas campestris there are problems of the large energy consumption by long fermentation time, the mass transfer of oxygen and nutrients by high viscous fermentation broth. In this study, the media optimization and the fed batch fermentation were carried out to decrease fermentation time and increase Xanthan gum yield. The $O_2$ uptake rate (OUR) and $CO_2$ evolution rate(CER) which were obtained from the analysis of fermentation exit gas using a gas chromatograph were investigated. As a result, the fermentation time decreased at optimal assimilable nitrogen concentration but increased at poor or rich assimilable nitrogen concentration, the Xanthan gum biosynthesis was stimulated under the limited condition of assimilable nitrogen source and the optimum fermentation medium was obtained as follow; Glucose=30g / l, Peptone=8.0g / l, $K_2HPO_4=2.0g/l$, $MgS0_47H_2O=10g/l$, Sodium acetate=20g/l, Sodium pyruvate=0.5g/1. As the agitation speed and nitrogen concentration increased, the $O_2$ uptake rate and $CO_2$ evolution rate increased. The OUR and CER were 37.3mmol $O_2/\;l$ hr and 20.2 mmol $CO_2/\;L$ hr at peptone 11g / l and agitation speed 990RPM, respectively. In fed batch fermentation, the final concentration of Xanthan gum was enhanced up to 29g / l.