$Ar/N_2 및 Kr/N_2$혼합가스의 교류절연파괴 특성

이상우,김인식,이동인,이광식,김이국,Lee, Sang-Woo,Kim, In-Sik,Lee, Dong-In,Lee, Kwang-Sik,Kim, Lee-Kook 대한전기학회 2001 전기학회논문지C Vol.50 No.12

In this paper, the ac breakdown characteristics of pure Ar, Kr and $N_2$ gas with gas pressure range of 58.8-137.3[kPa] under uniform and non-uniform fields were investigated, and the measured values were compared with those In Ar/$N_2$ and Kr/$N_2$ gas mixtures with pressure varying. Summarizing the experimental results, the breakdown voltages of Pure $N_2$gas, under uniform and non-uniform fields, were increased about 4.8 and 1.1 times than those of pure Ar gas, and about 4.4 and 1.2 times than those of pure Kr gas, and the ac breakdown voltage increased with the pressure increasing. The breakdown voltages of Ar/$N_2$ gas mixtures were decreased with decreasing the mixture ratio of Pure $N_2$ gas. In case of Ar(85%)/$N_2$ (15%) and Ar(70%)/$N_2$ (30%) gas mixtures comparing to the pure Ar gas, the breakdown voltages under uniform field were increased about 1.8 and 2.2 times, and under non-uniform field were increased about 1.1 and 1.3 times at the pressure of 101.3[kPa]. Also, in case of Kr(85%)/$N_2$ (15%) and Kr(70%)/$N_2$ (30%) gas mixtures comparing to the pure Kr gas, the breakdown voltages under uniform field were increased about 1.7 and 2.0 times, and under non-uniform field were increased about 1.0 and 1.2 times. Corona inception voltage of Kr(70%)/$N_2$(30%) gas mixtures under non-uniform fields were increased about 1.28 times than those of Ar(70%)/$N_2$ (30%) gas mixtures. In case of practical incandescent lamps, luminous and lifetime of Kr(70%)/$N_2$ (30%) gas mixtures were increased about 1.15 and 1.21 times than those of Ar(70%)/$N_2$ (30%) gas mixtures.

평등 및 불평등 전계하에서 순수 Kr, N_2 가스와 Kr/N_2 혼합 가스의 교류절연파괴 특성

金寅湜,金利國,李相雨 慶一大學校 2002 論文集 Vol.18 No.-

In this paper, the AC breakdown characteristics of pure Kr and N2 gas with gas pressure range of 58.8∼137.3[kPa] under uniform and non-uniform fields were investigated, and the measured values were compared with those in Kr/N2 gas mixtures with pressure varying. Summarizing the experimental results, the breakdown voltages of pure N2 gas, under uniform and non-uniform fields, were increased about 4.4 and 1.2 times than those of pure Kr gas, and the AC breakdown voltage increased with the pressure increasing. The breakdown voltages of Kr/N2 gas mixtures were decreased with decreasing the mixture ratio of N2 gas. In case of Kr(85%)/N2(15%) and Kr(70%)/N2(30%) gas mixtures comparing to the pure Kr gas, the breakdown voltages under uniform field were increased about 1.7 and 2.0 times, and under non-uniform field were increased about 1.0 and 1.2 times at the pressure of 101.3[kPa]. Also, corona inception voltage of Kr(70%)/N2(30%) gas mixtures under non-uniform fields were increased than those of pure Kr gas.

압력변화에 따른 Ar/N2 및 Kr/N2 혼합가스의 절연파괴 특성

이상우,이동인,이광식,김인식,김이국,배영호 한국조명.전기설비학회 2002 조명·전기설비학회논문지 Vol.16 No.1

In this paper, breakdown characteristics of pure Kr, Ar and N2 gas with gas pressure range were investigated, and the measured values were compared with those in Ar/N2 and Kr/N2 gas mixtures with pressure varying. Also, various characteristics with gas mixtures in practical incandescent lamps were investigated. Summarizing the experimental results, the breakdown voltages of N2 gas were increased than those of Kr and Ar gas with large molecular weight, and the breakdown voltage increased with gas pressure increasing. The breakdown voltages of Ar/N2 and Kr/N2 gas mixtures were decreased with decreasing the mixtures ratio of N2 gas, and corona inception voltage of Kr/N2 gas mixtures under non-uniform fields were increased than those of Ar/N2 gas mixtures. In case of practical incandescent lamps, luminous and lifetime of Kr(70%)/N2(30%) gas mixtures were increased about 94[㏐] and 380[hr] than those of Ar(70%)/N2(30%) gas mixtures. and injection pressure of gas mixtures with cooling temperature of 20[℃] in incandescent lamps were increased about 13[%] than those with cooling temperature of 40[℃]. 본 연구는 방전쳄버내에 각종 가스의 압력(58.8-137.3[㎪]) 변화에 따른 순수가스인 Kr, Ar 및 N2가스의 절연 특성을 조사하고, 혼합가스인 Ar/N2 및 Kr/N2가스의 절연 특성과 비교하였다. 또한, 실용 백열전구내의 혼합가스에 위한 각종 특성을 조사하였다. 실험 결과, N2가스의 압력변화에 따른 절연 특성은 큰 분자량을 가진 Kr 및 Ar가스에 비하여 증가되었으며, 가스의 압력이 증가됨에 따라 절연파괴전압은 증가되었다. Ar/N2 및 Kr/N2가스의 절연파괴전압은 N2가스의 혼합비가 적을수록 감소되었으며, Kr(70%)/N2(30%)가스의 코로나개시전압은 Ar(70%)/N2(30%)가스에 비해 증가되었다. 일반 백열전구에서 Ar(70%)/N2(30%)가스인 경우에 비해, Kr(70%)/N2(30%)가스에서 광속과 수명이 대략 94[㏐] 및 380[hr]으로 증가되었다. 백열전구내의 냉각온도가 20[℃]일 때 혼합가스 주입압력은 40[℃]에 비해 대략 13[%] 증가되었다.

평등 및 불평등 전계하에서 순수 Ar, $N_2$가스와 Ar/$N_2$혼합 가스의 교류절연파괴 특성

이상우,김인식,이동인,이광식,김이국 한국조명전기설비학회 2001 조명·전기설비학회논문지 Vol.15 No.5

본 연구에서는 평등 및 불평등 전계하에서 58.8~137.3[kPa]의 가스 압력변화에 따른 순수 Ar 및 $N_2$가스의 교류절연파괴 특성을 조사하였다. 그리고 가스 압력 변화에 따른 Ar/$N_2$ 혼합 가스의 교류절연파괴 특성과 비교하였다. 실험 결과를 요약하면, 평등 및 불평등 전계하에서 순수 $N_2$가스의 압력 변화에 따른 교류절연파괴 특성은 순수 Ar 가스에 비해 약 4.8배 1.1배 증가된 것으로 나타났으며, 압력이 증가됨에 따라 교류절연파괴전압은 증가되었다. Ar/$N_2$혼합 가스의 절연파괴전압은 순수 $N_2$가스의 혼합비가 적을수록 감소되었으며, 혼합 가스 압력이 101.3[kPa]일 때, 순수 Ar 가스에 비해 Ar 가스 혼합 비율이 각각 85[%] 및 70[%] 인 경우, 교류절연파괴전압은 평등 전계하에서는 약 1.5 및 2.1배 증가되었으며, 불평등 전계하에서는 약 1.1 및 1.3배 증가되었다. 또한 불평등 전계하에서 Ar(70%)$N_2$(30%) 혼합 가스의 코로나개시전압은 순수 Ar 가스에 비해 약 1.5배 증가되었다. In this paper, the AC breakdown characteristics of pure Ar and $N_2$gas with gas pressure range of 58.8~137.3[kPa] under uniform and non-uniform fields were investigated, and the measured values were compared with those in Ar/$N_2$gas mixtures with pressure varying. Summarizing the experimental results, the breakdown voltages of pure $N_2$gas, under uniform and non-uniform fields, were increased about 4.8 and 1.1 times than those of pure Ar gas, and the AC breakdown voltage increased with the pressure increasing. The breakdown voltages of Ar/$N_2$ gas mixtures were decreased with decreasing the mixture ratio of $N_2$gas. In case of Ar(85%)/$N_2$(15%) and Ar(70%)/$N_2$(30%) gas mixtures comparing to the pure Ar gas, the breakdown voltages under uniform field were increased about 1.5 and 2.1 times, and under non-uniform field were increased about 1.1 and 1.3 times at the pressure of 101.3[kPa]. Also, corona inception voltage of Ar(70%)/$N_2$(30%) gas mixtures under non-uniform field were increased about 1.5 times than those of pure Ar gas.

N2 Gas 유량에 따른 TiNOx/Ti/Al 흡수율 변화

김진균,김현후,장건익 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.2

Ti was deposited on the Al substrate using DC magnetron sputtering with changing the N2 gas for thepossible application of a solar absorbing layer. N2 gas ranged from 50 to 75 sccm was systematically applied inthe 5 sccm interval and the variation of the absorption rate was investigated. Microstructural examination andelemental analysis indicate that Ti was reacted with N2 gas and formed TiNOx compound. As compared with thefilm without any exposure of N2 gas, absorption rate improved by more than 20%. Typically the averageabsorption of TiNOx fim with 65% of N2 gas was about 99% in the visible range, and the average absorption wasmore than 90% in the infrared absorption region respectively. DC magnetron sputtering 장비를 사용하여 Al 기판 위에 N2 gas의 유량을 변화시켜 Ti층을 증착시켜 태양열 흡수층을 제작하였다. N2 gas의 유량을 각각 50∼75 sccm으로 5 sccm 간격으로 조절하며 흡수율의 변화를 조사하였다. 미세구조와 원소 분석을 위해 Ti를 N2 gas와 반응시켜 TiNOx을 형성하였다. N2 gas와 반응하지 않는 것과 비교하여 흡수율이 20% 이상 향상되었다. 일반적으로 N2 gas가 65 sccm일 때 형성한 TiNOx 층은 가시광 영역에서 99% 평균 흡수율을 보였으며, 적외선 영역에서는 90% 이상의 평균 흡수율을 나타냈다.

Structure, stability, and storage capacity of CO₂+N₂O mixed hydrates for the storage of CO₂+N₂O mixture gas

Kyung, Daeseung,Lee, Woojin Elsevier 2018 INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL Vol.76 No.-

<P><B>Abstract</B></P> <P>In this study, we evaluated the feasibility of using CO<SUB>2</SUB>+N<SUB>2</SUB>O mixed gas hydrates for the development of advanced greenhouse gas (GHG) sequestration technology. Structural characteristics of gas hydrates at different mole fractions of the gas mixture (CO<SUB>2</SUB>:N<SUB>2</SUB>O = 0.7:0.3 and 0.5:0.5) was analyzed using Raman spectroscopy and high-resolution X-ray powder diffraction. The mixed gas hydrates can contain both CO<SUB>2</SUB> and N<SUB>2</SUB>O molecules simultaneously, in small and large cages of structure I hydrate without structural deformation. Their volume can be expanded by increase of the N<SUB>2</SUB>O portion. The phase equilibrium condition of the mixed gas hydrates was more stable than that of pure CO<SUB>2</SUB> hydrates, and estimated dissociation enthalpies of the mixed gas hydrates were higher than those of the CO<SUB>2</SUB> hydrates. We confirmed that the mixed gas hydrates can reduce massive amounts of GHG emissions due to their potentially higher storage capacity. These research results provide basic knowledge useful for the simultaneous mitigation of the effects from major GHGs and application of the CO<SUB>2</SUB>+N<SUB>2</SUB>O mixed hydrates to advanced offshore GHG sequestration in marine sediment environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CO<SUB>2</SUB>+N<SUB>2</SUB>O mixed gas hydrates for greenhouse gas (GHG) sequestration was studied. </LI> <LI> CO<SUB>2</SUB>+N<SUB>2</SUB>O mixed gas is entrapped in s-I hydrates without structural deformation. </LI> <LI> Thermodynamic stability of mixed hydrates is greater than that of pure CO<SUB>2</SUB> hydrates. </LI> <LI> Storage capacity of mixed hydrates is greater than that of pure CO<SUB>2</SUB> hydrates. </LI> <LI> These results can provide fundamental knowledge for offshore GHG sequestration. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

고에너지 전자선을 조사한 피부의 세포막모델에서 공기 중의 O 2 -N 2 혼합기체의 분리투과 특성

고인호(In-Ho Ko),여진동(Jin-Dong Yeo) 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.2

본 논문에서는 고에너지 전자선(6MeV)을 조사한 피부의 세포막 모델에서 공기의 주요 구성성분인 N 2 -O 2 혼합기체가 압력차에 따른 투과도차의 변화를 나타내고 결국 N 2 -O 2 분리투과성의 변화로 나타내어 기체분 자가 분리 전달되는 특성을 연구하였다. 이 실험에 사용한 재료로 피부의 세포막 모델은 polydimethyl siloxa ne (PDMS)분말을 polysulfone과 결합시킨 비다공성 복합막, 압축공기와 순도 99.9%인 산소, 질소기체통, 산소분석기(LC-700H, Japan), soap-bubble flow meter, wet-test meter, pressure regulator, back-pressure regulator, permeation cell, Linac 전자선 조사기 등을 사용하였다. 실험방법으로는 N 2 -O 2 기체투과 장치를 이용하여 피부세포막모델의 온도는 36.5℃로 고정한 후에 기체의 온도도 15℃로 고정하고 조작압력법위를 1∼6 kg f /㎠ 로 하며 각각 1 kg f /㎠ 단위로 측정하였다. 방사선을 조사한 피부의 고분자막(세포막모델)에서 공기를 구성한 N 2 -O 2 혼합기체의 분자가 압력차에 따른 투과도차가 발생하여 피부세포에 비정상적으로 전달되는 과정을 실험을 한 결과 아래와 같은 결론을 추론하게 되었다. 피부의 고분자 막(세포막모델)에서 N 2 -O 2 혼합기 체의 투과분리특성의 변화에 대하여 알아본 결과 방사선을 조사하지 않은 때 질소와 산소의 투과도 변화는 각각 1.19 × 10 -4 ∼ 2.43 × 10 -4 과 1.72 × 10 -4 ∼ 2.6 × 10 -4 [㎤(STP)/㎠ · sec · cmHg]이며 방사선조사로 질소와 산소의 투과도 변화는 각각 0.19 × 10 -4 ∼ 0.56 × 10 -4 과 0.41 × 10 -4 ∼ 0.76 × 10 -4 [㎤(STP)/㎠ · sec · cmHg]이며 4∼10배 정도 낮아짐을 알 수가 있었고 방사선을 조사하지 않은 때 질소에 대한 산소의 이상분리인자 α * 의 값은 1.32∼0.42로 나타내었으며 방사선조사로 질소에 대한 산소의 이상분리인자 α * 의 값은 0.237∼0.125이며 4∼5배 정도 낮아짐을 나타내었다. 또한, 압력차가 1∼6 kg f /㎠로 증가함에 따라서 작업변수인 cut가 0에 접근할수록 투과도상의 산소부화도는 증가하지만 반면에 압력비 Pr이 0에 가까워 질수록 투과도상의 산소부화도는 방사선조사로 4∼19배 정도 감소하였다. 방사선의 조사 유·무에 관계없이 압력차가 1∼6 kg f /㎠ 로 증가함에 따라서 질소, 산소 및 공기의 투과도는 증가하였지만 질소에 대한 산소의 선택성은 감소하였다. The separation permeation characteristics of N 2 -O 2 gas in air at cell membrane model of skin which irradiated by high energy electron(linac 6 MeV) were investigated. The cell membrane model of skin used in this experiment was a sulfonated polydimethyl siloxane(PDMS) non-porous membrane . The pressure range of N 2 and O 2 gas were appeared from 1 kg f /cm 2 to 6 kg f /cm 2 . In this experiment(temperature 36.5 ℃), the permeation change of N 2 and O 2 gas in non-porous membrane by non-irradiation were found to be 1.19 × 10 -4 - 2.43 × 10 -4 , 1.72 × 10 -4 - 2.6 × 10 -4 cm 3 (STP)/cm 2 ·sec·cmHg, respectively. That of N 2 and O 2 gas in non-porous membrane by irradiation were found to be 0.19 × 10 -4 - 0.56 × 10 -4 , 0.41 × 10 -4 - 0.76 × 10 -4 cm 3 (STP)/cm 2 ·sec·cmHg, respectively. The irradiated membrane was significantly decreased about 4-10 times than membrane which was not irradiated. And ideal separation factor of N 2 and O 2 gas by non-irradiation was found to be from 1.32 to 0.42 and that of N 2 and O 2 gas by irradiation was found to be from 0.237 to 0.125. The irradiated membrane was significantly decreased about 4-5 times than membrane which was not irradiated. When the operation change(cut) and pressure ratio(Pr) by non-irradiation were about 0, One was increased to the oxygen enrichment and the other was decreased to the oxygen enrichment. The irradiated membrane was significantly decreased about 4-19 times than membrane which was not irradiated. As the pressure of N 2 and O 2 gas was increased, the selectivity was decreased. As separation permeation characteristics of N 2 -O 2 gas in cell membrane model of skin were abnormal, cell damages were appeared at cell.

Isostructural and cage-specific replacement occurring in sII hydrate with external CO₂/N₂ gas and its implications for natural gas production and CO₂ storage

Seo, Young-ju,Park, Seongmin,Kang, Hyery,Ahn, Yun-Ho,Lim, Dongwook,Kim, Se-Joon,Lee, Jaehyoung,Lee, Joo Yong,Ahn, Taewoong,Seo, Yongwon,Lee, Huen Elsevier 2016 APPLIED ENERGY Vol.178 No.-

<P>A replacement technique has been regarded as a promising strategy for both CH4 exploitation from gas hydrates and CO2 sequestration into deep-ocean reservoirs. Most research has been focused on replacement reactions that occur in sI hydrates due to their prevalence in natural gas hydrates. However, sII hydrates in nature have been also discovered in some regions, and the replacement mechanism in sII hydrates significantly differs from that in sI hydrates. In this study, we have intensively investigated the replacement reaction of sII (C3H8 + CH4) hydrate by externally injecting CO2/N-2 (50:50) gas mixture with a primary focus on powder X-ray diffraction, Raman spectroscopy, NMR spectroscopy, and gas chromatography analyses. In particular, it was firstly confirmed that there was no structural transformation during the replacement of C3H8 + CH4 hydrate with CO2/N-2 gas injection, indicating that sll hydrate decomposition followed by sI hydrate formation did not occur. Furthermore, the cage-specific replacement pattern of the C3H8 + CH4 hydrate revealed that CH4 replacement with N-2 in the small cages of slI was more significant than C3H8 replacement with CO2 in the large cages of sII. The total extent of the replacement for the C3H8 + CH4 hydrate was cross-checked by NMR and GC analyses and found to be approximately 54%. Compared to the replacement for CH4 hydrate with CO2/N-2 gas, the lower extent of the replacement for the C3H8 + CH4 hydrate with CO2/N-2 gas was attributable to the persistent presence of C3H8 in the large cages and the lower content of N-2 in the feed gas. The structural sustainability and cage-specific replacement observed in the C3H8 + CH4 hydrate with external CO2/N-2 gas will have significant implications for suggesting target gas hydrate reservoirs and understanding the precise nature of guest exchange in gas hydrates for both safe natural gas production and long-term CO2 sequestration. (C) 2016 Elsevier Ltd. All rights reserved.</P>

생물학적 하폐수처리과정에서 N₂O 배출 및 저감에 관한 고찰

조경숙 ( Kyung-suk Cho ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 한국미생물·생명공학회지 Vol.46 No.3

Nitrous oxide (N₂O) is a potent greenhouse gas as well as an ozone-depleting substance. N₂O is emitted during the biological nitrogen removal process in wastewater treatment systems (WTSs), and has significant environmental impacts. In this study, N₂O emission in WTSs was comprehensively reviewed to better understand the effects of key parameters on N₂O emission and obtain useful guidelines for N₂O mitigation strategies in WTSs. Three biological pathways leading to N₂O emission are hydroxylamine oxidation, nitrifier denitrification, and heterotrohic denitrification. Measurements at lab-, pilot- and full-scale WTSs have shown large variations in N₂O emission (0-95% of N-loaded) during wastewater treatment. In the full-scale WTSs (0-14.6% N₂O of N-loaded), the average and median values were 1.95% and 0.2% of N-loaded, respectively. Dissolved oxygen, nitrite concentrations, and chemical oxygen demand (COD)/N ratio are the most important parameters leading to N₂O emission. A variety of operational strategies have been suggested to minimize N₂O emission from WTSs. A new N₂O mitigation strategy involving the introduction of microorganisms with high N₂O reductase activity or oxygenic denitrification ability has been proposed as an alternative canonical denitrification.

모델링에 의한 하수처리공정의 아산화질소(N2O) 배출량 비교분석: 기존산정방식 vs 모델링

안세영,김해림 대한환경공학회 2023 대한환경공학회지 Vol.45 No.8

This study examined the existing methodologies and the applicability of process modeling concerning the estimation of nitrous oxide (N2O) emissions from wastewater treatment processes. The method of extimating N2O emissions from wastewater occurring during biological nitrification and denitrification processes can be divided into those before and after legal nitrogen effluent quality enhancement for domestic wastewater treatment plant. Initial IPCC guidelines such as IPCC 1996 GL, GPG 2000, and IPCC 2006 GL, provided methods for estimating N2O emissions throughout domestic wastewater, while the revised version, IPCC 2019 RF, proposed methods for estimating each N2O emission by distinguishing wastewater treatment and effluent after the advancement of wastewater treatment plants. The National Greenhouse Gas Inventory Report (NIR) in Korea adopted the methodology of GPG 2000, and the Emissions Trading System (ETS) applies the estimation method of IPCC 2006 GL in the wastewater treatment plants. This study utilized process modeling to consider the process characteristics and operating conditions of wastewater treatment plants. IPCC, NIR, and ETS estimate N2O emissions based on nitrogen behavior activity data and emissions factors. On the other hand, process modeling estimates N2O emissions in each unit process of the wastewater treatment plant using a 4-step AOB nitrification/4-step denitrification model and a liquid/gas transfer model. The estimation results of N2O issions from modeling method were compared with the estimation results of IPCC, NIR, and ETS to analyze the suitability of the estimation method. Through this, it was evaluated how appropriate process modeling is for estimating N2O emissions in domestic wastewater treatment plants. 본 연구는 하수처리과정에서 배출되는 아산화질소(N2O)의 산출방법과 관련하여 기존 방법론을 분석하고 공정모델링의 적용성을 조사하였다. 생물학적 질산화 및 탈질화 과정에서 발생하는 하수의 N2O 배출량 산정방법은 하수처리 고도화 이전과 이후로 구분할 수 있는데, IPCC 초기 가이드라인인 IPCC 1996 GL, GPG 2000, IPCC 2006 GL은 하수 전반의 N2O 배출량 산정방법을 제시하였고, 개정된 버전인 IPCC 2019 RF는 하수처리장 고도화 이후 하수처리와 방류수를 구별하여 각 N2O 배출량 산정방법을 제안하고 있다. 국내 국가온실가스인벤토리보고서(NIR)는 GPG 2000의 방법론을 채택하였고, 배출권거래제(ETS)는 하수처리장 영역에서 IPCC 2006 GL의 산정방법을 적용하고 있다. IPCC, NIR, ETS는 질소 거동의 활동자료와 배출계수로 N2O 배출량을 산정한다. 반면에, 공정모델링은 하수처리장 각 단위공정에서 4단계 AOB 질산화 및 4단계 탈질화 모델과 액체/기체 가스전달 모델을 사용하여 N2O 배출량을 산출한다. 모델링에서 산출된 N2O 배출량 결과를 IPCC, NIR, ETS의 산정결과와 비교하여 모델링 산출방법의 적합성을 분석하였다. 이를 통해 공정모델링이 N2O 배출량 산정에 어느정도 적절성을 가지는지 평가하였다.