질소 도핑된 이산화티타늄 박막의 구조적 변화

이승재,장지원,서혜원 한국물리학회 2021 새물리 Vol.71 No.1

We have grown nitrogen-doped titanium dioxide thin films by using DC magnetron sputtering methods. During the growth, the nitrogen flow was altered to adjust the amount of nitrogen into the titanium-dioxide films. By a comparative study of X-ray diffraction and Raman spectroscopy results, we found that the insertion of nitrogen led to a reduction in crystal size/volume, distortion of Ti-O bending, and displacement of Ti atoms. As the nitrogen flow was increased, the degradation of crystal quality became more severe. A blue shift of the optical energy bandgap was observed for the titanium-dioxide films with nitrogen, which is possibly related to quantum-confinement effects. 직류 전류 마그네트론 스퍼터링 방법을 사용하여 질소가 도핑된 이산화 티타늄 박막을 성장하였다. 성장시 질소 유량을 바꿔가며 박막에 삽입되는 질소의 양을 조절하고자 했다. 이렇게 성장 시킨 박막을 엑스레이회절과 라만 분광 방법으로 분석하여서, 질소의 존재가 티타늄 이산화막의 결정 크기나 체적의 감소를 야기함과 동시에 티타늄 원자의 자리 옮김을 유도함을 확인하였다. 질소 유량이 늘어남에 따라 이산화 티타늄박막의 결정 결함의 정도는 더욱 심각해짐을 또한 관찰하였다. 이때 측정한 UV-Vis 결과에 따르면 질소유량 변화에 따라 박막의 에너지 청색 편이가 확인 되었는데, 이는 양자 크기 효과에 기인한 것으로 판단된다.

물시멘트비에 따른 모르타르의 이산화질소 흡착 성능

이보연(Lee, Bo Yeon),이재승(Lee, Jae-Seoung) 대한건축학회 2018 대한건축학회 학술발표대회 논문집 Vol.38 No.1

It has been revealed that cementitious materials have capability of adsorbing atmospheric nitrogen dioxide. However, the mechanism of the adsorption is not clearly identified. In this study, the effect of water-to-cement ratio of mortar on the adsorptive performance of nitrogen dioxide was investigated. Two water-to-cement ratios were used at 0.40 and 0.60 on two cementitious materials for comparison. The results suggest that water-to-cement ratios used in this research does not notably affect the nitrogen dioxide adsorption efficiency. This demonstrate that microstructure, and thus specific surface area variation due to water-to-cement ratio does not have meaningful effect on the nitrogen dioxide adsorption.

PSA법을 이용하여 CH₄/CO₂/N₂ 혼합가스 중에서 메탄의 분리

조우람(Woo-Ram Cho),정구현(Gu-Hyun Jeong),신영환(Young-Hwan Shin),유희찬(Hee-Chan Yoo),나병기(Byung-Ki Na) 한국청정기술학회 2011 청정기술 Vol.17 No.4

DME 예혼합 압축착화 엔진에서 질소와 이산화탄소의 영향

장진영(Jinyoung Jang),윤현숙(Hyeonsook Yoon),염기태(Kitae Yeom),배충식(Choongsik Bae) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The combustion and exhaust emission characteristics were investigated in an DME fueled HCCI engine. Carbon dioxide, nitrogen and mixed gas, which was composed of carbon dioxide and nitrogen, were used as control parameters of combustion and exhaust emission. As the oxygen concentration in induction air, which was occurred by Carbon dioxide, nitrogen and mixed gas, was reduced, the start of auto-ignition was retarded and the bum duration was extended due to obstruction of combustion and reduction of combustion temperature. Due to these fact, indicated mean effective pressure was increased and indicated combustion efficiency was decreased by Carbon dioxide, nitrogen and mixed gas. In case of exhaust emission, hydrocarbon and carbon monoxide was increased by reduction of oxygen concentration in induction air. Especially, partial burning was appeared at lower than about 18 % of oxygen concentration by supplying carbon dioxide. However it was overcome by intake air heating.

밭 토양에서 다양한 바이오차 시용에 따른 이산화탄소 및 아산화질소 감축효과

이선일(Sun Il Lee),김건엽(Gun Yeob Kim),최은정(Eun Jung Choi),이종식(Jong Sik Lee),정현철(Hyun Cheol Jung) 유기성자원학회 2018 유기물자원화 Vol.26 No.2

다양한 농업 부산물을 열분해하여 바이오차를 생산하고 이를 밭 농경지에 투입함에 따라 토양 화학적 변화와 온실가스 발생량에 대해 비교하여 평가하였다. 실내 인큐베이터 실험으로 항온조건은 미생물 활성이 가장 활발한 조건인 수분보수력 70%, 온도는 25℃ 조건에서 8주간 실험을 수행하였다. 그 기간 동안 주기적으로 가스시료를 채취하여 온실가스를 각각 분석하였다. 누적 이산화탄소 발생량은 바이오차를 투입하지 않은 대조구에서 258.6 g CO₂/㎡ 그리고 바이오차를 투입한 처리구에서는 207.1에서 255.2 g CO₂/㎡의 범위로 발생하였다. 즉 바이오차가 투입됨에 따라 이산화탄소 발생량이 증가하지 않고 비슷하거나 조금 감소하는 경향을 나타냈다. 아산화질소의 누적 발생량은 대조구에서 2,890.6 mg N₂O/㎡ 그리고 바이오차를 투입한 처리구에서는 379.7에서 525.2 mg N₂O/㎡의 범위로 발생하였다. 바이오차가 투입됨에 따라 아산화질소 발생량은 80% 이상 감축할 수 있었다. 따라서 바이오차를 밭 농경지에 적용한다면 아산화질소 발생량을 감축할 수 있는 소재로 활용할 수 가 있을 것이다. Biochar is a carbon-rich solid product obtained by the pyrolysis of biomass. It has been suggested to mitigate climate change through increased carbon storage and reduction of greenhouse gas emission. The objective of this study was to evaluate carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions from soil after various biochars addition. The biochars were produced by pyrolysing pear branch, rice hull and bean straw at 400 ~ 500℃. The treatments were consisted of a control without input of biochar and three type biochars input as 5.0 Mg/ha. Emissions of CO₂ and N₂O from upland soil were determined using closed chamber for 8 weeks at 25℃ of incubation temperature. It was shown that the cumulative CO₂ were 207.1 to 255.2 g CO₂/㎡ for biochar input treatments and 258.6 g CO₂/㎡ for the control after experimental periods. The cumulative CO₂ emission was slightly decreased in biochar input treatment compared to the control. It was appeared that cumulative N₂O emissions were 2,890.6 mg N₂O/㎡ for control, 379.7 to 525.2 mg N₂O/㎡ for biochar input treatment at the end of experiment. All biochar treatments were found to significantly reduce N₂O emission by 82~87%. Consequently the biochar from byproducts such as pear branch, rice hull and bean straw could suppress the soil N₂O emission. The results from the study imply that biochar can be utilized to reduce greenhouse gas emission from the upland field.

탄소함량이 높은 플라이애쉬를 함유한 시멘트 페이스트의 질소산화물 흡착 성능

이보연(Lee, Bo Yeon) 대한건축학회 2018 大韓建築學會論文集 : 構造系 Vol.34 No.3

The use of fly ash in construction materials is increasing worldwide due the various advantages of using it, such as to produce durable concrete, or to use less cement and thus lower carbon dioxide emissions. The quality of fly ash is often determined by loss on ignition value (LOI), where an upper limit of LOI is set in each country for quality control purpose. However, due to many reasons, production of high LOI fly ash is increasing that cannot be utilized in concrete, ending up in landfill. In this study, the effect of fly ash use in cementitious materials on nitrogen oxides adsorption is examined. In particular, the effect of using high LOI, and thus high carbon content fly ash on nitrogen oxides adsorption is investigated. The results suggest that the higher carbon content fly ash is related to higher nitrogen dioxide adsorption, although normal fly ash was also more effective in nitrogen dioxide adsorption than ordinary portland cement. Also, higher replacement rate of up to 40% of fly ash is beneficial for nitrogen dioxide adsorption. These results demonstrate that high carbon fly ash can be used as construction materials in an environmentally friendly way where strength requirement is low and where nitrogen oxides emissions are high.

질소산화물 제거를 위한 TiO₂-mayenite 제조 방법에 관한 연구

박지혜(Ji Hye Park),박정준(Jung Jun Park),박희주(Hee Ju Park),이광복(Kwang Bok Yi) 한국청정기술학회 2020 청정기술 Vol.26 No.4

한국과 중국의 도시별 위성기반 CO/CO2, CO/NO2 비율 특성

유지은,김재민,장진아,유정아,김승연,이윤곤 대한원격탐사학회 2023 大韓遠隔探査學會誌 Vol.39 No.2

This study analyzed the ratio of carbon monoxide (CO) and carbon dioxide (CO2), CO andnitrogen dioxide (NO2) for cities and regions in Korea and China using column-averaged carbon dioxidedry-air mole fraction (XCO2) of the Orbiting Carbon Observatory-2/3, CO and NO2 vertical columndensity (named XCO, XNO2 in this study) of TROPOspheric monitoring instrument from April 2018 toApril 2022, and presented the relationship between socioeconomic indicators (population, number ofvehicles, Gross Regional Domestic Product) and ratio, and differences in characteristics between Koreaand China. First, CO2 and CO were analyzed after calculating ΔXCO2 and ΔXCO removing thebackground value and trend line due to the difference in atmospheric residence time of three gaseoussubstances (CO2, CO, and NO2). Comparing the three values by regions, ΔXCO and ΔXCO2 wererelatively higher in China and XNO2 were higher in Korea and the ratio of both values (ΔXCO/ΔXCO2,ΔXCO/XNO2) was higher in China than in Korea. ΔXCO/ΔXCO2, ΔXCO/XNO2 and socioeconomicindicators have a positive correlation suggesting that the concentration of air pollutants and greenhousegases is higher as the city is large and the economic activity is active. Regarding the differences in theratio characteristics of Korea and China, the relationship between ΔXCO and ΔXCO2 showed a negative correlation in Korea and a positive correlation in China. When the relationship between ΔXCO andXNO2 was examined for summer and winter, the change of ΔXCO by season was not significant inKorea, whereas the change of ΔXCO and XNO2 by season was large in China resulting in the relationshipbetween two countries appeared differently. These results suggest that seasonal variability and nationalemission characteristics should be considered in the process of analyzing the ratio of greenhouse gasesto air pollutants.

도로 구조물 적용을 위한 TiO2 콘크리트의 장기공용성에 대한 실험적 연구

이준희,김영규,이승우 대한토목학회 2015 대한토목학회논문집 Vol.35 No.3

In the area of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides(NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide(TiO2), that is one of photocatalytic reaction material, is very efficient for removing NOx. Therefore, application of TiO2 concrete is a good alternative in order to remove NOx which is a main cause of air pollution. This experimental study aimed to evaluate the long-term performance of TiO2 concrete such as NOx removal efficiency due to performance period and environmental resistance for application of road structures. It was found that the TiO2 is reasonable applicable on the road structure because TiO2 concrete has a long-term performance. 대도시와 인접한 고속도로와 같이 교통량이 많은 경우 스모그와 산성비의 주요 원인이 되는 많은 양의 질소산화물이 발생하여 대기오염이 심각한 상황이다. 이에 최근 들어 전세계적으로 질소산화물 제거의 중용성이 부각되고 있다. TiO2는 광촉매 소재의 하나로써 질소산화물 제거에 매우 효과적이므로 대기오염의 주요 원인인 질소산화물을 제거하기 위하여 TiO2 콘크리트를 도로 구조물에 적용하는 방안이 있다. 이에 본 실험적 연구에서는 TiO2 콘크리트의 현장 적용을 위하여 공용에 따른 질소산화물 제거 효율변화와 함께 환경 하중 저항성을 평가하였다. 이로 인해 TiO2 콘크리트의 장기적인 기능성 유지가 확인되었으며 인접 도로 구조물에 적용이 타당할 것으로 판단된다.

<SUP>13</SUP>C NMR을 이용한 질소 및 이산화탄소 혼합 가스의 메탄 하이드레이트 치환 속도 규명 연구

Igor L Moudrakovski,John A. Ripmeester,서유택(Yutaek Seo),강성필(Seong-Pil Kang),이재구(Jae Goo Lee) 한국신재생에너지학회 2008 한국신재생에너지학회 학술대회논문집 Vol.2008 No.05

지구 온난화 문제의 심각성이 대두되면서 이산화탄소 저감 기술에 대한 관심이 증폭되고 있다. 가장 이상적인 방법은 탄소가 포함되지 않은 청정 재생 에너지원이지만, 에너지 공급 규모 면에서 보면 근 미래에도 화석 연료가 에너지 수요에 대한 주요 공급원으로 남아있을 것이라는 의견이 지배적이다. 많은 화석 연료 중 천연가스는 탄소 배출량이 가장 적은 청정 연료로 지난 10년간 수요가 폭발적으로 증가해왔다. 이를 고려해볼 때 탄소 배출량이 적은 천연가스를 생산하면서 이산화탄소를 격리 시킬수있는 기술은 매우 매력적 이다. 본 연구에서는 심해저의 메탄 하이드레이트로부터 천연가스를 생산하는 기술로서 이산화탄소와 질소의 혼합 가스를 사용하는 기술 개발의 일환으로 혼합 가스에 의한 메탄 하이드레이트 해리 속도를 13C NMR을 이용해 측정한 결과를 제시하고자 한다.