• 한국대기환경학회지
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• 제24권3호
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• pp.329-335
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• 2008

Volatile organic compounds emitted to the atmosphere can cause adverse effects on human health and participate in photochemical smog formation reactions. The destruction of a series of VOCs has been carried out by non-thermal plasma in other researches. And the characteristic of non-thermal plasma was operated at atmospheric pressure and low temperature. A new type non-thermal plasma reactor was investigated combined Glidarc plasma with water jet in this research. Also, it was found that the water-jet had an significant effect on the toluene removal efficiency. But too much water content does not favor toluene decomposition by decreasing of reaction temperature. The input toluene concentration, gas flow rate, water flow rate and specific energy input were used as experiment variables. The toluene removal efficiency, energy efficiency and specific energy input were 75.3%, 146.6 g/kWh and $1.12kWh/m^3$ at a water flow rate of 100 mL/min.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.4799-4804
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• 2013

저탄소 녹색 환경 조성 및 성장을 위한 그린 IT 기술 개발은 미래형 신기술 분야이다. 따라서, 본 논문에서는 응용 RFID 모듈에 대한 보안 데이터를 생성하여 건물 환경에 대한 통합 감시 및 관리를 할 수 있는 스마트 그린빌딩 조성용 다기능 센서 통합 모듈 시스템을 개발하였다. 논문에서 구현한 다기능 센서 통합 모듈 시스템은 열 감지센서, 온도 감지센서, 스모그 감지센서, CO2 감지센서, O2 감지센서, 장력 감지센서 및 파손 감지센서를 통합 모듈로 개발하고 이를 실시간으로 모니터링 해줌으로써 건물 내부 환경에 대한 스마트 그린빌딩 환경을 구현할 수 있는 시스템을 설계, 개발하였다.

• 환경위생공학
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• 제16권3호
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• pp.104-110
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• 2001

NOx coming from combustion make photochemical smog and acid rain, cause chronic respiratory disease resulting in critical hazard to environment and human health. Most composition of NOx coming from combustion is NO and the remaining small amount of $NO_x$ is $NO_2$. Currently, many technologies are developed and used to control NO release. One of these technologies is control technology through use of the adsorbent. In this study, two methods were used to make the adsorbent and compared. KOH and ${\gamma}{\;}-alumina$ were mixed by using two methods. Then, the experimental conditions were as follows: the concentrations of KOH used were 1 mole, 0.5 mole, and 0.1 mole, respectively and the amount of ${\gamma}{\;}-alumina$$250^{\circ}C$. As a result, precipitation method, which is one of the production methods of the adsorbent, showed the most removal efficiency as KOH concentration as 1 mole and reaction temperature as $100^{\circ}C$ were used. This study shows 40 to 60% of micropores of ${\gamma}{\;}-alumina$ was lost by the reaction with KOH through the analysis of SEM and BET Finally, KOH is the most predominant factor to control the removal of NO rather than micropore of the adsorbent.

• 설비공학논문집
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• 제24권8호
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• pp.599-604
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• 2012

Most air pollution and smog are a result of the burning of fossil fuels. The use of fossil fuels also causes acid rain and global warming. So the need for solar energy utilization is increased. It is essentially important to make efforts to reduce usage of fossil energy resources. In this study, we analyzed the correlation between climatic elements(Cloud cover, Duration of sunshine, Temperature) and the photovoltaic power generation. Cloud cover of the correlation coefficient was 0.87. And duration of sunshine of the correlation coefficient was 0.93. The order of the correlation coefficient was duration of sunshine, cloud cover, temperature. To accurately analyze of the degree of correlation for the photovoltaic power generation, additional research about climatic elements that show a high correlation is needed.

• 한국추진공학회지
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• 제21권2호
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• pp.26-31
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• 2017

고체 추진제의 환경적 문제는 고체 로켓에서 중요한 이슈로 부각되고 있다. 예를 들어 고체추진제의 산화제인 ammonium perchlorate (AP)는 염산과 같은 독성 가스와 대기 오염을 발생시켜 환경적 문제를 야기한다. 산화제 중 N-guanylurea dinitramide (GuDN)는 높은 성능과 압력 지수를 가지고 있으며, 가스발생기 추진제에서 연소하는 동안 친환경적인 연기를 배출하는 성질을 가지고 있기 때문에 환경친화적으로 효과적인 후보 물질이다. 본 논문에서는 가스발생기 추진제로서 특성에 대하여 이론적 분석, 추진제 제조공정성, 추진제 경도 특성 및 연소특성에 대하여 연구하였다.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.35-42
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• 2001

The diesel engine exhaust gas is know as one of the causes to produce photochemical smog, which causes damage on environmental. However, due to the high thermal efficiency and low carbon dioxide emission, the usage of a diesel engine is prevailed. In this study, the DC non-thermal plasma technology used to the particulate matter (PM) aftertreatment. The exhaust gas characteristics and energy density were investigated on the dynamometer test bed and chassis dynamometer with CVS-75 mode in a passenger diesel car. It was reported that the smoke removal efficiency has around the 70% in the dynamometer test with 80W energy consumption and the PM removal efficiency has the 68% in the real car test. The NOx also reduced the 20% according to electrode type respectively. Considering these results, plasma technology is one of the ways to simultaneously removing method the particulate matter (PM) and NOx.

• 공학교육연구
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• 제23권2호
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• pp.14-23
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• 2020

Based on the constructivist learning environments model and the learner-centered psychological principles, STEAM education program with the theme of eliminating smog was developed. Through the program, senior elementary school students will learn and apply the convergence knowledge of science, technology, engineering, arts and mathematics such as the human body's respiratory system (S), immune system (S), big data (M, T), computer programming(M), and aduino sensor utilization (E) directly to solve the problem. After expert validity testing, we found that developed program meet the standards of STEAM education program development and can develop creative thinking skills to find and solve problems in students' daily lives. In addition, this study is meaningful in providing a reference example for the development of STEAM education programs that enhance convergence knowledge in the future.

• 반도체디스플레이기술학회지
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• 제11권1호
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• pp.55-59
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• 2012

NOx is one of the toxin gases, which is mainly causing the optic-chemical smog phenomena, and decreasing in the function of nose and taste. Especially, NO is easily reacting with $O_3$, and then becoming the $NO_2$. $NO_2$ is mainly causing the acidulation rain. So, we should develop the NOx gas sensing system to detect NOx gas. In this paper, we present the microstructure and the NOx gas detecting properties of the nitrocellulose/MWCNT thin film coated by the air-spray on the glass substrate. The nitrocellulose/MWCNT-based gas sensors have been studied detecting NOx molecules of a ppm-level at the temperature range of $30{\sim}120^{\circ}C$. The resistance of the sensors decreases when the sensors are exposed to NOx gas. As a results, we obtained the nitrocellulose/MWCNT sensors with the sensitivity of 0.6%/sec under the 0.8 ppm of NOx gas concetration. Also, we get the activation energy of 0.202eV from the sensor for the 0.3 ppm of NOx gas concentration.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1166-1171
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• 2008

Through Korean high speed train development project "G7 Leading Technology Development Project" from 1996 to 2002, HSR-350X has been developed. It can run the maximum operating speed of 350 km/h. Based on this technology, KTX-2 which will be served commercially has been developed till 2007. This paper introduces the aerodynamic analysis of the High-Speed EMU and shows the results of optimized aerodynamic nose shape design techniques and clean pantograph panhead original techniques study. These are the important parts of developments for high speed train which maximum speed is 400 km/h. Especially for decrease of tunnel micro pressure waves, the optimized nose area distributions were derived and the characteristics of micro pressure wave were analyzed. The robust optimized pantograph panhead shapes investigated to improve the performance and decrease the vortex flow which is thought to be its noise source. These shapes are clean and robust to external disturbances like unsteady accelerated flow or side wind was derived. Finally aerodynamic performances was verified with PIV and smog visualization by wind tunnel test.

• 한국대기환경학회지
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• 제10권2호
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• pp.137-145
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• 1994

A visibility analysis model based on the Mie theory is applied to the measurements during the fall, 1993 in Seoul. Model estimations of the total extinction coefficient $b_{ext}$, and the particle scattering coefficient, $b_{sp}$ are in good agreement with the measured values by a transmissometer and a nephelometer, respectively. These values show strong dependency on the mass loading of fine particles( $D_{p}$ ＜3.0${\mu}{\textrm}{m}$) but show no apparent relation with that of coarse particles(3.0${\mu}{\textrm}{m}$＜ $D^{p}$ ＜10${\mu}{\textrm}{m}$). Relative humidity plays an important role in determining the size of particles which in turn, affects the optical efficiency of aerosol. Based on the composition analysis with cut size nitrate concentration is higher than the sulfate concentration in PM3-10 but they are comparable to each other in PM3. Considering in 1985, it demonstrates a drastic increase of nitrate concentration between 1985 and 1993. It is found that measured and estimated light extinction budget were in good agreement within 10% and that scattering by particles is responsible for about 50-55% and 70-80 % of total extinction during clear and smoggy periods respectively.y.