• 한국기후변화학회지
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• 제4권4호
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• pp.359-369
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• 2013

본 논문에서는 소형자동차에 이동식 배출가스 측정장비(PEMS)를 탑재하여 서울 도심의 실제 도로를 주행하고, 주행인자와 $CO_2$ 배출량 간의 상관관계를 분석하였다. 주요 주행인자로는 평균차속, 상대가속도(RPA-Relative Positive Acceleration), 정지비율을 선정하였고, 도로유형을 단속류와 연속류로 구분하여 분석하였다. 주행거리 기반의 이동평균구간 계산 방법을 적용하여 다양한 주행조건에서의 평균값을 구하고, 다중 선형 회귀분석 방법을 통해 주행인자와 $CO_2$ 배출량 간의 상관관계를 조사하였다. 이러한 분석을 통해 자동차의 $CO_2$ 배출량은 평균차속이 증가함에 따라 감소하고, RPA와 정지비율의 증가에 따라 증가하는 경향이 있음을 통계적인 방법으로 확인하였다. 단속류는 연속류와 비교하였을 때 평균차속이 상당히 낮고, RPA와 정지비율은 높게 나타나는데, 이러한 주행인자분포의 차이로 인해 단속류의 단위주행거리 당 $CO_2$ 배출량이 높은 것으로 판단된다.

• 대한환경공학회지
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• 제33권3호
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• pp.183-190
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• 2011

소형방출챔버를 이용하여 반응조건(시료량, 온도, 환기횟수)에 따라 방향제에서 방출되는 휘발성 유기화합물의 배출특성을 조사하였다. 시료부하량($1.4{\sim}551.0g/m^2$)에 따라 방향제에서 방출되는 TVOC 방출량은 방출시험 5시간 후 $0.7{\sim}64.4mg/m^2{\cdot}hr$로 나타났다. Limonene, ${\alpha}$-pinene과 linalool 등 방향제에서 방출된 주요 휘발성 유기화합물은 온도와 환기횟수가 클수록 방출량이 증가한 것으로 나타났다. 이들 연구결과는 방향제와 같은 생활용품의 오염물질 방출시험방법 및 방출기준을 정립하기 위한 기초자료로 활용될 것으로 생각된다.

• 한국대기환경학회지
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• 제28권3호
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• pp.273-281
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• 2012

The government is carrying forward a sustainable development which reduces green-house gas and environmental pollution by preparing 'Low Carbon Green Development' policy basis as a new paradigm of national development. This study aims to understand the status of atmosphere contamination which Seoul has by finding correlation among social, economical indexes and carbon, the humanities and social characteristic materials which best express types of city and correlation and to suggest implications. According to the results of the analysis, first the carbon emission volume of Seoul recorded 0.56 ppm, Jongno, Jung-Gu, Kuro, Kangnam and Songpa were more than the average of Seoul and Kwangjin-Gu & Kangbuk-Gu, relative north east regions, Yeongdeungpo-Gu and Dongjak-Gu, south west regions showed lower CO occurrences. Second, according to the correlation and factor analysis, elements which affect CO emission volume of Seoul are largely represented by regional level, traffic level and development density level. Third, when the importance of influence factors based on the analyzed standard coefficient by a regression model, traffic and development density level were most important by recording traffic level (0.967), environmental level (0.385), regional level (0.530) and development density (0.561). Consequently, it was revealed that the traffic level most affected CO emission.

• Plant Biotechnology Reports
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• 제3권1호
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• pp.57-65
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• 2009

Cultured Cupressus lusitanica cells induced by various stresses are thought to produce different complexes of defense chemicals to optimize defense. To compare the induced products of two stimulations, we investigated the emission of monoterpenes, biosynthesis of ${\beta}-thujaplicin$, and accumulation of lignin in mechanically stressed and fungal elicited cultured C. lusitanica cells. Both mechanical stress and fungal elicitor caused emission of qualitatively similar monoterpene blends indicating de novo biosynthesis of these compounds after stimulation, while mechanical stress alone is sufficient to induce fungal elicitor-related monoterpene emission. Sabinene and limonene were the dominant compounds over the time course in both volatile blends. Although the emitted volatile blends were qualitatively similar, the time course and the relative ratios of the constituents of the volatile blends differed with the type of stimulation. While fungal elicited cells produced significant amounts of ${\beta}-thujaplicin$ over the 5-day time course, no ${\beta}-thujaplicin$ was observed in the mechanically stressed cells. The production of ${\beta}-thujaplicin$ was the main dissimilarity of the induced products of these two treatments, suggesting that synthesis of ${\beta}-thujaplicin$ is not a general response to all types of stresses, but is a specific response and serves as a strong toxic compound against already invaded fungus. Significantly higher amounts of lignin accumulations were observed in the fungal elicited and mechanically stressed cells on the 5th day after induction. Based on these results, we suggest the composition of induced products was dependent on the method of stimulation.

• Journal of Biosystems Engineering
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• 제28권3호
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• pp.225-230
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• 2003

This study was carried out to analyze the environmental variation of layer house at Iowa State in the USA. The analyzed seasons for this study were summer and winter. Analyzing factors are inside temperature and relative humidity, carbon dioxide concentration, ammonia concentration and emission. All factors were collected every 30 second from each house with portable monitoring units. In this study, two types of laying hen houses were monitored at the same season. One was a manure belt house, the other was a high-rise house. In order to estimate the ventilation rates of the laying hen houses, carbon dioxide concentration balance was used in this study. Ammonia concentrations and emission rates of the manure belt house are much lower than those of the high rise house. Daily mean ammonia concentrations in the manure belt house and high-rise house ranged from 3 to 7 ppm and 5 to 34 ppm, respectively. The daily ammonia emission rates averaged 0.68g/h$\cdot$500kg and 0.73g/h$\cdot$500kg for the manure belt house and 0.93g/h$\cdot$500kg and 2.89g/h$\cdot$500kg for the high-rise house in summertime and wintertime, respectively. Summertime is associated with much higher ammonia emission rates than wintertime because of much higher ventilation rates and ambient air temperature, even though the concentrations may be lower.

• 에너지공학
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• 제22권2호
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• pp.128-135
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• 2013

산지마다 상이한 성분을 갖는 천연가스의 가스호환성 및 연소특성을 판정하기 위해서는 많은 시간과 비용이 소비되고 그 범위도 넓어 어려움이 있어, 천연가스를 모사하는 등가가스를 대체하여 사용하는 방법이 사용되고 있다. 등가가스는 천연가스와 발열량, 압축계수, 상대밀도, CO 배출농도 및 연소속도에 차이가 거의 없다고 알려져 있지만, 실제 가스기기에 대한 화염형상, NOx 배출농도 및 효율에 대한 연구는 아직 보고되고 있지 않다. 본 연구에서는 천연가스를 모사하는 등가가스를 대상으로 기존에 보고된 CO 배출농도, 연소속도 및 화염온도 등을 재확인하고, 화염형상, NOx 배출농도 및 효율에 대해서 수치해석 및 실험을 통해 비교 검토함으로써 등가가스의 유효성을 검토하였다. 그 결과 천연가스와 등가가스의 차이는 미세하였으며, 등가가스를 이용하여 천연가스의 연소특성 및 호환성 범위를 검토하는데 문제가 없을 것으로 판단되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.530-537
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• 2015

The objective of this study was to evaluate the in vitro effects of flavonoid-rich plant extracts (PE) on ruminal fermentation characteristics and methane emission by studying their effectiveness for methanogenesis in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The PE (Punica granatum, Betula schmidtii, Ginkgo biloba, Camellia japonica, and Cudrania tricuspidata) known to have high concentrations of flavonoid were added to an in vitro fermentation incubated with rumen fluid. Total gas production and microbial growth with all PE was higher than that of the control at 24 h incubation, while the methane emission was significantly lower (p<0.05) than that of the control. The decrease in methane accumulation relative to the control was 47.6%, 39.6%, 46.7%, 47.9%, and 48.8% for Punica, Betula, Ginkgo, Camellia, and Cudrania treatments, respectively. Ciliate populations were reduced by more than 60% in flavonoid-rich PE treatments. The Fibrobacter succinogenes diversity in all added flavonoid-rich PE was shown to increase, while the Ruminoccocus albus and R. flavefaciens populations in all PE decreased as compared with the control. In particular, the F. succinogenes community with the addition of Birch extract increased to a greater extent than that of others. In conclusion, the results of this study showed that flavonoid-rich PE decreased ruminal methane emission without adversely affecting ruminal fermentation characteristics in vitro in 24 h incubation time, suggesting that the flavonoid-rich PE have potential possibility as bio-active regulator for ruminants.

• 자원ㆍ환경경제연구
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• 제21권2호
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• pp.211-235
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• 2012

이산화탄소 저감에 대한 사회 경제적 관심이 높아지면서 실제 이산화탄소 배출의 변화요인을 추정하고 그 영향력을 파악하는 분해분석의 중요성이 높아지고 있다. 본 연구는 1980년~2007년의 OECD 27개 국가를 대상으로 방향거리함수를 활용한 이산화탄소 분해산식을 정의하고 각 요인별 변화효과를 추정하였다. 특히 생산 과정에 투입되는 에너지 사용량을 화석연료와 비-화석연료로 구분하고 각 에너지원에 따른 이산화탄소 변화효과를 계측하였다. 상대적으로 급격한 경제성장을 경험한 국가는 표본기간내 생산성 하락과 배출집약도 증가를 동시에 보여주고 있고 규모 확대로 인한 이산화탄소 배출압력을 효과적으로 제어하지 못하고 있었다. 특히 효율 및 기술 변화요인이 이산화탄소의 저감을 유도하지 못하였고 이산화탄소의 배출량 증가에 가장 주요한 요인으로 작용하고 있었다. 또한 적절한 환경규제가 작용하지 않는 상태에서 이루어진 경제성장이 배출집약도의 상승을 유도하고 있고 강력한 환경정책 설정의 필요성을 확인할 수 있었다. 반면 실제 이산화탄소의 감소를 보이는 국가는 생산성의 성장, 에너지 투입의 효율성 상승, 배출집약도의 하락을 동시에 보여주고 있었다. 비-화석연료의 사용비중 증대와 강력한 환경정책 등으로 인한 환경친화적 생산전환을 확인할 수 있었고 대부분이 환경에 대한 사회 경제적 관심이 높은 유럽국가라는 공통점이 있었다. 특히 이들 국가는 기술변화에 의한 저감효과가 강하게 나타났고, 이산화탄소의 배출량 증가속도가 빠른 국가에 비해 그 효과가 확대되는 모습을 보였다.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.13-17
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• 2013

In lighting system where several large-area organic light-emitting diode (OLED) lighting panels are involved, panel aging may appear differently from each other, resulting in a falling-off in lighting quality. To achieve uniform light output across large-area OLED lighting panels, we have employed an optical feedback circuit. Light output from each OLED panel is monitored by the optical feedback circuit that consists of a photodiode, I-V converter, 10-bit analogdigital converter (ADC), and comparator. A photodiode generates current by detecting OLED light from one side of the glass substrate (i.e., edge emission). Namely, the target luminance from the emission area (bottom emission) of OLED panels is monitored by current generated from the photodiode mounted on a glass edge. To this end, we need to establish a mapping table between the ADC value and the luminance of bottom emission. The reference ADC value corresponds to the target luminance of OLED panels. If the ADC value is lower or higher than the reference one (i.e., when the luminance of OLED panel is lower or higher than its target luminance), a micro controller unit (MCU) adjusts the pulse width modulation (PWM) used for the control of the power supplied to OLED panels in such a way that the ADC value obtained from optical feedback is the same as the reference one. As such, the target luminance of each individual OLED panel is unchanged. With the optical feedback circuit included in the lighting system, we have observed only 2% difference in relative intensity of neighboring OLED panels.

• 산업경영시스템학회지
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• 제24권68호
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• pp.51-65
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• 2001

This study is to make LCIA(Life Cycle Impact Assessment) easier as a methodology of environmental scores(called E-score) that integrated environmental load of each emission substance based on environmental damage such as in human health, ecosystem and resources category. The concept is to analyzes the LCI(Life Cycle Inventory) and defines the level of environment damages for human health, ecosystem and resources to objective impact assessment standard, and makes the base of marginal damage to calculate the damage factor, which can present the indication that can establish the standard value of environmental impact. First, damages to human health are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of health effect as a DALY(Disability Adjusted Life Years) unit. Second, damages to ecosystem are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of the effect as a PDF(Potentially Disappeared Fraction) unit through linking potentially increased disappeared fraction. Third, damages to resources are carried out by resource analysis and damage analysis for linking the lower fate to surplus energy conception to get damage factor as a MJ(Mega Joule) unit. For the ranking of relative environment load level each other, LCIA can be carried out effectively by applying this E-score methodology to the particular emission substances. A case study has been introduced for the emission substances coming out of a tire manufacturer in Korea. It is to show how to work the methodology. Based on such study result, product-designers or producers now can apply the E-scores presented in this study to the substances of emission list, and then calculate the environment load of the product or process in advance at any time and can see the environment performance comparatively and expected to contribute to the environmental improvement in view of environmental pollution prevention.