• 한국토양비료학회지
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• 제36권1호
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• pp.32-40
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• 2003

물관리와 유기물 시용이 상이한 벼논에서 메탄 배출을 측정하였다. 벼 식물체를 통한 메탄수송을 밝히려고 벼 생육기간중 분얼기, 감수분열기, 출수기, 수확기중 각 1일씩 주야로 2시간 간격으로 벼를 심은 chamber와 벼를 심지 않은 chamber에서 메탄가스 배출을 측정하였다. 상이한 생육기에서 벼 식물체를 통한 메탄 배출은 엽면적 지수, 건물중이 최대로 될 때까지는 증가하였지만 그 후로는 감소하였다. 6월 18-19일 (분얼기)에 벼 식물체가 매개한 메탄 배출은 NPK구, RSC구 (볏짚퇴비를 5월에 시응한 구). RS2구 (볏짚을 2월에 시용한 구)에서 각기 38.4%, 36.5%, 64.3%였었다. 7월 30일-31일 (감수분열기)에 벼 식물체가 매개한 메탄 배출은 NPK구, RSC구, RS2구에서 각기 70.4%, 74.3%, 74.4%였었다. 8월 20일-21일 (출수기)에 벼 식물체가 매개한 메탄 배출은 NPK구, RSC구, RS2구에서 각기 80.1%, 84.5%, 74.8%였었다. 9월 28일-29일 (수확기)에 벼 식물체가 매개한 메탄 배출은 NPK구, RSC구, RS2구에서 각기 69.9%, 65.9%, 64.4%였었다.

• 한국대기환경학회지
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• 제21권6호
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• pp.649-655
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• 2005

Automotive exhaust is suspected to be one of the main reasons of the rapid increase in greenhouse effect gases in ambient air. Although methane emissions are generally orders of magnitude lower than emissions of $CO_{2}$, the global warming potential (GWP) of methane is greater than that of $CO_{2}$. The environmental impact of methane emissions from vehicles is negligible and is likely to remain so for the foreseeable future. In this study, in order to investigate greenhouse gas emission characteristics from gasoline passenger cars, 20 vehicles were tested on the chassis dynamometer and methane emissions were measured. The emission characteristics by model year, mileage, vehicle speed were discussed. Test mode is CVS-15 mode that have been used to regulate for light-duty vehicle in Korea. It was found that $CH_{4}$ emissions showed higher for cold start, old model year and long mileage than hot start, new model year and short mileage, respectively. These results were compared with IPCC emission factors and the overall our results were anticipated to contribute for domestic greenhouse gas emissions calculation.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.108-121
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• 1998

Using gas chromatography, the light hydrocarbon emissions were analyzed from SI engine fueled with methane and liquified petroleum gas(LPG), and the effects of fuel and engine operating condition were discussed. For this purpose, 14 species of light hydrocarbon including 1, 3-butadiene were separated, calibrated with standard gas, and measured from undiluted emissions. The brake specific hydrocarbon emission(BSHC) and ozone forming potential(BSO)3 were calculated and discussed with the changes of fuel, engine speed, load, fuel/air equivalence ratio, coolant temperature, and spark timing. As a result, exhaust emission was composed of mainly fuel composed of mainly fuel comp- onent and other olefin components of similar carbon number. The olefin components such as ethylene and propylene determine most of the ozone forming potential. The fraction of fuel component in total hydrocarbon emission was bigger with methane fuel than with LPG fuel. Also fuel fraction increased at high speed or high speed or high temperature of exhaust gas, and to lesser extent with high coolant temperature and retarded spark. However, the effect of equivalence ratio had different tendency according to fuels.

• 한국축산시설환경학회지
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• 제20권4호
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• pp.139-146
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• 2014

This research was conducted to examine the temporal methane ($CH_4$) and nitrous oxide ($N_2O$) emission trends in livestock agriculture from year 1990 to 2011 with Tier 1 national greenhouse gas (GHG) inventory reporting method, which was related to efforts of decreasing GHG emissions and to achievement of voluntary GHG mitigation target. Methane emissions from enteric fermentation were calculated with default $CH_4$ emission factors of IPCC. Methane and $N_2O$ emissions from manure treatment processes were calculated with Tier 1 and mixture of Tier 1 and Tier 2 including $N_2O$ emission factors of manure treatment systems and nitrogen excretion rate of livestock, respectively. According to 2013 National GHG Inventory Monitoring, Reporting, and Verification report, GHG emission fluctuations from enteric fermentation and manure treatment processes were similarto livestock head fluctuation. GHG emissions from enteric fermentation were mainly affected by beef cattle including Hanwoo, while manure treatment processes were affected by various livestock.

• 조명전기설비학회논문지
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• 제25권11호
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• pp.103-112
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• 2011

This paper is tried to analysis the optical emission spectroscopy related to the position of inductive load coil and flow rates of methane and oxygen in the RF inductive plasma process. According to the position of load coil, peak of $H_{\alpha}$, $H_{\beta}$, and CH were appeared strongly at the middle position of the coil and it decreased both direction. The electron temperature was approximately 0.9[eV] at that position. Emission intensities of $H_{\alpha}$, $H_{\beta}$, and CH increased linearly by increasing input power. In addition, intensities of $H_{\alpha}$ and $H_{\beta}$ increased by increasing the flow rate of oxygen. It might be ascribed that the oxygen species were bonded with $C_nH_m$ by suppressing the combination with hydrogen atoms. Consequently, the optimal position of the inductive coil is decided to the intermediate position between 4th and 5th turns, the wanted carbon thin-film is possible to deposit by controlling flow rates of methane and oxygen.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2401-2404
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• 2012

• 한국기후변화학회지
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• 제8권4호
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• pp.347-355
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• 2017

Methane and nitrous oxide are main greenhouse gases from agricultural system and their global warming potential are 25 and 258 times stronger than that of $CO_2$, respectively. In 2016, the emission was $21,290Gg\;tone\;CO_2-eq$. which was emitted from agriculture sector and about 3.1% of total GHG emission of Korea. Those guidelines that were published by IPCC have methodology for GHGs emission calculation as well as emission factor and so on. For recent 5 years, GHGs emissions in Korea have calculated by MRV which has been improved every year based on IPCC guidelines. Analysis as estimating method improvement showed that the methane emissions from rice cultivation were the lowest on 2012 methodology, and the highest on 2014 methodology. On the other hand, the emissions of agricultural soils were the lowest on 2015 methodology and the highest on 2012 methodology. Total emissions from agriculture sector were the lowest on 2015 methodology and the highest on 2012 methodology. Compared with 2016 methodology, the GHGs emitted as few as $-1,865Gg\;tone\;CO_2-eq$ and as many as $2,717Gg\;tone\;CO_2-eq$. GHGs emissions can vary greatly, depending on how to use the emission factor and activity data. Therefore, it need constantly a detailed analysis for methodology and GHGs emission in the future.

• 한국초지조사료학회지
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• 제34권4호
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• pp.283-287
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• 2014

본 연구는 다양한 사료들을 유지수준에서 섭취한 한우 암소 경산우의 에너지 대사 시험의 결과로 부터 섭취에너지 균형과 메탄배출계수를 구하였다. 오차드그라스(orchard grass) 위주의 혼합목건초 섭취 7두, 혼합목건초의 30~50% 를 볏짚으로 대체한 12두, 혼합목건초와 볏짚에 밀기울 (wheat bran) 1 kg 추가급여한 6두, 총 25 개체의 대사실험 성적을 분석하였다. 실험축은 10일간 대사틀에서 개체별로 각각의 실험사료 적응 및 7일간 분 뇨 시료채취 후, indirect respiratory chamber 1대에 교대로 수용되어 1일간 호흡대사 실험이 이루어졌다. 혼합목건초 단독 급여구와 비교하여 나머지 두 처리구의 평균 건물섭취량은 약 11%, 15% 높았으나 통계적인 유의성은 없었고, gross energy (GE) 섭취량도 차이가 없었다. 총 섭취에너지 중 메탄으로 손실된 에너지 비율인 메탄전변율(methane conversion rate, Ym)과 메탄배출계수(emission factor, kg/head/year)도 각각 0.055~0.062 (평균 0.058)와 33.6~38.6(평균 35.2) 범위로 처리간 유의성이 없었다. 본 실험에서는 혼합목건초를 볏짚으로 대체하거나 또는 밀기울 추가급여에 의한 메탄발생량 차이가 없었으나, 메탄발생량을 줄일 수 있는 것으로 알려진 양질 조사료 급여효과 연구는 축산현장의 온실가스 감축 사업 참여가 가능한 분야이기 때문에 추가 연구들을 통해 시급히 증명되어져야 된다고 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.806-811
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• 2012

This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle) were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2%) in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively) filled with $O_2$-free $N_2$ gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at $39^{\circ}C$ for 24 h. Total gas production in all plant extracts was higher (p<0.05) than that of the control, and total gas production of ginger extract was highest (p<0.05). The methane emission was highest (p<0.05) at control, but lowest (p<0.05) at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM). Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%). Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53) than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens community in added wormwood, garlic, mandarin orange and honeysuckle extracts increased more than that of the others. The addition of onion extract increased R. albus diversity, while other extracts did not influence the R. albus community. The R. flavefaciens population in added wormwood and garlic extracts decreased, while other extracts increased its abundance compared to the control. In conclusion, the results indicated that the plant extracts used in the experiment could be promising feed additives to decrease methane gas emission from ruminant animals while improving ruminal fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제30권12호
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• pp.1702-1710
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• 2017

Objective: The study examined the effect of condensed tannins (CT) containing Ficus infectoria and Psidium guajava leaf meal mixture (LMM) supplementation on nutrient metabolism, methane emission and performance of lambs. Methods: Twenty four lambs of ~6 months age (average body weight $10.1{\pm}0.60kg$) were randomly divided into 4 dietary treatments (CT-0, CT-1, CT-1.5, and CT-2 containing 0, 1.0, 1.5, and 2.0 percent CT through LMM, respectively) consisting of 6 lambs each in a completely randomized design. All the lambs were offered a basal diet of wheat straw ad libitum, oat hay (100 g/d) along with required amount of concentrate mixture to meet their nutrient requirements for a period of 6 months. After 3 months of experimental feeding, a metabolism trial of 6 days duration was conducted on all 24 lambs to determine nutrient digestibility and nitrogen balance. Urinary excretion of purine derivatives and microbial protein synthesis were determined using high performance liquid chromatography. Respiration chamber study was started at the mid of 5th month of experimental feeding trial. Whole energy balance trials were conducted on individual lamb one after the other, in an open circuit respiration calorimeter. Results: Intake of dry matter and organic matter (g/d) was significantly (p<0.05) higher in CT-1.5 than control. Digestibility of various nutrients did not differ irrespective of treatments. Nitrogen retention and microbial nitrogen synthesis (g/d) was significantly (p<0.01) higher in CT-1.5 and CT-2 groups relative to CT-0.Total body weight gain (kg) and average daily gain (g) were significantly (linear, p<0.01) higher in CT-1.5 followed by CT-1 and CT-0, respectively. Feed conversion ratio (FCR) by lambs was significantly (linear, p<0.01) better in CT-1.5 followed by CT-2 and CT-0, respectively. Total wool yield (g; g/d) was linearly (p<0.05) higher for CT-1.5 than CT-0. Methane emission was linearly decreased (p<0.05) in CT groups and reduction was highest (p<0.01) in CT-2 followed by CT-1.5 and CT-1. Methane energy (kcal/d) was linearly decreased (p<0.05) in CT groups. Conclusion: The CT supplementation at 1% to 2% of the diet through Ficus infectoria and Psidium guajava LMM significantly improved nitrogen metabolism, growth performance, wool yield, FCR and reduced methane emission by lambs.