• 대한환경공학회지
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• 제39권12호
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• pp.672-678
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• 2017

본 연구에서는 도시고형폐기물 소각시설을 대상으로 3회에 걸쳐 도시고형폐기물을 수거하여 폐기물의 성상 및 물리화학적 조성을 조사하였다. 또한 소각시설에서 배출되는 $N_2O$를 연속적으로 측정하여 발생량을 조사하였으며, IPCC에서 제시한 폐기물의 온실가스 배출량 산정방법으로 산출된 발생량과 비교하였다. 도시고형폐기물 소각시설에서 발생하는 $N_2O$ 발생량은 IPCC 산출방법에 의한 발생량보다 2배 이상 크게 조사되었다. 도시고형폐기물 소각시설에서 $N_2O$ 저감설비가 도입될 경우 온실가스 저감목표를 만족하기 용이하고, 탄소배출권 거래제도를 활용하여 경제적인 효과도 발생할 수 있는 것으로 조사되었다.

• 한국농공학회논문집
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• 제60권1호
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• pp.79-87
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• 2018

Water management impacts both methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from rice paddy fields. Although irrigation is one of the most important methods for reducing $CH_4$ emission in rice production systems it can also $N_2O$ emissions and reduce crop yields. A feasibility study on the system of rice intensification (SRI) methods with respect to irrigation requirements, greenhouse gas (GHG) emissions was conducted for either 2 or 3 years depending on the treatment in Korea. The SRI methods (i.e. SRI and midsummer drainage (MD) with conventional practice (CT)) reduced the irrigation requirement by 49.0 and 22.0 %, respectively. Global warming contribution of GHG to different depending on the type of GHG. Therefore, the emission of $CH_4$ and $N_2O$ shall be converted to Global Warming Potential (GWP). The GHG emission from the conventional practice with midsummer drainage (MD) and the SRI plots, in GWP were reduced by 49.1 and 77.1 %, respectively. Application of SRI water management method could help to improve Korea's water resources and could thus contribute to mitigation of the negative effects of global warming.

• 한국추진공학회지
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• 제17권5호
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• pp.37-46
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• 2013

2상유체 동축형 다공성재 분사기는 중심포스트에서 분사되는 액체제트 주위로 형성된 다공성재 실린더의 내부 표면에서 기체를 반경방향으로 분사한다. 동축형 다공성재 분사기의 추진제 혼합비에 따른 연소성능을 분석하기 위하여 에탄올/아산화질소 추진제를 사용한 단일 축소형 분사기의 연소시험이 수행되었으며, 수집된 데이터 및 계산된 성능인자들에 대하여 불확실도 해석이 이루어졌다. 연소시험에 의한 추진제 혼합비에 따른 특성속도 경향은 CEA 이론값과 유사하였으나 최대값을 가지는 혼합비 영역이 이론혼합비영역에 가까웠다. 특성속도효율은 산화제 과잉 영역으로 갈수록 더 높게 나타났다.

• 대한소아치과학회지
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• 제25권1호
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• pp.38-46
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• 1998

Management of children who show negative response to treatment was difficult. Usually the dentist used the restraintor sedatives for these children. Especially it is very difficult to management of definitely negative behavior patients who resist to ordinary sedative technics including psychosedation and various sedatives. These patients were managed with general anesthesia. Midazolam was used for sedation of non-cooperative pediatric patients and halothane for induce initial sleepness, If the patient shows negative response to management after 15 minutes of midazolam administration, used the halothane in 30 to 120 seconds for calm down the patient. After induce sleepness, cut off the halothane administration and maintain the sedation with $N_2O$ in 50-70 vol.% concentration. This technic reduce the toxity and untoward effects of major anesthetics. To compare the difference of sedation effect by dosage, dose of 0.2mg/kg and 0.3mg/kg were injected respectively. Though there's no statistical difference in duration and results between two dosage but show the increment of score with age, If the patients show positive response to management after midazolam administered. try to conscious sedation with nitrous oxide in 30 to 70 vo.% concentration. Nitrous oxide concentration was administered slowly according to their consciousness and response to treatment by increment or decrement. The success rate of conscious sedation were 21.2% in 0.2mg/kg and 30.3% in 0.3mg/kg. There's many factors in proceed of conscious sedation. The most important factors are age of patient and experience of children for dental care.

• 한국토양비료학회지
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• 제50권6호
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• pp.574-587
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• 2017

Excessive application of nitrogen (N) fertilizer to support switchgrass growth for bioenergy production may cause adverse environmental effects. The objective of this study was to determine optimum N application rate to increase biomass yield of switchgrass and to reduce adverse environmental effects related to N. Switchgrass was planted in May 2008 and biomass yield, N uses of switchgrass, nitrate ($NO_3$) leaching, and nitrous oxide ($N_2O$) emission were evaluated from 2010 through 2011. Total N removal significantly increased with N rate despite the fact that yield did not increased with above $56kg\;N\;ha^{-1}$ of N rate. Apparent nitrogen recoveries were 4.81 and 5.48% at 56 and $112kg\;N\;ha^{-1}$ of N rate, respectively. Nitrogen use efficiency decreased into half with increasing N rate from 56 to $112kg\;N\;ha^{-1}$. Nitrate leaching and $N_2O$ emission were related to N use of switchgrass. There was no significant difference of cumulative $NO_3$ leaching between 0 and $56kg\;N\;ha^{-1}$ but, it significantly increased at $112kg\;N\;ha^{-1}$. There was no significant difference of cumulative $N_2O$ emission among N rates in crest, but it significantly increased at $112kg\;N\;ha^{-1}$ in toe. Excessive N application rate (above $56kg\;N\;ha^{-1}$) beyond plant requirement could accelerate $NO_3$ leaching and $N_2O$ emission in switchgrass field. Overall, $56kg\;N\;ha^{-1}$ might be optimum N application rate in reducing economic waste on N fertilizer and adverse environmental impacts.

• 아태비즈니스연구
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• 제12권1호
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• pp.209-223
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• 2021

Purpose - The purpose of this study was to investigate the relationship between Korea agricultural productions and Greenhouse Gas (GHG) emissions based on Environmental Kuznets Curve (EKC) hypothesis. Design/methodology/approach - This study utilized time series data of economic growth, greenhouse gas, agricultural productions, trade dependency, and energy usages. In order to econometric procedure of EKC hypothesis, this study utilized unit root test and cointegration test to check staionarity of each variable and also adopted Vector Error Correction Model (VECM) and Ordinary Least Square (OLS) to analyze the short and long run relationships. Findings - In the short run, greenhouse gas emissions resulting from economic growth show an inverse U-shape relationship, and an increase in agricultural production and energy consumption led to increase in greenhouse gas emission. In the long run, total GHG emissions and CO2 emissions show an N-shaped relationship with economic growth, and an increase in agricultural production has resulted in a decrease in total GHG and CO2 emissions. However, methane (CH4) and nitrous oxide (N2O) emissions showed an inverse U-shape relationship with economic growth, which indicated the environment and production process of agricultural production. Research implications or Originality - Korea agricultural production has different effects on the GHG emission sources, and in particular, methane (CH4) and nitrous oxide (N2O) emissions show to increase as the agricultural production expansions, so policy or technological development in related sector is required. Especially, in the context of the 2030 GHG reduction road-map, if GHG-related reduction technologies or policies are spread, national GHG emission reduction targets can be achieved and this is possible to predict the decline in production in the sector and damage to the related industries.

• 한국추진공학회지
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• 제23권3호
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• pp.1-8
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• 2019

아산화질소($N_2O$) 열분해를 위해 아크 플라즈마를 이용한 점화 실험을 수행하였다. 기존의 점화기들은 신뢰성 및 즉각적인 응답을 얻기 어렵다는 단점을 해결하기 위한 방안으로 플라즈마를 활용하는 방안을 제시하고자 하며, 점화기로써의 가능성을 보기 위해 가스 온도 측정 및 연소 실험을 수행하였다. 1 g/s, 0.7 A 조건에서 가장 안정적인 방전 특성을 보였으며 이때 측정된 벽면 부근의 온도는 약 $960^{\circ}C$이었다. 이를 바탕으로 하이브리드 로켓 연소 실험을 수행하였다. 플라즈마 방전 이후 약 3.1 sec만에 총 유량 10 g/s의 메인 연소가 성공적으로 이루어졌으며 점화에 필요한 플라즈마 발생을 위한 에너지 소모량은 1,780 J이었다.

• 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.

• Journal of Animal Science and Technology
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• 제63권1호
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• pp.16-24
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• 2021

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55℃ that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권1호
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• pp.49-60
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• 2022

Background: Although dental sedation helps control anxiety and pain, side effects and serious complications related to sedation are gradually increasing. Due to the introduction of new drugs and sedation methods, insurance rates, legal regulations, drugs, and methods used for dental sedation are inevitably changed. In the Republic of Korea, National Health Insurance is applied to all citizens, and this study investigated changes in the use of sedatives using this big data. Methods: This study used customized health information data provided by the Healthcare Insurance Review & Assessment Service of Korea. Among patients with a record of use of at least one of eight types of sedatives for dental sedation between January 2007 and September 2019 were selected; the data of their overall insurance claims for dental treatment were then analyzed. Results: The number of patients who received dental sedation was 786,003, and the number of dental sedation cases was 1,649,688. Inhalational sedation using nitrous oxide (N₂O) accounted for 86.8% of all sedatives that could be claimed for drugs and treatment. In particular, it was confirmed that the number of requests for sedation using N₂O sharply increased each year. Midazolam showed an increasing trend, and in the case of chloral hydrate, it gradually decreased. Conclusion: According to our analysis, the use of N₂O and midazolam gradually increased, while the use of chloral hydrate gradually decreased.