• Title/Summary/Keyword: Nitrous oxide ($N_2O$)

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The Differences of Nitrous Oxide (N2O) Emissions as Crop Presence and Location of Gas Sampling Chambers in Upland (밭토양에서 챔버 위치와 작물체 유·무에 따른 아산화질소 배출량 차이 분석)

  • Jeong, Hyun Cheol;Choi, Eun Jung;Lee, Jong Sik;Kim, Gun Yeob;So, Kyu Ho
    • Journal of Climate Change Research
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    • v.7 no.4
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    • pp.427-432
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    • 2016
  • Nitrous oxide is one of the main sources of greenhouse gases and its concentration has increased from 273 ppb in 1,750 to 315 ppb in 2005. Specially, nitrogen fertilizer used in agricultural soils is considered as an important source of atmospheric $N_2O$ emission. This study was conducted to estimate the difference of nitrous oxide emission as chamber position on furrow and ridge and crop existence in gas sampling chamber on upland. Four treatments used in this experiment were (1) no-fertilizer without crop in chamber on ridge, (2) fertilizer application without crop in chamber on ridge, (3) fertilizer application with crop in chamber on ridge, (4) fertilizer application without crop in chamber on ridge and furrow. Nitrous oxide emission at fertilizer application with crop in chamber on ridge were the highest while were the lowest at no-fertilizer without crop in chamber on ridge. There was no significant difference of nitrous oxide emission by chamber position, but total emission by crop existence in chamber was significant difference. Therefore, in order to estimate greenhouse gases emission using chamber method in upland, it should be considered in correlation with crop existence in chamber and characteristic changes like as the soil moisture, microbial flora by crop growth stage.

Spectrum of nitrous oxide intoxication related neurological disorders in Korea: a case series and literature review

  • Lee, Jungsoo;Park, Yangmi;Kim, Hyunkee;Kim, Nakhoon;Sung, Wonjae;Lee, Sanggon;Park, Jinseok
    • Annals of Clinical Neurophysiology
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    • v.23 no.2
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    • pp.108-116
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    • 2021
  • Background: Nitrous oxide (N2O) is used in surgery and dentistry for its anesthetic and analgesic effects. However, neurological and psychiatric manifestations of N2O abuse have been increasingly reported among Korean adults. The aim of this study was to demonstrate laboratory findings of N2O abuse in Korean patients. Methods: Patients diagnosed with N2O-induced neuropathy or myelopathy from August 2018 to December 2019 were enrolled. Their clinical presentations and laboratory and imaging findings were analyzed. Results: Sensory changes and limb weakness were present in nine of the enrolled patients. The laboratory findings revealed that seven patients had high homocysteine levels and five had high methylmalonic acid levels in their blood. Nerve conductions studies indicated that axonal neuropathy was present in four cases and longer F-wave and Hoffman's-reflex latencies were present in two cases. Signal changes in cervical spine imaging occurred in five patients, while two had normal results. Conclusions: Chronic N2O abuse can cause neurological damage or psychiatric problems. Because N2O is illegal for recreational use in Korea, patients tend to hide their history of use. Even though the spinal imaging results were normal, clinicians should consider the possibility of N2O use, and further electrophysiological tests should be applied for precise evaluations.

Effect of Sesame Straw Biochar Application on Soil Physics and Nitrous Oxide Emission in Upland Soil

  • Kang, Se-Won;Cho, Ju-Sik;Kim, Hyun-Tae;Seo, Dong-Cheol;Moon, Sung-Dong
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.3
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    • pp.259-264
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    • 2016
  • The effect of biochar application on soil physics and nitrous oxide ($N_2O$) emission from upland soil for broccoli cultivation was investigated. Sesame straw biochar (SB) was applied at amounts 0 (IF), 50 (SB50), 100 (SB100), 200 (SB200) kg $10a^{-1}$, respectively. SB addition to the upland soil decreased bulk density, and increased porosity and soil respiration. The $N_2O$ emission rates in all treatments were higher in the order of IF $${\geq_-}$$ SB50 > SB100 $${\geq_-}$$ SB200 treatments. Global warming potential in SB200 treatment decreased by 15.1% compared to IF treatment. Therefore, SB application in upland soil can improve soil physics and reduce $N_2O$ emission.

The Relevance of Soil N2O Emissions Measured by a Closed Chamber Technique on the Physico-chemical Soil Parameters (Closed chamber를 이용한 토양 N2O 배출량과 주요 토양 인자들과의 상관성)

  • Kim Deug-Soo;Oh Jin Man
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.6
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    • pp.749-758
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    • 2004
  • Nitrous oxide ($N_2$O) has been known as an important trace gas due to the greenhouse gas and the major source of stratospheric oxide of nitrogen (NO). Soil is the major source of $N_2$O in nature. The physicochemical characteristics of soils affect the emission of $N_2$O from soil. These physicochemical parameters are soil moisture, soil temperature, and soil N content. Since these parameters are correlated to the flux of $N_2$O from soil individually and compositely, there still remain many unknowns in the mechanism to produce $N_2$O in soil and the roles of such physicochemical parameters which affect the soil $N_2$O emission. Soil $N_2$O fluxes were measured at different levels in water filled pore space (WFPS), soil temperature and soil N contents from the same amounts of soils which were sampled from agriculturally managed upland field in a depth of ~30 cm at Kunsan. The soil $N_2$O flux measurements were conducted in a laboratory with a closed flux chamber system. The optimum soil moisture and soil temperature were observed at 60% of WFPS and ~13$^{\circ}C$. The soil $N_2$O flux increased as soil N contents increases during the whole experimental hours (up to 48 hours). However, average $N_2$O flux decreased after ~30 hours when organic carbon was mixed with nitrogen in the sample soils. It is suggested that organic carbon could be important for the emission of $N_2$O, and that the ratio of N to C needs to be identified in the process of $N_2$O soil emission.

Assessment of Nitrous Oxide (N2O) Emissions from Farmland in 2011 with IPCC Guideline Methodology

  • Jeong, Hyun Cheol;Kim, Gun Yeob;Lee, Jong Sik;Choi, Eun Jung;Ko, Jee Yeon;So, Kyu Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.570-574
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    • 2013
  • This study was conducted to assess $N_2O$ emissions in agricultural soils of Korea under the 1996 IPCC (Intergovernmental Panel on Climate Change) methodology. $N_2O$ emissions in agricultural soils were calculated the sum of direct emission and indirect emission by the N sources and emissions by field burning of crop residues. $N_2O$ emission was highest in animal manure as 1,547 $CO_2$-eq Gg. Indirect emissions by atmospheric deposition and leaching and runoff were 1,463 and 1,753 $CO_2$-eq Gg, respectively. $N_2O$ emission by field burning of crop residues was highest in pepper due to the residue/crop ratio and field burning ratio.

INVESTIGATION OF EMISSION RATES OF AMMONIA, NITROUS OXIDE AND OTHER EXHAUST COMPOUNDS FROM ALTERNATIVE- FUEL VEHICLES USING A CHASSIS DYNAMOMETER

  • Huai, T.;Durbin, T.-D.;Rhee, S.-H.;Norbeck, J.-M.
    • International Journal of Automotive Technology
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    • v.4 no.1
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    • pp.9-19
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    • 2003
  • Exhaust emissions were characterized for a fleet of 10 alternative-fuel vehicles (AFVx) including 5 compressed natural gas (CNG) vehicles. 3 liquefied petroleum gas (LPG) vehicles and 2 85% methanol/15% California Phase 2 gasoline (M85) vehicles. In addition to the standard regulated emissions and detailed speciation of organic gas compounds, Fourier Transform Infrared Spectroscopy (FTIR) was used to measure ammonia (NH$_3$) and nitrous oxide ($N_2$O) emissions. NH$_3$, emissions averaged 0.124 g/mi for the vehicle fleet with a range from <0.004 to 0.540 g/mi. $N_2$O emissions averaged 0.022 g/mi over the vehicle fleet with range from <0.002 to 0.077 g/mi. Modal emissions showed that both NH$_3$, and $N_2$O emissions began during catalyst light-off and continued as the catalyst reached its operating temperature. $N_2$O emissions primarily were formed during the initial stages of catalyst light-off. Detailed speciation measurements showed that the principal component of the fuel was also the primary organic gas species found in the exhaust. In particular, methane, propane and methanol composed on average 93%, 79%, and 75% of the organic gas emissions, respectively, for the CNG, LPG. and M85 vehicles.

Effect of no-tillage and green manure practices on the nitrous oxide emission from cropland (농경지에서 무경운 및 녹비 투입에 따른 아산화질소 배출특성)

  • Lee, Sun-Il;Kim, Gun-Yeob;Lee, Jong-Sik;Choi, Eun-Jung
    • Korean Journal of Environmental Biology
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    • v.37 no.3
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    • pp.309-316
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    • 2019
  • Cropland is a major source of atmospheric nitrous oxide (N2O) and we need technologies in the field of agriculture that can reduce the presence of N2O. In this study, a field experiment encompassing six treatments was conducted to determine the efflux of N2O in cropland during the growing season. An experimental plot was composed of two main sectors, no-tillage (NT) and conventional tillage (CT), which were subdivided into three plots according to types of nitrogen (N) sources: CF, chemical fertilizer; HV, hairy vetch+chemical fertilizer; and RY, rye+chemical fertilizer. The cumulative N2O emissions were 179.8 mg N2O m-2 for CF-CT, 108.1 mg N2O m-2 for HV-CT, 303.5 mg N2O m-2 for RY-CT, 86.7 mg N2O m-2 for CF-NT, 73.8 mg N2O m-2 for HV-NT, and 122.7 mg N2O m-2 for RY-NT during the fallow season. The CT, HV, and RY of no-tilled soils were reduced by 51.8, 31.7 and 59.6%, respectively (p<0.001). Our results indicate that the use of no-tillage and hairy vetch practice rather than conventional tillage and chemical fertilizer practice can decrease N2O emission.

Photodissociation of Nitrous Oxide by Slice Ion Imaging: The Stagnation Pressure Dependence

  • Cheong, Nu-Ri;Park, Hye-Sun;Nam, Sang-Hwan;Shin, Seung-Keun;Cho, Soo-Gyeong;Lee, Hai-Whang;Song, Jae-Kyu;Park, Seung-Min
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2661-2664
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    • 2009
  • Photodissociation of nitrous oxide near 203 nm has been studied by a combination of high resolution slice ion imaging technique and (2+1) resonance-enhanced multiphoton ionization (REMPI) spectroscopy of $N_2(X^1{{\Sigma}_g}^+)$ via the (a″$^1{{\Sigma}_g}^+$) state. We have measured the recoil velocity and angular distributions of $N_2$ fragments by ion images of the state-resolved photofragments. The $N_2$ fragments were highly rotationally excited and the NN-O bond dissociation energy was determined to be 3.635 eV. Also, we investigated the photofragment images from the photodissociation of $N_2O$ clusters with various stagnation pressures.

Nitrous oxide and carbon dioxide efflux of cropland soil during fallow season (휴경기간 녹비재배 농경지 토양에서 아산화질소 및 이산화탄소 배출특성)

  • Lee, Sun-Il;Kim, Gun-Yeob;Choi, Eun-Jung;Lee, Jong-Sik;Jeong, Hyun-Cheol
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.4
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    • pp.386-396
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    • 2018
  • Cropland is sources of atmospheric nitrous oxide ($N_2O$) and carbon dioxide ($CO_2$). However, the contribution of the fallow season to emission of these gases has rarely been determined. In this study, a field experiment encompassing three treatments was conducted to determine efflux of $N_2O$ and $CO_2$ in cropland during fallow season. The treatments were hairy vetch (H.V.), rye and control (Con.). The H.V. and rye were sown in middle October and early November, respectively. The soil $N_2O$ efflux among all three treatments in the fallow season (November-April) were $0.014-2.956mg\;N_2O\;m^{-2}{\cdot}d^{-1}$. The cumulative $N_2O$ emissions were $104.4mg\;N_2O\;m^{-2}$ for Con., $85.8mg\;N_2O\;m^{-2}$ for H.V. and $85.0mg\;N_2O\;m^{-2}$ for Rye during the fallow season. The highest $N_2O$ emissions occurred in Con., while H.V. and Rye emissions were similar. Cumulative $CO_2$ emissions were $293.1g\;CO_2\;m^{-2}$ for Con., $242.2g\;CO_2\;m^{-2}$ for H.V., $275.2g\;CO_2\;m^{-2}$ for Rye during fallow season. This study showed that soil $N_2O$ and $CO_2$ average daily emission during fallow season were 28.3% and 27.4%, respectively of the growing season. Our results indicate that $CO_2$ and $N_2O$ emissions from agricultural systems continue throughout the fallow season.