• 제목/요약/키워드: carbon dioxide concentration

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Development of a New Disinfestation Method Using Methyl Bromide and PH3 in Cut Rose Fumigation (절화장미 훈증처리시 Methyl Bromide와 PH3를 이용한 새로운 살충방법의 개발)

  • Son, Ki-Cheol;Byoun, Hye-Jin;Kim, Mi-Kyoung;Yun, Jae-Gil;Kim, Eui- Young
    • Horticultural Science & Technology
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    • v.16 no.3
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    • pp.370-373
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    • 1998
  • Fumigation by combination of methyl bromide/phosphide ($MB/PH_3$) was much more effective in disinfestating the rose insect pests (Aphis gossypii, Tetranychus urticae, and Frankliniella occidentalis) than that by individual MB or $PH_3$. Fumigation for 2 hours in the chamber using ;$MB/PH_3$ at the concentration of $10/3g{\cdot}m^{-3}$ brought about 91.3% and 100% mortality in aphids and thrips, respectively. Fumigation for 3 hrs using ;$MB/PH_3$ at the concentration of 5/3 or $7/3g{\cdot}m^{-3}$ showed over 96% mortalities in mites and thrips as well as no phytotoxicity symptoms, e.g. tip burn or bent neck, in cut roses, while mortalities of mites and thrips were not influenced by increasing $CO_2$ concerntration from 0.03% to 10% or decreasing $O_2$ concentration up to 15% in fumigation chamber.

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Measurement of $\textrm{CO}_2$ Concentration and Leaf Area Index for Crop Photosynthesis Model in Sweet Pepper (단고추의 작물 광합성 모델을 위한 $\textrm{CO}_2$ 농도와 엽면적지 수 측정)

  • Lee, Beom-Seon;Chung, Soon-Ju;Jang, Hong-Gi
    • Journal of Bio-Environment Control
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    • v.8 no.3
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    • pp.192-201
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    • 1999
  • This study was aimed to introduce the measurement of $CO_2$ concentration and leaf area index in the phytotron for predicting the effect of CO.E, light and leaf area index on the instantaneous photosynthetic rate of sweet pepper with the existing ASKAM model. Measurements were made in 2 semi-closed phytotron compartments in which three different $CO_2$ concentrations were applied at random. Plants were grown on containers with circulating nutrient solution at 21$^{\circ}C$ and 80-95% relative humidity. The model estimates crop net $CO_2$ uptake for short time intervals during the day based on short-term data of daily radiation, temperature and $CO_2$ concentration. During the photosynthesis measurements, $CO_2$ concentrations in both compartments and in the basement were measured every minute. This was also done for the flow of pure $CO_2$ into the compartment, global radiation, photosynthetic active radiation inside the compartment, temperature and relative humidity. Crop growth models summarize our knowledge on crop behavior and have as such a wide range of applications in analysis, crop management and thus as a farm management tool.

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Characterization of $PM_{10}$ and $PM_{2.5}$ Levels inside Train and in Platform of Subway (서울 일부 지하철 객차와 승강장에서 측정한 $PM_{10}$$PM_{2.5}$농도의 특성)

  • Park, Dong-Uk;Yun, Kyung-Sup;Park, Soo-Taek;Ha, Kwon-Chul
    • Journal of Environmental Health Sciences
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    • v.31 no.1
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    • pp.39-46
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    • 2005
  • This study was performed to investigate the concentration of $PM_{10}$ and $PM_{2.5}$ in inside train and platform of subway 1, 2, 4 and 5 in Seoul, KOREA. $PM_{10}$, $PM_{2.5}$, temperature, humidity and carbon dioxide were monitored using Portable Aerosol Spectrometer at afternoon (between 13:00 and 16:00). The concentrations of $PM_{10}$ and $PM_{2.5}$ in inside train were monitored to be higher than those measured in platform. In addition, $PM_{10}$ concentration in both platform and inside train were found to be greatly higher than range of from 35 ${\mu}g/m^3$ to 81${\mu}g/m^3$ in ambient air reported by Ministry of Environment. This study found that there were many inside train in subway 1, 2, 4 line where exceeded 150 ${\mu}g/m^3$ of Korean PM10 standard. The average percentage that exceeded PM10 standard was 83.3% in line 1, 37.9% in line 2 and 63.1% in line 4, respectively. In particular, most of inside train in subway line 1 were over PM10 limit. PM2.5 concentration ranged from 77.7 ${\mu}g/m^3$ to 158.2 ${\mu}g/m^3$, which were found to be greatly higher than ambient air PM2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 hours arithmatic mean : 65 ${\mu}g/m^3$, year average : 15 ${\mu}g/m^3$). The percentage of $PM_{2.5}$ in $PM_{10}$ was 86.2% in platform, 81.7% in inside train, 80.2% in underground and 90.2% in ground. These results indicated that fine particles ($PM_{2.5}$) accounted for most of $PM_{10}$.

Effect on Quality Change of Cherry Tomato by $CO_2$ Concentration of Flushed Gas and Storage Period (충전가스의 $CO_2$ 함량 및 노출기간의 변화가 방울토마토의 품질변화에 미치는 영향)

  • Lee, Seung Yuan;Lee, Seung Jae;Choi, Dong Soo;Hur, Sun Jin
    • Culinary science and hospitality research
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    • v.20 no.6
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    • pp.200-210
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    • 2014
  • The purpose of this study was to investigate the quality changes and contamination of microorganisms such as Escherichia coli, mold and yeast in cherry tomatoes during storage at different temperatures, gas composition and periods(7 and 14 days). This study determined pH, color change and the growth pattern of microorganisms in cherry tomato during storage at $5^{\circ}C$, $10^{\circ}C$ and $15^{\circ}C$. According to the results, pH level was a little raised with storage period. On average, $L^*$, $a^*$ and $b^*$ value of cherry tomato were irregular value of increase and decrease of all gas packaging with storage period. In regard of the types of microorganism, aerobic count plate, coliform count, mold and yeast were detected when cherry tomatoes were stored at $5^{\circ}C$, $10^{\circ}C$ and $15^{\circ}C$ during storage for 14 days. Equally, all microorganisms of cherry tomato were irregular with storage period and complex gas packaging. However, this study determined that packaging with a higher $CO_2$ concentration than $O_2$ concentration can reduce growth of microorganism. These studies can be used as primary data for determining the optimal complex gas to storage enlargement.

Biogas Production from Sewage Sludge in 30L Microbial Electrolysis Cell (30L 미생물전기분해전지의 하수슬러지로부터 바이오가스 생산 특성)

  • Lee, Myoung-Eun;Ahn, Yongtae;Shin, Seung Gu;Seo, Sun-Chul;Chung, Jae Woo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.4
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    • pp.25-33
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    • 2019
  • Operating characteristics of a 30 L microbial electrolysis cell (MEC) for producing biogas from sewage sludge was studied. During the 32-day inoculation period, carbon dioxide concentration decreased and methane concentration increased with operating time, and the overall methane content of biogas was 69.1% with a production rate of 171.6 mL CH4/L·d. In fed-batch experiments for 6 operating cycles, CH4 concentration of 66.5~77.2% was obtained at a production rate of 184.9~372.9 mL CH4/L·d, COD, TS and VS removal efficiency ranged from 28.2 to 42.1%, 20.7 to 37.5% and 18.5 to 36.9%, respectively. The MEC system was observed to be stabilized as operating cycles were repeated after inoculation. In the last operating cycle, 5221 mL/L of methane was produced with CH4 yield of 316.7 L CH4/kg CODrem, and the energy recovery was 73%.

Cultural Characteristics and Fruiting-body Productivity of New Variety 'Hwadam' (Lentinula edodes) According to Filter Treatment in Boxes (상자에 필터처리에 따른 표고 신품종 '화담'의 재배특성 및 자실체 생산성)

  • Kim, Jeong-Han;Kang, Young-Ju;Baek, Il-Sun;Shin, Bok-Eum;Ha, Tai-Moon;Jung, Gu-Hyun
    • The Korean Journal of Mycology
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    • v.48 no.2
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    • pp.95-102
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    • 2020
  • This study was carried out to develop a new method of cultivation of 'Hwadam' a new variety of Lentinula edodes, to improve fruiting body productivity and reduce labor. To determine the optimum filter number for box cultivation, L. edodes were assessed for their cultural characteristics and mushroom yield. During spawn running of L. edodes in the box, the temperature gradually increased to the highest value of 25.8℃, 23.7℃, and 23.0℃ on day 18 for the four filter, two filter, and no treatment groups, respectively. Oxygen concentration displayed an opposite trend to carbon dioxide concentration, reaching the lowest value on day 21. The oxygen concentration progressively increased as more filters were used (5.4%, 8.2%, and 8.9% treatment with no, two, and four filters, respectively. Growth of L, edodes in the box resulted in the highest yield (2,228 g/7kg substrate) and biological efficiency (70.7%) using four filters. The biological efficiency of the four filter treatment was 29.4% higher compared to bag cultivation (41.3%). Further studies are necessary to verify stable productivity of fruiting bodies through repeated cultivation.

Physio-Chemical Studies on the After-Ripeng of Hot Pepper Fruit -Part VII. Effects of Ethephon on the Major Compoments- (신미종(辛未種) 고추의 추숙(追熟)에 관(關)한 생리화학적(生理化學的) 연구(硏究) -제7보 주요성분(主要成分)에 미치는 Ethephon의 효과(?果)-)

  • Lee, Sung-Woo;Kim, Kwang-Soo;Kim, Soon-Dong
    • Korean Journal of Food Science and Technology
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    • v.7 no.4
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    • pp.194-199
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    • 1975
  • The physiological and chemical investigations to explain the after-ripening processes in got green pepper fruit were carried out by treating the fruit with ethephon either alone or with phenylalanine. The studied metabolic changes in fruit during after-ripening period was carbon dioxide and oxygen concentration in interior of the pepper fruit, total carotenoid, ${\beta}-carotene$, total sugar, and free reducing sugar in pepper fruit. These metabolic changes were explained inrelation to the color enhancement judged by the color score to explain the after-ripening processes. Ethephon treatment at 500 ppm significantly accelerated color enhancement as compared to the control and further ethephon treatment increased the number by 20 percent which was not possible in control during same after-ripening period. The oxygen concentration in interior of the pepper fruit during after-ripening period was increased in control when the color score (color enhancement) increased rapidly. However, with ethephon treatment, the oxygen concentration was decreased when the color score increased. Although total and free reducing sugar content were decreased during the after-ripening period total carotenoid and ${\beta}-carotene$ content was increased by 50 and 200 percent, respectively, over control. Also the capsaicin contents was increased by 20 percent by ethephon treatment over control. Although phenylalanine treatment did not affect the capsaicin content, capsaicin content tended to be increased by phenylalanine treatment when treated with ethephon. Acknowledgements: This work was supported by funds from Korean Traders Scholarship Foundation.

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Photosynthetic Responses of Populus alba×glandulosa to Elevated CO2 Concentration and Air Temperature (CO2 농도 및 기온 상승에 대한 현사시나무의 광합성 반응)

  • Lee, Solji;Oh, Chang-Young;Han, Sim-Hee;Kim, Ki Woo;Kim, Pan-Gi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.1
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    • pp.22-28
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    • 2014
  • This study was conducted to investigate the photosynthetic characters of Populus alba${\times}$glandulosa cuttings in response to elevated $CO_2$ concentration and air temperature for selecting tree species adaptive to climate change. The cuttings were grown in environment controlled growth chambers with two combinations of $CO_2$ concentration and air temperature conditions: (i) $22^{\circ}C$ + $CO_2$ 380 ${\mu}mol$ $mol^{-1}$ (control) and (ii) $27^{\circ}C$ + $CO_2$ 770 ${\mu}mol$ $mol^{-1}$ (elevated) for almost three months. The cuttings under the elevated treatment showed reduced tree height and photosynthetic pigment contents such as chlorophyll and carotenoid. In particular, the elevated treatment resulted in a marked reduction in the chlorophyll a closely associated with $CO_2$ fixative reaction system. Different levels of reduction in photosynthetic characters were found under the elevated treatment. A decrease was noted in photochemical reaction system parameters: net apparent quantum yield (7%) and photosynthetic electron transport rate (14%). Moreover, a significant reduction was obvious in $CO_2$ fixative reaction system parameters: carboxylation efficiency (52%) and ribulose-1,5-bisphosphate(RuBP) regeneration rate (24%). These results suggest that the low level of photosynthetic capacity may be attributed to the decreased $CO_2$ fixative reaction system rather than photochemical reaction system.

In vitro evaluation of nano zinc oxide (nZnO) on mitigation of gaseous emissions

  • Sarker, Niloy Chandra;Keomanivong, Faithe;Borhan, Md.;Rahman, Shafiqur;Swanson, Kendall
    • Journal of Animal Science and Technology
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    • v.60 no.11
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    • pp.27.1-27.8
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    • 2018
  • Background: Enteric methane ($CH_4$) accounts for about 70% of total $CH_4$ emissions from the ruminant animals. Researchers are exploring ways to mitigate enteric $CH_4$ emissions from ruminants. Recently, nano zinc oxide (nZnO) has shown potential in reducing $CH_4$ and hydrogen sulfide ($H_2S$) production from the liquid manure under anaerobic storage conditions. Four different levels of nZnO and two types of feed were mixed with rumen fluid to investigate the efficacy of nZnO in mitigating gaseous production. Methods: All experiments with four replicates were conducted in batches in 250 mL glass bottles paired with the ANKOM$^{RF}$ wireless gas production monitoring system. Gas production was monitored continuously for 72 h at a constant temperature of $39{\pm}1^{\circ}C$ in a water bath. Headspace gas samples were collected using gas-tight syringes from the Tedlar bags connected to the glass bottles and analyzed for greenhouse gases ($CH_4$ and carbon dioxide-$CO_2$) and $H_2S$ concentrations. $CH_4$ and $CO_2$ gas concentrations were analyzed using an SRI-8610 Gas Chromatograph and $H_2S$ concentrations were measured using a Jerome 631X meter. At the same time, substrate (i.e. mixed rumen fluid+ NP treatment+ feed composite) samples were collected from the glass bottles at the beginning and at the end of an experiment for bacterial counts, and volatile fatty acids (VFAs) analysis. Results: Compared to the control treatment the $H_2S$ and GHGs concentration reduction after 72 h of the tested nZnO levels varied between 4.89 to 53.65%. Additionally, 0.47 to 22.21% microbial population reduction was observed from the applied nZnO treatments. Application of nZnO at a rate of $1000{\mu}g\;g^{-1}$ have exhibited the highest amount of concentration reductions for all three gases and microbial population. Conclusion: Results suggest that both 500 and $1000{\mu}g\;g^{-1}$ nZnO application levels have the potential to reduce GHG and $H_2S$ concentrations.

Analysis of the Characteristics and High Concentrations of Carbon Dioxide Measured at the Gosan Site in Jeju, Korea in 2007 (2007년 제주 고산의 이산화탄소 농도 현황 및 고농도 사례 분석)

  • Kim, Seung-Yeon;Lee, Jae-Bum;Yu, Jeong-Ah;Hong, Yu-Deog;Song, Chang-Geun
    • Journal of Climate Change Research
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    • v.2 no.1
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    • pp.1-14
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    • 2011
  • In order to identify the current state of the $CO_2$ concentrations at the Gosan site in Jeju, the data from the Gosan station was compared with the ones from domestic and foreign sites registered in the World Data Centre for Greenhouse Gases(WDCGG). As a result, the $CO_2$ concentrations in the Asian region including Gosan site were higher than in the other continents, which can be explained that the $CO_2$ emissions in the Asian region have been rapidly increasing due to the recent economic growth. In comparison with ther Asian-Pacific sites (i.e., Ryori, Waliguan, and Mauna Loa), Gosan site showed the highest $CO_2$ concentrations because this site can be easily affected by China emissions. With the trajectory analysis and the ratios of air pollutants, we found that the high concentrations of Gosan site in January were mainly caused by the long-range transport from China, while in August the high concentration in the night time by the stagnation and the active plant respiration. Also, in May and November it occurred as the polluted air from China was transported with migratory cyclone.