• 한국환경과학회지
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• 제29권7호
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• pp.691-702
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• 2020

Carbon biomass of plankton community, Total Organic Carbon (TOC) and Chlorophyll a (chl.a) concentration were examined in the SeoNakdong river from January to December in 2014, to assess composition of phyto- and zoo-plankton variation, to certify the correlation between chl.a and TOC and to determine the level of contribution of plankton carbon content to TOC in the reservoir-river ecosystem. The correlation level between TOC and chl.a was low in the year 2014 but exceptionally was highly correlated only during the period with cyanobacterial bloom. The high level of contribution of plankton carbon content to TOC was attributed to cyanobacterial carbon biomass from May to November and to Cladocera carbon biomass from March to May, November and December despite of its low abundance. These results suggest that there were inter-relationships between phytoplankton, zooplankton and TOC and also subtle consistency of their properties through the year. These patterns should be discussed in relation to the physiochemical and biological characteristics of the environment, as well as to allochthonous organic matters from non-point pollution sources.

• 한국토양비료학회지
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• 제39권6호
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• pp.396-402
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• 2006

토양 유기탄소는 토양의 질 및 토양 비옥도의 평가 또는 시비량의 결정 등에 주요한 요인으로 고려되어 왔으며 온실가스의 방출 및 지구 온난화에 영향을 주고 있다. 따라서 토양 유기탄소의 적절한 관리는 토양의 질을 향상시키는 것뿐만 아니라 온실가스원을 관리하는 차원에서 중요성이 더욱 강조되고 있다. 이 연구의 목적은 압력센서를 이용한 무기탄소 측정 장치를 이용하여 토양중 무기탄소량을 측정하고 건식연소법과 습식연소법을 이용하여 석회암에서 유래된 토양의 유기탄소을 분석 비교 하고자 하였다. 건식연소법으로 측정된 총탄소의 값에서 무기탄소 측정장치를 통해 얻어진 무기탄소값을 뺀 값을 유기탄소량으로 계산하였다. 탄산석회 ($CaCO_3$)를 이용한 무기탄소 표준시료의 양과 개발된 무기탄소 측정장치 출력 값 간에 매우 유의한 직선의 관계가 얻어졌다. 충청북도 및 강원도 일대 석회암 지역에서 채취한 토양시료를 이용하여 건식연소법과 무기탄소 분석 장치를 이용하여 탄소함량을 분석한 결과 총 탄소 중량대비 약 22-28%의 무기탄소가 관측되었다. 습식연소법과 건식연소법으로 측정한 토양의 유기탄소간에 유의한 상관관계를 나타냈다. 결론적으로 개발된 토양무기탄소 분석장치는 토양 중 무기탄소의 간편한 측정을 통하여 석회암등에서 유래된 토양의 유기탄소를 효과적으로 분석하는데 기여할 수 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권4호
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• pp.11-19
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• 2019

This paper examines an assessment method for terminating the post-closure maintenance of a landfill using a simplified landfill gas model. The case study site is the Sudokwon Landfill in Incheon city, which was closed in 2000. The deviations of the results obtained by the regular model and the simplified model were both slightly over 10% from the measured data. Also, the deviation of the simplified model from the regular model has been less than 5% since 2005. Thus, the simplified model could be applied to other landfills that have been closed for at least 5 years. Additionally, the results of the mass balance analysis using the simplified landfill gas model indicated that 39% of the organic carbon was discharged, leading to organic carbon and organic matter content of 7.2 and 17.6%, respectively, in the landfill by the end of 2018.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.174-178
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• 1998

Blowout of NR and SBR vulcanizates was studied using a microwave oven. Rubber vulcanizates with different contents of carbon black (0, 30, 50, 70 phr) and various cure systems (conventional, semi-EV, and EV) were prepared. Unfilled rubber vulcanizates did not exploded by irradiation of microwave, while carbon black-filled ones exploded within 10 min. A blowout time of the carbon black-filled rubber vulcanizate decreases with an increase of the content of carbon black in the vulcanizate. A blowout temperature of the organic additive-extracted vulcanizate is higher than that of the not-extracted one, but the extracted vulcanizate blows out faster than the not-extracted one. A blowout temperature of the overcured vulcanizate is higher than that of the undercured one with the same cure system. Temperatures of unfilled SBR vulcanizates heated by the microwave irradiation are lower than those of unfilled NR ones. The carbon black-filled SBR vulcanizates blow out at higher temperatures than the carbon black-filled NR ones. Blowout times of the carbon black-filled SBR vulcanizates are longer than those of the carbon black-filled NR ones.

• 한국해양바이오학회지
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• 제6권2호
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• pp.68-75
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• 2014

This study investigated the potential use of various organic carbon sources (glucose, glycerol and acetate) and different concentrations of $CO_2$ for culturing marine microalga Dunaliella tertiolecta. Cell growth and lipid production were monitored under heterotrophic, mixotrophic and photoautotrophic modes of cultivation. D. tertiolecta showed the ability to grow under mixotrophic (acetate and glucose), heterotrophic (glucose) and photoautotrophic condition under high $CO_2$ concentration (15%). With all the organic carbon sources (glucose, glycerol and acetate) tested in this study, 1~5% acetate enhanced cell growth rate and lipid content, while higher concentrations of acetate (10% and 15%) were inhibitory and resulted in cell death.

• Carbon letters
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• 제16권1호
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• pp.51-56
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• 2015

Carbonate-type organic electrolytes were prepared using propylene carbonate (PC) and dimethyl carbonate (DMC) as a solvent, quaternary ammonium salts, and by adding different contents of 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMImBF_4$). Cyclic voltammetry and linear sweep voltammetry were performed to analyze conducting behaviors. The surface characterizations were analyzed by scanning electron microscopy method and X-ray photoelectron spectroscopy. From the experimental results, increasing the $EMImBF_4$ content increased the ionic conductivity and reduced bulk resistance and interfacial resistance. In particular, after adding 15 vol% $EMImBF_4$ in 0.2 M $SBPBF_4$ PC/DMC electrolyte, the organic electrolyte showed superior capacitance and interfacial resistance. However, when $EMImBF_4$ content exceeded 15 vol%, the capacitance was saturated and the voltage range decreased.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.268-272
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• 2002

Kinetic experiments on the biological oxidation of $Fe^{2＋}$ by Acidithiobacillus ferrooxidans were conducted by measuring the total organic carbon content. The total organic carbon in the solution was determined with different initial concentrations of $Fe^{2＋}$(4, 9, 15, and 20 mg/ml). The growth of At. ferrooxidans and substrate utilization were described by the Monod expression. The total organic carbon was found to be an indicator of the biomass concentration and thus may be effectively utilized for estimating cell growth rates in kinetic model development.

• Journal of the korean society of oceanography
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• 제34권3호
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• pp.144-150
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• 1999

Slope sedimentation on the modern west Florida continental margin is controlled by pelagic carbonate accumulation and off-shelf sedimentation of neritic carbonates and terrigenous fines. Production and deposition of pelagic carbonates by planktonic foraminifera and coccoliths have played a significant role in the total slope sedimentation and are mainly promoted by sea-surface productivity. Organic carbon data reflect the relatively high biological productivity in surface waters, indicating high accumulation of biogenic calcareous sediments. The surface-water productivity in the study area is supported by the relation among microfossil assemblages, carbonate mineralogy and sedimentary organic carbon.

• 환경영향평가
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• 제8권2호
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• pp.95-107
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• 1999

The organic contents of reservoir sediment can offer a good indicator to events in history of lake life. Reservoir sediment have many information of the past and future fingerprint about development direction of life cycle in biological animals. So, in this study we made an effort to know the distribution of organic contents in Daecheong reservoir sediment. Items for this investigations are such as follows: Loss on ignition, COD, Organic carbon, TN, TP, heavy metal contents, Loss on ignitions were determined in 6.44~15.91% and COD were determined in 1.606~6.859%, organic carbon in 1,077~3.743%. Contents of TP and TN were in the range of 0.083~0.757%, and 0.645~0.926%, respectively.

• 한국해양학회지:바다
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• 제28권4호
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• pp.158-177
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• 2023

하구역은 강과 하천을 통해 육상과 해양을 연결하는 전이수역으로 해양으로 공급되는 많은 물질들은 연안환경의 일차 생산성을 결정하는 중요한 역할을 담당하며, 이러한 연안생태계는 생물량에 의해 제거되는 탄소인 블루카본의 탄소 저장소로서 기후변화를 완화시키는 역할을 한다. 우리나라의 서-남해 하구역(한강, 금강, 영산강, 섬진강, 낙동강)과 동해 용승해역에서 지난 6년간 표층퇴적물의 평균입도와 유기탄소 함량의 변화와 두 인자들 사이의 상관관계를 분석하였다. 조사기간(2015-2020년) 동안 서-남해 하구역과 동해 용승해역 표층퇴적물의 평균입도와 유기탄소 함량은 계절적 변화가 관찰되지 않았으며, 전반적으로 각 해역의 다양한 해양환경 및 수리역학적 조건에 의해 두 인자들이 조절되는 것으로 해석된다. 조사된 모든 시료채취의 동시성이 없는 문제점에도 불구하고 연구지역에서 분석된 모든 퇴적물 평균입도들의 평균값과 유기탄소 함량의 평균값은 양의 상관관계를 보이며 각 하구역과 동해 용승해역을 구분한다. 동일한 양의 상관관계를 보이는 각 하구역에서는 아마도 같은 과정에 의한 퇴적물 점토입자의 퇴적이 유기탄소 축적에 중요한 역할을 담당한다. 그러나 동해 용승해역은 하구역과 다르게 추가적인 유기탄소 축적의 요인이 나타난다. 국내 주요 하구역들이 연안환경에서 중요한 탄소저장소로서 평가되기 위해서는 탄소 저장량 계산을 위한 추가적인 자료(퇴적률, 전밀도 등)가 요구된다.