• Title/Summary/Keyword: Carbon Source

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Evaluation of COD Solubilization and Reduction of Waste Activated Sludge by pH Control (pH 조절을 통한 폐활성 슬러지의 COD 가용화 및 감량화 평가)

  • Kim, Youn Kwon;Moon, Yong Taik;Kim, Ji Yeon;Seo, In Seok
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.5
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    • pp.551-558
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    • 2007
  • From the view point of biological wastewater treatment, C/N ratio is one of the most important factor in biological nutrient removal process. However, municipal sewage in Korea is characterized by extremely low content of carbon source and relatively higher portion of N source. Accordingly, it is necessary to dose external carbon source in order to obtain higher degree of carbon source within the process. In this study, the effects of pH pretreatment as an alternative plan for increasing carbon source on the cell disruption and COD solubility of waste activated sludge were conducted under well defined experimental conditions. During 5 hours, the value of COD solubilization rate ($S_R$) at pH 11.5 is approximately 4.4 times higher than the value of $S_R$ at pH 9.5. It is expected that the level of SCOD increased due to the result from cell disruption. However, VSS/TSS ratio was not significantly changed after 5 hours. As Alkalinity changes gradually from less than 15, 30 and 60 meq NaOH/L, average RBCOD/SCOD fraction showed 34, 36 and 45%,respectively.

Global Carbon Budget and Ocean Buffering against Rising Atmospheric CO2 Concentration

  • Kwon, O-Yul
    • Journal of Environmental Science International
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    • v.11 no.8
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    • pp.773-781
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    • 2002
  • The natural carbon cycle has been perturbed since the mid-19th century by anthropogenic CO$_2$emissions from fossil fuel combustion and deforestation due to population growth and industrialization. The current study simulated the global carbon cycle for the past 42 years using an eight-box carbon cycle model. The results showed that since the terrestrial biospheric carbon sink was roughly offset by the deforestation source, the fossil fuel emission source was partitioned between the atmospheric and oceanic sinks. However, the partitioning ratio between the atmosphere and the ocean exhibited a change, that is, the carbon accumulation rate was faster in the atmosphere than in the ocean, due to a decrease in the so-called ocean buffering capacity. It was found that the ocean buffering capacity to take up excess CO$_2$decreased by 50% in terms of the buffer factor over the past 42 years. Accordingly, these results indicate that if the current CO$_2$emission trend continues, the future rate of increase in the atmospheric CO$_2$concentration will accelerate.

Effect of Carbon Source and Carbon to Nitrogen Ratio on Carotenogenesis of Rhodotorula glutinis

  • Nam, Hee-Sop
    • Journal of Microbiology and Biotechnology
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    • v.1 no.1
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    • pp.75-78
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    • 1991
  • The carotenoid biosynthesis of a red oleaginous yeast, Rhodotorula glutinis was significantly changed when the yeast was grown on different carbon substrates. The highest carotenoid production was obtained on culture medium containing glucose when the carbon to nitrogen ratio (C/N ratio) was adjusted to 25.7. Galactose stimulated the biosynthetic rate of torularhodin, a xanthophyll component of the yeast. With decreasing C/N ratio of the medium, significant changes of $\gamma$-carotene and torularhodin were observed such that increase in the torularhodin concentration was nearly equal to the decrease in $\gamma$-carotene. It was speculated that the nature of carbon substrate affected the metabolic rate of the cell, and accompanied by the different pattern of carotenoid accumulation in the cell.

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Effect of Carbon Source on Porosity and Flexural Strength of Porous Self-Bonded Silicon Carbide Ceramics (탄소 원료가 다공질 Self-Bonded SiC (SBSC) 세라믹스의 기공율과 곡강도에 미치는 영향)

  • Lim, Kwang-Young;Kim, Young-Wook;Woo, Sang-Kuk;Han, In-Sub
    • Journal of the Korean Ceramic Society
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    • v.45 no.7
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    • pp.430-437
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    • 2008
  • Porous self-bonded silicon carbide (SBSC) ceramics were fabricated at temperatures ranging from 1700 to $1850^{\circ}C$ using SiC, silicon (Si), and three different carbon (C) sources, including carbon black, phenol resin, and xylene. The effects of the Si:C ratio and carbon source on porosity and strength were investigated as a function of sintering temperature. Porous SBSC ceramics fabricated from phenol resin showed higher porosity than the others. In contrast, porous SBSC ceramics fabricated from carbon black showed better strength than the others. Regardless of the carbon source, the porosity increased with decreasing the Si:C ratio whereas the strength increased with increasing the Si:C ratio.

Assimilation of Peptides and Amino Acids and Dissimilation of Lactate During Submerged Pure Cultures of Penicillium camembertii and Geotrichum candidum

  • Aziza, M.;Adour, L.;Amrane, A.
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.124-127
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    • 2008
  • The behavior of Penicillium camembertii and Geotrichum candidum growing in submerged pure cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and lactate as a second carbon source was examined. Similar to the behavior previously recorded on a simple substrate (glutamate), a clear differentiation between the carbon source and the energy source was also shown on peptones and lactate during P. camembertii growth, since throughout growth, lactate was only dissimilated, viz., used for energy supply by oxidation into $CO_2$, whereas peptides and amino acids from peptones were used for carbon (and nitrogen) assimilation. Because of its deaminating activity, G candidum preferred peptides and amino acids to lactate as energy sources, in addition to being assimilated as carbon and nitrogen sources. From this, on peptones and lactate, G candidum grew faster than P. camembertii (0.19 and 0.08 g/l/h, respectively) by assimilating the most readily utilizable peptides and amino acids; however, owing to its lower proteolytic activity, the maximum biomass was lower than that of P. camembertii (3.7 and 5.5 g/l, respectively), for which continuous proteolysis and assimilation of peptides were shown.

Effect of Inoculum and Carbon Sources Difference on Characteristics of Anaerobic Digestion (접종원 및 탄소원의 차이가 혐기소화 특성에 미치는 영향)

  • Choi, Yong Jun;Ryu, Jeong Won;Lee, Sang Rak
    • Journal of Korea Society of Waste Management
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    • v.34 no.5
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    • pp.474-481
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    • 2017
  • This study was conducted to investigate the effects of inoculum and carbon sources on anaerobic digestion characteristics. The treatments were combinations of inoculum (digestate of cattle manure and rumen fluid) with carbon sources (starch, cellulose, and xylan). Anaerobic digestion was performed in triplicate at $37^{\circ}C$ for 18 days at 100 rpm. Sampling was performed at 0, 1, 2, 3, 4, 5, 7, 9, 12, 15, and 18 days to measure pH, ammonia-N, volatile solids reduction, the cumulative methane content, and the cumulative methane production. There was a significant difference in methane content depending on the carbon source and there was a significant difference in pH, ammonia-N, methane production, and methane content depending on the inoculum (P < 0.05). The results of methane production were higher in the digestate of cattle manure treatment than in the rumen fluid treatment (P < 0.05). In this study, different digestive patterns depending on the type of carbon source could be used as basic research data to set the hydraulic residence time of anaerobic digestion facilities. In addition, the use of ruminal fluid as an inoculum may help accelerate the hydrolysis and acid production steps.

Carbon Source-Dependent Regulation of the Schizosaccharomyces pombe pbh1 Gene

  • Kim, Su-Jung;Cho, Nam-Chul;Ryu, In-Wang;Kim, Kyung-Hoon;Park, Eun-Hee;Lim, Chang-Jin
    • Journal of Microbiology
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    • v.44 no.6
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    • pp.689-693
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    • 2006
  • Pbh1, from the fission yeast Schizosaccharomyces pombe, is a baculoviral inhibitor of apoptosis (IAP) repeat (BIR) domain-containing protein. Its unique encoding gene was previously found to be regulated by nitric oxide and nitrogen starvation. In the current work, the Pbh1-lacZ fusion gene was used to elucidate the transcriptional regulation of the pbh1 gene under various carbon sources. When fermentable carbon sources, such as glucose (at a low concentration of 0.2 %), sucrose (2.0 %) and lactose (2.0 %), were the sole carbon source, the synthesis of $\beta$-galactosidase from the Pbh1-lacZ fusion gene was reasonably enhanced. However, the induction by these fermentable carbon sources was abolished in the Pap1-negative S. pombe cells, implying that this type of induction of the pbh1 gene is mediated by Pap1. Ethanol (2.0%), a nonfermentable carbon source, was also able to enhance the synthesis of $\beta$-galactosidase from the fusion gene in wild-type cells but not in Pap1-negative cells. The results indicate that the S. pombe pbh1 gene is up-regulated under metabolic oxidative stress in a Pap1-dependent manner.

Carbon-Nanotube FED;Japanese National Project

  • Soichiro, Okuda
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.855-859
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    • 2004
  • The Japanese National Project "Carbon Nanotube FED" is developing a high image-quality and low power-consumption field emission display (FED) by applying carbon nanotube (CNT) to the electron source. A uniform electron source with a flat-film CNTs and fine structure triodes Fir suppressing the deviation of emission is required. For realizing an FED panel, it is also necessary to develop the glass-bulb technologies for vacuum sealing, and display technologies for driving the panel by circuit electronic and for evaluating the picture quality by measuring. By achieving these technologies, an FED compatible with conventional Cathode Ray Tubes (CRTs) will be realized.

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A Fundamental Study on the Construction Scenario for Prediction of Carbon Emissions in Construction Site (건설현장 시공과정의 탄소배출량 예측 시나리오 구축에 관한 연구)

  • Lee, Chung-Won;Lim, Hyo-Jin;Tae, Sung-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.247-248
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    • 2023
  • As carbon neutrality becomes an issue around the world, research is actively being conducted to achieve reduction targets for each industry by declaring 2050 carbon neutrality in Korea and implementing the greenhouse gas target management system and emission trading system. The construction industry quantitatively predicts and evaluates carbon emissions by stages through the evaluation of the entire building process, but research on this is insufficient in the case of the construction process. Therefore, as part of the research on predicting and reducing carbon emissions generated at construction sites, data from actual construction sites were collected to analyze the facilities and characteristics of each energy source, and a scenario was proposed to quantitatively predict the use of each energy source.

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