• Journal of Environmental Science International
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• v.21 no.3
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• pp.383-390
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• 2012

For the cost-effective biological nitrogen removal (BNR) process whose characteristics of influent have low COD/N ratios, the automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in an anoxic reactor has been developed. In this study, it was carried out with a pilot-scale Bardenpho process which was consisted of anoxic 1, aerobic 1, aerobic 2, anoxic 2, aerobic 3 tank and clarifier. Firstly, the correlation coefficient ($R^2$) of the dosage of external carbon source and ORP value was about 0.97. Consequently, the automatic control system using ORP showed that the dosage of external carbon source was decreased by about 20% compared with a stable dosage of 75 mg/L based on the COD/N ratio of the anoxic influent.

• Journal of Power System Engineering
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• v.7 no.4
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• pp.31-37
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• 2003

This paper is a study on application of warm air circulator by using the carbon heating element with particle type. The main variables are the input current and amount of carbon heating source for experimental characteristics. The experimental results are obtained as follows. As the input current and temperature are increased, the resistance of heat source is decreased about $20{\sim}25%$ by the effect of negative resistance. As the amount of heating source is small, Joule heat is large with the input current. When the amount of heating source is 300 and the input current is 15A, the value of Joule heat is about 4604.6kJ/h. The heat production efficiency of carbon heating source is larger about 10% than the sheath heater.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.208-211
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• 2003

The dielectric carbon nitride thin films were deposited onto Si(100) using a pulsed laser ablation of pure graphite target combined with a high voltage discharge plasma in nitrogen gas atmosphere. We can be calculated dielectric constant, ${\varepsilon}_s$, with a capacitance Sobering bridge method. We reported to investigate the influence of the laser ablation of graphite target and DC high voltage source for the plasma. The properties of the deposited carbon nitride thin films were influenced by the high voltage source during the film growth. Deposition rate of carbon nitride films were found to increase drastically with the increase of high voltage source. Infrared absorption clearly shows the existence of C=N bonds and $C{\equiv}N$ bonds. The carbon nitride thin films were observed crystalline phase, as confirmed by x-ray diffraction data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.7
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• pp.641-646
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• 2003

The dielectric carbon nitride thin films were deposited onto Si(100) substrate using a pulsed laser ablation of pure graphite target combined with a high voltage discharge plasma in the presence of a N$_2$ reactive gas. We calculated dielectric constant, $\varepsilon$$\_$s/, with a capacitance Schering bridge method. We investigated the influence of the laser ablation of graphite target and DC high voltage source for the plasma. The properties of the deposited carbon nitride thin films were influenced by the high voltage source during the film growth. Deposition rate of carbon nitride films were increased drastically with the increase of high voltage source. Infrared absorption clearly shows the existence of C=N bonds and C=N bonds. The carbon nitride thin films were observed crystalline phase confirmed by x-ray diffraction data.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.532-539
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• 2004

For efficient lincomycin production from Streptomyces lincolnensis L1245, various vegetable oils, natural nitrogen sources, and surfactants were investigated at the pilot-scale level in the flask. Olive oil as the sole carbon source was the most suitable one for producing lincomycin. When 20 g/lof olive oil was used, the lincomycin concentration and lipase activity reached 1.01 g/land 182 U/ml, respectively, after 5 days of culture. Among the various unsaturated fatty acids, when linolenic acid was used, the cell growth and lincomycin production were markedly decreased. On the other hand, when 0.2 g/l of oleic acid was added to the culture broth, the maximum lincomycin concentration was 1.0 g/l, which was about 1.7-fold higher than that obtained without the addition of oleic acid. Among the various natural nitrogen sources, pharmamedia or soybean meal was the most suitable nitrogen source. In particular, in the case of a mixture of 10 g/l of pharmamedia and soybean meal, 1.5 g/l of lincomycin concentration and 220 U/ml of lipase activity were obtained. When Span 180 was used as the surfactant, lincomycin production, lipase activity, and oil consumption increased. The correlation between the consumption rates of oil and lincomycin production in a culture using olive oil as the sole carbon source was also investigated. The lincomycin production depended on the consumption rate of olive oil. Using these results, fed-batch cultures for comparing the use of olive oil and starch as a conventional carbon source were carried out in a 5-1 fermentor. When olive oil was used as the sole carbon source, 34 g/l of olive oil was consumed after 7 days of culture. The maximum lincomycin concentration was 3.0 g/l, which was about 2.0-fold higher than that of starch medium after 7 days of culture. The product yield was 0.09 gig of consumed carbon source, which was about 3.0-fold higher than that of starch medium after 7 days of culture.

• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.56-65
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• 2014

Contamination of explosive compounds in the soils of military shooting range may pose risks to human and ecosystems. As shooting ranges are located at remote places, active remediation processes with hardwares and equipments are less practical to implement than natural solutions such as bioremediaton. In this study, a series of experiments was conducted to select a suitable carbon source and to optimize dosing rate for the enhanced bioremediation of explosive compounds in surface soils and sediments of shooting ranges with indigenous microorganisms activated by external carbon source. Treatability study using slurry phase reactors showed that the presence of indigenous microbial community capable of explosive compounds degradation in the shooting range soils, and starch was a more effective carbon source than glucose and acetic acid in the removal of TNT. However, at higher starch/soil ratio, i.e., 2.0, the acute toxicity of the liquid phase increased possibly due to transformation products of TNT. RDX degradation by indigenous microorganisms was also stimulated by the addition of starch but the acute toxicity of the liquid phase decreased with the increase of starch/soil ratio. Taken together, the optimum range of starch/soil ratio for the degradation of explosive compounds without significant increase in acute toxicity was found to be 0.2 of starch/soil.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.25-30
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• 2006

This paper represents the numerical analysis in unsteady state on the variation of diameter and environmental velocity of carbon heating source. In general heating system, the oil and sheath heater is widely used, but these systems have many problems. So, the heating source with carbon ingredient has been researched in many country about manufacture, thermal and electrical properties. In this research, the carbon heating source was studied through numerical analysis on several conditions of unsteady state, heat generation, diameter and environmental velocity. The temperature distributions at steady state are appeared as a non-proportional linear pattern with variations of environmental velocity due to the Nesselt number with convective heat flux is proportioned to 0.805 of Reynolds number. As the radius is increasing, the temperature distributions is appeared the minus tilt because of the environmental condition is cooling by constant temperature. So, the correlation equation between temperature at steady state and environmental velocity was obtained.

• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.1-3
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• 2002

This study was to evaluate on the removal efficiencies of total nitrogen and phosphorus in municipal wastewater at MUNR process using sludge carbon source for environmental micro-organism. The removal efficiencies of total suspended solid were 85.9~91％, total nitrogen were 38.6~87.2％ and total phosphorus were 30.8~39.0％, respectively. It was shown that removal efficiency of nitrogen was effectively influenced by sludge carbon source treated with ultrasonication. The removal efficiency of total phosphorus was low because the sludge was not wasted during this treatment.

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.93-97
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• 2002

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus with municipal wastewater in ultrasonic nutrient removal (UNR) process using ultrasonic sludge carbon source. The removal efficiency for total nitrogen was 44.2% at biological nutrient removal (BNR) process, 50.8% at UNR process. The removal efficiency for total phosphorus was 45.6% at BNR process, 46.2% at UNR process. The removal of nitrogen was effectively influenced by ultrasonic sludge carbon source.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.381-386
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• 2007

A porous reaction bonded silicon carbide (RBSC) was fabricated by a molten Si infiltration method. The porosity and flexural strength of porous RBSC fabricated in this study were dependent upon the amount of carbon source used in the SiC/carbon preform as well as the amount of Si infiltrated into the SiC/carbon preform. The porosity and flexural strength of porous RBSC were in the range of $20 vo1.{\sim}49 vo1.%$ and $38{\sim}61 MPa$, respectively. With increase of carbon contents and molten Si for infiltration, volume fraction of the pores was gradually decreased, and flexural strength was increased. The porous RBSCs fabricated with the same amount of molten Si show less residual Si around neck with increase of carbon source, as well as a new SiC was formed around neck which resulted in the decreased porosity and improvement of the flexural strength. In addition, decrease of the porosity and increase of the flexural strength were also obtained by increase of the amount of molten Si with the same amount of carbon source. However, it was found that the flexural strength of porous RBSC depends on the porosity rather than the amount of the newly formed SiC in neck phase between SiC particles used as a starting material.