• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.588-597
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• 2016

In this study, we attempted to improve the biogas production efficiency by varying the mixing ratio of the mixed sludge of organic wastes in the improved single-phase anaerobic digestion process. The types of organic waste used in this study were raw sewage sludge, food wastewater leachate and livestock excretions. The biomethane potential was determined through the BMP test. The results showed that the biomethane potential of the livestock excretions was the highest at $1.55m^3CN4/kgVS$, and that the highest value of the composite sample, containing primary sludge, food waste leachate and livestock excretions at proportions of 50%, 30% and 20% respectively) was $0.43m^3CN4/kgVS$. On the other hand, the optimal mixture ratio of composite sludge in the demonstration plant was 68.5 (raw sludge) : 18.0 (food waste leachate) : 13.5 (livestock excretions), which was a somewhat different result from that obtained in the BMP test. This difference was attributed to the changes in the composite sludge properties and digester operating conditions, such as the retention time. The amount of biogas produced in the single-phase anaerobic digestion process was $2,514m^3/d$ with a methane content of 62.8%. Considering the value of $2,319m^3/d$ of biogas produced as its design capacity, it was considered that this process demonstrated the maximum capacity. Also, through this study, it was shown that, in the case of the anaerobic digestion process, the two-phase digestion process is better in terms of its stable tank operation and high efficiency, whereas the existing single-phase digestion process allows for the improvement of the digestion efficiency and performance.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.341-345
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• 2009

Continuous dry anaerobic digestion of organic solid wastes (30% TS, Total Solids) comprised of food waste and paper was performed under mesophilic condition. During the operation, hydraulic retention time (HRT) was decreased as follows: 150 d, 100 d, 60 d, and 40 d, which corresponded to the solid loading rate of 2.0, 3.0, 5.0, and 7.5 kg TS/$m^3$/d, respectively. Volumetric biogas production rate ($m^3$/$m^3$/d) increased as HRT decreased, and the highest biogas production rate of 3.49${\pm}$0.31 $m^3$/$m^3$/d was achieved at 40 d of HRT. At this HRT, high volatile solids (VS) reduction of 76% was maintained, and methane production yield of 0.25 $m^3$/kg $TS_{added}$ was achieved, indicating 67.4% conversion of organic solid waste to bioenergy. The highest biogas production yield of 0.52 $m^3$/kg $TS_{added}$ was achieved at 100 d of HRT, but it did not change much with respect to HRT. For the ease feed pumping, some amount of digester sludge was recycled and mixed with fresh feed to decrease the solid content. Recirculation volume of 5Q was found to be the optimal in this experimental condition. Specific methanogenic activity (SMA) of microorganisms at mesophilic-dry condition was 2.66, 1.94, and 1.20 mL $CH_4$/g VS/d using acetate, butyrate, and propionate as a substrate, respectively.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2008.04a
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• pp.113-116
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• 2008

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.93-98
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• 1998

도시생활용수 및 공업용수의 급격한 수요증가 때문에, 이로 인해서 발생되는 배수와 폐수에 의한 수질오염은 큰 사회문제고 대두되었으며 시급히 해결해야 하는 할 과제이다. 따라서 처리방법은 활성탄 흡착, 오존산화, 약품침전, 이온교환, 전기투석, 역침투 및 포말분리등 여러가지의 방법을 선택할 수 있으나 그 처리방법은 궁극적으로 폐수의 성상과 장치의 효율에 따라 결정될 수밖에 없다. (중략)

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.34-38
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• 2007

The experiment was done to investigate extinguishing concentrations of different inert gases of verying concentrations made in contact with Kerosene. The experimental results obtained are as follows; at a standard amount of air flow was 40L/min, the extinguishing concentration of Argon, Nitrogen, Carbon dioxide and Helium for Kerosene were 36.5%, 27.3%, 17.4%, 12.3%, respectively. And, according to these results, Helium of 12.3% showed the lowest extinguishing concentration.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2002.11a
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• pp.60-67
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• 2002

• Electric Engineers Magazine
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• v.182 no.10
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• pp.31-38
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• 1997

최근 전선 및 케이블은 전력, 정보의 전달 경로로서 그 중요도를 더해가고 있으며 만일 이러한 케이블이 어떠한 원인으로 착화, 연소하는 경우 절연재, 피복재는 발열량이 많을 뿐 아니라 진한 연기와 유독 가스가 발생하고 피난, 유도, 소화할동 등이 곤란해지며 많은 인명이나 중요한 기기에 큰 손해를 초래하게 된다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2000.11a
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• pp.34-38
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• 2000

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.11a
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• pp.135-136
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• 2007

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.126-131
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• 2003