• Korean Journal of Microbiology
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• v.55 no.1
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• pp.83-85
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• 2019

Pseudomonas sp. PAMC 29040 was isolated from a maritime tundra soil in Antarctica for its ability to degrade lignin and subsequently confirmed to be able to depolymerize heterogeneous humic substance (HS), a main component of soil organic matter. The draft genome sequences of PAMC 29040 were analyzed to discover the putative genes for depolymerization of polymeric HS (e.g., dye-decolorizing peroxidase) and catabolic degradation of HS-derived small aromatics (e.g., vanillate O-demethylase). The information on degradative genes will be used to finally propose the HS degradation pathway(s) of soil bacteria inhabiting cold environments.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.05a
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• pp.137-138
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.91-91
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• 2004

유압시스템은 1795년 J. Bramah가 물을 작동유체로 사용한 Press를 개발해 사용한 이래 2세기 이상 인간생활의 다양한 분야에 이용되어 왔다. 초기 유압시스템은 쉽게 구할 수 있고, 저장이 용이한 물을 작동유체로 사용하였다. 그러나 물은 부식성, 낮은 점성계수로 인한 저 윤활성과 많은 누설량, 그리고 저온에서의 동결 등과 같은 문제점을 가졌다. 당시에는 물에 대한 부식성이 없는 재료나 물의 누설을 막을 수 있을 만큼의 가공기술이 부족하였으므로 이러한 물의 문제점을 해결하기 위해 1906년 Wiliams와 Janney가 물 대신 기름을 작동유체로 사용하기 시작했다.(중략)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.600-610
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• 1995

When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.8-14
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• 2017

Due to the financial crisis in 2008, the world economy collapsed leading to an increase in oil prices and a decrease in freight by shipping. To overcome this crisis, major shipping companies ordered larger ships, changed their trading route and improved operating of ships to overcome deficits. In particular, low-speed navigation was much favored by many companies so that it can reduce fuel consumption. However, the long-term operation of high-speed optimized engines in low-speeds has affected the jacket cooling fresh water (J.C.F.W.) system as they fail to maintain the normal operational temperature. The temperature of J.C.F.W. system dropped leading to low temperature corrosion. As a result, when the engine is operating at minimal load the functioning of existing J.C.F.W cooler is decreased and the use of fresh water generator is substantially limited. Therefore, an improvement in the functioning of J.C.F.W. system is necessary. In this paper, in order to review the improvements required for the operation of J.C.F.W. of low-speed operating marine diesel, an experiment was conducted by comparing and analyzing the results of the main engine J.C.F.W. system of a Panamax class bulk carrier 82k and a Cape class bulk carrier 180k by installing and uninstalling the J.C.F.W. Cooler. Thus, this paper proposed an improved design of the J.C.F.W. system that is suitable for the present low-speed operation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.407-414
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• 2017

In this study, a performance evaluation was conducted using a SUS 304 plate applied to low-temperature co-fired coating as a replacement for titanium plates. As a result of computational fluid dynamic analysis, the SUS 304 plate, applied to low-temperature co-fired coating, showed better heat transfer performance than a titanium plate, for 100 micron thickness coating. The result of the experiments using an actual heat exchanger revealed that a coated SUS 304 plate showed better heat transfer performance than a titanium plate. Furthermore, as the degree of corrosion and scale formation of the plate was confirmed through an overhaul inspection, the corrosion resistance of a coated SUS 304 plate was found to be almost the same as that of a titanium plate, and the inhibition effect of scale formation by sea water was better with a coated SUS 304 plate.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.85-90
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• 2006

The purpose of this research is to design an imitation boiler similar to the waste heat boiler installed on a plasma melting furnace in order to acquire a capability of a thermal design as to the circulation of heat and the discharge of noxious gas inside a boiler and to improve the efficiency of a waste heat boiler using the CFD (Computation Fluid Dynamics) program. The position of corrosion and the generation of a clinker inside a boiler due to temperature changes, combustion gas flows, and corrosive gases inside a boiler are examined to design the structure of an efficient boiler and recycle energy. As a result of this research, the boiler installed on a plasma melting furnace met the conditions of design by cooling the combustion gases discharged after the second combustion from an exhaust port, originally at 1,200 degrees Celsius, down to around 450 degrees Celsius. On the other hand, the circulation of corrosive gases (SOx and HCL) may lead to the generation of corrosion or a clinker in the upper and lower parts of an exhaust port more easily than any other parts of a boiler. Accordingly, the corrosion on the inside and outside walls of a boiler may result in a shortened lifespan of a boiler and an inability to recycle waste heat in an efficient manner. A prevention against corrosion at high and low temperatures needs to be considered in detail.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.378-387
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• 2017

To stabilize the supply of kimchi by extending the storage period of spring kimchi cabbage, this study manufactured kimchi from spring kimchi cabbage under varying storage conditions and periods, and analyzed their quality and sensory characteristics following the maturing period. Trimming loss was lowest in the group of plasma+reverse direction+predrying+HDPE film processing. The salting yield of spring kimchi cabbage stored for 12 weeks was lower than that of spring kimchi cabbage stored for 6 weeks, and the kimchi yield was low in the pre-treatment group of spring kimchi cabbage stored for 12 weeks. The firmness was slightly different according to the storage period from one month of maturation. From the perspective of pH and acidity, the maturation in the reverse direction+pre-drying+HDPE film processing group was slower than that in the normal group (<0.05). In the sensory evaluation, the preference was increased in the low temperature storage processing group as the maturation period was increased (<0.05).

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.167-170
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• 1996

석탄의 고압 유동층연소는 기존의 PC 보일러보다는 저온 연소로써 NOx의 발생이 억제되며 탈황제를 동시에 주입하여 SOx 발생을 줄일 수 있는 것이 큰 잇점으로서 석탄 신에너지 개발에 유력한 시스템이다. 본 시스템에서 집진은 연소가스 중의 입자가 고온고압에서 고속으로 터빈에서 충돌될 때 일어나는 터빈의 마모, 침식, 및 부식 등을 방지하기 위하여 필수적이다. PFBC 연소기에서 연소된 가스가 정제후에 바로 가스터빈에 주입되기 때문에 PFBC의 집진은 매우 가혹한 조건이다. 뿐만 아니라 차세대에 더욱 높은 열효율 향상과 가스터빈의 수명 연장을 위하여 집진조건이 더욱 가혹해지고 엄격해질 전망이다. 그 동안 PFBC 집진의 연구가 다방면으로 진행되고 있으나 상용화를 위한 준비가 아직 갖추어지지 않았으며 모든 집진 시스템이 잠정적인 문제점을 갖고 있다. 그 중에서도 세라믹 캔들 필터는 성능이 우수하고 가장 많은 운전경험을 갖고 있기 때문에 가장 가까운 시기에 상용화에 성공할 수 있는 집진 시스템이다. 본 고에서는 세라믹 캔들필터 개발의 현황과 핵심 개발과제에 대하여 논의코자 했다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.155-156
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• 2013

본 연구는 사용후핵연료 수송 저장 용기인 저합금강(SA350 LF3)에 일정의 감마선을 조사하고 감마선 조사 전후 물성 및 내식 특성 변화와 표면처리에 의한 내식성 개선 효과에 관하여 연구하였다. 상온 항복강도 및 인장강도의 기계적 물성은 감마선 조사 여부에 따라 물성의 차이는 보이지 않았지만, 저온충격 특성은 감마선 조사를 하지 않은 충격 흡수에너지에 비교하여 조사후 시험편의 충격 흡수 에너지가 감소되었다. 양분극 곡선에 측정에 의해 관찰된 저합금강의 내식성은 감마선 조사된 시험편에서 감마선을 조사하지 않은 시험편 보다 낮은 부식전위를 나타내었다.