• Animal Systematics, Evolution and Diversity
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• v.29 no.4
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• pp.308-311
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• 2013

A sea urchin was collected from Geomundo Island of Jeollanam-do, Korea on July 3, 2009. This specimen was classified as Spatangus luetkeni A. Agassiz 1872 belonging to the family Spatangidae of order Spatangoida based on the morphological characteristics. This genus and species are newly recorded in Korea. It is distinct morphological characters that test is thick and strong, six to eight primary tubercles are in 1 and 4 interambulacra, sternum is equipped with little keel, and color in alcohol is dark violet. This species inhabits tropical waters and usually distributes over the West Pacific from southern Japan to New Zealand.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.129-132
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• 2014

A study on laminar coflow jet flames diluted with helium and nitrogen has been conducted to investigate self-excitations. The stability map was provided with a function of nozzle exit velocity and fuel mole fractions of propane or methane. The results show that there exist three types of self-excitations; (1) buoyancy-driven self-excitation (BDSE), (2) Lewis number induced self-excitation coupled with buoyancy (LCB) and (3) Lewis number induced self-excitation (LISE).

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.367-369
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• 2014

A study on laminar coflow jet flames diluted with helium and nitrogen has been conducted to investigate self-excitations. The stability map was provided with a function of nozzle exit velocity and fuel mole fractions of propane or methane. The results show that there exist three types of self-excitations; (1) buoyancy-driven self-excitation (BDSE), (2) Lewis number induced self-excitation coupled with buoyancy (LCB) and (3) Lewis number induced self-excitation (LISE).

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.502-508
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• 2005

Fouling causes serious maintenance problems on heat exchanger tubes and process facilities. To avoid such fouling problems, numerous efforts have been tried. e.g., diagnosis of fouling, reducing and eliminating the fouling. etc.. The objective of the present study is to develop an innovative diagnostic system of fouling, which can detect the scaling attached to the wall non-homogeneously. The performance of the diagnostic system has been evaluated with a scaling simulator that generates scaling on tested tube wall. The measured values with the diagnostic system were compared with the amounts of the scaling generated by the simulator. In addition to, we showed the data that have been executed in field test for reliability verification.

• The Korean Journal of Ecology
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• v.16 no.1
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• pp.51-61
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• 1993

Crystal violet, a typical triphenylmenthane dye (N, N, N', N', N", N"-hexa methylparaosaniline), extensively used in textile dye, industry and research, has been suggested to cause tumor growth in botton-feeding fishes. For the isolation of crystal violet degrading bacteria, wastewaters were sampled from plants' wastewater treatment facility, textile treatment facility, textile wastewater treatment plant and etc.. The most efficient strain in crystal violet degrading bacteria was identified as Klebsiella oxytoca. Added sole carbon source in PAS minimal media was 10mg/l crystal violet, which incubated at 30。C, the degrading efficiency was maximum 12.3%. When fructose, glucose, sucrose and yeast-extract were added 0.01% in PAS media respectively, the degrading efficiency were all 96% within 24 hours.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.116-124
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• 2006

A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree. which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity Prediction program (VPP) The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.256-259
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• 2008

The gasification of biomass, sawdust, was carried out in order to investigate gasification characteristics. The experiment was performed using a down-draft fixed bed gasifier to surpass tar components generation in the gasification process. In the experiments, we investigated synthetic gas composition by varying reaction temperature, steam/carbon ratio, and excess ratio (ER), respectively. Higher reaction temperature, $700^{\circ}C$ to $900^{\circ}C$, could obtain higher $H_2$ yield. However, we could not obtain any meaning data by varying S/C ratio. Using $O_2$-LNG burner in the top of the gasifier may surpass water-gas shift reaction by increasing $CO_2$ concentration from the LNG-$O_2$ combustion reaction.

• Proceedings of the KWS Conference
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• v.43
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• pp.213-215
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• 2004

Water jet propulsion system has high efficiency on middle to high speed, and it provides better safety than conventional screw propeller because it has not projected propeller and rudder. So many leisure boat and high-speed ferries use this propulsion system. We developed water-jet propulsion unit for small planning boat, and launched that in the boat, after that we tested water-jet unit in the lake. As a result, we certify heat dissipation at the bearing housing and reverse duct's shape for neutral position are important at the design, and alignment water-jet unit and keel line are important at the launching, and ship's resistance performance and jet's propulsion performance also are needed to consideration.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.134-140
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• 1992

Teh $polA^{+}$ gene can be transducted in a multicopy mini-Mu plasmid, but not cloned because the product of this gene is lethal when overproduced. Although, we obtained one surviving cell, in which the ColEl-derived mini-Mu plasmid suffered a spontaneous deletion exactly at the region where the $polA^{+}$ gene was cloned. The $PolA^{+}$ unstream flanking sequence containing the promoter and pribnow-box was delected in vivo ; consequently this gene is not able to be expressed.

• Journal of electromagnetic engineering and science
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• v.5 no.4
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• pp.161-165
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• 2005

We prepared Mn-Zn ferrite Electromagnetic(EM) wave absorbers. The Mn-Zn ferrite EM wave absorbers were coated with Sr ferrite powders and $Al(OH)_3$ powders. The coated Mn-Zn ferrite EM wave absorbers show improved absorption compared with non-coated Mn-Zn EM wave absorbers.