• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.465-472
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• 2001

The effects of water level reduction in rearing tank and fish transference during fish selection process on the stress response (hematological factors, cortisol, glucose, lactic acid and osmolality) of tank-reared olive flounder Paralichthys olivaceus of large (FL), small (FS) and Japanese croaker, Nibea japonica (JC) were examined in running seawater culture system. The water level of rearing unit was lowered from 33 cm to 8 cm in the course of 2 minutes in the water level reduction experiment. The fish were removed from rearing tank (12 ton) to 450 L tank in 30 seconds after capture in the fish transference experiment, In water level reduction, the hematocrit of FL was significantly increased from $14.6\%$ at beginning to $23.5\%$ after 10 hours, However, it decreased to the value of beginning after 46 hours. Plasma cortisol concentration of FL was the highest concentration (13.7 ng/mL) after 22 hours, but it decreased to 4.0 ng/mL at the end of experiment. Cortisol concentration of FS did not show any significant difference during the experiment. The cortisol concentration of JC were significantly higher at 4 hours (282.3 ng/mL) and 22 hours (350.5 ng/mL), Glucose concentration of JC was the highest (138.0 mg/dL) at 22 hours. Lactic acid concentration was not different between experimental groups. In the fish transference experiment, red blood cell of FL was increased from $1.9\times10^6\;cell/{\mu}\;L\;to\;4.2\times10^6\;cell/{\mu}L$ in 24 hours. Blood hemoglobin of JC were significantly elevated in 24 hours. At 1 hour after transference, plasma cortisol concentrations in both fish species were increased to 95.3 ng/mL in FL and 175.5 ng/mL in JC. Glucose concentration of JC was increased to 132.5 mg/dL at 1 hour, 129.5 mg/dL at 3 hours after transference.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.72-74
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• 2001

Transgenic Nicotiana tabacum cells were cultivated for the production of murine granulocyte macrophage-colony stimulating factor (mGM-CSF) in both a stirred tank bioreactor and an airlift bioreactor with draft tube. Cell growth and mGM-CSF production in the airlift bioreactor were found to be better than those achieved in the stirred tank bioreactor. In the airlift bioreactor, 9.0g/L of cells and 2.2ng/mL of mGM-CSF were obtained (11.0g/L and 2.4ng/mL, respectively in shake flasks). Although the lag period was prolonged and mGM-CSF production was lowered by 33% in the stirred thank bioreactor as compared to the control culture, the maximum cell density was increased up to 12.0g/L due to better mixing by agitation at the higher cell density.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1346-1351
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• 2004

This study is concerned with the thermal analysis during the cool-down period of 135,000 $m^3$ class GT-96 membrane type LNG carrier under IMO design condition. The cool-down is performed to cool the insulation wall and the natural gas in cargo tank for six hours to avoid the thermal shock at the start of loading of $-163^{\circ}C$ LNG. During the cool-down period, the spraying rate for the NG cooling decreases as the temperature of NG falls clown from $-40^{\circ}C$ to $-130^{\circ}C$ and the spraying rate for the insulation wall cooling increases as the temperature gradient of the insulation wall is large. It was confirmed that there existed the largest temperature decrease at the 1 st barrier and 1st insulation, which are among the insulation wall, especially in the top side of the insulation wall. By the 3-D numerical calculation about the cargo tank and the cofferdam during the cool-down period, the temperature variation in hulls and insulations is precisely predicted.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.89-93
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• 2007

The Boil-off gas (BOG) generation during the voyage is inevitable since Natural Gas (NG) in normally liquefied below -160 degree C in atmosphere condition and small heat ingress due to relatively hot outside keeps evaporating continuously. The one of major issue in LNG carriers is to handle generated BOG from cargo tank. The generated BOG affects to increase the cargo tank pressure and Gas Management System (GMS) for LNG carriers is closely related to cargo tank pressure maintenance. Economically, BOG is generally used as fuel in LNG carrier. Newly developed GMS for LNG carrier in boiler propulsion system, VaCo System, not only accomplish automatic control in GMS but also ensure safer operation.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.326-334
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• 2012

To determine the concentrations and the mass flow of selected 10 perfluorinated compounds (PFCs), a field study was conducted in a wastewater treatment plant. Raw influent, primary influent, primary effluent, aeration tank effluent, secondary effluent, final effluent, dehydration liquor, primary sludge, thickened sludge, final sludge were collected over 3 days in the summer and the winter respectively. Collected samples were equally mixed and then served as an analytical sample. Total 10 compounds were analyzed. In terms of treated water, the concentration of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) were in range of N.D.~26.29 ng/L and N.D.~38.15 ng/L respectively. Perfluorononanoate (PFNA) and perfluorohexanesulfonate (PFHxS) were ranged from N.D. to 36.79 ng/L and from N.D. to 24.36 ng/L. In terms of sludges, a concentration of PFOS, PFOA, and perfluorodecanesulfonate (PFDS) were detected from 6.82 to 59.37 ng/g, from 0.13 to 0.37 ng/g, from N.D. to 0.83 ng/g respectively. Mass loading for PFCs increased during wastewater treatment except for PFNA. The observed increase in mass flow of PFCs may have resulted from biodegradation of precursor compounds.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1390-1397
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• 2004

This study is concerned with the thermal analysis during the cool-down period of 135,000㎥ class GT-96 membrane type LNG carrier under IMO and USCG design condition. During the cool-down period, the spraying rate for the NG cooling decreases as the temperature of NG falls down from -4$0^{\circ}C$ to -l3$0^{\circ}C$, and the spraying rate for the cooling of the insulation wall increases as the temperature gradient of the insulation wall is large. It was confirmed that there existed the largest temperature decrease at the first barrier and the first insulation, which are among the insulation wall, especially in the top side of the insulation wall under IMO and USCG design condition. Also, as the NG temperature distribution is fixed, the outer temperature condition under the design condition has influence on the temperature variation at the insulation. By the 3-D numerical calculation about the cargo tank and the cofferdam during the cool-down period, the temperature variation in hulls and insulations is precisely predicted under IMO and USCG design condition. From the comparison between two conditions; IMO design condition shows more severe temperature gradient than USCG design condition, therefore, it provides the conservative estimation of the BOG.

• Journal of the Korean Institute of Gas
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• v.9 no.4 s.29
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• pp.1-5
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• 2005

An investigation was made on the fatigue characteristics of type 304 stainless steel membrane manufactured by plastic working. To investigate the effect of plastic deformation, tests were performed with 5 types of specimens having different amount of plastic deformation. Fatigue tests were executed under both room and LNG temperatures $(-162^{\circ}C)$. All the test results were compared with the fatigue data provided by RPIS (Recommended Practice for Inground LNG Storage Tank). On the basis of these results, it was confirmed that RPIS's design fatigue curve could be applied to evaluate fatigue life of KOGAS membrane manufactured by pressing.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.164-167
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• 2006

The influence of temperature and agitation on the growth of Escherichia coli expressing hepatitis B core antigen (HBcAg) in stirred tank bioreactor were investigated. The highest specific growth rate for E. coli$(0.844 h^{-1})$ was achieved at a temperature of $37^{\circ}C$ and an agitation speed of 250 rpm. The activation energy for the growth of the E. coli strain W3110lQ in the stirred tank bioreactor was estimated to be 11 kcal/mol. The highest protein yield was achieved at a temperature of $44^{\circ}C$ and an agitation speed of 250 rpm. The relative protein concentration at $44^{\circ}C$ is 30 and 6% higher compared to that at 30 and $37^{\circ}C$, respectively.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.271-278
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• 2004

Epoxy resins are mostly used as a molding material for drinking water tank. Bisphenol A is used at a constituent material for epoxy resins and is widely suspected to act as an endocrine disrupter. In this study, we investigated embryo hatching in zebrafish reared in water undergone leaching process of expoxy resin, and found a decreased survival rate. Bisphenol A eluted from epoxy resin in drinking water tank was completely degraded by TiO$_2$ photocatalysis. We detected 7.8 ng/ml of bisphenol A in epoxy resin tank, and observed that the concentration was undetectable after 48h photocatalysis over TiO$_2$. There was no toxicity in hatching rates in zebrafish and morphogenesis after photocatalysis. The effect of TiO$_2$ photocatalytic reactions on the catalase activities in the f]y stage of zebrafish was also examined. At 1 week post hatching, cataiase activities were higher both in the group of epoxy resin with 48 h TiO$_2$ photocatalysis and in the TiO$_2$ photocatalysis for 48 hours were higher than control group. However catalase activities of the treatment group of epoxy resin by TiO$_2$ photocatalysis for 48 hours were similar to control in 5 weeks post hatching fries. In conclusion, the toxicity of TiO$_2$ photocatalysis was not observed in this zebrafish.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.2
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• pp.120-128
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• 2013

This paper presents the results of sloshing experiments having different fluids in model tanks with various density ratios. The experimental model consisting water and air at ambient, which has been commonly used, is not consistent in density ratio with that of an actual LNG cargo tank. Therefore, an advanced experimental scheme is developed to consider the same density ratio of LNG and NG by using a mixed gas of sulfur hexafluoride ($SF_6$) and nitrogen ($N_2$). For experimental observation, a two-dimensional model tank of 1/40 scale and a three-dimensional model tank of 1/50 scale have been manufactured and tested at various conditions. Two different fillings with various excitation frequencies under regular motions have been considered for the two-dimensional model tank, and three different filling levels under irregular motions have been imposed for the three-dimensional model tank. The density ratio between gas and liquid varies from the ratio of the ambient air and water to that of the actual LNG cargo container, and the different composition of gas is used for this variation. Based on the present experimental results, it is found that the decrease of sloshing pressure is predicted when the density ratio increases.