• Transactions of the Korean hydrogen and new energy society
• /
• v.26 no.4
• /
• pp.324-330
• /
• 2015

The electrolyte flow rates of vanadium redox flow battery play very important role in terms of ion transfer to electrolyte, kinetics and pump efficiency in system. In this paper a vanadium redox flow battery single cell was tested to suggest the optimization criteria of electrolyte flow rates on the efficiencies. The compared electrolyte circulation flow rates in this experimental work were 15, 30 and 45 mL/min. The charge/discharge characteristics of the flow rate of 30 mL/min was the best out of all flow rates in terms of charging and discharging time. The current efficiencies, voltage efficiencies and energy efficiencies at the flow rate of 30 mL/min were the best. The IR losses obtained at thd current density of $40mA/cm^2$, at the flow rates of 15, 30 and 45 mL/min were 0.085 V, 0.042 V and 0.115 V, respectively. The charge efficiencies at the current density of $40mA/cm^2$ were 96.42%, 96.45% and 96.29% for the electrolyte flow rates of 15, 30 and 45 mL/min, respectively. The voltge efficiencies at the current density of $40mA/cm^2$ were 77.34%, 80.62% and 76.10% for the electrolyte flow rates of 15, 30 and 45 mL/min, respectively. Finally, the energy efficiencies at the current density of $40mA/cm^2$ were 74.57%, 77.76% and 73.27% for the electrolyte flow rates of 15, 30 and 45 mL/min, respectively. The optimum flow rates of electrolytes were 20 mL/min in most of operating variables of vanadium redox flow battery.

• Journal of Chest Surgery
• /
• v.24 no.5
• /
• pp.429-437
• /
• 1991

Beta hydroxytrimethylammonium butyrate[L-carnitine] is highly concentrated in myocardium and it is essential substance for transfer of fatty acids into the mitochondria. We respect that L-carnitine has protective action to myocardium during ischemia. I studied coronary flow and CK - MB isoenzyme of coronary effluent of Langendorff`s isolated rat heart model. As a control group 5 Sprague-Dowley species rat hearts were connected to Langendorff`s isolated rat heart model and perfused for 30 minutes with Kreb-Henseleit buffer solution. After cessation of perfusion for 30 minutes they were reperfused for 30 minutes. In experimental group 10 Sprague-Dowley species rat hearts were perfused with 10mmole /L of L-carnitine contained in Kleb-Henseleit buffer solution. In equilibrium state, coronary flow was 1.7 times greater in experimental group. During reperfusion, both group showed equally decreased flow amount of about 60% of that of equilibrium state. CK-MB isoenzyme level of perfused coronary fluid showed no significant difference in equilibrium state. In reperfusion. CK-MB isoenzyme levels of control group were 17.61$\pm$8. 68U/L at 25 minutes, 23.32$\pm$4.15U /L at 30 minutes; and in experimental group, 13.63$\pm$6. 08U/L at 15 minutes and 13.6$\pm$8.41U /L at 30 minutes respectively. Those values in both states showed significantly lower CK-MB level in experimental group. In conclusion, L-carnitine prevent ischemic myocardial damage during ischemic and reperfusion state of Langendorff`s isolated rat hearts and also I suggest the L-carnitine act potent coronary vasodilator during preischemic and postischemic states of rat hearts.

• Journal of Life Science
• /
• v.15 no.5 s.72
• /
• pp.739-742
• /
• 2005

This experiment was carried out to clarify the effect of pyroligneous liquor and coconut water on plantlet multiplication and in vitro flowering of Dendrobium moniliforme. Plantlet growth and multiplication was good in 1.0 ml/L pyroligneous liquor treatment which was added to the basal media of 3 g/L hyponex and 4 g/L peptone ($H_{3} P_{4}$) containing 0.1 mg/L NAA and 1.0 mg/L kinetin. In the treatment of 30 ml/L coconut water showed good results on plantlet growth and multiplication. In vitro flowering showed highest rate in the treatment of 1.0 ml/L pyroligneous liquor and 30 ml/L coconut water which were added to the basal media of $H_{3} P_{4}$ containing 0.1 mg/L NAA and 1.0 mg/L kinetin.

• Korean Journal of Ichthyology
• /
• v.12 no.1
• /
• pp.46-53
• /
• 2000

Artificial gonadal maturation and spawning inducement of striped knife-jaw Oplegnathus fasciatus were studied. Effects of water temperature and photoperiod under different regims on gonadal activity and maturation of three years old O. fasciatus were investigated histologically. In experiment I (Exp. I), water temperature was gradually increased from $14.5^{\circ}C$ to $21.0^{\circ}C$ and photoperiod was also gradually increased from 10 : 30 L to 15 : 30 L from December 1996 to February 1997 and this conditions were maintained till April. In experiment II (Exp. II), water temperature was increased in the same way from Exp. I and photoperiod was controlled as natural condition till early March and then increased to 15 : 30 L immediately. Control fish were reared in net-cage culture system in the sea from December 1996 to April 1997. Gonadal activity was initiated by increasing water temperature in both Exp. I and II from January. In Exp. I, gonadal maturation and spawning were induced from February when water temperature and photoperiod reached at $21.0^{\circ}C$ and 15 : 30 L, respectively. In Exp. II, complete gonadal maturation was not induced until early March but after treated by compensatory long photoperiod (15 : 30 L), the gonad was matured and subsequently spawning occurred.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2001.09a
• /
• pp.30-30
• /
• 2001

• Korean Journal of Mathematics
• /
• v.30 no.1
• /
• pp.121-130
• /
• 2022

In this paper, we prove that every semi-conformal harmonic map between Riemannian manifolds is L-harmonic map. We also prove a Liouville type theorem for L-harmonic maps.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.1
• /
• pp.107-112
• /
• 2011

In this study, photocatalytic degradation and mineralization of bisphenol A (BPA), which has been listed as one of endocrine disruptors, were carried out in the CPC system using $Tio_2$ slurry and UVA irradiation. The degradation efficiency has been investigated under the controlled parameters including initial concentration (5, 10, 20 mg/L), dosage of $Tio_2$ (0.1, 0.5, 1.0 g/L), UVA power (0, 80, 120 W) and temperature (0, 20, 30). At 10mg/L of initial concentration, BPA was degraded above 80% after 10min, BPA were degraded 97% and 49% at 20 mg/L and 30 mg/L, respectively. At $Tio_2$ dosage was 0.1 and 0.5 g/L, the degradations of BPA showed similar trend and were about 70% after 1 hr, and the degradation of BPA was above 80% after 30 min at 1 g/L of $Tio_2$ dosage. The increase of degradation seem to be due to the increase in the total surface area, namely number of active sites, available for the photocatalytic reaction as the dosage of photocatalyst increased. When the UVA power was 120 W, BPA was degraded rapidly above 60% after 10min of reaction time. To investigate the effect of temperature, carried out experiment controlled temperature, there were no significant differences depending on the temperature. After 1hr, the degradation of BPA were 46%, 67%, and 69% at 10, 20 and $30^{\circ}C$.

• Journal of Environmental Health Sciences
• /
• v.21 no.2
• /
• pp.12-19
• /
• 1995

The objectives of this research prograln were to study the ozonation characteristics of phenol contaminated wastewater in the continuous packed column reactor (PCR) and the bubble column reactor (BCR) using ozone that has a strong oxidizing potential, and to provide the fundamentals of ozonizing the phenol contaminated wastewater. Among various influencing factors on phenol decomposition through the oxidation by ozone, phenol/ozone mde ratio was chosen as reaction parameters. Concerning the phenol/ozone mde ratio, as the influent phenol concentration increased from 30 mg/l to 150 mg/l, the phenol removal efficiency decreased from 99% for 30 mg/l to 83.7% for 150 mg/l, in PCR. PCR also showed higher treatment efficiency than BCR by 1% for 30 mg/l and 2.2% for 150 mg/l, respectively. The ozone utilization efficiency of PCR for the phenol concentration 30 mg/l was higher than that of BCR while the efficiency of both reactors was 99.9% for the phenol concentration of 150 mg/l.

• Food Science of Animal Resources
• /
• v.30 no.2
• /
• pp.345-350
• /
• 2010

Various extracts from 30 medicinal plants were evaluated for their antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) and cytotoxicity in MDCK cell culture. The plant material (30 g) was extracted with methanol (300 mL) at room temperature for 24 h, after which the methanolic extracts were filtered, evaporated, and subsequently lyophilized. Evaluation of the potential antiviral activity was conducted by a viral replication inhibition test. Among these medicinal plants, Tussilago farfara, Brassica juncea, Prunus armeniaca, Astragalus membranaceus, Patrinia villosa, and Citrus unshiu showed marked antiviral activity against influenza virus A/H1N1 at concentrations ranging from 0.15625 mg/mL to 1.25 mg/mL, 0.3125 mg/mL to 10 mg/mL, 5 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, and 0.3125 mg/mL to 5 mg/mL, respectively. The extracts of Tussilago farfara showed cytotoxicity at concentrations greater than 2.5 mg/mL, whereas the other five main extracts showed no cytotoxicity at concentrations of 10 mg/mL. Taken together, the present results indicated that methanolic extracts of the six main plants might be useful for the treatment of influenza virus H1N1.

• Food Science of Animal Resources
• /
• v.34 no.1
• /
• pp.20-25
• /
• 2014

This study evaluated the effects of frankfurter fat content on Listeria monocytogenes resistance to heat stress and gastric fluid, and the Caco-2 cell invasion efficiency of the pathogen. A 10-strain mixture of L. monocytogenes was inoculated on frankfurters formulated with 10%, 20%, and 30% fat content (10%: F10, 20%: F20, 30%: F30) and stored at $10^{\circ}C$ for 30 d. The samples were analyzed for L. monocytogenes resistance to heat stress and a simulated gastric fluid challenge. The total bacteria and L. monocytogenes survival rates were measured on tryptic soy agar plus 0.6% yeast extract and Palcam agar, respectively. L. monocytogenes colonies inoculated on F10, F20, and F30 samples were used for a Caco-2 cell invasion assay. In general, no obvious differences were observed between the survival rates of total bacteria and L. monocytogenes grown on different fat contents under heat stress and gastric fluid challenge. However, L. monocytogenes obtained from the F30 samples had a significantly higher Caco-2 cell invasion efficiency than those in the F10 and F20 samples (p<0.05). These results indicate that although high fat content in food may not be related to L. monocytogenes resistance to heat stress and gastric fluid, it may increase the Caco-2 cell invasion efficiency of the pathogen.