• Journal of Aquaculture
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• v.8 no.1
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• pp.59-67
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• 1995

Growth rate, first reproductive age, life span and total offspring numbers were measured to study the effects of water temperature and salinity on the propagation of rotifer, Brachionus plicatilis. Three types of rotifer, Large (L), Small (S) and Thailand Small (TS)-types, were cultured in the $4\times4$ factorial culture conditions with four different salinities (5, 15, 25 and $35\%o$) at each of four different water temperatures (15, 20, 25 and $29^{\circ}C$). The results are as follows; Under the 4 different salinity gradients %$(5\%o,\;15\%o,\;25\%o,\;and\;35\%o)\;at\;29^{\circ}C$, the mean growth rates of L, Sand TS-type were 0.60, 0.84 and 0.96, respectively. The first reproductive age of three types rotifer appeared to be early at high water temperature. The total offspring numbers of the three types were higher at $25^{\circ}C\;and\;29^{\circ}C$, with the maximum value of 28.3 on the average at $29^{\circ}C$ for TS-type, and the minimum value at $15^{\circ}C$ for S-type. Life span decreased with high water temperature and increased with low water temperature. L-type and TS-type rotifer showed the longest life span of 13.5 days on the average at $15^{\circ}C$, and S-type showed shortest 6.2 days on the average at $29^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.60-66
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• 1995

Vibrio cholerae non-O1 and Vibrio mimicus, food poisoning bacteria, have detected frequently in fresh water and brackish water. To estabilsh prevention measures of food poisoning outbreak by these bacteria, the adaptability and population changes were examined in fresh water, brackish water $(10\%o\;NaCl)$ and seawater $(30\%o\;NaCl)$. Both species poorly survived as temperature increased regardless of water types employed. However, survival time was the shortest in fresh water and longest in seawater at $4^{\circ}C$. In case of brackish water, the bacteria survived best at $15^{\circ}C$ and population were varied only in small numbers. Any significant difference was not observed to both species with respect to water types and temperatures except V. mimicus survived about 5-6 days longer in brackish water. In conclusion, V. cholerae non-O1 and V. mimicus were not likely to be recovered In normal fresh water, brackish water and seawater, and both biological and physicochemical factors could affect survival of these species.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1425-1430
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• 2007

This study was conducted to investigate the effect of ozonated water and ozonated water+hydrogen peroxide treatment of residual procymidone in perilla leaf containing 20 mg/L procymidone. Samples was treated with ozonated water containing 1.0, 2.0 and 3.0 mg $O_3/L$ ozone and hydrogen peroxide water containing 1.0, 2.0 and 3.0 mg $H_2O_2/L$ hydrogen peroxide in pH 5, 7 and 9, respectively, at $15^{\circ}C$. Procymidone removal rate was 26.5% in 7 days at $15^{\circ}C$ and optimum condition of procymidone removal was the case of treating with ozonated water containing 2.0 mg $O_3/L$ and pH 9. As the result procymidone removal rate was about 96.5%. In this case of adding hydrogen peroxide, optimum condition of procymidone removal was $1:0.5{\sim}1(O_3:H_2O_2)$. However, procymidone was nearly removed with the treatment of hydrogen peroxide water only.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.471-477
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• 2006

We investigated the relationship between the $TiO_2$ photocatalytic decomposition of bisphenol A in water and biological toxicity to zebrafish (Danio rerio) during $1\sim28$ weeks post development stage. The bisphenol A in water was completely degraded by the $TiO_2$ photocatalysis in 50 hours. After the photocatalysis, no toxic effects on the morphogenesis of the zebrafish were observed during the development, growth, and maturate stages. Catalase activity of control group was not different from $1\sim5$ week post fertilized group. However, toxic effect on the catalase activity of adult stage(28 weeks) decreased 50% than control group.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.107-111
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• 2002

The OSS2 (Oj？me-Shavitt-Singer 2)[L. Oj？me et al., J. Chem. Phys. 109, 5547 (1998)] model for the solvated proton in water is examined for $H_2O,\;H_3O^+,\;H_5O_2^+,\;H_7O_3^+,\;and\;H_9O_4^-$ by molecular dynamics (MD) simulations. The equilibrium molecular geometries and energies obtained from MD simulations at 5.0 and 298.15 K agree very well with the optimized calculations.

• Korean Journal of Pharmacognosy
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• v.51 no.1
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• pp.55-64
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• 2020

In this study, 15 compounds were elucidated from the hot-water extract of Perillae Folium. Fifteen isolates were determined to be protocatechuic acid (1), caffeic acid (2), (R)-rosmarinic acid (3), (S)-shisoflavanone A (4), luteolin-7-O-β-D-glucuronopyranoside (5), scutellarein-7-O-β-D-glucuronopyranoside (6), apigenin-7-O-β-D-glucuronopyranosyl(1→2)-O-β-D-glucuronopyranoside (7), luteolin-7-O-β-D-glucuronopyranosyl(1→2)-O-β-D-glucuronopyranoside (8), kelampayoside A (9), trans-N-feruloyloctopamine (10), 3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxyphenyl)-2-methoxyethyl]acrylamide (11), perilloside C (12), perilloside A (13), (6S,9R)-9-hydroxy-megastigma-4,7-dien-3-one-9-O-β-D-glucopyranoside (14) and (6S,9R)-roseoside (15) through spectroscopic evidences. The HPLC analysis revealed that hot-water extract of Perillae Folium contained caffeic acid, rosmarinic acid and glycosides of apigenin, luteolin and scutellarein as main constituents.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.52-61
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• 1998

Nitrification and denitrification are important processes in the landfill site as they are deeply related with degradation and stabilization of refuse. Also nitrous oxide ($N_2O$) which is released from both nitrification and denitrification is known as greenhouse gas (GHG). The purpose of this study was to clarify the process by which $N_2O$ produced using $^{15}N$ isotope. Nitrate which was labeled to 10.08% with $^{15}KNO_3$ was used and $N_2O$ was analyzed with GC mass. Results was that even also when $O_2$ of bulk was 15%, $N_2O$ was released from denitrification. And as concentrations of $O_2$ increase, sum of $N_2O$ was released from denitrification. And as concentrations of $O_2$ increase, sum of $N_2O$ and $N_2$ was decreased and ratios of $N_2O$ in the reduced gases were increased. FISH technics also adaped to confirm whether which of nitrifiers existed in the substrates. When NEU was used of which the target was ammonia oxidizing bacteria, nitrifier was not detected at all. So it was confirmed that during the reaction denitrification was dominant process. Total bacteria distributions which were detected by EUB probe explained that as $O_2$ increase the number of bacteria also increase, but between the 10-15% of $O_2$ there was no any differences.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.889-896
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• 2013

Advanced Oxidation Processes (AOP) have been interested for removing micropollutants in water. Most of water treatment plants (WTPs) located along the lower part of Nakdong River have adopted the $O_3/BAC$ process and have interesting in peroxone process a kind of AOP. This study evaluated the removal characteristics of residual hydrogen peroxide ($H_2O_2$) combining with the biofiltration process in the next BAC process when the hydrogen peroxide is applied for the WTP operating $O_3/BAC$ process. In the experiment, changing the temperature and the concentration of $H_2O_2$ of influent, the biofiltration process showed rapidly dropped the biodegradability when the $H_2O_2$ concentration was increased and lowered water temperature while BAC process maintained relatively stable efficiency. The influent fixed at $20^{\circ}C$ and the concentration of $H_2O_2$ at 300 mg/L was continuously input for 78 hours. Most of the $H_2O_2$ in the influent did not remove at the biofiltration process controlled 5 to 15 minutes EBCT condition after 24~71 hours operating time while BAC process controlled 5 to 15 minutes EBCT showed 38~91% removal efficiency condition after 78 hours operating time. Besides, after 78 hours continuously input experiment, the biomass and activity of attached bacterial on the biofilter and BAC were $6.0{\times}10^4CFU/g$, $0.54mg{\cdot}C/m^3{\cdot}hr$ and $0.4{\times}10^8CFU/g$, $1.42mg{\cdot}C/m^3{\cdot}hr$ respectively. These biomass and activity values were decreased 99% and 72% in biofilter and 68% and 53% in BAC compared with initial condition. The biodegradation rate constant ($k_{bio}$) and half-life ($t_{1/2}$) in BAC were decreased from $1.173min^{-1}$ to $0.183min^{-1}$ and 0.591 min to 3.787 min respectively according to increasing the $H_2O_2$ concentration from 10 mg/L to 300 mg/L at $5^{\circ}C$ water temperature and the $k_{bio}$ and $t_{1/2}$ were $1.510min^{-1}$ to $0.498min^{-1}$ and 0.459 min to 1.392 min at $25^{\circ}C$ water temperature. By increasing the water temperature from $5^{\circ}C$ to $15^{\circ}C$ or $25^{\circ}C$, the $k_{bio}$ were increased 1.1~2.1 times and 1.3~4.4 times. If a water treatment plant operating $O_3/BAC$ process is considering the hydrogen peroxide for the peroxone process, post BAC could effectively decrease the residual $H_2O_2$, moreover, in case of spilling the $H_2O_2$ into the water process line, these spilled $H_2O_2$ concentration can be able to decrease by increasing the EBCT at the BAC process.

• Advances in nano research
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• v.15 no.3
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• pp.191-201
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• 2023

In order to develop better method to enhance and control the flow and heat transfer inside the radiator of electronic device, the synergistic effect of MHD nanofluids and porous medium on the flow and heat transfer in rectangular opened channel is simulated using Lattice Boltzmann method. Three nanofluids of CuO-water, Al₂O₃-water and Fe₃O₄-water are studied to analyze the influence of the type of nanofluid on the synergistic effect. The simulation results show that the porous medium can increase the flow velocity in fluid zone adjacent to the porous medium and enhance the heat transfer on the surface of the channel. Under no magnetic field, when the porosity of porous medium is 0.8, the Nusselt number is 4.46% higher than when the porosity is 0.9. Al₂O₃-water has the best heat transfer effect among the three nanofluids. At Ф=0.06, Ha=100, θ=90°, ε=0.9, Nu of Al₂O₃-water is 6.51% larger than that of CuO-water and 5.05% larger than that of Fe₃O₄-water. Magnetic field enhances seepage in porous medium and inhibits heat transfer in the bottom wall. When Ha=30 and 60, the inhibiting effect is the most significant as the magnetic field angle is 90°. And when Ha=100, the inhibiting effect is the most significant as the magnetic field angle is 120°.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.51-55
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• 2004

Sopungsungi-won has been used as a traditional medicine for diabetes and it has been proved to be a potential remedy for type 2 diabetes mellitus. We previously reported that water extract of Sopungsungi-won exhibits anti-diabetic effects both in vivo and in vitro experiments. In the present study, we have chosen to examined anti-apoptotic effect of Rheum undulatum, which is the main component of Sopungsungi-won, on pancreatic ${\beta}-cells$, HIT-T15, against hydrogen peroxide $(H_2O_2)$. oxidative stress. To investigate the anti-apoptotic effect of Rheum undulatum water extract (RUWE) against $H_2O_2-induced$ apoptosis in pancreatic ${\beta}-cell$ line of hamster, HIT-T15, MTT assay, DAPI staining, TUNEL assay, RT-PCR and caspase-3 enzyme assay were performed. The morphological analysis demonstrated that cells treated with $H_2O_2$ exhibited classical apoptotic features, while such changes was reduced in cells pre-treated with RUWE. In addition, RUWE pre-treated cells prior to $H_2O_2$ treatment induced increase of levels of bcl-2 expression and decrease of caspase-3 enzyme activity compared to cells treated with $H_2O_2$ only. These results provide the possibility of usage of RU in patients with progressively deteriorated diabetes.