• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.110-115
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• 2000

This study was conducted to monitor the irrigation water qualities along Dong-Jin river watershed. The water quality was surveyed at 6 sites from April to september during $1994{\sim}1998$. And the results were as follows : In July and August, water quality was better than that of any other months due to dilution with rainwater. Whereas, it became worse in April but it involved lower contents than limitted contents affected to the crop damage. Content of inorganic components was higher at Jeong-up and Won-pyeong stream. The reason for it that Jeong-up stream was deteriorated with sewage water from Jeong-up city, and Won-pyeong stream has narrow width. Water quality in upstream of Dong-Jin river, was evaluated best conditions in all sampling sites. For investigated period, water quality got worse from 1994 to 1995 but it was getting better to 1998 after 1995, especially at Jeong-up stream. The total equivalent of cation and anion was the highest at April through all months and at Jeong-up stream in sampling sites. Equivalent ratio of cation to $anions({\Sigma}C/{\Sigma}A)$ was higher at May than any other months and lower at Won-pyeong streams than any other sites. The value of most inorganic components was highly correlated with those of other components. But the value of $NO_3\;^--N$ was not correlated with that of most components, and $PO_4\;^{3-}-P$ was not correlated with COD, $NH_4\;^+-N$, $NO_3\;^--N$, $SO_4\;^{2-}$.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.281-288
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• 2009

The strobilurin fungicides, azoxystrobin and kresoxim-methyl, were investigated to know the biological half-lives and dissipation patterns in Korean melon under plastic film house condition. Used pesticides for field application were 20% azoxystrobin of suspension concentrate and 47% kresoxim-methyl of water dispersible granule. Two pesticides were sprayed at recommended and double dose rate. Pesticide residues in Korean melon were analyzed until 14 days after application. The azoxystrobin was analyzed by HPLC equipped with UV detector after cleanup with florisil glass column. Initial residue concentrations of azoxystrobin in Korean melon at recommended and double dose rate were 0.09 mg/kg and 0.14 mg/kg, respectively. Those were less than 0.2 mg/kg maximum residue limit of Korean melon established by KFDA. The biological half-lives of azoxystrobin in Korean melon were 4.7 days at recommended dose rate and 7.8 days at double dose rate. Initial concentrations of kresoxim-methyl which was analyzed by GLC-ECD in Korean melon at recommended and double dose rate were 0.10 mg/kg and 0.23 mg/kg, respectively. Those were less than 1.0 mg/kg, MRL. The biological half-lives of kresoxim-methyl in Korean melon were 4.1 days at recommended dose rate and 4.8 days at double dose rate. The residue amounts of both pesticide was lower than MRL and biological half-lives were not so long. Because the weight of Korean melon under plastic film house condition was fast increased during cultivation.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Biomedical Science Letters
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• v.3 no.2
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• pp.107-114
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• 1997

Recent reports indicate that the clinical usefulness of prostate specific antigen (PSA), particulary in the differentiation of benign prostate hyperplasia from prostate cancer, can be improved by measuring the amount of free PSA in serum. Measuring free PSA is especially useful in attempts to improve diagnositc performance of PSA in the diagnostic gray zone of total PSA. The objective of this study was to develop free PSA assay kit using sandwich microplate enzyme immunoassay format. We chose a test format with polyclonal anti-PSA antibodies coated on the wells and monoclonal anti-free PSA antibodies for quantification to gain higher test sensitivity. We adpoted 10 uL of specimen and 2 hours of first incubation time with detecting antibody for free PSA EIA format using microplate. The within-day and between-day precision (%CV) in the high and low concentration ranges were below 4%. The correlation coefficient between in-house free PSA assay and commercial assay kit was r=0.9965 (slope=0.0984, y intercept=0.0173, N=27). No hook effect was found by 40 ng/mL and correlation coefficient (r) value of the fitted linear regression was over 0.995. The recovery tests were in the range of 98.9∼104.1％ for free PSA. In conclusion, in-house free PSA enzyme immune assay is cost effective, simple and rapid and could be useful for the prognosis after theraphy as well as for the differential diagnosis between prostate cancer and benign prostate hyperplasia.

• Biomedical Science Letters
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• v.3 no.2
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• pp.125-130
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• 1997

Taxol, an anticancer drug that has diterpenoid conformation, has been used as an effective chemotherapeutical agent in the treatment of breast and ovarian cancers. Because of its toxicity like other anticancer drugs, monitoring the taxol level in serum is important procedure during cancer therapy. The various monitoring methods using HPLC, ELISA, and RIA have been adopted, and RIA technique is known to be superior than other methods in trems of sensitivity and convenience. In this study, in order to develope taxol RIA system using $^{125}$I labelled antigen, first of all we synthesized taxol derivatives. 2'-hemisuccinyltaxol was obtained with about 80％ yield by esterification of taxol at C-2' hydroxyl group on C-13 carbon with succinic anhydride. [$^{125}$I]iodotyramine was prepared with 58％ labelling yield by radioiodination of tyramine and purified by gel chromatography. 2'-[$^{125}$I]iodotyramine-hemisuninyltaxol, $^{125}$I labelled antigen for taxol RIA, was synthesized with 96% yield from conjugation of 2'-hemisuccinyltaxol and [$^{125}$I]iodotyramine. Anti-taxol serum was produced from the rabbit immunized with 2'-hemisuccinyltaxol-BSA synthesized by 2'-hemisuccinyltaxol and BSA. The antiserum titer was determined by RIA using 2'-[$^{125}$I]iodotyramine-hemisuccinyltaxol. The titer of 1:20 was obtained with about 40% of B/T. The results suggest that taxol RIA using $^{125}$I labelled antigen can be applied to monitor the taxol level in serum.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.740-747
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• 2015

This research was performed to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation. It was conducted in batch test as fundamental research for in situ soil flushing. The 30% of initial TPH concentration was removed by shaking only in batch test. The removal efficiency of TPH in case of groundwater as surfactant dilution solution was approximate 2~6% lower than that of distilled water. Mixing ratio of soil to surfactant solution did not practically effect on the TPH removal efficiency. In the experiment of using single or mixed surfactant solution with 0.1~4.0 wt%, Tween-80, SWA-1503, SWA-1503+SDS showed averagely over 80%. It was determined that the optimum surfactant concentration was 0.1 wt% because there was no significant difference between concentrations of 0.1~4.0 wt%.

• Journal of the Korean Chemical Society
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• v.22 no.3
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• pp.158-163
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• 1978

The four 1,1-disubstituted 2-vinylcyclopropanes, 1,1-diphenyl-2-vinylcyclopropane (1a), 1,1-dicyano-2-vinylcyclopropane(1b), ethyl 1-cyano-2-vinylcyclopropanecarboxylate(1c), and diethyl 2-vinylcyclopropane-1,1-dicarboxylate(1d) rearranged below $300{\circ}C$ to the corresponding 4,4-disubstituted cyclopentenes, 4,4-diphenylcyclopentene(2a), 3-cyclopentene-1,1-dicarboxylate(2d). Diphenpyl derivative 1a rearranged almost quantitatively to 4,4-diphenylcyclopentene(2a) at the temperature of $250{\circ}C$. Although dicyano derivative 1b in solution underwent the thermal rearrangement at rather low temperature of $170{\circ}C$, the other vinylcyclopropanes, 1c and 1d, in solution rearranged thermally above $220{\circ}C$. In the thermal reaction of 1b, 1c, and 1d considerable amounts of polymers 3 were also produced. Also detected product was the ring-opened diene, ethyl 2-cyano-2,4-hexadienoate(4), in case of the pyrolysis of 1c. The observed facile rearrangement of disubstituted vinylcyclopropanes was explained by the radical stabilization effect of substituents on the diradical intermediates 5.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1193-1199
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• 2012

A cup burner experiment was performed to investigate the effect of the oxidizer velocity and concentration on flame instability near extinction. Heptane was used as a fuel and air diluted by nitrogen and carbon dioxide was used in the oxidizer stream. Two types of flame instabilities at the flame base and at axial downstream were observed near extinction. The instability at the flame base could be characterized by cell, swing, and rotation modes, and the cell mode changed to the rotation mode through the swing mode as the oxidizer velocity increased. To assess the parameters for the flame instability, the initial mixture strengths, Lewis number, and adiabatic flame temperature were investigated under each condition. The Lewis number might be the most important among them, but it is impossible to generalize because of the insufficient number of cases. Furthermore, the axial periodic flickering motion disappeared at low and high oxidizer velocities near extinction. This resulted from the fact that low oxidizer velocity induced evaporated fuel velocity below the critical velocity and high velocity made the reacting fuel velocity comparable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1415-1421
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• 2015

This study was performed to investigate the effects of puffed-red ginseng (PRG) powder and drink on blood glucose level and serum lipid profile in streptozotocin (STZ)-induced diabetic rats. For the experimental design, STZ-induced diabetic rats were fed PRG powder-supplemented diets (0.3%, 0.6%) and diluted drinks (0.14%, 0.28%) for 6 weeks. Concentrations of blood glucose during the experimental period decreased to 18.3 mg/dL in the 0.6% PRG diet group and 15.1 mg/dL in the 0.14% PRG drink group. Average reduction rate of blood glucose in the last week compared to reference blood glucose concentration decreased by 19.2% (A group), 37.4% (B group), 18.7% (C group), and 17.3% (D group) in the PRG treatment groups, respectively. These results indicate that PRG affects blood glucose via ginseng saponins administered in diet or drinking water, thereby suggesting that PRG has the ability to prevent increasing blood glucose in mild-induced diabetic rats.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.753-757
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• 2014

Anode electrode in a microbial fuel cell (MFC) should transfer the receiving electron as well as provide large surface area that can be immobilized microorganisms. Microorganisms' population is one of important factors to improve the current generation and to treat the livestock wastewater by biological treatment. These studies were attempted to investigate if stainless-steel wire skein (SSWS) could be used as anode electrode replacement a graphite felt electrode in microbial fuel cell. For these studies, pretreated livestock wastewater was used diluted to 500 mg/L as COD before use. At this time, the current showed a little difference of about 5% when using each of a SSW and graphite felt (control). There was no significant difference in the current value. The organic removal rate in the microbial fuel cells used graphite felt and SSWS was 82.4% and 88.3%, respectively. The COD removal in the MFC used the SSWS was higher than that of graphite felt. Ammonium nitrogen was showed similar trend in two case all. These results about current generation and organic matter reduction seem possible that SSWS was used to anode electrode. When SSWS is used, the initial investment for system construction is expected to be able to reduce by approximately 1/50.