• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.98-108
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• 2020

The purpose of this study was to evaluate water quality in Hapcheon dam via using the Hydrological Simulation Program-Fortran (HSPF) model and applied livestock reduction scenarios. Hapcheon dam watershed input data for the HSPF model were established using the stream, land use, digital elevation map and meteorological data and others. The HSPF model was calibrated and validated using the observed water quality data from 2000 to 2016. For water quality simulation, we calculated the generated and discharge loads of the population, livestock, industry and land use following the guideline provided by the Ministry of Environment. The pollutant data were obtained from National Institute of Environmental Research (NIER). The monthly discharge load were estimated by applying the delivery rate. The calibration and validation results showed that the annual mean BOD had a difference of 0.22 mg/L and an error of ±13 %, T-N had a difference of 0.66 mg/L and an error of ±16 % and T-P had a difference of 0.027 mg/L and an error of ±13 %. In order to evaluate the nonpoint pollutants management effects, we applied livestock reduction scenarios because livestock consists of the largest portion of pollutants. As a result of the 20 % of livestock reduction, BOD, T-N and T-P decreased by 3 %, 1 % and 3 %, respectively. When 40 % of livestock reduction was applied, BOD, T-N and T-P decreased by 5 %, 3 % and 4 %, respectively. Based on the results of this study, effective pollutant management methods can be applied to improve the water quality and achieve the target water quality of Hapcheon dam watershed.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.589-596
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• 2004

In this study, the reduction rates of nutrients were suggested to prevent eutrophication on the Hwaong reservoir in the year of 2008 and 2012. With EPA's WASP6 model, future water quality were simulated. In 2008, T-N would be 1.36mg/L and T-P 0.100mg/L on average. ; In 2012, T-N 2.66mg/L and T-P 0.128mg/L. With all the water quality management plans that the government authorities are carrying out, these results indicate that the reservoir would be reach the eutrophic or hypertrophic state according to the Vollenweider's trophic states. Therefore, the Hwaong reservoir requires additional plans for nutrients management. Here, the target water quality to prevent eutrophication of the reservoir sets into mesotrophic state ; T-N 0.475mg/L and T-P 0.02mg/L.(median of Vollenweider index for mesotropphic state) The reduction rates of nutrients on Namyang and Eoeun streams were estimated with uniform treatment method to meet the goal. The results showed that nutrients from two streams should be reduced up to 78% in 2008, and 84% in 2012. Since the ratio of T-N/T-P would be higher than 16 at target years, T-N was not considered as the limiting factor and was not reduced.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.472-479
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• 2006

In this research, speciation of phosphorus in sediment and overlying water dependent upon pH and ORP(Oxidation Reduction Potential) was studied. Three possible conditions were simulated: open system with circulation, closed system with stratification and closed system with sand capping on the sediment. Phosphorus release rate from sediment was increased for both open system and closed system if pH was less than 6.0. Phosphorus concentration for closed system was increased from 0.9 mg/L to 0.51 mg/L, and stabilized at 0.34 mg/L if anaerobic conditions were maintained in the overlying water. When sand capping was implemented, phosphorus concentrations of overlying water were maintained less than those of closed system.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.23-27
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• 1993

Ion effects on $11{\alpha}-hydroxylation$ of progesterone and $5{\alpha}-reduction\;of\;11{\alpha}-hydroxyprogesterone$ by Rhizopus nigricans were investigated. Metal ions such as $Cu^{2+},\;Cd^{2+},\;Co^{2+},\;Mn^{2+},\;Zn^{2+},\;Fe^{2+},\;Mg^{2+},\;Fe^{3+}\;and\;Na^+$ reduced the $11{\alpha}-hydroxylation$ activity, while $K^+$ stimulated the same reaction. Enzyme activity for the $5{\alpha}-reduction$ of $11{\alpha}-hydroxyprogesterone$ was increased in the presence of $Fe^{2+},\;Mn^{2+},\;Mg^{2+},\;Co^{2+},\;Zn^{2+},\;Fe^{3+},\;K^+\;and\;Na^+$, whereas it was decreased in the presence of $Cd^{2+}\;and\;Cu^{2+}$. Potassium ion of $10^{-3}\;M\;$ of concentration was found to be effective for the promotion of $11{\alpha}-hydroxylation$. On the other hand, cadmium ion of $10^{-4}\;M$ was proved to suppress the $5{\alpha}-reduction$ reaction. Progesterone is reported to be transformed into $11{\alpha}-hydroxyprogesterone$ which, in turn, is converted further into $11{\alpha}-hydroxy-allopregnane-3$, 20-dione by R. nigricans. From this point of view, the highest yield of $11{\alpha}-hydroxyprogesterone$ could be obtained when potassium ion of $10^{-3}\;M$ was given initially followed by addition of cadmium ion of $10^{-4}\;M$ to limit conversion of 11{\alpha}-hydroxyprogesterone into $11{\alpha}-hydroxy-allopregnane-\;3$, 20-dione.

• Korean Journal of Acupuncture
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• v.20 no.4
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• pp.31-40
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• 2003

Objectives : The purpose of this study is to investigate whether Haenggan(LR2) Reduction in Acupuncture affects cerebral hemodynamics〔regional cerebral blood flow(rCBF), mean arterial blood pressure(MABP)〕in normal rats, and to make manifest whether Haenggan(LR2) Reduction in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. Methods : This experiments was to investigate at the other changes of rCBF and MABP at Haenggan(LR2) Reduction in Acupuncture in normal rats, pretreated rats with indomethacin(1 mg/kg, i.v.) and pretreated rats with methylene blue$(10\;{\,u}g/kg,\;i.v.)$. Results : 1. Haenggan(LR2) Reduction in Acupuncture was significantly increased rCBF during acupuncture and after withdrawing of the needle. 2. Haenggan(LR2) Reduction in Acupuncture was decreased MABP during acupuncture, but Haenggan(LR2) Reduction in Acupuncture was increased MABP in compared with normal condition. 3. Pretreatment with indomethacin(1 mg/kg, i.v.) was significantly inhibited Haenggan(LR2) Reduction in Acupuncture induced increase of rCBF, but was increased Haenggan(LR2) Reduction in Acupuncture induced increase of MABP. 4. Pretreatment with methylene blue$(10\;{\mu}g/kg,\;i.v.)$ was significantly decreased Haenggan(LR2) Reduction in Acupuncture induced increase of rCBF and MABP. This results suggest that Haenggan(LR2) Reduction in Acupuncture increased rCBF by dilating pial arterial diameter, and the mechanism of Haenggan(LR2) Reduction in Acupuncture is mediated by guanylate cyclase.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.409-412
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• 2019

We investigated the development of a micropropagation protocol for multiplication of calla 'Gagsi' by using shoots as explant. The callus was induced on Murashige and Skoog (MS) basal medium containing cefotaxime antibiotics (25, 50, 100 mg/L). Also, MS basal medium with NAA 0.5 mg/L and BA 1.0 mg/L was used. The callus induction and browning rates were compared by treatment supplemented cefotaxime 25, 50 and 100 mg/L in basal MS medium. The callus induction rate was 10.5 % and browning rate was also, 10.5 % on the MS containing 25 mg/L. In the MNB containing cefotaxime, the callus induction rate was 34.5 % and browning rate was 27.0 %. The cefotaxime experiment has been widely used in previous studies. It is thought that it will help establish the mass multiplication system by positively affecting the growth and browning reduction of calla plants.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.68-74
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• 2010

Since ${NO_3}^-$ is amore favorable electron acceptor than Fe, high ${NO_3}^-$ loads function as a redox buffer limiting the reduction of Fe and following release of ${PO_4}^{3-}$ in flooded paddy soil. The effect ${NO_3}^-$ loaded through irrigation water on Fe reduction and ${PO_4}^{3-}$ release in paddy soil was investigated. Pot experiment was conducted where irrigation water containing 5 or 10 mg N $L^{-1}$ of ${NO_3}^-$ was continuously applied at 1 cm $day^{-1}$, and changes of ${NO_3}^-$, $Fe^{2+}$ and ${PO_4}^{3-}$ concentrations in soil solution at 5 and 10 cm depths beneath the soil surface were monitored as a function of time. Irrigation of rice paddy with water containing 5 mg N $L^{-1}$ of ${NO_3}^-$ led to reduced release of $Fe^{2+}$ and prevented solubilization of P at 5 cm depth beneath the soil surface. And application of irrigation water containing 10 mg N $L^{-1}$ of ${NO_3}^-$ could further suppress Fe reduction and solubilization of P through 10 cm depth soil layer beneath the surface. These results suggest that the introduction of high level ${NO_3}^-$ with irrigation water in rice paddy can strongly limit Fe reduction and P solubilization in root zone soil layer in addition to the excessive supply of N to rice plants.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.275-282
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• 2020

As pesticide safety was extended to agricultural environments and Positive List System was carried out, Pesticide safety management in soils has become even more important. To improve pesticide safety in soils needs the degradation technology of the residues in soils and reduce plant uptake of pesticides. In this study, biochars and quicklime as the degradation methods of pesticides (azoxystrboin, procymidone and tricyclazole) were used to identify the reduction effects. The experimental methods were putting biochars and quicklimes (0, 0.5, 1.0, 2.0% per 15 cm soil weight) in soils and analyzing the pesticide residues at 0, 10, 20, 35, 50 day. To identify the reduction effects of uptake from soil to korean cabbages (roots, leave, stems) by biochar treatment, the residues in samples were analyzed. As a results, azoxystrobin (36-96%), procymidone (40-117%) and tricyclazole (26-83%) were reduced in soils when treated with 2.0% quicklime (p<0.05). There were no reduction effect in soils when treated with 1.0% or less biochar. However, the amounts of residues translocated to roots (0.11-1.62 mg/kg), leave (0.05-0.29 mg/kg), stems (0.06-0.1 mg/kg) were reduced treated with 2.0% biochar treatments. The biochar and quicklime can be applicable to agricultural field to improve pesticide safety in soils.

• International Journal of Human Ecology
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• v.4 no.1
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• pp.25-34
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• 2003

High dietary phytate is a known factor in reducing the bioavailability of minerals such as zinc and calcium which are already chronically low in the Korean diet. This study was conducted to develop methods for reducing dietary phytate through the addition of phytate and/or the substitution of high phytate foods with low phytate foods. Ten units of phytase per 100g of uncooked brown rice were added to brown rice gruel resulted in a 16.2% phytate reduction after a 3-hour incubation period; an 18.2% reduction was produced after a 6-hour incubation period. The addition of ten units of phytase per 100g of soybean curd residue at 45$^{\circ}C$, followed by refrigeration for 3 hours, resulted in a 19.1% phytate reduction. The addition of 20 units of phytase under the same conditions reduced phytate content by 24.6%. In this study, two typical Korean meals consisting of legumes and unrefined cereals were prepared as high phytate meals; these were then compared to low phytate meals that had been prepared by treating the foods with phytase and substituting unrefined with refined cereals (i.e., brown rice with white rice, whole wheat bread with white bread). The phytate content of the two high phytate meals was 1878.2mg and 1811.8mg. After the addition of phytase and the food substitution, the phytate content of the low phytate meals was reduced to 788.9mg and 606.0mg. The phytate to zinc molar ratio of high phytate diets was 22.4 and 21.3 and 9.4 and 7.9 for the low phytate meals. These results indicate that the nutritional status of Koreans in terms zinc and other minerals can be improved by phytate reduction. This can be accomplished through the change of milling process for some cereals and/or the enzyme treatment of some high phytate food items.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.675-680
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• 2013

This research was done to evaluate the potential for destruction of perchlorate in municipal sewage. Laboratory experiments were conducted in flasks containing 3 liters of raw sewage. Sewage was mixed with defined amount of perchlorate and various additives. Perchlorate reduction in sewage did occur, but was quite variable, ranging from 0 to 72% over 72 hour. Addition of even a small amount of perchlorate acclimated biomass (167 mg/L SS) significantly reduced the lag and resulted in complete perchlorate removal. Perchlorate reduction in sewage-brine mixtures was inhibited when the dissolved oxygen level was greater than 2 mg/L, and when the mixture salinity was relatively high (conductivity = 14 mS with equivalent TDS = 8 g/L). When nitrate ($NO_3{^-}$) was present with perchlorate in the laboratory flask tests of sewage-brine mixtures, nitrate reduction proceeded first. A significant amount of nitrite ($NO_2{^-}$) accumulated in the sewage-brine mixtures, accounting for about 66% of initial nitrate nitrogen ($NO_3$-N).