• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.102-108
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• 2012

This study has performed comparative analysis on characteristics of reservoirs in their use through correlation analysis on seasonal variation of water quality factors in agricultural reservoirs and multipurpose dams. Agricultural reservoirs show the high relationship between Chl-a and other water quality factors while the correlation among COD, BOD, and SS is strong in multipurpose dams. Agricultural reservoirs have the high relationship between various water quality factors in season such as Chl-a and pH ($R^{2}=0.294$) in Spring, pH and water temperature ($R^{2}=0.246$) in Summer, and Chl-a and BOD ($R^{2}=0.435$) in Fall, and between COD and BOD ($R^{2}=0.370$) in Winter, respectively, for Sapgyo reservoir while Chl-a and T-P ($R^{2}=0.739$) in Spring, T-P and SS ($R^{2}=0.876$) in Summer, and Chl-a and SS ($R^{2}=0.600$) in Fall, and between COD and SS ($R^{2}=0.998$) in Winter, respectively, for Seokmun reservoir. Boryeong dam has the strong relationship between T-P and SS ($R^{2}=0.511$) in Spring while the relation between COD and SS is high in other seasons with the values of $R^{2}$ of 0.362, 0.665, and 0.500 in Summer, Fall, and winter, respectively. The first and second water quality factors in relationship are COD and BOD in Sapgyo and Seokmun reservoirs, which is similar to the characteristics in Winter for multipurpose dams. Chl-a has no relationship with other water quality factors in Boryeong dam in operation for both flood control and low water regulation purposes. The result of this research is expected to provide contributions to the seasonal water quality control and analysis on characteristics for each reservoir by monitoring.

• Journal of Korean Society on Water Environment
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• v.37 no.1
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• pp.32-46
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• 2021

South Korea has been divided into quantities and water quality, and due to a revision of the Government Organization law in June 2018, the controversial water management system was integrated into the Ministry of Environment. The total Maximum Daily Loads System has been called the flower of water quality control, and since 2004, all three major river systems which have been introduced into the Han River system, despite its various difficult environments, and subsequently leading to all of the four major rivers undergoing obligatory implementation since 2013. Currently, the target TMDL (Han River Phase 1 and Other Water Systems Phase 3) for the 2020 stage has been implemented. The domestic TMDL established a basic plan for calculating the load which complies with the unit watershed's target water quality, as well as an implementation plan for annual load management, both which have been institutionalized in order to evaluate load compliance on a repeated annual basis. Local governments ask external organizations to conduct investigations every year in order to assess the transition, which thereby requires tens of millions of won every year. Therefore, an assessment and management model that can be easily operated at the TMDL personnel level is required. In this study, when the Han river Water System TMDL was implemented in earnest, we confirmed the the water quality improvement effect when TMDL was introduced to major inflow tributaries (TancheonA, JungnangA, AnyangA) under the Seoul City's jurisdiction through the use of the total amount control unit basin evaluation technique. By presenting customized management measures, we propose the guidelines that are necessary for determining more effective water environmental policies.

• Journal of Aquaculture
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• v.18 no.1
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• pp.7-12
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• 2005

This study was conducted to investigate antioxidant enzyme activity (catalase and superoxide dismutase) and Heat Shock Protein 70 (HSP70) mRNA variation in hepatopancreas of abalone (Haliotis discus hannai) cultured under several acute water temperatures. Abalones were cultured at 10, 15, 20, 25 and $30^{\circ}C$, for 0, 6, 12, 24 and 48 hours, respectively. The HSP70 mRNA expression in hepatopancreas was more increased at $30^{\circ}C$ compared to those at 10. 15, 20 (control) and $25^{\circ}C$. The superoxide dismutase (SOD) activity was increased in hepato-pancreas at all water temperature conditions compared to the control ($20^{\circ}C$). The SOD activity at high water temperature (25 and $30^{\circ}C$) tended to be increased after 12 hours, and was increased immediately after exposure to low water temperature (10 and $15^{\circ}C$). and then was recovered to starting level after the increase. Also, catalase (CAT) activity in hepatopancreas was increased in all the groups except for at $10^{\circ}C$ than the control ($20^{\circ}C$). Survival rate of abalone was $100\%$ at 10, 15, 20 and $25^{\circ}C$, but $92\%$ at $30^{\circ}C$. Thus, according to our study, when abalone is appeared at $20^{\circ}C$, defense mechanism against stress at low water temperature can be accelerated to be stabilized at about $5^{\circ}C$. In the case of exposure of abalone to high water temperature, antioxidant enzyme and HSP70 expression were increased due to elevated physiological stimulation factor, such as temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.412-417
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• 1993

This experiment was conducted to study the effect of old antler extracts on the hepatic detoxifying enzyme activities of the benzo(a)pyrene (B(a)P)-induced rats. Male Sprague-Dawley rats were divided into four groups and fed either AIN-76 diet or modified AIN-76 diet with old antler extracts (Water-ext, Neutral-ext, Ether-ext) four weeks. B(a)P treatment significantly decreased growth performance of rats. But this decrement was prevented by supplementation of old antler extracts. B(a)P treatment elevated glutathione peroxidase (GSH-Px) activity of rats, but this increment was reduced by old antler extracts supplementation. There was a tendency of lower cytochrome P-450 contents in B(a)P treated rats. However administration of old antler extracts increased this enzyme activity. Hepatic glutathione (GSH) levels were not affected by the old antler extracts administration. Lipid peroxide (LPO) levels were higher in the B(a)P treatment than in the control group and lower by old antler extracts supplementation. Present data showed that old antler extracts influenced on B(a)P-treated rats, and also the degree of antihepatotoxic effect was greater in water extract supplemented rats.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.117-133
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• 2008

Objectives : Since ancient times, Koreans have applied medicinal spabaths for treatment of various diseases. The objective of this study was to investigate the effect of strontium, one of the common ingredients of such baths, experimentally on acute skin barrier damage. Materials and Methods : Male hairless mice, average weight 20g, were divided into six groups. Each group consisted of five mice. The first was the normal, non-treated group. The second was the control group with acute skin barrier damage intentionally induced by TS. The third was the Ba-Sr1 group bathed in 1mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fourth was the Ba-Sr7 group bathed in 7mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fifth was the Sr1 group bathed in 1mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. The sixth was the Sr7 group bathed in 7mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. External changes of skin, skin erythema level, transepidermal water loss level, and GOT and GPT level of each group were checked immediately before and after TS, 3 hrs, 5 hrs and 24 hrs after inducing acute skin barrier damage. Then, tissue samples were made and examined for damage to epithelial cells, stratum corneum, change of mucous polysaccharide in dermis and amount of mast cells. Statistical analysis was performed by one way-ANOVA, Scheffe and Duncan for a post hoc test and pairwise comparison for comparing for difference between each time. Statistical significance was achieved if the probability was less than 5% (p<0.05) Results : 1. From skin erythema and TEWL level indicating the function of the skin barrier, we can know that it is helpful to the skin barrier to bathe in a water solution including a low concentration of strontium. 2. In the control group with acute skin barrier damage induced by TS, skin barrier damage persisted until 3-5 hrs and recovered after 5-24 hrs. Differently from the control group, in the case of taking a bath in a water solution including strontium, skin barrier damage recovered after only 3-5 hrs. Therefore, the bath with a water solution including strontium can promote recovery of the skin barrier. 3. Bathing in water solution including a higher concentration of strontium was more beneficial to recovery of skin barrier damage. 4. There was no influence on serum GOT and GPT from bathing in a water solution including strontium. Conclusions : The strontium was effective for recovery and mitigation of acute skin barrier damage induced by tape stripping. I suggest that strontium (Sr) can be used as an external treatment medicine, addedinto bath water to treat acute skin barrier damage.

• Journal of Environmental Impact Assessment
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• v.16 no.2
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• pp.143-156
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• 2007

This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.327-334
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• 2006

In tomato perlite bag culture, the available water content was analyzed for several sorts of perlite so that the irrigation safety was investigated and thus the irrigation strategy controlled by time clock was established. The reduction trends of water content in perlite bags were monitored for tomatoes, of which fruits were harvested until the fifth cluster. The amount of daily reduction of water in the bag was on the decrease as the total water in the bag was decreased. In terms of time interval from when the water content based on weight was reduced more than 50g to when it was dropped again, the longest time interval in a day was retarded gradually. It means plant activity was recovered later than the previous day. The available water content in perlite bag of 40 liters was about 30% which was 12 kg in weight, which satisfied daily water demand of 6 tomato plants. The appropriate time irrigated by time clock was recommended for the case that it was irrigated 5 or 10 times a day with the daily integrated solar radiation of 601 or $1,519W/m^2$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.45-49
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• 1972

The following are some results obtained from a series of experiments in rotifer culture and its usage for the food of tiny fish fry: 1, Outdoor concrete ponds, each being $16m^2$, were used to culture the rotifers, Brachionus calyciflorus, and Filinia longiseta. Brachionus calyciflorus usually attained the population of about 100 individuals per ml of pond water. Dipterex was usually applied to control Daphni,a and other crustaceans that generally appear and feed on rotifers. A concentration of 0.16 to 0.2 ppm in the pond water was sufficiently effective to control these natural enimies of rotifers. Poultry dung was very effectively used to multiplicate rotifers. The fertilization ratio was about 8 kg each pond with 30cm depth of water. 2. The tiny rotifer, Filinia longiseta attained a very high population density of about 1,000 individuals per ml of pond water, but they were very sensitive to dipterex, and for this aspect future investigation may be needed. 3. In the outdoor ponds, the multiplication of rotifers significantly decreased when the water temperature falls to about $20^{\circ}C$ in autumn. 4. In the laboratory room, unicellular planktonic algae such as Scenedesmus or Chlorella, as the food of rotifers, were collected from the outdoor ponds by dipping them together with water, and were effectively used for the culture of Brachionus calyciflorus. If the planktonic algae are cultured in specially designed containers, the sun-light would be the most effective means as the source of light. 5. Brachionus calyciflorus cultured in the outdoor ponds by the dipterex controlled method was highly efficient to rear the early fry of marble gourami. The dipterex content mixed in the water to control the crustacean emmies of rotifers sieved no harm to the gourami fish fry.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.877-887
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• 2020

A 3-Dimensional hydrodynamic and water quality model was applied to evaluate the effects of weir gate operations on water quality and harmful algal bloom (HAB) occurrences at selected locations in the Nakdong River, Geum River, and Yeongsan River. For the Geum River and Yeongsan River, when the gates are left open, annual and summer Chl-a and HABs were decreased at upstream locations, Sejong Weir and Seungchon Weir, but summer average concentrations of Chl-a and HABs were increased at downstream locations, Baekje Weir and Juksan Weir. For the open scenario, the reduced hydraulic residence time in the upper stream areas of the Geum River and Yeongsan River would allow less available time for nutrient consumption that would result in higher dissolved inorganic phosphorus concentrations followed by higher algal growth in the downstream areas. However, in the case of the Nakdong River, both annual and summer Chl-a and HABs were increased in all locations for the open scenario. This condition seems to be resulted in due to increased light availability by reduced water depths. Changes in Chl-a and HABs occurrences due to the water gate control in the study sites are different due to differences in physical, chemical, and biological conditions in each location.

• Journal of Korea Water Resources Association
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• v.50 no.2
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• pp.111-119
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• 2017

The underflow type movable weirs were arranged in a multi-stage way along a reach at the Chiseong River, where flooding has been observed frequently. With management water level of the movable weirs the control effects of storage and flood were suggested and the control effects were compared with those of existed weir system. The water level for the targeted storage and flood elevation was suggested by building the artificial neural network model. When the underflow type of movable weirs were arranged in a multi-stage way, the peak flood elevation decreased by 68.28% in the downstream compared with the existed weir system, and the total storage of the target section of multi-stage movable weirs increased by 216%. As a result of numerical simulation to build the artificial neural network model, 60%, 20%, and 20% among 216 data were used for the training, validation, and test, respectively. The training result of mean square error was $0.1681m^2$ and the high coefficients of determination were 0.9961, 0.9967, and 0.9943 in the training, validation, and test, respectively. As a result the water level management of each movable weir for the controls of flood elevation in the targeted downstream and targeted storage was suggested by using the artificial neural network.