• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.951-962
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• 2019

Producing consistent, accurate soil moisture data to be utilized as a reference dataset for researches related to hydrological cycle and natural disaster is being critical, but such techniques (e.g. quality control) are still limited to improve reliability of soil moisture data. In this study, analyses of soil moisture's behavior and quality control based on International Soil Moisture Network's (ISMN's) criteria were carried out in Yongdam study watershed, which is UNESCO-IHP' representative examination area in South Korea, to suggest a direction to improve the quality of soil moisture data. The results of the behavior analysis showed normal increasing/decreasing patterns following precipitation events in all stations except two (i.e. Bugui, Ancheon). As a result of applying quality flagging technique, there were no observation recordings in abnormal range, and freezing of soil moisture occurred within general range (~20%). Soil moisture rise without prior rainfall appeared about 4% and there were less than 0.01% for spike and 5% for plateau. Producing more reliable reference data will be possible if site-specific criteria for quality control are considered enough in the future.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.167-173
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• 1991

Various formulations of oxyfluorfen were tested to evaluate effect of weed control efficacy and rice injury as affected by different degrees of water leakages. Rice injury was increased with increased water leakages. The formulations of Elvan, Coal slag and Chitosan gave slight injury to rice under all conditions included in terms of visual ratings, plant height and fresh weight production. However, weed control of most formulations was decreased and increased with increased water leakages for annual weeds and perennial weeds, respectively, Annual weeds were controlled greater than 90~ by all treatments, but perennial weed control was relatively low. Scirpus juncoides was the most tolerant annual weed to Oxyfluorfen. Elvan formulation showed somewhat decreased control of barnyardgrass with increased water leakages. The promising formulations of Oxyfluorfen were Chitosan, Coal slag, Bentonite B and Elvan (if the first releasing rate increased), which injured rice slightly and controlled annual weeds excellently regardless of degrees of water leakages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.262-266
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• 2003

The present study was carried out to investigate the relationships among intertillage and muddying by free-ranging ducks (Chinese native ducks) and pH, dissolved oxygen of irrigation water, and physicochemical properties of soil. Two paddy fields comprised of the muddying (muddy water without physical stimulation to a rice plant by the ducks) and the control plots (no ducks) were used for this study. As a muddying plot, 50 hills were randomly selected and each hill was fenced with a wire net in order to prevent from stimulating physically by the ducks. The variation in irrigation pH was smaller in the muddying plot than the control plot, and the pH was around 7.4. Dissolved oxygen was significantly higher (P＜0.01) in the muddying plot than the control plot during the first half period after the ducks were introduced. Then it decreased rapidly as the rice plants grew in all plots. The contents of the suspended soil and turbidity in irrigation water were not changed over the free-ranging period, but $\textrm{NH}_3\textrm{-N}$ and $\textrm{P}_2\textrm{O}_5$ were decreased by intertillage and muddying by the ducks. There were no differences in both the soil physics and chemistry between the muddying plot and the control plot during and after finishing of the free-ranging period. These results indicate that intertillage and muddying by the ducks resulted in a small variation in stagnant water pH, and reduced the dissolved oxygen and $\textrm{P}_2\textrm{O}_5$, although the physiochemical properties of soil were not changed.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.367-377
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• 2014

Paldang lake which is the most important water resource in Korea is classified as a stream type reservoir and water quality of Paldang lake can be significantly influenced by external pollutant source. So this study was aimed to determine focused control BOD and TP sources of each unit watershed upper Paldang lake through analysis of pollutant source distribution and pollutant runoff characteristics. Generated load, discharge load, delivery load and each load density of 11 unit watersheds upper Paldang lake were calculated using data of water quality and flow rate from pollutant sources and 74 small streams. As a result of generated load, discharge load and delivery load of BOD and TP from pollutant sources, the most BOD generated load was taken by livestock with 66% of total BOD discharge load and domestic had the most BOD discharge load, 42.7%. The ratio of delivery load of livestock and domestic was 36.4% and 34.3%, respectively. Livestock occupied high ratio of TP generated load, discharge load and delivery load with 82.5%, 44.4% and 46.7%, respectively. Gyeongan watershed which had high population density showed the highest BOD delivery load density of $14.6kg/km^2/d$ and the highest TP delivery load density with $1.23kg/km^2/d$ was analyzed in Cheongmi watershed including the biggest number of livestock. From these results, management of domestic sewer and livestock excrement was determined as a focused control pollutant source. And intensive management about domestic sewer in Gyeongan stream and livestock excrement in Cheongmi stream is required for water quality improvement of Paldang lake.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.195-205
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• 1997

This paper is to assess the effect of Adaptagen as a radioprotector in which main component is alkaloid fraction of ginseng. Evaluation was made in vitro and in vivo study with NIGP(S) mouse by the measurement of regeneration of jejunal crypt cell and micronucleus assay to analyze radioprotective effect of ginseng alkaloid fraction in comparison with that of water fraction after whole body irradiation. The results were as follows, 1. The degree of radiation damage of mouse jejunal crypt cell was diminished in both of alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group. Regeneration of mouse jejunal crypt cell was higher both in alkaloid and water fraction groups than control group. 3. In vitro study, frequency of micronucleus was diminished in tendency for the treated groups than control group but statistically insignificant. 4. In vitro study, frequency of micronucleus was diminished in both alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group.

• Journal of Radiation Protection and Research
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• v.19 no.3
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• pp.222-229
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• 1994

Radiostrontium passes the placental barrier in pregnant rodents very well. Chitosan, a natural nontoxic chelator, was reported to reduce whole body retention of radiostrontium in mice. The aim of the present study was to evaluate water soluble chitosan as a blocking agent of transplacental transfer of radiostrontium in pregnant mice. Twenty pregnant mice were divided into four groups: control and three groups of chitosan treatment (groups 1 to 3). Sr-85(15KBq in 0.2ml saline) was subcutaneously injected into pregnant mice at the 17th day of pregnancy. In control mice, 0.2ml saline was given 5 hours after the injection of Sr-85. In group 1, 1% water soluble chitosan was given subcutanously for two days, twice daily after the injection of Sr-85. In group 2, 10% water soluble chitosan was given orally for 15 days before conception. In group 3, 0.3% water soluble chitosan was injected intravenously for 15 days, once daily before conception. Gamma counting of newborns were done at days 0, 2 and 7 after their births. Whole body retention of Sr-85 in newborns of control mice at days 0, 2, 7 were $3.1{\pm}0.3%,\;2.9{\pm}0.3%,\;2.8{\pm}0.3%$ respectively. In experimental groups, whole body retention of Sr-85 was significantly lower than that of control (p<0.01) and no statistical difference was noted between them. In group 1, the values were $2.1{\pm}0.3%,\;1.4{\pm}0.1%,\;1.4{\pm}0.1%$, respectively. In group 3, they were $2.1{\pm}0.2%,\;1.7{\pm}0.2%,\;1.6{\pm}0.2%$, respectively. In conclusion, the water soluble chitosan reduced transplacental contamination of radiostrontium in pregnant mice.

• The Journal of Internal Korean Medicine
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• v.37 no.3
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• pp.427-441
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• 2016

Objectives: This study investigated the aconitine contents analysis of Buja extracts (raw material of Buja, hot water extract of Buja, and hot water extract of Sambu-tang) and the single oral dose toxicity of Sambu-tang-R in six-week-old Sprague-Dawley rats in order to compare the toxicity of Buja extracts.Methods: Aconitine content analysis is that Buja extracts were hold purity test. To detect single oral dose toxicity, six-week-old Sprague-Dawley rats were divided into two groups, a normal control group and a sambutang-R (2,000 mg/kg) group. For 14 days of treatment, clinical signs, body weight, clinical chemistry, necropsy, and histopathology were examined.Results: The aconitine contents of the Buja extracts were Buja-RH (0.1738%), Buja-RD (0.1746%), and Sambu-tang-R (0.0961%). There were no cases of death in either the control group or the experimental group. Nor was there any disorder to the clinical signs or any significant change in body weight in either group. There was no significant change of clinical chemistry or disorder of necropsy findings in either the control or the experimental group. And there was no difference in histopathological findings in comparing the control group with the experimental group.Conclusions: These results suggest that the aconitine content of the hot water extract of Buja was similar to the raw material of Buja, but the hot water extract of Sambu-tang had greatly decreased aconitine content. These results also suggest that a single oral lethal dose of Sambu-tang-R for Sprague-Dawley rats exceeds 2,000 mg/kg for both female and male rats.

• Journal of Life Science
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• v.18 no.6
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• pp.852-857
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• 2008

The effects of Bulnesia sarmienti water extract on lipid metabolism were investigated in type-1 diabetes rats. The rats were fed a basal diet and B. sarmienti water extract for 8 weeks. The rats were randomly assigned to each treatment group: normal, control, three kinds of treatment group (BWO: 0.45 mg/ml, BW1: 0.9 mg/ml, BW2: 1.8 mg/ml). After 8 weeks of experimental diets consumption, the body weights and food efficiency ratio of B. sarmienti water extract fed groups were not change with those in the control group. The concentration in plasma total-cholesterol, LDL-cholesterol, triglyceride were significantly decrease in the B. sarmienti water extract groups compared with those in the control group. Although it was not possible to observe blood glucose control effects of eight weeks of B. sarmienti water extract feeds in type-1 diabetes model, it was discovered that the feeds are highly effective in lowering the levels of blood lipid substances triglycerides, total-cholesterol, and LDL-cholesterol.

• Applied Microscopy
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• v.41 no.1
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• pp.21-29
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• 2011

Balneotherapy has been widely used for the treatment of skin diseases in the world. The purpose of this study was to determine the bath effect of the alkaline reduced spring water with the properties of high pH and low oxidation reduction potential (ORP) on the skin injury induced by ultra violet (UV) irradiation. For this purpose, hairless mice were irradiated with UV-B to cause skin injury, and individually taken a bath in spring water (experimental group) and tap water (control group) once a day for 40 min during 21 days. We observed histological changes of the back skin through macro- and microscopic methods compared to the control group. We found that skin injury of the experimental group was more quickly recovered than that of the control group. Under the light microscope, the experimental group showed that epidermal thickening (p<0.01) and the mast cell activation (p<0.001) were lower compared with the control group, in addition infiltration of inflammatory cells and degranulation of mast cells were less observed. These results suggest that regular bath in the spring water with the properties of high pH and low ORP has a positive effect on the skin injury induced by UV irradiation.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.350-357
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• 2023

Marine accidents frequently occur due to the unreasonable operation of ships excluded from ship departure control during marine special weather warnings within smooth water areas. Coastal wave buoys installed in smooth water areas are major reference indicators for ship departure control and can be seen as being directly connected to the safety of ships navigating smooth water areas and the coast. In this study, the location appropriateness of currently operating coastal wave buoys and additional installation in the smooth water areas were assessed by analyzing coastal marine accidents over the past 30 years (1991-2020), the main wind direction and wind speed of each major trading port, and the GICOMS ship track data in 2018. The study results showed that an additional coastal wave buoy should be installed at each of the major trading ports(Inchon Port, Pohang Port, Ulsan Port, and Busan Port) and that the location of the coastal wave buoy needs to be moved in the case of Busan Port. Based on various data analysis in this study, the suggestion for an additional installation and movement of the coastal wave buoy presented in this study is expected to contribute to improving the reliability of ship departure control and resolving safety blind spots.