• Korean Journal of Environment and Ecology
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• v.16 no.3
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• pp.239-248
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• 2002

This study was conducted to investigate the hydrological characteristics of groundwater level change and rainfall-runoff processes at the Moojechi Bog located in Mt. Jeungjok, Ulsan. The average runoff rate of bog was 0.58 which is similar to that of general mountainous watershed. In the short term hydrograph, runoff was increased slowly and It took a long time to arrive peak flow. After that time, the decreasing pattern of runoff was slower than that of general mountainous watershed. In case of the long term water budget, the Moojechi Bog had a abundant base flow and runoff was continued in spite of non rainfall period. The groundwater level was arrived peak flow immediately after rain stop but was decreased very slowly until the next rain. The change pattern of long term groundwater level was very similar to that of the amount of rain and discharge. The higher rainfall intensity was, the lower slope of recession curve on the groundwater level was and the longer rainfall duration was, the longer peak flow was. Judging from these results, Moojechi bog could be evaluated to have a constant groundwater level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.143-150
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• 1990

The changesin hardness activities of pectinestrase and polygaacturonase and amounts of pectic substances of cucumber during salting at 1$0^{\circ}C$ were investigated, The hardness of the cucumber was decreased dramatically after 3 weeks whereas activities of pectinestrase and polygalacturonase were increased until 3 weeks and 2 weeks respectively and then decrea-sed. The level of alcohol insoluble solid and protopectin in the cucumber were decreased but those of pectic acid and water soluble pectin were increased during the whole salting periods, Protopectin fractionated from alcohol insoluble solid during salting of cucumber was separated using Sephacryl S-500 It showed that high average molecular weight(AMW) of 100,000 was decreased however lower molecular weight compounds was increased. Pectic acid was observed to be decomposed from AMW 200,000 to AMW 500,000 Water soluble pectin from fresh cucumber contained higher level of pentose with peak I of AMW 2,000,000, however after 6 weeks of saltinf peak II which represented AMW 100,000 was separated. From the changes of sugar composition, the phenomena of softness during the salting was probably caused by solubilization of hemicellulose associated with pectin and decomposition of pectic substances.

• Journal of Korea Water Resources Association
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• v.47 no.1
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• pp.83-93
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• 2014

This research was carried out for suggesting design criteria and procedure for maximizing flood control capacity by building flood control facilities like flood retention basin built in connection with existing facilities in order to cope with increased uncertainty due to factors such as urbanization and climate change. We suggested the procedure for the analysis under the various scenarios applicable for the cases of determining retention basin capacity as provision for the flood water level increase in main river channel or estimating flood water level reduction effect when retention basin capacity is given. Procedure for estimating design flood hydrograph at any duration using Intensity-Duration-Quantity (IDQ) originated from the existing IDF, and its application example were provided. Based on rainfall estimated by the IDQ analysis, it is possible to calculate an equivalent peak hydrographs under various scenarios, e.g. lower frequency hydrograph under same rainfall duration with water level higher than existing hydrograph, hydrograph with same peak and higher volume due to increased rainfall duration, hydrograph with higher peak and volume than existing hydrograph, etc.

• Journal of Naturopathy
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• v.10 no.2
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• pp.108-113
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• 2021

Background: Results on the action of antioxidants in extracts of Equisetum hyemale stems and roots have already been reported, but the antioxidant properties have not been analyzed. Purpose: This study was to determine the molecular structure of antioxidants in substances extracted from E. hyemale stems and roots. Methods: Component analysis was analyzed by HPLC and LC-MS after extraction with hot water and ethyl alcohol. Results: The HPLC chromatogram of stem and root extracts showed four significant peaks at a wavelength of 205 nm. Peak 1 at 280 nm is a typical simple phenolic type, and both peaks 2-4 near 280 nm and 370 nm are typical flavonoid glycosides. As for the antioxidant level of the extract by HPLC analysis, the sum of the peaks at 740 nm was the highest at 3,669 mAU in the 100% ethanol extract, 3,096 mAU in the 70% ethanol extract, and 2,868 mAU in the hot water extract. As a result of LC-MS analysis of the antioxidant extract, kaempferol-3-sophoroside-7-glucoside with a molecular weight of 772 da at peak 3, and kaempferol-3-sophoroside-8-glucoside with a molecular weight of 788 and 772 at peak 4 was identified. Conclusions: The above results show that two types of antioxidants were identified in the antioxidant extract of E. hyemale exrtracts. Therefore, the potential as a raw material for functional cosmetics has increased.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.2
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• pp.111-122
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• 2010

As the Jamsu-bridge and the floodplains of the Han River can be flooded during the rainy season, the exact prediction of the peak flood time is very important for mitigation of flood hazard. This study analyzes the effect of outflow of Paldang Dam and tide of Yellow Sea on the Han River. A target area is from the Paldang dam to Jeonryu gauging station. Water level of Jeonryu as a downstream boundary condition was estimated through multi linear regression analysis with outflow of Paldang dam and tide level of Incheon, because it was influenced by both a tide of Yellow Sea and outflow of Paldang dam. In this study, Water Level Rising Travel Time of the Jamsu-bridge and some floodplains in the Han River are estimated. Also, The second order polynomial expressions for relationships of outflow of Paldang Dam and Water Level Rising Travel Time were developed considering the outflow of Paldang dam and tide of Yellow Sea.

• Geomechanics and Engineering
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• v.24 no.5
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• pp.479-490
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• 2021

Pre-drainage of groundwater in the roof aquifer by boreholes is the main method for prevention of roof water disaster, and the drop in the water level during the drainage leads to the variation of the local stress in the overlying strata. Based on a multitude of boreholes for groundwater drainage from aquifer above the 1303 mining face of Longyun Coal Mine, theoretical analysis and numerical simulation are used to investigate the local stress variation in the process of borehole drainage. The results show that due to the drop in the water level of the roof aquifer during the drainage, the stress around the borehole gradually evolved. From the center of the borehole to the outside, a stress-relaxed zone, a stress-elevated zone, and a stress-recovered zone are sequentially formed. Along with the expansion of drainage influence, the stress peak in the stress-elevated zone also moves to the outside. When the radius of influence develops to the maximum, the stress peak position no longer moves outward. When the coal mining face advances to the drainage influence range, the abutment pressure in front of the mining face is superimposed with the high local stress around the borehole, which increases the risk of stress concentration. The present study provides a reference for the stress concentration caused by borehole drainage, which can be potentially utilized in the optimal arrangement of drainage boreholes in underground mining.

• Journal of Environmental Science International
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• v.17 no.2
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• pp.239-248
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• 2008

The purpose of this study is to examine appropriate sub-basin division numbers that best reflect the hydrological characteristics of the basin so as to propose the criterion for dividing the sub-basin in analyzing flood runoff in the future. The characteristics of flood runoff variations were based on the WMS HEC-1 model, and the area in the upstream of the Dongbyeon water level observatory and the Geum-ho water level observatory was chosen for analysis, and examined the characteristics of the changes in flood runoff. First of all, in the targeted basin, if the sub-basin division number was 4 (that is, the area of the divided sub-basin was about 25% of the total area). Next, as the sub-basin division number gradually increased, the peak rate of runoff increased as well, and in case the sub-basin was not divided, the peak rate of runoff occurred at the earliest time. Given these results, the spatial change characteristics will be best reflected when the sub-basin is divided for analysis of flood runoff in such a way that the area of the divided sub-basin is about 25% of the total area of the basin. However, as these results are based on a limited number (4) of storms, more storm events and other basins need to be included in the review of the sub-basin division methodology.

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.62-70
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• 2002

The objective of this study was to evaluate the effects of processing parameters of co-rotating twin screw extruder and dry methods on the level of resistant starch (RS) and the properties of extrudate prepared from normal maize starch. The processing parameters were used 90, 110, 130$^{\circ}C$ in temperature, 25.0~30.0% in moisture content, 150, 200, 250 rpm in screw speed and hot and cool air drying and drying after refrigerating in drying methods. The barrel temperature and drying methods had affected the level of resistant starch of extrudate. RS levels of extrudates were ranged from 2.4 to 15.5% by AOAC method. The extrudates, extruded at 110$^{\circ}C$ and then stored at 4$^{\circ}C$, showed the highest level of RS level (15.5%). Water absorption index increased with increasing moisture content and peak temperatures and viscosities of extudates decreased compare to that of raw starch from 94$^{\circ}C$ to 50~65$^{\circ}C$ and from 220 to 46~98 RVU, respectively. Extudates treated in 90$^{\circ}C$ and 110$^{\circ}C$ showed strong peak at $2{\theta}=6.7{\sim}17.0^{\circ}$ by X-ray diffractometry and had ~150$^{\circ}C$ endotherm like as that of RS3 starch by differential scanning calorimetry. In case of 130$^{\circ}C$, extrudates showed strong peak at $2{\theta}=20.0^{\circ}$ and had 106$^{\circ}C$ endotherm.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.103-111
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• 2014

This study was to develop the flood analysis module (FAM) for implementation of a web-based real-time agricultural flood management system. The FAM was developed to apply for an individual watershed, including agricultural reservoir. This module calculates the flood inflow hydrograph to the reservoir using effective rainfall by NRCS-CN method and unit hydrograph calculated by Clark, SCS, and Nakayasu synthetic unit hydrograph methods, and then perform the reservoir routing by modified Puls method. It was programmed to consider the automatic reservoir operation method (AutoROM) based on flood control water level of reservoir. For a $15.7km^2$ Gyeryong watershed including $472{\times}10^4m^3$ agricultural reservoir, rainfall loss, rainfall excess, peak inflow, total inflow, maximum discharge, and maximum water level for each duration time were compared between the FAM and HEC-HMS (applied SCS and Clark unit hydrograph methods). The FAM results showed entirely consistent for all components with simulated results by HEC-HMS. It means that the applied methods to the FAM were implemented properly.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.46-46
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• 2021

The first purpose of this study was to evaluate the scavenging capacity (SC) of DPPH and ABTS free radicals for ethanol extract (STR-E) and its active fractions from Sophora tonkinensis root (STR). Four different fractions from STR-E were prepared by using different types of solvents such as chloroform (STR-E-C), ethyl acetate (STR-E-EA), n-butanol (STR-E-B), and water (STR-E-W). STR-E-C showed the highest value of total phenolic content, while STR-E showed the highest value of total flavonoid and terpenoid content. In STR-E and its four fractions, STR-E-EA showed the strongest SC with the lowest SC50 values of the DPPH radicals and ABTS radicals. The second purpose of this study was to evaluate anti-inflammatory activity in the lipopolysaccharide (LPS)-induced RAW 264.7 macrophages treated with STR-E, STR-E-C, and STR-E-EA, respectively. No cytotoxic effect to RAW 264.7 cells was observed at 20 ~ 25 ㎍/ml of STR-E, 10 ㎍/ml of STR-E-C, and 5 ㎍/ml of the STR-E-EA, presenting cell viability values close to that of the untreated control (100%). STR-E, STR-E-C, and STR-E-EA significantly suppressed the LPS-induced nitric oxide (NO) in a dose-dependent manner. Results of reverse-transcription (RT)-qPCR analysis showed that the peak mRNA levels of IL-1β, TNF-α, iNOS, IL-6, and IL-10 were observed in the LPS-stimulated macrophages at 4 h, 2 h, 12 h, 12 h, and 12 h, respectively. The peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 were significantly reduced in the LPS-stimulated macrophages co-treated with 20 ㎍/ml and 25 ㎍/ml of STR-E, respectively. In the case of IL-10, its peak mRNA level slightly increased without statistical significance. Compared with the LPS-stimulated macrophages, the peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 reduced in the LPS-stimulated macrophages co-treated with 10 ㎍/ml and 20 ㎍/ml of STR-E-C, respectively. In contrast, the peak mRNA level of IL-10 significantly increased at 8 h. Compared with the LPS-stimulated macrophages, the peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 reduced in the LPS-stimulated macrophages co-treated with 5 ㎍/ml and 10 ㎍/ml of STR-E-EA, respectively. In contrast, the peak mRNA level of IL-10 increased at 4 h. Taken together, our data indicated that STR-E, STR-E-C, and STR-E-EA activate macrophages to secrete both pro-inflammatory and anti-inflammatory cytokines.