• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.145-152
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• 2006

Industry development caused numerical and quantitative increase of noxious chemical substances that contain risk assessment in water resources. For use of efficient water resources a pre-treatment of contaminant source which is flowed in water resources is recognized in essential process. Therefore, the discharged water quality from discharged company began to control contaminant by total amount of pollutant in domestic. However, to estimate closely chemical substances it is not proved up to now, monitoring is very important. This study achieved a monitoring of micro noxious chemical substance by fiber and chemistry industrial wastewater inflow to examine risk assessment of the water system of Nakdong river. Chloroform was measured highest among volatile organic compounds (VOCs) that the results of water quality of influent and effluent are detected from 7 companies of study area. The other side, because measured value of detected chloroform is indefinite detection level in the same company, it is difficulty in management of water quality. However it may not be much effects of the water system of Nakdong river because these company's effluent is high treatment efficiency of chloroform (more than 88%) in sewage treatment plant. On the other hand, in the investigated results for the European Union specified priority substance that is detected to relationship influent and effluent from fiber/chemistry associated industries, these substances were not detected and domestic data was hardly referred. Therefore, data construction of continuous monitoring about this water quality may have to be achieved certainly to utilize as country policy.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.31-39
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• 2020

Cheonji, the largest caldera lake in Asia, is located at the summit of Baekdu Mountain. Cheonji is covered with snow and ice for about six months of the year due to its high altitude and its surrounding environment. Since most of the sources of water are from groundwater, the water temperature is closely related to the volcanic activity. However, in the 2000s, many volcanic activities have been monitored on the mountain. In this study, we analyzed the dimension of ice produced during winter in Baekdu Mountain using Sentinel-1 satellite image data provided by the European Space Agency (ESA). In order to calculate the dimension of ice from the backscatter image of the Sentinel-1 satellite, 20 Gray-Level Co-occurrence Matrix (GLCM) layers were generated from two polarization images using texture analysis. The method used in calculating the area was utilized with the Support Vector Machine (SVM) algorithm to classify the GLCM layer which is to calculate the dimension of ice in the image. Also, the calculated area was correlated with temperature data obtained from Samjiyeon weather station. This study could be used as a basis for suggesting an alternative to the new method of calculating the area of ice before using a long-term time series analysis on a full scale.

• Journal of Conservation Science
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• v.35 no.6
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• pp.641-651
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• 2019

This study investigates three buildings arranged alongside at the same level, namely, the Josadang, the Buljojeon, and the Palsangjeon. Their backside is blocked by an embankment with an environmental condition unsuitable for wooden buildings. The pillar behind the Josadang had termite damage for which termite damage and environmental investigations had been conducted for the past four years. The termite damage was monitored four times using the termite detection dogs, and the environmental factors were surveyed 27 times, except during the winter season. As a result, the locations of the columns with a high frequency of responses from the termite detection dogs were found and damage was confirmed. According to the surface moisture content investigations, the surface moisture content was highest in the Josadang and lowest in the Buljojeon. After a statistical analysis, the mean, the median, and the mode values were compared. The difference between the mean and the median was found to be less, however, the mode varied significantly. The mode values of the Josadang and the Palsangjeon were 14.5% and 10.8%, respectively, higher than the 6.1% mode value of the Buljojeon. It was concluded that the temperature and the water content affected the termite damage, which increases if the temperature and the water content remain constant owing to the environmental factors.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.461-470
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• 2019

This study was carried out to quantify the drought stress in grafted watermelon seedlings non-destructively by using chlorophyll fluorescence (CF) imaging technique rather than the visual judgment. Six-day old watermelon seedlings were grown under uniform irrigation for 3 days, and then given drought stress. Afterward, the sensor for the measurement of water content in plug tray cell unit was used to classify the drought-stress level into nine groups from D1 (53.0%, sufficient moisture state) to D9 (15.7%, extremely dry stress), and the 16 CF parameters were measured. In addition, re-irrigation was performed on the drought stressed seedlings(D5 - D9) to determine the growth and photosynthesis recovery level, which was not confirmed by visual judgment. The kinetic curve patterns of CF in three different drought stressed seedling groups were found to be different for the early detection of drought stress. All the 16 CF parameters decreased continuously with exposure to drought stress and drastically decreased from D5 (32.1%) where the visual judgment was possible. The fluorescence decline ratio (Rfd_Lss) started to decrease from the initial drought stress level (D5 - D6), and the Maximum PSII quantum yield (Fv/Fm) was significantly decreased in the later extreme drought stress range (D7 - D9) by re-irrigation recovery test. Thus, Rfd_Lss and Fv/Fm parameters were finally selected as potent indicators of growth and photosynthesis recovery in the initial and later stages of drought stress. Also, to the differences in the numerical values of the individual chlorophyll fluorescence parameters, the drought stress level was intuitively confirmed through the image. These results indicate that Rfd and Fv/Fm can be considered as potential CF parameters for the detection of low and extremely high drought stress, respectively. Furthermore, Fv/Fm can be considered as the best CF parameters for recovery at re-irrigation.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.43-50
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• 2014

To describe the macroscopic anatomy and ovarian-physiological difference of the genital organs of the female Korean water deer, organs from captured animals in a wild area of Korea were dissected. The ovary of estrus group was about $1.10{\pm}0.02mm$ long and weighed about $0.50{\pm}0.02g$. And pregnant group was about $1.3{\pm}0.10mm$ long and weighed about $0.40{\pm}0.05g$. And the crowns of corpora lutea were found in the estrus group, but we couldn't find crowns at the pregnant group. Especially, the estrus ovaries tended (p=0.04) to be heavier than the ovaries during pregnancy. The MMP-9 activity was higher at the Graafian follicles of pregnant group than that in estrus group. However, with regard to follicles of estrus group, MMP-2 level was higher than that in pregnant group. Furthermore, apoptosis detection marker (Casp-3) was highly expressed in Graafian follicle of the pregnant group and the corpora lutea of estrus group. Thus, the differential expression of MMPs observed in this study suggests that the reflected the mechanisms underlying of monovulatory in estrus and/or pregnancy. Our results may be very useful as it provides with information that may be considered for the development of reproductive biotechnologies in endangered animals.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.473-480
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• 2018

The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for pre-deposition was $35.0g/m^2$. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited $35.0g/m^2$ $FeO_xH_y$, $MnFe_2O_4$ and $Fe_3O_4$ on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was $FeO_xH_y$ > $MnFe_2O_4$ > $Fe_3O_4$. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.615-624
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• 2010

The aims of this study were to investigate and confirm the occurrence and distribution patterns of synthetic musk compounds (SMCs) in Nakdong river basin (mainstream and its tributaries). 4 (HHCB, AHTN, AHMI and ADBI) out of 6 polycyclic musk compounds (PMCs) and 1 (musk xylene, MX) out of 5 nitro musk compounds (NMCs) were detected in 29 sampling sites and HHCB (>50%) was predominant compound followed by musk ketone (MK) and AHTN. The total concentration levels of SMCs on February 2009 and on September 2009 in surface water samples ranged from N.D. to 2147 ng/L and N.D. to 1386 ng/L, respectively. The highest concentration level of SMCs in the mainstream and tributaries in Nakdong river were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the SMCs levels in river and the SMCs levels decreased with downstream because of dilution effects.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1375-1382
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• 2007

A column preconcentration method with pulverized Amberlite XAD-4 loaded with bismuthiol I (BI) has been developed for the determination of trace Cd(II) and Cu(II) in various real samples by flame atomic absorption spectrophotometry. Various experimental conditions, such as the size of XAD-4, adsorption flow rate, amount of bismuthiol I, stirring time for adsorbing bismuthiol I on XAD-4, pH of sample solution, amount of XAD-4- BI, desorption solvent, and desorption flow rate, were optimized. Also, the adsorption capacity and the adsorption rate of Cd(II) and Cu(II) on XAD-4-BI were investigated. The interfering effects of various concomitant ions were investigated, Bi(III), Sn(II) and Fe(III) were found to affect the determination. But the interference by these ions was completely eliminated by adjusting the amount of XAD-4-BI resin to 0.70 g, although the adsorption flow rate was slower. For Cd(II) our proposed technique obtained a dynamic range of 0.5-40 ng mL-1, a correlation coefficient (R2) of 0.9913, and a detection limit of 0.3 ng mL-1. For Cu(II), the corresponding values were 2.0-120 ng mL-1, 0.9921 and 1.02 ng mL-1. To validate this proposed technique, the aqueous samples (stream water, reservoir water, tap water and wastewater), the diluted brass sample and the plastic sample, as real samples, were used. Recovery yields of 91-103% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. Our proposed method was also validated using rice flour CRM (normal, fortified) samples. From the results of our experiment, we found that the technique we present here can be applied to the determination of Cd(II) and Cu(II) in various real samples.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.66-74
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• 1992

A method for the multiresidual simultaneous analysis of 11 thiocarbamates was studied using HPLC. Thiocarbamate in Chinese cabbage was analyzed in the order of extraction, partition, and cleanup in their optimum condition. Acetone was chosen as an extracting solvent. As a partitioning solvent, the mixture of 50% methylene chloride and petroleum ether containing extremely small water content showed good recoveries of thiocarbamate from the water layer. Partition efficiency was affected by pH of the water layer; it remained almost constant under the acidic and neutral condition while decreasing under the basic condition. The comparison done in cleanup step showed that the column chromatographic method is superior to the treatment of coagulating reagent. As an absorbent, the mixture of charcoal, magnesia, and celite with the ratio of 1 : 2 : 4 gave better recoveries and also effectively removed chlorophyll. Over the total procedure, the average recoveries for thiocarbamates in Chinese cabbage were 91% at about 2 ppm fortification level within the relative standard deviation of 8%, and the minimum detection limit (MDL) was 2.2${\sim}$9.3 ng.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.424-424
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• 2017

Several studies of the world have analyzed the regional rainfall trends in large data sets. However, it reported that the long-term behavior of rainfall was different on spatial and temporal scales. The objective of this study is to determine the local trends of rainfall indices in the Yom River Basin, Thailand. The rainfall indices consist of the annual total precipitation (PRCTPOP), number of heavy rainfall days ($R_{10}$), number of very heavy rainfall days ($R_{20}$), consecutive of dry days (CDD), consecutive of wet days (CWD), daily maximum rainfall ($R_{x1}$), five-days maximum rainfall ($R_{x5}$), and total of annual rainy day ($R_{annual}$). The rainfall data from twelve hydrological stations during the period 1965-2015 were used to analysis rainfall trend. The Mann-Kendall test, which is non-parametric test was adopted to detect trend at 95 percent confident level. The results of these data were found that there is only one station an increasing significantly trend in PRCTPOP index. CWD, which the index is expresses longest annual wet days, was exhibited significant negative trend in three locations. Meanwhile, the significant positive trend of CDD that represents longest annual dry spell was exhibited four locations. Three out of thirteen stations had significant decreasing trend in $R_{annual}$ index. In contrast, there is a station statistically significant increasing trend. The analysis of $R_{x1}$ was showed a station significant decreasing trend at located in the middle of basin, while the $R_{x5}$ of the most locations an insignificant decreasing trend. The heavy rainfall index indicated significant decreasing trend in two rainfall stations, whereas was not notice the increase or decrease trends in very heavy rainfall index. The results of this study suggest that the trend signal in the Yom River Basin in the half twentieth century showed the decreasing tendency in both of intensity and frequency of rainfall.