• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.161-168
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• 2016

In this study, growth enhancing effect of hatchery waste egg decomposed liquid fertilizer in pepper plant cultivation through chlorophyll fluorescence (O-J-I-P) analysis. In a whole growth period, egg decomposed fertilizer treated pepper grew well than non treated plant, though it was not statistically significantly different. Amount of chlorophyll fluorescence of non treated plant was higher thant that of fertilizer treated plant. It is determined that eventually lead to increased photosynthesis. In this study, six parameters, Fo, ABS/RC, RC/ABS, TRo/RC, DI0/RC, and DF Total ABS were the important factors represent efficiency of photochemical responses of pepper plant treated with hatchery waste egg decomposed fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.119-127
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• 2018

Veterinary antibiotics (VAs) has been used to treat animal disease and to increase body weight. However, released VAs in the soil via spreading of compost can transport to plant and affect its growth. Main purpose of this research was i) to monitor VAs concentration in plant and ii) to evaluate inhibition effect of VAs residuals on the plant growth. Red lettuce (Lactuca sativa) was cultivated for 35 days in the pot soil spiked with 3 different concertation (0.05, 0.5, $5.0mg\;kg^{-1}$) of chlortetracycline (CTC) and sulfamethazine (SMZ). After 35 days of cultivation, concentration of CTC and SMZ in the plant was measured. Residual of CTC and SMZ was only quantified at the range of $0.007-0.008mg\;kg^{-1}$ and $0.006-0.017mg\;kg^{-1}$ in the leaf and root respectively when high concentration ($5.0mg\;kg^{-1}$) of antibiotic was spiked in the soil. Leaf length and root mass was statistically reduced when $0.05mg\;kg^{-1}$ of CTC was spiked in the soil while no statistical difference was observed for SMZ treatment. This result might indicated that high $K_{ow}$ and $K_d$ value are the main parameters for inhibiting plant growth. Antibiotics that has a high $K_{ow}$ causing hydrophobicity and easy to bioaccumulate in the lipid cell membrane. Also, antibiotics that has a high $K_d$ properties can be sorbed in the root causing growth inhibition of the plant. Overall, management of VAs should be conducted to minimize adverse effect of VAs in the ecosystem.

• Korean Journal of Pharmacognosy
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• v.52 no.3
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• pp.186-191
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• 2021

We developed a method to identify and quantify 6-hydroxyluteolin 7-O-glucoside in the powder of Salvia plebeia (PS) using high-performance liquid chromatography coupled with diode array detector (HPLC/DAD) and equipped with reverse-phase INNO C18 column. The analytical method was optimized and validated using novel parameters. The obtained values for the limits of detection and quantification were 3.60 and 10.90 ㎍/mL, respectively. Calibration curve showed good linearity in the concentration range tested (0.00625-0.1 mg/mL, r² = 1.0000), high accuracy (96.2-101.4%), and precision values (RSD ≤ 0.27%). Our analysis support the use of our method for accurately identifying and quantifying 6-hydroxyluteolin 7-O-glucoside from PS in routine analyses and large-scale extraction processes for content determination.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.398-407
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• 2021

Using salt-tolerant bacteria to protect plants from salt stress is a promising microbiological treatment strategy for saline-alkali soil improvement. Here, we conducted research on the growth-promoting effect of Brevibacterium frigoritolerans on wheat under salt stress, which has rarely been addressed before. The synergistic effect of B. frigoritolerans combined with representative salt-tolerant bacteria Bacillus velezensis and Bacillus thuringiensis to promote the development of wheat under salt stress was also further studied. Our approach involved two steps: investigation of the plant growth-promoting traits of each strain at six salt stress levels (0, 2, 4, 6, 8, and 10%); examination of the effects of the strains (single or in combination) inoculated on wheat in different salt stress conditions (0, 50, 100, 200, 300, and 400 mM). The experiment of plant growth-promoting traits indicated that among three strains, B. frigoritolerans had the most potential for promoting wheat parameters. In single-strain inoculation, B. frigoritolerans showed the best performance of plant growth promotion. Moreover, a pot experiment proved that the plant growth-promoting potential of co-inoculation with three strains on wheat is better than single-strain inoculation under salt stress condition. Up to now, this is the first report suggesting that B. frigoritolerans has the potential to promote wheat growth under salt stress, especially combined with B. velezensis and B. thuringiensis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.238-246
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• 2005

Rice yield and protein content have been shown to be highly variable across paddy fields. In order to characterize this spatial variability of rice within a field, two-year experiments were conducted in 2002 and 2003 in a large-scale rice field of $6,600m^2$ In year 2004, an experiment was conducted to know if variable rate treatment (VRT) of N fertilizer, that was prescribed for site-specific management at panicle initiation stage, could reduce spatial variation in yield and protein content of rice while increasing yield compared to conventional uniform N topdressing (UN, 33kg N/ha at PIS) method. VRT nitrogen prescription for each grid was calculated based on the nitrogen (N) uptake (from panicle initiation to harvest) required for target rice protein content of $6.8\%$, natural soil N supply, and recovery of top-dressed N fertilizer. The required N uptake for target rice protein content was calculated from the equations to predict rice yield and protein content from plant growth parameters at panicle initiation stage (PIS) and N uptake from PIS to harvest. This model· equations were developed from the data obtained from the previous two-year experiments. The plant growth parameters for the calculation of the required N were predicted non-destructively by canopy reflectance measurement. Soil N supply for each grid was obtained from the experiment of year 2003, and N recovery was assumed to be $60\%$ according to the previous reports. The prescribed VRT N ranged from 0 to 110kg N/ha with an average of 57kg/ha that was higher than 33 kg/ha of UN. The results showed that VRT application successfully worked not only to reduce spatial variability of rice yield and protein content but also to increase rough rice yield by 960kg/ha. The coefficient of variation (CV) for rice yield and protein content was reduced significantly to $8.1\%$ and $7.1\%$ in VRT from $14.6\%$ and $13.0\%$ in UN, respectively. And also the average protein content of milled rice in VRT showed very similar value of target protein content of $6.8\%$. In conclusion the procedure used in this paper was believed to be reliable and promising method for reducing within-field spatial variability of rice yield and protein content. However, inexpensive, reliable, and fast estimation methods of natural N supply and plant growth and nutrition status should be prepared before this method could be practically used for site-specific crop management in large-scale rice field.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.184-192
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• 2016

A profiling monitoring system has been developed to monitor the water quality variations according to each water depth and applied for a test-bed. The key parameters were derived to disclose the aquatic ecology and environment of river systems, and the real-time monitoring techniques to profile the variations of each parameter were verified. Monitoring parameters were configured to include water quality, hydrodynamic, and weather conditions. Considering the water depth of the 4 major rivers in Korea, a profiling monitoring system with 1.0 m water depth interval for each monitoring has been established. To understand the real-time variation properties in the Han river, the monitoring system has been installed and operated at the YangHwa-Dock as a test-bed. Based on the results of the detailed analyses on the spring season, as the characteristic diurnal and water-depth-related variations for water temperature, pH, dissolved oxygen (DO), and chlorophyll-a were observed, it could be concluded that the real-time water-depth profiling monitoring system is a very effective tool for the proper management of river environment.

• Toxicological Research
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• v.28 no.4
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• pp.279-288
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• 2012

Rats were administered zearalenone (ZEA) via gavage at dosages of 0, 1, 5, and 30 mg/kg for 36 days. On treatment day 8, inactivated porcine parvovirus vaccine (Vac) was injected intraperitoneally. Antibody production against porcine parvovirus was then measured as a function of ZEA treatment. Compared to the vaccine alone, ZEA treatment, with or without Vac, decreased the serum level of IgG. The level of IgM decreased in all ZEA groups at day 22, but the decrease was sustained only in the medium-dose ZEA group at day 36. The level of IgA was unchanged in the Vac only and ZEA groups at day 22, but was decreased in the 5 mg/kg ZEA plus Vac group compared to the Vac only group at day 36. The level of IgE was decreased by all doses of ZEA at day 22, but was unaffected in ZEA plus Vac groups compared to the Vac only group. The levels of IL-1 in the thymus and spleen; INF-${\gamma}$ in serum; IL-2, IL-6, and IL-10 in the thymus; and IL-10 and IFN-${\gamma}$ in the spleen decreased after ZEA administration. Furthermore, the levels of IL-$1{\beta}$ in the spleen and mesenteric lymph node, IL-$1{\beta}$ in the thymus, IL-2 in the thymus and spleen, IL-6 in the thymus, IL-10 and IFN-${\gamma}$ in the spleen, and GM-CSF and TNF-${\alpha}$ in the thymus decreased after vaccination in rats exposed to ZEA. In conclusion, these results suggest that ZEA exposure via drinking water can cause an immunosuppressive effect by decreasing immunoglobulins in serum and cytokines in lymphoid organs.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.427-436
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• 2017

A fixed-precision-level sampling plan was developed to establish control of the two-spotted spider mite, Tetranychus urticae, in two strawberry greenhouses (conventional plot, natural enemy plot). T. urticae was sampled by taking a three-leaflet leaf (1 stalk) from each plant (3 three-leaflet leaves) from each sampling position. Each leaflet was divided into three different units (1-leaflet, 2-leaflet, and 3-leaflet units) to compare relative net precision (RNP) values for selection of the appropriate sampling unit. The relative net precision values indicated that a 1-leaflet unit was more precise and cost-efficient than other units. The spatial distribution analysis was performed using Taylor's power law (TPL). Homogeneity of the TPL parameters in each greenhouse was evaluated by using the analysis of covariance (ANCOVA). A fixed-precision-level sequential sampling plan was developed using the parameters of TPL generated from the combined data of the conventional plot and natural enemy plot in a 1-leaflet sampling unit. Sequential classification sampling plans were also developed using the action threshold of 3 and 10 mites for pooled data. Using the results obtained in the independent data, simulated validation of the developed sampling plan by Resampling validation for sampling plan (RVSP) indicated a reasonable level of precision.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4195-4208
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• 2022

In this study, operator habitability was numerically evaluated in the event of a fire at the main control bench board (MCB) in a reference main control room (MCR). It was investigated if evacuation variables including hot gas layer temperature (HGLT), heat flux (HF), and optical density (OD) at 1.8 m from the MCR floor exceed the reference evacuation criteria provided in NUREG/CR-6850. For a fire model validation, the simulation results of the reference MCR were compared with existing experimental results on the same reference MCR. In the simulation, various input parameters were applied to the MCB panel fire scenario: MCR height, peak heat release rate (HRR) of a panel, number of panels where fire propagation occurs, fire propagation time, door open/close conditions, and mechanical ventilation operation. A specialized-average HRR (SAHRR) concept was newly devised to comprehensively investigate how the various input parameters affect the operator's habitability. Peak values of the evacuation variables normalized by evacuation criteria of NUREG/CR-6850 were well-correlated as the power function of the SAHRR for the various input parameters. In addition, the evacuation time map was newly utilized to investigate how the evacuation time for different SAHRR was affected by changing the various input parameters. In the previous studies, it was found that the OD is the most dominant variable to determine the MCR evacuation time. In this study, however, the evacuation time map showed that the HF is the most dominant factor at the condition of without-mechanical ventilation for the MCR with a partially-open false ceiling, but the OD is the most dominant factor for all the other conditions. Therefore, the method using the SAHRR and the evacuation time map was very useful to effectively and comprehensively evaluate the operator habitability for the various input parameters in the event of MCB fires for the reference MCR.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.743-750
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• 2008

In water treatment plant the Dissolved Ozone Flotation(DOF) System may be employed because this system has various abilities, such that it can remove SS using microbubbles, and it can exert strong oxidation power in removing taste and odor, color, and microbial agents. In order to investigate effectiveness of the DOF system in water treatment, removal characteristics of various water quality parameters were observed depending on the different levels of ozone concentrations. Removal efficiencies of water quality parameters in DOF system were compared with those in DAF(Dissolved Air Flotation) system and in CGS(Conventional Gravity Settling) system. Optimum ozone dose obtained in the pilot experiments was 2.7 mg/L. With increasing ozone dose higher than 2.7 mg/L, removal rates of turbidity, KMnO$_4$ consumption, UV$_{254}$ absorbance, and TOC were reversely lowered. High concentration of ozone dissociate organic matter in water, so that increasing dissolved organic level in effluent. Removal rates of water quality parameters at optimum ozone dose were obtained, such that removal rates of turbidity, KMnO$_4$ consumption, TOC, and UV$_{254}$ asorbance were 88.9%, 62.9%, 47%, and 77.3% respectively. Removal rate of THMFP was 51.6%. For all the parameters listed above, the DOF system was more effective than the DAF system or the CGS system. It is found that the DOF system may be used in advanced water treatment not only because the DOF system is more efficient in removing water quality parameters than the existing systems, but because the DOF system is also required smaller area than the CGS system for the treatment plant.