• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.178-185
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• 2013

We measured salinity and $^{222}Rn$ concentration to explore submarine spring along the coastal areas (Mundongri, Icheon-ri, Jukseong-ri, Daebyeon-ri, Yeonhwa-ri, and Dadae-po) including Ilkwang Bay of Busan Metropolitan City in 2009 and 2010. Before field observation, we selected the potential and possible locations of submarine spring based on the lineament distribution and rose diagram analysis. Salinity and radon concentration were measured within the 1~2 km from the coastal lines. Radon activity decreased gradually from onshore to offshore. Vertical profiles of salinity at some stations showed lateral transport of water mass characterized by low salinity. Vertical profiles of salinity in the Ilkwang Bay, which is a unique bay in the south-eastern coastal area of Busan Metropolitan City, also showed the occurrence of low salinity in the bottom seawater. Our results suggest the possible occurrence of submarine discharge of fresh groundwater in the coastal areas around Busan Metropolitan City. In the future, intensive research should be conducted for the exploration methods of submarine spring as well for the possible utility of submarine groundwater as alternative water resources.

• Journal of fish pathology
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• v.26 no.3
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• pp.283-287
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• 2013

The susceptibility of marine medaka, Oryzias dancena to fish pathogenic viruses (infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), hirame rhabdovirus (HIRRV), infectious hematopoietic necrosis virus (IHNV), and lymphocystis disease virus (LCDV)) was investigated. The cumulative mortalities of fish immersed with IPNV (experimental condition: $15^{\circ}C$ sea water (SW)), VHSV ($15^{\circ}C$ SW), HIRRV ($15^{\circ}C$ fresh water (FW)) were 30%, 40% and 60%, respectively. In the fish immersed with IPNV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), VHSV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), HIRRV ($15^{\circ}C$ SW), IHNV ($15^{\circ}C$ FW and SW), LCDV ($15^{\circ}C$ FW and SW, $18^{\circ}C$ FW and SW), and mock-challenged group, mortality rate was less than 10%. IPNV, VHSV and HIRRV were re-isolated from the dead fish. These results suggest that marine medaka is susceptible to IPNV, VHSV and HIRRV, although their susceptibility depends on the environmental conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.397-403
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• 2015

Heavy metals reduce the photosynthetic efficiency and disrupt metabolic reactions in a concentration-dependent manner. Moreover, by replacing the metal ions in metalloproteins that use essential metal ions, such as Cu, Zn, Mn, and Fe, as co-factors, heavy metals ultimately lead to the formation of reactive oxygen species (ROS). These, in turn, cause destruction of the cell membrane through lipid peroxidation, and eventually cause the plant to necrosis. Given the aforementioned factors, this study was aimed to understand the physiological responses of rice to cadmium (Cd) and arsenic (As) toxicity and the effect of essential metal ions on homeostasis. In order to confirm the level of physiological inhibition caused by heavy metal toxicity, hydroponically grown rice (Oryza sativa L. cv. Dongjin) plants were exposed with $0-50{\mu}M$ cadmium (Cd, $CdCl_2$) and arsenic (As, $NaAsO_2$) at 3-leaf stage, and then investigated malondialdehyde (MDA) contents after 7 days of the treatment. With increasing concentrations of Cd and As, the MDA content in leaf blade and root increased with a consistent trend. At 14 days after treatment with $30{\mu}M$ Cd and As, plant height showed no significant difference between Cd and As, with an identical reduction. However, As caused a greater decline than Cd for shoot fresh weight, dry weight, and water content. The largest amounts of Cd and As were found in the roots and also observed a large amount of transport to the leaf sheath. Interestingly, in terms of Cd transfer to the shoot parts of the plant, it was only transported to upper leaf blades, and we did not detect any Cd in lower leaf blades. However, As was transferred to a greater level in lower leaf blades than in upper leaf blades. In the roots, Cd inhibited Zn absorption, while As inhibited Cu uptake. Furthermore, in the leaf sheath, while Cd and As treatments caused no change in Cu homeostasis, they had an antagonist effect on the absorption of Zn. Finally, in both upper and lower leaf blades, Cd and As toxicity was found to inhibit absorption of both Cu and Zn. Based on these results, it would be considered that heavy metal toxicity causes an increase in lipid peroxidation. This, in turn, leads to damage to the conductive tissue connecting the roots, leaf sheath, and leaf blades, which results in a reduction in water content and causes several physiological alterations. Furthermore, by disrupting homeostasis of the essential metal ions, Cu and Zn, this causes complete heavy metal toxicity.

• Journal of the Korean Society of Floral Art and Design
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• no.45
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• pp.3-12
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• 2021

The 1-methylcyclopropene (1-MCP) is the gaseous ethylene action inhibitor, which delay senescence and wilting by blocking the binding of its receptors. We investigated the effects of 1-MCP with different treated duration (0h (Control), 1h, and 4h) in cut flowers of Eustoma grandiflorum 'Voyage' and Cymbidium 'Lapine Hat'. The relative water uptake increased by 14.5% than control (9.8%) and the flower diameter maintained high from 3 to 11 days in 1-MCP treatment for 4h in E. grandiflorum 'Voyage'. The relative fresh weight was averagely high in 1-MCP treatment for 4h, however, the vase life was not significantly different in both cut flowers. Since the effects of 1-MCP treatment was differently responded by plant species and cultivars, interacted studies of duration and levels of 1-MCP are needed for the pronounced effects of postharvest quality.

• Analytical Science and Technology
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• v.21 no.3
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• pp.191-200
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• 2008

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aquatic environmental samples. Therefore, it required rapidly and certainly analytical method for pharmaceuticals which are existed in environment. In this study, Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) was used to measure the concentrations of 7 pharmaceuticals (quinoxaline-2-carboxylic acid, acetylsalicylic acid, diclofenac-Na, naproxen, ibuprofen, mefenamic acid, talniflumate) from environmental water or aquatic samples simultaneously. Effective sample clean-up by solid-phase extraction (SPE) prior to LC-MS/MS analysis is necessary. For further purification, Mixed Cation eXchange (MCX) and Hydrophilic-Lipophilic Balance (HLB) solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. LODs (Limits of Detection) and MDLs (Method Detection Limits) for the spiked sample in fresh water were in the range of 0.05~1.50 pg/mL and 0.17~4.90 pg/mL, respectively. The absolute recovery in the concentration of 1.0 ng/mL were between 81.9 and 116.3%. The acidic pharmaceuticals were detected in concentrations of 0.018~16.925 ng/mL in aquatic environmental samples.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.60-65
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• 2014

This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.281-290
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• 2019

BACKGROUND: As the demand for strawberries increases, people are paying attention to food safety in strawberry, especially pesticide residues. To remove the pesticides from strawberry, various washing and processing technique in households are additionally required. METHODS AND RESULTS: Strawberries were washed with water, detergent, alcohol, and ultrasonication and processed to strawberry jam. The mean reduction efficiency according to the washing solvent and method was found to be higher in the order of detergent (42.5%) > alcohol (41.7%) > water (41.3%) > ultrasoniation with alcohol (40.2%) > ultrasoniation with water (38.6%) > ultrasoniation with detergent (36.9%), but there was no significant difference among the treatments. The residue levels of pesticides during processing to jam decreased by 11.9-94.4% for etoxazole, fluopyram, procymidone, spiromesifen, and prochloraz, while the other pesticides were concentrated by boiling, or rather increased by 11.8-40.2%. However, when the residue levels were converted to residual amounts in consideration of the change in weight after processing, the residual amounts of the tested pesticides were reduced by 59.8-98.4% during processing. The processing factor (PF) were different for each pesticide, but PFs were < 1 for all washing solvents and methods, and 0.06-1.40 when processed into jam. CONCLUSION: To ensure the consumption of pesticide-free strawberry, the most efficient washing method is to immerse the strawberry in fresh water for few minutes, followed by rinsing them under running water.

• Development and Reproduction
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• v.12 no.3
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• pp.231-241
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• 2008

The present study was designed to clarify aspects of the annual reproductive cycle of the fresh water mitten crab, Eriocheir japonicus inhabiting Sumjin river, and to determine the adequate conditions of temperature, photoperiod and salinity on the gonadal maturation and breeding of adult female crabs. Based on the seasonal changes of GSIs and gonadal histology of adult crabs, the annual reproductive cycle could be divided into 4 periods as follows: previtellogenesis period (from September to October) when GSIs were low value and ovaries had oocytes in previtellogenesis stage and meiotic prophase stage; maturing period (from November to March of the next year) when GSIs increased gradually and ovarian oocytes accumulated yolk globules; spawning period (from April to June) when high value of GSI of female was kept and ovigerous female appeared; resting period (from July to August) when GSIs decreased rapidly, and vitellogenic oocytes degenerated. Gonadal maturation was influenced by water temperature, but not photoperiod and salinity. GSI more increased in experimental regime of $18^{\circ}C$ than that of $10^{\circ}C$ regardless of photoperiod conditions (12L12D and 15L9D). However, in $26^{\circ}C$ regime of both photoperiod conditions, the value of GSI was not changed, and vitellogenic oocytes were not observed. Spawning was considerably influenced by water temperatures and salinities regardless of photoperiods. Vitellogenic female crabs did not spawn at $10^{\circ}C$ in any salinity conditions. However, at $18^{\circ}C$ and $26^{\circ}C$, over a half of rearing female crabs spawned in condition of 30% sea water (salinity 9.6%o) and 60% sea water (salinity 19.2%o), while no female spawned in freshwater condition (salinity 0.0%o).

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.232-240
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• 2009

The aim of this study was to determine the processing and reduction factors for ginseng and its commodities during ginseng processing to obtain information of pesticide residue in ginseng. For this study, azoxystrobin was used in two field containing 6 years old ginseng plants. Ginsengs were harvested and processed to obtain different commodities (Dried ginseng, red ginseng and ginseng water and alcohol extracts, red ginseng water and alcohol extracts) for pesticide analysis. The amount of residue levels from wonju and icheon for fresh ginseng were 0.05, $0.03\;mg\;kg^{-1}$ dried ginseng were 0.12, $0.14\;mg\;kg^{-1}$, red ginseng were both $0.05\;mg\;kg^{-1}$, ginseng alcohol extract were 0.28, $0.33\;mg\;kg^{-1}$, ginseng water extract were 0.22, $0.16\;mg\;kg^{-1}$, red ginseng alcohol extract were 0.31, $0.20\;mg\;kg^{-1}$ and red ginseng water extract were 0.09, $0.11\;mg\;kg^{-1}$ respectively. These data were under MRLs notified by KFDA. The processing factors for ginseng products were 3.25, 1.34, 7.84, 4.63, 6.15 and 2.56 respectively. The reduction factors for ginseng products were 1.19, 0.51, 3.41, 1.91, 2.74 and 1.00 respectively. These data showed increment during processing which could be due to concentration but considering water contents, residue levels were similar or decreased than the initial residue level during processing.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.339-345
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• 2013

This study is to derive from the required performances and the optimum mix proportion of the roof concrete placed in the in-ground LNG storage tank with a capacity of 200000 $m^3$, and propose the actual data for site concrete work. The concrete placing work without sliding and segregation in the fresh concrete condition is very important because the slope of domed roof is varied in the large range by its curvature. Also the control of hydration heat and the strength development at test ages are classified with massive section about 1.4 m thick and considered to the pre-stressing work and removal of air support after concrete placing work. Considering above condition, slump range is selected $100{\pm}25$ mm under the slope $20^{\circ}$ and $150{\pm}25$ mm over the slope $20^{\circ}$ s until 60 minutes of elapsed time. Also, the roof concrete is satisfied with compressive strength range including design strength at 91 days (30 MPa), pre-stressing work at 7 days (10 MPa), air support removal work at 21 days (14 MPa). Replacement ratio of limestone powder is determined by confined water ratio test and main design factors include water-cement ratio (W/C), sand-aggregate ratio and dosage of admixture. As test results, the optimum mix proportion of the roof concrete used low heat cement is as followings. 1) Replacement ratio of limestone powder 25% by confined water ratio test 2) Water-cement ratio 57.8% 3) Sand-aggregate ratio 42.0%. Also, test results for the adiabatic temperature rising test is satisfied with its criteria and shown the lower value compared to preceding storage tank (TK-13, 14). These required performances and the optimum mix proportion is to apply the actual construction work.