• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.201-210
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• 2001

Salinity, DIN, DIP, DIN/DIP and indigenous algal assay were determined to estimate the limiting nutrient for phytoplankton growth in Gwangyang Bay, South Sea of Korea. Seawater samples were collected at surface and bot-tom water in 4 November 1999 (dry season) and 2 September 2000 (after heavy rain). In 4 November 1999, the salinity, DIN, DIP and DIN/DIP were 29.92 psu, 13.59 ${\mu}M$, 3.41 ${\mu}M$ and 4.14 respectively. In 2 September 2000, These values were 24.62 psu, 27.77 ${\mu}M$, 2.82 ${\mu}M$ and 9.79 respectively. The DIN and DIP concentrations in this study were higher than Deukryang, Yeoja and Gamak Bay, South Sea of Korea. Especially, DIP concentration was 8 times high compared to Deutryang, Yeoja and Gamak Bay. The main sources of nitrogen seem to be freshwater runoff from Somjin River and industrial wastewater. But, the main sources of phosphorus seem to be industrial wastewater around Gwangyang Bay. The limiting nutrient was nitrogen at all station in 4 November 1999. The limiting nutrient was also nitrogen in 2 September 2000 in spite of heavy rain observed because of relatively much volume of phosphorus sup-plied from point sources than nitrogen. In case of below 20 psu in salinity by heavy rain, the limiting nutrient willbe shift from nitrogen to phosphorus at some area of Somjin River estuary. But the limiting nutrient will be never shift to phosphorus throughout Gwangyang Bay, eastern coast of Yeoja and Dolsan because of much volume of phosphorus runoff from point source in coastal area of Gwangyang Bay.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.825-836
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• 2005

This study was carried out to evaluate the quality characteristics of the fermented pork with soy sauce, red pepper paste and soybean paste. The ham of pork were cut to cube (7 × 10 × 2 cm³) and Korea traditional seasonings such as soy sauce (T1), red pepper paste (T2), soybean paste (T3) were seasoned by the proportions of meat to seasonings (1:1), respectively. The pH of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning at 1 and 28 days of storage, but were significantly lower at 14 days of storage. The water-holding capacity of fermented pork with soy sauce seasoning were significantly higher compared to those for fermented pork with red pepper and soybean paste seasoning at 28 days of storage. The surface meat L* values of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning, but a* and b* values of fermented pork with red pepper paste seasoning significantly higher. The volatile basic nitrogen (VBN) of fermented pork with soybean paste seasoning were significantly lower compared to those for fermented pork with soy sauce seasoning at 1 and 28 days of storage. The shear force and thiobarbituric acid reactive substances (TBARS) of fermented pork with soybean paste seasoning were significantly lower compared to those for fermented pork with soy sauce and red pepper paste seasoning. The total plate counts of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning at 14 days of storage, but were significantly lower at 28 days of storage. The Escherichia coli of fermented pork with soy sauce and soybean paste seasoning were significantly lower compared to those for fermented pork with red pepper paste seasoning at 1 day of storage. The Lactobacilli spp. of fermented pork with red pepper paste seasoning were significantly lower compared to those for fermented pork with soy sauce and soybean paste seasoning.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.837-850
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• 2005

This study was conducted to investigate the changes of quality characteristics on seasoned pork with Korean traditional 4 types seasoning such as soybean sauce(T1); Kimchi sauce(T2); pickled shrimps sauce(T3); onion sauce(T4). The seasoned samples were aged at 10±1℃ for 13 days. The results obtained were as follows; Except for T2, pH of treatments were significantly decreased(P<0.05) as aging period increased. Salinity(%) and saccharinity(%) of seasoned meat were tended to increased during aging period. Thiobarbituric acid reactive substances(TBARS) were increased significantly during storage in all treatment(P<0.05). T4 showed the highest TBARS among the all treatment groups. Volatile basic nitrogen(VBN) values of all treatments were significantly increased(P<0.05) as storage period increased. There were no significant differences in water holding capacity(WHC) among the all treatments, and those values were not changed by the passage of storage days. Shear force values of all treatments were tended to decreased by the passage of storage days. In surface color, the values of L*, a* and b* showed a tendency of increasing value along the storage days. The values of a* and b* of T2 were significantly higher than other treatments during aging period(P<0.05). In inner color, a* and b* values of T2 were significantly higher than those of other treatments during aging period(P<0.05). In the sensory evaluation of cooked meat, T3 treatment resulted in lower score in aroma, flavor, tenderness, juiciness and overall acceptability. The number of total plate counts and Lactobacilli spp. tended to increase with storage in all treatments group. The numbers of Escherichia coli were not changed by the passage of storage time.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.13-20
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• 2010

Acid mine drainage (AMD) from abandoned mine sites typically has low pH and contains high level of various heavy metals, aggravating ground- and surface water qualities and neighboring environments. This study investigated removal of heavy metals in a biological treatment system, mainly focusing on the removal by adsorption on a substrate material. Bench-scale batch experiments were performed with a mushroom compost to evaluate the adsorption characteristics of heavy metals leached out from a mine tailing sample and the role of SRB in the overall removal process. In addition, adsorption experiments were perform using an artificial AMD sample containing $Cd^{2+}$, $Cu^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ to assess adsorption capacity of the mushroom compost. The results indicated Mn leached out from mine tailing was not subject to microbial stabilization or adsorption onto mushroom compost while microbially mediated stabilization played an important role in the removal of Zn. Fe leaching significantly increased in the presence of microbes as compared to autoclaved samples, and this was attributed to dissolution of Fe minerals in the mine tailing in a response to the depletion of $Fe^{3+}$ by iron reduction bacteria. Measurement of oxidation reduction potential (ORP) and pH indicated the reactive mixture maintained reducing condition and moderate pH during the reaction. The results of the adsorption experiments involving artificial AMD sample indicated adsorption removal efficiency was greater than 90% at pH 6 condition, but it decreased at pH 3 condition.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.413-423
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• 2020

Over the wide area, King Sejong Station and the nearby land are uncovered with snow and ice conditions. Therefore, the active layer on the permafrost has been formed to be much thicker than the other Antarctica region. Electrical resistivity survey of Wenner and dipole-dipole arrays was undertaken at a series of time in the freezing season at the King Sejong Station to delineate subsurface structure and to monitor active layer in permafrost terrain. Time-lapse resistivity structures are well in terms of the vegetation distribution, ground surface temperature, and snow depth. Horizontal high resistivity belt(>1826 Ωm) at very shallow depth is thickening with the lapse of time, probably caused by the freezing of the water in the pore spaces with decrease of ground temperature. Subsurface structures for the area of low snow-cover and vegetated zone area are comprised of 0~0.5 m deep high-resistive gravel-rich soil, 0.5~3 m deep low-resistive active layer, and the underlying permafrost. In contrast, the unvegetated area and high snow-buildup is characterized with high resistivities larger than approximately 2000 Ωm due to freezing of the soil throughout the year. Data interpretation and correlation schemes explored in this paper can be applied to confirm the active layer, which is expected to get thinner in additional survey during the thawing season.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.109-116
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• 2002

The objective of this study was to know the qualities of soil and shallow groundwater in plastic film house fields around Central Part of Korea. The study was conducted at 11 sites in Suweon, Hwasung, Pyungtaek, Yongin and Chuncheon through May to August in 1999. Soil textures of plastic films house were mainly sandy loam or loam. Electric conductivity and organic matter content of surface soils mostly exceeded the critical levels for crop production. Average concentration of $NO_3-N$ in the sha]low groundwater was 19.1 mg/L, and it reached almost the limiting level of agricultural groundwater quality (20 mg/L). Moreover about 36% of survey sites exceeded the limiting level of agricultural groundwater quality. Sulfate concentrations also at some sites exceeded agricultural groundwater quality limit level (50 mg/L). Nitrate-N, one of the most important factors in the groundwater quality, had positive correlations with other ions in foundwater.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.352-359
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• 1997

The visual acuity of filefish Stephanolepis cirrhifer was studied through a series of experiments by observing their responses to target plates. The fish were trained to respond to the target plates made of white acrylic resin with a vertical black line 5cm long in the center. The width of the black line ranged from 0.2mm to 8.0 mm. The line width was diminished unto the fish could no longer distinguish the line at a distance of 100 cm from the target plate. This was repeated under light intensities of 400, 20, 5, 3 and 1 lx at the water surface. Fish were rewarded with bait in front of the target plate if the fish went to the target date (i.e., success).The results show that the training effect of 1lensh had a success rate of over 80% and that the reach times to the target plates were 4~5 seconds over 210 experimental tunes. The success rate was high using the thick line with strong apparent contrast, but was low at the 1 lx. The visible critical width of line became thick with decreasing light intensity, 0.24mm at 400 lx, followed by 0.30mm at 20 lx, 0.40mm at 5 lx, 0.46 mm at 3 lx and 2.87mm at 1 lx. The apparent contrast for visible critical width of line increased with decreasing light intensity, 0.01 at 400 and 20 lx, 0.02 at 5 lx, 0.03 at 3 lx and 0.09 at 1 lx. The line acuity of filefish was best 1.21 at the 400 lx, followed by 0.97 at 20 lx, 0.73 at 5 lx, 0.63 at 3 lx and sharply decreased to 0.10 at 1 lx. The visible ranges for 1mm and 6mm in width of line were about 4.2 m and 25.0 m at the 400 lx light intensity and decreased m 1/14 times and 1/12 times of the 400 lx at 1 lx, respectively.

• Journal of fish pathology
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• v.4 no.1
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• pp.1-11
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• 1991

Histopathological changes and methemoglobinemia of the eels (Anguilla japonica) reared at six culture farms in the vicinity of Y$\check{o}$su city were investigated under the conditions of $22.0{\sim}29^{\circ}C$, 4.33~7.33ppm of D.O., pH 6.1~8.2 and 0.03~10.1ppm of nitrite from December, 1989 to June, 1990. All of the eels showed no any abnormal state in action, color and blood, but the eels reared in pH 6.0 had planty of mucus and stickiness on their body surface. Methemoglobin levels were 1.03~9.86% of total erythrocyes in Dec. and 5.05~25.69% in June, and poikilocyte levels were 5.8~30.17% in Dec. and 8.67~74.45% in June. These results indicate the fact that the water management of the culture farms was worse in summer than in winter, even though not good in winter. Hypertrophy was found in the gill, hepatic and kidney tissue of the eels in all the culture farms. In March and June, Fish of all culture farms appeared the detachment of gill lamella epithelium cells, pyknosis and sinusoids of nucleus in the hepatic tissue and hemosiderosis in the kidney tissue. The trend of increase in methemoglobin levels appeared in the fish of culture farms with high nitrite concentration, which didn't appear equally in all the culture farms. However, in the culture farms of pH 6.0, methemoglobin and poikilocyte levels were increased independently of concentration of nitrite, and degeneration in the tissue of the gill, liver and kidney was also appeared.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.1-8
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• 2011

We investigated developmental stages of embryo and early life history of the Korean indigenous fish, the northern loach, Cobitis pacifica in 2009 in order to understand fundamental knowledges for conservation of this species. Eggs were obtained after hormones injections (LHRH-a, HCG) and were artificially fertilized by the dry method. The embryo was spherical, separative demersal, faint white, and averaged $1.09{\pm}0.04\;mm$ (n=20) in diameter. The hatching of the embryo took place in about 48 hours after fertilization under water temperature of $21.0{\sim}24.0^{\circ}C$ and the newly hatched larvae averaged $2.87{\pm}0.05\;mm$ (n=20) in total length (TL). Four days after hatching, the larvae grew up to $6.86{\pm}0.10\;mm$ (n=10) in TL and york sac absorption, mouth and anus opening were shown. Fourteen days after hatching, most of fin-rays appeared at $10.71{\pm}0.34\;mm$ (n=10) in TL and color spots on the body surface were attained. Twenty six days after hatching, the larvae grew up to $14.88{\pm}0.45\;mm$ (n=10) in TL, and all their fin-rays were formed. Therefore, according to current study regarding the morphological development of Cobitis pacidica, the conversion from larval to juvenile stages occurred at 26 days after hatching. Eighty days after hatching, the larvae were $33.3{\pm}1.25\;mm$ (n=10), and their body shape and color pattern were similar to adult fish. In this study, embryonic development and early life history of the northern loach, Cobitis pacifica show morphological characteristics of Cobitidae family. We expected that our results can be used as an fundamental knowledges for restoration study of indigenous fish species.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.