• Analytical Science and Technology
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• v.23 no.4
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• pp.371-382
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• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• Economic and Environmental Geology
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• v.35 no.4
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• pp.299-316
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• 2002

The Samkwang gold-silver deposits consist of gold-silver-bearing hydrothermal massive quartz veins which filled the fractures along fault shear (NE, NW) zones within Precambrian banded or granitic gneiss of Gyeonggi massif. Ore mineralization of this deposits occurred within a single stage of quartz vein which was formed by multiple episodes of fracturing and healing. Based on vein mineralogy and paragenesis, massive quartz veins are divided into two main paragenetic stages which are separated by a major faulting event. Main ore mineralization occurred at stage I. Wall-rock alteration from this deposits occur as mainly sericitization, chloritization, silicification and minor amounts of pyritization, carbonitization, propylitization and argillitization. Ore minerals are composed mainly of arsenopyrite (29.21-32.24 As atomic %), pyrite, sphalerite (6.45-13.82 FeS mole %), chalcopyrite, galena with minor amounts of pyrrhotite, marcasite, electmm (39.98-66.82 Au atomic %) and argentite. Systematic studies of fluid inclusions in early quartz veins and microcracks indicate two contrasting physical-chemical conditions: 1). temperature (215-345$^{\circ}$C) and pressure (1296-2022 bar) event with $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids (0.8-6.3 wt. %) related to the early sulfide deposition, 2). temperature (203-441$^{\circ}$C) and pressure (320 bar) event with $H2_{O}$-NaCI $\pm$ $CO_{2}$ fluids (5.7-8.8 wt. %) related to the late sulfide and electrum assemblage. The H20-NaCI $\pm$ $CO_{2}$ fluids represent fluids evolved through fluid unmixing of an $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids due to decreases in fluid pressure and influenced of deepcirculated meteoric waters possibly related to uplift and unloading of the mineralizing suites. Calculated sulfur isotope compositions (${\delta}^{34}S_{fluid}$) of hydrothermal fluids (1.8-4.9$\textperthousand$) indicate that ore sulfur was derived from an igneous source. Measured and calculated oxygen and hydrogen isotope compositions (${\delta}^{18}O_{I120}$, ${\delta}D$) of ore fluids (-5.9~10.9$\textperthousand$, -102~-87$\textperthousand$) indicate that mesothermal auriferous fluids at Samkwang gold-silver deposits were likely mixtures of $H_{2}O$-rich, isotopically less evolved meteoric water and magmatic fluids.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.104-112
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• 2012

BACKGROUND: Agricultural inputs (fertilizer and organic inputs) and water conditions can influence $CH_4$ and $CO_2$ emission from agricultural soils. This study was conducted to investigate the effects of agricultural inputs (fertilizer and organic inputs) under changing water regime on $CH_4$ and $CO_2$ emission from a soil in a laboratory incubation experiment. METHODS AND RESULTS: Four treatments were laid out: control without input and three type of agricultural inputs ($(NH_4)_2SO_4$, AS; pig manure compost, PMC; hairy vetch, HV). Fertilizer and organic inputs were mixed with 25 g of soil at 2.75 mg N/25 g soil (equivalent to 110 kg N/ha) in a bottle with septum, and incubated for 60 days. During the first 30-days incubation, the soil was waterlogged (1 cm of water depth) by adding distilled water weekly, and on 30 days of incubation, excess water was discarded then incubated up to 60 days without addition of water. Based on the redox potential, water regime could be classified into wetting (1 to 30 days), transition (31 to 40 days), and drying periods (41 to 60 days). Across the entire period, $CH_4$ and $CO_2$ flux ranged from 0 to 13.8 mg $CH_4$/m/day and from 0.4~1.9 g $CO_2$/m/day, and both were relatively higher in the early wetting period and the boundary between transition and drying periods. During the entire period, % loss of C relative to the initial was highest in HV (16.4%) followed by AS (8.1%), PMC (7.5%), and control (5.4%), indicating readily decomposability of HV. Accordingly, both $CH_4$ and $CO_2$ fluxes were greatest in HV treatment. Meanwhile, the lower $CH_4$ flux in AS and PMC treatments than the control was ascribed to reduction in $CH_4$ generation due to the presence of oxidized compounds such as ${SO_4}^{2-}$, $Fe^{3+}$, $Mn^{4+}$, and ${NO_3}^-$ that compete with precursors of $CH_4$ for electrons. CONCLUSION: Green manure such as HV can replace synthetic fertilizer in terms of N input, however, it may increase $CH_4$ emission from soils. Therefore, co-application of green manure and livestock manure compost needs to be considered in order to achieve satisfactory N supply and to mitigate $CH_4$ and $CO_2$ emission.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.836-844
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• 2010

This study was carried out to investigate plant characteristics and nutritional components of the genetically modified (GM) Chinese cabbage and its control line grown in the central and northern parts of Korea in order to establish the evaluating protocol and standard assessment. The GM and non-GM Chinese cabbage was planted with normal and concentrated density at two locations in spring and fall of 2008 and 2009. From the statistic analysis on plant characteristics and nutritional components, there were not many significant differences between GM and non-GM Chinese cabbage. Only few differences in the plant characteristics were found between the dense and normal planting. In the dense planting, there was no significant difference between GM and non-GM Chinese cabbages except for three out of 18 plant traits, such as leaf shape, hairiness and midrib length. On the other hand, nine plant traits including leaf length, leaf width, leaf color, leaf shape, fresh weigh of ground part, number of leaf, midrib length, midrib width and root diameter were slightly different between GM and non-GM Chinese cabbage in the normal planting. In case of leaf length, midrib length, midrib width and fresh weigh of ground part, there were significantly differences not only between two lines, but also between two locations. From nutritional component analysis, only five fatty acids were identified in the Chinese cabbage: palmitic acid, oleic acid, stearic acid, linoleic acid and linolenic acid. Except linoleic acid, four fatty acids in one gram of dried sample from GM line were little higher than those from non-GM line. However, there were no significant differences in total contents of fatty acids not only between GM and non-GM Chinese cabbage line, but also between northern and central cultivating areas in the normal and dense planting. According to the composition of inorganic elements identified in the samples from both lines, there were six macro-elements, such as N, P, Ca, K, Mg and Na, and four micro-elements, Cu, Fe, Mn and Zn. Based on the result from PCA analysis, specific clusters were not found between GM Chinese cabbage and the control line, but found between two regions.

• Journal of Life Science
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• v.21 no.3
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• pp.375-384
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• 2011

This study was performed to evaluate the antioxidant and antimicrobial activity of methanol extract from Rosmarinus officinalis L. and its fractions. The ethyl acetate fraction of rosemary had a higher antioxidant activity in both DPPH ($3.22\;{\mu}g/ml$) and ABTS ($5.05\;{\mu}g/ml$) compared to other extracts and fractions. Based on the results of the FRAP assay, the ethyl acetate fraction of rosemary showed a value of $5.9{\pm}0.3\;{\mu}M/{\mu}g$, and buthanol fraction and rosmarinic acid exhibited values of $4.8{\pm}0.2\;{\mu}M/{\mu}g$ and $5.1{\pm}0.1\;{\mu}M/{\mu}M$, respectively. Measurements of the antimicrobial activities of the extracts, fraction against gram positive, negative bacteria revealed that the methanol extract, hexane, ethyl acetate, and chloroform fraction of rosemary caused Staphylococcus aureus and Escherichia coli to form clear zones greater than 12 mm. Furthermore, the methanol extract and chloroform fraction showed high antibacterial activity, with inhibition zone exceeding 13 mm. The methanol extract and chloroform fraction of rosemary had broad antimicrobial spectrums and low MIC values. Therefore, methanol extracts of rosemary could serve as potential antibacterial agents to inhibit pathogen growth in food and hand sanitizers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.278-286
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• 2003

Alcohol is well known agent which can damage the human tissues such as liver via stimulating lipid peroxidation. On the other hand, carotenoids in addition to vitamins A, C and I play important roles in protecting these oxidative damages as well as preventing the production of free radicals. This study was carried out to investigate the effect of dietary vitamin A on lipid peroxidation and antioxidants status in ethanol-treated rats. In the experiment, male Sprague-Dawley rats weighing 160~180 g were given a liquid diet containing 36% of total calories as ethanol for 7 weeks. The pair-fed control rats received an isocaloric amount of diet containing sucrose instead of ethanol on the following day Additionally, the liquid diet contained adequate amount of $\beta$-carotene, retinyl acetate or 13-sis-reinoic acid except vitamin A-deficient diet. The results obtained are as follows. The levels of plasma and hepatic lipid peroxide were increased after chronic ethanol feeding in rats. Retinyl acetate supplementation significantly reduced lipid peroxidation induced by ethanol feeding Glucose 6-phosphatase activity was significantly reduced in rats fed vitamin A-deficient diet with ethanol and alkaline phosphatase activity was significantly induced in rats fed 13-cis-reinoic acid diet with ethanol. Catalase and alcohol dehydrogenase activities did not show a consistent tendency in experiment groups. The hepatic antioxidant enzyme activities did not significantly changed by chronic ethanol feeding groups. The striking decrease in conversion of $\beta$-carotene to retinol was observed in rats fed a $\beta$-carotene diet with ethanol feeding The level of retinol and retinoic acid in plasma and liver was decreased after chronic ethanol administration Based on this result, these data suggest that ethanol feeding enhances oxidative stress especially in those fed a vitamin A-deficient diet, and vitamin A supplementation, especially, retinyl acetate intake can prevent enhanced lipid peroxidation and related damage to some extent.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.253-264
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• 2012

This study was carried out to investigate growth characteristics, yield, chemical compositions and nutrients yield of corn hybrids for silage in the newly reclaimed hilly land. The experimental design was arranged in a randomized block design with three replications. The seeding time was at May 6. The harvest time of four treatments was milk stage (97 days), dough stage (105 days), yellow stage (112 days) and late yellow stage (119 days after seeding). Plant height, ear height, leaf numbers and ear length were highest in yellow stage (p<0.05, 0.01), but dead leaf, stem hardness and sugar degree (Brix) were higher in late yellow than other treatments. Leaf width, tip filling degree and fresh yield were not significantly different. Dry matter yield increased as the maturity stage progressed (p<0.01). Crude protein and crude fat were not significantly different. NDF and ADF decreased as the maturity stage progressed (p<0.01). Ca content was the highest at milk stage (p<0.05), Fe and P were the highest at dough stage (p<0.05, 0.01). However another minerals were not significantly different. Essential amino acid (EAA), nonessential amino acid (NEAA) and total amino acid were highest at yellow stage, but no significant differences were found among the treatments. Total free sugar contents were higher in the order of Milk > dough > yellow > late yellow stage, but no significant differences were found among the treatments. Crude protein yield was the highest at yellow stage, but crude fat yield, amino acid yield and TDN yield were highest at late yellow stage (p<0.01). Total mineral yield showed no significant difference. Based on the above results, yellow and late yellow stage compared to other maturity stage have been shown to increase dry matter yield and nutrients yield, when silage corn grow cultivate in the newly reclaimed hilly land.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.119-128
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• 2016

This study was conducted to compare nutritional composition and taste-related compounds of breast and thigh meats from four lines of Korean native chickens (KNC) Yeonsan Ogye, Hyunin Black, Hwangbong, and Hoengseong Yakdak. White Leghorn (WL) was used as a control. Fifteen male chickens (three chickens in each line) were grown under same condition and slaughtered at 53 weeks old. The contents of Fe and K in KNC, especially Hwangbong breast meat and thigh meat of Hyunin Black and Hoengseong Yakdak, were higher than WL. The contents of Na were lower in KNC compared with WL regardless of parts (p<0.05). Vitamin A contents were higher in thigh meat of WL and Hyunin Black, and vitamin $B_1$ contents were lower in Hoengseong Yakdak than other lines. Vitamin $B_3$ were higher in breast meat of four lines of KNC and thigh meat of Hoengseong Yakdak than WL. Total amino acid contents were higher in breast meat of KNC than WL. The level of good-tasting amino acids were significantly higher in breast meat of Hoengseong Yakdak and WL, and thigh meat of Hyunin Black and WL than other lines of chickens (p<0.05). The ratio of good-tasting amino acids to bitter tasting amino acids was higher in breast meat of Hoengseong Yakdak and thigh meat of Hyunin Black than WL. IMP contents were higher in Hyunin Black and WL than other lines of chickens. Based on these results, it can be concluded that four lines of KNC may have superior nutritional quality and taste when compared with WL.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.2
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• pp.76-90
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• 2018

To determine the distribution of mercury (Hg) in the coastal surface sediments around the Korean peninsula, the baseline concentration of Hg was estimated, the extent of contamination was assessed, and the factors controlling the distribution were discussed. The concentrations of Hg in surface sediments were significantly high in Jinhae-Masan Bay in the South Sea, Ulsan-Onsan Bay and Yeongil Bay in the East Sea, but Hg in other sediments showed a similar distribution to Cs and relatively very low concentration between 0.21 and $39.5{\mu}g/kg$ ($13.6{\pm}7.80{\mu}g/kg$). Compared to the sediment quality guidelines in Korea, 8 % of the surface sediments (n=282) analyzed in this study exceeded the values of the threshold effects level (TEL), and six sediments collected around Onsan Port were higher than the value of the probable effects level (PEL). The contamination levels of Hg were assessed by the enrichment factors using the baseline concentration (2.06Cs+1.75) based on the residual analysis from the linear regression line for Cs, and further, factors controlling the distribution of Hg were discussed by the comparison with geochemical substances depending upon the Hg enrichment level. Hg concentrations were correlated well with Cs concentration in the range of less than 1.69 of EF implying grain size control, while in the range of 1.69 and 4.03 Hg concentrations were correlated well with Fe oxyhyroxide and organic carbon contents, which indicates Hg was enriched by superior sorption capability. On the meanwhile, samples with higher EFs (4.03 to 74.9) showed fairly positive correlations with other metals (Cu, Zn, Pb) rather than geochemical substances. For samples in Youngil Bay and Ulsan-Onsan Bay (n=30), Hg concentrations were correlated only with other metals rather than geochemical substances implying simultaneous supply of metal particles from metal refineries. But samples at Gosung, Sokcho and Uljin coast were correlated well with organic carbon even though they had high EFs. In addition, samples in Jinhae-Masan Bay with high contents of S were enriched by relatively high sulfide formation.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.65-71
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• 2013

This research was conducted to evaluate the influence of $NO_3{^-}:NH_4{^+}$ ratios in fertilizer solution on the vegetative growth and fruit yield of hot pepper (Capsicum annuum L.) through pot cultivation. The Hoaglad's solution was modified to contain various $NO_3{^-}:NH_4{^+}$ ratios such as 100:0 (A), 73:37 (B), 50:50 (C), 27:73 (D), 0:100 (E), and no nitrogen (F). Plants were transplanted into root substrates and the modified solutions were applied as plant needed in plastic house. There were no statistical significances among the treatments from A through D in the fresh and dry weights, and number of leaves 31 days after transplanting, but elevation of $NH_4{^+}$ ratios in the solution decreased the fresh fruit weight 62 days after transplanting with statistical differences. In the results of inorganic element analysis based on the dry weight of fully expanded mature leaves, N and P contents as well as micro cations such as Fe, Mn, Zn, and Cu increased as $NH_4{^+}$ ratios were elevated 62 days after transplanting. However, those of macro cations such as K, Ca, and Mg resulted in decreasing tendency. The elevation of $NH_4{^+}$ ratios in fertilizer solution resulted in the increase of EC and total N concentrations ($NO_3{^-}+NH_4{^+}$), but this decreased the pH as well as Ca and Mg concentrations in soil solution 62 days after transplanting. The K concentration in soil solution was the highest in the treatments of C and followed by D, B, E, and A. The above results indicate that the proper $NO_3{^-}:NH_4{^+}$ ratio in the nutrient solution is 73:27 (B) or 100:0 (A) and the B solution is proper for the vegetative growth and that of A is proper for reproductive growth stage.