• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.117-122
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• 1990

The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ？미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

• Journal of the Korean Institute of Gas
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• v.9 no.4 s.29
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• pp.17-25
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• 2005

The dealuminated and alkali/alkaline-earth metal exchanged Y-zeolites were prepared as a catalyst. Elemental compositions and structures of the prepared catalysts were analyzed by the various spectroscopic techniques such as inductively coupled plasma-atomic emission spectroscopy(ICP-AES), X-ray fluorescence(XRF) and X-ray diffraction(XRD), and the desorption behaviors of adsorbed species on the catalyst surfaces were investigated via NO-TPD experiment. Comparing with the composition of the starting material of NaY zeolite, the magnitudes of Si/Al ratio in catalytic materials were increased after dealumination. The Si/Al ratio of catalytic materials after dealumination followed by Cs and Ba cation exchange were additionally decreased. Dealumination to catalysts induced a destruction of basic frame due to a detachment of aluminum, which results in reducing framework structure, while increasing non-framework structure. This phenomenon becomes more serious with increasing time of steam treatment and even more significant for the cation exchanged catalysts. In NO-TPD experiments, the desorption peaks of NO which indicates an activity point of catalysts shifted to the low temperature region after dealumination and cation exchange. The desorption peaks of the NO-TPD profiles taken after steam treatment also shifted to the low temperature region as the steam treatment time increased. In dealuminated and cation exchanged Y-zeolites, the catalytic activities were more influenced by exchanged cation and the formation of non-framework structure.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.142-148
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• 2001

An indigenous antagonistic bacterium Bacillus sp. 7079 was isolated from a local soil sampled at Kyongju area in Korea . The strain has strong antagonistic ability which was originated from multifunctional mechanisms of chitinase and antibiotic and is a powerful antagonistic biocontrol agent against red-pepper rotting fungus Phytophthora capsici and Wilt fungus Fusarium oxysporum. The chitinase might degrade the cell wasll for Fusarium species. The selected Bacilus sp. 7079 was identified as a Bacillus amyloliquefaciens 7079. The maximal production of the chitinase from B, amyloliquefaciens 7079 were obtained in chitin-yeast extract medium containing 0.7%, $K_2$$HPO_4$, $0.2KH_2$$PO_4$, 0.1% ($NH_4$)$_2$$SO_4$, 0.05% sodium cirate, 0.01% $MgSO_4$$7H_2$O, 0.1% yeast extract and 0.1% colloidal chitin after cultivation of 3 days at pH 7.0 and $30^{\circ}C$. The best carbon and nitrogen sources for the production of the chitinase from B amyloliquefaciens 7079 were determined to be 0.1% colloi- dal chitin and 0.15% proteose peptone NO 3 respectively, The antagonistic activity of B amyloliquefaciens 7079 was confirmed using P. capsici by in vivo pot test with red-pepper plant.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.326-332
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• 2015

Greenhouse-gas emission factors are widely used to estimate emissions arising from a defined unit of a specific activity. Such estimates are used both for international reporting to the United Nations Framework Convention on Climate Change (UNFCCC) and for a myriad of national and subnational reporting purposes. The Intergovernmental Panel on Climate Change (IPCC) provides a methodology for national and sub-national estimation of known greenhouse gas emissions including $N_2O$ for each sector from which the emissions arise. The objective of this study was to develop an emission factor to estimate the direct $N_2O$ emission from an agricultural field cultivated with Chinese cabbage during spring season in 2010-2012. An estimated emission factor of $N_2O$ calculated over three years from field experiment accounting for cumulative $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0056{\pm}0.00254$ (95% CI) Kg $N_2O-N/kg$ N. More extensive studies are needed to develop $N_2O$ emission factors for other upland crops in various regions of Korea because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties agricultural practices and crop species.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.385-390
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• 2011

The purpose of this study was undertaken to evaluate of cryopreservation efficiency in ${\alpha}$ 1,3-galactosyltransferase knock-out(GalT KO) cloned miniature pig sperm. To compare ability of frozen-thawed sperm characteristics, three different pig strains (GalT KO) cloned miniature pig, PWG miniature pig and Duroc were used. The ejaculated semen from the three pig species was diluted with same volume extender and added to LEY solution for freezing. The diluted semen was placed in 0.5 ml straws, and freezing was initiated by exposing the straws to liquid nitrogen ($LN_2$) vapours for 10 min before placing them into $LN_2$ for cryopreservation. After thawing, the sperm ability were assessed for viability (SYBR-14/PI staining), abnormality (Rose Bengal staining), and acrosome status (intactness, intensity and capacitation) (chlorotetracycline, CTC staining). The viability of frozen-thawed GalT KO pig sperm had no significant difference as compared with Duroc and PWG miniature pig sperm. However, The CTC pattern of frozen-thawed GalT KO cloned miniature pig spermatozoa showed significantly lower rates in F pattern and AR pattern (p<0.05) and significantly higher rates in B pattern than Duroc and PWG miniature pig (p<0.05). The abnormality of GalT KO cloned miniature pig sperm was significantly lower as compared to Duroc and PWG miniature pig sperm (p<0.05). In conclusion, GalT KO cloned miniature pig semen can be cryopreserved successfully and used for artificial insemination reasonably.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.346-351
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• 2006

The study was performed to investigate the effect of incorporation of green manures (GM) into a sandy loam soil for organic vegetable production in the condition of plastic film house, relating to growth and yield of tomato crop. Three species of GM as perennial ryegrass, sudangrass and soybean are cultivated during the rest time of summer season and incorporated into soil just after the harvest. Thereafter tomato crop was transplanted as the following crop to soil incorporated GM. Among GM, soybean was proper as GM crop for organic farming, due to the effect of yield increase by continuous supply of nitrogen on following the tomato crop. Yield of tomato crop after soybean incorporation into soil was $4.2Mg\;ha^{-1}$ similar to $4.4Mg\;ha^{-1}$ of N-P-K standard fertilization (conventional) treatment. But perennial ryegrass and sudangrass were improper, because the biomass yield of perennial ryegrass was very low due to growth retardation by high temperature during summer season and soil incorporation of sudangrass as GM results in yield decrease of following the tomato crop caused by high C/N ratio of sudangrass itself. In conclusioa soybean incorporation into soil had advantage of producing conventional level on following the tomato yield and therefore it could recommend as GM for organic vegetable production.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.34-39
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• 2006

The land use pattern, water quality and vegetation were investigated in the six tributaries, including Hanggeumcheon and Satancheon of the Namhan hydrosphere, Iksancheon, Jeonjucheon and Gosancheon of the Mankyung hydrosphere as well as Jongeupcheon of the Dongjin hydrosphere. Forest and farmland area were extensive in Hanggeumcheon, Satancheon and Gosancheon. Farmland and livestock area were wide in Iksancheon. Jeonjucheon were occupied with broad urban. Industrial and urban area were extensive in Jongeupcheon. The loading amounts of biochemical oxygen demand (BOD), total nitrogen (T-N), total phosphorus (T-P) of Iksancheon and chemical oxygen demand (COD) of Jeonjucheon were determined to be very high, respectively. The quality of water in Hanggeumcheon, Satancheon and Gosancheon were determined to be good quality. The species diversity was lower in the down stream than in the upper stream except for the Gosancheon. Life form of plane were mostly perennial plane in the upper stream and annual plants in the down stream of rivers. It was estimated that there is high level of disturbance in the down stream of rivers. The quality of water was significantly correlated with farmland and forest area. In conclusion, human impact, such as farmland and housing lot exerted an influence on the disturbance of down stream and the water quality of rivers.

• The Korean Journal of Pharmacology
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• v.21 no.1
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• pp.34-48
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• 1985

In vitro effects of nitrofurantoin, an antimicrobial agent for acute and chronic urinary tract infection, on the lung microsomal lipid peroxidation and the generation of reactive oxygen radicals were investigated to elucidate the biochemical mechanisms of its in vivopulmonary toxicity. The interaction of nitrofurantoin with porcine lung microsome resulted in significant lipid peroxidation. In addition, nitrofurantoin stimulated the generation of reactive oxygen radicals, $O^{-}_{2}{\cdot},\;H_2O_2$ as well as a highly reactive secondary oxygen species, $OH{\cdot}$. The stimulation of lipid peroxidation was inhibited not only by superoxide dismutase and catalase, but also by hydroxyl radical scavengers, mannitol and thiourea. Neither singlet oxygen $({^1}O_{2})$ was detected during the incubation of microsome with nitrofurantoin, nor lipid peroxidation was inhibited by singlet oxygen scavengers. When incubated anaerobically under the nitrogen atmosphere, the ability of nitrofurantoin to stimulatle lipid peroxidation was abolished. It appears that NADPH-dependent metaboliam of nitrofurantoin in pulmonary microsome under aerobic condition is accompanied by the stimulation of lipid peroxidation through the mediation of reactive oxygen radicals, particularly hydroxyl radical. It is strongly suggested from these results that the stimulation of pulmonary microsomal lipid peroxidation by the reactive oxygen radical may be a in vivo mechanism of pulmonary toxicity caused by nitrofurantoin.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.561-572
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• 2017

The global commercial cultivation of transgenic crops, including glyphosate-tolerant soybean, has increased widely in recent decades with potential impact on the environment. The bulk of previous studies showed different results on the effects of the release of transgenic plants on the soil microbial community, especially rhizosphere bacteria. In this study, comparative analyses of the bacterial communities in the rhizosphere soils and surrounding soils were performed between the glyphosate-tolerant soybean line NZL06-698 (or simply N698), containing a glyphosate-insensitive EPSPS gene, and its control cultivar Mengdou12 (or simply MD12), by a 16S ribosomal RNA gene (16S rDNA) amplicon sequencing-based Illumina MiSeq platform. No statistically significant difference was found in the overall alpha diversity of the rhizosphere bacterial communities, although the species richness and evenness of the bacteria increased in the rhizosphere of N698 compared with that of MD12. Some influence on phylogenetic diversity of the rhizosphere bacterial communities was found between N698 and MD12 by beta diversity analysis based on weighted UniFrac distance. Furthermore, the relative abundances of part rhizosphere bacterial phyla and genera, which included some nitrogen-fixing bacteria, were significantly different between N698 and MD12. Our present results indicate some impact of the glyphosate-tolerant soybean line N698 on the phylogenetic diversity of rhizosphere bacterial communities together with a significant difference in the relative abundances of part rhizosphere bacteria at different classification levels as compared with its control cultivar MD12, when a comparative analysis of surrounding soils between N698 and MD12 was used as a systematic contrast study.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.169-175
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• 2007

The Bio Best Bacillus(B3) and Rotating Activated Bacillus Contactor(RABC) processes, in which Bacillus strains are predominating, are reported to remove nitrogen and phosphorus as well as organic matter effectively. Nevertheless the nutrient removal characteristics of the Bacillus strains have not been studied in detail so far. This study investigated the organic and nutrient removal by Bacillus strains, Bacillus megaterium(KCTC 3007), Paenibacillus polymyxa(KCTC 3627), and Bacillus sp. A12, C21, F12, and L1(isolated from a B3 process), by incubating the strains in 0.2% nutrient broth at $30^{\circ}C$. Burkholderia cepacia(KCTC 2966), a common activated sludge organism, was used as a reference species for comparison. Although the degradation rate was affected by the population sire, the specific removal rates of organic matter by Bacillus strains were greater by $2\sim5$ times than that of Burkholderia. In particular, the culture bottles inoculated with the endospores of Bacillus megaterium and Bacillus sp. C21, F12, and N12 showed significantly higher degradation rate than those of vegetative cells.