• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.273-278
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• 2011

By introducing RPS(Renewable Portfolio Standard) for reduction of greenhouse gas, Renewable energy has becoming widespread gradually. Due to a large number of advantages, wind power, which is one of Renewable energy, has standing in the spot-light rather than other Renewable energy. Wind power, however, is difficult to control output and because of severe output fluctuation, it would cause some problems when it is connected with system. Using battery as a solution for these problems has been researched all over the world. In this paper, the reliability modeling of windfarm connected battery and reliability evaluation of system are executed. Also the optimum battery capacity is selected through evaluating reliability cost.

• Journal of fish pathology
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• v.5 no.1
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• pp.19-27
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• 1992

A formalized bacterin(FKC) of Edwardsiella tarda, conjugated with/without Freund's complete adjuvant(FCA), Freund's incomplete adjuvant(FIA) and potassium aluminium sulfate(PAS), was administered by intraperitoneal injection to tilapia respectively. The tilapia were reared under indoor recirculating filter system. There were agglutinin titer increment in the tilapia which were administered not only FKC bacterin but also adjuvanted vaccines. But the producing time of the highest level of antibody in the immunized tilapia was different among vaccine preparation, i. e. FKC+FCA group and PAS+FKC group are between the 2nd and the 4th week, and FKC alone group is the 2nd week. In the challenge experiment with $2.5{\times}10^7\;CFU/ml$ or $2.5{\times}10^8\;CFU/ml$ of E. tarda T1123 to the tilapia immunized with vaccines, RPS above sixty was recorded both challenge dose in the tilapia which were 3 weeks after immunization with FKC+FCA, PAS+FKC and FKC alone, and the former dose 8 weeks after immunization with FCA+FKC and PAS+FKC. There were some resistance enhancement against E. tarda in the tilapia which were injected with adjuvant alone than that of control. As the results, the FCA or PAS adjuvanted vaccine is effective to sustain the defensible period against edwardsiellosis.

• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.85-96
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• 2022

The plant "Hong-do-go-deul-ppae-gi" has been considered as Crepidiastrum × muratagenii, a hybrid between C. denticulatum and C. lanceolatum, based on its morphological traits and geographical distribution. To reveal the hybrid origin of Hong-do-go-deul-ppae-gi, we examined additional morphological traits of this plant and its putative parents (C. denticulatum, C. lanceolatum, C. platyphyllum) and analyzed one nuclear ribosomal internal transcribed spacer (ITS) region and four chloroplast regions (trnT-L, trnL-F, rpl16 intron, and rps16 intron). As a result of examining the morphological traits, putative hybrid individuals were classified into three types based on the habit, cauline leaf, outer phyllary, and achene beak traits. A molecular analysis found that the ITS sequences of Type 1 and Type 2 individuals showed additive species-specific sites of C. denticulatum and C. lanceolatum. Plastid sequences of Type 1 and Type 2 individuals showed C. denticulatum and C. lanceolatum sequences, respectively. However, Type 3 individuals had ITS and plastid sequences corresponding to C. denticulatum. Accordingly, Type 1 and Type 2 individuals not only share morphological traits with C. denticulatum and C. lanceolatum but also show additive species-specific sites for C. denticulatum and C. lanceolatum, and not C. platyphyllum, supporting its origin as a hybrid between C. denticulatum and C. lanceolatum. Type 3 had morphological traits similar to other hybrid types but was distinguished with respect to outer phyllaries and demonstrated some resemblance to C. denticulatum. In a molecular analysis, Type 3 was found to be identical with regard to the sequence of C. denticulatum and was judged to be an ecological variation of C. denticulatum.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.525-529
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• 2016

Biomass co-firing to existing thermal power plants is one of the most economical and efficient way to reduce $CO_2$ emission from the plant. There are several methods of co-firing and it can be categorized into (1) Parallel co-firing, (2) Indirect co-firing, and (3) Direct co-firing. Parallel co-firing is the most expensive way to high-ratio co-firing because it requires biomass dedicated boiler. Direct co-firing is widely used because it does not need high capital cost compared with the other two methods. Regarding the direct co-firing, it can be classified into three methods- Method 1 does not need retrofit of the facilities because it uses existing coal mills for pulverizing biomass fuels. In this case high-ratio co-firing cannot be achieved because of poor grindability of biomass fuels. Method 2 needs biomass-dedicated mills and revision of fuel streams for the combustion system, and Method 3 needs additional retrofit of the boiler as well as biomass mills. It can achieve highest share of the biomass co-firing compared with other two methods. In Korea, many coal power plants have been adopting Method 1 for coping with RPS(Renewable portfolio standards). Higher co-firing ratio (> 5% thermal share) has not been considered in Korean power plants due to policy of limitation in biomass co-firing for securing REC(Renewable Energy Certificate). On the other hand, higher-share co-firing of biomass is widely used in Europe and US using biomass dedicated mills, following their policy to enhance utilization of renewable energy in those countries. Technical problems which can be caused by increasing share of the biomass in coal power plants are summarized and discussed in this report. $CO_2$ abatement will become more and more critical issues for coal power plants since Paris agreement(2015) and demand of higher share of biomass in the coal power plants will be rapidly increased in Korea as well. Torrefaction of the biomass can be one of the best options because torrefied biomass has higher heating value and grindability than other biomass fuels. Perspective of the biomass torrefaction for co-firing is discussed, and economic feasibility of biomass torrefaction will be crucial for implementation of this technology.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.200-207
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• 2019

The aim of this study was to provide the basic information necessary to identify Korean fir (Abies holophylla), momi fir (A. firma), and Nikko fir (A. homolepis), and other fir trees planted in South Korea that are protected by law. Analysis of the morphological characteristics of the needles from each sample was investigated. The shape of the needle-leaf tip from A. holophylla was acute, whereas that from A. firma and A. homolepis was emarginate and that from the protected fir trees was obtuse. The number of stomata on the needles was not significantly different between A. holophylla and A. firma, and the number of stomata on the needles from A. homolepis and the protected fir trees were highly similar. In addition, the genetic differences among the Abies species were analyzed using the sequences of five chloroplast DNA regions-matK, atpF-atpH, rpoC2-rps2, rpoC1, and psbA-trnH.The atpF-atpH and psbA-trnH regions were useful for discriminating A. firma from the other species, but there were no differences among A. holophylla, A. homolepis, and the protected fir trees. The same chloroplast sequences were found in both A. holophylla and A. homolepis, which suggests that additional genetic studies might be necessary to identify the Abies species planted in both South Korea and Japan.

• Journal of fish pathology
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• v.15 no.1
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• pp.25-35
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• 2002

Effects of medicinal herb extract on nonspecific immune responses, hematology and disease resistance against Edwardsiella tarda in olive flounder, Paralichthys olivaceus were evaluated. Wormwood, Artemisia asiatica NAKAI and barrenwort, Epimedium koreanum NAKAI were mixed at a ratio of 7 : 3 (w/w) for 2-herbs extract and wormwood, barrenwort, Korean forsythia, Forsythia koreana NAKAI, chrysanthemum, Chrysanthemum zawadskii var. latilobum KITAMURA, peppermint, Mentha arvensis L. var, piperascens MALINV., great burnet, Snaguisorba afficinalis L., Lizard tail. Saururus chinensis BAILL., mulberry, Morus alba L., and star anise, Illicium varum HOOK, f, at the same weight for 9-herbs extract. Two-herbs of 9-herbs extract were prepared by heating after adding 10㎖ of distilled water per g of the herb mixtures. Fish (10.3$\pm$2.5g) were fed the experimental diets supplemented with the 2-herbs or 9-herbs extract at the different concentrations of 0%, 0.1%, 0.5% and 1% per kg diet for 12 weeks. Lysozyme and bactericidal activities of serum, and hematological characteristics were examined during experimental period. After feeding test period, all experimental groups were challenged with E. tarda. Lysozyme activity from the fish fed the diet supplemented with 0.1% or 0.5% of 2-herbs extract was significantly higher than the control. But there was no difference both in bactericidal activity and hematology among each group. Sixty seven % of relative percent survival values (RPS) in the group fed the diet supplemented with 0.1% of 2-herbs was higher than the other group and the control. These results suggest that supplenmentation of 0.1% of 2-herbs extract to a commercial diet may enhance disease resistance in olive flounder. Although both 0.1% and 0.5% 9-herbs extract did not improve non-specific immune reponses, they could enhance disease resistance of 53% RPS, respectively.

• Journal of the Korea Convergence Society
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• v.2 no.2
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• pp.47-56
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• 2011

Korea Ministry of Knowledge Economy has estimated that wind power (WP) will be occupied 37% in 2020 and 42% in 2030 of the new energy sources, and also green energies such as photovoltaic (PV) and WP are expected to be interconnected with the distribution system because of Renewable Portfolio Standard (RPS) starting from 2012. However, when a large scale wind power plant (over 3[MW]) is connected to the traditional distribution system, protective devices (mainly OCR and OCGR of re-closer) will be occurred mal-function problems due to changed fault currents it be caused by Wye-grounded/Delta winding of interconnection transformer and %impedance of WP's turbine. Therefore, when Double-Fed Induction Generator (DFIG) of typical WP's Generator is connected into distribution system, this paper deals with analysis three-phase short, line to line short and a single line ground faults current by using the symmetrical components of fault analysis and PSCAD/EMTDC modeling.

• Journal of fish pathology
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• v.34 no.2
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• pp.185-199
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• 2021

Vibriosis is an important septicemic bacterial disease that affects a variety of commercial fish species, including cultured Dicentrarchus labrax. Nanotechnology has become an important modern tool for fish diseases prevention. Furthermore, nanomaterials have the ability to prevent and treat fish diseases. The current study was aimed to identify the causative agent of massive mortality of D. labrax commercial farm in Alexandria, Egypt. Experimental infection and the median lethal dose (LD50) of pathogenic isolate were assessed. Also, the effect of ginger nanoparticles (GNPs) and Sacchromyces cerevisiae as feed additives for prevention of vibriosis in D. labrax was carried out. Similarly, the tissue immunstimulant genes, IL-1β and TLR2 were measured in the spleen of feeding groups. The clinical signs of naturally diseased D. labrax showed corneal opacity and paleness of gills with excessive mucous secretion. The post-mortem abnormalities were severe hemorrhage and adhesion of internal organs. After bacteriological isolation and identification, the causative agent of mortality in the current study was Vibrio alginolyticus. The LD₅₀ of V. alginolyticus was 1.5×10^5.4 CFU/ml. The experimentally infected D. labrax showed ulceration, exophthalmia and skin hemorrhages. The post-mortem findings of the experimentally infected D. labrax revealed internal hemorrhage, spleen darkness and paleness of liver. There is no mortality and 100% RPS in groups fed GNPs then injected with V. alginolyticus, in those fed a combination of GNPs and S. cerevisiae and a group fed normal diet then injected with physiological saline (control negative), respectively. Contrarily, there was 10% mortality and 87.5 RPS in the group fed S. cerevisae then injected with V. alginolyticus. On the other hand, the control positive group showed 79% mortality. The spleen IL-1β and TLR2 immunostimulant genes were significantly increased in groups of fish fed GNNP, S. cerevisiae and a combination of GNPs and S. cerevisiae, respectively compared to control group. The highest stimulation of those immunostimulant genes was found in the group fed a combination of GNPs and S. cerevisiae, while fish fed S. cerevisiae had the lowest level. Dietary combination of GNPs and S. cerevisiae was shown to be efficient in preventing of vibriosis, with greatest stimulation of spleen IL-1β and TLR2 immunostimulant genes.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.247-253
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• 2018

To replace the imported biomass and to effectively cope with growing RPS(Renewable Portfolio Standard) in power sector, the domestic forest biomass resources for wood pellets were estimated from the preceding research and annual growth rate of forest trees in this study. Assuming that 20% of the by-product from forest trees processing were used as raw material for wood pellet and the wood pellet production capacity was based on the average value derived from the above two methods, unused by-product and residues generated 1.99million tons in 2016, 2.28million tons in 2020 and 3.08million tons in 2030. If 20% of by-products(pebbles, sawdust, etc.) from roundwood processing were used as raw material for wood pellets, the wood pellet could be produced 2.74million tons/year in 2016, 2.95million tons/year in 2020, 3.98million tons/year in 2030. Therefore, total amounts of wood pellet would be increased to 2.74million tons/year in 2016, 3.14million tons/year in 2020, 4.23million tons/year in 2030 when it considered unused by-product and residues from wood processing as raw materials.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1563-1570
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• 2010

To construct a highly sensitive detection system for endocrine disruptors (EDs), we have compared the activity of promoters with the n-alkane-inducible cytochrome P450 gene (ALK1), isocitrate lyase gene (ICL1), ribosomal protein S7 gene (RPS7), and the translation elongation factor-1${\alpha}$ gene (TEF1) for the heterologous gene in Yarrowia lipolytica. The promoters were introduced into the upstream of the lacZ or hERa reporter genes, respectively, and the activity was evaluated by ${\beta}$-galactosidase assay for lacZ and Western blot analysis for hER${\alpha}$. The expression analysis revealed that the ALK1 and ICL1 promoters were induced by n-decane and by EtOH, respectively. The constitutive promoter of RPS7 and TEF1 showed mostly a high level of expression in the presence of glucose and glycerol, respectively. In particular, the TEF1 promoter showed the highest ${\beta}$-galactosidase activity and a significant signal by Western blotting with the anti-estrogen receptor, compared with the other promoters. Moreover, the detection system was constructed with promoters linked to the upstream of the expression vector for the hER${\alpha}$ gene transformed into the Y. lipolytica with a chromosome-integrated lacZ reporter gene under the control of estrogen response elements (EREs). It was indicated that a combination of pTEF1p-hER${\alpha}$ and CXAU1-2XERE was the most effective system for the $E_2$-dependent induction of the ${\beta}$-galactosidase activity. This system showed the highest ${\beta}$-galactosidase activity at $10^{-6}\;M\;E_2$, and the activity could be detected at even the concentration of $10^{-10}\;M\;E_2$. As a result, we have constructed a strongly sensitive detection system with Y. lipolitica to evaluate recognized/suspected ED chemicals, such as natural/synthetic hormones, pesticides, and commercial chemicals. The results demonstrate the utility, sensitivity, and reproducibility of the system for identifying and characterizing environmental estrogens.