• Title/Summary/Keyword: secondary

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Clues to Understand the Regulatory Metabolisms Governing the Biosynthesis of Fungal Secondary Metabolites

  • Choi, Yoon-E
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.14-14
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    • 2015
  • Fungi are of particular interest due to their capacity to produce an extensive array of secondary metabolites. While many secondary metabolites have no known functions to the producing fungal organisms, these metabolites have tremendous importance to humans with beneficial (e.g., antibiotics) or detrimental (e.g., mycotoxins) properties. In this study, two important filamentous fungi, Fusarium verticillioides and Mycosphaerella graminicola were selected as target species and the genes regulatory functions on the biosynthesis of secondary metabolisms were studied. Functional genomics including forward and reverse genetics, and proteomics were utilized to better understand the complex secondary metabolism regulations in both F. verticillioides and M. graminicola. Identified genes in either F. verticillioides or M. graminicola background were CPP1 (a putative protein phosphatase gene), GAC1 (encoding a GTPase activating protein), MCC1(encoding c-type cyclin), and the velvet gene, MVE1. Our data suggest that there are diverse regulatory genes on fungal secondary metabolites with distinct or overlapping functional roles.

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Analysis of the Gas Flow Field of Primary Combustion Chamber with the Conditions of Secondary Air Injection (2차 공기 주입 조건 변화에 따른 소형 소각로 내부의 유동장 분석)

  • Choi, Byung-Dae;Kim, Sung-Joon
    • Journal of Industrial Technology
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    • v.22 no.A
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    • pp.9-17
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    • 2002
  • This analysis is aimed to find out how the conditions of secondary air injection affects the residence time and the turbulence energy of flue gas and flow field in a small incinerator. A commercial code, PHOENICS, is used to simulate the flow field of an Incinerator. The computational grid system is constructed in a cartesian coordinate system In this numerical experiment, an independent numerical variable is the conditions of secondary air injection and dependants are the residence time of flue gas and the mean value of turbulence energy in a primary combustion chamber. The flow field and the distribution of turbulence energy are analysed to evaluate the residence time of flue gas and the turbulence energy The computational results say that the tangential injection of secondary air make the residence time much longer than the radial injection and that the radial injection of secondary make turbulence much stronger than the tangential injection.

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SECONDARY ELECTRONS IN CLUSTERS OF GALAXIES AND GALAXIES

  • HWANG CHORNG- YUAN
    • Journal of The Korean Astronomical Society
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    • v.37 no.5
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    • pp.461-463
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    • 2004
  • We investigate the role of secondary electrons in galaxy clusters and in ultra-luminous infrared galaxies (ULIGs). The radio emission in galaxy clusters and ULIGs is believed to be produced by the synchrotron radiation of relativistic electrons. Nonetheless, the sources of these relativistic electrons are still unclear. Relativistic secondary electrons can be produced from the hadronic interactions of cosmic-ray nuclei with the intra-cluster media (ICM) of galaxy clusters and the dense molecular clouds of ULIGs. We estimate the contribution of the secondary electrons in galaxy clusters and ULIGs by comparing observational results with theoretical calculations for the radio emission in these sources. We find that the radio halos of galaxy clusters can not be produced from the secondary electrons; on the other hand, at least for some ULIGs, the radio emission can be dominated by the synchrotron emission of the secondary electrons.

An Experimental Study on the NOx Formation of Fuel Staged Combustor (연료다단 연소기의 NOx 발생특성에 관한 실험적 연구)

  • 정진도;안국영;한지웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.6
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    • pp.73-79
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    • 2003
  • The characteristics of NOx emission in multi fuel/air staged combustor have been experimentally studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is act as a pilot flame for the secondary combustion stage combustion zone, where most of fuel burns. Experiments were performed on a semi-industrial scale (thermal input 0.233 ㎿) in a laboratory furnace and Liquefied Petroleum Gas(LPG) was used as primary and secondary fuels. The study included parametric study to identify the optimum operating conditions which are primary/secondary fuel ratio, primary/secondary air ratio, primary swirl intensity and secondary swirl intensity for reducing NOx emission. The test demonstrated that NOx emission can be reduced by >70% in accordance with operating conditions.

Micromorphological Characteristics of Frost Rings in the Secondary Xylem of Pinus radiata

  • Lee, Kwang Ho;Kim, Jong Sik;Singh, Adya P.;Kim, Yoon Soo
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.2
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    • pp.1-8
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    • 2007
  • Frost ring formed in the secondary xylem of Pinus radiata was examined using various microscopic techniques. Cell walls in a frost ring were poorly developed, lacking in the proportion of wall components. Formation of secondary cell wall was imperfect and thickness of secondary wall was varied. Cytochemical examinations provided the evidence that the synthesis of structural polysaccharides and lignin was inhibited, resulting in the malformation of secondary cell walls. Judging by the highly irregular nature of the cell wall, it appears that cellulosic/hemicellulosic framework was affected and the template for lignification by frost.

Analysis of Operating Time of Li-polymer Secondary Cell with or Without Flyback Converter Active Balancing BMS (Flyback Converter Active Balancing BMS 적용 유·무에 따른 리튬폴리머 이차전지 가용시간 분석)

  • Kim, Young-Pil;Choi, Chul-Hyung;Ko, Seok-Cheol;Kim, Si-Kyung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.5
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    • pp.786-791
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    • 2017
  • In this paper, the run time of Li-polymer secondary cell with and without Active Balancing BMS is analyzed. The Active Balancing System using Flyback Converter with two-way power control facility, his designed for optimal characteristics of balancing. The run time of Li-polymer secondary cell is drastically increased employing the Flyback Convert Active Balancing BMS. The run time performance of Li-polymer secondary cell with or without Flyback Converter Active Balancing BMS is analyzed with the discharging and charging experiment of Li-polymer secondary cell.

Secondary Carotenoid Accumulation in Haematococcus (Chlorophyceae): Biosynthesis, Regulation, and Biotechnology

  • Jin Eon-Seon;Lee Choul-Gyun;Polle Jurgen E.W.
    • Journal of Microbiology and Biotechnology
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    • v.16 no.6
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    • pp.821-831
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    • 2006
  • Unicellular green algae of the genus Haematococcus have been studied extensively as model organisms for secondary carotenoid accumulation. Upon environmental stress, such as strong irradiance or nitrogen deficiency, unicellular green algae of the genus Haematococcus accumulate secondary carotenoids in vesicles in the cytosol. Because secondary carotenoid accumulation occurs only upon specific environmental stimuli, there is speculation about the regulation of the biosynthetic pathway specific for secondary carotenogenesis. Because the carotenoid biosynthesis pathway is located both in the chloroplast and the cytosol, communication between both cellular compartments must be considered. Recently, the induction and regulation of astaxanthin biosynthesis in microalgae received considerable attention because of the increasing use of this secondary carotenoid as a source of pigmentation for fish aquaculture, as a component in cancer prevention, and as a free-radical quencher. This review summarizes the biosynthesis and regulation of the pathway, as well as the biotechnology of astaxanthin production in Haematococcus.

The experimental study on the NOx formation of fuel staged combustor (연료다단 연소기의 NOx 발생특성에 관한 실험적 연구)

  • Han, Ji-Woong;Ahn, Kook-Young;Kim, Han-Seok;Chung, Jin-Do
    • 한국연소학회:학술대회논문집
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    • 2001.06a
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    • pp.163-171
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    • 2001
  • The characteristics of NOx emission in multi fuel/air staged combustor have been experimentally studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is act as a pilot Dame for the secondary combustion stage combustion zone, where most of fuel bums. Experiments were performed on a semi-industrial scale (thermal input 0.233 MW) in a laboratory furnace and Liquefied Petroleum Gas(LPG) was used as primary and secondary fuels. The study included parametric study to identify the optimum operating conditions which are primary/secondary fuel ratio, primary/secondary air ratio, primary swirl intensity and secondary swirl intensity for reducing NOx emission. The test demonstrated that NOx emission can be reduced by ${>}$70% in accordance with operating conditions.

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Wound-rotor induction generator system for random wave input power

  • Kim, Moon-Hwan
    • Journal of information and communication convergence engineering
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    • v.7 no.1
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    • pp.46-51
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    • 2009
  • In this paper, the two-axis theory is adopted to analyze the secondary excited induction generator applied to random wave input generation system. The analysis by the two-axis theory helps to know the transmitted power of the induction machine. The electric variables, like as primary and secondary currents, voltages, and electric output power, were able to express as equations. These equations are help to simulate the generation system numerical model and to know the transient state of the system. As it is preferred to stabilize the output voltage and frequency in the constant level, microcomputer controlled VSI connected to the secondary windings supplies the secondary current with slip frequency. For testing the appropriateness of this method, the input torque simulator in the laboratory to drive the secondary excited results show the advantage of secondary excited induction generator system for the random input wave generation system.