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        검색결과 274

        203.
        2008.06 KCI 등재 구독 인증기관·개인회원 무료
        푸른 곰팡이병을 일으키는 병원균은 매우 다양하며, 현 재까지 밝혀진 병원균은 Trichoderma spp., Gliocladium spp., Penicillium spp. 그리고 Aspergillus spp.로 이 중에서 Trichoderma spp.는 자낭균류에 속하는 Hypocrea spp.의 무성세대로서 발생빈도가 가장 높은 것으로 알려져 있다. 버섯의 병해 중에서 가장 방제가 어렵고 버섯의 발생 및 수확에 가장 큰 영향을 미치는 대표적인 병의 하나인 푸른 곰팡이병은 고온다습한 조건에서 많이 발생하며 발생초 기에는 버섯균과 비슷한 백색을 띄다가 포자가 형성되면 서 황록색 내지 진녹색으로 변하고, 골목의 표면에 부정형 의 병반을 형성하면서 버섯균의 생장을 억제하여 결국에 는 버섯균을 죽게 한다. 현재 버섯 재배농가에서는 버섯균 사생장 기간동안에 푸른 곰팡이병의 발생을 억제하기 위 하여 버섯배지 살균 전에 균상표면에 벤레이트, 판마쉬, 스포르곤수화제를 살포하는 것이 최대의 방제법이다. 따 라서 본 연구는 버섯 병해의 주범인 그린몰드(green mold)의 생장을 제어하기 위하여 수목추출물 및 nhexane 용해부의 효능을 비교 평가하였다. 수목추출물의 그린몰드에 대한 항균활성은 T. aggressivum 34.7%, T. atroviride 35.7%, T. harzianum 34.9%, T. koningii 31.0%, T. viride 30.7%로, 평균 33.4%의 항균 활성을 나타내었고, T. atroviride에서 수목추출물이 가장 높은 항균활성을 나타내었다. n-Hexane 용해부의 그린몰드에 대한 항균활성은 T. aggressivum 52.3%, T. atroviride 65.6%, T. harzianum 47.1%, T. koningii 48.5%, T. viride 51.1%로, 평균 52.9%의 항균활성을 나타내었고, T. atroviride에서 nhexane 용해부가 가장 높은 항균활성을 나타내었다. 수목추출물과 n-hexane 용해부의 그린몰드에 대한 항 균활성은 추출물의 농도에 따라서 5% 수준에서 유의성이 나타났다. 수목추출물과 n-hexane 용해부의 항균활성을 비교하 였을 때 수목추출물보다 수목 n-hexane 용해부에서 더 높은 항균활성이 나타났다.
        204.
        2008.06 KCI 등재 구독 인증기관·개인회원 무료
        표고, 느타리, 양송이, 팽이등 버섯의 종류에 관계없이 발생되고 있는 푸른곰팡이병은 그린몰드(green mold)가 그원인으로 알려져 있으며 이들의 피해는 심각하다. 푸른 곰팡이병을 일으키는 곰팡이로는 Trichoderma, Gliocladium, Aspergillus, Penicillum 등이 현재 알려져 있다. 푸른곰팡 이 병원균은 균사생장 시 균상에 발생하여 버섯균의 균사 생장을 방해하거나 기생하여 버섯균사를 사멸시키며, 버 섯수확기에 병해를 발생시키고 있다. 따라서 본 연구는 버 섯의 수확을 저하시키는 Trichoderma를 억제하기 위하 여 수목추출물 2종을 혼합한 다음 그 효능을 평가하였다. Trichoderma에 대하여 항균력을 나타내는 유효 화합 물질을 확인하기 위하여 GC/MS를 이용하여 편백 휘발성 추출물을 분석한 결과, 50개의 테르펜계 화합물이 존재한 다는 것을 확인하였고 대부분의 물질이 동정되었다. 편백 휘발성 추출물의 주요 화학적 조성은 모노테르펜류인 sabinene 11.62%, limonene 4.31%, isobornyl acetate 6.23%, α-terpinyl acetate 11.75%였으며, 세스퀴테르 펜류로 elemol 11.08%, β-eudesmol 4.02%, epibicyclosesquiphellandrene 4.18%가 나타났다. 소나무와 편백 추출물의 혼합비율 10 : 1(g/g) 제제는 T. aggressivum에서 20.4%, T. atroviride에서 14.0%, T. harzianum에서 32.0%, T. koningii에서 26.8%, T. viride에서 19.0%의 항균활성을 나타냈다. Trichoderma 균주는 편백 추출물의 첨가량이 증가함에 따라 항균활성 이 감소하는 경향을 나타냈다. Trichoderma 균주는 편백 추출물보다는 소나무 열수추출물에 대하여 영향을 받았다.
        206.
        2006.06 구독 인증기관 무료, 개인회원 유료
        The growing oocytes become progressively capable of resuming meiosis, and full meiotic competence appear when they are about 80% of the size of fully grown oocytes. As hormonal influences vary at different stages of reproductive cycle, the size of oocytes may vary according to the reproductive stages. The present study was designed to compare the diameter between the ovulated and freshly collected immature canine oocytes. The ovulated oocytes were collected 72 hr after ovulation by oviductal tube flushing by laparotomy under general anesthesia. Immature oocytes were collected by ovarian slicing method. Diameter of all oocytes was measured directly using epiflurescence microscope with a calibrated micro-eyepiece micrometer at ×200 magnification. The thickness of zona pellucida and diameter of cytoplasm were measured separately and recorded. A total of 2209 zona intact oocytes were collected, among them 628 from anestrus, 675 from follicular, 838 from luteal and 68 by fallopian tubes flushing methods. The average number of oocytes was 104.7, 168.8, 119.7 and 11.3 for anestrus, follicular, luteal and fallopian tubes flushing methods, respectively. The average diameters of the ooplasm and oocyte were significantly varied in different reproductive stages as well as with ovulated oocytes (P<0.05). The average diameter of ooplasm and oocyte was 115.6 and 127.7, 143.0 and 162.0, 134.6 and 150.6, 159.6 and 185.6 for anestrus, follicular, luteal and ovulated oocytes, respectively. Highest number of oocytes with larger diameter could be collected from the follicular and luteal stages. In conclusion, the follicular and luteal ovaries are the best sources of oocytes for canine IVM.
        4,000원
        207.
        2006.06 KCI 등재 구독 인증기관·개인회원 무료
        The yields of the n-hexane-soluble, ethyl acetate-soluble, methanol-soluble and methanol-insoluble fractions from the powdered water extracts were 8.2%, 10.6%, 32.0% and 49.2%, respectively (Table 1). The antifungal activities of water extracts, n-hexane-soluble fraction, ethyl acetate-soluble fraction, methanol-soluble fraction and methanol-insoluble fraction against L. edodes were 23.5%, 26.2%, 41.5%, 25.4% and 2.5%, respectively, at 1000ppm (Figure3). The ethyl acetate-soluble fraction showed much higher antifungal activity than the other fractions. The antifungal activity of the ethyl acetate-soluble fraction against L. edodes at 1000 ppm showed a statistically significant difference in the fractions of n-hexane-soluble, ethyl acetate-soluble, methanol-soluble and methanol-insolub
        208.
        2006.06 KCI 등재 구독 인증기관·개인회원 무료
        The yields of the fractions of n-hexane-soluble, ethyl acetate-soluble and methanol-soluble from the P. densiflora sawdust were obtained 1.36%, 2.21% and 4.03% using organic solvents, respectively (Table 1). The antifungal activity of the n-hexane extracts against L. edodes at concentrations 125, 250, 500, 750 and 1000 ppm were 36.5%, 41.2%, 43.1%, 45.4% and 47.6%, respectively (Table 2). The percent of antifungal activity against L. edodes was the greatest for the n-hexane extracts, ranging from 36.5% to 47.6% at a concentrations of 125 ppm to 1000ppm, with the values for all concentrations significantly different from one another. In this experiment, the antifungal activity by the n-hexane extracts was the highest. This result supposed that the n-hexane extracts have not only many more inhibitory compounds against L. edodes than the ethyl acetate and methanol extracts but also the inhibitory compound may be more easily dissolved by n-hexane than by ethyl acetate or methanol.
        211.
        2005.09 KCI 등재 구독 인증기관·개인회원 무료
        1. Antifungal activity of water extracts The antifungal activity of the water extracts against L. edodes was proportional to the concentration of the water extracts. The antifungal activity of the water extracts at 1000 ppm was the highest among the tested concentration against L. edodes mycelia. The antifungal activity were significantly different from each concentration of the water extracts. Therefore, it can be concluded that the water extracts of the P. densiflora sawdust have inhibitory compounds to the growth of L. edodes mycelia. 2. Yield and antifungal activity of fractions from water extracts The powdered water extracts was further treated serially using organic solvents in order to separate the water extracts into the fractions of n-hexane-soluble, ethyl acetate-soluble, methanol-soluble and methanol-insoluble. The ethyl acetate-soluble fraction showed much higher antifungal activity than the other fractions. The antifungal activity of the ethyl acetate-soluble fraction against L. edodes at 1000 ppm showed a statistically significant difference in the fractions of n-hexane-soluble, ethyl acetate-soluble, methanol-soluble and methanol-insoluble. And, there was not significantly difference between the antifungal activities of the n-hexane-soluble and methanol-soluble fractions at 1000 ppm. 3. Antivungal activity of fractions of organic solvent extracts The fractions were isolated from each organic solvent by the silica-gel column chromatography and then the fractions were confirmed and divided on the values of Rf by the thin-layer chromatography. The fractions were produced six band of the n-hexane, nine band of the ethyl acetate and eight band of the methanol extracts. The HIII fraction from the n-hexane extracts showed the highest growth inhibition against L. edodes mycelium.
        212.
        2005.09 KCI 등재 구독 인증기관·개인회원 무료
        After having inoculated the mycelium of L. edodes on the block medium, the P. densiflora sawdust of the B and C groups were the slowest of their respective groups on day 169.4 and day 169.9 harvesting times. The first harvest of the fruiting body from the Q. variabilis sawdust of the control medium was obtained on day 162.9
        215.
        2004.10 구독 인증기관 무료, 개인회원 유료
        The significant attention has been given to implementing a performance measurement system as one of the key enablers for supply chain integration. And yet, there is little guidance to practitioners as to how to develop the system. We propose a design framework for a performance measurement system (PMS) that supports effective supply chain integration among partners, along with the discussion of critical issues in the PMS design framework. Also, this framework provides a step-by-step guideline for building a conceptual PMS design,
        3,000원
        220.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon/carbon composites are ideal candidates for a number of aerospace applications including structural materials for advanced vehicles, leading edges, structures of re-entry and hypersonic vehicles and propulsion systems. One serious defect for such application of the carbon/carbon composites is their poor oxidation resistance in high temperature oxidizing environments. SiC coating was employed to protect the composites from oxidation. It is mechanically and chemically stable under extreme thermal and oxidative environments, provides good adhesion to the substrate, and offers good thermal shock resistance. The SiC layer on the nozzle machined from the carbon/carbon composites was formed by pack-cementation method. Then, erosion characteristic of SiC coated carbon/carbon nozzle was examined by combustion test using a liquid rocket motor. The erosion rates were measured as function of combustion pressure, ratio of oxygen to fuel, combustion time, density of the composites and geometry of reinforced carbon fibre in the composites. The morphology change of the composites after combustion test was investigated using SEM and erosion mechanism also was discussed.
        4,000원
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