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        검색결과 225

        141.
        2008.05 구독 인증기관·개인회원 무료
        Commercial plant essential oils from 27 plant species were tested for their nematicidal activities against the pinewood nematode, Bursaphelenchus xylophilus. Good nematicidal activity against B. xylophilus was achieved with essential oils of coriander (Coriandrum sativum), styrax (Liquidamber orientalis) and valerina (Valeriana wallichi). Analysis by gas chromatography-mass spectrometry led to identification of 26, 10 and 4 major compounds from coriander (Coriandrum sativum), styrax (Liquidamber orientalis) and valerina (Valeriana wallichi) oils, respectively. These compounds from three plant essential oils were tested individually for their nematicidal activities against the pine wood nematode. Among compounds, benzaldehyde, trans-cinnamyl alcohol, cis-asarone, octanal, nonanal, decanal, trans-2-decenal, undecanal, dodecanal, decanol, and trans-2-decen-1-ol showed strong nematicidal activity. The essential oils and their described herein merit further study as potential nematicides against the pine wood nematode.
        142.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Wood vinegar, an extract from Acer Tegmentosum Maximowicz, was evaluated for its hypoglycemic and anti-diabetic properties by using normal and diabetic rats. The extract was dissolved in water and administered daily for six or seven weeks. In experiment 1, thirty normal Sprague- Dawley (SD) male rats were randomly divided into five treatments of 6 rats each. The treatments were T1 (mineral water), T2 (mineral water), T3 (silver solution), T4 (wood vinegar), and T5 (silver solution + wood vinegar) and diabetes was induced by intravenous injection of streptozotocin except T1. In experiment 2, sixteen diabetic Goto-Kakizaki (GK) male rats were randomly divided into four treatments of 4 rats each. The treatments were T1 (mineral water), T2 (silver solution), T3 (wood vinegar), and T4 (silver solution + wood vinegar). Streptozotocin-induced diabetic rats showed less body weight gain, more food intake and less water consumption as compared with normal non-diabetic rats. Oral administration of wood vinegar resulted in more weight gain, lower blood glucose concentration and urine pH among all the diabetic rats. In experiment 2, diabetic GK rats administrated with wood vinegar showed higher weight gain, food intake and less water intake when compared with control. However, supplementation with wood vinegar did not result in any decrease of blood glucose concentrations. It could be concluded that wood vinegar extracted from Acer Tegmentosum Maximowicz exerted hypoglycemic effect in diabetic-induced normal rats, but not in diabetic GK rats.
        4,000원
        143.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polypropylene (PP) composites with wood flour/wax/coupling agent were manufactured by melt compounding and injection molding. The influence of wood flour(WF), wax, and coupling agent on the mechanical and thermal properties of the composites was investigated. The addition of wood flour to neat PP has the higher tensile modulus and strength compared with neat PP. The presence of wax also improved the tensile modulus. At the same loading of PP and WF, the addition of coupling agent highly decreased the tensile modulus, and increased the tensile strength. From thermogravimetric analysis (TGA), the addition of wax improved the thermal stability of the composites in the later stages of degradation. The presence of MAPP and wood flour in turn decreased thermal stabilities of composites. From differential scanning calorimetry analysis (DSC), neither the loading of wax. nor the presence of MAPP has shown significant effect on the thermal transition of composites.
        4,200원
        144.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two experiments were conducted to determine the effect of wood vinegar (WV) on the fecal microbes and gas emission in weaned pigs. In Exp. 1, 224 weaned piglets (L×Y×D, 21 d-old, initial BW 6.02 ± 0.52 kg) were assigned to four treatments of different WV levels in randomized completely block design with four replicates (14 piglets/pen) for 28 days, including phases I (0-2 wk) and phase II (3-4 wk). The dietary treatments were 0, 0.1, 0.2 and 0.3% of WV added to a corn-soybean meal basal diet. The concentration of ammonia measured at 0 h and 24 h in feces did not differ among dietary treatments (p>0.05), but it was linearly decreased (p<0.05) in 0.2% and 0.3% addition level measured at 48 h and 72 h. The concentration of hydrogen sulfide had no significant change (p>0.05) within treatments measured at different time. The fecal total bacteria (TBC), Lactobacilli(LAB) and E. coli were measured on 14 d and 28 d. TBC were higher (p>0.05) in WV added treatments than the control. Similar results were obtained for LAB. But E. coli populations were decreased (p<0.05) in treatments added WV compared to control measured on 14 d and 35 d. In Exp. 2, 288 weaned piglets (L×Y×D, 21 d-old, initial BW 6.62 ± 0.31 kg) were assigned to four treatments in a randomized completely block design with four replicates (18 piglets/pen) for 28 days. The dietary treatments were basal diet (negative control, NC), 0.2% organic acid (positive control, PC), 0.2% antibiotic (AT) and 0.2% WV added to a corn-soybean meal basal diet. The fecal total bacteria (TBC), Lactobacilli(LAB) and E. coli were measured on 14 d and 28 d. TBC, LAB and E. coli showed lower counts in pigs fed AT diets than others. In conclusion, these results indicated that wood vinegar could reduce the NH3 concentration of feces and inhibited the growth of harmful bacteria.
        4,000원
        145.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a part of enhancing the performance of wood-plastic composites (WPC), polypropylene (PP)/ nanoclay (NC)/ wood flour (WF) nanocomposites were prepared using melt blending and injection molding process to evaluate their thermal stability. Thermogravimetric analysis (TGA) was employed to investigate thermal degradation kinetics of the nanocomposites both dynamic and isothermal conditions. Dynamic scans of the TGA showed an increased thermal stability of the nanocomposites at moderate wood flour concentrations (up to 20 phr, percentage based on hundred percent resin) while it decreased with the addition of 30 phr wood flour. The activation energy (Ea) of thermal degradation of nanocomposites increased when nanoclay was added and the concentration of wood flour increased. Different equations were used to evaluate isothermal degradation kinetics using the rate of thermal degradation of the composites, expressed as weight loss (%) from their isothermal TGA curves. Degradation occurred at faster rate in the initial stages of about 60 min., and then proceeded in a gradual manner. However, nanocomposites with wood flour of 30 phr heated at 300℃ showed a drastic difference in their degradation behavior, and reached almost a complete decomposition after 40 min. of the isothermal heating. The degree of decomposition was greater at higher temperatures, and the residual weight of isothermal degradation of nanocomposites greatly varied from about 10 to 90%, depending on isothermal temperatures. The isothermal degradation of nanocomposites also increased their thermal stability with the addition of 1 phr nanoclay and of wood flour up to 20 phr. But, the degradation of PP100/NC1/MAPP3/WF30 nanocomposites with 30 phr wood flour occurs at a faster rate compared to those of the others, indicating a decrease in their thermal stability.
        4,000원
        146.
        2006.12 구독 인증기관 무료, 개인회원 유료
        This paper reports the application of Wood's national policy framework (Wood, 2002) to the use of computers in Chinese schools in order to evaluate the impact of and reaction to information and communications technology (ICT) policy on the future of schooling and society. With its highly centralized system of schooling, the "centralized regulation of schooling" scenario is considered to be sufficiently close to enable current ICT policy and possible future developments to be examined. The analysis arising/rom Wood's framework has significant implications for developing countries, such as China, which have limited funding and experience to address the range of issues relating to ICT integration. 81
        4,300원
        147.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        During the repair and restoration of the Daewoongjeon Hall of Youngguksa Temple, species identification and tree-ring dating for both present wood elements and charred ones excavated under the Hall, were conducted. The species of 74 wood elements of Daewoongjeon Hall, were identified as Pinus densiflora Sieb. et Zucc. and only 1 was identified as exotic Pinus species. The latter wood, which was used in the laths, seems to have been replaced during past repairs. Many documentary records and various artifacts pertaining to Youngguksa Temple are being excavated, but none described precisely the construction date of the present Daewoongjeon Hall. Also, from beneath the Daewoongjeon Hall, cornerstone and foundation of previous building and several charred wood elements were excavated. In comparing the direction of the stone columns of foundation of the previous structure and the existing Daewoongjeon Hall, the previous structure was rotated in an angle of approximately $15^{\circ}$. Therefore, in order to find the association of the previous structure with the present Daewoongjeon Hall, tree-ring dating was conducted. The dating of 41 original timbers and 14 roof-filling timbers of the present construction elements revealed that the last annual ring was of A. D. 1703 with complete latewood, indicating that those woods was cut some time between the autumn of 1703 and spring of 1704, and the building was erected in 1704 when we assume no period of wood storage. The year of the last annual ring of the charred elements, which were excavated from beneath the Daewoongjeon Hall, was analyzed as 1674. The cutting year of the woods used for the present building began in 1698, therefore, it can be presumed that the Daewoongjeon Hall before the fire was a structure that was elected shortly after 1674 and that a catastrophic fire occurred some time between 1674 and 1698.
        4,900원
        153.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 실험의 목적은 침엽수(Paraserianthes falcataria) 와 활엽수(Shoreasp) 골목에서 두 개의 Ganoderma lucidum 균주의 자실체 발생과 성장을 연구하고 자실체의 organic germanium 과 crude ganoderic acid 함량을 측정하기 위함이다. 두 개의 Ganaderma lucidum중 하나는 인도네시아 본지에서 분리한 것이고 또 다른 하나는 Fungi Perfecti, USA에서 구입한 것을 사용하였다. 일반적으로 활엽수에서 생성된 자실체의 농도가 침엽수에서 자란 것보다 훨씬 높다. 두 종류의 골목 모두에서 상업용 균주에서 생산된 자실체의 organic germanium 농도가 인도네시아의 균주에서 생산된 자실체의 organic germanium 농도보다 높았다. 이에 반하여 버섯 자실체의 crude ganoderic acid 농도는 두 개의 균주로부터 생산된 자실체에서 거의 같은 농도를 보였다. 인도네시아 균주는 상업용 분리균주와 비교했을 때 생산된 자실체의 총 organic germanium과 총 crude ganoderic acid의 생산성이 높았다.
        4,000원
        158.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is well known that the porosity and adsorption capacity in a carbon depends on the nature of precursor, pyrolysis and activation conditions and the ash content. The studies on carbon prepared from the dry and wet babbool wood were under taken to ascertain the effect of initial state of precursor on the development of porosity in the resulting activated carbon. The characterization and adsorption studies carried out shows the presence of mainly mesoporosity in the carbon prepared from dry wood while more of microporosity was observed in the activated carbon prepared from wet wood. The results on porosity in both the cases have been compared and correlated with their processing conditions.
        4,000원
        159.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유기농자재인 목초액과 키토산의 농업적 이용을 위하여 고추의 생육과 양분흡수 및 토양미생물상에 미치는 영향을 살펴본 결과는 다음과 같다. 키토산 처리구에서 토양의 방선균수가 증가하고 사상균 수는 감소하는 경향으로 A/F 및 B/F비가 커졌으며, 정식 후 50일에 경경이 약간 큰 편이었으나, 엽록소함량은 처리별 큰 차이를 보이지 않았다. 병해충은 관행에 비해 키토산 및 목초액 처리구 모두 발생률이 많아 병해충의 방제효과는 볼 수 없었다. 식물체 분석 결과 키토산과 목초액 처리구 모두 Ca, K가 관행보다 다소 높았으며 키토산 처리구는 과실의 무기성분 중 Ca와 K와 같은 양이온 함량이 다소 많은 편이었다 키토산과 목초액 처리에 의한 수량은 병해충 발생으로 관행에 비하여 모든 시험구에서 감소하여 수량증대효과는 기대할 수 없었으나. 과중 등의 과실특성이 좋게 나타나 키토산 10회 처리의 경우 관행대비 92.4%로 관행에 가까운 수량지수를 보였다.
        4,000원
        160.
        2001.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 조경수목의 목질 내부의 상태 진단과 변색 및 부후 부위의 탐색을 통하여 병든 부위를 조기에 제거. 병의 확산 방지 및 효율적인 예방관리를 위해 Shigometer의 이용가능성을 제시하고자 하였다. 본 연구대상지는 충남 천안시 성환흡 수향리에 위치한 연암축산원예대학으로 하였으며, 대학 구내에 식재된 조경수를 대상수종으로 하였다. 대상수종은 침엽수 7종과 활엽수 16종으로 총 23종을 선정하였다. 조사한 조경수목의 내부 전기저항치는 수종별로 매우 다양하게 나타났다. 평균 내부 전기저항치가 500kΩ이상인 수종은 은행나무, 섬잣나무, 소나무, 단풍나무, 중국단풍. 홍단풍이었으며, 개체간 차이와 측정 깊이에 따른 차이도 심하지 않았다. 그러나 메타세쿼이아, 수양버들, 자귀나무, 회화나무는 200kΩ이하의 낮은 내부 전기저항치를 나타냈다. 측정 깊이에 따른 변화가 심한 수종은 전나무, 메타세쿼이아, 수양버들, 느티나무, 튤립나무, 목련, 일본목련, 핀오크, 벚나무등으로 이들은 측정 깊이에 따라 전기저항치가 갑자기 하락하는 부위를 포함하고 있었으며, 전기저항치가 갑자기 하락하는 부위의 목재는 부후되어 있었다. 결론적으로 Shigometer는 가시적인 피해증상이 나타나기 전 초기단계에서 목재의 변색 및 부후 부위를 찾아내는데 유용하게 이용될 수 있을 것으로 판단된다.
        4,000원