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        검색결과 2,998

        1641.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 용액 캐스팅법을 이용하여 각기 다른 함량의 VMT가 첨가된 SPAES/VMT 복합막이 제조되었다. SPAES 매트릭스 내의 VMT입자 분산은 전자주사현미경으로 관찰된 평균분포에 의해 확인되었다. 1 wt%보다 적은 함량을 포함한 복합막은 고분자 매트릭스 내에 좋은 분산성을 나타내어 막의 상부층과 하부층에 매끈한 표면을 가졌다. 복합막의 함수율은 온도가 증가함에 따라 급격하게 증가되었으며 VMT는 높은 이온교환능력으로 인하여 강한 수분친화도를 가짐으로 인해 높은 모든 흡착된 수분은 bound water인 것으로 확인하였다. VMT의 함량이 1 wt%보다 적게 첨가된 복합막에서 증가된 이온전도도와 낮아진 메탄올 투과도를 확인할 수 있었다. 모든 복합막 중에서 SPAES/VMT 1.0 wt% 복합막은 선택도 측면에서 가장 뛰어난 연료전지 성능을 가졌으며 Nafion 112과 비교하여 두배 이상 우수한 값을 나타내었다. 이것은 SPAES/VMT 1.0 wt% 복합막이 직접메탄올 연료전지의 구동을 위한 가장 우수한 조건이 될것이라 사료된다.
        4,000원
        1642.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present research was carried out to evaluate the possibility of increasing female offspring production ratios using artificial insemination buffer (AIB) before artificial insemination (AI). In this experiment, we optimized AIB composition, made an AIB gun and analyze factors affecting AI non-return rate after AIB treatment. The AIB was made with the base of Tris-buffer supplemented with L-arginine and several other chemicals that might reduce the motility of male sperm compared to the female counterpart, therefore, increasing the possibility of fertilization by female sperm. AIB must be deposited into to cervix by AIB gun. After 15 min of AIB deposition, frozen semen was deposited into the same place. A total of 348 cattle were inseminated with AIB insemination, and there were no significant differences between AIB and traditional AI non-return rates (56.8% vs. 55.7%). The AI non-return rate in AIB group, however, differed significantly among 7 Hanwoo farms. The parturition numbers ( to ) of cows did not affect AIB AI rate. The proportion of AIB AI success rates was significantly higher in Hanwoo cows than in dairy cows (61.0% vs. 48.7%), but the average AI success rate did not differ significantly between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in to cervix deposition place was significantly higher than that in the uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than that in 2 ml (77.7%, 78.7% vs. 51.8%, p<0.05), but there were no differences in AIB injection volume between 5 and 10 ml. The best exposure time of AIB in the cervix was 10 to 15 min rather than 5 min (79.2%, 77.2% vs. 52.6%, p<0.05). AIB therefore needs to have an exposure time of at least over 10 min for a higher production rate of female offspring. In conclusion, AIB could be used in AI industry to increase the female offspring ratio and AIB AI can increase the AI success rate.
        4,000원
        1643.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bacterial diversity based on the denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene sequences was determined for soil samples from two abandoned mine sites and the corresponding enrichment cultures using soil sample as
        4,000원
        1644.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the post-thawed characteristics of leopard cat semen. In this experiment, semen was collected from two leopard cats (A and B) at wild animal center in Seoul Grand Park in Korea. After collection, the sperms were washed with D-PBS and diluted by the freezing medium (Irvine science, USA) and stored in liquid nitrogen. The post-thawed concentration was for A and for B. The viability of post-thawed sperm from A and B individual was 24.0% and 19.0%, respectively. Pre-freezing motility of A and B individual semen was 68.54% and 56.65. Leopard cat A had more normal sperm than that of B (69.5% vs. 54.5%). Acrosome integrity analysis detected live (14.5% vs. 9.0%), damage (39.0% vs. 44.0%) and dead (46.0% vs. 47.0%) in leopard cat A and B, respectively. The present results concluded that leopard cat semen can be collected successfully by electro-ejaculation method and cryopreserved successfullyfor future use in different assisted reproductive technologies. The cryopreservation protocol needs to be modified for increasing post-thawed viability of leopard cat spermatozoa.
        4,000원
        1645.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We discuss the influence of few-walled carbon nanotubes (FWCNTs) treated with nitric acid and/or sulfuric acid on field emission characteristics. FWCNTs/tetraethyl orthosilicate (TEOS) thin film field emitters were fabricated by a spray method using FWCNTs/TEOS sol one-component solution onto indium tin oxide (ITO) glass. After thermal curing, they were found tightly adhered to the ITO glass, and after an activation process by a taping method, numerous FWCNTs were aligned preferentially in the vertical direction. Pristine FWCNT/TEOS-based field emitters revealed higher current density, lower turn-on field, and a higher field enhancement factor than the oxidized FWCNTs-based field emitters. However, the unstable dispersion of pristine FWCNT in TEOS/N,N-dimethylformamide solution was not applicable to the field emitter fabrication using a spray method. Although the field emitter of nitric acid-treated FWCNT showed slightly lower field emission characteristics, this could be improved by the introduction of metal nanoparticles or resistive layer coating. Thus, we can conclude that our spray method using nitric acid-treated FWCNT could be useful for fabricating a field emitter and offers several advantages compared to previously reported techniques such as chemical vapor deposition and screen printing.
        4,200원
        1646.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,800원
        1648.
        2011.12 구독 인증기관 무료, 개인회원 유료
        This paper seeks to present, discuss, and analyze the differences as well as the similarities between English and Korean. It is generally agreed that the categories of culture differ across different types of societies and cultures. It is also believed that Western culture differs from Eastern culture. So we tend to think that people in a different culture speak differently, eat differently, wear differently, and interact differently from those in another culture. But it is not necessarily and not always true. I prove this by focusing on how people in a different culture speak a different language without knowing that they actually use the same expressions as those in another culture use. I will deal not only with cultural barriers due to the differences between English and Korean but also with how to work out the problems through the similarities between the two languages.
        4,000원
        1649.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 등분포 하중에 종속된 폼내장 콘크리트 샌드위치 패널 (foam insulated concrete sandwich panel)의 구조거 동특성을 파악하였다. 유한요소모델이 콘크리트, 폼 그리고 철근의 비선형거동과 연결부재 (connector)의 상세 전단 저항거동을 모사하기위해 사용되었다. 개발된 모델은 미주리대학 (University of Missouri)에서 수행된 정적실험자료 를 사용하여 검증되었다. 합성 및 비합성 거동이 샌드위치패널의 구조거동에미치는 영향을 정확히 모사하기 위해 전단연결재의 저항력을 모델에 정확히 반영하는 것이 중요하다. 본 연구에서 개발된 모델은 구조물의 극한강도및 좌굴이후의 거동까지 모사하였고 미국콘크리트 학회 (ACI)의 설계예제와 비교하였다. 본연구의 결과는 정적 및 동 적하중에 종속된 폼내장 콘크리트 샌드위치 패널의 해석및 설계에 유용한 정보를 제공할것이다.
        4,000원
        1650.
        2011.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since 1960, the international community has established a plenty of multilateral agreements on liability regime for ultra-hazardous activities, particularly in the area of international nuclear and space law. The liability regime of nuclear damage has imposed compensation exclusively on operators of nuclear installations whether private or State under strict liability principle of the international conventions. Moreover, new changes of international nuclear conventions following Chernobyl incident reflect a significant change of liability for nuclear accidents. Although there was similar incident, called Cosmos 954 case, with nuclear activity, international space law has not developed and remained ambiguous in certain respects, while imposing absolute liability on State actors. This paper, thus, studies whether States, alone, should be liable for all damage from space activities caused by private operator, similar to the liability scheme of international nuclear law. Moreover, vague term in international space law, for instance, damage and other relevant concepts such as space safety standard and international space organization have been taken into account by comparative approach with the terms of international nuclear law.
        6,700원
        1651.
        2011.11 구독 인증기관·개인회원 무료
        To establish the optimum artificial light illumination method for Pleurotus eryngii in closed mushroom factory system, the effects of red/blue LED light quality on growth was investigated. The following parameters fresh weight, height, width, chromaticity and hardness of the pileus were considered for studying the effect of LED light on the growth of mushroom. Pleurotus eryngii : The humidity was maintained more than 90% and temperature was 15~16℃, and CO2 density was 500ppm. The fresh weight and height were higher under red LED light (650nm, 73.1 Pmol/m2s), green LED light (525nm,89.1Pmol/m2s) comparing with blue LED light (450nm,105.8Pmol/m2s).