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        검색결과 58

        43.
        2000.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Raman spectroscopy has been used to investigate the structure of coal tar pitch heat-treated up to 3000℃ by using 514.5 run Ar ion laser line. Four critical temperature ranges were found on pyrolyzing coal tar pitch, which correspond to four distinct processes from disordered carbons to the well-ordered graphite structure. The range of heat treat temperature (HTT) below 1000℃ corresponds to gas evolution during the pyrolysis of coal tar pitch. Above the HTT are correlated to rearrangements of enlarged molecules, growth of the molecules along the direction of plane, finally stacking in the normal direction of the plane, in the respective HTT ranges of 1000-2000, above 2000 and 2500-3000℃.
        4,000원
        49.
        2003.09 서비스 종료(열람 제한)
        Bovine embryos produced by in vitro maturation, feretilization and development was examined for presevation and transfer. The fertilization medium used BO medium with 5 mM/ caffeine and 10/ heparin and adjusted to a pH of 7.2 to 7.4. The final concentration of spermatozoa was adjusted to 1 cells/ motile sperm during fertilization in vitro. At 8~10 hrs after insemination, the oocytes were transferred into CR1aa medium and cultured for 7 days. Embryos were preserved by vitrification method for transfer. When the embryos of early, blastocyst and expanded blastocyst stages were frozen-thawed, the proportions of embryos with normal morphology 83.6, 88.1 and 85.2%. (중략)
        50.
        2003.09 서비스 종료(열람 제한)
        The purpose of this is to investigate the effects of vitrification in open pulled straws (OPS) on in vitro survival of porcine embryos. Blastocysts were produced by in vitro fertilization of slaughterhouse-derived, in vitro matured oocytes with frozen-thawed boar semen, and subsequent culture on granulosa cell monolayer. After frozen-thawing, embryos were culture in NCSU-23 medium with 5 mM hypotaurine, 4 mg/ BSA and 10 ng/ for 48 hrs to survival tests. When blastocysts were frozen-thawed by OPS methods, the embryos with normal morphology were 32.1, 34.5 and 38.9 % in early blastocyst, blastocyst and expanded blastocyat stages. The rates of partial damaged embryos were significantly (P<0.05) higher in early biastocysts than expanded blastocysts. In another experiment, the embryos frozen by OPS methods were cultured for 48 hrs for survival and developmental rates in vitro. The proportions of embryos hatched were 11.8, 20.2 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. On the other hand, The proportions of embryo with normal morphology after culture were 23.5, 25.0 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. These finding indicate the possible broader application for OPS methods that this procedure described is relatively harmless, that it can be used for blastocysts of different developmental stages.
        56.
        1991.12 서비스 종료(열람 제한)
        This work aims to : establish a model of the container physical distribution system of Pusan port comprising 4 sub-systems of a navigational system, on-dock cargo handling/transfer/storage system, off-dock CY system and an in-land transport system : examine the system regarding the cargo handling capability of the port and analyse the cost of the physical distribution system. The overall findings are as follows : Firstly in the navigational system, average tonnage of the ships visiting the Busan container terminal was 33,055 GRT in 1990. The distribution of the arrival intervals of the ships' arriving at BCTOC was exponential distribution of Y=e-x/5.52 with 95% confidence, whereas that of the ships service time was Erlangian distribution(K=4) with 95% confidence, Ships' arrival and service pattern at the terminal, therefore, was Poisson Input Erlangian Service, and ships' average waiting times was 28.55 hours In this case 8berths were required for the arriving ships to wait less than one hour. Secondly an annual container through put that can be handled by the 9cranes at the terminal was found to be 683,000 TEU in case ships waiting time is one hour and 806,000 TEU in case ships waiting is 2 hours in-port transfer capability was 913,000 TEU when berth occupancy rate(9) was 0.5. This means that there was heavy congestion in the port when considering the fact that a total amount of 1,300,000 TEU was handled in the terminal in 1990. Thirdly when the cost of port congestion was not considered optimum cargo volume to be handled by a ship at a time was 235.7 VAN. When the ships' waiting time was set at 1 hour, optimum annual cargo handling capacity at the terminal was calculated to be 386,070 VAN(609,990 TEU), whereas when the ships' waiting time was set at 2 hours, it was calculated to be 467,738 VAN(739,027 TEU). Fourthly, when the cost of port congestion was considered optimum cargo volume to be handled by a ship at a time was 314.5 VAN. When the ships' waiting time was set at I hour optimum annual cargo handling capacity at the terminal was calculated to be 388.416(613.697 TEU), whereas when the ships' waiting time was set 2 hours, it was calculated to be 462,381 VAN(730,562 TEU).
        58.
        1969.12 KCI 등재 서비스 종료(열람 제한)
        쌀 단백질 함량의 품종과 환경에 따른 변이를 알고자 한국재래품종 11, 한국에서 육성된 현장려품종 12 및 일본에서 도입된 현장려품종 10, 합계 33 품종을 보통재배하고, 한편 Indica 2품종과 Japonica 2품종을 유기물과 질소시용량을 달리하여 재배하고, 이들 현미의 질소를 분석하여 이것을 단백질 함량으로 환산하여 검토한 결과를 요약하면 다음과 같다. 1. 11개 재래품종군의 단백질 함량은 평균 6.82%, 국내에서 육성된 장려품종군의 평균은 6.51%, 도입된 장려 품종균의 평균은 6.40%로 통계적으로 유의하지 않았으나 재래 품종군이 높은 편이었다. 2. 대체로 조생종일수록 단백질 함량이 높은 경향이었으며, 공시된 Indica 품종들이 단백질함량은 현저하게 높았다. 3. 질소비료의 증시는 단백질 함량을 현저하게 증가시켰지만 유기물과 석회의 시용은 거의 영향이 없었다. 4. 수확기가 늦어질수록 단백질 함량은 감소하는 경향이 있었다. 5. 재식밀도가 높아짐에 따라 단백질함량이 높아지는 경향이 있었으나 본시험의 밀도범위에서는 각 품종들은 일정한 경향을 보이지 않았다.
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