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        검색결과 1,884

        1461.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기울어진 자전축을 갖는 회전계에서, 일정한 각속도로 회전하는 동서풍이 있는 경우에 대해서 로스비하우어비츠 파동의 섹터모드(적도에 대한 반구 비대칭의 첫 번째 모드)와 균형을 이루는 지위고도장을 해석적으로 유도하였다. 균형장은 발산방정식으로부터 시간변화를 제거하고 라플라시안 연산자를 역산함으로써 구하였다. 역산은 비선형항의 계산과 포이슨 방정식의 해를 구하는 두 단계의 연산과정으로 이루어져 있다. 두 번째 단계에서, 구면조화함수로 표현되는 강제력의 항은 구면조화함수의 선형관계를 이용하였고, 그 이외의 항은 구면조화함수를 적분함으로써 구하였다. 균형장은 여섯 개의 동서파수 성분으로 표현됨이 드러났다. 본 연구에서 구한 균형장은 적도에 대하여 비대칭의 구조를 가지기 때문에, 대칭의 구조만을 가지는 것에 비하여 미분방정식의 수치해의 검종법으로서의 활용도가 높다. 일정한 각속도를 갖는 배경 동서풍이 지구의 자전각속도와 같거나 1/2에 해당하는 경우에는, 일부 동서파수 성분이 제거되는 것으로 나타났다. 이론적으로 구한 균형장은 정교한 수치모델을 통하여 구한 균형장과 거의 정확하게 같은 것으로 밝혀져, 이론적 해의 타당성이 입증되었다. 마지막으로, 로스비하우어비츠 파동의 섹터모드와 균형을 이루는 지위고도장의 안정성을 장기간시간적분을 통하여 살펴보았다.
        4,200원
        1466.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The application of membrane bioreactors for the depuration of wastewater coming from the washing of mineral oil storage tanks is described. Microfiltration hollow-fibre membranes were used in the submerged configuration. Filtration tests were carried out with a biomass concentration of about 15 g/L in order to assess the critical flux of the hollow fibre membrane used. Then particular care was taken in carrying out the performance runs in the sub-critical flux region. The reactor performance was very high, with removal efficiencies ranging between 93% and 97% also when the concentration of hydrocarbon was very high. Some kinetic parameters for the COD and the hydrocarbon removal were estimated.
        4,000원
        1467.
        2007.06 구독 인증기관 무료, 개인회원 유료
        Insulin-like growth factor II (IGF2) and H19 genes are mutually imprinted genes which may be responsible for abnormalities in the cloned fetuses and offspring. This study was performed to identify putative differentially methylated regions (DMRs) of porcine H19 locus and to explore its genomic imprinting in in vitro fertilized (IVF) and somatic cell nuclear transferred (SCNT) embryos. Based on mice genomic data, we identified DMRs on H19 and found porcine H19 DMRs that included three CTCF binding sites. Methylation patterns in IVF and SCNT embryos at the 2-, 4-, 8~16-cells and blastocyst stages were analyzed by BS (Bisulfite Sequencing)-PCR. The CpGs in CTCF1 was significantly unmethylated in the 2-cell stage IVF embryos. However, the 4- (29.1%) and 8~16-cell (68.2%) and blastocyst (48.2%) stages showed higher methylation levels (p<0.01). On the other hand, SCNT embryos were unmethylayted (0~2%) at all stages of development. The CpGs in CTCF2 showed almost unmethylation levels at the 2-, 4- and 8~16-cell and blastocyst stages of development in both IVF (0~14.1%) and SCNT (0~6.4%) embryos. At all stages of development, CTCF3 was unmethylated in IVF (0~17.3%) and SCNT (0~1.2%) embryos except at the blastocyst stage (54.5%) of IVF embryos. In conclusion, porcine SCNT embryos showed an aberrant methylation pattern comprised to IVF embryos. Therefore, we suggest that the aberrant methylation pattern of H19 loci may be a reason for increased abnormal fetus after embryo transfer of porcine SCNT embryos.
        4,000원
        1468.
        2007.06 구독 인증기관 무료, 개인회원 유료
        'Directions of APEC Future Policy for JCT in Education' aims at identifYing trends of APEC policy for ICT in education, its related issues, and makes recommendations for future policies. The results of this research are expected to provide a benchmark for educational ICT policy making in APEC economies with reference to policy trends produced by this project. They also provide insights and hindsight on ICT educational policymaking to all parties concerned. APEC economies should find the results beneficial in terms of new policymaking and enhancement of present policies. The recommended policy areas should be translated to generate businesses suited for industries related to ICT and education. As to the methodology, from eleven APEC economies the sample is reduced to eight due to complications in communications and documentation. Information needed was obtained through the internet. The project leader organized and distributed the collected data online to other members of the project (PR. China & Thailand) for analysis. The technique of content analysis was applied and trends on APEC educational JCT policy were identified. Findings from the data analysis were tabulated and are attached as appendices in the APEC white paper.
        6,000원
        1471.
        2007.02 구독 인증기관 무료, 개인회원 유료
        To improve water quality of Buji Stream and Shenzhen River, the Bujihe Wastewater Treatment Plant has been reconstructed from the original coagulkation-flocculation sedimentation system into the enhanced hybrid submerged biofilm-activated sludge (EHYBFAS)system developed by the authors. The main design parameters of the EHYBFAS system, process characteristics, operational performance, techno-economic index, and experience in design, construction and operation are described,which set up an example of the municipal wastewater treatment plants using the novel process of EHYBFAS, which has lots of advantages, such as stable and high operational performance with the final effluent quality well meeting 1A-1B standard of GB 18918-2002( Chinese national standard for pollutants of effluent from the MWWTPs), much less footprint of 1ha/(100×103m3/d)) vs 4-5ha/(100×103m3/d), much lower capital and operation costs of 700-800 Yuan(RMB)/(m3/d) and 0.5 Yuan(RMB)/m3 vs 1200-1500 Yuan/(m3/d)and 1.0-1.2 Yuan/m3 and much less sludge production of 0.3g dry solid/g removed BOD5 vs 0.7 g dry solid/removed BOD5 respectively for the MWWTP with AS process.
        5,100원
        1472.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The complex analysis of male reproductive system of vines and fruit-tyees growing in zone of the Armenian Nuclear Power Plant (ANPP) is realized. The obtained data demonstrate that the homogeneous pollen with high fertility and optimal morphometric parame
        3,000원
        1477.
        2006.09 구독 인증기관·개인회원 무료
        [ ] nanocomposite powders with a nominal composition of were prepared by HDDR combined with mechanical milling. The microstructure was studied by Mossbauer spectrometry and TEM. The magnetic properties were investigated by VSM using bonded magnet samples. The results showed that the annealing temperature had significant influence on both the recombination kinetics and the grain size of the and phases, and the bonded magnets presented the best magnetic properties when the nanocomposite powders were prepared by annealing at for 30 min.
        1478.
        2006.09 구독 인증기관·개인회원 무료
        The well-established Universal Powder Press UPP, designed by the Swiss press manufacturer Osterwalder AG in Lyss, went through a major improvement process. The result is a high efficient production machine with state-of-the-art technology. It will be shown the technical design, some process engineering as well as the influence of PRP - =Part-Related-Programming, first published in 1994 - on the set-up time. This development has enabled Osterwalder to round off their range of presses, the mechanical-hydraulic KPP as well as the hydraulic CA-NC II and UPP, to an attractive offer ranging from 120 kN up to 10'000 kN.
        1480.
        2006.09 구독 인증기관·개인회원 무료
        Study about the feasibility and effect of high-energy ball milling on a specific Mg alloy under protection medium of alcohol was presented via comparing with conventional vacuum milling. More fine particles with wider powder size distribution but more irregular shape were shown of the powder milled under alcohol. No obvious oxide was revealed from the two kinds of Mg alloy powders with limited milling time. And since slip induced in a preferential direction, the (002) texture was formed in the Mg alloy powders at the initial stage of alcohol milling. More O and Fe contaminants were introduced into the powders milled under alcohol according to the EDS analysis.