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        검색결과 30

        7.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a flat-type photocatalytic reactor is applied under solar irradiation for simultaneous treatment of target pollutants: reduction of Cr(VI) to Cr(III) and oxidation of EDCs (BPA, EE2, E2). An immobilized type of photocatalyst was fabricated to have self-grown nanotubes on its surface in order to overcome limitations of powdery photocatalyst. Moreover, Ti mesh form was chosen as substrate and modified to have both larger surface area and photocatalyst content. Ti mesh was anodized at 50V and 25°C for 30min in the mixed electrolytes (NH4F-H2O-C2H6O2) and annealed at 450°C for 2 hours in ambient oxygen to have anatase structure. Surface characterization was done with SEM and XRD methodologies. Fabricated NTT was applied to water treatment, and coexisting Cr(VI) and organics (EDCs) enhanced each other's reactions by scavenging holes and electrons and thus impeding recombination. Also, several experiments were conducted outdoor under direct sunlight and it was observed that both solar-tracking and applying modified photocatalyst were proven to enhance reaction efficiency.
        4,000원
        8.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.
        4,000원
        9.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        인터넷 통신의 보편화에 따라 멀티미디어 관련 콘텐츠 서비스가 이루어지고 있으며, 이러한 서비스는 교육용 학습 콘텐츠 및 시스템 분야로 확장되고 있다. 고급화된 멀티미디어 학습 시스템을 지원하기 위해 3D 그래픽스 기반의 학습 서비스 시스템이 개발되고 있지만 대부분의 시스템이 마우스와 키보드와 같은 컨트롤 기반의 콘텐츠를 가지고 있어 현실감이 떨어지는 단점이 있다. 본 논문에서는 Kinect를 이용하여 사용자 손 영역을 추출하고, 추출된 사용자 손영역에서 손 제스처를 인식하여 가상공간에서 전자교과서를 선택하고, 열고, 페이지를 넘기는 시스템을 소개한다.
        4,000원
        11.
        2012.06 구독 인증기관·개인회원 무료
        Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        12.
        2011.05 구독 인증기관·개인회원 무료
        The Samia cynthia ricini (Lepidoptera: Saturniidae) is a commercial silk-producing insect belonging to an insect family Saturniidae in Bombycoidea. The species that has presumably been originated in India, is distributed in India, China, and Japan. Unlikely domestic silkworm the prime host plant for the species is a castor-oil plant (Ricinus communis in Euphorbiaceae). Recently, the eri-silkworm also is reared in Korea and is expected to be utilized for a diverse purpose. In this report, we present the complete mitochondrial genome of the species with the emphasis of a few major characteristics. The 15,384-bp long S. cynthia ricini (Lepidoptera: Saturniidae) mitochondrial genome was amplified into three long overlapping fragments (from COI ~ ND4, ND5 ~ lrRNA, and lrRNA ~ COI) and subsequent several short fragments using the long fragments as temperate. The primers for both long and short fragments were designed solely for lepidopteran genomes, without any species-specific primers. As a usual the genome is composed of 37 genes: 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes, and one large non-coding region termed the A+T-rich region. Arrangement of the genome is identical to those of other lepidopteran mitochondrial genome, but this differs from the common arrangement found in a diverse insect order, by the movement of tRNAMet to a position 5’- up stream of tRNAIle. Unlikely previous report on the start codon for COI gene in Lepidoptera S. cynthia ricini COI gene starts with typical ATT codon located between tRNATyr and the beginning region of COI gene. The 22 tRNAs that are interspersed throughout the mitogenome ranged in length from 62 to 71 bp. All tRNAs but tRNASer(AGN) were shown to be folded into the expected cloverleaf secondary structures. More detailed structural and phylogenetic analyses among Bombycidae and Saturniidae in connection with other families in the Bombycoidea will be performed soon
        13.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 액상유기성 슬러지로부터 용존 유기물을 회수하기 위한 막결합형 발효 시스템의 여과특성의 검토에 초점을 두었다. 0.1 μmsim5 μm 범위에서 6종류의 막공경을 대상으로 한 슬러지 발효액의 정밀여과 특성으로 막공경이 작을수록 전체저항이 큰 값을 나타내었고 케?층의 형성에 의한 저항이 전체저항의 68~88%를 차지하여 막투과유속의 저하는 주로 입자간의 물리화학적 상호작용에 의한 막표면에의 강한 입자침전에 기인함을 알 수 있었다. 발효액의 고형물 농도가 증가함에 따라 막투과유속은 감소하였으나 일정이상의 고형물 농도에서는 비례관계를 보이지 않았다. 막면유속이 증가할수록 그리고 5.0~6.0의 pH범위에서 높은 막투과유속이 얻어졌고 에너지 효율측면에서는 가능한 낮은 압력에서 여과하는 것이 유리한 것으로 나타났다. 0.1μm과 0.2μm의 막공경에서는 100%의 미생물 제거율을 보였다 액상 유기성 슬러지로부터 용존 유기물을 효율적으로 회수하기 위한 최적 막공경은 제안된 기준의 관점에서 볼 때 1μm 정도라 판단되어진다.
        4,000원
        14.
        1998.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        청둥오리의 압란유의 기능성 특성을 알아보기 위하여 흰쥐를 모델로 하여 streptozotocin(STZ)을 투여하여 당뇨병을 유발시킨 다음, 혈액 중의 당 농도, 지질의 변화 및 동맥경화 지표와의 상관관계를 검토하였고, 또한 Sarcoma-180을 쥐에 이식하여 이에 대한 항암 효과를 실험하였다. STZ로 당뇨병을 유발시킨 흰쥐를 청둥오리의 압란유를 15일간 투여하였던 바 혈중의 당 농도는 정상상태로 유지되었고 phospholipid 및 triglyceride의 함량은 STZ를 처리한 압란유의 경우에는 증가하였으나, STZ 처리군에 압란유를 투여하였을 때 감소되었다. 혈중 total cholesterol, LDL+VLDL의 cholesterol 및 동맥경화의 지표는 STZ 처리군에서는 증가하였으나, 시료를 150㎎/㎏ 투여시에는 감소하였다. 한편 Sarcoma-180에 대한 성장억제율은 압란유를 150㎎/㎏ 투여시 63.89%로 나타났고 수명연장 실험에서는 압란유의 경우 15.4%로 나타났다.
        4,000원
        16.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to determine the number of days required to break a plant’s dormancy and promote subsequent crop growth in new varieties of Gomchwi through the 4℃ treatment. Three new varieties of Gomchwi namely, ‘Sammany’, ‘Gommany’, and ‘Damogy’ were observed in this study. The rate of leaf emergence of ‘Sammany’ after 15-day of 4℃ treatment was 100%, while ‘Gommany’, and ‘Damogy’ took 20-days and 10-days, respectively to reach to 97.9% rate of leaf emergence. After 10-days of 4℃ treatment, ‘Damogy’ grew faster than the other varieties. and Harvest time for ‘Damogy’ was on January 18th, after 5-days of 4℃ treatment and yield was observed to be the highest at 15-days of 4℃ treatment. ‘Sammany’ was next with a minimum of 10-days of 4℃ treatment, although 15-days is more preferred for better harvest. ‘Gommany’ on the other hand, did not grow enough for harvest by January 18th, and its harvest time was delayed to January 31st. It needed a minimum of 15-days and preferentially 20-days of 4℃ treatment to grow normally and be ready for harvest. The plant height, leaf length and leaf petiole length appeared to grow better by extending duration of the 4℃ treatment. The number of leaves of ‘Sammany’ and ‘Gommany’ varieties was three leaves for the 5-days treatment which may be due to the incomplete breaking of dormancy. Regarding the yield per plant, ‘Sammany’ yielded 112.3 grams (g) in 15-days treatment, and ‘Gommany’ yielded 106.5 g in 25-days treatment. In the case of ‘Damogy’, it yielded 123.5 g and 183 g in the 10-days and 25-days treatment respectively. It is concluded that ‘Damogy’, ‘Sammany’ and ‘Gommany requires 10, 15, and 20 days of 4℃ treatment to break the plant’s dormancy and promote better plant growth.
        17.
        2011.08 KCI 등재 서비스 종료(열람 제한)
        We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml O2 kg-1 ww h-1 under constant conditions. In case of increasing temperature from 25 to 38℃, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until 36℃. Above 36℃, the rhythms of the OCR dampened and the OCR decreased rapidly at around 36 - 37℃. The OCR of the eels exhibited the maximum value at 38℃, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around 36 - 37℃ when water temperature increased at 0.5℃/14 h following the acclimation at 25℃. In case of decreasing temperature (0.5℃/14 h) from 25 to 0℃, the OCR of the eels displayed a abrupt decrease up to 23℃, and between at 23 and 20℃, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below 9℃, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at 36℃, with a lower thermal limit at 9℃. The biochemical aspects of the eels influenced by water temperature need to be further studied.
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