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        검색결과 115

        1.
        2023.10 구독 인증기관·개인회원 무료
        Spodoptera litura Fabricius, 1775 (Lepidoptera: Noctuidae) is a serious crop pest with a long-distance migratory flight. To date, the DNA barcode region has been widely used in genetic diversity analysis studies of Spodoptera litura. However, the DNA barcode region showed maximum variation rate of S. litura, which from 18 regions in South Korea, was 0.608% (nine haplotypes) in previous study. In this study, four mitochondrial genes (ND4, ND4L, ND1, 16s rRNA) have higher intra-specific variation rates than the DNA barcode region. Among the four genes, The variation rate of the 16s rRNA region was confirmed to be a minimum of 0.203% (2bp) and a maximum of 1.824% (18bp). Finally, the 16s rRNA region with the highest PCR amplification efficiency and highest variation rate was selected as a high-efficiency molecular marker.
        3.
        2023.05 구독 인증기관·개인회원 무료
        A disposal research program for HLW has been carried out since 1997 with the aim of establishing the preliminary concept of geological disposal in Korea. The preliminary studies were conducted by conducting manufacture and installation of an in-situ nuclide migration system in KAERI Underground Research Tunnel (KURT). Nuclides could be released from a deep underground disposal facility due to thermal and physicochemical changes into the surrounding environments. Understanding on the migration and retardation processes of nuclides in a fractured rock is very important in the safety assessment for the radioactive waste disposal. In this study, we evaluated fracture filling minerals and aperture distribution (3D map) along the fracture surfaces under the controlled conditions. The fractured granite block which has a single natural fracture of 1 m scale was sampled in a domestic quarry (Iksan), which groundwater had been flowed through. This rock has an interconnected porosity of 0.36 with the specific gravity of 2.57. The experimental set-up with the granite block with dimensions of 100×60×60 (cm). A flow of de-ionized water through the fracture between pairs of boreholes was initiated and the pressure required to maintain a steady flow was measured. In additions, fracture filling minerals were sampled and examined by mineralogical and chemical analyses. There are phyllosilicate minerals such as illite, kaolinite, and chlorite including calcite, which are fracture filling minerals. The illite and kaolinite usually coexist in the fracture, where their content ratio is different according to which mineral is predominant. For the evaluation of fracture, surface was divided into an imaginary matrix of 20×20 sub-squares as schematically. The calculated results are expressed as a two dimensional contour and a three dimensional surface plot for the aperture distribution in the fracture. The aperture value is distributed between 0.075 and 0.114 mm and the mean aperture value is 0.095 mm. The fracture volume is about 55 ml. Also the 137Cs sorption (batch test) distribution coefficients increased to Kd = 800~860 mL/g in the fractured rock because of the presence of secondary minerals formed by weathering processes, compared to the bedrock (Kd = 750~830 mL/g). These results will be very useful for the evaluation of environmental factor affecting the nuclides migration and retardation.
        5.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        미토콘드리아 시토크롬 c 산화효소 1 (COX1) 유전자 염기서열(658 bp)을 사용하여, 콩 포장에서 채집된 어리팥나방(Matsumuraeses falcana)과 팥나방(Matsumuraeses phaseoli)의 종을 실험실 집단의 종들과 비교하여 동정하였다. COX1 염기서열 분석에서, 어리팥나방 47개체 로부터 10개의 하플로타입이 발견되었고, 종내 유전적 거리는 0.15~0.46%이었다. 이중 하프로타입 A형이 약 70%로 우점형이었다. 팥나방의 30개체로부터는 모두 동일한 하나의 서열만이 확인되었고, 어리팥나방과의 종간 유전적 거리는 4.11~4.61%이었다. 두 종의 COX1 염기서열을 번역한 아미노산 서열은 모두 동일하여 동의적 염기서열 변이(동의치환, 同義置換, synonymous substitution)를 확인할 수 있었다. 포장 조사에 서 두 종의 유충이 콩의 잎과 꼬투리를 가해하였고, 한 포장에서 동시에 발생하였다. 전체 포장에서 어리팥나방의 평균 밀도는 팥나방보다 약 1.5 배 높았다. 이 결과는 콩이 두 종의 동일 기주임을 명백하게 제시하였다. 별도로 이 속의 유충 기생파리로서 Elodia flavipalpis (파리목: 기생파리 과)가 발견되었고, COX1 서열로 동정되었다.
        4,000원
        6.
        2022.10 구독 인증기관·개인회원 무료
        Regulations on the concentration of boron discharged from industrial facilities, including nuclear power plants, are increasingly being strengthened worldwide. Since boron exists as boric acid at pH 7 or lower, it is very difficult to remove it in the existing LRS (Liquid Radwaste System) using RO and ion exchange resin. As an alternative technology for removing boron emitted from nuclear power plants, the electrochemical boron removal technology, which has been experimentally applied at the Ringhal Power Plant in Sweden, was introduced in the last presentation. In this study, the internal structure of the electrochemical module was improved to reduce the boron concentration to 5 mg/L or less in the 50 mg/L level of boron-containing waste liquid. In addition, the applicability of the electrochemical boron removal technology was evaluated by increasing the capacity of the unit module to 1 m3/hr in consideration of the actual capacity of the monitor tank of the nuclear power plant. By applying various experimental conditions such as flow rate and pressure, the optimum boron removal conditions using electrochemical technology were confirmed, and various operating conditions necessary for actual operation were established by configuring a concentrated water recirculation system to minimize secondary waste generation. The optimal arrangement method of the 1 m3/hr unit module developed in this study was reviewed by performing mathematical modeling based on the actual capacity of monitor tank and discharge characteristics of nuclear power plant.
        7.
        2022.10 구독 인증기관·개인회원 무료
        Bentonite has been considered as a buffer material in a deep geological repository for high-level radioactive waste (HLW). Bentonite may come into contacted with various chemical solutions during the long-term storage. In particular, solutions containing K+ can affect stability of bentonite (e.g., illitization). The bentonite can be gradually saturated with the inflow of groundwater, and the temperature can rise simultaneously due to the decay of HLW. This study aimed to evaluate the bentonite stability in contacted with very highly concentrated K+ solutions with different pHs at 150°C. Batch reaction tests using KJ-II bentonite were performed for 30–150 days in teflon-stainless steel reactors. De-ionized (DI) water (pH = 6.0) and 1 M KCl (pH = 6.0), and 1 M KOH (pH = 12.5) solutions were used as reaction solutions. After completing batch reaction tests, the reacted samples were analyzed using various analytical techniques. For DI water, chemical, mineralogical, and physicochemical properties of reacted samples were similar to those of unreacted samples. For 1 M KCl solutions, cation exchage for Ca by K and slight changes in mineralogical properties of reacted samples were observed, but there are no significant changes in the physicochemical properties. In contrast, for 1 M KOH solutions, changes in chemical, mineralogical, and physicochemical properties of reacted samples were observed. Results of X-ray diffraction (XRD) analysis indicated dissolution of montmorillonite and formation of zeolite minerals, which were confirmed by thermogravimetricdifferential thermal analysis (TGA-DTA) and fourier transform infrared (FTIR) analysis. These results suggest that highly concentrated K+ (1 M) solution combined with high pH (12.5) and high temperate (150°C) may affect bentonite alteration. These prelimiary experiments were intended to qualitatively evaluate the mechanism and influncing factors of the buffer material alteration under extreme experimental conditions, and it is revealed that the conditions do not reflect the actual repository environment.
        8.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) is an N6-methyladenosine (m6A) RNA modification regulator and a key determinant of premRNA processing, mRNA metabolism and transportation in cells. Currently, m6A reader proteins such as hnRNPA2/B1 and YTHDF2 has functional roles in mice embryo. However, the role of hnRNPA2/B1 in porcine embryogenic development are unclear. Here, we investigated the developmental competence and mRNA expression levels in porcine parthenogenetic embryos after hnRNPA2/B1 knock-down. HhnRNPA2/B1 was localized in the nucleus during subsequent embryonic development since zygote stage. After hnRNPA2/B1 knock-down using double stranded RNA injection, blastocyst formation rate decreased than that in the control group. Moreover, hnRNPA2/B1 knock-down embryos show developmental delay after compaction. In blastocyste stage, total cell number was decreased. Interestingly, gene expression patterns revealed that transcription of Pou5f1, Sox2, TRFP2C, Cdx2 and PARD6B decreased without changing the junction protein, ZO1, OCLN, and CDH1. Thus, hnRNPA2/B1 is necessary for porcine early embryo development by regulating gene expression through epigenetic RNA modification.
        4,000원
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, M/G/1 priority queues with a finite buffer for high-priority customers and an infinite buffer for low-priority customers have applied to the analysis of communication systems with two heterogeneous traffics : delay-sensitive traffic and loss-sensitive traffic. However, these studies are limited to M/G/1 priority queues with finite and infinite buffers under a work-conserving priority discipline such as the nonpreemptive or preemptive resume priority discipline. In many situations, if a service is preempted, then the preempted service should be completely repeated when the server is available for it. This study extends the previous studies to M/G/1 priority queues with finite and infinite buffers under the preemptive repeat-different and preemptive repeat-identical priority disciplines. We derive the loss probability of high-priority customers and the waiting time distributions of high- and low-priority customers. In order to do this, we utilize the delay cycle analysis of finite-buffer M/G/1/K queues, which has been recently developed for the analysis of M/G/1 priority queues with finite and infinite buffers, and combine it with the analysis of the service time structure of a low-priority customer for the preemptive-repeat and preemptive-identical priority disciplines. We also present numerical examples to explore the impact of the size of the finite buffer and the arrival rates and service distributions of both classes on the system performance for various preemptive priority disciplines.
        4,600원
        12.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cell adhesion plays an important role in the differentiation of the morphogenesis and the trophectoderm epithelium of the blastocyst. In the porcine embryo, CDH1 mediated adhesion initiates at compaction before blastocyst formation, regulated post-translationally via protein kinase C and other signaling molecules. Here we focus on muscle RAS oncogene homolog (M-RAS), which is the closest relative to the RAS related proteins and shares most regulatory and effector interactions. To characterize the effects of M-RAS on embryo compaction, we used gain- and loss-of-function strategies in porcine embryos, in which M-RAS gene structure and protein sequence are conserved. We showed that knockdown of M-RAS in zygotes reduced embryo development abilities and CDH1 expression. Moreover, the phosphorylation of ERK was also decreased in M-RAS KD embryos. Overexpression of M-RAS allows M-RAS KD embryos to rescue the embryo compaction and blastocyst formation. Collectively, these results highlight novel conserved and multiple effects of M-RAS during porcine embryo development.
        4,000원
        20.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As buildings are becoming larger, demand for mega-sized composite columns (over 1-meter diameter) is increased. We have developed and commercialized welded built-up CFT column (ACT Column I) since 2005 which are structurally stable and economical using cold-formed steel with rib. However, there has a limit in size of cross section (618˟618mm) by a fabrication facilities. And due to characteristics of closed cross section, there has a limit to construction of connection of moment frame. Composite mega column (ACT Column II) has same concept of forming closed cross section. But in order to enlarge cross sectional size, thick plate is inserted between cold-formed steels. Since composite mega column can control thickness and width of thick plate, steel or composite beams can be directly attached to the connection. In this study, we propose strength formula of composite mega column to beam connections with T-shaped stiffener as internal diaphragm and verified through finite element analysis and simple tensile experiment.
        4,000원
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