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        검색결과 604

        61.
        2022.05 구독 인증기관·개인회원 무료
        As the number of aging nuclear power plants increases, the market for dismantling nuclear power plants is growing rapidly. About 40% of the cost of dismantling nuclear power plants is the waste treatment cost incurred during the dismantling process, of which concrete waste accounts for a significant portion of the total waste. Securing technology for reducing and recycling concrete waste is very important not only in terms of economy but also in terms of environment. The objective is to synthesize geopolymer using inorganic materials from cement fine powder in concrete waste. Cement fine powder in concrete waste has a large amount of inorganic elements necessary for filing materials for radioactive waste treatment such as CaO and SiO2. In particular, Ca(OH)2 is synthesized by extracting Ca2+ from concrete waste. It can be used as an alkali activator to synthesize geopolymer. The mortar from crushed concrete was used as a source of calcium. The first step is to react with concrete waste and hydrochloric acid to extract ions. The second step is to react with NaOH and synthesize Ca(OH)2. The product was divided into two stages according to the reaction method and order. The first and second products were washed and dried, and then XRD and XRF were performed. The second product was matched only Ca(OH)2 and CaCO3 at the XRD peak. In the case of XRF, it was analyzed to have a purity of 67.80–78.73%. Synthesis of geopolymer by recycling materials extracted from concrete waste can reduce disposal costs and improve the utilization rate of disposal sites.
        62.
        2022.05 구독 인증기관·개인회원 무료
        High level nuclear waste (HLW) is surely disposed in repository in safe by being separated from human life zone. Deep geological disposal method is one of the most potent disposal method. Deep geological repository is exposed to high pressure and groundwater saturation due to its depth over 500 m. And it is also exposed to high temperature and radiation by spent fuels. Thus, HLW repository suffers extremely complex thermo-hydro-mechanical-radioactive condition. Long-term integrity of repository should be verified because the expected lifetime of the repository is over 10,000 years. However, the integrity of monitoring sensors are not reach the endurance lifetime of the repository with present technology. And the disposal condition, thermo-hydro-mechanical-radioactive, should shorten the estimated lifetime of the monitoring sensors. Therefore, it is necessary to improve the long-term integrity of the monitoring sensors. Although long-term tests are required to identify the prolonged durability of monitoring sensors, accelerated tests can help curtail test period. Accelerated tests is classified into accelerated stress test and accelerated degradation test and their methodology and theories are investigated. Their tests are design and proceed by following process: 1) identify failure modes, 2) select accelerated stress parameter, 3) Determine stress level, 4) Determine testing time and number of specimens, 5) Define measurement paremeter and failure criteria, 6) Suggest measurement method and measurement duration. Literature reviews were conducted to identify the influence of the disposal conditions such as thermo-hydro-mechnical-radioactive on integrity of material and monitoring sensors. The investigated data reported in this paper will be utilized to verify the improvement of integrity of monitoring sensors.
        70.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Functional dyspepsia (FD) is a gastrointestinal disorder with diverse symptoms but no structural or organic manifestations. Benachio-F® (herein named ‘BF-1’) is an over-the-counter liquid digestive formulated with multiple herbal extracts, which has been reported to improve symptoms of FD. A total two experiments were conducted. First, we examined whether BF-1 can modulate the progression of FD through two experimental rat models. A total of three doses (0.3x, 1x, 3x of the human equivalent dose) were used. In the gastric emptying model, both 1x (standard) or 3x (3-fold-concentrated) BF-1 enhanced gastric emptying was compared with that of vehicle-treated animals. In a feeding inhibition model induced by acute restraint stress, treatment with 1x or 3x BF-1 led to a similar degree of restoration in food intake that was comparable to that of acotiamide-treated animals. Among the constituents of BF, fennel is known for its choleretic effect. Thus, we next investigated whether a novel BF-based formula (named ‘BF-2’) that contains an increased amount of fennel extract (3.5-fold over BF-1), has greater potency in increasing bile flow. BF-2 showed a superior choleretic effect compared to BF-1. Furthermore, the postprandial concentration of serum secretin was higher in animals pretreated with BF-2 than in those pretreated with BF-1, suggesting that the increased choleretic effect of BF-2 is related to secretin production. Our results demonstrate that BF-1 can modulate the pathophysiological mechanisms of FD by exerting prokinetic and stress-relieving effects, and that BF-2 has a better choleretic effect than BF-1.
        4,000원
        71.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The PoN (Proof of Nonce) distributed consensus algorithm basically uses a non-competitive consensus method that can guarantee an equal opportunity for all nodes to participate in the block generation process, and this method was expected to resolve the first trilemma of the blockchain, called the decentralization problem. However, the decentralization performance of the PoN distributed consensus algorithm can be greatly affected by the network transaction transmission delay characteristics of the nodes composing the block chain system. In particular, in the consensus process, differences in network node performance may significantly affect the composition of the congress and committee on a first-come, first-served basis. Therefore, in this paper, we presented a problem by analyzing the decentralization performance of the PoN distributed consensus algorithm, and suggested a fairness control algorithm using a learning-based probabilistic acceptance rule to improve it. In addition, we verified the superiority of the proposed algorithm by conducting a numerical experiment, while considering the block chain systems composed of various heterogeneous characteristic systems with different network transmission delay.
        4,000원
        72.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have prepared MIL-101/graphene oxide (GO) composites with various mixing molar ratio of Fe-containing metal– organic frameworks (MOFs) against GO. When synthesizing MOFs, it was possible to synthesize uniform crystal powders using hydrothermal method. MIL-101 consists of a terephthalic acid (TPA) ligand, with the central metal composed of Fe, which was the working electrode material for supercapacitors. Field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis had been done to ascertain microstructures and morphologies of the composites. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge measurements were performed to analyze the electrochemical properties of the composite electrodes in 6 M KOH electrolyte. By controlling the metal ligand mole ratio against GO, we prepared a changed MOF structure and a different composite morphology, which could be studied as one of the promising optimized electrode materials for supercapacitors.
        4,200원
        73.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mesenchymal stem cells (MSCs) have been recognized as a therapeutic tool for various diseases due to its unique ability for tissue regeneration and immune regulation. However, poor survival during in vitro expansion and after being administrated in vivo limits its clinical uses. Accordingly, protocols for enhancing cell survivability is critical for establishing an efficient cell therapy is needed. CDDOMe is a synthetic C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid, which is known to stimulate nuclear factor erythroid 2-related factor 2 (Nrf2)- antioxidant response element (ARE) pathway. Herein, report that CDDO-Me promoted the proliferation of MSCs and increased colony forming units (CFU) numbers. No alteration in differentiation into tri-lineage mesodermal cells was found after CDDO-Me treatment. We observed that CDDO-Me treatment reduced the cell death induced by oxidative stress, demonstrated by the augment in the expression of Nrf2-downstream genes. Lastly, CDDO-Me led to the nuclear translocation of NRF2. Our data indicate that CDDO-Me can enhance the functionality of MSCs by stimulating cell survival and increasing viability under oxidative stress.
        4,000원
        74.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the effect of a synthetic complement peptide C3a on the outcome of Brucella abortus 544 infection in a murine macrophage cell line RAW264.7 cell. First, we determined the highest non-cytotoxic concentration of the peptide in the cell line. We also found that the peptide significantly increased the growth of the bacteria at 8 and 24 h. Although the number of bacterial CFU was also elevated at 48 and 72 h, the increases were not significant as compared to controls. We further investigated the effect of C3a peptide on the growth of Brucella by pre-incubating the peptide at various temperatures and found that the effect was reversed at 24 h post-incubation suggesting that incubation of peptide at high temperatures including 65°C or 95°C could inactivate its action. This also could indicate the beneficial effect of high temperature during infection. Although several studies reported the inhibitory effect of different antimicrobial peptides including C3a, the present study preliminarily revealed that it had no positive contribution on the control of B. abortus 544 infection in vitro and indirectly to its receptor, CD88, which belongs to GPCR. Moreover, the encouraged further exploration of the effect of other similar peptides would be performed for the purpose of finding Brucella-host cell interaction for the control of disease progression.
        4,000원
        75.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Seasonal forecasting has numerous socioeconomic benefits because it can be used for disaster mitigation. Therefore, it is necessary to diagnose and improve the seasonal forecast model. Moreover, the model performance is partly related to the ocean model. This study evaluated the hindcast performance in the upper ocean of the Global Seasonal Forecasting System version 5-Global Couple Configuration 2 (GloSea5-GC2) using a multivariable integrated evaluation method. The normalized potential temperature, salinity, zonal and meridional currents, and sea surface height anomalies were evaluated. Model performance was affected by the target month and was found to be better in the Pacific than in the Atlantic. An increase in lead time led to a decrease in overall model performance, along with decreases in interannual variability, pattern similarity, and root mean square vector deviation. Improving the performance for ocean currents is a more critical than enhancing the performance for other evaluated variables. The tropical Pacific showed the best accuracy in the surface layer, but a spring predictability barrier was present. At the depth of 301 m, the north Pacific and tropical Atlantic exhibited the best and worst accuracies, respectively. These findings provide fundamental evidence for the ocean forecasting performance of GloSea5.
        5,200원
        76.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cymbidium is one of the most popular and economically important species cultivated as a commercial ornamental crop. The objectives of this study were to determine the appropriate electrical conductivity (EC) treatments of nutrient solution, which gives the highest spike production and quality. Three-year-old Cymbidium ‘Lovely Smile’ plants were grown in the environmentally controlled Information and Communication Technology (ICT) smart greenhouse at Seoul Women’s University. The EC of the nutrient solution was changed in three distinct stages: vegetative, flower initiation, and flower development. The EC treatments were 1-0-1 (dS·m-1, EC101), 1-1-1 (dS·m-1, EC111), 2-1-2 (dS·m-1, EC212), 2-2-2 (dS·m-1, EC222), 3-2-3 (dS·m-1, EC323), 3-3-3 (dS·m-1, EC333) and the pH was adjusted to 6.0–6.5. Pseudobulb diameter increased in the plants treated with EC 101 and EC111 compared to the plants treated with EC 2.0–3.0 dS·m-1 at the reproductive stage 28 weeks after nutrient solution treatment. Flower spike production per pot and pseudobulb showed the highest values in the plants treated with EC111 of 3.3 and 1.4, respectively. Flower spikes length was the highest in the plants treated with EC 1.0 dS·m-1 and stem thickness, number of flowers, and fresh weight were the largest in the plants with EC 1.0 dS·m-1 among the EC treatments. Flower spikes had the worst quality (e.g., plant growth and flowering quality) in the plants treated with EC 3.0 dS·m-1 among the EC treatments. Floral bud and flower development took place 1–2 weeks earlier in the plants treated with EC 101, 111, and 212 than the other treatments. Flower diameter showed the highest values in the plants treated with EC 1.0 dS·m-1 among the EC treatments and flower color showed higher L* and b* values and lower a* values in the plants treated with EC 3.0 dS·m-1 compared to EC 1.0 and 2.0 dS・m-1. Nutrient solution of EC 1.0 dS·m-1 (EC111) can be recommended to improve flower spike quality and advanced flower development of Cymbidium.
        4,000원
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