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        검색결과 24

        1.
        2023.10 구독 인증기관·개인회원 무료
        기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.
        2.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Porous carbons are considered promising for CO2 capture due to their high-pressure capture performance, high chemical/ thermal stability, and low humidity sensitivity. But, their low-pressure capture performance, selectivity toward CO2 over N2, and adsorption kinetics need further improvement for practical applications. Herein, we report a novel dual-templating strategy based on molten salts (LiBr/KBr) and hydrogen-bonded triazine molecules (melamine–cyanuric acid complex, MCA) to prepare high-performance porous carbon adsorbents for low-pressure CO2. The comprehensive investigations of pore structure, microstructure, and chemical structure, as well as their correlation with CO2 capture performance, reveal that the dual template plays the role of porogen for multi-hierarchical porous structure based on supermicro-/micro-/meso-/ macro-pores and reactant for high N/O insertion into the carbon framework. Furthermore, they exert a synergistic but independent effect on the carbonization procedure of glucose, avoiding the counter-balance between porous structure and hetero-atom insertion. This enables the preferred formation of pyrrolic N/carboxylic acid functional groups and supermicropores of ~ 0.8 nm, while retaining the micro-/meso-/macro-pores (> 1 nm) more than 60% of the total pore volume. As a result, the dual-templated porous carbon adsorbent (MG-Br-600) simultaneously achieves a high CO2 capture capacity of 3.95 mmol g− 1 at 850 Torr and 0 °C, a CO2/ N2 (15:85) selectivity factor of 31 at 0 °C, and a high intra-particle diffusivity of 0.23 mmol g− 1 min− 0.5 without performance degradation over repeated use. With the molecular scale structure tunability and the large-scale production capability, the dual-templating strategy will offer versatile tools for designing high-performance carbon-based adsorbents for CO2 capture.
        4,300원
        3.
        2022.10 구독 인증기관·개인회원 무료
        For safe management of spent nuclear fuels, they should be delivered to repository or waste disposal site. As the amount of spent nuclear fuel transportation is expected to increase in the future due to the provision of an intermediate storage facility, the necessity to secure transportation cask is emerging. In order to secure the spent nuclear fuel transportation cask, it is necessary to analyze the regulatory processes for domestic and foreign spent nuclear fuel transportation cask. In this study, the regulatory processes for domestic and foreign spent nuclear fuel transportation cask was analyzed. In this study, the IAEA, US, and Korea spent nuclear fuel transportation cask regulatory processes were analyzed. The domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of design phase, manufacturing phase, and operation phase. In the design stage, the transport requirements are designed in accordance with the safety requirements of international organizations and countries. The application to be submitted when applying for approval should include a safety analysis report, evidence proving compliance with safety requirements et al. In the manufacturing stage, it is a stage to check whether the safety requirements are satisfied before the first use after manufacturing the transportation cask. Inspections include welding inspection, leakage inspection, shielding inspection, and thermal inspection. In the operation stage, it is a stage of periodically performing inspections for continuous maintenance of the package when the transportation cask is used. The inspection items to be performed are similar to the manufacturing stage and typically include performance inspection of components and leakage inspection. In this study, domestic and foreign spent nuclear fuel transportation cask regulatory processes were analyzed. It was found that the domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of the design phase, the manufacturing phase, and the operation phase. The results of this study can be used as basic data for policy decision-making for the spent nuclear fuel cask.
        4.
        2022.05 구독 인증기관·개인회원 무료
        In Korea, research on the introduction of dry storage facility is being conducted as an alternative to saturation of temporary storage facilities for spent nuclear fuel. The introduction of dry storage facilities requires a radiological impact assessment on the workers of the facility, and for this, an appropriate exposure scenario must be derived through work procedure analysis. In this study, the procedure for storing spent nuclear fuel in dry storage facilities was analyzed based on the case of evaluating the radiological impact of workers in dry storage facilities abroad. We investigated cases of radiological impact assessment on workers at on-site dry storage facilities by PNNL, Dominion, and P. F. Weck. PNNL and Dominion analyzed the storage work procedure of the VSC (Vertical Storage Cask) method using CASTOR V/21, TN-32, respectively, and conducted a radiological impact assessment. P. F. Weck analyzed the storage work procedure of various spent nuclear fuel casks for VSC and HSM (Horizontal Storage Module), conducted a radiological impact assessment. As a result of comparing the procedure for storing spent nuclear fuel by case, it was found that the storage procedure was determined by the storage method and the cask type. In the case of VSC method, canister-type casks and basket-type casks are used, and the storage procedure are partially different according to each. Canister-type cask requires repackaging from transfer overpack to storage overpack, but basket-type cask doesn’t require that procedure. In the case of the HSM method, only the canister type cask was found to be used. However, the storage procedure was different depending on the type of HSM system. Depending on the type of HSM system, the necessity of cask for on-site transport was different. In this study, we investigated and analyzed the work procedure according to the storage method of dry storage facilities abroad. It was found that the dry storage procedure of spent nuclear fuel different according to the storage method and type of cask. The results of this study can be used as basic when deriving the exposure scenario for spent nuclear fuel dry storage workers suitable for the domestic situation.
        5.
        2021.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Colorectal cancer causes the most cancer-associated death worldwide, having a high cancer incidence. Pectin is a complex polysaccharide present in various fruits, emerging as an anti-carcinogenic candidate. Although pectin has a suppressive capacity for colon carcinogenesis, the effect of reactive oxygen species (ROS) generation and colonic aberrant foci formation in the colon carcinogenesis mouse model remains unclear. Therefore, this study investigates the regulatory effect of pectin supplementation on colon carcinogenesis induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in mice. In an animal experiment, thirty male institute for cancer research (ICR) mice were divided into two experimental groups; AOM/DSS (control group) and AOM/DSS + pectin (5% in drinking water). Furthermore, the number of aberrant crypt foci (ACF) and aberrant crypt (AC) on colonic mucosa were counted, and thiobarbituric acid-reactive substances (TBARS) assay was performed to estimate lipid peroxidation in feces. Pectin treatment significantly decreased the number of ACF and AC per colon compared with the control. Additionally, fecal TBARS level in the pectin group was significantly lower than those in the control group. Conclusively, these findings indicate that pectin-inhibited hyperplastic alteration and oxidative stress suppress colitis-associated colon carcinogenesis.
        4,000원
        12.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of the study was to investigate the effects of incentive spirometry and Ujjayi breathing technique on the pulmonary function of smokers. Subjects were individuals who had a smoking habit of at least a year. Subjects were randomly divided into 3 groups: the incentive spirometry group (n=8), Ujjayi breathing technique (n=9), and a group applying both incentive spirometry as well as Ujjayi breathing technique (n=8). Each intervention was performed twice a day, 5 times a week, for a total of 8 weeks whereupon the change in pulmonary function was evaluated. A spirometer was used to measure FVC, FEV1, and FEV1/FVC. The survey used for this study included the Fagerström Test of Nicotine Dependence (FTND) and the Shortness of Breath Questionnaire (SOBQ). Study results for the comparison within groups showed that in the group that performed both the incentive spirometry and Ujjayi breathing technique, FEV1 improved with statistical significance (p<.05). Furthermore, within this comparison the FEV1/FVC improved with statistical significance. Comparison amongst the groups showed no statistically significant differences in all areas. Following, to effectively increase pulmonary function in young adult smokers, both incentive spirometry and Ujjayi breathing technique should be employed together.
        4,000원
        13.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A powder injection molding process is developed and optimized for piezoelectric PAN-PZT ceramics. Torque rheometer experiments are conducted to determine the optimal solids loading, and the rheological property of the feedstock is evaluated using a capillary rheometer. Appropriate debinding conditions are chosen using a thermal gravity analyzer, and the debound specimens are sintered using sintering conditions determined in a preliminary investigation. Piezoelectric performance measures, including the piezoelectric charge constant and dielectric constant, are measured to verify the developed process. The average values of the measured piezoelectric charge constant and dielectric constant are 455 pC/N and 1904, respectively. Powder injection molded piezoelectric ceramics produced by the optimized process show adequate piezoelectric performance compared to press-sintered piezoelectric ceramics.
        4,000원
        16.
        2016.10 서비스 종료(열람 제한)
        Background : Korean Indigenous Hylotelephium erythrostictum is widely distributed in South Korea and is used in Korean traditional medicine. In this study, the phylogenetic analysis of Korean native Hylotelephium erythrostictum and related plants on Internal Transcribed Spacer (ITS) sequences were investigated to distinguish its origin. Methods and Results : The phylogenetic analysis of 6 species of Hylotelephium were investigated by ITS. The dendrogram was constructed by UPGMA(Unweighted Pair Group Method with Arithmetic Mean) clustering algorithm based on genetic similarity of ITS. In the ITS sequence analysis, the size of total was varied from 676 to 779 bp. The size of ITS 1 was rated at 287bp, while ITS 2 was rated at 123bp. The G+C content of ITS region was ranged from 60 to 66%. In the ITS tree, six species of Hylotelephium were monophyletic, and H. viviparum was the first branching within the clade. Conclusion : H. spectabile formed a clade with H. erythrostictum, while H. verticillatum formed with H. viviparum.
        17.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study about the phenolic metabolites in ginseng especially depending on the cultivation soil and the fertilizer types. Therefore, this study aims to develop an (-)ESI-LC-MS/MS analytical method for the measurement of selected phenolic compounds in the ginseng root. Methods and Results : Total phenol content in ginseng root was measured with the Folin-Ciocalteau method using UV/Vis spectrophotometer. Then, the 56 selected phenolic metabolites in ginseng root were measured with the (-)ESI-LC-MS/MS. The brief LC-MS/MS analytical conditions were as follows; Thermo Scientific Syncronis C18 HPLC Column (250 × 4.6 mm, 5 μm) was used. Optimized instrument settings were as follows: Curtain gas 20 psi, collision gas 2 psi, ion spray voltage –4500 V, nebulizer gas 40 psi, heating gas 70 psi, and its temperature 350℃. Total phenol content was higher in the ginseng cultivated in the paddy-converted field than that in upland. In particular, the total phenol content was about 6% decreased in the ginseng root cultivated with the food waste fertilizer compared to the control (p < 0.05). Six phenolic constituents including caffeic, chlorogenic, p-coumaric, ferulic, gentisic, and salicylic acids were found in the ginseng root by using the LC-MS/MS in MRM (multiple reaction monitoring) Mode. These six phenolic compounds occupied approximately 20% of the total phenol content measured in the corresponding ginseng root. The chlorogenic acid was the most abundant phenolic metabolite found in the ginseng root, accounting for ≥ 95% of the sum of six phenolic compounds, in this study. Conclusion : This preliminary study can be useful for the study on content and composition of phenolic metabolites in ginseng root with the aspect of metabolomics. We plan to further optimize the LC-MS/MS analytical method and then provide the extended understanding on the phenolic metabolism in the ginseng root with respect to the ginseng cultivation conditions.
        20.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        A new barley (Hordeum Vulgare L.) cultivar ‘Wooho’ was developed by Honam National Agricultural Research Institute (HARI) in 2005. It had good forage characteristics (smooth awn) and showed high forage production in the 5 locations of paddy field. ‘Wooho’ was developed from the cross between SB87125〔Oweol//(SB77011)/SB79124 (Bengei//Hagane/ Bunong) ///Y7213-SD607-CM67-Milyang12〕and SB83024 (1012.2-IB65/Ol//Samheung/Suwon18-Gang) made in 1994. Subsequent selections were made throuhg bulked and pedigree selection methods. SB94104-B-B-B-B-79 was selected for smooth awn and agronomic performance in 2001 and placed in preliminary yield trial. In 2003, it was designated as ‘Suwon 396’ and performed regional yield trials. The average forage yield of ‘Wooho’ were 11.0 MT/ha and 10.9 MT/ha at May 20 and drought stage, respectively. The shattering rate of ‘Wooho’ was lower than that of ‘Ol’. It showed superior forage quality to the check variety when harvest early drought stage. ‘Wooho’ would be recommended as a cultivar of barley for whole crop forage with smooth awn.
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