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        검색결과 23

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aligned with the recent shift in fruit consumption trends, there is a growing increase in the cultivation of these fruits. Thus, various types of small fruits, including blueberries, have recently been introduced and cultivated in Korea. According to the data, there has been a notable uptick in blueberry farming, in stark contrast to the decline in cultivation of black raspberries, black chokeberries, and blackcurrants. New varieties of blueberries continue to be introduced and cultivated, aligning with the recent consumption trends and are expected to be consistently cultivated in the future. Despite the decrease in the other berries, health benefits associated with all berries have ignited growing consumer interest, resulting in domestic and international market expansion. In conclusion, this research underscores the importance of identifying plant varieties that are well-suited to Korea's climatic conditions, validating efficient cultivation strategies, and establishing robust distribution networks to foster sustainable development in the berry industry.
        4,000원
        2.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A beverage was developed using the Abeliophyllum distichum leaf (AL). The beverage was prepared by adding it to apple juice by concentration, and physicochemical quality, antioxidant activities, and sensory evaluation were measured. Soluble solid and reducing sugar content of the control were 12.57 °Brix and 11.40%, respectively, and there was no difference from the group with addition of the AL extract. However, pH was slightly increased upon addition of AL extract. Lightness and yellowness increased when AL extract was added. Verbascoside content was not detected in the control, but it increased as the concentration of AL extract increased. The contents of ascorbic acid and flavonoids were 5.38 and 20.42 mg%, respectively, and there was no significant difference between the groups. However, the content of polyphenols increased as the concentration of the AL extract increased. DPPH radical and metal ion scavenging activity were increased by addition of the AL extract, but there was no difference in the ABTS radical scavenging activity. As a result of the sensory evaluation, there was no difference from the control even wihen the AL extract was added; thus, it was considered that there was no problem with the degree of acceptability when added within about 300 ppm.
        4,000원
        5.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To enhance the efficacy of Abeliophyllum distichum leaves, extracts were prepared using different solvents for hydrolytic enzyme-treated Abeliophyllum distichum leaves. Physicochemical quality and antioxidant activity were measured. Soluble solids, reducing sugar, ascorbic acid, flavonoids, and polyphenols contents showed the lowest values in the control without enzyme treatment. However, they showed high contents in ethanol extract. In the case of enzyme treatment, their values were higher than those of the control. In particular, verbascoside content increased about 220 times more than that of the control group when treated with enzymes and extracted with 50% ethanol. pH was lowered upon enzymatic treatment. Regarding DPPH radical scavenging activity, for enzyme-free, 25% ethanol extract showed the highest activity among extracts with different solvents. For cellulase and pectinase-treated leaves, water extract showed the highest DPPH radical scavenging activity among extracts with different solvents. For leaves treated with enzyme combination, 50% ethanol extract showed the highest DPPH radical scavenging activity among extracts with different solvents. Regarding ABTS radical scavenging activity, it was generally higher in the 50% ethanol extract than in the water extract and 25% ethanol extract. In particular, verbascoside content was increased when the extract was prepared by co-treatment with enzymes and 50% ethanol.
        4,000원
        7.
        2022.10 구독 인증기관·개인회원 무료
        Radioactive source terms are important factor in design, licensing and operation of SMR (Small Modular Reactor). In this study, regulatory requirements and evaluation methodology for normal operation on NuScale SMR, which received standard design certification approval on September 11, 2020 from US NRC, are reviewed. The radioactive waste management system of nuclear power reactor should be designed to limit radionuclide concentration in effluents and keep radioactive effluents at restricted area boundary ALARA according to 10 CFR 20 and 10 CFR 50 Appendix I. Also, in general, the coolant source term to calculate the off-site radiological consequences for normal operation of SMR should be determined by using models and parameters that are consistent with regulatory guide 1.112, NUREG- 0017 and the guidance provided in ANSI/ANS-18.1-1999, and the result should be corrected by reflecting the design characteristics of SMR. The coolant source term of NuScale, unlike the case of large NPPs, cannot rely solely on empirical source term data, because the NuScale source term is based on first principle physics, operational experience from recent industry, and lessons learned from large PWR operation. Fission products in reactor coolant are conservatively calculated using first principle physics in SCALE Code assuming 60 GWD/MTU. The release of fission products from fuel to primary coolant based on industry operational experience is determined as fuel failure fraction of 0.0066% for normal operation source term and 0.066% for design basis source term while coolant source term of large NPP is calculated by using ANSI/ANS-18.1 for normal operation and fuel failure fraction of 1% for design basis source term. Water activation products in reactor coolant are calculated from first principles physics and corrosion activation products are calculated by utilizing current large PWR operating data (ANSI/ANS 18.1- 1999) and adjusted to NuScale plant parameters. Also, because ANSI/ANS 18.1-1999 is not based on first principle physics models for CRUD generation, buildup, transport, plate-out, or solubility, NuScale has incorporated lessons learned by using ERPI’s primary water chemistry and steam generator guidelines to ensure source term is conservative and design of materials used cobalt reduction philosophy to help ensure the coolant source term are conservative. Based on the coolant source term calculated according to the above-described method, the annual releases of radioactive materials in gaseous and liquid effluents from NuScale reactor are evaluated. Currently, Small Modular Reactors such as ARA, SMART 100 are under review for licensing in Korea. This study will be helpful to understand how the reactor coolant system source terms are defined and evaluated for SMR.
        10.
        2021.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        정전용량 수분측정 센서는 수경용 배지 양쪽에 구리 및 테플론으로 절연된 전극판(30cm×10cm)을 부착하 여 배지의 넓은 부분에 걸쳐 측정하도록 개발되었다. 본 연구는 콘덴서형 정전용량 센서로부터 출력되는 정전용량 값을 배지 함수량으로 변환하는 것이다. 정량화 실험은 양액을 공급하면서 배지 물무게와 정전용량 변화를 측정하고 그 값을 비교하는 방식으로 수행되었다. 배지 함수량과 정전용량은 본 연구를 위해 특별히 개발된 소프트웨어와 함께 센서와 로드셀을 사용하여 20~30초마다 측정되었다. 상용 curve-fitting 프로그램을 이용하여 배지 함수량과 정전용량을 변수로 정전용량 값으로 배지 함수량을 추정하였다. 공급하는 물의 양이 증가하면 정전용량도 증가하는 경향을 보였다. 배지 내 물무게에 따른 정전용량에 대한 변동계수(coefficient of variation, cv)는 배지 내 물무게가 1.0kg 수준에서 다른 무게에 비해 높아 함수량 보정은 물무게를 1.7~6.0kg 수준에서 수행하였다. 정전용량과 물무게 사이의 상관 계수는 0.996이었고 보정식에 의해 정전용량으로 추정된 함수량은 로드셀로 측정한 배지 함수량과 비교하였다.
        4,000원
        11.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electrochemical removal (ECR) of water pollutants by activated carbon fiber (ACF) electrodes from wastewater was investigated over wide range of electrochemical reaction time. The ECR capacities of ACF electrodes were associated with their internal porosity and were related to physical properties and to reaction time. And, surface morphologies and elemental analysis for the ACFs after electrochemical reaction are investigated by SEM and EDX to explain the changes in adsorption properties. The FT-IR spectra of ACFs for the investigation of functional groups show that the electrochemical treatment is consequently associated with the homogeneous removal of pollutants with the increasing surface reactivity of the activated carbon fiber surfaces. The ACFs were electrochemically reacted to waste water to investigate the removal efficiency for the COD, T-N and T-P. From these removal results of pollutants using ACFs substrate, satisfactory removal performance was obtained. The outstanding removal effects of the ACFs substrate were determined by the properties of the material for adsorption and trapping of organics, and catalytic effects.
        4,000원
        13.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        본 연구는 기계주입 방식으로 간단히 재충전 할 수 있는 TPS 공법을 사용하여 실제 건설현장에 적용한 후 콘크리트 균열에 미치는 영향을 알아보고자 하였는데, 그 결과를 요약하면 다음과 같다. 먼저, 초음파 속도의 경우 TPS 공법을 사용하였을 시 주사기 공법에 비해 평균 약 36 mm/sec로 초음파가 빠른 속도로 통과하는 것을 알 수 있었고, 주입깊이의 경우 주사기 공법에서는 부분 충전되는 것을 확인하였으나 TPS 공법의 경우 강한 주입 압력으로 모든 배합에서 보수재가 100% 충전되는 우수한 경향을 나타내었다. 또한, 압축강도의 경우는 TPS 공법 사용 시 평균 16.8 % 증가하는 것으로 나타나 구조적으로 우수한 것으로 나타났다. 이상을 종합하면 주사기 공법에 비해 TPS 공법을 사용하였을 시 균열부위에 주입재가 밀실하게 충전되어 강도 증진으로 인한 품질 향상 및 확인창 설치로 인한 균열보수제의 거동이 확인 가능하다. 또한, TPS 공법 시공구간 532 m에 대하여 약 5일의 공사 기간이 단축됨에 따라 시공성이 우수하여 콘크리트 구조물에 균열 보수공법으로 사용성이 확대될 것으로 기대된다.
        14.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Early diagnosis of crop growth at various growth stages will help to make an optimum fertilization. If we can diagnose crop growth at around the time of topdressing of N fertilizer, N fertilization can be made based on crop growth and target crop yield, which may provide economic and environmental benefits as compared with fixed rate fertilization. In this study we devised methods to diagnose rice growth non-destructively at panicle initiation stage and to determine N topdressing rate. SPAD-502, Field Scout CM1000 and Green Seeker GNDVI were used to diagnose the growth status of rice grown at different soil N fertilities. The values measured by the diagnostic equipments at rice panicle initiation stage were then regressed to rice grain yield. It was found that CM1000 and GNDVI were more efficient than SPAD to diagnose rice growth. Therefore, a multivariate model with CM1000 and GNDVI values was developed to make a decision of N fertilization at rice panicle initiation stage. In a subsequent field study, N fertilization determined by non-destructive growth diagnose by CM1000 and GNDVI, and the multivariate model could minimize N fertilizer use to achieve our target yield, resulted in significant reduction of N fertilizer as compared with fixed rate N fertilization.
        19.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to establish the elaborate nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy. The nitrogen uptake by rice plants was insignificant until 25 days after seeding, and increased gradually thereafter. During this early growth stage, rice plants absorbed only the 4~% of basal applied N, while the 45~% of N fertilizer remained in the paddy soil. The absorption of basal N by rice plants was almost completed at 46 days after application. Nitrogen top-dressed at 5-leaf stage was well matched to crop nutrient demand, so it could be absorbed so actively in 8days after application. As a result, we could cut down the amount of N fertilizer to 36~% of the basal N level without significant difference in yield. Plant recoveries of fertilizer 15N applied with different application timings were 7.8~% for basal, 9.4~% for 5-leaf stage, 17.1~% for tillering stage, and 23.4~% for panicle initiation stage, respectively. When urea was applied with nitrogen fertilization practice based on basal incorporation (BN), plant recovery of 15N at harvest was 31.0~% , which was originated from 13.7~% for grain, and 21.3~% of the fertilizer 15N remained in the soil, and the rest could be uncounted. Plant recovery of fertilizer 15N applied with nitrogen fertilization practice based on topdressing at 5-leaf stage (TN), where N rate was reduced by 18~% compared with BN, was 35.1~% (grain 15.6~% ), and 19.9~% of the fertilizer 15N remained in the soil, and the rest could be uncounted. TN showed a higher 15N recovery than BN because it was to apply N fertilizer at a time to well meet the demand of rice plant direct-seeded on flooded paddy. We concluded that TN would be the nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy.
        20.
        2001.09 KCI 등재 서비스 종료(열람 제한)
        Helianthus tuberosus has been known to inhibit the growth of weeds and other plants sharing its habitat. This study was conducted to identify the allelochemicals of Helianthus tuberosus which were extracted with water and solvents. Aqueous extracts of leaf, stem, root, tuber and tuber peel of Helianthus tuberosus except tuber did not show significant differences in phytotoxicity to alfalfa seedlings. It was considered that Helianthus tuberosus contained fewer or less potential water-soluble substances that were toxic to alfalfa. Methanol extract of leaves of Helianthus tuberosus was sequentially partitioned in increasing polarity with n-hexane, ethylacetate and n-butanol. Each extract had a yield of 148, 12, 15.7 and 9.5g, respectively. Inhibitory effects on germination of alfalfa seeds treated with four fractions were not significantly different. But the significant reductions on hypocotyl length were observed for all the solvent extracts. Among the four fractions, the ethylacetate fraction showed the most significant inhibition effect on bioassay with alfalfa. Further separation of the active ethylacetate fraction by open column chromatography led to the 25 subfractions. In bioassay of each sub-fraction with alfalfa seeds, sub-fraction No. 13 showed the most inhibitory effect on seedling growth. 1 H NMR and gas chromatography-mass spectrometry analysis revealed that sub-fraction No. 13 was the mixture of straight-chain saturated fatty acids.
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