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        검색결과 1,253

        201.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        초식, 포식, 분해 등 생태학적 서비스를 제공하는 지표 배회성 절지동물은 사과원의 중요한 구성 요소이며, 이들의 군집에 영향을 미치는 잡초는 유기재배와 관행재배 사과원에서 다르게 관리된다. 잡초 관리와 관련된 과수원 관리가 지표 배회성 절지동물의 풍부도와 다양도에 미치는 영향을 평가하기 위해 3년간 연구를 수행하였다. 대부분의 절지동물은 상위분류군과 섭식 기능군으로 분류하였으며, 딱정벌레류는 종 수준으로 분류하였다. 지표 배회성 절지동물의 주요 우점군은 딱정벌레목으로 나타났다. 초식자와 포식자의 풍부도는 유기재배 사과원에서 높은 결과를 보였으며, 딱정벌레류의 풍부도와 다양도 또한 관행재배 과원보다 유기재배 사과원에서 높은 결과를 보였다. 거미목, 딱정벌레목 또는 딱정벌레류의 풍부도는 잡초 관리 빈도와 음의 상관관계를 보였다. 지표 배회성 절지동물은 농업 시스템보다 잡초 관리에 영향을 더 많이 받는 것으로 나타났다.
        4,000원
        202.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biomass porous carbons derived from Laminaria japonica were prepared by KOH and H3PO4 activation methods, respectively. The results indicated that the chemical activation had an apparent effect on the molecular framework and space of materials. To enhance the selective adsorption for organic acids, biomass carbons were modified by dopamine combined with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The SEM and BET results illustrated the effect of the chemical activation approach on the morphology and porous texture. The biomass porous carbon using KOH activation method had the highest surface area (up to 1558 m2/ g). Compared with unmodified materials, the modified materials showed higher adsorption capacity for organic acids (27.90 μg/mL for chlorogenic acid and 25.47 μg/mL for caffeic acid). It was suggested that modification of porous carbons might be a viable pathway to increase the specific adsorption affinity and efficiency for organic acids in dried jujube samples.
        4,000원
        203.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was conducted to identify the anti-inflammatory and anti-cancer effects in sprouts of mouse-eyed bean (Rhynchosia nulubilis), ginseng (Panax ginseng), perilla (Perilla frutescens), broccoli (Brassica oleracea var. italica), and lettuce (Lactuca sativa) grown with organic germanium concentrate. Western blot analysis was performed to assess the antiinflammatory activity of the extract. All extracts exhibited noticeable anti-oxidant activity, indicating a significant correlation between the germanium content and anti-oxidant activity (p<0.05). In particular, rat-eyed bean sprouts with the highest germanium content showed significant anti-inflammatory activity (p<0.05) by significantly inhibiting the expression of the inflammatory complexes, NLRP3, cytokines IL-1β and caspase-1. Ginseng and broccoli sprouts showed strong anti-cancer properties and had high anti-oxidant effects (p<0.001). Germanium-concentrated water allows the mass production of agricultural products containing high concentrations of organic germanium. Agricultural produce grown with germanium concentrate add organic germanium to various physiological active ingredients, increasing the anti-oxidant and anti-cancer effects. These results strongly suggest that agricultural products containing high germanium concentrations can be used as novel health supplements to improve health.
        4,000원
        204.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        나노여과를위한 박막 나노복합체(TFN) 멤브레인 기술의 발전은 천연 자원에서 오염 물질을 제거하는 데 중요하 다. 최근에는 기존의 박막 복합체(TFC) 및 나노복합체 멤브레인에서 불가피한 단점을 극복하기 위해 다양한 금속유기구조체 (MOF) 수정이 테스트되었다. 일반적으로 MIL-101(Cr), UiO-66, ZIF-8 및 HKUST-1 [Cu3(BCT2)]은 용매 투과성 및 용질 제 거 측면에서 막 성능을 현저하게 향상시키는 것으로 입증되었다. 이 리뷰에서는 이러한 MOF가 나노 여과에 미치는 영향에 대 한 최근 연구가 논의될 것이다. 서로 다른 금속유기구조체의 동시 사용 및 고유한 금속유기구조체 레이어링 기술(예: 딥 코팅, 스프레이 사전 배치, Langmuir-Schaefer 필름 등)과 같은 다른 새로운 기능도 멤브레인 성능을 향상시켰다. 이러한 MOF 변 형 TFN 멤브레인은 각각의 TFC 및 TFN 멤브레인에서 분리 성능을 향상시키는 것으로 자주 나타났을 뿐만 아니라 많은 보 고서에서 비용 효율적이고 환경 친화적인 공정에 대한 잠재력을 설명한다.
        5,100원
        205.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Activated carbon fibers (ACFs) were treated by electroless plating of CuO to improve their removal performance for volatile organic compounds (VOCs). The properties of these samples(CuO@ACFs) were evaluated by X-ray photoelectron spectroscopy (XPS), BET and N2O chemisorption to determine the area and dispersion of metallic CuO. The removal efficiency for benzene was investigated by gas chromatography (GC). The breakthrough time of CuO@ACFs increased by approximately 120% compared to that of untreated ACFs at benzene of 100 ppm. CuO@ACFs removed 100% of the benzene in 20 h, indicating this material can be used as a removal technology for VOCs.
        4,000원
        206.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수출 팽이버섯에서 L. monocytogenes가 검출되어 리콜 됨에 따라 팽이버섯의 안전성을 확보하기 위하여 유통 온도에 따른 팽이버섯 중 L. monocytogenes의 생존을 조사하고 유기산을 이용한 팽이버섯 중 L. monocytogenes 의 저감화 기술을 개발하였다. 저장 온도에 따른 팽이 버섯 중 L. monocytogenes의 생존을 조사하기 위하여 L. monocytogenes가 오염된 팽이버섯(초기 농도 4.5 Log CFU/g)을 1-35 ̊C에 각각 저장하고 균수변화를 조사하였다. 그 결과 팽이버섯을 1 ̊C에 저장하였을 때 L. monocytogenes 는 1개월 내에 증식하지 않았고 30 ̊C, 35 ̊C에서는 각각 36시간, 24시간이내에 3.0 log CFU/g 증가하였다. 팽이버섯 중 L. monocytogenes의 저감화를 위하여 1-3% 유기산 3종 (초산, 젖산, 말산)에 10-30분 동안 처리하였을 때 팽이버섯 중 L. monocytogenes는 초산보다는 말산, 젖산의 저감효과가 높았고 젖산과 말산의 처리 농도가 증가할수록 저감효과는 증가하는 것으로 나타났다. 3% 젖산과 말산을 10분 이상 처리하면 약 3.0 log CFU/g이상 감소하였다. 따라서 팽이버섯의 안전성을 확보하기 위해서는 수출할 때는 1 ̊C 내외의 저온을 유지하고 소비단계에서는 3% 젖산과 말산에서 10분 정도 처리 후 섭취하는 것이 필요하다.
        4,000원
        207.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-pressure membrane system like nanofiltration(NF) and reverse osmosis(RO) was investigated as a part of water treatment processes to produce high quality potable water with low organic matter concentration through membrane module tests and design simulation. River water and sand filtration permeate in Busan D water treatment plant were selected as feed water, and NE4040-90 and RE4040-Fen(Toray Chemical Korea) were used as NF and RO membranes, respectively. Total organic carbon(TOC) concentrations of NF and RO permeates were mostly below 0.5 mg/l and the average TOC removal rates of NF and RO membranes were 93.99% and 94.28%, respectively, which means NF used in this study is competitive with RO in terms of organic matter removal ability. Different from ions rejection tendency, the TOC removal rate increases at higher recovery rates, which is because the portion of higher molecular weight materials in the concentrated raw water with increasing recovery rate increases. Discharge of NF/RO concentrates to rivers may not be acceptable because the increased TDS concentration of the concentrates can harm the river eco-system. Thus, the idea of using NF/RO concentrate as the raw water for industrial water production was introduced. The design simulation results with feed water and membranes used in this work reveal that the raw water guideline can be satisfied if the recovery rate of NF/RO system is designed below 80%.
        4,000원
        208.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biological phosphorus removal is accomplished by exposing PAO(phosphorus accumulating organisms) to anaerobic-aerobic conversion conditions. In the anaerobic condition, PAO synthesize PHB(polyhydroxybutyrate) and simultaneously hydrolysis of poly-p resulting phosphorus(Pi) release. In aerobic condition, PAO uptake phosphorus(Pi) more than they have released. In this study, cyanobacteria Synechococcus sp., which is known to be able to synthesize PHB like PAO, was exposed to anaerobic-aerobic conversion. If Synechococcus sp. can remove excess phosphorus by the same mechanism as PAO, synergistic effects can occur through photosynthesis. Moreover, Synechococcus sp. is known to be capable of synthesizing PHB using inorganic carbon as well as organic carbon, so even if the available capacity of organic carbon decreases, it was expected to show stable phosphorus removal efficiency. In 6 hours of anaerobic condition, phosphorus release occurred in both inorganic and organic carbon conditions but SPRR(specific phosphorus release rate) of both conditions was 10 mg-P/g-MLSS/day, which was significantly lower than that of PAO. When converting to aerobic conditions, SPUR(specific phosphorus uptake rate) was about 9 mg-P/g-MLSS/day in both conditions, showing a higher uptake rate than the control condition showing SPUR of 6.4 mg-P/g-MLSS/day. But there was no difference in terms of the total amount of removal. According to this study, at least, it seems to be inappropriate to apply Synechococcus sp. to luxury uptake process for phosphorus removal.
        4,000원
        209.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 다공성 활성탄소와 금속유기골격체 복합재료 기반의 전극 재료와 “이온젤” 이라고 불리는 고분자 고체 전해질을 이용하여 슈퍼커패시터를 제작 하였으며, 금속유기골격체의 함량에 따른 전기화학적 거동을 관찰하여 보았다. 슈퍼커패시터의 전기화학적 특성은 순환전압전류법(CV), 전기화학적 임피던스 분광법(EIS) 및 전정류 충·방전법(GCD)으로 분석하였으며, 그 결과로, 다공성 활성탄소 대비 금속유기골격체를 0.5 wt% 첨가 하였을 때 가장 높은 전기용량값을 확인 할 수 있었으며, 0.5 wt% 이상의 금속유기골격체의 함유량은 전기화학적 특성 감소에 영향을 주는 것으로 사료되며, 이러한 결과를 바탕으로 제조된 다공성 활성탄소/금속유기골격체 복합재료 기반의 슈퍼커패시터는 다양한 분야에 활용이 가능 할 것으로 판단된다.
        4,000원
        210.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concentration of TVOCs in public transportation in the spring and summer of 2018 was measured. Public transportation measured the concentration of TVOCs on six subway lines in Seoul, two lines of high-speed trains, and intercity buses. The measurements were taken during the operation of each route of the surveyed public transportation from the origin to the destination. In addition, the measurement time was divided into the congestion time and the non-congestion time. In the spring of 2018, in the order of subway, train A, train B, and intercity buses, TVOC concentrations during the congestion time zone were 205.9 μg/m3, 121.3 μg/m3, 171.1 μg/m3, and 88.7 μg/m3, respectively. During the non-congestion time zone, the concentrations were 177.2 μg/m3, 108.8 μg/ m3, 118.2 μg/m3, and 126.1 μg/m3, respectively. In the summer of 2018, TVOC concentrations in the order of the aforementioned transportation modes during the congestion time zone were 169.8 μg/m3, 175.8 μg/m3, 78.0 μg/ m3, and 185.3 μg/m3, respectively. During the non-congestion time zone, the concentrations were 210.8 μg/m3, 116.1 μg/m3, and 162.7 μg/m3, respectively. An analysis of BTEX concentration among VOCs in public transportation in descending order were followed by toluene > xylene > ethylbenzene > benzene. Toluene, which has the highest concentration among the BTEX compounds, was found to be 12.86 μg/m3 to 91.41 μg/m3 during spring congestion time and 7.10 μg/m3 to 39.52 μg/m3 during non-congestion time. During the summer congestion time, the concentration was 6.68 μg/m3 to 249.48 μg/m3 and 13.23 μg/m3 to 214.5 μg/m3 during the non-congestion time. The concentration of benzene was mostly less than 5 μg/m3 in transportation. Particularly in the case of toluene, the concentration is significantly higher than that of other VOCs. Accordingly, further study of toluene exposure hazards will be needed. Five percent of the surveyed TVOC concentrations exceeded the recommended indoor air quality standard of 500 μg/m3, and all 13 cases representing this percentage were found in the subway. In addition, nine of the 13 cases that exceeded the recommended standard were measured during congestion time. Therefore, VOCs in public transportation vehicles during congestion time need to be managed.
        4,000원
        219.
        2020.11 구독 인증기관·개인회원 무료
        The small tea growers (STGs) constitute a significant part of the tea industries in several tea producing countries in the world. STGs constitute 70 percent of the tea cultivation by area and 60 percent of the total tea production by volume. However, low profitability, limited marketing options, inefficient supply chain, and dependency on the large tea estates for processing has emerged as a serious threat to the sustainability of the STGs. Mostly, the STG’s role in the tea supply chain is confined merely to the cultivation of the tea leaves. In India too, the STGs are confronted with similar challenges. India is the second-largest tea producer in the world with about 50 percent of the total tea production coming from the STGs. Notably, considering the economic and environmental benefits, some of the STGs have taken to organic cultivation of tea. Further, some of them who adopted organic cultivation also took to processing and marketing of made tea like hand-made green tea, black tea, and other specialty products by themselves. This study seeks to understand and analyze the role of organic cultivation in providing market linkages and the development of value chain(s) for the STGs. The study was conducted in the state of Assam, which is recognized worldwide for the presence of one of the oldest and the largest tea industries. It used a qualitative value chain approach to analyze the current situation of the STGs involved in the production of organic tea. The study mostly relied on primary data collected from the various actors of the emerging tea value chain through a semi-structured interview schedule, in-depth interviews, and focused group discussions. The processing and marketing of tea by the organic STGs in Assam has indeed led to the development of tea value chain(s) for the STGs. Adoption of sustainable agriculture systems like organic cultivation has opened up new opportunities for the STGs to earn from tea processing and marketing by themselves. Although such developments are in a very initial stage, understandings from the present scenario add to the literature on the development of value chain and market linkages for the smallholders in the tea sector with implications for other agricultural sectors as well. Encouraging the STGs to produce orthodox tea products, especially green and black tea varieties, in larger quantity by mobilizing them for collective actions is likely to locate them in the global tea value chain. The study suggests such suitable policy measures to bring about transformations in the tea sub-sector. Appropriate institutional changes to develop sustainable tea value chain(s) controlled by the STGs would be the key to impart overall sustainability to the industry. Such developments are likely to help the tea industry in Assam and other tea producing regions to meet the changing consumer aspirations and sustain global competition.
        220.
        2020.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH3NH3PbBr3, MAPbBr3) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr3 nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100%) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr3 nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.
        4,000원