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        검색결과 215

        1.
        2023.11 구독 인증기관·개인회원 무료
        When dismantling a power plant, a large amount of radioactive tanks are generated, and it is estimated that a significant amount of sludge will accumulate inside the tanks during long-term operation. In the process of dismantling a radioactive tanks, it is important to know the composition of the sludge because the sludge present inside must first be removed and then disposed of. In the case of certain tanks, it can be predicted that corrosion products generated due to system corrosion are the main cause of sludge formation. However, in the case of some tanks, it is not easy to predict the sludge composition because various dispersed particles in addition to corrosion products may be mixed with the wastewater. Even if it is collected and analyzed, the sludge composition can change significantly depending on the operation history, so the analysis results cannot be considered representative of the composition. In the case of LHST, surfactant components introduced during the washing and shower process, oil components and dispersed particles dissolved by the surfactant accumulate inside the tank, making sludge difficult to remove. In addition, even if it is removed by ultra-high pressure spraying, unexpected problems may occur in the subsequent treatment process due to the surfactant contained therein. Therefore, it is necessary to analyze in more detail the characteristics of sludge accumulated in LHST and prepare countermeasures. A test procedure was prepared to evaluate the characteristics of sludge accumulating in LHST. According to the test results, the long-term sludge accumulation tendency of the LHST is summarized as follows. ① Initially, the sludge settling speed increases slowly until a surface sludge layer is formed. ② After the surface sludge layer is formed, the sludge rapidly settles until the sludge layer becomes somewhat thicker. ③ When the sludge layer is formed to a certain extent, the sludge escape rate increases and the sludge accumulation rate decreases again. It is assumed that the sludge escape speed is closely related to the fluid flow speed in the relevant area. It is believed that the combined effect of these phenomena will determine the thickness of the sludge layer that will accumulate inside the tank, but it was not possible to evaluate how much the sludge layer would accumulate based on the experimental results alone. However, it can be assumed that significant sludge accumulation occurred in areas where fluid flow was minimal and sludge formation nuclei easily accumulates.
        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대조차 개방형 조간대 퇴적물에 대한 태풍 효과를 한국 서해안 고창 동호리 조간대에서 연구하였다. 2010년 태 풍 곤파스 전·후와 2018년 솔릭 전·후에 나타난 표층 퇴적물 조직, 집적률, 퇴적상 변화를 관측하였다. 두 개의 태풍 곤파스와 솔릭은 각각 2010년 9월 1일과 2일, 2018년 8월 23일과 24일 사이에 한반도 남서부 연안에 상륙하여 내륙을 관통하였다. 태풍 곤파스 전·후와 솔릭 전·후에 고창 동호리 조간대의 측선을 따라 30m 간격으로 표층 퇴적물을 채취 하고 집적률을 측정하였다. 동호리 조간대를 평균고조면, 평균해수면, 평균저조면을 기준으로 고조대, 중조대, 저조대로 세분하여 연구하였다. 두 태풍 모두 태풍 후에 고조대는 퇴적되었고 중조대와 저조대는 침식되었다. 고조대에서 저조대 방향으로 갈수록 집적률이 감소하였다. 고조대의 표층 퇴적물 조직은 두 태풍 모두 태풍 후에 평균 입도는 세립해지고 분급은 양호해졌다. 중조대의 표층 퇴적물 조직은 변화가 거의 없었으며, 저조대는 일부 구간에서 태풍 후에 띠 형태의 퇴적체가 나타났다.
        5,200원
        3.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본고는 중국 도농관계의 문화적 구성에서 발견되는 양가성에 초점을 맞추어 개혁 개방 후 40여 년이 지난 오늘날에도 여전히 지속되고 있는 도농이원구조의 정치경제 적·문화적 원리를 조명하는 연구이다. 본고의 요점은 크게 네 가지로 압축된다. 첫째, 개혁개방 후 발생한 도농관계의 급진적인 재구성에도 불구하고 중국의 도농이원구조 와 도농불평등은 여전히 지속되고 있다. 둘째, 도농관계의 문화적 구성을 관통하는 양가성 그리고 이를 기반으로 한 도농관계 재현의 유연성이 중국의 도농이원구조를 재생산하는 문화적·이데올로기적 기제로 작용한다. 셋째, 도농관계의 문화적 구성 그리고 이와 연동되어 재생산되고 있는 도농이원구조가 중국에서 “항구적인 본원적 축 적”을 가능하게 하는 특정한 조건으로 작용하고 있다. 넷째, 이러한 중국 특색의 도 농이원구조가 해체되지 않는 한 농촌부문으로부터의 대규모 가치전유를 기반으로 한 시장사회주의 중국의 본원적 축적은 당분간 지속될 것이다
        7,800원
        4.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate quality and anthocyanin content of ‘Tarocco’ orange fruit in order to support early harvest. Harvest times were set at 280 days after anthesis (DAA), 300 DAA, and 320 DAA (conventional harvest). The fruits were classified as those having an intense reddish color or a yellowish orange color in the rind. The fruits were stored during 45 days at 8oC, for low temperature storage, or 18oC, for room temperature storage in winter. The changes in the fruit quality were measured at 15-days interval. The reddish rind fruit had slightly higher sugar content than the orange fruits with yellowish rind, but had similar acidity. A sugar content of 13.0 oBrix or more was recorded for fruits harvested 280 DAA with 45 days of low-temperature storage. A similar finding was recorded after 15 days of low temperature storage for the fruits harvested 300 DAA with 30 days for the conventional harvest. The anthocyanin content was higher for fruits with later harvest time (37.8 mg·L-1) and longer storage period in both low and winter room temperatures (25.2-53 mg·L-1 and 10.3-51.9 mg·L-1, respectively). For all harvest periods, the peel and juice color intensity increased after 15 days of low temperature storage and remained constant regardless of the storage temperature. The result indicated that the fruit quality and anthocyanin content of fruits harvested 300 DAA was better than fruits harvested 320 DAA (conventional harvest), stored 15 days at 8oC or 30 days at 18oC after harvesting 300 DAA.
        4,000원
        6.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P2O5. As the treatment of RSC under 30 mg kg-1 As-contaminated soils increased, EC, OM, and available P2O5 increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.
        4,000원
        7.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2011년 동일본대지진에 의해 발생한 후쿠시마 원자력 발전소 사고와 최근 국내 지진 발생 빈도의 증가는 원자력 발전소의 지진 안전성에 대한 불안감을 야기하였다. 더불어 최근(2021년) 일본 동경전력은 후쿠시마 원전 오염수의 태평양 방류를 결정하였으며, 이로 인해 국내외 수산물을 통한 방사능 오염 가능성이 높아지면서 국민들의 우려가 급증하고 있다. 후쿠시마 원전사고 이후 해양으로 의 인공방사능 유입에 관한 연구는 국제적으로 많이 이루어졌으나, 한국인의 주요 식재료인 동아시아 연근해의 수산물에서 인공방사능의 분포 현황 및 축적에 대한 연구는 상대적으로 부족한 실정이다. 따라서 이 논문에서는 후쿠시마 원전사고 이후, 국내산 수산물에서의 원전 기원 인공방사능(예, 137Cs, 239,240Pu, 90Sr 등)의 분포 특성과 관련한 최근 연구 사례들을 소개하고자 한다. 또한, 후쿠시마 원전 오염수의 방류와 더불어 2030년까지 계획된 중국의 신규 원전 시설로 인한 향후 한반도 주변해역의 방사능 유출 영향에 대한 대비 및 사전 연구가 필요한 시점이기에 향후 연구 방향들을 제안하고자 한다.
        4,300원
        9.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the antioxidative and lipid accumulation inhibitory effects of 14 plants from Mongolia and Myanmar on 3T3-L1 and HepG2 cells. The total phenolic and flavonoid contents (TPC and TFC) of 14 plant extracts were measured, and the antioxidative activities were analyzed using DPPH, ABTS, FRAP, and ORAC. After measuring the pancreatic lipase levels and performing the thiobarbituric acid assay, the degree of lipid accumulation was determined by lipid (Oil Red O) staining and triglyceride assay in 3T3-L1 and HepG2 cells. M. paniculate (259.43 mgGAE/g) and C. benghalensis (130.78 mgNAE/g) had the highest TPC and TFC, respectively, among the 14 plants. R. acicularis Lindl. had the highest antioxidant activity in DPPH. The ABTS, FRAP, and ORAC results showed that the antioxidant activity of 11 species was higher than that of the positive control. The pancreatic lipase inhibitory effect of C. angustifolium Scop. was reduced to 23.65% at 0.1 mg/mL, and the level of lipid peroxidation of C. abrorescens Lam. was 0.63 nmol/mg. Five selected plants inhibited the lipid accumulation and triglyceride content, respectively, in 3T3-L1 and HepG2 cells. These results provide scientific evidence for developing functional foods using 14 plants from Mongolia and Myanmar, which have antioxidant activities and lipid accumulation reduction effects.
        4,500원
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of present study was to investigate regulatory mechanism of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on nuclear and cytoplasmic maturation of porcine oocytes. Basically, immature cumulus-oocyte complexes (COCs) were incubated for 22 h in IVM-I to which hormone was added, and then further incubated for 22 h in IVM-II without hormone. As a result, relative cumulus expansion was increased at 22 h after IVM and it was enhanced by treatment of ALA compared with control group (p < 0.05). During IVM process within 22 h, cAMP level in oocytes was decreased at 6 h (p < 0.05) and it was recovered at 12 h in ALA-treated group, while oocytes in control group recovered cAMP level at 22 h. In cumulus cells, it was reduced in all time point (p < 0.05) and ALA did not affect. Treatment of ALA enhanced metaphase-I (MI) and MII population of oocytes compared with oocytes in control group at 22 and 44 h, respectively (p < 0.05). Intracellular GSH levels in ALA group was increased at 22 and 44 h after IVM (p < 0.05), whereas it was increased in control group at 44 h after IVM (p < 0.05). In particular, the GSH in ALA-treated oocytes during 22 h of IVM was higher than control group at 22 h (p < 0.05). Lipid amount in oocytes from ALA group was higher than control group (p < 0.05). Treatment of ALA did not influence to absorption of glucose from medium. Cleavage and blastocyst formation of ALA-treated oocytes were enhanced compared with control group (p < 0.05). These findings suggest that supplementation of ALA could improve oocyte maturation and development competence through increasing GSH synthesis, lipid storage, and regulation of cAMP accumulation during early 22 h of IVM, and these might be mediated by cumulus expansion.
        4,000원
        11.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cadmium (Cd) toxicity is a serious limitation for agricultural production. In this study, we explored tolerance mechanism associated with Cd toxicity tolerance in alfalfa plants. We used three distinct alfalfa cultivars M. sativa cv. Vernal, M. sativa cv. Zhung Mu, and M. sativa cv. Xing Jiang Daye in this study. Cd showed declined chlorophyll score in Xing Jiang Daye compared with Zhung Mu and Vernal. No significant change observed among the cultivars for root and shoot length. Atomic absorption spectroscopy analysis demonstrated a significant accumulation of Cd, Fe, S and PC in distinct alfalfa cultivars. However, Zhung Mu and Xing Jiang Daye declined Cd accumulation in root, where Fe, S and PC incremented only in Zhung Mu. It suggests that excess Cd in Zhung Mu possibly inhibited in root by the increased accumulation of Fe, S and PC. This was further confirmed by the response of Fe (MsIRT1) and S transporters (MsSULTR1;2 and MsSULTR1;3), and MsPCS1 genes associated with Fe, S and PC availability and translocation in roots and shoots. It suggests that specially the transcript signal inducing the responses to adjust Cd especially in Zhung Mu. This finding provides the essential background for further molecular breeding program for forage crops.
        4,000원
        13.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Particulate matter (PM) has recently been considered one of the most harmful air pollutants to public health. Plants have been known to degrade and deposit particle pollutants with epicuticular wax (EW), and this capacity can be influenced by environmental conditions including relative humidity (RH). The present study examined the effects of RH on EW generation and PM deposition upon leaf surfaces within Asplenium nidus ‘Avis’. The plants were treated in growth chambers with two levels of RH (low: 30% - 40% and high: 80% - 90%) for a period of four weeks, and subsequently exposed to a 30 μg・m-3 concentration of TiO2 particles as a PM resource for 72 hours. The EW ultrastructure on the leaf surface was observed as the thin films type, which was not morphologically changed in the condition of low or high RH treatment. For four weeks of RH treatment, the fresh weight and leaf area per plant were not significant between low and high RH treatment, while dry weight was significantly higher in the high RH condition. We also found that greater amounts of EW per fresh weight, dry weight and leaf area were generated in high RH. However, the total amounts of PM deposition (surface PM + in-wax PM) of the plants were higher within the low RH treatment with a higher proportion of surface PM. In contrast the proportion of in-wax PM was 15% higher within the high RH. These results suggest that EW generation is affected by air humidity and that proportion of PM deposition in the EW layer were influenced by the amount of total wax load.
        4,000원
        14.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 oleic acid로 지방생성이 유도된 HepG2 세포에서 자색옥수수 색소 1호 포엽 및 속대 추출물이 간 세포 내 지방생성에 미치는 영향을 구명하는 것이다. 자색옥수수 색소 1호 포엽 및 속대 추출물에 의한 HepG2 세포 내 지방 축적의 변화를 확인하기 위하여 배양된 세포에 oleic acid로 지방 축적을 유도하고 추출물에 의한 중성지방생성 억제 효과를 측정하였으며 추출물을 처리하지 않은 대조군과 추출물을 처리한 실험군의 지방합성 및 축적에 관련된 유전자와 단백질 발현량을 RT-PCR과 Western blot을 통하여 측정하였다. Oil Red O와 Nile Red 염색을 통하여 추출물의 처리로 HepG2 세포 내 중성지방 축적이 억제된 것을 확인하였다. RT-PCR에 의하여 mRNA 발현량을 측정한 결과, oleic acid에 의하여 지방 생성이 유도된 대조군에 비하여 모든 추출물 처리군의 SREBP-1c와 SREBP-1a 유전자 발현량이 유의적으로 감소되었다. Western blot을 실시하여 p-AMPK, p-SREBP1, PPARα, FAS 단백질의 발현량을 측정한 결과, 간에서 지질대사에 관여하는 주요 인자인 SREBP1 단백질의 발현은 추출물의 처리 농도에 따라 유의하게 감소하였으며 지방산의 생합성 경로에 관여하는 주요 효소인 FAS의 단백질 발현향은 모든 처리 농도에서 현저하게 감소된 것이 확인되었다. 본 연구 결과는 자색옥수수 색소 1호 포엽 및 속대 추출물이 간세포 내에서 중성지방의 축적을 억제시키고 지질 합성에 관련된 유전자 및 단백질의 발현을 억제시킴으로써 간 세포 내 지질 축적을 완화할 수 있는 기능성 소재로의 활용가치가 높다고 판단된다.
        4,000원
        15.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the prevalence of hyperlipidemia has been increasing, and consequently, the need to identify safe and effective treatments to control this chronic disease has also increased. The beneficial effects of probiotics have been revealed by several studies over the past few years, including their effects on hypertriglyceridemia. However, the mechanisms of action of probiotics are still unclear. The anti-obesity effects of Lactobacillus plantarum Q180 on lipid accumulation have already been demonstrated using an in vitro HepG2 cell model, and therefore, we investigated its efficacy and mechanism of action. Lipid accumulation was induced in HepG2 cells by palmitic acid treatment and then the cells were incubated with L. plantarum Q180 lysate or supernatant to investigate changes in lipid accumulation and expression of lipid metabolism-related genes. The results showed that the L. plantarum Q180-treated group exhibited significantly lower levels of lipid accumulation and mRNA expression of lipid synthesis- and adipogenesis-related genes than the palmitic acid-treated group did. These results indicate that L. plantarum Q180 may contribute to alleviating hypertriglyceridemia by inhibiting lipid synthesis.
        4,000원
        16.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Soil acidity or alkalinity are serious limitations for crop production. The purpose of this study was to clarify the negative effects of extreme pH stress (low and high) on alfalfa vegetative growth (VG) and biomass accumulation (BA). Two-week-old alfalfa seedlings were exposed to different pH (4.0, 4.5, 7.0, 8.0 and 8.5, respectively) levels for 72 hours. Alfalfa grown at pH 4.0 and 8.5 significantly reduced VG and BA, wherein as neutral pH (7.0) comparably exhibited better growth and biomass yield. These results indicate that extreme acidic or alkaline level are critical limiting factors for growth and biomass yield in alfalfa.
        4,000원
        17.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        인산염 농도 변화에 따른 Hizikia fusiforme의 무기비소 축적량 및 생장률을 분석하였다. 무기비소에 14일간 노출 하였을 때, 2 mg L-1의 높은 인산염 농도에서 무기비소 축적량이 증가하지 않았다. 하지만 인산염 농도가 0.02 mgL-1로 낮은 경우에 무기비소 축적량이 3배 이상 증가하였다. 또한 H. fusiforme는 인산염 농도가 낮은 경우 생장률이 14.5%, 무기비소 (10 μg L-1)에 노출되었을 경우 생장률이 대조구 대비 30% 감소하였다. H. fusiforme는 인산염과 무기비소를 구분하지 못하여 인산염의 농도가 낮은 경우 무기비소 축적량이 증가하게 되고, 축적된 무기비소는 광합성 저해 및 세포분열을 방해하여 생장률을 억제한다. 특히 우리나라의 대표적인 양식생물인 H. fusiforme는 다른 해조류에 비해 상대적으로 무기비소 축적량이 높다고 알려져 있기 때문에, H. fusiforme의 식품안전성을 확보하기 위해 다양한 연구가 필요하다.
        4,000원
        19.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we examined antioxidative effects and the anti-adipogenesis effect of different parts of Cudrania tricuspidata (C), and Morus alba (M). Total polyphenol contents were highest in M-root (34.56±0.045 mg GAE/g), and there was no significant difference, between C-root and M-leaf. Total flavonoid contents of C-root were highest (23.07±0.004 mg QE/g). To examine antioxidant activities of C and M extracts, DPPH and ABTS radical scavenging activity, and FRAP assay, was used. Results show that antioxidant activities of C and M extracts increased, in a dose-dependent manner. Adipocytes are generated by preadipocyte differentiation, during adipogenesis. Matured adipocytes accumulate in abnormal and cause obesity. We investigated effects of leaf and root extracts of C and M, on lipid accumulation, in 3T3-L1 adipocytes. Changes in cell morphology, and degrees of lipid accumulation in adipocytes, were evaluated by Oil Red O staining. Root extracts of C and M, reduced lipid content in a dose-dependent manner. Therefore, root extracts of C and M, may be good candidates for managing obesity.
        4,000원
        20.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to evaluate novel usability as natural anti-obesity supplement of Selaginella tamariscina extract. The total phenol contents and total flavonoid contents were 60.29±3.11 GAE mg/g and 14.90±0.34 QE mg/g, respectively. To evaluate anti-obesity activity of Selaginella tamariscina extract, pancreatic lipase inhibition activity as well as its inhibition effect of lipid accumulation in adipocytes were conducted by Oil Red O staining and lipolysis assay. The result of pancreatic lipase inhibition activity of S. tamariscina extract showed a wide range between 40 and 73% dose dependently. While the incubation of 3T3-L1 cells with S. tamariscina extract inhibited differentiation of preadipocytes and reduced lipid accumulation, the level of released free glycerol into culturing medium was increased in multiple concentrations. These results showed that S. tamariscina extract inhibit adipogenesis and pancreatic lipase activity. Thus, S. tamariscina extract can be a candidate for regulating lipid accumulation in obesity.
        4,000원
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