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        검색결과 4,148

        10.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ethylene-responsive factors (ERFs) are important plant transcription factors (TFs) that regulate plant responses against various abiotic stresses. However, little information of ERF genes involved in abiotic stress is available in petunia (Petunia ×hybrida). In this study, a petunia ERF gene, PhERF039, was cloned and functional analysis was performed. The quantitative PCR analysis revealed that PhERF039 was induced at the early stage of water deficit stress. Under-expression of PhERF039 (UE) exhibited rosette growth habit, higher number of branches, and delayed flowering compared to the wild type (WT). The UE petunia was evaluated under various volumetric water contents (θ): 0.25, 0.15, 0.10, or 0.05 m3·m-3 using an automated irrigation system. Transgenic plants did not delay plant wilting, but the θ for UE reached to the set point later than that for WT. A lower stomatal conductance was observed in UE than WT under all treatments. These results suggested that PhERF039 could be involved in plant responses under water deficit by regulating stomatal movements as well as branching pattern and flower development.
        4,600원
        11.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study develops a model to determine the input rate of the chemical for coagulation and flocculation process (i.e. coagulant) at industrial water treatment plant, based on real-world data. To detect outliers among the collected data, a two-phase algorithm with standardization transformation and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is applied. In addition, both of the missing data and outliers are revised with linear interpolation. To determine the coagulant rate, various kinds of machine learning models are tested as well as linear regression. Among them, the random forest model with min-max scaled data provides the best performance, whose MSE, MAPE, R2 and CVRMSE are 1.136, 0.111, 0.912, and 18.704, respectively. This study demonstrates the practical applicability of machine learning based chemical input decision model, which can lead to a smart management and response systems for clean and safe water treatment plant.
        4,000원
        12.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to establish various physiological changes according to soil water stress and to compare the degree of water stress between two species of grapevines (‘Jinok’ as a new breeding cultivar and ‘Campbell Early’ as a control) using thermography. Soil water potentials were treated at -70, -30, and -5 kPa with waterlogging for 7 days. Regarding the photosynthetic rates (A) of the two cultivars, they showed an order of –30 kPA > -5 kPa > -70 kPa in order. With -70 kPa and waterlogging treatments, a decrease of photosynthetic rate was observed at 3 days after treatment, with a more significant decrease accumulating over time. At 7 days after treatment, photosynthetic rates of ‘Campbell Early’ (33.3, 45.6%) and ‘Jinok’ (56.6, 57.3%) grapes decreased compared to those with -30 kPa treatment. H2O2 and proline synthesis were the highest with the waterlogging treatment. In terms of proline synthesis, ‘Campbell Early’ had a relatively higher rate than ‘Jinok’. Leaf and stem water potential were the lowest with the -70 kPa treatment and the highest with the - 30 kPa treatment f or both cultivars. Crop water stress index (CWSI) showed the following order: waterlogging > -70 kPa > -5 kPa > -30 kPa, which was the opposite result of water vapor transfer (IG). As a result of correlation analysis between factors, photosynthetic rate showed negative correlations with the water potential of leaf and stem and crop water stress index but a positive correlation with the relative water content of leaves. Thus, tolerance to water stress of ‘Campbell Early’ was relatively stronger than that of ‘Jinok’ grape. It is possible to compare water stress using infrared imaging.
        4,000원
        13.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The skid resistance between tires and the pavement surface is an important factor that directly affects driving safety and must be considered when evaluating the road performance. In especially wet conditions, the skid resistance of the pavement surface decreases considerably, increasing the risk of accidents. Moreover, poor drainage can lead to hydroplaning. This study aimed to develop a prediction equation for the roughness coefficient—that is, an index of frictional resistance at the interface of the water flow and surface material—to estimate the thickness of the water film in advance to prevent human and material damage. METHODS : The roughness coefficient can be changed depending on the surface material and can be calculated using Manning's theory. Here, the water level (h), which is included in the cross-sectional area and wetted perimeter calculations, can be used to calculate the roughness coefficient by using the water film thickness measurements generated after simulating specific rainfall conditions. In this study, the pavement slope, drainage path length, and mean texture depth for each concrete surface type (non-tined, and tined surfaces with 25-mm and 16-mm spacings) were used as variables. A water film thickness scale was manufactured and used to measure the water film thickness by placing it vertically on top of the pavement surface along the length of the scale protrusion. Based on the measured water film thickness, the roughness coefficient could be back-calculated by applying Manning's formula. A regression analysis was then performed to develop a prediction equation for the roughness coefficient based on the water film thickness data using the water film thickness, mean texture depth, pavement slope, and drainage path length as independent variables. RESULTS : To calculate the roughness coefficient, the results of the water film thickness measurements using rainfall simulations demonstrated that the water film thickness increased as the rainfall intensity increased under N/T, T25, and T16 conditions. Moreover, the water film thickness decreased owing to the linear increase in drainage capacity as the mean texture depth and pavement slope increased, and the shorter the drainage path length, the faster the drainage, resulting in a low water film thickness. Based on the measured water film thickness data, the roughness coefficient was calculated, and it was evident that the roughness coefficient decreased as the rainfall intensity increased. Moreover, the higher the pavement slope and the shorter the drainage path length, the faster the drainage reduced the water film thickness and increased the roughness coefficient (which is an indicator of the friction resistance). It was also evident that as the mean texture depth increased, the drainage capacity increased, which also reduced the roughness coefficient. CONCLUSIONS : As the roughness coefficient of the concrete road surface changes based on the environmental factors, road geometry, and pavement surface characteristics, we developed a prediction equation for the concrete pavement roughness coefficient that considered these factors. To validate the proposed prediction equation, a sensitivity analysis was conducted using the water film thickness prediction equation from previous studies. Existing models have limitations on the impact of the pavement type and rainfall intensity and can be biased toward underestimation; in contrast, the proposed model demonstrated a high correlation between the calculated and measured values. The water film thickness was calculated based on the road design standards in Korea—in the order of normal, caution, and danger scenarios—by using the proposed concrete pavement roughness coefficient prediction model under rainy weather conditions. Specifically, because the normal and caution stages occur before the manifestation of hydroplaning, it should be possible to prevent damage before it leads to the danger stage if it is predicted and managed in advance.
        4,600원
        14.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Flexible electrodes, particularly paper electrodes modified with polypyrrole, have shown promise in energy-related applications. We have earlier demonstrated the usage of paper electrodes modified with polypyrrole as a flexible and suitable photoanode for photoelectrochemical water splitting (PEC). Further, modification of this electrode system with an appropriate tandem absorber system for solar fuel production is interesting in developing efficient photoanodes. In this study, we study the PEC performance of flexible polypyrrole-based paper photoanodes (PPy-PAs) by decorating them with rGO@Cu2Zn- SnS4 chalcopyrites (rGO@CZTS/PPy-PAs). The lower bandgap (~ 1.5 eV) of the rGO@CZTS/PPy-PAs system allows for efficient visible light absorption, substantially improving PEC water-splitting reactions. The rGO@CZTS/PPy-PAs exhibited an enhanced current density of ~ 13.2 mA/cm2 at 1.23 V vs RHE, ABPE of ~ 1.5%, and a hydrogen evolution rate of 177 μmoles/min/cm2. Overall, rGO@CZTS/PPy-PAs showed 2.1-fold, 1.1-fold, and 1.4-fold enhancement in photocurrent activity over PPy-PAs, CZTS/PPy-PAs, and rGO/PPy-PAs, respectively. The usability of rGO@CZTS/PPy-PAs is established in the form of stable photocurrent for more than 200 min. These findings open new possibilities for developing modified PPy PAs as flexible PEs for efficient solar-driven PEC devices and give directions on improving flexible PEs for flexible and efficient solar-driven PEC systems.
        4,000원
        15.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It was found in this study that fluorinated microporous carbon aerogels with enhanced hydrophobicity could be successfully prepared by direct fluorination to separate water-in-oil emulsions at high flux. The fluorinated carbon aerogel (F-CA) surface treated by the fluorination method had a water contact angle of 151.2° and could immediately absorb oil. In addition, the unique network structure of F-CA and its hydrophobicity allow surfactant-stabilized water-in-oil emulsions to be effectively and simply separated under gravity without requiring external forces such as vacuum or pressurization. The network structure of F-CAs consists of randomly connected spherical particles that form fluorinated permeation channels, which induce high flux during emulsion separation. The F-CA spherical particles have nanosized pores and high hydrophobicity, which repel and trap water droplets to increase the separation purity. Therefore, F-CA exhibited excellent performance, such as high filtrate purity (up to 99.9954%) and flux (up to 11,710 L/m2h). Furthermore, F-CA reusability was demonstrated as it did not lose its hydrophobicity and maintained its performance even after repeated use. This type of aerogel has great potential to be utilized throughout various environmental fields, including oil remediation.
        4,200원
        16.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have intended and preparation of hierarchically absorbent materials were covered with a NiMn2O4 and acts as a catalyst for azo dye degradation. The polyaromatic-based (PA) absorbent compounds were initially constructed by bromomethylated aromatic hydrocarbons which undergo self-polymerization in presence of ZnBr as a reagent and cross linker is bromomethyl methyl ether. The absorbent black materials with a 3D network were prepared by direct carbonization and activation of the as-prepared PA. The hydrothermal method was adapted for the preparation of carbon hybrid material C@NiMn2O4 powder's catalytic activity is effective in reducing p-nitrophenol to p-aminophenol and decolorizing carbon-based dyes like methyl orange (MO), methyl yellow (MY), and Congo red (CR) in aqueous media at 25 °C when NaBH4 is added. UV–visible spectroscopy was used to analyze the dyes' breakdown at regular interval.
        4,000원
        17.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for tiamulin (TML) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with TML at the concentration of 25 g/L (TML-1, n=24) and 50 g/L (TML-2, n=24) for 5 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 1, 2, 3 and 5 days, respectively. According to the previously established analysis method, residual TML concentrations in poultry tissues were determined using LC-MS/MS. In TML-1, TML in all tissues was detected less than LOQ at 2 days after drug treatment. In TML-2, TML in liver and kidney was detected more than LOQ at 2 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of TML-1 and TML-2 in poultry tissues were established to 0 and 2 days, respectively. In conclusion, the estimated WT of TML in poultry tissues is shorter than the current WT recommendation of 5 days for TML in broiler chickens.
        4,000원
        18.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Traditional medicine and herbal remedies are gaining popularity worldwide, comprising a significant portion of healthcare research, advancements, and market demand. Growing scientific evidence supports their substantial efficacy as pharmaceutical ingredients and dietary supplements in preventive healthcare. When developing pharmaceuticals, it is crucial to ensure that ingredients are free from side effects and toxicity in order to prioritize safety. Geckos, known as shou gong, are a diverse group of lizards that are widely utilized for treating various diseases in Korean Medicine. This study was conducted to assess the potential acute toxicity of a water extract Gekko gecko by a single oral dose in Sprague-Dawley rats. Twenty rats of each sex were randomly assigned to four groups (5 rats each). Test articles were administrated once by oral gavage to rats at dose levels of 0, 500, 1,000, or 2,000 mg/kg body weight. Mortality, changes of body weight, and clinical signs of gross observation were monitored for 14 days after dosing. At the end of a 14-day observation period, all animals were sacrificed and complete macroscopic and hematological examinations were performed. There was no dead animal or test article-related effect on clinical signs, body weight, or gross finding. Other specific changes were not found between control and treated groups in hematology. Results showed no adverse effect at a dose of 500, 1,000, or 2,000 mg/kg in rats. The minimal lethal dose was considered to be over 2,000 mg/kg body weight in rats.
        4,000원
        19.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Over the past decade, there has been global expansion in the advancement of underwater cleaning technology for ship hulls. This methodology ensures both diver safety and operational efficiency. However, recent attention has been drawn to the harmful effects of ship hull-cleaning wastewater on marine animals. It is anticipated that this wastewater may have various impacts on a wide range of organisms, potentially leading to populationand ecosystem-relevant alterations. This concern is especially significant when the wastewater affects functionally important species, such as aquaculture animals and habitat-forming species living in coastal regions, where underwater cleaning platforms are commonly established. Despite this, information on the ecotoxicological effects of this wastewater remains limited. In this mini review, we discuss the adverse effects of wastewater from in-water cleaning processes, as well as the current challenges and limitations in regulating and mitigating its potential toxicity. Overall, recent findings underscore the detrimental effects posed by sublethal levels of wastewater to the health status of aquatic animals under both acute and chronic exposure.
        4,000원
        20.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기능성 화장품 소재로서 생태교란종으로 지정되어있는 가시박 (Sicyos angulatus L., SA)의 이용 가능성을 알아보기 위하여 항산화, 미백, 항균, 항염증 효능 평가를 수행한 후, 에멀션 안정성을 확인하였다. SA는 초순수 (SAW)와 70% EtOH (SAE)로 추출하였다. SAE는 SAW와 비교하 여 DPPH radical 및 ABTS+ radical에 대한 소거 활성과 SOD 유사 활성이 보여 항산화의 효능이 뛰어 나며, tyrosinase의 활성을 저해하여 멜라닌 생성을 억제하였다. SAW는 Escherichia coli (E.c), Staphylococcus epidermidis (S.e), Staphylococcus aureus (S.a), Pseudomonas aeruginosa (P.a), Cutibacterium acnes (C.a) 균주에 대한 항균 효과가 없는 반면, SAE는 S.a를 제외한 E.c, S.e, P.a, C.a 균주에서 clear zone이 생성되어 항균 활성을 나타내었다. LPS를 처리한 RAW 264.7 세포에서 SAE는 SAW보다 iNOS 및 COX-2의 발현량이 억제됨으로써 NO의 생성량을 억제하여 항염증에 대한 효능을 나타내었다. SAE을 첨가한 에멀션을 4℃, 25℃, 50℃의 온도에서 분리 현상이 관찰되지 않고, pH와 점 도는 수치상 큰 변화가 없었으며, 입자크기가 대조군 에멀션의 입자와 유사하므로 제형에 영향을 끼치지 않음을 확인하였다. 본 연구 결과를 기반으로, 기능성 화장품 연구에 새로운 소재로서의 활용 가능성을 제시하고자 한다.
        4,800원
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