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        검색결과 804

        1.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According to previous studies, the El Niño Southern Oscillation (ENSO) does not appear to regulate TC activity over Korea. By dividing the TC season into two sub-seasons, i.e. summer and autumn, we found the opposite response of TC activity over Korea to ENSO phases between the sub-seasons. In summer, about 1.2 more TCs affect Korea during El Niño than during La Niña, while about 1.2 fewer TCs do so in autumn. The opposite responses to ENSO could reduce the statistical significance of the relationship between ENSO and TC activity over Korea when the entire TC season (July to October) is considered. In summer, the southerly anomaly over the southern sea of the Korean peninsula due to the eastward retreating subtropical high allows a greater number of TCs to approach Korea during El Niño compared to La Niña. On the other hand, in autumn, the northwesterly anomaly due to the westward extension of the subtropical high leads to a smaller number of TC approaches.
        4,000원
        2.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, the search on fabrication of highly efficient, stable, and cost-effective alternative to Pt for the hydrogen evolution reaction (HER) has led to the development of new catalysts. In this study, we investigated the electrocatalytic HER activity of the Toray carbon substrate by creating defect sites in its graphitic layer through ultrasonication and anodization process. A series of Toray carbon substrates with active sites are prepared by modifying its surface through ultrasonication, anodization, and ultrasonication followed by anodization procedures at different time periods. The anodization process significantly enhances the surface wettability, consequently resulting in a substantial increase in proton flux at the reaction sites. As an implication, the overpotential for HER is notably reduced for the Toray carbon (TC-3U-10A), subjected to 3 min of ultrasonification followed by 10 min of anodization, which exhibits a significantly lower Tafel slope value of 60 mV/dec. Furthermore, the reactivity of the anodized surface for HER is significantly elevated, especially at higher concentrations of sulfuric acid, owing to the enhanced wettability of the substrate. The lowest Tafel slope value recorded in this study stands at 60 mV/dec underscoring the substantial improvements achieved in catalytic efficiency of the defect-rich carbon materials. These findings hold promise for the advancement of electrocatalytic applications of carbon materials and may have significant implications for various technological and industrial processes.
        4,000원
        3.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Complex structure constituting of several layers of heteroatom-doped N-CDs are used as a main sensing film along with aluminum electrodes in conductometric gas sensing system for sensitive and selective monitoring of CO2 and CO gases diluted with normal air, which are extensively prevalent in the atmosphere primarily due to the industrial revolution, locomotives, and numerous natural phenomena’s and the limit of detection (LOD) turned out to be 400 ppm and 30 ppm, respectively, with 20% relative humidity at 30 °C and pressure 1 (atm) which are good for healthy air quality checks. The sensor performance was satisfactory and bidirectional at ambient room temperature (30 °C) and pressure (1 atm) conditions but the relative humidity (50%) at 30 °C had a detrimental impact on the sensing responses, therefore intermittent heating at 80 °C for several minutes between the sensing responses was provided to the sensing chip or one should use gas filter membranes to block humidity, thereby maintaining its constant performance with great ease and accuracy. The cyclic voltammetry revealed well-defined oxidation and reduction peaks, with excellent stability and reversibility. In a nutshell, heteroatom-doped N-CDs’ nanocomposite material can revolutionize in a better environmental pollution monitoring by sensing gases in an extensively lesser response and recovery times.
        4,500원
        4.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bio-efficacies of two different types of fungicides, Diniconazole and Paclobutrazol with their effects as plant g rowth regulators f or Kimchi Cab bage were e valuated o n February 4 to A pril 13, 2024 in Los Baños, Laguna, Philippines. The experiment was done during the off-season planting of Kimchi Cabbage in the country. Yield and other horticultural characteristics were observed for seven different groups: group 1, untreated control; group 2, recommended rate of granular fertilizer (RR-G); group 3, recommended rate of granular fertilizer plus recommended rate of Diniconazole; group 4, recommended r ate of D iniconazole (alone); g roup 5 , recommended rate o f Paclob utrazol (RR-PBZ), group 6, RR-G plus RR-PBZ; and group 7, RR-G plus ½ RR-PBZ. Results showed that combination of recommended rate of granular fertilizer plus the full recommendation of Paclobutrazol (group 6) resulted in a significantly higher yield of 64.9 tons/ha than other groups with yields ranging from 23.3 to 55.3 tons/ha. Such significantly higher yield in group 6 was also attributed to the number of leaves produced by plants at the time of harvest. Regarding effects of two chemical treatments, the combination of Diniconazole a nd P aclob utrazol a s recommended granular f ertilizers h elped in t he heading of K imchi Cabbage during hot conditions with an average temperature of 32-35°C from March to April at the heading stage plus a f actor of b eing planted a t a lowland area i n the country. T he a dvantage o f Paclobutrazol aside from yield is its availability in the country as compared to Diniconazole (Binnari).
        4,300원
        10.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The interface area of the face sheet and core of the sandwich composite is seen as a weakness due to its low de-bonding toughness. To overcome this concern, it is critical to develop a suitable modification strategy to enhance the de-bonding toughness of the face sheet/core interface. In the present study, the corrugated core reinforced sandwich composite was prepared through co-curing and secondary bonding approaches. The MWCNTs reinforced adhesive was induced in the face sheet/core interface in different weight concentrations. The MWCNT-reinforced adhesive was prepared using the sonication technique, and its dispersion was examined using atomic force microscopy (AFM). The three-point bending test revealed that sandwich composite prepared using the co-cure method has higher flexural strength than secondary bonded samples due to better bonding face sheet and corrugated core. Compared with MWCNT-free corrugated core reinforced co-cured sandwich composites (CCSC), the flexural strength of 1 wt.% MWWCNT-induced sandwich composite was increased by 101.28%. The microstructural study showed that secondary bonded samples had extensive fibre breakage at the face plate due to early de-bonding of the face sheet and corrugated core. Furthermore, the free vibrational analysis was performed to evaluate the natural frequency and damping values of the corrugated core reinforced sandwich composite. The modal test results indicated that inducing 1wt.% MWCNTs in the face sheet/core interface had enhanced the natural frequencies of co-cured sandwich composites. The present study provides a suitable method to address the weaker de-bonding toughness concerns of face sheet/core interface region of sandwich structures.
        4,000원
        11.
        2024.04 구독 인증기관·개인회원 무료
        Spodoptera frugiperda, commonly known as the fall armyworm (FAW), is a major pest across the globe due to its broad host range and distribution worldwide. We investigated the function of microRNAs (miRNAs) in the detoxification of insecticides, with a specific focus on its susceptibility to chlorantraniliprole which is widely utilized insecticide for its management. miRNAs are small non-coding RNA molecules, crucial for post-transcriptional regulation of gene expression. This study aims to elucidate the impact of these miRNAs on the expression of cytochrome P450 genes, which play a significant role in conferring insecticide resistance. We identified notable changes in the abundance of two specific miRNAs, sfr-miR-10465-5p and sfr-miR- 10476-5p through RNA sequencing, after chlorantraniliprole exposure. These miRNAs exhibited significantly high expression in the fat body tissue, while showing relatively lower expression in the head, midgut, and malpighian tubules. Further analysis suggested that these miRNAs might target specific cytochrome P450 genes, like CYP4C1 and CYP4C21, which are known to play a role in insecticide resistance development. Experimentation with miRNA mimics through microinjection revealed a notable increase in the survival rates of S. frugiperda larvae when subjected to chlorantraniliprole exposure, with a significant reduction in CYP4C1 and CYP4C21 gene expression levels. This suggests a direct connection between the miRNAs and the increased tolerance of Spodoptera larvae to the insecticide. Our research presents the complex function of miRNAs in gene expression regulation related to insecticide resistance, offering valuable insights into the molecular mechanisms of chlorantraniliprole resistance in S. frugiperda. These findings pave the way for further investigations into miRNA roles and their potential in managing pesticide resistance in agricultural pests.
        12.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The untreated effluent dropping into the environment from various textile industries is a major issue. To solve this problem, development of an efficient catalyst for the degradation of macro dye molecules has attracted extensive attention. This work is mainly focused on the synthesis of nickel–manganese sulfide decorated with rGO nanocomposite (Ni–Mn-S/rGO) as an effective visible photocatalyst for degradation of textile toxic macro molecule dye. A simple hydrothermal method was used to synthesize Ni–Mn-S wrapped with rGO. The prepared composites were characterized using various techniques such as X-ray diffraction (XRD), high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infra-red spectrometer (FTIR), and ultra violet–visible (UV–Vis) spectroscopy. The photocatalytic performance of nickel sulfide (NiS), manganese sulfide (MnS), nickel–manganese sulfide (Ni–Mn-S), and Ni–Mn-S/rGO nanocomposite was assessed by analyzing the removal of acid yellow (AY) and rose bengal (RB) dyes under natural sun light. Among these, the Ni–Mn-S/rGO nanocomposite showed the high photocatalytic degradation efficiency of AY and RB dyes (20 ppm concentration) with efficiency at 96.1 and 93.2%, respectively, within 150-min natural sunlight irradiation. The stability of photocatalyst was confirmed by cycle test; it showed stable degradation efficiency even after five cycles. This work confirms that it is an efficient approach for the dye degradation of textile dyes using sulfide-based Ni–Mn-S/rGO nanocomposite.
        4,600원
        13.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Environmental pollution has become an alarming issue for the modern world due to the extensive release of untreated chemical waste into freshwater bodies. Untreated chemical waste poses significant negative impacts on aquatic life and human health. The phenolic compounds are widely used in different industries for dyeing, as food preservatives, and for the production of pesticides. 2,4,6-Trichlorophenol (TCP) is among the most hazardous phenolic compounds that cause several serious health effects. Thus, it is important to monitor TCP in the environmental samples frequently. In the current work, it was aimed to develop a highly sensitive zinc oxide-doped (ZnO) reduce graphene oxide (rGO) composite-based electrochemical sensor for TCP monitoring in the real samples. In this regard, graphene oxide (GO) was simultaneously reduced and doped with ZnO using a facile microwave-assisted synthesis strategy. The resulting ZnO/rGO composite was successfully utilized to fabricate ZnO/rGO-modified glassy carbon electrode (ZnO/rGO/GCE) for the selective and trace level determination of TCP. The conductivity and electrocatalytic behaviors of ZnO/rGO/GCE were examined through different modes of electrochemical setup. Under the optimal operating conditions such as a scan rate of 80 mV.s−1, PBS electrolyte (pH 7.0), and the concentration range of 0.01–80 μM, the fabricated electrochemical sensor manifested outstanding responses for monitoring TCP. The limit of detection (LOD) and limit of quantification (LOQ) of the ZnO/rGO/GCE for TCP were found as 0.0067 μM and 0.019 μM, respectively. Moreover, the anti-interference profile and stable nature of ZnO/rGO/GCE made the suggested electrochemical sensor a superb tool for quantifying TCP in a real matrix.
        4,600원
        14.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present research focuses on the tribological behavior of the AA5083 alloy-based hybrid surface composite using aluminosilicate and multi-walled-carbon nanotube through friction stir processing for automotive applications. The friction stir processing parameters (tool rotation and traverse speed) are varied based on full factorial design to understand their influence on the tribological characteristics of the developed hybrid composite. The surface morphology and composition of the worn hybrid composite are examined using a field-emission scanning electron microscope and an energy-dispersive x-ray spectroscope. No synergistic interaction is observed between the wear rate and friction coefficient of the hybrid composite plate. Also, adhesive wear is the major wear mechanism in both base material and hybrid composite. The influence of friction stir process parameters on wear rate and the friction coefficient is analyzed using the hybrid polynomial and multi-quadratic radial basis function. The models are utilized to optimize the friction stir processing parameters for reducing the rate of wear and friction coefficient using multi-quadratic RBF algorithm optimization.
        4,800원
        15.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The nanostructured dysprosium oxide ( Dy2O3) was synthesized by the co-precipitation method and incorporated with graphitic carbon nitride (g-C3N4) using the ultrasonication method. The resultant product is denoted as Dy2O3/ g-C3N4 nanocomposite which was further used for electrochemical sensing of riboflavin (RF). The physicochemical properties of Dy2O3/ g-C3N4 nanocomposite were examined using several characterization techniques. The obtained results exhibit the nanocomposite formation with the preferred elemental compositions, functional groups, crystalline phase and desired surface morphology. The electrocatalytic performance of Dy2O3/ g-C3N4 nanocomposite was scrutinized with a glassy carbon electrode (GCE) via differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques with the conventional three-electrode system. The modified electrode distributes more active surface area suggesting high electrocatalytic activity for the RF detection with two linear ranges (0.001–40 μM and 40–150 μM), a low detection limit of 48 nM and sound sensitivity (2.5261 μA μM−1 cm− 2). Further, the designed sensor possesses high selectivity, excellent stability, repeatability and reproducibility. Finally, the fabricated sensor was successfully estimated for the detection of RF in actual food sample analysis using honey and milk with better recovery.
        5,200원
        16.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The dyeing process is a very important unit operation in the leather and textile industries; it produces significant amounts of waste effluent containing dyes and poses a substantial threat to the environment. Therefore, degradation of the industrial dye-waste liquid is necessary before its release into the environment. The current is focusing on the reduction of pollutant loads in industrial wastewater through remediating azo and thiazine dyes (synthetic solutions of textile dye consortium). The current research work is focused on the degradation of dye consortium through photo-electro-Fenton (PEF) processes via using dimensionally stable anode (Ti) and graphite cathode. The ideal conditions, which included a pH of 3, 0.1 (g/L) of textile dye consortium, 0.03 (g/L) of iron, 0.2 (g/L) of H2O2, and a 0.3 mAcm-2 of current density, were achieved to the removal of dye consortium over 40 min. The highest dye removal rate was discovered to be 96%. The transition of azo linkages into N2 or NH3 was confirmed by Fourier transforms infra-red spectroscopic analysis. PEF process reduced the 92% of chemical oxygen demand (COD) of textile dye consortium solution, and it meets the kinetics study of the pseudo-first-order. The degradation of dye through the PEF process was evaluated by using the cyclic voltammetric method. The toxicity tests showed that with the treated dye solution, seedlings grew well.
        4,800원
        17.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A thermochemical conversion method known as hydrothermal carbonization (HTC) is appealing, because it may convert wet biomass directly into energy and chemicals without the need for pre-drying. The hydrochar solid product’s capacity to prepare precursors of activated carbon has attracted attention. HTC has been utilized to solve practical issues and produce desired carbonaceous products on a variety of generated wastes, including municipal solid waste, algae, and sludge in addition to the typically lignocellulose biomass used as sustainable feedstock. This study aims to assess the in-depth description of hydrothermal carbonization, highlighting the most recent findings with regard to the technological mechanisms and practical advantages. The process parameters, which include temperature, water content, pH, and retention time, determine the characteristics of the final products. The right setting of parameters is crucial, since it significantly affects the characteristics of hydrothermal products and opens up a range of opportunities for their use in multiple sectors. Findings reveal that the type of precursor, retention time, and temperature at which the reaction is processed were discovered to be the main determinants of the HTC process. Lower solid products are produced at higher temperatures; the carbon concentration rises, while the hydrogen and oxygen content declines. Current knowledge gaps, fresh views, and associated recommendations were offered to fully use the HTC technique's enormous potential and to provide hydrochar with additional useful applications in the future.
        6,300원
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