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        검색결과 7,850

        281.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal-free N–S- and N–P-doped nanocarbon (SCNP and PCNP) electrocatalysts prepared through sustainable microwaveassisted synthesis using hemigraphis alternata plant leaves. The prepared heteroatom-doped nanocarbon materials are active catalysts for the two-electron oxygen reduction reaction (ORR) to produce 65–70% of hydrogen peroxide. As evidenced from the XPS, most proportion of the doped heteroatoms contain the oxygen functional groups in the nanocarbons. These attributes are the critical factors to see the selective two-electron transfer ORR for the PCNP and SCNP. This approach shed light on the critical role of dual heteroatoms doping and the oxygen functionalities in nanocarbon towards the selectivity of ORR. We believe that this method would allow the preparation of heteroatom that contains oxygen functionalities. Our work paves a sustainable way of preparation of nanocarbon based ORR catalysts that are only selective for two-electron transfer process.
        4,000원
        282.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the current study, the epoxy material was mixed with 10%, and 30% weight percent carbon material as filler in different thicknesses (1 cm, 1.5 cm, and 2 cm). Transmission electron microscope (TEM) measurements showed the average size of the nano-carbon was 20 nm with a standard deviation of 5 nm. The morphology of samples was examined using scanning electron microscopy (SEM), which showed the flatness of the epoxy surface, and when the content of carbon increases, the connection between the epoxy array and carbon increases. The compression test indicates the effect of nano-size on enhancing the mechanical properties of the studied samples. To survey the shielding properties of the epoxy/carbon composites using gamma-rays emitted from Am-241, Ba-133, Cs-137, Co-60, and Eu-152 sources, which covered a wide range of energies from 0.059 up to 1.408 MeV, the gamma intensity was measured using the NaI (Tl) detector. The linear and mass attenuation coefficients were calculated by obtaining the area under each peak of the energy spectrum observed from Genie 2000 software in the presence and absence of the sample. The experimental results obtained were compared theoretically with XCOM software. The comparison examined the validity of experimental results where the relative division rate ranged between 0.02 and 2%. Also, the measurement of the relative division rate between linear attenuation coefficients of microand nano-composites was found to range from 0.9 to 21% The other shielding parameters are calculated at the same range of energy, such as a half-value layer (HVL), mean free path (MFP), tenth-value layer (TVL), effective atomic number (Zeff), and the buildup factors (EBF and EABF). The data revealed a consistent reduction in the particle size of the shielding material across various weight percentages, resulting in enhanced radiation shielding capabilities. The sample that contains 30% nano-carbon has the lowest values of TVL (29.4 cm) and HVL (8.85 cm); moreover, it has the highest value of the linear attenuation coefficient (LAC), which makes it the best in its ability to attenuate radiation.
        4,500원
        283.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The most significant threat to the ecosystem is emerging pollutants, which are becoming worse each year and harming the planet severely and permanently. Many organic and inorganic contaminants are present and persistent due to various world events and population growth. As a result, there is a greater need for new technology and its application to address the problems caused by developing pollutants. Carbon composite nanomaterials have significant potential in the fight against numerous environmental contaminants due to their distinctive attributes. This review discusses the reports of customized carbon composite nanomaterials to meet the need for specific elimination of emerging contaminants. Physical and chemical features such as high surface area, conductivity (thermal and electrical), and vibroelectronic properties, size, shape, porosity, and composite nature are making these tailored materials of carbon-based nanomaterials an emerging and sustainable tool to remove persistent compounds like emerging contaminants in aqueous solution. Different composite materials are well discussed in this review, along with their adsorption efficiency of diverse emerging contaminants, including Bisphenol A, estradiol, metformin, etc. This review provides insight into the recent trends limited to 2017–2023. The limitations of carbon-based nanomaterials, such as regeneration and cost-effectiveness, have also been overcome in recent years by diverse modifications in the production process, which can be further improved to make these materials well suited for an extended group of emerging contaminants.
        6,100원
        286.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The detailed understanding of fluorescence emission processes is still unclear. This study demonstrates Aegle marmelos derived luminescent heteroatoms (N, Ca, K) doped carbon quantum dots (CQDs) using an economically and ecologically sustainable synthesis process without the necessity for any doping precursors due to its phytochemical, vitamin and mineral content. Carboxyl functionalization was done by adding lemon juice to the fruit extract. The morphological, physiochemical, compositional, crystallinity, and surface functional groups having heteroatom doped CQDs were analysed by HRTEM, EDX, XPS, XRD, FTIR etc. Besides, CQDs exhibited pH and solvent-dependent tuneable fluorescence characteristics. In fact, beyond pH 7.77, a protonation-deprotonation-driven red-shift was observed together with a decrease in the contribution of prominent peaks. Meanwhile, the features of solvatochromic fluorescence were examined in a range of aprotic and protic solvents with low and high polarity. Based on the studied Kamlet–Taft parameters and the obtained spectroscopic characterizations, a suitable fluorescence emission mechanism is provided. The observed solvatochromic fluorescence is thought to be caused by a combination of dipole moment polarisation, intramolecular charge transfer processes with or without H-bond stabilisation via the interaction of heteroatoms doped CQDs with solvent mediated by electron donation and acceptance from various surface functional groups such as hydroxyl, carboxyl with solvent molecules. Hence, this study is believed to promote the development of eco-tuneable fluorescent heteroatom doped CQDs and provide further insights into the fundamental fluorescence mechanisms, which include the relationship between morphology, surface properties and plausible quantum effects between CQDs and solvents.
        4,000원
        287.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Herein, the present work focuses on the effective counter electrode for dye-sensitized solar cells. The bottom–up approach was adapted to synthesize Mn2O3 nanorods via the hydrothermal method and the reduced graphene oxide was merged with Mn2O3 to prepare a nanocomposite. The prepared nanocomposites were subjected to physio-chemical and morphological characterizations which revealed the crystalline nature of Mn2O3 nanorods. The purity level rGO was characterized using the Raman spectrum and the Fourier transform infrared spectroscopy employed to find the functional groups. The morphological micrographs were visualized using SEM and TEM and the high aspect ratio Mn2O3 nanorods were observed with 5–7 nm and supported by rGO sheets. The electrocatalytic nature and corrosion properties of the counter electrode towards the iodide electrolyte were studied using a symmetrical cell. The as-synthesized nanocomposites were introduced as counter electrodes for DSSC and produced 4.11% of photoconversion efficiency with lower charge transfer resistance. The fabricated DSSC devices were undergone for stability tests for indoor and outdoor atmospheres, the DSSC stability showed 93% and 80% respectively for 150 days.
        4,000원
        288.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon dots (CDs) are versatile nanomaterials with tunable luminescent properties. We used a natural plant kaempferol as a carbon source to synthesize multicolor CDs by reacting it with various nitrogen sources. Blue, green, and red CDs (B-CDs, G-CDs, and R-CDs) with emission wavelengths of 445 nm, 510 nm, and 600 nm respectively were successfully synthesized. Their photoluminescence quantum yields of are up to 37.4%, 20.1%, and 30.8%, respectively. Surface analysis revealed abundant nitrogen groups influencing luminescence. B-CDs and G-CDs show excitation-dependent emissions, indicating a potential correlation between their luminescence and particle sizes, while R-CDs exhibit excitation-independent emission, suggesting they belong to molecular state CDs. All three CDs exhibit stable luminescent performance, as well as good salt resistance and photobleaching resistance. The practical application of multicolored CDs in anti-counterfeiting fluorescent inks was further explored. This work offers a straightforward, eco-friendly route to synthesize multicolor CDs.
        4,000원
        289.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Accurate and rapid detection of antibiotics is critical for protecting human health and the environment. To this end, we report a novel electrochemical sensor for the simultaneous detection of Levofloxacin (LFX) and Tryptophan (TRP) in dairy samples. Outstanding electrocatalytic activity for the oxidation of LFX and TRP is exhibited by the Activated Nanodiamond (AND) and Ti3AlC2 max phase ( Ti3AlC2max) nanocomposite-modified glassy carbon electrode ( Ti3AlC2max AND/GCE) featured in our sensor. High selectivity and sensitivity are achieved by the sensor, with limits of detection (LOD) of 20.47 nM and 0.309 μM for LFX and TRP, respectively. Moreover, strong anti-parasite capacity is demonstrated by the developed sensor, making it an excellent candidate for the establishment of a reliable sensing platform for antibiotic detection. Findings suggest that this novel sensor could serve as a valuable tool for monitoring the content of LFX and TRP in dairy samples and enhancing the safety of these products.
        4,300원
        292.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Traditional culture contributes to the diversification of modern fashion design and the inheritance of local cultural identity. This study aims to identify the characteristics of traditional handicrafts reflected in modern fashion design in India. For this purpose, it focused on Sabyasachi Mukherjee, Manish Malhotra, and Ritu Kumar, who are currently leading the Indian fashion design field. The methodology involved conducting literature research and analyzing case studies. In the literature, the techniques of Indian traditional crafts such as embroidery, dyeing, and weaving were examined and five design elements of traditional crafts were defined. Through content analysis of 30 images from the three designers’ Instagram accounts, the design characteristics of traditional handicrafts expressed in contemporary Indian fashion design were derived: cultural inheritance using traditional Indian clothing items, traditional materials and practices applied to contemporary clothing, craftsmanship that artistically improves complex details using embroidery techniques, various combinations based on the traditional meaning of colors, and narrative expression using patterns containing India’s cultural identity. Incorporating these traditional handicrafts into fashion design, closely linked to everyday life, aids in conveying and enhancing their significance. The cases demonstrate the successful integration of conservation into contemporary fashion design. This study sheds light on the application of traditional culture in modern fashion design.
        5,800원
        293.
        2024.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To fabricate intermetallic nanoparticles with high oxygen reduction reaction activity, a high-temperature heat treatment of 700 to 1,000 °C is required. This heat treatment provides energy sufficient to induce an atomic rearrangement inside the alloy nanoparticles, increasing the mobility of particles, making them structurally unstable and causing a sintering phenomenon where they agglomerate together naturally. These problems cannot be avoided using a typical heat treatment process that only controls the gas atmosphere and temperature. In this study, as a strategy to overcome the limitations of the existing heat treatment process for the fabrication of intermetallic nanoparticles, we propose an interesting approach, to design a catalyst material structure for heat treatment rather than the process itself. In particular, we introduce a technology that first creates an intermetallic compound structure through a primary high-temperature heat treatment using random alloy particles coated with a carbon shell, and then establishes catalytic active sites by etching the carbon shell using a secondary heat treatment process. By using a carbon shell as a template, nanoparticles with an intermetallic structure can be kept very small while effectively controlling the catalytically active area, thereby creating an optimal alloy catalyst structure for fuel cells.
        4,000원
        294.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined whether the perceptions of the theory of planned behavior (TPB) and individual and environmental factors related to healthy eating changed after the COVID-19 pandemic among adults living in Daqing, China. Data were collected through two rounds of online surveys conducted from April to May 2021 and from March to April 2023, using a questionnaire previously validated for use in Daqing. Using the snowball sampling method, 571 adult participants were recruited, most of whom were Daqing oilfield workers or members of their families. Multiple linear regression analyses were used to determine if the differences in the perceptions of the TPB and dietary environments exist during and after the pandemic after controlling for potential confounders. Scores of several subcomponents of TPB and mean scores of longterm intentions increased but scores of subcomponents and overall mean of motivation decreased after the outbreak. Multiple linear regression showed that only motivation for healthy eating decreased after the pandemic. Influenced by the pandemic, people increased their healthy eating behaviors. Nevertheless, as the pandemic subsided and the pace of life accelerated, people tended to choose convenient foods over healthy options. Consequently, the motivation for healthy eating has declined post-pandemic compared to during the pandemic.
        4,500원
        295.
        2024.04 구독 인증기관·개인회원 무료
        Pollination is an important ecosystem service mostly provided by diversity of pollinating insects and other animals. As in the anthropocene biodiversity crisis with the climate change, pollination systems are experiencing strongly challenged such as pollinator diversity and abundance decline, pollinator health weakness, pollinator-plant network instability as well as the crop-pollinator habitat fragmentation and insuitability. Here we present some research progress conducted from our group in the last decade. As the pollination dependence of Korean agriculture increases, pollination contribute ap. one forth of national agricultural production, and is responsible substantial portion of vitamin and mineral provisioning. Pollinator diversity is declining in various crop systems and network connectivity is decreasing. Still in agricultural landscape, honeybee (Apis spp) is the main pollinator, accounting ap. 70% of bees, and showed the possible resource partitioning between the native, A. cerana and the introduced, A. mellifera. Simulation of crop-pollinating insect distribution suitability showed up and down directional responses, but more on the negative Further research area for better understanding and stabilizing the plant-pollinator system was proposed.
        296.
        2024.04 구독 인증기관·개인회원 무료
        서식반경이 좁고 개체수가 감소하는 경향을 보이고 있어 멸종위기 종으로 지정된 뚱보주름메뚜기(Haplotropis brunneriana Saussure 1888)를 대상으로 개체군 추이와 적절한 모니터링 방법을 확인하기 위해 방형구법과 선조 사법을 이용하여 밀도 조사를 수행하였다. 뚱보주름메뚜기에 대한 조사 자료가 부족하여 먼저 방형구법을 이용 하여 2021년 3월부터 6월까지 월 1회 서식지 내 개체군 밀도를 확인한 결과 6개체/100㎡(3월), 2개체/100㎡(5, 6월)로 각각 영월과 제천에서 가장 많은 개체가 확인되었고, 지역 간에 유의한 차이는 나타나지 않았다(p > 0.05). 선조사법을 이용하여 2022년 3월부터 6월까지 월 3회 개체군 밀도를 확인한 결과 1.5(±0.79)개체/100㎡, 0.76(±0.11)개체/100㎡로 각각 영월과 제천에서 4월에 가장 많은 개체가 확인되었고, 지역 간에 유의한 차이는 나타나지 않았다(p > 0.05). 조사 방법에 따라 시기와 면적에 차이가 있어 이 두 방법을 정확히 비교할 수 없으나, 공통 적으로 3, 4월 약충 시기에 많은 개체가 확인되는 것을 알 수 있었다.
        297.
        2024.04 구독 인증기관·개인회원 무료
        Field surveys were conducted to collect and refine "Natural resource survey" and ecosystem research data of 23 National parks in South Korea, including Hallasan on Jeju Island and Palgongsan newly designated as national park in 2023. Among the collected data, a total of 1,538 species from 54 families of Hymenoptera insects were recorded. Within these families, the largest number of species was recorded in the family Ichneumonidae with 514 species, followed by Formicidae (118 species), Braconidae (112 species), and Tenthredinidae (135 species), exhibiting relatively high species diversity. Among the National parks, Jirisan, the first designated National park in South Korea with a relatively large area compared to other parks, recorded the highest species diversity with 618 species, while Taebaeksan recorded relatively low species diversity with 77 species. Correlation analysis between the number of Hymenoptera species and other factors revealed a statistically significant and relatively strong positive correlation (P > 0.005, R = 0.864) with the total number of insects, and a statistically significant but relatively weak positive correlation (P > 0.005, R = 0.615) with the park's area.
        298.
        2024.04 구독 인증기관·개인회원 무료
        The genus Campylomyza Meigen, 1818, from the Micromyinae subfamily of the Cecidomyiidae, includes 40 known species globally. The genus Campylomyza has been primarily studied within the Palearctic region, with 39 species, 2 from the Nearctic region, and 1 from the Oriental region. As of now, four species have been documented in Korea: Campylomyza appendiculata, C. flavipes, C. furva, and C. spinata. Our research from 2017 to 2020 uncovered five previously unreported species in Korea (C. abjecta, C. aborigena, C. cornuta, C. cavitata, and C. cingulata) and introduces seven new species (C. angusta sp. nov., C. ambulata sp. nov., C. convexa sp. nov., C. cornigera sp. nov., C. hori sp. nov., C. odae sp. nov., and C. yeongyangensis sp. nov.). These findings are based on morphological evidence and DNA analysis. We present comprehensive data, including the mitochondrial COI sequences, diagnoses, detailed descriptions, and identification keys for these species. This work was supported by a grant from the National Institute of Biological Resources (NIBR), funded by the Ministry of Environment (MOE) of the Republic of Korea.
        299.
        2024.04 구독 인증기관·개인회원 무료
        The genus Helictes is a small group of the subfamily Orthocentrinae, comprising 11 species from worldwide, most species from the Palaearctic region, four species from the Nearctic, and two species from the Neotropical region. This subfamily is wide morphological variation between genera but most are readily recognizable as orthocentrines. They are generally small sized, clypeus strongly convex and malar space long. Among them, this genus is reported for the first time from South Korea. In this study, description, photographs of diagnostic characterists are provided.
        300.
        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.