검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 233

        1.
        2024.04 구독 인증기관·개인회원 무료
        The genus Vespa consists of 22 species worldwide, and their phylogenetic relationships are well established through adult morphology and molecular analyses. However, taxonomic studies of larvae are lacking. In this study, we provided descriptions and taxonomic keys for eight species of Korean Vespa larvae.
        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An eco-friendly material was synthesized through interfacial polymerization of aniline on particles of g-C3N4 with arginine, resulting in Arg-PANI@g-C3N4 composite. The as-synthesized composite was characterized by the Brunauer, Emmett, and Teller (BET) surface area, X-ray energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The adsorption capability of as-synthesized composite towards Orange G (OG) dye has been evaluated under several experimental conditions, such as the adsorbent dosage, initial dye concentration, contact time under agitation, pH of dye solution and temperature. Thermodynamics parameters such as free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) were also calculated and suggested that the adsorption process is spontaneous and endothermic in nature. The kinetics data revealed that the adsorption of OG dye onto Arg-PANI@g-C3N4 follows the pseudo-second order kinetics model. The maximum adsorption capacity was found to be 80.54 mg·g−1. Furthermore, the Arg-PANI@g-C3N4 surface exhibited a Langmuir-like adsorption isotherm in contrast to a Freundlich isotherm due to homogeneous active site distribution. Regeneration investigation showed the excellent reusability of Arg-PANI@g-C3N4 composite during the cleaning up of solution containing OG dye molecules.
        4,300원
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : A model for minimizing cutting loss and determining the optimum layout of blocks in pavements was developed in this study. METHODS : Based on literature review, a model which included constraints such as the amount, volume, overlap, and pattern, was developed to minimize the cutting loss in an irregular pavement shape. The Stach bond, stretcher bond, and herringbone patterns were used in this model. The harmony search and particle swarm algorithms were then used to solve this model. RESULTS : Based on the results of the model and algorithms, the harmony search algorithm yielded better results because of its fast computation time. Moreover, compared to the sample pavement area, it reduced the cutting loss by 20.91%. CONCLUSIONS : The model and algorithms successfully optimized the layout of the pavement and they have potential applications in industries, such as tiling, panels, and textiles.
        4,000원
        4.
        2023.10 구독 인증기관·개인회원 무료
        The soluble epoxide hydrolase (sEH) plays a crucial role in insect immunity and development by metabolizing oxylipins such as EpOMEs and EETs. This study investigates sEH's involvement in insect antiviral response against Autographacalifornicanuclear polyhedrosis virus (AcNPV) infection. Viral infection assays were performed on Plutellaxylostellaand Marucavitrata, utilizing occlusion bodies (OB, via feeding) and budded virus (BV, through injection). Insect mortality was monitored every 12 h for up to 7 days. Our findings demonstrated a dose-dependent impact of both virus forms (OB and BV) on insects. Additionally, the sEH inhibitor, AUDA (12-(3-adamantan-1-yl-ureido) dodecanoic acid), was employed alongside the virus. The results indicated that combining AUDA with the virus increased insect mortality. Furthermore, fluorescence assays revealed the gradual movement of the virus from the gut to hemolymph and fat body. AUDA was observed to expedite virus infection. Moreover, sEH expression rapidly increased along with the viral infection in Spodoptera exigua. RNA interference of sEH expression enhanced the viral virulence against S.exigua. These suggest that EpOMEs play crucial roles in immune resolution against viral infection in insects.
        5.
        2023.07 구독 인증기관·개인회원 무료
        Previous research on green product innovation (GPI) has primarily focused on the performance of new product development, neglecting the critical, early fuzzy front-end (FFE) phase. Drawing upon the firm's resource-based view (RBV) and dynamic capabilities perspective, this study explores how co-production affects FFE outcomes (creative idea and product definition proficiency) of GPI and whether joint learning ambidexterity is a mediating mechanism in international buyer-supplier relationships. Additionally, we provide a contingency perspective by considering the moderating role of the innovation ecosystem on the relationship between co-production and joint learning ambidexterity. Finally, this study contributes to a theoretical understanding, analyzing co-production as a predictor, joint learning ambidexterity as a mediator, and innovation ecosystem as a moderator.
        6.
        2023.07 구독 인증기관 무료, 개인회원 유료
        Digital entrepreneurship refers to the pursuit of business opportunities based on the utilisation of digital media and other information and communication technologies. The use of digital technologies provides an avenue of unleashing female entrepreneurs from the hierarchical and practice of obedience in a high cultural context. In this sense, the potential of digital entrepreneurship in promoting female entrepreneurship can be examined in terms of entrepreneurship as emancipation. Our research contributes to the women entrepreneurship literature on the use of digital technologies in the context of a very hostile environment such as in the case of Yemeni civil war. A semi-structured interview format will be used to gather information on a common set of questions focusing on how digital technology enabled the entrepreneurial activities. The researchers will adopt a qualitative interpretive methodology. This approach focuses on the participants’ own reflections on their experiences.
        3,000원
        7.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The emission of off-gas streams from used fuel recycling is a concern in nuclear energy usage as they contain radioactive compounds, such as, 3H, 14C, 85Kr, 131I, and 129I that can be harmful to human health and environment. Radioactive iodine, 129I, is particularly troublesome as it has a half-life of more than 15 million years and is prone to accumulate in human thyroid glands. Organic iodides are hazardous even at very low concentrations, and hence the capture of 129I is extremely important. Dynamic adsorption experiments were conducted to determine the efficiency of sodium mordenite, partially exchanged silver mordenite, and fully exchanged silver mordenite for the removal of methyl iodide present at parts per billion concentrations in a simulated off-gas stream. Kinetic analysis of the system was conducted incorporating the effects of diffusion and mass transfer. The possible reaction mechanism is postulated and the order of the reaction and the values of the rate constants were determined from the experimental data. Adsorbent characterization is performed to investigate the nature of the adsorbent before and after iodine loading. This paper will offer a comprehensive understanding of the methyl iodide behavior when in contact with the mordenites.
        5,500원
        13.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Combination of liquid-phase exfoliation and hydrothermal method has progressed in recent years mainly on production of 2D materials. In this study, graphene was successfully synthesized via combinatorial of liquid-phase exfoliation and hydrothermal method with the aid of various conductive surfactants perylene-3, 4, 9, 10-tetracarboxylate (PTCA), lithium perylene-3, 4, 9, 10-tetracarboxylate (LiPTCA) and sodium perylene-3, 4, 9, 10-tetracarboxylate (NaPTCA). The effect of the lithium ( Li+) and sodium ( Na+) cations toward the efficiency of the graphene exfoliation process and its electrical properties was thoroughly investigated. Based on the characterization techniques, it is revealed that NaPTCA is the ideal conductive surfactant to exfoliate graphene sheets. X-ray diffraction spectra verified that the Na+ cation certainly can enhance the exfoliation process by expanding the interlayer spacing. The lateral size of the graphene sheets with Na-PTCA surfactant was the smallest (4.17 μm) as observed from SEM micrograph. The maximum concentration of the graphene yield was achieved up to 0.151 mgmL− 1 in NaPTCA surfactant alongside with excellent electrical conductivity of 746.27 Sm− 1 and relevant specific capacitance of 129 Fg− 1.
        5,200원
        14.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In additive manufacturing, the flowability of feedstock particles determines the quality of the parts that are affected by different parameters, including the chemistry and morphology of the powders and particle size distribution. In this study, the microstructures and flowabilities of gas-atomized heat-resistant alloys for additive manufacturing applications are investigated. A KHR45A alloy powder with a composition of Fe-30Cr-40Mn-1.8Nb (wt.%) is fabricated using gas atomization process. The microstructure and effect of powder chemistry and morphology on the flow behavior are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and revolution powder analysis. The results reveal the formation of spherical particles composed of single-phase FCC dendritic structures after gas atomization. SEM observations show variations in the microstructures of the powder particles with different size distributions. Elemental distribution maps, line scans, and high-resolution XPS results indicate the presence of a Si-rich oxide accompanied by Fe, Cr, and Nb metal oxides in the outer layer of the powders. The flowability behavior is found to be induced by the particle size distribution, which can be attributed to the interparticle interactions and friction of particles with different sizes.
        4,000원
        15.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bacterial phytopathogen Pectobacterium causes soft rot disease in several vegetable crops globally, resulting in heavy agricultural losses at both the pre and postharvest stages. The present work was carried out to screen Kimchi cabbage genetic resources conserved at the National Agrobiodiversity Center, Rural Development Administration, Korea, for resistance against the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum KACC 21701 over a period of three years (from 2020 to 2022). Infection of the phytopathogen was carried out at four-leaf stage and for each accession, twenty-five plants per germplasm were infected with KACC 21701. Kimchi cabbage cultivars Wangmatbaechu, Seoulbaechu, and CR Kiyoshi were used as control. Seven-days post-infection, the Disease Index (DI) values were manually recorded from zero to four, zero matched perfectly heathy plants and four completely dead plants. The 682 accessions of Kimchi cabbage exhibited varying degrees of disease resistance to KACC 21701 and thirty accessions, exhibiting a DI≤2, were considered for replication studies. During the replication studies, four landrace germplasms (IT102883, IT120036, IT120044, and IT120048) and one cultivar (IT187919) were confirmed to be moderately susceptible to KACC 21701. Results of the preliminary screening as well as replication studies were documented for the all the 682 germplasms. Addition of such information to the passport data of stored germplasms might serve as potential bio-resource for future breeders and researchers to develop resistant varieties or study the mechanisms involved in resistance of plants to such phytopathogen.
        4,000원
        16.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Few studies have been performed on ZrB2- graphite platelet composite made by spark plasma sintering (SPS) technique. In this research, the influence of adding graphite platelets (Gp) with and without SiC on the fracture toughness of ZrB2 ceramic was studied. The ZrB2- 10Gp, ZrB2- 15Gp, ZrB2- 30SiC-10Gp, and ZrB2- 30SiC-15Gp specimens were sintered by the SPS method at the temperature of 1850 °C for 8 min. The fracture toughness and work of fracture (WOF) were evaluated using the Single-Edge Notched Beam (SENB) technique. It was found that the fracture toughness and WOF were improved by the alone and combined addition of Gp and SiC to the monolithic ZrB2. The maximum fracture toughness of 4.8 ± 0.1 MPa m1/ 2 was obtained for the ZrB2- 15Gp specimen. It seems that adding Gp alone was more effective in enhancing the fracture toughness of ZrB2 than the combined addition of Gp and SiC. While the addition of Gp and SiC simultaneously modified the densification behavior to reach full-densified samples.
        4,000원
        17.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The aim of this study is to review freeze-and-thaw testing apparatuses, develop a freeze-and-thaw testing setup with a test protocol, test the freeze-and-thaw properties of soils collected from different parts of South Korea, and suggest an index for frost susceptibility criteria for soils found in South Korea. METHODS : Based on a literature review, a new freeze-thaw testing setup was developed. In addition, a test protocol was developed for freeze-thaw testing. Soils collected from different parts of South Korea and bedding sand used for block pavements were tested to determine whether the measurements from the newly developed test setup could capture important freeze-thaw characteristics of the soils. Finally, to develop local frost susceptibility criteria, a parameter including both the vertical deformation and thermal conductivity characteristics of the soils was suggested. RESULTS : The results from the laboratory experiments indicate that the newly developed freeze-and-thaw setup captures the required parameters to quantify the responses of soils subjected to cyclic freeze-and-thaw testing. In addition, a vertical deformation of up to 2.437 mm is measured. Moreover, seven soils out of the nine tested soils are classified as having a medium frost susceptibility, whereas the remaining two show low frost susceptibility. The bedding sand experiment also shows that there is a possibility of having a frost susceptible condition based on the moisture content. When submerged, the bedding sand is classified as having a medium frost susceptibility. CONCLUSIONS : The "HEART" freeze-thaw testing setup was able to capture the parameters required for evaluating the frost susceptibility of soils. This setup and testing procedure could be further used to test and prepare criteria for classifying the frost susceptibility of soils found in South Korea.
        4,000원
        1 2 3 4 5