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        검색결과 12

        1.
        2023.07 구독 인증기관·개인회원 무료
        This study examines the impact of influencer-audience and audience-audience interactions in Livestream e-commerce by extending halo of the influencer to the brand and snowballing the opinions that empower other watchers. It finds that halo effect generates from influencer physical attraction and bandwagon effect from audience live comments significantly influenced product preference and purchase intentions.
        2.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrogen energy is a promising source of renewable and clean energy for various industries, such as chemical, automobile, and energy industries. Electrolysis of water is one of the basic methods for the production of hydrogen energy. However, the high overpotential of the oxygen evolution reaction (OER) in water electrolysis has hindered the effective production of hydrogen using this method. Thus, the development of high-efficiency non-precious metal-based electrocatalysts for OER is extremely significant. In this study, we adopted a one-step hydrothermal method to fabricate Ni-based catalysts with N/Sdual doped graphene oxide/carbon nanotube (GO/CNT) supports using thiourea ( CH4N2S) and urea as the S source and the N source. It was observed that the amount of thiourea utilized in the synthesis of the catalyst affected the morphology, composition, and the electrochemical properties of the catalyst. For a GO/CNT-to-thiourea mass ratio of 1:10, the catalyst exhibited the highest activity, where the OER overpotential was 320 mV at a current density of 10 mA/cm2. This was attributed to the high specific surface area, high conductivity, and fast electron transport channels of the N/S-dual doped GO/ CNT composite. Furthermore, sulfurization of the Ni particles to form nickel sulfide played a significant role in enhancing the catalytic performance.
        4,000원
        3.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Highly luminescent carbon quantum dots (CQDs) are developed as fluorescent probes for selective detection of the heavy-ion Fe3+, where the CQDs exhibit excellent nontoxicity, functionalizability, sensitivity, and selectivity. Biomass-based CQDs and nitrogen-doped CQDs (N-CQDs) are synthesized for the selective detection of Fe3+ by using H2O2 as an oxidant and polyetherimide (PEI) as a nitrogen precursor by a green hydrothermal synthesis method. The prepared CQDs and N-CQDs exhibit an elliptical morphology and with an average particle size of 7 and 4 nm, respectively, and emit blue photoluminescence at 445 and 468 nm under excitation at 367 and 343 nm, respectively. The CQDs and N-CQDs exhibit good water solubility because of the abundant hydroxyl and carboxyl/carbonyl groups and graphic/pyrrolic/pyridinic nitrogen on the surfaces, giving rise to a quantum yield of about 24.2% and 30.7%, respectively. Notably, the Matrimony vine-PEI-based CQDs exhibit excellent Fe3+ selectivity and sensitivity relative to the Matrimony vine-based CQDs due to complexation of the numerous phenolic hydroxyl groups and nitrogen-containing groups with Fe3+, leading to increased fluorescence quenching, which greatly improves the sensitivity of detection. The minimum detection limit was 2.22 μmol L− 1 with a complexation constant of 44.7.
        4,000원
        4.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nitrogen-doped carbon dots (N-CDs), derived from the biomass (anthocyanin), are the novel additive to the nanocarbon materials, which is expected to bring a wide spectrum of novel applications. Moreover, metallic oxides are emerging for their unique potential for electrocatalysis. Herein, we report the synthesis of N-CDs for the selective detection of Fe3+ with a limit of detection of 2.57 μM in the range of 5–60 μM using ethylenediamine and H2O2 by a hydrothermal method. The obtained N-CDs displayed a spherical morphology with a particle size range of 2–7 nm and emitted blue luminescence at 394 nm under excitation at 319 nm. Meanwhile, we have demonstrated the fabrication of cost-efficient electrocatalysts for oxygen evolution reaction (OER) in an alkaline medium, employing N-CDs. Owing to the successful incorporation of N-CDs into NiO nanospheres, the resulting N-CDs/NiO with large surface areas, fast charge transfer, and increased conductivity vastly improved the catalytic activity. Remarkably, the optimal of N-CDs/NiO composite requires the overpotential of only 380 mV at a current density of 10 mA cm− 2 and a relatively low Tafel slope of 57.96 mV dec− 1 compared with pure NiO. These results open up a facile route for the application of N-CDs and offer prospects for CD-metal hybrids as high OER catalysts in electrochemical energy devices.
        4,300원
        5.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hierarchical porous carbons (HPCs) have been successfully prepared by a facile carbonization and subsequent CO2 activation process using corncob as a natural carbon precursor and Mg(C2H3O2)2 as a MgO nano-template precursor. The prepared corncob-based hierarchical porous carbons (C-HPCs) with desirable micropores and mesopores feature the excellent absorbency of gas (i.e., CO2 and CH4) and solution (i.e., methylene blue (MB)). Increasing the ratio of Mg(C2H3O2)2/corncob enlarged the specific surface area up to 1004 m2/ g, micropore and mesopore volumes, CO2, CH4, and MB adsorption capacities (112, 31 and 230 mg/g after 325 min, respectively). The results indicated that the pore structures of C-HPCs can be easily and suitably controlled by the amount of the template precursor and CO2 activation effecting concurrently, which leads to fascinating adsorption capacity for CO2, CH4, and MB.
        4,200원
        6.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 한국의 대학에 재학하고 있는 한국인 여대생과 중국인 여대생을 대상으로 캐주얼 셔츠 소재의 주관적인 감각과 선호도의 차이를 파악하고자 수행되었다. 춘추용 캐주얼 셔츠의 소재로 시판되는 소재 중에서 섬유조성이 상이한 7가지 종류의 흰색 셔츠 직물을 선정하였다. 캐주얼 셔츠 소재에 대한 주관적 감각 및 촉감 선호도의 평가자는 한국인 여대생과 중국인 여대생으로 40명이었다. 참가자들은 7종 소재를 관찰하고 나서 주관적인 감각과 촉감 선호도에 대한 평가를 설문지를 사용하여 작성하였다. 캐주얼 셔츠 소재의 주관적 감각을 요인분석한 결과, 평활감, 경량감, 유연감, 신축감의 4개 요인으로 분류되었다. 주관적 감각 요인은 소재의 섬유조성별 국적에 따라 부분적으로 유의한 차이를 보였다. 한국인 여대생은 중국인 여대생 보다 면 100% 소재를 더 가볍다고 평가하였고, 폴리에스터 50%/모달 50% 소재와 P100 소재를 더 신축성이 있다고 평가하였으나, 중국인 여대생은 폴리에스터 50%/면 45%/스판덱스 5% 소재를 더 가볍다고 평가하였다. 캐주얼 셔츠 소재의 섬유조성별 촉감 선호도는 국적에 따라 유의한 차이를 보였다. 한국인 여대생은 중국인 여대생에 비해 면 80%/폴리에스터 20% 소재, 폴리에스터 50%/면 45%/스판덱스 5% 소재, 아마 100% 소재를 더 선호하였다. 한편, 캐주얼 셔츠 소재의 주관적 감각 요인이 촉감 선호도에 미치는 영향은 국적에 따른 차이를 보였다. 한국 여대생의 경우, 평활감과 유연감이 캐주얼 셔츠 소재의 촉감 선호도에 긍정 적 영향을 미치는 반면, 중국인 여대생은 평활감, 유연감, 신축감이 촉감 선호도에 긍정적 영향을 미치는 것을 알 수 있었다. 이처럼 캐주얼 셔츠 소재에 대한 주관적 감각 및 촉감 선호도는 한국인 여대생과 중국인 여대생간의 차이를 보였다. 따라서 여대생을 대상으로 캐주얼 셔츠 소재 기획시 이러한 감성의 차이를 반영하는 것이 필요하다.
        4,000원
        7.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A γ-aminobutyric acid (GABA) producing microorganism was isolated from Sun-Tae Jeotgal, a Korean traditional fermented seafood. Two thousand presumptive lactic acid bacteria (LAB) isolates were screened for GABA production by thin layer chromatography. One isolate, T118, produced GABA profusely, and identified as Lactobacillus brevis. Growth of Lb. brevis T118 was examined during 120 h cultivation in MRS broth under different conditions. Lb. brevis T118 grew well at 30-37℃, initial pH of 4-7, and up to 5% NaCl (w/v). A gene, gadB, encoding glutamate decarboxylase (GAD) was cloned by PCR. gadC encoding a glutamate/GABA antiporter was cloned and gadC located immediately upstream of gadB, indicating gadCB operon structure. The operon structure was confirmed by reverse transcription (RT)-PCR. gadB was overexpressed in Escherichia coli BL21 (DE3) and recombinant GAD was purified. The size of recombinant GAD was 54.4 kDa by SDS-PAGE, which matched well with the calculated size from the nucleotide sequence.
        4,000원
        9.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the amendment of Child Welfare Law in 2003, the regional centers for children have been a part of the child welfare system, providing child-care services for families in poverty. In Korea, the regional centers for children were established during the poverty movement in the 1970s and have been developed as childcare providers for poor children since the financial crisis. However, the identity of regional centers for children is being threatened as the universal perspective on caring and the public values of caring services are being strengthened. There has raised a controversy around the role of regional centers for children that provide child-care services for vulnerable families. In addition, the survival of the regional centers for children is being threatened due to some issues regarding the content of their program as it is similar to those of other child-care agencies, the lack of cooperation among the ministries of government addressing public needs for child-care services, the poor working conditions of center employees, and the poor quality of services. The purpose of this study is to examine the formation process of the regional centers for children. After that, we discuss the current issues of the regional centers for children and seek alternatives that can settle the problems and respond properly to social changes.
        4,300원
        10.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nitrogen-doped carbons have attracted much attention due to their novel application in relation to gas storage. In this study, nitrogen-doped porous carbons were synthesized using SBA-15 as a template, polypyrrole as the carbon and nitrogen precursor, and KOH as an activating agent. The effect of the activation temperature (600–850°C) on the CO2 adsorption capacity of the obtained porous carbons was studied. Characterization of the resulting carbons showed that they were micro-/meso-porous carbon materials with a well-developed pore structure that varied with the activation temperature. The highest surface area of 1488 m2 g–1 was achieved at an activation temperature of 800°C (AC-800). The nitrogen content of the activated carbon decreased from 4.74 to 1.39 wt% with an increase in the activation temperature from 600 to 850°C. This shows that nitrogen is oxidized and more easily removed than carbon during the activation process, which indicates that C-N bonds are more easily ruptured at higher temperatures. Furthermore, CO2 adsorption isotherms showed that AC-800 exhibited the best CO2 adsorption capacity of 110 mg g–1 at 298 K and 1 bar.
        4,000원
        11.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to comparatively examine techniques and expressive characteristics of batik by focusing on the work of DanZhai and that of ZhenNing Buyi. We collected 50 pieces of batik each from Miao and Buyi in Chinese GuiZhouSheng and then analyzed their colors and patterns. The findings show that most of Miao’s batik had deep and soft tones, while that of Buyi most often had blackish tone since the number of dyes in the latter is higher than that in the former. Miao often used patterns expressing animals or animals and plants, while Buyi frequently used geometric ones. An examination of specific motifs demonstrated that butterflies, fish, and flowers were most often used by Miao, while dots, vortexes, lines, and lozenges were frequently utilized by Buyi. For expressive techniques, both Miao and Buyi commonly used simple stylized expression or complex expression combining stylized and geometric techniques. Maio’s motifs were often decoratively expressed with delicate curves, while Buyi’s motifs had simple structures, so pictures were neatly expressed with thick lines and wide and simple planes. For the composition of the motifs, incomplete symmetry between top and bottom and between left and right often appeared in Maio, while in Buyi complete symmetry was frequently shown.
        4,900원
        12.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 대학생 소비자의 선호 감성을 반영한 패션소재기획에 도움을 주고자 수행되었다. 8종의 데님소재를 대상으로 색채 특성과 역학적 특성 등의 객관적 특성을 평가하였으며, 데님소재의 색채 선호도, 주관적 감각, 촉감 선호도를 대학생을 대상으로 조사하였다. 또한 데님소재의 색채 선호도와 촉감 선호도가 데님 슬랙스의 구매 선호도에 미치는 영향을 파악하였다. 데님소재의 색채 선호도는 데님소재의 개별 시료에 따른 유의한 차이를 보였다. 대학생들은 데님소재의 색채특성 중 -b*값과 C값이 낮게 측정된 남색(PB)의 데님소재를 선호하였다. 데님소재의 역학적 특성 중에서 마찰계수 평균편차(MMD), 마찰계수(MIU), 기하학적 거칠기(SMD) 등의 표면특성과 전단 히스테리시스(2HG5) 등의 전단특성은 주관적 감각에 중요한 영향을 미치는 요인이었다. 한편, 데님소재의 촉감 선호도는 개별 시료에 따른 유의한 차이를 보였다. 폴리우레탄이 혼방된 데님소재에 대한 촉감 선호도가 높게 나타났으며, 면섬유 100%로 구성된 상대적으로 두껍고 무거운 데님소재의 촉감 선호도는 낮았다. 또한 촉감 선호도에 영향을 미치는 주관적 감각은 평활감, 유연감, 경량감 등의 순이었다. 데님 슬랙스에 대한 구매 선호도는 모두 평균 4점 이상의 점수를 나타내어 선호하였다. 데님소재의 색채 선호도와 촉감 선호도는 데님 슬랙스 구매 선호도에 영향을 미쳤는데, 색채 선호도가 더욱 영향을 주었다.
        4,000원