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        검색결과 1,892

        28.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The surface of carbon films deposited with inverted plasma fireballs is analysed in this paper. Measurements were conducted with Raman spectroscopy, atomic force microscopy and nanoindentation. The latter was used to obtain Young’s modulus as well as Martens and Vickers hardness. The roughness of the film was measured by atomic force microscopy and its thickness was measured. It was shown with Raman spectroscopy that the films are homogeneous in terms of atomic composition and layer thickness over an area of about 125 × 125 mm. Furthermore, it was demonstrated that inverted plasma fireballs are a viable tool for obtaining homogeneous, large area carbon films with rapid growth and very little energy consumption. The obtained films show very low roughness.
        4,000원
        29.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ultrasonic method is an alternative to the conventional route to produce structured carbon materials, offering the advantages of synthesis in a short period of time under room temperature. The main objective of this work is to synthesize a sulfonated mesoporous carbon catalyst from a phenolic resin composed of phloroglucinol and formaldehyde. The synthesis was performed by the soft-template method in an ultrasonic processor and the product was subsequently carbonized and sulfonated for application in the esterification model reaction. Functionalization with sulfuric acid of MCS5-6 h sample brought about a decrease in porosity but simultaneously resulted in the generation of functional groups of an acidic nature. The MCS5-6 h catalyst with a sulfonic density of 1.6 mmol g− 1, surface area of 402 m2 g− 1 and pore diameter of 10.6 nm maintained in mesoporous even after acid treatment. MCS5-6 h showed excellent activity in the esterification reaction with 95% oleic acid conversion. The recyclability of MCS5-6 h was satisfactory during five reaction cycles. The present work addressed a promising alternative for the synthesis of carbon catalysts using ultrasound irradiation, thus providing an alternative with a lower cost of time and energy for large-scale production.
        4,600원
        30.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lead sulfide ( PbS ) nanocrystals anchored on nitrogen-doped multiwalled carbon nanotubes ( CNx ) have been synthesized employing an environmentally friendly and inexpensive wet chemistry process. CNx∕PbS composites have been examined by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Theorical ab initio calculations have been developed to determine the samples structural, morphological and optical properties to explain the experimental evidences. The PbS nanoparticles exhibit of 4 nm to 27 nm particle size with a face-centered cubic crystal structure and are homogeneously distributed along the carbon nanotubes. The nitrogen-doped CNTs acts as binding sites for the PbS clusters as ab initio theoretical study suggests.
        4,000원
        31.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문은 연극적 패러다임(theatrical paradigm)과 관련된 개념들 (연설-행동, 대행, 드라마, 공연, 시뮬레이션, 즉흥연주 등)을 사용하여 신학적 교육과 선교적 실천을 향상시키는데 목적을 두고 있다. 이러한 개념들은 하나님과 인간의 상호관계, 창조-구속 역사, 성육신-선교적 운동, 또는 하나님 나라의 종말론적 관점을 이해하는 데 중요한 비유를 제공하는 “Theodrama”라는 주제로 통합될 수 있다. 본 논문의 목적은 Theodrama 연극적 패러다임의 기독교 삶과 선교적 함의에 관하여 살펴보 는 것이다. 논문의 개요는 다음과 같다. (1) Theodrama의 이론적 근거 (화행론, 행위주체론, 공연론, 드라마 내러티브 관점); (2) Theodrama의 실제적 방법론 (무대에서의 시뮬레이션, 삶의 즉흥성); (3) Theodrama의 선교적 의미 (해석학적 과정, 선교적 적용).
        8,700원
        32.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The biocarbon (SKPH) was obtained from Sargassum spp., and it was evaluated electrochemically as support for the CO2 reduction. The biocarbon was synthesized and activated with KOH, obtaining a high surface area (1600 m2 g− 1) due to the activation process. Graphitic carbon formation after pyrolysis was confirmed by Raman spectroscopy. The XRD results show that SKPH has an amorphous structure with peaks corresponding to typical amorphous carbonaceous materials. FTIR was used to determine the chemical structure of SKPH. The bands at 3426, 2981, 2851, and 1604 cm− 1 correspond to O–H, C-H, and C-O stretching vibrations, respectively. Then, it compares SKPH films with different carbon films using two electrolytic systems with and without charge transfer. The SKPH film showed a capacitive behavior in the KOH, H2SO4, and, KCl systems; in the acid medium, the presence of a redox couple associated with carbon functional groups was shown. Likewise, in the [Fe(CN)6]−3 and Cu(II) systems, the charge transfer process coupled with a capacitive behavior was described, and this effect is more noticeable in the [Fe(CN)6]−3 system. Electrodeposition of copper on SKPH film showed two stages Cu(NH 3)2+ 4 /Cu(NH 3)+ 2 and Cu(NH 3)+ 2 ∕Cu in ammonia media. Hydrogen formation and the activity of CO2 are observed on SKPH film and are favored by the carbon’s surface chemistry. Cu/SKPH electrocatalyst has a catalytic effect on electrochemical reduction of CO2 and inhibition of hydrogen formation. This study showed that the SKPH film electrode responds as a capacitive material that can be used as an electrode for energy storage or as metal support.
        4,900원
        40.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The main objective of the research was to deposit thin films of silver on a graphite carbon paste in a phosphate buffer medium using an electrochemical method. To construct a nitrofurazone detection sensor that is highly sensitive. Different manufacturing parameters, such as electrodeposition potential, pH effect, potential scan rate effect, and number of scan cycles, were examined in this section. The parameters were optimized to improve the deposited silver layers various electrocatalytic characteristics. The Nitrofurazone reduction process is diffusion controlled, as seen by the linear variation of Epc with log(v). The constructed Ag-NPs@CPE electrod has excellent electrical characteristics a large active surface area and low background with extremely high electrical conductivity, according to structural and electrochemical characterizations such as Scanning electron microscopy, X-ray diffraction (XRD) and cyclic voltammetry. The constructed sensor has a very remarkable analytical performance for nitrofurazone molecule identification, with a very low detection limit of about 10– 8 M. The detection of nitrofurazone using our Ag-NPs@CPE sensors in real samples contaminated with the antibiotic nitrofurazone, such as tap water and urine. In the selected sample, the electroanalytical findings reveal a very satisfactory recovery rate of more than 94 percent.
        4,600원
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