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        검색결과 35

        1.
        2024.06 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
        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, synergetic and separate influence of nano-carbon black (C.Bn) and SiC on the microstructure and flexural strength of ZrB2 were investigated. So, ZrB2 and ZrB2- 30vol%-based composites containing 10 and 15 vol% C.Bn as well as ZrB2- 15 vol% SiC were fabricated via spark plasma sintering at 1850 °C for soaking time of 8 min under the applied pressure of 35 MPa. Relative density was measured by Archimedes method. Microstructural evaluation was carried out by applying the field emission electron microscopy (FESEM), and flexural strength was measured by three-point bending test. It was found the relative density improves in the presence of C.Bn and SiC especially in synergetic state so that the full densification was gained in Z30Si10C.Bn and Z30Si15C.Bn composites through their reactions with impurities at 1850 °C. In the monolithic ZrB2 system, the C.Bn addition improves the flexural strength slightly to 300 MPa and 315 MPa from 290 MPa. However, co-doped 10 vol% C.Bn with 30 vol% SiC resulted to achieve maximum flexural strength of 486 MPa in comparison with individually applying each of them (395 MPa for Z30Si and 300 MPa for Z10 C.Bn).
        4,000원
        3.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To develop a high capacity lithium secondary battery, a new approach to anode material synthesis is required, capable of producing an anode that exceeds the energy density limit of a carbon-based anode. This research synthesized carbon nano silicon composites as an anode material for a secondary battery using the RF thermal plasma method, which is an ecofriendly dry synthesis method. Prior to material synthesis, a silicon raw material was mixed at 10, 20, 30, 40, and 50 wt% based on the carbon raw material in a powder form, and the temperature change inside the reaction field depending on the applied plasma power was calculated. Information about the materials in the synthesized carbon nano silicon composites were confirmed through XRD analysis, showing carbon (86.7~52.6 %), silicon (7.2~36.2 %), and silicon carbide (6.1~11.2 %). Through FE-SEM analysis, it was confirmed that the silicon bonded to carbon was distributed at sizes of 100 nm or less. The bonding shape of the silicon nano particles bonded to carbon was observed through TEM analysis. The initial electrochemical charging/ discharging test for the 40 wt% silicon mixture showed excellent electrical characteristics of 1,517 mAh/g (91.9 %) and an irreversible capacity of 133 mAh/g (8.1 %).
        4,000원
        4.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In today’s world, carbon-based materials research is much wider wherein, it requires a lot of processing techniques to manufacture or synthesize. Moreover, the processing methods through which the carbon-based materials are derived from synthetic sources are of high cost. Processing of such hierarchical porous carbon materials (PCMs) was slightly complex and only very few methods render carbon nano-materials (CNMs) with high specific surface area. Once it is processed, which paves a path to versatile applications. CNMs derived from biological sources are widespread and their application spectrum is also very wide. This review focuses on biomass-derived CNMs from various plant sources for its versatile applications. The major thrust areas of energy storage include batteries, super-capacitors, and fuel cells which are described in this article. Meanwhile, the challenges faced during the processing of biomass-derived CNMs and their future prospects are also discussed comprehensively.
        7,000원
        6.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fluorescent carbon nano-materials with quantum confinement and edge effects have recently piqued attention in a variety of applications, including biological imaging, drug delivery, optoelectronics and sensing. These nano-materials can be synthesized from a variety of carbon-based precursors using both top-down and bottom-up methods. Coal and its derivatives typically include a vast crystalline network and condensed aromatic ring cluster, which can be easily exfoliated by chemical, electrochemical, or physical processes to produce nano-materials. As a result, they are regarded as a low-cost, abundant and efficient carbon source for the fabrication of high-yield nano-materials. Nano-materials synthesized from coal-based precursors have outstanding fluorescence, photostability, biocompatibility and low toxicity, among other properties. Their properties in optical sensors, LED devices, bio-imaging, and photo and electro-catalyst applications have already been investigated. In this review, we have highlighted current developments in the synthesis, structural properties and fluorescence properties of nano-materials synthesized from coal-based precursors.
        7,800원
        7.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The production of macroalgae-derived adsorbent is of great importance to realize the idea of treating pollutants with invaluable renewable materials. Herein, a novel meso-micro porous nano-activated carbon was prepared from green alga Ulava lactuca in a facile way via chemical activation with zinc chloride. The resultant activated carbon possesses a significant specific surface area 1486.3 m2/ g. The resulting activated carbon was characterized and investigated for the adsorption of Direct Red 23 (DR23) dye from an aqueous environment. Batch method was conducted to study the effects of different adsorption processes on the DR23 dye adsorption from water. Isotherms and kinetics models were investigated for the adsorption process of DR23 dye. It was found that the adsorption data were well fitted by Langmuir model showing a monolayer adsorption capacity 149.26 mg/g. Kinetic experiments revealed that the adsorptions of DR23 dye can be described with pseudo-secondorder model showing a good correlation (R2 > 0.997). The prepared activated carbon from Ulava lactuca was exposed to a total of six regeneration experiments. The regeneration result proved that the fabricated activated carbon only loses 19% of its adsorption capacity after six cycles. These results clearly demonstrated the high ability of the obtained active carbon to absorb anionic dyes from the aqueous environment.
        4,900원
        8.
        2022.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the proper wattage and installation distance for the efficient use of nano-carbon fiber infrared heating lamp (NCFIHL), a heating device advantageous for heating energy saving, when the production of watermelon plug seedlings in the plug seedling nursery in winter season. Six small beds were divided into plastic film, and 700 W and 900 W nano-carbon fiber infrared heating lamps were installed at 100 cm above the bed. 1 lamp at central (control), 60 cm interval (2 lamps), and 40 cm interval (3 lamps) heating lamps were installed in each bed inside the greenhouse. All treatments, except the control, were set to keep the night air temperature at 20℃ after lighting the NCFIHL. The leaf temperature showed a tendency to increase fast as the install distance was narrow. The leaf length and leaf width tended to increase as the installation distance of the 700 W heating lamp was narrow. The compactness was high in 700 W heating lamp with 40 cm of installation distance. Therefore, in consideration of maintaining the set temperature at night, installing 700 W electric lamps at 40 cm was an efficient power and installation distance for watermelon grafted seedlings considering economic feasibility.
        4,000원
        9.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There is increasing demand for the development of a new material with high strength, high stiffness, and good electrical conductivity that can be used for high-voltage direct current cables. In this study, we develop aluminumbased composites containing C60 fullerenes, carbon nanotubes, or graphene using a powder metallurgical route and evaluate their strength, stiffness, coefficient of thermal expansion, and electrical conductivity. By optimizing the process conditions, a material with a tensile strength of 800 MPa, an elastic modulus of 90 GPa, and an electrical conductivity of 40% IACS is obtained, which may replace iron-core cables. Furthermore, by designing the type and volume fraction of the reinforcement, a material with a tensile strength of 380 MPa, elastic modulus of 80 GPa, and electrical conductivity of 54% IACS is obtained, which may compete with AA 6201 aluminum alloys for use in all-aluminum conductor cables.
        4,000원
        10.
        2018.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To produce carbon electrodes for use in perovskite solar cells, electrode samples are prepared by mixing various weight ratios of 35 nm nano carbon(NC) and 1 μm graphite flakes(GF), GF/(NC+GF) = 0, 0.5, 0.7, and 1, in chlorobenzene(CB) solvent with a ZrO2 binder. The carbon electrodes are fabricated as glass/FTO/carbon electrode devices for microstructure characterization using transmission electron microscopy, optical microscopy, and a field emission scanning electron microscopy. The electrical characterization is performed with a four-point probe and a multi tester. The microstructure characterization shows that an electrode with excellent attachment to the substrate and no surface cracks at weight ratios above 0.5. The electrical characterization results show that the sheet resistance is < 70 Ω/sq and the interface resistance is < 70 Ω at weight ratios of 0.5 and 0.7. Therefore, a carbon paste electrode with microstructure and electrical properties similar to those of commercial carbon electrodes is proposed with an appropriate mixing ratio of NC and GF containing a CB solvent and ZrO2.
        4,000원
        12.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In vivo assay of glucose detection was described using a skin tattoo film electrode (STF), and the probe was made from carbon nano tube paste modification film paper. Here in the square-wave stripping anodic working range obtained of 20-100 mgL-1 within an accumulation time of 0 seconds only in sea water electrolyte solutions of pH 7.0. The relative standard deviations of 50 mg glucose that were observed of 0.14 % (n=12), respectively, using optimum stripping accumulation of 30 sec, the low detection limit (S/N) was pegged at 15.8 mg/L. The developed results can be applied to the detect of in vivo skin sensing in real time. Which confirms the results are usable for in vitro or vivo diagnostic clinical analysis.
        4,000원
        13.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated to the heat transfer performance of coating nano-structure with various shapes and patterns on the heat transfer surface. As a result of the measurement of the 3D nano shape, it was confirmed that the roughness generally increases when the adhesive is sprayed on the coating surface and finished durability experiment. In the case of TEOS adhesive, the roughness increased by 0.074 ㎛, 0.012 ㎛ and 0.015 ㎛, and the contact angle decreased 12.64°, 1.31°, 9.84° at the coating time of 120 seconds, 180 seconds and 240 seconds, respectively. In the case of PVA adhesive, the roughness increased by 0.069 ㎛, 0.056 ㎛ and 0.03 ㎛, and the contact angle decreased 2.85°, 4.82°, 6.96° at the coating time of 120 seconds, 180 seconds and 240 seconds, respectively. In the case of DGEBF adhesive, the roughness increased by 0.042 ㎛, 0.053 ㎛ and 0 ㎛, and the contact angle decreased 0.81° at the coating time of 120 seconds, increased 4.82°, 6.96° at the coating time of 180 seconds and 240 seconds, respectively. As a result, the durability tends to decrease as more nano-structures are deposited, and 3D nano shapes, contact angles and SEM photographs showed that the performance of the PVA adhesive was superior among the three adhesives.
        4,000원
        14.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        동절기에 공정육묘장에서 난방 에너지 절감과 우량묘 생산을 위해 나노탄소섬유적외선 난방등(NCFIHL, nanocarbon fiber infrared heating lamp)의 적정 전력과 설치 높이를 구명하는 것이 본 연구의 목적이다. 벤로형 유리 온실 내부에 수박 접목묘를 재배하기 위해 700과 900W NCFIHL을 육묘 베드(1.2 × 2.4m)에서 0.7, 1.0, 및 1.3m 높이로 각각 설치하였다. 수박(Citrullus lanatus (Thunb.) Manst.) ‘지존꿀’과 박(Lagenaria leucantha Rusby.) ‘선봉장’은 각각 접수와 대목으로 사용되었다. 접수와 대목은 편엽합접 방식으로 접목되었다. NCFIHL의 광도는 모든 처리에서 1μmol·m-2·s-1 이하였다. NCFIHL의 광분포는 대부분 적외선 영역에서 나타났다. 외기온도가 10oC 이하일 때 700과 900W NCFIHL을 0.7m 높이로 설치한 처리구와 900W NCFIHL을 1.0m 높이로 설치한 처리에서 야간 설정온도(20oC)를 유지하였다. 열화상 촬영에서는 900W NCFIHL을 0.7m 높이로 설치한 처리에서 가장 빨리 식물체의 온도가 올라갔다. Compactness는 700W NCFIHL을 1.3m 높이로 설치한 처리에서 우수하였다. 결과적으로 700W NCFIHL을 1.0m 이상으로 설치하는 것이 바람직하다고 판단된다.
        4,000원
        15.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tin is one of the most promising anode materials for next-generation lithium-ion batteries with a high energy density. However, the commercialization of tin-based anodes is still hindered due to the large volume change (over 260%) upon lithiation/delithiation cycling. To solve the problem, many efforts have been focused on enhancing structural stability of tin particles in electrodes. In this work, we synthesize tin nano-powders with an amorphous carbon layer on the surface and surroundings of the powder by electrical wire explosion in alcohol-based liquid media at room temperature. The morphology and microstructures of the powders are characterized by scanning electron microscopy, Xray diffraction, Raman spectroscopy, and transmission electron microscopy. The electrochemical properties of the powder for use as an anode material for lithium-ion battery are evaluated by cyclic voltammetry and a galvanometric dischargecharge method. It is shown that the carbon-coated tin nano-powders prepared in hexanol media exhibit a high initial charge specific capacity of 902 mAh/g and a high capacity retention of 89% after 50 cycles.
        4,000원
        16.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This review presents current progress in the preparation methods of liquid crystalline nanocarbon materials and the liquid crystalline spinning method for producing nano-carbon fibers. In particular, we focus on the fabrication of liquid crystalline carbon nanotubes by spinning from superacids, and the continuous production of macroscopic fiber from liquid crystalline graphene oxide.
        4,000원
        17.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        GNPs have several excellent mechanical properties including high strength, a good young’s modulus, thermal conductivity, corrosion resistance, electronic shielding, etc. In this study, CF/GNP/Epoxy composites were manufactured using GNP weight ratios of 0.15 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt% and 1 wt%. The composites were manufactured with a mechanical method (3-roll-mill). Tensile, impact and wear tests were performed according to ASTM standards D3039, D256 and D3181, respectively. The results show that the CF/GNP0.3wt%/Epoxy composites have good mechanical properties, e.g., tensile strength and impact and wear resistance. In this study, both carbon fabric and GNPs were used as reinforcements in the composites. The mechanical properties increased and weight loss decreased as the GNP content in the resin films was increased.
        4,000원
        18.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nano Pd spot-coated active carbon powders were synthesized by a hydrothermal-attachment method (HAA) using PVP capped Pd colloid in a high pressure bomb at , 450 psi, respectively. The PVP capped Pd colloid was synthesized by the precipitation-redispersion method. PVP capped Pd nano particles showed the narrow size distribution and their particle sizes were less than 8nm in diameter. In the case of nano Pd-spot coated active carbon powders, nano-sized Pd particles were adhered in the active carbon powder surface by HAA method. The component of Pd was homogeneously distributed on the active carbon surface.
        4,000원
        19.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This carbon nano heating system was consisted of power supply equipment, a carbon fiber and a stainless flexible hose. carbon nano heating system was manufactured by carbon fiber of a power capacity 30kw/h and light-oil hot air heater in control plot was the heating capacity 30,000kcal/h, As the result, Temperature difference due to carbon nano heating system and hot air heater in greenhouse showed that air temperature at experimental greenhouse, comparison greenhouse were 14.8℃, 13.4℃ respectively. It was found that carbon nano heating system and light-oil hot air heater heating cost were 1,095,740won, 2,683,628won. therefore as heating cost saving 60%. Yield of tomatoes cultured in greenhouse using carbon nano heating pipe was 4% inclease. Economic analysis comparison between the carbon nano heating pipe and the hot air heater in greenhouse were 41% respectively.
        4,000원
        20.
        2009.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to assess the removal efficiency of formaldehyde using carbon nano colloid (CNC) which was produced by comparatively easy and cheap method. In this study, carbon nano colloid based on water was produced by an electro‐chemical method. The particles which have mostly a spherical shape whose diameter was, what is called,‘nano‐size’were produced. Non‐woven fabric filter, which is currently on the market as a medium filter, was used for the removal efficiency test. Known concentration (0.5 ppm) of formaldehyde standard gas was used as a pollutant. The overall results indicate that (1) nanosize carbon colloids which have a stable dispersibility of which diameter is approximately 10 nm or less, (2) filters treated with carbon nano colloids showed higher removal efficiency, 44.47 ㎍ of HCHO removed/g of carbon and 19.28 ㎍ of HCHO removed/g of carbon, compared to the control experiment using a normal carbon filter, 1.45 ㎍ of HCHO removed/g of carbon.
        4,000원
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