The Experts below are selected from a list of 11577 Experts worldwide ranked by ideXlab platform
Xinghong Zhang - One of the best experts on this subject based on the ideXlab platform.
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in situ growth of core sheath heterostructural sic nanowire arrays on carbon fibers and enhanced electromagnetic wave Absorption Performance
ACS Applied Materials & Interfaces, 2017Co-Authors: Changqing Hong, Guangdong Zhao, Yehong Cheng, Shun Dong, Dongyang Zhang, Xinghong ZhangAbstract:Large-scale core–sheath heterostructural SiC nanowires were facilely grown on the surface of carbon fibers using a one-step chemical vapor infiltration process. The as-synthesized SiC nanowires consist of single crystalline SiC cores with a diameter of ∼30 nm and polycrystalline SiC sheaths with an average thickness of ∼60 nm. The formation mechanisms of core–sheath heterostructural SiC nanowires (SiCnws) were discussed in detail. The SiCnws-CF shows strong electromagnetic (EM) wave Absorption Performance with a maximum reflection loss value of −45.98 dB at 4.4 GHz. Moreover, being coated with conductive polymer polypyrrole (PPy) by a simple chemical polymerization method, the SiCnws-CF/PPy nanocomposites exhibited superior EM Absorption abilities with maximum RL value of −50.19 dB at 14.2 GHz and the effective bandwidth of 6.2 GHz. The SiCnws-CF/PPy nanocomposites in this study are very promising as absorber materials with strong electromagnetic wave Absorption Performance.
Changqing Hong - One of the best experts on this subject based on the ideXlab platform.
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in situ growth of core sheath heterostructural sic nanowire arrays on carbon fibers and enhanced electromagnetic wave Absorption Performance
ACS Applied Materials & Interfaces, 2017Co-Authors: Changqing Hong, Guangdong Zhao, Yehong Cheng, Shun Dong, Dongyang Zhang, Xinghong ZhangAbstract:Large-scale core–sheath heterostructural SiC nanowires were facilely grown on the surface of carbon fibers using a one-step chemical vapor infiltration process. The as-synthesized SiC nanowires consist of single crystalline SiC cores with a diameter of ∼30 nm and polycrystalline SiC sheaths with an average thickness of ∼60 nm. The formation mechanisms of core–sheath heterostructural SiC nanowires (SiCnws) were discussed in detail. The SiCnws-CF shows strong electromagnetic (EM) wave Absorption Performance with a maximum reflection loss value of −45.98 dB at 4.4 GHz. Moreover, being coated with conductive polymer polypyrrole (PPy) by a simple chemical polymerization method, the SiCnws-CF/PPy nanocomposites exhibited superior EM Absorption abilities with maximum RL value of −50.19 dB at 14.2 GHz and the effective bandwidth of 6.2 GHz. The SiCnws-CF/PPy nanocomposites in this study are very promising as absorber materials with strong electromagnetic wave Absorption Performance.
Yong Tae Kang - One of the best experts on this subject based on the ideXlab platform.
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CO2 Absorption Performance enhancement by dodecane nanoemulsion absorbents
Journal of CO 2 Utilization, 2019Co-Authors: Ronghuan Xu, Chang Kyoung Choi, Yong Tae KangAbstract:Abstract Among the CO2 capture technologies, the physical Absorption is one of the most common Absorption methods. However, the physical Absorption process is operated at extremely low temperature, and therefore huge freezing energy is required. The objective of this study is to develop the nanoemulsion absorbents that can be operated at room temperature. The nanoemulsion absorbents are prepared by the ultrasonication method. Based on the chemical properties, Span 60 and Tween 60 are added to maintain a good dispersion stability. CO2 Absorption experiments using a porous nozzle absorber are conducted for various dodecane concentration (0.005–0.5 vol%) and CO2 flow rate (0.06–0.12 g/s). It is found that the CO2 Absorption Performance of 0.05 vol% nanoemulsion absorbents is 10% higher than that of pure methanol. Through the single CO2 bubble Absorption visualization experiments, it is confirmed that the nanoemulsion absorbents cause faster bubble Absorption than pure methanol does. The turbidity index (Nephelometry turbidity unit) of nanoemulsion absorbents is kept constant for seven days, which means a good dispersion stability. The enhancement mechanism of CO2 Absorption is explained based on the Einstein-Stokes’ equation, cryogenic transmission electron images, and droplet size measurements. The key idea is that nano-sized dodecane (64 nm) absorbs the CO2 molecules and transports it to the bulk region by the Brownian diffusion. A random walk model is used to investigate the droplet size prediction and CO2 Absorption Performance enhancement.
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Evaluation of dispersion stability and Absorption Performance enhancement of binary nanoemulsion fluids
Transactions of The Korean Society of Mechanical Engineers B, 2012Co-Authors: Myung Chul Shin, Yong Tae KangAbstract:This paper aims to examine the effect of nanodroplets on pool-type Absorption heat transfer enhancement and to find the relationship between the dispersion stability and the Absorption Performance. The concentrations of oil and surfactant are considered as the key parameters. and Tween20 are used as the surfactants and N-decane oil is added to the solution to make the binary nanoemulsion fluids. Binary nanoemulsion fluids are dispersed by the ultrasonic vibrator and the stirrer under specific conditions. The dispersion stability of binary nanoemulsion fluids for each oil concentrations is evaluated from the droplet size and Tyndall effect analysis. The Absorption Performance of binary nanoemulsion fluids is compared with the result of dispersion stability. In addition, it is found that the binary nanoemulsion fluid is a strong candidate as a new working fluid for Absorption applications.
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Absorption Performance enhancement by nano particles and chemical surfactants in binary nanofluids
International Journal of Refrigeration-revue Internationale Du Froid, 2007Co-Authors: Junyoung Jung, Yong Tae KangAbstract:Abstract The objectives of this paper are to visualize the bubble behavior during the NH 3 /H 2 O Absorption process with chemical surfactant and nano-particles and to study the effect of nano-particles and surfactants on the Absorption characteristics. Binary nanofluid which means binary mixture with nano-sized particles is tested to apply nanofluid to the Absorption system. Cu, CuO and Al 2 O 3 nano-particles are added into NH 3 /H 2 O solution to make the binary nanofluids, and 2-ethyl-1-hexanol, n -octanol and 2-octanol are used as the surfactants. The concentration of ammonia in the basefluid, that of nano-particles in the nanofluid, and that of surfactants in the nanofluid are considered as the key parameters. The results show that the addition of surfactants and nano-particles improves the Absorption Performance up to 5.32 times. It can be concluded that the addition of both surfactants and nano-particles enhances significantly the Absorption Performance during the ammonia bubble Absorption process.
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The Effect of Binary Nanofluids and Chemical Surfactants on the Absorption Performance
2006Co-Authors: Junyoung Jung, Yong Tae KangAbstract:The objectives of this paper are to visualize the bubble behaviour in the ammonia/water Absorption and to study the effect of nanoparticles and surfactants on the Absorption characteristics. Binary nanofluid which means binary mixture with nano sized particles is tested to apply nanofluid to the Absorption system. Cu, CuO and Al2O3 nanoparticles are added to make the binary nanofluids into ammonia/water solution, and 2-ethyl-1-hexanol, noctanol and 2-octanol are used as the surfactants. The concentration of ammonia in the basefluid, that of nanoparticles in the nanofluid, and that of surfactants in the nanofluid are considered as the key parameters. The results show that the addition of surfactants and nanoparticles improves the Absorption Performance up to 5.32 times. It can be concluded that the addition of surfactants and the application of binary nanofluid enhance significantly the Absorption Performance during the ammonia bubble Absorption process.
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the effect of nano particles on the bubble Absorption Performance in a binary nanofluid
International Journal of Refrigeration-revue Internationale Du Froid, 2006Co-Authors: Junyoung Jung, Yong Tae KangAbstract:Abstract The objectives of this paper are to examine the effect of nano particles on the bubble type Absorption by experiment and to find the optimal conditions to design highly effective compact absorber for NH3/H2O Absorption system. The initial concentrations of NH3/H2O solution and the kinds and the concentrations of nano particles are considered as key parameters. The results show that the addition of nano particles enhances the Absorption Performance up to 3.21 times. Moreover, the Absorption rate increases with increasing concentration of nano particles and the nano particles are more effective for lower Absorption potential solution. The potential enhancement mechanism for binary nanofluid is suggested. The experimental correlations of the effective Absorption ratio for each nano particles, Cu, CuO, and Al2O3, are suggested within ±10% error-band.
Chuguang Zheng - One of the best experts on this subject based on the ideXlab platform.
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so2 Absorption Performance enhancement by ionic liquid supported on mesoporous molecular sieve
Energy & Fuels, 2015Co-Authors: Xiaoshan Li, Liqi Zhang, Ying Zheng, Chuguang ZhengAbstract:TMGL (tetramethylguanidinium lactate) is believed to be a potential medium for SO2 removal. However, direct use of TMGL in SO2 Absorption exhibits unsatisfactory Absorption rate and desorption Performance, mainly because of its hyperviscosity. In this work, mesoporous molecular sieve MCM-41 (mobil composition of matter no. 41) was employed as support material to prepare a novel absorbent (MCM-41-TMGL). The uptake of SO2 depends on TMGL, and the Absorption rate depends on the porous feature of MCM-41-TMGL. Results show that MCM-41-TMGL dramatically improved the Absorption kinetics and desorption efficiency, largely attributed to enhanced gas–liquid interface. Moreover, the absorbed SO2 in MCM-41-TMGL can be easily stripped out by heating at 90 °C under vacuum, allowing MCM-41-TMGL-10% to maintain 95% of the initial Absorption capacity after 10 cycles of regeneration. In addition, the Absorption Performance of MCM-41-TMGL was investigated under different conditions, including Absorption temperature, SO2 con...
Yehong Cheng - One of the best experts on this subject based on the ideXlab platform.
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in situ growth of core sheath heterostructural sic nanowire arrays on carbon fibers and enhanced electromagnetic wave Absorption Performance
ACS Applied Materials & Interfaces, 2017Co-Authors: Changqing Hong, Guangdong Zhao, Yehong Cheng, Shun Dong, Dongyang Zhang, Xinghong ZhangAbstract:Large-scale core–sheath heterostructural SiC nanowires were facilely grown on the surface of carbon fibers using a one-step chemical vapor infiltration process. The as-synthesized SiC nanowires consist of single crystalline SiC cores with a diameter of ∼30 nm and polycrystalline SiC sheaths with an average thickness of ∼60 nm. The formation mechanisms of core–sheath heterostructural SiC nanowires (SiCnws) were discussed in detail. The SiCnws-CF shows strong electromagnetic (EM) wave Absorption Performance with a maximum reflection loss value of −45.98 dB at 4.4 GHz. Moreover, being coated with conductive polymer polypyrrole (PPy) by a simple chemical polymerization method, the SiCnws-CF/PPy nanocomposites exhibited superior EM Absorption abilities with maximum RL value of −50.19 dB at 14.2 GHz and the effective bandwidth of 6.2 GHz. The SiCnws-CF/PPy nanocomposites in this study are very promising as absorber materials with strong electromagnetic wave Absorption Performance.
