The Experts below are selected from a list of 136254 Experts worldwide ranked by ideXlab platform
Xianglin Cheng - One of the best experts on this subject based on the ideXlab platform.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.
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modified characteristics of mesophase pitch prepared from coal tar pitch by adding waste polystyrene
Fuel Processing Technology, 2008Co-Authors: Xianglin Cheng, Xuejun Li, Xiaojun YangAbstract:Abstract The toluene soluble of coal tar pitch was carbonized with waste polystyrene. The properties of mesophase pitches were characterized using polarized light optical microscope, apparent viscometer, FT-IR, 1 H NMR and X-ray diffractometer. After adding the waste polystyrene into the toluene soluble of coal tar pitch, the soluble mesophase were was increased from about 9% to 52% and the mesophase pitches were changed from 74% with coarse mosaic texture to 100% with Flow Domain texture. The mesophase pitches were transformed from thixotropy to unthixotropy. By waste polystyrene added into the toluene soluble of coal tar pitch, the methylene group was increased a lot. The presence of more alkyl groups modified the characteristics of mesophase pitches and improved the assembly of mesophase pitch molecules.
Xiaojun Yang - One of the best experts on this subject based on the ideXlab platform.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.
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modified characteristics of mesophase pitch prepared from coal tar pitch by adding waste polystyrene
Fuel Processing Technology, 2008Co-Authors: Xianglin Cheng, Xuejun Li, Xiaojun YangAbstract:Abstract The toluene soluble of coal tar pitch was carbonized with waste polystyrene. The properties of mesophase pitches were characterized using polarized light optical microscope, apparent viscometer, FT-IR, 1 H NMR and X-ray diffractometer. After adding the waste polystyrene into the toluene soluble of coal tar pitch, the soluble mesophase were was increased from about 9% to 52% and the mesophase pitches were changed from 74% with coarse mosaic texture to 100% with Flow Domain texture. The mesophase pitches were transformed from thixotropy to unthixotropy. By waste polystyrene added into the toluene soluble of coal tar pitch, the methylene group was increased a lot. The presence of more alkyl groups modified the characteristics of mesophase pitches and improved the assembly of mesophase pitch molecules.
Rainer Helmig - One of the best experts on this subject based on the ideXlab platform.
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coupling staggered grid and mpfa finite volume methods for free Flow porous medium Flow problems
Journal of Computational Physics, 2020Co-Authors: Martin Schneider, Kilian Weishaupt, Dennis Glaser, Wietse M Boon, Rainer HelmigAbstract:Abstract A discretization is proposed for models coupling free Flow with anisotropic porous-medium Flow. Our approach employs a staggered-grid finite volume method for the Navier-Stokes equations in the free-Flow subDomain and a MPFA finite volume method to solve Darcy Flow in the porous medium. After appropriate spatial refinement in the free-Flow Domain, the degrees of freedom are conveniently located to allow for a natural coupling of the two discretization schemes. In turn, we automatically obtain a more accurate description of the Flow field surrounding the porous medium. Numerical experiments highlight the stability and applicability of the scheme in the presence of anisotropy and second-order grid convergence was found in both Domains, verifying our approach.
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multirate time integration for coupled saturated unsaturated porous medium and free Flow systems
Computational Geosciences, 2015Co-Authors: Iryna Rybak, Rainer Helmig, Jim Magiera, Christian RohdeAbstract:A model formulation to describe fluid Flows in coupled saturated/unsaturated porous medium and adjacent free Flow regions is proposed. The Stokes equations are applied in the free Flow Domain, while the Richards equation is used to model the porous medium system. These two Flow problems are coupled at the fluid-porous interface via an appropriate set of interface conditions. A multiple-time-step scheme is developed to solve the coupled problem efficiently. Numerical simulation results are presented for a model problem and a realistic setting that demonstrate the convergence and efficiency of the proposed computational algorithm. Time-splitting multistep methods can be successfully applied for modeling other physical systems where the processes evolve on different time scales, and these potential extensions are discussed.
Wanjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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can complementary preferential Flow and non preferential Flow Domains contribute to soil water supply for rubber plantation
Forest Ecology and Management, 2020Co-Authors: Xiaojin Jiang, Sissou Zakari, Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun ZhangAbstract:Abstract Preferential Flow has always been hotspot of research regarding soil water Flow, biological activity, and carbon and nitrogen dynamics. However, the mechanism of water Flow exchange between two adjacent zones (with and without root system) and the pattern of soil water supply for rubber are still unclear. In the present study, we considered two plots experiencing similar farming history: in the first plot we measured soil physical properties and soil volumetric water content (VWC) during rainfall, and the second plot was used to visualise water Flow path and to measure root biomass. Besides, a model was developed on preferential Flow Domain (PFD, matching the root zone) and on non-preferential Flow Domain (NPFD, matching the remote root zone) to compute differences in soil properties between the PFD and NPFD. The results revealed that the dominant Flow type in the PFD was preferential Flow and the one in the NPFD was capillary Flow. Dye stained area and wetting front rate negatively correlated with bulk density, while they positively correlated to non-capillary porosity and root biomass. Accordingly, PFD showed a quick response to rainfall. Indeed, during the rain, a lateral Flow (driven by water gravity and pressure head gradient) predominantly carried water (0.95, 0.27, and 0.44 cm3 cm−3 for various rainfall events 1, 2, and 3, respectively) from PFD to NPFD. During the soil drainage stage, the lateral Flow direction changed, and water (about 0.63, 0.30, and 0.39 cm3 cm−3 for rainfall events 1, 2, and 3, respectively) Flowed from NPFD to PFD. As a result, PFD presented low storage and high Flow characteristics compared with NPFD, suggesting this complementary relationship for water interaction between the two Domains could be beneficial for rubber plants growth and development.
Jingtao Zhong - One of the best experts on this subject based on the ideXlab platform.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.
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needle coke formation derived from co carbonization of ethylene tar pitch and polystyrene
Fuel, 2009Co-Authors: Xianglin Cheng, Jingtao Zhong, Xiaojun YangAbstract:Abstract Ethylene tar pitch was co-carbonized with waste polystyrene to prepare needle coke. The modified properties of mesophase, which were greatly improved due to increasing naphthenic and other alkyl content, availed the formation of needle coke with high quality. The coefficient of thermal expansion value was decreased from 3.2 × 10−6/°C to 0.3 × 10−6/°C and the optical texture of the coke was changed from coarse mosaic texture to Flow Domain of high uniaxial orientation after adding waste polystyrene into ethylene tar pitch. The low viscosity of the mesophase pitches favored the development of mesophase and highly uniaxial arrangement. The increase in alkyl group content greatly improved characteristics of the needle coke.