The Experts below are selected from a list of 150225 Experts worldwide ranked by ideXlab platform
Zhongzhi Zhang - One of the best experts on this subject based on the ideXlab platform.
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determining mean first passage time on a class of treelike regular Fractals
Physical Review E, 2010Co-Authors: Yuan Lin, Zhongzhi ZhangAbstract:Relatively general techniques for computing mean first-passage time (MFPT) of random walks on networks with a specific property are very useful since a universal method for calculating MFPT on general graphs is not available because of their complexity and diversity. In this paper, we present techniques for explicitly determining the partial mean first-passage time (PMFPT), i.e., the average of MFPTs to a given target averaged over all possible starting positions, and the entire mean first-passage time (EMFPT), which is the average of MFPTs over all pairs of nodes on regular treelike Fractals. We describe the processes with a family of regular Fractals with treelike structure. The proposed Fractals include the T Fractal and the Peano basin Fractal as their special cases. We provide a formula for MFPT between two directly connected nodes in general trees on the basis of which we derive an exact expression for PMFPT to the central node in the Fractals. Moreover, we give a technique for calculating EMFPT, which is based on the relationship between characteristic polynomials of the Fractals at different generations and avoids the computation of eigenvalues of the characteristic polynomials. Making use of the proposed methods, we obtain analytically the closed-form solutions to PMFPT and EMFPT on the Fractals and show how they scale with the number of nodes. In addition, to exhibit the generality of our methods, we also apply them to the Vicsek Fractals and the iterative scale-free Fractal tree and recover the results previously obtained.
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the exact solution of the mean geodesic distance for vicsek Fractals
Journal of Physics A, 2008Co-Authors: Zhongzhi Zhang, Shuigeng Zhou, Lichao Chen, Ming Yin, Jihong GuanAbstract:Vicsek Fractals are one of the most interesting classes of Fractals and the study of their structural properties is important. In this paper, the exact formula for the mean geodesic distance of Vicsek Fractals is found. The quantity is computed precisely through the recurrence relations derived from the self-similar structure of the Fractals considered. The obtained exact solution exhibits that the mean geodesic distance approximately increases as a power-law function of the number of nodes, with the exponent equal to the reciprocal of the Fractal dimension. The closed-form solution is confirmed by extensive numerical calculations.
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exact solution of mean geodesic distance for vicsek Fractals
arXiv: Disordered Systems and Neural Networks, 2008Co-Authors: Zhongzhi Zhang, Shuigeng Zhou, Lichao Chen, Ming Yin, Jihong GuanAbstract:The Vicsek Fractals are one of the most interesting classes of Fractals and the study of their structural properties is important. In this paper, the exact formula for the mean geodesic distance of Vicsek Fractals is found. The quantity is computed precisely through the recurrence relations derived from the self-similar structure of the Fractals considered. The obtained exact solution exhibits that the mean geodesic distance approximately increases as an exponential function of the number of nodes, with the exponent equal to the reciprocal of the Fractal dimension. The closed-form solution is confirmed by extensive numerical calculations.
Keka Ojha - One of the best experts on this subject based on the ideXlab platform.
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integrated Fractal description of nanopore structure and its effect on ch4 adsorption on jharia coals india
Fuel, 2018Co-Authors: Paul Naveen, Mohammad Asif, Keka OjhaAbstract:Abstract Internal pore surface heterogeneity and pore matrix irregularities have a decisive influence on the gas adsorption capacity and transportation in the coalbed methane (CBM) reservoir. This study integrates novel idea of relating the multiple approaches to customize the obtained results from analytical techniques to attain efficient elucidation and quantification of pore features and its influence on gas storage and transport in CBM reservoirs. Fractal profiles are analyzed to evolve Fractal dimensions from LPA-N2 and imaging techniques for surface Fractals and matrix Fractals. Measured results of Fractal dimension depict surface texture, complexity and heterogeneity of pore structure, thereby its relationship with CH4 adsorption are investigated. A 3D model of pore structure and connectivity are reconstructed to quantify the porous regions using 2D FE-SEM data and 3D tomographic interface-Amira software. In contrast to the conventional surface Fractal approaches, this technique helps to illustrate pore structure and provides realistic pore connectivity. Study analysis reveals that the pores with higher surface Fractal dimension, i.e. (DS > 2.65) have possibly large amount of adsorption sites, where adsorption of gases becomes easier than desorption due to surface roughness. However, the higher matrix Fractal dimension results in a more complex pore microstructure in contrary to that of surface Fractal dimension, which directly effects the adsorption mechanism causing pore filling adsorption and the adsorption capacity decreases because of relatively higher liquid/gas surface tension.
Jihong Guan - One of the best experts on this subject based on the ideXlab platform.
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the exact solution of the mean geodesic distance for vicsek Fractals
Journal of Physics A, 2008Co-Authors: Zhongzhi Zhang, Shuigeng Zhou, Lichao Chen, Ming Yin, Jihong GuanAbstract:Vicsek Fractals are one of the most interesting classes of Fractals and the study of their structural properties is important. In this paper, the exact formula for the mean geodesic distance of Vicsek Fractals is found. The quantity is computed precisely through the recurrence relations derived from the self-similar structure of the Fractals considered. The obtained exact solution exhibits that the mean geodesic distance approximately increases as a power-law function of the number of nodes, with the exponent equal to the reciprocal of the Fractal dimension. The closed-form solution is confirmed by extensive numerical calculations.
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exact solution of mean geodesic distance for vicsek Fractals
arXiv: Disordered Systems and Neural Networks, 2008Co-Authors: Zhongzhi Zhang, Shuigeng Zhou, Lichao Chen, Ming Yin, Jihong GuanAbstract:The Vicsek Fractals are one of the most interesting classes of Fractals and the study of their structural properties is important. In this paper, the exact formula for the mean geodesic distance of Vicsek Fractals is found. The quantity is computed precisely through the recurrence relations derived from the self-similar structure of the Fractals considered. The obtained exact solution exhibits that the mean geodesic distance approximately increases as an exponential function of the number of nodes, with the exponent equal to the reciprocal of the Fractal dimension. The closed-form solution is confirmed by extensive numerical calculations.
Paul Naveen - One of the best experts on this subject based on the ideXlab platform.
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integrated Fractal description of nanopore structure and its effect on ch4 adsorption on jharia coals india
Fuel, 2018Co-Authors: Paul Naveen, Mohammad Asif, Keka OjhaAbstract:Abstract Internal pore surface heterogeneity and pore matrix irregularities have a decisive influence on the gas adsorption capacity and transportation in the coalbed methane (CBM) reservoir. This study integrates novel idea of relating the multiple approaches to customize the obtained results from analytical techniques to attain efficient elucidation and quantification of pore features and its influence on gas storage and transport in CBM reservoirs. Fractal profiles are analyzed to evolve Fractal dimensions from LPA-N2 and imaging techniques for surface Fractals and matrix Fractals. Measured results of Fractal dimension depict surface texture, complexity and heterogeneity of pore structure, thereby its relationship with CH4 adsorption are investigated. A 3D model of pore structure and connectivity are reconstructed to quantify the porous regions using 2D FE-SEM data and 3D tomographic interface-Amira software. In contrast to the conventional surface Fractal approaches, this technique helps to illustrate pore structure and provides realistic pore connectivity. Study analysis reveals that the pores with higher surface Fractal dimension, i.e. (DS > 2.65) have possibly large amount of adsorption sites, where adsorption of gases becomes easier than desorption due to surface roughness. However, the higher matrix Fractal dimension results in a more complex pore microstructure in contrary to that of surface Fractal dimension, which directly effects the adsorption mechanism causing pore filling adsorption and the adsorption capacity decreases because of relatively higher liquid/gas surface tension.
Wenhui Huang - One of the best experts on this subject based on the ideXlab platform.
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Fractal characterization of adsorption pores of coals from north china an investigation on ch4 adsorption capacity of coals
International Journal of Coal Geology, 2008Co-Authors: Dazhen Tang, Shuheng Tang, Wenhui HuangAbstract:To better understand the characteristics of adsorption-pores (pore diameter <100 nanometers) and their influence on CH 4 adsorption capacity of coals, we have conducted Fractal analysis for 13 fresh coal samples (R o from 0.79 to 4.24%) in North China. Isotherms of N 2 gas adsorption/desorption analyses indicate that coals have different adsorption characteristics at relative pressure of 0-0.5 and 0.5-1. On this basis, two Fractal dimensions D 1 and D 2 (at relative pressure of 0-0.5 and 0.5-1, respectively) were obtained using the Fractal Frenkel-Halsey-Hill (FHH) method, in which both proposed Fractal exponents, '(Z)-3)/3' and '(D-3)' were investigated. The results show that the Fractal exponent '(Z)-3)' provides more realistic results than Fractal dimensions calculated from (D-3)/3. The two Fractal dimensions, D 1 and D 2 , have different correlations with CH 4 adsorption capacity of coals. The CH 4 adsorption capacity does not vary with increasing Fractal dimension D 1 up to about 2.5, but thereafter increases with D 1 In contrast, the CH 4 adsorption capacity varies negatively with D 2 within the entire data range. Further investigation indicates that D 1 represents Fractals from pore surface area generated by surface irregularity of coals, while D 2 characterizes Fractals related to pore structures that are controlled by the composition (e.g., ash, moisture, carbon) and pore parameter (e.g., pore diameter, micropores content) of coals. Higher Fractal dimension D 1 correlates to more irregular surfaces that provide more space for CH 4 adsorption. Higher Fractal dimension D 2 represents higher heterogeneity of pore structure and higher liquid/gas surface tension that reduce CH 4 adsorption capacity. Therefore, more irregular coal surface and more homogeneous pore structure indicate higher CH 4 adsorption capacity of coals.
