Modeling multiple anomalous diffusion behaviors on comb-like structures

2021 ◽  
Vol 148 ◽  
pp. 111009
Author(s):  
Zhaoyang Wang ◽  
Ping Lin ◽  
Erhui Wang
2015 ◽  
Vol 19 (4) ◽  
pp. 1177-1181
Author(s):  
Yan-Mei Qin ◽  
Hua Kong ◽  
Kai-Teng Wu ◽  
Xiao-Ming Zhu

Fractional calculus can always exactly describe anomalous diffusion. Recently the discrete fractional difference is becoming popular due to the depiction of non-linear evolution on discrete time domains. This paper proposes a diffusion model with two terms of discrete fractional order. The numerical simulation is given to reveal various diffusion behaviors.


2020 ◽  
Vol 4 (2) ◽  
pp. 28 ◽  
Author(s):  
Maike Antonio Faustino dos Santos

Nowadays, the stochastic resetting process is an attractive research topic in stochastic process. At the same time, a series of researches on stochastic diffusion in complex structures introduced ways to understand the anomalous diffusion in complex systems. In this work, we propose a non-static stochastic resetting model in the context of comb structure that consists of a structure formed by backbone in x axis and branches in y axis. Then, we find the exact analytical solutions for marginal distribution concerning x and y axis. Moreover, we show the time evolution behavior to mean square displacements (MSD) in both directions. As a consequence, the model revels that until the system reaches the equilibrium, i.e., constant MSD, there is a Brownian diffusion in y direction, i.e., ⟨ ( Δ y ) 2 ⟩ ∝ t , and a crossover between sub and ballistic diffusion behaviors in x direction, i.e., ⟨ ( Δ x ) 2 ⟩ ∝ t 1 2 and ⟨ ( Δ x ) 2 ⟩ ∝ t 2 respectively. For static stochastic resetting, the ballistic regime vanishes. Also, we consider the idealized model according to the memory kernels to investigate the exponential and tempered power-law memory kernels effects on diffusive behaviors. In this way, we expose a rich class of anomalous diffusion process with crossovers among them. The proposal and the techniques applied in this work are useful to describe random walkers with non-static stochastic resetting on comb structure.


1990 ◽  
Vol 51 (13) ◽  
pp. 1387-1402 ◽  
Author(s):  
A. Giacometti ◽  
A. Maritan

2012 ◽  
Vol 9 (2) ◽  
pp. 65-70
Author(s):  
E.V. Karachurina ◽  
S.Yu. Lukashchuk

An inverse coefficient problem is considered for time-fractional anomalous diffusion equations with the Riemann-Liouville and Caputo fractional derivatives. A numerical algorithm is proposed for identification of anomalous diffusivity which is considered as a function of concentration. The algorithm is based on transformation of inverse coefficient problem to extremum problem for the residual functional. The steepest descent method is used for numerical solving of this extremum problem. Necessary expressions for calculating gradient of residual functional are presented. The efficiency of the proposed algorithm is illustrated by several test examples.


2021 ◽  
Vol 52 (1) ◽  
pp. 1088-1090
Author(s):  
Jae Bum HAN ◽  
Young-Gil Park ◽  
Soo Im Jeong ◽  
Nari Ahn

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 587
Author(s):  
Lijuan Ni ◽  
Renxing Wang ◽  
Qingya Liu ◽  
Junfei Wu ◽  
Yue Pan ◽  
...  

To better understand the mass transfer behaviors in CaC2 production from CaO and coke, this paper studies the diffusion behaviors of CaO and graphite, with or without ash, at 1500 and 1700 °C. CaO and graphite are pressed into tablets and heated alone or in close contact. Physical and chemical changes in these tablets are analyzed by XRD and SEM+EDX. In some experiments, thin Mo wires are placed between the closely contacted CaO and graphite tablets to identify the diffusion direction. It is found that the diffusion between CaO and low-ash graphite is very limited. SiO2 in a high-ash graphite diffuses into CaO tablet and reacts with CaO to form Ca2SiO4, which then diffuses into the graphite tablet easily and leads to CaC2 formation at 1700 °C.


2021 ◽  
Vol 28 (8) ◽  
pp. 083703
Author(s):  
Biswajit Dutta ◽  
Pratikshya Bezbaruah ◽  
Nilakshi Das

2001 ◽  
Vol 280 (1-2) ◽  
pp. 97-103 ◽  
Author(s):  
V.B. Kokshenev ◽  
N.S. Sullivan

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