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Modeling the mobility with memory1
by Jeehye Choi, Jang-Il Sohn, K.-I. Goh & I.-M. Kim
“We study a random walk model in which the jumping probability to a site is dependent on the number of previous visits to the site, as a model of the mobility with memory. To this end we introduce two parameters called the memory parameter α and the impulse parameter p. From extensive numerical simulations, we found that various limited mobility patterns such as sub-diffusion, trapping, and logarithmic diffusion could be observed. Through memory, a long-ranged directional anticorrelation kinetically induces sub-diffusive and trapping behaviors, and transition between them. With random jumps by the impulse parameter, a trapped walker can escape from the trap very slowly, resulting in an ultraslow logarithmic diffusive behavior. Our results suggest that the memory of walker’s has-beens can be one mechanism explaining many of the empirical characteristics of the mobility of animated objects…”
Electrical breakdown and volt-ampere characteristics in water vapor in microgaps2
by M. Klas, Š. Matejčik, M. Radmilović-Radjenović and B. Radjenović
“Although the physics for breakdown initiation in gases in generally well understood, the process of breakdown initiation in liquids is much less clear. A large number of experimental data on the breakdown in water revealed that the breakdown voltage in water is of the same magnitude as in the case of gases. This means that the breakdown in liquids can occur not at the extremely high electric fields required by the Paschen curve, but at those that only slightly exceed the breakdown electric fields in atmospheric-pressure molecular gases. This letter contains the results of experimental study on electrical breakdown characteristics in water vapor in microgaps between two parallel electrodes. Measurements were performed for the pressures of 24.15 torr, 20.85 torr and 14.55 torr with the gap size ranging from 40 μm to 900 μm. Considering that the atmospheric pressure sources operate in ambient air which unavoidably contains water vapor it is of great importance to investigate the basic processes and properties of discharges in water vapour…”
Soft deformable self-propelled particles3
by A. M. Menzel and T. Ohta
“In this work we investigate the collective behavior of self-propelled particles that deform due to local pairwise interactions. We demonstrate that this deformation alone can induce alignment of the velocity vectors. The onset of collective motion is analyzed. Applying a Gaussian-core repulsion between the particles, we find a transition to disordered non-collective motion under compression. We here explain that this reflects the reentrant fluid behavior of the general Gaussian-core model now applied to a self-propelled system. Truncating the Gaussian potential can lead to cluster crystallization or more disordered cluster states. For intermediate values of the Gaussian-core potential we observe for the first time laning for deformable self-propelled particles. Finally, without the core potential, but including orientational noise, we connect our description to the Vicsek approach for self-propelled particles with nematic alignment interactions…”
- Choi, Jeehye. (2012-09-04) Modeling the mobility with memory. EPL (Europhysics Letters), 99(5), 50001. DOI: 10.1209/0295-5075/99/50001 [↩]
- Klas, M. (2012-09-04) Electrical breakdown and volt-ampere characteristics in water vapor in microgaps. EPL (Europhysics Letters), 99(5), 57001. DOI: 10.1209/0295-5075/99/57001 [↩]
- Menzel, A. M. (2012-09-04) Soft deformable self-propelled particles. EPL (Europhysics Letters), 10(5), 10163. DOI: 10.1209/0295-5075/99/58001 [↩]
