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In fully-developed pressure-driven flow, the spreading of a dissolved solute is enhanced in the flow direction due to transverse velocity variations in a phenomenon now commonly referred to as Taylor-Aris dispersion. It is well understood…

Fluid Dynamics · Physics 2022-10-04 Garam Lee , Alan Luner , Jeremy Marzuola , Daniel M. Harris

In this work we investigate the effect of density dependent nonlinear diffusion on pattern formation in the Brusselator system. Through linear stability analysis of the basic solution we determine the Turing and the oscillatory instability…

Mathematical Physics · Physics 2015-06-17 G. Gambino , M. C. Lombardo , M. Sammartino , V. Sciacca

We analyze the influence of boundary conditions on numerical simulations of the diffusive properties of a two dimensional granular gas. We show in particular that periodic boundary conditions introduce unphysical correlations in time which…

Statistical Mechanics · Physics 2009-10-31 C. Henrique , G. Batrouni , D. Bideau

Diffusion on a quenched heterogeneous environment in the presence of bias is considered analytically. The first-passage-time statistics can be applied to obtain the drift and the diffusion coefficient in periodic quenched environments. We…

Statistical Mechanics · Physics 2020-05-06 Takuma Akimoto , Keiji Saito

We study the Brownian motion of a classical particle in one-dimensional inhomogeneous environments where the transition probabilities follow quasiperiodic or aperiodic distributions. Exploiting an exact correspondence with the…

Statistical Mechanics · Physics 2009-10-31 F. Igloi , L. Turban , H. Rieger

We study the role of ambipolar diffusion (AD) on the non-linear evolution of the MRI in protoplanetary disks using the strong coupling limit, which applies when the electron recombination time is much shorter than the orbital time. The…

Earth and Planetary Astrophysics · Physics 2015-05-27 Xue-Ning Bai , James M. Stone

A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given…

Optics · Physics 2007-05-23 T. A. Bobrova , L. I. Ognev

The onset of the Rayleigh-Benard instability in a horizontal fluid layer is investigated by assuming the fluid as a binary mixture and the concentration buoyancy as the driving force. The focus of this study is on the anomalous diffusion…

Fluid Dynamics · Physics 2024-06-18 A. Barletta , B. Straughan

To take advantage of high-resolution optics sensitive to a broad energy range, future X-ray imaging instruments will require thick detectors with small pixels. This pixel aspect ratio affects spectral response in the soft X-ray band, vital…

Linear diffusion processes serve as canonical continuous-time models for dynamic decision-making under uncertainty. These systems evolve according to drift matrices that specify the instantaneous rates of change in the expected system…

Machine Learning · Computer Science 2025-06-10 Mohamad Kazem Shirani Faradonbeh , Sadegh Shirani , Mohsen Bayati

Exciton diffusion length plays a vital role in the function of opto-electronic devices. Oftentimes, the domain occupied by an organic semiconductor is subject to surface measurement error. In many experiments, photoluminescence over the…

Numerical Analysis · Mathematics 2017-12-15 Jingrun Chen , Ling Lin , Zhiwen Zhang , Xiang Zhou

Water diffusion MRI is a very powerful tool for probing tissue microstructure, but disentangling the contribution of compartment-specific structural disorder from cellular restriction and inter-compartment exchange remains an open…

Medical Physics · Physics 2024-02-09 Eloïse Mougel , Julien Valette , Marco Palombo

Anomalous diffusion occurs at very different scales in nature, from atomic systems to motions in cell organelles, biological tissues or ecology, and also in artificial materials, such as cement. Being able to accurately measure the…

Machine Learning · Computer Science 2021-08-09 Òscar Garibo i Orts , Miguel A. Garcia-March , J. Alberto Conejero

Structured x-rays carrying an orbital angular momentum break spatial inversion symmetry and have been proposed as a means to probe chirality. We theoretically investigate twisted non-resonant x-ray diffraction from chiral molecules and…

Optics · Physics 2026-03-02 Akilesh Venkatesh , Phay J. Ho , Jérémy R. Rouxel

We report on an experimental investigation of the tumbling of microrods in the shear flow of a microchannel (40 x 2.5 x 0.4 mm). The rods are 20 to 30 microns long and their diameters are of the order of 1 micron. Images of the…

Fluid Dynamics · Physics 2013-10-30 J. Einarsson , A. Johansson , S. K. Mahato , Y. Mishra , J. R. Angilella , D. Hanstorp , B. Mehlig

Context. High-precision pulsar-timing experiments are affected by temporal variations of the Dispersion Measure (DM), which are related to spatial variations in the interstellar electron content. Correcting for DM variations relies on the…

Anomalous diffusion is frequently described by scaled Brownian motion (SBM), a Gaussian process with a power-law time dependent diffusion coefficient. Its mean squared displacement is $\langle x^2(t)\rangle\simeq\mathscr{K}(t)t$ with…

Statistical Mechanics · Physics 2014-12-24 J. -H. Jeon , A. V. Chechkin , R. Metzler

Dispersion relations govern wave behaviors, and tailoring them is a grand challenge in wave manipulation. We demonstrate inverse design of phononic dispersion using non-local interactions on one-dimensional spring-mass chains. For both…

Materials Science · Physics 2023-11-01 Arash Kazemi , Kshiteej J. Deshmukh , Fei Chen , Yunya Liu , Bolei Deng , Henry Chien Fu , Pai Wang

We analytically and numerically study the temporal intensity pattern emerging from the linear or nonlinear evolutions of a single or double phase jump in an optical fiber. The results are interpreted in terms of interferences of the…

Optics · Physics 2020-07-07 Anastasiia Sheveleva , Christophe Finot

Motivated by recent experiments, the theoretical study of wave propagation in time varying materials is of current interest. Although significant in nearly all such experiments, material dispersion is commonly neglected in theoretical…

Optics · Physics 2025-11-25 Bryce Dixon , Calvin M. Hooper , Ian R. Hooper , Simon A. R. Horsley