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This paper explores the phenomena of enhanced dissipation and Taylor dispersion in solutions to the passive scalar equations subject to time-dependent shear flows. The hypocoercivity functionals with carefully tuned time weights are applied…

Analysis of PDEs · Mathematics 2023-09-29 Daniel Coble , Siming He

We introduce Adjoint Sampling, a highly scalable and efficient algorithm for learning diffusion processes that sample from unnormalized densities, or energy functions. It is the first on-policy approach that allows significantly more…

Taylor dispersion analysis is an increasingly popular characterization method that measures the diffusion coefficient, and hence the hydrodynamic radius, of (bio)polymers, nanoparticles or even small molecules. In this work, we describe an…

Soft Condensed Matter · Physics 2014-08-27 Luca Cipelletti , Jean-Philippe Biron , Michel Martin , Hervé Cottet

Structured environment controls dynamics of light-matter interaction processes via modified local density of electromagnetic states. In typical scenarios, where nanosecond-scale fluorescent processes are involved, mechanical conformational…

Hypothesis:Diffusion in confinement is an important fundamental problem with significant implications for applications of supported liquid phases. However, resolving the spatially dependent diffusion coefficient, parallel and perpendicular…

We present a new splitting method for time-dependent convection-dominated diffusion problems. The original convection diffusion system is split into two sub-systems: a pure convection system and a diffusion system. At each time step, a…

Mathematical Physics · Physics 2013-02-19 Feng Shi , Guoping Liang , Yubo Zhao , Jun Zou

The dispersion of solute in porous media shows a non-linear increase in the transition from diffusion to advection dominated dispersion as the flow velocity is raised. In the past, the behavior in this intermediate regime has been explained…

Fluid Dynamics · Physics 2014-09-23 B. Ph. van Milligen , P. D. Bons

The transport of an infinitely thin, hard rod in a random, dense array of point obstacles is investigated by molecular dynamics simulations. Our model mimics the sterically hindered dynamics in dense needle liquids. The center-of-mass…

Statistical Mechanics · Physics 2008-09-22 Felix Höfling , Erwin Frey , Thomas Franosch

Diffusion of a solute along a channel is enhanced by hydrodynamic flow, a phenomenon known as Taylor dispersion. In microfluidic applications, the compliance of the channel boundaries modifies the hydrodynamic flow and thus solutal…

Soft Condensed Matter · Physics 2026-04-08 Aditya Jha , Masoodah Gunny , Joshua D Mcgraw , Yacine Amarouchene , Thomas Salez

In many physical systems, degrees of freedom are coupled \emph{via} hydrodynamic forces, even in the absence of Hamiltonian interactions. A particularly important and widespread example concerns the transport of microscopic particles in…

Soft Condensed Matter · Physics 2025-02-11 Juliette Lacherez , Maxime Lavaud , Yacine Amarouchene , David S. Dean , Thomas Salez

Diffusion models have achieved remarkable success across various domains. However, their slow generation speed remains a critical challenge. Existing acceleration methods, while aiming to reduce steps, often compromise sample quality,…

Machine Learning · Computer Science 2025-03-26 Huiyang Shao , Xin Xia , Yuhong Yang , Yuxi Ren , Xing Wang , Xuefeng Xiao

Spreading of bacteria in a highly advective, disordered environment is examined. Predictions of super-diffusive spreading for a simplified reaction-diffusion equation are tested. Concentration profiles display anomalous growth and…

Biological Physics · Physics 2007-05-23 John H. Carpenter , Karin A. Dahmen

In this paper, based on a theoretical model [1], it has been shown experimentally that the initial stage of development of a nanosecond breakdown in liquids is associated with the appearance of discontinuities in the liquid (cavitation)…

Plasma Physics · Physics 2014-04-02 Mikhail Pekker , Yohan Seepersad , Mikhail Shneider , Alexander Fridman , Danil Dobrynin

Using multispeckle x-ray photon correlation spectroscopy, we have measured the slow, wave-vector dependent dynamics of concentrated, disordered nanoemulsions composed of silicone oil droplets in water. The intermediate scattering function…

Soft Condensed Matter · Physics 2007-05-23 H. Guo , J. N. Wilking , D. Liang , T. G. Mason , J. L. Harden , R. L. Leheny

While evaporating solvent is a widely used technique to assemble nano-sized objects into desired superstructures, there has been limited work on how the assembled structures are affected by the physical aspects of the process. We present…

Soft Condensed Matter · Physics 2013-11-20 Shengfeng Cheng , Gary S. Grest

Using molecular dynamics simulations, we show that free diffusion of a nanoscale particle (molecule) with asymmetric structure critically depends on the orientation in a finite timescale of picoseconds to nanoseconds. In a timescale of ~100…

Soft Condensed Matter · Physics 2013-07-29 Nan Sheng , Yusong Tu , Pan Guo , Rongzheng Wan , Haiping Fang

Of primary interest in this paper is the numerical approximation of a time dependent fractional, in space, diffusion equation where the domain is assumed to be nonhomogeneous, having different axial diffusion coefficients. This work is…

Numerical Analysis · Mathematics 2026-05-12 T. Catoe , V. J. Ervin

We study the effect of a single driven tracer particle in a bath of other particles performing the random average process on an infinite line using a stochastic hydrodynamics approach. We consider arbitrary fixed as well as random initial…

Statistical Mechanics · Physics 2016-11-03 A. Kundu , J. Cividini

Subsurface flows are commonly modeled by advection-diffusion equations. Insufficient measurements or uncertain material procurement may be accounted for by random coefficients. To represent, for example, transitions in heterogeneous media,…

Numerical Analysis · Mathematics 2021-01-25 Andrea Barth , Andreas Stein

We performed a thorough investigation of the drying dynamics of a charged colloidal dispersion drop in a confined geometry. We developed an original methodology based on Raman micro-spectroscopy to measure spatially-resolved colloids…

Soft Condensed Matter · Physics 2016-12-13 Charles Loussert , Anne Bouchaudy , Jean-Baptiste Salmon