Diffusion refers to the net spreading of the distribution of molecules due to random molecular motion. Think about an individual molecule in a gas, say some CO molecule coming out of a car's exhaust.

In this chapter the basic equation of molecular diffusion and simple applications are developed. The basic diffusion of matter, also called molecular diffusion, is described by Fick’s law, first stated by …

Diffusion describes the spread of particles (which can also be atoms, molecules) through random motion usually (but not always) from regions of higher concentration to regions of lower concentration. The …

Particles diffuse from regions of high concentration to low. There is NO external force. It is an entropic force, that arises because there is more entropy when the system is well mixed, i.e a uniform …

At each time step, update concentrations based on reactions of molecules within a voxel, and diffusion between neighboring voxels based on concentration differences (i.e., the diffusion equation)

Advection, diffusion and heat flow may be modeled using partial differential equations (PDEs). We describe some of the ideas and methods in an idealized one dimensional setting.

Diffusion – How do atoms move through solids? Diffusion is material transport by atomic motion. Inhomogeneous materials can become homogeneous by diffusion. For an active diffusion to occur, …