For example, for a 12'x25' single-car driveway with a 9 bed of gravel (in three layers), convert 9 to 0.75'; multiply 0.75 x 12 x 25, which equals 8.34 cubic yards, or roughly 10-14 tons. A 4 layer of gravel to resurface an existing 12'x25' driveway requires about 2.78 cubic yards or roughly 3.33-4.73 tons.
Diffusion [edit]. Diffusion of KMnO4 in water. Diffusion is the process of a substance spreading out to evenly fill its container or environment. In a solution, a concentrated solute diffuses to spread evenly in its solvent. In air, gas molecules diffuse to mix thoroughly. Substances diffuse from areas of high concentration to low concentration.
For the marketing term, see Diffusion of innovations. In probability theory, a branch of mathematics, a diffusion process is a solution to a stochastic differential equation. It is a continuous-time Markov process with almost surely continuous sample paths. Brownian motion, reflected Brownian motion and OrnsteinâUhlenbeck processes are examples of diffusion processes.