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  2. Deal–Grove model - Wikipedia

    en.wikipedia.org/wiki/Deal–Grove_model

    Taking the short and long time limits of the above equation reveals two main modes of operation. The first mode, where the growth is linear, occurs initially when + is small. The second mode gives a quadratic growth and occurs when the oxide thickens as the oxidation time increases.

  3. Langevin equation - Wikipedia

    en.wikipedia.org/wiki/Langevin_equation

    In physics, a Langevin equation (named after Paul Langevin) is a stochastic differential equation describing how a system evolves when subjected to a combination of deterministic and fluctuating ("random") forces. The dependent variables in a Langevin equation typically are collective (macroscopic) variables changing only slowly in comparison ...

  4. Vlasov equation - Wikipedia

    en.wikipedia.org/wiki/Vlasov_equation

    In plasma physics, the Vlasov equation is a differential equation describing time evolution of the distribution function of collisionless plasma consisting of charged particles with long-range interaction, such as the Coulomb interaction.

  5. Fick's laws of diffusion - Wikipedia

    en.wikipedia.org/wiki/Fick's_laws_of_diffusion

    In the ultrashort time limit, in the order of the diffusion time a 2 /D, where a is the particle radius, the diffusion is described by the Langevin equation. At a longer time, the Langevin equation merges into the Stokes–Einstein equation. The latter is appropriate for the condition of the diluted solution, where long-range diffusion is ...

  6. Doubling time - Wikipedia

    en.wikipedia.org/wiki/Doubling_time

    For example, with an annual growth rate of 4.8% the doubling time is 14.78 years, and a doubling time of 10 years corresponds to a growth rate between 7% and 7.5% (actually about 7.18%). When applied to the constant growth in consumption of a resource, the total amount consumed in one doubling period equals the total amount consumed in all ...

  7. Method of averaging - Wikipedia

    en.wikipedia.org/wiki/Method_of_averaging

    It turns out to be a customary problem where there exists the trade off between how good is the approximated solution balanced by how much time it holds to be close to the original solution. More precisely, the system has the following form x ˙ = ε f ( x , t , ε ) , 0 ≤ ε ≪ 1 {\displaystyle {\dot {x}}=\varepsilon f(x,t,\varepsilon ...

  8. Half-life - Wikipedia

    en.wikipedia.org/wiki/Half-life

    Half-life (symbol t ½) is the time required for a quantity (of substance) to reduce to half of its initial value.The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.

  9. Logistic map - Wikipedia

    en.wikipedia.org/wiki/Logistic_map

    However, equation (3-11) is a 16th-order equation, and even if we factor out the four solutions for the fixed points and the 2-periodic points, it is still a 12th-order equation . Therefore, it is no longer possible to solve this equation to obtain an explicit function of a that represents the values of the 4-periodic points in the same way as ...