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  2. Detection limit - Wikipedia

    en.wikipedia.org/wiki/Detection_limit

    The instrument detection limit (IDL) is the analyte concentration that is required to produce a signal greater than three times the standard deviation of the noise level. This may be practically measured by analyzing 8 or more standards at the estimated IDL then calculating the standard deviation from the measured concentrations of those standards.

  3. Fick's laws of diffusion - Wikipedia

    en.wikipedia.org/wiki/Fick's_laws_of_diffusion

    Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...

  4. Etendue - Wikipedia

    en.wikipedia.org/wiki/Etendue

    The limit on maximum concentration (shown) is an optic with an entrance aperture S, in air (n i = 1) collecting light within a solid angle of angle 2α (its acceptance angle) and sending it to a smaller area receiver Σ immersed in a medium of refractive index n, whose points are illuminated within a solid angle of angle 2β. From the above ...

  5. Mass diffusivity - Wikipedia

    en.wikipedia.org/wiki/Mass_diffusivity

    Diffusivity, mass diffusivity or diffusion coefficient is usually written as the proportionality constant between the molar flux due to molecular diffusion and the negative value of the gradient in the concentration of the species. More accurately, the diffusion coefficient times the local concentration is the proportionality constant between ...

  6. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.

  7. Standard deviation - Wikipedia

    en.wikipedia.org/wiki/Standard_deviation

    Particle physics conventionally uses a standard of "5 sigma" for the declaration of a discovery. A five-sigma level translates to one chance in 3.5 million that a ...

  8. Mean free path - Wikipedia

    en.wikipedia.org/wiki/Mean_free_path

    The typical number of stopping atoms in the slab is the concentration n times the volume, ... Calculate mean free path for mixtures of gases using VHS model

  9. Warburg coefficient - Wikipedia

    en.wikipedia.org/wiki/Warburg_coefficient

    C b is the concentration of the O and R species in the bulk; C is the concentration of the electrolyte; A denotes the surface area; Θ denotes the fraction of the O and R species present. The equation for A W applies to both reversible and quasi-reversible reactions for which both halves of the couple are soluble.