enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Propagation of uncertainty - Wikipedia

    en.wikipedia.org/wiki/Propagation_of_uncertainty

    Any non-linear differentiable function, (,), of two variables, and , can be expanded as + +. If we take the variance on both sides and use the formula [11] for the variance of a linear combination of variables ⁡ (+) = ⁡ + ⁡ + ⁡ (,), then we obtain | | + | | +, where is the standard deviation of the function , is the standard deviation of , is the standard deviation of and = is the ...

  3. Equivalent concentration - Wikipedia

    en.wikipedia.org/wiki/Equivalent_concentration

    Here, ⁠ 1 / f eq ⁠ can have a fractional (non-integer) value. In precipitation reactions, the equivalence factor measures the number of ions which will precipitate in a given reaction. Here, ⁠ 1 / f eq ⁠ is an integer value. Normal concentration of an ionic solution is also related to conductivity (electrolytic) through the use of ...

  4. Darcy friction factor formulae - Wikipedia

    en.wikipedia.org/wiki/Darcy_friction_factor_formulae

    The Haaland equation was proposed in 1983 by Professor S.E. Haaland of the Norwegian Institute of Technology. [9] It is used to solve directly for the Darcy–Weisbach friction factor f for a full-flowing circular pipe. It is an approximation of the implicit Colebrook–White equation, but the discrepancy from experimental data is well within ...

  5. Davies equation - Wikipedia

    en.wikipedia.org/wiki/Davies_equation

    The Davies equation is an empirical extension of Debye–Hückel theory which can be used to calculate activity coefficients of electrolyte solutions at relatively high concentrations at 25 °C. The equation, originally published in 1938, [ 1 ] was refined by fitting to experimental data.

  6. Fanno flow - Wikipedia

    en.wikipedia.org/wiki/Fanno_flow

    The equation above can be used to plot the Fanno line, which represents a locus of states for given Fanno flow conditions on an H-ΔS diagram. In the diagram, the Fanno line reaches maximum entropy at H = 0.833 and the flow is choked. According to the Second law of thermodynamics, entropy must always increase for Fanno flow. This means that a ...

  7. Retardation factor - Wikipedia

    en.wikipedia.org/wiki/Retardation_factor

    An R F value will always be in the range 0 to 1; if the substance moves, it can only move in the direction of the solvent flow, and cannot move faster than the solvent. For example, if particular substance in an unknown mixture travels 2.5 cm and the solvent front travels 5.0 cm, the retardation factor would be 0.50.

  8. Logarithm - Wikipedia

    en.wikipedia.org/wiki/Logarithm

    Moving it appropriately, the area fits the graph of the function f(x) = 1/x again. Therefore, the left hand blue area, which is the integral of f(x) from t to tu is the same as the integral from 1 to u. This justifies the equality (2) with a more geometric proof. A visual proof of the product formula of the natural logarithm

  9. Mayo–Lewis equation - Wikipedia

    en.wikipedia.org/wiki/Mayo–Lewis_equation

    The Mayo–Lewis equation or copolymer equation in polymer chemistry describes the distribution of monomers in a copolymer.