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'drop') is one of the most common methods for measuring surface tension. The principle is to measure the weight of drops of a fluid of interest falling from a capillary glass tube, and thereby calculate the surface tension of the fluid. We can determine the weight of the falling drops by counting them.
The formula represents the liquid-drop model proposed by George Gamow, [1] which can account for most of the terms in the formula and gives rough estimates for the values of the coefficients. It was first formulated in 1935 by German physicist Carl Friedrich von Weizsäcker , [ 2 ] and although refinements have been made to the coefficients ...
Chilton–Colburn J-factor analogy (also known as the modified Reynolds analogy [1]) is a successful and widely used analogy between heat, momentum, and mass transfer.The basic mechanisms and mathematics of heat, mass, and momentum transport are essentially the same.
The response factor can be expressed on a molar, volume or mass [1] basis. Where the true amount of sample and standard are equal: = where A is the signal (e.g. peak area) and the subscript i indicates the sample and the subscript st indicates the standard. [2]
The first general metric for green chemistry remains one of the most flexible and popular ones. Roger A. Sheldon’s environmental factor (E-factor) can be made as complex and thorough or as simple as desired and useful. [10] The E-factor of a process is the ratio of the mass of waste per mass of product:
This value is generally used to measure the effectiveness factor of pellets. The Thiele modulus is represented by different symbols in different texts, but is defined in Hill [ 2 ] as h T . h T 2 = reaction rate diffusion rate {\displaystyle h_{T}^{2}={\dfrac {\mbox{reaction rate}}{\mbox{diffusion rate}}}}
The symmetry factor and the charge transfer coefficient are dimensionless. [1] According to an IUPAC definition, [2] for a reaction with a single rate-determining step, the charge transfer coefficient for a cathodic reaction (the cathodic transfer coefficient, α c) is defined as:
The Scherrer equation, in X-ray diffraction and crystallography, is a formula that relates the size of sub-micrometre crystallites in a solid to the broadening of a peak in a diffraction pattern. It is often referred to, incorrectly, as a formula for particle size measurement or analysis. It is named after Paul Scherrer.