Form-specific packing factor

To apply this equation, which is based on the evaluation of experimental data and valid in the range of Reynolds numbers Rey (200-20000), it is necessary to ascertain the geometric packing data a and s as well as the proportion of the perforated surface area of the packing wall (pp. This parameter is a form-specific packing factor, also known as form factor (pp. 

The form of the above equations suggests that the only properties of the bed on which the pressure gradient depends are its specific surface S (or particle size d) and its voidage e. However, the structure of the bed depends additionally on the particle size distribution, the particle shape and the way in which the bed has been formed in addition both the walls of the container and the nature of the bed support can considerably affect the way the particles pack. It would be expected, therefore, that experimentally determined values of pressure gradient would show a considerable scatter relative to the values predicted by the equations. The importance of some of these factors is discussed in the next section. 

Consider a mixture of two molecules A and B which are both approximately spherical in shape. As perfect spheres they can pack together in a face-centered cubic lattice to form a liquid with a coordination number c of 12 in each pure liquid. The mixture packs in the same way provided the molecular sizes are not too different, more specifically, provided the molecular volumes do not differ by more than a factor of two [4]. If the free volume between molecules in the mixture does not differ from the sum of those in the two pure liquids used to form the mixture, then the volume of mixing is effectively zero, and the interaction energy experienced by a given molecule in the mixture may be calculated by summing the contributions from nearest neighbors. Mixtures with these properties are strictly regular. 

Numerous geometrical factors of the specific interconnection will also influence anisotropic adhesive formulation and processing, including lead planarity, IC pad metallization, and IC test patterns. The planarity of the leads on the substrate and/or device and the compliance of the conductive particles will determine if anisotropically conductive adhesives can be used in a particular application. For systems with large disparities between lead height, no electrical interconnection will be formed, as shown in Fig. 5. Fine-pitch IC packages for surface-mounted applications, such as the plastic quad flat pack (PQFP), often use gullwing leads that olfer much compliance to the joint. Even if the... 

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