Free surface area

FIG. 13 A schematic illustration of the effects of the free surface area of lipid bilayer membranes on the permeation of two permeants with the same molecular volume, but different cross-sectional areas, (a) A lower free surface area, (b) A higher free surface area. 

The flocculation rate dependency on the fractional surface coverage 0 in Equation (1) has been qualitatively confirmed (13, 14), although the maximum rate appears to occur for a surface coverage of less than 50%. The adsorption rate is also a function of 0, and it has been shown (15) for adsorption onto a smooth solid surface that the rate is proportional to the fraction of polymer-free surface area, 1-0. This approach has not... 

Figure 6 (Left) Schematic of a configuration of particles (black) with exclusion spheres (gray). (Right) The cross-hatched volume of available space that is formed upon removal of the particle is equal to that particle s free volume V. The surface area of the cavity is that particle s free surface area Sf. (Adapted from Ref. 71).

The calculation of free volumes and free surface areas requires an efficient way of extending the cavity algorithm. To calculate the free volume of a particle i, the particle and its associated exclusion sphere are effectively removed from a snapshot of the particle configuration. The volume and surface area of the cavity that is produced in the absence of particle i are equal to the free volume and free surface area of particle i, respectively. 

Similar to the definition of free volume, the mean free surface area per lipid molecule is related to the area occupied by one phospholipid molecule, A. A0(= 40.8 A) is the area of a phospholipid molecule in the crystal and o (= A0/A) is the reduced surface density. For the surface density data see ref. 5. 

The shape factor for a rubber block, for example a circular disk of diameter d and height h , is usually defined as the ratio of one bounded surface to the free surface area. Hence, one obtains with Eq. (50) ... 

L]s is defined as the available free surface area of the stationary phase. 

At equilibrium, the rate of adsorption of each component is equal to its rate of desorption. The rate of adsorption is proportional to the concentration and to the free surface area, Sq. The rate of desorption is proportional to the surface area occupied by the molecules of that component. For each of them, we have at equilibrium ... 

For an atom in the enzyme or the substrate to interact with the solvent it must be able to form Van der Waals contact with water molecules. The accessible surface area of an atom is defined as the area on the surface of a sphere, radius R on each point of which the centre of a solvent molecule can be placed in contact with the atom without penetrating any other atoms of the molecule (Fig. 12). R is the sum of the Van der Waals radii of the atom and solvent molecule [27]. There is a linear relationship between the solubility of hydrocarbons and the surface area of the cavity they form in water [28]. It has been estimated that the hydrophobicity of residues in proteins is 100 J/mole/A of accessible surface area [29]. The surface tension of water is 72 dynes/cm so to form a free surface area of water of 1 A costs 435 J/mole/A. The implication is that the free energy of cavity formation in water to receive the hydrophobic group is offset by favourable interactions (dispersion forces) between the solute and water. 

Double-layer capacitance The doublelayer capacitance has also been used as a measure of the free surface area [42]. 

Here, a is the film-free surface area fraction, iio( iP) is a certain function of the iron surface potential with the origin at equilibrium, and threshold potential. As follows from the definition of I lo, its sign must be reversed at the point (Figure 5, Curve 1). It is then obvious that I z a ... 

If the exposed free surface area around a crevice is large compared with the crevice area, the corrosion rate of stainless steel will be high when corrosion has first... 

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