Form factor envelope

K )dP ( ) hI (s ) is the form factor envelop of the scattering, made from the form factor of ideal spheres and the attenuation term describing a smooth transition of the density at the phase boundary (cf. p. 124). 

The form factor is, in fact, an envelope, because it limits the visibility of the reflections Outside the... 

The distribution of drugs depends on both the physicochemical properties of the drug molecules and the composition of tissue membranes. These factors can either result in a uniform or uneven distribution of dmgs into the various body compartments and fluids. In the extreme, distribution may tend toward an accumulation of drugs in particular tissues or to an almost complete exclusion of the drag from a particular compartment in a defined length of time. One unique compartment that has to be considered in this respect is the brain, which is separated from the capillary system of the blood by the blood-brain barrier, whose membrane has a special structure. It consists of a cerebral capillary network formed by a capillary endothelium that consists of a cell layer with continuous compact intercellular junctions. It has no pores, but special cells, astrocytes, which support the stability of the tissues, are situated at the bases of the endothelial membrane separating the brain and CSF from the blood. The astrocytes form an envelope around the capillaries. 

The form factor is, in fact, an envelope, because it Umits the visibility of the reflections Outside the region where it has decayed to virtually 0, no scattering is observed. Sometimes the envelope is visible We see the spherical, the cylindrical or the layer shape of the fundamental domains in the oriented material. 

From (5.25) we may conclude that the total intensity of scattering of a crystal is a product of a sharp stmcmre factor and a smooth form-factor that is a series of sharp peaks with a smoothly decaying envelope The structure factor can be found from the experimental angular dependence of the scattering intensity. But what is the relation between structure factor 5(q) and density function ... 

Grover et al., Rachel,and others have examined the response of the electrical sensing zone method to blood cells and have proposed a "form factor" of 1 for an elongated object oriented along the axis of the aperture, 1.5 for a sphere, and 2.8 for a disc perpendicular to the flow. The analogy is that somehow the electrical path flows around a streamlined envelope, or outline, of the particle, thereby making the particle appear to be larger than it is. 

This approach implicitly considers that CB effect on modulus is essentially hydrod5mamic. The anisometry factor (or form factor) reflects the ratio large axis/small axis of a revolution ellipsoid, considered as the best envelope for an aggregate. When using/= 6, it is found that Equation 5.14 fit well experimental data with N330 CB up to <1>=0.3. Note that alternative equations have been proposed, for instance by Guth ... 

An analysis of the calculated values of AW shows that the damping factor in the indirect interaction is dr1, as exemplified in Fig. 8.8, for Cr and Ti substrates and 77 = 1.667. Envelope curves of the form ad x are shown, where a is chosen, so that the curve passes through the data point corresponding to d = 4. The fit to d 1 is seen to improve as d increases, agreeing with the asymptotic nature of the interaction law. 

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