Cohesion effect

The effective magnitude of cohesive effects depends primarily on two factors the intensity and nature of the cohesive forces (e.g., electrostatic, van der Waals, capillary) and the packing density of the material (which determines the number of interparticle contacts per unit area). This dependence on density is the source of great complexity cohesive materials often display highly variable densities that depend strongly on the immediate processing history of the material. 

The stabilizing or cohesive effect in condensed phases can be expressed in terms of the cohesive energy density, defined as... 

Size, which is used to treat warp yams prior to weaving, commonly consists of an adhesive and an emulsified lubricant. The function of the adhesive is to bind together the fibres or filaments of a yarn, thus supplementing the cohesive effect of twist, and to form a film on the surface of the threads as protection against the abrasive action of the loom. The requirements of the adhesive are that it must be water dispersible or soluble, form a film, have good adhesion, allow separation of each warp yam, be flexible and, finally, must be easily removed from the woven material during desizing. 

Frictional force generally is believed to be derived from three major components (1) the force required to shear welded asperity (high spot) contact areas (2) the force required to push asperities of one surface through those of the other and (3) the force needed to overcome cohesive effects between the surfaces of these interlocking mountains and valleys . Very little force is needed to shear welded contact areas, and any interlocking is also easily sheared or plowed through . 

Aloe vera also stimulates fibroblast which in turn stimulates production of collagen and elastin fibers (Smjushe et al., 2008). Consequently, skin is more elastic and less wrinkled. Moreoever, it exhibits cohesive effects on the superficial flaking epidermal cells by sticking them together, resulting in softening of the skin. Amino acids present in Aloe vera as well... 

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