Working interface assessment

Working interface assessment (percent safe practices). For eacample. frequency of compiiance with best practices, such as the foiiowir ... 

Supercomputers become more and more useful, and the Insights they can generate become more and more unique, as the complexity of the system modelled Is Increased. Thus Interfaclal phenomena are a very natural field for supercomputation. In addition to the examples In this volume It may be useful to mention the work of Llnse on liquid-liquid benzene-water interfaces, which he studied with 504 H2O molecules, 144 CgHg molecules, and 3700 Interaction sites. He generated over 50 million configurations In 56 hours on a Cray-lA, and he was able to quantitatively assess the sharpness of the Interfaclal density gradient, which Is very hard to probe experimentally. Similarly Spohr and Helnzlnger have studied orientational polarization of H2O molecules at a metallic Interface, which is also hard to probe experimentally. 

The assessment of surface area may sometimes present difficulties, e.g. with smectites N2 adsorption measurements grossly underestimate the area that is exposed in solution when the layers are fully expanded. In an attempt to overcome this problem a simple theoretical model has recently been developed (j4) for deriving double-layer potentials for the clay-solution interface from co-ion exclusion measurements. The results of this work suggest that the surfaces of montmorlllonlte and illite have constant potentials and do not behave like constant-charge surfaces as is generally assumed. 

Various mechanical testing methods have been used to assess the bioadhesive properties of materials and formulations. Review of the literature reveals that the technique most commonly used is the tensile test [82,85]. This test provides the measure of the force needed to detach a layer of the tested material or formulation from a mucosal substrate as a function of the displacement occurring at the bioadhesive interface. Besides maximum force of detachment, another parameter provided by tensile test is the work of adhesion calculated as the area under the force versus displacement curve. Such a parameter gives more complete... 

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