Geometric and mechano-sorption modification of fumed nanosilica in the gaseous dispersion media

Methods of geometric and solvate-stymulated mechano-sorption-activated modification of fumed nanosilica in the gaseous dispersion media were developed and used to prepare functionalyzed nanofillers for polymeric systems. Non-volatile high- and low-molecular weight compounds (such as polymers, organic bioactive compounds, organic and inorganic salts) can be used as modifiers of nanofillers.

The Use of 14C in Natural Materials to Establish the Average Gaseous Dispersion Patterns of Releases from Nuclear Installations

The Harwell Low Level measurements Laboratory has been measuring a variety of natural materials from locations close to United Kingdom nuclear installations since 1977. The measurements are made first, to establish the past effects of releases to the atmosphere of 14C as observed from individual tree rings and second, to establish dispersion contours averaged over extended periods. The main study area has been in Cumbria, around the BNFL nuclear installation at Sellafield. 14C, which can be measured to good precision even at values close to the normal natural levels, provides a powerful technique for the provision of practical experimental values much wanted for theoretical dispersion models.

Gaseous dispersion in laminar flow through a circular tube with mass transfer to a retentive layer

The dispersion of a pulse of a gaseous tracer injected into a flowing stream of a second gas has been studied under conditions where the tracer can also exchange by diffusion with a stagnant gaseous zone held in a porous solid. Such a system closely models that used in gas chromatography with capillary columns, and it has the advantage that the geometric and physical parameters may be controlled and measured more accurately than in a chromatographic column. From the study of the concentration profiles of the tracer with a thermal conductivity detector (katharometer) it is found that the experimental results for gas velocities between 1 and 30 cm/s agree well with the analytical solution to the problem given by Aris. It is shown that dispersion of the tracer may also be correlated with the structure of the porous solid and consequently such measurements may be of value in the study of gaseous diffusion in catalysts and other porous materials.