Experimental Studies of Some Irradiated Heterogeneous Systems

Experimental Studies of Some Irradiated Heterogeneous Systems 

This subsection describes a few physical properties of the catalysts mentioned in the part of this paper related to the experimental works of our laboratory. The data given here are not essential for complete understanding of this paper however, they are necessary to calculate radiochemical yields (see Section II,B and Appendices A and B), and are also useful for supporting certain points of the discussion. The solids used by other authors 

Our experiments are carried out in the presence of various types of micro-porous solids. They consist principally of alumina (CA), silica (CS), and activated charcoal (EC). For irradiation purposes with fission fragments, uranium is incorporated as an oxide by impregnation or coprecipitation methods. Microporous solids with variable uranium content are made available in this way with, as supporting phase, alumina (CAU), silica (CSU), and activated charcoal (ECU) 8, 9), respectively. Quite apart from the chemical composition, the knowledge of the physical structure of these solids is particularly important. For this reason a series of systematic measurements have been carried out on these solids of granulometry between 15 and 30 mesh. 

The apparent density expresses the ratio of weight to volume for a large number of grains loosely piled up without compression. 

The mercury density is determined by measuring the volume accessible to mercury under atmospheric pressure this volume only consists of pores with a radius exceeding 6/i. 

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II. Experimental Studies of Some Irradiated Heterogeneous Systems. 56... 

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