Process spectroscopy,—characterization color

In another smdy, samples of depleted uranium oxide manufactured through different processes were characterized (Hastings et al. 2008). Three types of uranium oxides were prepared from uranyl nitrate hexahydrate (U02(N03)2-6H20) at different temperatures UO2 at 500°C-700°C, UjOg at 800°C-1100°C, and UO3 at 350°C-450°C. Optical spectroscopy and particle fractionation were used to characterize the oxides. The color of the oxides, their density, and granular appearance (aerodynamic diameter and size distribution) were somewhat affected by the preparation conditions. The gamma spectrum of the samples was also recorded. The conclusion was that variations in the processing conditions of the uranium oxides were reflected in the density and particle size distribution and these characteristics could be used for nuclear forensics. 

This chapter discusses the dynamic mechanical properties of polystyrene, styrene copolymers, rubber-modified polystyrene and rubber-modified styrene copolymers. In polystyrene, the experimental relaxation spectrum and its probable molecular origins are reviewed further the effects on the relaxations caused by polymer structure (e.g. tacticity, molecular weight, substituents and crosslinking) and additives (e.g. plasticizers, antioxidants, UV stabilizers, flame retardants and colorants) are assessed. The main relaxation behaviour of styrene copolymers is presented and some of the effects of random copolymerization on secondary mechanical relaxation processes are illustrated on styrene-co-acrylonitrile and styrene-co-methacrylic acid. Finally, in rubber-modified polystyrene and styrene copolymers, it is shown how dynamic mechanical spectroscopy can help in the characterization of rubber phase morphology through the analysis of its main relaxation loss peak. 

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