Barium nuclear properties

The properties of hydrated titanium dioxide as an ion-exchange (qv) medium have been widely studied (51—55). Separations include those of alkaH and alkaline-earth metals, zinc, copper, cobalt, cesium, strontium, and barium. The use of hydrated titanium dioxide to separate uranium from seawater and also for the treatment of radioactive wastes from nuclear-reactor installations has been proposed (56). 

Highly pure lanthanum oxide is used to make optical glass of high refractive index for camera lenses. It also is used to make glass fibers. The oxide also is used to improve thermal and electrical properties of barium and strontium titanates. Other applications are in glass polishes carbon arc electrodes fluorescent type phosphors and as a diluent for nuclear fuels. In such apph-cations, lanthinum oxide is usually combined with other rare earth oxides. 

Bonding in the silica-type covalent phosphate structure is illustrated in Fig. 8.5. Because this bonding is covalent, the resulting minerals are very hard and their aqueous solubility is extremely low. These properties make them attractive for the disposal of radioactive barium and strontium isotopes formed during nuclear reactions. These two isotopes may be converted to their covalent phosphate structures as Sr3(P04)2 and Ba3(P04)2 and can be disposed or stored in repositories safely. 

At the southern end of this family are the metals strontium, barium, and radium. The kingdom s patterns are beginning to be established, and since patterns are the foundation of prediction we are able to predict that these regions will be much more reactive than those to the north. Indeed, they are too aggressive to their environment to be of much use, and nature has found no use for them. Nature s child, humanity, though, has put them to use. Radium is highly radioactive (a nuclear, not a chemical, property), and is used to kill unwanted proliferating cells. A radioactive form of strontium, strontium-90, is a component of nuclear fallout, and if it accumulates in place of calcium in bone it can kill cells that are needed for life and induce leukemia. 

Schaefer et al. (19) studied the interphase microstructure of ternary polymer composites consisting of polypropylene, ethylene-propylene-diene-terpolymer (EPDM), and different types of inorganic fillers (e.g., kaolin clay and barium sulfate). They used extraction and dynamic mechanical methods to relate the thickness of absorbed polymer coatings on filler particles to mechanical properties. The extraction of composite samples with xylene solvent for prolonged periods of time indicated that the bound polymer around filler particles increased from 3 to 12 nm thick between kaolin to barium sulfate filler types. Solid-state Nuclear Magnetic Resonance (NMR) analyses of the bound polymer layers indicated that EPDM was the main constituent adsorbed to the filler particles. Without doubt, the existence of an interphase microstructure was shown to exist and have a rather sizable thickness. They proceeded to use this interphase model to fit a modified van der Poel equation to compute the storage modulus G (T) and loss modulus G"(T) properties. 

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