The interdiffusion coefficients of barium and fluoride in glasses, in the system Na2O/K2O/Al2O3/SiO2 with BaF2 additions, were determined from the diffusion profiles using energy dispersive X-ray analysis in a scanning electron microscope. The diffusivities were in agreement with Arrhenius-equation. Diffusion coefficients of fluoride were in the range from 4.5 10 15 m s 1 to 30 10 15 m s 1 at 5...

Two-dimensional magic angle flipping (MAF) was employed to measure the Q((n)) distribution in a (29)Si-enriched potassium disilicate glass (K(2)O.2SiO(2)). Relative concentrations of [Q((4))] = 7.2 +/- 0.3%, [Q((3))] = 82.9 +/- 0.1%, and [Q((2))] = 9.8 +/- 0.6% were obtained. Using the thermodynamic model for Q((n)) species disproportionation, these relative concentrations yield an equilibrium ...

The black shale of Chimiari region of Khyber Pakthunkhawa Pakistan is sieved for its mineral evaluation of various fractions. Disc Pulverizer made by Mine and Smelter Supply Co. Denver USA used for grinding and Tyler series for sieving to get the required range of fractions. Study showed a gradual decrease in concentration of S iO2, Al2O3, K2O, V2O5 and TiO2 from higher fraction size to lower f...

The objective of this work is to develop bioactive glass coatings for metallic orthopedic implants. A new family of glasses in the SiO2–Na2O–K2O–CaO–MgO–P2O5 system has been synthesized and characterized. The glass properties (thermal expansion, softening and transformation temperatures, density and hardness) are in line with the predictions of established empirical models. The optimized firing...