摘要：The aim of present study was to use QbD approaches to evaluate the effect of independent product variables and their interaction on particle size of sodium fluoride and then obtain the optimized experimental condition for predefined particle size of sodium fluoride. The sodium fluoride is mainly used in dental preparation for delivering the fluoride ion to the tooth enamel for that nano-particle size is required. Nowadays the milling process is used to reduce the particle size. But that process has some limitations due to crystalline nature of sodium fluoride;for overcoming those limitations, lyophilization method is used. A 43 level full factorial design was used to study the significant influence of process and product variables i.e. 1) Concentration of sodium fluoride, 2) Concentration of PVP, 3) Sample volume, 4) Drying surface, on particle size of sodium fluoride. The experimental design result shows that independent product variables significantly modify the structure and improve particle size reduction of sodium fluoride.

摘要：This study was carried out to investigate the possibility of titanium alloy metal powder production using low-power plasma *** argon DC non-transferred arc plasma torch was designed,and numerical analysis was conducted to determine the plasma jet properties and wire *** highest velocities inside the nozzle attachment were between 838 and 1178 m/*** velocities of the jets at the apex were between 494 and 645 m/s for different gas flow *** studied plasma gas flow rates had no significant effect on the effective plasma jet *** was shown that the plasma jet length can be estimated by numerical analysis using the temperature and velocity changes of the plasma jet over *** was observed that the powders produced were spherical without any *** a result of this study,a plasma torch was developed and powder production was performed successfully by using relatively low torch power.