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Densification and mechanical properties of dental zirconia ceramics were evaluated by different sintering methods. Y-TZP zirconia block was used in this study. Sintering were performed in electric heating furnace and microwave sintering furnace, and then experimented and analyzed on a change in densification according to the sintering time, a change in densification according to thickness, flexural strength and micro-structure of zirconia specimens. Microwave sintering was very effective in considerable mechanical properties such as flexural strength and bulk density was drastically increased than conventional electric heating method. It is also shown that microwave sintering was faster and more economical than common method to be present in qualities which equal or exceed. It will be important to seek the accurate sintering condition of dental zirconia by microwave sintering method and the continuous research is necessary for the study of relationship between sintering methods and mechanical properties.

To replace bottom ash for natural sand completely, the mix proportions of bottom ash in concrete was adjusted according to tab density and replacement ratio of polymeric resin/Potland cement(PC) were established. And then testing for slump, setting time, and compressive strength was conducted. According to test results, the compressive strength of concrete using the bottom ash was lower than that of concrete using natural sand (BA0 concrete). But by adjusting the amount of bottom ash in concrete according tab density so that the fine aggregate proportions change 44% to 38%, the compressive strength of concrete using the bottom ash could even be higher than BA0 concrete. And as the polymeric resin content of bottom ash concrete increased, strength would be increased drastically, but proper dispersant should be cooperated with polymeric resin cement with fine bottom ash powders.