http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
치과용 CAD/CAM 시스템을 이용한 지르코니아 코핑의 정확성에 관한 연구
윤성근,최병환,Yoon, Seong-Geun,Choi, Byung-Hwan 대한치과기공학회 2011 대한치과기공학회지 Vol.33 No.2
Purpose: To evaluate the accuracy of zirconia copings in terms of clinical verified for the clinical application of CAD/CAM. Methods: Zirconia copings (n=5) were prepared using CAD/CAM system and were sintered using the relevant electrical induction furnace, which uses a 2h sintering program with a maximum temperature of $1500^{\circ}C$. The copings placed at the models and the interval values were measured. Results: The meas interval values between the die and the zirconia copings were $44.14{\mu}m$(A), $44.57{\mu}m$(B), $44.72{\mu}m$(C). 51.05 ${\mu}m$(D). Conclusion: The maximum interval values between the die and the zirconia copings were $51.3{\mu}m$ which is acceptable for clinical use. ${\mu}m$ Proper understanding of the test conditions will help enhancing the accuracy of zirconia coping.
P-7 : Retrofitting Heat Exchanger Network for the Ethyl-benzene Process
윤성근,박선원 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.2
Chemical plants generally consume much energy to convert raw materials into products. Supplying energy needs cost, and the energy cost contributes a significant portion of the total operating cost. Especially for ever-rising energy cost, energy saving is an important issue to chemical industries. This study deals with retrofittng heat exchanger network as an alternative for saving energy. A target case of this study is a process to manufacture ethyl-benzene. It is manufactured by alkylation between ethylene and benzene, and the ethyl-benzene is used for manufacturing styrene monomer process. Annual energy cost of the ethyl-benzene process is about 7 billion won. If 10% of this cost can be saved, 700 million won is saved. To find possibility for saving, the current heat exchanger network is analyzed using pinch retrofit analysis. Based on this result, improved heat exchanger network is proposed. Acknowledgement This work was supported by the BK21 Project, the IMT2000(project number: 00015993) in 2003, and Center for Ultramicrochemical Process Systems sponsored by KOSEF.