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Improvement in the efficiency of solid electrolytes requires the use of low electrolyte operating temperatures even though the ionic conductivity of electrolytes generally decreases at low temperatures. In this study, we propose the use of gadolinia-doped ceria (GDC) that has relatively high conductivity even at low temperature (200°C) as a solid electrolyte for potential application in liquid sodium, and we investigate its thermochemical stability in the liquid sodium environment. The results of microstructural analyses, thermochemical stability tests, and total conductivity measurements in liquid sodium at 200°C are discussed. Potentiometric cell with gadolinia-doped ceria (GDC) as a solid electrolyte and a In/In2O3 reference electrode were also tested in oxygen saturated liquid sodium environment in order to measure the emf. The emf in sodium environment is compared with theoretical data. The emf values measured in this study show a narrow range at low temperatures: however, the emf rapidly decreases with increasing temperature. The reason is caused by the mixed ionic electronic conductivity of GDC in oxygen-saturated sodium environment. [ABSTRACT FROM AUTHOR]

Objective: We compared the skeletal and dental changes that resulted from the use of two methods of intermaxillary fixation (IMF)--miniscrews and surgical archwire-in 74 adult patients who had Class III malocclusion and were treated with the same orthognathic surgical procedure at a hospital in Korea. Methods: All the patients underwent Le Fort 1 osteotomy and bilateral sagittal split ramus osteotomy with rigid fixation. They were divided into two groups according to the type of IMF used-group 1 underwent surgical archwire fixation and group 2 underwent orthodontic miniscrew fixation. In a series of cephalograms for each patient, we compared vertical and horizontal tooth-position measurements: (a) immediately after surgery (T1), (b) 3 months after surgery (T1), and (c) 6 months after surgery (T2). Cephalometric changes within each group were examined using one-way analysis of variance (ANOVA) while the independent samples t-test procedure was used to compare the two groups. Results: After surgery, the maxillary incisors tended to be proclined in both groups although there were no significant differences. Incisor overbite increased significantly in both groups from T0 to T1 and the miniscrew group (group 2) showed slightly greater overbite than the archwire group (group 1). Conclusions: This study suggest that the use of orthodontic miniscrews and orthodontic surgical archwire for IMF in adult patients results in similar skeletal and dental changes. [ABSTRACT FROM AUTHOR]