Electric loading - Induced cracking behavior at electrode edges in PZT ceramics

Fatigue damage behavior under repeated electric loading was investigated on two kinds of PZT ceramics with discontinuous electrodes. Intergranular cracking was observed at the electrode edge in soft PZT under electric fields greater than ±400 V/mm. However, under the same loading conditions, no damage was observed in hard PZT. When cracking occurred, permittivity of specimens decreased with the number of cycles corresponding to the amount of mechanical damage. FEM analyses of the electroelastic field of the specimens showed that cracking due to cyclic electric loading was related to 180° domain switching caused by concentrated electroelastic field

Evaluation of Interfacial Strength of BNT Films Hydrothermally Deposited on Titanium Substrates

Lead-free piezoelectric (Bi1/2Na1/2)TiO3 (abbreviated as BNT) films were deposited on 0.2 mm thick pure titanium(Ti) substrates by a hydrothermal method. Scratch tests and Vickers indentation tests were performed to quantitatively assess the adhesion strength between BNT films and Ti substrates. Some of Ti substrates were pretreated by chemical polish and mechanical polish respectively prior to BNT film deposition with a view of investigating the effects of substrate surface pretreatments on the adhesion of BNT films. In the scratch test, the critical force was determined from the variations of the tangential force and the acoustic emission (AE) signals with the normal force. The scratch test results revealed that the chemical polish pretreatment effectively improved the adhesion of BNT films. In addition, the critical substrate strain inducing the adhesion failure of BNT films has been investigated by the Vickers indentation test combined with finite element analysis (FEM)

William Courten's lists of 'things bought' from the late seventeenth century

Among the Sloane manuscripts now at the British Library are papers relating to the naturalist and collector William Courten (1642–1702), whose collection at Middle Temple could be visited from around 1685. The papers contain lists of acquisitions by Courten from the late 1680s, and record dates, objects, prices and the people from whom he purchased collectable objects, both naturalia and artificialia. These lists, transcribed in an online appendix, provide evidence of his daily collecting habits and of the availability of collectable items in London; several of Courten’s suppliers were Londoners who are otherwise unknown.This is the author accepted manuscript. The final version is available from Oxford University Press via http://dx.doi.org/10.1093/jhc/fhv04

Thomas Kirke’s Copy of Philosophical Transactions

In this paper, I discuss a drawing that substituted for an engraving in a copy of Philosophical Transactions once owned by Thomas Kirke (1650–1706, FRS 1693). I suggest that prints allowed Kirke to train his eye as well as his hand. His case is useful for raising further questions about visual representations in early modern science

Microsurgical Anatomy of the Superior Wall of the Mandibular Canal and Surrounding Structures: Suggestion for New Classifications for Dental Implantology

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154467/1/ca23456_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154467/2/ca23456.pd

Undetected Small Accessory Mental Foramina Using Cone-Beam Computed Tomography.

INTRODUCTION: The accessory foramina could not be identified on some imaging modalities such as surface-rendered images. The purpose of this study was to investigate the ability of surface-rendered images in detecting these foramina. MATERIALS AND METHODS: We analyzed 20 accessory mental foramina (AMF) in nine mandibles removed from cadavers with cone-beam computed tomography (CBCT) and assessed in surface-rendered images. All AMF were divided into three groups depending on their visibility. RESULTS: Group 1 included AMF that were clearly visible as foramina, Group 2 were not clearly visible but could be recognized with concave parts, and Group 3 were not visible and the smooth surface of the bone was observed. Group 1 ranged from 1.3 to 5.1 mm CONCLUSIONS: The clinician should be aware that smaller foramina might not be detected on these images