1 S U P E R C O N D U C T O R S INTRODUCTION Superconductivity is a phenomena displayed by certain metallic and ceramic materials whose electrical resistance falls to zero at a specific critical temperature. Unfortunately, until very recently, the temperatures were so cold that they were attainable only with the use of liquid helium. In 1986, IBM researchers Georg Bednorz and Alex Müller report...

Little information regarding variation of basic preparation guidelines in stress distribution of teeth covered with ceramic crows has been available. The incomplete fit of full crown restorations remains a critical problem for dentists, leading many researchers to study this problem. Finite element analyses have been used for many investigations, because they can reproduce structures of various...

the fracture resistance of all-ceramic restorations is one of the major concerns in clinical applications of these materials. before initiating a time-consuming and costly clinical investigation, an in vitro study can help to estimate the in vivo usability of a new dental material. mechanical properties of all-ceramic materials are frequently evaluated to predict their clinical performance. sin...

there is no doubt that just a healthy and balanced society could reach intellectual, technical, political and moral developments. there are some important and effective elements that wellbeing of society refers to them. no doubt that one of them is islamic hijab. accordingly, fiqh of islam insists on operation of hijab and we try to demonstrate that islamic hijab is not a personal or unimportan...

PURPOSE The aim of the present study was to assess the influence of pre-treatments of zirconia by sandblasting and/or heat treatment on the flexural strength of zirconia and debonding/crack-initiation strength of porcelain-veneered zirconia ceramic. MATERIALS AND METHODS Zirconia ceramic specimens were divided into four groups according to treatment (grinding as controls, sandblasting, heat t...