The aim of the present study was to investigate slot deformation and the equivalent torque capacity of polycarbonate brackets with and without a metal slot in comparison with those of a metal bracket. For this purpose, the expansion characteristics and, in a further investigation, the labial crown torque of an upper central incisor, were measured in a simulated intra-oral clinical situation, us...

Thermal behaviour of blends of a liquid crystalline copoly(ester amide) (Vectra B950) with two isotropic polymers has been studied by differential scanning calorimetry. One of the isotropic polymers is an amorphous polymer — polycarbonate, the other is a semi-crystalline polymer — poly(ethylene terephthalate). It was found that the glass transition temperature of polycarbonate decreases with in...

A series of drop weight tests were conducted to evaluate the dynamic flatwise compression strength and flexural strength of sandwich panels with a novel core structure. This sandwich core material, known as Norcore, consists of interconnected cells in a unique configuration of truncated pyramid with sloping cell walls. Core materials made of thermoplastic including virgin Lexan, polycarbonate, ...

background : this research provides an insight into exposure information and particle size distributions of bisphenol a (bpa), a common environmental hormone, at polycarbonate (pc) molding plants in southern taiwan. methods : the inhalable dust sampler as iom and the micro-orifice uniform deposition impactor (moudi) were used for samples collection to evaluate the level and particle size distri...

We have investigated conditions for making nanoindents on a polycarbonate using a carbon nanotube tip in terms of structural stability of the nanotube tip. Even under a weak force of ∼ 50 nN acting in the axial direction to the nanotube, the indents with mean depth of 3.91 nm were successfully realized on the polycarbonate in air at room temperature. In this case, there were no structural chang...

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the sur...