The present research concerns an electrodeposited cobalt-tungsten alloy coating on graphite fibers. Annealed and unannealed coated fibers were analyzed by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS), x-ray diffraction (XRD), and transmission electron microscopy (TEM). The mole fraction of tungsten in the as-deposited cobalt-tungsten coating was found to be (7.10 ...

OBJECTIVE The aim of this study was to make a quantitative assessment of the sealing ability of Super-EBA, IRM, and Pro Root MTA root-end fillings subjected to 3 different finishing techniques. STUDY DESIGN Eighty-one ultrasonically prepared root-end cavities in human canines were separated randomly into 3 test groups of 27 roots each. The cavities were filled with Super-EBA, IRM, or Pro Root...

The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting surface roughness. In the present study, 156 samples were realized with three composite materials, -microfilled, nanofilled and silorane-, and treated with differen...

Tungsten carbide (WC) is a widely used engineering material which is usually prepared at high temperature. A new mechanism for synthesizing nanoscaled WC at ultralow temperature has been discovered. This discovery opens a novel route to synthesize valuable WC and other carbides at a cost-efficient way. The novel formation mechanism is based on an ion-exchange resin as carbon source to locally a...

We report local spectra of the near-field thermal emission recorded by a Fourier transform infrared spectrometer, using a tungsten tip as a local scatterer coupling the near-field thermal emission to the far field. Spectra recorded on silicon carbide and silicon dioxide exhibit temporal coherence due to thermally excited surface waves. Finally, we evaluate the ability of this spectroscopy to pr...

this paper deals with the investigation of the microstructure and hardness of steel samples cladded with satellite 6-wc composites by using gas tungsten arc welding (gtaw) process. for this purpose, steel samples were coated with unreinforced and reinforced stellite (by 20, 30 and 40 wt.% wc). the cladded samples were evaluated by metallographic studies, microhardness measurement and x-ray diff...

PURPOSE To search if the shear bond strengths of brackets would change after two different base-cleaning procedures such as sandblasting or carbide bur cleaning, and to determine if a previously bonded tooth surface had any effect on bond strength. MATERIALS AND METHODS A total of 120 new brackets were first bonded to 120 extracted premolars and then debonded and bond strength was recorded. T...

Combustion synthesis has been used to produce Fe-(Ti,W)C composites. A simple reactor was designed which made it possible to ignite the samples under controlled atmosphere. Samples with different W/Ti ratio were ingnited under argon atmosphere by an electric arc and a self-propagating reaction was initiated in each sample. Different composites such as WC in Fe-Ti matrix, WC+(Ti,W)C in Fe matrix...