background and aims. polymerization efficacy affects the properties and performance of composite resin restorations. the purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using fourier transformation infrared (ft-ir) spectroscopy and vicke...

Silica exists in Rice husk, an agriculture waste, as a naturally occurring phase. In first step, acidic pre-treatment and calcination of the rice husk were performed to obtain nano-silica, in which various sizes of the nano-silica, totally with sizes under 80 nm, were achieved. Second, to reduce nano-silica to elemental Si and subsequently formation of the composite, Mg used as the reducing age...

in this paper the influence of two different sizes of silica particles (micro-silica and nano-silica) was studied on mechanical properties of sulfur and sulfur composite. to improve the structural properties, sulfur was plasticized using dicyclopentadiene (dcpd) and methyl styrene (mst). plasticized sulfur composite was prepared by melt blending of plasticized sulfur and silica particles. the i...

In this article, transverse vibration of a cantilever nano- beam with functionally graded materials and carrying a concentrated mass at the free end is studied. Material properties of FG beam are supposed to vary through thickness direction of the constituents according to power-law distribution (P-FGM). The small scale effect is taken into consideration based on nonlocal elasticity theory of E...

the purpose of this study was to evaluate effects of nano-clay particles and oxidized polypropylene as compatibilizer on the decay resistance of wood plastic composite against coriolus versicolor fungi. in order to provide oxidized polypropylene as compatibilizer, polypropylene was oxidized in the presence of air oxygen in 2 hours by internal mixer. afterwards, wood fibers, polypropylene, nano-...

Composite shell linings consist of primary and secondary sprayed concrete linings separated by a layer of spray-applied waterproofing membrane. In order to design such a lining configuration, a calibrated numerical simulation approach is needed and the impact of interface properties on the composite mechanical behaviour should be understood. A programme of laboratory tests was carried out on be...

The vapor deposition of open-networked carbon nanostructures and carbon nanotubes (CNTs)-reinforced composites have been developed and studied parametrically. Carbon nanostructures, including nano-tubes, nano-foams, nanoparticles, and nano-walls, have been deposited on catalyst-assisted substrates using microwave plasma electron cyclotron resonance-chemical vapor deposition (ECR-CVD) system at ...

Metal matrix nano composite coatings possess enhanced properties such as corrosion and wear resistance. This paper aims to study the corrosion behavior of pure Co and Co-BN nano composite coatings deposited with different particles concentration (5-20 g L-1) on copper substrates using electroplating technique. Morphology and elemental compositions of the coatings were investigated by means of s...

Due to the presence of through-thickness reinforcement, 3D woven composites have superior fracture toughness, fatigue life, and damage tolerance compared to laminated composites. Furthermore, 3D woven composites exhibit a progressive damage behavior which is more benign than the typical catastrophic failure behavior of laminated composites. These properties lead to high specific energy absorpti...

OBJECTIVES The purpose of this study was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. MATERIALS AND METHODS Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT) was us...