OBJECTIVE To test the hypothesis that there is no difference in the stability and resistance to rotational moments of early loaded sandblasted and acid-etched (SLA) mini-implants and those of machined-surface implants of the same size and shape. MATERIALS AND METHODS A randomized complete block design was used in 12 skeletally mature male beagle dogs. Ninety-six orthodontic mini-implants were...

Abstract: In this research plasma nitriding of pure aluminium and effect of iron elemental alloy on the formation and growth of aluminium nitride was investigated. Also corrosion properties of formed AlN were investigated. After preparation, the samples were plasma nitrided at 550oC, for 6, 9 and 12 h and a gas mixture of 25%H2-75%N2. The microstructure and phases analysis were investigated usi...

Objective: Introduction of fiber-reinforced composites (FRC) greatly enhanced the restoration of fractured anterior teeth. The purpose of this study was to assess the effect of fiber reinforcement on fracture resistance of incisal edge composite restorations of variable thicknesses. Methods: Forty extracted sound human maxillary incisors were divided into four groups of 10. Incisal reduction wa...

In this study, the experimental analysis on the bare hull resistance coefficient of submarine at snorkel depth is represented. The experiments are conducted in marine laboratory of Admiral Makarov University. The results are presented for surface condition and snorkel condition. Snorkel depth is regarded equal to one diameter of submarine hull beneath the water surface as usual in submarines. P...

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

surface roughness is one of the most important parameters that plays very critical role in determining the quality of engineering components. a good surface quality resulting in improve of fatigue strength, corrosion and wear resistance of the workpiece. on the other hand, increasing cutting speed and decreasing time of machining are desirable for manufacturers in order to reduce costs and incr...

since the introduction of engine-driven nickel-titanium (niti) instruments, attempts have been made to minimize or eliminate their inherent defects, increase their surface hardness/flexibility and also improve their resistance to cyclic fatigue and cutting efficiency. the various strategies of enhancing instrument surface include ion implantation, thermal nitridation, cryogenic treatment and el...

Introduction: The purpose of this study was to evaluate surface topography of WaveOne Gold (WOG) and WaveOne (WO) files using SEM before and after use. Methods: Twelve primary files from each system were scanned for surface defects before instrumentation at 100x and 750x. Each file was planned ti be used to instrument six root canals and then examined under SEM after preparing one, three and six...

Ozone modification method and air-oxidation were used for the surface treatment of polyacrylonitrile(PAN)-based carbon fiber. The surface characteristics of carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS). The interfacial properties of carbon fiber reinforced polyamide 6 (CF/PA6) composites were investigated by means of the single fiber pull-out tests. As a result...

The lay-up configuration (unidirectional, crossply and quasi-isotropic) and thickness (8–24 laminae) affect the damage self-sensing characteristics of continuous carbon fiber epoxy-matrix composites. The damage is by drop impact directed at the top surface of the laminate. The oblique resistance (i.e., resistance at an angle between the longitudinal and through-thickness directions) is an effec...