objective: different methods have been suggested to overcome the polymerization shrinkage of composite restorations. changing the light curing protocol to improve polymerization by using new light curing units is among these methods. the new devices are more efficient, portable and durable and produce less heat. this study aimed to assess the marginal microleakage of class v composite restorati...

     Salt crystallization is one of the most powerful weathering agents that may cause a rapid change in the mechanical properties of stones, and thus limit their durability. Consequently, determining the mechanical properties of stones due to salt crystallization is important for natural building stones used in marine environmental and mild climatic conditions, which expose excessive salt crys...

Asymmetric cycles with more than half of the cycle spent shortening enhance the mechanical power output of muscle during flight and vocalisation. However, strategies that enhance muscle mechanical power output often compromise efficiency. In order to establish whether a trade-off necessarily exists between power and efficiency, we investigated the effects of asymmetric muscle length trajectorie...

This research developed new nanostructured Al–Fe3O4 composites via accumulative roll bonding (ARB). X-ray diffraction (XRD) analysis and field emission scanning electron microscopy were conducted to examine microstructural characteristics and particle distribution in the nanocomposites. Hardness and tensile strength tests were employed to examine their mechanical propertie...

In this paper, cyclic flaring and sinking (CFS) as a new severe plastic deformation (SPD) method was employed to produce the ultrafine grain (UFG) copper tubes. The extra friction has eliminated in the CFS method that provided the possibility for production of longer UFG tubes compared to the other SPD methods. This process was done periodically to apply more strain and consequently finer grain...

results: the average of dyssynchrony in eight cycles showed a positive correlation with dyssynchrony in target beat rr1/rr2 = 1. average of dyssynchrony in target beat was 46.77 msec, and average of 8 cycle was = 47.701, (p value = 0.776, pearson linear correlation 0.769). objectives: we proposed to evaluate intraventricular mechanical dyssynchrony by measuring time-to-peak systolic velocity be...

In this study accumulative roll bonding (ARB) process up to 8 Cycles (equivalent strain of 6.4) at ambient temperature was used in order to improve the mechanical properties of Commercial purity titanium (CP-Ti).Several experiment has been done and Mechanical properties of specimen has been discussed. For investigating optical microscope punching and hardness test were utilized. This is the fir...