Sharif Digital Repository

Due to the strong magnetic anisotropy energy, the L10 FePt nanocrystals are considered as one of promising candidates for magnetic recording media with ultrahigh densities. The surfaces of Si and SiO2 wafers have been covered by FePt nanoparticles (NPs) and heated at 600 °C for 1 h to form the L10 phase. Bonding of NPs with the SiO2 surface in the presence of magnetic field during annealing process controls the L10 FePt NPs size and their uniform surface distribution. In the presence of perpendicular magnetic field to the surface, the size of NPs obtains up to 30 nm with coercivity of 5.8 kOe and in parallel magnetic field, the NPs size reaches to 45 nm with coercivity of 2.9 kOe. These... 

A series of low speed wind tunnel tests were conducted on a section of a 660 kW wind turbine blade to examine the effects of distributed surface contamination on its performance characteristics. The selected airfoil was tested with a clean surface, two types of zigzag roughness, strip tape roughness and distributed contamination roughness. The straight and zigzag leading edge roughness models simplify the contamination results in an early turbulence transition. In this study, surface contamination was simulated by applying 0.5 mm height roughness over the entire upper surface of the airfoil. The distribution density varied from the leading edge to the trailing edge of the model. Our data...