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The nano fluid consist of Al2O3 nanoparticles was dissolved by double distilled water (DDW) in three concentrations, 0.5% wt, 1%wt, and 1.5%wt of nanomaterials. The effect of adding nano materials on the viscosity and thermal conductivity was calculated experimentally at room temperature. Some mathematical models were used to calculate the viscosity and the thermal conductivity and compare it with the experimental work. The results showed that viscosity and thermal conductivity increased with increasing concentration of Al2O3 nanoparticles, and there is a great convergence between the theoretical and measured viscosity and thermal conductivity. The SEM images showed that there is homogeneity in the distribution of the nano fluid at 1%wt., and some agglomerations were detected at a concentration 1.5%. The EDS spectrum showed that the percentage of aluminum increased gradually with increasing the Al2O3 concentration. The X-Ray diffraction indicated slight increase in the intensity of diffraction with increasing the Al2O3 concentration. [ABSTRACT FROM AUTHOR]

A maximum static deflection and natural frequency of aluminium cantilever stepped beam (two steps) were investigated experimentally and theoretically for different values of small and large diameters and for different lengths of larger diameter step. Eighty samples of aluminium beams were manufactured using turning machine. The range of the beam diameter was 12–20 mm and the length of beam was 45 cm. Classical Rayleigh method, modified Rayleigh method and finite element using ANSYS software method were adopted to calculate the maximum static deflection and the natural frequency. A good agreement was found for the static deflection at different positions of applied load between the experimental results and the theoretical results, ANSYS and modified Rayleigh method. The experimental results of the natural frequency showed that there was a consistent with the theoretical results particularly when there is a minor difference between the larger and smaller diameters of the stepped beam. [ABSTRACT FROM AUTHOR]

This research was aimed to perform a symmetric investigation regarding the influence of two types of nanoparticles, on some mechanical and morphological behaviors of the Kevlar/epoxy nanocomposites. Composites were prepared by dispersing nanoparticles of nano ZnO and TiO2 at loading of 1, 2 and 4 wt.% of each in (Kevlar/epoxy) composite using high speed mechanical mixer followed by sonication, then injecting them inside the cavity of a two plates glass mold. After curing they were characterized by tensile tests, flexural test, creep test and SEM. The results showed that the maximum increase of mean stress (41%) and the maximum flexural strength was obtained for system containing 4 wt.% of both nano ZnO and TiO2 particles, i.e., EKZ4 and EKT4 . SEM images for processed specimens were taken to observe the analogy distribution of both nanoparticles through the fiber/epoxy system. The improvement in the mechanical properties of nanocomposite EKT2 (2% TiO2)and EKZ2 (2% ZnO) attributed by the homogeneity of the nanoparticles distribution inside the epoxy which appear in SEM images. Also, the semispherical shape of nanoparticles led to uniform distribution of the nano particles inside Epoxy-keflar resin. [ABSTRACT FROM AUTHOR]