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This paper presents an experimental and numerical study to evaluate the ballistic performance of E-glass/epoxy and S2-glass/epoxy composites. Composite materials were produced by vacuum assisted resin infusion molding method. All the specimens were then subjected to ballistic impact tests by gas-gun system. Residual velocities were measured by high-speed camera for different velocities. Ballistic limits of all composites were obtained by curve fitting residual velocity-impact velocity data. It was found that S2-glass/epoxy composite has a higher ballistic limit than E-glass/epoxy. S2-glass/epoxy has also more specific absorbed energy and absorbed energy density than E-glass/epoxy. Numerical results were in good agreement with experimental results. [ABSTRACT FROM AUTHOR]

Promote the conductivity of the nanocomposite thin films Co3O4:Cr2O3/C to produce a spectroscopic selective surface with high performance to absorb solar light. The nanocomposite coating Co3O4:Cr2O3/C has been fabricated by a spin coating method and casting method. Different concentrations of nanoparticles (Co3O4:Cr2O3) were immersed in the carbon ash (C) to comprise the economic nanocoating. The XRD test of the patterns has been carried out for all the specimens to prove the crystalline structure of nanocomposite thin films. The nanocomposite thin film Co3O4:Cr2O3/C has been tested at a frequency range between 375 kHz and 1.5 MHz, and the electrical properties of the thin films have been investigated for real and imaginary of the dielectric constant, conductivity, volume with surface energies of losses, and loss factor. The content of carbon (C) in the nanocomposite Co3O4:Cr2O3/C is fixed ratio (7% wt.), but the concentration of Co3O4 has various ratios (0.5, 1, 1.5, 2, and 2.5% wt.), and Cr2O3 has several ratios (2.5, 2, 1.5, 1, and 0.5% wt.), that have the symbols F, G, H, I, and K. These nanoparticles exhibited a worthy improvement in the structure of carbon ash, thereby, the XRD inspection of topography confirm the nanocomposite Co3O4:Cr2O3/C thin films have a crystalline structure. Generally, the results have demonstrated that these nanocomposite Co3O4:Cr2O3/C thin films have good conductivity. Therefore, thin films of nanocomposite can use in photovoltaics, solar cell, and coating over a flat plate collector owing to their properties as the high absorption to light. [ABSTRACT FROM AUTHOR]