Thermal Properties of Pineapple Leaf Composite and its Suitability as a Viable Alternative for Efficient Roofing Material

For self-cooling building designs, the thermal properties of pineapple (Ananas Comosus) stalk composite were investigated and compared with those of asbestos with a view to establishing its suitability as ceiling material. Sample boards from pineapple leaves were prepared by drying and grinding, then forming them into boards without an external binder. The major parameter, thermal conductivity К was determined using Lee’s Disc apparatus. Other parameters determined were specific heat capacity c, density ρ, thermal resistivity ρth, thermal diffusivity λ, and thermal absorptivity α, were determined by using the appropriate experimental methods or calculations. The thermal conductivity of Ananas Comosus was determined to be 0.0719±0.0007Wm-1K-1. Using the same Lee’s Disc apparatus method, the thermal conductivity of the commercial asbestos ceiling sheet was measured to be 0.195Wm-1K-1. This value is about 85% of the value (0.17Wm-1K-1) \) quoted in textbooks. Our pineapple stalk sheet is clearly a poorer heat conductor than the asbestos sheet.  Other parameters determined here – the specific heat capacity, the thermal diffusivity, etc, support our findings that the investigated material can serve as a good material for efficient “cool roof” building desig

Friction and wear behavior of nitrogen-doped ZnO thin films deposited via MOCVD under dry contact

Most researches on doped ZnO thin films are tilted toward their applications in optoelectronics and semiconductor devices. Research on their tribological properties is still unfolding. In this work, nitrogen-doped ZnO thin films were deposited on 304 L stainless steel substrate from a combination of zinc acetate and ammonium acetate precursor by MOCVD technique. Compositional and structural studies of the films were done using Rutherford Backscattering Spectroscopy (RBS) and X-ray Diffraction (XRD). The frictional behavior of the thin film coatings was evaluated using a ball-on-flat configuration in reciprocating sliding under dry contact condition. After friction test, the flat and ball counter-face surfaces were examined to assess the wear dimension and failure mechanism. Both friction behavior and wear (in the ball counter-face) were observed to be dependent on the crystallinity and thickness of the thin film coatings