A simple and cheap chemical deposition method was used to produce a nickel oxide (NiO) thin film on glass substrates from a solution that contained Ni 2+ and monoethanolamine. Thermal treatment of the film at temperatures above 350 ℃ for 1 h caused decomposition of the nickel hydroxide into nickel oxide. Structural, optical and electrical properties of the film were studied using X-ray diffraction (XRD), spectrophotometry, current-voltage measurements and scanning electron microscopy (SEM). The film was found to be polycrystalline with interplanar spacing of 0.241 nm, 0.208 nm and 0.148 nm for (111), (200) and (220) planes respectively, the lattice constant was found to be 0.417 nm. The film had a porous surface morphology, formed from a network of nanowalls of average thickness of 66.67 nm and 52.00 nm for as-deposited and annealed films respectively. Transmittance of visible light by the as-deposited film was higher and the absorption edge of the film blueshifted after annealing. The optical band gap of the annealed film was 3.8 eV. Electrical resistivity of the film was Ωcm.

Noise is considered as the most pervasive pollutant, it constitutes the most disturbing among the city pollutants and is a serious urban crisis in Ado Ekiti metropolis. Noise pollution was monitored at five different locations in Ado-Ekiti, the capital town of Ekiti State of Nigeria. The study was done using a Virtual Instrument; a Sound Pressure Level mobile application installed on a mobile phone. The equivalent noise level using A-weighting was taken every fifteen minutes in each location between 6:00 am and 9:00 pm and the L Aeq,T of each location was calculated. Maximum L Aeq,6h of 105.40 dB was obtained in marketplace between 6:00 am and 12:00 pm while the minimum value of L Aeq,6h obtained for a residential area in the same period is 69.51 dBA. The residents are exposed to average noise levels of 75-98 dB (A) or more every day which is higher than the recommended value of 60 dBA by WHO. This is very dangerous to the health of the people in these areas, and the results obtained in this study are useful as reference and guideline for future regulations on noise limit to be implemented for urban areas in Nigeria.

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We report on effect of surface morphology on the optical and electrical properties of chemical bath deposited Zinc oxide (ZnO) nanostructures. ZnO nanostructures were deposited on the seeded conducting indium doped tin oxide substrate positioned in three different directions in the growth solution. Field emission scanning electron microscopy was used to evaluate the morphological properties of the synthesized nanostructures and revealed that the positioning of the substrate in the growth solution affects the surface morphology of the nanostructures. The optical absorbance, photoluminescence and Raman spectroscopy of the resulting nanostructures are discussed. The electrical characterization of the Schottky diode such as barrier height, ideality factor, rectification ratios, reverse saturation current and series resistance were found to depend on the nanostructures morphology. In addition, current transport mechanism in the higher forward bias of the Schottky diode was studied and space charge limited current was found to be the dominant transport mechanism in all samples.