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A long essay or dissertation or thesis involving personal research, written by postgraduates of University of Ghana for a university degree.
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Item Photocatalytic degradation of Rhodamine dyes using zinc oxide nanoparticles(Materials Today: Proceedings, 2020) Dodoo-Arhin, D.; Asiedu, T.; Agyei-Tuffour, B.; et al.This paper presents the synthesis of nanocrystalline zinc oxide (ZnO) particles via the sol-gel method using zinc acetate as a precursor. The calcination temperature of the ZnO was varied to determine its effect on particle size. The resultant samples were characterized using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UltraViolet–visible Spectroscopy (UV–Vis) and Scanning Electron Microscopy (SEM). Nanocrystalline wurtzite ZnO particles with crystallite sizes ranging from 16 nm to 30 nm were produced. The Energy Band gap of the synthesized zinc oxide nanoparticles decreased with increasing calcination temperature and crystallite size. SEM Micrographs showed rice-like microstructure morphology of ZnO nanoparticles. The usage of the ZnO nanoparticles as a photocatalyst was also explored in the degradation of Rhodamine B dye using UV light, with particular attention paid to the effect of particle size and catalyst load on the degradation efficiency of the dyes. The nanoparticles calcined at 400 C with a crystallite size of 16 nm resulted in the highest degradation efficiency of 95.41% when 0.2 g catalyst loading was applied. 2019 Elsevier Ltd. All rights reserved. Selection and peer review under the responsibility of the scientific committee of the International Symposium on Nanostructured, Nanoengineered, and Advanced MaterialsItem Hydroxyapatite ceramics prepared from two natural sources by direct thermal conversion: From material processing to mechanical measurements(Materials Today: Proceedings, 2020) Akpan, E.S.; Dodoo-Arhin, D.; Dauda, M.; et al.In this study, hydroxyapatite (HAp) was extracted from catfish bones (CB) and non-separated animal bones (NB). The bioceramic samples were prepared by a facile synthesis route and the representative scaffolds were prepared by cold compaction and sintered at 900 C, 1000 C, and 1100 C. To evaluate the properties of the produced HAp, X-ray diffraction (XRD) and Fourier Transform Spectroscopy (FT IR) analyses were carried out. The evaluation of the hardness of the representative bio-derived scaffolds was experimentally conducted while the fracture toughness and brittleness index were obtained by calculation using the hardness test parameters. The experimental data showed that as temperature increased up to 1000 C for CB, there was a consequential increase in hardness, while for NB, hardness values reduced throughout the sintering regimes. These gradients in mechanical measurements are ascribed to phase changes during heat treatment. 2020 The Authors. Published by Elsevier Ltd. This is an open-access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by nc-nd/4.0). Selection and Review under the responsibility of the scientific committee of the International Conference & Exposition on Mechanical, Material and Manufacturing Technology