Department of Mechanical Engineering

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    A comprehensive review of hydrogen production and storage: A focus on the role of nanomaterials
    (The University of Edinburgh, 2022-05-20) Emmanuel I. Epelle; Kwaghtaver S. Desongu; Winifred Obande; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Jude A. Okolie; Burcu Gunes
    Nanomaterials are beginning to play an essential role in addressing the challenges associated with hydrogen production and storage. The outstanding physicochemical properties of nanomaterials suggest their applications in almost all technological breakthroughs ranging from catalysis, metal-organic framework, complex hydrides, etc. This study outlines the applications of nanomaterials in hydrogen production (considering both thermochemical, biological, and water splitting methods) and storage. Recent advances in renewable hydrogen production methods are elucidated along with a comparison of different nanomaterials used to enhance renewable hydrogen production. Additionally, nanomaterials for solid-state hydrogen storage are reviewed. The characteristics of various nanomaterials for hydrogen storage are compared. Some nanomaterials discussed include carbon nanotubes, activated carbon, metal-doped carbon-based nanomaterials, metal-organic frameworks. Other materials such as complex hydrides and clathrates are outlined. Finally, future research perspectives related to the application of nanomaterials for hydrogen production and storage are discussed.
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    Synthesis and Characterization of Eggshell-derived Hydroxyapatite for Dental Implant Applications
    (EDP Sciences, 2023-01-01) Jamiu Kolawole Odusote; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Peter Omoniyi; Tien-Chien Jen; G. Odedele; Jude A. Okolie; Esther Titilayo Akinlabi
    Hydroxyapatite (HAp) production from eggshells for dental implant purposes involved a novel approach utilizing a wet chemical precipitation technique. The eggshells, finely ground to a size below 250 μm, underwent calcination at a high temperature of 900°C for 2 hours. This thermal treatment facilitated the conversion of calcium carbonate into calcium oxide (CaO) while eliminating any organic components in the eggshell. To initiate the synthesis of HAp, a solution comprising 0.6 M phosphoric acid was added to the CaO dispersed in water. The resulting mixture was allowed to undergo aging at different time intervals ranging from 0 to 24 hours, promoting the formation of HAp. Subsequently, the HAp particles were oven-dried at 100°C for 2 hours to remove residual moisture. Finally, the dried particles were sintered at 1200°C in a muffle furnace to achieve the desired properties for dental implant applications. XRD peaks at 25, 33, 40, and 50° confirm the synthesized material as HAp. Vibrational modes of phosphate (PO43-), hydroxyl (OH-), and carbonate (CO32-) groups indicate carbonated HAp. Synthesized HAp holds potential for biomedical applications.
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    Combustion characteristics of fuel briquettes made from charcoal particles and sawdust agglomerates
    (Elsevier, 2019-10-14) H. A. Ajimotokan; A.O. Ehindero; Kabiru Sulaiman AJAO; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Y. L. Shuaib-Babata
    The combustion characteristics of fuel briquettes made from Idigbo (Terminalia ivorensis) charcoal particles, pinewood (Pinus caribaea) sawdust and their agglomerates using gelatinized cassava peels were investigated. The charcoal particles and pine sawdust were blended in the mixing ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively and vice-versa. More so, briquettes were produced from pure charcoal particles and pine sawdust separately for the purpose of comparison with the blended briquettes. The gelatinized binder was 5% of the total briquettes weight. The briquettes were produced using a pressure of 5 MPa with a dwelling time of 5 min in a hydraulic briquetting machine. Proximate, elemental compositions and heating value analyses were carried out on the raw charcoal, sawdust, cassava peel, and their briquettes. The results showed that variations in the mixing ratios of the bio-residues had significant effects on all the properties investigated. An increase in the charcoal particles led to an increase in the fixed carbon content and heating value of the briquettes. Conversely, higher pine sawdust content in the briquette resulted in higher volatile matter content and lower heating value. The briquette made from pure charcoal particles had the highest heating value (24.9 MJ/kg) and ash content (6.0%). Its carbon, hydrogen, and oxygen contents were in the range of 44.6–50.1%, 5.1–5.6% and 34.4–41.5%, respectively. The proximate analysis, elemental composition analysis, and heating values of the produced fuel briquettes depicted that they have better combustion properties when compared to the raw charcoal, pine dust, and cassava peel. Thus, the produced briquettes would serve as good fuel for domestic and industrial applications.