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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 Surface Functionalized MXenes for Wastewater Treatment-A Comprehensive Review(Global Challenges, 2022) Damptey, L.; Dodoo-Arhin, D.; Jaato, B.N.; et al.Over 80% of wastewater worldwide is released into the environment without proper treatment. Whilst environmental pollution continues to intensify due to the increase in the number of polluting industries, conventional techniques employed to clean the environment are poorly effective and expensive. MXenes are a new class of 2D materials that have received a lot of attention for an extensive range of applications due to their tuneable interlayer spacing and tailorable surface chemistry. Several MXene-based nanomaterials with remarkable properties have been proposed, synthesized, and used in environmental remediation applications. This work, a comprehensive review of the state-of-the-art research progress on the promising potential of surface-functionalized MXenes as photocatalysts, adsorbents, and membranes for wastewater treatment are presented. The sources, composition, and effects of wastewater on human health and the environment are displayed. Furthermore, the synthesis, surface functionalization, and characterization techniques of merit used in the study of MXenes are discussed, detailing the effects of a range of factors (e.g., PH, temperature, precursor, etc.) on the synthesis, surface functionalization, and performance of the resulting MXenes. Finally, the limits of MXenes and MXene-based materials as well as their potential future research directions, especially for wastewater treatment applications are highlighted.Item High energy milling of Cu2O powders(2011) Dodoo-Arhin, D.; Vettori, G.; D’Incau, M.; et al.Whole Powder Pattern Modelling was employed to investigate the microstructure changes in Cu2O powders milled in a vibrating cup mill. The reduction in the average size of coherently scattering domains - and simultaneous narrowing of the size distribution - occurs in the first minutes. An asymptotic limit of ca. 10 nm is obtained. The size reduction is obtained at the expense of introducing a massive quantity of dislocations in the system, reaching a limit of ca. 4×10-16 m-2. A proper nanocrystalline microstructure can be obtained with an effective milling time of ca. 20 min.Item Characteristics Of Stabilized Shrink-Swell Deposits Using Eggshell Powder(2013) Nyankson, E.; Agyei-Tuffour, B.; Annan, E.; et al.Shrink-swell soils expand and heave or contract and crack during periods of high and low moisture content. The expansion and contraction cause the lifting and or sinking of structures, crack development, and eventual collapse of engineering structures. The need to stabilize such plastic soils to improve their load-carrying capacities cannot be overemphasized. Therefore in this article, the effect of lime contained in eggshells and its application in the stabilization of shrink-swell soils have been explored. 4wt% and 8wt% of eggshell powder were mixed with equal masses of two different soil samples from Dodowa (DD) and Adalekope (AD) in Ghana. The samples were characterized with X-ray fluorescence (XRF), Plasticity Index analysis (PI), Free Swell Index (FSI), pH test, and a grading test. The x-ray fluorescence results showed that eggshell contains about 52wt% of CaO, which is largely responsible for soil stabilization. The sample mixed with 8wt% eggshell powder showed a decreased PI, FSI, and a high silt/clay fraction. The results obtained have been discussed and can influence the application of eggshell powders for large-scale stabilization of expansive soils.Item Limiting spread of COVID-19 in Ghana: Compliance audit of selected transportation stations in the Greater Accra region of Ghana(PLOS ONE, 2021) Bonful, H.A.; Addo-Lartey, A.; Aheto, J.M.K.; et al.Globally, little evidence exists on transmission patterns of COVID-19. Recommendations to prevent infection include appropriate and frequent handwashing plus physical and social distancing. We conducted an exploratory observational study to assess compliance with these recommendations in selected transportation stations in Ghana. A one-hour audit of 45 public transport stations in the Greater Accra region was carried out between 27th and 29th March 2020. Using an adapted World Health Organization (WHO) hand hygiene assessment scale, the availability and use of handwashing facilities, social distancing, and ongoing public education on COVID-19 prevention measures were assessed, weighted, and scored to determine the level of compliance of stations. Compliance with recommendations was categorized as “inadequate” “basic”, “intermediate” and “advanced”, based on the overall score. The majority (80%) of stations in Accra have at least one Veronica Bucket with flowing water and soap, but the number of washing places at each station is not adequate. Only a small minority (18%) of stations were communicating the need to wash hands frequently and appropriately and to practice social/physical distancing while at the station. In most stations (95%), hand washing practice was either not observed, or only infrequently. Almost all stations (93%) did not have alcohol-based hand sanitizers available for public use, while social distancing was rarely practiced (only 2%). In over 90% of the stations, face masks were either not worn or only worn by a few passengers. Compliance with COVID-19 prevention measures was inadequate in 13 stations, basic in 16 stations, intermediate in 7 stations, and advanced in 9 stations. Compliance with COVID-19 prevention measures in public transportation stations in the Greater Accra region remains a challenge. Awareness creation should aim to elevate the COVID-19 risk perception of transportation operators and clients. Transport operators and stations need support and guidance to enforce hand washing and social distancing.Item High-performance symmetric electrochemical capacitor based on graphene foam and nanostructured manganese oxide(AIP Advances, 2013) Bello, A.; Dodoo-Arhin, D.; Gogotsi, Y.; et al.We have fabricated a symmetric electrochemical capacitor with high energy and power densities based on a composite of graphene foam (GF) with ∼80 wt% of manganese oxide (MnO2) deposited by hydrothermal synthesis. Raman spectroscopy and X-ray diffraction measurements showed the presence of nanocrystalline MnO2 on the GF while scanning and transmission electron microscopies showed needle-like manganese oxide coated and anchored onto the surface of graphene. Electrochemical measurements of the composite electrode gave a specific capacitance of 240 Fg−1 at a current density of 0.1 Ag−1 for symmetric supercapacitors using a two-electrode configuration. A maximum energy density of 8.3 Whkg−1 was obtained, with a power density of 20 kWkg−1 and no capacitance loss after 1000 cycles. GF is excellent support for pseudo-capacitive oxide materials such as MnO2, and the composite electrode provided a high energy density due to a combination of double-layer and redox capacitance mechanisms.Item Chemical adsorption of NiO nanostructures on nickel foam-graphene for supercapacitor applications(Journal of Materials Science, 2013) Bello, A.; Dodoo-Ahrin, D.; Makgopa, K.; et al.Few-layer graphene was synthesized on a nickel foam template by chemical vapor deposition (CVD). The resulting three-dimensional (3D) graphene was loaded with nickel oxide nanostructures using the successive ionic layer adsorption and reaction (SILAR) technique. The composites were characterized and investigated as electrode material for supercapacitors. Raman spectroscopy measurements on the sample revealed that the 3D graphene consisted of mostly few layers, while X-ray diffractometry (XRD) and scanning electron microscopy (SEM) revealed the presence of nickel oxide. The electrochemical properties were investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and potentiostatic charge-discharge in aqueous KOH electrolyte. The novelty of this work is the use of the 3D porous cell structure of the nickel foam which allows for the growth of highly conductive graphene and subsequently provides support for uniform adsorption of the NiO onto the graphene. The NF-G/NiO electrode material showed excellent properties as a pseudocapacitive device with a high specific capacitance value of 783 Fg-1 at a scan rate of 2 mVs-1. The device also exhibited excellent cycle stability, with 84% retention of the initial capacitance after 1,000 cycles. The results demonstrate that composites made using 3D graphene are versatile and show considerable promise as electrode materials for supercapacitor applications.Item Surfactant Assisted Synthesis of Copper Oxide (CuO) Leaf-like Nanostructures for Electrochemical Applications(American Journal of Materials Science, 2014) Bello, A.; Dodoo-Arhin, D.; Makgopa, K.; et al.Three different copper oxide (CuO) leaf-like nanostructures have been synthesized by micelles microemulsion method using a surfactant of copper dodecyl sulfate (Cu(DS)2) by varying the concentration of sodium hydroxide (NaOH). This study was carried out to investigate the effect of NaOH concentration on the stability, crystalline domain, and pseudocapacitance behavior of the leaf-like nanostructures. The samples were characterized by X-ray diffraction (XRD), thermogravimetry analysis (TGA), Raman spectroscopy, Fourier-Transform Infrared (FTIR), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). It was observed that the crystalline domain size (12 nm-18 nm) and size distribution of the as-synthesized nanocrystals decreased with increasing concentration of NaOH. The interaction mechanism and formation of the leaf-like structure have been elucidated and correlated with various analytical techniques. The domain size and NaOH concentration tend to influence the charge transfer resistance.Item A cross-sector approach to explore socio-ecological associations with treatment engagement behaviours in Northern Ghana(Journal of Cancer Policy, 2024-07-14) Tuck,C.; Gray,L.; Suraj,H.; Timtoni,A.R.I.; Tampuri,A.R.; Aryeetey,R.; Braimah,A.B.; Akparibo,R.; Cooper,R.Background: Cancer presents a growing global burden, not least in African countries such as Ghana where high cancer treatment dropouts has been identified due to numerous social, cultural and financial reasons. There is little understanding regarding patterns of treatment access behaviour, especially in Northern Ghana, which this study was designed to explore. Methods: Through cross-sector collaboration, we extracted and clinically validated cancer patient records available in the Tamale Teaching Hospital. These were analysed descriptively and through multi-variate logistic regression. A treatment mapping process was also applied to highlight challenges in data collection. Multiple imputation with chained equations was conducted for high levels of missing data. Sensitivity analysis was applied to assess the impact of missing data. Results: Treatment drop-out was high even when uncertainty due to missing data was accounted for, and only 27 % of patients completely engaged with treatment. High drop-out was found for all cancers including those covered by the Ghana National Health Insurance scheme. Multi-variate logistic regression revealed that social, health condition and systemic factors influence treatment engagement until completion. High missing data was observed for liver, ovarian, colorectal, gastric, bladder, oesophageal and head and neck and skin cancers, and soft tissue sarcomas, which limited model fitting. Conclusion: Treatment drop-out is a critical issue in Northern Ghana. There was high missing data due to the dynamic, complex and decentralised treatment pathway. Future studies are needed to understand the complex challenges in data recording. Policy summary: Treatment drop out is a pertinent issue that policy makers should look to address. Further discussion with stakeholders involved in cancer treatment and data collection is required to better understand challenges to routine data collection in the local setting. This will allow policy to be designed to cater for the impact of multiple intersecting health and social factors on treatment completion.Item Modelling the drivers of land use and land cover change of the great Amanzule wetland ecosystem to inform the development policy of the southwestern oil-rich region of Ghana(Heliyon, 2024-08-20) Adarkwah,F.; Awuni,S.; Hajek,M.; Kübler,D.; Mattah,M.; Gordon,C.; OwusuE.H.This study focused on the current and future drivers of land-use change and its impact on the Amanzule wetland. It suggests policy implications for reviewing and strengthening existing policies for sustainable land use. This study employed remote sensing and GIS techniques, including participatory rural appraisal techniques. The administration of questionnaires and focus group discussions were conducted in the Ellembelle and Jomoro municipalities, where the Amanzule wetland provides economic and social services. The results showed increased land use over the last 32 years driven by various drivers, including food crop production, rubber plantations, oil and gas establishments, and infrastructure development. The study further revealed that these drivers could influence land-use change in 18 years (2018–2036). Urbanisation, cropland, rubber plantations, and shrubland will drive land-use change in the study area between 2036 and 2054. The Amanzule wetland area is expected to decrease from 272.34 ha in 2018 to 210.60 ha by 2036. The wetland area is expected to further decrease from 210.60 ha in 2036 to 174.33 ha by 2054. Other land use classes, such as mangrove and swamp forests, are also expected to decrease within the same period. The study recommends advocating for a wetland policy, enforcing the Land Use and Spatial Planning Act 925 and the Petroleum Exploration and Production Act 919 for sustainable development.Item Exploring Perspectives of the Validity, Legitimacy and Acceptability of Environmental Valuation using Q Methodology(Journal of Ocean and Coastal Economics, 2021) Ankamah-Yeboah, I.; Armstrong, C.; Tinch, R.There is increasing interest from research providers, policymakers, and private sector decision-makers in using the economic valuation of ecosystem goods and services to improve decision-making (Austen et al., 2019). Market systems and economic appraisal methods offer powerful tools for supporting decisions about allocating scarce resources (Tinch et al., 2019). However, there are many Important aspects of human activity that are not fully reflected in market prices. These include our impacts on the natural world and our dependence on the many valuable goods and services ecosystems provide. Assessing the values of these impacts, goods, and services in monetary terms, combined with various economic analysis and appraisal tools, could help environmental management.