Theses
Permanent URI for this communityhttp://197.255.125.131:4000/handle/123456789/22146
A long essay or dissertation or thesis involving personal research, written by postgraduates of University of Ghana for a university degree.
Browse
7933 results
Search Results
Item The effect of NaOH catalyst concentration and extraction time on the yield and properties of Citrullus vulgaris seed oil as a potential biodiesel feed stock(South African Journal of Chemical Engineering, 2018) Efavi, J.K.; Kanbogtah, D.; Apalangya, V.; et al.In this work, oil was extracted from Citrullus vulgaris (watermelon) seeds for potential feedstock in biodiesel production. The results showed that the oil content from Citrullus vulgaris seeds oil during extraction reached an average yield of 50%. Biodiesel was produced via transesterification using NaOH as a catalyst. The effect of NaOH on the yield of the biodiesel was investigated at three different traditions; 0.13, 0.15, and 0.18 g, and oil to methanol ratio of 5:1 under different reaction times; 90, 120 and 150 min at 60 C. The yield of biodiesel from NaOH concentration of 0.13 g was found to be 70% compared to those of concentrations of 0.15 g and 0.18 g which were 53% and 49% respectively. Gas chromatography was used to identify the methyl ester groups present in the biodiesel and the results revealed both concentration and time-dependent increase in oil yield. The physicochemical properties of the watermelon seed oil such as flash point (141.3 ± 0.4e143.4 ± 0.2), density (0.86 ± 0.04 e0.91 ± 0.01 g/cm3 ), kinematic viscosity (30.50 ± 0.1e31.20 ± 0.04 mm2 /s) and acid value (mg KOH/g) are similar to conventional vegetable oils. This work, therefore, highlights the potential utility of watermelon seeds for biodiesel production.Item Comparison of Two School Feeding Programmes in Ghana, West Africa(International Journal of Child Health and Nutrition, 2016) Owusu, J.S.; Colecraft, E.K.; Aryeetey, R.N.O.; et al.Background: Malnutrition of children in Ghana continues during school years. There is limited information on how school meals meet nutrient recommendations in Ghana. Objectives: This study aimed to compare the energy and nutrient content of meals served by Ghana School Feeding Programme (GSFP) and Non-Governmental School Feeding Programme (NGSFP) and adherence to nutrient recommendations. Methods: This was a cross-sectional study design involving the observation of school meals at two sites: GSFP and NGSFP. The average weights of a week’s meal were converted to energy and nutrient equivalence and compared with international recommendations. Differences were assessed with t-tests. Results: NGSFP provided significantly higher portion size (416 ± 96 g vs. 243 ± 50 g; p=0.007), energy (776 ± 427 kcal vs. 315 ± 24 kcal; p=0.042) and fats (17± 8 vs. 6 ± 2; p=0.019) but similar micronutrient contributions to GSFP. NGSFP met energy and macronutrient recommendations set by the World Food Programme; whereas, GSFP did not meet the recommendations. Conclusion and Recommendations: The NGSFP had more energy and macronutrients per serving size than the GSFP. Regulation of meals served by GSFP should be reviewed to ensure they contribute to the adequacy of children’s diets as well as meet recommendations set by the World Food Programme.Item Factors influencing the use of adequately iodated salt in Ghana(African Journal of Food Science, 2012) Ahiadeke, C.; Ackah, C.; Aryeetey, R.; Acquah, A.Ghana is one of the largest producers of salt in the West African region yet, access to and the use of adequately iodized salt is not widespread. Using the Ghana Multiple Indicator Cluster Survey (MICS) 2006, this paper examined the factors influencing the use of adequately iodized salt in Ghana. Factors that influence the use of adequately iodized salt include knowledge, access to information, and wealth status. Where access to formal education opportunities was not available, access to information through media still served as an important instrument to educate the public and increase the community’s knowledge on the nutritional value of consuming adequately iodized salt. Based on these findings, it was recommended that the cost of iodized salt should be reduced to make it more affordable particularly for the poor since wealth is an important factor influencing the use of adequately iodized salt. Furthermore, monitoring and ensuring enforcement of the law of salt fortification with iodine would help Ghana achieve universal salt iodization.Item Farmers’ pesticide use and knowledge of aquatic ecosystem contamination with its perceived health risk from contaminated fish consumption in northern Ghana(Scientific African, 2024) Orou-Seko,A.; Chirawurah,D.; Ndago,J.A.; Nkansah-Baido,M.; Pwatirah,D.; Kolekang,A.S.; Adokiya,M.N.Pesticide residues in agricultural environments pose significant threats to aquatic ecosystems and human health. Most studies investigate the quantity, environmental, and risk assessment of pesticides in agricultural landscapes. However, farmers’ pesticide use and their knowledge on aquatic ecosystem contamination remain limited and poorly documented. This study evaluated pesticide residue concerns in agricultural settings, focusing on farmers’ uses and knowledge. It addressed pesticide application methods and their effects on aquatic ecosystems and human health through fish consumption. A cross-sectional design was employed and 300 farmers were selected using a multi-stage sampling technique from two agricultural districts – Savelugu Municipal and Tamale Metropolis. The study revealed that maize was most cultivated (29.6 %) with extensive pesticide treatment, particularly herbicides in the study setting. Findings revealed pesticide overuse (22.3 %), mixing of pesticides at the water bodies (24.7 %), improper leftover pesticide disposal methods (39.0 %) and inadequate storage practices (63.0 %) among farmers. About 21.3 % and 74.0 % of farmers have insufficient knowledge of the resulting consequences and the discharge of pesticides into the aquatic environment, respectively. Though the farmers are aware of the detrimental impact of pesticides on human health, there is still a lack of comprehension regarding the indirect consequences for aquatic ecosystems and non-target species. In the study setting, extension services may be important sources of knowledge. Thus, emphasizes the significance of improving extension programmes and utilizing peer-to-peer communication channels to support the adoption of best practices in pesticide management such as licenced high-temperature incinerators and cement kilns with sufficient emission controls. Focused training and outreach programmes designed to enhance farmers’ knowledge andItem ‘Being Ekklēsia’ According To Revelation 2:1 ̶3:22: An Exegetical And Theological Analysis(University of Ghana, 2023) Zotoo, N.M.The Greek word e vkklhsi ,a (congregation, assembly, gathering, ‘church’) designates the community of the followers of Jesus, the extension of his humanity, the locus where it is possible to experience his presence (cf. Matt. 18:20). Christian communities in Ghana have experienced an exponential growth, but they are besieged with two main challenges namely, diversity and fragmentation, and apparent low impact on the Ghanaian society. Their diversity and fragmentation raised a hermeneutic challenge because all appeal to the New Testament to define their identity and mission. Furthermore, their apparent low impact on the morality of Ghanaian society questions their authenticity and relevance. Against this backdrop, the research examined the identity and mission of the e vkklhsi ,a through an exegetical and theological analysis of Rev. 2⸻3. Holladay’s Theological Conversation Model was the theoretical framework that guided the study. The literary unit was analysed using Rhetorical Criticism, following Kennedy’s Rhetorical Criticism model, to discover how the literary unit portrays the identity and mission of the evkklhsi ,a, the rhetorical devices the author used to describe the features of the seven communities, and the perlocutionary effect of the text on its original readers. The research revealed that Rev. 2⸻3 portrayed the church as a spiritual entity created by God’s love (cf. 1:5; cf. Eph. 5:25) and designed to love God as well as love their fellow humans. She participates in the ‘world to come,’ lives in the horizon of the kingdom of God, and should embody its values, principles, and objectives. The e vkklhsi ,a as a ‘human’ entity is on a journey of continuous conversion (semper reformanda), to testify and imitate the Risen Lord, who is the faithful witness (cf. 1:5) and the Lamb who was slain (5:6). Conforming to her Lord, the church will be also persecuted. To impact his readers, the author employed several rhetorical devises such as: recipient formular, graphon imperative, tade legei formular, descriptive phrases about Jesus Christ, knowledge formular, indictment formular, exhortative formular, proclamation formular, promise of victory formular. The perlocutionary effect of the literary unit on the original readers was to offer comfort, and encouragement in time of crisis; to exhort them to persevere during persecution (cf. 2:10; 3:10-12). It urges them to pursue brotherly love, as a defining characteristic of the community of Jesus (cf. 2:5) and resist false teaching (cf. 2:2-3, 14-16, 20-23). It enjoins the churches to live a Christ-centered life and spirituality (cf. 2:20). The study recommends further research to contextualize the findings of this research in specific Christian communities in Ghana; furthermore, there is the need to study the theme of the identity and mission in the entire book of Revelation. Finally, the Christian communities in Ghana should commit to effective Bible training of their leaders and membership, to refocus their identity and mission on what is essential, discipleship of Jesus (Matt. 28:18-20), instead of popularized doctrines that are not biblically founded.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.