Dissertations & Theses https://ir.cut.ac.zw:8080/xmlui/handle/123456789/268 2026-06-06T01:36:39Z 2026-06-06T01:36:39Z Manuhwa, Martin https://ir.cut.ac.zw:8080/xmlui/handle/123456789/579 2025-03-25T06:28:00Z 2025-02-15T00:00:00Z

Sustainable Energy and Infrastructure Development in Africa: A Systems Thinking and Critical Realism Approach to Zimbabwe’s Net-zero and Just Energy Transition Manuhwa, Martin This thesis explores sustainable engineering solutions for Zimbabwe's energy and infrastructure, employing critical realism, mixed-methods research, and systems thinking. A central hypothesis is that “through synergistically linking sustainable engineering solutions and strategic policy interventions, besides public-private partnerships cooperation, much can be done in Zimbabwe to improve energy resilience and sustainability”. In addition, the research found that investments in modern grid technology or regulatory incentives are crucial for removing barriers to the current levels of energy sustainability. Key findings include: • Grid Modernization and Renewable Energy Integration: Investments in smart grids and renewable sources can stabilise Zimbabwe’s energy sector. • Policy-Driven Incentives: Aligning regulations with international sustainability standards fosters investment in sustainable solutions. • Public-Private Partnerships (PPPs): Collaboration among stakeholders is essential for financing large-scale energy projects. • Implementation Challenges: Existing sustainability policies face gaps in enforcement and funding, which impede progress. The study develops a conceptual model linking policy design to real-world implementation, validating the hypothesis. It concludes with recommendations for enhancing Zimbabwe’s energy resilience through smart grids, circular economy principles, and institutional capacity-building, providing a roadmap for long-term sustainability in Africa’s energy sector. The thesis concluded that these factors are the prerequisites for a just energy transition towards attaining net zero by 2050 for Zimbabwe. The thesis revealed that Africa faces significant challenges in sustainable energy and infrastructure development, particularly in Zimbabwe, which is hindered by an ageing power grid and limited renewable technology adoption.

2025-02-15T00:00:00Z Kamusoko, Reckson https://ir.cut.ac.zw:8080/xmlui/handle/123456789/396 2023-11-14T07:31:09Z 2023-08-01T00:00:00Z

Isolation and characterization of cellulolytic bacteria for improving biogas production from crop residues through biological pretreatment and codigestion Kamusoko, Reckson Biofuel production from renewable resources is a rising concern due to depletion of fossil fuels, increasing fuel prices and green house gas emissions in the world. Zimbabwe is renowned for its agricultural industry, which generates millions of tonnes of crop residues, such as straw, husks, cobs, stover and hulls. Crop residues contain large amounts of organic matter that can be converted into biofuels. Anaerobic digestion (AD) is a technology which combines biogas production and sustainable waste management in a circular bioeconomy. Biogas is a clean renewable energy carrier with numerous benefits. The main objective of the study was to isolate, identify and characterize cellulolytic bacteria that can be used to enhance biogas production from crop residues through biological pretreatment and codigestion. The recalcitrant nature of crop residues makes pretreatment an essential step towards sustainable biogas production. In order to select the most suitable pretreatment strategy for crop residues, a systematic study was conducted using the PRISMA method. Biological pretreatment was found to be the best-fit option for improving the hydrolysis of crop residues. It was regarded as an ecofriendly technology with low capital and energy needs, and no generation of toxic compounds. As a result, there was need to promote biological pretreatment as a technology that enhances biogas production from crop residues. The focus was on isolating cellulolytic bacteria from hot springs for potential pretreatment agents. Of all the strains screened from hot springs, only three strains designated as LB-4, LB-6 and LB-8 had high cellulolytic activity. The strains were preliminarily identified as rod shaped, Gram positive and appeared to belong to a group of motile bacillus through morphological and biochemical identification. Homology analysis against the NCBI GenBank showed strains LB-4, LB-6 and LB-8 to be 99.13%, 98.26% and 98.91% related to Bacillus subtilis, Bacillus sp., and Bacillus licheniformis, respectively. Using submerged fermentation, the optimum cellulase activity of the strains were observed after 24 hours at pH 7 and 40ºC while utilizing 1% CMC as a carbon source and 1% yeast extract as a nitrogen source. Comprehensive analysis of maize stover, wheat straw and soybean straw for proximate composition showed a significant variability among the three crop residues. All the crop residues were reported to contain more than 30% cellulose and revealed high potential for biogas production. Cellulose, hemicelluloses and lignin content in crop residues ranged from 34.6 - 37.8%, 19.7 - 28.2% and 16.2 - 23.5%, respectively. Wheat straw had a higher cellulose (37.8%) and hemicellulose content (28.2%) than the other crop residues. Soybean straw reported the highest lignin content of 23.5%. However, the acidic nature (pH 5.3 - 5.5) and high total nitrogen content (3.1 - 8.2%) of the crop residues highlighted the need for codigestion with other organic substrates. Strains B. subtilis LB-4, Bacillus sp. LB-6 and B. licheniformis LB-8 were used to construct a hot spring cellulolytic microbial consortium (HSCMC). The HSCMC consortium was applied for biological pretreatment of crop residues. The pretreated feedstocks were characterized for total reducing sugar, ash, total solids (TS) and volatile solids (VS). Significant variation between pretreated crop residues and control conditions was observed in relation to chemical iii characteristics. The highest decline in VS (69.2%) content was reported from maize stover, whereas wheat straw showed maximum reduction of 83.9% in TS content. The TRS concentrations for pretreated hydrolysates of maize stover, wheat straw and soybean straw were significantly enhanced by 60.9, 96.3 and 84.7%, respectively. The biomethane potential assay was performed using batch fermentation to evaluate the feasibility of pretreating crop residues using the HSCMC consortium. Results established that pretreatment of crop residues using HSCMC can significantly improve the cumulative methane yield of maize stover, wheat straw and soybean straw by 50.2%, 50.6% and 56.6%, respectively. Cattle manure with pH, ash, VS and TS content of 7.12, 15.10%, 47.20% and 51.34%, respectively, was selected as a cosubstrate for this study. Codigestion of pretreated crop residues with cattle manure increased methane yield in the range of 13.3 - 25.1% compared to unpretreated groups. In conclusion, bacteria with high cellulolytic ability were successfully isolated from hot springs and an effective microbial consortium, HSCMC was developed. The HSCMC consortium enhanced methane yield of crop residues after pretreatment and codigestion with cattle manure. This study provides useful information and original contribution that could validate the upscaling of bench-scale findings to pilot- and demonstration-scale towards commercialization

2023-08-01T00:00:00Z Dhliwayo, Itai https://ir.cut.ac.zw:8080/xmlui/handle/123456789/395 2023-10-19T10:21:47Z 2023-08-01T00:00:00Z

Emerging threats and the socio-ecological resilience of local communities, South-East Zimbabwe Dhliwayo, Itai Threats to livelihoods for people living in the Great Limpopo Transfrontier Conservation Area (GLTFCA) continue to put stress on communities. These threats include climate change, food security crisis, plant pests and diseases, and human-wildlife conflict. As the magnitude and impact of emerging threats increases, aggravated by growing poverty, more households and communities become less able to absorb, recover and adapt. There is a growing and unsustainable reliance on natural resources, food aid and remittances, and an increasingly tense relationship between livestock production, wildlife ranching and conservation in the study area. Without information about communities living within the GLTFCA, policy makers are faced with challenges when the need to address poverty in areas adjacent to protected areas arises. This study analysed the emerging threats that affect local communities living on Zimbabwe’s part of the GLTFCA in Chiredzi Rural District (Sengwe), Save Valley Conservancy (Gudo community) and Beitbridge Rural District (Matibe), and the social and ecological resilience processes communities adopt in response to these numerous threats encountered. Mixed method design was adopted in this study where data collection instruments including focus group discussion, semi structured interviews and questionnaires were used and data was quantitatively and qualitatively analysed and presented. Local communities are faced with increasing numerous and complex threats starting from displacement as they were relocated to pave way for the creation of the park, the majority have negative perceptions towards the establishment and conservation initiatives, while a few are beginning to appreciate the positive impacts of Transfrontier Conservation Area (TFCA) initiatives of enhancing livelihoods and promoting biodiversity on the peripheries. Community involvement and participation in conservation initiatives is key and this enhances local community resilience to threats through community capacitation and improves relationships between the people and the park management. The existing socio-ecological resilience systems, mechanisms, strategies and pathways are weak and cannot measure up to the changing and multiplying facets of threats in the GLTFCA. Generally, threats are on the increase and livelihoods have been undermined in the GLTFCA as local communities are finding it difficult to adapt mainly due to incapacitation. It is concluded that the majority of the people in the study area regard their relationship with protected area management in a negative way, there is limited participation by local communities in wildlife conservation projects. While there are conflicting relationships between the local community and protected area management, co-existence and harmony is iii still achievable. The study contributes towards strengthening and improving local resilience and adaptation to emerging threats in the study area. It is recommended that local communities be capacitated to be able to manage their own natural resources and sustain their livelihoods.

2023-08-01T00:00:00Z Kiwa, Fungai Jacqueline https://ir.cut.ac.zw:8080/xmlui/handle/123456789/392 2023-10-19T08:04:54Z 2023-07-01T00:00:00Z

Developing an animated interactive digital game in relevance to intangible cultural heritage with Shona as a vehicle Kiwa, Fungai Jacqueline Since animation comes in 2D and 3D graphics, a lot of motion techniques are used to make them into a reality of significant quality picture. The thesis sought to prove the benefit that an interactive digital game has on the transference of Intangible Cultural Heritage (ICH) and to show that a country can preserve a lot of value when its people maintain their identity through playing the game. Important knowledge has been lost because of the increased pace of old people dying with their knowledge and not prioritizing cultural knowledge transference. The younger generations appear too preoccupied with other things, in particular digital gadgets and works, rather than sitting in moonlit meetings and receiving wisdom from the older generation. The reason the historical artifacts, representations and instruments are not being passed down with the knowledge they contain is primarily that the ways of passing down knowledge are tedious to today's younger generation. The development of Nzanga interactive digital game has been in this study used as a strategy to revive the interest of young people in the living heritage and related morals and practical skills that can be useful for their livelihoods. The computer tools used to develop the digital game are namely Android Studio 2021, Blender 3.0, FL Studio 20.8, Genymotion 2022, GIMP 2.10, Inkscape 1.0, NetBeans 12.6, Unity Hub 3.0.1 and Unreal Engine 4. The Nzanga game brings about knowledge of all three selected ICH attributes through answering game questions. The game includes two traditional games which are Pada and Tsoro which bring back that traditional vibe of game play. As the children play the game, they gain ICH knowledge of the Hurungwe Korekore people with the Chundu story as a background of the Nzanga game, thus achieving all the objectives of this thesis. The main objective is the creation of a game that is very entertaining which revives the ICH of Hurungwe Korekore culture with localized background and language. The target group were children between the ages of 13 and 16 years, four peri-urban secondary schools and fourteen rural secondary schools with an estimation of one hundred students. Life cycle models were chosen for the digital games’ development process based on the combination of a game being software and a game being multimedia. Some of the reults after the game testing included children getting more ICH questions correctly, increased number in the children who liked playing digital games and increased hours spent on playing digital games. 4 The Nzanga interactive digital game serves as the main instrument which acts as a medium bridging the older generation's intangible cultural heritage knowledge and the younger on

2023-07-01T00:00:00Z