https://ir-library.mmust.ac.ke/xmlui/handle/123456789/36 2026-08-01T14:38:40Z https://ir-library.mmust.ac.ke/xmlui/handle/123456789/3705 OPTIMIZATION OF TURBINE BLADE PITCH ANGLE OF A HOMEBUILT TURBINE FOR MAXIMUM POWER OUTPUT MUGO, SAMMY GUTU The increasing demand for renewable energy sources has led to a growing interest in wind energy as a viable and sustainable option. Home built wind turbines offer a cost effective and accessible way for individuals and small communities to generate their own electricity. However, optimizing the performance of these turbines is crucial to maximize their power output and ensure their efficiency and reliability Wind energy greatly reduces the world’s dependence on fossil fuels (oil and natural gas) and is environmentally friendly. One of the most cost-effective alternatives of energy sources is wind power. This study used a horizontal axis wind turbine to investigate the optimal blade pitch angle that can give maximum electrical output. Specific areas of studies will be to identify the various pitch angles, then validate the pitch angels for the maximum power produced by the turbine. A proportional integral derivative pitch controller was used to establish blade pitch angles. Wind speeds of 3, 4, 5 and 6 m/s were run at every pitch angle respectively, and a maximum electrical power output was 1124.7W at a blade pitch angle of 16.80 when a wind speed of 6 m/s was used. Every wind speed had was run for 100 seconds. A simulation, using Visual Basic 6 software, was done at the respective blade pitch angles, and a wind speed of 6 m/s. The electricity produced was recorded. The simulated electrical power produced yielded a relationship that predicted the electrical power output with a coefficient of determination (R2) of 0.9752; this shows a very close agreement with actual electric output values. It is recommended that a similar study be conducted to investigate maximum power output for vertical wind turbines. 2024-11-01T00:00:00Z https://ir-library.mmust.ac.ke/xmlui/handle/123456789/3649 EFFECT OF MICRO LIME ON THE ENGINEERING PROPERTIES OF AMBIENT TEMPERATURE-CURED SUGARCANE BAGASSE ASH-BASED GEOPOLYMER CONCRETE Thuku, Keithy Kamau significant carbon emissions. Advancing concrete technology places geopolymer concrete as a potential green concrete by completely replacing Ordinary Portland Cement. However, the geopolymerization process is initiated at elevated temperatures, which demands that curing at elevated temperatures be conducted for several hours, limiting its application. Calcium ions in Geopolymer concrete (GPC) allow the formation of Calcium Aluminate Silicate and Calcium Silicate Hydrate gels, allowing ambient temperature curing. To study the effect of micro lime on the engineering properties of ambient temperature-cured sugarcane bagasse ash-based GPC, this research used Sugarcane Bagasse Ash (SCBA) as source material; one part of sodium Hydroxide 16M solution and two parts of sodium silicate were used as the alkaline activator. Crushed stones and river sand were utilized as the coarse and fine aggregates, respectively. A sodium naphthalene formaldehyde (SNF) based superplasticizer was added at 3% of the SCBA. Micro lime was added as an admixture in varying proportions as a percentage weight of SCBA. In the fresh state, it was found that the workability decreased with the increase of micro lime content. The ambient temperature curing of the SCBA-based GPC was achieved at a 1% addition of the micro lime. The SCBA-based GPC's compressive strength increased with the micro lime increase, up to 7%. The ambient temperature cured SCBA-based GPC at 3% had the best water absorption resistance. The SCBA based GPC had no significant weight loss on 2.5% sulfuric acid exposure. The 5 and 7% micro lime mix had no significant change in compressive strength under the condition of sulfuric acid, unlike the 0,1 and 3%. The results from this research contribute to the body of knowledge on ambient temperature-cured SCBA-based geopolymer concrete. It reveals the possibility of expanding the applications of GPC made from the locally available source material, SCBA. 2024-10-01T00:00:00Z https://ir-library.mmust.ac.ke/xmlui/handle/123456789/3630 CO-DIGESTION OF A MIXTURE OF COW DUNG AND MAIZE STALK RESIDUES AND ITS INFLUENCE ON BIOGAS PRODUCTION TUM, REUBEN KIRWA The rapid exhaustion of finite non-renewable energy sources like fossil fuels has resulted in adverse effects on human health, environmental deterioration, and global climate change. Two primary factors dominate Kenya's energy scene: a heavy dependence on declining biomass energy resources for the rural household to meet energy needs and a significant reliance on petroleum imports to meet contemporary economic needs. The expanded use of renewable energy was one of the factors needed to drive sustainable development. Production of biogas energy from cow dung in Kenya using agricultural residues because of the high C/N ratio is one option for producing energy derived from renewable resources. The altered C/N ratio is partially responsible for the creation of biogas by co-digestion. The study utilized response surface approach to maximize the critical parameters that influence biogas output from co-digestion and Na2CO3 pre-treatment using a digester. The parameters studied were substrates (cow dung and maize residues) and percentage soda ash. The study's objective was to examine the influence of the duration of pretreatment of maize stalks regarding biogas production when cow dung and maize stalks were co-digested in an anaerobic digestion process. The maize residue was prepared based on the design of the experiment where different samples were pretreated at different Na2CO3 concentrations and varied duration. Under different Na2CO3 concentration, the maize stalk pretreated by 7% Na₂CO₃ concentration for 4 days achieved the highest total solid of 15.15% which was 7.26% higher than that of untreated one, and was subsequently used to carry out co digestion with the core substrate which was the cow dung. The study found that the optimum substrate ratio for biogas production by the co-digestion of cow dung, pre treated maize stalks, and dilution was 1:1:3, with cow dung and maize stalks being in equal proportions, these optimum substrate ratios and dilution made favorable conditions for the multiplication of bacteria. The daily average biogas yield produced by the above-mentioned ratio was 203.64mL which is 2.12 times greater than that of cow dung mono-digestion as per the experiment. Co–digestion bioreactors operating with low cow dung concentration vis a vis maize stalks, yielded low biogas compared with the ones with balanced substrate ratios or cow dung being slightly higher. It was deduced that co-digestion improves the effectiveness of the digester, resulting in a higher yield of biogas. The findings demonstrated that higher dilution levels resulted in greater material degradation, hence enhancing the production of biogas and methane. Conclusions were made based on proximate analysis, the proportion of biogas produced, and effects of soda ash as pretreatment media. Therefore, co-digestion of cow dung and maize stalk residues typically improves the biogas yield compared to digesting cow dung alone. This is because maize stalk residues add additional organic matter and increase the carbon-to-nitrogen (C/N) ratio, which can optimize the anaerobic digestion process. It was recommended that there should always be ensured that the carbon-to-nitrogen (C/N) ratio is balanced between cow dung and maize stalk residues and by regular monitoring of this ratio can improve microbial activity and enhance biogas yield. Furthermore, more research to determine the ideal mixing ratios of cow dung and maize stalk residues for specific local conditions to maximize biogas yield and ensure consistent production. 2024-11-01T00:00:00Z https://ir-library.mmust.ac.ke/xmlui/handle/123456789/3625 ANALYSIS OF DEMONSTRATIVE-KINESTHETIC TEACHING ON ROBOT MANIPULATOR FOR EFFICIENT INDUSTRIAL MATERIAL HANDLING APPLICATIONS MABONG, PILOT GRIFFIN Robots significantly improve productivity and production efficiency due to process optimisation and low production costs. Job enrichment and fulfilment can be achieved through improved workflows and role distribution. This will also lead to an improved capacity to handle complex assignments, perform tedious and sophisticated tasks quickly, enhance workers' safety, and improve the customization of goods and services. The adoption of robots in Kenyan small and medium-sized enterprises (SMEs) manufacturing industries has been gradual and faces many challenges. Key among the challenges is the few skilled labourers with robot programming capabilities for the varying manufacturing environments. This has led to the need for more competitiveness in the manufacturing sector with other countries, especially on the global stage. This can be immensely magnified in flexible manufacturing systems, especially when switching product types to robotised systems requires higher costs and time. The inferior skill set of people interacting with the robots warrants designing and generating user-friendly programming approaches using kinesthetic teaching and augmented and virtual reality. The Kenyan government's development agenda aims to achieve the 2030 goals using emerging innovative technologies, including robotics, machine learning, and artificial intelligence (AI). This research purposed to analyse the demonstrative-kinesthetic teaching (DKT) approach to robotic manipulators for efficient material handling applications. The robotic arm was programmed using structured texts and DKT to determine coordinate configurations, the desired position's accuracy, and the DKT's efficiency. A control platform was created using Visual Studio to allow the arm to be programmed demonstratively using the lock arm button. This allowed the arm to record the demonstrations while the user did the programming. Palletizing and contour path welding experiments were conducted to validate the study and collect the requisite data. Structured texts were used as the control for the experiment. The results found that the mean inverse kinematics were the same for both methods at the α=0.05 significance level, F=0.03, P=0.86, and Fcritical =5.98. Joint 2 had a low percentage error at 2.12 % and a high for joint 4 at 5.24%, majorly due to user level of accuracy. The DKT had an 80% and 66.67% efficiency on experimental time for palletising and contour path welding, respectively, compared to structured text. The conclusion was that DKT provided a means of finding the joint configurations in concurrence with analytical solutions. The robotic manipulator was able to trace paths and desired positions accurately. DKT provided more accessible programming for non-skilled floor operators than structured texts. Some recommendations were the inclusion of wearable devices in the DKT approach and shifting the control platform created to universal set-up platforms. 2024-11-01T00:00:00Z