Higher-end science and technology facilitate the human community with a sophisticated life despite it curses by abundant pollution. The alarming demand for sustainability pressurizes the manufacturing sector to ensure sustainable manufacturing. Since Molybdenum di sulfide (MoS₂) and avocado oil are known solid and liquid lubricants respectively, hence, it is a worthwhile attempt to implement the bio-based degradable avocado oil enriched with nano Molybdenum di sulfide (nMoS₂) particles as a potential machining fluid for CNC-end milling. Different proportions of avocado oil and nMoS₂ were used to synthesise four distinct machining fluids to assess the individual impact of avocado oil and nMoS₂ particles. The emulsification and sonication were employed to synthesise the fluids. A hybrid Grey Relational Analysis (GRA) coupled with Principal Component Analysis (PCA) was followed to scrutiny the effect of novel machining fluid on machining objectives. The experimental results of physio-chemical properties revealed that avocado-rich 0.5% nMoS₂ excels among others. The L₁₆ orthogonal array experiments associated with statistical analysis explored the developed machining fluid (A6W4/0.5) that significantly impacts the machining objectives. The experimental results manifest that nearly 64.87% of surface roughness and 93.3% of tool wear have been reduced during machining in the presence of A6W4/0.5 fluid than A4W6/0.75. The improved performance of the novel machining fluid upholds its potential to replace conventional fluids and ensure green manufacturing.

Injera is a popular food in Ethiopia. Currently, approximately 70-80% of the primary energy for cooking in Ethiopia comes from biomass. The collection of wood for fuel and its combustion in inefficient stoves lead to local scarcity and ecological damage. This extensive use of biomass in traditional ways contributes to drought, environmental pollution, greenhouse gas (GHG) emissions, and health issues. To mitigate these problems, there is a growing emphasis on promoting alternative renewable energy sources, such as biogas technology, which is both energy-efficient and cost-effective. Currently, biogas in Ethiopia is primarily used for lighting and cooking. However, previously implemented biogas injera baking stoves have faced challenges, including uneven heat distribution, heat loss, and high fuel consumption. This study aims to analytically design and develop an improved biogas injera baking stove and its performance. This project is focusing on key parameters such as cooking time, biogas consumption, temperature, efficiency, energy requirements, and the quality of injera. The newly developed stove completed the baking process in just 120 sec. The experimental results demonstrate that the newly developed biogas injera baking stove outperforms the existing model, showing significant reductions in both baking time and biogas consumption. Additionally, this study highlights the economic feasibility of the new stove, with a positive net present value.

This study investigates the optimization of Fused Deposition Modeling (FDM) parameters for Polyethylene Terephthalate Glycol (PETG) a material widely utilized in clinical and biomedical applications due to its favorable combination of lightweight properties, durability, and versatility. By applying a Grey-Taguchi methodology, the research systematically addresses how manufacturing variables influence mechanical performance, specifically focusing on tensile and compressive strength. Through rigorous signal-to-noise (S/N) ratio evaluations, the investigation identified the optimal parameter settings for individual mechanical properties. For tensile strength, a peak performance of 48.264MPa was achieved using level 1 extrusion temperature, a 55% infill density, and a printing speed of 20mm/s. Conversely, maximizing compressive strength to 47.762MPa required level 1 extrusion temperature, a higher infill density of 60%, and an increased printing speed of 30mm/s. Analysis of Variance (ANOVA) further confirmed that extrusion temperature, infill density, and printing speed all exert a statistically significant influence on these mechanical outcomes. Because biomedical and clinical components often require a balance of multiple mechanical traits, the study utilized Grey Relational Analysis (GRA) to establish a multi-response setting configuration of 1-3-3. This configuration yielded a peak grey relational grade of 1, representing the ideal compromise and overall optimal condition for dual-performance requirements. To ensure reliability, experimental validation tests were conducted. The results showed error margins of 4.01% for tensile strength and 6.14% for compressive strength. Because both error values remain well within acceptable engineering thresholds, the findings successfully verify the efficacy and precision of this optimization framework for additive manufacturing applications.

This study investigates the mechanical performance and synergistic optimization of hybrid composites reinforced with alkaline-treated Enset and bamboo fibers within an unsaturated polyester matrix. To enhance interfacial adhesion, both natural fibers were subjected to a 55% sodium hydroxide (NaOH) surface treatment to remove amorphous impurities and expose reactive cellulose hydroxyl groups. Bamboo provides exceptional stiffness and tensile strength due to its high cellulose content and dense vascular bundles, while Enset fibers contribute enhanced impact resistance, flexibility, and elongation at break. Hybridization synergistically balances brittleness and flexibility. Both Enset and bamboo are rapidly renewable, eco-friendly plant resources. Unlike synthetic glass or carbon fibers, which are petroleum derived and persist in landfills, the natural fibers in this hybrid composite significantly reduce the carbon footprint and enhance the end-of-life biodegradability of the material. Utilizing a Taguchi-based Design of Experiments (DoE) coupled with Grey Relational Analysis (GRA) and Analysis of Variance (ANOVA), the study evaluates the influence of key fabrication parameters such as fiber weight fractions and stacking configurations on ultimate tensile strength, flexural modulus, impact resistance, and moisture absorption. From Taguchi analysis the optimized multi-response enset-bamboo/polyester fiber hybrid composite parameters was achieved by using the parameters are enset fiber (25%), bamboo fiber (20%), and polyester (55%) and the optimized hybrid composite formulation demonstrates superior multi-objective performance, highlighting its viability as an eco-friendly, lightweight structural substitute for traditional synthetic composites in engineering applications.

In light of the current global economic crisis and environmental pollution issues, this project focuses on the extraction of essential oil from jatropha seeds, with a particular emphasis on extraction technology. Jatropha curcas (jatropha) is recognized as a promising feedstock for biodiesel due to its adaptability to semi-arid lands. The biodiesel industry is rapidly expanding in response to rising petroleum prices and growing concerns about global climate change, positioning jatropha as a productive and effective source of essential oil. In Ethiopia, where petrol is primarily imported at high costs, the development of essential oil production is crucial for reducing expenses. This thesis is significant for several reasons: it promotes the cultivation of jatropha trees to help farmers generate income, provides manufacturers with a low-power, space-efficient oil extraction machine, and encourages the government to prioritize the production of essential oils (biodiesel) through simplified and cost-effective systems. The primary objective of this study is to enhance oil production, improve efficiency, and minimize time wastage. Addressing pressing environmental concerns, this thesis highlights the environmental benefits of biodiesel. While diesel fuel emits 9% CO ₂ , biodiesel emits only 1.33%. Additionally, diesel emits 5% O ₂ compared to biodiesel’s 17.67%, illustrating its positive impact on environmental balance. Notably, biodiesel produces 0% CO emissions, making it a significant contributor to reducing greenhouse gas emissions and promoting environmental sustainability. This paper reviews global research on jatropha seed oil extraction, mentioning technologies such as the Komet oil press and Rose Downs’s oil press, which use components like screws, gearboxes, feeding sections, bearings, and screw shafts. However, our design differs from these systems in specific components and an extraction method employed.

This research aims to identify the optimal machining parameters for turning Aluminium Alloy 075-T651 using a tungsten carbide insert cutting tool and a flood coolant system, applying the Grey-based Taguchi method. Aluminium Alloy 075-T651 is commonly utilized in the automotive, marine, machine tools, and aerospace industries due to its excellent weight-to-strength ratio. A key focus of the study are the surface roughness and material removal rate, which is critical in machining. The research explores how various turning parameters affect surface roughness and material removal rate with investigates the role of coolant in these operations. Heat generated during machining can adversely affect tool life, workpiece dimensions, and surface quality. To address these challenges, an environmentally friendly, biodegradable, and non-toxic avocado oil-based cutting fluid was employed. An orthogonal array from the Taguchi method guided the experiments, with surface roughness and material removal rate measured as a response. Minitab software facilitated the statistical analysis of process parameters. Key performance metrics included material removal rate, and surface roughness, influenced by cutting speed, feed rate, depth of cut, and avocado oil proportion. So, an avocado oil (9%), depth of cut (1.0 mm), cutting speed (1000 rpm), and feed rate (85 mm/min) are an optimized parameter.