https://repository.ju.edu.et//handle/123456789/1215 Thu, 09 Apr 2026 17:09:58 GMT 2026-04-09T17:09:58Z https://repository.ju.edu.et//handle/123456789/9521 Relationship between the heterogeneity in mechanical properties, bone density and composition parameters of cortical bone to design and develop bone scaffolds and implants: Analysis of bone microstructure Kalsi, Sachin; Singh, Jagjit; Sharma, N.K.; et al. Bone is heterogeneous and anisotropic because its mechanical characteristics vary by anatomic location and loading direction. Previous research established a correlation between bone density, mineral, organic content, and porosity and mechanical qualities. Medical and bioengineering researchers can learn about bone hetero geneity and anisotropy by analysing bone density and later composition parameters across the bone diaphysis in both longitudinal and transverse orientations. This research examines bone density and composition parameters in bovine femoral cortical bone from higher, middle, and lower diaphysis regions and longitudinal and transverse orientations. At three homogeneous diaphysis sites, these properties did not alter in longitudinal or transverse orientations. At the upper and lower diaphysis locations, mineral and organic content were statistically different in both longitudinal and transverse orientations, contributing to anisotropy. At the middle location, all measured parameters were not statistically different. Transverse bone density and water heterogeneity were greater, while longitudinal values were higher for the other metrics. Upper and lower sites had increased bone variability due to %water, although mineral content was more homogenous. The longitudinal and transverse organic content and apparent density heterogeneity was greater at the middle position. At the later site, bone density and mineral content were more homogenous longitudinally and transversely. Lamellar bone microstructure with canalicular/ vascular network, cavities, and holes contributed to bone materials’ %water content. Collagen fibres contributed to bone material’s organic composition, whereas intrafibrillar and extra fibrillar minerals contributed to its mineral content. Mon, 01 Jan 2024 00:00:00 GMT https://repository.ju.edu.et//handle/123456789/9521 2024-01-01T00:00:00Z https://repository.ju.edu.et//handle/123456789/9520 Predictive modeling of MRR, TWR, and SR in spark-EDM of Al-4.5Cu–SiC using ANN and GEP Debnath, Shantanu; Sen, Binayak; Patil, Nagaraj; et al. In this study, Al-4.5Cu alloy was reinforced with varying weight percentages of SiC particles (2%, 4%, 6%, and 8%) to create metal matrix composites via the stir casting method. The formation of intermetallic compounds was confirmed through energy dispersive spectroscopy and x-ray diffraction analysis. This article compares the performance of Artificial Neural Network (ANN) and Gene Expression Program ming (GEP) models in predicting the Metal Removal Rate (MRR), tool wear rate, and surface roughness in the die-sinking electro-discharge machining (EDM) process of the ex-situ developed Al-4.5%Cu–SiC composites. The study considers three machine parameters—pulse on time (TON), pulse off time (TOFF), and current (I)—along with the weight fraction of SiC particles as input variables for the models. Both ANNand GEP models demonstrated high predictive accuracy for the EDM performance metrics, with correlation coefficients (R) ranging from 0.97368 to 0.98065 for the ANN model and 0.98011 to 0.98259 for the GEP model. Notably, the GEP model exhibited superior pre dictive capability, as evidenced by its higher correlation coefficients and lower root mean square error, indicating greater effectiveness in predicting the EDM process outcomes than the ANN model. Mon, 01 Jan 2024 00:00:00 GMT https://repository.ju.edu.et//handle/123456789/9520 2024-01-01T00:00:00Z https://repository.ju.edu.et//handle/123456789/9518 Minimum quantity blended bio-lubricants for sustainable machining of superalloy: An MCDMmodel-based study Sen, Binayak; Kothapalli, Sunil Kumar; Kumar, Raman Theimperative shift toward sustainability has driven contemporary scholars to explore the lubricating and cooling properties of vegetable oils in traditional metal-cutting processes. Palm oil, as an environmentally conscious derivative, emerges as a preferable option for the base fluid in Minimum Quantity Lubrication (MQL). However, its high viscosity impedes fluidity, limiting industrial applicability. In contrast, sunflower oil offers superior lubricating qualities and flowability. Consequently, efforts have been directed toward enhancing the lubricating efficacy of palm oil. Six blends of palm and sunflower oils (ranging from 1:0.5 to 1:3) were utilized as MQL fluids, followed by evaluations of machining outcomes, including average surface roughness, specific cutting energy, and tool wear. In addition, an integrated Shannon’s Entropy-based Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) framework was employed to determine the optimal volume ratio of the palm–sunflower oil blend. The TOPSIS analysis confirmed that the 1:2 ratio yielded the most favorable outcomes. Subsequent compara tive analysis demonstrated that this optimal blend resulted in reductions of 16.79% and 14.92% in surface roughness, 11.82% and 10.98% in specific cutting energy, and 10.19% and 8.45% in tool wear compared to pure palm and sunflower oil media, respectively. Finally, sustain ability assessments of various cooling media revealed that a minimal quantity of the blended bio-lubricant-based medium outperforms both compressed air and flooded media. Mon, 01 Jan 2024 00:00:00 GMT https://repository.ju.edu.et//handle/123456789/9518 2024-01-01T00:00:00Z https://repository.ju.edu.et//handle/123456789/9499 INNOVATIVE COMPOSTING PROCESS FOR ENHANCING ORGANIC WASTE MANAGEMENT IN URBAN AREAS JAISANKAR, S.; ARPUTHABALAN, JESWIN; SURESH, S.; et al. Towns and cities produce large quantities of organic waste which is problematic for waste management structures. This work assesses contingency of new approaches to composting in the fight against the management of organic waste in urban areas. The research focuses on three key composting methods which include aerobic composting, anaerobic digestion and vermicomposting. Samples were obtained from the urban communities that practiced these measures for one year. It was revealed that aerobic composting if implemented lowers the quantity of organic waste through composting to sixty-five percent and attains the compost maturity index of 0.85 and simultane ously producing 40% less total greenhouse gasses compared to those produced when landfilling. Biogas from the anaerobic digestion with a methane content of 60% offers 1.2 kWh of energy per kilogram of the waste and results in a 70% minimisation in the waste. A survey of urban residents participating in these programs had a 70% satisfac tion level, further proving that the community is willing to participate in sustainable waste management. This work also reveals that composting strategies are useful in addressing the increasing problems of urban organic waste while lessening the effects on the environment and encouraging the growth of innovations in urban agricultural practices. Further studies should be conducted to look at how these techn Mon, 01 Jan 2024 00:00:00 GMT https://repository.ju.edu.et//handle/123456789/9499 2024-01-01T00:00:00Z