http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/60 2026-05-03T13:44:20Z 2026-05-03T13:44:20Z Isah, I. Jumare, M. A. Sa'ad, A. Muhammadu, M. M. http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/30552 2026-04-21T18:48:18Z 2026-02-11T00:00:00Z

Title: Thermodynamic performance analysis of retrofitted simple cycle gas turbine power plant Authors: Isah, I.; Jumare, M. A.; Sa'ad, A.; Muhammadu, M. M. Abstract: The combined cycle power plant (CCPP) utilizes both gas and steam turbines to generate more than 50% electricity using the same fuel than the conventional simple cycle gas turbine power plant. The waste heat from the gas turbine is harnessed by the steam turbine utilizing the heat recovery steam generator (HRSG) to generate additional electricity, increase efficiency and reducing emission. Thermodynamic performance analysis of a retrofitted simple cycle gas turbine power plant was carried out. The studied gas turbine unit is the Siemens SGT5-2000E (3 units) gas turbine model with an installed capacity of 145 MW each located at the Geregu gas turbine power plant in Ajaokuta Kogi State. A one-year data covering March, 2018 to February, 2019 was used for the study in other to investigate the effect of ambient temperature on the performance parameters such as compressor work, turbine work, pump work, steam turbine work, power output and efficiency of the combined cycle power plant. The different control volumes of gas and steam turbines were subjected to thermodynamic study, and comparisons between simple and combined cycles were made. The analysis's predicted findings indicate that a drop in ambient temperature will boost power output, improve efficiency, and reduce emissions. Similar to this, a combined cycle power plant would produce more electricity and have a higher efficiency than a simple cycle gas turbine power plant. Description: Journal

2026-02-11T00:00:00Z Jonah, I. Abdullahi, Aliyu Alhaji http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/30402 2026-03-24T16:34:35Z 2025-02-25T00:00:00Z

Title: Circular Economy Frameworks for Manufacturing Industry- A Review Authors: Jonah, I.; Abdullahi, Aliyu Alhaji Abstract: Manufacturing industries have been played a significant role in terms of production in attempt to improve economy worldwide. However, in a traditional linear economy setting, it becomes unrealistic prove to achieve sustainable production and consumption patterns. The concept of circular economy has been proved to be the only way out in the present environmental issues and unavailability resources, it aims at eventually severing this link, through keeping resources in the loop. Through a systematic literature review, this paper attempts to revisit the concept of circular economy in the manufacturing industries in order to determine whether the body of research has improved beyond framework development and into verified implementation in manufacturing industry. The review shows that the research field has indeed advanced from purely conceptual framework into empirical studies and research into implementation tools. However, in empirical studies and framework development the sustainability impact of CE practices is completely addressed only through the environmental issues, neglecting the social dimension, economic dimension and even the percentage of virgin material usage for production is neglected. Further, a key finding is that the generality of narrow approaches to sustainability in manufacturing results to a risk that circular economy implementation efforts will become difficult if percentage of virgin materials usage by industries are not evaluated. Holistic approaches are needed to avoid the implementation of solutions that may be framed as circular, but neglect the sustainability component.

2025-02-25T00:00:00Z Abdullahi, Aliyu Alhaji Choudhury, I. A. Azuddin, M. http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/30401 2026-03-24T16:21:06Z 2025-05-05T00:00:00Z

Title: Thermal Characterisation of Binder Constituents and Wax-Based Aluminium Metal Injection Moulding Feedstock for Micro-Metal Parts Authors: Abdullahi, Aliyu Alhaji; Choudhury, I. A.; Azuddin, M. Abstract: Thermal decomposition behaviours of the binder constituents have been identified to influenced the quality of metal injection moulding (MIM) feedstock and sintered parts. This research investigates the thermal characterisation of the binder constituents and wax-based aluminium MIM feedstock. The binder system is composed of paraffin wax (PW) – 65 wt.%, high density polyethene (HDPE) – 30 wt.% and Stearic acid (SA) – 5 wt.%. While, the wax-based aluminium MIM feedstock is formulated with the proportions of the binder constituents and 99.999% pure aluminium powder at solid loading of 62 vol.%. Thermal characterisation technique employed for the evaluation of the binder constituents and wax-based aluminium MIM feedstock were differential scanning calorimetry and thermogravimetric analysis (TGA). Significant changes were observed for the binder constituents at various temperatures 45 °C and 60 °C (PW), 135 °C (HDPE), 75 °C (SA) and 45 °C, 60 °C, 135 °C (Wax-based aluminium MIM feedstock) on the DSC profiles. While TGA results revealed that binder constituents can be removed completely around 580 °C from the wax-based aluminium MIM feedstock. Thermal behaviour of the binder system established will be useful for setting suitable injection moulding temperature, development of the thermal profile(s) for debinding and sintering processes of the aluminium MIM micropart production.

2025-05-05T00:00:00Z Irechukwu, C. C. Lawal, S. A. Sadiq, I. O. Abdullahi, Aliyu Alhaji Abutu, J. http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/30394 2026-03-23T20:03:43Z 2025-12-27T00:00:00Z

Title: Optimization of FCA and MIG welding parameters for AISI-1045 Steel Authors: Irechukwu, C. C.; Lawal, S. A.; Sadiq, I. O.; Abdullahi, Aliyu Alhaji; Abutu, J. Abstract: Welding is a vital industrial process for joining metals and thermoplastics, with Metal Inert Gas (MIG) and Flux Cored Arc (FCA) welding widely used due to their versatility and effectiveness. This study optimized FCA and MIG welding parameters for AISI 1045 alloy steel using Response Surface Methodology (RSM) via Central Composite Design (CCD) L20(5)3 in Minitab 20. The parent material and weldments were characterized through standard testing methods. X-ray fluorescence (XRF) analysis confirmed the material as galvanized medium-carbon steel containing 0.376% carbon and 22–25% iron, while revealing a crystalline structure with features indicating crystal size and possible defects. Mechanical testing showed UTS values for welds were generally lower than the base metal, high joint efficiencies confirmed good bonding. Also, optimal conditions for hardness (FCAW: 4.6 kgm/s, 73.2 A, 28 mm; MIG: 8 kgm/s, 73.2 A, 24.6 mm), UTS (FCAW: 10 kgm/s, 73.2 A, 26 mm; MIG: 8 kgm/s, 73.2 A, 24.6 mm), and impact strength (MIG: 6 kgm/s, 106.8 A, 26 mm), with gas flow rate as the dominant factor and refined microstructures confirming superior weld quality and bonding. Both welds were free from porosity and cracks, underscoring the importance of parameter optimization for superior weld quality and mechanical performance.

2025-12-27T00:00:00Z