DEPARTMENT OF MATERIALS AND METALLURGICAL ENGINEERING

This study investigates the effectiveness of clove oil extract as a green corrosion inhibitor for mild steel immersed in simulated seawater. Corrosion in chloride-rich marine environments leads to rapid metal degradation, and natural plant-based inhibitors offer a sustainable alternative to synthetic chemicals. Clove oil was extracted using ethanol-based solvent extraction, and mild steel specimens were exposed to 3.5% NaCl solutions containing 0.1, 0.2, and 0.3 mL of the extract. Electrochemical analyses, including Open Circuit Potential (OCP), Electrochemical Impedance Spectroscopy (EIS), and Tafel polarization were conducted, alongside surface characterization using FTIR, SEM, and EDS. Results showed that the optimum inhibitor concentration (0.3 mL) produced a significant noble shift in OCP, stabilizing around +0.07 V compared to the unstable blank sample. Tafel analysis revealed a reduction in corrosion current density from 2.287 × 10⁻⁶ A/cm² (control) to 0.887 × 10⁻⁶ A/cm², corresponding to an inhibition efficiency of 61.22%. EIS results confirmed enhanced surface protection, with charge-transfer resistance increasing from 1.8 × 10⁵ Ω·cm² for the blank to 1.0 × 10⁶ Ω·cm² at 0.3 mL. SEM images showed a smoother, film-covered surface at higher inhibitor concentrations, while EDS detected reduced Fe intensity and increased oxygen content. FTIR confirmed the presence of O–H, C–O, and aromatic C=C functional groups responsible for adsorption. This study concluded that clove oil extract has a strong protective effect, confirming its potential as an efficient eco-friendly corrosion inhibitor for mild steel in saline environments. It is recommended that future studies explore clove extract synergistically with other natural inhibitors to further improve corrosion resistance.

This study investigates the effectiveness of clove oil extract as a green corrosion inhibitor for mild steel immersed in simulated seawater. Corrosion in chloride-rich marine environments leads to rapid metal degradation, and natural plant-based inhibitors offer a sustainable alternative to synthetic chemicals. Clove oil was extracted using ethanol-based solvent extraction, and mild steel specimens were exposed to 3.5% NaCl solutions containing 0.1, 0.2, and 0.3 mL of the extract. Electrochemical analyses, including Open Circuit Potential (OCP), Electrochemical Impedance Spectroscopy (EIS), and Tafel polarization were conducted, alongside surface
characterization using FTIR, SEM, and EDS. Results showed that the optimum inhibitor concentration (0.3 mL) produced a significant noble shift in OCP, stabilizing around +0.07 V compared to the unstable blank sample. Tafel analysis revealed a reduction in corrosion current density from 2.287 × 10⁻⁶ A/cm² (control) to 0.887 ×
10⁻⁶ A/cm², corresponding to an inhibition efficiency of 61.22%. EIS results confirmed enhanced surface protection, with charge-transfer resistance increasing from 1.8 × 10⁵ Ω·cm² for the blank to 1.0 × 10⁶ Ω·cm² at 0.3 mL. SEM images showed a smoother, film-covered surface at higher inhibitor concentrations, while EDS detected reduced Fe intensity and increased oxygen content. FTIR confirmed the presence of O–H, C–O, and aromatic C=C functional groups responsible for adsorption. This study concluded that clove oil extract has a strong protective effect, confirming its potential as an efficient eco-friendly corrosion inhibitor for mild steel in saline environments. It is recommended that future studies explore clove extract synergistically with other natural inhibitors to further improve corrosion resistance.

In order to fuse two metal components, electric arc welding uses electrical heat to cause melting, which, when cooled, forms a solid connection. In order to protect the molten metal from exposure to the atmosphere and stop chemical reactions, slag is injected throughout this operation. A power source that creates an electric arc between the metal material and the electrode to be fused is necessary for this process. Both consumable and non-consumable electrodes, as well as alternating or direct current, are used by welders. An electrode is a conductor that creates the heat required for melting and fusing by sending electric current to the metal to be welded. Whether an electrode is consumable or non- consumable depends on the specific arc welding process being used. The electrical energy needed for the arc welding process may be obtained from a variety of power source methods. Constant voltage and constant current power sources are the most common varieties.

This project addresses the challenge of optimizing solar energy capture through the design and implementation of a single-axis solar tracking device. Traditional fixed solar panels are limited by their stationary nature, resulting in suboptimal energy harvesting as the sun moves across the sky. The research aims to develop a cost-effective, efficient solar tracking system that continuously adjusts panel orientation to follow the sun's path. The methodology involved evaluating multiple design concepts, including passive liquid-based trackers, Raspberry Pi-controlled systems, and an Arduino Nano-based solution with Light Dependent Resistors (LDRs). The final design utilized Arduino Nano microcontroller, servo motors, and LDRs to detect sunlight intensity and adjust panel orientation accordingly. Testing revealed that the tracking system outperformed stationary panels in energy output during an 8-hour evaluation period. The tracked panel maintained consistently higher voltage readings throughout the day. Challenges encountered included ambient light interference with sensors and software-related overtilting issues, which were addressed through design modifications. The study concludes that single-axis solar tracking represents a viable approach to enhancing solar energy efficiency, with recommended future improvements including more robust components, advanced tracking algorithms, dual-axis capabilities, and power supply optimization for increased durability and performance.

Industrialization is the backbone of any meaningful global development while material selection forms the basis or bedrock for industrial development and improvements (Ashby & Johnson, 2013). In the industries, there are key aspect of industrial processes among which is the transportation of materials (Roemer, 1979). Getting the right selection of materials for transporting a specific and the right kind of materials is one of the challenges that has bedeviled the industrial sector, which the engineers have been looking for ways to proffer solutions to this humongous challenge for several decades (Constable & Somerville, 2003). A lot of research has been done in getting materials that are corrosion resistant that is, having high resistance to
chemical attacks (Mévrel, 1989). Nonetheless, this has not been eradicated as we still have lots of materials that are still highly corrosive. In the oil and gas sector for example, both the crude materials and refined products are mostly transported through pipes over long distance (Koch, 2017).

In this study, the fabrication of a hybrid composite abrasive sandpaper using coconut shell and crab shell particles embedded in polyester resin is investigated, aiming to address resource depletion and environmental issues associated with conventional synthetic abrasive materials. The mechanical properties and abrasive behavior of the fabricated composite are investigated through meticulous methodology involving sourcing, cleaning, drying, mechanical processing, and production of abrasive specimens. Varying levels of hardness, compressive strength, density, and water absorption are revealed across different compositions of coconut shell and crab shell. The most optimal properties are demonstrated by Sample 5, with a proportion of 35% coconut shell and 65% crab shell, which exhibits reduced water absorption, enhanced hardness, competitive compressive strength, and favorable density characteristics. Comparative analysis with Garnet sandpaper suggests that the hybrid composite sandpaper samples offer competitive or superior performance. Further research is recommended to optimize composition, utilize advanced characterization techniques, and explore sustainable manufacturing practices to enhance the performance and applicability of hybrid composite abrasive materials.