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    RSM-Based Predictive Modelling of Gravimetric Corrosion Characteristics of Welded and Tempered UNS G10400 Carbon Steel in a Seawater Environment
    (Portugaliae Electrochimica Acta, 2024-02-07) Silas Oseme Okuma
    In this study, gravimetric analysis was used to determine corrosion properties, i.e., WL and CR of welded and tempered UNS G10400 CS exposed to Sw. In order to determine optimal WL and CR, RSM approach was utilized to develop a prediction model. 20 runs of the experiment were used for statistical ANOVA. As response variables, the experimental design matrix included WL and CR. To optimize the results of GC method and develop a predictive regression model, CCD was utilized. By ANOVA, the generated models for WL and CR indicated a significant p-value (which is probability, under the null hypothesis assumption, of obtaining a result equal to or higher than the one observed) of < 0.0001. F-values and R2 showed good statistical correlation between experimental and predicted values. Optimal conditions for WL and CR occurred at 25 °C(as-welded), with an ET of 17 days, and their optimum values were 0.744 g and 0.769 mm/year, respectively. Validation of optimized predicted results showed an UE of 1.6 and 2.9%, for WL and CR, respectively, which was below 5%. This revealed that the generated model adequately predicted CP of welded and tempered UNS G10400 CS in a Sw environment.
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    Object Detection in Self-Driving Vehicle Using CARLA Simulator and YOLOv8
    (Journal of Science and Technology, 2025-12-30) Martins Obaseki; Silas Oseme Okuma
    This study develops an object detection system for autonomous vehicles using the YOLOv8 model integrated with the CARLA simulator. The research addresses gaps in multi-camera setups and real-time detection by training YOLOv8 on a custom dataset generated from CARLA simulations. Results show high performance with a mean Average Precision (mAP@50) of 0.990 in single-camera configurations, outperforming multi-camera setups due to computational constraints. While Proportional-Integral-Derivative (PID) and Model Predictive Control (MPC) integration was explored conceptually, empirical evaluation revealed enhanced navigation accuracy in simulated scenarios, though real-world validation is needed. The work highlights trade-offs between accuracy and speed, suggesting optimizations for practical deployment.
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    Green synthesis, characterization, and thermal stability of Albizia adianthifolia leaf–mediated CaO nanoparticles for anticorrosion applications
    (Next Nanotechnology, 2026-03-06) Silas Oseme Okuma
    This study presents the first report on the green synthesis of ultrasmall calcium oxide nanoparticles (AA–CaO NPs) using Albizia adianthifolia leaf extract and provides a systematic evaluation of their corrosion inhibition performance in 1 M HCl solution. Transmission electron microscopy revealed predominantly quasi-spherical nanoparticles with an exceptionally narrow size distribution of 1–3 nm (average diameter 2.45 ± 0.81 nm), which is significantly smaller than the particle sizes typically reported for plant-mediated oxide systems.UV–Vis spectroscopy showed an absorption edge at 309 nm (4.0 eV), indicative of wide band-gap behavior, while FTIR analysis confirmed phytochemical surface functionalization through the presence of hydroxyl and C–O/C–O–C functional groups. Thermogravimetric analysis demonstrated high thermal stability, with ≥ 99% mass retention up to 184 ◦C.Corrosion inhibition performance was evaluated using gravimetric, atomic absorption, and ther mometric techniques. A maximum inhibition efficiency of 97.20% at 298 K (gravimetric) and 88.96% at 318 K (thermometric) was achieved at optimal concentrations of 1.0–1.5 g⋅L⁻¹ . The inhibition efficiency exhibited adsorption-controlled behavior, with a slight decline at higher concentrations due to surface-site saturation. Significant reductions in weight loss and Fe dissolution confirmed effective suppression of metal dissolution kinetics. The enhanced corrosion protection is attributed to a synergistic dual mechanism involving adsorption mediated barrier formation by phytochemical capping ligands and localized acid neutralization through CaO hydration to Ca(OH)₂. Furthermore, the ultrasmall particle size enhances adsorption density and promotes the formation of a compact, low-permeability protective film, resulting in thermally stable and highly efficient corrosion inhibition.Overall, these findings establish AA–CaO nanoparticles as a viable, high-performance, and environmentally sustainable alternative to conventional synthetic inhibitors for use in aggressive chloride environments.
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    Adsorption, kinetic, thermodynamic, thermal stability, and RSM optimization studies of Mitragyna speciosa as a green corrosion inhibitor for API 5 L X65 steel in aggressive oil and gas well treatment fluids
    (Chemical Thermodynamics and Thermal Analysis, 2026-02-21) Silas Oseme Okuma; Cynthia C. Nwaeju-Okechukwu
    The present study reports, for the first time, the use of Mitragyna speciosa leaf extract (MSLE) as a sustainable corrosion inhibitor for API 5 L X65 pipeline steel under high-temperature acidic conditions representative of oil and gas well treatment environments. An integrated approach combining adsorption modeling, kinetic– thermodynamic evaluation, thermal stability assessment (TGA/DTA), and response surface methodology (RSM) optimization was employed to provide comprehensive mechanistic insight into inhibitor performance at elevated temperatures (323–343 K), concentrations of 0.2–0.8 g/L, and immersion times of 2–10 h.Adsorption behavior was evaluated using Langmuir, Freundlich, and Temkin isotherms (R² = 0.942–0.995), demonstrating strong model agreement and confirming spontaneous adsorption through negative ΔGads values. The thermodynamic parameters indicate a mixed adsorption mechanism involving both physical and chemical interactions. The presence of MSLE increased the apparent activation energy relative to the uninhibited system, confirming adsorption-mediated surface blocking. Transition state analysis revealed an endothermic activation process accompanied by reduced interfacial disorder in the inhibited system.Thermogravimetric analysis showed negligible mass loss below 120 ◦C, corresponding to moisture and volatile removal, while major decomposition occurred between 250 and 380 ◦C, confirming adequate thermal stability under corrosion-testing and oilfield acidizing conditions. RSM analysis demonstrated satisfactory predictive capability (R² = 0.8098), with inhibitor concentration identified as the dominant factor influencing inhibition efficiency. The maximum experimental inhibition efficiency of 98.40% was achieved at 0.8 g/L, 333 K, and 2 h, while numerical optimization predicted optimal operating conditions at 0.8 g/L, 343 K, and 9.13 h with a validated efficiency of 90.24%.The novelty of this work lies in the integrated thermodynamic–kinetic–thermal–statistical evaluation of MSLE under elevated temperature oilfield conditions. This comprehensive framework not only elucidates the inhibition mechanism but also establishes a systematic basis for optimizing the performance of plant-derived corrosion inhibitors in aggressive acidic environments, contributing to the advancement of sustainable corrosion mitigation strategies.
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    STRUCTURAL INTERPRETATION OF “ZULU” OIL FIELD, NIGER DELTA
    (Scientia Africana, 2014) Amarachukwu A. Ibe
    Standard method for structural analysis was applied in the delineation of subsurface structures using seismic and well log data from “ZULU” oil field Niger Delta. Hydrocarbon potential of “ZULU” oil field was evaluated to delineate the geometry of the reservoir of interest. The tops of the modeled reservoir were obtained at 2,365 m; 2,335 m; 2,331m and 2,265 m for well-1, well-2, well-3, and well-4 respectively. Faults were interpreted and identified (F1, F2, and F3) using fault sticks, which was modeled to generate the skeletons. It was observed that the fault skeletons showed pillar gridded pattern that produced the reservoir which shows enclosed anticline structures that serves as a good traps for hydrocarbon accumulation.