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Recent Submissions

Synthesis and Characterization of Zinc Oxide Thin Films for Photovoltaic Applications
(Materials International, 2026-03) SULEMAN Kamaldeen Olasunkanmi
Owing to its potential to significantly improve photovoltaic performances of solar cells, zinc oxide nanoparticles (ZnO NPs) thin films have attracted significant interest from researchers working towards enhancing the performance of organic solar cells. In the present study, ZnO NPs thin films were synthesized by spin coating. The structural and morphological properties of the ZnO NPs thin films were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy. XRD analysis revealed the crystalline structure of the ZnO NPs thin films, while SEM images showed a surface morphology with a particle size distribution of approximately 36 nm. Analyses showed that the ZnO NPs thin films exhibited excellent crystallinity, uniform surface morphology, and a direct bandgap energy of approximately 3.30 eV. The photovoltaic performance of organic solar cells with a thin ZnO NPs film was tested, and the results showed a significant improvement in short-circuit current density (Jsc) and power conversion efficiency (PCE) compared to chemically prepared ZnO NPs. Investigations are underway on ZnO thin films with meticulously controlled micro-scale morphology, which are considered promising alternatives to indium tin oxide (ITO) films for various photovoltaic applications.
Seasonal Variation and Machine Learning-Based Prediction of Atmospheric Refractivity over Southwestern Nigeria
(Ladoke Akintola University of Technology, 2026-03) SULEMAN Kamaldeen Olasunkanmi
Atmospheric radio refractivity strongly influences radio wave propagation, link reliability and signal quality in tropical regions. In south-western Nigeria, pronounced wet and dry seasonal transitions cause large variability in refractivity, yet data-driven predictive tools remain limited. This lack of reliable prediction poses a challenge for communication system planning and performance optimisation in the region. This study investigates the seasonal variation of surface atmospheric refractivity over south-western Nigeria and evaluates the effectiveness of machine learning techniques for its prediction. Four years of meteorological data from an automatic weather station were used to compute refractivity using the Smith–Weintraub formulation. Seasonal and monthly patterns were analysed using descriptive statistics, correlation analysis, and timeseries techniques, including trend and anomaly detection. Supervised machine learning models, including Support Vector Regression, Random Forest, Gradient Boosting, and a Multi-Layer Perceptron, were trained to predict daily refractivity from meteorological inputs. Results show seasonal dependence, with higher refractivity during the wet season driven by increased humidity. Among the models, Support Vector Regression achieved the highest predictive accuracy (R² ≈ 0.9999, RMSE ≈ 0.066), followed by Random Forest. The findings demonstrate that machine learning is a reliable and effective approach for predicting atmospheric refractivity and capturing its seasonal variability in tropical environments.
Effect of Hole Transporting Material on Perovskite Based Solar Cells Using One Dimensional Solar Cell Capacitance Simulator (SCAPS-1D)
(Global Scientific Journal, 2019-12) SULEMAN Kamaldeen Olasunkanmi
In this research, the simulation of Sandwiched Perovskite Based Solar Cells (PSCs) was investigated using a computer based software known as solar cell capacitance simulator (SCAPS-1D). The effect of Hole Transporting Material (HTM) on the sandwiched perovskite was determined by the electrical. The solar cell structures used are n-FTO/ZnO/p-CZTS/p-PSC/p CZTS/HTM and n-FTO/ZnO/p-CZTS/p-PSC/p-CZTS. The simulations were performed under ambient temperature (300K) and AM 1.5 Sun of the Solar spectrum parameters (Voc, Jsc, FF) and efficiency generated by the SCAPS-1D. From the results obtained, the model band gap for the two devices and graphs were plotted and the efficiencies recorded. It was observed that with the increase of perovskite thickness from 50 to 500 nm, the efficiencies of the sandwiched perovskite increases. It was also observed that the device with HTM had a greater efficiency than the device without the HTM. The efficiencies of 20.56 % and 15.53 % were recorded for the sandwiched perovskite with HTM and the sandwiched Perovskite without HTM. The continuous increase in the efficiencies of the device with HTM shows that it has a positive effect on the perovskite.
Assessment of Tropospheric Duct Characteristics and their Implications for Microwave Signal Propagation over Port Harcourt, Nigeria.
(Al-Hikmah University, Ilorin, Nigeria., 2025-12) SULEMAN Kamaldeen Olasunkanmi
Complexity and non-linear trend in the internal activities of the troposphere has been a great factor influencing the transmission and receiving of good quality signal globally. The formation of Duct is the most severe and deviation from the standard propagation conditions which occurs majorly in coastal and maritime areas. The tropospheric duct significantly affects the design and performance of communication system and can also enhance signal to travel beyond radio horizon which can lead to unexpected interference. Consequently, in this study, we focused on how factors like temperature, humidity, and pressure influence radio refractivity and the formation of tropospheric ducts at different heights (200 m and 300 m) in Port Harcourt, Nigeria, using ten years (2015-2024) of meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-5 reanalysis. The analysis of the result showed that modified refractivity remains consistently high throughout the year with the value above 330 Nunit at both altitudes
Appraisal of the Impact of e-Banking and Cashless Society in the Nigerian Economy
(HATASO, USA (Management and Economics Research Journal), 2015-09-01) Umanhonlen O. Felix, Umanhonlen I. Rebecca, Omoruyi K. Igbinoba
The article appraises the impact of e-banking and cashless society in the Nigerian economy. The study explores various aspects of e-banking and cashless economy using the banking sector of the Nigerian economy as a focal point. Specifically, the paper articulates empirical opinions that highlight the possible ways these policy measures have direct links to beneficiaries and the weighted outcomes when divergence is noticed and how to bring back the soundness, sustainable and rebranding policy that ensures economic growth. The paper holds that for a sustainable cashless society to emerge all hands must be on desk; banks should de emphasize all odds and ensure that efficiencies of e-banking mechanisms are of utmost priority. It, therefore, recommends that adequate plans be in place to sensitize the general public about the effects and lay down procedures to check possible drawbacks. It, however, concludes by imploring all avenues and reports that relevant agency, service providers, operators, and those who have direct access to information to advocate as timely as when necessary about the implicit needs and benefits behind the cashless economy.

Nigeria Maritime University Institutional Repository

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