The Nigerian Journal of Physics (NJP) is a peer-reviewed open access journal published quarterly (March, June, September and December) by the Nigerian Institute of Physics (NIP). It publishes original research papers, review articles, technical reports and short communications in all aspects of Physical Sciences, Engineering and Technology.
Segmented Rotor Magnetic Flux Switching Device for High-Performance Electric Motorcycles and Scooters Applications
The global transition toward sustainable transportation and carbon-neutral mobility has intensified research into advanced electric propulsion systems for light two-wheel electric vehicles. Conventional electric scooters and motorcycles commonly employ surface-mounted permanent magnet synchronous motors (SPMSMs) and permanent magnet direct current (PMDC) motors. However, these machines suffer from operational limitations associated with rotor-mounted permanent magnets, including thermal demagnetization, excessive rotor eddy-current losses, limited overload capability, and reduced efficiency during high-speed flux-weakening operation. This paper presents a high-performance, three-phase, 12-stator-slot / 10-rotor-pole (12S/10P) permanent magnet flux switching machine (PMFSM) employing an outer segmental rotor topology optimized for direct-drive electric scooter and motorcycle applications. The proposed machine integrates radially magnetized stator-mounted permanent magnets and concentrated armature windings with a passive, robust segmented rotor to improve torque density, thermal reliability, and electromagnetic flux modulation. Machine geometry and electromagnetic parameters were developed using modern electric mobility constraints and analyzed via two-dimensional finite element analysis (2D-FEA) in JMAG Designer. Simulation results demonstrate significantly enhanced electromagnetic performance compared with conventional commercial SPMSMs. The proposed machine achieves a peak electromagnetic torque of 112 N.m and a continuous power output exceeding 6.2 kW at a rated speed of 1900 rpm, while exhibiting minimized rotor losses and an expanded constant-power speed range. Furthermore, the segmental rotor topology improves magnetic loading capability and mechanical robustness while reducing active rare-earth material utilization by approximately 15 %. The study establishes that the proposed outer-rotor segmental PMFSM topology represents a highly viable and promising propulsion solution for next-generation, high-efficiency, long-range electric two-wheelers.
Copyright (c) 2026 Kasim Ibrahim Mohammed, Mohammed Ahmed https://creativecommons.org/licenses/by-nc/4.0
A Study of Pre-Earthquake Ionospheric Anomaly (PEIA) in Low Latitude/ Equatorial Region TEC Using the Wavelet Power Spectrum Method
Earthquakes are major natural hazards that often result in significant loss of life and property. Previous studies indicate that the ionosphere exhibits anomalous behavior prior to seismic events. This study investigates pre-earthquake ionospheric anomalies (PEIA) associated with five earthquakes of magnitude M ≥ 7.0 in the low-latitude/equatorial region using Total Electron Content (TEC) data. Earthquake parameters were obtained from the United States Geological Survey (USGS), while TEC data were sourced from the International GNSS Service (IGS) via Ionolab, covering 10 days before and 5 days after each event. To distinguish seismic effects from external influences, geomagnetic and solar conditions were assessed using Dst, Kp, AE, and F10.7 indices from the OMNI database. Analysis using time series and Wavelet Power Spectrum (WPS) methods revealed significant TEC anomalies up to 10 days before each earthquake. WPS results further showed enhanced power intensity during the pre-earthquake period compared to quiet conditions. These findings demonstrate the role of lithosphere–atmosphere–ionosphere coupling mechanisms prior to major earthquakes, suggesting that PEIA is driven by multiple mechanisms.
Copyright (c) 2026 Afolabi Adegboyega Kotoye, Olukayode Elijah Falayi, Johnson Olufemi Adepitan, Bolarinwa John Adekoya, Ayobamidele Dele Adelaja, Kayode Johnson Bamidele https://creativecommons.org/licenses/by-nc/4.0
Synthesis, Spectroscopic Studies and Biological Activity of Cu(II) Complex of Schiff Base Ligand 3-((2-(2,4-dinitrophenyl)hydrazineylidene)methyl)pyridine with Triphenylphosphine as Ancillary Ligand
In this study we synthesized, characterized, and evaluated the antibacterial activity of a new mixed-ligand Cu(II) complex containing a Schiff base derived from 3-pyridinecarboxaldehyde and 2,4-dinitrophenylhydrazine, together with triphenylphosphine as ancillary ligand. The compound was characterized using Fourier Transform Infrared (FTIR) spectroscopy, UV-Visible spectroscopy, and magnetic susceptibility measurements. Antibacterial screening was carried out using agar well diffusion method against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. FTIR analysis confirmed coordination through the azomethine and pyridyl nitrogen atoms with characteristic bands at 1618 and 1584 cm⁻¹, while retaining nitro group absorptions at 1508 and 1325 cm⁻¹. The complex displayed an average inhibition zone of 26.25 mm, surpassing the standard drug Ofloxacin (23.50 mm) and showing significant enhancement over the free ligands and copper salt. Magnetic susceptibility measurements revealed paramagnetic behaviour. The synthesized heteroleptic Cu(II) complex demonstrated excellent broad-spectrum antibacterial activity, highlighting the synergistic effect of the Schiff base and triphenylphosphine ligands.
Copyright (c) 2026 Olufemi S. Odulaja, Christiana I. Ayangbesan, Adetutu V. Williams, Christiana A. Adeleye, Taofeeq F. Adeleye, Oyinlola O. Olugbile, Taiwo A. Abiola, Adejumoke Morilat Hashimi, Muritala Adeniyi Olusola, Emmanuel O. Bamiro https://creativecommons.org/licenses/by-nc/4.0
Simulation and Optimization of CdTe and CIGS Thin-Film Solar Cells with Dual ETLS (CdS, ZnO) Using SCAPS-1D: A Comparative Approach
Thin-film solar cells offer promising alternatives to crystalline silicon photovoltaics, combining reduced material consumption with flexibility and cost-effectiveness. Among them, cadmium telluride (CdTe) and copper indium gallium selenide (CIGS) remain the most commercially successful technologies, though their performance depends strongly on structural and electronic parameters. This work employs SCAPS-1D simulations to investigate CdTe- and CIGS-based devices incorporating two electron transport layers (ETLs), cadmium sulfide (CdS) and zinc oxide (ZnO). The analysis explores absorber and ETL thickness, doping concentration, interface defect density, and bulk defect density. Baseline simulations show that CdTe devices achieved efficiencies of 18.7% (Voc = 0.59 V, Jsc = 43 mA/cm²), while CIGS devices reached up to 35.1% efficiency (Voc = 1.37 V, Jsc = 28 mA/cm²). Correlation studies reveal that CdTe efficiency improvements are mainly linked to doping-driven increases in Voc and FF, whereas CIGS efficiency is governed by Jsc enhancements from optimized thickness. CdTe demonstrated tolerance to interface and defect variations, in contrast to CIGS, which exhibited efficiency collapse under high recombination conditions. The novelty of this study lies in its comparative and integrated optimization of CdTe and CIGS using two ETLs under identical SCAPS-1D conditions, bridging a gap in prior literature where these absorbers are typically studied separately. The findings highlight a trade-off: CIGS provides higher efficiencies but requires strict defect and interface control, while CdTe offers robustness under fabrication variability. These results inform both material selection and device engineering strategies for advancing scalable thin-film photovoltaic technologies.
Copyright (c) 2026 Damian E. Adukwu, Solomon Denen Igba, Peverga R. Jubu, Adebayo Ademola https://creativecommons.org/licenses/by-nc/4.0
Investigating the Structural, Elastic, Electrical, and Thermodynamic Characteristics of NbCoSn and VRhSn Half-Heusler Compounds Using First-Principles Calculations
In this work, we used first-principles calculations utilising density functional theory (DFT) to examine the structural, elastic, electrical, and thermodynamic features of NbCoSn and VRhSn HH compounds. It was discovered that the calculated lattice constants of the NbCoSn and VRhSn compounds agreed with both the existing theoretical and experimental data. Because the compounds' elastic constants meet the Born-Huang requirements for cubic system stability, they are mechanically stable. VRhSn and NbCoSn are dynamically stable because there are no imaginary phonons. Because NbCoSn has a higher shear modulus and Vicker's hardness than VRhSn HH, it is harder. The presence of band gaps in both compounds indicates that they are semiconductors. VRhSn has a smaller band gap than the NbCoSn HH combounds. Additionally, thermodynamic properties are calculated and investigated in detail. The results show that NbCoSn and VRhSn HH compounds are promising thermoelectric materials; however, VRhSn HH compound stability might be improved by doping and alloying.
Copyright (c) 2026 Eddy Enorense Aigbekaen, Fidelia Chukwudumebi Ighrakpata https://creativecommons.org/licenses/by-nc/4.0
Porosity and Geomechanical Characteristics of banded Iron Ore from Itakpe, North Central Nigeria
The microstructural characteristics of geological materials are fundamentally influenced by their pore configuration and geomechanical properties. The banded iron ore samples from Itakpe, North Central Nigeria, have been examined using: (i) X-ray fluorescence (XRF) spectroscopy for preliminary iron content assessment; (ii) low-field nuclear magnetic resonance (NMR) and water imbibition porosity (WIP) techniques for pore structure evaluation; and (iii) bulk density and stress-strain analysis for the geomechanical characterisation. The average weight of haematite, silica, alumina and iron contents in the samples are 53%, 22%, 12%, and 37%, respectively. These values show that the Itakpe iron ores are low-grade and hence, significant enrichment is required for economic viability. The pore system of the ore samples is basically bimodal without any indication of macropores, in agreement with the metasedimentary origin of the ores. The transverse relaxation time ranges for the pore regions are: (a) micropores (0.2818 – 1.413 ms) and (b) mesopores (7.943 – 79.43 ms). The mean porosities estimated via NMR and WIP techniques are 0.365 p.u. and 0.488 p.u., respectively. Computed porosity and water content from NMR and WIP techniques show high degree of correlation which are 87% and 76%, respectively. The average UCS, elastic modulus and dry bulk density of the samples are 101.28 MPa, 3.94 GPa and 3.46 g/cm3, respectively showing high strength ores. The plots of UCS versus dry bulk density for the samples shows an increasing exponential relation, while the UCS versus NMR porosity, modulus ratio versus dry bulk density as well as modulus ratio versus UCS all show decreasing exponential relations. The UCS is negatively correlated with NMR porosity but positively correlated with bulk density. Integrating NMR and geomechanical techniques can reliably: (i) predict mechanical behaviour without destructive testing; (ii) complement traditional porosity methods; and (iii) assist in mine design for safety and ore optimisation.
Copyright (c) 2026 Amidu Abiola Ige-Adeyeye, Olawale Babatunde Olatinsu, Vitalis Chidi Ozebo, Lionel Esteban https://creativecommons.org/licenses/by-nc/4.0
Comparison of Cosmic Ray Intensity Variations at Moscow and Oulu Stations
The impact of cosmic rays (CRs) on space weather remains a cutting-edge field of study. However, the complex variability of CR flux complicates the analysis of both short- and long-term trends. Forbush decreases (FDs), which represent significant short-term intensity changes, are frequently used to investigate the relationship between CRs and various atmospheric phenomena. While manual event detection is currently predominant, it is often ineffective; therefore, this work employs an automated approach for event detection. Fourier harmonic decomposition and an FD-location algorithm were employed. The results reveal distinct differences and similarities between CR flux variations at the Moscow and Oulu stations.
Copyright (c) 2026 Firew Meka Menteso, Ogbonnaya Okike, Patience I. Akande-Rowland, Miracle Okoro Ikoro, Augustine Ogonna Chikwendu, Meka Firew Menteso https://creativecommons.org/licenses/by-nc/4.0
Radiological Dose and Health Risk Assessment of Naturally Occurring Radioactive Materials at Kataeregi Artisanal Mining Site, Niger State Using RESRAD Code
This study examined the distribution of naturally occurring radioactive materials (NORMs) and the corresponding gamma radiation exposure in Kataeregi artisanal mining area of Minna, Niger State, Nigeria. To assess radioactive exposure and possible health hazards, a combination of experimental measurements and RESRAD modeling was used. Activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K were found to be 18.74<!-- [if gte msEquation 12]><m:oMath><m:r>±</m:r></m:oMath><![endif]--> <span lang="EN-GB" style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.5pt; mso-text-raise: -3.5pt; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-no-proof: yes;"> 0.8, 9.12<!-- [if gte msEquation 12]><m:oMath><m:r>±</m:r></m:oMath><![endif]--> <span lang="EN-GB" style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.5pt; mso-text-raise: -3.5pt; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-no-proof: yes;"> 1.23 and 360.13<!-- [if gte msEquation 12]><m:oMath><m:r>±</m:r></m:oMath><![endif]--> <span lang="EN-GB" style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.5pt; mso-text-raise: -3.5pt; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-no-proof: yes;"> 11.96, respectively. Excess lifetime cancer risk (ELCR), annual effective dose (AED), and external gamma dose rates were calculated using the average concentrations. According to the results, the overall dose gradually drops from roughly 4.0 × 10⁻² to 2.2–2.6 × 10⁻¹ mSv/yr, mostly as a result of the decrease in the ⁴⁰K contribution. However, long-term exposure is dominated by 226Ra, which stays relatively steady, whereas ²³²Th gradually increases until stabilizing. According to the pathway analysis, ingestion pathways, especially fish intake, contribute very little but gradually grow over time, whereas external exposure from contaminated soil accounts for over 85–90% of the overall dose. Low radiological danger is shown by the calculated dose values, which are far lower than the recommended public exposure limit of 1 mSv/yr and the global average of 0.07 mSv/yr. However, the persistence of long-lived radionuclides indicates continual low-level exposure, emphasizing the need for constant monitoring and efficient radiation protective measures.
Copyright (c) 2026 Abdullahi Muhammad https://creativecommons.org/licenses/by-nc/4.0
Reservoir Quality Evaluation Using Petrophysical Logs and Seismic Attribute Techniques: A Case Study of GOTO Field, Niger Delta
The 21st-century global energy demand necessitates advanced reservoir characterization to optimize hydrocarbon exploitation and minimize drilling risks. This study integrates petrophysical analysis and multi-attribute seismic interpretation to evaluate the hydrocarbon potential of the GOTO Field in the Niger Delta. Using suites of well logs from seven wells and 3D post-stack seismic data, four reservoir sands (A, B, C, and D) were delineated and correlated across the field. Petrophysical evaluation reveals that Sand A is the most prospective unit, exhibiting excellent reservoir quality with average effective porosity of 29.3%, permeability reaching 758 mD, and moderate water saturation. Sands C and D show moderate quality with localized potential, while Sand B is identified as predominantly water-saturated (91–96%). Seismic interpretation identified major structural traps, including rollover anticlines and fault-assisted closures. Analysis of seismic attributes—including RMS Amplitude, Average Energy, and Sweetness—revealed strong anomalies in Sands A, C, and D that conform to structural highs, serving as direct hydrocarbon indicators (DHIs). The high degree of consistency between petrophysical data and seismic attribute responses demonstrates that this integrated quantitative approach significantly reduces exploration uncertainty and improves the precision of reservoir evaluation in complex deltaic environments.
Copyright (c) 2026 Igonoh David Asuba, Emujakporue Godwin Omokenu, Inichinbia Sonny https://creativecommons.org/licenses/by-nc/4.0
Enhancing the Visibility of Microcalcifications in Breast Tissue Using Morphological Operations and Gaussian Smoothing Techniques: A Phantom Study
Breast cancer is one of the major causes of death among women. Microcalcification (MC) deposits could be an early sign of breast cancer. This study aims to investigate image contrast enhancement techniques that facilitate breast cancer diagnosis in dense breast tissues. A polyvinyl alcohol (PVAL) breast phantom, with embedded MCs was produced. Acquired mammogram images were analysed using morphological operations and the Gaussian smoothing techniques to enhance image contrast. The performances of all the filters were measured qualitatively by visual inspection, and quantitatively by evaluating the MSE, PSNR, and SNR. All experiments were conducted on MATLAB R2020a platform. Qualitative analysis showed that the Gaussian Smoothing filter recorded the best performance. Quantitatively, Low values of MSE with high PSNR/SNR depict better image quality enhancement. The closing morphological filter recorded the least mean value of MSE (32.86 ± 1.30) with the highest PSNR and SNR of 32.97 ± 0.20 and 22.91 ± 0.13 respectively. The Gaussian Smoothing filter came second with MSE, PSNR and SNR values equals 287.43 ± 10.65, 23.55 ± 0.17 and 12.83 ± 0.29 respectively. Therefore, the closing morphological filter produced a superior result quantitatively.
Copyright (c) 2026 Franca Oyiwoja Okoh, Norlaili Ahmad Kabir, John Actor Ocheje, Mohd Fahmi Mohd Yusof, Ahmad Sufril Azlan Mohammed, Rafidah Zainon, Ezekiel Yangde, Moses Ejike Onudibia https://creativecommons.org/licenses/by-nc/4.0
Reservoir Characterization Using Integrated Petrophysical Evaluation, Seismic Attributes, and AVO Modeling in JASMI Field, Niger Delta Basin
This study presents an integrated reservoir characterization workflow aimed at delineating the hydrocarbon potential of the JASMI Field in the Niger Delta Basin. The research focuses on transforming raw subsurface data into a predictive geological model to minimize exploration uncertainty and optimize field development strategies. The multidisciplinary approach integrates petrophysical evaluation, structural seismic interpretation, multi-attribute analysis, and Amplitude Versus Offset (AVO) modeling. Data from seven wells and a 3-D post-stack seismic volume were analyzed using Schlumberger Petrel and Hampson Russell software. Four key reservoir intervals (Sands A, B, C, and D) were identified and correlated across the field. Petrophysical analysis identified Sand A as the premier reservoir, exhibiting excellent storage and flow capacity with average effective porosity of 29.3% and permeability reaching up to 758 mD. Sands B and C showed moderate reservoir properties; however, fluid saturation analysis revealed that Sand B is largely water-saturated (Sw ~94%), while Sand C holds selective potential in structurally advantageous zones. Seismic attribute analysis (RMS amplitude, sweetness, and average energy) successfully identified direct hydrocarbon indicators (DHIs). These high-amplitude anomalies strongly correlate with anticlinal features and fault-assisted closures, particularly for Sands A and D. AVO responses further validated these findings with Class II/III anomalies, confirming the presence of hydrocarbons in the mapped reservoirs. The study concludes that Sand A represents the most prospective target for commercial exploitation due to its superior petrophysical quality and strong seismic conformity. Sands B and C offer secondary interest, whereas Sand D exhibits limited economic viability due to lower porosity and higher heterogeneity. This integrated approach enhances reservoir prediction accuracy and provides a robust framework for optimized drilling and future field development in the Niger Delta.
Performance Evaluation of Satellite Gravity on Variable Test Points and Geophysical Models in Gongola Basin, Nigeria
The recent advent of new satellite missions provides models of gravity data with high quality and global coverage that is on par with conventional gravity measurements. A drawback is the myriad of models to choose from and the number of test points to use for validation. As a result, an accuracy assessment needs to be performed to isolate the best model. Therefore, this paper compared 21 satellite models at varying testing points. Furthermore, the best gravity model was assessed based on 2-D (Two-Dimensional) geophysical modeling constrained by the aeromagnetic survey. XGM2019e_2159 gravity model attained the highest performance indicator value from the quantitative analysis of the Gongola Basin. It has an RMSE (0.847861), MAE (4.102917), RMSPE (14.24%), MAPE (12.24%) and highest correlation (0.847861) with the terrestrial Bouguer anomalies, for this reason, it is deemed most suitable for the application of this research. Overall, based on the mean accuracy of the whole set of points, the best six (6) satellite models in decreasing accuracy are XGM2019e-2159, XGM2016, GECO, EGM-2008, EIGEN-6C4 and GGM05C. Generally, a set of data points might perform better than another set, one should use as much available data set for selecting the best model ensuring the data sets are well distributed across the research area. The satellite data performed slightly better than the terrestrial data based on the geophysical modeling by a discrepancy of ±2 mGal. Generally, a set of data points might perform better than another set, therefore one should use as much available data set for selecting the best model ensuring the data sets are well distributed across the research area.
Copyright (c) 2026 Adamu Aliyu Bagare https://creativecommons.org/licenses/by-nc/4.0
Measurement of Scattered and Leakage Radiation in X-Ray Facilities from Selected Centers in Warri Metropolis, Delta State
Measurements were carried out to determine the amount of scattered and leakage radiation in X-ray facilities in Warri metropolis. A total of twenty (20) Sampled X-ray units were studied. Exposures were made with film to focus distance (FFD) of 100 cm using mAs and kVp of routine abdominal radiological examinations. The results show that 85% of the investigated X-ray units have cathode side leakage radiation higher than the anode side leakages, 5% anode side leakage radiation higher than the side cathode leakages and 10% having similar anode and cathode side leakage radiation. The mean leakage from individual X-ray unit ranges from 0.21 mR/hr to 100.27 mR/hr with an overall mean value of 25.67 mR/hr. It was observed that only one unit, A10, had mean leakage radiation value of 100.27 mR/hr which was above 100 mR/hrAmerican Association of Physicist Medicine (AAPM) set limit, this therefore means there is no probability that the general public may experience cancer from exposure to these machines or immediate radiological health hazard arising from the leakage radiation from these X-rays’ facilities.
Copyright (c) 2026 Sylvester Obakpororo Ovwasa, Joy Amuofu Adonuja, Kparobo Godwin Agbajor, Franklin Anita Akpolile https://creativecommons.org/licenses/by-nc/4.0
Elemental Analysis of Particulate Matter at Relief Market, Egbu, Imo State
Urban markets are often located in high-traffic areas, contributing to air pollution. Particulate matter (PM) in the market poses significant health risks due to the presence of heavy metals, which could cause several respiratory and cardiovascular disease when ingested into the human body. This study focused on the elemental composition of particulate matter deposit at Relief market, Egbu (Owerri North/Egbu area situated around latitude 5°29'41" North and longitude 7°04'23" East), Nigeria. The method of sample collection was direct deposition method under gravity. The mass of particulate matter collected from the market for a period of one week (December 12th - December 19th, 2025) is 0.06g. The Atomic Absorption Spectroscopic analyses of the particulate matter samples revealed the presence of 5 metals, which include; magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn) and lead (Pb). Earlier related research have shown that some of these metals constitute serious health issue to human when inhaled, hence there is need for proper air quality monitoring, control and public awareness to mitigate the health risk associated with these metals in the market environment. Regulatory policies should be enforced to ensure cleaner air and safe market. Some emission control activities should be put in place, such as paving road surfaces and banning open waste burning within commercial areas, to reduce health risks to traders and buyers.
Copyright (c) 2026 Chisom Ugonna Obi, James James Robert, Theodore Chidiezie Chineke https://creativecommons.org/licenses/by-nc/4.0
Effect of Temperature and Retention Time on the Quality of Biochar of Some Agricultural Waste
The conversion of biomass and waste into valuable energy products via pyrolysis offers a sustainable solution to energy poverty and waste management challenges in Northern Nigeria. This study investigated the effects of temperature and retention time on the quality of biochar derived from three local feedstocks: groundnut shell (GS), millet husk (MH), and rice husk (RH) in Jigawa State, Nigeria. The primary objective was to determine optimal pyrolysis conditions for producing high-quality biochar. Biomass samples were pyrolyzed in a furnace at 400°C, 450°C, 500°C, and 550°C, with retention times of 30, 45, and 60 minutes. Biochar quality was evaluated through proximate analysis, ultimate analysis, calorific value measurement, and thermogravimetric analysis (TGA). Results show that higher temperatures decrease biochar yield but increase fixed carbon content. Groundnut shell char produced at 450°C achieved the highest calorific value (26.93 MJ/Kg). Millet husk char exhibited the highest carbon content (79.27%), while rice husk char had the highest ash content (39.80%). Notably, retention times exceeding 30 minutes had minimal influence on product characteristics. Overall, pyrolysis effectively converts agricultural waste into high-quality biochar. Groundnut shells and millet husk are identified as promising feedstocks for clean cooking fuel and soil amendment in rural communities..
Copyright (c) 2026 Lawan Haruna, Aliyu Aminu Safana, Ibrahim Murtala Musa, Hafeez Y. Hafeez, Umar M. Dankawu, Muhammad M. Machina https://creativecommons.org/licenses/by-nc/4.0
Synthesis of Polyvinylidene Fluoride-Graphene Based Polymer Nanocomposite with Enhanced Piezoelectric Properties
Piezoelectric energy harvesting has gained attention due to its potential to aid the designing of self-sustaining energy devices. This study examines the effect of graphene nanoplatelets (GNPs) incorporation on the piezoelectric, dielectric, and mechanical properties of polyvinylidene fluoride (PVDF). The PVDF was doped with 0.5 wt% and 1.0 wt% GNPs as filler material through melt intercalation. The piezoelectric voltage constant, dissipation factor, modulus of elasticity, and resistivity were evaluated to assess improvements in performance. There was an enhancement in piezoelectric voltage constant due to addition of GNPs. The piezoelectric voltage constant increased by 59.7% and 5.5% with the addition of 0.5 wt% and 1.0 wt% GNPs respectively, suggesting better mechanical energy conversion efficiency at lower filler concentration. Lower dissipation factor was observed with increase in the concentration of filler, around power frequency (50 Hz), while maintaining higher resistivity, indicative of good dielectric performance. Mechanical analysis revealed that the Young’s modulus improved with increase in GNPs addition, confirming enhanced stiffness and stress transfer. Although 1.0 wt% loading of GNPs shows better dielectric performance, 0.5 wt% graphene loading significantly enhanced PVDF’s piezoelectric sensitivity and mechanical strength, making it a promising material for flexible sensors and energy-harvesting applications.
Copyright (c) 2026 Aliyu Abdulraheem, Sadiq Umar, Sanda Abubakar Sadiq, Abdelghaffar Amoka Abdelmalik https://creativecommons.org/licenses/by-nc/4.0
Quantum-Enhanced Solar Cell Efficiency: A Theoretical and Empirical Framework for Photovoltaic Storage Degradation Optimization
The integration of photovoltaic (PV) and energy storage systems (ESSs) in modern smart grids has significantly increased the issue of component degradation, which in turn has negatively impacted the system's efficiency, operational expenses, and long-term reliability. However, the stochastic and nonlinear nature of PV module and battery degradation are not well captured by conventional classical optimization methods, which leads to suboptimal dispatch strategies and premature system aging. In this work, an empirical study of a quantum enhanced degradation pathway optimization framework that combines hybrid quantum-classical computing methods to maximize energy dispatch efficiency and extend system lifetime. The three-layer hierarchical optimization framework is realized by combining quantum-assisted Monte Carlo simulations on a D-Wave Advantage quantum annealer with a reinforcement learning-based classical engine and utilizes the quantum annealer to dynamically adjust its operational strategies in real time. The framework was validated with a simulated 5 MW PV array and a 2.5 MWh lithium-ion battery storage system, with a 5-year operational time horizon. Results show a 25% decrease in battery degradation-induced wear, a PV module lifespan increase of around 2.5 years, and more than 47% increase in energy dispatch efficiency compared to classical mixed-integer linear programming baselines. The quantum-assisted model demonstrates statistically significant performance gain in several degradation scenarios, temperature profiles, and load demand conditions, through sensitivity analyses.
Copyright (c) 2026 Priscilla O. Osuhor, Samuel Kanayo https://creativecommons.org/licenses/by-nc/4.0
Hydrothermally Synthesized Doped Non-Aqueous Cds Thin Films for Degradation of Methylene Blue under Sunlight Radiation
Cadmium sulfide (CdS) thin films have attracted significant attention for environmental remediation applications due to their suitable band gap, high photosensitivity, and excellent photocatalytic properties. In this study, non-aqueous CdS thin films were hydrothermally synthesized using cadmium nitrate tetrahydrate and thiourea as precursor materials in methanol medium. The films were prepared at varying precursor concentrations of 0.10 M, 0.20 M, and 0.30 M. To enhance the photocatalytic performance of CdS, 0/005g of bismuth ferrite (BiFeO₃) and 0.005g tin oxide (SnO₂) were incorporated as dopants in separate preparation. The synthesis was carried out in a Teflon-lined autoclave at 180 °C for 8 h, followed by washing, drying, and pulverization of the obtained products. The structural, morphological, optical, and photocatalytic properties of the synthesized samples were investigated using appropriate characterization techniques. The influence of precursor concentration and dopant incorporation on crystallite size, surface morphology, and optical band gap was evaluated. Photocatalytic activity was assessed through the degradation of methylene blue dye under natural sunlight irradiation. The results revealed that both BiFeO₃ and SnO₂ doping significantly improved the photocatalytic efficiency of non aqueoud CdS to 70.0 & 72.8% respectively by enhancing charge separation and reducing electron–hole recombination. The findings demonstrate that hydrothermally synthesized non-aqueous CdS thin films doped with BiFeO₃ and SnO₂ are promising photocatalysts for the degradation of organic pollutants in wastewater under sunlight irradiation, offering a cost-effective and environmentally friendly approach for water purification applications.
Copyright (c) 2026 Joseph Ayodele Owolabi, Sunday Aboritoli, David Matthew Femi https://creativecommons.org/licenses/by-nc/4.0
Geophysical Investigation and Protective Capacity of Frequently Failed Road Sections of Selected Roads in Delta State, Nigeria
Geophysical survey has been successfully carried out along failed road sections situated in Delta State, Nigeria to delineate the causes of failure along portions of the road. These were executed by using forty Vertical Electrical Sounding (VES) from Schlumberger array along road sections using SAS 1000 ABEM Terrameter. The recorded field data were processed via Winresist software. Resistivity values ranging from 22 to 1026 <span lang="EN-US" style="font-size: 10.0pt; line-height: 107%; font-family: Symbol; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; color: black; mso-themecolor: text1; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-char-type: symbol; mso-symbol-font-family: Symbol; mso-bidi-font-style: italic;">Wm at 15 m depth from surface were traced along Amukpe, Ekpan-Ovu, Aghalokpe, Okpara to Otumara. At Eku, Igun, Oria, Erho, and Abraka and Obiaruku, the resistivity figures procured ranged from 11 to 500 <span lang="EN-US" style="font-size: 10.0pt; line-height: 107%; font-family: Symbol; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; color: black; mso-themecolor: text1; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-char-type: symbol; mso-symbol-font-family: Symbol; mso-bidi-font-style: italic;">Wm at depth of 5.5 m via the topsoil, 21.5 m from sub-grade and 9.76 to 50 m along few profiles. Umutu, Urhomehe, Abavo, Urhonigbe and Agbor signal resistivity ranging from 59 to 1468 <span lang="EN-US" style="font-size: 10.0pt; line-height: 107%; font-family: Symbol; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; color: black; mso-themecolor: text1; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-char-type: symbol; mso-symbol-font-family: Symbol; mso-bidi-font-style: italic;">Wm for stable (lasting) and unstable (unsteady) segments of the road at 15 m depth for some profiles. Low resistivity values (≤197<span lang="EN-US" style="font-size: 10.0pt; line-height: 107%; font-family: Symbol; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; color: black; mso-themecolor: text1; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-char-type: symbol; mso-symbol-font-family: Symbol; mso-bidi-font-style: italic;">Wm) were observed in some trenchant regions of the profiles comprising collapsible, expansive, compressible sandy clay materials which have the capability of absorbing water. The results of the geoelectric study revealed that the failure of road portions can be attributed to the presence of incompetent clayey materials used for the filling materials and low standard materials found underneath the built road. The protective capacity echelon ranges from poor-moderate. Competent filling soil should replace the low resistivity soils from 5-7 meters below the surface when rehabilitating the road.
Copyright (c) 2026 Ogheneovo Akpoyibo, Onoriode Ezekiel Abriku, Otitie Star Umayah, Felix Chukwuka Ugbe, Ochuko Anomohanran https://creativecommons.org/licenses/by-nc/4.0
PM₂.₅ Emissions from Office Laser Printers: Real-Time Exposure Assessment and Risk Mitigation
Laser printers are emerging sources of indoor air pollution, emitting fine particulate matter (PM₂.₅) and trace heavy metals. This study assessed exposure risks in 20 office environments using real-time PM₂.₅ monitoring and toner analysis. The PM₂.₅ levels were recorded with a TSI DustTrak DRX during work hours over two weeks. Toner types (OEM, compatible, remanufactured, drill-fill) were analyzed for Cu, Fe, Ni, Pb, and Cd via atomic absorption spectrophotometry. Risk assessments were based on U.S. EPA models. The PM₂.₅ concentrations ranged from 6.2 to 59.1 µg/m³ and correlated with print volume (r = 0.77). Lead and nickel were primary contributors to non-cancer (Hazard Quotient > 1) and cancer risks (up to 1.15 × 10⁻⁷). While metal levels in toner met regulatory limits, cumulative PM₂.₅ exposure raises concern. High-Efficiency Particulate Air (HEPA) filtration and use of low-metal toners reduced PM₂.₅ by 40% and lead exposure by 25%. Effective mitigation is essential in managing office air quality. Laser printers were identified as significant indoor sources of PM₂.₅ and trace metals, with risks strongly influenced by print volume and ventilation. Lead and nickel posed the greatest health concerns, while HEPA filtration and low-metal toners effectively reduced exposures.
Copyright (c) 2026 Oluwasayo Peter Abodunrin, Oluwaseun Dosunmu, Inioluwa Olowofila, Oladipupo Olanrewaju, Augustine Kolapo Ademola https://creativecommons.org/licenses/by-nc/4.0
Design and Sizing of an Off-Grid Solar Photovoltaic (PV) System for an Office Unit at Modibbo Adama University, Yola-Nigeria
The average performance of a 100 W, 23.3 V monocrystalline silicon solar PV module for three days measurements were determined under Modibbo Adama University Yola climatic conditions. The performance parameters were used for more accurate sizing of a PV system of an office unit. The average values of the performance parameters of the modules were found to be 71.63 W, 16.00 V, 4.48 A, 22.53 V and 4.90 A for Pmax, Vmp, Imp, Voc and Isc respectively at an overall average solar irradiance of 667.54 W/m2. These values differ significantly from those of manufacturer’s data sheet. The average daily energy consumption of the office unit and the total rated power of the AC loads were found to be 9.78 kWh/day and 3.272 kW respectively. About 13 parallel modules, 2 series modules, 3 parallel batteries (Lithium Iron Phosphate- 48 V, 300 (Ah) and 2 voltage charge controllers are required to maintain stable power supply. The capacity of an inverter needed for stable conversion to AC supply is 4 kW. The average performance efficiency of the PV system is found to be 13.49%. The yearly energy yield and capacity utilization factor were determined as 13,297,680 Wh/year and 58.38% respectively. The initial capital cost of the proposed solar PV system is ₦ 8,853,772 and a levelized cost of electricity (LCOE) as ₦ 29.48/kWh.
Copyright (c) 2026 Mohammed Faisal Isa, Haruna Sallau Bayel, Muktar Bello, Joseph Aidan https://creativecommons.org/licenses/by-nc/4.0
Volterra Adaptive Filter for Real-Time OTDR Monitoring and Fault Localisation in Fibre Optic Networks
Locating a fault in a fibre-optic cable is often comparable to searching for a needle in a haystack of noisy backscattered signals. To address this challenge, this paper presents a Volterra Adaptive Filter (VAF) framework for enhanced Optical Time Domain Reflectometry (OTDR)–based monitoring and fault detection in fibre-optic networks. The proposed approach is centred on a first-order Volterra adaptive filter with optimised memory length and momentum-stabilised learning, designed to improve prediction stability and tracking accuracy under noisy conditions. Comprehensive experimental validation was conducted using a 20 km operational fibre route in Lagos, Nigeria. The system achieved a prediction root-mean-square error of 0.759 dB, a mean absolute error of 0.064 dB, and a correlation coefficient of 0.9974, indicating excellent agreement with measured OTDR traces. An integrated multi-criteria fault detection scheme attained 80 % precision and 80 % recall, corresponding to an F1-score of 0.800, while processing 19 980 samples using only 20 adaptive parameters. The proposed system localises faults to specific, named network components and translates complex reflectometry signatures into actionable maintenance information for field personnel. Operating in real time at processing rates exceeding 1 500 samples per second, the framework demonstrates the robustness and computational efficiency required for deployment in live fibre-optic network operations.
Copyright (c) 2026 Ozuem Edward, Johnson Ayeni, Ndifreke U. Ebong https://creativecommons.org/licenses/by-nc/4.0
Assessment of Excess Lifetime Cancer Risk from Indoor Radon Exposure in Obio-Akpor Local Government Area, Rivers State, Nigeria.
Analysis of indoor radon levels and associated health risk parameters was carried out in residential areas of Obio-Akpor Local Government Area, Rivers State, Nigeria. Indoor radon concentrations were measured using a Corentium Arthings digital radon detector over a monitoring period of 60 days. Geographical coordinates of each sampling location were recorded using a handheld GPS device. A total of ten houses were sampled across three major communities, resulting in 30 sample points. In Eneka, radon concentration ranged from 2 − 30 Bq m⁻³, with an annual effective dose rate ranged from 0.050576 − 0.758640 mSv/yr. The excess lifetime cancer risk (ELCR) over 70 years ranged from 0.177− 2.301. In Rumuokwurshi, radon concentration ranged from 3 − 19 Bq m⁻³, the annual effective dose varied from 0.075864 − 0.480472 mSv/yr, and the ELCR ranged from 0.266− 1.682. In Elimgbu, radon levels ranged from 2 − 102 Bq m⁻³, annual effective dose ranged from 0.05058 − 2.57938 mSv/yr, and ELCR ranged from 0.177 − 3.869. The indoor radon concentrations and dose rates are within the ICRP recommended safety limits, but the calculated ELCR values indicate a need for awareness and mitigation strategies to reduce long-term health risks.
Copyright (c) 2026 Diamond George, Margaret Apaemi Briggs-Kamara, Chinoye Amakiri Raymond https://creativecommons.org/licenses/by-nc/4.0
Time Series Modelling of Three-Dimensional Temperatures across Nigeria Using Data from Cosmic
This study examined time series modelling of three-dimensional temperatures across Nigeria using data from COSMIC. A preliminary check on the time series plot of the data showed seasonal variation suggesting that the series was not stationary. Time Series methodology was employed. In order to test the stochastic fluctuation of daily temperature, the researcher used the Q-Q plot to examine the normality of the difference of the temperature. Similarly, daily temperature fluctuations exhibit randomness and continuous change as temperatures vary throughout the day. From the graphical analysis it can be observed that there will be an upward trend of temperature with time from the 2021 to 2030. Hence, there will be a positive relationship between temperature and time for the same period of time. From the graph also, it showed that 98% of temperature can be accounted for by time. The result suggests that the predicted temperature is increasing over the years. From 2006 to 2020, there was a strong negative and significant relationship between temperature and altitude. Also, the mean temperature is increasing in many stations. Hence, the temperature exhibit elements of time-varying characteristics over the study period. At the end, it was recommended that studying and carefully applying mathematical models could help track future rise in monthly temperatures.
Copyright (c) 2026 Ugochukwu Ihemaguba, Chidi Emmanuel Akujor, Romanus E. Ugwoke, Costecia Ifeoma Onah https://creativecommons.org/licenses/by-nc/4.0
The Energy Spectra of Soluble Potentials Within the Framework of the Variational Method
In this article, we demonstrated the use of the variational approach in solving the bound state solutions of the Schrödinger equation for solvable potential functions. The method has been applied to determine the exact analytical excited states energy spectra for the Coulomb, and Pseudo-harmonic potentials. Also, the exact analytical ground state energy spectra for the Hulthén and Pöschl-Teller-type potentials have been obtained in closed form. In addition, we obtained the approximate energy eigenvalues of an exponential potential which does not admit exact analytical closed form solution. By minimizing the total variational energy, the variational parameters were derived. The results for these potential functions align perfectly with those obtained through other methods in the existing literature and numerical solution with the Matrix Numerov approach. The results demonstrate that the accuracy of the variational approach is strongly correlated with the use of accurate trial wave functions.
Copyright (c) 2026 Ekwevugbe Omugbe, Etido P. Inyang, Clement A. Onate https://creativecommons.org/licenses/by-nc/4.0
Optimizing Quantum-dot Cellular Automata Circuits for Nano communication: A Reversible Hamming Code Implementation
Quantum-dot cellular automata (QCA) is a transistor-free computing paradigm that allows the realisation of quicker, denser, and more energy-efficient nanoscale circuits. When compared to traditional complementary metal-oxide-semiconductor (CMOS) circuits. Its tiny size along with low power dissipation are some of its advantages in reversible logic. A major concern is the high cell count required for the implementation of these circuits, which hinders energy and area optimisation. This study suggests a concept of a 58-cell low-power HCG circuit that uses a reversible Feynman gate to process three-bit data. Using six-bit message signals, an error detector parity bit (EDP) circuit for Hamming code was implemented using 88 cells. To make sure the circuit functions correctly, Quantum Dot Cellular Automata Designer simulator version 2.0.3 is used to verify the proposed circuits, and QCA Designer-E is utilised to analyse the circuits' energy dissipation. According to the simulation results, the suggested HCG circuits require 50% less area and 20.5% fewer cells. The EDP circuit further enhances the area occupied by 20.7% and the number of cells by 50%. The outcome also demonstrates that the suggested circuit's energy dissipation rises with the number of cells. As a result of this, the suggested reversible QCA design shows enhanced performance and emphasises the applicability of QCA for upcoming high-density and energy-efficient nanoscale communication systems.
Copyright (c) 2026 Bahijja Yahaya Galadima, Shaawanatu Aminu, Maryam Ibrahim https://creativecommons.org/licenses/by-nc/4.0
Adomian Decomposition Method for Numerical Solution of 1-D and 2-D Seismic Wave Equations
The concept of real seismic wave equations has several applications through physics, geology, geophysics, and engineering. A precise and effective technique for simulating seismic wave propagation in the Earth's media must be developed to ascertain the Earth's structure. Over the past few decades, wave field simulation has developed into a potent instrument in seismological research, enabling researchers to better understand seismic events and improve predictions of earthquake impacts on various geological structures. The current study employs the well-known Adomian decomposition method (ADM) to solve the one- and two-dimensional seismic wave equations directly to obtain approximate and exact solutions without converting the seismic wave equations into ordinary differential equations (ODEs). The graph of each exact solution of seismic wave equations was plotted to show the movement of various types of seismic wave equations. The obtained results show the applicability and usefulness of the Adomian decomposition method to approximate solutions of seismic wave equations, making it suitable for geophysical applications such as exploration and subsurface imaging.
Copyright (c) 2026 Ramoni Adebola Soneye; Ayobamidele Sunday Odesola, Abiodun Sufiat Ajani, Oluseye Samuel Olayemi https://creativecommons.org/licenses/by-nc/4.0
Health Risk Assessment of Heavy Metal Concentrations in Sewage Compost Manure Used for Agriculture in Zaria, Nigeria
The increasing use of sewage composts as fertilizer has raised concerns regarding the accumulation of heavy metals in agricultural soils. This study examined the health risks of the composts used by farmers in Zaria Metropolis, Nigeria. Ten compost samples and two reference soil samples were collected as representative samples and analyzed at the Center for Energy Research and Training, Ahmadu Bello University, Zaria, using Neutron Activation Analysis (NAA). A total of six (6) heavy metals, namely Fe, Mn, Zn, Cr, Co, and As were detected. The results showed that the mean concentrations of these heavy metals in the compost were significantly higher than those in the reference soils, with Fe (19677.2±305.7 mg/kg) having the highest concentration, followed by > Mn (328.1±4.32 mg/kg) > Zn (124.31±20.87 mg/kg) > Cr (27.777±2.554 mg/kg) > Co (9.231±0.366 mg/kg) and As (0.452±0.064) in that order. The elevated concentrations indicate potential environmental and health risks associated with prolonged applications of these sewage compost. The study highlights the need for continuous monitoring and regulation of compost use in agriculture to prevent soil contamination and food chain transfer of toxic elements.
Instrumental neutron activation analysis
Copyright (c) 2026 Emmanuel Itodo Okpokwu, Matthew Agu, Christiana Akusu https://creativecommons.org/licenses/by-nc/4.0
A Comparative Study for the Estimation of Downward Longwave Radiation under Clear Sky Condition across the Midland Climatic Zone of Nigeria
Downward Longwave Radiation (DLR) is a crucial component of the Earth's surface radiation budget, important for both local weather forecasting and global climate modeling. This study investigates the clear-sky DLR in Minna and Zaria, with the aim at comparing and estimating the DLR under a cloudless sky for the region. The specific objectives include examining the influence of DLR on relative humidity and air temperature, evaluating the performance of eleven widely used existing empirical models, developing five new locally calibrated regression models, and ranking all sixteen models to ascertain their reliability and applicability in the study area. Monthly average daily meteorological data of relative humidity, air temperature, and DLR, spanning a forty-year period (1984–2023) were utilized for the study. Model performance was assessed using five statistical indicators: Mean Bias Error (MBE), Root Mean Square Error (RMSE), Mean Percentage Error (MPE), t-test, and Index of Agreement (IA), supplemented by correlation coefficient (R) for the proposed modified models. For Minna, maximum DLR of 424.7500 Wm-2 was recorded in April, while the minimum of 360.6771 Wm-2 occurred in December. At Zaria, the peak DLR of 412.0104 Wm-2 was observed in May, with the lowest value of 333.6875 Wm-2 recorded in December. Among the eleven existing models evaluated, the Idso model ranked best for both Minna and Zaria with overall ranking scores of 12 and 5 respectively, while the Dilley and O'Brien model performed least. Among the five newly developed modified regression models, the modified Idso model proved most accurate for Minna, and the modified Guest model was found most suitable for Zaria. Generally, the developed modified DLR models outperformed the existing models, which can be recommended for the estimation of DLR for midland climatic zone in the absence of the measured DLR.
Copyright (c) 2026 Davidson Odafe Akpootu, Oluwamayowa Emmanuel Agidi, Musa Momoh, Isah Ibrahim Garba https://creativecommons.org/licenses/by-nc/4.0
Photovoltaic Performance of Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Three Acalypha Leaf Species
Dye-sensitized solar cells (DSSCs) have attracted considerable attention as cost-effective alternatives to conventional solar cells; however, the use of expensive and toxic synthetic dyes remains a major challenge. Natural pigments from plants offer a sustainable and eco-friendly alternative due to their availability, low cost, and broad light absorption properties. In this study, natural pigments were extracted from the leaves of three Acalypha species: Acalypha torta, Acalypha onata, and Acalypha wilkesiana, and used as sensitizers in TiO₂-based dye-sensitized solar cells. These pigments exhibited strong and broad absorption across the visible region (400–700 nm) and showed good attachment to the TiO₂ surface. The fabricated DSSCs produced open-circuit voltages in the range of 0.36–0.62 V and short-circuit current densities between 1.7 and 2.9 mA cm⁻². Their incident photon-to-current conversion efficiencies (IPCE) ranged from 11% to 27%. Among the three extracts, Acalypha wilkesiana gave the highest performance, indicating its superior photosensitizing ability and potential as an effective natural sensitizer for DSSC applications.
Acalypha species, DSSCs, TiO2, solar cells, photosensitization
Copyright (c) 2026 Teju Philip Olakunle, Adebowale Clement Adebisi, Gbadebo Taofeek Yusuf, Kamorudeen Taiwo Alasi, Dolapo Eleyele, Sunday Adeoye, Hammidu Ayodeji Rasheed https://creativecommons.org/licenses/by-nc/4.0