Nigerian Journal of Physics
type: channel
description: 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.
publisher: Nigerian Institute of Physics (NIP)
language: en
publication name: Nigerian Journal of Physics
issn: 1595-0611
items: Segmented Rotor Magnetic Flux Switching Device for High-Performance Electric Motorcycles and Scooters Applications
items: A Study of Pre-Earthquake Ionospheric Anomaly (PEIA) in Low Latitude/ Equatorial Region TEC Using the Wavelet Power Spectrum Method
items: 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
items: Simulation and Optimization of CdTe and CIGS Thin-Film Solar Cells with Dual ETLS (CdS, ZnO) Using SCAPS-1D: A Comparative Approach
items: Investigating the Structural, Elastic, Electrical, and Thermodynamic Characteristics of NbCoSn and VRhSn Half-Heusler Compounds Using First-Principles Calculations
items: Porosity and Geomechanical Characteristics of banded Iron Ore from Itakpe, North Central Nigeria
items: Comparison of Cosmic Ray Intensity Variations at Moscow and Oulu Stations
items: Radiological Dose and Health Risk Assessment of Naturally Occurring Radioactive Materials at Kataeregi Artisanal Mining Site, Niger State Using RESRAD Code
items: Reservoir Quality Evaluation Using Petrophysical Logs and Seismic Attribute Techniques: A Case Study of GOTO Field, Niger Delta
items: Enhancing the Visibility of Microcalcifications in Breast Tissue Using Morphological Operations and Gaussian Smoothing Techniques: A Phantom Study
items: Reservoir Characterization Using Integrated Petrophysical Evaluation, Seismic Attributes, and AVO Modeling in JASMI Field, Niger Delta Basin
items: Performance Evaluation of Satellite Gravity on Variable Test Points and Geophysical Models in Gongola Basin, Nigeria
items: Measurement of Scattered and Leakage Radiation in X-Ray Facilities from Selected Centers in Warri Metropolis, Delta State
items: Elemental Analysis of Particulate Matter at Relief Market, Egbu, Imo State
items: Effect of Temperature and Retention Time on the Quality of Biochar of Some Agricultural Waste
items: Synthesis of Polyvinylidene Fluoride-Graphene Based Polymer Nanocomposite with Enhanced Piezoelectric Properties
items: Quantum-Enhanced Solar Cell Efficiency: A Theoretical and Empirical Framework for Photovoltaic Storage Degradation Optimization
items: Hydrothermally Synthesized Doped Non-Aqueous Cds Thin Films for Degradation of Methylene Blue under Sunlight Radiation
items: Geophysical Investigation and Protective Capacity of Frequently Failed Road Sections of Selected Roads in Delta State, Nigeria
items: PM₂.₅ Emissions from Office Laser Printers: Real-Time Exposure Assessment and Risk Mitigation
items: Design and Sizing of an Off-Grid Solar Photovoltaic (PV) System for an Office Unit at Modibbo Adama University, Yola-Nigeria
items: Volterra Adaptive Filter for Real-Time OTDR Monitoring and Fault Localisation in Fibre Optic Networks
items: Assessment of Excess Lifetime Cancer Risk from Indoor Radon Exposure in Obio-Akpor Local Government Area, Rivers State, Nigeria.
items: Time Series Modelling of Three-Dimensional Temperatures across Nigeria Using Data from Cosmic
items: The Energy Spectra of Soluble Potentials Within the Framework of the Variational Method
items: Optimizing Quantum-dot Cellular Automata Circuits for Nano communication: A Reversible Hamming Code Implementation
items: Adomian Decomposition Method for Numerical Solution of 1-D and 2-D Seismic Wave Equations
items: Health Risk Assessment of Heavy Metal Concentrations in Sewage Compost Manure Used for Agriculture in Zaria, Nigeria
items: A Comparative Study for the Estimation of Downward Longwave Radiation under Clear Sky Condition across the Midland Climatic Zone of Nigeria
items: Photovoltaic Performance of Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Three Acalypha Leaf Species

Segmented Rotor Magnetic Flux Switching Device for High-Performance Electric Motorcycles and Scooters Applications
type: item
description: 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 propu…
subject: Articles
  topic: section
subject: Permanent Magnet
  topic: keywords
subject: Flux Switching Device
  topic: keywords
subject: Segmental Rotor
  topic: keywords
subject: Electric Vehicle Propulsion
  topic: keywords
subject: Electric Scooter
  topic: keywords
subject: Finite Element Analysis
  topic: keywords
subject: JMAG Designer
  topic: keywords
subject: Sustainable Mobility
  topic: keywords
creator: Kasim Ibrahim Mohammed
creator: Mohammed Ahmed
rights: Copyright (c) 2026 Kasim Ibrahim Mohammed, Mohammed Ahmed https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-03
publication date: 2026-07-03
starting page: 36
ending page: 41
doi: 10.62292/njp.v34i2.2025.633

A Study of Pre-Earthquake Ionospheric Anomaly (PEIA) in Low Latitude/ Equatorial Region TEC Using the Wavelet Power Spectrum Method
type: item
description: 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.
subject: Articles
  topic: section
subject: Earthquake
  topic: keywords
subject: TEC
  topic: keywords
subject: WPS
  topic: keywords
subject: Low-latitude/equatorial region
  topic: keywords
subject: PEIA
  topic: keywords
creator: Afolabi Adegboyega Kotoye
creator: Olukayode Elijah Falayi
creator: Johnson Olufemi Adepitan
creator: Bolarinwa John Adekoya
creator: Ayobamidele Dele Adelaja
creator: Kayode Johnson Bamidele
rights: 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
date: 2026-07-27
publication date: 2026-07-27
starting page: 186
ending page: 201
doi: 10.62292/njp.v35i4.2026.635

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
type: item
description: 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.
subject: Articles
  topic: section
subject: Schiff base
  topic: keywords
subject: Triphenylphosphine
  topic: keywords
subject: Heteroleptic
  topic: keywords
subject: Antibacterial-activity
  topic: keywords
subject: Synergistic
  topic: keywords
creator: Olufemi S. Odulaja
creator: Christiana I. Ayangbesan
creator: Adetutu V. Williams
creator: Christiana A. Adeleye
creator: Taofeeq F. Adeleye
creator: Oyinlola O. Olugbile
creator: Taiwo A. Abiola
creator: Adejumoke Morilat Hashimi
creator: Muritala Adeniyi Olusola
creator: Emmanuel O. Bamiro
rights: 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
date: 2026-07-27
publication date: 2026-07-27
starting page: 179
ending page: 185
doi: 10.62292/njp.v35i4.2026.626

Simulation and Optimization of CdTe and CIGS Thin-Film Solar Cells with Dual ETLS (CdS, ZnO) Using SCAPS-1D: A Comparative Approach
type: item
description: 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.
subject: Articles
  topic: section
subject: CdTe thin-film solar cells
  topic: keywords
subject: CIGS photovoltaics
  topic: keywords
subject: SCAPS-1D simulation
  topic: keywords
subject: Electron transport layers (CdS, ZnO)
  topic: keywords
subject: Absorber thickness optimization
  topic: keywords
creator: Damian E. Adukwu
creator: Solomon Denen Igba
creator: Peverga R. Jubu
creator: Adebayo Ademola
rights: Copyright (c) 2026 Damian E. Adukwu, Solomon Denen Igba, Peverga R. Jubu, Adebayo Ademola https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-27
publication date: 2026-07-27
starting page: 101
ending page: 117
doi: 10.62292/njp.v35i4.2026.636

Investigating the Structural, Elastic, Electrical, and Thermodynamic Characteristics of NbCoSn and VRhSn Half-Heusler Compounds Using First-Principles Calculations
type: item
description: 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.
subject: Articles
  topic: section
subject: Half-Heusler
  topic: keywords
subject: Band gap
  topic: keywords
subject: Bulk modulus
  topic: keywords
subject: Semiconductor
  topic: keywords
subject: Phonons
  topic: keywords
subject: Thermodynamic
  topic: keywords
creator: Eddy Enorense Aigbekaen
creator: Fidelia Chukwudumebi Ighrakpata
rights: Copyright (c) 2026 Eddy Enorense Aigbekaen, Fidelia Chukwudumebi Ighrakpata https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-27
publication date: 2026-07-27
starting page: 171
ending page: 178
doi: 10.62292/njp.v35i4.2026.629

Porosity and Geomechanical Characteristics of banded Iron Ore from Itakpe, North Central Nigeria
type: item
description: 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 min…
subject: Articles
  topic: section
subject: Itakpe iron ore
  topic: keywords
subject: porosity
  topic: keywords
subject: uniaxial compressive strength
  topic: keywords
subject: elastic modulus
  topic: keywords
subject: modulus ratio
  topic: keywords
creator: Amidu Abiola Ige-Adeyeye
creator: Olawale Babatunde Olatinsu
creator: Vitalis Chidi Ozebo
creator: Lionel Esteban
rights: Copyright (c) 2026 Amidu Abiola Ige-Adeyeye, Olawale Babatunde Olatinsu, Vitalis Chidi Ozebo, Lionel Esteban https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-27
publication date: 2026-07-27
starting page: 145
ending page: 170
doi: 10.62292/njp.v35i4.2026.654

Comparison of Cosmic Ray Intensity Variations at Moscow and Oulu Stations
type: item
description: 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.
subject: Articles
  topic: section
subject: Cosmic Rays
  topic: keywords
subject: Forbush Decreases
  topic: keywords
subject: Cosmic Ray Variation
  topic: keywords
subject: Automated Method
  topic: keywords
subject: Manual Method
  topic: keywords
subject: Algorithm
  topic: keywords
creator: Ogbonnaya Okike
creator: Patience I. Akande-Rowland
creator: Miracle Okoro Ikoro
creator: Augustine Ogonna Chikwendu
creator: Meka Firew Menteso
rights: 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
date: 2026-07-14
publication date: 2026-07-14
starting page: 118
ending page: 125
doi: 10.62292/njp.v35i4.2026.618

Radiological Dose and Health Risk Assessment of Naturally Occurring Radioactive Materials at Kataeregi Artisanal Mining Site, Niger State Using RESRAD Code
type: item
description: 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-…
subject: Articles
  topic: section
subject: Radionuclide
  topic: keywords
subject: Residual Radioactive Materials (RESRAD)
  topic: keywords
subject: Gamma Spectrometry
  topic: keywords
subject: Activity Concentration
  topic: keywords
subject: Pathways
  topic: keywords
creator: Abdullahi Muhammad
rights: Copyright (c) 2026 Abdullahi Muhammad https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-03
publication date: 2026-07-03
starting page: 26
ending page: 35
doi: 10.62292/njp.v34i2.2025.588

Reservoir Quality Evaluation Using Petrophysical Logs and Seismic Attribute Techniques: A Case Study of GOTO Field, Niger Delta
type: item
description: 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.
subject: Articles
  topic: section
subject: Niger Delta
  topic: keywords
subject: Reservoir Characterization
  topic: keywords
subject: Petrophysics
  topic: keywords
subject: Seismic Attributes
  topic: keywords
subject: Hydrocarbon Potential
  topic: keywords
creator: David Asuba Igonoh
creator: Godwin Omokenu Emujakporue
creator: Sonny Inichinbia
rights: Copyright (c) 2026 Igonoh David Asuba, Emujakporue Godwin Omokenu, Inichinbia Sonny https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-13
publication date: 2026-07-13
starting page: 376
ending page: 397
doi: 10.62292/njp.v35i3.2026.648

Enhancing the Visibility of Microcalcifications in Breast Tissue Using Morphological Operations and Gaussian Smoothing Techniques: A Phantom Study
type: item
description: 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.
subject: Articles
  topic: section
subject: Breast cancer
  topic: keywords
subject: Microcalcification
  topic: keywords
subject: Morphological operations
  topic: keywords
subject: Gaussian elimination
  topic: keywords
subject: MSE
  topic: keywords
subject: SNR
  topic: keywords
creator: Franca Oyiwoja Okoh
creator: Norlaili Ahmad Kabir
creator: John Actor Ocheje
creator: Mohd Fahmi Mohd Yusof
creator: Ahmad Sufril Azlan Mohammed
creator: Rafidah Zainon
creator: Ezekiel Yangde
creator: Moses Ejike Onudibia
rights: 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
date: 2026-06-18
publication date: 2026-06-18
starting page: 46
ending page: 55
doi: 10.62292/njp.v35i3.2026.518

Reservoir Characterization Using Integrated Petrophysical Evaluation, Seismic Attributes, and AVO Modeling in JASMI Field, Niger Delta Basin
type: item
description: 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 f…
subject: Articles
  topic: section
subject: Petrophysical Analysis
  topic: keywords
subject: Seismic Attributes
  topic: keywords
subject: AVO Analysis
  topic: keywords
subject: Reservoir Characterization
  topic: keywords
subject: Niger Delta Basin
  topic: keywords
subject: Hydrocarbon Prospectivity
  topic: keywords
creator: David Asuba Igonoh
creator: Godwin Omokenu Emujakporue
creator: Sonny Inichinbia
rights: Copyright (c) 2026 Igonoh David Asuba, Emujakporue Godwin Omokenu, Inichinbia Sonny https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-03
publication date: 2026-07-03
starting page: 42
ending page: 58
doi: 10.62292/njp.v35i4.2026.641

Performance Evaluation of Satellite Gravity on Variable Test Points and Geophysical Models in Gongola Basin, Nigeria
type: item
description: 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.
subject: Articles
  topic: section
subject: Aeromagnetic
  topic: keywords
subject: Gongola
  topic: keywords
subject: Forward Modelling
  topic: keywords
subject: Gravity
  topic: keywords
subject: Satellite
  topic: keywords
creator: Adamu Aliyu Bagare
rights: Copyright (c) 2026 Adamu Aliyu Bagare https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-22
publication date: 2026-07-22
starting page: 132
ending page: 144
doi: 10.62292/njp.v35i4.2026.591

Measurement of Scattered and Leakage Radiation in X-Ray Facilities from Selected Centers in Warri Metropolis, Delta State
type: item
description: 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.
subject: Articles
  topic: section
subject: Dose
  topic: keywords
subject: X-ray
  topic: keywords
subject: ALARA
  topic: keywords
subject: Risk
  topic: keywords
subject: Leaking radiation
  topic: keywords
creator: Sylvester Obakpororo Ovwasa
creator: Joy Amuofu Adonuja
creator: Kparobo Godwin Agbajor
creator: Franklin Anita Akpolile
rights: Copyright (c) 2026 Sylvester Obakpororo Ovwasa, Joy Amuofu Adonuja, Kparobo Godwin Agbajor, Franklin Anita Akpolile https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-22
publication date: 2026-07-22
starting page: 126
ending page: 131
doi: 10.62292/njp.v35i4.2026.573

Elemental Analysis of Particulate Matter at Relief Market, Egbu, Imo State
type: item
description: 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.
subject: Articles
  topic: section
creator: Chisom Ugonna Obi
creator: James James Robert
creator: Theodore Chidiezie Chineke
rights: Copyright (c) 2026 Chisom Ugonna Obi, James James Robert, Theodore Chidiezie Chineke https://creativecommons.org/licenses/by-nc/4.0
date: 2026-06-29
publication date: 2026-06-29
starting page: 176
ending page: 180
doi: 10.62292/njp.v35i3.2026.502

Effect of Temperature and Retention Time on the Quality of Biochar of Some Agricultural Waste
type: item
description: 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..
subject: Articles
  topic: section
subject: Pyrolysis
  topic: keywords
subject: Biochar
  topic: keywords
subject: Proximate analysis
  topic: keywords
subject: Ultimate analysis
  topic: keywords
subject: Calorific values
  topic: keywords
creator: Lawan Haruna
creator: Aliyu Aminu Safana
creator: Ibrahim Murtala Musa
creator: Hafeez Y. Hafeez
creator: Umar M. Dankawu
creator: Muhammad M. Machina
rights: 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
date: 2026-07-02
publication date: 2026-07-02
starting page: 1
ending page: 7
doi: 10.62292/njp.v35i4.2026.600

Synthesis of Polyvinylidene Fluoride-Graphene Based Polymer Nanocomposite with Enhanced Piezoelectric Properties
type: item
description: 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.
subject: Articles
  topic: section
subject: PVDF-Graphene Nanocomposite
  topic: keywords
subject: Piezoelectric Voltage Constant
  topic: keywords
subject: Resistivity
  topic: keywords
creator: Aliyu Abdulraheem
creator: Sadiq Umar
creator: Sanda Abubakar Sadiq
creator: Abdelghaffar Amoka Abdelmalik
rights: Copyright (c) 2026 Aliyu Abdulraheem, Sadiq Umar, Sanda Abubakar Sadiq, Abdelghaffar Amoka Abdelmalik https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-09
publication date: 2026-07-09
starting page: 84
ending page: 90
doi: 10.62292/njp.v35i4.2026.539

Quantum-Enhanced Solar Cell Efficiency: A Theoretical and Empirical Framework for Photovoltaic Storage Degradation Optimization
type: item
description: 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.
subject: Articles
  topic: section
subject: Quantum-enhanced optimization
  topic: keywords
subject: PV degradation
  topic: keywords
subject: Hybrid quantum-classical computing
  topic: keywords
subject: Energy storage longevity
  topic: keywords
subject: Predictive maintenance
  topic: keywords
creator: Priscilla O. Osuhor
creator: Samuel Kanayo
rights: Copyright (c) 2026 Priscilla O. Osuhor, Samuel Kanayo https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-14
publication date: 2026-07-14
starting page: 368
ending page: 375
doi: 10.62292/njp.v35i3.2026.651

Hydrothermally Synthesized Doped Non-Aqueous Cds Thin Films for Degradation of Methylene Blue under Sunlight Radiation
type: item
description: 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.
subject: Articles
  topic: section
subject: Cadmium sulfide
  topic: keywords
subject: Hydrothermal synthesis
  topic: keywords
subject: Non-aqueous medium
  topic: keywords
subject: Bismuth ferrite
  topic: keywords
subject: Tin oxide
  topic: keywords
subject: Photocatalysis
  topic: keywords
subject: Methylene blue
  topic: keywords
subject: Sunlight irradiation
  topic: keywords
subject: Thin films
  topic: keywords
subject: Dye degradation
  topic: keywords
creator: Joseph Ayodele Owolabi
creator: Sunday Aboritoli
creator: David Matthew Femi
rights: Copyright (c) 2026 Joseph Ayodele Owolabi, Sunday Aboritoli, David Matthew Femi https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-14
publication date: 2026-07-14
starting page: 357
ending page: 367
doi: 10.62292/njp.v35i3.2026.650

Geophysical Investigation and Protective Capacity of Frequently Failed Road Sections of Selected Roads in Delta State, Nigeria
type: item
description: 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-l…
subject: Articles
  topic: section
subject: Assessment
  topic: keywords
subject: Delta State
  topic: keywords
subject: Failed portions
  topic: keywords
subject: Geophysical
  topic: keywords
subject: Protective capacity
  topic: keywords
creator: Ogheneovo Akpoyibo
creator: Onoriode Ezekiel Abriku
creator: Otitie Star Umayah
creator: Felix Chukwuka Ugbe
creator: Ochuko Anomohanran
rights: Copyright (c) 2026 Ogheneovo Akpoyibo, Onoriode Ezekiel Abriku, Otitie Star Umayah, Felix Chukwuka Ugbe, Ochuko Anomohanran https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-14
publication date: 2026-07-14
starting page: 333
ending page: 356
doi: 10.62292/njp.v35i3.2026.649

PM₂.₅ Emissions from Office Laser Printers: Real-Time Exposure Assessment and Risk Mitigation
type: item
description: 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.
subject: Articles
  topic: section
subject: PM₂.₅ Emissions
  topic: keywords
subject: Laser Printers
  topic: keywords
subject: Heavy Metals
  topic: keywords
subject: Occupational Exposure
  topic: keywords
subject: Inhalation Risk Assessment
  topic: keywords
subject: HEPA Filtration
  topic: keywords
subject: Office Air Quality
  topic: keywords
creator: Oluwasayo Peter Abodunrin
creator: Oluwaseun Dosunmu
creator: Inioluwa Olowofila
creator: Oladipupo Olanrewaju
creator: Augustine Kolapo Ademola
rights: Copyright (c) 2026 Oluwasayo Peter Abodunrin, Oluwaseun Dosunmu, Inioluwa Olowofila, Oladipupo Olanrewaju, Augustine Kolapo Ademola https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-09
publication date: 2026-07-09
starting page: 75
ending page: 83
doi: 10.62292/njp.v35i4.2026.644

Design and Sizing of an Off-Grid Solar Photovoltaic (PV) System for an Office Unit at Modibbo Adama University, Yola-Nigeria
type: item
description: 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.
subject: Articles
  topic: section
subject: Solar PV performance
  topic: keywords
subject: Off-grid Solar PV system
  topic: keywords
subject: PV module
  topic: keywords
subject: battery
  topic: keywords
subject: Inverter
  topic: keywords
subject: voltage regulator
  topic: keywords
creator: Mohammed Faisal Isa
creator: Haruna Sallau Bayel
creator: Muktar Bello
creator: Joseph Aidan
rights: Copyright (c) 2026 Mohammed Faisal Isa, Haruna Sallau Bayel, Muktar Bello, Joseph Aidan https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-13
publication date: 2026-07-13
starting page: 91
ending page: 100
doi: 10.62292/njp.v35i4.2026.630

Volterra Adaptive Filter for Real-Time OTDR Monitoring and Fault Localisation in Fibre Optic Networks
type: item
description: 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.
subject: Articles
  topic: section
subject: Volterra Adaptive Filter
  topic: keywords
subject: Fault Detection
  topic: keywords
subject: Fibre Optic Monitoring
  topic: keywords
subject: Adaptive Filtering
  topic: keywords
subject: Optical Time-Domain Reflectometry
  topic: keywords
creator: Ozuem Edward
creator: Johnson Ayeni
creator: Ndifreke U. Ebong
rights: Copyright (c) 2026 Ozuem Edward, Johnson Ayeni, Ndifreke U. Ebong https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-08
publication date: 2026-07-08
starting page: 66
ending page: 74
doi: 10.62292/njp.v35i4.2026.623

Assessment of Excess Lifetime Cancer Risk from Indoor Radon Exposure in Obio-Akpor Local Government Area, Rivers State, Nigeria.
type: item
description: 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.
subject: Articles
  topic: section
subject: indoor radon
  topic: keywords
subject: annual absorbed dose
  topic: keywords
subject: annual effective dose
  topic: keywords
creator: Diamond George
creator: Margaret Apaemi Briggs-Kamara
creator: Chinoye Amakiri Raymond
rights: Copyright (c) 2026 Diamond George, Margaret Apaemi Briggs-Kamara, Chinoye Amakiri Raymond https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-08
publication date: 2026-07-08
starting page: 59
ending page: 65
doi: 10.62292/njp.v35i4.2026.610

Time Series Modelling of Three-Dimensional Temperatures across Nigeria Using Data from Cosmic
type: item
description: 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.
subject: Articles
  topic: section
subject: Time series
  topic: keywords
subject: Modelling
  topic: keywords
subject: Temperature
  topic: keywords
subject: COSMIC
  topic: keywords
creator: Ugochukwu Ihemaguba
creator: Chidi Emmanuel Akujor
creator: Romanus E. Ugwoke
creator: Costecia Ifeoma Onah
rights: Copyright (c) 2026 Ugochukwu Ihemaguba, Chidi Emmanuel Akujor, Romanus E. Ugwoke, Costecia Ifeoma Onah https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-02
publication date: 2026-07-02
starting page: 8
ending page: 16
doi: 10.62292/njp.v35i4.2026.609

The Energy Spectra of Soluble Potentials Within the Framework of the Variational Method
type: item
description: 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.
subject: Articles
  topic: section
subject: variational method
  topic: keywords
subject: Coulomb potential
  topic: keywords
subject: Pseudoharmonic potential
  topic: keywords
subject: Hulthen potential
  topic: keywords
subject: Poschl-Teller-type potential
  topic: keywords
creator: Ekwevugbe Omugbe
creator: Etido P. Inyang
creator: Clement A. Onate
rights: Copyright (c) 2026 Ekwevugbe Omugbe, Etido P. Inyang, Clement A. Onate https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-03
publication date: 2026-07-03
starting page: 17
ending page: 25
doi: 10.62292/njp.v34i2.2025.569

Optimizing Quantum-dot Cellular Automata Circuits for Nano communication: A Reversible Hamming Code Implementation
type: item
description: 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.
subject: Articles
  topic: section
subject: Area optimisation
  topic: keywords
subject: Energy dissipation
  topic: keywords
subject: Error detection parity
  topic: keywords
subject: Nanoscale communication systems
  topic: keywords
subject: Reversible logic
  topic: keywords
creator: Bahijja Yahaya Galadima
creator: Shaawanatu Aminu
creator: Maryam Ibrahim
rights: Copyright (c) 2026 Bahijja Yahaya Galadima, Shaawanatu Aminu, Maryam Ibrahim https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-01
publication date: 2026-07-01
starting page: 326
ending page: 332
doi: 10.62292/njp.v35i3.2026.616

Adomian Decomposition Method for Numerical Solution of 1-D and 2-D Seismic Wave Equations
type: item
description: 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.
subject: Articles
  topic: section
subject: Adomian Decomposition
  topic: keywords
subject: Approximate Solution
  topic: keywords
subject: Seismic Wave
  topic: keywords
subject: 1-D
  topic: keywords
subject: 2-D
  topic: keywords
creator: Ramoni Adebola Soneye
creator: Ayobamidele Sunday Odesola
creator: Abiodun Sufiat Ajani
creator: Oluseye Samuel Olayemi
rights: Copyright (c) 2026 Ramoni Adebola Soneye; Ayobamidele Sunday Odesola, Abiodun Sufiat Ajani, Oluseye Samuel Olayemi https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-01
publication date: 2026-07-01
starting page: 315
ending page: 325
doi: 10.62292/njp.v35i3.2026.611

Health Risk Assessment of Heavy Metal Concentrations in Sewage Compost Manure Used for Agriculture in Zaria, Nigeria
type: item
description: 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.
subject: Articles
  topic: section
subject: Heavy metals
  topic: keywords
subject: Sewage compost
  topic: keywords
subject: Instrumental neutron activation analysis
  topic: keywords
subject: Environmental monitoring
  topic: keywords
subject: Soil contamination
  topic: keywords
subject: Nigeria
  topic: keywords
creator: Emmanuel Itodo Okpokwu
creator: Matthew Agu
creator: Christiana Akusu
rights: Copyright (c) 2026 Emmanuel Itodo Okpokwu, Matthew Agu, Christiana Akusu https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-01
publication date: 2026-07-01
starting page: 307
ending page: 314
doi: 10.62292/njp.v35i3.2026.606

A Comparative Study for the Estimation of Downward Longwave Radiation under Clear Sky Condition across the Midland Climatic Zone of Nigeria
type: item
description: 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.
subject: Articles
  topic: section
subject: Clear-sky condition
  topic: keywords
subject: Downward Long wave Radiation
  topic: keywords
subject: Meteorological Parameters
  topic: keywords
subject: Midland Climatic Zone
  topic: keywords
subject: Validation Test Indicators
  topic: keywords
creator: Davidson Odafe Akpootu
creator: Oluwamayowa Emmanuel Agidi
creator: Musa Momoh
creator: Isah Ibrahim Garba
rights: Copyright (c) 2026 Davidson Odafe Akpootu, Oluwamayowa Emmanuel Agidi, Musa Momoh, Isah Ibrahim Garba https://creativecommons.org/licenses/by-nc/4.0
date: 2026-07-01
publication date: 2026-07-01
starting page: 291
ending page: 306
doi: 10.62292/njp.v35i3.2026.603

Photovoltaic Performance of Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Three Acalypha Leaf Species
type: item
description: 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.
subject: Articles
  topic: section
subject: Acalypha species, DSSCs, TiO2, solar cells, photosensitization
  topic: keywords
subject: Acalypha species
  topic: keywords
subject: DSSCs
  topic: keywords
subject: TiO2
  topic: keywords
subject: solar cells
  topic: keywords
subject: Solar cells
  topic: keywords
subject: Photosensitization
  topic: keywords
creator: Teju Philip Olakunle
creator: Adebowale Clement Adebisi
creator: Gbadebo Taofeek Yusuf
creator: Kamorudeen Taiwo Alasi
creator: Dolapo Eleyele
creator: Sunday Adeoye
creator: Hammidu Ayodeji Rasheed
rights: 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
date: 2026-07-01
publication date: 2026-07-01
starting page: 284
ending page: 290
doi: 10.62292/njp.v35i3.2026.599