ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT

Towards Irrigation Modernisation in the Ogun-Oshun River Basin, Nigeria: Opportunities, Challenges, and Improvement Options

Mon, 02 Mar 2026 00:00:00 +0000

Irrigated agriculture is very crucial in achieving the Sustainable Development Goal (SDG) and ensuring food security in Nigeria. The study examines the opportunities and the challenges of the selected thirteen Irrigation Farm Projects in the Ogun Oshun River Basin Authority (OORBA). Data were obtained by interviews from the stakeholders in the management of the irrigation schemes. The study reveals that land areas range from 150 ha for the Lower Ogun Irrigation Project in Mokoloki to 3,500 ha for the Middle Ogun Irrigation Project in Iseyin. However, the level of utilisation of the land resources varies from 6.2% to 100%. Interestingly, it was observed that a good correlation between the irrigable land area and the area actually irrigated (r2 = 0.7982), and the irrigable areas and the actual irrigated areas under large Irrigation Farm Projects (r2 = 0.70) exist, unlike the small
Irrigation Farm Projects (r2 = 0.09). Therefore, it indicates that the smallholder farmers in the large Irrigation Farm Projects utilised the land resources better. However, where underutilisation was pronounced, it is due to ageing irrigation and energy infrastructure, poor access roads and networks, and inadequate modern farm machinery. Surface water resources are abundant in the selected Irrigation Farm Projects, which, if well explored, could transform the irrigated agriculture in the basin and reposition OORBD as the food basket for the Southwest, Nigeria and the neighbouring African countries. The poor performance of the public Irrigation Farm Projects in the OORBD is due to low financial investment in the
projects, poor economic conditions, lack of weather early warning systems and networks to mitigate the effects of climate change. Opportunities for transforming irrigated agriculture in the basin are the application of sensors in irrigation water management and drones for smart agriculture, renewable energy, micro-irrigation systems, access roads and market, regular training of farm managers and the early warning systems networks.

Analysis of Bama Gravel as Coarse Aggregate in Concrete Production: A Review

N. Muazu, H. I. Muazu, A. S. Isa — Mon, 02 Mar 2026 12:20:33 +0000

Bama gravel, a naturally occurring riverbed aggregate in Borno, Northeastern Nigeria, is widely used in concrete production due to its abundance and low cost. This naturally occurring aggregate from Bama ridge, extends over a distance of approximately 300 km. In the past few years, attention has been shifted by researchers to exploring the engineering potential of the aggregate. The review adopted systematic approach by collecting and analyzing studies on Bama gravel between 1999 and 2025. A total of 10 documents were identified, of which seven met the inclusion criteria and were analyzed to identify performance trends and research gaps. The review shows that more than 90% of the studies carried out on the aggregate are by indigenous researchers. This is due to the prior knowledge of these researchers on how the material is being patronized by local communities
in the catchment area. The review also shows that existing studies are focused on grading of the aggregate, mix ratio optimization and partial replacement of cement or aggregates, demonstrating its suitability for producing medium and high strength concrete. However, key research gaps remain, as lack of established probabilistic properties of Bama gravel which are vital for reliability-based design. This limits its global applicability in the design of concrete. Its mineralogical composition is also undocumented, despite its potential impact on reactivity, strength, and durability. Long-term performance under diverse environmental conditions remains unstudied. Furthermore, the microstructural behavior within the cement matrix, including the interfacial transition zone and bonding characteristics, is unexplored. To our knowledge there never been any study that assessed its
resistance to Sulphate attack, a critical factor for exposure to aggressive environments. Addressing these gaps will advance the understanding and global acceptance of Bama gravel as a durable and reliable aggregate for concrete production.

Optimization of Performance Parameters of an Off-Grid Wind Solar Hybrid Power System Using HOMER Pro for Enhanced Energy Reliability at Kashim Ibrahim University, Maiduguri

M. M. Hamidu, H. A. Abdulrahman — Mon, 02 Mar 2026 15:06:17 +0000

Kashim Ibrahim University, Maiduguri faces persistent energy shortages due to unreliable grid supply and reliance on diesel generators. Earlier proposals for stand alone solar PV systems overlooked wind resources and full techno-economic optimization, highlighting the need for a more resilient hybrid approach. This study aims to evaluate and optimize an off-grid wind–solar hybrid power system for reliable and sustainable electricity supply at Kashim Ibrahim University. The assessment was carried out using hourly electrical load data and validated site specific meteorological data, including solar irradiance, wind speed, and temperature, modeled and optimized in HOMER Pro software. The optimal configuration includes 9.25 MW PV, 678 kW wind, lead-acid storage, and a bidirectional converter, which could provide 100% renewable energy with negligible unmet load. With a levelized cost of energy (LCOE) of ₦85.18/kWh and a 3.9 year payback period, the system outperforms grid and diesel alternatives by producing 17.63 GWh yearly to satisfy the 3.21 GWh demand. Over a 25-year period, the system prevents more than 308,000 tonnes of CO₂ emissions and reduces air and noise pollution. Strong temperature resilience is confirmed by sensitivity analysis, where temperature variation between 25–35°C results in only a 3.5% reduction in energy production. The optimized wind–solar hybrid system offers a cost effective, reliable, and environmentally sustainable energy solution for institutional power supply in northeastern Nigeria. Phased implementation is recommended for Kashim Ibrahim University and other institutions facing persistent energy insecurity.

Production of Goat Horn Particles Reinforced Epoxy Resin Composite for Automobile Brake Pad

M. M. Dukku, H. Maidawa, I. N. Dogo, N. M. Tahir, M. Y. Zadawa — Mon, 02 Mar 2026 15:19:07 +0000

The development and evaluation of goat horn as asbestos-free friction material for the production of automotive brake pad was carried out in this work. Asbestos friction material that been used has been found to be carcinogenic and has prompted several research efforts for its replacement in brake pads application. In this research, six samples of composites were produced using goat horn particulate size of 300 µm and 600 µm as reinforced material with epoxy resin as the matrix with the following percentage compositions for specimen A, B, C, D, E, and F (21 wt% goat horn and 60 wt% epoxy resin, 21 wt% goat horn, 60 wt% epoxy resin, 26 wt% goat horn and 55 wt% epoxy resin, 26 wt% goat horn and 55 wt% epoxy resin, 31 wt% goat horn and 50 wt% epoxy resin and 31 wt% goat horn and 50 wt% epoxy resin with 3 wt% iron chips, 7 wt% silica, 4 wt% graphite, and 4 wt% CaCO3; in each sample) respectively. These specimens were made by compression molding method and subjected to mechanical and physical tests to ascertain their performance in service using standard test procedures, materials and equipment. The result showed that specimens composite samples A and B gave optimum performance for water and oil absorption of 0.725%, and 0.494%, hardness and compressive strength of 121.21 MPa and 10.313 respectively. furthermore, samples E and F gave the optimum performance for coefficient of friction (0.47) and abrasion resistance (4.297x10-6g/m) respectively. It was observed that increase in the reinforcement content increased hardness, water and oil absorption and coefficient of friction of the composite brake pad, while wear rate and compressive strength decreased. The results showed that goat horn particles are an effective replacement for asbestos in automotive brake pad application.

Limited Adoption of Advanced BIM Tools in Architectural Education: Evidence from Southwestern Nigeria

B. A. Orola, A. C. Uzoagwa — Mon, 02 Mar 2026 15:28:38 +0000

This study examined the availability and utilization of Building Information Modelling (BIM) tools among architectural educators in three public universities in southwestern Nigeria. Using a purposive sampling technique, a structured questionnaire was distributed to 80 architectural educators, out of which 41 valid responses were received, yielding a response rate of 51%. The survey collected data on the BIM tools accessible to educators, the specific categories of BIM tools they used, and the frequency of such use in teaching and research activities. Findings revealed substantial variability in BIM tool usage across the institutions. 3D Modelling and Rendering & Visualization were used most frequently, while advanced tools linked to multi-disciplinary collaboration, such as MEP Systems Design, Clash Detection, Construction Simulation (4D), and Cost Estimation (5D), were rarely utilized. This pattern indicates that although foundational BIM capabilities are present, higher-level, interoperability-driven tools remain under integrated in architectural education within the selected universities. The study concludes that BIM utilization is uneven and generally limited to basic functions, underscoring the need for more comprehensive integration of advanced BIM tools in architectural curricula in southwestern Nigeria.

Particle Swarm Optimization Based Resource Allocation for High Altitude Platform Networks

H. S. Zubairu, D. S. Shuaibu, M. M. Sa'ad — Mon, 02 Mar 2026 15:57:46 +0000

High Altitude Platforms (HAPs) are emerging as cost-effective aerial communication nodes capable of providing broadband wireless coverage over large geographical areas. However, efficient resource allocation remains a key challenge due to channel variability, power constraints, and user heterogeneity. This paper proposes a Particle Swarm Optimization (PSO)–based framework for joint subcarrier and power allocation in an OFDMA-based HAP communication system. The proposed approach employs PSO for adaptive subcarrier assignment and integrates the water-filling algorithm for power allocation. Performance is evaluated against conventional resource allocation schemes, including Max-SNR, Round Robin, and Proportional Fair. Simulation results demonstrate that the proposed PSO-based framework achieves competitive spectral and power efficiency, a more balanced distribution of user capacity, and a significant reduction in computational complexity, with an average execution-time reduction of approximately 97% compared to conventional methods. These results highlight the practicality of the proposed approach for real-time and adaptive resource management in next generation HAP-based aerial communication networks.

Physico-Mechanical Characterization of Hybrid Composite Gasket Developed Using Sugarcane Bagasse Ash, Soda-Lime Waste Glass Powder, and Epoxy Resin

E. A. Idowu, N. O. Adekunle, F. O. Akinmusire, R. O. Raji — Mon, 02 Mar 2026 16:09:56 +0000

The environmental and health risks posed by conventional gasket materials such as asbestos and synthetic rubbers have created a pressing need to develop sustainable alternatives for mechanical sealing applications. This study investigated the potential of hybrid composite gaskets composed of sugarcane bagasse ash, soda-lime waste glass powder, and epoxy resin as an environmentally friendly alternative. Five different compositions were formulated using the hand lay-up method and evaluated for mechanical and thermal properties such as density, porosity, hardness, tensile strength, thermal endurance, Scanning Electron Microscopy (SEM), and X-ray Fluorescence (XRF) analysis. The results showed that Sample C1 (10% bagasse ash, 30% glass powder, 60% epoxy) demonstrated optimal performance, recording the highest tensile strength of 30.91 N/mm² and a thermal resistance of 170oC. These values exceed the typical performance range of NBR (Nitrile Butadiene Rubber) gaskets, which generally show a tensile strength of 17 N/mm² and a thermal resistance range of 120°C. All samples exhibited low porosity (0.01%–0.04%), supporting effective sealing capability, although still higher than the NBR control gasket (0.008%). XRF analysis revealed that SiO2 was the dominant oxide in both fillers, contributing to thermal stability, hardness, and wear resistance, while Al2O3 and CaO enhanced structural rigidity. SEM examination of the optimal sample (Sample C1) revealed that its superior performance was primarily due to regions of uniform filler dispersion and strong interfacial bonding. While high-resolution imaging at 6,000x and 7,000x identified localized micro-voids and filler pull-out, these were isolated instances that did not compromise the structural integrity of the composite. The high tensile strength indicates that the well-bonded regions in the optimal 30:10 (Glass:Ash) ratio effectively dominated the load-transfer mechanism. The presence of micro-voids, visible only at high magnifications, provided the physical basis for the 0.04% porosity without significantly impairing the primary mechanical and thermal performance of the sample.

Geotechnical Performance Evaluation of Flood-Impacted Subgrade of Fori Road, Maiduguri, Borno State, Nigeria

A. Kobiowu, Y. Ibrahim, A. G. Bukar, I. Halliru — Mon, 02 Mar 2026 16:20:37 +0000

This research investigates the properties and suitability of subgrade soils in Fori area of Maiduguri for road pavement foundations in flood prone environments. Soil samples were collected from three locations along Fori road over an approximately 300 m stretch, after the Fori community bridge area, Maiduguri. Some of the soil sample properties analysed includes grain size distribution, Atterberg limits, Standard Proctor compaction and California Bearing Ratio (CBR) tests on soil samples from 0.5 m and 1.0 m depths. The results of the Particle size distribution and Atterberg limits show that the soils is classified as fine sand A-3(0) according to the America Association for State Highway and Transportation Officials (AASHTO), exhibiting low cohesion and high moisture sensitivity. However, compaction results indicated a relatively flat moisture density curves, with maximum dry densities of 1.71 g/cm³ (0.5 m) and 1.55 g/cm³ (1.0 m) corresponding to optimum moisture contents of 12.89 % and 19.4 %, respectively. Soil compressibility was quantified using the liquid limit, yielding values of 0.11 and 0.10, which indicates moderate compressibility of the flood impacted subgrade. Similarly soaked CBR values showed a significant strength reductions down to 1.36 % (0.5 m) and 2.85 % (1.0 m) after 48 hours. The soil is thus, regarded as “very poor” category for subgrades according to TRRL standards. Comparative analyses with existing literature shows that these characteristics are typical of fine grained, non-cohesive soils under flooding and are consistent with global observations of weakened subgrades. The study therefore concludes that the native soils are unsuitable for direct use as pavement subgrades in their natural state. To ensure durable road performance in Fori’s flood prone environment, measures such as chemical stabilization, profile elevation, improved drainage and possible geosynthetic reinforcement are recommended.

Finite Element Modeling and Performance Evaluation of Bamboo Reinforced Concrete Beams and Columns

B. B. Muhammad, K. Mohammed, N. Muazu, S. Mohammed — Mon, 02 Mar 2026 16:43:20 +0000

The rising cost and environmental impact of steel reinforcement pose significant challenges to the construction industry. Bamboo, with its favourable mechanical properties and sustainability benefits, offers a promising alternative for reinforced concrete structures. However, accurately predicting its behaviour within concrete requires advanced modelling techniques. This study evaluates the structural performance of bamboo-reinforced concrete (BRC) beams and columns using Finite Element Analysis (FEA) in ABAQUS, validated against experimental data. Three beam configurations and five column configurations, featuring varying bamboo diameters and strip arrangements, were analysed using concrete grades M20 and M25. The results revealed a strong correlation between numerical and experimental outcomes, with correlation coefficients (R²) ranging from 0.985 to 0.999. Experimentally, ultimate failure loads for beams ranged from 2.3 kN to 19.06 kN, while numerical predictions ranged from 2.89 kN to 18.0 kN. For columns, experimental failure loads varied between 127 kN and 357 kN, with numerical estimates deviating by less than 12%. A notable discrepancy of 26% was observed for Beam 3, primarily due to the weak bond between bamboo and concrete; a key limitation highlighted in this study. Overall, the findings demonstrate that finite element modelling can reliably predict the structural behaviour of BRC elements, particularly in lightly loaded applications. The study underscores the critical influence of reinforcement type and arrangement on failure loads and deflections.

Comparative Analysis of Structural Response to Blast Loading in Plain and Reinforced Concrete Walls

N. Muazu, B. G. Mustapha, K. Mohammed, I. A. David — Mon, 02 Mar 2026 16:55:22 +0000

This study presents a comparative numerical evaluation of the structural response of plain and reinforced concrete (RC) walls subjected to blast loading, with emphasis on the influence of wall geometry and reinforcement on blast resistance. Finite element simulations were conducted in ANSYS AUTODYN using a 100 kg TNT charge at a stand-off distance of 1 m. Three wall configurations, flat, L shaped, and U-shaped, were analyzed with and without reinforcement, and their performance was assessed in terms of equivalent stress, strain, total deformation, and damage evolution. The results show that flat plain concrete walls experienced the most severe response, with peak stresses exceeding 9 MPa, strains above 13 mm/mm, large deformations of approximately 385 mm, and rapid damage progression leading to early failure. Reinforcement improved performance in all geometries; however, geometric configuration played a more dominant role in blast mitigation. Among all configurations, the U-shaped reinforced concrete wall exhibited superior performance, recording minimal peak stress (~0.3 MPa), the lowest strain response (~3 mm/mm), negligible deformation (< 0.05) in damage reduction across wall types, leading to the rejection of the null hypothesis. The findings demonstrate that the combination of reinforcement and optimized U-shaped geometry provides the most effective blast resistance, offering critical guidance for the design of blast-resilient concrete wall systems in high-risk environments.

A Hilbert-Wavelet Fusion for Enhanced Wideband Spectrum Sensing in Cognitive Radio

S. B. Joseph, D. P. Yusuf, E. G. Dada, L. L. Muzong — Tue, 03 Mar 2026 08:24:07 +0000

The rapid growth of wireless technology has escalated demand for the finite radio spectrum. Cognitive Radio addresses this by enabling dynamic access to underutilized bands, yet its effectiveness depends on accurate spectrum sensing. Current sensing methods often suffer from poor performance in noisy environments and low-signal conditions, creating a critical reliability gap. This study presents an enhanced sensing technique that integrates the Hilbert Transform with Discrete Wavelet Packet Transform. The hybrid design sharpens signal analysis across sub-bands, and an adaptive threshold mechanism improves vacancy detection. The system was rigorously evaluated through simulation. Key results demonstrate a significant performance improvement. The proposed technique achieves, on average, a 77% better signal representation across decomposed channels compared to conventional wavelet sensing. Furthermore, Receiver Operating Characteristic (ROC) curves confirm a higher probability of detection at signal-to-noise ratios of -5dB, 0dB, and 5dB. These metrics substantiate that the fused method offers superior detection capability and reliability. The work provides a validated approach for making cognitive radio networks more robust and spectrum utilization more efficient.

Design, Construction, and Calibration of a Low-Cost Portable Dip-Coating Machine for Laboratory Applications

M. A. Abdulrahman, M. Sumaila, M. Dauda, O. K. Abubakre — Tue, 03 Mar 2026 08:41:16 +0000

Precise control of withdrawal speed and immersion height is essential for achieving uniform coatings and ensuring process reproducibility in dip-coating techniques. Commercial dip-coating systems capable of such control are often costly, limiting their accessibility to emerging and resource-constrained laboratories. This work reports the design, fabrication, and performance evaluation of a simple, portable, and low-cost automated dip-coating system intended for laboratory-scale surface coating applications. The system integrates mechanical and electronic subsystems, with the motor–lead screw assembly selected based on fundamental mechanical design principles. Automated control of immersion and withdrawal processes was implemented using an Arduino Uno microcontroller. Calibration of immersion height and withdrawal speed was performed using a Vernier caliper and a tachometer, respectively. The assembled system demonstrated reliable operation within an immersion height range of 70–220 mm and a withdrawal speed range of 0.5–7 mm s⁻¹, with maximum deviations of 0.75% and 2.0%, respectively. The total material cost of the dip coater was approximately USD 97. The adjustable immersion height feature enables reduced operational time and improved energy efficiency during coating processes. Owing to its accuracy, reproducibility, and affordability, the developed system offers a practical alternative to commercial dip coaters for thin-film deposition and surface protection research.

Hybrid Renewable-Hydrogen and Natural Gas Methanol Synthesis: A Techno-Economic Analysis

H. Uthman, D. T. Agboola, M. U. Garba, O. S. Azeez — Tue, 03 Mar 2026 13:04:30 +0000

Conventional methanol production is highly carbon-intensive due to its reliance on fossil-derived hydrogen from reforming processes. The purpose of this study is to assess the viability of incorporating renewable hydrogen from solar-powered electrolyzers to reduce the environmental impact of natural gas-based methanol production and replace the requirement for reformer hydrogen. Aspen HYSYS 14.0 was used to model and compare two hybrid configurations: Steam Methane Reformer–Autothermal Reformer (SMR–ATR) with electrolyzer and Autothermal Reformer–Heat Transfer Exchange Reformer (ATR-HTER) with electrolyzer, with their conventional counterparts in a steady-state techno-economic and environmental assessment. All process configurations' technical viability was confirmed by mass and energy balance analyses. The findings showed that the configurations differ significantly in terms of production costs, methanol purity, and utility demand. Although it produced methanol with a purity of only 50.43%, requiring downstream upgrading, the SMR–ATR with electrolyzer design achieved the lowest levelized cost of methanol (LCOM) at USD 95.29 per tonne and the lowest utility requirement (468,113 kWh). The ATR–HTER with electrolyzer design, on the other hand, needed a significantly higher electricity consumption of about 11.76 million kWh, raising the LCOM to USD 119.12 per tonne despite achieving high methanol purity (98.56%) and efficient renewable hydrogen integration. These results suggest that excessive energy usage might negatively impact economic performance, even if electrolyzer integration can improve carbon efficiency and lessen reliance on fossil-based hydrogen when powered by low carbon electricity. Overall, electrolyzer-assisted methanol production is most economical in regions with plentiful natural gas and access to low-cost renewable electricity, such as Nigeria, which helps to advance United Nations Sustainable Development Goals 7, 9, and 13.

KayusQoS: A Mobile-Driven Software Framework for Real-Time QoS Data Collection and Knowledge Discovery in Nigerian GSM Networks

A. Y. Kazeem, A. S. Ahmadu, B. Y. Baha — Tue, 03 Mar 2026 18:46:51 +0000

The Nigerian telecommunications industry relies largely on expensive and manually intensive drive-test systems for monitoring Quality of Service (QoS), which limits the frequency, coverage and affordability of performance assessment, particularly in semi-urban environments. This study presents KayusQoS, a mobile-driven software framework for automated QoS data collection and knowledge discovery in Global System for Mobile Communications (GSM) networks. The framework integrates an Android-based application for real-time capture of Key Performance Indicators (KPIs) and a Knowledge Discovery in Databases (KDD) analytical process for data preprocessing, analysis and interpretation. The study adopted a hybrid research design combining system development and experimental validation. Using the KayusQoS application, a total of 2,944 valid call records were collected from four major GSM operators, namely MTN, Airtel, GLO and 9Mobile, across selected Local Government Areas of Nasarawa State, Nigeria. Five Key Performance Indicators—Call Setup Success Rate, Call Drop Rate, Handover Success Rate, Received Signal Strength and Retainability Rate—were computed and benchmarked against Nigerian Communications Commission Quality of Service thresholds. Results indicate that the KayusQoS framework achieved full automation and 100 percent geo-tagging accuracy. MTN demonstrated the highest overall Quality of Service performance, while Airtel showed moderate compliance with regulatory benchmarks. GLO and 9Mobile exhibited lower performance levels in several indicators. The study concludes that KayusQoS is a reliable, low-cost and effective alternative to conventional drive-test systems and can serve as a complementary tool for regulatory monitoring and network optimization in Nigeria.

Household Carbon Footprint Assessment Using Real-Time Monitoring Devices: A Case Study of Talba Estate, Minna, Nigeria

J. G. Ambafi, U. S. Dauda, K. E. Jack, H. O. Idakwo, L. Olatomiwa — Tue, 03 Mar 2026 19:01:03 +0000

The study focuses on the design, validation, and pilot deployment of a low-cost, real-time household carbon monitoring system in the Talba Estate, Minna, Nigeria, addressing the limited availability of affordable household-level emission monitoring tools in developing urban contexts. Due to ethical access and resource constraints, ten (10) households were randomly selected. This served as an exploratory pilot study to capture diurnal fluctuations of indoor CO₂ concentration and the household electricity consumption over a period of 30 days. Each sensor node, comprised of a Raspberry Pi 3B and an NDIR CO₂ sensor, was calibrated to a reference gas source recording an accuracy of ±2.8% (R² = 0.985). The study incorporated data on energy consumption, transportation, and the socio-economic status of households to determine the CO₂-equivalent emissions on a household basis. Emission levels were found to be significantly lower as the average household emission was 24.57 ± 4.21 kg CO₂ eq day⁻¹, almost 35% lower than the national average and significantly correlated with household income (r = 0.71) and with household size (r = 0.63). The findings emphasis that household emissions may be meaningfully reduced with targeted interventions that enhance energy efficiency. The created prototype served its purpose of consistent monitoring in resource-limited environments and did so at a cost 80% less than competing commercial systems. Overall, the study offers a complete and localised empirical analysis, aiding the formulation of sustainable policies for climate change mitigation in alignment with SDG 13 and the NDC targets of Nigeria. The study also provides a scalable model for localized carbon monitoring and responsive planning in adaptive environmental management for developing urban areas.

Effect of Sand Addition on the Geotechnical Properties of Clay

J. Godwin, D. E. Kwaghchimin — Tue, 03 Mar 2026 19:10:04 +0000

Clay is commonly characterized by high plasticity, low permeability, and significant volume changes, which can result in reduced bearing capacity, excessive settlement, and instability of geotechnical structures. This study investigates the stabilization effect of sand addition on the geotechnical performance of clay for construction applications. Clay-sand mixtures containing 0% to 60% sand were prepared to evaluate Atterberg limits, soil classification, compaction behavior, unconfined compressive strength (UCS), shear strength, and hydraulic conductivity under both heavy (BSH) and light (BSL) compaction energies. The results showed that increasing sand content significantly reduces the Plasticity Index (PI) from 41.5% to 12.96%, aligning with the USCS recommended PI threshold of < 20% for suitable fill materials. Soil classification improved from CH (A-7-6) to SC (A-2 6), indicating enhanced constructability. Compaction results showed that maximum dry density increased from 1.848 to 2.17 g/cc, while optimum moisture content decreased from 16% (BSH) and 19% (BSL) to 9.6% (BSH) and 11.2% (BSL), meeting performance expectations for engineered fill. UCS increased from 120.51 kPa to 199.49 kPa, and internal friction angle rose from 8.2° to 22.3°, demonstrating greater strength and stability. In addition, hydraulic conductivity increased nearly fivefold, enhancing drainage characteristics. Overall, sand-clay mixtures with 40–60% sand content meet or approach USCS criteria for low plasticity, high density, and improved permeability, making them suitable for road embankments.

Orthogonal Frequency Division Multiplexing (OFDM) Sub-Band Channel Classification Based on Adaptive Thresholding

B. Stephen, S. B. Joseph, P. Y. Dibal, Y. Ayuba — Tue, 03 Mar 2026 19:23:01 +0000

The radio frequency (RF) spectrum has experienced increased congestion due to a growing number of wireless devices and escalating demand for higher data rates. Cognitive radio (CR) enables wireless devices to sense their environment and efficiently utilize available spectrum resources. However, spectrum sensing in CR systems still remains a challenge due to the increased demands for higher data rates and efficiency. Existing research often trades complexity for accuracy, however a balance between accuracy and complexity is required for a good wireless communication. This study proposes a low-complexity, high-accuracy spectrum sensing method for Orthogonal Frequency Division Multiplexing (OFDM) based cognitive radio. It combines a Fast Fourier Transform (FFT) filter bank for signal decomposition with a novel convex-optimized adaptive threshold algorithm to classify sub-band occupancy. Then, an optimal Adaptive threshold technique is designed through convex optimization, enhancing classification accuracy by optimizing statistical properties. Simulation results show improved accuracy compared to other related works, with a higher probability of detection achieving a probability of detection (????????) of 0.9686 at a probability of false alarm (????????????) of 0.1 and an SNR of 10 dB indicating the proposed technique's promise for efficient spectrum utilization.

Battery Energy Storage System with Fuzzy Logic Control Strategy for Low Voltage Ride-Through Enhancement in Grid Connected Solar Photovoltaic Systems

M. Aminu, I. Asogo, S. Y. Musa, J. Angeti — Tue, 03 Mar 2026 19:33:58 +0000

This paper presents a battery energy storage system (BESS) integrated with a Fuzzy Logic Control (FLC) to enhance low voltage ride-through (FRT) capability in grid-connected solar photovoltaic (PV) systems during grid disturbances. The increasing penetration of PV systems into modern power grids raises concerns over their reliability and stability under fault conditions. Conventional PV inverters often disconnect during grid faults, compromising grid integrity. To address this problem, a solar PV system integrated with BESS and a Mamdani-type FLC (termed as Fuzzy-BESS) is proposed in this paper. The fuzzy logic controller dynamically managed the energy exchange between the BESS and the grid based on voltage dip severity and the state of charge (SOC) of the battery. The system was subjected to a three-phase-to-ground fault to evaluate its dynamic performance. Simulation results revealed that, without the Fuzzy-BESS, the system experienced severe voltage sags (up to 50% of nominal value) and delayed recovery when subjected to a three-phase-to-ground fault. However, with the integration of Fuzzy-BESS, the system-maintained grid voltage support above ≈88% of nominal value and achieved near-instantaneous recovery (≤0.05 s) after fault clearance. These results confirmed that the proposed Fuzzy-BESS effectively enhanced LVRT capability, improved grid voltage stability, and enabled reliable grid code compliance during fault conditions.