UNIZIK Journal of Engineering and Applied Sciences
type: channel
description: Formerly known as the Journal of Engineering and Applied Sciences UNIZIK Journal of Engineering and Applied Sciences (UJEAS) is an international journal published by the Faculty of Engineering, Nnamdi Azikiwe University, Awka. It is a specialized journal aimed at fostering the growth of educational, scientific, and industrial research. UJEAS is a pathbreaking journal that adopts an open-source approach to publication, viewing research as a cooperative enterprise between authors, editors, referees, and readers. You are strongly encouraged to join the journal's community and become a registered reader. As such, you can comment on articles. And, of course, you can always submit a paper as a registered author. Prospective authors can also submit directly to the journal email via ujeas@journals.unizik.edu.ng
publisher: Faculty of Engineering, Nnamdi Azikiwe University, Awka Nigeria
language: en
publication name: UNIZIK Journal of Engineering and Applied Sciences
issn: 2992-4383
items: Molinillo Seed (Hura crepitans) Subjected to Different Drying Techniques and the Effects on the Bio-oil Quality Potentials
items: Design, implementation and performance evaluation of a low cost AC-DC converter trainer for engineering education
items: Fuzzy PID–Based Automatic Irrigation Control for Enhanced Agricultural Performance
items: Improving battery technology using ANN based ultracapacitor
items: Development of sensitivity index-based technique for unified power flow controller placement with contingency analysis on Nigeria 330Kv transmission network
items: Development of an artificial intelligence model for predicting students’ performance in an engineering department of a Nigerian university
items: Synthesis and Structural Characterisation of Polyaniline (PANI)- Iron oxide (Fe2O3), nanocomposites for Optoelectronics application
items: Speech Emotion Recognition System for Human-Machine Interaction on Edge–Cloud System
items: Plant Spacing and Stand Density Effects on Aphid–Braconid Wasp Dynamics in Okra (Abelmoschus esculentus) in Benin City, Edo State
items: Biomass in Nigeria: The Present State, Obstacles, and Potential as Alternative Fuel Energy
items: Boundary-Mediated Phase Ordering and Collision-Free Dynamics in a Vibro-Impact Multi-Particle System
items: Impact of Carbon-based Nanoparticles on Biogas Yield from Anaerobic Co-Digestion of Cow Dung and Yam Peels
items: Transient Simulation of a 240/120V Step Down Three-Phase to Five-Phase Transformer for Multiphase Drive Applications
items: Purification of Oil-Polluted Sea Water using Carbonized Rice Husk Adsorbent Prepared in a Closed Reactor
items: Enhancing the Performance of DC Servomotor Based Antenna Position Control System in Satellite Communication Using PID-LQR
items: Hydrogeophysical assessment of aquifer vulnerability in some parts of Amawbia and its environs, south east, Nigeria
items: Analysis and Characteristics of Hydrochar and Liquid Products Produced via Hydrothermal Liquefaction of Poultry Wastes
items: Participation in WhatsApp and Facebook Farmer Groups and Adoption of Smart Agriculture Techniques among Smallholder Farmers
items: Fretting wear mitigation: development of wear-resistant coconut shell particulate/aluminium composite
items: Adoption and Limitations of Smartphone Plant Disease Identification Apps in Early Disease Detection Among Crop Farmers in Atiba Local Government Area, Oyo State, Nigeria
items: Enhancing dynamic line rating using fuzzy based ultracapacitor
items: Mechanical performance optimization of thatch grass-based particleboard bonded with Arabic gum binder using Response Surface Methodology
items: Influence of Mineralogical and Chemical Composition on the geotechnical index properties and compaction characteristics of Borrow Pit Soils and Onitsha River Sand, Anambra State, Nigeria
items: Effect of Palm Stalk Ash Reinforcement on the Microstructural, Thermal and Mechanical Properties of Ugwuoba Clay for Refractory Applications
items: Optimization of the Industrial use of Renewable Energy for a Sustainable and Hazard-free Environment
items: Mechanical Properties Enhancement of Concrete Sand Bulking using Egg Shell Ash Particulates
items: An Experimental Analysis of Embedding Separability and SVM Classification in Hybrid Face Recognition Systems
items: Evaluating the impact of moisture content on the Foundry performance of Eco-friendly sand from Nyama River Beach for Sustainable Casting Applications
items: Contingency Investigation of Nnamdi Azikiwe University, Awka Hybrid Distribution System
items: Automotive V-Belt as Autoclave Door Gasket Improvise in a Financially Constrained Healthcare Facility

Molinillo Seed (Hura crepitans) Subjected to Different Drying Techniques and the Effects on the Bio-oil Quality Potentials
type: item
description: This study assessed the impact of different drying processes on the bio-oil yield and physicochemical parameters of molinillo seed (Hura crepitans), an underused non-edible oilseed with promise for renewable energy applications. Using a complete randomized design with three separate trials, seeds were dried by oven, vacuum, solar and sun, with an undried sample that served as control. Whilst solar and sun drying occurred in ambient settings, oven and vacuum drying were carried out at 40, 50, 60, and 70 °C respectively. Soxhlet extraction with n-hexane was used to extract bio-oil, and the oil yield was calculated. Using conventional AOAC and ASTM procedures, as well as some modified methods, the extracted oils were examined for acid value, saponification value, iodine value, peroxide value, specific gravity, and flash point. Analysis of variance was used to statistically examine the data at an accuracy level of 95%. The findings demonstrated significantly increased oil yield with the oven and vacuum drying, where vacuum drying generally yielded more stable oil, in comparison to solar and sun drying. Oven drying at 40°C yielded the maximum oil output (49.70%), while sun-dried sample yielded the lowest (36.97%). Oils with reduced acid and peroxide values, and improved oxidative stability due to reduced moisture were also, consistently obtained by the vacuum drying. Iodine values (83.0–87.5 g I₂/100 g) and saponification values (193.55–200.30 mg KOH/g) showed suitability of the oil for industrial uses, such as, the manufacturing of soap and biodiesel.
subject: Articles
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subject: Array
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creator: Ugochukwu Christian Abada
creator: Victor I. O. Ndirika
creator: Udochukwu N. Onwuka
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Design, implementation and performance evaluation of a low cost AC-DC converter trainer for engineering education
type: item
description: This study presents the design, implementation, and performance evaluation of a low-cost, modular AC–DC converter trainer developed to enhance practical instruction in electrical power conversion. In contrast to conventional AC–DC trainer systems, which are often expensive, rigid, and limited in measurement accessibility, the proposed design incorporates a flexible architecture with multiple regulated outputs and accessible test points for real-time observation of circuit behaviour. The system converted a 220–240 V AC mains supply into regulated DC outputs through a step-down transformer, full-wave bridge rectifier, filter capacitor network, and linear voltage regulators (7805, 7812, and LM317). The design process was supported by detailed analytical modeling, including transformer rating selection, rectifier peak voltage estimation, ripple minimization, capacitor sizing, and regulator thermal considerations. The key contributions of this work included the development of a cost-optimized trainer suitable for resource-constrained laboratories, the integration of fixed (5 V and 12 V) and adjustable (1.3–19 V) outputs within a single platform and the provision of enhanced measurement nodes to improve pedagogical effectiveness. Experimental results under no-load and load conditions indicated an unregulated DC output of 15.92 V, ripple voltage below 0.5 V, and stable regulated outputs across all channels. The system achieved an efficiency range of 75% – 78%, which is comparable to or slightly higher than the 70% – 75% typically reported for existing linear AC–DC trainer designs. These results demonstrate that the proposed trainer meets standard performance requirements while offering improved functionality, affordability, and instructional versatility. The system therefore provided a novel and relevant contribution to engineering education, particularly in technical institutions where cost, accessibility, and hands-on learning are critical considerations.
subject: Articles
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subject: Array
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creator: Kingsley Onyeka Odo
creator: Charles Nwakanma Akwuruoha
creator: Yerima Omosun
creator: Nnaemeka Chijioke Onyenagbagha
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Fuzzy PID–Based Automatic Irrigation Control for Enhanced Agricultural Performance
type: item
description: This paper presents a Fuzzy PID–based automatic irrigation control system aimed at improving agricultural performance through intelligent water management. A dynamic model of the irrigation process was developed and implemented in simulation to integrate soil moisture dynamics, crop type, and water flow characteristics. The proposed controller combined conventional PID control with fuzzy logic tuning to enhance adaptability under varying environmental conditions. Simulation studies were carried out to compare the proposed Fuzzy PID controller with a conventional/manual control approach using key performance indices such as response time, overshoot, steady-state error, and moisture regulation accuracy. Results showed that the Fuzzy PID system achieved faster settling time, smoother response, and near-zero steady-state error, with improved soil moisture tracking under different crop conditions. To validate the simulation, an experimental prototype was developed using soil moisture sensors, a microcontroller-based control unit, and an automated pump system. Experimental results closely matched simulation predictions, confirming reliable real-time performance and robustness of the controller. Quantitatively, the proposed system reduced water overflow by 100%, improved soil water level regulation by 21%, optimized water supply rate by 9%, and enhanced pump control efficiency by 22% compared to the conventional method. Overall, the results demonstrated that the Fuzzy PID–based irrigation system provides efficient, stable, and precise water management, making it a viable solution for smart agriculture applications.
subject: Articles
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subject: Array
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creator: Nnaemeka Chijioke Onyenagbagha
creator: Kingsley Onyeka Odo
creator: Bartholomew Ikechukwu Osondu
creator: Faith Mendie Edet
creator: Muhammad Sulaiman
creator: Abba-Stephen Benjamin
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Improving battery technology using ANN based ultracapacitor
type: item
description: The paralytic form of business activities that mostly depended on battery for their daily routine business were caused by these factors low energy storage capability, slow charge rate, limited discharge capability, high internal resistance, excessive voltage sag, thermal instability, short operational lifespan, rapid aging, poor power handling, inefficient energy conversion, over-dependence on battery, load fluctuation stress, poor response to transients, ineffective energy management and high self-discharge. This was overcoming by introducing improving battery technology using ANN based ultracapacitor. To perfectly achieve this, it was done in this manner, battery technology was characterized and the causes of poor battery technology was established, conventional SIMULINK model for battery technology was designed and ANN was trained in the Causes of Poor Battery Technology Performance for an effective performance. Then, SIMULINK model for ultracapacitor was designed, SIMULINK model for improving battery technology using ANN based ultracapacitor was equally designed and the results obtained were validated and justified. The results obtained were the conventional Low energy storage capability that causes poor battery technology performance was28 J·kg⁻¹ ×10³. On the other hand, when an ANN based ultracapacitor was integrated into the system, it simultaneously improved to33.8 J·kg⁻¹ ×10³ and the conventional Load fluctuation stress that causes poor battery technology performance was17A. Meanwhile, when an ANN based ultracapacitor was imbibed into the system, it instantly reduced to15A. Finally, with these results obtained, it meant that the percentage improvement in battery technology when ANN based ultracapacitor was incorporated into the system was11.8%.
subject: Articles
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subject: Array
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creator: Nwogbu Celestine Chidi
creator: Chukwuagu Ifeanyi
creator: Adindu Charles .O.
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Development of sensitivity index-based technique for unified power flow controller placement with contingency analysis on Nigeria 330Kv transmission network
type: item
description: Persistent power failure that disrupted business activities was mainly caused by poor placement of the Unified Power Flow Controller (UPFC) due to voltage instability in the Nigerian 330 kV transmission network. This study developed a Sensitivity Index–Based Technique for Optimal UPFC Placement with Contingency Analysis to improve system stability. Load flow analysis was first conducted to identify weak buses whose voltage levels fell outside the acceptable stability range of 0.95 through1.05 p.u. A conventional UPFC placement model was designed and compared with the proposed sensitivity index–based technique implemented using a SIMULINK model. Results showed that the conventional system produced a bus voltage of 0.909 p.u. at Bus 4 and line loading sensitivity of 75%, indicating instability. However, when the proposed technique was applied, the voltage improved to 1.05 p.u. and line loading sensitivity increased to 90%. This represents a 15% improvement in system performance, demonstrating that the sensitivity index–based technique significantly enhances UPFC placement and voltage stability in the Nigerian 330 kV transmission network.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Nwogbu Celestine Chidi
creator: Chukwuagu Ifeanyi
creator: Adindu Charles .O.
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Development of an artificial intelligence model for predicting students’ performance in an engineering department of a Nigerian university
type: item
description: Students seeking admission into Nigerian tertiary institutions are required to possess some requirements. However, the efficacy of these requirements in predicting students’ performance has been a subject of discussion. This study examines the effectiveness of current admission requirements in predicting academic performance among engineering students in a Nigerian university. Using data from 340 students admitted between 1996 and 2016, variables such as age, gender, UTME scores, O’Level results, and final CGPA were analysed. With Microsoft Excel and Python, Data pre-processing was carried out. Multiple machine learning models that include Support Vector Machine, Decision Tree, Random Forest, Naïve Bayes, and K-Nearest Neighbours were developed using 311 training samples. To enhance classification accuracy, a One-Vs-One binary classifier based on Decision Tree networks was implemented for three performance categories. Pearson correlation analysis indicated a very weak relationship (0.0075) between UTME scores and CGPA, signifying that UTME alone is a poor predictor of academic performance. But, WAEC scores (0.32), year of birth (0.31), and year of O’Level examination (0.29) showed relatively stronger correlations with CGPA. The exploratory analysis confirmed that the current admission criteria may be inadequate, and a combination of other factors are likely to be better predictors of students’ performance. The resulting ML model which explored broader variables offers a more effective decision support tool for processing undergraduate admissions in Nigerian universities.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Kelechi Favour Francis
creator: Victor Oluwasina Oladokun
creator: Adekunle Kolawole
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Synthesis and Structural Characterisation of Polyaniline (PANI)- Iron oxide (Fe2O3), nanocomposites for Optoelectronics application
type: item
description: In this investigation, polyaniline (PANI), Iron oxide (Fe2O3) nanoparticles and polyaniline- Fe2O3 nanocomposites were successfully synthesized by chemically oxidative polymerization of aniline in the presence of hydrochloric acid using ammonium persulfate as an oxidizing agent. The purpose of this study is to synthesize and investigate polyaniline/ iron oxide nanocomposite for optoelectronics application. The synthesized nanocomposite was characterized to ascertain possible applications of the nanocomposite. The x- ray diffraction (XRD) analysis was carried out using x-ray diffraction machine. The results of the structural analysis showed that the formed polyaniline is a polymer with peak <!-- [if gte msEquation 12]><m:oMath><m:r>2</m:r><m:r>θ</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 115%; 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: 5.5pt; mso-text-raise: -5.5pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> at<!-- [if gte msEquation 12]><m:oMath><m:r> 25.36</m:r><m:r>°</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 115%; 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: 5.5pt; mso-text-raise: -5.5pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> . X – ray diffraction pattern of iron oxide nanoparticles shows that the fabricated iron oxide nanoparticles are of rhombohedral phase of iron oxide with mineral name Hematite and corresponding to JCPDS file number (00 – 033 – 0664). Two theta an…
subject: Articles
  topic: section
creator: Okafor A.A
creator: Okafor L.U.
creator: Ifowodo H.F.
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07

Speech Emotion Recognition System for Human-Machine Interaction on Edge–Cloud System
type: item
description: Speech emotion recognition (SER) is another major area of affective computing where machines are also capable of detecting and responding to human emotions real time. Nevertheless, it has been found that implementing deep learning-based SER systems on low-power microcontrollers is still a challenge because of computation and memory constraints, and inference time. The research paper describes the design and implementation of an AI-based SER system to provide human-machine interaction (HMI) with the help of an ESP32 microcontroller, an INMP441 digital MEMS microphone, and a MAX98357A audio output module. Preprocessing of speech signals was done by resampling, normalization, and trimming of silences and, features were extracted with Mel-Frequency Cepstral Coefficients (MFCC), Linear Predictive Coding (LPC), and a combined MFCC+LPC representation. The RAVDESS dataset was trained and tested using Convolutional Recurrent Neural Networks (CRNN), Convolutional Neural Networks (CNN), and Recurrent Neural Networks (RNN). The experimental results showed that the CNN model with hybrid MFCC + LPC features had the most favorable performance with an accuracy of 92.01%, precision of 92.11%, recall of 92.52%, and F1-score of 92.03% relative to the RNN and CRNN architecture. The system was shown to be able to perform stable real-time inference at a latency of less than 400 ms, confirming its applicability to embedded applications. These results establish the practicability of successful implementation of high-performing SER systems on the resource-constrained platforms, and present applications in assistive robotics, healthcare, education, and emotion-sensitive IoT devices
subject: Articles
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subject: Array
  topic: keywords
creator: Nnamdi S. Okomba
creator: Sobowale A. Adedayo
creator: Adebimpe O. Esan
creator: Bolaji A. Omodunnbi
creator: Taiwo A. Awoyemi
creator: K. A Owoseni
rights: Copyright (c) 2026 Authors
date: 2026-06-04
publication date: 2026-06-04
starting page: 3526
ending page: 3538

Plant Spacing and Stand Density Effects on Aphid–Braconid Wasp Dynamics in Okra (Abelmoschus esculentus) in Benin City, Edo State
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description: Aphid infestations represent a major constraint in okra production, yet their population dynamics are strongly influenced by crop configuration, growth stage, and prevailing weather conditions. Field experiment using a Randomized Complete Block Design (RCBD) was conducted to assess the effects of plant spacing and stand density on aphid abundance and associated parasitoid. Results indicated that plant spacing and stand density did not significantly (p ˃ 0.05) affect aphid populations, although numerically higher infestations were observed under closer spacing (40 × 25 cm). In contrast, aphid abundance varied significantly across weeks after sowing (WAS), with populations remaining low at 2–3 WAS, rising sharply from 4–6 WAS, and peaking between 7–10 WAS. Pooled aphid populations across treatments reached maximum density (1202.00 individuals/five plants) at the 43rd meteorological week (8 WAS) while parasitoid populations peaked (14.50 individuals/five plants) earlier at the 39th week (4 WAS). Correlation analysis showed that aphid abundance was positively associated with temperature (r = 0.86) and parasitoid density (r = 0.71), but negatively correlated with humidity (r = –0.75) and rainfall (r = –0.79). Parasitoid abundance was significantly linked to aphid density but not to weather parameters, indicating a density‑dependent response. These results underscore the importance of integrating crop growth stage, planting configuration, and climatic monitoring into pest management strategies for sustainable okra production.
subject: Articles
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subject: Array
  topic: keywords
creator: Magdalene Ehinomen Omoregie
creator: Deborah Ehigiator-Anthony
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3518
ending page: 3525

Biomass in Nigeria: The Present State, Obstacles, and Potential as Alternative Fuel Energy
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description: This study presents a structured review of biomass energy in Nigeria, focusing on its current status, technological pathways, challenges, and future prospects. A systematic search of peer-reviewed literature, reports, and databases was conducted to synthesize evidence on present State of biomass energy potentials in Nigeria, analyse technologies of biomass conversion, and obstacles and future prospects. Nigeria generates approximately 144 million tonnes of biomass annually, with an estimated technical energy potential of about 2.33 EJ. Despite this abundance, biomass utilization remains largely traditional and inefficient. The review identifies key barriers, including technological limitations, weak policy implementation, financial constraints, and environmental concerns. The findings further reveal that advanced conversion technologies such as pyrolysis, gasification, and anaerobic digestion remain underdeveloped in Nigeria. The paper highlights opportunities for sustainable bioenergy development through improved policy support, investment in modern technologies, and integration into national energy strategies. This review contributes by providing a critical synthesis of existing knowledge and identifying research and policy gaps necessary for advancing biomass energy utilization in Nigeria.
subject: Articles
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subject: Array
  topic: keywords
creator: Abubakar Hamzat
creator: Hassan Mudathir Abdulsalam
creator: Abdulkabir. Raji
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3502
ending page: 3517

Boundary-Mediated Phase Ordering and Collision-Free Dynamics in a Vibro-Impact Multi-Particle System
type: item
description: This study investigates a mechanically realizable vibro-impact system exhibiting collision-free multi-particle motion under boundary-induced excitation. The system consists of identical spherical particles undergoing one-dimensional ballistic motion under gravity and repeated impacts with a structured vibrating boundary. While individual particles obey identical free-flight and restitution laws, experiments reveal the spontaneous emergence of temporally ordered, collision-free motion when multiple particles interact with a common impulsive base. To explain this behavior, a minimal non-smooth dynamical model is formulated using Newtonian mechanics and impact-based boundary conditions. The governing equations define an event-driven discrete impact map advancing the system between successive collisions. Although no explicit inter-particle forces are introduced, collective dynamics arise through boundary-mediated timing regulation. Under bounded excitation, the discrete update preserves temporal separation, suppresses synchronous impacts, and stabilizes staggered impact sequences as attracting configurations. The formulation extends classical single-particle bouncing-ball theory to a multi-particle setting and demonstrates how structured boundary excitation induces phase ordering in non-smooth impact systems. Numerical simulations and controlled laboratory measurements confirm the theoretical predictions. The results provide a dynamical explanation of collision-free behavior in vibro-impact systems and establish a framework for boundary-induced regulation in multi-particle impact dynamics.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Nicholas N. Topman
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3487
ending page: 3501

Impact of Carbon-based Nanoparticles on Biogas Yield from Anaerobic Co-Digestion of Cow Dung and Yam Peels
type: item
description: The aim of this work is to evaluate the impact of carbon-based nanoparticles on biogas yield from anaerobic co-digestion of cow dung and yam peels. The biomass used for the work include sawdust, cow dung and yam peels. The sawdust was obtained from a saw mill and carbonized in a muffle furnace at 600oC. It was then ground into fine particles using hammer mill. The Nano-sized sample was chemically activated using 0.85 M phosphoric acid at a 1:1 (by weight) ratio of the sample to the dilute acid. The sample was washed with distilled water until a neutral pH of 7 was obtained. It was then dried in an electric oven at a temperature of 80oC for 3 hours to obtain the activated carbon-based nanoparticles (ACBNPs). The ACBNPs was characterized using DLS, SEM-EDS, FTIR, XRD and BET. The DLS show that it has a dominant particle size of 11.89 nm confirming that the sample fall within the nanoscale. The SEM results show that the sample has good morphology with contrasts on the surface while the EDS shows that the atomic concentration of carbon in the sample is 71.22, meaning that the carbonization process was successful. The BET results show it has a specific surface area of 250 m2/g and mesoporous particles with good adsorptive properties. The cow dung was collected from a cattle market while the yam peels were collected from a restaurant, pretreated and put in a paste form. The substrates, cow dung and yam peels, were characterized. Microbial assay on the cow dung showed the presence of the microorganisms that are active in anaerobic digestion. Design of experiment (DOE) was generated (a total of 20 runs) using CCD of the design expert software to evaluate the individual and interactive effects of three factors - time, substrate ratio and nanoparticle concentration. Batch experiments were conducted and the daily biogas yields were measured by downward displacement of water in measuring cylinders. Experimental method was employed to evaluate the performance of the anaerobic di…
subject: Articles
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subject: Array
  topic: keywords
creator: Achugbu O.E.
creator: Nwabanne J.T.
creator: Okoye C.C.
creator: Okonkwo C.A.
creator: Okoubulu A.B.
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3475
ending page: 3486

Transient Simulation of a 240/120V Step Down Three-Phase to Five-Phase Transformer for Multiphase Drive Applications
type: item
description: The increasing adoption of five-phase electrical machines in high-reliability and high-performance applications calls for efficient phase conversion from conventional three-phase utilities. Existing solutions predominantly rely on power electronic converters, which sadly introduce switching losses, electromagnetic interference, and increased system complexity. This paper builds on existing approach for developing a passive three-phase to five-phase transformer system with additional step-down functionality and electromagnetic validation. A generalized transformation matrix is derived to synthesize balanced five-phase voltages with 72° phase displacement from a 120° three-phase source. Winding turn relationships are formulated to integrate step-down voltage functionality without compromising phase symmetry. Magnetic circuit analysis by finite element analysis methods are used to evaluate flux distribution. Results demonstrate that balanced five-phase output stepped down from 240V to 120V can be achieved. The core loss obtained for the system is 2.87% with a symmetric flux distribution around the central limb and a flux density in the linear region of the B-H curve. The output voltage has a THD of 7.66%. These findings validate the proposed passive transformer system as a viable alternative for fixed-frequency multiphase applications requiring high reliability and galvanic isolation.
subject: Articles
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subject: Array
  topic: keywords
creator: Ifeanyichukwu Kalu Onwuka
creator: Christopher Kalu Okoro
creator: Miracle Tochukwu Uwakwe
creator: Chukwuemeka Joseph Ejeagba
creator: Marvelous Uchechi Ubani
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3466
ending page: 3474

Purification of Oil-Polluted Sea Water using Carbonized Rice Husk Adsorbent Prepared in a Closed Reactor
type: item
description: The study involves purification of oil polluted sea water using carbonized rice husk (CRH) as adsorbent. Carbonization was carried out in a closed reactor. Important properties of the rice husk (RH) and carbonized rice husk (CRH) were determined using standard methods. Six sets of experiments were carried out with initial oil concentration of 1.35 mg/L and CRH dosages of 0, 6.67, 13.33, 20, 26.67, 33.33 g/L, separately to determine the optimal adsorption dosage and percentage of oil removal. Secondly, five sets of experiments were carried out under the adsorption time of 1 h, 2 h, 3 h, 4 h, and 5 h, with the optimal dosage for adsorption determined from the result of the first experiment to determine the optimal adsorption time. Lastly, another five sets of experiments were carried out under the adsorption time of 0 h, 1 h, 3 h, 5 h, and 7 h with the same optimal dosage for adsorption determined from the result of the first experiment to determine the COD removal. The surface area, bulk density, and thermal conductivity of the RH and CRH were respectively 0.78 and 97.4 m2/g, 0.1 and 0.19 g/cm3, and 0.04 and 0.035 W/(m. K). 13.33 g/L was determined as the optimal dosage for adsorption in this study. The oil removed with the optimal dosage was 71.85% at 3 h optimal time, while the total oil removed was 85.01%. The COD removed at this optimal time was 34% while the highest COD removal was 48%. The CRH showed ideal effects in the purification of oil-polluted sea water with excellent adsorption ability for oil in the oil polluted sea water.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Joseph Jideofor Obodoeze
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3458
ending page: 3465

Enhancing the Performance of DC Servomotor Based Antenna Position Control System in Satellite Communication Using PID-LQR
type: item
description: In this work, a control system has been designed based on Proportional Integral Derivative (PID) optimized discrete-time Linear Quadratic Regulator (LQR) called PID-LQR and implemented with a DC servomotor-based antenna positioning control system in MATLAB/Simulink environment. The system response was analyzed considering the uncompensated state, the results obtained were presented in terms of steady-state transient response characteristics, which were rise time, peak time, settling time, overshoot, and steady-state error. In the uncompensated state, the rise time was 0.52s, peak time was 1.30s, settling time was 4.35s, overshoot was 34.7%, and steady-state error was 0. Considering the high value of overshoot, a LQR was designed and incorporated into the system to form a closed-loop control system, and simulation conducted revealed that the cycling associated with the uncompensated because of high overshoot (34.7%) was greatly reduced to 6.43% and steady-state error of 0 was achieved. The performance of LQR was further optimized by integrating PID parameter. PID-LQR reduced the rise time from 2.02s to 1.98s, peak time from 4.20s to 3.49s, settling time from 6.11s to 3.94s, and overshoot from 6.43% to 3.80%. These reductions in transient response parameters revealed that the designed PID-LQR yielded the most effective response in terms of stability. This is because the PID-LQR provided most smooth and most stable response compare to other control systems measured against the uncompensated system. Therefore, the use of the PID-LQR provided more stable and reliable tracking for antenna positioning system in satellite dish antenna for deep space application.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Kingsley Ugochukwu Anyanwu
creator: Chidiebere Nnaedozie Muoghalu
creator: Patience Nkiruka Achebe
creator: Ikenna Uzoma Ajere
creator: Matthew Chinedu Okechi
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3447
ending page: 3457

Hydrogeophysical assessment of aquifer vulnerability in some parts of Amawbia and its environs, south east, Nigeria
type: item
description: The rapid increase in the population of Amawbia has led to a growing demand for groundwater resources. This increase has necessitated the evaluation of aquifer protective capacity in order to protect it from contamination. The electrical resistivity measurements were used to assess the aquifer protective capacity of Amawbia. Vertical electrical sounding data were collected at four locations and the interpretation was done using Winresist software. The result revealed that the lithology of the area comprised mainly of laterite, clayey sand, shale, dry sand and saturated sand. The longitudinal conductance was computed using the resistivity and thickness values obtained from the interpreted data to evaluate the protective capacity. The protective capacity values ranged from 0.0081 to 1.3486 mhos. The results further revealed that most of the areas investigated are vulnerable to groundwater contamination.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Obichukwu Obiemeka Obiajulu
creator: Ezenwa Gabriel Nneji
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3447
ending page: 3454

Analysis and Characteristics of Hydrochar and Liquid Products Produced via Hydrothermal Liquefaction of Poultry Wastes
type: item
description: Hydrothermal liquefaction (HTL) of poultry waste is a potential method for converting high-moisture organic wastes into energy-dense solid and liquid products. In this study, the conversion of poultry waste into biocrude and hydrochar via HTL was explored. The fuel properties and chemical structure of biocrude and hydrochars were examined using standard fuel analytical and spectroscopic techniques. The products were produced from poultry waste via HTL at temperatures ranging from 200 to 350 °C, in 50 °C increments, with a reaction time of 30 minutes. The findings revealed a clear relationship between temperature and product distribution. Specifically, the yield of hydrochar decreased from 24.78 wt% at 200 °C to 23.05 wt% at 300 °C, and the liquid yield increased from 12.14 wt% to 21.15 wt%, indicating that higher temperatures promote better depolymerization and solubilization. Elemental analysis revealed a higher carbon content of 67.26% and a lower oxygen content of 18.96%. This led to an increase in the higher heating value of 31.10 MJ kg⁻¹. The liquid products had an acidic pH level of 5.5, which indicated the presence of organic acids. However, elemental analysis revealed a significant nitrogen content of 5.13% in biocrude. As a result, bio-oil produced from HTL of poultry waste should be upgraded through hydrotreatment (hydrodeoxygenation and hydrodenitrogenation) with H2 or a catalyst to minimize oxygen and nitrogen before utilization as a transportation and heating fuel. Therefore, conducting HTL at higher temperatures significantly increases liquid yield and energy density while minimizing solid waste. These findings highlight the significant potential for using poultry waste in HTL to produce sustainable bioenergy and valuable liquid intermediates.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Emozino Donatus Edafiadhe
creator: Jeremiah Lekwuwa Chukwuneke
creator: Chinonso Hubert Achebe
creator: Henry Chukwuemeka Olisakwe
creator: Oghenerobo Cyril Uyeri
rights: Copyright (c) 2026 Authors
date: 2026-04-14
publication date: 2026-04-14
starting page: 3435
ending page: 3446

Participation in WhatsApp and Facebook Farmer Groups and Adoption of Smart Agriculture Techniques among Smallholder Farmers
type: item
description: This study investigated the relationship between participation in WhatsApp and Facebook farmer groups and the adoption of smart agriculture techniques among smallholder farmers in Oyo State. A cross-sectional survey of 392 farmers across three agricultural zones was conducted over five months using structured questionnaires. Data were analysed with descriptive statistics, Chi-square tests, and multiple regression. Findings revealed that 71.2% of farmers used WhatsApp groups, 48.5% used Facebook, and 34.4% used both platforms. Farmers with high participation (daily/weekly) adopted an average of 8.7 smart practices, compared to 2.3 among low-participation farmers, indicating a significant adoption gap of 36.3 percentage points (χ² = 156.82, p < 0.001). The practices included mobile-based advisory services, weather-informed decision-making, pest forecasting, fertilizer micro-dosing, improved seed access, and variable-rate input application. Regression results showed that participation frequency (β = 0.468), information quality (β = 0.412), and digital confidence (β = 0.321) significantly influenced adoption (R² = 0.681). Key barriers identified were poor internet connectivity (67.3%), high data costs (62.1%), low trust in online information (58.7%), and limited smartphone capacity (51.8%). The study concludes that social media platforms are effective tools for promoting smart agriculture, though their impact depends on content quality, digital literacy, and improved infrastructure.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Olumide Olutayo Oyedare
creator: Olusola Olakunle Ogunjinmi
creator: Adenike Mary, Durojaiye
creator: Olufunmilola Oludoyin Oluwadiran
rights: Copyright (c) 2026 Authors
date: 2026-04-08
publication date: 2026-04-08
starting page: 3425
ending page: 3434

Fretting wear mitigation: development of wear-resistant coconut shell particulate/aluminium composite
type: item
description: Fretting wear has remained a dominant problem in engineering, and efforts geared towards its mitigation have continued to gain attention within the research community. One of the ways of solving problems of fretting wear is through the design and development of wear-resistant materials, of which aluminium matrix composites are the material employed in this research. Aluminium matrix composites (AMCs) are widely employed in engineering applications requiring high strength-to-weight ratios; however, their mechanical and tribological performances are highly dependent on reinforcement strategy. This study presents a comprehensive evaluation of the mechanical and tribological properties of aluminium matrix composites incorporating carbonised coconut shell particulate reinforcement, using Response Surface Methodology (RSM) as an optimisation framework. Unreinforced aluminium alloy was included as a control sample to establish baseline mechanical and tribological behaviour. Ultimate tensile strength (UTS) and hardness were evaluated as key mechanical responses, while wear rate served as a tribological response. Results demonstrated that reinforcement significantly enhances mechanical and tribological performances relative to the control sample. The UTS values ranged from 42.907 to 74.403 MPa, with maximum strength observed at 212 µm particle size, 15 wt% reinforcement, and 2 minutes of stirring. Hardness reached 190.25 LHN, while wear rate decreased to 0.0055 mm³/m for the composite with 75 <!-- [if gte msEquation 12]><m:oMath><m:r>μ</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 115%; 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: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bid…
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Paul Okpala
creator: Sam Omenyi
creator: Ugochukwu Okonkwo
creator: Jeremiah Chukwuneke
creator: Jude Dara
rights: Copyright (c) 2026 Authors
date: 2026-04-08
publication date: 2026-04-08
starting page: 3404
ending page: 3424

Adoption and Limitations of Smartphone Plant Disease Identification Apps in Early Disease Detection Among Crop Farmers in Atiba Local Government Area, Oyo State, Nigeria
type: item
description: Crop diseases pose a major threat to agricultural productivity in sub-Saharan Africa, with estimated yield losses of 20–40% annually, while traditional diagnostic services remain out of reach for many smallholder farmers. This study assessed awareness, adoption and constraints related to smartphone-based plant disease identification applications among 150 crop farmers in Atiba Local Government Area, Oyo State, Nigeria, using a descriptive survey design and multistage sampling. Data were collected through face-to-face administration of structured questionnaires and analysed using descriptive statistics and chi-square tests. The socioeconomic profile showed a predominantly middle-aged population with generally low to moderate education and digital experience, and although all respondents either owned or had access to smartphones, awareness of disease identification applications was only 47.3%. Adoption remained modest, with 25.3% regular users, 15.3% occasional users, and 52.7% never-users. Chi-square results indicated that age group, educational level, smartphone ownership and digital experience were all significantly associated with adoption status. Among users, perceived benefits include early disease detection (mean = 3.42), reduced crop loss (3.31), improved yield (3.18) and reduced chemical costs (3.05) all exceeded the decision threshold of 2.50. Major constraints were poor internet connectivity (3.48), high data costs (3.36), concerns about diagnostic accuracy (3.12), and low digital literacy (3.05). The study concludes that increasing adoption will require integrated efforts to improve rural connectivity and data affordability, strengthen farmers’ digital skills and embed validated localised applications within extension systems.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Olusola Olakunle Ogunjinmi
creator: Olumide Olutayo Oyedare
creator: Adenike Mary Durojaiye
creator: Olufunmilola Oludoyin Oluwadiran
rights: Copyright (c) 2026 Authors
date: 2026-04-08
publication date: 2026-04-08
starting page: 3395
ending page: 3403

Enhancing dynamic line rating using fuzzy based ultracapacitor
type: item
description: The efficiency and reliability of power transmission networks are increasingly challenged by the limitations of static line ratings, which often lead to underutilization of transmission capacity and increased congestion. This research focuses on Enhancing Dynamic Line Rating (DLR) Using Fuzzy-Based Ultracapacitor Technology to address these challenges. The proposed system integrates a fuzzy logic controller with an ultracapacitor energy storage system to provide rapid and intelligent support to transmission lines under fluctuating environmental and load conditions. The fuzzy controller dynamically assesses real-time parameters such as conductor temperature, wind speed, and solar radiation to optimize the use of the ultracapacitor, thereby enhancing the dynamic line capacity safely and efficiently. Simulation results demonstrate that the fuzzy-based ultracapacitor system significantly improves the responsiveness of DLR mechanisms, reduces thermal overload risks, and maximizes line utilization without compromising system stability. The study offers a novel approach for modernizing power transmission infrastructure, enabling smarter, more adaptive grid operations, and paving the way for higher integration of renewable energy sources. The findings suggest that intelligent energy storage-based compensation can be a key driver in the future development of resilient and efficient transmission networks. The conventional High Ambient Temperature that causes poor dynamic line rating was25%. On the other hand, when Fuzzy based ultracapacitor was incorporated into the system, it drastically reduced to21.7% and the conventional high solar radiation that causes poor dynamic line rating was 10%. Meanwhile, when Fuzzy based ultracapacitor was imbibed into the system, it simultaneously reduced to8.7%. Finally, with these results obtained, it showed that percentage enhancement dynamic line rating when Fuzzy based ultracapacitor was integrated in the system was 1.3%.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Nwogbu Celestine Chidi
creator: Chukwuagu Ifeanyi
creator: Adindu Charles .O
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3382
ending page: 3394

Mechanical performance optimization of thatch grass-based particleboard bonded with Arabic gum binder using Response Surface Methodology
type: item
description: This study investigates the optimization of mechanical and physical properties of particleboard manufactured from thatch grass (Hyparrhenia spp.) bonded with Arabic gum as a bio-based adhesive. The increasing demand for sustainable alternatives to conventional wood-based panels has driven research toward utilizing agricultural residues and natural binders. A Face-Centered Central Composite Design (FCCCD) under Response Surface Methodology (RSM) was employed to optimize five process parameters: particle size, resin loading, press pressure, holding time, and pressing temperature. A total of 50 experimental runs were conducted, and mechanical properties including Modulus of Rupture (MOR), Modulus of Elasticity (MOE), Internal Bond Strength (IB), and Compressive Strength were evaluated alongside physical properties such as density, water absorption, and thickness swelling. The results demonstrated that MOR values ranged from 6.674 MPa to 14.532 MPa, MOE from 1,100 MPa to 2,055 MPa, and IB from 0.120 MPa to 0.420 MPa. The optimized particleboard, produced with particle size of 195.117 μm, resin loading of 43.219%, press pressure of 5 MPa, holding time of 6 minutes, and pressing temperature of 174.988°C, achieved MOR of 13.597 MPa, MOE of 1943.687 MPa, IB of 0.401 MPa, compressive strength of 12.406 MPa, and density of 699.999 kg/m³. Life Cycle Assessment confirmed significantly lower environmental burdens compared to conventional particleboards. The study demonstrates that thatch grass-based particleboard bonded with Arabic gum represents a viable, sustainable alternative to traditional wood-based panels for general-purpose applications.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Hillary Ejike Chukwu
creator: Harold Chukwuemeka Godwin
creator: Moses Chikaodili Uzochukwukamma
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3367
ending page: 3381

Influence of Mineralogical and Chemical Composition on the geotechnical index properties and compaction characteristics of Borrow Pit Soils and Onitsha River Sand, Anambra State, Nigeria
type: item
description: The engineering behavior of soils used for construction in Awka Municipal, Anambra State, Nigeria, is strongly influenced by their mineralogical and chemical composition. This study investigates how these factors affect the basic properties of three commonly used soils: Onitsha River sand (ON100) and borrow-pit soils from Amansea (AM100) and Ebenebe (EB100). Laboratory testing included particle size distribution, Atterberg limits, specific gravity, linear shrinkage, natural moisture content, compaction (OMC and MDD), X-ray diffraction (XRD) for mineral identification, and X-ray fluorescence (XRF) for oxide composition. Quartz was the main mineral in all samples (86–96%), with smaller amounts of kaolinite (3–7%), illite/muscovite (<1–4%), and feldspars (3–5%), while the main oxides were SiO2 (80–84%), Al2O3 (5–6.5%), Fe2O3 (1.4–6.4%), and TiO₂ (1.1–2.5%). Clear patterns showed that quartz and kaolinite had opposite effects on optimum moisture content, illite improved maximum dry density through better packing, feldspars lowered it by producing extra fines during weathering, SiO2 strongly increased MDD, TiO2 sharply reduced OMC, and Al2O3 and Fe2O3 reduced MDD due to cementing and aggregation. The borrow-pit soil contained moderate silt-rich fines but remained almost non-plastic, while the river sand was nearly pure quartz, uniform, and non-plastic. These results show that mineralogical and chemical composition primarily controls the index properties of soils and can be used to predict their engineering behavior
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Lilian Nnenna Chukwubude
creator: Chidozie Maduabuchukwu Nwakaire
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3342
ending page: 3351

Effect of Palm Stalk Ash Reinforcement on the Microstructural, Thermal and Mechanical Properties of Ugwuoba Clay for Refractory Applications
type: item
description: The growing demand for sustainable refractory materials has stimulated interest in the utilization of agro-waste additives for enhancing the performance of clay-based ceramics. In this study, Ugwuoba clay reinforced with 20.66 wt.% Palm Stalk Ash (PSA) was investigated to evaluate its suitability for foundry crucible applications. The clay–PSA composite was prepared, shaped, and fired at temperatures ranging from 1100 °C to 1200 °C, and its microstructural, mineralogical, physical, thermal, and mechanical properties were scientifically examined. Microstructural analysis revealed that PSA incorporation modified the clay matrix by introducing a heterogeneous but well-bonded structure, while X-ray diffraction confirmed enhanced formation of thermally stable calcium silicate and silica-rich phases. Apparent porosity and water absorption decreased with increasing firing temperature, accompanied by a corresponding increase in bulk density, indicating improved densification. Linear shrinkage results demonstrated accelerated sintering attributable to the fluxing action of PSA. Thermal conductivity exhibited temperature-dependent behaviour governed by porosity reduction and microstructural consolidation. Thermogravimetric analysis showed minimal mass loss beyond the dehydration and organic decomposition stages, confirming good thermal stability at elevated temperatures. Cold crushing strength increased significantly with firing temperature, reflecting enhanced mechanical integrity and load-bearing capacity. Overall, the results demonstrate that reinforcement of Ugwuoba clay with 20.66 wt.% PSA improves thermal stability, mechanical strength, and densification characteristics, making the composite a promising, sustainable candidate for foundry crucible and other high-temperature refractory applications.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Kenechukwu ThankGod Onyena
creator: Oluwaseyi Omotayo Taiwo
creator: SamuelMary Onwubiko Obiorah
creator: Nkem Emelike Nwankwo
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3331
ending page: 3341

Optimization of the Industrial use of Renewable Energy for a Sustainable and Hazard-free Environment
type: item
description: The benefits associated with the utilization of renewable energy sources such as improved electricity access, economic development and energy sustainability can never be over-emphasized. Nigeria being a developing country with an acute electricity problem is blessed with renewable energy resources. Due to capital intensive nature of renewable energy sources, most of these energy sources remain unexploited in Nigeria. This study aims at developing a general framework that can be utilized in Nigeria to minimize the total cost of installing renewable energy technologies while satisfying some predetermined constraints which include demand and supply, renewable energy potentials. There is inequitable access of rural communities to electricity services in the country as demand supersedes the generation. This paper presents three case scenarios namely prospective off-grid which accesses electricity level below 50%, on-grid which accesses electricity level above 50% and all-off-grid which finds the optimal cost of installing off-grid renewable energies. The results show that the total installation costs of the first and second scenarios are $97.46 and $114.03 billion respectively while that of the third scenario is found to be $244.33 billion. Further analysis of the results obtained revealed that the combination of the off-grid and on-grid installations have the minimum installation cost and it is to be adopted especially in the rural and remote areas.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Christian Onyewuchi Njoku
creator: Anthony Victor Gambo
creator: Uche Emmanuel Uche
creator: Yekini Bello
creator: Rexcharles Enyinna Donatus
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3323
ending page: 3330

Mechanical Properties Enhancement of Concrete Sand Bulking using Egg Shell Ash Particulates
type: item
description: The research work investigated the Pozzolanic and filling effects of the egg shell ash particulate on concrete sand bulking. The materials used are eggshell ash particulate, Otamili river sand, water and wooden mold. The sand bulking, workability, compressive and tensile strengths were tested with varying compositions of the egg shell ash (0%, 1%, 2% and up to 10%) in the mix. The regression statistical model was used to analyze the data. Results obtained showed that percentage sand bulking, compressive and tensile strengths were rising at 60 %, 45% and 41% respectively with the egg shell ash concentration due to the increased binding effect of the ash on the mix compositions while the workability decreased slightly owing to the increase in the water repellent property of the concrete mix with rise in eggshell ash concentration. These results are in consonance with the result of the statistical linear regression model obtained. This indicates the positive use of agricultural wastes to tackle sand bulking and to produce sound and eco-friendly concretes, thus paving the way for a sustainable material development, shunning dependence on synthetic alternatives and above all maximizing industrial profit through the reduction of material input cost
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Nwambu, C N
creator: Okoro B
creator: Ekwedigwe, C. M
creator: Nwoke V
creator: Obiorah, S.M.O
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3314
ending page: 3322

An Experimental Analysis of Embedding Separability and SVM Classification in Hybrid Face Recognition Systems
type: item
description: This paper presents an experimental analysis of embedding separability and classification performance in a hybrid face recognition system combining Multitask Cascaded Convolutional Neural Network-based face detection, FaceNet-based embedding learning, and Support Vector Machine (SVM) classification. The study focuses on the effect of margin-based loss functions on the geometric structure of learned face embeddings and their influence on downstream recognition accuracy. ArcFace- and CosFace-trained embeddings are evaluated using classification metrics and cosine-distance–based separability analysis. Experimental results show that margin-based losses significantly improve intra-class compactness and inter-class separation, enabling the SVM to construct stable linear decision boundaries with improved generalization under limited training samples. The hybrid framework achieves competitive recognition performance with lower inference complexity compared to end-to-end deep classifiers. With a dataset that has 10,946 training samples and 2,737 testing samples, the framework had an Overall accuracy (%) of 99.77%, Precision (weighted) of 99.85%, Recall (weighted) of 99.77% and F1-score (weighted) of 99.75%. These findings highlight the importance of embedding geometry in hybrid face recognition systems and support their suitability for real-world attendance management and access control applications.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Onyemaechi Paul Aruegbe
creator: Azubuike Nzubechukwu Aniedu
creator: Theophilus Leonard Alumona
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3302
ending page: 3313

Evaluating the impact of moisture content on the Foundry performance of Eco-friendly sand from Nyama River Beach for Sustainable Casting Applications
type: item
description: This study evaluates the effect of moisture content on the foundry performance of eco-friendly sand derived from Nyama River Beach for sustainable casting applications. The objective was to determine the suitability of locally sourced sand combined with Edda clay as a binder for environmentally sustainable moulding sand. Grain size distribution was analyzed using a mechanical sieve shaker, showing that more than 70% of the sand particles were retained at key mesh sizes of 0.18 mm, 0.125 mm, and 0.09 mm. The calculated grain fineness number (GFN) of 73.80 indicates an optimal grain distribution suitable for foundry applications. Chemical characterization using X-ray fluorescence (XRF) and X-ray diffraction (XRD) revealed the major oxide compositions as SiO₂ (73.64%), Al₂O₃ (7.98%), and MgO (1.45%), confirming the silica-rich nature of the sand. Foundry performance was evaluated through tests including green compressive strength, green shear strength, dry compressive strength, dry shear strength, compactability, and permeability. The results showed a green compressive strength of 9.50 kN/m² and green shear strength of 236.40 kN/m², indicating good mechanical stability under moist conditions. Compactability and permeability were recorded at 26.10% and 190.09%, respectively, demonstrating adequate moulding and drainage properties. The optimal composition was achieved with 5% Edda clay and 3.85% moisture content, which significantly improved the moulding characteristics of the sand. The findings indicate that Nyama River sand, when properly conditioned with Edda clay, can serve as a sustainable alternative to conventional bentonite-bonded moulding sand, particularly for non-ferrous casting applications, while promoting environmental sustainability and reducing dependence on non-renewable material
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Alfred Ogbodo Agbo
creator: Okwuchukwu Innocent Ani
creator: Thomas Chinedu Aniokete
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3290
ending page: 3301

Contingency Investigation of Nnamdi Azikiwe University, Awka Hybrid Distribution System
type: item
description: Electric power distribution systems are prone to disturbances such as voltage instability, line and ground faults, overloading, equipment aging, natural disasters, and human operational activities, all of which affect system stability and reliability. The distribution network of Nnamdi Azikiwe University (UNIZIK) faces similar challenges. This study presents a contingency analysis of the university’s hybrid electric power distribution system to identify system vulnerabilities and propose measures to improve stability. The methodology involved load distribution surveys, analytical power system calculations, and modelling and simulation using the Electrical Transient Analysis Program (ETAP). Contingency assessments were performed under N-1 and N-2 outage scenarios to evaluate voltage performance, reactive power adequacy, and thermal loading of key system components. Results show that although the system has adequate generation capacity, weak distribution feeders limit its performance. Voltage violation severity indices reached 37%, while reactive power severity indices rose to 26,491.81 under critical contingencies. The DigLib–HostelM feeder also operated at 94% of its rated capacity. The study recommends reactive power compensation and feeder reinforcement to enhance system reliability.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Izuogu O. K
creator: Anionovo U. E
creator: Nworabude F. E
creator: Okoli M. O
creator: Anazia E. A
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3275
ending page: 3289

Automotive V-Belt as Autoclave Door Gasket Improvise in a Financially Constrained Healthcare Facility
type: item
description: This study seeks to document our experience with the use of an automotive V-belt as an autoclave door seal improvise in a financially constrained healthcare facility with respect to the experiment and outcome. The investigation was conducted using a 150-liter vertical steam autoclave in the Central Sterilization and Supply unit of a healthcare facility in Ebonyi state Nigeria. The standard lid seal was replaced with a locally sourced multi-ply automotive/industrial V-belt of the same circumference. The improvised seal was used over a number of sterilization cycles under standard conditions (121oC, ~15psi steam). The result indicated initial effective sterilization. However, after repeated cycles, the improvised seal exhibited material fatigue, loss of elasticity, and diminished compression. This outcome suggests that while a V- belt may serve as a temporary stop-gap in emergencies, it is not a substitute to standard autoclave gasket.
subject: Articles
  topic: section
subject: Array
  topic: keywords
creator: Innocent, C. Ekuma
creator: Chilee, M. Ekwedigwe
creator: Chidume, N. Nwambu
creator: Benjamin, Okechukwu Ezurike
creator: Ikenna, U. Mbabuike
rights: Copyright (c) 2026 Authors
date: 2026-04-07
publication date: 2026-04-07
starting page: 3270
ending page: 3274