Nnamdi Azikiwe University Journals
Not a member yet
5579 research outputs found
Sort by
Modeling and Optimization of Fibreboard Production from Corn Husk using Response Surface Methodology
No full textThis study optimizes the production of fiberboard from corn husk using Response Surface Methodology (RSM). RSM was employed to identify the optimal conditions for achieving superior strength and durability. The effect of key process parameters such as Fiber/rLDPE ratio, press time, press temperature, and press pressure, on the mechanical properties of the fiberboard was assessed. Instrumental analyses, including Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA), were performed to assess the fiberboard\u27s microstructure and thermal stability. The optimal process parameters were a Fiber/rLDPE ratio of 12.5, press time of 7 minutes, press temperature of 190°C, and press pressure of 10 MPa. Under these conditions, the Modulus of Rupture (MOR) reached 41.86 MPa, Modulus of Elasticity (MOE) was 2718.8 MPa, and Internal Bond (IB) strength was 1.72 MPa. SEM revealed a uniform surface structure with good interfacial bonding, while TGA indicated high thermal stability with a weight loss of 15% at 350°C. The fiberboard had a density of 844 kg/m³ and exhibited minimal thickness swelling (4.76%) and water absorption (4.93%). These results show that corn husk fiberboard meets industry standards for strength, durability, and sustainability, making it a viable and eco-friendly alternative to conventional wood-based panels for industrial applications
Interfacial Adhesion and Physicomechanical Behaviours of Optimally Acetylated Kapok Fiber–Polymethylmethacrylate Composites for Prosthodontic Applications : Acetylated kapok fiber reinforced polymethylmethacrylate denture base material
No full textInterfacial adhesion and physicomechanical behaviours of optimally acetylated kapok fiber–polymethylmethacrylate (PMMA) composites for prosthodontic applications was investigated. Kapok fiber was extracted using water retting technique and chemically modified using acetic anhydride. The central composite design of response surface methodology (RSM) was employed to optimize the kapok fiber modification using 3-15 % of acetic anhydride and 30-150 minutes. Polymethyl methacrylate denture base material (95.25-99.25%) was modified with optimally acetylated kapok fiber (0.75-3.75%) and optimized based on tensile, flexural, hardness and impact properties. The density, water absorption and water absorption kinetics were determined. At optimum preparation of acetylated kapok fiber-PMMA, the tensile strength, hardness and interfacial adhesion were improved by 13.16, 8.06 and 67.93%, respectively, with reduced flexural strength (49.62%) and modulus (65.18%), and impact strength (22.52%). Acetylation reduced the density and water absorption of kapok fiber-PMMA by 8.6 and 117.53 %, restored the non-fickian water absorption behaviours and reduced coefficient. Hence optimized acetylated kapok fiber-PMMA denture base material enhanced the quality and durability with reduced residual monomer that may lead to cytotoxicity of oral cavity
Modeling, Simulation and Analysis of Natural Gas Processing Routes Using HYSYS Design Applications
No full textThis paper focuses on the modeling and simulation of natural gas processing routes using HYSYS design applications, aimed at understanding the performance of gas processing routes. The objective is to simulate and analyze the thermodynamic behavior of the system under different operation. HYSYS, a leading process simulation software, was employed to model various unit operations, including the slug catcher, de-ethanizer, lean gas purifier, and debutanizer, to evaluate the material and energy balances, pressure-temperature relationships, and phase transition points. The results revealed key trends, such as the relationships between pressure, temperature, volume, enthalpy, and entropy, which are crucial for understanding the process dynamics, The study identified the specific conditions under which phase changes occur, including the bubble points, and emphasized the importance of accurate modeling in predicting the performance of each unit operation. The simulation also highlighted potential areas for improvement, such as the reduction of impurities in lean gas, which can enhance product yield and profitability. Overall, this research demonstrates the effectiveness of HYSYS simulation in modeling natural gas processing. The findings serve as a foundation for further studies aimed at improving the economic and environmental sustainability of natural gas processing industries by optimizing key parameters of the system such as pressure, temperature, etc
Thermophilic Anaerobic Digestion of Pig Dung with Snail Shell Additive Supplementation for Enhanced Biogas Production
No full textThe study investigated the thermophilic anaerobic digestion of pig dung with snail shell as additive for enhanced biogas production. Pig dung and additive was weighed and mixed with distilled water in a 500 ml round-bottom flask. The flask containing the slurry was connected to a Soxhlet extractor workstation, and was placed in a heating mantle. When heat was applied, the gas was conveyed through the thimble to the shell and tube heat exchanger, where the gas was condensed. The results show that the optimal conditions for biogas production were additive dosage at 3.5 g, pig dung/ water ratio at 0.16 g/ml, time at 60 mins and temperature at 700C, under these conditions the biogas yield was 24.45 %. CCD of RSM was applied to enhance process optimization and predict the optimal outcome. The model demonstrated significant results, with a p-value of less than 0.0001. The R2 of 0.9835, ANOVA results indicate that the model effectively describes the anaerobic digestion of pig dung for biogas production. The produced biogas contains 66.9% methane and 27.2% CO2 by volume with other constituents present as shown by gas chromatography and FTIR, therefore, the feedstocks used in this study have the potential to support the efficient and sustainable operation and production of biogas plants on a large scale
Field Oriented Control for Efficient and Simplified Wind Power Generation Using DFIG
No full textThis paper presents the modeling, simulation, and performance analysis of a Doubly-Fed Induction Generator (DFIG)-based wind energy conversion system (WECS) using Field-Oriented Control (FOC) due to its structural simplicity and ability to meet desired dynamic performance requirements. The study includes comprehensive dynamic modeling of key WECS components from the wind turbine to the grid interface developed in a MATLAB/Simulink environment. The FOC strategy is applied to independently regulate active and reactive power, ensuring effective energy conversion and stable grid integration. Simulation results demonstrate the system’s capacity to maintain steady active and reactive power output and achieve a low Total Harmonic Distortion (THD) of 4.57% in the grid voltage, indicating improved power quality. The novelty of this work lies in its system-wide modeling and performance validation of an FOC-controlled DFIG system in a compact, simulation-based approach suited for low-cost, efficient wind power applications. The results show that a well-implemented standard FOC approach can achieve effective control without the need for algorithmic complexity
Artificial Intelligence and Machine learning - Driven Real-Time on Vibration Signal Analysis in Automotive Engines
No full textThis research presents an open-source Python-based framework designed for real-time analysis of engine vibration signals using artificial intelligence (AI) and machine learning (ML) techniques. Unlike conventional approaches that depend heavily on manual feature extraction and offline diagnostics, the proposed system employs automated processing to enable immediate fault detection. Advanced models, including deep convolutional neural networks (CNNs), support vector machines (SVMs), and random forests (RFs), are utilized to facilitate rapid and accurate diagnostics. Vibration data were gathered via piezoelectric sensors attached to engine blocks operating under controlled conditions, resulting in a dataset comprising approximately 1.2 million data points across diverse engine cycles. Signal preprocessing and feature extraction were conducted using MATLAB R2024a, while model training and inference were implemented in real time using Python 3.10, with support from TensorFlow 2.11, PyTorch 2.0, and scikit-learn 1.2.3. Platforms such as VibroSight and DASYLab 2023 were employed for data acquisition, signal visualization, and automation of the diagnostic workflow. Statistical analyses, including one-way ANOVA and independent t-tests, revealed that a hybrid CNN–RF model (referred to as Hybrid Design 4) attained the highest mean diagnostic accuracy at 90.4%, significantly outperforming a traditional threshold-based model which achieved 78.5%. The reliability and statistical significance of these results were confirmed through 95% confidence intervals and p-values below 0.05. These findings underscore the potential of AI/ML integration in real-time vibration monitoring systems, promoting the development of predictive maintenance (PdM) solutions and enhancing the reliability of next-generation autonomous vehicle engine
Design and Implementation of a Noise Pollution Monitoring and Alert System
No full textThis research effort addresses the challenges caused by uncontrolled noise which can impair academic integrity and cause students to lose focus. Then, design and implementation of a noise pollution monitoring and alert system specifically designed for academic settings is provided. The solution involves three omnidirectional microphones connected through a multiplexer to an ESP32 microcontroller. Real-time sound input is mapped to approximate decibel levels by a threshold-based logic system that is built with the Arduino IDE which triggers a tri-colour LED alert mechanism for disturbances. The noise level is observed from several input locations using a web interface built on Flask, which offers real-time monitoring capabilities. The results show that the microcontroller started the proper alert logic after processing the readings in an average time of 0.34 seconds, the constructed device exhibits a quick response time of 0.7 seconds and dependable performance for two and a half hours. It functions well without constant internet connectivity, which is a significant improvement over the existing designs. The modular architecture guarantees scalability to other domains like offices and libraries. The system would improve examination invigilation and adherence to recommended acoustic standards
Phytochemical and Mineral Properties of Zobo Drink Processed with Miracle Leaf and Wonderful Kola Extract
No full textThis study investigated the phytochemical and mineral compositions of Zobo drink fortified with varying concentrations of miracle leaf and wonderful kola extracts. A mixture design was used generating five samples. Phytochemicals and mineral analysis were carried out on the samples using standard methods. Phytochemical analysis revealed significant variations with saponin content ranging from 0.20 to 1.20 mg/g, alkaloid from 0.07 to 1.00 mg/g, flavonoid from 14.10 to 19.59 mgQE/g, phenol from 16.02 to 26.25 mgGAE/g and tannin from 20.95 to 31.30 mg/g. Sample Bsc (60 % Zobo, 8 % miracle leaf extract, and 32 % wonderful kola extract) showed the highest levels of saponin (1.20 mg/g), alkaloid (1.00 mg/g), and tannin (31.30 mg/g), indicating its potential for cholesterol-lowering, immune-boosting, and antioxidant properties. Mineral analysis indicated significant increases in calcium (12.85–62.01 mg/100g), magnesium (38.83–84.79 mg/100g), iron (2.12–3.61 mg/100g), and sodium (10.20–17.45 mg/100g). Sample Bsc- (60% Zobo, 8% miracle leaf extract, and 32% wonderful kola extract), consistently showed the highest concentrations of these minerals, making the fortified drink particularly beneficial for bone health, iron supplementation, and cardiovascular function fortifying Zobo drink with miracle leaf and wonderful kola significantly enhances its nutritional and medicinal properties, offering a functional beverage with improved antioxidant activity, enhanced mineral bioavailability and therapeutic potential
Assessment of Arable Farmers’ Response to the Impact of Urbanisation in Ilorin Metropolis, Kwara State, Nigeria
No full textExpansion of urban areas, causing demand for more residential, commercial, and industrial spaces, poses profound impacts on rural farming community land that feeds the populace. Urbanization not only reduces the amount of land available for food production but also leads to fragmentation of agricultural landscapes, making farming activities more challenging. This study sought to assess the response of arable farmers to the impacts of urbanization in Ilorin Metropolis, Kwara State, Nigeria. A three-stage sampling procedure was used in selecting one hundred and sixty-seven respondents for the study. Data were obtained using a structured questionnaire and was analyzed through frequencies, percentages, means, standard deviation and chi-square. The result revealed that majority of the respondents were males (73.7%), married (87.4%) and with an average age of about 56.7 years. About half (59.1%) of the respondents indicated awareness of urban farming techniques. Diversification into livestock production (x̄=1.67) and engaging in non-farming activities (x̄ =1.55) were the major responses of the farmers to the impacts of urbanization. The results also revealed that age, primary occupation and household size have a significant relationship with the farmers’ responses to the impacts of urbanization at p<0.05 level of significance. The study concluded that more awareness in the form of educational programmes should be deployed to farmers on urban agriculture practices and recommended formulation of policies that balance urban development with agricultural sustainability in Nigeria
RELATIONSHIP MARKETING AND PATRONAGE OF CONVENIENCE STORES IN C ALABAR
No full textThe study examined the effect of relationship marketing and patronage of convenience stores in Calabar. In deed the dynamic approach to selling has moved to relationship based in a way. The study reviewed related literature based on the objectives. The study adopted a survey research design with the survey of a structured questionnaire based on five point likert scale. It was used to measure trust, commitment and competence as the independent variables. Systematic sampling procedure was adopted while the Topman’s formula was used to get the sample size. The use of multiple regression analysis was used to test the formulated hypotheses. The result of the analysis revealed that all the three variables (trust, commitment and competence) were statistically significant to induce patronage of convenience stores in Calabar Metropolis