LAUTECH Journal of Engineering and Technology (LAUJET)
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Fuzzy Synthetic Evaluation of the Level of Service of Agba Dam Water Treatment Plant
Get PDFThis study addresses the critical need for a robust evaluation of water treatment plant performance, with a focus on the level of service at the Agba Dam Water Treatment Plant in Nigeria. The objective was to apply fuzzy set theory for objective assessment. The methodology involved collecting 1664 water quality parameter measurements, including pH, conductivity, turbidity, and total dissolved solids. Of these, 354 valid entries served as performance indicators. These data were integrated into a fuzzy synthetic evaluation model assessing service level against prescribed regulatory and expert limits. The key result showed water quality across all sampled parameters was consistently within limits, with mean values: pH = 7.15, conductivity = 176.62 ?S/cm, turbidity = 1.23 NTU, and total dissolved solids = 87.18 mg/L. Consequently, it's concluded that the Agba Dam Water Treatment Plant delivers an excellent level of service, scoring 2.75 on a defined 3-point fuzzy evaluation scale. This scale was explicitly defined using a Likert-type system with linguistic terms 'Poor', 'Good', and 'Excellent', and was validated by expert biochemists and principal scientists from the plant
Green Synthesis and Characterization of Tin (IV) Oxide Nanoparticles from Fresh and Dried Senna alata Leaf Extract
Get PDFDespite the growing interest in plant-mediated nanoparticle synthesis, limited research has examined how the condition of plant material (fresh or dried) has affected the efficiency and quality of synthesized nanoparticles. This study reports the green synthesis of tin (IV) oxide (SnO?) nanoparticles using aqueous extracts from fresh and dried Senna alata leaf as reducing, stabilizing, and capping agents, with 1.0 M Tin (II) chloride dihydrate (SnCl?·2H?O) as the precursor. Structural, morphological, optical, and thermal properties of the synthesized nanoparticles were investigated. XRD analysis confirmed the formation of crystalline tetragonal rutile-phase SnO?, with average crystallite sizes of 3.7 nm for fresh-leaf extract and 8.19 nm for dried-leaf extract. FTIR spectra revealed stronger and more distinct functional groups (O–H, C–H, C–O, and NO??) in nanoparticles derived from fresh extracts. SEM and TEM analyses showed uniformly distributed, spherical nanoparticles with minimal agglomeration and average particle sizes of 9.88 nm (fresh extract) and 9.80 nm (dried extract). EDX analysis confirmed elemental purity with dominant Sn and O signals and complete removal of chlorine residues. Optical studies demonstrated that fresh-leaf-derived nanoparticles exhibited higher absorbance, lower transmittance, and a narrower band gap (3.21 eV) compared to the dried-leaf counterpart (3.58 eV). Thermal conductivity results indicated superior heat-transport performance for nanoparticles synthesized from fresh leaves, particularly at lower temperatures. These findings demonstrated that fresh Senna alata leaf extract provides a potential sustainable and efficient route for producing high-quality SnO? nanoparticles with enhanced optical and thermal properties for advanced technological applications
Optimization of Green Corrosion Inhibitor Dosage in Acidic Medium: A Case Study of Hunteria umbellata Seed Extracts
Get PDFThis study investigated the corrosion inhibition performance of Hunteria umbellata seed Extract (HUE) on mild steel in an acidic medium. A Box-Behnken design (BBD)-based optimization was used to analyze the factors affecting inhibition efficiency such as inhibitor concentration, temperature and time. Corrosion studies were carried out using gravimetric weight loss measurement and electrochemical polarization methods. The identification of the constituents of the HUE was done using phytochemical screening and GC-MS analysis. The surface morphology of the coupon was assessed using scanning electron microscopy (SEM). The research revealed that the inhibitor demonstrated good inhibition potential with optimum inhibition efficiency of 89.677% at a concentration of 0.98 g/L, after an immersion time of 10 h at a temperature of 30.22 °C
Development and performance evaluation of a fixed bed pyrolyser for valorization of selected biomass
Get PDFEfficient waste management in the forestry and wood industries is essential for conserving resources, energy, and costs. This study presents the design and fabrication of a fixed-bed pyrolysis system for the production of bio-oil, bio-char, and syngas from Cola nitida sawdust residues. The system comprises a reactor, condenser, heating unit, and discharge unit, all designed in accordance with ASTM standards (ASTM A36, ASTM C182 and ASTM C133) and fabricated at the Technical Support Unit, Faculty of Technology, University of Ibadan. Dried and sieved sawdust fractions of 0.5, 1.5, and 3.0 mm particle size and mass of 200 ±5 g mass were pyrolyzed at residence time of 30, 45 and 60 minutes respectively with three replicates runs each under controlled conditions to assess the effects of particle size and residence time on product yield and composition. Results showed that smaller particles (0.5 mm) yielded the highest liquid fraction (45.8%) due to enhanced heat transfer and rapid devolatilization, while larger sizes (1.5 - 3.0 mm) produced less bio-oil but more bio-char, with 3.0 mm yielding the most bio-char (38.7%) and prolonged residence times promoted secondary cracking, reducing liquid yield. The developed system, with a total fabrication cost of USD 173 (?276,600), effectively volatilized Cola nitida sawdust
Impact of hyperparameter tuning on hybridised convolutional neural networks for pathloss modelling in mobile communication systems
Get PDFThe performance of machine learning models, particularly Convolutional Neural Networks (CNNs), is profoundly influenced by effective hyperparameter tuning. However, a comprehensive understanding of how these hyperparameters affect the predictive accuracy of CNN-based pathloss models has not been adequately carried out. This study explores the role of hyper-parameter tuning in a hybridised CNN architecture that integrates DenseNet121 and ResNet50 to enhance pathloss prediction in mobile network environments. Field measurements were conducted along strategically selected urban and suburban routes in Ilorin, Kwara State, Nigeria. The results revealed the critical influence of key hyperparameters, such ashidden layers, batch size, training epochs, and computational efficiency, on model performance. Initially, with only two (2) hidden layers, the model showed suboptimal predictive accuracy, characterised by an MAE of 25.15, a MSE of 34.43, and a highly negative R² value of 6.01. However, increasing the hidden layers to seventeen(17) yielded a substantial improvement, with the MAE reducing to 2.08, the MSE decreasing to 7.35, and the R² shifting positively to 0.80. Further analysis of batch sizes revealed that smaller sizes resulted in poor model performance, increasing it to 8 significantly enhanced accuracy. Additionally, an increase in training epochs from 50 to 200 led to a marked reduction in prediction errors, albeit at the expense of extended training time per iteration. These findings underscore the pivotal role of strategic hyperparameter selection in optimising CNN-based pathloss modelling, offering valuable insights for enhancing predictive performance in mobile network systems
Development of an Optimized Deep Learning Technique for Tomato Leaf Diseases Recognision
Get PDFTomatoes are among the most widely cultivated and consumed vegetables globally, valued for their rich nutritional content and versatility in culinary applications. However, tomatoes are bedevilled with diseases and pests that wipe out approximately half of farmers’ harvests every year. Recent advancements in deep learning provide promising solutions for automating disease recognition; however, challenges still persist in achieving high accuracy and hyperparameter tuning. Hence, this research optimized Convolutional Neural Network (CNN) with Hippopotamus Optimizer (HO) for Tomato Leaf Diseases Recognition. Four thousand five hundred and thirty-six (4536) images of tomato leaf were downloaded from kaggle.com. The acquired images were grouped into four (4) classes: bacterial spot, early blight, leaf mould, and healthy leaves. The images were preprocessed by cropping to remove unwanted elements, converting to gray-scale for colour complexity reduction, normalizing and filtering to reduce noise. An optimized Convolutional Neural Network (CNN) using Hippopotamus Optimizer (HO), (HO-CNN) was developed. The HO-CNN was employed to select optimal values of number of neurons and dropout rates for CNN hyperparameters; The HO-CNN was implemented using MATLAB R(2023a). The evaluation metrics used were False Positive Rate (FPR), Specificity (Spec), Sensitivity (Sen), Precision (Pre), Accuracy (Acc), and Recognition Time (RT), and the HO-CNN was compared with the traditional CNN. The FPR, Spec, Sen, Pre, Acc, and RT for HO-CNN were 2.59%, 97.41%, 95.11%, 95.67%, 96.55% and 38.16 s, respectively. The corresponding values for CNN were 5.29%, 94.71%, 90.61%, 91.14%, 93.17% and 81.66 s, respectively. A Hippopotamus optimized-Convolutional Neural Network (HO-CNN) improves tomato leaf disease recognition accuracy by about 3.6%, reduces false detections by approximately 51%, and decreases recognition time by nearly 53% compared to the traditional CNN. The HO-CNN developed can be applied for tomato leaf disease recognition in real-world agricultural development.
Optimization of Ethylene – Vinyl Acetate Dosage for Rheological and Physico-Mechanical Properties of Loda Bitumen
Get PDFHeavy reliance on road transportation, especially in developing countries, has necessitated the construction of durable roads using localized materials such as natural bitumen. However, using natural bitumen as a binder in pavement construction gave poor performance and hence, the need for its modification prior to application. This study investigated ethylene–vinyl acetate (EVA) as a modifier and optimized its dosage for improved rheological, physical, and mechanical properties of Loda natural bitumen. A D-optimal mixture design coupled with Response Surface Methodology (RSM) was deployed for evaluating the effect of EVA content (1.5–6 wt%) on penetration, softening point, ductility, viscosity, and flash point. Thirteen experimental runs were analyzed using ANOVA to develop predictive and experimentally validated models. The result showed that EVA modification reduced penetration, increased softening and flash points, enhanced ductility, and reduced the viscosity of the base Loda bitumen. Multi-objective optimization identified an optimal composition of 95.6 wt% bitumen and 4.4 wt% EVA, yielding a penetration of 17.95 mm, softening point of 59.79 °C, ductility of 117.32 cm, flash point of 290.25 °C, and viscosity of 2658.22 MPa·s. These results demonstrate that optimized EVA modification significantly enhances Loda natural bitumen, supporting its use in durable pavements and promoting sustainable utilization of local bitumen resources
Comparative Investigation of the Effect of Pulverized Egg Shell and Potato Peel Powder as Additives on Rheological Properties of Water-Based Drilling Fluid
Get PDFThe typical additives applied in mud preparation for oil well drilling usually have detrimental effects on the environment and crew safety. However, additives of biodegradable origin have the capacity to eliminate these effects. This study employed a mixture of two food wastes (egg shell and potato peel powders), which were dried and pulverized as alternative drilling fluid additives. A variety of muds prepared with different quantities of the additives (potato peel powder (PPP) and egg shell powder (ESP)) were subjected to rheological and filtration testing. According to the results obtained, ESP lowers the yield point and filtrate loss by an average of 65 % and 2.2 %, respectively, while increasing plastic viscosity and mud density by 50% and 0.75%, respectively, at higher concentrations. Additionally, the additions were able to lower the pH by one unit. In contrast, PPP demonstrated a decrease of about 50% in each of plastic and apparent viscosities, yield point, and pH, while boosting mud density and filtrate reduction at higher doses. When coupled, ESP and PPP indicated a 25 % drop in plastic viscosity and yield point but enhanced mud density, lowered filtrate, and enhanced mudcake formation at lower concentrations. These findings suggest that while ESP and PPP can change a range of fluid properties, their careful combination in drilling mud formulation has great potential to improve all desirable rheological and filtration features when compared to traditional additives like sodium carbonate and xanthan gum
Eco-Friendly Calcium Nanoparticle Coatings: A Sustainable Strategy for Postharvest Preservation of Food Crops
Get PDFTomato spoilage remains a major postharvest challenge in Nigeria, where poor preservation methods cause 40–50% annual yield losses. This study explored the use of eco-friendly calcium nanoparticles (CaNPs) synthesized from orange peel extract (OPE) as a sustainable coating to extend tomato shelf life. OPE was prepared by aqueous extraction at 60 °C for 1 hour and reacted with 1 mM calcium nitrate (Ca(NO?)2) to produce CaNPs via green synthesis. Colour transition from light to deep golden brown was observed, with UV–Visible spectroscopy showing maximum absorbance at 326 nm and TEM revealing spherical nanoparticles and particle size (72.35–93.34 nm). Fresh tomatoes coated with 0.5 mM and 0.8 mM CaNPs were stored for 28 days at ambient temperature and compared with uncoated controls. Coated fruits retained higher moisture (84.01–84.22%) and showed enhanced crude protein, fat, fibre, and carbohydrate contents. Colour analysis (L*, a*, b*) indicated better retention of brightness, redness, and yellowness. CaNPs coatings effectively preserved nutritional and sensory qualities, reducing water loss and pigment degradation. Using orange peel as a reducing agent valorises agricultural waste and promotes green nanotechnology as a low-cost, biodegradable strategy for reducing postharvest losses and improving food security in developing nations’ economies
Development of Cassava Leaf Disease Detection System using Convolutional Neural Network-Based Zebra Optimization Algorithm
Get PDFCassava is a widely cultivated root crop valued for its starchy tubers and nutritional importance in tropical regions; however, its productivity is severely affected by diseases and pests, resulting in substantial yield losses for farmers. Although recent advances in deep learning offer effective solutions for automated disease detection, challenges related to model accuracy and hyperparameter tuning remain. This study optimizes a Convolutional Neural Network (CNN) using the Zebra Optimization Algorithm (ZOA) for cassava leaf disease detection. A total of 19,620 cassava leaf images were obtained from Kaggle and categorized into four classes: Cassava Mosaic Disease, Cassava Green Mite, Cassava Bacterial Blight, and healthy leaves. Image preprocessing techniques, including cropping, grayscale conversion, and normalization, were applied to enhance training efficiency. The ZOA was employed to optimize key CNN hyperparameters, specifically the number of neurons and dropout rate. The ZOA-CNN model was implemented using MATLAB R2023a and evaluated using false positive rate, specificity, sensitivity, accuracy, and recognition time. Experimental results show that the ZOA-CNN achieved an FPR of 1.11%, specificity of 98.89%, sensitivity of 95.28%, accuracy of 98.12%, and recognition time of 37.70 s, outperforming the conventional CNN. These results demonstrate that the ZOA-CNN improves detection accuracy, reduces false detections, and enhances computational efficiency, making it suitable for real-world cassava disease monitoring applications