Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Stress Relaxation Behavior of Different Varieties of Potato Tubers Under Compressive Mechanical Loading
Get PDFPotatoes tubers obtain several mechanical injuries during its harvesting, handling and storage and the knowledge of the mechanical properties of potatoes is very important for improving these operations. The stress relaxation of three varieties of Benue State-grown potato tubers was determined using the universal testing machine to study the behavior of the named varieties; orange potato, purple potato and white potato tubers under loading. The potato tubers were cut into cubes of 2700 mm3 and the stress relaxation was observed under the application of compressive force. It was observed that the compressive stress at total relaxation across the three varieties of potato ranged from 0.040-0.071 MPa with orange potato having the highest value of 0.071 MPa while white potato had the least value of 0.040 MPa. The compressive strain at total relaxation for the three varieties of potato tubers ranged from 0.00010 to 0.00011 mm/mm. The compressive load at total relaxation for the three varieties of potato ranged from 15.937 to 28.293 N. The compressive extension at total relaxation for the three varieties of potato tubers ranged from 0.0015 to 0.0020 mm. The load at total relaxation for the three varieties of potato tubers ranged from 15.937 to 28.293 N. Extension at total relaxation for the three varieties of potato tubers ranged from 0.0015 to 0.0020 mm. The maximum compressive stress for the three varieties of potato tubers ranged from 0.133 to 0.188 MPa. The compressive strain at maximum compressive stress for the three varieties of potato tubers ranged from 0.0598 to 0.0601 mm/mm. The compressive load at maximum compressive stress for the three varieties of potato tubers ranged from 53.274 to 75.170 N. The extension at maximum compressive stress for the three varieties of potato tubers ranged from 1.196 to 1.202 mm. Load at maximum compressive stress for the three varieties of potato tubers ranged from 53.27 to 75.17 N. ANOVA and Duncan test at 95% confidence level revealed there was no significant difference across the stress relaxation of the three varieties of potato tubers investigated. The data generated on the three varieties of potatoes indicate that it is safe if the various potatoes varieties are packaged and transported together, and that this will not cause any mechanical damage to the potatoes. It can be concluded that the various varieties of Benue grown potato can use the same post harvest processing and handling machines. These data are also important for maximum efficiency in designing equipment for further processing of potatoes and the reduction of its mechanical damage during postharvest operations such as transportation, packaging and storage of potato tubers
Characterization and Experimental Analysis of AA7075 Aluminium Alloy and Rice Husk Ash Reinforced Hybrid Composite
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Improved Energy-Based Efficient Routing Protocol for Underwater Wireless Sensor Networks
No full textUnderwater Wireless Sensor Networks (UWSNs) rely on small, energy-constrained sensors deployed at varying sea depths for applications such as surveillance, environmental monitoring, and data collection. However, high energy consumption and end-to-end delay, exacerbated by dynamic depth and turbidity variations, significantly impact communication efficiency. Existing protocols, such as the Neighboring-Based Energy-Efficient Routing Protocol (NBEER), attempt to optimize energy usage but fail to adapt to these environmental changes, leading to reduced network performance. To address this, an Improved Energy-Based Efficient Routing Protocol (IEBERP) was developed, integrating a Distributed Underwater Clustering Scheme (DUCS) for efficient cluster formation and a Strata Adaptation Scheme (SAS) to dynamically reassign displaced nodes to the nearest cluster head (CH) after depth or turbidity changes. The protocol was simulated in MATLAB (R2024b), and results showed significant performance improvements over NBEER, achieving 9.68 TEC, 81.45 PDR, 46.42 E2ED, 234 NAN, and 35,191 NPR, compared to NBEER’s 12.60 TEC, 78.50 PDR, 53.00 E2ED, 198.30 NAN, and 22,500 NPR. These results highlight IEBERP’s enhanced energy management and adaptive clustering, leading to improved routing efficiency, reduced latency, and higher packet delivery rates. This makes IEBERP a promising solution for reliable and energy-efficient communication in dynamic underwater environments
Effect of Oil Palm Biomass Cellulosic Content on Molecular Structure of Biochar
No full textBiochar is attractive mainly due to its diverse surface functionality bringing the possibility of multipurpose utilization. The purpose of this study was to evaluate the effect of biomass cellulosic content on evolution of molecular structures of biochar. Commercial cellulose, oil palm front, and palm kernel shell were pyrolyzed at 630 °C, and their biochar structures were analyzed using ultimate and proximate compositions, pH point of zero charge, FTIR and XRD. Evaluation of biochar nanotexture based on cellulosic content (100% for commercial cellulose, 39.5% for oil palm front and 20.5% for palm kernel shell) revealed that commercial cellulose decomposed rapidly into non-graphitizing large size crystallites (65 nm) with substantial defects within their graphene sheets. The thermal decomposition mechanism for cellulose and lignin differs: cellulose decomposed rapidly to form O heterocyclic rings before final phase transition to graphene sheets at a much lower temperature, whereas lignin decomposed slowly and begins forming graphene sheets after series of condensation reactions at higher temperatures. Amorphous chars derived from lignin were thermally stable, slowing down the rapid formation of crystallites in biochar from palm kernel shell. Conclusively, highly cellulosic biomass is highly thermally unstable and tends to decomposed into biochar with lower surface functionality compared to biochar derived from highly lignified biomass
Impact of Conductor Slots on Inductance and Efficiency of a Machine
Get PDFThe number of conductor slot and its winding arrangement would always affect the performance of electric machines; this would include effect on its efficiency and inductance profiles, which is indispensable in the accurate prediction of machine’s output values. Similarly, stator and rotor pole selections of PM machines are critical in determining the machine’s output performances. Impact of conductor slot number on machine’s performance indices such as: cogging torque, flux, inductances and torque ripple of a double stator (DS) machine is researched and presented in this study. The study provides a guide to machine designers and operators on the electromagnetic implications of doubling or halving the slot number of a given electric machine. The compared machine types have six (6) and twelve (12) conductor slots; however, with a fixed pole number of fourteen (14), designated as DS 6-14 and DS 12-14, for the six (6)-slot and twelve (12)-slot machine types respectively. ANSYS/MAXWELL-2D software simulation package is utilized in the entire analyses and it is implemented through finite element analysis method. Predicted torque per magnet volume of the DS 6-14 and DS 12-14 machine types at a copper loss of 30 W is 226.56 kNm/m3 and 291.62 kNm/m3 respectively. This implies that it would be more economically viable to manufacture the DS 12-14 machine type than its 6-stator slot counterpart, considering its output torque per magnet volume. It is also revealed that the DS 6-14 configuration has larger inductances and higher quadrature (Q)-axis flux compared to its counterpart, albeit; with higher number of undesirable features such as high cogging torque and torque ripple amplitudes. However, the DS 12-14 machine type exhibits greater value of direct (D) axis flux compared to its equivalent 6-slot machine, in addition to other advantages
Effects of Torrefaction Parameters on the Properties of Brimstone (Morinda lucida) Wood
Get PDFBiomass energy is a possible replacement for the conventional energy due to its environmental effects. However, raw biomass has poor combustible properties which can be enhanced by torrefaction. This research studied the torrefaction properties of brimstone wood as potential energy source. Existing torrefaction device was modified by incorporating a thermocouple and temperature regulator and rectangular reactor was used for the torrefaction of brimstone wood. Harvested samples of the materials were manually processed into smaller pieces and sun dried. The sun-dried samples were crushed and sieved into 8, 10 and 12 mm particle sizes. The sieved samples were subjected to ultimate (Carbon (C), Oxygen (O), Hydrogen (H), Nitrogen (N), Sulphur (S) and energy contents) compositions analysed using standard methods. A 3 by 3 Box Behnken experimental design in the Design Expert 12.0.2 software was used to design the experiment. The influence of heating temperature (220, 260 and 300 0C), heating time (30, 60 and 90 min) and particle size (8, 10 and 12 mm) on the weight of biochar products were studied. Model equations were developed and used to evaluate Biochar Mass Yield (BMY), Energy Yield (BEY) and Energy density (BED) and evaluated based on the heating temperature, heating time and particle size ranges. The data obtained from the experimental design were analysed statistically with Analysis of Variance (ANOVA) at 95 % confidence level. The carbon, oxygen, hydrogen, nitrogen, sulphur and energy contents for brimstone wood were 52.20, 36.88, 2.40, 0.54, 0.89% and 245.89 kcal/100g. R2 values of BMY, BEY and BED were 0.9499, 0.9348 and 0.9990 at P≤0.05 for brimstone wood. Torrefied brimstone wood has been identified as potential sources of energy, with heating temperature and heating time as critical parameters that affect properties of torrefied materials
Assessment of the Level of Quality Control of Cement and Sandcrete Block Materials Available in Maiduguri Metropolis
Get PDFVariations in material properties, such as strength or durability, material defects and substandard materials can affect the structure’s performance. This study assesses the level of quality control of building materials (Cement, sand and blocks) available in Maiduguri Metropolis. Generally, it included the Survey and collection of data of the existing supply markets, samples collection, laboratory tests, and analyses of results were conducted. Observation made from the survey showed that the price of blocks 150mm and 225mm thick range from 450 - 500 naira and 550 - 650 naira respectively. The particle size distribution of the sand sample used in the sand combination shows that the sand fell mostly in zone 2 except one which fell in zone 3 in accordance with Federal Ministry of Works and Housing Design Manual (FMWH). The average dry density of the investigated sandcrete blocks ranged from 1777.10kg/m3 - 2098.67kg/m3. The average compressive strength of the 150 mm thick blocks ranged between 0.12 - 0.45N/mm2. The maximum value 0.45N/mm2 recorded is less than 85% of the recommended minimum strength. The findings on the hydration properties of cement are within the BS 449 standard. The results show that the quality control of the building materials in Maiduguri Metropolis is generally inadequate, with many suppliers and contractors are unaware or failing to adhere to standard specifications and regulations
Modeling and Simulation of a Solar Farm Using Homer Pro Software for University of Maiduguri Senate Complex
Get PDFThe current state of energy insecurity in Maiduguri calls for immediate action to explore and implement alternative energy sources, especially off-grid sources such as solar power, wind power etc. which could provide reliable, cost-effective, and sustainable energy solutions to the town and neighbourhoods. The University of Maiduguri is not an exception, equally faced with electricity disruptions that almost ground down the academic and administrative activities. This study aims at modeling and simulation of a solar farm using HOMER PRO software for University of Maiduguri senate complex to enhance power supply. It involves conducting an energy audit to determine the complex's electrical energy consumption, Prediction of future energy demand using HOMER PRO software, designing a solar farm model based on the energy audit and the predicted energy demand of the Senate Complex using same software. Data collected were analysed and optimised for system sizing. Based on the optimization results, model 1682 Canadian Solar Max Power CS6U-340M, 340 W per panels, 144 lead acid generic batteries rated at 1KW each (totalling 4603Ah) and 2 inverters with a combined capacity of 318kW were designed, which met the annual load demand of the complex (1.03 GWh). This study, if implemented will address the power challenges faced by the Senate complex building, thereby reducing the administrative and academic bottle neck faced by the University
Machine Learning Framework for Predictive Maintenance of Distribution Transformers in Resource-Constrained Power Systems
No full textAging power infrastructure in developing nations faces challenges from increasing demand, renewable integration, and limited replacement capital. Nigeria's grid exemplifies these constraints, with 70% of transformers exceeding design lifetime and 15% annual failure rates causing substantial losses. Traditional time-based maintenance proves unsustainable, while existing predictive frameworks require unaffordable infrastructure. This study developed a lightweight machine learning framework for transformer failure prediction using standard Supervisory Control and Data Acquisition data. Four algorithms- Random Forest, Gradient Boosting, Support Vector Machine, and Long Short-Term Memory networks were compared using 60 months of data from 1247 transformers. Physics-informed feature engineering extracted degradation patterns from voltage, current, temperature, and load measurements. Random Forest achieved optimal performance with 94.7% accuracy, 92.3% precision, and 91.8% recall for 30 to 90 day predictions, representing 62% improvement over threshold methods. The framework identified 87% of critical failures while reducing false alarms by 64%. Economic analysis demonstrates a 260%t return on investment, an 8.3-month payback, and 8.5 billion-naira annual savings. This research proves sophisticated predictive maintenance achieved excellent results in resource-constrained environments without massive investment, offering replicable solutions for developing utilities.  
Numerical Analysis of a Seamless Mild Steel Pole for Low and Medium-Tension Power Transmission Line in Borno State Nigeria
No full textThis work presents a computational method of evaluating structural performance of a seamless mild steel pipe material under various load conditions for supporting low and medium-tension power transmission lines. The low and medium tension power transmission line seamless mild steel (LMTPTL-SMS) pole material was specifically analyzed for reliability and resilience considering the environmental and operational conditions of Borno State, Nigeria. Borno State’s power infrastructure is subjected to significant challenges, one of which is stochastic wind loads due to harsh environmental factors. This threat has led to poles failure resulting in vandalism and power outages. To ensure the reliability and resilience of the power network, a robust pole structural design is critical. In this work a 9.7536m seamless mild steel pole material ASME SA-106 Grade B was selected based on availability and cost for analysis. COMSOL Multi-physics 5.2 numerical code was used to develop and analyze the behavior of the pole material based on predefined loading conditions and on the assumptions of Euler-Bernoulli’s beam-column theory. Using the code’s solid mechanics interface displacement and stress distribution response on the pole when subjected to static, dynamic and aerodynamic loads simultaneously were computed and analyzed at an excitation frequency of 110 GHz. The result shows a frequency response of the transfer function in terms of electric field norm of 3.7 ???? 10−79????????−1 under the predefined loading conditions, which was greater than 8.5 ???? 10−78????????−1 the response established by the manufacturers of the mild steel pipe material. The maximum stress recorded was 8.82????107 ????/???? which is less than the 8????108 ????/???? yield strength of the selected pole material. It was observed that the displacement is from 0???? at the root to maximum value of 0.11???? at the top. The maximum displacement recorded was 0.39m. This value is 22% less than the determined critical displacement of the pole material, which was 0.50m... Thus, the displacement was within the elastic limit of the pole material based on the defined geometry and boundary condition. Furthermore, the F-Test statistical tool used to validate these results with an experimental one carried out shows that there is no significant difference between the two results. Therefore, the analysis established that the selected pole material was reliable under the predefined simultaneously applied extreme loads, thus, the LMTPTL-SMS pole will be suitable for use in Borno State, Nigeria, thus objective of the work was achieved