ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT

Analysis of Normal Radar Signal Based on Different Time-Frequency Distribution Configurations.

2024-12-20T03:27:52+00:00

The electromagnetic environment is becoming more complex, and radar technology is always evolving, as such, a sizable number of contemporary radars with agile waveforms have appeared on the battlefield. Relying solely on traditional recognition models to identify radar signals in electronic warfare systems is a significant challenge. In response to the this problem, this paper proposed an analysis of normal radar signal based on different time-frequency distribution (TFDs) configurations which include Wigner-Ville Distribution (WVD), Windowed Wille-Ville Distribution (WWVD), Filtered Wigner-Ville Distribution (FWVD), Choi Williams Distribution (CWD), and hybrid distributions that combined FWVD and CWD.A two-stage process in other to achieve the aim of this research is presented. The first stage is the modelling and generating a normal (simple) radar signal of pulse-to-pulse constant frequency, while the second stage involved designed of these TFDs and using them to analyse the radar signals. The result showed that most of the TFDs captured the time and frequency parameters of the radar signals modelled around of pulse width (PW) of 1µs, pulse repetition interval (PRI) of 2 µs, center and sampling frequencies of 10 MHz and 40 MHz respectively. Therefore, these TFDs can further be analysed using signal processing and classification tools such as instantaneous power, instantaneous frequency, and machine learning for automatic waveform recognition.

Groundwater Contamination Risk Assessment: Pahs Pollution from Crude Oil Leaching in Ogbia, Bayelsa State

2025-02-09T18:57:02+00:00

Groundwater is the largest reservoir of drinkable water, accounting for approximately 22% of the world’s freshwater. However, regular crude oil spills have resulted in severe groundwater contamination by Polycyclic Aromatic Hydrocarbons (PAHs), which harm human health and the environment. This investigated the presence and concentration of PAHs in groundwater in Ibelebiri in Ogbia, Bayelsa State, Nigeria, following an oil spill, to determine contamination pathways and potential consequences. Soil samples were taken from three locations (L1, L2, L3) and three depths (topsoil, subsoil, and aquifer) and examined for PAHs such as Naphthalene, Acenaphthene, Fluorene, Pyrene, Anthracene, and Benzo(a)anthracene. Laboratory results found that Naphthalene had the highest concentration in all samples, particularly topsoil, whereas heavier PAHs such as Pyrene and Anthracene had lower quantities, notably in aquifer samples. The Leach Pollution Index (LPI) ranged from 81,199.25 to 83,374.10, indicating a high level of contamination potential. Statistical analysis using ANOVA revealed significant variation in the concentrations of lighter PAHs such as Naphthalene (P-value = 0.00059193) and Fluorene (P-value = 0.002376112) between soil layers, while heavier PAHs such as Pyrene (P-value = 0.969122843), Anthracene (P-value = 0.984906863), and Benzo(a)anthracene (P-value = 0.358155023) showed no significant differences across the samples. The findings underline the necessity for focused remediation measures to mitigate groundwater contamination while safeguarding public health and environmental quality.

Characterisation of Rice Husk and Wood Ash as Constituents for Production of Phosphorus and Potassium

2025-02-09T19:23:25+00:00

This study investigated the potentials of rice husk and wood ashes from various species (Mahogany, Iroko and Mghelina) as sustainable sources of phosphorus (P) and potassium (K). The raw rice husk sample was obtained from Dala rice mill while different wood species such as Mahogany, Iroko and Mghelina, were obtained from Baga road timber shade both in Maiduguri, Borno State. Both raw materials were carbonized at different temperatures ranging between 350-750°C respectively. The laboratory analysis of the ash samples was conducted using atomic absorption spectrophotometer (AAS) to determine the presences of K, and P. The result shows that rice husk ash contains a mean value in terms of mg/100g of K2O (3.593) and P2O5(1.382). Also, Mahogany wood ash contains 4.48mg of K and 0.55 mg of P. Similarly, Iroko wood ash was found to consist of 5.14g of K and 0.56g of P. In addition to Mghelina wood ash(Beech wood), it was found that compounds present has a mean values in terms of g/100g of K (10.4) and P (0.96). It is noteworthy that P was highest in wood ash (mghelina) amongst the materials tested. Therefore, the presence of these compounds in wood and rice husk ashes could be a potential low-cost resource for the production of inorganic fertilizer.

Rheological Properties of Malted and/or Fermented Faro 44 Rice Plus Soybean-Based Complementary Foods

2025-02-09T19:59:24+00:00

High nutrient density foods are required by infants for optimal healthy growth. This can be achieved by an established food processing technology. So, the study investigated the rheological properties (concentrations, stress or shear rate, viscosities or consistency indices, activation energies, frequency factors) of rice-based formulated food products as affected by either malting and/or fermentation. FARO 44 rice cultivar was processed, and different flours obtained were further formulated with processed soybean (Glycine max) flour. In each of those mixing ratios, 16% protein (PAG’s recommendations) was obtained by a material balance equation. A digital viscometer was used to measure the viscosities of the gruels at levels of 4 concentrations, 4 shear rates and 6 temperatures. Subsequently, the Power law fluids model, Arrhenius kinetic type equation, and linear regression analysis (at levels of 4 concentrations, 4 shear rates and 6 temperatures) were employed to generate the rheological parameters of the gruels. Results showed that viscosity decreased with an increase in temperature within the 30 - 80 ^oC range studied and shear rate (6 - 60 rpm.) but increased with an increase in concentration (5 - 20%) of gruels. Regardless of temperature or concentration, the consistency indices (1.68 to 714.32 Nsnm-2) of gruels, and their respective flow behaviour indices (n) and activation energy ranged from 0.01 to 0.43 and 5.25 to 36.97 kJ/mol. All formulated products exhibited pseudoplasticity and sensitivity to temperature change. Malting and/or fermentation showed a significant (p < 0.05) reduction in viscosities and revealed that it can be used to increase the nutrient density required by infants.

Performance of Concrete Using Metakaolin as Cement Partial Replacement Material

2025-02-09T20:32:06+00:00

Concrete, due to its versatility and ready availability, continues to be of great importance around the world, and with the increasing need for shelter, the force pulled by construction activity brought about the high demand for construction materials and a devastating effect on the environment due to the activities from the raw materials needed in the production of cement and concrete. This research investigates the effect of metakaolin as a partial replacement of cement for concrete production. Cement was partially replaced by metakaolin at 5%, 10%, 15%, 20%, 25% and 30%. A constant water/binder ratio of 0.50 was used. The parameters investigated include the chemical composition of metakaolin, setting time, workability, density, compressive strength, split tensile strength, and flexural strength. The results showed that metakaolin is a good pozzolan with combined SiO2, Al2O3 and Fe2O3 to equal 92.89%. The results from the test show that the inclusion of metakaolin increased the setting time of cement metakaolin paste and resulted in the workability reduction of concrete as partial cement replacement with metakaolin increases. This research reveals that partial cement replacement with 0% and 10% MTK in concrete both gave an average compressive strength of 28.9 N/mm2, at 28 days. Meanwhile, the highest value for compressive strength obtained at 90 days is 34.8 N/mm2, which was at 10% replacement with MTK. The result shows that metakaolin (MTK) has a pozzolanic effect, considering the strength activity index and improved compressive strength, split tensile strength and flexural strength of concrete. The optimum cement replacement was 10% metakaolin, which performed better than the control concrete. At later stages of curing, 15% also shows promising results. When metakaolin is calcined, it is expected to undergo pozzolanic reactions with cement hydrates, forming secondary Calcium Silicate Hydrate (C–S–H), which aids strength development. It can be concluded that metakaolin is a suitable material for partial replacement of cement up to 10%. Thus, using MTK as a partial replacement for cement in concrete at a lower replacement volume will reduce cement usage, production costs, and environmental pollution from cement production.

Effect of Binders on The Performance of Charcoal Briquettes Produced from Selected Biomass

2025-02-09T21:22:52+00:00

Globally, renewable resources are widespread which has comparatively little pollution emission effect on the environment. This study was conducted to assess the potential impact of different binders in the production of charcoal briquette using mango leaves, black plum leaves and rice husk as biomass. The organic binder materials used are cow dung, ficus citrofolia (durumi) and okra (butt) while the inorganic binder used was clay. Thus, the mix ratio adopted in the study are 1:1 and 1:2 (biomass:binder). In addition, some of the parameters such as bulk density, moisture content in dry basis, compressive strength, ash content, volatile matter and calorific value were determined to identify the briquettes with highest integrity. The results show that briquettes produced from black plum leaves with clay as binder had the highest density of (1.587g lcm3 and 1.574glcm3) and lowest moisture content of (0.56% and 0.57%) and highest compressive strength of (4.45N/mm2 and 3.90N/mm2) from both mix ratios. Similarly, briquette produced from black plum leaves with okra as binder had the lowest ash content of 2.1% for both mix ratios. However, briquettes produced from black plump leaves with durumi and that of rice husk with durumi as binders yielded highest volatile matter of 36.5% and 37.2% respectively. It is noteworthy that the highest heating values of 33.81mj/kg and 28.43mj/kg was observed in briquettes produced using mango leaves with clay as binder from a mix ratio of 1:1 and 1:2. Furthermore, the lowest heating values of 15.94mj/kg and 16.27mj/kg were observed from briquettes obtain from rice husk with cow dung as binder from both mix ratios. Therefore, it is evident that clay is a better binder for briquette production with significant combustion property, which is cost effective and readily available for both domestic and small-scale commercial purposes.

Impact of Conductor Slots on Inductance and Efficiency of a Machine

2025-02-09T22:26:16+00:00

The 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.

Development of a Pipe Leakage Detection with Simulated Acoustic Model for Water Distribution System

2025-02-10T09:14:08+00:00

The paper presents a method for detecting pipe leakage in a water distribution system using a simulated acoustic model. The study utilized Particle Swarm Optimization (PSO) to determine the optimal position for the leakage point in relation to the sensors. The objective function was created, and time delays were optimized using PSO simulated via MATLAB. The analysis focused on examining both vertical and horizontal flow configurations. The system was calibrated, data was extracted, and it was utilized for leakage automation. The study found that the optimal leakage point is 10.12 cm, measured to the left sensor1 in the horizontal configuration with a 0.02 second time delay. The second leakage point in the horizontal configuration has a time delay of 0.05 seconds, while the third point has a delay of 0.08 seconds. Eight false alarm frequencies were detected in the water flow and no leakage mode, with 100% of the false alarms indicating no flow or leakage. The system false alarm disappears when the system is pressurized for a long period of time. The study demonstrates the importance of detecting pipe leakage in water distribution systems using a simulated acoustic model in rural areas, developing countries, and small and medium-sized industries.

Design and Analysis of Flight Performance of a Hybrid Energy Source for Unmanned Aerial Vehicle

2025-02-10T09:41:11+00:00

This study presents a hybrid energy harvesting system for Unmanned Aerial Vehicle (UAV), that integrates solar power and hydrogen fuel cells to enhance flight performance. The study commenced with the analysis of the case study UAV flight power design specifications using analytical methods. the estimation of number of solar cells and the hybridization of the solar and hydrogen fuel cells. A Computer Aided Design (CAD) model of the solar cell arrangement is created using industrial software which enables the visualization of the arrangement on the wing in a virtual environment. The mission performance analysis was carried out using Excel tool and Matrix Laboratory (MATLAB). The redesigned system increased available power to 580 Watts with a weight penalty of 1.5 Kg thereby reducing the payload mass from 4.627 kg to 3.085 kg. To assess the structural implications of this result, a stress analysis was performed using Computer Aided Three-dimensional Interactive Application (CATIA) and Abaqus software which revealed a negligible failure index of 0.000757. The hybrid system achieved a 120% increase in power that extended the endurance from 4.2 hours to 16.3 hours and the range from 6 km to 230 km. The design offers a promising solution for enhanced UAV performance.

Effects of Torrefaction Parameters on the Properties of Brimstone (Morinda lucida) Wood

2025-02-10T10:14:08+00:00

Biomass 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.

Solidworks Modeling of Mechanical Strength of an Optimum High Pressure A360 Die Cast

2025-02-10T18:01:30+00:00

In this study, SolidWorks modeling was utilized to analyze the mechanical strength of high pressure A360 die castings. The model incorporates all necessary factors, such as material properties and design features, to accurately predict the tensile strength and flexural strength of A360 die cast components. From the input data, a statistical analysis was performed to identify key factors that affect the mechanical strength of the die cast materials. These factors were then used to build a regression model that accurately predicts the mechanical strength of the materials. By simulating various stress and strain scenarios, this research provides an in-depth understanding of the material's strength and its behavior under different loading conditions. The results showed that the maximum tensile stress of 13.401 MPa was recorded on application of 1000 N tensile load. The maximum elongation associated with 1000 N tensile load was 0.0139 mm. The maximum stresses due to concentrated and distributed 1000 N flexural loads were 66.820 MPa and 43.506 MPa respectively. The maximum deflection of 0.0527 mm was recorded due to concentrated flexural load of 1000 N and the maximum deflection due to distributed flexural loading of 1000 N/mm was 0.0371 mm. The results of this study can be used to optimize the design process of high pressure A360 die cast components, leading to improved performance and increased reliability. This will greatly aid in the design and manufacturing process, allowing for optimized designs and improved product performance. This study serves as a valuable resource for engineers and manufacturers looking to optimize the mechanical strength of their high pressure A360 die castings.

Development of Plaster of Paris (Pop) From Gypsum Deposits of Fune - Yobe State, Nigeria by Calcination Process

2025-02-10T18:25:17+00:00

Gypsum is a common sulfate mineral which has significant commercial value mostly made up of hydrated calcium sulphate. over dependence on foreign/imported POP into the country is in the high rise, local economy is affected and local miners are not patronized. Thus, the study produced and characterized POP from Fune Local Government Area of Yobe State- Nigeria (Alangefe deposit site). The Gypsum sample was collected at three layers of 0.5m each after excavating the top soil. The samples were beneficiated and calcined at the Civil Engineering Laboratory of Eighteenth Engineering Company at 1700C. Porosity, shrinkage, compressive strength and density tests were carried out on these samples. The gypsum collected were processed and characterized with the sample having porosity of 53.37% on the average, 0% shrinkage, compressive strength of up to 23.03N/mm2 and 21.04N/mm2, density of 0.91g/cm2 and 1.01g/cm2. Water:POP ratio of 80-100:100 gave the best results. The properties of the characterized POP from Fune (Alangefe) mining site had excellent properties as compared with the POP obtained in the market. Thus, the produced POP can replace the ones being sold in the market in terms of availability and its properties.

Compressive Strength Assessment of Metakaolin Hollow Sandcrete Blocks

2025-02-10T18:41:07+00:00

This study examines the effect of partially substituting metakaolin (MK) for cement on the hollow sandcrete block’s compressive strength. Sandcrete hollow blocks measuring 225 x 225 x 450 mm were made using a 1:6 mix ratio, which is one part cement to six parts fine aggregate (sand). The study was carried out by partially replacing metakaolin with cement at 0% to 35% at 5% intervals to assess the impact on the hollow sandcrete block’s strength. The blocks were cured using the sprinkling method, and compressive strength tests were conducted on the hollow sandcrete block samples at 1, 3, 7, 14, 21, and 28 days. The compressive strength of hollow sandcrete blocks samples ranges from 3.65 N/mm2 to 0.86 N/mm2. The compressive strength results showed that the optimum percentage of metakaolin (MK) replacement by weight of cement was 10% having a strength of 3.65 N/mm2 after 28 days of curing. These value meets the stipulated requirement specified by Nigeria Industrial Standard NIS 87 (2000), BS 6073, and National Building Code (2006) and are adequate for usage as non-bearing and load-bearing structures in areas where moisture infiltration may occur. The research was aimed at using metakaolin (MK) as a partial replacement of cement in the production hollow sandcrete blocks to curtail the reduction of cement components by block producers to produce low-quality sandcrete block for structural purposes and improve the strength properties of blocks in terms of its production.

Evaluation of Noise Levels in an Urban Market, Federal Capital Territory, Nigeria

2025-02-10T19:13:41+00:00

This study assessed noise pollution levels in and around Gwagwalada urban market and the likely effects on human health. Measurements of noise level were done using sound level meter (Smart Sensor Model AR854), at ten (10) selected points, whose coordinates were predetermined. The measurements were carried out at different times of the day (6-8am, 1-3pm and 5-7pm) for five (5) days, i.e. two traditional and three non-traditional market days. The data obtained were used to assess the variation in temporal and spatial noise level in and around the market, as well as the difference in noise level between the traditional and non-traditional market days, using ANOVA and t-test statistical tools. Results showed that highest noise level were generated in the evening hours (5-7pm) and the analysis of variance (ANOVA) in noise level at the different times showed significant variation at F(2) = 13.982, P≤0.05. Spatially, points PCC and AIS had the highest mean noise level of 84.64dB and 81.38dB, respectively and were higher than NESREA and WHO permissible limits. The ANOVA test for spatial noise level in the selected locations showed significant spatial variation with F(9) = 6.029, P≤0.05. Furthermore, paired t-test in the analysis of noise level between traditional (70.28 ± 10.15dB) and non-traditional (66.16 ± 8.28dB) market days, showed statistically significant difference at t(9)=2.766, P≤0.05. The high noise levels were due to sounds from power generators, use of sound amplifiers for product marketing among others. Noise pollution poses significant health risk and there is need to monitor and control noise level in and around the market, through the combined efforts of government, professionals and citizens. Additionally, there should be periodic assessment of the health status of traders in Gwagwalada market.

Evaluation of Performance Against Contractors’ Tender Position on Selected Public Construction Projects

2025-02-10T19:52:16+00:00

Previous studies have investigated tendering of construction projects and project performance in silos. This study examines project performance of contractors, based on their tender positions as perceived by clients. Quality and speed of delivery of construction projects formed the study remit. A questionnaire was administered to selected public clients (Federal Ministries and Departments). Responses received were analyzed with aid of simple means and percentages. The analysis showed that 76.92% of tenders submitted were below the mean tender sum. Similarly, 23.08% of the tenders were above the mean Tender sum. Further examination revealed that 23.08% of projects were completed at costs significantly higher than the original contract price. Accordingly, 80.77% of the contractors delivered their projects within the contract price. Inadvertently, clients’ rating of the performance of contractors showed that their projects were delivered within budget at final accounts, with performances below average as Clients disapproved the quality and speed of delivery by such contractors. On the other hand, contractors whose projects overran their budgets were rated above average in terms of performance and delivery quality. The mean tender sum was recommended as the most important benchmark for clients in early projects decision at tender.

The Impact of Stator Tooth and Pole Combinations on Output of a Dual Stator Electric Machine

2025-02-11T18:16:35+00:00

Abstact

Effect of Particle and Fiber Loading on Tensile, Flexural and Impact Properties of Hybridized Balanite Shell Particles and Palmyra Fiber Reinforced Epoxy Composite

2025-02-11T18:44:13+00:00

The new trend of using natural fibers and fillers has greatly improved the formulation of composites. It has been established over the years that natural fibers and fillers have the required characteristics to reinforce polymers. In this study, Palmyra fiber and Balanite shell particles were used to reinforce epoxy C28H3002. Palmyra fiber and Balanite shell particles together formed the reinforcement having equal weight percentage of 50:50. The particle size of the Balanite was 150µm while 90 mm length of the Palmyra fiber was utilized. The compounding ratio of reinforcements to epoxy was 10:90, 20:80, 30:70, 40:60 and 50:50 respectively in order to see the effect of reinforcements loading of the Epoxy on the hybrid composite’s mechanical properties. Palmyra fiber was treated with 5% NaOH solution before compounding in order to improve fiber-particle matrix adhesion. The composite was formulated based on the mixing plan using hand lay-up method which was followed up by a compression molding operation at 2.5 MPa of pressure in order to have good compaction of the composite and further matrix distribution. These formulated composites were named Balanite Palmyra Epoxy (BPE), that is, BPE1, BPE2, BPE3, BPE4 and BPE5 with the numbers describing weight percentage loading of reinforcements of 10, 20, 30, 40 and 50 respectively. Characterization of the composites were done to determine their tensile strength, flexural strength and impact strength. Scanning electron microscopy (SEM) was also carried out in order to know the interaction of the matrix and reinforcements. BPE3 with 30% reinforcement was found to have had the highest tensile strength of 52.99 MPa from 30 MPa of the pure Epoxy, resulting in 44% improvement of the tensile property of the matrix with elongation at break gradually dropping with material loading as a result of reduced flexibility of the matrix resulting from interruptions of its extension by the reinforcements; impact strength of 0.494 J/mm was obtained which gave about 63% improvement of the matrix. BPE2 with 20% reinforcement gave the highest flexural strength of 141.2 MPa and presented an improved flexural property of the matrix by 34%. Tensile modulus increased with reinforcements loading while flexural modulus dropped after 20% loading mainly because of the brittle nature of the matrix. The properties obtained from the hybrid composite make it suitable for low to medium load applications.

Stress Relaxation Behavior of Different Varieties of Potato Tubers Under Compressive Mechanical Loading

2025-02-11T19:06:14+00:00

Potatoes 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.

Optimization of Arc Welding Parametric Influence on Mechanical Properties of Dissimilar Metals

2025-02-11T19:31:15+00:00

Welding dissimilar metals require technical expertise to achieve moderate cost, quantity, and quality, but selecting the right parameters is challenging due to various operating conditions. The paper optimized welding process parameters for two dissimilar metals, INCONEL 625 and GL E360, focusing on mechanical properties like tensile strength and hardness. The welding process parameters were optimized using Gas Metal Arc Welding power sources, Flux Cored Wire Electrode (FCWE), design experts, and response surface methodology, and tensile strength and hardness tests were conducted. At the anticipated optimal process welding parameters of 52.86 m/s welding speed, 5.28 m/min welding feed rate, and 23.16 volts, three confirmation experiments were carried out. The study revealed that the tensile strength and hardness of the welding process significantly influenced response variables, ranging from 380 MPa to 500 MPa. The most noticeable effect was observed at a welding speed of 52 m/s, a feed rate of 5.6 m/min, and a voltage of 26 V. The empirical model's tensile strength and hardness were validated using experimental results, and the software predicted 53 welding speed, 5 welding feed rate and 23 voltages. The welding process parameters significantly impacted tensile strength and hardness, while the welding feed rate parameter had the least impact on both.

Retrofit Design of Heat Exchanger Networks for Kaduna Refinery’s Vacuum Distillation Unit

2025-02-11T20:01:41+00:00

Effective Heat Exchanger Network (HEN) design is pivotal for improving energy efficiency and realizing substantial cost savings in chemical and petrochemical sectors. While contemporary refineries reap the benefits of economical HEN designs, there is an urgent need to enhance the utility and cost-saving features of aging refineries. These older facilities often suffer from suboptimal designs, characterized by high energy requirements and limited cost savings. To address this issue, a thorough analysis of HEN design and retrofit options is essential. The pinch design approach standout as a preferred tool for retrofitting HENs due to its physical insight and ease of application. In this study, based on pinch technology (PT), various retrofit design scenarios (re-sequencing, addition of heat exchangers, and area addition) were explored for improving the HENs of the refinery section’s vacuum distillation unit (VDU). The study revealed that the base case design achieved a Total Annual Cost (TAC) of $1.738 × 106. Significant cost savings were attained through re-sequencing, addition of area, and addition of a new heat exchanger, amounting to $439.5/year, $746.6/year, and $33,810 respectively. These retrofit strategies are exceptional in reducing utility demand and improving operating cost savings. However, they required a substantial capital expenditure of $1,733, $3,191, and $167,100 respectively, with payback periods of 3.9, 4.3, and 4.9 years respectively. Therefore, it is critical to explore additional retrofit possibilities to further optimize cost savings.

Effects of Ergonomic Intervention Approach on Some Occupational Hazards in Automobile Workshop in South Western Nigeria

2025-02-11T20:49:40+00:00

Automobile workshops house the auto-mechanic, auto-electrical, painting, and panel-beating units. Activities carried out in these units expose the workers to some occupational hazards and some musculoskeletal risk factors with perceived consequences on their health. Therefore, this study assessed selected automobile workshops within southwestern Nigeria to establish the prevalence of ergonomic hazards. A sample size of 496 auto-repair workshops (auto-mechanic, auto electrical, painting, and panel-beating units) was randomly considered. Data was collected using observation, interaction, and structured questionnaires. The structured questionnaires were administered to the respondents to seek their demography and occupational hazards information. Standard weighing scale and stadiometer were used to collect the weights and status of the respondents, respectively. Some of the common hazards identified in the auto-repair workshops are poor workstation design, poor equipment and tool layout, noise, wet floors, poor lighting, and an unguarded working area, which often lead to slips, trips, and falls, muscle strains, equipment accidents, overexertion injuries, and scald injuries, among others. Common occupational risk factors in different workstations across the workshops visited were identified and ranked to establish their prevalence as non-usage of personal protective equipment, PPE, awkward posture, repetitive motion, repetitive manual tasks, and exposure to sharp objects. However, panel beaters (55%) and auto-mechanic technicians (49%) have the highest percentage of people who are normal weight, while painters (62%) and auto-electricians (38.5%) have the highest percentage of people who are above normal weight. Quick Exposure Check, QEC results showed that lower back pain and neck pain are the most prevalent musculoskeletal disorders (MSDs) and are majorly caused by awkward posture at work in an auto-repair workshop. According to this study, vehicle repair professionals were exposed to a variety of risks and hazards, with the lower backs of the workers being the most severely impacted. Auto-mechanical technicians in auto-repair workshops are most at risk.

Analytical Study of Single- And Double-Layer Coating System for Controlled Drug-Releasing Orthopedic Implants Using Differential Transform Method

2025-02-11T21:14:05+00:00

The analytical study of single- and double-layer coating system for controlled drug releasing orthopedic implants using differential transform method has been presented. Drug release when transported across single- or double-layer boundaries have the potentials of smart fluid properties which can be controlled by various parameters. In the present study, the developed governing model for single- or double-layer coating system for controlled drug-releasing orthopedic implants is a set of coupled partial differential equations for the unsteady diffusion processes with intractable solution. Hence, the solution was obtained with Differential Transform Method and was validated with both Runge-Kutta Order four numerical scheme and experimental results. Good agreement was established among them. The effects of thickness ratio, diffusion period, porosity term, and effective diffusion coefficient on concentration profile are investigated. From the obtained results, it was observed that increase in the interface layer thickness ratio d of 0.2 to 0.8 resulted in decrease from 1 to 0 (zero) in the concentration profiles for all the different dimensionless durations considered. In addition, augmentation of two (2) layers of varying thickness ratio from d = 0.2 to 0.8 in the release parameter resulted in a decrease in the concentration profile to 0 (zero) for the three cases of thickness ratios. The studies show that effective diffusion coefficients for a period of five (5) seconds increases from 0 to 100% is the dominant parameter in the model and so provides considerable flexibility for design process. Hence, the developed model and the obtained solutions provide the benchmark for the optimized and enhanced control of drug-releasing orthopedic implants.

Design, Construction and Performance Evaluation of a Manual Cum Motorized Orange Juice Extracting Machine

2025-02-11T21:34:07+00:00

A manual cum motorized operated juice extractor was designed and fabricated using locally sourced materials. Polytetrafluoroethylene (PTFE) a synthetic fluoro polymer was used in the construction of the screw shaft and stainless steel for the extraction chamber. Rotational motion needed by the screw shaft to compress and transport the fruits was supplied both manually cum motorized to the machine through a handle and electric motor device of 10w because this has capacity to handle the performance operation. The screw shaft crushes, squeeze and facilitate the movement of residues to the waste outlet while the juice passes through the screen to the juice collector. Tests were carried out to investigate the performance of the machine on the basis of juice yield, extraction efficiency and extraction loss. The fruits were washed and weights (1kg, 1.5kg and 2kg respectively) of fruit slice (8 and 16 slices) were then processed using the extractor to extract the Juice. The juice yield, extraction loss and extraction efficiency were determined by standard Formula and methods. Maximum juice yield of 64.6 % extraction efficiency of 68.2 % and Corresponding extraction loss of 7.05 % were obtained from the 16 slice lengths orange fruits were used for the test. The juice produced from the extractor was of good quality which further proves the effectiveness of the extractor. The manual fruit juice extractor is cheap(N48770), durable and cost of operation is low while motorized juice extractor is faster in terms of operation or extraction efficiency and extraction loss, and also it could be used by an average Nigerian household and small-scale farmers.