FACULTY OF ENGINEERING

This research explores the effect of using Waste Glass Powder (WGP) as a partial substitute for cement in concrete production. The study focused on identifying optimal WGP replacement levels that achieve comparable or improved strength, maintain
workability, and ensure structural integrity. A comprehensive experimental program was conducted to evaluate key concrete properties, including compressive strength, water absorption, sieve analysis and workability. Waste Glass Powder (WGP) was sourced, crushed, and ground into a fine powder .A control concrete mix was prepared using Portland Limestone Cement (PLC), fine and coarse aggregates, and water. Cement was replaced with WGP at 5%, 10%, 15%, and 20% by weight, and the concrete was mixed thoroughly. Concrete samples were casted in standard molds and cured for 7, 14, and 28 days. The samples were then tested for compressive strength, water absorption, and workability using the slump test. After 7,14 and 28 days of curing, the results of the study indicate that incorporating Waste Glass Powder (WGP) at low replacement levels (5% and 10%) resulted (19.06 and 15.64) at 28 days, having a minimal impact on the mechanical performance of the concrete, with compressive strengths at these levels being comparable to, or only slightly lower than, the control mix. However, higher replacement levels (15% and 20%) resulted (15.14 and 10.88) at 28 days, in significant reductions in both compressive and flexural strengths were observed, as well as an increase in water absorption, due to the increased porosity and altered microstructure caused by the finer nature of WGP, which has a lower specific gravity than ordinary Portland cement. Slump test results also showed improved workability with higher WGP content, but excessive replacement could compromise the concrete's structural integrity. Overall, the study concludes that WGP can be a viable partial cement replacement, with optimal performance at 5–10% replacement levels, and suggests further research on optimizing mix designs using chemical admixtures and conducting long-term durability studies in various environmental conditions.

This study focuses on evaluating the relationship between destructive and nondestructive testing methods for predicting the in-situ compressive strength of concrete. The main aim is to develop a reliable regression-based model capable of estimating concrete strength using non-destructive approaches. The study specifically examined Grade 20 (C20) and Grade 25 (C25) concrete to determine the correlation between rebound hammer results, and conventional compressive strength tests. The experimental procedure involved casting and curing concrete cubes and beams in the laboratory under controlled conditions. Both destructive tests (compressive and flexural strength) and non-destructive tests (rebound hammer) were carried out at curing ages of 7, 14, and 28 days, following BS EN 12390-3:2019, ASTM C39, and BS EN 12504- 2:2012 standards. Rebound hammer readings were taken before compression tests on each specimen to establish a correlation between rebound number and actual strength. The data obtained were analyzed statistically using regression techniques to develop predictive models capable of estimating compressive strength from non-destructive test results. The findings revealed that compressive and flexural strengths increased consistently with curing age for both concrete grades. At 28 days, C20 achieved an average compressive strength of 20.16 N/mm², while C25 reached 25.15 N/mm², aligning with their design targets. Rebound hammer values showed a strong positive correlation with destructive test results, with a prediction accuracy of about ±5%. The study concludes that properly calibrated non-destructive methods, particularly the rebound hammer tests, can effectively predict the in-situ compressive strength of concrete. This approach provides a cost-effective, rapid, and non-invasive means for quality control and structural assessment in modern construction practice.

The growing global demand for renewable energy has driven significant advancements in solar energy technology, particularly in photovoltaic (PV) systems and inverters, which convert solargenerated DC into usable AC. Despite progress, traditional inverters face challenges such as inefficiency, high harmonic distortion, and limited adaptability to dynamic environmental conditions.This project aims to design a microcontroller-based solar inverter that integrates
advanced control algorithms like Maximum Power Point Tracking (MPPT) and Pulse-Width Modulation (PWM) to enhance efficiency, reliability, and adaptability. By leveraging modern microcontroller technology, the project seeks to improve energy conversion, reduce costs, and address the limitations of conventional designs, contributing to the broader adoption of solar energy systems. The process begins with modeling the photovoltaic (PV) array using Simulink’s Simscape Electrical library, incorporating real-world parameters such as irradiance and temperature to simulate I-V and P-V curves. The MPPT algorithm, specifically the Perturb and Observe (P&O) method, is implemented to optimize power extraction under varying conditions. PWM is generated using a PID controller to regulate the DC-DC boost converter, which steps up the PV voltage. An H-Bridge inverter, controlled by Sinusoidal PWM (SPWM), converts the boosted DC into a clean AC waveform. The complete system integrates the PV array, MPPT, boost converter, and inverter, with simulations conducted to validate performance under diverse environmental and load conditions. This project successfully designed and simulated a microcontroller-based solar inverter system. The PV array, modeled under varying irradiance and temperature conditions, consistently generated around 5300W, operating near its maximum power point. The boost converter efficiently stepped up the PV voltage to 275.1V with over 90% efficiency, while the H-bridge inverter produced a clean 220V AC output with minimal harmonic distortion. System integration demonstrated robust performance under diverse environmental and load conditions, achieving an overall efficiency exceeding 90%.

The essence of this project lies in the creation of a prototype that serves as an educational tool, offering a tangible insight into the world of offshore logistics. This prototype, a scaled -down version of a Platform Supply Vessel (PSV), is designed to mimic the functionalities of a real PSV. The highlight of this educational resource is its physical design. The prototype features a distinctive hull design and bow shape, mirroring those of a real PSV. These elements not only add to its visual appeal but also play a crucial role in optimizing performance. Thus, This prototype stands as a unique innovation in the realm of educational resources for offshore logistics.

Accurate estimation of Stock Tank Oil Initially in Place (STOIIP) is essential for effective reservoir management and production planning. This study validates geological STOIIP estimates through the Material Balance (MBAL) method, comparing it with the volumetric approach to evaluate their reliability. The research focuses on Reservoir Q, which spans 1,000 acres, has a thickness of 75 feet, and an estimated oil volume of 105 million stock tank barrels (MMSTB). A comparative analysis of both methods showed no significant differences, with STOIIP estimates of 102 MMSTB and 105 MMSTB, respectively, being nearly identical. This consistency enhances confidence in the accuracy of geological reserve assessments and supports improved reservoir performance optimization and hydrocarbon recovery strategies. The study underscores the importance of MBAL as a validation tool to reduce uncertainties and enhance resource estimation. These findings contribute to the advancement of petroleum engineering methodologies by demonstrating the effectiveness of MBAL in verifying geological STOIIP estimates. The research also highlights the necessity for ongoing reservoir monitoring and data integration to enhance decision-making in field development and maximize hydrocarbon recovery.

Water-logged soils are a persistent challenge in geotechnical engineering, especially in tropical regions where high rainfall and poor drainage lead to saturated ground conditions. These soils typically exhibit low shear strength, high compressibility, and poor load-bearing capacity, making them unsuitable for construction without prior treatment. In this study, bamboo ash, especially bamboo leaf ash (BLA), was assessed for its ability in improving soil strength, reducing permeability, and enhancing durability. Soil samples were collected from water-logged areas and classified using standard geotechnical tests. These soils fell under the category of high-plasticity clays or silts, which are prone to swelling, shrinkage, and settlement. Bamboo leaves were collected from a local source market. The bamboo ash was mixed with soil in varying proportions of 2%, 4%, 6%, 8%, and 10% by weight. The mixture was thoroughly blended and compacted using standard procedures. Tests that were carried out include Atterberg Limits test to assess changes in plasticity and consistency; compaction tests to determine optimum moisture content (OMC) and maximum dry density (MDD); and California Bearing Ratio to evaluate load-bearing capacity. The results showed that bamboo ash significantly increases shear strength, especially at an optimal content of around 4% to 6%; the plasticity index decreases, indicating better dimensional stability and reduced swelling/shrinkage behavior; and CBR values improved, making the soil more suitable for subgrade and foundation applications.

The components of bio-waste are particularly abundant in essential minerals like calcium and potassium, which are essential for the manufacture of effective biocatalysts for biodiesel. This study evaluated the potential of bio-based heterogeneous catalyst of fused cockle shells and watermelon peels for the transesterification of waste vegetable oil. At 900°C and 500℃, the waste materials were dried, calcined, and carbonized, respectively. In order to evaluate the compositional, morphological, structural, and thermal features of both the catalyst and the precursor materials, they were both characterized. The Box-Behnken design was utilized to generate 29 experimental runs to examine the impact of operational parameters such catalyst loading, temperature, methanol-to-oil molar ratio, and reaction time. The presence of basic (calcium and potassium) and acidic oxides (silicon and nickel) demonstrated that the catalyst was bifunctional. The catalyst's surface area (105.35 m2 /g) and pore volume (0.60 cm3 /g) obtained from the BET analysis contributed to a 91.77% biodiesel yield at 63.34 °C reaction temperature, 149.41 min reaction time, 1.05wt% catalyst loading, and a 14.45:1 methanol to oil ratio. The physicochemical parameters of the biodiesel produced were measured and determined to be acceptable according to the European National (EN) and American Society for Testing of Materials (ASTM) quality standards, demonstrating the product's suitability for use as fuel.

To understand the popularity of electric vehicles circa 1900, it is also important to understand the development of the personal vehicle and the other options available. At the turn of the 20th century, the horse was still the primary mode of transportation. Steam emerged as a reliable energy source with a proven track record, notably powering factories and locomotives. In the late 1700s, steam also played a role in some of the earliest self-propelled vehicles. However, despite its early adoption in various applications, it wasn't until the 1870s that steam technology began to gain traction in the automotive industry. One significant reason for the delayed adoption of steam technology in cars was its impracticality for personal vehicles. Steam-powered vehicles faced several challenges that hindered their widespread use. For instance, they required considerable startup times, often up to 45 minutes, particularly in cold conditions. Additionally, steam vehicles needed frequent refilling with water, which imposed limitations on their range and practicality for everyday use. These drawbacks underscored the challenges associated with steam-powered cars and contributed to their eventual decline in favor of alternative propulsion methods, such as internal combustion engines and electric motors, which offered greater convenience and efficiency for personal transportation. As electric vehicles came onto the market, so did a new type of vehicle, the gasoline-powered car thanks to improvements to the internal combustion engine in the 1800s. Although gasolinepowered vehicles had potential, they were not without problems. They took a lot of human labor to operate because shifting gears was a difficult operation, and starting them required turning a hand crank, which some drivers found challenging. Gasoline-powered vehicles were also notorious for their noisy engines and nasty exhaust. (TOTAL ENERGIES, 2020) In contrast, electric cars did not suffer from the issues associated with steam or gasoline vehicles. They were quiet, easy to drive, and did not emit the noxious pollutants characteristic of other cars of the time. Consequently, electric cars rapidly gained popularity among urban residents, particularly women. They proved ideal for short journeys within the city, especially considering the poor road conditions outside urban areas, which limited the travel range of all types of vehicles. (Nilesh Wani, 2020)

A study was carried out based on societal use of electric power for the purpose of domestic cooking resulting in the observation that a substantial number of households do, occasional or seriously use electric power for cooking through heat generating electric stoves. An ensuing market survey around Benin City also revealed that various brands of electric cooking stoves are being sold in the markets. A close observation further revealed that virtually all the brands on sale in the markets are imported and are quite expensive. Based on these findings the idea of providing a locally fabricated alternative for these foreign brands of electric cooking stove was conceived and it led to the execution of this project. An extensive study of used and broken electric stoves as well as an extensive literature review showed that it is possible to design and fabricate from locally available materials, with the purchase of just two of the main components, the heating element and the thermostat. With this understanding, basic engineering knowledge was then applied to design all the components of a basic electric cooking stove. The components included the Frame, the Heat Generating Compartment, the Support Ceramic for the heating element, the Heating Element, the Internal Wiring, the Thermostat and the External Wiring and Plug. The designed components were fabricated and assembled to produce the electric stove which was tested and found to operate to a very high level. The main findings from this project work shows that the unit fabricated was not only more affordable, it was more sturdy and able to support cooking pots larger than what the imported brands could support. The design was also made to generate higher temperatures that leads to faster cooking thus balancing the total cost of power usually needed to cook the same amount of food.

This study aims to investigate the potential of using pulverized glass as a partial substitute for fine aggregate in concrete, focusing on how it affects the mechanical properties of the resulting composite. By exploring various replacement levels of pulverized glass, the project identified an optimal balance that enhances both the sustainability and performance of concrete. An experimental work was performed to study the slump, unit weight, compressive strength, dry density and water absorption of concrete partially substituted with pulverized glass. A concrete mix with a target mean strength of 20N/mm² was designed using a standard 1:2:4 mix ratio. Pulverized glass was used to partially replace the fine aggregate at replacement percentages of 0%, 5%, 10%, and 15% in accordance to relevant literature. The concrete was then cast into cubes and allowed to cure for 7, 14, and 28 days at room temperature in a laboratory. The results indicate that workability increases with higher pulverized glass content, with slump values rising from 30 mm for the control mix to 46 mm at 15% replacement. However, compressive strength generally decreased as the replacement percentage increased. The 5% replacement mix achieved the highest compressive strength among the modified mixes, with an average 28-day strength of 19.72 N/mm² compared to 20.68 N/mm² for the control mix. Nine concrete mixes were examined using discarded glass in place of 0%, 5%, and 15% of the weight of sand. The study concludes that, crushed glass can substitute up to 5% of fine aggregate in concrete, which helps lessen the effects of sand mining. This concrete can be regarded as eco-friendly since it uses less raw materials and has fewer negative environmental effects.