A. I. Obanor

The growing concern over ineffective waste management in rapidly urbanizing areas has continued to threaten environmental sustainability, public health, and urban aesthetics— particularly in developing nations such as Nigeria. Conventional waste collection methods, which rely on manual inspections, static collection schedules, and minimal automation, are increasingly inadequate for modern cities. These traditional systems often result in overflowing waste bins, unhygienic surroundings, and increased exposure of sanitation workers to hazardous waste. To mitigate these challenges, the adoption of smart waste management systems has become a practical solution, harnessing Internet of Things (IoT) technologies to enhance operational efficiency, reduce health risks, and support global sustainability goals. This project presents the design and development of an improved smart dustbin system, which integrates sensors, automation, and wireless communication for efficient and hygienic waste collection. The system was engineered to address major limitations of existing smart waste bin models—such as lack of automation, low adaptability to environmental conditions, and poor sustainability—by introducing enhanced features that improve functionality, reliability, and user safety. The prototype incorporates ultrasonic sensors for detecting the fill level and load cell sensors for measuring the weight of accumulated waste. These sensors interface with an Arduino microcontroller, which interprets real-time data and initiates corresponding control actions. A key innovation in this design is the dual alert and communication mechanism, facilitated by a GSM module (SIM900D) that transmits SMS notifications and also initiates automated phone calls to designated waste management personnel once the bin reaches its full capacity. In addition, the system integrates a GPS module that tracks the exact location of the bin, simplifying collection logistics and enabling efficient route planning. To further enhance automation, the system features a linear actuator that performs self-compaction, reducing the waste volume and increasing the storage capacity before the next collection. Importantly, once the waste bin reaches its maximum threshold, the lid is automatically locked, preventing further deposit of waste and ensuring cleanliness until the bin is emptied and reset for operation. This mechanism helps prevent overflow and reduces contact with potentially contaminated waste. The system is powered by a 24W rechargeable lithium battery supported by a DC–DC converter, ensuring stable power supply and efficient energy usage. The software component was developed using Embedded C/C++ on the Arduino IDE, enabling real-time sensor monitoring, threshold detection, and GSM/GPS communication control. Comprehensive testing was carried out to evaluate sensor accuracy, power efficiency, communication reliability, and the responsiveness of the compaction and locking mechanisms. Results from both hardware and software testing confirmed that the system achieved reliable waste level detection, efficient data transmission, timely alert notifications, and effective compaction cycles. The automatic locking feature also performed accurately, preventing waste input once the bin reached capacity. By combining IoT technology, automation, and sustainable material selection, the improved smart dustbin system demonstrates a viable, scalable, and eco-friendly approach to modern waste management. Its ability to autonomously monitor fill levels, compress waste, lock when full, and communicate through both SMS and phone calls significantly enhances efficiency, hygiene, and sustainability. This prototype provides a foundation for large-scale implementation in residential, institutional, commercial, and municipal environments, contributing to cleaner cities and smarter waste management systems that align with sustainable development goals.

This study investigates the hull resistance and pressure distribution of a container vessel operating in both freshwater and saltwater environments using Computational Fluid Dynamics (CFD) simulation. The analysis employs the Reynolds-Averaged Navier–Stokes (RANS) equations with the k–ω SST turbulence model and the Volume of Fluid (VOF) method to accurately capture hydrodynamic behavior around the hull. Results reveal that total resistance increases quadratically with speed in both environments but is consistently higher in saltwater due to its greater density and viscosity, which amplify dynamic pressure and wave-making effects. Pressure contour analysis shows high-pressure zones at the bow and low-pressure regions near the stern, influencing overall resistance characteristics. The findings emphasize the significance of environmental conditions on vessel performance, offering
valuable insights for hull form optimization, propulsion efficiency, and energysaving ship design

This systematic review examines the effectiveness and feasibility of heating and ventilation systems as critical interventions to mitigate substantial post-harvest maize losses in Nigeria, which currently range from 20% to 30%. The core challenge stems from Nigeria's humid, tropical climate, where high temperatures and relative humidity foster pest infestations, microbial growth, and the dangerous production of aflatoxins by Aspergillus species. The study finds that uncontrolled heat, particularly in structures like metal silos, encourages harmful moisture migration and spoilage , while controlled heating remains a potential solution for active grain drying. Ventilation is identified as the key defense mechanism, but its implementation is complicated: traditional natural airflow systems often fail in the humid southern regions, and powered aeration faces significant constraints due to high ambient humidity and an unreliable electricity supply. The analysis concludes that a universal, one-size-fits-all approach to technology dissemination is inappropriate. Success depends on context-specific technology recommendations tailored to Nigeria's distinct agro-ecological zones, differentiated by production scale, and supported by complementary institutional capacity development. There is an urgent research and innovation gap in developing affordable, intelligent ventilation systems specifically designed for local climate zones. Furthermore, successful adoption relies on coupling technology promotion with market development strategies that enable farmers to realize economic premiums for improved grain quality.

This study investigates the technology employed in the production of Type 4 Liquefied Petroleum Gas (LPG) composite cylinders and explores potential improvements to enhance their performance, safety, and cost-effectiveness. Type 4 cylinders, composed of a polymer liner fully wrapped with fiber-reinforced composites, represent the most advanced generation of LPG storage vessels due to their lightweight structure, corrosion resistance, and superior burst strength. Data for the research were obtained through field observations at Don Mac Limited, review of standard operating procedures (SOPs), and engineering simulations. The study analyzed each stage of the production process—from liner molding and surface preparation to filament winding, curing, testing, and inspection—based on ISO 11119-3 and EN 12245 standards. Simulation results revealed that substituting high-density polyethylene (HDPE) liners with polyamide (PA11) and E-glass fibers with hybrid carbon–glass reinforcements increased burst pressure from 50 bar to 70 bar while maintaining a high factor of safety.

Marine pollution is an escalating issue, particularly in shipping operations, where factors such as oil spills, ballast water discharge, and plastic waste pose serious threats to marine ecosystems and global trade. This study seeks to assess the impact of marine pollution on both shipping operations and the marine environment, offering insights into its root causes, consequences, and potential solutions. This thesis describes the nature of marine pollution, its key sources and their effects which brings to light the escalating pollution problem and its consequences on marine biodiversity, fisheries, the economic viability of coastal communities and shipping operations. It highlights the regulatory measures such as Marine Pollution (MARPOL) and the Ballast Water Management Convention. The research methodology employs a descriptive survey design that gathers data from marine engineers, ship operators, port officials and environmental officers. These findings are used to propose solutions such as stricter enforcement of environmental regulations, adoption of sustainable fuels and enhanced waste management strategies. This research emphasizes the dire need for industry-wide cooperation to diminish pollution, balance economic interests with environmental sustainability, and ensure the long-term resilience of both shipping operations and marine environment.

This systematic review examines the effectiveness and feasibility of heating and ventilation systems as critical interventions to mitigate substantial post-harvest maize losses in Nigeria, which currently range from 20% to 30%. The core challenge stems from Nigeria's humid, tropical climate, where high temperatures and relative humidity foster pest infestations, microbial growth, and the dangerous production of aflatoxins by Aspergillus species. The study finds that uncontrolled heat, particularly in structures like metal silos, encourages harmful moisture migration and spoilage , while controlled heating remains a potential solution for active grain drying. Ventilation is identified as the key defense mechanism, but its implementation is complicated: traditional natural airflow systems often fail in the humid southern regions, and powered aeration faces significant constraints due to high ambient humidity and an unreliable electricity supply.