This study examines the use of banana fibres as reinforcement in concrete and the need to evaluates their effectiveness for building and construction application. Concrete samples with varying proportions of banana fibres were tested for tensile strength, flexural strength, and crack resistance. The design of analysis was done with particle integration between at 0%, 0.04%, 0.05%, and 0.06% volume. From all indication, especially for the comprehensive strength test, 0.06% strength was noticed to improve across the fiber induced concrete although, lower than the control. Considering the curing response, the trends increase with curing age, however, addition of small percentage of composite fibers decreases the strength compared to the control. This suggests that the additive of banana fiber at all level negatively affect tensile and comprehensive behaviour but higher percentage mitigate some of the pore’s evolution.
Geotechnical investigations are widely regarded as a crucial component of the safe, durable and cost-effective construction of structural and highway infrastructure in Nigeria. Rapid urbanization and increasing infrastructure demand have forced the need for detailed subsurface characterization in Nigeria, but lack of geotechnical research is still one of the leading reasons for construction failure. In this paper we have investigated the effectiveness of geotechnical investigations in structural and highway construction in Nigeria, the method of subsurface characterization and the application of it in the construction of foundations and highways and the impact of a lack of geotechnical research. The study adopts a descriptive approach that is based on synthesis and comparison of literature and comparative case studies and highlights five challenges which are undermining the effectiveness of geotechnical investigations in Nigeria: poor funding, lack of skilled personnel, limited access to modern technology, regulatory deficiencies, and pronounced soil variability across geomorphic zones. We have seen in case studies in Lagos, Port Harcourt, Abuja and in the Niger Delta that the lack of geotechnical investigation is contributing to foundation failures, pavement collapse and high-cost escalation. The paper finishes with policy, regulatory, financial and technological recommendations to make the standards of geotechnical investigation and infrastructure performance in Nigeria better.
The growing demand for sustainable energy and the environmental impacts of fossil fuel dependence have intensified interest in biomass-derived fuels, particularly in developing countries such as Nigeria where agricultural residues remain largely underutilized. This study assessed bio-oils obtained from agricultural biomass in comparison to traditional fossil fuels as a source of industrial energy. Using a vertical silo reactor, bio-oils were produced from mimosa seed pods, banana peels, and cashew nut shells via three thermochemical procedures: torrefaction (200–300 °C), slow pyrolysis (300–500 °C) and fast pyrolysis (>600 °C). The resulting bio-oils were characterized in terms of key physicochemical and fuel properties, including density, viscosity, calorific value, water content, flash point, cloud point, sulphur content, and ash content, and benchmarked against diesel (EN 590), kerosene (ASTM D1655) and heavy fuel oil (ISO 8217 RMG 380) standards. The highest bio-oil yields were obtained through fast pyrolysis, where banana peels yielded a maximum of 65 mL, while mimosa seed pods and cashew nut shells each yielded 35 mL. Cashew nut shell bio-oil had the most favourable fuel properties, including the highest density (0.86 g/cm3), calorific value (31.0 MJ/kg) and flash point (106 °C), suggesting high energy capacity and a higher level of safety performance. Banana peel bio-oil showed greater chemical stability (pH 6.80), and mimosa-derived bio-oil exhibited favourable volatility and cold-flow behaviour. All bio-oils had low sulphur (less than 0.031 wt%) and ash (less than 0.15 wt%) levels, indicating cleaner combustion compared to conventional fossil fuels. Overall, cashew nut shell bio-oil was the most viable diesel and kerosene replacement, though additional upgrading or blending is necessary to close the remaining performance gaps. This study highlights the potential of bio-oil as a transitional fuel in developing countries with minimal energy infrastructure, using readily available agricultural waste.
Manual and conventional electronic attendance systems in African universities suffer from major drawbacks such as vulnerability to proxy attendance e.g., card swapping and Quick Response (QR) code sharing and heavy dependence on unreliable power and internet connectivity. The consequences of these drawbacks necessitated a system that can accurately track attendance in a classroom setting without relying on electricity or internet connectivity. This study designed, implemented, and evaluated an air-gapped attendance tracking system. The device computes a six-digit Time-Based One-Time Password (TOTP) on authentication success using the algorithm defined in RFC 6238 and a 128-bit secret key. Students manually enter the codes into the web portal developed using the Django framework and backed by PostgreSQL. The server verifies the code independently using the same algorithm and local secret key. The performance analysis carried out on 500 genuine attempts and 500 impostor attempts showed a false acceptance rate of 0%, and a true acceptance rate of 100%. The average time taken for authentications was 7.8 seconds, while the mean latency of server verification was 534 milliseconds. The developed system is completely offline in the classroom setting, does not permit proxy attendance and guarantees tamper-proof logging.
This investigation assesses polynomial regression model development in the context of computationally efficient surrogates for parametric modelling of minibus aerodynamic drag coefficient . Three alternative regression models (Models A, B, C), based on sets of three dimensionless terms ( ), were compared using a dataset of 114 CFD simulations with the windows closed. Although Model C, a 4th-order, 3-input model, showed the best in-sample fit (R2 = 0.8024, RMSE = 0.0199), 10-fold cross-validation revealed it to be the most over fit. Model B, a 4th-order, 2-input model, consistently achieved the lowest mean CV-RMSE (0.0280), establishing it as the most stable regression model. Statistical analysis indicates that the aerodynamic profile is predominantly multivariable, with strong three-variable interactions ; the effects of higher-order speed terms are negligible. Residual vs. fitted plots and the normal Q-Q plot show that the polynomial models successfully capture the global response trend, while local fit could be improved through refinements or more flexible machine-learning surrogates to better quantify the extreme nonlinear dynamics at the edges of the parameter space.
