Comparative Bioactivity of Bamboo Leaf Ash and Bularafa Diatomaceous Earth against Maize Weevil (Sitophilus zeamais Motschulsky)

Maize is one of the major staple foods in Sub-Saharan Africa and there is serious loss in maize storage due to insect damage. This study compared the bioactivity of Bamboo Leaf Ash (BLA) and Bularafa Diatomaceous Earth (BDE) against Maize Weevil (Sitophilus zeamais Motschulsky) under laboratory conditions. Insecto®, a commercialized DE was also tested as standard check. Adults of the insects were exposed on maize admixed with the BLA at dose rate of 5,000, 10,000 and 20,000ppm; BDE and insecto® at a dose rate of 1,000ppm, at 28.20C and 82.2% relative humidity. Mortality increased with increasing exposure duration and all treatments showed mortality of more than 80% after 14days post-treatment compared to negative control with 0%.The treatments suppressed F1 progeny. Treated grains have weight loss less than 4%, kennel damage less than 14% and grain germination showed no significant change. The decreasing efficacy of the dusts against this insect is Insecto®> BLA > BDE. BLA and BDE have potential for the management of insect pests of stored grain in Nigeria

Technical appraisal of some maize shellers in Oyo and Kwara States of Nigeria

This study assessed the performance of some maize shellers in use in grain markets in Oyo and Kwara States, Nigeria. A preliminary survey conducted identified shellers in use as basic maize sheller (BMS) without blower, maize sheller with blower attachment (MSB) and the multi-purpose sheller (MPS). The shelling/cleaning performance of the shellers were assessed using yellow maize (SWAN 1 variety) and some key equipment parameters, which impact performance were measured. The air velocity for MSB and MPS ranged between 0.4 and 2.4 m/s which was not sufficient for efficient cleaning of chaff from shelled grains. Shaft speed for BMS, MSB and MPS were 845, 920 and 820 rpm, respectively. Average throughput for BMS, MSB and MPS was 1,714, 600 and 840 kg/hr, respectively with mean shelling efficiencies of 92.9, 82.7 and 97.9%, respectively. Mean cleaning efficiencies were 54.0 and 57.7% for MSB and MPS, respectively. The percentage grain loss for BMS, MSB and MPS were 17, 7.1 and 1.9%, respectively. It was observed that many fabricators do not consult agricultural engineers when producing machines, relying more on previous experience. Additionally, there was a lack of consideration for operator safety with the exposure of moving parts of the equipment in all the designs evaluated. A key recommendation from this study is that sheller designs should be standardized to ensure the provision of quality and highly efficient machinery for processors

Evaluation of corrosion damage in reinforced concrete structures in terms of the rebar’s residual cross-section

Corroding reinforced concrete structures are frequently assessed to determine the rate of corrosion propagation and the level of deterioration, which might compromise the structure’s reliability. Appropriate measures should be considered in deciding when and how to implement maintenance if safety must be ensured. However, the influential factor that governs or informs such decisions is corrosion damage quantification. Nonetheless, the current non-destructive methods of corrosion damage quantification often lead to ambiguity, and most do not evaluate corrosion damage in terms of the rebar’s cross-section loss, which is the primary effect of corrosion. To address these shortcomings, this paper proposes an effective, reliable, and less-complicated model for quantifying corrosion damage in reinforced concrete structures based on the cross-sectional area of the corroding bar. The study was conducted through experimental (laboratory-based) and numerical investigations of the relationship between the level of corrosion and the corrosion-induced crack width. Based on the investigations’ findings, appropriate relationships and essential parameters were identified, and the model was derived analytically. The derived model assesses corrosion damage in terms of the corroding bar’s residual cross-section and requires only a few input parameters, which can be obtained by non-destructive testing if not known. The model was tested against data obtained from the laboratory experiment and against other experimental and analytical data from the literature, and the results showed a good correlation

Technical Appraisal of some Maize Shellers in Oyo and Kwara States of Nigeria

This study assessed the performance of some maize shellers in use in grain markets in Oyo and Kwara States, Nigeria. A preliminary survey conducted identified shellers in use as basic maize sheller (BMS) without blower, maize sheller with blower attachment (MSB) and the multi-purpose sheller (MPS). The shelling/cleaning performance of the shellers were assessed using yellow maize (SWAN 1 variety) and some key equipment parameters, which impact performance were measured. The air velocity for MSB and MPS ranged between 0.4 and 2.4 m/s which was not sufficient for efficient cleaning of chaff from shelled grains. Shaft speed for BMS, MSB and MPS were 845, 920 and 820 rpm, respectively. Average throughput for BMS, MSB and MPS was 1,714, 600 and 840 kg/hr, respectively with mean shelling efficiencies of 92.9, 82.7 and 97.9%, respectively. Mean cleaning efficiencies were 54.0 and 57.7% for MSB and MPS, respectively. The percentage grain loss for BMS, MSB and MPS were 17, 7.1 and 1.9%, respectively. It was observed that many fabricators do not consult agricultural engineers when producing machines, relying more on previous experience. Additionally, there was a lack of consideration for operator safety with the exposure of moving parts of the equipment in all the designs evaluated.  A key recommendation from this study is that sheller designs should be standardized to ensure the provision of quality and highly efficient machinery for processors