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This study investigates the failure of leaf springs used in the suspension system of heavy-duty vehicles in Ghana. Primary and secondary data were collected using both open and closed-ended questionnaires. Welders and fabricators of Sarkyoyo enterprise at the Suame Spare parts dealership area in Kumasi were engaged in the survey. The elastic strain and stress mathematical models were used to determine the stress points in a loaded leaf spring with the aid of ANSYS. The factors considered in the analysis were the leaf spring SAE design specification, the recommended Ghana Highway Authority load limit for heavy-duty vehicles, and the terrain. Analysis was done for both the standard and variable curvature leaf springs. The mode of failure was found to be fatigue loading. The causes of failure were determined to be loaded beyond the recommended 43 tons per wheel limit, bad roads, and reckless driving. It was also observed that loading causes the edges of the leaf spring to bend outwardly from the top, making the edges more prone to failure. Results further showed that the leaf spring with variable curvature recorded strain energy 2.5 times higher than the standards leaf spring.

This research seeks to test the performance of a palm nut-fibre cake breaker and separator machine to alleviate the problem of hand separation by local oil producers. It takes into consideration the standard cylindrical shape of a palm nut-fibre cake. The machine operated on an electric motor of 2.2 kW at 1420 rpm. The average throughput capacity of the machine was 107.72 kg/hr with the capacity weight of 120 kg. Test results indicated a separation efficiency of 92%. Also, cost estimation indicated that the annual savings in using the machine with less labour than manual labour entirely was $466. The study outcome is relevant to small-scale producers on the need to utilize a cost-effective machine to facilitate a high separation yield of nuts and fibres from the cake obtained from processing palm oil and improve the production output of palm kernel oil processed from the nuts.

Rapid increases in the prices of conventional turbine blade making materials as well as future sustainability issues is attracting research interest in the development of polymer composites for turbine blade applications. This study examines the suitability of using a novel bamboo fibre and recycled plastics composite developed for wind turbine blade application. Bamboo fibre was extracted from raw bamboo by chemical and mechanical processes. Recycled High Density Polyethylene (HDPE) was collected, cut into pieces, cleaned and combined with extracted bamboo fibre to form the composite. The percentage ratio of fibre content in the ten specimens ranged from 2.5% to 25%. A series of mechanical tests were conducted on the specimens, including tensile test, impact test, water absorption test and sun radiation test. Results established that as the percentage of bamboo fibre in the specimen increased, the tensile strength and impact energy also increased. Water absorption and sun radiation tests conducted on specimen X revealed no meaningful impact its mechanical properties. Hence, the most significant deduction from this study is that the specimen with 25% bamboo fibre and 75% HDPE matrix possesses the quality that qualifies it to be used as a material for wind turbine blade fabrication.

Wind energy, as a sustainable energy option is gaining research attention due to its price competitiveness relative to conventional energy sources. This study presents the fabrication and testing of a low-cost wind turbine blade using bamboo fibre with recycled plastic. Bamboo fibre was extracted from raw bamboo and combined with adequately conditioned Recycled High-Density Polyethylene (RHDPE) to form a composite which is 25% bamboo fibre and 75% RHDPE. The composite materials was then used to fabricate a turbine blade which was tested and the results compared with typical performance indices for a turbine blade made of fibre glass for comparative analysis. The turbine blades were installed at a height of 10 meters at the test site and monitored. Results showed the energy per unit cost (kWh) for the composite material was lower than that of the glass fibre with a life cycle of 107 for glass fibre and 106 cycles for the bamboo plastic. Stress and deformation analysis showed a higher value for glass fiber compared with the composite material. It can be deduced that composite material matrix possesses the desired properties and energy per unit cost ratio for consideration in building wind turbine blades.

c-Si solar cell interconnection damages from thermal cycles emanate from cumulative damage contributions from the various load steps in a typical thermal cycle. In general, a typical thermal cycle involves five thermal load steps, namely: 1st cold dwell, ramp-up, hot dwell, ramp-down, and 2nd cold dwell. To predict the contributions of each of these load steps to creep damage in soldered interconnections, each of the respective load steps needs to be profiled to accurately fit a function capable of predicting the damage contributions from a given number of thermal cycles. In this study, a field thermal cycle profile generated from in situ thermal cyclings at a test site in Kumasi, a hot humid region of sub-Saharan Africa, is used to predict damage in solar cell interconnections from accumulated creep energy density using finite element analysis (FEA). The damage was assessed for two different solder formulations, namely: Pb60Sn40 and Sn3.8Ag0.7Cu (lead-free). The results from the FEA simulations show that the cooling (ramp-down) load steps accounted for the highest accumulated creep energy density (ACED) damage in solder interconnections. The ramp-up load steps followed this closely. The cumulative contributions of the two load steps accounted for 78% and 88% of the total damage per cycle in the Pb60Sn40 and Sn3.8Ag0.7Cu solder interconnections, respectively. Furthermore, a study of the damage profiles from each of the five load steps revealed that each of the damage functions from the various load steps is a step function involving the first two thermal cycles, on one hand, and the remaining 10 thermal cycles on the other hand. The damage from the first two thermal cycles can be predicted from a logarithmic function, whereas the damage from the remaining 10 thermal cycles is predicted using six-order polynomial functions. The ACED results computed from the damage functions are in close agreement with the results from the FEA simulation. The functions generated provide useful relations for the prediction of the life (number of cycles to failure) of solder interconnections in solar cells. The systematic approach used in this study can be repeated for other test sites to generate damage functions for the prediction of the life of c-Si PV cells with SnPb and lead-free solder interconnections.