In this paper, the effects of build parameters on the mechanical properties of 3D-printed acrylonitrile butadiene styrene (ABS) produced using fused deposition modeling (FDM) are investigated. Full factorial experimental design incorporating a 2-level, 3-factor design with raster angle, layer thickness and interior fill style was carried out. Tensile tests were performed at four different strain rates to determine how the build parameters influence the mechanical properties of the 3-D printed ABS and to assess its strain rate sensitivity under quasi-static loading. It was found that the modulus of toughness of ABS material is most influenced by raster angle, while the interior fill style is the most dominant build parameter that dictates the specimen's modulus of resilience, yield strength and ultimate tensile strength. At all strain rates, it is further revealed that higher mean values of yield strength, ultimate tensile strength and modulus of resilience were obtained when the interior fill style is solid as opposed to high density. This can be attributed to the denser structure and higher effective cross-sectional area in solid interior fill style in comparison with high density interior fill style. However, the influence of the layer thickness on the investigated mechanical properties was found to be inconsistent. It was noted that specimens built with both 0.254 mm layer thickness and the cross [0˚/90˚] raster angle had superior mechanical properties when compared to those built with the 0.3302 mm layer thickness and cross [0˚/90˚] raster angle. This suggests that there is a key interaction between the layer thickness and the raster angle. At any FDM build parameter, it was found that all the mechanical properties investigated in this work exhibited modest sensitivity to strain rates. This study has provided a platform for an appropriate selection of build parameters combinations and strain rates for How to cite this paper: Hibbert, K.,

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In this paper, the primary synthesis and secondary treatment of Aluminium matrix composites (AMCs) has been reviewed. The renewed quest for component materials with high strength-to-weight ratio, unusual and superlative combination of properties for applications in automotive, aerospace, marine and warfare armoury manufacturing industries has increased the versatility potential of aluminium alloy-based composites. Several categories (synthetic and agro-based ceramics) of reinforcement materials for aluminium composite are discussed. The manufacturing/fabrication techniques which could be solid phase (powder metallurgy and rapid prototyping or 3 D printing method) or liquid phase (casting and pressure infiltration) methods are discussed in this review work. Secondary treatment such as heat treatment, forging and other thermomechanical treatments which improves the properties of as-synthesized composites are also discussed. A review synopsis of recent studies provides opportunity for concise but a more robust understanding of potential benefits and detrimental effects associated with the use of various primary synthesis routes and secondary treatment for manufacturing of ceramic reinforced AMCs. Despite the laudable research efforts that have been made towards development and enhancement of the properties of AMCs, this review work revealed that literature is very sparse on synergetic adoption of multi-synthesis route and multi-approach secondary treatment for producing AMCs. Sequel to the aforementioned unexplored research concept, some lacunae are identified and suggested for further elaborations and study.

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Solar Photovoltaic (PV) can be considered as one of the most reliable and promising renewable systems. This is of great importance for developing countries like Nigeria especially in the rural communities where there is little or no access to electricity. The use of solar energy will no doubt contribute to the improvement of the living conditions of these villagers. Solar PV systems have been installed in some villages in Nigeria but unfortunately, the expected benefits from using these systems have been jeopardized. The objective of this work is to embark on performance assessments of in- stalled Solar PV system in Oke-Agunla, Akure local government of Ondo State in Nigeria. Visits were conducted to the village; equipments on ground were examined while the people were interviewed. Both functional and non-functional facilities were traced to their manufacturers using the identification data on them and rated to ensure their efficiencies. Energy demands were also prorated, and observed the need to improve on the present energy supplied. Results of the assessments shows that PV facilities used were inadequate, trained technicians were not available giving room for quacks working on the facilities occasionally resulted in further complications and poor facilities maintenance. The assessment result shows that just 14.52% of the 4.5 kW installed solar PV was utilized due to significant malfunctioning and deterioration in performance. It can be concluded from this study that the installed solar PV systems was inefficient as a result of poor maintenance, lack of technical know-how and inability of the project contractors or managers to take these factors into consideration while embarking on the solar PV installations

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In this paper, smooth specimens of three aluminum alloys: AA 2219-T8, AA 2519-T8 and AA 2624-T351, were subjected to the same level of uniaxial (tension/compression) fatigue loading to compare their fatigue responses. Fractographic investigations of the failed specimens after fatigue loading was also conducted using a scanning electron microscope. The fatigue test results showed considerable differences in the fatigue lives of the three investigated alloys with AA 2219-T8 having the shortest fatigue life and AA 2624-T351 the longest fatigue life. The fractographic analysis showed that coalescence of micropores, microvoids, particles cleavage and microcracks are the predominant features in the fracture surface of AA 2219-T8. The fracture surface features of AA 2519-T8 revealed higher resistance to fatigue cracks nucleation and growth when compared to AA 2219-T8. The features depicted mainly partly ductile and partly brittle fracture. The AA 2624-T351 fracture surface features revealed noteworthy ductile failure mechanism. The results suggest a strong correlation between the surface fractographic features and the fatigue lives of the alloys. It is also observed that in addition to the yield strengths and ultimate tensile strengths, the total strain energy densities (SED) may provide a reasonable indication of the relative fatigue performance of the three alloys. AA 2219-T8 had the lowest SED and the lowest fatigue life, while AA 2624-T351 had the highest SED and the highest fatigue life. Thus, AA 2624-T351 would be the most suitable materials for components subjected to fatigue loading.