This paper reported on the possibility of using organic materials in the production of green epoxy conductive composites. Epoxy composite samples were produced through the hybridization of carbonized coconut fibre filler (CCS), raffia palm fibre (RPF), carbon black (CB), and carbon fibre (CF), using the simple hand lay-up technique. Then the electrical properties (electrical resistivity and electrical conductivity) and the mechanical properties (tensile strength) of the composite samples were tested accordingly, using the ASTM D6343 – 14, ASTM B193 and ASTM D 3039 approved methods. Results obtained from the laboratory tests revealed that both the CCS and RPF (organic materials) have significant influence on the mechanical and electrical properties of the composite samples. It was observed that the electrical conductivity of the composite samples increased (4.34x10-3 S/cm to 4.48x10-3 S/cm) as the CCS loading increased from 3% to 6% (by mass); before it started to decline after 9% (by mass) CCS loading, recording lowest conductivity of 9x10-4 S/cm at 15% CCS volume. The electrical resistivity of the composite samples was noted to decline from 2.90x107 Ωcm to 2.83x107 Ωcm as the CCS content in the composite increased from 3% to 6%, before it started to increase after 9% CCS quantity, with the S5 composite sample (15% CCS quantity) having the highest electrical resistivity of 3.80x107 Ωcm. Regarding the composite’s mechanical properties, the study depicted that the S1 composite sample had the highest tensile strength of 98.3 MPa, while the S5 composite developed the lowest tensile strength of 62.7 MPa, portraying that the CCS and RAF has a substantial effect on the composites samples’ tensile strength. This study’s results portrayed the possibility of producing lightweight, high-tensile strength conductive composite from organic waste materials, which can be utilized in several engineering applications.

Bio-composites have been widely introduced as sustainable alternative engineering materials, due to their environmental friendliness. The aim of this study was to assess the variations in the mechanical and biodegradation behaviours of natural fibres (raffia palm and plantain fibres) reinforced composites, and compared them to artificial fibres composites. Bio-composite samples produced through hybridization of glass fibre, plantain fibre and raffia palm fibre, were tested (mechanical and biodegradability tests) in accordance with ASTM International accepted procedures. The biodegradability results indicated that, the tensile strength and tensile elongation for all composites decreased non-linearly during the 28 days of soil treatment. Also, it was observed that the mechanical properties of the natural fibres reinforced bio-composites declined faster, when compared to the synthetic fibre reinforced composite. The bio-composite produced solely with natural fibres (PFRF) had the highest tensile strength reduction rate (43.86%), while the composite produced with solely synthetic fibre (glass fibre) had the minimum tensile strength declining rate (2.18%), at the end of the soil treatment. Regarding the tensile elongation, the PFRF bio-composite had the highest decrement (89.98%), when compared to the 53.28 and 45.92% recorded in the CFPF and CFRF reinforced bio-composites, respectively. With respect to weight loss, it was observed that the weight loss was gradual during the initial period of the soil treatment. However, the bio-composite with the two natural fibres (PFRF) exhibited more pronounced weight loss (46.4%); while the sample with the synthesized fibre (CF) exhibited more resistance to biodegradation (6.23% weight loss). The study results demonstrated that plantain fibre and raffia fibre are environmentally friendly, and composites produced from them developed appreciable tensile properties; hence, they can be used to produce composite for automobile parts.

Considering the fact that Warri is located in the sub-tropical region of Nigeria which is characterized by excessively high temperature and high humidity, it is necessary to develop an air-conditioning system which can reduce the hot and ambient temperature within a confined space for human comfort. This research presents the design of an air-conditioning system for comfort of occupants in a 400-Seater auditorium. The three independent variables considered for this design are; the number of occupants, air exchange rate and the outdoor temperature. The auditorium was properly measured and the heat generated by the bulbs, appliances and occupants were adequately considered to get the required cooling load. Regression analysis was used to predict and determine the cooling load. Optimization analysis was also done to determine the optimal condition for maximum cooling load. The plant capacity that will provide thermal comfort for the 400 occupants was calculated to be 25 ton of refrigeration (TR).