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After harvest and storage problems are major dilemma, which requires to be looked into carefully in developing nation like Nigeria. This paper presents a development of low-cost hybrid solar dryer for food preservation with the objective of setting optimum drying parameters for the preservation of cassava and tomato products. The work was carried out by designing, constructing and finally evaluating the hybrid dryer for effective performance. The optimization of the drying parameters was done using composite technique (Response surface method). The assessment of the dryer shows that 150 Kg cassava mesh and 5000 grams of tomato with 35% and 94% moisture content, respectively were dried to 100 Kg and 334 g with 10% moisture level for 4 hours and 11 hours respectively, for cassava and tomato. The optimization result shows that the dryer will perform optimally with drying temperature of 62°C and 48°C for cassava and tomato respectively with 24% and 91% moisture uptake. Therefore, sustainable techniques for preservation of food are essentially required. Hybrid solar dryer is an alternative to consider in the situation.

There have been various developments of security system such as computer security systems which prevent unauthorized access to personal files, but there is more to this. Security ensures that there is no damage to your data and that only authorized users can read your files. This work focuses on the dimension of remote controlled alert system for automobile access using password credential. This remote control alert was done by research on how remote controlled systems and automatic gates work and the transfer of frequency signals through transmitters to receiver module to be used at homes, schools, industries and companies. The remote alert system was developed by combining major systems: the power generation system or power source, transmission system, reception system (the alert system, the actuation system and the display system. Results showed that at smaller distance of 15 cm, the response time was 0.12s while at a longer distance of 100 cm; the response time was 15.91s. A valid signal was received on the receiver output display for automobile access into a premise; therefore TLP 315MHz RF transmitter and the RLP 315 MHz RF receiver can be used for a shorter distance.

A crucible furnace is a piece of equipment used in the foundry industry for melting metals for casting operations. This research work focuses on the design of a 30-kilogram capacity aluminium crucible furnace that is fired with diesel fuel. The furnace drum has an overall combustion capacity of 0.1404m3. It is fitted with a chimney to allow for the easy escape of combustion gases. The air blower discharges air into the furnace at the rate of 0.3m3/s with an air/fuel ratio of 400:1. The aluminium crucible furnace is designed to consume 4 litres of diesel fuel with a rating of 139000kJ/gallon which is required to completely melt 30-kilogram of aluminium over a period of 18 min. The designed operation temperature range of the aluminium crucible furnace is 500°C to 800°C. The cost of the aluminium crucible furnace is one hundred and eighty-two thousand nine hundred naira (N182, 900.00).

The application of polymer matrix composites has found valuable in many engineering fields like electrical, marine, aerospace, electronics and microelectronics. Thus, a new technique like microwave through electromagnetic energy was explored for processing of polymer matrix composite. The roles of microwave in the post curing of polymer matrix composites cannot be underestimated, as it has the capacity to improve the mechanical and micro-structural properties of the composite produced. The aim of the study is to investigate the effect of microwave post curing on the mechanical and micro-structural properties of particulate reinforced polymer matrix composites. These effects were compared with composites post cured using conventional autoclave oven with the objective of investigating the significance of microwave curing on the tensile strength and structural qualities in terms of defects of the produced composites. A specific study comprising of aluminum filled polyester based composite and carbon black filled polyester based composite were investigated using two different composite curing methods (microwave oven and conventional autoclave oven). The investigation, through experimentation was based on mechanical property (tensile strength) and micro-structural quality (defects) of the produced composites. Comparing the results of the post-curing of the composites using microwave and conventional methods, there is direct relationship between the tensile strength and the percentage weight fraction of the fillers with respect to the post curing methods. 30% aluminium filled, post cured in microwave has 0.01 MPa tensile strength, 20% aluminium filled (microwave) has 0.0076MPa while 30% aluminium filled (conventional oven curing) has 0.0092MPa and 20% aluminium filled (conventional oven curing) has 0.0068MPa. Also, composites post-cured with microwave show less voids defect compared to that post-cured by conventional autoclave oven. It was shown in this paper that post-curing of the particulate composites through microwave was able to improve the tensile strength and minimize defects better as compared to conventional autoclave method.