This work focused on the development of a 120kg load lifting capacity scissor elevator platform (SEP) with a horizontally positioned rack and pinion gear actuating mechanism which is driven by a DC motor. The time of lift to an elevated height of 0.9m is 30s. Simulation of a typical SEP structure in the 3D workspace of a Computer Aided Design (CAD) software package was carried out to investigate the balance of the SEP structure, the stresses experienced, the efficiency, and safety of operations. A prototype was also fabricated for the physical demonstration of SEP. The SEP can be used for a range of engineering applications such as making an adjustable workbench for workshop use, solving the problem of table adjustment for height-challenged personnel, or used as a load-transferring device if mobile to transfer loads between two or more elevated locations during construction or maintenance work. Calculated results give the platform weight as 136.693N, the scissor arms weight as 188.205N, the total structure weight as 1502.098N, the stress in the scissor arm at maximum platform elevation as 1.702MPa, the stress in the scissor arm at minimum platform elevation as 4.928MPa, the maximum actuation force as 4126.980N, and the power required to drive the mechanism as 26.963W. Autodesk Inventor Pro simulation results show that a wide range of data can be sourced when one considers the real-time behavior of SEP. The results also indicated the values of the reaction forces, reaction moments, stresses, strains, and displacements developed at every joint, link, hinged support, and every other point in a 3D workspace.

This research work focuses on the design and development of Class 2B-lpl compliant constant-force compression slider mechanism. It also expresses the desire to simplify the behavioral model for easy usage. Results obtained indicated an average non-dimesionalized parameter value of 1.2573, 1.2991, 1.3483, and 1.4081 for a 10, 20, 30, and 40% displacement respectively. The result also shows that the average force generated by the mechanism for a 10, 20, 30, and 40% displacement were 901.23N, 316.56N, 171.17N, and 110.44N respectively using the maximum flexible segments parameter values for the different percentages of mechanism slider displacement. This indicates clearly that using the non-dimensionalized parameter, the average force generated by this class of mechanism can easily be determined which greatly simplifies its usage.

This work focuses on the design and development of a mixed-mode domestic solar dryer in which the slices of pepper, okra and yam were dried simultaneously by both direct radiation through the transparent glass roof of the drying chamber and by the heated air from the solar collector. The dryer was made up of the solar collector, the desiccant chamber and the drying chamber which contains a rack of three trays. The air comes in through the air inlet and heated up within the solar collector and then channeled through the drying chamber by natural convection where it is utilized for drying purposes. The development was done using locally sourced and readily available materials such as wood, transparent glass sheet, mild steel metal sheet, mosquito galvanized wire mesh and chicken galvanized wire mesh. The maximum temperature attained by the solar collector, drying chamber during test were 69oC and 55oC respectively, with a corresponding ambient temperature of 39oC. The mass of water removal of 43g, 136g and 255g from pepper, okra and yam slices respectively was achieved making use of the passive solar food dryer as against the water removal of 39g, 126g and 218g from pepper, okra and yam slices respectively achieved using the sun drying method which indicates a difference of 4g, 10g and 37g for pepper, okra and yam slices respectively. The rapid rate of drying achieved with the use of this dryer shows that it has the ability to dry food items rapidly to an acceptable moisture content level.