Prediction And Optimization Of En8 Mild Steel Material Removal Rate And Surface Roughness Using Response Surface Methodology

The demand for EN8 mild steel in the industry is high due to its integral mechanical properties. However, conventional machining of EN8 mild steel is a challenging task. In this research work, prediction and optimization of EN8 mild steel Material Removal Rate (MRR) and Surface Roughness (Ra) using Response Surface Methodology (RSM) was investigated. The dimension of the EN8 mild steel material was 120 mm diameter and 80 mm in length. The turning operation of the ENS mild steel was carried out using a M42 HSS single point cutting tool. To minimize any form of error, the machining operation was done in a dry environment. A TR 100 Surface Roughness Tester was used to carry out the surface roughness measurement of the EN8 mild steel in a transverse direction. This process was repeated three times and the average value of three measurements recorded. The data generated was analyzed using Response Surface Methodology. The results obtained revealed an R2 value of 0.9985 and 0.9978 for Material Removal Rate (MRR) and Surface Roughness (Ra) respectively. Besides, it was observed that the feed rate, spindle speed, and depth of cut, had significant influence on material removal rate.  Nevertheless, unlike the other parameters evaluated, it was only feed rate that had significant influence on surface roughness. The results obtained from the numerical optimization solution revealed that optimum machining setting of spindle speed of 220 rpm, feed rate of 0.14 mm/min and a depth of cut of 1.5 mm will result in a turning process with an optimum material removal rate of 12598.5 mm3/min and surface roughness of 0.87785 µm, and with a composite desirability value of 98.9%

Review on Solid Waste Generation and Management in Sub-Saharan Africa: A Case Study of Nigeria

Nigeria just likes every other country in sub-Sahara Africa is faced with solid waste generation and management. Solid waste is dump indiscriminately and seen in huge heaps on any piece of unused land, around buildings, drainage system, institutions, playing ground, roads side, and in the open market places in major cities and towns. Living with solid wastes littered around seems to be an acceptable way of life among the people in this part of the world. This research work reported intensive review on solid wastes generation and management in this region using Nigeria as a case study. The application of knowledge of solid waste generation and management approach is crucial for inculcating a change of attitude towards improving the management of generated solid waste in this region. From the review, it was observed that biodegradable solid waste that can be managed via the biogas technology and landfill technology have the highest percentage fraction while the remaining fraction that comprised of non-biodegradable and combustible solid waste can be managed via other technology such incineration, gasification, pyrolysis, etc. Besides, the inefficient management of generated solid waste by individuals, households, institution, consumers and waste management companies can be attributed to inadequate information on waste management benefits, insufficient academic research and industry linkages, financial constraint, economic constraint, cultural constraint, lack of planning and projection, social constraint, lack of producers’ involvement in waste management as well as poor implementation of government policies and lack of comprehensive legal framework.Keywords: Solid waste generation, solid waste management, biodegradable solid waste, combustible solid waste

Effects of Landfill Gas Flow Trajectories at Three Distinct Temperature Phases on the Stress-Strain-Displacement Properties of a Gas Extraction Pip

The rate of MSW generation is increasing and at present, there is no single engineered landfill designed to address the challenges posed by MSW generation in Nigeria. Unmanaged open dump sites and uncontrolled MSW disposal is currently practiced in Nigeria, thus this research work which is focused on the effects of landfill gas flow trajectories at three distinct temperature phases on the stress-strain-displacement properties of a gas extraction. Conservation mass equation was derived for solid, liquid, and gaseous phase. A PVC plastic with a linear elastic isotropic property was used. Von Mises Stress was used as the default failure criterion. The material yield and tensile strength were 52 N/mm^2 and 30 N/mm^2. Other properties of the material include; elastic modulus of 3000 N/mm^2, poisson's ratio of 0.394, mass density of 1020 g/cm^3, shear modulus of 318.9 N/mm^2, and thermal expansion coefficient of 79/K. The results obtained reveal that the rate of gas generation in a landfill is dependent on the increase in temperature and pressure within the landfill system, usually causing subsurface pressures in the landfill to be higher than either the atmospheric pressure or indoor air pressure.Keywords: Landfill, Gas flow trajectory, temperature, pressure, PVC plastic, open dump sit

Design and simulation of continuous melon fruit depodding machine

Melon fruits are usually depodded in Nigeria using traditional/manual method which is not only curbersome, but equally time consuming, and poor quality of finished products obtained. In other to curb these problems, a continuous melon fruit depodding machine was designed and simulated for failure. The Melon fruit depodding machine was made up of the following main units; hopper, depodding chamber, electric motor, chain, sprocket, bearings, and frame which act as supporting base. The depodding machine has a maximum capacity of 0.185m3, and this volume can take melon fruit of 28.25 kg powered by 2.5 hp, 1440 rpm electric motor. The following parameters were design for; depodding force, torque, power, shaft diameter, bearing, density, basic dynamic load on bearing, basic dynamic life of bearing, velocity ratio, etc. The results obtained from the detail design show that a depodding force of 277.13 N and torque of 27.713 Nm was required for the operation of the machine. SolidWorks CAD was used for the simulation of the machine. The Von Mises stress obtained was less than the yield stress, thus the design is safe. The mass of melon fruit and depodded melon fruit were used to calculate the efficiency. The results obtained showed that an average efficiency of 73.55% was obtained.Keywords: Design, Simulation, Melon Fruit, Depodding Machine, SolidWorks CAD, Efficienc