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This work aims to analyze the effect of mechanical activation on structural disordering (amorphization) in an alumina-silica ceramics system and formation of mullite most…
This work aims to analyze the effect of mechanical activation on structural disordering (amorphization) in an alumina-silica ceramics system and formation of mullite most notably at a lower temperature using X-ray diffraction (XRD). Also, an objective of this work is to focus on a low-temperature fabrication route for the production of mullite powders.
A batch composition of kaolin, alumina and silica was manually pre-milled and then mechanically activated in a ball mill for 30 and 60 min. The activated samples were sintered at 1,150°C for a soaking period of 2 h. Mullite formation was characterized by XRD and scanning electron microscopy (SEM).
It was determined that the mechanical activation increased the quantity of the mullite phase. SEM results revealed that short milling times only helped in mixing of the precursor powders and caused partial agglomeration, while longer milling times, however, resulted in greater agglomeration.
It is noted that, a manual pre-milling of approximately 20 min and a ball milling approach of 60 min milling time can be suggested as the optimum milling time for the temperature decrease succeeded for the production of mullite from the specific stoichiometric batch formed.
Considering pollution problems and the energy crisis today, investigations have been concentrated on lowering the concentration of toxic components in combustion products…
Considering pollution problems and the energy crisis today, investigations have been concentrated on lowering the concentration of toxic components in combustion products and decreasing fossil fuel consumption by using renewable alternative fuels. In this work, the effect of ethanol addition to gasoline on the exhaust emissions of a spark ignition engine at various speeds was established. Ethanol was extracted from groundnut seeds using fermentation method. Gasoline was blended with 20 - 80% of the extracted ethanol in an interval of 20%. Results of the engine test indicated that using ethanol-gasoline blended fuels decreased carbon monoxide (CO) and hydrocarbon (HC) emissions as a result of the lean- burn effects caused by the ethanol, and the carbon dioxide (CO2) emission increased because of a near complete combustion. Finally, the results showed that blending ethanol in a proportion of 40% with gasoline can be used as a supplementary fuel in modern spark ignition engines as it is expected that the engine performs at its optimum in terms of air toxic pollutants reduction, by virtue of that mix.
The effects of electrode types on the mechanical properties of weldments produced from three steel samples made locally in Nigeria have been investigated. Oerlikon…
The effects of electrode types on the mechanical properties of weldments produced from three steel samples made locally in Nigeria have been investigated. Oerlikon, Santan, Power Master and Magnum electrode samples were separately used to join Homus, Universal and Spanish steel samples. The chemical compositions of the steel samples, electrodes core and coating were obtained using spectrometer before using them for the research. Mechanical properties of the weldment produced were determined and compared to the unwelded samples. This was done in order to provide information on which combination of steel and electrode type will produce weldment with optimum mechanical properties. Oerlikon electrode produces weldments with optimum tensile strength of 508.25 N/mm2 and impact energy of 152.76J for Homus Steel, it also produced highest tensile strength of 449.92 N/mm2 and impact energy of 103.042J for Spanish Steels while Power Master Electrode produced weldment with highest tensile strength of 482.96N/mm2 and impact energy of 137.033J for Universal Steel. The results show that single electrode type cannot produce weldment with highest properties for all the selected steel samples.
Efforts have been made to turn empty water sachet (commonly called pure water nylon), palm kernel shell and iron filings, which are all wastes released into the…
Efforts have been made to turn empty water sachet (commonly called pure water nylon), palm kernel shell and iron filings, which are all wastes released into the environment from different sectors of production in Nigeria into a useful material of good physical and mechanical properties. These wastes, especially the empty water sachet, pose a great challenge on the effort of achieving a clean and safe environment, mostly by their contribution to flooding during the rainy season. A recycling aimed research was carried out, making use of these materials to produce a new composite material and proffer suggestions for the possible use of the newly developed composite material. The empty water sachet was used as a matrix, which was reinforced by carbonized palm kernel shell particulate and iron filings. The percentage composition of iron fillings was maintained at 5%wt, while that of palm kernel shell ash was varied from 5%wt - 20%wt at an interval of 5%. The composites were compounded and compressively moulded. Physical and mechanical properties of the composites were tested for and the results obtained shows that the composite material could be used to produce automobile bumper among other parts due to their Impact Strength and low Density. After results analysis, materials with 5%wt of CPKS and that with 10%wt of CPKS were recommended for the automobile bumper production following their high impact strength - density ratio of 0.26 and 0.19 respectively, which are higher as compared to that of Peugeot 406 bumper measured alongside the composite materials.
The general-purpose engine lathe is the most basic turning machine tool. As with all lathes, the two basic requirements for turning are a means of holding the workpiece…
The general-purpose engine lathe is the most basic turning machine tool. As with all lathes, the two basic requirements for turning are a means of holding the workpiece while it rotates as well as a means of holding cutting tools and moving them relatively to the workpiece. In this paper, we present the results of finite element analysis (FEA) performed to investigate nature of stress and their distribution at optimum point along the two turning tables of a micro-controller based versatile machine tool desktop learning module. Commercial Autodesk Inventor was used to create both three-dimensional (3D) and 2D models as well as performing simulation. Dynamics simulation generated the motion load expected to act on the tables when used for real-life operation which were in turn used to perform the FEA. The motion of the DC stepper motor driving the tables and other parts of the module is designed to be controlled by programmable chips. Before creating FEA simulation for the tables, numerical divergence were prevented by varying the mesh settings to obtain the settings at which the results of the analyses converges which was obtained at 0.03 average element size and 0.04 minimum element size. Finite element analysis carried out on the tables shows that aluminium alloy 4032-T6 chosen will serve in the fabrication of physical prototype. FEA revealed the nature and level of stresses that will be experienced on the tables, it also revealed region where these stresses will concentrate on them. The analysis also estimated the expected weight of the turning tables 1&2 to be 1.23536 and 0.257182 kg respectively and show that the minimum factor of safety was constantly 15 ul within the tables which means that they will not fail during operation.