Influence Of Electrode Diameter On The Corrosion Rate Of Welded Mild Steel in Cassava Juice

Welding is the major form of assemblage of cassava processing machines.  It has been observed that most of the machines often fail in service due to corrosion. This study was carried out to investigate the effect of electrode diameter on this phenomenon.  The mild steel samples used in this study were welded with electrodes of gauges 2.5mm, 3.5mm and 4.0mm respectively.  Cassava juice was used as corroding medium.  An electronic weighing balance was used to take the weights at 4 days interval progressively for 32 days.  The least weight loss was obtained in gauge 2.5mm sample (3.45g), followed by 3.5mm (4.96g) and greatest loss was recorded for 4.0mm sample (11.46g).  This shows that corrosion rate in cassava processing plant can be minimised through the choice of electrodes.  In this case, gauge 2.5mm is recommended for the construction of cassava processing machines. &nbsp

TRANSVERSE VIBRATION AND STABILITY PARAMETERS ANALYSES OF AN OFFSHORE FLUID-CONVEYING PIPE

The vibration and the stability behaviour of a simply supported offshore pipe conveying fluid was investigated in this research work. The governing differential equation for the transverse vibration of the system was derived according to Euler Bernoullis’ equation for the fluid-pipe system and solved using the integral Fourier- Laplace Transformation. The effect of some flow parameters like mass ratios, Coriolis force and velocity of flow were analysed. The results revealed that natural frequency increased with increase in mass ratios and pipe thickness while it decreased with increase in pipe length. Flutter instability was observed in the system due to the presence of complex natural frequency where the imaginary part dominated the flow situation. The instability was made worse when Coriolis force was neglected&nbsp

INVESTIGATION OF CORROSION INHIBITION OF MILD STEEL IN 0.5 M HCL WITH AZADIRACTHAINDICA AND SPONDIAMOMBIN

The corrosion behaviour of mild steel in 0.5 M HCl solution in the presence of Azadiracthaindica and Spondiamombin (AS) was investigated using potentiodynamic polarization and weight loss techniques. Pulverized barks of 60 g of each plant were soaked in 1500 ml, 0.5 M HCl for 48 hours, filtered and mixed in the ratio of 1:1 giving a concentration of 400 g/L (serving as 100 % concentration). The AS mixture was then diluted to 20, 40, 60 and 80% (80, 160, 240 and 320 g/L). The weight loss experiment was carried out for 192 hours at ambient temperature (25oC) and corrodant solution without AS served as the control. Potentiodynamic polarization study was carried out using a device called AutolabPotentiostatGalvanostat (PGSTAT101) in the potential range of ±1.5v versus corrosion potential at a scan rate of 0.005 ms-1. The results obtained showed that corrosion rate reduced in the presence of all the concentrations of AS extract investigated. Highest inhibition efficiency of 99.6% obtained was for the polarization measurement why the highest obtained for gravimetric study was 75.39%. Gibb’s free energy of -3.859 kJ mol-1 was obtained, indicating physisorption and the correlation coefficient was 0.996. The study showed that AS was a very good corrosion inhibitor of mild steel in 0.5 M HCl acid.&nbsp

RESPONSE INTERACTION OF ARTERY UNDER MECHANICAL VIBRATION

Hypertension or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated.  The aim of this work was to analyse mathematically the vibration of the artery and show its relationship to hypertension related cases.  Principles of conservation of mass and momentum inline with Euler-Bernoulis method were used.  By idealising the artery resting on the tissue as an elastic beam that is resting partially on an elastic continuum and simply supported, a boundary value partial differential equation governing the blood- artery- interaction mechanics was formulated. The governing partial differential  equation for the problem was obtained and after linearization was solved using integral methods of Fourier-Laplace Transform.  Simulations for some cases were carried out varying some choice parameters.  Findings show that natural frequency of the artery decreases with increase in the mean arterial pressure (MAP).  It was equally found out that vibration of the artery generally increases with increase in MAP and increase in mode.  It was thus concluded that mechanical vibration of the artery increases with increase in blood pressure, and continuous vibration can lead to fatigue and failure which can cause obstruction in the supply of blood to other parts of the body and may lead to stroke.     &nbsp

COMPARISON BETWEEN KAOLIN AND QUARTZITIC CLAY PERFORMANCE IN THE EFFECT OF WOOD ASH ADDITION ON THE MECHANICAL AND OTHER PROPERTIES OF PORCELAINISED STONEWARE TILES

Porcelain represents the foundation of the ceramic discipline and one of the most complex ceramic materials. Composed primarily of clay, feldspar and quartz, porcelains are heat treated to form a mixture of glass and crystalline phases. This focuses on raw materials with the addition of wood ash processing and mechanical behaviors. The use of wood ash as in manufacturing ceramic tiles can increase the utilization, as well as reduce the cost of raw materials in the tile industry and provide a competitive edge to Nigerian tile Manufactures against foreign competitions. Ring was taken ensured completion of the pozzolainic reactions instituted by the wood ash and the production of dense compounds acting as filler within the pores of the porcelain mass. It was also found that the higher the wood ash content in the porcelainª¤? the lower their strength and density, the permeability 5-10 % cow dung un clays is the best ratio that gives the desired combination of opposing qualities and density, thus the ratio that gives the optimum mechanical and other properties. It was noticed from this research work, clay with kaolinitic content is better used than clay with quartzitic content in formulating porcelainised stoneware tile specimenª¤? consisting of the mixture of both quartizitic and kaolinitic clay has better performance than ordinary quartzitic clay sample.ª¤

Exergetic analysis of breakfast cereal production in Nigeria

This work comprehensively studied energy and exergy analyses of breakfast cereal production in Nigeria. The process analysis method of energy accounting wa s used to evaluate the energy requirement for each of the five defined unit operations. The total energy used in the operation is 1,287.94 MJ. The types of energy used in breakfast cereal production were electrical, thermal and manual and the respective pe rcentages are 48.87%, 50.53% and 0.60%. It was estimated that an average energy intensity of 11.27 MJ/kg was required for the production of breakfast cereals. The most energy intensive operation was identified as the mixing operation followed by milling with energy intensities of 665.10 MJ/kg and 383.04 MJ/kg, respectively. The exergy analysis revealed that the roller dryer was responsible for most of the inefficiency (over 65.94%) followed by the wet mixer (27.40%). Suggestions for energy saving which will help in the reducing the high expenditure on energy and thus improve the profit margin were provided. Keywords : Energy, Exergy, Efficiency Breakfast Cerea

Structural behaviour of metakaolin infused concrete structure

This work researched into the use of metakaolin as a partial substitute for cement in concrete, metakaolin was obtained by the calcination of kaolin clay to about 700 0C Cement was replaced with the metakaolin at 0, 5, 10, 15, 20, 25, 30, and 35% at water cement ratio of 0.5. Tests such as chemical analysis, compressive strength, flexural or modulus of rupture and bond strength were carried out on the concrete samples. Chemical analysis results showed that the metakaolin is a class “N” pozzolan, while the mechanical test showed that the strength of concrete increased from 5% to 20% replacement, and the strength peaked at 20%, but decreased above this value; concrete made with metakaolin performed better than the control sample at all the percentage replacements used in this work.Keywords: Metakaolin, Calcination, Pozzolan, Chemical test, Mechanical tes

ANALYSIS OF A PIPE RESTING ON WINKLER FOUNDATION AND CONVEYING A NON-NEWTONIAN FLUID

Fluid conveyance pipes are subject to vibration and the attendant dynamic stresses lead to instability and sometimes failure. The fluid inside the pipe dynamically interacts with the motion of the pipe, therefore, the material properties of the fluid are expected to play important roles on it. This paper analyzed the deformation of a pipe resting on Winkler foundation and conveying a non-Newtonian fluid. Euler-Bernoullis beam and plug flow models are employed in this work. The resulting transverse differential equation was non-dimensionalized, discretized and solved by means of the finite element method. Effects of the fluid materials and other flow conditions were computed and their implications on the pipe integrity analyzed. Natural frequency increased with flow index, Winkler foundation and mass ratios. Critical velocity also increased with Winkler foundation

Evaluation of A Clay Mineral Deposit in Abeokuta, South-West Nigeria

Clay, in regard to its origin is unique. The kaolin of the mine of Ajebo has a hydrothermal geological formation. It presents itself a fragile and crumbly material, of whitish colour. Therefore, the objective of this paper was to evaluate the clay mineral of Ajebo deposit, its microstructure using scanning electron microscopy, X-ray diffraction and thermal analysis (DSC/TG). The results showed that Ajebo clay belongs to the kaolin group (Kaolinite, nacrite, dickite, and halloysite). Elementary analysis showed the mineral to be composed mainly of aluminium, oxygen and silicon, with a low content of iron. The dehydrated state of the mineral was confirmed by XRD analysis; the basal spacing reflections indicate a sharp peak at 7Å of d001 and the absence of a peak at 10Å, which is indicative of hydrated kaolin. The SEM/SE studies indicated that Ajebo clay mineral particles are smaller than 10μm, forming agglomerates. &nbsp

DESIGN AND PRODUCTION OF ASBESTOS FREE BRAKE PAD USING CASHEW NUTSHELL

A brake is a mechanical device used in controlling the speed of a moving vehicle using a frictional material and dissipates the absorbed kinetic energy as heat to the surroundings. A new brake pad composition has been developed with the Cashew Nutshell (CNSL), Silicon Carbide (SC), Steel Dust (SD), Carbon Black (CB), Epoxy Resin and Hardener (ERH). Five different samples of varying constituents were made with two different sieve sizes for each sample was investigated. The result showed that sample D of the 100 μm with composition 55g of (CNSL), 15g of (SC), 10g of (SD), 5g of (CB) and 15g of Epoxy resin and hardener had the best properties. The Brinell hardness value, Coefficient of Friction, Porosity, Ash content, Density and Wear rate were 75.65, 0.3528 1.925, 45.6, 1.521 kg/m3  for 100 μm and 1.17  respectively. These values are acceptable, though the 75μm samples fared better in many of the test results but lacked in the aspect of density when compared with the other sieve grades.  This shows that Cashew Nutshell can be used as filler in the production of eco-friendly brake pads