ABSTRACT Intelligent Tool Condition Monitoring (TCM) is an essential requirement in the drive towards automated machining operations. In this paper, a Multi-Layered Perceptron (MLP) neural net-work model has been developed for on-line condition monitoring of tool wear in high-speed turning of Titanium-based alloy (Ti-6Al-4V). Machining trials were conducted for typical rough and finish turning operations with cutting speed (90 – 120 m/min), feed rate (0.15 – 0.2 mm/rev), and depth of cut ...
Abstract This paper presents experimental and simulation study of the effects of stress on microstructure and failure morphology of low carbon steel under plane stress conditions. The study has revealed large extension of grains at the point of fracture and, stress and strain looped around the pearlitic faces of the microstructure matrix. The stress and strain distributions in the microstructure have shown that concentration of stress and strain on the pearlite were instrumental to oblique fr...
Abstract This paper investigates the dynamical behaviour of a duffing oscillator using bifurcation diagrams. There has been growing interest and challenges in engineering dynamics to characterize dynamical systems that are chaotic using bifurcation diagrams. The relevant second order differential equations using Runge-Kutta method were solved for ranges of appropriate parameters. The solutions obtained were used to produce the bifurcation diagrams using Microsoft excel 2007. Since an average ...
ABSTRACT Solar Photovoltaic (PV) can be considered as one of the most reliable and promising renewable systems. This is of great importance for developing countries like Nigeria especially in the rural communities where there is little or no access to electricity. The use of solar energy will no doubt contribute to the improvement of the living conditions of these villag- ers. Solar PV systems have been installed in some villages in Nigeria but unfortunately, the expected benefits from us- in...
Abstract This research assessed, among others, the current status and the impact of Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) applications in the Nigerian industrial and technological sector. Two prominent cities Lagos and Ibadan were selected as centers of case studies to establish the level of the applications. Data was collected from industries within the 2 cities in the areas of manufacturing, design, production, construction and consultancy service units during a...
Abstract Abundant energy supply is the lifeblood of modern civilisation. Energy poverty arising from poor management despite appreciable energy resource base continues to be a major constraint on the socio-economic development of Nigeria. The crucial challenge of the energy sector in the country includes inadequate energy supply, its security and sustainability. In this paper we briefly examine the roles of the major primary energy forms in the country as well as some of the alternative energ...
ABSTRACT In this study, the feasibility of an artificial neural network (ANN) based model for the prediction of solar energy potential in Africa was investigated. Standard multilayered, feed-forward, backpropagation neural networks with different architecture were designed using NeuroSolutions®. Geographical and meteorological data of 172 locations in Africa for the period of 22 years (1983- 2005) were obtained from NASA geo-satellite database. The input data (geographical and meteorological...
Abstract Energy uti Iisatiou at V~)I"ki11 tile labour-i ntensi ve bui leiing industry is of prim importance to contractors who match people to jobs. This paper provides an insight into modelling energy expenditure ill a specific task, namely brick laying in various postures. It therefore lakes previous "generic" biomechanical-energy prediction models, and makes the case Ior apply: Ilg and adapting broader theoretical models to a specific occupational task. This refinement of established model...
ABSTRACT Porosity is a majw defect in cast aluminum alloys affecting in particuIm, the fatigue strength. l%e pom sewe cr9 points of saess concenmrion mdpolnts of crud initiation for evenfwI f~ilwe. In this work Fractal undysis was used to numericdy chmucferke the pores in mi-directiondly solidfleddl 4.5 WI % Cu alloy microgrqhs, nrnlsverse section at a distance of I4mm porn the mefaUchitl mold inteflme. l%e Spatial Point PaTtern (SPP) and the Multi-stage randbm samplng (MR$l methd were used 1...
ABSTRACT Power transmission shafts, such as the crankshaft, impeller shaft, propeller shafts, camshafts ere, are essential machine elements with wide application in mechanical systems. The manual shaft design procedure is known to be tedious and complex because of large numbers of formulas, many. computations and' iteration procedures involved in the design. However, the use of Computer Aided Software (CAS) offers improved accuracy, high speed computations, reduced rigorousness and cumbersome...
Abstract This work investigated the control of chaotic behavior of a harmonically perturbed DufTing Oscillator using vibration absorber. The system of two degrees of freedom governing equations were simu Eated nu rner i~allyu sing classical fourth order Runge-Kutta algorithm for a constant time step. The solution time history, phase plots and Poincare maps were usd to validate tbe simulation. Essentially, the details of the' Poincare map were used numerically to determine the periodicity ofDu...
ABSTRACT This study analyzed the connection between tribological and other forms of processes in manufacturing industries to productivity in such outfits. Results from the study showed that 54% of the visited industries recorded the highest hours of downtime due to tribological processes, while,15% and 31% of the industries had the highest downtimes hours resulting from electrical and other processes respectively. Also 23% of the total industries were observed to have more electrical faults, ...
AbstractThe effects of carburising time, temperature and percentage energiser on the case-depth and hardness of a steel ST37-2 have been studied. For carburising medium consisting of hardwood charcoal and coke and various amount of sodium carbonate as energiser, increasing carburising time and temperature increased both the depth and hardness of the case. Increasing both the amount of energiser and carburising time lowered the activation energy for the carburisation process. The average hardn...
ABmm Homeholds lequire significant amount of tnqy to meet various servicm like lighting, cooling, heating, cooking, refigeration, electronic enterhimmt ek. There's virtually any household activity that can be canried out without the use energy- The requirement fur household energy in Nigeria has been @owing over time. There are varioua energy sources available to houeolds in the country. Thy include fud woo4 charcoal, saw&& gas, petrol kerome and electricity. It is fairly settled fmm Literatu...