ABSTRACT This paper presents a new methodology for weld-metal properties optimization from welding flux ingredients. The methodology integrates statistical design of mixture experiment with mathematical programming optimization technique. The mixture experiment is responsible for the modeling of the weld-metal properties as a function of welding flux levels while mathematical programming optimizes the model. Data and confirmed models from the literature were used to perform optimization on th...
ABSTRACT . The ice-maker freezer) was designed, constructed and tested. The ice-making machine is to freeze 27kg of water in 9 diflerent comparlments in 12 hrs. The quantity of heat lo be rmoved in order to achieve peezing is 12556.89 and this is used to determine the refiigeration tonnage of the machine (0.124 ton).' Polyurethane and Galvanized steel sheets have been selected for insulation and cabinet materials respectively due to their low thermal conductivities and high 'corrosion resista...
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 A gas-fired oven for commercial production of bread was designed and constructed using locally available material, and was subjected to various'tests to come out with its performance characteristics. Itsperformance was evaluated and then compared withsrespect to the total time required to bake a specified mass of white flour dough using the gas oven with that used by clay wood fired oven for the same mass of white flour dough. ., The outcome of the test result indicated that the ni&x...
ABSTRACT A survey was carried out to identify the types of crops popularly stored, the structures commonly used and problems experienced with produce storage in the Kingdom of Swaziland. Respondents included operators of government storage facilities, non-governmental organizations providing food relief, millers, large-scale farms, homesteads and artisans who fabricate metal tanks. Maize, the national staple food, was stored by all homesteads essentially for family consumption. It was the com...
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...
Photovoltaic Characteristics of Thin Film of CU2SNS3
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. The level of utilization of many public utilities is, most often. influenced by their locations. Huge public funds are spent annually on the provision of several public infrastructures, such as pedestrian bridges, that are grossly underutilized due to their poor location or citing. This study was aimed at developing a fuzzy logic based decision support system for the optimal location of pedestrian bridges in a typical Nigerian city. Various factors. and their interactions. that affe...
Abstract: Fiscal regimes are very important in the global Petroleum Exploration and Production (E&P) industry. They sharpen policies, management strategies and revenue (take) by governments while defining the attractiveness of the industry to investors. One of the major parameters in fiscal regimes is royalty oil, which could be fixed or adjustable on a sliding scale. Nigeria, which has used fixed royalty scale since the first oil in 1958, is now proposing a change to the sliding royalty scal...
Abstract The welding workstation usually generates intense heat during operations, which may affect the welder's health if not properly controlled, and can also affect the performance of the welder at work. Consequently, effort to control the conditions of the welding workstation is essential, and is therefore pursued in this paper. This paper develops a mathematical model that maximises the work output while minimising energy consumption at the welding workstation. Particular emphasis is pla...
ABSTRACT The Power Holding Company of Nigeria (PHCN) is responsible for generating, transmitting, distributing and selling electric power to the various consumers throughout the country. The paper presents the results of an investigation conducted on some of the operations of Power Holding Company of Nigeria (PHCN) to determine some of the major factors affecting the availability of power supply to consumers in Benin City area of Nigeria. The average number of operating transformers in va...