FUOYE Journal of Engineering and Technology (FUOYEJET - Federal University Oye-Ekiti)
Not a member yet
287 research outputs found
Sort by
Effect of Iron Ore Tailings Particle Sizes on the Thermal Properties of Epoxy and Polypropylene Matrix Composites
No full textThermal properties of materials such as plastic matrix composite is one of the important parameters for determining their behaviour and relevant applications. This present work focuses on determining the thermal behaviour of epoxy and polypropylene (PP) matrix composite reinforced with iron ore tailings (IOT) particulates of sizes 150 µm, 212 µm and 300 µm at various loadings of 5%, 10%, 15%, 20%, 25%, and 30%. The thermal behaviour of the developed composites was investigated experimentally using a KD2 pro thermal analyser. The results obtained from the experiment showed that increasing filler loading in epoxy leads to increased specific heat capacity and thermal resistivity. The maximum values recorded for the thermal resistivity and specific heat capacity were 0. 592°C.m/W and 2.352 J/kgK respectively. Thermal conductivity and thermal diffusivity of values 0.168W/mK and 0.089 mm²/s respectively were the lowest obtained for the epoxy matrix composite. It was also observed that addition of IOT in PP had significant effect on the thermal properties of the PP composite. Thermal conductivity and thermal diffusivity were found to increase with increased particle loading compared to the pure PP sample; the highest value being 2.235 W/mK and 5.51 mm²/s for thermal conductivity and thermal diffusivity respectively while low values of 0.05 Cm/W and 0.371 J/kgK was recorded for thermal resistivity and specific heat capacity. The presence of iron ore tailings reduces the thermal conductivity and diffusivity in epoxy but increases the conductivity and diffusivity in polypropylene. Keywords— Composite, Epoxy, IOT, Polypropylene, Composite, Thermal Conductivit
Performance Characteristics of GE Frame 8 Gas Turbine Power Plant at Different Climatic Zones in Nigeria
No full textClimatic conditions such as the ambient temperature and relative humidity has been reported to affect the performance of gas turbines. Nigeria has three major climatic zones: the tropical rain forest, savanna zone, and swampy zone. The different climatic conditions at these zones will affect the performance of power plant. In this work, the performance characteristics of a 125 MW General Electric (GE) frame 8 gas turbine plant were studied at these zones. Sokoto, Lagos and Delta states were used as the representative states for the Savanna zone, Tropical rain forest, and swampy zone, respectively. Thermodynamic analysis of various components of the gas turbine was carried out using Engineering Equation Solver (EES) software. The model developed was validated using operating data of 2016 for a currently installed power plant located in Ondo state, Nigeria. The predicted and actual power generated were observed to follow the same trend. The maximum deviation between the predicted power generated using the model developed and actual power generated is less than 4%. Results further showed that when relative humidity was considered, the power generated from the modeled gas turbine was higher than the power generated when the relative humidity was neglected. By neglecting the effect of humidity, the power output from a GE frame 8 gas turbine can be under-predicted by about 2.3%. This represents an average daily under prediction of about 65 MWh. The power generated by GE frame 8 gas turbine in the month of January was highest in Sokoto state, while the power generated in the months of April, July and October were highest in power plant located in Delta state. The power plant located in Delta state will generate 6,157 MWh and 1,244 MWh more power annually than power plants located in Sokoto and Lagos state, respectively.Kewords- Frame 8 gas turbine, Engineering Equation solver software, Performance characteristics, Nigeria, climatic zone
Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel
No full textThere is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructure
Effect of Some Thermodynamic Properties of Cutting Fluids on Machinability of Carbon Steel
No full textCutting fluids are used to reduce heat generated during machining, however some have been discovered to pose health challenges hence the search for viable alternatives. In this paper, three machining conditions (dry machining, wet machining with soluble oil and wet machining with used-engine oil) were conducted on high carbon steel, with a sole aim of investigating the suitability of engine oil as an alternative to soluble oil. Measurements related to effective use of oil as metal cutting fluids were determined and the machining parameters used were cutting speed (750 – 1750 rpm), feed rate (40 – 120 mm/rev), and depth of cut (0.1 – 0.3 mm). The experimental procedure was formulated using Minitab software version 18 and the machining responses investigated were maximum temperature at the cutting interface, surface roughness, and tool wear rate (TWR). Thermodynamic properties investigated include, flashpoint, specific heat capacity, viscosity and density. The experimental results showed that cutting temperature reduced from an average of 440oK during dry machining to 369.8oK (16% improvement) during machining with used-engine oil and 362.6oK (18% improvement) during machining with soluble oil. The surface roughness produced was generally higher while machining with used-engine oil with an average improvement of 39% in surface integrity. However, when soluble oil was used as cutting fluid, average improvement in surface integrity increased to 70%. Hence, used-engine oil offered impressive lubricating and cooling properties and could replace soluble oil as a cutting fluid during machining.Keywords—Cutting Fluid, Cutting Speed, Machining, Surface Roughness, Tool Wea
Studies on the Physicochemical and Physico-Mechanical Properties of Activated Palm Kernel Shell blended with Carbon Black filled NR Vulcanizates
Get PDFPalm kernel shell was activated using chemical activation of H3PO4 and KOH. Various amounts of activated palm kernel shell (APKS) couple with carbon black (CB) and other conventional ingredients were used to produce natural rubber vulcanizates (NR vulcanizates). The NR vulcanizates were compounded on a two-row mill and tested for its physico-mechanical properties. The results for characterization of physicochemical properties carried out on APKS were ash content (2.06%), moisture content (8.06%), %carbon (54.41%), particle size (4.00, 3.35, 2.00, 1.18mm), bulk density (0.62g/ml) and pH (5.3).The results show significant values for all, the moisture and ash content were within the recommended standard of ASTM (3-10max) and (< or =8) respectively. The filler loading concentrations CB/APKS were labeled as mixes 1 to 7. The composition of CB/APKS filler loading ratios were 30:0, 25:5, 20:10, 15:15, 10:20, 5:25, and 0:30 samples 1,2,3,4,5,6 and 7 respectively. Results obtained showed that CB/APKS filled vulcanizates exhibited improvement in the physico-mechanical properties investigated. The results obtained for CB/APKS across the samples filler loading shows that CB composition possess higher UTS, EB and rubber fatigue test while APKS filler loading composition exhibited higher hardness and young modulus. Abrasion resistance was excellent for both CB and APKS filler loading composition.Keywords: Activated Palm Kernel Shell, filler, carbon black, Chemical Activation, Natural Rubber
An Efficient Seven-Step Block Method for Numerical Solution of SIR and Growth Model
Get PDFIn this article, a new implicit continuous block method is developed using the interpolation and collocation techniques via Power series as the basis function. A constant step length within a seven-step interval of integration was adopted. The selected grid points were evaluated to get a continuous linear multistep method. The evaluation of the continuous method at the non-interpolation points produces the discrete schemes which form the block. The basic properties of the block method were investigated and found to be consistent, zero stable and hence convergent. The new method was tested on real life problems namely: SIR and Growth model. The results were found to compare favourably with the existing methods in terms of accuracy and efficiency. Keywords: Block method, Growth Model, implicit, power series and SIR model
A Model for Determining the Effect of Irregular Power Supply on Machining Foundry Products in a Developing Economy
Get PDFIn this paper, profit is maximized (or production cost is minimized) by developing an Integer programming (IP) model to determine, at a given respective unit cost, optimal numbers of outputs obtainable per production cycle (time) using public electricity generated from national grids and alternate electricity from generators subject to production output capacity or demand constraint. The results obtained showed that production cycle time has a great impact on the determination of optimal outputs for the respective conditions. Also, increase in cost of public electricity per unit product has an upper limit beyond which it has negative effect on the profitability. The results served as determinant factors for production industry in establishing the level of outputs that sustained the profitability by providing optimal cost of public electricity to operate without having any effect on the profit, at a given cycle time. Keywords— Constraint, cycle time, integer programming, optimal number, mode
The Role of State and Professional Bodies in Developing Code for Structural Concrete – Learning from other Nations
Get PDFIn order to arrest the rampant structural failures of buildings, there have been call for the development and adoption of structural design codes that will capture all relevant environmental issues that are peculiar to Nigeria. This paper presents the results of analysis of data collected from the public domain (libraries and internet sources) on Nations with acceptable structural design codes in concrete and allied materials. Some of the findings are that: (i) Code or Standard does not necessarily need to be a legal document or backed by the state to enjoy wider acceptance or be recognized, (ii) it is possible for people in the same professions to form professional association and regulate the operation of the profession by setting standard of practice which can be recognized, not only by people, but also acceptable to the State and (iii) whether a standard developed as a legal document or recommendations of professional association, openness and consideration for the inputs for all are necessary. This is to ensure that the operation of the standard will not run contrary to the public good, or in violation of the common law, or infringe the rights of a subject/citizen. Keywords — Building failures, Codes, Concrete, Legal document, Professional bodies, Structures
A Mobile Percussograph for Medical Examination of the Torso
No full textMedical percussion is a free, low-risk procedure used by physicians during physical examination of patients. Although it is very useful procedure, a downside to manual percussion is that its results are subjective, with typically low inter-observer agreement. Not much work has been done, however, to create automated and reliable percussion devices or percussograph. This paper reports the development of a mobile percussograph. A spring-loaded solenoid was used as the plessor generating mechanical impact for application to a subject’s skin. Generated signals were amplified and digitized at a rate of 22.1 kHz. Thereafter, Frequency B-Spline (FBSP) base wavelet transform at 512 scales was used for feature extraction. Spectrographs generated from the wavelet coefficients were used for training a MobileNet network with 17 inverted layers for a 3-way classification. Training employed a cross entropy loss function and the Adam optimization algorithm. Learning rate was 0.001, and first and second moment decay rates were 0.9 and 0.999 respectively. Subject-specific test accuracies of 92.9 %, 93.7 %, and 96.4 % were obtained for three subjects, while the cross-subject classification accuracy was 95.0 %. As this is the first reported general purpose mobile percussograph reported in the literature, these results are state-of-the-art. This study has established the viability of implementing mobile percussography in a standard, repeatable and accurate manner, which can lead to faster and more reliable medical percussion globally.Keywords— MobileNet, Percussion, Percussograph, Percussography, Wavelet
Computer Aided Modelling of the Impact of Irregular Power Supply on Machining Foundry Products
No full textComputer aided models such as Dynamic, Quadratic, and Integer programming have been developed to solve production challenges relating to Manpower, Inventory and Maintenance assuming constant and regular power supply, which is a hard condition to meet in a developing country like Nigeria where power supply is irregular. This paper developed a Computer aided model to address this challenge using Integer programming (IP), by considering profit (Z) as a function of cost and revenue of a machined foundry product. Software was developed to serve as database and the same time analyzed complex mixed – model system where parallel workstation, shift or batch production is allowed. The software was designed to have graphic user interface (GUI), which enable the user to input data like values of product code (identification number for each product), capacity of machine, established unit cost of production, production cycle time, selling cost and the unit cost of production to determine the impact when electricity power from national grid is used, as opposed to fueling a diesel-engine generator, for machining foundry products. Costs and production capacity data were collected from Ruthade Foundry Engineering Services, Akure, Ondo State, to validate the model. The results revealed that output per unit time is higher when power from national grid is holistically utilized than when power from generator was used for machining foundry product. The results serve as genuine guiding tool for foundry operators in selecting a particular course of action on electricity utilization during production and enhance sustainability of production industry. Keywords— Constraint, cycle time, integer programming, Microsoft Visual Basic, model, optimal numbe