FUOYE Journal of Engineering and Technology (FUOYEJET - Federal University Oye-Ekiti)
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Computational Fluid Dynamics Modelling of the Heat Pump Drying of Banana: Preliminary Studies
Get PDFThe distribution of local temperature, moisture and velocity gradients obtained in CFD calculations can be used to develop models for predicting the parameters in a drying process. This article reports a preliminary result on the efforts to characterizing the performance of a heat pump dryer using Computational Fluid Dynamics (CFD). A three dimensional, pressure based, transient, laminar, incompressible model of heat pump drying of banana slices using Ansys 14.5 (15), a CFD package- FLUENT was investigated. Turbulent cases were also examined. The geometry was considered as elemental volume with symmetrical walls while the banana slices were designed as solids with pores containing a mixture of water and air. Parameters/variable/geometry investigated include velocity, moisture and temperature distribution of the air within the dryer and of the banana slices. The result of the numerical simulation was validated with experimental results from a heat pump dryer and there were agreements. The model is successful in predicting the temperature profile and mass fraction of moisture. Keywords— Ansys, Banana, Computational Fluid Dynamics (CFD), Contour plots, Drying, Velocity and temperature distributio
Performance Evaluation of Kernel-Based Feature Extraction Techniques for Face Recognition System
Get PDFFace recognition is considered to be one of the most reliable biometrics where security issues are of concerned. Feature extraction which is a functional block of a face recognition system becomes a critical problem when there is need to obtain the best feature with minimum classification error and low running time. Most existing face recognition systems have adopted different non-linear feature extraction techniques for face recognition but identification of the most suitable non-linear kernel variants for these systems remain an open problem. Hence, this research work analyzed the performance of three kernel feature extraction technique (Kernel Principal Component Analysis, Kernel Linear Discriminant Analysis and Kernel Independent Component Analysis) for face recognition system. A database of 360 face images was created by obtaining facial images from LAUTECH Biometric Research Group consisting of six facial expressions of 60 persons. Images were preprocessed (gray scaling, cropping and histogram equalization) and the kernel variants were used to extract distinctive features and reduce the dimensionality of each of the images from 600x800 pixels to four smaller dimensions: 50x50, 100x100, 150x150 and 200x200 pixels. Euclidean Distance similarity measure was used for classification. The performance of the three kernel variants was evaluated for face recognition system using 180 images for training and 180 images for testing using the following metrics: Recognition Accuracy (RA) and Recognition Time (RT). Empirical result indicate that KLDA performs best for face recognition system with an average accuracy of 94.52%. The larger image dimension also results in better recognition performance. We intend to experiment on other classifiers for face recognition system in our future work. Keywords— Biometrics, Face, Feature extraction, Kernel, KICA, KPCA, KLDA, Linear, Non-linear
Applications of Materials Science and Engineering in the Pharmaceutical Industry; a Short Review and the Current State in Nigeria
No full textThis paper briefly reviews the applications of materials science and engineering in the pharmaceutical industry. The materials characterization techniques highlighted in the paper as being utilized in the pharmaceutical industry are dynamic light scattering and photon correlation spectroscopy, mercury intrusion, gas density pycnometry and energy density analysis, thermogravimetric analysis and differential scanning calorimetry, x-ray diffraction, nuclear magnetic resonance and Raman microscopy. The other areas of applications of materials science and engineering in the pharmaceutical industry briefly discussed are materials processing, materials research and development, and materials selection. This paper further highlighted that the program as it is currently offered by various institutions in Nigeria is yet to incorporate the courses in pharmaceutical materials. It concluded by pointing out that some institutions outside Nigeria have incorporated pharmaceutical materials in the programs of materials science and engineering. Suggestions were made for the materials science and engineering programs in Nigeria to build further capacity for effective applications in the pharmaceutical industry. Keywords— Applications, materials engineering, pharmaceutical industr
Tribological and mechanical behaviours of nanostructured aluminium alloys and nanocomposites at elevated temperatures: A short review
No full textAluminium alloys demonstrate exceptional properties such as high strength-weight ratio and corrosion resistance are used for general engineering applications, automobile, automotives and in aerospace industries. However, they suffer some limitations as wear and creep at high temperatures. With the trending developments from nanometallurgy, diverse nano-particle compounds of mono and heterogeneous compositions have been used in reinforcing aluminium and its alloys as widely reported in the public domains. This paper reviews some of the vast literature on the enhancement of nanostructured aluminium alloys and reinforced aluminium nanocomposites. Importance is laid on the tribological and mechanical behaviours of the manufactured composites and nano-composites with respect to their production methods and applications at elevated (high) and cryogenic (low) temperatures. Keywords— Tribology; mechanical behaviours; nanostructure; aluminium alloys; nano-composites; elevated temperatures
Investigating Predictive Capabilities of RBFNN, MLPNN and GRNN Models for LTE Cellular Network Radio Signal Power Datasets
Get PDFEfficient radio frequency signal coverage planning with well configured transmitters and receivers’ communication channels, is the heart of any cost-effective cellular network design, deployment and operation. It ensures that both network quality and coverage are simultaneously make best use of (i.e. maximized). This work aim to appraise the adaptive learning and predictive capacity of three neural network models on spatial radio signal power datasets obtained from commercial LTE cellular networks. The neural network models are radial basis function neural network (RBFNN), multilayer perceptron neural network (MLPNN) trained with Bayesian regulation algorithms and general regression neural network (GRNN) models. Largely, it is established from the results that ANN prediction methods can tolerate and adapt to measurement errors of attenuating LTE radio signals. Performance comparisons reveal that all the neural network models can predict the propagated LTE radio signals with considerable errors. Specifically, RBFNN delivered the overall best performance with the smallest mean absolute percentage error, root mean square error, mean absolute error and standard deviation values. The GRNN model also gave better prediction results with marginal errors compared to the MLPNN. Thus, the predictive abilities of RBFNN and GRNN models can be explored as a useful tool to successfully plan or fine-tune mobile radio signal coverage area. Keywords: Neural networks; Signal power; attenuating radio signals; radial basis function multilayer perceptron, general regression neural network, Adaptive signal predictio
Effects of Welding Power Input on the Microstructure and Impact Toughness of the Heat Affected Zone of 304L Austenitic Stainless Steel
Get PDFThe effects of welding power input on the microstructural characteristics and impact behaviour of the Heat Affected Zone (HAZ) of type 304L austenitic stainless steel were investigated. This is with a view to optimize the welding process and ensure high weldment integrity of the heat affected zone. Chemical analysis of the as-received 304L austenitic stainless steel was determined using an Optical Emission Spectrometry AR 4 30 metal analyzer. Thereafter, 30 samples of the as-received 304L austenitic stainless steel plate with dimensions of 70 mm length, 45 mm breadth and 8 mm thickness were cut and labeled into A, B and C each of 10 numbers. The grouped samples were further cut into two equal halves with hacksaw and welded using Gas Metal Arc Welding (GTAW) process and 304L electrode to produce butt joint HAZ square geometry samples. The obtained HAZ and as-received samples were machined to standard charpy impact test specimens. Also, the HAZ and as-received specimens were prepared for microscopy studies using optical microscopy. Results obtained showed that the microstructures are composed majorly of mixture of austenite and ferrite phases, also variations in volume fraction and grain size of the phases were observed under varied range of power input. In addition, chromium carbide formation and precipitation due to sensitization was seen at the grain boundaries. Optimum impact toughness (IT) of 42 J was obtained for HAZ sample at power input of 12.0 KW while the least IT of 39 J was obtained from sample welded using power input of 4.6 KW as compared with the as-received with IT of 58 J.Keywords - 304L austenitic stainless steel; gas metal arc welding; impact toughness; microstructures
Study of High Viscous Multiphase Flow Using OLGA Flow Simulator
Get PDFThe continuous depletion of conventional reserves of the world oil and gas has spurred investigation towards the exploration and production from unconventional sources of hydrocarbons such as heavy oil. However, heavy oils are known for their high liquid viscosities making them even more difficult and expensive to produce and transport in pipelines at ambient temperatures. As a consequence of this, a critical understanding of multiphase flow characteristics is vital to aid engineering design it has become imperative to investigate the rheology of high viscosity oils and ways of enhancing its production and transportation. In this study, the characteristics of high viscous oil flows were studied using OLGA flow simulator. A comparison between simulation results from the flow simulator and those of data acquired for high oil-gas viscosity experiments (i.e. for oil viscosity ranging from 0.7-5.0 Pa.s) for two phase flow parameters such liquid holdup and pressure gradient exhibited huge discrepancies and under prediction. Keywords— High viscosity oil, Liquid holdup, OLGA, Pressure gradien
Dynamical Control Model of the Cascaded Kainji-Jebba Hydropower Operating Head
Get PDFOperation and design of control system for the cascaded Kainji-Jebba hydropower system poses a great challenge to researchers and engineers. The difficulties arose from the fact that the system is affected by several nonlinear interacting factors such as variations in inflows, stochastic factors that are weather related, availability of the turbo-alternators, and numerous other constraints that are influenced by the system dynamics. All these makes the mathematical representation of the system difficult. This paper presents the development of a dynamical model for the operation and optimal control of the operating heads of the cascaded system. The mathematical models were developed from energy conversion equation and Bernoulli’s equation. The model was calibrated and tuned using measured data. Upon validation by comparing the response of the model with measured head, a deviation within was observed, making it a good prediction of the system response and appropriate for control system design. Keywords— Control model, Discharge, inflows, Operating head, Turbo-alternator
Optimal Setting of Interline Power Flow Controller for Congestion and Contingency Management
Get PDFThe effect of outages in transmission lines and generator units can be predictable for stable and reliable operation of power system through contingency assessment. Hence, contingency assessment is an important task for stable and effective operation of power system. In this paper, a method of placement of interline power flow controller (IPFC) based on the probability of severity has been proposed. Contingency ranking of lines has been done using Composite Severity Index which is a probabilistic based strategy for the placement of IPFC. IPFC is placed on the line with highest probability of severity during the occurrence of different outages. Thereafter, the size of the IPFC was optimized using cuckoo search algorithm. The proposed methodology has been applied on the IEEE 14 bus system data and results presented. The system overall CSI, active and reactive power were reduced by 7.31%, 10.17% and 14.46% respectively. The results show that optimal placement of IPFC effectively reduces line congestion, improves voltage stability and reduces the active and reactive power loss of the system.Keyword- Power Flow, line utilization factor, severity index, Contingency Managemen
A Study on Suitability of Foamed Sandcrete Solid Block with Fly-Ash as Partial Replacement of Sand
Get PDFIn this study, the properties of foamed sandcrete solid block (FSSB) with varying percentage of sand replacement with fly-ash were investigated. These properties include workability, wet and dry density, stability, water absorption capacity and compressive strength. 150mm cube specimens were used for the determination of both the compressive strength and the dry density of the FSSB. The plastic density was investigated using a container of known volume, and its workability determined using the slump test. The fly-ash content was varied from 0 to 50% at interval of 10%. The specimens without the fly-ash served as the control. At the designed density of 1500kg/m3, the results for the control specimens at 28 day curing age was 3.74N/mm2. As for 50% sand replacement with fly-ash, the compressive strength were 2.37 N/mm, and 3.31 N/mm2 at 7-days 28-days curing age respectively, both satisfied the minimum compressive strength of 1.8N/mm2 and 2.5N/mm2 at the curing age of 7-days and 28-days respectively for conventional sandcrete block for building wall unit as allowed by Nigerian Industrial Standard (N.I.S). The result also shows an appreciable decrease in density of FSSB with 1411.8kg/m3, as compared to dense sandcrete solid block with average of 1950kg/m3, which will significantly reduce the overall dead load of the building structure. FSSB with 50% sand replacement with fly-ash also showed a much improved water absorption capacity of 9.81% as control specimen of 11.73%. Fly-ash can be used to reduce the quantity of sand used in FSSB production; thus ridding our environment of potentially harmful wastes, as well as reduce the consumption of non-renewable resources. Keywords— Foamed Sandcrete, Compressive Strength, fly-ash, dry density, stability, cemen