DSpaceCRIS@UNITENhttp://dspace.uniten.edu.my/jspuiThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Fri, 20 Apr 2018 06:34:43 GMT2018-04-20T06:34:43Z5051- Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire. Part A: Using finite element methods to develop mathematical model for wood columnhttp://dspace.uniten.edu.my/jspui/handle/123456789/10175Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire. Part A: Using finite element methods to develop mathematical model for wood column
Authors: Elshayeb, M.; Rashid Ab Malik, A.; Ideris, F.; Hari, Z.; Ab Razak, N.; Siang, J.E.L.; Anuar, Z.
Abstract: The mathematical model to predict the temperature history for wood column is needed in order to determine its fire resistance when exposed to fire. In this paper, an intelligent methodology called Finite Element Method (FEM) of performing analysis for the square and circular wood columns by virtually or artificially developing a temperature history mathematical model. Numerical simulation model has been developed for the wood column by using two-dimensional mathematical model. The two-dimensional mathematical model was developed by using Galerkin's Weighted Residual technique. This model focuses on the regional material of the wood column for describing its thermal behavior. When the temperature history in a column and relevant materials properties are known, the strength of the column can be calculated at any time during fire. Therefore, the development of the temperature history mathematical model is a must before any further study to be carried out for the wood columns. The flow of convection will result in minimal increase in the rate of heat energy reaching the column core. The analysis shows that the temperature of the column increases with respect to the duration of exposure to fire.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101752006-01-01T00:00:00Z
- Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part C: Sensitivity analysishttp://dspace.uniten.edu.my/jspui/handle/123456789/10173Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part C: Sensitivity analysis
Authors: Elshayeb, M.; Malik, A.R.A.; Ideris, F.; Hari, Z.; Razak, N.A.; Siang, J.E.L.; Anuar, Z.
Abstract: Theoretical studies have been carried out to predict the fire resistance of different configuration of wood columns as done in Part A and Part B of this set of research papers. This theoretical study is a continuation of previous studies, which were carried out at National Research Council Canada. Mathematical models to calculate the temperatures, deformations and fire resistance of the columns have been developed for Part A and Part B. Calculated results are compared with those measured in several tests. The results indicated that the model is capable of predicting the fire resistance of wood columns with an excellent accuracy. By using the model, the fire resistance of wood columns can be evaluated for any value of the significant parameters such as load, physical dimensions, mechanical properties and even the chemical properties without the necessity of experiment. This research paper carried out sensitivity analysis of a square column at elevated temperature in order to know the effect of some parameters towards the mechanical strength of the column. The parameters that have been studied are initial moisture content, Young's modulus, initial compression stress, specific gravity, thermal conductivity and the physical dimension of the column cross section. Both of the temperature history versus time for the selected elements and the fire resistance has been analyzed using existing results. All the analyses have been carried out for the square cross-section under axial load 1380 kN.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101732006-01-01T00:00:00Z
- A study of mill scale derived hematite process for NiZn ferrite as EMI suppressor in terms of magnetic propertieshttp://dspace.uniten.edu.my/jspui/handle/123456789/10172Title: A study of mill scale derived hematite process for NiZn ferrite as EMI suppressor in terms of magnetic properties
Authors: Hari, Z.; Alias, M.W.H.; Anuar, A.; Hamid, N.A.
Abstract: Mill scale iron waste from the steel industry can be extracted into useful hematite and produced into a NiZn ferrite as an EMI suppressor. The function of an EMI suppressor is to 'choke' the electromagnetic interference produced by almost all electronic equipment, electrical wiring, wireless networks, etc. The most widely used material is NiZn ferrite as it can work at high frequency. Some good characteristics of NiZn ferrite toroid core is low permeability and high loss, namely resistivity, Relative Loss Factor (RLF) impedance and coercivity. To help the environmental waste problems and reducing cost, hence the idea to convert mill scale from the steel industry waste into hematite (Fe2O3) which is the most important element in producing NiZn ferrite. Successful conversion of the mill scale into hematite was proven by X-Ray Diffraction (XRD) analysis by designing and fabricating a magnetic separator. The NiZn ferrites were prepared by solid state reaction technique. The 3 samples of different methods of hematite extraction were prepared. The ferrites were tested by XRD, Scanning Electron Microscopy (SEM), permeability, RLF and coercivity. The process of hematite conversion by running the HM sample through the magnetic separator followed by permanent magnet shows the best result. It was proven by the sample HM that has the best characteristics for an EMI suppressor such as low permeability (63.6), high RLF (1.23) and high coercivity (5.873 Oe). © Medwell Journals, 2017.
Sun, 01 Jan 2017 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101722017-01-01T00:00:00Z
- Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part B: Analysis of column temperature and fire resistancehttp://dspace.uniten.edu.my/jspui/handle/123456789/10174Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part B: Analysis of column temperature and fire resistance
Authors: Elshayeb, M.; Malik, A.R.A.; Ideris, F.; Hari, Z.; Razak, N.A.; Siang, J.E.L.; Anuar, Z.
Abstract: Mathematical models of Part A [1] are used to calculate the temperatures, deformations and fire resistance of rectangular, hexagonal, octagonal and I-cross section columns for the purpose of Part B. In this paper the comparison among the configurations of the column has been carried out to predict the temperature history for the column elements for preventing the spread of fire and prolonging the structural time collapse. The columns are varied in section size, among them are the rectangular, hexagonal, octagonal and I-cross section column of Keruing timber. The developed mathematical models defined the failure point as the point which the column can no longer support the applied load. From the comparison, the I-cross section column is the worst configuration than the other configuration.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101742006-01-01T00:00:00Z
- Evaluating engineering students performance in physics courses during foundation studieshttp://dspace.uniten.edu.my/jspui/handle/123456789/10171Title: Evaluating engineering students performance in physics courses during foundation studies
Authors: Hari, Z.; Anuar, A.; Mokhtar, M.Z.; Mokhtar, R.
Abstract: Student who intends to pursue bachelor engineering program at Universiti Tenaga Nasional (UNITEN) must undergo a one-year foundation program. For mechanical (ME) and electrical (EE) engineering students, Physics courses are among the main subjects that they need to take during their foundation study. Physic 1 generally focuses more on mechanical topics, while Physics 2 focuses more on electrical topics. This paper describes the study that was carried out in the engineering foundation programs at UNITEN to see the performance of two different students' groups (ME and EE) taking the same subject. The results from the past four years were analysed. It was found that, for Physics 1, there is no significant different between mechanical engineering and electrical students (t(636)=-1.044, p=.297 >0.05). Similarly for Physics 2, no significant different was also found ((596)=-1.929, p=.054 >0.05). This finding provides a new insight on and ongoing process to improve the teaching and learning approach for Physic courses. © 2016 IEEE.
Sun, 01 Jan 2017 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101712017-01-01T00:00:00Z