IIUM Engineering Journal
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NATURAL CONVECTIVE HEAT TRANSFER IN A POROUS MEDIUM WITHIN A TWO DIMENSIONAL ENCLOSURE
Get PDFIn this paper, to achievement the effect of increase number of heating components arrangement on the rate of heat transfer of natural convection, that others have been less noticed. Therefore, in each stage increase the number of heating components so much the space occupied by them remains constant. Then by calculating the amount of heat transfer in different Rayleigh number became clear that minify and distributing heating solid phase in the enclosure increases the total Nusselt number and heat transfer, One reason could be high intensity of fluid motion in corners and near walls of the enclosure. In the next section with the solid phases on the enclosure can be made porous media model. As the results showed an increase in average Rayleigh number, Nusselt number has increased. Also be seen in the lower Darcy numbers, speed of increase in Nusselt number with increase in average Rayleigh number is higher. It can be said that in enclosure by any number of solid pieces with certain Darcy number, with an increase in average Rayleigh number, circular flow inside the enclosure becomes more intense and isothermal lines near walls with constant temperature are so dense, that represents an increase in rate of heat transfer. Also by increasing the Darcy number, rate of heat transfer from the porous media has decreased, as regards that a large share of heat transfer in porous media is done by conduction, although increasing Darcy number increases heat transfer of natural convection but decrease a heat transfer of conduction, therefore decrease total of heat transfer
PURIFICATION AND PARTIAL CHARACTERIZATION OF L-ASPARAGINASE ENZYME PRODUCED BY NEWLY ISOLATE BACILLUS SP.
Get PDFA newly bacterial producing L-asparaginase was successful isolated from Sungai Klah Hot Spring, Perak, Malaysia and identified as Bacillus sp. It was the best L-asparaginase producer as compared to other isolates. Production of L-asparaginase from the microbial strain was carried out under liquid fermentation. The crude enzyme was then centrifuged and precipitated with ammonium sulfate before further purified with chromatographic method. The ion exchange chromatography HiTrap DEAE-Sepharose Fast Flow column followed by separation on Superose 12 gel filtration were used to obtain pure enzyme. The purified enzyme showed 10.11 U/mg of specific activity, 50.07% yield with 2.21 fold purification. The purified enzyme was found to be dimer in form, with a molecular weight of 65 kDa as estimated by SDS-PAGE. The maximum activity of the purified L-asparaginase was observed at pH 9 and temperature of 60°C
THE PHILOSOPHICAL FOUNDATIONS OF MODERN BIOENGINEERING
Get PDFThis paper investigates the philosophical foundations of modern bioengineering to articulate its ethical framework. Engineering as an ultimate mechanism to transform knowledge into practice is essential for both physical and biological sciences. It reduces data, concepts, and designs to pictorial forms. The integration of engineering with the newly emerging biosciences, has presented a unique opportunity to overcome the major challenges that face the environmental and human health. To harness potentials of bioengineering and establish a sustainable foundation for green technology, modern scientists and engineers need to be acquainted with the normative questions of science. In addition to acquiring the general principles of scientific research and identifying the intrinsic goals of the endeavour, philosophy of bioengineering exposes bioengineers to both the descriptive ‘how’ questions of the physical world as well as the normative ‘why’ questions of values. Such an interdisciplinary approach is significant, not only for inspiring to acquire the genuine knowledge of the existing world, but also to expose the bioengineers to their ethical and social responsibilities. Besides introducing the conceptual framework of bioengineering, this paper has investigated the three major philosophies that have been dominating the theoretical presuppositions of scientific research method in history. Namely, (i) Systems biology approach; (ii) Evolutionary biology approach; and (iii) Mechanical view approach. To establish the ethical foundation of modern bioengineering, the paper, also has conducted an analytical study on various branches of the emerging discipline of bioscience.The paper has concluded that adopting the interdisciplinary approach in research and education is essential to harness potentials of bioengineering and to establish foundations of green technology. To achieve the final objectives of bioengineering, both the practical and theoretical knowledge of values must be acquired. The former is essential for invention and innovation; meanwhile the later exposes bioengineers to the integrated discipline of knowledge and values.Â
A BRIEF ACCOUNT OF RIVER REHABILITATION EXPERIENCES
Get PDFRehabilitation of polluted rivers has gained great importance to many countries in the world since the last century as the river is a vital water resource and it is being altered because of urbanization and industrialization causing great threat to the environment. Literatures on river rehabilitation projects have been reviewed focusing on the developing part of the world such as USA, UK, Japan etc. Rehabilitation issues of rivers crossing borders have also been discussed in this paper. Key lessons from different experiences in different regions have been extracted and comparison has been done. Statistics on different experiences has also been presented. Finally, some guidelines have been provided based on different experiences, which should be helpful for developed and developing nations making river rehabilitation efforts
LIPS TRACKING IDENTIFICATION OF A CORRECT QURANIC LETTERS PRONUNCIATION FOR TAJWEED TEACHING AND LEARNING
Get PDFMastering the recitation of the holy Quran is an obligation among Muslims. It is an important task to fulfill other Ibadat like prayer, pilgrimage and zikr. However, the traditional way of teaching Quran recitation is a hard task due to the extensive training time and effort required from both teacher and learner. In fact, learning the correct pronunciation of the Quranic letters is the first step in mastering Tajweed (Rules and Guidance) in Quranic recitation. The pronunciation of Arabic letters is based on its points of articulation and the characteristics of a particular letter. In this paper we implement the lip identification technique from video signal acquired from expert to extract the movement data of the lips while pronouncing the correct Quranic letters. The extracted lip movement data from expert helps in categorizing the letters into 5 groups and in deciding the final shape of the lips. Later the technique was then tested among a public reciter and then compared for similarity verification between the public and the professional reciter. The system is able to extract the lips movement of the random user and draw the displacement graph and compared with the pronunciation of the expert. The error will be shown if the user has mistakenly pronounced the letter and suggested for improvement. More subjects with different background will be tested in very near future with feedback instructions. Machine learning techniques will be implemented at later stage for the real time application for learning process
RADIATION PERFORMANCE OF GAN AND INAS/GAAS QUANTUM DOT BASED DEVICES SUBJECTED TO NEUTRON RADIATION
Get PDFIn addition to their useful optoelectronics functions, gallium nitride (GaN) and quantum dots (QDs) based structures are also known for their radiation hardness properties. With demands on such semiconductor material structures, it is important to investigate the differences in reliability and radiation hardness properties of these two devices. For this purpose, three sets of GaN light-emitting diode (LED) and InAs/GaAs dot-in-a well (DWELL) samples were irradiated with thermal neutron of fluence ranging from 3×1013 to 6×1014 neutron/cm2 in PUSPATI TRIGA research reactor. The radiation performances for each device were evaluated based on the current-voltage (I-V) and capacitance-voltage (C-V) electrical characterisation method. Results suggested that the GaN based sample is less susceptible to electrical changes due to the thermal neutron radiation effects compared to the QD based sample
CENTRIFUGAL COMPRESSOR EFFICIENCY CALCULATION WITH HEAT TRANSFER
Get PDFIn this paper we present a case study of apparent performance variation ofan optimized centrifugal compressor design when its metal parts are cold - before the conjugated heat transfer between the fluid and parts reaches an energetic equilibrium. The methods used are numerical, using full viscous 3D computational fluid dynamics with heat transfer. Three cases were considered, an adiabatic wall baseline, an all-blade cooling at 293 K and a more realistic stator row cooling at 293 K. Results indicate an apparent yet erroneous isentropic efficiency reading increase beyond 100% - which was to be expected due to the fluid cooling. However the isentropic and polytropic efficiencies could be estimated and were used to more accurately assess the performance of the compressor. Power consumption decreased to approximately 97% of the original load while the pressure ratio was marginally increased. This alone does not, however, explain the non-physical efficiency readings, which are mainly due to the assumptionsand manner under which the efficiency itself is calculated. The paper presents a more robust approach to measuring efficiency, regardless of the heat transfer within the turbomachinery itself. Possible applications of the study may range from cold-start regime simulation to the optimization of inter-cooling setup or even flow angle control without mechanically actuated OG
A DIFFERENT APPROACH IN OPTIMUM DESIGN PROCESS AND FEA VALIDATION OF LOW-SPEED MULTI-PHASE IPMSMS
No full textMagnets placement effects on permanent magnet motors performance, because of its different magnetic flux density distribution. Therefore, different types of magnet placement should be examined experimentally or by valid simulations. In this paper, first, an interior permanent magnet synchronous motor (IPMSM) called spoke type with specifications related to the propulsion of ships is designed and then optimized by ant colony algorithm to increase the torque-to-volume ratio. The design procedure and its formulas presented as simple as possible. Then, to verify the optimization results of the optimized motor, a Two-dimensional finite element analysis (FEA) is done. Also in this analyze the core and the slot saturation was studied
A STUDY ON CAPABILITIES OF DIFFERENT ELECTRODE MATERIALS DURING ELECTRICAL DISCHARGE MACHINING (EDM)
Get PDFElectrode material inelectro discharge machining EDM process plays an important role in terms of material removal rate (MRR), electrode wear rate (EWR) and surface roughness (Ra). The purpose of this research is to investigate the capability of different electrode materials: copper, aluminum and graphite in EDM of AISI 304 stainless steel as a work piece. The research focuses on three current settings: 2.5A, 4.5A and 6.5A using kerosene as dielectric fluid. The experiment is planned and analyzed using full factorial of the experimental design using response surface methodology (RSM). two outputs have been investigated: MRR and EWR. The results indicated that the responses increased with the increase in current. Finally the desirability function method have been used to determine the optimum values. The resulat show that the maximum MRR and  the minimum EWR were achieved by using graphite electrode at current 6.5A
COMMUNITY BASED HOME ENERGY MANAGEMENT SYSTEM
Get PDFIn a Smart Grid (SG) scenario, domestic consumers can gain cost reduction benefit by scheduling their Appliance Activation Time (AAT) towards the slots of low charge. Minimization in cost is essential in Home Energy Management Systems (HEMS) to induce consumers acceptance for power scheduling to accommodate for a Demand Response (DR) at peak hours. Despite the fact that many algorithms address the power scheduling for HEMS, community based optimization has not been the focus. This paper presents an algorithm that targets the minimization of energy costs of whole community while keeping a low Peak to Average Ratio (PAR) and smooth Power Usage Pattern (PUP). Objective of cost reduction is accomplished by finding most favorable AAT by Particle Swarm Optimization (PSO) in conjunction with Inclined Block Rate (IBR) approach and Circular Price Shift (CPS). Simulated numerical results demonstrate the effectiveness of CPS to assist the merger of PSO & IBR to enhance the reduction/stability of PAR and cost reduction