Skip Navigation LinksVolume : Volume 14 No.2 2005

  
  
  
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voltage_regulation_of_uninterrupted_power_supplies.pdfVOLTAGE REGULATION OF UNINTERRUPTED POWER SUPPLIES
  
ABSTRACT:
Uninterrupted Power Supply (UPS) systems are used as a solution to power quality problems and to provide ultimate protection for power disturbances   such as power blackouts and brownouts. Many UPS systems suffer from poor   output voltage regulation especially with heavy loads. This work is aimed to design   and implement the UPS system capable of producing continuous and constant  230Vac' 50 Hz output supply. A feedback loop has been implemented using   microcontroller to adjust the de level supplying the UPS inverter. Tests have been   carried out to determine the reliability and effectiveness of the designed system,   and good results have been obtained in improving the voltage regulation.       

KEYWORDS: UPS, voltage regulation, batteries, power continuity, AMF

Author: J. Jasni, S. M. Bashi and N. Mariun
Year: 2005
review_of_advances_in_transformer_dielectric_insulating_fluids.pdfREVIEW OF ADVANCES IN TRANSFORMER DIELECTRIC INSULATING FLUIDS
  
ABSTRACT :
This paper discusses a summary of recent work on a natural edible seed-oilbased dielectric fluid. Evidence has shown some property deficiencies with the presently used petroleum and mineral oils for transformer cooling. The present efforts by researchers to develop  and provide alternative means of cooling and insulating transformers is pivoted around the   obvious importance of transformers in electrical power supply network. Most important is the  ability of natural vegetable dielectric fluids to comply with environmental and health regulation  laws in cases of spillage.   The treated natural vegetable oils have been found to meet specifications since they have high flash points (up to 300°C), high fire points (250°-300°C), lower pour points (50KV). These conditions comply with IEEE C57, IEEE   637, ASTM 06781 and IEC 60296 (standards). Finally, its biodegradability makes it safe for use in densely populated areas and close to waterways. Today, not only technical performance   is of essence in material selection, but also the overall environmental and total life-cycle cost is   becoming part of the analysis. Malaysia stands to gain a lot from this type of research, since   it is one of the world leaders in palm oil production.       

KEYWORDS : Transformer oil, insulating vegetable fluid, vegetable oil coo

Author: S M Bashi, Robia Yunus, M. Mohibullah , U. U Abdullahi and A. N. Abdul Aziz
Year: 2005
retrofitted_engine_performance_and_emissions_comparison_with_gasoline_and_natural_gas_fuel.pdfRETROFITTED ENGINE PERFORMANCE AND EMISSIONS COMPARISON WITH GASOLINE AND NATURAL GAS FUEL
  
ABSTRACT :
Natural gas is considered to be a desirable fuel by energy experts, policy makers   and environmentalists alike. As the whole world is concerned about air pollution and energy   security, the future engine manufacturers are committed to lowering automotive emissions. High   octane rating of compressed natural gas (CNG) allows the CNG powered engine to operate with   a high compression ratio and produce more power. For efficient use of the natural gas engines as   an alternative to gasoline, the enhancement of engine performance is an absolute necessity. In  the present study, Magma 12 valve spark ignition retrofitted engine was run on gasoline and   natural gas. The performance and exhaust emissions of the engine were analysed and compared   for the two fuels. Based on the experimental results, it is clear that natural gas shows lower emissions of CO, C02 and HC, low specific fuel consumptions, low power and higher NO.. It is  evident that new direct injection compressed natural gas (CNG/DI) engine will offer the potential   for significant performance and emissions benefits compared to gasoline/retrofitted engine. 

KEYWORDS : Engine performance, alternative fuel, compressed natural gas, air pollution,   energy security     

Author: M.U. Aslam, H.H. Masjuki, M.A. Maleque and M.A. Kalam
Year: 2005
removal_of_phenol_and_cod_via_catalytic_treatment_using_activated_carbon_and_alumina_with_ozone.pdfREMOVAL OF PHENOL AND COD VIA CATALYTIC TREATMENT USING ACTIVATED CARBON AND ALUMINA WITH OZONE
  
ABSTRACT:
The removal of aqueous phenol and COD (chemical oxygen demand) was examined by ozonation, adsorption and catalytic ozonation with granular activated carbon (GAC) and alumina. Adsorption and catalytic ozonation tests were performed   on 100 ppm phenol at 30°C. Results of the experiments indicated that GAC removed   up to 71.2% of phenol and 75.4 % of COD in two hours via adsorption, and is potentially a promising adsorbent to remove phenol compared to alumina, which does not remove phenol and COD to any significant extent. Add ition of ozone into the system resulted   in larger phenol removal with 100% and 95.1 % removal achieved by GAC and alumina  respectively. However, the COD removal achieved by ozonation with GAC was more  complete with 93.4% removal compared to alumina with 57.9% removal. Therefore, combination of ozone with GAC is potentially a suitable alternative to treat wastewater containing phenol.       

KEYWORDS : Ozonation, catalytic ozonation, phenol, alumina, activated carbo

Author: Nor Aishah Saidina Amin, Harjit Kaur Man Singh and M. Rashid
Year: 2005
pointing_performance_of_combined_energy_and_attitude_control_system.pdfPOINTING PERFORMANCE OF COMBINED ENERGY AND ATTITUDE CONTROL SYSTEM
  
ABSTRACT :
Combining the conventional energy and attitude control system is a   feasible solution for small satellites to improve the space missions. In this combined   energy and attitude control system (CEACS) a double rotating flywheel in the pitch   axis is used to replace the conventional battery for energy storage as well as to   control the attitude of an earth oriented satellite. Each flywheel is to be controlled in   the torque mode. The energy and attitude inputs for the flywheels' control architecture   are also in the torque mode. All related mathematical representations along with the   relevant transfer functions are developed. The required numerical calculations are performed using Matlab™ for studying the system performances. The goals of this work are to determine the CEACS attitude performance in the torque mode with   respect to the ideal and non-ideal test cases for chosen reference missions.       

KEYWORDS : Attitude control, energy storage, flywhee

Author: Ibrahim Mustafa Mehedi and Renuganth Varatharajoo
Year: 2005
improvement_in_machine_performance_to_reduce_development_time_for_new_model_in_automotive_industry_-.pdfIMPROVEMENT IN MACHINE PERFORMANCE TO REDUCE DEVELOPMENT TIME FOR NEW MODEL IN AUTOMOTIVE INDUSTRY
  
ABSTRACT :
A study of improvement in machine performance to reduce   development time for new model in automotive industry is presented in this   paper. The approach taken are by studying the exist ing practice in car  development and suggesting various ways for method improvement such as   through the reduction in errors during software introduction , the increase of   automation and the increase in machine safety. The result s are summarised   in a table through SWOT analysis.       

KEYWORDS : Machine improvement, automotive industry, time reducti       

Author: N.M.Z.N. Mohamed, H.Y. Sastra, S.M. Sapuan, N. lsmail and A.B. A . Hamid
Year: 2005
harmonic_reduction_in_three-phase_single_switch_power_factor_correction_circuit.pdfHARMONIC REDUCTION IN THREE-PHASE SINGLE - SWITCH POWER FACTOR CORRECTION CIRCUIT
  
ABSTRACT :
Diode rectifiers are commonly used at the front end of a power converter   as an interface with the electric utility. The rectifiers are nonlinear and generate  harmonic currents into the ac power source. A harmonic injection technique, which   reduces the line frequency harmonics of single switch three-phase boost rectifier,   was developed in this study. In this method, a periodic voltage was injected into the   control circuit to vary the duty cycle of the rectifier switch within a line cycle so that the fifth-order harmonic of the input current is reduced to meet the total harmonic   distortion (THD) requirement. As the injected voltage signal that is proportional to   the inverted ac component of the rectified three-phase line-to-line input voltage is   employed; the injected duty cycle variations are inherently synchronized with the  three-phase line-to-neutral input voltage. 

KEYWORDS : Discontinuous conduction mode, harmonic injection, boost converter,  power factor correction              

Author: S.M. Bashi, N. Mariun and H.S. Athab
Year: 2005
friction_materials_for_brakes_application.pdfFRICTION MATERIALS FOR BRAKES APPLICATION
  
ABSTRACT :
In this paper, an overview on the friction materials fo(brakes is  presented. Friction materials are used in components such as clutch facings, brake pads and linings in which elements of a controlled friction level are necessary. They have more stringent requirements than almost any other sliding components, therefore their important functional properties are discussed . Ingredients for the friction materials   include fibres, fillers, binder, friction modifiers and lubricants. This paper gives an   example of the ingredients and the outline of their roles. Short descriptions on material      formulations are also discussed . These include asbestos-based, non-asbestos   organic, semi-metallic, metallic matrix, and carbon-based friction materials. Different   material formulations are used in different models of brakes. A general description of  the production process is presented. It includes raw material blending, pre-forming,   hot-pressing, curing and finishing. Friction materials are among the most critical   components and therefore testing to determine their properties and performance is of great importance. The types of tests before final approval are described and the   purpose of each is discussed. 

KEYWORDS: Friction material, brake pad, friction coefficient9       

Author: Mohmad Soib bin Selamat
Year: 2005
doppler_effect_method_for_speed_tb.ap_detector.pdfDOPPLER EFFECT METHOD FOR SPEED TB.AP DETECTOR Year:2005
  
ABSTRACT:
One of the many reasons of fatal accidents on the road is vehicle speeding  beyond the allowable limit. The enforcement authority has tried to implement many preventive   actions to overcome the problem including increasing speed trap operations. In an operation, vehicles which exceed the speed limit will receive a summon. This research is to develop an  effective speed detector system that uses Doppler effects and is controlled by a   microcontroller. The 8-bit MC68HC11 microcontroller is used to receive speed data from a  Doppler radar speed sensor. It is programmed to detect the signal, calculate the speed of vehicle, display data on LCD, and concurrently send the data to a PC through a RS-232 port   via a Serial Communication Interface. The GUI (Graphical User Interface) for the PC is   developed with VB6 programming to receive data from the microcontroller and to capture   the image. VB6 is programmed to capture images in both the manual and auto modes. The image is saved in a directory if the speed of the vehicle exceeds the speed limit and programmed into the microcontroller. The Microsoft Access programming is used to save   and record the data in a database.     

KEYWORDS: Radar gun, speed trap system, Doppler radar speed sensor microcontroller   interfacing, VB programming, graphical user interface 

Author: Wan Zuha A.H., Zulkifli A.R., Samsul B.M.N, MKhair H., Liakot A. and Syed A.R.
Year: 2005
development_of_fuzzy_logic_controller_for_movement_control_of_robotic_system.pdfDEVELOPMENT OF FUZZY LOGIC CONTROLLER FOR MOVEMENT CONTROL OF ROBOTIC SYSTEM
  
ABSTRACT :
This research focuses on design and development of a fuzzy logic controller   that is suitable to control movement of the robotic system. A fuzzy logic controller is designed, developed and attached to th~ designed robotic system in order to control speed of the robot  under specified direction and during dynamic changes. The Simulink block diagram and an  interactive graphical user interface (GUI) system have been developed to simulate and analyse   performance and stability of the robotic system during its movement.The simulation result and  the output characteristic· show the alteration speed of the system due to the change of signals from other systems such as sensor system, obstacle avoidance system, line tracking system  and mechanical designed movement system. The GUI will display the movement of overall system into two-dimensional visualisation output based on the fuzzy logic control approach. The result has shown that the implementation of fuzzy logic controller in the robotic system can   improve the overall output speed performance. With the fuzzy logic control blocks, the designed  system can be improved to handle imprecise signals which are very common in the real wor1d.  Whenever the signals alter, the speed of the robotic system is adjusted using the fuzzy logic controller to give an appropriate movement correction.       

KEYWORDS : Movement control, intelligent control, fuzzy logic controller, robotic systems, graphical user interface (GUI)       

Author: Azura Che Soh, Mohd Khair Hassan, Mohd Amran Mohd Radzi and Li Hong Fey
Year: 2005
computational_fluid_dynamics_simulations_of_flows_and_pressure_distributions_in_a_96_mw_combined_cycle_diverter_damper.pdfCOMPUTATIONAL FLUID DYNAMICS SIMULATIONS OF FLOWS AND PRESSURE DISTRIBUTIONS IN A 96 MW COMBINED CYCLE DIVERTER DAMPER
  
ABSTRACT :
A diverter damper is commonly used where the gas _is either to be directed to   alternate outlets or enters the system from alternate inlets. For combined cycle power plant, the  diverter damper is used to direct exhaust gas of the gas turbine either into the waste heat recovery   boiler or, when running under open cycle mode, exits directly to the by-pass stack. The damper  also allows control of the proportion of flow entering the boiler. This paper describes Computational   Fluid Dynamics (CFO) simulations that have been performed in order to study the flow pattern  inside the diverter damper at various opening angle. The objective is to determine the net force   exerted by the exhaust gas on the damper at various opening angle. Data on the pressure distribution  on the damper will be utilised for structural loading calculations. Examination of the pressure distribution on the face of the damper showed that there is a non-uniform force across it. The inlet flow is not symmetrical and this causes a velocity gradient across the flow, which results in a  pressure gradient. The pressure is highest at the bottom right hand corner of the damper, especially   when the opening angle is very small. This may be significant in generating a twisting moment  on the diverter damper blade. 

KEYWORDS : CFO, diverter damper, combined cycle power plant, failure analysis          

Author: Mohd. Zamri Yusoff and Zainul Asri Mamat
Year: 2005
cathodic_protection_system_a_study_of_impressed_current_system.pdfCATHODIC PROTECTION SYSTEM : A STUDY OF IMPRESSED CURRENT SYSTEM
  
ABSTRACT:
Cathodic Protection System (CPS) is used to reduce corrosion by minimising the difference in voltage potential between the terminal of anode and cathode.   This can be achieved via impressed current system by applying a current from an electrical source to the structure to be protected. When enough current is applied, the whole structure will be at one potential , thus anode and cathode sites will not exist. CPS is commonly used on many types of structures such as pipelines, underground   storage tanks, locks and ship hulls. In this work, the two methods of applying cathodic   protection by using an impressed current system and sacrificial anode had been   reviewed. However, only impressed current system was measured experimentally. The   calculated and measured current values were obtained for impressed current system. The measurement of the output current taken each week showed that there is a decrease in the required current with time due to the reduction of anode surface during the lifespan   of the system.       

KEYWORDS: Cathodic protection system, corrosion , impressed current

Author: Nashiren Farzilah Mailah, Senan Mahmod Bashi
Year: 2005
a_survey_on_computer_integrated_manufacturing_cimin_malaysian_institutes_of_higher_education.pdfA SURVEY ON COMPUTER INTEGRATED MANUFACTURING (CIM) IN MALAYSIAN INSTITUTES OF HIGHER EDUCATION
  
ABSTRACT :
This paper is based on a survey carried out in 2001 on Computer Integrated   Manufacturing (CIM) conducted at Malaysian institutes of higher education . The main   objective of this paper is to provide empirical evidence of the institutions current and future  needs on CIM manpower expertise and facilities required. To achieve this objective, the  authors developed a questionnaire comprising of 17 main questions. The analyses from  28 institutions showed that there is a serious shortage in terms of number and expertise in  CIM technology in these institutions. In addition, the survey found that most of the CIM systems and equipment were imported from overseas and very few were locally manufactured. The paper also discusses the importance of CIM in enhancing Malaysian   companies competitiveness in the manufacturing industry. 

Author: Baba Md Deros*, Azmi Hassan, Che Hassan Che Haron and Yusoff Ali
Year: 2005
a_quantitative_titrimetric_method_and_ftir_monitoring_of_solid_phase_palladium-catalysed_reactions.pdfA QUANTITATIVE TITRIMETRIC METHOD AND FTIR MONITORIN OF SOLID PHASE PALLADIUM-CATALYSED REACTIONS
  
ABSTRACT:
A titration procedure quantifying the immobilisation of iodoaniline and bromoaniline onto PS-TsCI (polystyrene sulfonyl chloride) and a qualitative procedure   following the FTIR spectra of the reactants, intermediate products and the final product is   presented here. The titration of chloride ions released in the first step of the solid phase  combinatorial synthesis was carried out using the Mohr method. Quantitative measurements   were made using standard NaCl solution. Results show that the immobilisation and reaction yield with bromoaniline was far better than iodoaniline and that both solid phase reactions   were optimised by the 14th hour. Sensitivity tests show that chloride ions can be detected   with as low as 30 mg PS-TsCI. This simple and fast quantitative method not only serves as   a detection method but allows us to compare the reactivities of various types of anilines,   perform optimisation studies and quantify the reaction yields. FTIR spectroscopy was also   used to follow the reaction from the immobilisation stage of the PS-TsCI until its cleavage from the final product, while varying the R groups.       

KEYWORDS: solid phase, quantitative monitoring, palladium-catalysed , titrimetric

Author: Uma D. Palanisamy·, Lim Chuan Gee, Sulaiman., Vb, Saraswati S. Velu and Abd. Rahman, Noorsaadah
Year: 2005