Skip Navigation LinksVolume : Volume 15 No.1 2006

  
  
  
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thermogravimetric_and_kinetic_studies_on_palm_shells.pdfTHERMOGRAVIMETRIC AND KINETIC STUDIES ON PALM SHELLS
  
ABSTRACT:
Recently, owing to environmental and economic considerations, interest in utilising biomass   for the production of energy and chemicals is increasing. Malaysia being the largest producer of palm oil   has huge amount of oil palm wastes. In order to utilise these wastes efficiently, pyrolysis is emerging as a   promising thermo-chemical technique. In this study, pyrolysis of oil-palm shell waste was carried out using   thermogravimetric analysis (TGA). The effects of heating rate on the pyrolytic properties were investigated   for palm shell powder of 300 and 600 µm partic le size. Kinetic parameters were also determined for  different heating rates.   This paper also describes the results from a bench-scale Circulating Fluidised Bed (CFB) test rig, installed at   SIRIM Berhad, Shah Alam, suitable for gasification and combustion experiments using different biomass  materials. Using this rig, a better understanding of the effect of primary flow and feeding rate on the emission   behaviour was established. Experimental studies were also done to investigate the influence of temperature   on pyrolysis. The concentrations of CO, NOx and C02 in the flue gas were measured. The combustion   performances were evaluated by varying the primary gas flow through the CFB tubular furnace. The emission  of NOx ranged from 38-75 ppm while the CO emissions were high for higher primary air flow rates.       

KEYWORDS: Biomass, emission, kinetics, oil palm wastes, pyrolysis, Thermogravimetric analysis (TGA)

Author: Ahmad Hussain , Farid Nasir Ani, Amer Nordin Darus , Hamdan Mokhtar , Saiful Azam
Year: 2006
the_significance_of_hydrodynamics_difference_between_rushton_turbine_and_marine_impeller_on_thekla_in_a_16_litre_bioreactor.pdfTHE SIGNIFICANCE OF HYDRODYNAMICS DIFFERENCE BETWEEN RUSHTON TURBINE AND MARINE IMPELLER ON THEKLA IN A 16-LITRE BIOREACTOR
  
ABSTRACT:  
An investigation on the significance of hydrodynamic     difference between Rushton and marine impeller on the kLa in the  16-litre bioreactor was performed. By employing the static gassing out technique, the k L a values were calculated at different sets of   impeller speeds and air flow rates, and at various viscosities and   temperatures. The empirical correlation was employed to  investigate the dependence of k L a on the specific power input and superficial air velocity. Our experimental results discovered that   the Rushton turbine was more effective in gas distribution and   provided a greater oxygen transfer rate than the marine impeller. 

KEYWORDS : Empirical relationship, stirred bioreactor, marine   impeller, Rushton turbine, oxygen transfer coefficient     

Author: Muhd. Nazrul Hisham Zainal Alam, Firdausi Razali
Year: 2006
simulation_and_real_time_implementation_of_dc_servo_position_control.pdfSIMULATION AND REAL TIME IMPLEMENTATION OF DC SERVO POSITION CONTROL
  
ABSTRACT :
DC motor systems are used widely in various fields of technology. They are used in power   plants to generate electrical power and in industrial occupancies to furnish the required mechanical motive power to drive mechanical machinery and control various industrial processes. DC motor acts as one of the vital part, where the position control of the motor is the major part to be given attention to.   Efforts made on controlling the position of DC motor result in so many types of control scheme for t he   mentioned purpose. Some of these control schemes will be explained and d iscussed briefly in this st udy.   More detailed discussions will be centered upon the studied controllers , which are the PID and adaptive controllers. Detailed explanation on designing the controller via SIMULINK is also presented in this study   which includes the hardware configurations and software designs. Finally the designed controllers were   both implemented to the real plant via a real time software.       

KEYWORDS : PID Controller, real time, DC servo motor, position control, simulink       

Author: Erny Aznida Alwi, Samsul Bahari Mohd Noor, Azura Che Soh
Year: 2006
pembangunan_laman_pelayan_aktif_active_server_page_untuk_pemaparan_maklumat_satelit_gps.pdfPEMBANGUNAN LAMAN PELAYAN AKTIF (ACTIVE SERVER PAGE) UNTUK PEMAPARAN MAKLUMAT SATELIT GPS
  
ABSTRACT:
Active Server Page (ASP) Script by Microsoft can be used to retrieve, process, and   transmit information to users through web pages as normal HTML (HyperText Markup Language).   It is more stable and easier to develop dynamic web applications. Little time is used to maintain   internet and intranet website, and it is very suitable to display current information in real time. This paper explains the application of ASP software to develop a website to display GPS information at   remote locations and can be accessed locally through the website. The GPS (Global Positioning System) is made up of 24 satellites that were launched by the U.S. to transmit precise navigation  information such as velocity, time, and position of receiver. The web pages software that is   developed can display these information every three minutes from a GPS receiver that is located remotely and sent to the local station using modem (MOdulator and DEModulator). This navigation   information is used not only for geodetic and geoinformation , but also for scientific research such as radio propagation, measurements of total electron content in the ionosphere, and so on . This ASP is used to help users retrieve precise and reliable current information speedily and with ease.     

KEYWORDS : Global Positioning System, GPS, remote monitoring, Active Server Page, ASP 

Author: Mardina Abdullah , Ahmad Faizal Mohd. Zain , Norbahiah Misran dan Desmond Koh
Year: 2006
metal_injection_moulding_an_advanced_processing_technology.pdfMETAL INJECTION MOULDING : AN ADVANCED PROCESSING TECHNOLOGY
  
ABSTRACT:
The emphasis on miniaturisation, design flexibility, broad based  applications and low cost has been stretching the capabilities of conventional   manufacturing routes to the limit. An example of a new approach to meeting   such challenges has been the development of Metal Injection Moulding (MIM).   MIM is a growing advanced technology with the ability to produce large   numbers of small complex near net shape parts from different metals and   alloys at cost lower than machined parts. This process technology is an elegant   blend of plastic injection moulding, based on the use of fine powder particles   and the application of polymer science and conventional powder metallurgy,  which delivers structural materials using a forming technology previously restricted to polymers. This paper discusses some of the basic MIM processes  and applications. Attention is also given especially to recent MIM developments in SIRIM Berhad including the MIM facilities and research projects.       

KEYWORDS : Metal injection moulding, mixing, debinding, sintering         

Author: Mohd Afian Omar and Rosdi Ibrahim
Year: 2006
fatigue_mechanism_of_semi-metallic_brake_pads_during_braking_process.pdfFATIGUE MECHANISM OF SEMI-METALLIC BRAKE PADS DURING BRAKING PROCESS
  
ABSTRACT :
Fatigue wear mechanism was found to operate during braking process both during intermittent and continuous braking modes. In this study, a pair of brake pads   was pressed against a rotating cast iron brake disc at a constant rotating speed of 750   rpm, simulating braking condition. In the intermittent braking test mode, the test samples   were subjected to an applied load of 600 N for four different total braking times (400, 800,   1200 and 1600 seconds). The brake was applied for four different times (5, 10, 15 and 20   seconds) for 80 times with idling 5 seconds between each braking. Whereas, in the   continuous braking, the test samples were subjected to five different braking times (180,   360, 540, 720 and 900 seconds) and applied loads (100, 200, 400, 600 and 800 N). The   microstructural changes on the wear surface were observed using Scanning Electron   Microscopy (SEM). Microstructural examinations showed that the fatigue mechanism   started with the generation of plastic deformation in the subsurface of the brake pads. As   the braking time increased, the above phenomena caused the formation of striations on   the worn surface of the brake pad. With subsequent braking, the fatigue mechanism was   observed to nucleate at areas where pits and spalls were present. Finally, the wear   fragments were disposed from the worn surface.       

KEYWORDS: Brake pad, striation, microcrack, fatigue, wear

Author: R.J. Talib, A. Muchtar and C.H. Azhari
Year: 2006
electronic_control_unit_for_vehicles_issues_and_the_way_forward.pdfELECTRONIC CONTROL UNIT FOR VEHICLES: ISSUES AND THE WAY FORWARD
  
ELECTRONIC CONTROL UNIT FOR VEHICLES: ISSUES AND THE WAY FORWARD
ABSTRACT :
The latest generations of road vehicles have seen a tremendous   development in onboard electronic system, which controls increasingly large parts   of the vehicle's functionality. The automotive electronic revolution has significantly   improved the performance, reliability and comfort of the automobile. Electronic   Control Unit (ECU) is a system that plays a more and more important role in the   development of road vehicles. The increasing complexity and stringent quality and   cost requirements mandate tremendous improvements in all aspects of specification   and design process. This paper discusses the overall aspects of the new era of ECU, issues in emission regulations, algorithms and communications are addressed. 

KEYWORDS : ECU, ECM, EFI, automotive, engine control

Author: Ibrahim Mat, Ishak Aris, Mohd Khair Hassan, Roslina Mohd Sidek, Nik Anis Alina Nik Othman and Syed Malek Faisal
Year: 2006
effects_of_shear_stress_and_shear_time_on_rheological_properties_of_zeolites.pdfEFFECTS OF SHEAR STRESS AND SHEAR TIME ON RHEOLOGICAL PROPERTIES OF ZEOLITES
  
ABSTRACT :
The rheological properties of dry powders dispersed in liquid enable  prediction of microstructure and ease of dispersion of the powders in slurry form. This   paper highlights the differences in the rheological roperties of various zeolite powder   with similar size range of 3.9 - 4.6 µm when subjected to constant shear stress of 0.85 - 8 Pa and shearing time of 720 s. When the value of the imposed shear stress increased , the  viscosity of zeolite vegabond ZVXD decreased with increasing shear rate. As for zeolite   doucil P, ZDP, the critical shear stress where the viscosity level was inverted, occurred at  7 Pa. In the case of zeollite wessalith P (ZWP), there was no s ignificant reduction of   viscosity of ZWP dispersions at low shear stress times as seen in the profiles of ZVXD   and ZDP. Knowing viscosity profiles can lead to better formulation of detergents where   zeolite powders are the active ingredients. In addition, the characteristics of structural   breakdown could be made from the generated viscosity curves. It was found that the  rheological properties of zeolites with similar size range differs when subjected to constant   shear stress and shearing time. The viscosity curves of standard ized dispersion were   studied using Carrimed CSL 100, a controlled stress rheometer. 

KEYWORDS : Rheology, zeolite, controlled stress rheometer, microstructure

Author: Suzana Yusup, Suriati Sufian and Khalik M Sabil
Year: 2006