The Production Of Cast Metal Matrix Composite By A Modified Stir Casting Method

In a normal practice of stir casting technique, cast metal matrix composites (MMC) is produced by melting the matrix material in a vessel, then the molten metal is stirred thoroughly to form a vortex and the reinforcement particles are introduced through the side of the vortex formed. From some point of view this approach has disadvantages, mainly arising from the particle addition and the stirring methods. During particle addition there is undoubtedly local solidification of the melt induced by the particles, and this increase the viscosity of the slurry. A top addition method also will introduced air into the slurry which appears as air pockets between the particles. The rate of particle addition also needs to be slowed down especially when the volume fraction of the particles to be used increases. This is time consuming for a bigger product. This study propose a new approach of producing cast MMC. When all substances are placed in a graphite crucible and heated in an inert atmosphere until the matrix alloy is melted and then followed by a two-step stirring action before pouring into a mould has advantages in terms of promoting wettability between the silicon carbide particle and the A359 matrix alloy. The success of the incorporation of silicon carbide particles into the matrix alloy showed that the wettability between silicon carbide particles and mechanical properties such as hardness and tensile strength are comparable with previous data produced by other researchers

Maintenance management and servises (case study: PERKESO building's in penisular of Malaysia)

Maintenance Management and Services is a combination of several actions in which to retain or restore an item to perform its required action. PERTUBUHAN KESELAMATAN SOSIAL (PERKESO) as one of the semi government sector in Malaysia that has many assets, needs maintenance to prevent the assets from deterioration. Maintenance in PERKESO was monitor and control by Property Unit and Local PERKESO Office. There are two maintenance system presently implemented at PERKESO: Preventive maintenance and Corrective Maintenance. The maintenance and services in PERKESO are divided to two building type: stand alone building and shop lot building. Maintenance and services for stand alone PERKESO building is total preventive maintenance and services scope and for shop lot PERKESO building scope maintenance and services only cover cleaning, M&E preventive maintenance and Pest Control. Aim of this study to propose maintenance management & services system. To achieve the aim of this study, five objectives have been set, to study the maintenance management system presently implemented. To identify the common problem in maintenance management and services. To identify the tenant satisfactory level upon the maintenance and services implemented. To identify tenant opinion to make improvement for maintenance management and services. From the data analyze and propose maintenance management and services system. This research focused on PERKESO Building’s in Peninsular of Malaysia. To obtain the data the following knowledge acquisition methods were used by interview, questionnaire and archives. An interview were set for two session, pre-interview done before set questionnaire and interview after the analysis data had done Result of the study showed the responds of the end user customer for the overall building conditions and the services given is fair. To achieve the tenants’ satisfaction level, a new maintenance management system is proposed

Blogs of their own: a story of two Malaysian Women Bloggers

Over the last few years, with the introduction of easy-to-use and integrated services such as Windows Live Spaces, blogging has moved into the mainstream in Malaysia, with women making up 64% of bloggers. Blogging has become popular because it provides an outlet for netizens who find blogosphere a liberating place, so unlike Malaysian traditional print which is censored and licensed. This article is an analysis of two blogs written by Malaysian women that show them negotiating in contradictory ways the line between the private and public dimensions of their lives. The idea that the “personal is political” and the importance of experience still retain an important place in feminist contemporary thought. I argue that many seemingly “trivial and personal” issues have produced a politics formed from the bloggers‟ personal experiences and reflections

Menjana pemodulatan lebar denyut (PWM) penyongsang tiga fasa menggunakan pemproses isyarat digital (DSP)

Baru-baru ini, penyongsang digunakan secara meluas dalam aplikasi industri. Walaubagaimanapun, teknik Pemodulatan Lebar Denyut (PWM) diperlukan untuk mengawal voltan keluaran dan frekuensi penyongsang. Dalam tesis ini, untuk Pemodulatan Lebar Denyut Sinus Unipolar (SPWM) penyongsang tiga fasa adalah dicadang menggunakan Pemproses Isyarat Digital (DSP). Satu model simulasi menggunakan MATLAB Simulink dibangunkan untuk menentukan program Pemodulatan Lebar Denyut Sinus Unipolar (SPWM) Program ini kemudian dibangunkan dalam Pemproses Isyarat Digital (DSP) TMS320f28335. Hasilnya menunjukkan bahawa voltan keluaran penyongsang tiga fasa boleh dikendalikan

Improving the indoor air quality (IAQ) through application of the air cleaning technologies for offices building simulated in environmental chamber

Indoor air quality (IAQ) is very important issue in residential and commercial buildings, because human spend almost 90% of their life indoor. IAQ problems effect on the health of the occupants, and lead to reduction of the efficiency and output in workplaces. The main objective of this study is to improving the (IAQ) and to reduce energy consumption in offices building, through experimental and simulation investigation. The method used in this study was by using environmental chamber to represent the real office. The results of the experimental were validated the simulation. The chamber was modified by installing two mechanical filters with low pressure drop; minimum efficiency reporting value rate 13 (MERV 13) and activated carbon filter (ACF) on the air handling unit. The IAQ parameters which include temperature, relative humidity, air velocity, air flow rate, pressure drop, CO2 concentration and particle matters PM 10 and PM 2.5 concentration for upstream and downstream were considered in this study. These variables were measured inside the chamber using IAQ devices and these data were used as an input data for simulation by using ANSYS 16.1 software. The simulation generated the air distribution via air velocity, temperature, CO2 concentration and the particle distribution in the room. The results from experiment showed good agreement for combining filters efficiency value from 86.20% to 84.60% and from 86% to 82.35% for PM 10 and PM 2.5 particle removal respectively during occupied period. The CO2 concentration decreased during the measurement period from 816 ppm to 700 ppm and the distribution was in the acceptable range compare with ASHRAE standard 55-2004 and Malaysian industry code of practice on IAQ. Also, the validation with simulation showed below 10% error ratio compare with experiment results. The significance of study is to balance between enhancing thermal comfort inside workplace and (IAQ) for occupants, leading to reduction of energy consumption