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

Optimization of stand-alone photovoltaic system by implementing fuzzy logic MPPT controller

A photovoltaic (PV) generator is a nonlinear device having insolation-dependent volt-ampere characteristics. Since the maximum-power point varies with solar insolation, it is difficult to achieve an optimum matching that is valid for all insolation levels. Thus, Maximum power point tracking (MPPT) plays an important roles in photovoltaic (PV) power systems because it maximize the power output from a PV system for a given set of condition, and therefore maximize their array efficiency. This project presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on a comparative study between most conventional controller namely Perturb and Observe (P&O) algorithm and is compared to a design fuzzy logic controller (FLC). The introduction of fuzzy controller has given very good performance on whatever the parametric variation of the system

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