Abdullah Mohd Mustafa Al Bakri

Study on Physical and Chemical Properties of Fly Ash from Different Area in Malaysia

Fly ash is residue from the combustion of coal which widely available in worldwide and lead to waste management proposal. Moreover, the use of fly ash is more environmental friendly and save cost compared to OPC. Fly ash mostly consists of silicon dioxide (SiO2), aluminium oxide (Al2O3) and iron oxide (Fe2O3). The chemical compositions of the sample have been examined according to ASTM C618. Different sources of fly ash may result in different chemical composition. The fly ash is mainly an amorphous material with the presents of crystalline phase of quartz and mullite. Fly ash consists of mostly glassy, hollow and spherical particles.

Characterization of Soils as Potential Raw Materials for Soil Stabilization Application Using Geopolymerization Method

Soft soil has been associated to many problems especially in engineering field. Continues research and studies are done to find other alternatives in soil stabilization that environmental friendly and economic. Geopolymerization is one of the developing fields that can fulfill those requirements. In this preliminary study, three samples of soil (Soil 1, 2 and 3) were examined to investigate their potential for geopolymerization method based on their characterization. X-ray fluorescence, X-ray diffraction and scanning electron microscope were conducted. From the results, the soils do have potential, however, further investigations need to be done after this study to evaluate whether the soils are suitable using geopolymerization method for soil stabilization.

Feasibility Study on Composition and Mechanical Properties of Marine Clay based Geopolymer Brick.

Geopolymer is an inorganic polymer performed in synthesis process of an aluminosilicate material which activated by alkaline activator solution. Marine clay, considered to be a waste substance which have an important aluminosilicate sources in developing geopolymer synthesis since it contains sufficient amounts of alumina and silica. In this experimental study, local marine clay composition was been identified to determine the amount of alumina and silica. The raw sample compositions were identified by using X-ray fluorescence (XRF). Incorporated with it composition, compressive strength of brick were been tested in aged of 1, 2 and 3 day and compared with local production of cement brick (CB). This research is aimed at determining the properties of Kuala Perlis marine clay in order to verify its suitability as a pozzolana materials as well as the sufficient amount of Al and Si to enhance the properties of geopolymer brick.

Three Dimensional Simulation of Thermal Pad Using Nanomaterial, Nanosilver in Semiconductor and Electronic Component Application

Thermal pad is new technology in this world that been used in PLCC in order to reduce junction temperature to the minimum level in electronic components. In electronic industry, the electronic components that exceed 70°C will malfunction and damage due to the overheated. The design is used nanosilver as main material in thermo pad because it has high value of thermal conductivity and enables to dissipate heat very efficiently. The simulation of thermal pad in semiconductor is using FLUENTTM software. The results from simulation is been compared to the results from experiment. The differences between those results are less than 10%. The advantages of thermal pad are enables to reduce junction temperature of PLCC 20-30%. It also had constant thickness in order to get constant and accurate results.

New Processing Method of Kaolin-Based Geopolymer Brick by Using Geopolymer Brick Machine

With increased activity in construction, deficiency of building materials and construction waste improvements have encouraged the development of new building materials. Conventional construction bricks are usually made from clay and sand, which are mixed and molded in various method and need to be dried and burned. Geopolymer bricks making process consume less energy and low cost in term of production compared to conventional bricks. The development of geopolymer brick is an important step towards produce bricks with better performance and environmental friendly material This research focusing on the processing process of the clay-based geopolymer brick from the mixing until the curing by using a geopolymer brick making machine.

Effect of Fly Ash/Alkaline Activator Ratio and Sodium Silicate/NaOH Ratio on Fly Ash Geopolymer Coating Strength

Fly ash geopolymer coating material potential used to protect surface used in exposure conditions. Ratio of fly ash/alkaline activator and Na2SiO3/NaOH play important parameter on determining the best flexural strength of geopolymer coating material. Fly ash and alkali activator (Al2O3/Na2SiO3) were mixed with the solids-to-liquid ratios in range of 1.0-3.0 and different ratios of Na2SiO3/NaOH (1.0-3.0) to prepare geopolymer coating material at constant NaOH concentration of 10 M. Effect of fly ash/alkaline activator ratio and Na2SiO3/NaOH on geopolymer coating was determined with respect to the highest flexural strength of the 1200oC sintering temperature of geopolymer coating substrates. The results concluded that the highest strength for fly ash geopolymer coating material is achieved 42 MPa when the solid/liquid ratio is 2.0 and the Na2SiO3/NaOH ratio is 2.5.

Mean Imputation Techniques for Filling the Missing Observations in Air Pollution Dataset

Almost all real life datasets consist missing values. These are usually due to machine failure, routine maintenance, changes in siting monitors and human error. The occurence of missing values requires special attention on analysing the data. Incomplete datasets can cause bias due to systematic differences between observed and unobserved data. Therefore, the need to find the best way in estimating missing values is very important so that the data analysed is ensured of high quality. In this research, three types of mean imputation techniques that are mean, mean above and mean above below methods were used to replace the missing values. Annual hourly monitoring data for PM10 were used to generate missing values. Four randomly simulated missing data were evaluated in order to test the efficiency of the methods used. They are 5%, 10%, 15%, 25% and 40%. Three types of performance indicators that are mean absolute error (MAE), root mean square error (RMSE) and coefficient of determination (R2) were calculated to describe the goodness of fit for all the method. From all the method applied, it was found that mean above below method is the best method for estimating data for all percentages of simulated missing values.

Strength of Concrete with Ceramic Waste and Quarry Dust as Aggregates

This research focuses on a study of the strength of concrete with ceramic waste as coarse aggregate and quarry dust as fine aggregate. The sources of ceramic waste and quarry dust are obtained from the industrial in Malaysia. Presently, in ceramics industries the production goes as waste, which is not under going the recycle process yet. In this study an attempt has been made to find the suitability of the ceramic industrial wastes and quarry dust as a possible replacement for conventional crushed stone coarse and fine aggregate. Experiment were carried out to determine the strength of concrete with ceramic waste coarse aggregate and quarry dust fine aggregate to compare them with the conventional concrete made (with crushed stone coarse aggregate). From the results show that compressive strength of concrete with quarry dust as aggregates is the highest with 30.82 MPa with density 2251.85 kg/m3. This show, ceramic waste and quarry dust can be alternative aggregate for comparable properties.

Review on Development of Clay Based Geopolymer Ceramic Composites

Geopolymer results from the reaction of a source material that is rich in silica and alumina such as kaolin with alkaline activator solution. Geopolymers are inorganic aluminosilicate materials that possess relatively good mechanical properties and good thermal behavior but they exhibit failure behavior similar to brittle solids. This limitation may be readily overcome through the formation of ceramics of geopolymer and the addition of filler to improve strength and toughness. This paper review and summarize the current knowledge on geopolymer ceramic with addition of fine filler materials and the effect of filler content on the physical and mechanical characteristic of clay based geopolymer ceramic.

Compressive Strength and Morphology of Fly Ash Based Geopolymer as Artificial Aggregate with Different Curing Temperature

This paper presented the compressive strength of geopolymer paste with different NaOH concentration and morphology analysis for sintered artificial aggregate. This artificial aggregate was produce based on mix design with highest compressive strength which is 12 M. The sample was cured at 70 °C for 24 hours and then it was exposed to different temperature at range 500 °C to 700 °C. Scanning Electron Microscopy (SEM) has been used to identify the formation of microstructure. The geopolymer artificial aggregate was an alternative ways to produce a greener environmental. In this study, the compressive strength for different Na2SiO3/NaOH ratio has been analyzed. The morphology for best mix design then were analyze for different curing temperature. The result shows fly ash based geopolymer paste with 12 M of NaOH concentration shows excellent result with 7.30 MPa at 2.5 ratio of Na2SiO3/NaOH and for geopolymer artificial aggregate, when temperature of heat treatment increased, the open porosity of porous geopolymer surface decreased.